DE102016111686A1 - Method of improving blowby and EGR via a split outlet - Google Patents

Abstract

Provided methods and systems for a supercharged engine with a split exhaust system. In one example, a method includes directing exhaust gas from a first group of cylinders to a pre-compressor station, a post-compressor station, and / or an exhaust gas turbine, and directing exhaust gas from a second group of cylinders to the pre-compressor station and / or the exhaust turbine. Engine efficiency and knock control may be improved by routing exhaust gases to various locations based on engine operating conditions.

Description

Cross-reference to related applications

The present application is a continuation-in-part of US Application No. 14 / 157,167 entitled "METHOD TO IMPROVE BLOWTHROUGH VIA SPLIT EXHAUST", filed Jan. 16, 2014, the entire contents of which are hereby incorporated by reference for all purposes.

Technical area

The present application relates to a split outlet in an exhaust system of a supercharged internal combustion engine.

Background and abstract

Power machines may use boosting devices such as turbochargers to increase engine power density. However, due to the increased combustion temperatures, engine knock may occur. The engine knock may be dealt with by retarding the spark timing; however, a significant spark retard can reduce fuel economy and limit maximum torque. Knocking is particularly problematic under charged conditions due to the high charge temperatures.

One method of reducing the charge temperature, and thus knock, is by sparging, wherein intake air charged during a positive valve overlap phase is blown through the combustor to the outlet.

Another method of suppressing knocking is to dilute the intake air with cooled exhaust gas recirculation (EGR). An exemplary approach to controlling the flow of exhaust gases for an EGR is provided by Roth ( US 8495992 ), wherein a split exhaust system separates the exhaust gases exiting the combustion chamber during the pre-charge phase and the purge phase. The exhaust gases from the pre-discharge phase are distributed either to the turbine in a turbocharger system or to an EGR system which directs the cooled EGR gases to the intake manifold or upstream of the compressor into a turbocharger. Accordingly, exhaust gases from the purge phase are conveyed either to an exhaust gas purifier or to an EGR system which supplies the cooled gases to the intake manifold or to a location upstream of the compressor. The timings of the intake and exhaust valves are controlled to control the amount of exhaust gases flowing to the turbocharger and / or the EGR based on engine operating conditions.

The inventors herein have identified potential problems, including problems with the above approaches to dealing with knock limits. For example, an EGR throttle may be disposed in the inlet upstream of the compressor to increase EGR flow at a low backpressure, which may make the turbocharger more susceptible to pressure surges and increase pumping losses. Further, in the example where a blow through technique is used to reduce knock, the extra fuel injected to bring the exhaust gases to a stoichiometric ratio can cause over-temperature of the catalyst and affect emissions while increasing fuel economy , In addition, at lower engine loads, engine efficiency may be compromised and EGR may contribute to combustion instabilities.

The inventors have recognized the above problems and identified approaches to at least partially address the problems. In an exemplary approach, a method for an engine includes routing exhaust gas from a first group of cylinders to a pre-compressor station, a post-compressor station, and / or an exhaust gas turbine, and directing exhaust gas from a second group of cylinders to the pre-compressor station and / or the exhaust gas exhaust turbine. In this way, exhaust gases from separate groups of cylinders can be returned to distinct locations to improve performance and efficiency.

For example, a supercharged engine may include a first group of cylinders and a second group of cylinders, where the first group of cylinders includes cylinders that are different from the second group of cylinders. Exhaust gases from the first group of cylinders may be routed to at least one of three separate destinations, including a first location upstream of a compressor (pre-compressor), a second location downstream of the compressor (booster), and / or a third point directly upstream of an exhaust gas turbine. The second location downstream of the compressor may include a location downstream of an intake throttle and upstream of an intake manifold. Exhaust from the second group of cylinders may be directed to the first location upstream of the compressor and / or to the third location directly upstream of the exhaust turbine. Exhaust gas may be directed to one or more of the locations described above based on engine conditions. Exhaust from the first group of cylinders may be directed to the second location during mid-engine loads and low engine loads while exhaust from the second group of cylinders is simultaneously directed to the exhaust turbine. During higher engine loads, a higher proportion of exhaust gases from the first group of cylinders and the second group of cylinders may be directed to the exhaust turbine while a smaller portion of exhaust gases is directed to the location upstream of the compressor. Here, the smaller proportion of exhaust gases may be blown through cylinders upstream of the compressor along with fresh intake air by adjusting a valve timing such that a positive valve overlap between at least one intake valve and one exhaust valve of each cylinder of the first group of cylinders and the second group of Cylinders is allowed.

In this way, knocking can be reduced and engine efficiency improved during various engine conditions. Returning exhaust gases from the first group of cylinders to the location downstream of the compressor during certain engine conditions, e.g. As low and medium engine loads, can allow a reduction of pumping losses and heat loss. At the same time, by directing exhaust gases from the second group of cylinders to the exhaust turbine, the desired engine output can be provided. The reduced pumping losses and reduced heat loss can improve engine efficiency. Additionally, during higher engine loads, allowing fresh intake air to blow any residual hot exhaust gases in the cylinders may lower temperatures within the combustors. In addition, since the blow-through air is not sent to an exhaust gas purification device, maintaining a stoichiometric ratio in the exhaust gas by injecting additional fuel may not be required.

It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not intended to identify key features or essential features of the claimed subject matter, the scope of which is defined solely by the claims which follow the detailed description. In addition, the claimed subject matter is not limited to implementations that solve the disadvantages mentioned above or in another part of the present disclosure.

Brief description of the drawings

1 shows a schematic representation of a turbocharged engine system with a split exhaust manifold.

2 shows a power machine part view.

3 Forms exemplary cylinder intake valve and exhaust valve controls for one of the engine cylinders of 1 from.

4 FIG. 10 is an exemplary flowchart illustrating a routine for activating a compressor intake valve based on various engine operating conditions.

5 shows exemplary valve operations and the subsequent exhaust flow over the three passages of a cylinder of the engine in 1 , based on different engine conditions.

6 schematically shows a second embodiment of the turbocharged engine system of 1 ,

7 shows a schematic representation of the second embodiment of the turbocharged engine, including a Nockenprofilumschaltsystems.

8th FIG. 12 shows an example map of engine operating conditions that may be used to determine operating modes of the second embodiment of the turbocharged engine. FIG.

The 9A . 9B and FIG. 9C show exhaust valve controls for cylinders of the second embodiment of the turbocharged engine.

10 FIG. 10 is an exemplary flowchart illustrating a routine for adjusting exhaust valves of a plurality of cylinders of the second embodiment of the turbocharged engine based on engine operating conditions.

11 FIG. 10 is an exemplary flowchart illustrating a transition routine between various modes of operation of the multiple cylinders of the second embodiment of the turbocharged engine in response to changes in engine operating conditions. FIG.

12 FIG. 12 is a table listing the various modes of operation of the plurality of cylinders of the second embodiment of the turbocharged engine. FIG.

Detailed description

The following description relates to systems and methods for controlling knock in an engine, such as an engine. B. the engine system from the 1 - 2 by draining an engine cylinder through three distinct passages. In particular, in a combustion cylinder, a first or Vorlassanteil of an exhaust gas to a turbine of a turbocharger can be passed through a first passage, a second or purged portion of an exhaust gas can be passed via a second passage to an exhaust gas purification device, while a third part of exhaust gases towards the end of a Exhaust strokes, mixed with blowby air, may be passed through a third passage to an inlet of a compressor in a turbocharger. Each cylinder of the engine may thus comprise five valves: two intake valves, two exhaust valves and a compressor intake valve. An engine controller may be configured to execute a control routine, such as routine 4 to control the compressor intake valve based on various engine operating conditions, such as those described in US Pat 5 be shown to operate. The compressor intake valve controls may be coordinated with the exhaust valve and intake valve controls to allow exhaust gas recirculation (EGR) and blowby ( 3 ). In a second, in 6 In the illustrated embodiment, engine efficiency may be improved during low to medium engine loads. Here, a cam profile switching system can be used with each of the two exhaust valves and the compressor intake valve (FIG. 7 ) of each engine cylinder. Further, the second embodiment may include a fourth passage coupling each of the compressor intake valves of all engine cylinders to an intake manifold of the engine downstream of the compressor. By adjusting the valve controls ( 9A . 9B and 9C ) of the exhaust valves and the compressor intake valves of each engine cylinder, the engine can be operated in three different modes ( 10 ). A distinct mode of operation may be based on existing engine operating conditions ( 11 ), including existing engine loads and engine speeds ( 8th ). During a single engine cycle, exhaust gases from various periods of an exhaust stroke within each engine cylinder may be directed to particular locations in the engine system (FIGS. 12 ), thereby providing knock control via EGR and cooling of the cylinders via blow-by. Further, engine efficiency can be improved by varying the locations at which the exhaust gases are recirculated.

If it is stated in the following description that a valve is operational or activated, it means that it is open and / or closed in accordance with predetermined controls during the combustion cycle for a given set of conditions. Likewise, indicating that the valve is inactive or inoperative means that the valve is kept closed unless otherwise specified. The deactivated valve, when kept closed, may block a passing fluid stream (including gases).

1 shows a schematic representation of an internal combustion engine 10 with multiple cylinders, which may be included in a drive system of an automobile. The engine 10 may include a plurality of combustors (also referred to as cylinders) that may be covered at the top by a cylinder head (not shown). In the in 1 The example shown includes the engine 10 combustors 20 . 22 . 24 and 26 which are arranged in a row quad configuration. It goes without saying, though 1 four cylinders shows the engine 10 but any number of cylinders in any configuration, e.g. As V-6, I-6, V-12, 4-cylinder boxer engine, etc. may include.

Each combustion chamber may intake air from an intake manifold 27 via an air inlet line 28 receive. The intake manifold 27 can be coupled via inlet channels to the combustion chambers. For example, in 1 an intake manifold 27 shown over inlet channels 152 . 154 . 156 respectively. 158 to the cylinders 20 . 22 . 24 and 26 is coupled. Each intake port may supply air and / or fuel for combustion to the cylinder to which it is coupled. Each cylinder intake port may be selectively communicated with the cylinder via one or more intake valves. The cylinders 20 . 22 . 24 and 26 be in 1 each with two inlet valves shown. For example, the cylinder has 20 two inlet valves 32 and 34 , the cylinder 22 has two inlet valves 36 and 38 , the cylinder 24 has two inlet valves 40 and 42 , and the cylinder 26 has two inlet valves 44 and 46 , In one example, an intake manifold may be from the intake manifold 27 be formed, which is specifically associated with each inlet valve. In other embodiments, a single cylinder inlet conduit proximate the cylinder may be divided into two adjacent paths with a wall therebetween, each divided passageway communicating with a single inlet valve. In another example, each of the two intake valves may be controlled to open at specific engine speeds and therefore communicate with the intake manifold through a common intake port.

Each combustion chamber may deliver combustion gases via one or more exhaust ports coupled thereto. The cylinders 20 . 22 . 24 and 26 be in 1 shown coupled to two exhaust ports, respectively, to separately channel the exhaust and purge portions of the combustion gases. For example, outlet channels 33 and 35 with the cylinder 20 coupled, outlet channels 39 and 41 are with the cylinder 22 coupled, outlet channels 45 and 47 are with the cylinder 24 coupled, and outlet channels 51 and 53 are with the cylinder 26 coupled. Each outlet channel can be selectively connected via an outlet valve to the cylinder with which it is coupled. The outlet channels 33 . 35 . 39 . 41 . 45 . 47 . 51 and 53 For example, there are corresponding exhaust valves 122 . 132 . 124 . 134 . 126 . 136 . 128 and 138 in communication with their respective cylinders.

This is a split manifold system, with the exhaust ducts 33 . 39 . 45 and 51 in an exhaust manifold 55 can lead while the outlet channels 35 . 41 . 47 and 53 in an exhaust manifold 57 can be combined. The exhaust manifolds in this system may be configured to remove the combustion products from the cylinders 20 . 22 . 24 and 26 leave.

The engine 10 can a turbocharger 190 contain. The turbocharger 190 can be an exhaust gas turbine 92 and an intake compressor 94 included on a common shaft 96 are coupled. A wastegate 127 can over the turbine 92 be coupled. Specifically, the wastegate can 127 in a bypass 166 included between an inlet and an exhaust of the exhaust turbine to regulate an amount of the charge provided by the turbine.

The exhaust manifolds may be configured to separately channel the exhaust and purge components of the exhaust gas. The exhaust manifold 55 can the Vorlassimpuls the exhaust gas through a pipe 160 to the turbine 92 of the turbocharger 190 channel, while the exhaust manifold 57 the purge portion of the exhaust gas via a pipe 162 to a point downstream of the turbine 92 and upstream of an exhaust gas purification device 72 (Also referred to as exhaust emission device, catalytic converter, emission catalyst, etc.) can channel. For example, the exhaust valves channel 122 . 124 . 126 and 128 the proportion of exhaust gases passing through the exhaust manifold 55 and the pipe 160 to the turbine while the exhaust valves 132 . 134 . 136 and 138 the purge portion of the exhaust gases through the exhaust manifold 57 over the pipe 162 to an exhaust gas purification device 72 channel.

Exhaust gases, which the turbine 92 Leave, can also through the emission control device 72 flow through. The exhaust gas purification device 72 may contain several catalyst units in one example. In another example, multiple emission control systems may each be used with multiple building blocks. In some examples, the exhaust purification device 72 be a three-way catalyst. In other examples, the exhaust purification device 72 a Diesel Oxidation Catalyst (DOC) and / or a Selective Catalytic Reduction (SCR) catalyst. After flowing through the exhaust gas purification device 72 can the exhaust gas to a tailpipe 58 be directed.

Every cylinder of the engine 10 In addition, in addition to the two intake and two exhaust valves, a fifth valve, referred to as the "compressor intake valve", may also be included, as in FIG 1 shown. This fifth valve may also be referred to as a third exhaust valve. For example, the cylinders include 20 . 22 . 24 and 26 the compressor intake valves 112 . 114 . 116 respectively. 118 to her respective channels 31 . 37 . 43 and 49 are coupled. Further, each of the passages communicating with the compressor intake valves may become a distinct manifold 59 be combined over the pipe 164 with the inlet 28 upstream of the compressor 94 and downstream of the air filter 70 can be connected. For example, the compressor intake valve 112 in the cylinder 20 towards the end of an exhaust stroke to allow residual exhaust gases to pass through to the inlet of the compressor 94 stream. Furthermore, the compressor intake valve 112 remain open beyond the top dead center (oT) position of the piston to engage with intake valves 32 and or 34 of the cylinder 20 to overlap to allow fresh intake air to be blown through the combustion chamber and any remaining exhaust gas to the compressor 94 is rinsed out. The valve 125 can in the pipe 164 be included to control the flow of the EGR and the blow-through air into the compressor inlet. The valve 125 can also be used as a first exhaust gas recirculation valve (ERV - Exhaust Recirculation Valve) 125 be designated. In addition, the valve can 125 also be referred to as a supercharger ERV, as the valve 125 regulate the flow of exhaust gases and blow-by air to a location upstream of the compressor. The valve 125 may be a binary valve (eg, a two-way valve) that can be controlled to be either fully open or fully closed. A fully open position of a binary valve is a position where the valve does not restrict flow, and a fully closed position of the binary valve is a position where the valve limits all flow so that no flow can pass through the valve. In alternative embodiments, the valve 125 a continuously variable valve that can take positions between fully closed and fully open.

In one example, an amount of blow-through air and EGR supplied to the compressor inlet may be changed by changing the control, stroke, and / or duration of one or more compressor intake valves 112 . 114 . 116 and 118 to be controlled. In another example, the valve 125 in the pipe 164 be operated to the amount of blow-through air and EGR that the compressor 94 The compressor intake valve (s) can be operated with fixed controls, fixed lift and fixed time periods.

Thus, the burned gases leaving a cylinder may be divided into three parts via three distinct channels including the two exhaust ducts formed by the split exhaust manifold and a duct connecting the compressor intake valve to a location upstream of the turbocompressor become. For example, in a combustion cycle, a first exhaust valve 122 of the cylinder 20 a first portion of the exhaust gas, namely the Vorlassanteil, via a first channel (the pipe 160 ) to the turbine 92 channel. A second exhaust valve 132 the same cylinder ( 20 ) may include a second portion of exhaust gases downstream of the pre-let portion via a second channel (the pipe 162 ) to an exhaust gas purification device 72 conduct. The second part of the exhaust, via the second exhaust valve 132 leakage, may be mainly the purge component of exhaust gases. Towards the end of the exhaust stroke, the remaining exhaust gases from the compression chamber of the same cylinder ( 20 ) cleared by fresh intake air from blowing through and the compressor intake valve 112 and a third channel (the pipe 164 ) to the inlet of the turbocompressor 94 be transmitted. In particular, the second portion of exhaust gases mainly comprises exhaust gases without an amount of fresh air while the compressor intake valve 112 and the pipe 164 mainly carry fresh blow-by air with a smaller content of exhaust gases.

The first exhaust valve may open earlier than the second exhaust valve and the compressor intake valve to detect the blowdown pulse, and may be closed at a timing earlier than the second exhaust and compressor boost valves. The second exhaust valve may open later than the first exhaust valve but earlier than the compressor intake valve to detect the purge portion of exhaust gases. The first exhaust valve may be closed before the compressor intake valve opens, but the second exhaust valve may close after the compressor intake valve has been opened. The second exhaust valve may be closed substantially before the beginning of the intake stroke and the opening of the intake valves, while the compressor intake valve may be closed significantly after the beginning of the intake stroke. The intake valves may be opened just before the exhaust stroke ends at the piston's TDC position, and may begin shortly after the start of the compression stroke, e.g. B. in the position of the bottom dead center (uT) of the piston, closed. In effect, the compressor intake valve may channel the remaining exhaust gases towards the end of the exhaust stroke and may also channel blow-through together with the EGR by overlapping with one or more intake valves.

The inlet pipe 28 can be an intake throttle 62 (also referred to as throttle 62 ) downstream of a charge air cooler 90 contain. The position of the throttle 62 can through a tax system 15 via a throttle actuator (not shown) connected to the controller 12 communicatively coupled. By modulating the intake throttle 62 during operation of the compressor 94 Can a lot of fresh air from the atmosphere in the engine 10 introduced, from the intercooler 90 cooled and at compressor (or boosted) pressure across the intake manifold 27 supplied to the engine cylinders. To reduce pressure surges, at least a portion of the compressor 94 compressed air charge to be returned to the compressor inlet. A compressor return channel 168 may be for returning cooled compressed air from the compressor outlet downstream of the charge air cooler 90 be provided to the compressor inlet. A compressor return valve 120 may be provided for adjusting an amount of the cooled recycle stream returned to the compressor inlet.

In 1 Fuel injectors coupled directly to the combustion chambers are shown to deliver fuel in proportion to a pulse width of a signal FPW generated by the controller 12 for example, via an electronic driver is injected directly into it. Each cylinder is shown on each intake valve coupled with two injectors per cylinder. For example, fuel injectors 74 and 76 to the cylinder 20 coupled 78 and 80 are at the cylinder 22 coupled 82 and 84 are at the cylinder 24 coupled while fuel injectors 86 and 88 to the cylinder 26 are coupled, as in 1 will be shown. In this way, the fuel injectors provide so-called direct injection of fuel into the combustion chamber. For example, each fuel injector may be mounted in the side of the respective combustion chamber or on top of the respective combustion chamber. In some examples, one or more fuel injectors may be in the intake manifold 27 be arranged in a configuration that provides a so-called port injection of fuel into the intake ports upstream of the respective combustion chambers. Although in 1 not shown, fuel may be supplied to the fuel injectors through a fuel system including a fuel tank, a fuel pump, a fuel rail, and a fuel rail.

In some examples, a distributorless ignition system (not shown) may provide spark to spark plugs coupled to the combustion chambers in response to the control 12 provide. For example, in 1 spark 50 . 52 . 54 and 56 with cylinders 20 . 22 . 24 respectively. 26 shown coupled.

The engine 10 can be at least partially controlled by a tax system 15 that the controller 12 and controlled by input from a driver via an input device (not shown). The tax system 15 is shown as containing information from multiple sensors 16 (various examples of which are described herein) receive and control signals to multiple actuators 81 sends. As an example, sensors 16 Turbo compressor intake pressure and temperature sensors, as well as manifold air pressure (MAP) sensors, are included within the intake manifold. Other sensors may include a throttle inlet pressure (TIP) sensor for estimating a throttle inlet pressure (TIP) and / or a throttle temperature sensor for estimating a throttle air temperature (TCT) coupled downstream of the throttle in the inlet conduit. Additional system sensors and actuators will be referred to below 2 set out in more detail. As another example, actuators 81 Fuel injectors, valves 120 . 125 and 127 and a throttle 62 contain. The control 12 It may receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on an instruction or code programmed therein corresponding to one or more routines. An exemplary control routine will be described with reference to FIG 4 described.

Referring to 2 , this is a partial view 200 a single cylinder of an internal combustion engine 10 , So far in 1 Introduced components are shown with the same reference numbers and will not be re-introduced.

The engine 10 is with a combustion chamber (cylinder) 230 , a cooling jacket 214 and cylinder walls 232 with a piston positioned therein 236 shown with a crankshaft 240 connected is. The combustion chamber 230 is shown as having an inlet valve 252 and an exhaust valve 256 with an inlet pipe 146 or an outlet line 148 communicates. As before in 1 Each cylinder of the engine can be described 10 Deliver combustion products along three lines. In the illustrated view 200 represents an outlet conduit 148 the first exhaust duct leading from the cylinder to the turbine (such as the exhaust duct 33 from 1 ), while the second outlet conduit and the conduit leading to the compressor inlet are not visible in this view.

As already in 1 Running, every cylinder of the engine 10 in addition to a compressor intake valve, include two (or more) intake valves and two (or more) exhaust valves. In the illustrated view 200 are the inlet valve 252 and the exhaust valve 256 in an upper area the combustion chamber 230 , The inlet valve 252 and the exhaust valve 256 can from the controller 12 be controlled using respective cam actuation systems with one or more cams. The cam actuation system may vary one or more of: Cam Profile Switching (CPS), Variable Cam Timing (VCT), Variable Valve Timing (VVT) and / or Variable Valve Lift (VVL)) use the valve operation. In the example shown, each inlet valve 252 from an intake cam 251 controlled, and each outlet valve 256 is from an exhaust cam 253 controlled. The position of the inlet valve 252 and the exhaust valve 256 can by valve position sensors 255 respectively. 257 be determined.

In alternative embodiments, the intake and / or exhaust valve may be controlled by electric valve actuation. For example, the cylinder 230 alternatively, an intake valve controlled by electric valve actuation and an exhaust valve controlled via cam actuation, including CPS and / or VCT systems. In still other embodiments, the intake and exhaust valves may be controlled by a common valve actuator or actuation system or an actuator or variable valve actuation system. It should be noted that the compressor intake valve may be similarly controlled.

In one example, the intake cam comprises 251 separate and different cam lobes, the different valve profiles (eg, valve timing, valve lift, duration, etc.) for each of the two intake valves of the combustion chamber 230 provide. Similarly, the exhaust cam 253 separate and different cam lobes include different valve profiles (eg, valve timing, valve lift, duration, etc.) for each of the two exhaust valves of the combustion chamber 230 provide. Similarly, the (in 2 not shown) are controlled by a camshaft including separate and different cam lobes providing different valve profiles. In another example, the intake cam 251 comprise a common bump or similar bumps providing a substantially similar valve profile for each of the two intake valves.

In addition, various cam profiles may be used for the various exhaust valves to separate exhaust gases emitted at low cylinder pressure from exhaust gases discharged at exhaust pressure. For example, a first exhaust cam profile may be the first exhaust valve just before bottom dead center (uT) of the combustion chamber power stroke 230 from a closed position and close the same exhaust valve well before top dead center (oT) to selectively deliver blowdown gases from the combustion chamber. Further, a second exhaust cam profile may be positioned to open a second exhaust valve from about closed in the middle of the exhaust stroke and to close before the oT to selectively expel the purge portion of the exhaust gases. Still further, a compressor inlet cam profile may be adjusted to open the compressor intake valve from a closed position towards the end of the exhaust stroke. The compressor priming valve may be closed substantially after the oT after the beginning of the intake stroke to allow an overlap between the compressor intake valve and one or more of the intake valves that may be open during the intake stroke.

The compressor intake valve may be activated or deactivated based on the intake manifold air pressure. In particular, when the intake manifold air pressure is higher than the compressor suction pressure, exhaust gases within the cylinder may be drawn into the low pressure compressor inlet along with the blow through, reducing pumping losses. Conversely, if the manifold air pressure is lower than the compressor suction pressure, such as under throttled conditions, the operation of the compressor intake valve may be disabled during an entire engine cycle to prevent backflow of air from the compressor inlet via the cylinder and the compressor intake valve into the intake manifold. In this example, the exhaust gases can be diverted through the two exhaust valves without blowing through in their entirety to the turbine and the exhaust gas purification device.

Thus, the control of the first exhaust valve and the second exhaust valve may isolate the cylinder pilot exhaust gases from the purge portion of the exhaust gases while removing any remaining exhaust gases in the compression space of the cylinder during the positive valve overlap between the intake valve and the compressor intake valve with the blowing of fresh intake air. By flowing a first portion of the exhaust gas (eg, the higher pressure exhaust gas) through the turbine and a higher pressure outlet line and flowing a second portion of the exhaust gas (eg, the lower pressure exhaust gas) through catalyst devices and a second Lower pressure bleed passage while a third portion of the low pressure exhaust gas and bleed air is circulated to the compressor inlet, combustion temperatures may be reduced while improving turbine working efficiency and engine torque.

Furthermore, in 2 an exhaust gas sensor 226 with the outlet pipe 148 shown coupled. The sensor 226 may be positioned in the exhaust passage upstream of one or more emission control devices, such as the device 72 from 1 , The sensor 226 may be selected from a variety of suitable sensors suitable for providing an exhaust gas exhaust gas fuel ratio indication, such as a linear oxygen or wide-range exhaust gas oxygen sensor (UEGO) sensor, a dual-state oxygen sensor or EGO (as shown), a heated EGO (HEGO - Heated EGO), NOx, HC or CO sensor. The downstream exhaust purification devices may include a Three Way Catalyst (TWC), a NOx trap, various other emission control devices, or combinations thereof.

The exhaust temperature may be determined by one or more temperature sensors (not shown) in the exhaust passage 148 are estimated. Alternatively, the exhaust temperature may be derived based on engine operating conditions such as engine speed, load, air-to-fuel ratio (AFR), spark retard, and so on.

The cylinder 230 may have a compression ratio, which is the ratio of volumes when the piston 236 at bottom dead center or at top dead center. Usually, the compression ratio is in the range of 9: 1 to 10: 1. However, in some examples where other fuels are used, the compression ratio may be increased. This can be done, for example, when higher octane fuels or higher enthalpy enthalpy fuels are used. The compression ratio may also be increased when direct injection is used because of its effect on engine knock.

In some embodiments, each cylinder of the engine 10 a spark plug 91 to trigger combustion. In selected operating modes, the ignition system may 288 the combustion chamber 230 over a spark plug 91 in response to an ignition advance signal (SA - Spark Advance) from the controller 12 to give a spark. In some embodiments, the spark plug 91 however, also be omitted, for example, when the engine 10 Initiate combustion by auto-ignition or by injecting fuel, as may be the case with some diesel engines.

In some embodiments, each cylinder of the engine 10 be configured with one or more fuel injectors to supply fuel thereto. As a non-limiting example, the cylinder becomes 230 shown a fuel injector 66 contains. A fuel injector 66 gets directly to the combustion chamber 230 shown coupled to fuel in proportion to the pulse width of the signal FPW generated by the controller 12 via an electronic driver 268 is to inject directly into it. In this way, the fuel injector 66 That's what's ready as direct injection (also referred to as "DI" [Direct Injection]) of fuel into the combustion cylinder 230 is known. While 2 the injector 66 As a side injector, it may also be above the piston, for example near the position of the spark plug 91 to be positioned. Such a position can improve mixing and burning when the engine is operated on an alcohol-based fuel, due to the lower volatility of some alcohol-based fuels. Alternatively, the injector may be located above or in the vicinity of the inlet valve to enhance mixing. In an alternative embodiment, the injection nozzle 66 a duct injection nozzle, the inlet duct upstream of the cylinder 230 Supplying fuel.

Fuel can be the fuel injector 66 via a high pressure fuel system 8th containing fuel tanks, fuel pumps and a fuel rail. Alternatively, fuel may be supplied by a single stage fuel pump at lower pressure, wherein the adjustment of direct fuel injection may be more limited during the compression stroke than when using a high pressure fuel system. Although not shown, the fuel tanks may further have a pressure transducer that controls 12 provides a signal. Fuel tanks in the fuel system 8th may contain fuel with different fuel qualities, such as different fuel compositions. These differences may include a different alcohol content, different octane number, different heat of vaporization, different fuel mixtures, and / or combinations thereof. In some embodiments, the fuel system may 8th coupled to a fuel vapor recovery system including a reservoir for storing fuel vapors arising during refueling and during the course of the day. The fuel vapors may be purged from the reservoir into the engine cylinders during engine operation upon satisfaction of purge conditions. For example, the Purge vapors are drawn through the first inlet line at or under barometric pressure by self-priming into the cylinder.

The control 12 is in 2 shown as a microcomputer, which is a microprocessor unit 102 , I / O ports 104 , an electronic storage medium for executable programs and calibration values, which in this particular example is a read-only memory 106 shown is a random access memory 108 , a conservation store 110 and a data bus. The read-only memory 106 The storage medium may be programmed with computer readable data generated by the microprocessor 102 represent executable instructions for performing the methods and routines described below as well as other anticipated but not specifically listed variants. The control 12 can in addition to the previously explained signals different signals from with an engine 10 Receive coupled sensors, including measurement of the mass air flow (MAF) introduced by the mass air flow sensor 48 ; engine coolant temperature (ECT) from one to a cooling jacket 214 coupled temperature sensor 212 ; a profile ignition pickup signal (PIP) from one with the crankshaft 240 coupled Hall sensor 220 (or another type of sensor); Throttle position (TP) from a throttle position sensor; a manifold absolute pressure (MAP) pressure signal from the sensor 98 , the cylinder fuel-air ratio of the EGO sensor 226 and abnormal combustion of a knock sensor and a crankshaft acceleration sensor. From the PIP signal, the controller 12 generate an engine speed signal RPM (revolutions per minute). The manifold pressure signal MAP from a manifold pressure sensor may be used to provide an indication of the vacuum or pressure in the intake manifold.

Based on input from one or more of the above-mentioned sensors, the controller may 12 one or more actuators, such as a fuel injector 66 , a throttle 62 , a spark plug 91 , adjusting a compressor intake valve, intake / exhaust valves and cams, etc. The controller may receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on instructions or code programmed therein in accordance with one or more routines. An exemplary control routine will be described later with reference to FIG 4 described.

Referring now to 3 , represents the picture 300 Example valve timings with respect to a piston position, for an engine cylinder comprising 5 valves: two intake valves, two exhaust valves and a compressor intake valve, as in FIGS 1 - 2 described. The example of 3 is essentially drawn to scale, even if not every single point is labeled with number values. The relative differences of the timings can be estimated by the drawing dimensions. If desired, however, other relative timings may be used.

With 3 continuing, the cylinder is configured to receive the intake via two intake valves and deliver a first proportion of blowdown to a turbine inlet via a first exhaust valve, deliver a second purge rate via a second exhaust valve to an exhaust purification device, and a combination of low pressure exhaust and fresh blowby air via a compressor intake valve to flow to the inlet of a turbocompressor. By adjusting the timing of opening and / or closing the compressor intake valve to those of the two exhaust and two intake valves, residual exhaust gases may be exhausted from the compression chamber of the cylinder and returned together with fresh intake blow-through air as EGR.

The illustration 300 represents an engine position along the x-axis in degrees Crank Angle Degree (CAD). The curve 302 represents piston positions (along the y-axis) with respect to their position from top dead center (oT) and / or bottom dead center (uT) and also with respect to their position within the four strokes (intake, compression, work and exhaust) of an engine cycle represents.

During engine operation, each cylinder typically undergoes a four-stroke cycle that includes an intake stroke, a compression stroke, a power stroke, and an exhaust stroke. During the intake stroke, the exhaust valves generally close and the intake valves open. Air is introduced into the cylinder via the corresponding intake passage, and the cylinder piston moves to the bottom of the cylinder to increase the volume within the cylinder. The position in which the piston is near the bottom of the cylinder and at the end of its stroke (eg, when the combustion chamber is at its greatest volume) is typically referred to by those skilled in the art as bottom dead center (uT). During the compression stroke, the intake valves and exhaust valves are closed. The piston moves to the cylinder head to compress the air in the combustion chamber. The point at which The piston closest to the end of its stroke and cylinder head (eg, when the combustor is at its smallest volume) is typically referred to by those skilled in the art as top dead center (oT). In a process referred to herein as injection, fuel is introduced into the combustion chamber. In a process referred to herein as ignition, the injected fuel is ignited by known ignition means, such as a spark plug, resulting in combustion. During the power stroke, the expanding gases push the piston back to the UT. A crankshaft converts this piston movement into a torque of the rotary shaft. During the exhaust stroke, in a traditional design, the exhaust valves are opened to exhaust the combusted air-fuel residual mixture into the corresponding exhaust ducts and the piston returns to the TDC. In this description, the compressor suction valve may be opened toward the end of the exhaust stroke while the exhaust valves are closed to purge the exhaust fumes with the blow-through air.

The curve 304 represents a first intake valve timing, a lift and a duration for a first intake valve (Int_1) while the curve 306 2 illustrates a second intake valve timing, a lift and a duration for a second intake valve (Int_2) coupled to the intake pipe of the engine cylinder. The curve 308 FIG. 10 depicts an example exhaust valve timing, lift, and duration for a first exhaust valve (Exh_1) coupled to a first exhaust passage of the engine cylinder while the curves 310a and 310b map exemplary valve timings, strokes and durations for a second exhaust valve (Exh_2) coupled to a second exhaust passage of the engine cylinder. As already stated, the first exhaust line connects a first exhaust valve to the inlet of a turbine in a turbocharger, and the second exhaust line connects a second exhaust valve to a location downstream of the turbine and upstream of an exhaust gas purification device. The curve 312 illustrates exemplary valve timing, stroke and duration for a Compressor Inlet Valve (CIV) coupled to a third line connecting the CIV to the inlet of the turbocompressor. The first and second exhaust ducts and the third duct for flowing the EGR and the blow-by air may be separated from each other.

In the illustrated example, the first and second intake valves are fully opened in a common control from a closed position (curves 304 and 306 ), much closer to the TDC of the intake stroke, beginning just before CAD2 (eg, at or just before the TDC of the intake stroke), and starting shortly after the beginning of a subsequent compression stroke to CAD3 (eg, at or shortly after uT) closed. In addition, the two inlet valves, when fully opened, may be opened for the same duration D1 with the same amount of valve lift L1. In other examples, the two valves may be operated with a different control by adjusting the phasing, stroke, or duration based on engine conditions.

Now to the exhaust valves, wherein the control of the first and second exhaust valves is staggered with that of the compressor intake valve (CIV). In particular, the first exhaust valve is moved from a closed position to a first control (curve 308 ) opened earlier in the engine cycle than the controller (curves 310a . 310b ), in which the second exhaust valve is opened from closed, and earlier than the control (curve 312 ), in which the CIV is opened from closed. Specifically, the first control for the first exhaust valve is closer to the exhaust stroke uT, just before CAD1 (eg, at or just before the exhaust stroke), while the exhaust second exhaust control and CIV control is from the exhaust stroke uT is retarded - to CAD1, but before CAD2. The first (curve 308 ) and the second (curve 310a ) Exhaust valves may be closed before the end of the exhaust stroke while the CIV is left open beyond the TDC when the intake stroke has started to positively overlap with the intake valves. For example, the CIV may be closed before the midpoint of the intake stroke.

That is, at or before the beginning of an exhaust stroke (eg, within 10 degrees of the uT), the first exhaust valve may be fully opened from closed, fully open during a first portion of the exhaust stroke, and before the end of the exhaust stroke (FIG. eg, within 45 degrees of the TDC) to completely close the pre-discharge portion of the exhaust pulse. The second exhaust valve (curve 310a ) can be fully opened from a closed position at about the midpoint of the exhaust stroke (eg, between 60 and 90 degrees after the uT), left open during a second portion of the exhaust stroke, and can be fully closed before the exhaust stroke ends (FIG. eg, within 20 degrees before the TDC) to deliver the purge portion of the exhaust gas. The CIV may be fully opened towards the end of the exhaust stroke (eg, within 25 degrees of the TDC) from fully closed, may be left fully open until at least one subsequent intake stroke has commenced, and may be substantially past the TDC of the exhaust stroke (FIG. eg within 30 degrees after the TDC) completely getting closed. The intake valves may be fully opened from closed just before the exhaust stroke ends (eg, within 10 degrees before TDC), left open during the intake stroke, and at or just after the start of the compression stroke (eg, within 10 degrees after uT) completely closed. Therefore, the CIV and intake valves, as in 3 have a phase of positive valve overlap (eg, from 10 degrees before TDC to 30 degrees after TDC) to allow EGR blow through. This cycle, where all five valves are operational, may self-repeat based on engine operating conditions.

Further, the first exhaust valve may be fully closed and closed substantially before the CIV is fully opened while the second exhaust valve may be fully closed shortly after the CIV has been opened. Further, the first and second exhaust valves may intersect each other, and the second exhaust valve and the CIV may minimally overlap each other, and overlapping of the first exhaust valve and the CIV is not possible.

As already mentioned, the CIV may be ready for operation if the MAP is higher than the compressor intake pressure. However, if the MAP is lower than the compressor suction pressure, the CIV may be deactivated and left closed until the MAP is higher than the pressure at the compressor inlet. Specifically, the CIV may be closed if it is open or left closed to prevent reverse airflow from the engine intake via the cylinder into the intake manifold. Here, the control of the first exhaust valve may be the same as the first control as in the curve 308 from 3 Shown: Open just before the UDC when the exhaust stroke starts, and close significantly before the TDC at the end of the exhaust stroke. However, the second exhaust valve may be opened approximately midway through the exhaust stroke and may be left open until shortly after the end of the exhaust stroke (for example, 10 degrees after the oT) 310b ) to empty the cylinder from its exhaust. The second exhaust valve may be fully closed at or shortly after the end of the exhaust stroke, and no positive valve overlap may occur between the second exhaust valve and the intake valves to avoid blowby.

The controls of the second exhaust valve may be varied based essentially on the activation or deactivation of the CIV. If the MAP is higher than the compressor suction pressure and the CIV is ready during the combustion cycle, the second exhaust valve may be opened about halfway through the exhaust stroke and closed well before the end of the exhaust stroke (curve 310a ). In one example, the second exhaust valve may be opened about 80 degrees after the uT and closed within 20 degrees before the oT. If the MAP is lower than the compressor suction pressure and the CIV is deactivated and kept closed, the second exhaust valve may be opened approximately halfway through the exhaust stroke and fully closed at the end of the exhaust stroke at or shortly after the oT (see graph 310b ). For example, the second exhaust valve may be opened about 90 degrees after the uT and closed within 10 degrees of the oT. In the in 3 shown example of the second exhaust valve, the curves 310a and 310b have the same duration (the period) D3. In other examples, the periods may be varied along with the phasing of the second exhaust valve.

In addition, the first exhaust valve may be opened at a first control with a first amount of the valve lift L2, while the second exhaust valve may be opened with a second amount of the valve lift L3 (curve 310a ) and the CIV can be opened with a third amount of the valve lift L5. Still further, in the first control, the first exhaust valve may be opened for a duration D2 while the second exhaust valve may be opened for a duration D3 and the CIV may be opened for a duration D5. It will be appreciated that in alternative embodiments, the two exhaust valves may have the same amount of valve lift and / or the same duration of opening while opening with differently phased-timing controls.

In this way, using staggered valve controls, engine efficiency and performance can be increased by releasing the exhaust gases released at a higher pressure (eg, expanding exhaust fumes in a cylinder) from residual exhaust gases at low pressure (eg, exhaust gases exhausted) allowing it to remain in the cylinder) into the various channels. By conveying the residual low pressure exhaust gases as EGR along with the blowby air to the compressor inlet, the combustion chamber temperatures can be reduced, reducing knock and spark retard from maximum torque. Further, because at the end of the stroke, the exhaust gases are directed either downstream of a turbine or upstream of a compressor, both of which lower exhaust pressures, exhaust pump losses can be minimized to improve engine efficiency.

Consequently, the exhaust gases can be used more efficiently than simply directing all the exhaust of a cylinder through a single, common exhaust passage to a turbocharger turbine. Accordingly, several advantages can be achieved. For example, the average exhaust pressure supplied to the turbocharger may be increased by separating and directing the blowdown pulse into the turbine inlet to improve turbocharger output. In addition, fuel economy can be improved because the blow-by air is not directed to the catalyst, but instead is directed to the compressor inlet, and thus excess fuel can not be injected into the exhaust gases to maintain a stoichiometric ratio.

Now referring to 4 , becomes an exemplary routine 400 for operating the compressor intake valve (CIV) and the two exhaust valves according to the engine conditions. In particular, the routine may determine various valve positions based on engine operating conditions, including combustion stability, engine limitations, and transitions under other conditions.

Further, as explained below, the valves are operated by one or more combustion cycles during the duration of the specific engine condition.

at 402 Engine operating conditions may be estimated and / or measured. These may include, for example, ambient temperature and pressure, engine temperature, engine speed, crankshaft speed, battery state of charge, available fuels, catalyst temperature, driver requested torque, and so forth. at 404 For example, based on the estimated engine operating conditions, the function and operation of all valves may be determined. For example, under steady state conditions, the CIV may be operated during an engine combustion cycle to allow blowby, reduce exhaust pumping losses, and improve torque.

at 406 can be determined whether conditions are given for an engine start. An engine start may include starting the engine from rest via an engine, such as a starter motor. If conditions are given for an engine start, be included 408 the CIV and the first exhaust valve are deactivated and kept closed, while the entire exhaust gas portion is supplied via the second exhaust valve of the exhaust gas purification device. That is, during a combustion cycle under engine start conditions, the second exhaust valve may be fully opened just before the exhaust stroke begins and fully closed at the beginning of the intake stroke. During a cold start, the hot exhaust gases may assist in bringing the emission control device up to light-off temperature. During a warm start, the initial emissions may be dissipated by the exhaust gas purifier that has reached the light-off temperature.

at 410 can be determined whether a pedal is expected. In order to accelerate the starting up of the exhaust gas turbine in a turbocharger system in preparation for a pedal depression, the first exhaust valve may be activated in addition to the second exhaust valve to direct the venting proportion of the exhaust gas to the turbine. In particular, the first exhaust valve may be opened when the exhaust stroke begins and closed well before the end of the exhaust stroke to direct the blowdown pulse to the turbine. The second exhaust valve may be opened approximately halfway through the exhaust stroke and closed well prior to the end of the exhaust stroke to channel the purged portion of exhaust gas to the exhaust gas purifier.

If a pedal press is confirmed, the routine may be closed 412 determine if a manifold air pressure (MAP) is higher than the turbo compressor intake pressure. If it is confirmed that the MAP is higher, the CIV may be at 414 be activated to open it towards the end of the exhaust stroke, to allow the EGR and the blow-through air are transmitted to the compressor inlet.

If the MAP is lower than the compressor suction pressure, the CIV may be closed or closed and deactivated to prevent reverse airflow. For example, under throttled conditions, the intake air may possibly seek to flow from the upstream of the compressor to the intake manifold via the combustion chamber. To prevent this backflow, the CIV can be deactivated and closed while the second exhaust valve is about half way opened by the exhaust stroke and can be closed at or shortly after the beginning of the intake stroke.

at 418 can be determined whether there are signs of engine knock. If the presence of engine knock is confirmed, the routine includes 420 operating the CIV to allow for EGR and blow-by, allowing the combustor temperatures to be cooled. In particular, the CIV may be opened towards the end of the exhaust stroke and closed substantially after the start of the intake stroke. As previously described, the two exhaust valves may be operated to direct the pre-purge and purged portions to the turbine and exhaust gas purifier, respectively. Engine knock may be due to an abnormal combustion event occurring in a cylinder following a spark ignition event of the cylinder. To promote combustion stability, additional fuel may be injected into the blow-through air to enrich the EGR gases. By injecting fuel to enrich the EGR, engine knock may be mitigated without the use of spark retard, which improves engine torque.

Then you can join 422 determine whether the conditions for a fuel cut-off (SAS) or conditions of a pedal release are met. The SAS event may occur in response to a torque request that is lower than a threshold, such as during a pedal release. In this case, a fuel injection into the cylinder can be stopped selectively. If a SAS or pedal release is confirmed, the CIV may be activated 424 disabled and closed or closed to reduce an amount of residue that is supplied to the engine intake during deceleration. In particular, the CIV is closed and / or closed throughout combustion cycles as long as the SAS or pedal release continues. Further, the exhaust gases may be channeled as two portions: a previous proportion of venting via the first outlet valve and a second flushing portion via the second outlet valve. The engine settings may be adjusted to maximize the engine torque response after exiting the SAS. For example, the throttle may be positioned to provide a best transient response when pedaling.

If none of the engine conditions described above are present, at 426 the valves are operated based on the conditions of a stable state. In one example, during steady state conditions, if the MAP is higher than the compressor suction pressure, the CIV may be similar to step 414 activated and opened towards the end of the exhaust stroke and closed considerably after the beginning of the intake stroke. In another example, if the MAP is lower than the compressor suction pressure, the CIV may be as in step 416 be disabled and kept closed. The two exhaust valves may be operated as previously described: if the CIV is ready during the combustion cycle, both exhaust valves close substantially before the end of the exhaust stroke. If the CIV is not ready, the exhaust portion of the exhaust gas continues to be supplied via the first outlet of the turbine, while the second exhaust valve discharges the remaining exhaust gases to the exhaust gas purification device. Here blowby and EGR can not be channeled to the compressor inlet. In yet another example, under conditions of unstable condition, valve operation may be modified and adapted to existing conditions.

Now, referring to 5 various examples of engine conditions and resulting valve settings set forth. In particular, the table 500 lists exemplary combinations of draining a cylinder along three distinct conduits including a first exhaust conduit through a first exhaust valve leading to an exhaust turbine inlet, a second conduit through a second exhaust valve leading to an exhaust gas purifier, and a third conduit from a compressor intake valve to a location upstream of the turbocompressor. The three exhaust fractions may be emitted separately and at different times within the same engine combustion cycle as previously described with reference to FIG 3 was set out. Further, during all conditions described below, the intake valves are ready for use as described with reference to FIG 3 described. Both intake valves may be fully opened at the beginning of the intake stroke (eg, at or shortly before the TDC of the exhaust stroke) and fully closed at the end of the intake stroke (eg, at or shortly after the UH of the intake stroke).

During an engine start condition, the CIV and the first exhaust valve may be deactivated and left closed, while the second exhaust valve is operational throughout the exhaust stroke (eg, from near the end of the power stroke uT to shortly after the end of the exhaust stroke oT) and is open, whereby all the exhaust gas is passed to the exhaust gas purification device. Consequently, when the engine is started from rest or standstill, neither the turbine nor the compressor inlet receive one Proportion of the exhaust gas. During pedal depression both exhaust valves may be activated and ready for operation. A pre-proportion of the exhaust gas may be directed to the turbine by opening the first exhaust valve shortly before the end of the power stroke uT and closing the first exhaust valve before the end of the exhaust stroke. A second portion of the exhaust gases after pre-venting may be supplied to an exhaust purification device by opening the second exhaust valve approximately midway during the exhaust stroke. Both exhaust valves may be closed before the end of the exhaust stroke. A final fraction of low pressure exhaust gas (LP-EGR) combined with fresh blowby air may be achieved by operating the CIV to open towards the end of the exhaust stroke and maintaining a positive valve overlap with one or more intake valves during the intake stroke to the turbo-compressor inlet to get promoted. The CIV can significantly after the beginning of the intake stroke, z. B. considerably after the oT closed. Thus, the exhaust gas turbine with the energy recovered from the exhaust exhaustion pulse can be ramped up, while by returning LP EGR and blowing through the compressor inlet, knocking and other combustion instabilities can be reduced. The operation of the CIV may depend on the MAP. The CIV may be open only during the combustion cycle when the manifold air pressure is higher than the compressor suction pressure to allow the flow of fresh intake air through the cylinder and the CIV to transfer the remaining low pressure exhaust gases to the compressor inlet.

When an engine is operating under throttled conditions, the manifold air pressure may be lower than the compressor intake pressure. Therefore, the CIV may be deactivated during the cycle and remain closed while the two exhaust valves are ready to exhaust the combusted gases from the cylinder. The exhaustion pulse from the exhaust gas may be directed to the turbine of the turbocharger, while the purged portion of the exhaust gas may be conveyed to the exhaust gas purification device. The first exhaust valve may open shortly before the start of the exhaust stroke and may close significantly before the end of the exhaust stroke. The second exhaust valve may open about half way through the exhaust stroke and may close at the oT or shortly after the end of the exhaust stroke after the oT.

During unstable combustion conditions, when engine knock may be present, the CIV may be activated and opened toward the end of the exhaust stroke and may be fully closed substantially after the start of the intake stroke to allow EGR and blowby. In addition, additional fuel may be injected into the blow-through air to make the EGR richer and improve combustion stability. Thus, the CIV may transfer a mixture of unburned fuel, low pressure exhaust (as LP EGR), and blow-by air for return to the cylinder to the compressor inlet. The two exhaust valves are operated similarly to the processes described for the pedal return condition, which may be open during a portion of the exhaust stroke and may be closed significantly prior to the end of the exhaust stroke.

During a pedal release condition, when the engine is deactivated, the CIV may be deactivated and left closed to prevent EGR from flowing through the engine. The two exhaust valves are operable, whereby the first portion of the exhaust gases is discharged through the first exhaust valve to the turbine, while the remaining portion of the exhaust gases is discharged through the second exhaust valve to the exhaust gas purification device. The first exhaust valve is opened at or shortly before the end of the power stroke and is closed considerably before the end of the exhaust stroke. The second exhaust valve is opened halfway through the exhaust stroke and closed shortly after the start of the intake stroke.

Referring now to 6 , is another embodiment of the engine 10 out 1 shown. 6 represents a second embodiment 600 an engine 10 In addition, several components of the engine 10 that in the second embodiment 600 from 6 are pictured with those from 1 be identical. Accordingly, these components are numbered the same and will not be reintroduced.

The engine 10 out 6 can be the same as the engine 10 out 1 be, except that the second embodiment 600 a re-compressor line 664 (or a channel 664 ) contains. In other words, a fourth outlet, namely the Nachverdichterleitung 664 in the second embodiment 600 be included (compared to the engine embodiment 1 ), in addition to the already introduced three distinct outlet pipes. In particular, the after-compressor line is coupled 664 fluidically via a second exhaust gas recirculation valve 625 the manifold 59 with a spot located downstream of the compressor 94 and the intake throttle 62 located. Consequently, the after-compressor line couples 664 the manifold 59 with a spot after the compressor.

For example, the channel 664 the manifold 59 fluidically with a location immediately upstream of the intake manifold 27 couple. As in 6 can be shown, the Nachverdichterleitung 664 with the inlet pipe 28 coupled downstream of the intake throttle 62 at a mixer 626 , Alternative embodiments may be a fluidic coupling of the post-compression line 664 with a location downstream of the compressor 94 but upstream of the intake throttle 62 contain. The mixer 626 can be a uniform mixing of gases through the secondary compressor line 664 from the manifold 59 went in, and fresh intake air coming from the intake throttle 62 via an inlet pipe 28 go in, provide. In other words, in the mixer 626 a spatial and temporal mixing of exhaust gases, blow-through air and fresh intake air take place. Also an EGR cooler 690 is in the final compressor line 664 included from the manifold 59 to cool incoming exhaust gases.

A second exhaust gas recirculation valve 625 (or a second ARV 625 ) may be a binary valve (eg, an on-off valve) that is set between a fully closed and fully open position. If the second ARV 625 is completely closed, no gases from the manifold 59 through the second ARV 625 in the direction of the mixer 626 stream. If the second ARV 625 is fully open, it allows the passage of fluid. As will be explained in more detail below, during a certain operating mode, exhaust gases from the cylinder 20 the engine 10 past the compressor intake valve 112 to the manifold 59 along the after-compressor line 664 via a second ARV 625 through the EGR cooler 690 in the mixer 626 stream. Furthermore, exhaust gases from the cylinder 20 the engine 10 be mixed with fresh intake air coming from the intake throttle 62 in the mixer 626 received, and the entire mixture can be in the intake manifold 27 enter and into each cylinder of the engine 10 stream. In alternative embodiments, a second ARV 625 a continuously variable valve that can assume positions between the fully closed and fully open positions.

Consequently, combusted gases, which are a cylinder of a second embodiment 600 an engine 10 leave, are routed to at least one of four distinct locations via four separate conduits containing two exhaust conduits formed by the split exhaust manifold, a conduit connecting the compressor intake valve to upstream of the turbocompressor, and the after-compressor duct (or fourth exhaust duct), which couples the compressor intake valve with downstream of the turbocompressor. That is, exhaust gases from the multiple cylinders 20 . 22 . 24 and 26 may be directed to one or more of at least three locations, including directly to the exhaust gas purifier 72 (over a pipe 162 ), directly to the turbine 92 (over a pipe 160 ) and directly to the inlet of the compressor 94 over a pipe 164 and the ARV 125 , In addition to the three points described above, the burnt gases can escape from the cylinder 20 (alone) via the re-compressor line 664 to a fourth location (via the use of cam profile switching and a second ARV 625 ), located downstream of the compressor 94 and downstream of the intake throttle 62 is to be directed. The exhaust gases may be directed to specific locations based on engine operating conditions, as described below with reference to FIG 8th is described. Based on operating modes and resulting target locations for the EGR, the status of the first ARV can also be determined 125 and the second ARV 625 change. If an EGR is at a point upstream of the compressor 92 is desired, a first ARV 125 be open while a second ARV 625 can be completely closed. If an EGR is at a post-compressor station (eg mixer 626 ), the ARV 125 be completely closed while the second ARV 625 can be fully open (from closed).

Here can exhaust gases, which are the multiple cylinders of the engine 10 out 6 be routed to desired locations by using variable valve timing such as variable cam timing along with a cam profile switching system. 7 presents a more detailed view 700 an exemplary variable cam timing (VCT) system 702 and a cam profile switching system (CPS - Cam Profile Switching) 704 operative with a second embodiment of an engine 10 out 6 is coupled. It is understood that in 1 (and 6 ) engine components are similarly numbered and not re-introduced. It is also understood that several components of the engine 10 in 7 for the sake of simplicity and clarity of illustration are not shown. It is also noted that, although not shown, intake valves of each cylinder of the engine 10 can be actuated by an intake camshaft, with the VCT system 702 and the CPS system 704 operatively linked. Operation of intake valves of all cylinders of the engine 10 however, it will not be described here and the description focuses on operating the exhaust valves and the compressor intake valves for each cylinder.

Each exhaust valve and compressor intake valve of each cylinder of the engine 10 is between an open position, which can exhaust gas from a corresponding cylinder, and a closed position, which retains gas within the corresponding cylinder substantially, operable. 7 shows exhaust valves 138 . 128 . 136 . 126 . 134 . 124 . 132 and 122 as well as compressor intake valves 118 . 116 . 114 and 112 passing through a common exhaust camshaft 714 be operated. The exhaust camshaft 714 includes multiple exhaust cams configured to control the opening and closing of the exhaust valves. Each exhaust valve may be controlled by one or more exhaust cams, as described in more detail below. In some embodiments, one or more additional exhaust cams may be included to control the exhaust valves. Further, exhaust actuator systems may enable control of exhaust valves.

Exhaust valve actuator systems may also include pushrods, rocker arms, plungers, etc. Such devices and features may control the actuation of the intake valves and the exhaust valves by converting the rotational movement of the cams into a translational movement of the valves. In other examples, the valves may be actuated via additional cam lobe profiles on the camshafts, wherein the cam lobe profiles between the various valves may provide different cam lift height, cam duration, and / or cam timing. However, alternative camshaft arrangements (overhead and / or pushrod) may also be used, if desired. In still other examples, the exhaust valves and intake valves may be actuated by a common camshaft. However, in alternative embodiments, at least one of the intake valves and / or exhaust valves may be actuated by its own independent camshaft or other device.

The engine 10 of the second embodiment 600 may include a controller such as that with reference to 1 described control 12 which controls a subgroup of the plurality of cylinders in a manner different from a remaining number of the plurality of cylinders. Here, a subgroup of the plurality of cylinders includes a number of cylinders smaller than the total number of the plurality of cylinders. For example, a cylinder 20 (a subset) relative to controlling the remaining cylinders 22 . 24 and 26 of several cylinders 20 . 22 . 24 and 26 be controlled in a distinct way. In particular, exhaust valves 132 . 122 and the compressor intake valve 112 of the cylinder 20 relative to exhaust valves 138 . 128 . 136 . 126 . 134 and 124 and compressor intake valves 118 . 116 and 114 the remaining cylinders 22 . 24 and 26 be operated differently. exhaust 132 . 122 and the compressor intake valve 112 of the cylinder 20 can be from cams with compared to cams that use the exhaust valves 138 . 128 . 136 . 126 . 134 and 124 as well as compressor intake valves 118 . 116 and 114 operated, other and distinct profiles are operated.

exhaust 134 . 136 and 138 fluidly connected to the exhaust manifold 57 and with the exhaust emission device 72 over a pipe 162 can be coupled through a first exhaust cam 716 and a second exhaust cam 718 operated on a common exhaust camshaft 714 are arranged. First exhaust cam 716 may have a first cam lobe profile providing a first exhaust duration and a first exhaust stroke. In the example of 7 can first exhaust cams 716 of cylinders 22 . 24 and 26 have a similar first cam lobe profile that opens corresponding exhaust valves for a certain duration and stroke. Second exhaust cam 718 may have a second cam lobe profile providing a second exhaust duration and a second exhaust stroke. In the example of 7 can second exhaust cam 718 of cylinders 22 . 24 and 26 have a similar second cam lift profile that opens corresponding exhaust valves for a certain duration and stroke. First exhaust cam 716 can relative to that of the second exhaust cam 718 have a different and distinct cam profile. For example, second exhaust cams 718 corresponding exhaust valves open for a longer duration than those of the first exhaust cam 716 provided opening time.

exhaust 124 . 126 and 128 , which determines the proportion of exhaust gases passing through the exhaust manifold 55 and the line 160 to the turbine 92 can channel from any of a third exhaust cam 720 , a fourth exhaust cam 722 and a fifth exhaust cam 724 be operated. Third exhaust cam 720 may have a third cam lobe profile providing a third exhaust duration and a third exhaust stroke. In the example of 7 can third exhaust cam 720 of cylinders 22 . 24 and 26 have a similar third cam lobe profile that opens corresponding exhaust valves for a certain duration and stroke. Fourth exhaust cam 722 may have a fourth cam lift profile that provides a fourth exhaust duration and a fourth exhaust stroke. In the example of 7 can fourth exhaust cam 722 of cylinders 22 . 24 and 26 have a fourth cam lift profile that opens corresponding exhaust valves for a certain duration and stroke. As such, third exhaust cams 720 a relative to that of the fourth exhaust cam 722 have different and distinct cam profile. For example, fourth exhaust cams 722 opening corresponding exhaust valves for a longer duration than those of third exhaust cams 720 provided opening time. Furthermore, third exhaust cam 720 a relative to that of the first exhaust cam 716 and the second exhaust cam 718 have different and distinct cam profile. Similarly, fourth exhaust cams 722 a relative to that of the first exhaust cam 716 and the second exhaust cam 718 have different and distinct cam profile.

Fifth exhaust cam 724 are mapped as zero cam lobes that may have a profile to permit their respective exhaust valves through one or more engine cycles 124 . 126 and 128 in the fully closed (eg, deactivated) position. Thus, zero cam lobes during certain modes may disable corresponding exhaust valves 124 . 126 and 128 in appropriate cylinders 22 . 24 and 26 support.

Verdichteransaugventile 114 . 116 and 118 of cylinders 22 . 24 and 26 , the fluidically alone with the exhaust manifold 59 can be coupled by a sixth exhaust cam 726 and a seventh exhaust cam 728 be operated. Sixth exhaust cam 726 may have a sixth cam lift profile that provides a sixth exhaust duration and a sixth exhaust stroke. In the example of 7 can sixth exhaust cam 726 of cylinders 22 . 24 and 26 have a similar sixth cam lobe profile that opens corresponding exhaust valves for a certain duration and stroke. Sixth exhaust cam 726 For example, relative to that of the previously introduced exhaust cams, they may have different and distinct cam profiles. Seventh exhaust cams 728 can be zero cam elevations, on request compressor intake valves 114 . 116 and 118 keep completely closed. Thus, under certain engine conditions, compressor intake valves may be in cylinders 22 . 24 and 26 be deactivated.

exhaust 132 and 122 from cylinder 20 can be individually controlled via a separate set of cams. In particular, this may be with the exhaust manifold 57 communicating exhaust valve 132 through the eighth exhaust cam 730 , the ninth exhaust cam 732 and the zero outlet cam 733 be operated. The eighth exhaust cam 730 may have an eighth cam lobe profile providing an eighth exhaust duration and an eighth exhaust stroke. The ninth exhaust cam 732 may have a ninth cam lift profile providing a ninth exhaust duration and a ninth exhaust stroke. Eighth exhaust cam 730 may be one relative to that of the previously inserted cams and that of the ninth exhaust cam 732 have different and distinct cam profile. Furthermore, the zero outlet cam 733 if desired have a profile that the exhaust valve 132 in its fully closed (eg, deactivated) position.

Similarly with the exhaust manifold 55 fluidically coupled outlet valve 122 through the tenth exhaust cam 734 , the eleventh exhaust cam 736 and the zero outlet cam 738 be operated. The tenth exhaust cam 734 may have a tenth cam lift profile that provides a tenth exhaust duration and a tenth exhaust stroke. The eleventh exhaust cam 736 may have an eleventh cam lift profile providing an eleventh exhaust duration and an eleventh exhaust stroke. The eleventh exhaust cam 736 may be a relative to that of the previously introduced cams and that of the tenth exhaust cam 734 have different and distinct cam profile. Furthermore, the zero outlet cam 738 if desired have a profile that the exhaust valve 122 in its fully closed (eg, deactivated) position.

The compressor intake valve 112 of the cylinder 20 can through the twelfth exhaust cam 740 , the thirteenth exhaust cam 742 and the zero outlet cam 744 be operated. The twelfth exhaust cam 740 may have a twelfth cam lobe profile providing a twelfth exhaust duration and a twelfth exhaust stroke. The thirteenth exhaust cam 742 may have a thirteenth cam lobe profile providing a thirteenth exhaust duration and a thirteenth exhaust stroke. The twelfth exhaust cam 740 may be a relative to that of the previously introduced cams and that of the thirteenth exhaust cam 742 have different and distinct cam profile. Furthermore, the zero outlet cam 744 If desired, have a profile that the compressor intake valve 112 in its fully closed (eg, deactivated) position.

Other embodiments may include deviating mechanisms for deactivating the exhaust valves and compressor intake valves in cylinders known in the art. Such embodiments may not utilize null cam elevations for deactivation. These mechanisms may include, for example, shift tappets, rocker arms, or hydraulic pulley rocker arms.

Thus, each outlet valve 138 . 136 and 134 , coupled with the manifold 57 , operated by one of two exhaust cams. exhaust 128 . 126 and 124 however, may be actuated by one of three distinct exhaust cams during compressor intake valves 118 . 116 and 114 can be operated by one of two distinct exhaust cam. Even further, every exhaust valve can 128 . 126 and 124 and each compressor intake valve 118 . 116 and 114 during certain engine conditions be operated by at least one Nullauslassnocken. exhaust 132 and 122 and the compressor intake valve 112 of the cylinder 20 each can be actuated by one of three distinct exhaust cams. In addition, on request, each outlet valve 132 and 122 and the compressor intake valve 112 of the cylinder 20 Disabled via corresponding Nullauslassnocken.

All exhaust valves and the compressor intake valve may be actuated by a corresponding actuator system that is operatively connected to the controller 12 is coupled. Consequently, exhaust valves can 138 . 128 and the compressor intake valve 118 of the cylinder 26 via the actuator system 706 be operated. Similarly, exhaust valves 136 . 126 and the compressor intake valve 116 of the cylinder 24 via the actuator system 708 be operated. Furthermore, exhaust valves 134 . 124 and the compressor intake valve 114 of the cylinder 22 via the actuator system 710 be operated. Even moreover, exhaust valves can 132 . 122 and the compressor intake valve 112 of the cylinder 20 via the actuator system 712 be operated.

Other embodiments may include reduced actuator systems or other combinations of actuator systems without departing from the scope of the present disclosure. For example, the intake valves and exhaust valves of all cylinders may be addressed by a single actuator.

The CPS system 704 Can be configured to have certain parts of the exhaust camshaft 714 longitudinal displacement, causing operation of exhaust valves and compressor intake valves of all cylinders to vary between different exhaust cams, as explained earlier. For example, the operation of the exhaust valves 128 . 126 and 124 Based on this, whether the third exhaust cam will vary 720 , the fourth exhaust cam 722 or the fifth exhaust cam 724 is selected. Similarly, the operation of the compressor intake valve 112 of the cylinder 20 Based on that, the twelfth exhaust cam will vary 740 , the thirteenth exhaust cam 742 or the zero outlet cam 744 the compressor intake valve 112 actuated.

The VCT system 702 includes an exhaust camshaft adjuster 765 for changing the valve control. An intake camshaft adjuster may be included (although not specifically shown) without departing from the scope of this disclosure. The VCT system 702 may be configured to advance or retard the valve timing by advancing or retarding the cam timing (an exemplary engine operating parameter) and may be controlled by the controller 12 to be controlled. The VCT system 702 may be configured to change the timing of valve opening and closing events by changing the relationship between the crankshaft position and the camshaft position. For example, the VCT system 702 for turning the exhaust camshaft 714 be designed independently of the crankshaft to adjust the valve timing to early or late. In some embodiments, the VCT system may 702 a cam torque actuated device designed to rapidly change the cam timing. In some embodiments, the valve control, such as Intake Valve Closing (IVC) and Exhaust Valve Closing (EVC), may be changed by a Continuously Variable Valve Lift (CVVL).

The valve / cam controllers and systems described above may be hydraulically powered or electrically actuated or combinations thereof.

In an optional embodiment (dashed lines), in the actuator systems 706 . 708 . 710 and 712 Rocker arms included to operate the various exhaust cams that are common with the exhaust camshaft 714 coupled, the CPS system can 704 operatively coupled to the solenoid S1 and the solenoid S2, which in turn may be operably coupled to the actuator systems. Here, the rocker arms may be actuated by electric or hydraulic means via solenoids S1 and S2 to follow a selected exhaust cam for each exhaust valve and compressor intake valve. As shown, the solenoid S1 is operative and communicative with the actuator system alone 712 (via the dashed line 760 ) and non-operational (or communicative) with actuator systems 706 . 708 and 710 coupled. Similarly, the solenoid S2 is operatively and communicatively coupled to actuator systems 706 (above 772 ) 708 (above 774 ) and 710 (above 776 ), and non-operational (or communicative) coupled with the actuator system 712 ,

That is, the solenoid S1 can be operational and communicative only with the actuator system 712 from cylinder 20 and not with actuator systems 706 . 708 and 710 coupled with cylinders 26 . 24 respectively. 22 are coupled. Furthermore, the solenoid S2 can be operative and communicative with 706 . 708 and 710 , However not operational and communicative with 712 be coupled. Here, rocker arms may be actuated by electrical or hydraulic means to follow one of the previously described cams for each exhaust valve.

That way, the CPS system can 704 switch between cams for opening the corresponding exhaust valve for a certain duration and / or a specific stroke and / or a specific control. The CPS system 704 can signals from the controller 12 received to in the engine 10 switch between different cam profiles for different cylinders based on engine operating conditions.

8th shows an example picture 800 with engine load engine speed graph. In particular, the figure shows various speed-load regions in which distinct modes of operation of the exhaust valves and compressor intake valves of the various cylinders of the engine 10 can be used. The illustration 800 presents an engine speed, plotted along the x-axis, and an engine load (or mean brake pressure / BMEP - Brake Mean Effective Pressure), plotted along the y-axis. The line 802 represents a highest load at which a particular engine can operate at a certain speed. The illustration 800 Also includes three regions of distinct combinations of engine load and engine speed with the cylinders of the engine 10 can be operated in various ways to provide lower pumping losses and higher engine efficiencies.

The region 808 , defined by very low engine loads, may include engine operating conditions such as engine cold start, engine idle, and so on. As a non-limiting example, these very light engine loads may include a range of 0-2 bar BMEP. Here, the engine torque request may be significantly low. During these conditions with a very low engine load, the cylinders may be operated to provide a substantial portion, e.g. B. almost 100%, their exhaust gas to the catalytic converter, z. B. for the exhaust gas purification device 72 ,

Accordingly, cam profiles from the CPS system 704 from 7 be switched to over second exhaust cam 718 exhaust 138 . 136 and 134 to press. In particular, second exhaust cams 718 operate the appropriate exhaust valves to keep the entire duration of the corresponding exhaust strokes in the cylinders 26 . 24 and 22 to open. At the same time, the exhaust valve 132 of the cylinder 20 from the ninth exhaust cam 732 be operated. Here is the outlet valve 132 for the entire duration of the exhaust stroke in the cylinder 20 be kept open. At the same time can exhaust valves 128 . 126 . 124 . 122 and compressor intake valves 118 . 116 . 114 and 112 corresponding cylinder 26 . 24 . 22 and 20 be kept completely closed. In particular, exhaust valves 128 . 126 and 124 by actuating these exhaust valves 128 . 126 and 124 via their respective zero outlet cams, e.g. B. fifth exhaust cam 724 be kept closed (eg disabled) while compressor intake valves 118 . 116 and 114 about their corresponding zero cams, z. The seventh exhaust cam 728 to be kept closed. In the meantime, the exhaust valve can 122 of the cylinder 20 by actuating the zero cam 738 be kept closed while the compressor intake valve 112 of the cylinder 20 over the zero cam 744 can be kept fully closed.

Alternatively, a smaller portion of the outlet, e.g. B. a proportion of Vorlassimpulses, of all cylinders 20 . 22 . 24 and 26 directed to the exhaust turbine, while a larger part of the outlet of all cylinders to the exhaust gas purification device 72 can be performed.

The region 806 may represent low to medium engine loads, e.g. B. 2-10 bar BMEP. Here, the desired engine power can be low, z. During driving conditions, but relative to that in the region 808 desired higher. In other words, the region 806 represents engine loads higher than those in region 808 (and lower than those in region 804 ), however, the engine loads in region 806 classified as lower to medium loads in this disclosure.

When the engine in region 806 Operates, exhaust gases from a subset of the multiple cylinders to the engine 10 to be led back. For example, the CPS system 704 with the actuator 712 communicate between the various cams during low to medium engine loads, with exhaust valves 132 . 122 and the compressor intake valve 112 of the cylinder 20 are coupled. In particular, the compressor intake valve 112 be kept open for the entire duration of a Auslasshubs to all exhaust gases from the cylinder 20 to the manifold 59 to lead. The exhaust valves 132 and 122 can be kept closed by their respective zero cams 733 and 738 be operated. Further, by closing the first ARV 125 and opening the second ARV 625 Exhaust gases from the cylinder 20 in the manifold 59 were taken over the Nachverdichterleitung 664 to the mixer 626 be directed, which is downstream of the compressor 94 located.

At the same time and within a first engine cycle, when the compressor intake valve 112 of the cylinder 20 is kept open during the duration of the exhaust stroke during the same first engine cycle exhaust from the other cylinders, for. B. the cylinders 26 . 24 and 22 , directed to the turbine and the exhaust gas purifier. In particular, exhaust valves 128 . 126 and 124 be opened to a first part of the outlet, namely the Vorlassanteil, via a first channel (pipe 160 ) to the turbine 92 to channel. In the meantime, exhaust valves can 138 . 136 and 134 only a second portion of exhaust gases after the Vorlassanteil via a second channel (pipe 162 ) to an exhaust gas purification device 72 conduct. The second portion of the exhaust gases may be the purge portion of the exhaust gases, including a small fraction of residual exhaust gases. The exhaust valves 128 . 126 and 124 can open during an earlier part of the exhaust stroke while exhaust valves 138 . 136 and 134 during a later part of the same exhaust stroke. In particular, compressor intake valves 118 . 116 and 114 corresponding cylinder 26 . 24 and 22 disabled and during engine operation in the region 806 getting closed.

The region 804 contains high engine loads (eg, greater than 10 bar BMEP), with the engine working to meet a high torque demand. For example, conditions of high engine loads may include pedal return events, uphill driving with the vehicle, and so on. Furthermore, engine loads in region 804 higher than engine loads in the region 806 and in the region 808 be. The region 804 can contain significantly higher engine loads.

When the engine in region 804 operates, a significant portion of the exhaust gas may be transferred to the turbine of the turbocharger to produce the desired higher torque demand. Still further, to reduce knocking, cooling of combustion chambers may be activated by providing bleed-through of fresh intake air. Accordingly, the engine (including the plurality of cylinders) may operate during the pedal return condition as described with reference to FIG 5 described. In particular, a blowdown portion of the exhaust gas may be directed to the turbine by the first exhaust valve (eg, the exhaust valves 128 . 126 . 124 and 122 ) is opened shortly before the end of the power stroke uT and closed before the end of the exhaust stroke. A second portion of the exhaust gases after pre-admission may be opened by opening the second exhaust valve (eg, the exhaust valves 138 . 136 . 134 and 132 ) are fed approximately half way during the exhaust stroke of the exhaust gas purification device. Both exhaust valves may be closed before the end of the exhaust stroke. A final fraction of low-pressure exhaust gas (LP-EGR) combined with fresh blow-through air may be obtained by operating the CIV (eg, compressor intake valves 118 . 116 . 114 and 112 ) to open towards the end of the exhaust stroke and to be conveyed to the inlet of the turbocompressor by maintaining a positive valve overlap with one or more intake valves during the intake stroke.

It should be noted that when the relative loads are given as high or low, the indication refers to the relative load as compared to the range of available loads. As a result, low engine loads may be lower relative to medium and higher engine loads. High engine loads may be higher relative to medium (or moderate) and lower engine loads. Medium or moderate engine loads may be lower relative to high or very high engine loads. Furthermore, medium or moderate engine loads may be higher relative to low engine loads. In addition, very low engine loads may include engine loads that are less than low engine loads and less than medium and high engine loads.

Referring now to the 9A . 9B and 9C , contain these pictures 940 . 960 respectively. 980 , which illustrate example valve controls with respect to a piston position, for one or more engine cylinders, each comprising 5 valves: two intake valves, two exhaust valves and a compressor intake valve, such as those in FIGS 1 . 6 and 7 described cylinder. A CPS system like the CPS system 704 For example, a control of the opening and closing of the 5 valves may vary and vary a duration in which the 5 valves are kept open. The sample pictures in the 9A . 9B and 9C can the example of 3 resemble that they map valve controls relative to the piston position and crankshaft rotation. Accordingly, keep the picture 940 . 960 and 980 for the graph of the piston position (curve 302 ) and the intake valve controls (curves 304 and 306 ) similar numbering as in 3 ,

Each of the picture 940 . 960 and 980 represents an engine position along the x-axis in degrees crank angle (CAD). The curve 302 represents piston positions (along the y-axis) with respect to their position from top dead center (oT) and / or bottom dead center (uT) and also with respect to their position within the four strokes (intake, compression, work and exhaust) of an engine cycle represents.

The curve 304 makes in each picture 940 . 960 and 980 a first intake valve control, a lift and a duration for a first intake valve (Int_1) from while the curve 306 represents a second intake valve control, a lift, and a duration for a second intake valve (Int_2) coupled to the intake manifold of the engine cylinder. In the illustrated examples, the first and second intake valves are fully opened in a common time from a closed position (curves 304 and 306 ), much closer to the intake stroke td, beginning just before CAD2 (eg, at or just before the intake stroke td), and starting shortly after the beginning of a subsequent compression stroke according to CAD3 (eg, at or shortly after uT ) closed. In addition, the two inlet valves, when fully opened, may be opened for the same duration D1 with the same amount of valve lift L1. In other examples, the two valves may be operated with a different control by adjusting the phasing, stroke, or duration based on engine conditions.

It should be understood that each of the intake valves, each of the exhaust valves, and each of the compressor intake valves are independently actuated via the contiguous CPS and VCT systems.

Referring now to Figure 940 from 9A , shows these example valve controls for all cylinders in the engine 10 from the 6 and 7 if the engine in the region 808 the picture 800 is working. In particular, the figure contains 940 Example exhaust valve controls for engine operation during very low engine loads, e.g. B. 0-2 bar BMEP. As with reference to 8th compressor intake valves of each of the plurality of cylinders during engine operation can be kept closed at very low loads by operating the compressor intake valves via their respective null cams. Accordingly, curve shows 913 in that the CIV has no valve lift for a duration D7 (eg from before uT until just after the oT) (eg a zero valve lift). In other words, the CIVs of all cylinders are fully closed during the duration of the exhaust strokes when the engine is operating at very low or very light loads.

Furthermore, the first exhaust valves (eg the exhaust valves 128 . 126 . 124 and 122 ) be closed for the entire duration of the exhaust strokes when the engine is in the region 808 the picture 800 is working. In other words, the exhaust valves can 128 . 126 . 124 and 122 are actuated by their respective null cams and can be disabled. Accordingly, curve shows 911 in that the first exhaust valve of all the cylinders (Exh_1) does not have a valve lift for a duration D7 (eg from before uT until shortly after the oT) (eg a zero valve lift).

Curve 912 shows exemplary exhaust valve timing, lift and duration for second exhaust valves (Exh_2) of the engine cylinders, wherein the second exhaust valves are connected to a second exhaust pipe (eg, pipe 162 ) and the manifold 57 are coupled. Second exhaust valves can be valves 138 . 136 . 134 and 132 included with the manifold 57 communicate. As in the picture 940 For example, during the duration of the exhaust strokes (eg, from before CAD1 to just after CAD2), second exhaust valves may be fully opened (fully closed) when the engine is operating under significantly light loads. That is, second exhaust valves of the plurality of cylinders of the engine 10 can be kept open for a duration D7 as shown. Specifically, the second exhaust valves may be opened prior to the start of an exhaust stroke (eg, within 10 degrees before uT of the power stroke) while being kept fully open during the duration of the exhaust stroke, and fully closed (from open) shortly after the end of the exhaust stroke. (for example, within 10 degrees after oT in the exhaust stroke).

This means that all exhaust gases from all cylinders of the engine 10 can be passed to the catalytic converter when the engine is working with very low engine loads. Here, all exhaust gases can contain a proportion of preflash, a purge component and residual exhaust gases. For example, the second exhaust valves of cylinders 26 . 24 and 22 through their respective second exhaust cams 718 be operated. Similarly, the exhaust valve 132 from the ninth exhaust cam 732 be operated. Further, all the second exhaust valves may be opened with the second amount of the valve lift L3. For example, the second amount of the valve lift L3 may be a maximum opening of the second exhaust valves.

It is understood that a positive valve overlap may exist between the second exhaust valves and the corresponding intake valves when after OCT at CAD2 the subsequent intake stroke starts. Here, towards the end of the exhaust stroke, exhaust gases may be directed in a reverse direction from the respective combustion chambers into the intake manifold 27 to be pulled. In particular, during very low engine loads, the intake manifold 27 compared to pressures in the exhaust manifolds (eg manifold 57 and / or manifolds 55 ) are under a lower pressure. Accordingly, the low pressure exhaust gases remaining in the cylinders at the end of the exhaust stroke may flow from the cylinders into the intake manifold 27 stream. This flow of exhaust gases from the combustion chambers into the intake manifold may be referred to as "backward flow" as opposed to a "forward flow" in which exhaust gases flow from the combustion chambers into the exhaust manifolds. Exhaust gases in the reverse flow mode in the intake manifold 27 may later be blown into the engine cylinders via open intake valves in the subsequent intake strokes along with fresh intake air. These low pressure exhaust gases flowing into the engine cylinders during the intake stroke may act as internal EGR. It should be noted that fresh exhaust intake air can not flow into the exhaust manifold since the intake manifold is under reduced pressures compared to the exhaust manifold during very low engine loads.

It will also be understood that by flowing all exhaust gases to the exhaust gas purifier during low load operation (and without diverting exhaust gas to the turbine, precompression point, or post-compressor station), for example, during engine cold starts, the exhaust gas purifier may quickly reach light-off temperatures.

Optionally, when the catalytic converter has reached the light-off temperature and the engine is running at very low loads, a small portion of the blowdown pulse may be diverted toward the turbine via the first exhaust valves by opening first exhaust valves at the beginning of the exhaust strokes, as indicated by the dashed curve 908 will be shown. The dashed curve 908 exemplifies valve timing, lift and duration for the first exhaust valves to detect a portion of the pre-venting portion of the exhaust pulse. As shown, first exhaust valves of all cylinders may open at the first amount of valve lift L2 for a duration D6. Here the first exhaust valves can be opened shortly before oT or just before CAD1 (closed) and closed before the midpoint of the exhaust stroke between CAD1 and CAD2 (eg within 90 CAD of the exhaust stroke).

The second exhaust valves may be opened during the same exhaust stroke for the same valve timing, valve lift and valve duration as through the curve 912 will be shown. Alternatively, the second exhaust valves may be opened for a shorter duration than D7, such as through the dashed curve 909 will be shown. The dashed curve 909 FIG. 11 shows, by way of example, valve timing, lift and duration for second exhaust valves to determine a residual fraction (eg, an exhaust fraction following closure of the first exhaust valve, such as the dashed curve 908 shown remaining in the cylinder) of the exhaust pulse. As in the example of the dashed curve 909 As shown, the second exhaust valves may be opened just prior to closing the first exhaust valves (eg, between 45 CAD and 90 CAD of the exhaust stroke) and until shortly after OT of the exhaust stroke (eg shortly after CAD2, about CAD $ 10 CAD2 ) stay open. Further, the second exhaust valves may remain open for a duration D8, where D8 is shorter than the duration D7 of the curve 912 is. Here, the first exhaust valve (s) may be opened earlier in the engine cycle than in the control in which the second exhaust valve is opened from closed.

In this way, when the engine is operating at very low loads, for example, in the region 808 the picture 800 , all exhaust gases in the exhaust strokes of all cylinders, the cylinders via second exhaust valves (eg valves 138 . 136 . 134 and 132 ) in the manifold 57 and then toward the exhaust gas purification device 72 leave. Optionally, a small portion of the blowdown pulse in all cylinders may be via first exhaust valves (eg, valves 128 . 126 . 124 and 122 ) through the manifold 55 in the direction of the exhaust turbine 92 be directed. Here, the remaining portion of the exhaust pulse via the second exhaust valves in the manifold 57 and then toward the exhaust gas purification device 72 be streamed.

Referring now to Figure 960 from 9B , shows these example valve controls for all cylinders in the engine 10 from the 6 and 7, when the engine in the region 806 the picture 800 is working. In particular, the figure contains 960 Example exhaust valve controls for engine operation during low to medium engine loads, e.g. B. 2- 10 bar BMEP. As with reference to 8th described, during engine operation under low to medium loads, a subset of the plurality of cylinders of the engine 10 be operated by a remaining number of cylinders of the plurality of cylinders. Specifically, a number of cylinders lower than the total number of the plurality of cylinders may be operated in a different manner than the remaining number of cylinders of the plurality of cylinders.

In the in the 6 and 7 shown example of an engine 10 The subgroup of several cylinders contains the cylinder 20 while the multiple cylinders are the cylinders 20 . 22 . 24 and 26 contain. Thus, the subset of cylinders, z. B. the cylinder 20 , relative to the other cylinders, z. B. the cylinders 22 . 24 and 26 operated in a distinct way when the engine is in the region 806 the picture 800 is working. That is, all of the exhaust gas (including the exhaust pulse, purge pulse, and a small amount of residual gas) from the cylinder 20 is directed to a post-compressor station. At the same time, the exhaust gas from the remaining cylinders is not sent to the post-compressor station. Instead, the exhaust gas from the remaining cylinders is directed to the turbine and exhaust gas purifier.

The dashed curve 918 presents an example of exhaust valve timing, stroke and duration for a compressor intake valve (CIV) of the cylinder 20 alone. Here can the CIV of cylinder 20 during the duration of the exhaust strokes (eg before CAD1 until shortly after CAD2). As in picture 960 represented, the CIV 112 from cylinder 20 be open for a duration D7. In particular, the CIV of cylinder 20 to be opened before the start of an exhaust stroke (from closed, eg, within 10 degrees before uT of the power stroke), while being fully open during the duration of the exhaust stroke, and fully closed (from open) shortly after the end of the exhaust stroke ( eg within 10 degrees to oT). Between the CIV and the intake valves of cylinder 20 For example, a small amount of positive overlap may occur as the subsequent intake stroke begins. Thus, substantially all of the exhaust gases (eg, at least 95% of all exhaust gases) of cylinders 20 (eg, a subset of the cylinders) of the engine 10 to a location downstream of the compressor (also referred to as a booster) when the engine is operating at low to medium loads. The location may also be downstream of the intake throttle as in 6 shown. Dashed gray curves 911 and 915 represent the first exhaust valve and the second exhaust valve of cylinder, respectively 20 , As by the dashed gray curves 911 and 915 shown, the first exhaust valve and the second exhaust valve of cylinder 20 during the exhaust stroke (for periods D7) are kept completely closed. For the first exhaust valve 122 and the second exhaust valve 132 there can be no valve lifts. The valves 122 and 132 can be operated by their respective null cams.

The continuous curve 914 the picture 960 shows exemplary valve timing, stroke and duration of first exhaust valves of the remaining cylinders, z. B. the cylinder 22 . 24 and 26 , Furthermore presents the continuous curve 916 exemplary valve control, stroke and duration second exhaust valves of the remaining cylinders, z. B. the cylinder 22 . 24 and 26 , Furthermore presents the continuous curve 917 Example valve timing, stroke and duration of the CIVs of the remaining cylinders, z. B. the cylinder 22 . 24 and 26 , In particular, the first exhaust valve (s) will become the first exhaust valves from a closed position in a first control (continuous curve 914 ) opened in the engine cycle earlier than the control (continuous curve 916 ), in which the second exhaust valve is opened from closed. Specifically, the first control for the first exhaust valve occurs shortly before the stroke uT, just before CAD1 (eg, at or just before the power stroke uT), while the control for opening the second exhaust valve is retarded from the power stroke uT is, for. Eg to CAD1 but before CAD2. As shown, the second exhaust valves may open at the center of the exhaust stroke or in its vicinity (eg, midway between CAD1 and CAD2). The first exhaust valves may be closed before the end of the exhaust stroke, e.g. For example, before TDC, while the second exhaust valves are kept open until shortly after the TDC of the exhaust stroke (eg, until just after CAD2). For example, the first exhaust valves may close about 45 CAD prior to the oT of the exhaust stroke at CAD2. Further, the first exhaust valves of the remaining cylinders may be kept open for a duration D2.

The second exhaust valves may positively overlap the intake valves, but only for short periods of time. Since the engine is operating under low to medium load conditions, the intake manifold may be relative to outlet pressures in the exhaust manifold 55 or exhaust manifold 57 be under lower pressure. Thus, internal EGR may be provided when low pressure exhaust gases are drawn toward the rear end of an exhaust stroke during the positive valve overlap into the intake manifold. The same low pressure exhaust gases may be caused to flow into the cylinders of fresh intake air later during the subsequent intake stroke as internal EGR. Still further, fresh intake blowby air may not flow into the cylinders and into the exhaust manifold therethrough during the positive valve overlap because the exhaust manifolds are at a higher pressure than the intake manifold.

Still further, the second exhaust valves may be for a duration D3 (as in FIG 3 ), which has a duration from or around the midpoint of the exhaust stroke until just after the beginning of the subsequent intake stroke (eg, from about half between CAD1 and CAD2 to just after CAD2). The CIVs of remaining cylinders can during the duration of the Auslasshubs, z. From CAD1 to CAD2, as by the flat line of curve 917 shown.

Thus, exhaust gas from the remaining cylinders is directed to both the turbine and the emission catalyst during low to medium load engine operation. In particular, a first part of the exhaust gas can be supplied to the turbine, while the second, remaining part of the exhaust gas is passed to the exhaust gas purification device. In other words, the exhaust portion of the exhaust gas (at higher pressure) is directed to the turbine, which provides the desired engine output, while the purge portion of the exhaust gas is supplied to the emission catalyst at relatively lower pressure. The two exhaust gas fractions may be emitted separately and at different times within the same engine combustion cycle as shown in the figure 960 will be shown.

By closing the CIVs of the remaining cylinders, the other cylinders can not blow fresh air and no LP EGR flow. However, a larger portion of exhaust may be for EGR by providing all the exhaust from the cylinder 20 (eg, a subset of cylinders) are returned to the engine within the same engine cycle, in which also the exhaust gas from the remaining cylinders to the turbine and the emission catalyst is returned. In this way, the subset of cylinders may provide rich EGR (eg, by enriching the EGR from the cylinder 20 ), which promotes combustion stability and combustion rates. Remotely, by directing the exhaust gas from the subset of cylinders to the intake manifold (boost compressor) during low to medium load operation by reducing pump and heat losses, improved engine efficiency can be achieved.

Referring now to Figure 980 from 9C , shows these example valve controls for all cylinders in the engine 10 from the 6 and 7, when the engine in the region 804 the picture 800 is working. In particular, the figure contains 980 Example exhaust valve controls for engine operation during high engine loads, e.g. B. more than 10 bar BMEP. As with reference to 8th During high-load engine operation, a significant portion of the exhaust of all cylinders of the engine may be supplied to the turbine of the turbocharger during engine operation to produce the desired higher torque demand. Still further, to reduce knocking, cooling of all the combustors may be activated by providing fresh air blown through positive valve overlap.

Like through the bend 920 (similar to the curve 308 from 3 ), the first exhaust valves of the plurality of cylinders (eg, the valves 122 . 124 . 126 and 128 ) are fully opened from the closed position at or before the start of an exhaust stroke (eg, within 10 degrees before the U of the power stroke), remain fully open during a first part of the exhaust stroke, and before the end of the exhaust stroke (e.g. Within 45 degrees before the oT of the power stroke) to completely close the pre-venting portion of the exhaust pulse. The second exhaust valves (curve 922 ) of the plurality of cylinders may be fully opened from a closed position at about the midpoint of the exhaust stroke (eg, between 60 and 90 degrees after uT of the power stroke or CAD1), left open during a second portion of the exhaust stroke, and fully closed before the exhaust stroke ends (eg, within 20 degrees before the TDC of the exhaust stroke) to release the purge portion of the exhaust gas.

The CIVs of the multiple cylinders (curve 924 ) can be fully opened towards the end of the exhaust stroke (eg, within 25 degrees before the TDC of the exhaust stroke) from a closed position, can be left fully open, at least until a subsequent intake stroke has commenced, and can be significantly delayed Exhaust stroke oT (eg within 30 degrees of the oT) to be fully closed. The intake valves may be fully opened from closed just before the exhaust stroke ends (eg, within 10 degrees before TDC), left open during the intake stroke, and at or shortly after the start of the compression stroke (eg, within 10 degrees after the uT of the intake stroke). Therefore, the CIVs and the intake valves, as in 9C have a phase of positive valve overlap (eg, from 10 degrees BTDC to 30 degrees BTDC) to allow fresh intake air with EGR to be blown through to a supercharger location (eg, into a compressor inlet).

Thus, during high engine loads, each cylinder of the engine may be emptied via at least three distinct lines including a first exhaust line through a first exhaust valve leading to an exhaust gas turbine inlet, a second line through a second exhaust valve leading to an exhaust gas purifier, and a third line from a compressor intake valve to a location upstream of the turbocompressor. The three exhaust gas fractions may be emitted separately and at different times within the same engine combustion cycle as shown in the figure 980 will be shown.

Further, the first exhaust valves may be fully closed and closed substantially before the CIVs are fully opened while the second exhaust valves may be fully closed shortly after the CIVs have been opened. Further, the first and second exhaust valves may intersect each other, and the second exhaust valves and the CIVs may slightly overlap each other, but the first exhaust valves may not intersect with the CIVs.

In addition, the first exhaust valves may be opened at a first control with a first amount of the valve lift L2, while the second exhaust valves may be opened with a second amount of the valve lift L3 and the CIVs may be opened at a third amount of the valve lift L5. Still further, in the first control, the first exhaust valves may be opened for a duration D2, while the second exhaust valve may be opened for a duration D3 and the CIV may be opened for a duration D5. It will be appreciated that in alternative embodiments, the two exhaust valves may have the same amount of valve lift and / or the same duration of opening while opening with differently phased-timing controls.

In this way, the engine can be operated by adjusting valve timing, strokes and periods with lower pumping losses and higher efficiency at different load conditions. At low to medium loads, rich EGR reduces combustion instabilities. At higher engine loads, blowby and low pressure EGR can provide temperature reductions while improving turbocharger performance. Here, engine power can be improved by separating the various portions of the exhaust gas while reducing engine knock.

Referring now to 10 , becomes an example routine 1000 for adjusting exhaust valves and compressor intake valves of a multi-cylinder engine based on engine operating conditions to vary a location of supplying exhaust gases including EGR. The method allows the supply of exhaust gas to the turbine and exhaust catalyst and recycling to a pre-compressor and a post-compressor station based on existing engine conditions. routine 1000 as such, in relation to that in the 6 and 7 However, it should be understood that similar routines may be used with other systems without departing from the scope of this disclosure. Here are instructions for running routine 1000 can be controlled by a controller, such as 12 from the 6 and 7 based on instructions stored in a memory of the controller, and in conjunction with sensors of the engine system, such as those described above with reference to FIG 6 described sensors, received signals are executed. The controller may include engine actuators of the engine system, such as the actuators of the 6 and 7 , to adjust the engine operation according to the routines described below.

at 1002 includes the routine 1000 estimating and / or measuring engine operating conditions such as engine speed, torque demand, engine load, boost pressure, MAP, intake airflow, ambient conditions such as ambient pressure, temperature, humidity, exhaust gas catalyst temperature, etc. 1004 Based on the engine conditions, a mode of cylinder operation, e.g. B. adjusting the first and second exhaust valves and the compressor Ansaugvents selected. For example, engine operating loads may be critical to a mode of cylinder operation. Well, at 1006 a position of the first ARV (eg the first ARV 125 from 6 ) and the second ARV (eg the second ARV 625 from 6 ) based on engine operating conditions, as described below.

at 1008 can be determined whether a first mode has been selected. In one example, the controller may start the engine cylinders in response to very low engine loads and / or engine cold start conditions in the first mode. When the first mode is confirmed, the routine continues 1000 With 1010 to selectively adjust the CPS device coupled to the engine cylinder exhaust valves to selectively open the second exhaust valves of all the cylinders and supply hot exhaust gases to the exhaust purification device. In particular, the controller may send a signal to the CPS system, which in turn may communicate with the actuator systems operatively coupled to the exhaust camshaft. The exhaust camshaft may be offset to select a particular combination of cam lobes for operating the exhaust valves of the cylinders.

The controller may operate the engine cylinders in a first mode with the second exhaust valves open and all first exhaust valves and compressor intake valves (also referred to as third exhaust valves) closed to direct all of the exhaust gas to the catalyst. Accordingly For example, the first ARV and the second ARV can be kept completely closed. Here, the controller may send a signal to an electromechanical actuator which is coupled to a corresponding ARV. Further, the electromechanical actuator of each ARV may hold each ARV in its fully closed position. Consequently, exhaust gas can not pass either the supercharger ports (eg at the inlet of compressor 94 over pipe 164 ) or the post-compressor station (eg at the mixer 626 over the after-compressor line 664 ).

Optionally, the CPS system can be included 1012 Set the first exhaust valve to open for a short duration during the start of the exhaust strokes (as indicated by the dashed curve 908 in 9A shown) to direct a small proportion of exhaust gas to the turbine, while the remaining exhaust gas is supplied via the second exhaust valves of the exhaust gas purification device (as shown by the dashed curve 909 in 9A shown). This option can be used when the catalyst has reached light-off temperatures. routine 1000 then go with you 1030 which will be described in more detail below.

If at 1008 it is determined that the first mode is not selected, the routine proceeds 1000 With 1014 where it determines if a second mode has been selected. In one example, the controller may operate the cylinders in the second mode in response to engine operation at low to medium loads, as in region 806 of illustration 800 , When the second mode is confirmed, the routine continues 1000 With 1016 continue, where several actions can be triggered simultaneously.

at 1018 For example, a subset of the plurality of engine cylinders may be actuated relative to the remainder of the plurality of engine cylinders in a distinct manner. Here, the subset of cylinders is operated so that all of the exhaust gas from the subset of cylinders is directed to the post compressor station within a particular engine cycle, downstream of the intake throttle. Accordingly, the CPS system at 1018 Switch cam lobes, which are coupled to the subset of cylinders, z. B. cylinders 20 in power machine 10 to actuate the compressor sub-valve (s) of the subset of cylinders to fully open during the duration of the exhaust strokes. At the same time and within the same given engine cycle, the first exhaust valves and the second exhaust valves of the subset of cylinders are kept fully closed during the exhaust strokes. Then add 1020 the CPS adjust the first exhaust valves of the remaining cylinders to open during the first part of the exhaust strokes to supply the exhaust stroke advance pulses to the turbine of the turbocharger within the same given engine cycle. Further, about halfway through the exhaust strokes, the second exhaust valves are opened within the same engine cycle to direct the purge portions of the exhaust strokes to the exhaust catalyst. Moreover, the CPS system keeps the compressor intake valves of the remaining cylinders fully closed. All of the adjustments described above may occur for the remaining cylinders in the given engine cycle within the same exhaust stroke.

at 1022 becomes the second ARV 625 (also referred to as booster ARV) set to fully open, so that the exhaust from the cylinder 20 over the mixer 626 can flow into the intake manifold. In particular, the compressor may send a signal to the second ARV 625 output coupled electromechanical (or hydraulic, etc.) actuator to set the second ARV to a fully open position. Furthermore, the first ARV 125 (also referred to as pre-compressor ARV) are kept fully closed to block the flow of exhaust gas to the pre-compressor station. routine 1000 then join 1030 continued.

Returning to 1014 drives the routine 1000 if the second mode is not selected, at 1024 to determine if a third mode of cylinder operation has been selected. In one example, the controller may operate the cylinders in the third mode in response to engine operation at high engine loads, such as in region 804 of illustration 800 , When the third mode of cylinder operation is confirmed, the routine proceeds 1000 With 1026 with all cylinders operating to supply the turbine with a first portion of exhaust gas, the catalyst with a second portion of exhaust gas, and the compressor inlet with the remaining exhaust gases along with fresh blowby air (within the same combustion cycle).

at 1026 For example, the CPS system may adjust the cam lobes to actuate the first exhaust valves of all the cylinders to retract during a first (initial) duration of the exhaust strokes (turn 920 from 9C ) to transmit the Vorlassimpuls to the exhaust gas turbine. In particular, the first exhaust valves may be opened just when an exhaust stroke begins within a corresponding cylinder, and significantly be closed before the end of the exhaust stroke. The second exhaust valves may be opened about halfway through the exhaust stroke in the corresponding cylinder and closed prior to the end of the exhaust stroke to channel the purged portion of exhaust gas to the exhaust gas purifier. Still further, the CIVs may be activated to open towards the end of the exhaust stroke in the corresponding cylinder and close substantially after the beginning of the intake stroke following the exhaust stroke to allow low pressure EGR and blow-through air to transfer to the compressor inlet.

The combusted gases of exhaust strokes within all cylinders of the engine may be divided into three portions during a common engine cycle, as described above. In particular, first portions of each exhaust stroke (eg, bleed portions) of each cylinder during the common engine cycle may be supplied to the exhaust turbine, second portions of each exhaust stroke (eg, purged portions) of each cylinder during the common engine cycle may be provided to the exhaust catalyst be supplied. Moreover, residual exhaust gas in a compression space of the plurality of cylinders may be returned together with blow-through air from a third portion of each exhaust stroke (and initial periods of subsequent intake strokes) of each cylinder during the common engine cycle to a location upstream of the compressor within the same common engine cycle.

at 1028 Also, the supercharger ARV may be opened to allow the transfer of low pressure EGR and fresh blowby air to the intake line upstream of the compressor. In particular, the electromechanical actuator coupled to the first ARV may actuate the first ARV to a fully open position based on a signal from the compressor when the cylinders are operating in the third mode. However, booster ARVs can be kept fully closed to block EGR and blow-by air entering the post-compressor station.

routine 1000 then go with you 1030 to determine if there is a change in the operating conditions that may cause a change in the operating mode of the cylinders. If so, the routine goes 1000 With 1032 to adjust the CPS system to make the desired changes to cylinder operation to operate in the desired mode based on existing engine conditions. For example, if the engine originally ran at high engine loads and is now transitioning to medium engine load operation, cylinder operation may transition from the third mode to the second mode. In response to this change in cylinder mode operation, the CPS system may shift the cam lobes to allow the subset of cylinders to supply all of the exhaust gas to the post-compressor station while the remaining cylinders deliver their exhaust gas to the turbine and emission catalyst. In another example, engine operation may transition from operating at idle (eg, at very low loads) to a high load. In response to this change, the controller may change from the first mode to the third mode during operation of the engine cylinders. Then routine ends 1000 , If at 1030 instead, it is determined that there is no change in engine operating conditions, the routine ends 1000 ,

Thus, an example method for an engine during a first condition may include recycling a combination of residual exhaust gases and blowing air from a plurality of cylinders of the engine to a location upstream of a compressor in a first engine cycle, and during a second condition recycling all of the exhaust only a subset of the plurality of cylinders downstream of the compressor and supplying exhaust gases from remaining cylinders to an exhaust turbine in a second engine cycle. The first condition may include high engine load conditions, and the second condition includes medium engine load conditions. The second condition may also include low engine loads. As an example, the second condition may be the region 806 the picture 800 included while the first condition is the region 804 the picture 800 out 8th may contain. The method may further include, during the first condition, supplying a first bleed portion of exhaust gases to an exhaust turbine and supplying a second purge portion of exhaust gases to an exhaust purifier of the plurality of cylinders. Here, a first proportion of exhaust gases may be supplied via a first exhaust valve of each of the plurality of cylinders of the exhaust gas turbine, and the second purge portion of exhaust gases may be supplied via a second exhaust valve of each of the plurality of cylinders of the exhaust gas purification device. The combination of residual exhaust gases and blowby air may be supplied to a location upstream of the compressor via a third exhaust valve of each of the plurality of cylinders. The method may also include, during the second condition, supplying a first bleed portion of exhaust gases to an exhaust turbine and supplying a second purge portion of exhaust gases to an exhaust purifier from the remaining cylinders.

11 presents an exemplary routine 1100 for selecting an operating mode and switching between operating modes of the cylinders of the multi-cylinder engine in response to engine operating conditions. routine 1100 as such, in relation to that in the 6 and 7 However, it should be understood that similar routines may be used with other systems without departing from the scope of this disclosure. Here are instructions for running routine 1100 can be controlled by a controller, such as 12 from the 6 and 7 based on instructions stored in a memory of the controller, and in conjunction with sensors of the engine system, such as those described above with reference to FIG 6 (and 1 ), received signals are executed. The controller may include engine actuators of the engine system, such as the actuators of the 6 and 7 , to adjust the engine operation according to the routines described below.

at 1102 become like at 1002 from routine 1000 Engine operating conditions estimated and / or measured. at 1104 determines routine 1100 whether there is an engine cold-start condition. In one example, an engine cold-start may be confirmed when an exhaust catalyst temperature is less than a threshold, such as lower than a light-off temperature. In another example, an engine cold-start may be confirmed when an engine temperature is lower than a threshold temperature. Engine loads may be very low at an engine cold start.

If an engine cold start condition has been confirmed, the routine continues 1100 With 1106 continue to operate the cylinders of the engine in the first mode, wherein the second exhaust valves of all cylinders of the engine are fully open to supply the exhaust catalyst, bypassing the exhaust gas turbine, the entire exhaust gas. Furthermore, exhaust gas recirculation can not take place during operation in the first mode. Here, the first exhaust valves and the third exhaust valves (or CIVs) may be closed simultaneously during the exhaust strokes. The second exhaust valves of all cylinders may be open for the entire duration of the exhaust stroke, while first exhaust valves and the CIVs of all cylinders are fully closed during the entire duration of the exhaust strokes. In particular, all of the exhaust gas from all the cylinders of the engine may be routed to the exhaust gas purifier during a common engine cycle.

routine 1100 then join 1108 continued. When the engine cold start at 1104 is not confirmed, goes routine 1100 at 1108 confirming whether a pedal return event is occurring for a higher load. For example, there may be a sudden increase in the torque request indicative of a pedal depression in which the torque request rises above a threshold and a boost pressure above a threshold is commanded. The engine can now work with high loads. Furthermore, a rapid startup of the turbine of the turbocharger may be desired. In another example, the engine may operate under high loads when the vehicle is traveling uphill. If no pedal return event is detected for higher engine loads, then routine will run 1100 With 1112 continued. However, the high engine load conditions are added 1108 confirmed (for example, during a pedal return event), the routine continues 1100 With 1110 to operate the cylinders of the engine in the third mode (or transition).

Operation in the third mode involves supplying exhaust components of exhaust gas from all cylinders during a common engine cycle to the exhaust turbine, thereby enabling the turbocharger to start up quickly. Further, purged portions of exhaust gas from all cylinders are routed to the exhaust catalyst within the common engine cycle. Still further, a combination of residual exhaust gas in the compression chamber of all cylinders and fresh blowby intake air is supplied to the compressor inlet via the first ARV at the end of the exhaust strokes and the beginning of the following intake strokes in the common engine cycle. Thus, the third mode includes opening the first exhaust valve, the second exhaust valve, and the CIV of all of the plurality of cylinders during at least a portion of each exhaust stroke. Still further, during the third mode, the first ARV is opened so that residual exhaust gases and fresh blowby air flow into the compressor inlet. During the third mode, the second ARV may be closed.

routine 1100 then go with you 1112 to determine if engine conditions have changed to those with low to medium engine loads. For example, the vehicle can now travel at constant speeds. If so, the routine goes 1100 With 1114 to make a transition and / or to operate the cylinders of the engine in the second mode. Accordingly, the entire exhaust gas from a subset of the plurality of cylinders, z. B. the cylinder 20 the engine 10 in the 6 and 7 to a location downstream of the compressor (and downstream of the intake throttle) and returned upstream of the intake manifold. The second ARV may be opened to allow the exhaust gases from the subset of cylinders to flow to the pre-compression station while the first ARV is kept fully closed. At the same time, within the same engine cycle, with exhaust from the subset of the plurality of cylinders being supplied as EGR to the intake manifold, exhaust from the remaining of the plurality of cylinders is directed to the exhaust turbine and exhaust catalyst. In this way, exhaust gases of sufficiently high pressure turn the turbine of the turbocharger and provide the desired torque, while by supplying rich exhaust to the intake manifold, engine efficiency is improved. routine 1100 drives in 1116 continued.

If at 1112 it is determined that the engine conditions are not at low to medium loads, the routine continues 1100 With 1116 to determine whether the engine is idling or the engine is operating at very low loads again, albeit with the exhaust catalyst at or above the light-off temperature. When the exhaust gas purification device is adequately heated, the engine can operate under very light loads. If so, the routine goes 1100 With 1118 to establish a transition of the operation of the cylinders of the engine to the first mode. In particular, all of the exhaust from all cylinders may be supplied to the exhaust catalyst by setting the second exhaust valves of all cylinders open for the full duration of the respective exhaust strokes within a common engine cycle. At the same time in the common engine cycle, the first exhaust valves and CIVs of all cylinders can be kept closed for the entire duration of the exhaust strokes. Optionally, the first exhaust valves of all the cylinders may be open for a first, initial duration of the respective exhaust strokes to transmit a portion of the blowdown pulse to the exhaust turbine. Further, the second exhaust valves may be opened during the same respective exhaust strokes during the remainder of the respective exhaust strokes to supply residual exhaust gas to the exhaust gas purifying device. routine 1100 then go with you 1120 to adjust exhaust valves and CIVs of the individual cylinders to maintain the desired (eg, current) engine operation and then terminate.

Thus, an example system may include an engine having an intake manifold and an exhaust manifold, the exhaust manifold fluidly coupled to an exhaust purification device, an intake throttle in an intake passage coupled upstream of the intake manifold, a turbocharger having an intake compressor driven by an exhaust turbine For example, a plurality of cylinders, each including a first exhaust valve, a second exhaust valve, and a third exhaust valve (also referred to as a compressor intake valve), a first exhaust passage that fluidly couples the first exhaust valve directly to only one turbine of the turbocharger, a second exhaust passage the second exhaust valve fluidly coupled directly with only one exhaust gas purification device, a third line (eg 164 out 6 ), which fluidly couples the third exhaust valve directly to only one inlet of the intake compressor, a fourth line (eg, a post-compressor line) 664 out 6 ), which fluidly couples the third exhaust valve with the intake passage downstream of the intake compressor, downstream of the intake throttle and upstream of the intake manifold, a first exhaust gas recirculation valve (eg, valve 125 out 6 ) positioned within the third conduit, a second exhaust gas recirculation valve (eg, the second ARV 625 out 6 ) positioned within the fourth conduit and a cam profile switching system coupled to the first exhaust valve, the second exhaust valve, and the third exhaust valve of each of the plurality of cylinders.

The system may also include a controller with computer readable instructions stored in a nonvolatile memory to operate the plurality of cylinders in a first mode, wherein the second exhaust valve is open and the first exhaust valve and the third exhaust valve are closed to exhaust all of the exhaust attributed to the exhaust gas purifying device to operate in a second mode, the plurality of cylinders, wherein a subset of the plurality of cylinders (eg 20 the engine 10 in the 6 and 7 ) while the third exhaust valve is open and the first exhaust valve and the second exhaust valve are closed to return all the exhaust to the intake manifold, downstream of the intake compressor, and the remaining ones of the plurality of cylinders (eg, the cylinders) 22 . 24 and 26 the engine 10 ) while the first exhaust valve and the second exhaust valve are open and the third exhaust valve is closed to supply exhaust gas to the exhaust gas turbine and the exhaust gas purification device and to operate the plurality of cylinders in a third mode, the first exhaust valve second exhaust valve and the third exhaust valve are open to guide portions of exhaust gas to the inlet of the intake compressor, to the exhaust gas purification device and to the exhaust gas turbine. The controller may further include instructions for closing the first exhaust gas recirculation valve and the second exhaust gas recirculation valve when the plurality of cylinders are operating in the first mode, closing the first exhaust gas recirculation valve, and opening the second exhaust gas recirculation valve Working cylinder in the second mode, and to open the first exhaust gas recirculation valve and closing the second exhaust gas recirculation valve, when the plurality of cylinders operate in the third mode.

Referring now to 12 This makes a table 1200 depicting exemplary valve status and / or valve controls for the exhaust valves and CIVs of the plurality of cylinders, and the ARVs based on the operating mode of the plurality of cylinders of the engine 10 from the 6 and 7 , table 1200 Also indicates a target location of proportions of exhaust gas during the various modes of cylinder operation. As already mentioned, table becomes 1200 referring to the engine 10 from the 6 and 7 described. Further, the status of the exhaust valves, the ARVs, and the CIVs for a common engine cycle are represented within all distinct modes of operation.

It should be noted that the cylinder 20 separate from the cylinders 22 . 24 and 26 is listed. cylinder 20 can be the subgroup of multiple cylinders 20 . 22 . 24 and 26 the engine 10 be. Furthermore, the cylinders can 22 . 24 and 26 the remaining cylinders of the several cylinders. In alternative embodiments, the engines with a larger number of cylinders, z. B. 6 . 8th . 10 Cylinder, the subset of cylinders may contain more than one cylinder.

While the first mode of operation (eg, mode 1) occurs during very low engine loads, the first exhaust valves (Exh_1) and the CIVs (Exh_3) of all cylinders are kept closed throughout the exhaust stroke within the same common engine cycle. In particular, in the first operating mode, Exh_1 and Exh_3 are the cylinders 20 . 22 . 24 . 26 closed. During the same common engine cycle, the second exhaust valves (Exh_2) of all cylinders of the engine are 10 open for the entire duration of the exhaust strokes. That is, Exh_2 for the cylinders 20 . 22 . 24 and 26 is opened (from the closed position) just before the UT position of the corresponding piston towards the end of a power stroke, is kept open when the piston rises to the TDC of the subsequent exhaust stroke, and closed shortly after reaching the TDC position of the exhaust stroke. Further, in the following intake stroke, there may be a small degree of positive overlap between the second exhaust valve and the intake valves, allowing internal EGR. In alternative embodiments, there may not be a positive valve overlap.

The first mode of operation may additionally or optionally include opening the first exhaust valves (closed position) of all cylinders just before the oT position of the corresponding piston at the end of the power stroke (as indicated by the dashed curve) during very low engine loads 908 from 9A shown). This optional mode of operation may be used during very low engine loads, for example, after the emission control device has reached the light-off temperature. The first exhaust valves may be kept open until about half of the exhaust stroke (eg, 90 CAD after UDC in the exhaust stroke) and may be closed at about the midpoint of the exhaust stroke. Thus, a first part of the exhaust gas pulse of the exhaust gas turbine can be supplied. Further, the second exhaust valves of all the cylinders may be opened (closed) to supply the residual exhaust gas to the exhaust purification device. In one example, the second exhaust valves may be kept open for the entire duration of the exhaust stroke (eg, from the uT to the oT of the exhaust stroke). Here, the second exhaust valves may intersect with the first exhaust valves from the uT to the midpoint of the exhaust stroke. In another example (as shown by the dashed curve 909 in 9A shown), the second exhaust valves can be opened just before closing the first exhaust valves. In particular, the second exhaust valves may be opened just before the midpoint of the exhaust stroke and closed shortly after the end of the exhaust stroke (eg, shortly after the oT position of the corresponding piston at the end of the exhaust stroke).

During the first mode of operation, the first ARV (or pre-compressor ARV) and the second ARV (or booster ARV) are kept closed. Further, during the first mode of operation, all of the exhaust gas from all cylinders of the engine is directed to the exhaust gas purifier. In addition, in some embodiments, the first mode of operation may include supplying a small portion of the exhaust advance pulse to the turbine of the turbocharger. Here, the first exhaust valves of all cylinders (eg the cylinder 20 . 22 . 24 and 26 ) for the duration of a first part of the exhaust stroke while the second exhaust valves are open for the remainder of the same exhaust stroke.

During the second mode of operation (eg, mode 2), which occurs when the engine is operating at low to medium loads, Exh_3 becomes in the cylinders 22 . 24 and 26 kept closed during the entire duration of the corresponding exhaust stroke within a particular engine cycle. The first exhaust valves in the cylinders 22 . 24 and 26 but are opened in the relevant engine cycle just before the uT position of the corresponding piston towards the end of the power stroke (closed) and are kept open when the piston rises to the TDC of the subsequent exhaust stroke. Finally, the first exhaust valves are closed well before the TDC position (eg, about 45 CAD before TDC) of the corresponding pistons in the exhaust stroke within the same given engine cycle (from open). In the meantime, the second exhaust valves (Exh_2) of cylinders 22 . 24 and 26 in the same given cycle open when the corresponding first exhaust valves in the respective cylinders are at their maximum lift in the vicinity of the center of the respective exhaust strokes. Further, the second exhaust valves of cylinders 22 . 24 and 26 closed within the same given engine cycle shortly after the oT of the corresponding exhaust strokes.

During the second mode of operation, the cylinder becomes 20 relative to the operation of the remaining cylinders 22 . 24 and 26 operated in a distinct way. The first exhaust valve and the second exhaust valve of cylinder 20 are kept closed for the entire duration of the exhaust strokes within the same given engine cycle. Further, the third exhaust valve of cylinder 20 kept open for the entire duration of the corresponding exhaust strokes within the same given engine cycle. That is, the CIV of cylinder 20 is opened (from closed) just before the uT position of the corresponding piston towards the end of a power stroke, is kept open when the piston rises to the oT of the subsequent exhaust stroke, and closed shortly after reaching the oT position of the exhaust stroke. Further, in the following intake stroke, a positive overlap between the CIV and the intake valves of cylinder 20 to be present. Alternatively, a positive valve overlap can not occur.

Still further, during the second mode of operation, the second ARV (or boost compressor ARV) may return the entire exhaust gas contents from the cylinder 20 (eg from the subgroup of cylinders) to the post-compressor station via the after-compressor line 664 be open. In addition, the first ARV (or supercharger ARV) can be kept closed. During the second mode of operation, all of the exhaust gas from the cylinder 20 downstream of the compressor to a location immediately upstream of the intake manifold and downstream of the intake throttle. Accordingly, during the second mode, the exhaust gas from the cylinder 20 not to the turbine, not to the precompressor point (since the first ARV is closed) and also not to the emission catalyst. During the same given engine cycle, exhaust gas from the remaining cylinders (eg, the cylinders 22 . 24 and 26 ) to the turbine and the exhaust gas purifier. In particular, a first portion of exhaust gas, including the pre-discharge pulse, may be directed to the turbine at higher pressures, while a second portion of the exhaust gas, including the purged portion of the exhaust gas, may be directed to the emission control device. Thus, exhaust gas from the remaining cylinders can not be routed to the compressor inlet or to the post-compressor station, since the third exhaust valves of the remaining cylinders remain closed during the second operating mode for the entire duration of the exhaust strokes.

During the third mode of operation (eg, mode 3) occurring during high engine loads, the first exhaust valves, the second exhaust valves, and the CIVs of all cylinders may be opened for particular periods and portions of the corresponding exhaust strokes within a distinct common engine cycle. The first exhaust valves in all cylinders of the engine 10 can be opened (closed) just before the uT positions of the respective pistons toward the end of the power stroke and kept open when the piston rises to the td of the subsequent exhaust stroke. Finally, the first exhaust valves are closed (open) significantly before the TDC positions (eg, about 45 CAD before TDC) of the corresponding pistons in the exhaust stroke within the distinct common engine cycle.

In the distinct common engine cycle, the second exhaust valves of all cylinders of the engine become 10 from the closed state when the respective first exhaust valves in the respective cylinders are at their maximum lift in the vicinity of the center of the respective exhaust strokes. Further, the second exhaust valves of all cylinders are closed within the distinct common engine cycle before the oT (eg, within 20 degrees of oT) of the respective exhaust strokes. Finally, the CIVs of all cylinders may open (close) just before the TDC position of the respective pistons in the exhaust stroke, and may be kept open until about 30 degrees after the TDC in the subsequent intake stroke. In particular, the CIVs may be closed significantly after the oT position of the respective pistons, allowing positive valve overlap between the respective CIVs and the intake valves within the same cylinders. When the engine is operating under greater loads, the intake manifold may 27 under a higher pressure than the exhaust manifold 59 stand. Here, fresh inlet blow-through air can be forced into the cylinders and then through the open CIVs. It is understood that due to the backflow of low pressure exhaust gases into the intake manifold (as described earlier when the intake manifold is under lower pressure than the exhaust pressure in the exhaust manifolds), no internal EGR can occur at the end of the exhaust stroke.

In addition, the first ARV may be opened during the third mode of operation to allow flow of exhaust fumes together with fresh blow-through air from all cylinders toward the compressor inlet. Accordingly, during the third mode of operation, a first proportion of flue gas is supplied to the turbine, a second amount of flue gas is supplied to the emission catalyst, and a combination of blown air and low pressure EGR is transmitted through the pipe 164 and the first ARV 125 returned to Vorverdichterstelle.

It is understood that exhaust gas from cylinders 22 . 24 and 26 while none of the operating modes can be transported to the post-compressor station. Only exhaust gas from the subset of cylinders, z. B. of cylinders 20 , is transported to the post-compressor station during the second mode of operation.

In this way, an example method for an engine may include directing exhaust from a first group of cylinders (eg, cylinders 20 from engine 10 ) to a pre-compressor station, a post-compressor station and / or an exhaust gas turbine, and the routing of exhaust gas from a second group of cylinders (eg cylinder 22 . 24 and 26 from engine 10 ) to a Vorverdichterstellen and / or exhaust gas turbine include. The first group of cylinders and the second group of cylinders may mutually exclude each other and contain distinct cylinders. For example, the first group of cylinders may be with reference to the engine 10 out 6 a cylinder 20 included while the second group of cylinders cylinder 22 . 24 and 26 may contain. Thus, each group of cylinders may have distinct and separate cylinders, with cylinders included in the first group of cylinders not being part of the second group of cylinders. Exhaust from the first group of cylinders may be directed to the post-compressor location during medium engine load conditions. The method may further include, during medium load conditions, bypassing exhaust gas from the first group of cylinders to either the pre-compression unit or the exhaust turbine. Exhaust gas from the second group of cylinders may be directed to the exhaust turbine and not to the supercharger location during intermediate loads. Here, the supercharger location may include a location downstream of an intake throttle and upstream of an intake manifold.

It is noted that exhaust gas from the first group of cylinders may be directed to the supercharger location and the exhaust turbine under conditions of high engine load, and simultaneously exhaust gas from the second group of cylinders to the pre-compressor location and in a common engine cycle during high engine load conditions Exhaust gas is passed. The routing of exhaust gas to the pre-compressor station may include directing a combination of blow-by inlet air and residual exhaust gases to a location upstream of a compressor toward an end of an exhaust stroke in the first group of cylinders and the second group of cylinders. Further, directing the combination of blowby intake air and exhaust gases toward the end of the exhaust stroke in the first group of cylinders and the second group of cylinders may also provide positive valve overlap between at least one intake valve and a corresponding exhaust valve of each cylinder in the first group of cylinders and second group of cylinders. The method may also include, during high engine load conditions, exhausting exhaust from the first group of cylinders or the second group of cylinders to the post-compressor location. The routing of exhaust gas may include selectively opening one or more exhaust valves of the first group of cylinders and the second group of cylinders, wherein targeted opening includes actuating a cam profile switching device that includes cam lobes coupled to each of the one or more exhaust valves to vary a control of the opening and a duration of opening of the one or more exhaust valves.

In this way, an engine with a split exhaust manifold can be operated with increased efficiency and reduced knock. By modifying the exhaust valve operation to direct exhaust to various locations based on engine conditions, a higher amount of EGR may be communicated to the engine when the engine has a lower torque demand. When the engine is operating at a higher torque requirement, blow-by air can be used with low-pressure EGR to reduce combustion temperatures and thereby reduce knock. Overall, engine power can be improved.

While the above examples may include two exhaust valves per cylinder and a third compressor intake valve to divert exhaust gases from the cylinder, another illustration may be systems having exactly one exhaust valve and one compressor intake valve (CIV) per cylinder, at least for some cylinders and potentially for all cylinders. contain. In this illustration, the CIV may be referred to as a "second exhaust valve." This configuration can use the different methods and components that are available here as described above, wherein the exhaust valve is coupled to the inlet of the turbine via a first conduit and the CIV is coupled to the compressor inlet via a second conduit and the CIV is coupled to the inlet conduit at a pre-compression station via a third conduit.

With reference to 1 and as an example, cylinder 20 a first exhaust valve 122 Contain that via a manifold 55 and a pipe 160 with the inlet of a turbine 92 a turbocharger 190 is connected, and a compressor intake valve 112 that with the inlet of compressor 94 over a manifold 59 and a pipe 164 connected is. Furthermore, the compressor intake valve 112 also fluidically with an inlet line 28 downstream of the intake throttle, upstream of the intake manifold and downstream of the compressor 94 via a re-compressor line 664 and a second ARV 625 be coupled. Even more, the cylinder can 20 no exhaust valve 132 contain. In some examples, other cylinders of the engine may be used 10 Also includes two exhaust valves: the first exhaust valve and the compressor intake valve.

Cylinder operation during the operating modes described above may be similar. For example, during the first mode of cylinder operation, the first exhaust valves of all the cylinders of the engine 10 be open throughout the exhaust strokes to supply all of the combusted contents (eg, all exhaust gas) to the emission catalyst. During the second operating mode, CIV 112 from cylinder 20 for the entire duration of the exhaust stroke in the cylinder 20 be kept open to the entire exhaust from the cylinder 20 over the after-compressor line 664 and the second ARV 625 to lead to the post-compressor station. Furthermore, the first exhaust valve of cylinder 20 be kept closed. At the same time, within the same engine cycle, the first exhaust valves of the remaining cylinders (eg, the cylinder 22 . 24 and 26 ) during the entire duration of the respective exhaust strokes to supply all burned contents from these remaining cylinders to the exhaust turbine and then to the emission catalyst. Still further, the CIVs of all remaining cylinders may be kept fully closed during the respective exhaust strokes in the same engine cycle. During the third operating mode, all exhaust gases from the cylinder 20 via the outlet valve 122 and the compressor intake valve 112 be drained, with a greater proportion of gases through the exhaust valve 122 and a smaller portion of exhaust gases via the compressor intake valve 112 exit. The exhaust gases, the cylinder 20 via the compressor intake valve 112 Leave with fresh blow-through air from the intake manifold 27 combined and the Vorverdichterstelle over the pipe 164 and the first ARV 125 be supplied. Other cylinders of the engine may be operated in the same manner during the third mode.

It should be appreciated that the example control and estimation routines included herein are usable with various engine and / or vehicle system designs. The control methods and routines disclosed herein may be stored as executable instructions in nonvolatile memory and may be executed by the control system, including control along with the various sensors, actuators, and other engine equipment. The specific routines described herein may include one or more of any number of processing strategies, such as processing. As event-driven, interrupt-driven, multitasking, multithreading and the like. Therefore, various illustrated measures, operations and / or functions in the sequence shown can be performed, performed in parallel or omitted in some cases. Likewise, the processing order is not necessarily required to achieve the features and advantages of the embodiments described herein, but is provided for ease of illustration and description. One or more of the illustrated actions, operations, and / or functions may be repeatedly performed depending on the particular strategy being used. In addition, the described actions, operations, and / or functions may graphically represent code to be programmed into non-transitory memory of the computer-readable storage medium in the engine control system, the actions described being performed by executing the instructions in a system, including the various engine hardware components together with the electronic controller , be implemented.

It should be understood that the designs and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be construed in a limiting sense as numerous variations are possible. The above technology is applicable to, for example, V6, I4, I6, V12, 4-cylinder Boxer and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various systems and configurations and other features, functions, and / or properties disclosed herein.

The following claims particularly highlight certain combinations and sub-combinations that are believed to be novel and not obvious. These claims may refer to "a" element or "first" element or the equivalent thereof. Such claims are to be understood to include the inclusion of one or more of these elements, neither requiring nor excluding two or more of these elements. Other combinations and sub-combinations of the disclosed features, functions, elements and / or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether their scope is further, narrower, equal, or different with respect to the original claims, are also considered to be within the scope of the present disclosure. Explanation of symbols Fig. 10 1002 Estimate and / or Measure Engine Operating Conditions (eg, Ne, Load, Gain, Torque Demand) 1004 Determining the operating mode of cylinders based on operating conditions 1006 Determining the position of exhaust gas recirculation (ARV) valves based on operating conditions 1030 Do the engine conditions change so that the mode should be changed? 1032 Setting the CPS for a mode change based on existing engine conditions 1010 Adjusting the CPS to open the second exhaust valves on all cylinders and to exhaust the exhaust catalysts; Close both ARVs 1012 Adjusting the CPS to open the first exhaust valve to supply exhaust to the turbine 1018 Adjusting the CPS to open a corresponding third exhaust valve (s) of a subset of cylinders to deliver all of the exhaust gas to an after-compressor / post-throttle location 1020 Adjusting the CPS to open the first exhaust valve and supply pre-exhaust to the turbine and open the second exhaust valve to supply a purge component to the catalyst of the remaining cylinders. Keep closed the third exhaust valve 1022 Open the supercharger ARV and close the booster ARV 1026 Adjusting the CPS to open the first exhaust valve and supply bleed to the turbine, opening the second exhaust valve to deliver purge to the catalyst, opening the third exhaust valve to flow a mixture of blowby air and residual exhaust gases from all cylinders to the precompression point 1028 Open the supercharger ARV and close the booster ARV

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 8495992 [0005]

Claims (20)

 Method for an engine, comprising: Directing exhaust gas from a first group of cylinders to a pre-compressor station, a post-compressor station and / or an exhaust gas turbine; and Passing exhaust gas from a second group of cylinders to the pre-compressor station and / or the exhaust gas turbine.  The method of claim 1, wherein the first group of cylinders and the second group of cylinders exclude each other and include distinct cylinders.  The method of claim 1, wherein exhaust gas from the first group of cylinders is directed to the post-compressor location during medium engine load conditions.  The method of claim 3, further comprising venting exhaust gas from the first group of cylinders to either the precompression point or the exhaust turbine.  The method of claim 4, wherein exhaust gas from the second group of cylinders is directed to the exhaust turbine and not passed to the Vorverdichterstelle.  The method of claim 3, wherein the supercharger location includes a location downstream of an intake throttle and upstream of an intake manifold.  The method of claim 1, wherein exhaust gas from the first group of cylinders is directed to the supercharger location and to the exhaust turbine under high engine load conditions, and exhaust is directed from the second group of cylinders to the pre-compressor location and the exhaust turbine during high engine load conditions.  The method of claim 7, wherein directing exhaust gas to the precompression point includes directing a combination of blow-through inlet air and residual exhaust toward an end of an exhaust stroke in the first group of cylinders and the second group of cylinders.  The method of claim 8, wherein directing the combination of blowby intake air and exhaust gases toward the end of the exhaust stroke in the first group of cylinders and the second group of cylinders also provides positive valve overlap between at least one intake valve and a corresponding exhaust valve of each cylinder in the first group of cylinders and the second group of cylinders.  The method of claim 7, further comprising non-conducting exhaust gas from the first group of cylinders or the second group of cylinders to the post-compressor station.  The method of claim 1, wherein the routing of exhaust gas includes selectively opening one or more exhaust valves of the first group of cylinders and the second group of cylinders, wherein targeted opening includes actuating a cam profile switching device including cam lobes associated with each of the one or more the plurality of exhaust valves are coupled to vary an opening control and a duration of opening of the one or more exhaust valves.  Method for an engine, comprising: during a first condition, returning a combination of residual exhaust and blown air from a plurality of cylinders of the engine to a location upstream of a compressor in a first engine cycle; and during a second condition, returning all exhaust gases from only a subset of the plurality of cylinders to a location downstream of the compressor, and supplying exhaust gases from remaining cylinders to an exhaust turbine in a second engine cycle.  The method of claim 12, wherein the first condition includes high engine load conditions, and the second condition includes medium engine load conditions. The method of claim 12, further comprising, during the first condition, supplying a first vent portion of exhaust gases to an exhaust turbine and supplying a second vent portion of exhaust gases to an exhaust gas purification device of the plurality of cylinders.  The method of claim 14, wherein the first proportion of exhaust gases is supplied via a first exhaust valve of each of the plurality of cylinders of the exhaust gas turbine, and wherein the second purge portion of exhaust gases via a second exhaust valve of each of the plurality of cylinders of the exhaust gas purification device is supplied.  The method of claim 15, wherein the combination of residual exhaust gases and blow-by air is supplied to a location upstream of the compressor via a third exhaust valve of each of the plurality of cylinders.  The method of claim 16, further comprising, during the second condition, supplying a first vent portion of exhaust gases to an exhaust turbine, and supplying a second vent portion of exhaust gases to an exhaust gas purification device from the remaining cylinders.  A system comprising: an engine having an intake manifold and an exhaust manifold, the exhaust manifold fluidly coupled to an exhaust purification device; an intake throttle disposed in an intake passage coupled upstream of the intake manifold; a turbocharger including an intake compressor driven by an exhaust turbine; a plurality of cylinders each including a first exhaust valve, a second exhaust valve, and a third exhaust valve; a first exhaust passage fluidly coupling the first exhaust valve directly to only one turbine of the turbocharger; a second exhaust conduit that fluidly couples the second exhaust valve with only one exhaust purification device; a third conduit fluidly coupling the third exhaust valve to only one inlet of the intake compressor; a fourth conduit fluidly coupling the third exhaust valve directly to the intake conduit downstream of the intake compressor, downstream of the intake throttle and upstream of the intake manifold; a first exhaust gas recirculation valve positioned within the third conduit; a second exhaust gas recirculation valve positioned within the fourth conduit; and a cam profile switching system coupled to the first exhaust valve, the second exhaust valve and the third exhaust valve of the plurality of cylinders.  The system of claim 18, further comprising a controller with computer readable instructions stored in nonvolatile memory to: operating the plurality of cylinders in a first mode, wherein the second exhaust valve is open and the first exhaust valve and the third exhaust valve are closed to return all the exhaust gas to the exhaust purification device; operating the plurality of cylinders in a second mode, wherein a subset of the plurality of cylinders is operated while the third exhaust valve is open and the first exhaust valve and the second exhaust valve are closed to return all the exhaust to the intake manifold, downstream of the intake compressor, and remaining ones of the plurality of cylinders are operated while the first exhaust valve and the second exhaust valve are open and the third exhaust valve is closed to supply parts of exhaust gas to the exhaust turbine and the exhaust purification device; and operating the plurality of cylinders in a third mode, wherein the first exhaust valve, the second exhaust valve, and the third exhaust valve are open to bypass portions of exhaust gas to the inlet of the intake compressor, the exhaust gas purifier, and the exhaust turbine. The system of claim 19, wherein the controller includes further instructions to: close the first exhaust gas recirculation valve and the second exhaust gas recirculation valve when the plurality of cylinders are operating in the first mode; close the first exhaust gas recirculation valve and open the second exhaust gas recirculation valve when the plurality of cylinders are operating in the second mode; and open the first EGR valve and close the second EGR valve when the multiple cylinders are operating in the third mode.

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