GB2491595A - Engine cooling apparatus comprising a valve provided in a radiator bypass line - Google Patents

Abstract

A cooling apparatus for an internal combustion engine 110 comprises a radiator 70, a pump 20 for circulating a coolant in the internal combustion engine and in the radiator, and a bypass line 40 for bypassing the radiator. An on-off valve 30 is provided in the bypass line and it is electrically connected to an electronic control unit (ECU) 450, the ECU being configured to monitor a coolant temperature value measured by a temperature sensor 80 and to open the on-off valve if the monitored temperature value of the coolant reaches a predetermined threshold value. Preferably, the temperature sensor is inserted in the bypass line. The pump may be a mechanical pump, which may be driven by the engine. Preferably, the cooling apparatus comprises a thermostat 50 for regulating the flow of the coolant in the radiator.

Description

A CWLThC APPARATUS FOR AN ThTIERMVJ CCMBUSTION ENGINE The present disclosure relates to a cooling apparatus for an internal combustion engine.

Traditional internal ccztustion engines have an engine block defining a.t least one cylinder having a piston coupled to rotate a crankshaft.

A cylinder head cooperates with the piston to define a combustion chamber.

Fuel combustion in the combustion chamber generates a significant arrunt of heat and a cooling circuit is generally provided in order to manage the engine temperature during the various operating phases, allowing for a correct operation of the engine and avoiding possible damages to the engine canpcnents due to excessive tstip.rature.

An engine coolant is circulated in the cooling circuit and is sent by a coolant pump to the engine block and circulates therein exiting fran a cylinder head, since the engine block and the cylinder head

I

are equipped wIth a plurality of passageways cast or machined therein to allow the coolant fluid flow.

The coolant is then sent to a radiator which has the function of transferring heat absorbed by the coolant to the ambient air. The coolant may be a mixture of water and of an antifreeze compcnent.

The cooling circuit is generally equipped with a main circuit line and a by-pass line, the main circuit line being equipped with the radiator and with a thermostatic valve which has the function of limiting the cooling of the engine: for example at start up, until the engine has reached a tenperature sufficiently high to allow nonxl operation, the thermostatic valve closes temporarily the portion of the main cooling circuit that allows coolant to flow through the radiator..

The coolant may however flow through the by-pass line, even when the thermostat is closed.

Once the engine has reached a suitable operating temperature, the thermostat opens allowing cooling media to reach the radiator and cooling the media.

In the prior art, a switchabie coolant pump or an electrical coolant pump, Is often employed.

Accordingly, it is possible to reduce to zero the ccc. lant flow in the engine switching off the pump for a limited arrxunt of time, for example in order to acheve to a faster warm up of the coolant itself and of the engine lubricating oil, especially at engine startup in cold tenpcratures, thus reducing friction and obtaining better fuel econany.

These conventional solutions have several drawbacks.

A first drawback. is that components such as a switchable coolant pump or an electrical coolant pump are high costs components.

A second drawback is that a switchable coolant requires a dedicated managenent.

An object of an embodi: nt disclosed is to overcome the above mentioned drawbacks by taking advantage of the existing circuit layout.

Another object is to reduce manufacturing and component costs of the vehicle.

A further object of an EthodinEnt of the invention is to obtain a thermal management and related fuel economy similar to those obtainable with a switchable coolant pump or with an electrical coolant puip.

Still another object of the present disclosure is to meet these goals S by neans ot a simple, rational and alnst inexpensive solution.

These objects are achieved by a cooling apparatus for an internal combustion engine, by: an internal caubustion engine and by a method of operation thereof according to the independent claims.

The dependent claims delineate preferred and/or especially advantageous aspects. sY

An anbodirnt of the disclosure provides a cooling apparatus for an internal combustion engine, the apparatus comprising a radiator, a puip for circulating a coolant in the internal combustion engine and in the radiator and a by-pass line for by-passing the radiator, wherein an on-off valve is provIded in the by-pass line and it is electrically connected to an Electronic Control Unit, the Electronic Control Unit being configured to monitor a coolant temperature value measured by a temperature sensor and to open the on-off valve if the monitored temperature value of the coolant reaches a predetermined threshold thereof.

This embodiment takes advantage from the existing cooling circuit layout, improving it in terms of cczpactness and reduced cost of compcnents.

AccordIng to a further embodiment of the invention, the pump is a mechanIcal pump that may be driven by the engine.

An advantage of this embodiment is that it avoids the use of a switchable coolant pump or of an electrical coolant pump to tempcrarily reduce to zero the coolant flow in the engine, leading to costs savings.

According to still another embodiment of the invention, the radiator is provided in a main cooling circuit.

An advantage of this embcdiment is that it allows to transfer heat from the hot coolant to ambient air.

According to still another embodiment of the invention, the cooling apparatus comprises a thermostat for regulating the flow of the coolant in the radiator.

An advantage of this embodiment is that it allows to obtain a thermal management and a fuel economy similar to those obtainable with a switchable or an electrical cooling pump.

According to still another embodinent of the invention, the tenpcrature sensor monitoring the coolant temperature value is inserted, in the by-pass line.

An advantage of this embodime nt is that it allows to obtain a coolant tempErature value in the by-pass line useful to manage the cooling apparatus.

AccordIng to a further embodiment of the invention, an internal combustion engIne equipped with an Electronic Control Unit and with an engine cooling apparatus is provided, the apparatus comprising a radiator, a pump for circulating a coolant in the internal combustion engine and in the radiator and a by-pass line for by-passing the radiator, wherein an onoff valve is provided in the bypass line, the on-off valve being electrically connected to the Electronic Control Unit.

An advantage of this embodiment is that the provision of a pump and of an on-off valve reduces overall costs of the engine with respect to prior art solutIons involvIng a switchàble coolant pump or an electrical coolant pnip.

According to still another embodiment of the invention, a method for operatIng an internal combustion engine is provided, the method comprising a step of monitoring a temperature value of the coolant and a step of keeping closed the on-off valve in the by-pass line, until the nonitored temperature value of the coolant reaches a predetermined threshold thereof. r j

An advantage of this embodiment is that the on-off valve can be acted upon by the Electronic Control Unit according to various strategies, for example it can be opened when coolant temperature is above a predefined threshold temperature or reaches dangerous levels.

According to another embc.d ent of the invention, the monitoring of the temperature value of the coolant is done by measuring a signal from a temperature sensor, the signal being proportional to the coolant temperature.

BRIEF DESOCflICfl OF THE DRAWINGS The various embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows an automotive system; Figure 2 is a cross-section of an internal combustion engine belonging to the automotive system of figure 1; 2.5 Figure 3 s a schemetic representation of an internal combustion engine cooling apparatus according to an embodiment of the invention.

D$iIJ* DESCRIPflCI4 OF THE DBMU.

Preferred embodiments will now be described with reference to the enclosed drawings.

Some embodiments may include an autonotive system 100, as shown in Figures 1 and 2., that includes an internal cattustion engine (ICE) having an engine block 120 defining at least one cylinder 125 having a piston 140 coupled to rotate a crankshaft 145. A cylinder head 130 cooperates with the piston 140 to define a combustion chamber 150.

A fuel and air mixture (not shown) is disposed in the combust ion chamber 150 and ignited, resulting in hot expanding exhaust gasses causing reciprocal rrovement of the piston 140. The fuel is provided by at least one fuel Injector 160 and the air through at least one intake port 210. Injectors 160 in fig. 1 are represented i:n a purely scharatical way.

The fuel is provided at high pressure to the fuel injector 160 fran a fuel rail 170 In fluid cartnunication with a high pressure fuel pump that increase the pressure of the fuel received a fuel source 190.

Each of the cylinders 25 has at least two valves 215, actuated by a cam haft 135 rotating in time with the crankshaft 145. The valves 215 selectively allow air into the combustion charter 150 from the port 210 and alternately allow exhaust gases to exit through a port 220.

in some examples, a can. phaser 155 may selectively vary the timing between the camshaft 135 and the crankshaft 145.

The air may be distributed to the air intake port(s) 210 through an intake manifold 200. An air intake duct 205 may provide air from the ambient environment to the intake manifold 200. In other embodiments, a throttle body 330 may be provided to regulate the flow of air into the manifold 200.. In stIll other embodinents, a forced air system such as a turbocharger 230, having a compressor 240 rotationally coupled to a turbine 250, may be provided. Rotation of the compressor 240 increases the pressure and temperature of the air in the duct 205 and manifold 200. An intercooler 260 disposed in the duct 2.05 may reduce the temperature of the air. The turbine 250 rotates by receiving exhaust gases from an exhaust manifold 225 that directs exhaust gases from the exhaust ports 220 and through a series of vanes prior to expansion through the turbine 250. The exhaust gases exit the turbine 250 and are directed into an exhaust system 270.

This example shows a variable geometry turbine (VGT) with a VGT actuator 290 arranged to rteve the vanes to alter the flow of the exhaust gases through the turbine 250. In other embodi.ents, the turbocharger 230 may be fIxed geometry and/or include a waste gate.

The exhaust system 270 may include an exhaust pipe 275 having one or more exhaust aftertreatment devices 280. The aftertreatment devices may be any device configured to change the catposition of the exhaust S gases. Sara examples of aftertreatnent devices 280 include, but are not limited to, catalytic converters (two and three way), oxidation catalysts, lean NO, traps, hydrocarbon adsorbers, selective catalytic reduction (5CR) systems, and particulate filters. Other embodiments may include an exhaust gas recirculation (EGR) system 300 coupled between the exhaust manifold 225 and the intake manifold 200. The EGR system 300 may include an EGR cooler 310 to reduce the temperature of the ex?aust gases in the EGR system 300. An EGR valve 320 regulates a flow of exhaust gases in the EGR system 300.

The automotive system 100 may further include an electronic control unit (ECU) 450 in coninunication with one or more sensors and/or devices associated with the ICE 110. The EGO 450 may receive input signals from various sensors configured to qenerate the signals in proportion to various physical parameters associated with the ICE 110. The sensors include, but are not limited to, a mass airflow and tenpe rature sensor 340, a manifold pressure and temperature sensor 350, a cantustion pressure sensor 360, coolant and oil temperature and level sensors 380, a fuel rail pressure sensor 400, a cam position sensor 410, a crank position sensor 420, exhaust pressure and temperature sensors 430, an EGR temperature sensor 440, and an accelerator pedal position sensor 445. Furthermore, the Ecu 450 may generate output signals to various control devices that are arranged to control the operation of the IE 110, including, but not limited to, the fuel injectors 160, the throttle body 330, the EGR Valve 320, We VGT actuator 290, and the cain phaser 155. Note, dashed lines are used to indicate ccnnunication between the ECU 450 and the various sensors and devices, but some are omitted for clarity.

Turning now to the ECU 450, this apparatus may include a digital central processing unit (CPU) in corrntunication with a memory system, or data carrier 460, and an interface bus. The CPU is configured to execute instructions stored as a program in the memory system, and send and receive signals to/fran the interface bus. The memory system may include various storage typs including optical storage, magnetic storage, solid state storage, and other non-volatile memory. The interface bus may be configured to send, receive, and modulate analog and/or digital signals to/from the various sensors and control devices -More specifically, Figure 3 shows a schamatic representation of an internal combustIon engine cooling apparatus 10, according to an embodiment of the invention, for circulating a coolant. The coolant circulating in the engine cooling apparatus 10 may be a mixture of water and of an antifreeze component.

The engine cooling apparatus 10 comprises a main cooling circuit 60 for circulating the coolant through the internal combustion engine and a by-pass line 40.

The engine cooling apparatus 10 is equipped with a pump 20 that sends the coolant into the engine block 120, whereby the coolant circulates therein for cooling the engine and then exits fran the cylinder head of the engine 110.

Pump 20 is a mechanical pump that may be operated continuously. For example pump 2.0 nay be a centrifugal pump driven by the engine 110 through a drive belt.

The coolant circulating in the main cooling circuit 60 is sent to a radiator 70 having the function of transferring heat absorbed by the coolant to the ant ient air.

The main cooling circuit 60 is equipped with a thermostat 50 that has the function of limiting the cooling of the engine 110, for example at start up, until the engine 110 has reached a temperature sufficiently high to allow normal operation.

Once the engine 110 has reached its operating temperature, the the. stat 50 may work to regulate the temperature thereof by regulating the flow of coolant in the main circuit line 60 and then through the radiator 70 and the flow of coolant through the by-pass line 40.

According to an ertodlinent of the invention, an on-off valve 30 is inserted in the by-pass line 40.

The on-off valve 30 may be operated by the Electronic Control Unit 450 to open or to close the by-pass line 40.

In operation, at start-up of the engine 110, the thernstat 50 may be closed and this avoids the passage of the coolant in the main cooling circuit 60 through the radiator 70 and back to the engine 110.

At this stage, the on-off valve 30 may be closed to not allow flow of coolant through the by-pass line 40.

This allows the engine to reach quickly a suitable tperature for the nonnal operation, as the Internal Corfibustion Engine has no motion for the cooling media.

Temperatures in the engine coolant may be measured by a temperature sensor 80 electrically connected to the ECU 450.

The temperature sensor 80 may be placed in inserted in the by-pass line 40.

Once normal engine ternpcratures are reached, the thermostat 50 opens in order to allow the passage of the coolant in the main cooling circuit 60 through the radiator 70 and back to the engine 110, thereby performing a cooling of the engine 110.

According to a further embodiment of the invention, the Electronic Control Unit 450 may act on the on-off valve 30 to open it.

If the on-off valve 30 and the thermostat 50 are closed, the coolant crculat±on in engine 110 is caupletely stopped. In other words, there is no flow frw the coolant pump 20 outlet and the engine 110 may reach a higher temperature even more quickly.

If the on-off valve 30 is closed and the theric stat 50 is open, the coolant flows only through the main cooling circuit 60.

The on-off valve 30 can be acted upon by the Electronic Control Unit 450 according to various strategies, for example it can be opened when coolant temperature is above a predefined threshold temperature or reaches dangerous levels.

The threshold temperature may be predefined empirically through a calibration activity and may: depend on the design of the engine system and can be stored. in the data carrier 460 of the ECU 450.

The temperature of the coolant may be measured by temp rature sensor and signals representative of temperature values measured by the sensor 80 may be sent through electrical connections to the ECU 450.

While at least one exemplary embodinnt has been presented in the foregoing sinnary and detailed description, it should be appreciated that a vast number of variations exist. it should also be appreciated that the exemplary embodiment or exemplary thothments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing sumnary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary enbodir:nt without departing from the scope as set forth in the appended claims and their legal eguivalents a engine cooling apparatus coolant pump 30 on-off valve by-pass line thenrcstat coolant main circuit radiator 80 coolant tperature sensor automotive system internal combustion engine (ICE) engine block cylinder 130 cylinder head piston crankshaft combustion chamber cam phaser 160 fuel injector fuel rail fuel put fuel source intake manifold 205 air Intake duct 210 intake air port 215 valves of the cylinder 220 exhaust gas port 225 exhaust manifold 230 turbocharger 240 compressor 250 turbine 260 intercooler 270 exhaust system 275 exhaust pipe 280 exhaust afte.rtreatment device 290 VGT actuator 300 EGR system 310 EGR cooler 320 EGR valve 330 throttle body 340 mass airflow and temperature sensor 350 manifold pressure and temperature sensor 360 comk.*ustion pressure sensor 380 coolant and oil temperature and level sensors 400 fuel rail pressure sensor 410 cam position sensor 420 crank position sensor 430 exaust pressure and temperature sensor 445 accelerator pedal position sensor 450 electronic control unit (Ecu) 460 data carrier

Claims (8)

1. A cooling apparatus for an Internal combustion engIne (110), the apparatus comprising a radiator (70), a pump (20) for circulating a coolant in the internal combustion engine (110) and in the radiator (70) and a by-pass line (40) for by-passing the radiator, wherein an on-off valve (30) is provided in the by-pass line (40) and it is electrically connected to an Electronic Control Unit (450), the Electronic Control Unit (450) being configured to monitor a coolant temperature value measured by a temperature sensor (80) and to open the on-off valve (30) if the monitored temperature value of the coolant reaches a predetermined threshold thereof.

2. A cooling apparatus as in claim 1, wherein the pump (20) is a mechanical pump (20) that may be driven by the engine (100).

3. A cooling apparatus as in claim 1, wherein the radiator (70) is provided in a main cooling circuit (60).

4. A cooling apparatus as in claim 1, wherein the cooling apparatus comprises a thermostat (50) for regulating the flow of the coolant in the radiator (60).

5. A cooling apparatus as in claim I, wherein the temperature sensor (80) monitoring the coolant temperature value is inserted in the by-pass line (40).

6. An internal ccrnbustion engine equipped with an Electronic Control Unit (450) and with an engine cooling apparatus (10) comprising a radiator (70), a ptmip (20) for circulating a coolant in the internal cortustion engine (110) and in the radiator and a by- pass line (40) for by-passing the radiator (70), wherein an on- off valve (30) is provided, in the bypass line (40), the on-off-valve (30) being electrically connected to the Electronic Control Unit (450) -

7. A method for operating an internal conbustion engine (110) equipped with an Electronic Cc.ntrol Unit (450) and with an engine cooling apparatus (10) as in claims 1-5, the method ccrnprising a step of monitoring a temperature value of the coolant and a step of keeping closed the on-off valve (30) in the by-pass line (40), until the monitored temp rature value of the coolant reaches a predetermined threshold thereof

8. A method according to claim. 7, wherein the monitoring of the temperature value of the coolant is done by measuring a signal from a temperature sensor (80), the signal being proportional to the coolant temperature