DE102011108628A1 - Modular internal combustion engine for actuating generator for generation of electric energy, has cylinder of connecting rod, which is drivingly connected with single shaft to driving gear module - Google Patents

Abstract

The modular internal combustion engine (1) has a cylinder (2.1) of a connecting rod (3.1), which is drivingly connected with a single shaft (4.1) to a driving gear module (5.1). The driving gear module is activated or deactivated and each driving gear module is assigned with an electric machine. The electrical machine is a starter-generator (15.1), which is coupled with the single shaft. The electric machine has a starter motor and a coil for decreasing electrical energy, where the starter motor is coupled to the single shaft. An independent claim is included for a method for controlling a modular internal combustion engine.

Description

The invention relates to a modular internal combustion engine with shiftable cylinders and a correspondingly adapted method.

In diesel-electric drives, the internal combustion engine drives a generator for generating electrical energy. The electrical energy in turn is converted, for example via a hub motor in mechanical advance. In certain operating ranges or driving conditions, for example, low power demand, one or more cylinders of the internal combustion engine are switched off, whereby the fuel consumption is reduced. During cylinder deactivation, fuel is no longer injected into the selected cylinders. Since, however, all cylinders are connected via a connecting rod to a common crankshaft, the fired cylinders must carry the non-fired cylinders along. With regard to the energy balance of fuel used for generated electrical energy, this is not satisfactory.

An improvement is for example in the DE 31 45 381 A1 which discloses a modular internal combustion engine with shiftable cylinders. In this internal combustion engine, a first and a second cylinder are drivingly connected via a connecting rod with a first crankshaft. The first crankshaft is in permanent operation. A third and fourth cylinder are connected via a connecting rod with a second crankshaft. The second crankshaft and thus the third and fourth cylinders are coupled in the high load range of the internal combustion engine via a clutch with the first crankshaft. In the lower load range, however, the second crankshaft is mechanically decoupled from the first crankshaft. With regard to the energy balance, this solution still offers opportunities for optimization.

The invention is therefore based on the object to design a modular internal combustion engine with improved energy balance.

This object is achieved by a modular internal combustion engine with shiftable cylinders, in which a cylinder is drivingly connected via a connecting rod with a single shaft to a drive module. Each engine module can be activated / deactivated and each engine module is assigned an electrical machine. In an internal combustion engine with twelve cylinders, this means twelve activatable / deactivatable engine modules with twelve electric machines. The electric machine may be a starter generator coupled to the single shaft in a first embodiment. In a second embodiment, the electric machine is formed by a starter and a coil for the removal of electrical energy, wherein the coil is arranged on the piston-facing circumference of the cylinder liner. The starter is then coupled to the single shaft. Compared to the prior art with two crankshafts, the drag torque is significantly reduced in the inventive solution, which in turn causes fuel savings. For the operator, therefore, the lower operating costs are beneficial.

The problem is solved by a correspondingly adapted method for controlling a modular internal combustion engine. The control method is that a power deviation is calculated from a target and an actual power and a steady state or a transient state is set depending on the power deviation. When the transient state is set, the gradient of the target power is then calculated and compared with a limit value. If the gradient of the target power exceeds the limit value, all cylinders of the internal combustion engine are activated. Otherwise, the number of activated cylinders is calculated as a function of the target power and adjusted if necessary. If, on the other hand, the stationary state has been set, the current number of activated cylinders is retained. The method allows a needs-based operation of the modular internal combustion engine and a more precise adaptation to the performance of the operator. Compared to the prior art, the reaction time, for example, in an abrupt increase in the target power, significantly reduced due to the lower masses in the activation of the cylinder. The advantage is therefore the increased spontaneity.

In the figures, the preferred embodiments are shown. Show it:

1 a system diagram of the first embodiment,

2 a system diagram of the second embodiment and

3 a program schedule.

The 1 shows a system diagram of a first embodiment of the invention. Shown is an electronically controlled internal combustion engine 1 with common rail system and three identical engine modules. The number of engine modules can be seen as an example. The first drive module is denoted by the reference numeral 5.1 , the second engine module with the reference numeral 5.2 and the third engine module with the reference numeral 5.3 characterized. Each engine module consists of a cylinder, a connecting rod and a single shaft. For the first drive module 5.1 these are according to the first cylinder 2.1 , the first connecting rod 3.1 and the first single wave 4.1 , Each cylinder is frictionally connected to the single shaft via the connecting rod.

The general functionality of the common rail system is assumed to be known. As is known, the common rail system comprises a low-pressure pump as mechanical components 7 to pump fuel from a tank 6 , a suction throttle 8th for influencing the volume flow, a high-pressure pump 9 , a rail 10 and injectors for injecting fuel into the combustion chambers of the internal combustion engine 1 , So for example is about a first injector 11.1 the fuel into the combustion chamber of the first engine module 5.1 injected. Optionally, the illustrated common rail system can also be designed as a common rail system with individual memories. In this case, then in each injector a single memory is integrated as an additional buffer volume for the fuel. For example, in the first injector 11.1 this is the first single memory 12.1 ,

The internal combustion engine is controlled 1 via an electronic engine control unit 13 (ECU). In the 1 are the input variables of the electronic engine control unit 13 an example shows a rail pressure pCR, a target power P (SL) and a size ON. The desired power P (SL) is specified as a desired power either by an operator or by a system controller. The rail pressure pCR is transmitted via a rail pressure sensor 14 detected. The size ON is representative of the other input signals, for example for an engine speed and the feedback of an energy manager 16 , In a common rail system with individual memories of the individual storage pressure is another input of the electronic engine control unit 13 , For example, the first individual storage pressure pE1 of the first injector 11.1 , The illustrated outputs of the electronic engine control unit 13 are a PWM signal SD for controlling the suction throttle 8th , a power-determining signal for driving an injector and a size OFF. The size OFF is representative of the other control signals for controlling the internal combustion engine 1 , For example, a control signal for controlling an EGR valve. The power-determining signal is the start of injection and the duration of injection. Accordingly, the first injector 11.1 with the first power-determining signal ve1, the second injector 11.2 with the second power-determining signal ve2 and the third injector 11.3 controlled by the third power-determining signal ve3. For example, if the first engine module 5.1 be deactivated, so the injection is via the first injector 11.1 disabled. When deactivated, the first cylinder takes over 2.1 and the first single wave 4.1 a fixed position.

Each engine module is associated with an electric machine. In the first embodiment according to 1 the electric machine is a starter generator. In the case of the first engine module 5.1 this is the first starter genertor 15.1 , which from the first single wave 4.1 is driven. Each starter generator in turn is powered by the energy manager 16 controlled in its function as a starter or monitored in its function as a generator. The energy manager 16 distributes the electrical energy to the electric drive motors, such as wheel hub motor, and reports to the electronic engine control unit 13 the state of the starter generators. In practical operation, the activated cylinders are synchronized with each other in such a way that the outward forces and moments are minimized. By this measure, a consistently good smoothness is guaranteed.

The 2 shows a system diagram of a second embodiment of the invention. Shown is an electronically controlled internal combustion engine 1 with common rail system and three cylinders. Identical components for 1 are provided with identical reference numerals. The second embodiment of the invention is that the electric machine is designed here as a starter and coil. For the first engine module 5.1 So these are the first starter 17.1 and the first coil 18.1 , The sink 18.1 is on the piston-facing circumference of the first cylinder liner 19.1 arranged. For reasons of clarity, the cooling channels are omitted in the illustration. Due to the oscillating movement of the first cylinder 2.1 will be in the first coil 18.1 induced a corresponding voltage U1. The starters 17.1 to 17.3 and the coils are also in this embodiment of the energy manager 16 controlled and monitored.

In the 5 the method for controlling a modular internal combustion engine is shown in a program flowchart as a subroutine UP. The method can equally according to the first embodiment 1 as well as the second embodiment 2 be applied. At S1, the target power P (SL) is read, which is specified either by an operator, for example as accelerator pedal position, or via a system controller. Subsequently, the actual power P (IST) is determined at S2 and compared with the target power P (SL) at S3. This results in the performance deviation dP. At S4, the power deviation dP is then compared with a first limit value GW1. If the power deviation dP is greater than or equal to the first limit value GW1, Query result S4: yes, the program part S5 to S9 is run through. Otherwise the program part with S10 and S11. If it was determined at S4 that the power deviation dP has exceeded the first limit value GW1, the transient state is set at S5 and the gradient GRAD of the target power P (SL) is calculated at S6. If the gradient GRAD of the target power P (SL) exceeds a limit value GW, query result S7: yes, all cylinders are activated (nZYL = MAX) at S8, by moving a previously deactivated cylinder via the starter generator in a first step is offset and injected after a synchronization phase in a second step via the injector fuel. After that will return to the main program. If, on the other hand, the gradient GRAD of the target power P (SL) is smaller than the limit value GW, query result S7: no, then the number nZYL of the activated cylinders is dependent on the desired power P (SL), for example via a characteristic curve at S9 calculated. After that will return to the main program.

If, on the other hand, it has been determined at S4 that the power deviation dP is less than the first limit value GW1, query result S4: no, then the stationary state is set at S10 and the number nZYL of the activated cylinders is maintained at S11. After that will return to the main program.

LIST OF REFERENCE NUMBERS

1

Internal combustion engine

2.1

first cylinder

3.1

first connecting rod

4.1

first single wave

5.1

first engine module

5.2

second engine module

5.3

third engine module

6

tank

7

Low pressure pump

8th

interphase

9

high pressure pump

10

Rail

11.1

first injector

11.2

second injector

11.3

third injector

12.1

first single memory

13

electronic engine control unit (ECU)

14

Rail pressure sensor

15.1

first starter generator

15.2

second starter generator

15.3

third starter generator

16

energy Manager

17.1

first starter

18.1

first coil

19.1

first cylinder liner

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

• DE 3145381 A1 [0003]

Claims (10)

Modular internal combustion engine ( 1 ) with switchable cylinders ( 2.1 ) characterized in that a cylinder ( 2.1 ) via a connecting rod ( 3.1 ) with a single wave ( 4.1 ) to a drive module ( 5.1 ), each engine module ( 5.1 ) can be activated / deactivated and each engine module ( 5.1 ) is associated with an electrical machine. Modular internal combustion engine ( 1 ) according to claim 1, characterized in that the electric machine is a starter-generator ( 15.1 ) and the starter generator ( 15.1 ) with the single wave ( 4.1 ) is coupled. Modular internal combustion engine ( 1 ) according to claim 1, characterized in that the electric machine consists of a starter ( 17.1 ) and a coil ( 18.1 ) for the collection of electrical energy, wherein the starter ( 17.1 ) with the single wave ( 4.1 ) and the coil ( 18.1 ) on the piston-facing circumference of the cylinder liner ( 19.1 ) is arranged. Modular internal combustion engine ( 1 ) according to claim 2 or 3, characterized in that in the deactivated state of the cylinder ( 2.1 ) and the single wave ( 4.1 ) assume a fixed position. Modular internal combustion engine ( 1 ) according to claim 2 or 3, characterized in that an energy manager ( 16 ) is provided for determining the state of the electric machine. Method for controlling a modular internal combustion engine ( 1 ) with the features of claim 1, characterized in that a power deviation (dP) from a target power (P (SL)) and an actual power (P (IST)) is calculated and in dependence on the power deviation (dP) a stationary state or a transient state is set. Method according to Claim 6, characterized in that, when the transient state is set, the gradient (GRAD) of the desired power (P (SL)) is calculated, the gradient (GRAD) is compared with a limit value (GW) and all cylinders ( 2.1 ) of the internal combustion engine ( 1 ) are activated when the gradient (GRAD) of the target power (P (SL)) becomes greater than or equal to the limit value (GW). Method according to Claim 7, characterized in that the number (nZYL) of the activated cylinders ( 2.1 ) is calculated as a function of the target power (P (SL)) when the gradient (GRAD) of the target power (P (SL)) becomes smaller than the limit value (GW). Method according to Claim 6, characterized in that, when the stationary state is set, the number (nZYL) of the activated cylinders ( 2.1 ) is maintained. Method according to one of claims 6 to 9, characterized in that via the energy manager ( 16 ) the energy is distributed to the electric drive motors.

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