Vehicle control device

Abstract

To provide a vehicular control apparatus enabling a stop instruction in time for a fuel injection start period.SOLUTION: A vehicular control apparatus executes: stop processing for stopping a fuel supply to two stop-target cylinders (S26); and selection processing for selecting, from among the stop target cylinders, one cylinder that is a target of a stop instruction for stopping a fuel supply (S22). The selection processing is for selecting, from among the stop target cylinders, a cylinder for which a compression dead point comes up the earliest. A stoppable angle interval is a crank angle interval between a time from a stop instruction target cylinder is selected to a time when the stop instruction target cylinder is replaced by the next cylinder of the stop instruction target cylinders. A stop instruction to the selected cylinder is accepted before the fuel injection start period and in the stoppable angle interval. Further, the control apparatus executes delay-angle processing for delaying a fuel injection start period so that the stoppable angle interval includes a fuel injection start period (S20).SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a control device for a vehicle.

Background Art

[0002] Patent Document 1 discloses a hybrid vehicle including an engine having a plurality of cylinders and a motor generator. This hybrid vehicle is provided with an exhaust purification device for purifying exhaust discharged from the plurality of cylinders. The catalyst of the exhaust purification device exhibits exhaust purification ability at the activation temperature. Therefore, in the hybrid vehicle disclosed in Patent Document 1, when the temperature of the catalyst is low, catalyst warm-up for warming the catalyst to the activation temperature is performed.

[0003] The control device disclosed in Patent Document 1 executes a stop process of stopping the fuel supply to some of the plurality of cylinders of the engine while supplying fuel to the remaining cylinders when catalyst warm-up is required. As a result, oxygen is supplied to the exhaust purification device through the cylinders where the fuel supply is stopped. Then, the oxidation reaction at the catalyst is promoted and the temperature of the catalyst rises. In this way, the control device can promote catalyst warm-up by executing oxygen supply by the stop process.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] FIG. 1 shows a V-type 6-cylinder engine having six cylinders #1 to #6. The six cylinders #1 to #6 are arranged in order from the front. Cylinders #1, #3, and #5 constitute the right bank. Cylinders #2, #4, and #6 constitute the left bank.

[0006] Figure 2 shows the counters CNT for six cylinders #1 to #6. The 0 to 720 degrees of the counter CNT correspond to the combustion cycle. The 0 to 180 degrees of the counter CNT correspond to the expansion stroke. The 180 to 360 degrees of the counter CNT correspond to the exhaust stroke. The 360 to 540 degrees of the counter CNT correspond to the intake stroke. The 540 to 720 degrees of the counter CNT correspond to the compression stroke. The 720 degrees of the counter CNT correspond to the top dead center of compression. As shown in Figure 2, in the six cylinders #1 to #6, combustion is performed in this order. The angular interval at which combustion is performed is 120 degrees (= 720 degrees / 6).

[0007] When the above stop process is executed in a V-type six-cylinder engine, it is conceivable to stop the fuel supply to two opposing cylinders while supplying fuel to the remaining cylinders. The arrival timing of the top dead center of compression in one of the opposing cylinders is separated by 360 degrees in crank angle from the arrival timing of the top dead center of compression in the other of the opposing cylinders. The two opposing cylinders are, for example, cylinder #2 and cylinder #5. As described above, in the six cylinders #1 to #6, combustion is performed in this order. Therefore, stopping the fuel supply to the two opposing cylinders means stopping combustion at equal intervals when viewed from the entire engine. Thus, it is possible to suppress fluctuations in the output from the engine as compared with a configuration in which combustion is stopped at unequal intervals.

[0008] A case where the engine control device attempts to stop the fuel supply to cylinders #2 and #5 will be described. The determination as to whether or not to stop the fuel supply to cylinder #2 is preferably made immediately before the top dead center of compression appears in cylinder #2. Thereby, even when a request to stop the fuel supply to cylinder #2 occurs slightly before the top dead center of compression appears in cylinder #2, such a request can be immediately responded to. Similarly, the determination as to whether or not to stop the fuel supply to cylinder #5 is preferably made immediately before the top dead center of compression appears in cylinder #5.

[0009] The control device can only issue an instruction to stop the fuel supply to the cylinder among cylinders #2 and #5 where the compression top dead center will appear earlier when viewed from the current time. From time T11 to time T12 and from time T13 to time T14 in FIG. 3, the control device can only issue an instruction to stop the fuel supply to cylinder #5. From time T12 to time T13 and from time T14 to time T15, the control device can only issue an instruction to stop the fuel supply to cylinder #2. As a result, the computational load can be suppressed compared to a configuration in which the control device can issue instructions to stop the fuel supply to cylinder #2 and the fuel supply to cylinder #5 in parallel.

[0010] Here, assuming a situation where a stop process is to be started from a situation where port injection is being performed at a crank angle 540 degrees before the crank angle corresponding to the compression top dead center in each of cylinders #1 to #6. The port injection can be performed through a port injection valve provided in the intake passage connected to cylinders #1 to #6. In FIG. 3, the downward arrow indicates the fuel injection start timing in the port injection.

[0011] When the engine control device attempts to stop fuel supply to cylinders #2 and #5, it cannot execute the stop process as described below. As described above, from time T12 to time T13, the control device can only issue an instruction to stop fuel supply to cylinder #2. However, for the fuel supply to cylinder #2 when top dead center of compression appears at time T13, port injection has already been performed between time T11 and time T12. That is, since fuel supply to cylinder #2 has already been carried out, even if an instruction to stop fuel supply to cylinder #2 is issued during the period from time T12 to time T13, the fuel supply to cylinder #2 cannot be stopped. As described above, from time T13 to time T14, the control device can only issue an instruction to stop fuel supply to cylinder #5. However, for the fuel supply to cylinder #5 when top dead center of compression appears at time T14, port injection has already been performed between time T12 and time T13. Therefore, similarly, the fuel supply to cylinder #5 cannot be stopped either.

[0012] Thus, during the combustion cycle, if the fuel injection start time arrives before the period when an instruction to stop fuel supply can be issued, the fuel supply cannot be stopped.

Means for Solving the Problem

[0013] Hereinafter, the means for solving the above problems and their effects will be described. According to one aspect of the present disclosure, there is provided a control device for a vehicle including an internal combustion engine having a plurality of cylinders, the control device including a processing circuit and configured to execute a stop process of stopping fuel supply to two or more cylinders among the plurality of cylinders and supplying fuel to the remaining one or more cylinders. An operation from the start of an expansion stroke to the end of a compression stroke is a combustion cycle, and each of the plurality of cylinders is configured to repeatedly execute the combustion cycle such that a compression top dead center sequentially appears in the plurality of cylinders. The processing circuit is configured to execute, prior to the stop process, a selection process of selecting, each time a compression top dead center appears in any of the cylinders to be stopped from which fuel supply is stopped, one cylinder that is a target of a stop instruction to stop fuel supply among the cylinders to be stopped. The selection process is a process of selecting, among the cylinders to be stopped, the cylinder in which the compression top dead center appears earliest at the time of execution of the selection process. After the cylinder that is the target of the stop instruction is selected, a crank angle interval from when the cylinder that is the target of the stop instruction is selected until it switches to the next cylinder among the cylinders to be stopped is a stoppable angle interval. The stop instruction for the selected cylinder is received during the combustion cycle before a fuel injection start timing and within the stoppable angle interval. The processing circuit is configured to execute a retardation process of retarding the fuel injection start timing such that the fuel injection start timing is included in the stoppable angle interval. There is provided a control device for a vehicle.

[0014] During the combustion cycle, if the fuel injection start timing is before the stoppable angle interval, the stop instruction is not received. According to the above configuration, the processing circuit executes a retardation process of retarding the fuel injection start timing such that the fuel injection start timing is included in the stoppable angle interval. For this reason, in the stoppable angle interval, there is a section before the fuel injection start timing. The stop instruction is received in the section. By receiving the stop instruction in the section, fuel supply can be stopped in the section. That is, during the combustion cycle, by executing the retardation process for a configuration in which fuel supply cannot be stopped because the fuel injection start timing arrives before the stoppable angle interval, fuel supply can be stopped.

[0015] The internal combustion engine includes a plurality of intake ports each connected to a corresponding one of the plurality of cylinders, a plurality of port injection valves respectively provided in the plurality of intake ports, and a plurality of in-cylinder injection valves respectively provided in the plurality of cylinders. Each of the plurality of port injection valves is configured to perform port injection for injecting fuel into a corresponding intake port among the plurality of intake ports. Each of the plurality of in-cylinder injection valves is configured to perform in-cylinder injection for injecting fuel into a corresponding cylinder among the plurality of cylinders. The processing circuit may be configured to perform the retard processing by changing a fuel injection mode in the cylinder to be stopped from a port injection mode to an in-cylinder injection mode.

[0016] Port injection needs to be performed before the start of the compression stroke. In contrast, in-cylinder injection can be performed after the start of the compression stroke. According to the above configuration, the processing circuit performs the retard processing by changing the fuel injection mode from the port injection mode to the in-cylinder injection mode. Therefore, the injection start timing of the port injection can be significantly retarded compared to a configuration in which the injection start timing of the port injection is retarded while maintaining the port injection mode. Accordingly, the section in which the stop instruction is received can be increased.

[0017] The internal combustion engine includes a plurality of intake ports each connected to a corresponding one of the plurality of cylinders, and a plurality of port injection valves respectively provided in the plurality of intake ports. Each of the plurality of port injection valves is configured to perform port injection for injecting fuel into a corresponding intake port among the plurality of intake ports. The processing circuit may be configured to perform the retard processing by retarding the injection start timing of the port injection in the cylinder to be stopped.

[0018] In a configuration in which the internal combustion engine includes port injection valves but does not include in-cylinder injection valves, a section in which a stop instruction is received can be generated. In a configuration in which the internal combustion engine includes both port injection valves and in-cylinder injection valves, a section in which a stop instruction is received can be generated even while maintaining the port injection mode.

[0019] The vehicle includes a motor generator, and the processing circuit is configured to control the internal combustion engine and the motor generator so that the internal combustion engine and the motor generator cooperate to generate the output torque required for the vehicle. The processing circuit may be configured to execute a compensation process that compensates for a decrease in the output torque of the internal combustion engine caused by the stop process through the motor generator, together with the stop process.

[0020] According to the above configuration, the motor generator compensates for a decrease in the output torque of the internal combustion engine caused by the stop process. Therefore, fluctuations in the output torque of the vehicle can be suppressed. The number of the plurality of cylinders is six, and the stop process is a process of stopping the fuel supply to the cylinders to be stopped, which are two of the plurality of cylinders, and supplying fuel to the remaining four cylinders. The timing of the arrival of the compression top dead center in one of the cylinders to be stopped is separated by 360 degrees in terms of the crank angle from the timing of the arrival of the compression top dead center in the other of the cylinders to be stopped. The selection process is a process of alternately selecting one cylinder to be the target of the stop instruction to stop the fuel supply from among the cylinders to be stopped every 360 degrees in terms of the crank angle. The retardation process may be a process of retarding the fuel injection start timing so that the fuel injection start timing is included in the stoppable angle interval from the timing 360 degrees before the arrival timing of the compression top dead center in terms of the crank angle to the arrival timing of the compression top dead center.

[0021] According to the above configuration, by performing the retardation process in an internal combustion engine having six cylinders, it becomes possible to stop the fuel supply to two opposed cylinders.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0023] Hereinafter, a vehicle control device according to an embodiment will be described with reference to the drawings. <Regarding the Configuration of the Vehicle> As shown in FIG. 4, an internal combustion engine (hereinafter referred to as an engine) 10 includes six cylinders #1 to #6. Cylinders #1, #3, and #5 form the right bank. Cylinders #2, #4, and #6 form the left bank. Hereinafter, the members corresponding to the right bank will be described with the suffix "R" in their reference numerals. The members corresponding to the left bank will be described with the suffix "L" in their reference numerals. As shown in FIG. 5, the engine 10 has a cylinder block 11 and cylinder heads 15R and 15L. Various components are arranged in the cylinder block 11 and the cylinder heads 15R and 15L. FIG. 5 shows cylinder #1, which is one of the three cylinders #1, #3, and #5 forming the right bank, and cylinder #2, which is one of the three cylinders #2, #4, and #6 forming the left bank. As shown in FIG. 4, a throttle valve 14 is provided in the intake passage 12 of the engine 10. As shown in FIG. 5, port injection valves 16R and 16L for injecting fuel into the intake ports 12R and 12L, which are the downstream portions of the intake passage 12, are provided respectively. Specifically, the engine 10 includes a plurality of port injection valves 16R provided respectively in a plurality of intake ports 12R connected to each of the plurality of cylinders #1, #3, and #5. The engine 10 includes a plurality of port injection valves 16L provided respectively in a plurality of intake ports 12L connected to each of the plurality of cylinders #2, #4, and #6. Each of the plurality of port injection valves 16R and 16L performs port injection for injecting fuel into a corresponding one of the plurality of intake ports 12R and 12L. The air inhaled into the intake passage 12 and the fuel injected from the port injection valve 16R flow into the combustion chamber 20R as the intake valve 18R opens. The air inhaled into the intake passage 12 and the fuel injected from the port injection valve 16L flow into the combustion chamber 20L as the intake valve 18L opens. The engine 10 includes a plurality of in-cylinder injection valves 22R provided respectively in each of the plurality of cylinders #1, #3, and #5. The engine 10 includes a plurality of in-cylinder injection valves 22L provided respectively in each of the plurality of cylinders #2, #4, and #6. Each of the plurality of in-cylinder injection valves 22R and 22L performs in-cylinder injection for injecting fuel into a corresponding one of the plurality of cylinders #1 to #6. That is, fuel is injected into the combustion chambers 20R and 20L from the in-cylinder injection valves 22R and 22L.In addition, the air-fuel mixture in the combustion chambers 20R and 20L is subjected to combustion by the spark discharge of the spark plugs 24R and 24L.

[0024] The combustion energy generated when the air-fuel mixture is combusted is converted into the rotational energy of the crankshaft 26 as described below. The piston 13R is capable of reciprocating inside each of the cylinders #1, #3, and #5. The piston 13R is connected to the crank pin 26a of the crankshaft 26 via the connecting rod 13aR. The piston 13L is capable of reciprocating inside each of the cylinders #2, #4, and #6. The piston 13L is connected to the crank pin 26a of the crankshaft 26 via the connecting rod 13aL. As the pistons 13L and 13R reciprocate, the crankshaft 26 rotates.

[0025] The air-fuel mixture subjected to combustion in the combustion chamber 20R is discharged as exhaust into the exhaust passage 30R with the opening of the exhaust valve 28R. The air-fuel mixture subjected to combustion in the combustion chamber 20L is discharged as exhaust into the exhaust passage 30L with the opening of the exhaust valve 28L. As shown in FIG. 4, in the exhaust passage 30R, as an exhaust purification device, a three-way catalyst 32R having an oxygen storage capacity and a gasoline particulate filter (GPF 34R) are provided. In the exhaust passage 30L, as an exhaust purification device, a three-way catalyst 32L having an oxygen storage capacity and a gasoline particulate filter (GPF 34L) are provided. Note that the GPFs 34R and 34L are filters that collect PM and have a three-way catalyst supported thereon.

[0026] A crank rotor 40 provided with a tooth portion 42 is coupled to the crankshaft 26. Basically, the tooth portion 42 is provided on the crank rotor 40 every 10 degrees. 34 Therefore, on the crank rotor 40, a missing tooth portion 44 is provided at one location where the interval between adjacent tooth portions 42 is widened by two tooth portions 42 being lacking. This is for indicating the reference rotation angle of the crankshaft 26.

[0027] The crankshaft 26 is mechanically connected to the carrier C of the planetary gear mechanism 50 that constitutes the power split device. The rotating shaft 52a of the first motor generator 52 is mechanically connected to the sun gear S of the planetary gear mechanism 50. Also, the rotating shaft 54a of the second motor generator 54 and the drive wheel 60 are mechanically connected to the ring gear R of the planetary gear mechanism 50. An AC voltage is applied to the terminals of the first motor generator 52 by the inverter 56. Also, an AC voltage is applied to the terminals of the second motor generator 54 by the inverter 58.

[0028] <Regarding the control device 500> The control device 500 controls the engine 10, the first motor generator 52, and the second motor generator 54. The control device 500 includes an engine control unit 110 that controls the engine 10. Also, the control device 500 includes a motor control unit 130 that controls the first motor generator 52 and the second motor generator 54. Furthermore, the control device 500 includes a general control unit 100 that is connected to the engine control unit 110 and the motor control unit 130 and overall controls the vehicle. Note that these control units include a so-called microcomputer having a CPU, ROM, RAM, and an input / output interface, etc. Each control unit performs signal processing according to a program stored in advance in the ROM while using the temporary storage function of the RAM.

[0029] This control device 500 controls the engine 10, the first motor generator 52, and the second motor generator 54. That is, the control device 500 controls the vehicle's power train. The control device 500 controls the engine 10, the first motor generator 52, and the second motor generator 54 so that they cooperate to generate the output torque required by the vehicle. Detection signals from sensors provided in each part of the vehicle are input to the control device 500.

[0030] The engine control unit 110 operates the operating unit of the engine 10 to control the control amounts of the engine 10, such as torque and exhaust component ratio. The operating unit of the engine 10 is, for example, the throttle valve 14, the port injection valves 16R, 16L, the in-cylinder injection valves 22R, 22L, and the spark plugs 24R, 24L.

[0031] Also, the motor control unit 130 operates the inverter 56 to control the rotational speed, which is the control amount of the first motor generator 52. Further, the motor control unit 130 operates the inverter 58 to control the torque, which is the control amount of the second motor generator 54.

[0032] Figures 4 and 5 show the respective operation signals MS1 to MS6 of the throttle valve 14, the port injection valves 16R, 16L, the in-cylinder injection valves 22R, 22L, the spark plugs 24R, 24L, and the inverters 56, 58. The engine control unit 110 refers to the intake air amount Ga detected by the air flow meter 80 to control the control amount of the engine 10. Also, the engine control unit 110 also refers to the output signal Scr of the crank angle sensor 82 and the coolant temperature THW detected by the coolant temperature sensor 86. The engine control unit 110 also refers to the pressure PexR of the exhaust gas flowing into the GPF 34R detected by the exhaust pressure sensor 88R. The engine control unit 110 also refers to the pressure PexL of the exhaust gas flowing into the GPF 34L detected by the exhaust pressure sensor 88L. Further, the motor control unit 130 refers to the output signal Sm1 of the first rotation angle sensor 90 that detects the rotation angle of the first motor generator 52 to control the control amount of the first motor generator 52. The motor control unit 130 refers to the output signal Sm2 of the second rotation angle sensor 92 that detects the rotation angle of the second motor generator 54 to control the control amount of the second motor generator 54.

[0033] The engine control unit 110 and the motor control unit 130 are each connected to the integrated control unit 100 via a communication line. And each of the integrated control unit 100, the motor control unit 130, and the engine control unit 110 exchanges and shares information based on the detection signals input from the sensors and the calculated information through CAN communication.

[0034] An accelerator position sensor 101, a brake sensor 102, and a vehicle speed sensor 103 are connected to the integrated control unit 100. The accelerator position sensor 101 detects the accelerator opening. The brake sensor 102 detects the operation amount of the brake. The vehicle speed sensor 103 detects the vehicle speed, which is the speed of the vehicle.

[0035] In addition, air-fuel ratio sensors 81R and 81L are provided in the exhaust passages 30R and 30L. The air-fuel ratio sensors 81R and 81L are connected to the engine control unit 110. The air-fuel ratio sensors 81R and 81L detect the air-fuel ratio.

[0036] In addition, an upstream temperature sensor 87R for detecting the temperature of the exhaust gas between the three-way catalyst 32R and the GPF 34R in the exhaust passage 30R is connected to the engine control unit 110. An upstream temperature sensor 87L for detecting the temperature of the exhaust gas between the three-way catalyst 32L and the GPF 34L in the exhaust passage 30L is connected to the engine control unit 110. Also, a downstream temperature sensor 89R for detecting the temperature of the exhaust gas downstream of the GPF 34R is connected to the engine control unit 110. A downstream temperature sensor 89L for detecting the temperature of the exhaust gas downstream of the GPF 34L is also connected to the engine control unit 110.

[0037] The engine control unit 110 estimates the catalyst temperature and the GPF temperature based on the engine load factor KL, the engine rotational speed NE, and the temperatures of the exhaust gas detected by these upstream temperature sensors 87R, 87L and downstream temperature sensors 89R, 89L. The catalyst temperature is the temperature of the three-way catalysts 32R, 32L. On the other hand, the GPF temperature is the temperature of the GPFs 34R, 34L.

[0038] Also, the engine control unit 110 counts the number of times the output signal Scr of the crank angle sensor 82 is input and calculates a counter CNT which is a value corresponding to the crank angle. The value of the counter CNT corresponds to the crank angle and indicates that the larger the value, the larger the crank angle. And when it reaches a value corresponding to 720 degrees, that is, 0 degrees, it is reset to "0" again. Note that the crank angle at which the counter CNT is "0" is the crank angle at top dead center of compression.

[0039] <Regarding the fuel injection mode> The engine control unit 110 changes the fuel injection mode in the engine 10 according to the engine load factor KL and the engine rotational speed NE. For example, the engine 10 supplies fuel only by in-cylinder injection which is fuel injection by the in-cylinder injection valves 22R, 22L in the high load range. The engine 10 supplies fuel only by port injection which is fuel injection by the port injection valves 16R, 16L in the low load range. Also, the engine 10 may supply fuel by both port injection and in-cylinder injection. In this case, the engine control unit 110 changes the ratio of port injection and in-cylinder injection according to the engine load factor KL and the engine rotational speed NE. The engine 10 thus aims to form an air-fuel mixture suitable for combustion.

[0040] Note that the engine rotational speed NE is calculated by the engine control unit 110 based on the output signal Scr. Also, the engine load factor KL is calculated by the engine control unit 110 based on the intake air amount Ga and the engine rotational speed NE.

[0041] <Regarding the regeneration process> Fig. 6 shows the processing steps in the routine for the regeneration process executed by the engine control unit 110. In the following, it is assumed that port injection is being performed in the engine 10 and the flag F described later changes from 0 to 1. The routine shown in Fig. 6 is realized by the engine control unit 110 repeatedly executing a program stored in the memory, for example, at a predetermined cycle. Hereinafter, the step numbers of each process are represented by numbers with "S" added at the beginning.

[0042] In the routine shown in Fig. 6, the engine control unit 110 first acquires the engine rotational speed NE, the engine load factor KL, and the coolant temperature THW (S10). Next, the engine control unit 110 calculates the update amount ΔDPM of the deposition amount DPM based on the engine rotational speed NE, the engine load factor KL, and the coolant temperature THW (S12). Here, the deposition amount DPM is the amount of PM collected in the GPFs 34R and 34L. Specifically, the engine control unit 110 calculates the amount of PM in the exhaust gas discharged into the exhaust passages 30R and 30L based on the engine rotational speed NE, the engine load factor KL, and the coolant temperature THW. Then, the engine control unit 110 calculates the update amount ΔDPM based on the amount of PM in the exhaust gas and the GPF temperature.

[0043] Next, the engine control unit 110 updates the deposition amount DPM by adding the update amount ΔDPM to the deposition amount DPM (S14). Next, the engine control unit 110 determines whether the flag F is "1" (S16). The flag F indicates that the regeneration process for burning and removing the PM in the GPFs 34R and 34L is being executed when it is "1". On the other hand, the flag F indicates that the regeneration process is not being executed when it is "0". When the engine control unit 110 determines that the flag F is "0" (S16: NO), it determines whether the deposition amount DPM is greater than or equal to the regeneration execution value DPMH (S18). The regeneration execution value DPMH is a threshold value for determining that it is necessary to remove the PM based on the deposition amount DPM being greater than or equal to the regeneration execution value DPMH.

[0044] When the engine control unit 110 determines that it is equal to or higher than the reproduction execution value DPMH (S18: YES), it proceeds to S20. In S20, the engine control unit 110 executes retard processing and assigns "1" to the flag F. Retard processing is processing for retarding the fuel injection start timing so that the fuel injection start timing is included in the stoppable angular interval described later. The engine control unit 110 executes retard processing by changing the fuel injection mode of all cylinders #1 to #6 from the port injection mode to the in-cylinder injection mode. The retard processing will be described later with reference to FIG. 7. FIG. 7 shows the switching from the mode of performing port injection at the end point (180 degrees) of the expansion stroke to the mode of performing in-cylinder injection at the start point (540 degrees) of the compression stroke. Retard processing means such switching.

[0045] After executing the retard processing in S20, the engine control unit 110 proceeds to S22. In S22, the engine control unit 110 executes selection processing. The selection processing is processing for selecting, every time the top dead center of compression appears in either of cylinders #2 and #5, which are the cylinders to be stopped, one cylinder that is the target of a stop instruction for stopping the fuel supply among the cylinders to be stopped. The selection processing is processing for selecting the cylinder in which the top dead center of compression appears earliest among cylinders #2 and #5, which are the cylinders to be stopped, at the time of execution of the selection processing. In the present embodiment, the arrival timing of the top dead center of compression in one of the cylinders to be stopped is separated by 360 degrees in terms of the crank angle from the arrival timing of the top dead center of compression in the other of the cylinders to be stopped. For this reason, the selection processing is processing for alternately selecting, every 360 degrees in terms of the crank angle, one cylinder that is the target of a stop instruction for stopping the fuel supply among the cylinders to be stopped. As shown in FIG. 6, the engine control unit 110 executes the selection processing before the stop processing described later.

[0046] After executing the selection process of S22, the engine control unit 110 proceeds to S24. In S24, the engine control unit 110 determines whether or not the execution conditions for the reproduction process are satisfied. Here, the execution conditions may be set as the condition that the logical product of the following conditions (A) to (D) is true.

[0047] Condition (A): A condition that the engine torque command value Te*, which is the command value for the torque for the engine 10, is equal to or greater than a predetermined value Teth. Condition (B): A condition that the engine rotational speed NE is equal to or higher than a predetermined speed.

[0048] Condition (C): A condition that the MG2 torque compensation process of S28 can be executed. Condition (D): A condition that at the current time, it is before the fuel injection start time in the combustion cycle of the selected cylinder that is the target of the stop instruction among cylinder #2 and cylinder #5.

[0049] Regarding Condition (D), an explanation is provided here. Each of the plurality of cylinders #1 to #6 repeatedly executes a combustion cycle so that the top dead center of compression appears sequentially among the plurality of cylinders #1 to #6. Here, the operation from the start of the expansion stroke to the end of the compression stroke is the combustion cycle. The crank angle interval from when the cylinder targeted for the stop instruction is selected until the cylinder targeted for the stop instruction switches to the next cylinder among the cylinders targeted for stop is the stoppable angle interval. The stop instruction for the selected cylinder is accepted during the combustion cycle, before the fuel injection start time, and within the stoppable angle interval. Condition (D) is a condition regarding whether or not such requirements are satisfied.

[0050] When the engine control unit 110 determines that the logical product is true (S24: YES), it proceeds to S26. The engine control unit 110 executes a stop process at S26. The engine control unit 110 gives a stop instruction to the selected cylinder targeted for the stop instruction. Then, the engine control unit 110 makes the air-fuel ratio of the air-fuel mixture in cylinders #1, #3, #4, and #6 richer than the stoichiometric air-fuel ratio. That is, the regeneration process includes a stop process of stopping the fuel supply to cylinders #2 and #5, which are the cylinders to be stopped, and supplying fuel to the remaining cylinders #1, #3, #4, and #6. This process is for raising the temperature of the GPFs 34R and 34L by discharging oxygen and unburned fuel into the exhaust passages 30R and 30L to burn and remove the PM collected by the GPFs 34R and 34L. That is, the engine control unit 110 burns the unburned fuel in the three-way catalysts 32R and 32L and the like by discharging oxygen and unburned fuel into the exhaust passages 30R and 30L to raise the temperature of the exhaust gas. Thereby, the temperature of the GPFs 34R and 34L can be raised. Also, by supplying oxygen to the GPFs 34R and 34L, the PM collected by the GPFs 34R and 34L can be burned and removed.

[0051] The engine control unit 110 requests the motor control unit 130 to perform a process of compensating for torque fluctuations of the crankshaft 26 of the engine 10 caused by the stop of combustion control of cylinder #2 or cylinder #5 (S28). The motor control unit 130 that has received this request superimposes a compensation torque on the required torque for running with respect to the second motor generator 54. Then, the motor control unit 130 operates the inverter 58 based on the required torque on which the compensation torque is superimposed. In this way, the control device 500 executes a compensation process of compensating for a decrease in the output torque of the engine 10 caused by the stop process through the second motor generator 54 together with the stop process.

[0052] Note that the condition (C) for enabling the execution of this MG2 torque compensation process is that there is no abnormality in the second motor generator 54, that electric power necessary for executing the MG2 torque compensation process is stored in the battery, and the like. The condition (C) may further include that time required for communication between the engine control unit 110 and the motor control unit 130 is ensured. The condition (C) may be set in consideration of control delay caused by the control cycle of the motor control unit 130.

[0053] On the other hand, when the engine control unit 110 determines that the flag F is "1" (S16: YES), it proceeds to S30. In S30, the engine control unit 110 determines whether or not the deposition amount DPM is less than or equal to a stop threshold value DPML. The stop threshold value DPML is a threshold value for determining that the regeneration process may be stopped based on the deposition amount DPM being less than or equal to the stop threshold value DPML. The stop threshold value DPML is smaller than the regeneration execution value DPMH. When the deposition amount DPM becomes less than or equal to the stop threshold value DPML (S30: YES), the engine control unit 110 proceeds to S32. In S32, the engine control unit 110 ends the regeneration process and substitutes "0" into the flag F. Then, the engine control unit 110 proceeds to S34. In S34, the engine control unit 110 performs injection timing setting processing. The injection timing setting processing is processing for optimizing the fuel injection start timing when the fuel injection start timing set in S20 is not optimal for combustion. For example, the fuel injection start timing is advanced.

[0054] When the deposition amount DPM is greater than the stop threshold value DPML (S30: NO), the engine control unit 110 proceeds to S22. The engine control unit 110 executes the processing after S22 and later as described above.

[0055] Note that when the engine control unit 110 completes the processes of S28 and S34, or makes a negative determination in the processes of S18 and S24, the routine shown in FIG. 6 is temporarily terminated.

[0056] <Operation of this Embodiment> With reference to FIG. 7, the operation of this embodiment will be described. As described above, the reproduction process includes a stop process of stopping the fuel supply to cylinders #2 and #5, which are the cylinders to be stopped, and supplying fuel to the remaining cylinders #1, #3, #4, and #6. Cylinders #2 and #5 are referred to as opposed cylinders. The arrival timing of the compression top dead center in one of the opposed cylinders is separated from the arrival timing of the compression top dead center in the other of the opposed cylinders by 360 degrees in terms of the crank angle. As described above, combustion occurs in this order in the six cylinders #1 to #6.

[0057] As described above regarding the selection process of S22, the engine control unit 110 can only issue an instruction to stop the fuel supply to the cylinder among cylinders #2 and #5 where the compression top dead center will appear earlier from the current point in time. From time T21 to time T22 and from time T24 to time T25 in FIG. 7, the engine control unit 110 can only issue an instruction to stop the fuel supply to cylinder #5. The crank angle interval corresponding to the period from time T21 to time T22 is the stoppable angle interval regarding cylinder #5. Similarly, the crank angle interval corresponding to the period from time T24 to time T25 is the stoppable angle interval regarding cylinder #5. From time T22 to time T24 and from time T25 to time T26, the engine control unit 110 can only issue an instruction to stop the fuel supply to cylinder #2. The crank angle interval corresponding to the period from time T22 to time T24 is the stoppable angle interval regarding cylinder #2. Similarly, the crank angle interval corresponding to the period from time T25 to time T26 is the stoppable angle interval regarding cylinder #2. Thus, the stoppable angle interval is the interval from the timing 360 degrees before the arrival timing of the compression top dead center in terms of the crank angle to the arrival timing of the compression top dead center.

[0058] Here, assume a situation where a stop process is about to be started from a situation where port injection is being performed at a crank angle 540 degrees before the crank angle corresponding to top dead center compression in each of cylinders #1 to #6. The port injection can be performed through port injection valves 16R and 16L. In FIG. 7, the fuel injection start timing is indicated by a downward arrow.

[0059] When the engine control unit 110 of the engine 10 attempts to stop the fuel supply to cylinders #2 and #5, the stop process can be enabled by performing a retardation process as described below.

[0060] During times T21 to T23, the flag F is 0. Therefore, during times T21 to T23, the engine control unit 110 repeats the processes of S10, S12, S14, S16, and S18 in FIG. 6 in this order. That is, during times T21 to T23, the stop process of S26 is not executed.

[0061] At time T23, the flag F switches from "0" to "1". Specifically, the engine control unit 110 executes a retardation process in S20 of FIG. 6 and assigns "1" to the flag F. The retardation process is a process of retarding the fuel injection start timing, as indicated by the white arrow in FIG. 7. Regarding cylinder #5, the fuel injection start timing before retardation during times T22 to T25 is shown by a dashed line, and the fuel injection start timing after retardation during times T22 to T25 is shown by a solid line. Regarding cylinder #2, the fuel injection start timing before retardation during times T24 to T26 is shown by a dashed line, and the fuel injection start timing after retardation during times T24 to T26 is shown by a solid line. Regarding cylinder #5, the fuel injection start timing after retardation is within the period from time T24 to time T25. Regarding cylinder #2, the fuel injection start timing after retardation is within the period from time T25 to time T26. Thus, the retardation process is a process of retarding the fuel injection start timing so that the fuel injection start timing is included within the stoppable angle interval.

[0062] In this way, in the stoppable angular interval, there is a section before the fuel injection start timing. Specifically, in the period from time T24 to the fuel injection start timing of cylinder #5, the above-mentioned condition (D) is satisfied. Also, in the period from time T25 to the fuel injection start timing of cylinder #2, condition (D) is satisfied. Therefore, when all of the above-mentioned conditions (A) to (C) are satisfied, the engine control unit 110 can execute the stop process of S26.

[0063] At time T27, the flag F switches from "1" to "0". Specifically, the engine control unit 110 ends the reproduction process in S32 of FIG. 6 and assigns "0" to the flag F.

[0064] <Effects of the present embodiment> (1) During the combustion cycle, when the fuel injection start timing is before the stoppable angular interval, the stop instruction is not accepted. According to the above embodiment, the control device 500 executes a retardation process for retarding the fuel injection start timing so that the fuel injection start timing is included in the stoppable angular interval. For this reason, in the stoppable angular interval, there is a section before the fuel injection start timing. The stop instruction is accepted in this section. By accepting the stop instruction in this section, the fuel supply can be stopped in this section. That is, during the combustion cycle, compared with a configuration in which the fuel supply cannot be stopped because the fuel injection start timing arrives before the stoppable angular interval, by executing the retardation process, the fuel supply can be stopped.

[0065] (2) Port injection needs to be performed before the start of the compression stroke. On the other hand, in-cylinder injection can be performed after the start of the compression stroke. According to the above embodiment, the control device 500 can execute the retardation process by changing the fuel injection mode from the port injection mode to the in-cylinder injection mode. For this reason, the injection start timing can be significantly retarded compared to a configuration in which the injection start timing of port injection is retarded while maintaining the port injection mode. Therefore, the section in which the stop instruction is accepted can be increased.

[0066] (3) According to the above embodiment, the second motor generator 54 compensates for the decrease in the output torque of the engine 10 caused by the stop process. Therefore, fluctuations in the output torque of the vehicle can be suppressed.

[0067] (4) According to the above embodiment, by performing retardation processing on the six-cylinder engine 10, it becomes possible to stop the fuel supply to cylinders #2 and #5, which are two opposing cylinders.

[0068] <Modification Example> This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0069] · In the above embodiment, the case where cylinders #2 and #5 are the cylinders to be stopped has been described. For example, when ending the regeneration process in S32, cylinders #3 and #6 may be determined as the cylinders to be stopped in the next regeneration process. That is, the two cylinders to be stopped may be switched to another two cylinders to be stopped at an appropriate timing.

[0070] · In the above embodiment, the retardation process in S20 changes the fuel injection mode of all cylinders #1 - #6 from port injection to in - cylinder injection. However, this is merely an example. The engine control unit 110 may change only the fuel injection mode of cylinders #2 and #5, which are the cylinders to be stopped, to in - cylinder injection in the retardation process in S20. That is, the engine control unit 110 may execute the retardation process by changing the fuel injection mode in the cylinders to be stopped from the port injection mode to the in - cylinder injection mode.

[0071] · In the above-described embodiment, the stop process is a process of stopping the fuel supply to cylinders #2 and #5, which are the cylinders to be stopped, and supplying fuel to the remaining cylinders #1, #3, #4, and #6. However, this is merely an example. The stop process may be a process of stopping the fuel supply to two or more cylinders, which are the cylinders to be stopped, among the plurality of cylinders #1 to #6 and supplying fuel to the remaining one or more cylinders.

[0072] · In the above-described embodiment, the engine control unit 110 executes the retardation process by changing the fuel injection mode in the cylinder to be stopped from the port injection mode to the in-cylinder injection mode. The engine control unit 110 may execute the retardation process by retarding the injection start timing of the port injection in the cylinder to be stopped while maintaining the fuel injection mode in the cylinder to be stopped in the port injection mode. In a configuration in which the engine 10 includes the port injection valves 16R and 16L and the in-cylinder injection valves 22R and 22L, a section in which a stop instruction is received can be generated even while maintaining the port injection mode. The injection start timing in cylinders #1, #3, #4, and #6 other than the cylinders to be stopped may or may not be retarded.

[0073] · In the above-described embodiment, the engine 10 includes the port injection valves 16R and 16L and the in-cylinder injection valves 22R and 22L. However, this is merely an example. For example, a configuration in which the engine 10 includes the port injection valves 16R and 16L but does not include the in-cylinder injection valves 22R and 22L is also possible. The engine control unit 110 may execute the retardation process by retarding the injection start timing of the port injection in the cylinder to be stopped while maintaining the fuel injection mode in the cylinder to be stopped in the port injection mode. Thereby, a section in which a stop instruction is received can be generated.

[0074] ·The execution conditions for the regeneration process are not limited to those exemplified in the above embodiment. For example, regarding the three conditions of the above conditions (A) to (C), only two of them may be included in the execution conditions, or only one of them may be included in the execution conditions. Conditions (A) to (C) may be omitted. Condition (D) may be a condition that the current time is a predetermined time before the fuel injection start time in the combustion cycle of the selected cylinder targeted for the stop instruction. The predetermined time may be set, for example, in consideration of the communication delay related to the stop instruction.

[0075] ·The execution purpose of the stop process for oxygen supply is not limited to the regeneration process. For example, in the engine 10 that executes the stop process for warming up the three-way catalysts 32R and 32L, the retard angle process as in the above embodiment may be executed.

[0076] ·The estimation process for the deposition amount DPM is not limited to that exemplified in FIG. 6. For example, the deposition amount DPM may be estimated based on the pressure difference between the upstream side and the downstream side of the GPFs 34R and 34L and the intake air amount Ga. Specifically, when the pressure difference is large, the deposition amount DPM may be estimated to be a larger value than when it is small. Even when the pressure difference is the same, when the intake air amount Ga is small, the deposition amount DPM may be estimated to be a larger value than when it is large. Here, when the pressure on the downstream side of the GPFs 34R and 34L is regarded as a constant value, the above pressures PexR and PexL can be used instead of the differential pressure.

[0077] ·The layout of the three-way catalysts 32R and 32L and the GPFs 34R and 34L in the exhaust passages 30R and 30L may be a layout in which the GPFs 34R and 34L are provided upstream of the three-way catalysts 32R and 32L.

[0078] ·As GPF34R and 34L, it is not limited to a filter carrying a three-way catalyst, and it may be only a filter. Further, GPF34R and 34L are not limited to those provided downstream of the three-way catalysts 32R and 32L in the exhaust passages 30R and 30L. Further, it is not essential to include GPF34R and 34L. For example, even when the aftertreatment device consists only of the three-way catalysts 32R and 32L, as described above, a stop process may be executed to warm up the three-way catalysts 32R and 32L.

[0079] ·The MG2 torque compensation process of S28 may be omitted. ·The stop process of S26 may not include enrichment of the air-fuel ratio in cylinders other than the cylinders to be stopped. For example, in the case of the regeneration process of GPF34R and 34L, if the GPF temperature is high enough and oxygen is supplied so that particulate matter combustion occurs, combustion can be continued and regeneration can proceed without performing enrichment in the stop process.

[0080] · In the above embodiment, the control device 500 includes a CPU, a ROM, and a RAM, and executes software processing. However, this is merely an example. For example, the control device 500 may include a dedicated hardware circuit (such as an ASIC or the like) that processes at least a part of the software processing executed in the above embodiment. That is, the control device 500 may have any of the following configurations (a) to (c). (a) The control device 500 includes a processing device that executes all processing according to a program, and a program storage device such as a ROM that stores the program. That is, the control device 500 includes a software execution device. (b) The control device 500 includes a processing device that executes a part of the processing according to a program, and a program storage device. Further, the control device 500 includes a dedicated hardware circuit that executes the remaining processing. (c) The control device 500 includes a dedicated hardware circuit that executes all processing. Here, there may be a plurality of software execution devices and / or dedicated hardware circuits. That is, the above processing may be executed by a processing circuitry including at least one of a software execution device and a dedicated hardware circuit. There may be a plurality of software execution devices and dedicated hardware circuits included in the processing circuitry. The program storage device, that is, the computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer.

[0081] · In the above embodiment, the engine 10 includes six cylinders #1 to #6. However, this is merely an example. The number of cylinders included in the engine 10 can be appropriately changed. For example, the engine 10 may have eight cylinders. The engine 10 may be an in-line engine, a horizontally opposed engine, or a W-type engine.

[0082] · In the above embodiment, the vehicle includes a first motor generator 52 and a second motor generator 54. However, this is merely an example. For example, the vehicle may include only one motor generator.

[0083] ·The vehicle is not limited to a series-parallel hybrid vehicle, and may be, for example, a parallel hybrid vehicle or a series hybrid vehicle. Of course, it is not limited to hybrid vehicles, and may be, for example, a vehicle whose power generation device is only the engine 10.

Explanation of Signs

[0084] #1~#6…Cylinders 10…Internal combustion engine (engine) 12L, 12R…Intake ports 16L, 16R…Port injection valves 22L, 22R…In-cylinder injection valves 500…Control device

Claims

A control device for a vehicle equipped with an internal combustion engine having three or more cylinders, comprising: a processing circuit configured to execute a stop process of stopping fuel supply to two or more of the plurality of cylinders and supplying fuel to the remaining one or more cylinders; an operation from the start of an expansion stroke to the end of a compression stroke is a combustion cycle, and each of the plurality of cylinders is configured to repeatedly execute the combustion cycle so that a compression top dead center appears sequentially in the plurality of cylinders; the processing circuit is configured to execute a selection process of selecting one cylinder to be the target of a stop instruction for stopping fuel supply from among the cylinders to be stopped, each time a compression top dead center appears in any of the cylinders to be stopped, before the stop process; the selection process is a process of selecting the cylinder in which the compression top dead center appears earliest among the cylinders to be stopped at the time of execution of the selection process; a crank angle interval from when the cylinder to be the target of the stop instruction is selected until the cylinder to be the target of the stop instruction switches to the next cylinder among the cylinders to be stopped is a stoppable angle interval; the stop instruction for the selected cylinder is received during the combustion cycle, before the fuel injection start timing and within the stoppable angle interval; the processing circuit is configured to execute a retardation process of retarding the fuel injection start timing so that the fuel injection start timing is included in the stoppable angle interval. A control device for a vehicle.

2. The internal combustion engine includes a plurality of intake ports each connected to a corresponding one of the plurality of cylinders, a plurality of port injection valves each provided in a corresponding one of the plurality of intake ports, and a plurality of in-cylinder injection valves each provided in a corresponding one of the plurality of cylinders. Each of the plurality of port injection valves is configured to execute port injection of injecting fuel into a corresponding intake port among the plurality of intake ports, and each of the plurality of in-cylinder injection valves is configured to execute in-cylinder injection of injecting fuel into a corresponding cylinder among the plurality of cylinders. The processing circuit is configured to execute the retardation process by changing a fuel injection mode in the cylinder to be stopped from a port injection mode to an in-cylinder injection mode. The vehicle control device according to claim 1.

3. The internal combustion engine includes a plurality of intake ports each connected to a corresponding one of the plurality of cylinders, and a plurality of port injection valves respectively provided in the plurality of intake ports. Each of the plurality of port injection valves is configured to perform port injection for injecting fuel into a corresponding intake port among the plurality of intake ports. The processing circuit is configured to perform the retardation process by retarding an injection start timing of the port injection in the cylinder to be stopped. The vehicle control device according to claim 1.

4. The vehicle includes a motor generator, and the processing circuit is configured to control the internal combustion engine and the motor generator so that the internal combustion engine and the motor generator cooperate to generate an output torque required for the vehicle. The processing circuit is configured to perform a compensation process for compensating for a decrease in the output torque of the internal combustion engine caused by the stop process through the motor generator, together with the stop process. The vehicle control device according to any one of claims 1 to 3.

5. The number of the plurality of cylinders is six. The stop process is a process of stopping fuel supply to the cylinders to be stopped, which are two of the plurality of cylinders, and supplying fuel to the remaining four cylinders. The arrival timing of top dead center compression in one of the cylinders to be stopped is separated by 360 degrees in crank angle from the arrival timing of top dead center compression in the other of the cylinders to be stopped. The selection process is a process of alternately selecting, every 360 degrees in crank angle, one cylinder among the cylinders to be stopped that is the target of a stop instruction for stopping fuel supply. The retardation process is a process of retarding the fuel injection start timing so that the fuel injection start timing is included in the stoppable angle interval from a timing 360 degrees before the arrival timing of top dead center compression in crank angle to the arrival timing of top dead center compression. The vehicle control device according to any one of claims 1 to 3.

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