Hybrid vehicle control device

Abstract

To provide a control device of a hybrid vehicle which can predict a situation in which start-up of an engine by second start processing fails.SOLUTION: A control device of a hybrid vehicle executes engine start processing when an execution condition of start-up of an engine is satisfied. The engine start processing includes: first start processing (S14) for driving a motor generator so as to crank the engine; and second start processing (S20) to be executed when the first start processing fails. The second start processing includes driving of the motor generator so as to crank the engine after interrupting power supply to the motor generator. The control device executes count processing for counting the number of times when the first start processing fails and the second start processing is executed (S18). The control device prohibits idling stop of the engine even if the second start processing is successful (S26) when the number of times is a determination threshold or more (S28: YES).SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] Patent Document 1 discloses a control device for a hybrid vehicle having an engine and a motor generator connected to each other via a belt. If the control device determines that starting the engine by the motor generator has failed, the control device starts the engine by a starter.

[0003] The engine is started by the starter as follows: First, the pinion gear of the starter meshes with a drive plate attached to the crankshaft. Next, the starter is driven by power from the battery. This causes the crankshaft to rotate and start the engine. When the starter starts the engine, a large force is applied to the drive plate. For this reason, starting the engine by the starter is accompanied by a large noise.

[0004] In contrast, starting an engine with a motor generator is quieter than starting an engine with a starter, because driving an engine with a belt is quieter than driving an engine with gears.

[0005] The control device prohibits idling stop when starting of the engine by the starter, which is executed after starting of the engine by the motor generator, is successful. The control device does not prohibit idling stop as long as starting of the engine by the motor generator is successful. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-094827 A Summary of the Invention [Problem to be solved by the invention]

[0007] By prohibiting idling stop, the situation where the engine is started by the starter during a trip does not occur. This means that the situation where a loud noise is generated by starting the engine by the starter can be avoided. Note that a trip refers to the period from when the ignition switch is switched from off to on to when it is switched from on to off.

[0008] As described above, when it is determined that starting the engine by the motor generator has failed, the control device starts the engine by the starter. The control device has room for improvement in terms of reducing noise caused by the starter during a trip. [Means for solving the problem]

[0009] The means for solving the above problems and their effects will be described below. According to one aspect of the present disclosure, there is provided a control device for a hybrid vehicle including an engine and a motor generator connected to each other via a belt, a battery configured to supply power to the motor generator, and a starter configured to start the engine, the control device including a processing circuit, the processing circuit configured to execute an engine start process when an execution condition for starting the engine is satisfied, the engine start process including a first start process for supplying power from the battery to the motor generator to drive the motor generator in order to crank the engine, and a second start process executed when the first start process fails, the second start process including supplying power from the battery to the motor generator to drive the motor generator, and then increasing the power supply from the battery to the motor generator to crank the engine, to drive the motor generator; the processing circuit is configured to execute a counting process to count the number of times the first start-up process has failed and the second start-up process has been executed; if the number of times is equal to or greater than a determination threshold, the processing circuit is configured to prohibit idling stop of the engine even if the second start-up process is successful; and if the second start-up process has failed, the processing circuit is configured to start the engine by the starter and prohibit idling stop of the engine.

[0010] Normally, it is considered that the first start process will succeed in starting the engine. If the number of times the second start process has been executed is equal to or greater than the determination threshold, it is considered that there is an increased possibility that starting the engine by the motor generator will fail. According to the above configuration, even if the second start process, which is starting the engine by the motor generator, is successful, idling stop is prohibited if the number of times the second start process has been executed is equal to or greater than the determination threshold. Therefore, it is possible to predict a situation in which starting the engine by the second start process will fail and to prohibit idling stop before the second start process fails. If idling stop can be prohibited before the second start process fails, starting the engine by the starter can be avoided.

[0011] Therefore, with the above configuration, it becomes easier to avoid a situation in which loud noise is generated when the starter starts the engine during a trip. The processing circuit may be configured to determine that the first start-up process has failed when a transition condition is met that is a logical OR condition between an engine rotation speed, which is the rotation speed of the engine, becoming less than 0 during the first start-up process and the engine rotation speed being maintained at 0 for a predetermined period of time or more.

[0012] The processing circuit may be configured to execute a trip reset process for resetting the number of times when an ignition switch of the hybrid vehicle is turned off.

[0013] The judgment threshold may be an integer greater than or equal to 2, and the processing circuit may be configured to execute a first start-up reset process that resets the number of times based on the success of the first start-up process.

[0014] The decision threshold may be two. If the judgment threshold is too large, there is a high possibility that the second start process will fail. This means that there is a higher possibility of start-up by the starter occurring. In terms of suppressing start-up by the starter occurring, it is better for the judgment threshold to be small. In the above configuration, the judgment threshold is 2. Therefore, compared to a configuration in which the judgment threshold is 3 or more, it is easier to suppress start-up by the starter occurring.

[0015] The decision threshold may be one. If the judgment threshold is too large, the second start process is more likely to fail. This means that the possibility of start-up by the starter increases. In terms of suppressing start-up by the starter, it is better to have a small judgment threshold. In the above configuration, the judgment threshold is 1. Therefore, start-up by the starter can be suppressed to the greatest extent possible. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing a control device according to an embodiment and a hybrid vehicle that is an object of control by the control device; [Diagram 2] FIG. 2 is a diagram showing a combustion cycle. [Diagram 3] 4 is a schematic diagram showing the behavior of a plurality of cylinders in a first starting process and a second starting process. FIG. [Figure 4] 10A to 10C are diagrams illustrating the movement of the piston ring that occurs after the start of the second starting process. [Diagram 5] 2 is a flowchart of a process executed by the control device of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, a control device 34 which is a control device for a hybrid vehicle according to one embodiment will be described with reference to the drawings. <Configuration of Hybrid Vehicle 100> 1 shows a hybrid vehicle (hereinafter, vehicle) 100 that is an object to be controlled by a control device 34 according to one embodiment. The control device 34 is mounted on the vehicle 100. The vehicle 100 includes an internal combustion engine (hereinafter, engine) 10 and a motor generator 12. An air conditioning compressor (hereinafter, AC compressor) 14 is mounted on the vehicle 100. The engine 10 has a crank pulley 10a. The motor generator 12 has a motor generator pulley 12a. The AC compressor 14 has an AC compressor pulley 14a. The crank pulley 10a, the motor generator pulley 12a, and the AC compressor pulley 14a are connected to each other via a belt 16.

[0018] In this manner, in the vehicle 100, the engine 10 and the motor generator 12 are connected to each other via the belt 16. The control device 34 controls the vehicle 100. Furthermore, the vehicle 100 includes a transmission 18, a starter 20, a DC-DC converter 22, an auxiliary device 24, a high-voltage battery 26, and a low-voltage battery 28. The high-voltage battery 26 is, for example, a Li-ion battery. The low-voltage battery 28 is, for example, a lead battery. The transmission 18 is connected to the engine 10. The starter 20 is connected to the transmission 18. The starter 20 can drive the transmission 18. The engine 10 can be started by driving the transmission 18 with the starter 20. The high-voltage battery 26 is connected to the motor generator 12 and the DC-DC converter 22. The motor generator 12 can start the engine 10 by receiving power from the high-voltage battery 26. The low-voltage battery 28 is connected to the starter 20, the DC-DC converter 22, and the auxiliary device 24.

[0019] The engine 10 has four cylinders #1, #2, #3, and #4. When an intake valve 40 of each of the cylinders #1 to #4 is open, the intake air flows into a combustion chamber 38. Fuel is injected into the combustion chamber 38 by a fuel injection valve 44. In the combustion chamber 38, the mixture of air and fuel is burned by a spark discharge by an ignition device 46. Energy generated by the combustion is extracted as rotational energy of a crankshaft of the engine 10. The crankshaft of the engine 10 is connected to a transmission 18. The mixture subjected to the combustion is exhausted from the combustion chamber 38 when an exhaust valve 42 is open.

[0020] The control device 34 includes a so-called microcomputer having a CPU, ROM, RAM, an input / output interface, etc. The control device 34 performs signal processing according to a program pre-stored in the ROM while utilizing the temporary storage function of the RAM. The control device 34 is capable of controlling the engine 10, the motor generator 12, etc.

[0021] An engine rotation speed sensor 30 is provided in the engine 10. The control device 34 can obtain the engine rotation speed, which is the rotation speed of the engine 10, through the engine rotation speed sensor 30. A motor generator rotation speed sensor 32 is provided in the motor generator 12. The control device 34 can obtain the rotation speed of the motor generator 12 through the motor generator rotation speed sensor 32. The control device 34 can obtain, from an ignition switch 36, a signal indicating whether the ignition switch 36 is on or off.

[0022] <Factors Contributing to Successful Starting of Engine 10 by Motor Generator 12> Assume that the motor generator 12 starts the engine 10 from a state in which the engine rotation speed is zero.

[0023] As shown in FIG. 2, cylinder #1 is in the expansion stroke when the crank angle is between 0 and 180 degrees. Cylinder #1 is in the exhaust stroke when the crank angle is between 180 and 360 degrees. Cylinder #1 is in the intake stroke when the crank angle is between 360 and 540 degrees. Cylinder #1 is in the compression stroke when the crank angle is between 540 and 720 degrees.

[0024] As shown in FIG. 2, cylinder #2 is in the exhaust stroke when the crank angle is between 0 and 180 degrees. Cylinder #2 is in the intake stroke when the crank angle is between 180 and 360 degrees. Cylinder #2 is in the compression stroke when the crank angle is between 360 and 540 degrees. Cylinder #2 is in the expansion stroke when the crank angle is between 540 and 720 degrees.

[0025] As shown in FIG. 2, cylinder #3 is in the compression stroke when the crank angle is between 0 and 180 degrees. Cylinder #3 is in the expansion stroke when the crank angle is between 180 and 360 degrees. Cylinder #3 is in the exhaust stroke when the crank angle is between 360 and 540 degrees. Cylinder #3 is in the intake stroke when the crank angle is between 540 and 720 degrees.

[0026] As shown in FIG. 2, cylinder #4 is in the intake stroke when the crank angle is between 0 and 180 degrees. Cylinder #4 is in the compression stroke when the crank angle is between 180 and 360 degrees. Cylinder #4 is in the expansion stroke when the crank angle is between 360 and 540 degrees. Cylinder #4 is in the exhaust stroke when the crank angle is between 540 and 720 degrees.

[0027] In this way, at any crank angle, one of the four cylinders #1 to #4 is in the compression stroke, and another of the four cylinders #1 to #4 is in the expansion stroke. In the cylinder in the compression stroke or the expansion stroke, the intake valve 40 and the exhaust valve 42 are closed. Therefore, when the motor generator 12 starts the engine 10, the piston 50 in the cylinder in the compression stroke or the expansion stroke is difficult to move. That is, a load is applied to the motor generator 12. For example, when the motor generator 12 starts to drive the engine 10 from a crank angle of 0 degrees, a load is applied to the motor generator 12 due to the cylinders #1 and #3. For example, when the motor generator 12 starts to drive the engine 10 before the crank angle of 180 degrees, a load is applied to the motor generator 12 due to the cylinders #3 and #4 after the crank angle has passed 180 degrees.

[0028] If the motor-generator 12 can overcome the loads imposed on the cylinders in the compression stroke and the expansion stroke, the engine 10 will start successfully. <Outline of the first start-up process and the second start-up process> FIG. 3 shows a case where the motor generator 12 successfully starts the engine 10 through the first and second starting processes.

[0029] 3A shows a state where the crank angle is 45 degrees. At the crank angle of 45 degrees, cylinder #1 is in the expansion stroke and cylinder #3 is in the compression stroke. From the state where the crank angle is 45 degrees, the motor generator 12 starts to drive the engine 10.

[0030] 3(b) shows a state where the crank angle is 160 degrees. It is assumed that the engine speed becomes less than 0 at the crank angle of 160 degrees due to compressed air in cylinder #3. In response to the engine speed becoming less than 0, the control device 34 interrupts the supply of electric power from the high-voltage battery 26 to the motor generator 12.

[0031] In response to the control device 34 interrupting the supply of power to the motor generator 12, the crankshaft begins to rotate in the reverse direction. Eventually, the engine speed becomes 0, as shown in Fig. 3(c). Fig. 3(c) shows a state where the crank angle is 75 degrees.

[0032] Next, the control device 34 starts to drive the motor generator 12 by starting the supply of electric power to the motor generator 12. As shown in (d) of Figure 3, a state in which the crank angle is 180 degrees is achieved. In this case, the motor generator 12 succeeds in starting the engine 10.

[0033] The process from when the motor generator 12 starts driving the engine 10 from a crank angle of 45 degrees to when the engine speed becomes less than 0 corresponds to the first start process. The process after the engine speed becomes less than 0 corresponds to the second start process.

[0034] The reason why the engine 10 may be successfully started through the first and second starting processes will be described with reference to FIG. 4 shows a piston 50 in cylinder #3 during the compression stroke. A ring groove 52 is formed on the outer circumferential surface of the piston 50. A piston ring 54 is fitted in the ring groove 52.

[0035] From the time when the motor generator 12 starts to drive the engine 10 to the time when the engine rotation speed becomes zero, the lower part of the piston ring 54 is in close contact with the piston 50. At this time, the piston 50 is driven upward in FIG. 4 by the driving force of the motor generator 12. The air pressure in the cylinder #3 acts on the piston ring 54. Therefore, a force is acting on the piston ring 54 to push the piston ring 54 downward in FIG. 4. This causes the lower part of the piston ring 54 to be in close contact with the piston 50. In particular, as shown in FIG. 4(a), the lower part of the piston ring 54 is in close contact with the piston 50 at the time when the engine rotation speed becomes zero.

[0036] When the engine speed becomes less than 0 due to the repulsive force of the compressed air in cylinder #3, the second starting process is initiated. This causes the power supply to the motor generator 12 to be temporarily interrupted. When the power supply to the motor generator 12 is thus stopped, the force acting on the piston 50 to drive the piston 50 upward is eliminated. The piston 50 is then pushed down by the repulsive force of the compressed air.

[0037] As shown in Fig. 4(b) , immediately after the crankshaft starts to rotate in the reverse direction, when the force driving the piston 50 upward disappears and the piston 50 is pushed down as described above, the lower part of the piston ring 54 moves away from the piston 50. When the lower part of the piston ring 54 moves away from the piston 50, compressed air flows out of the combustion chamber 38 through the gap between the inner peripheral surface of the piston ring 54 and the ring groove 52. Eventually, as shown in Fig. 4(c) , the lower part of the piston ring 54 comes into close contact with the piston 50 again, and the outflow of compressed air from the combustion chamber 38 stops.

[0038] In the second start-up procedure, the amount of compressed air in cylinder #3 is smaller than in the first start-up procedure, which makes it easier for the motor-generator 12 to overcome the loads generated in the cylinders in the compression stroke and the expansion stroke.

[0039] <Flowchart of processing executed by the control device 34> The process executed by the control device 34 will be described with reference to Fig. 5. The control device 34 executes the engine start process shown in Fig. 5 when the execution conditions for starting the engine 10 are satisfied.

[0040] In step S10, the control device 34 determines whether or not to start the engine 10 for the first time during a trip. If the control device 34 makes an affirmative determination in step S10 (step S10: YES), the process proceeds to step S12. In step S12, the control device 34 sets the number of times Cnt to 0. The number of times Cnt will be described later. After executing the process of step S12, the control device 34 proceeds to step S14. If the control device 34 makes a negative determination in step S10 (step S10: NO), the process proceeds to step S14.

[0041] In step S14, the control device 34 executes a first start process. The first start process is a process in which power is supplied from the high-voltage battery 26 to the motor generator 12 to crank the engine 10, thereby driving the motor generator 12. If a transition condition is satisfied, the control device 34 determines that the first start process has failed. The transition condition is a logical OR condition between the engine speed, which is the rotation speed of the engine 10, becoming less than 0 in the first start process and the engine speed being maintained at 0 for a predetermined period or more. If the engine speed becomes equal to or greater than an engine speed threshold during execution of the first start process, the control device 34 determines that the engine 10 has been successfully started by the first start process. The engine speed threshold is set as a threshold for determining whether the engine 10 has been successfully started by the motor generator 12. If the control device 34 determines that the first start process has been successful or unsuccessful, it ends the first start process and proceeds to step S16.

[0042] If the first start-up process has failed (step S16: YES), the control device 34 proceeds to step S18. In step S18, the control device 34 counts up the number of times Cnt. That is, the control device 34 executes a count process to count the number of times Cnt that the first start-up process has failed and the second start-up process has been executed.

[0043] After executing step S18, the control device 34 proceeds to step S20. In step S20, the control device 34 executes a second start process. The second start process includes supplying power from the high-voltage battery 26 to the motor generator 12 to drive the motor generator 12 in order to crank the engine 10, after interrupting the supply of power from the high-voltage battery 26 to the motor generator 12. According to steps S16 and S20, the engine start process includes a second start process that is executed when the first start process fails.

[0044] If the second start process has failed (step S22: YES), the control device 34 proceeds to step S24. If a logical OR condition is established between the engine speed becoming less than 0 in the second start process and the engine speed being maintained at 0 for a predetermined period or more, the control device 34 determines that the second start process has failed. The control device 34 executes a starter start process in step S24. The starter start process is a process for starting the engine 10 by the starter 20. After executing step S24, the control device 34 proceeds to step S26. The control device 34 prohibits idling stop in step S26. Thus, according to steps S22, S24, and S26, if the second start process has failed, the control device 34 starts the engine 10 by the starter 20 and prohibits idling stop of the engine 10.

[0045] If the second start process is successful (step S22: NO), the control device 34 proceeds to step S28. If the engine speed becomes equal to or greater than the engine speed threshold during execution of the second start process, the control device 34 determines that the start of the engine 10 is successful by the second start process. In step S28, the control device 34 determines whether the number of times Cnt is equal to or greater than the judgment threshold CntTh. The judgment threshold CntTh is set as a threshold for predicting a situation in which the start of the engine 10 by the second start process fails. In this embodiment, the judgment threshold CntTh is 2. If the control device 34 makes an affirmative judgment in step S28 (step S28: YES), the control device 34 proceeds to step S26. The control device 34 prohibits idling stop in step S26. Thus, according to steps S22, S26, and S28, if the number of times Cnt is equal to or greater than the judgment threshold CntTh, the control device 34 prohibits idling stop of the engine 10 even if the second start process is successful. When the determination in step S28 is negative (step S28: NO), the control device 34 ends this flow.

[0046] If the first start process is successful (step S16: NO), the control device 34 proceeds to step S30. In step S30, the control device 34 sets the number of times Cnt to 0. That is, the control device 34 executes a first start reset process that resets the number of times Cnt based on the success of the first start process. After executing step S30, the control device 34 ends this flow.

[0047] <Action of this embodiment> When the execution conditions for starting the engine 10 are satisfied for the first time after the ignition switch 36 is turned on, the first start process is executed (step S14). It is assumed that the first start process is successful. After that, when the idling stop conditions are satisfied, the operation of the engine 10 is stopped.

[0048] Thereafter, if the execution conditions for starting the engine 10 are satisfied in the idling stop state, the first start process is executed (step S14). It is assumed that the first start process fails this time. In this case, the second start process is executed (step S20). It is assumed that the second start process is successful. Thereafter, if the idling stop conditions are satisfied, the operation of the engine 10 is stopped.

[0049] Thereafter, if the execution conditions for starting the engine 10 are satisfied in the idling stop state, the first start process is executed (step S14). Assume that the current first start process has failed. In this case, the second start process is executed (step S20). Assume that the second start process has been successful. This means that the second start process has been executed twice. According to steps S26 and S28, the control device 34 prohibits idling stop of the engine 10, even though the second start process has been successful.

[0050] Since idling stop is prohibited, the operation of the engine 10 will not be stopped during this trip unless the ignition switch 36 is turned off. This means that, during this trip, the engine start process will not be executed after idling stop is prohibited.

[0051] <Effects of this embodiment> (1) Normally, it is considered that the first start process will succeed in starting the engine 10. If the number of times Cnt the second start process is executed is equal to or greater than the judgment threshold CntTh, it is considered that the possibility of failure in starting the engine 10 by the motor generator 12 is increased. According to the above embodiment, even if the second start process, which is the start of the engine 10 by the motor generator 12, is successful, if the number of times Cnt the second start process is executed is equal to or greater than the judgment threshold CntTh, idling stop is prohibited. For this reason, it is possible to predict a situation in which starting the engine 10 by the second start process will fail, and to prohibit idling stop before the second start process fails. If idling stop can be prohibited before the second start process fails, starting the engine 10 by the starter 20 can be avoided.

[0052] Therefore, according to the above embodiment, it becomes easier to avoid a situation in which a large amount of noise is generated when the engine 10 is started by the starter 20 during a trip. (2) If the determination threshold CntTh is too large, the second start process is more likely to fail. This means that the possibility of start-up by the starter 20 occurring increases. In terms of suppressing start-up by the starter 20 occurring, it is better for the determination threshold CntTh to be small. In the above embodiment, the determination threshold CntTh is 2. For this reason, it is easier to suppress start-up by the starter 20 occurring compared to a configuration in which the determination threshold CntTh is 3 or more.

[0053] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0054] The configuration of the vehicle 100 can be changed as appropriate. In the above embodiment, the number of cylinders is four. However, this is merely an example. The number of cylinders can be changed as appropriate, and may be, for example, six.

[0055] In the above embodiment, there is no clutch that can connect or disconnect the engine 10 and the crank pulley 10a. However, a clutch may be provided between the engine 10 and the crank pulley 10a.

[0056] In the above embodiment, the second start process includes supplying power from the high-voltage battery 26 to the motor generator 12 to drive the motor generator 12 after interrupting the supply of power from the high-voltage battery 26 to the motor generator 12. This is an example of the second start process including reducing the supply of power from the high-voltage battery 26 to the motor generator 12 and then increasing the supply of power from the high-voltage battery 26 to the motor generator 12 to drive the motor generator 12. In other words, the second start process is not limited to a mode in which the supply of power is prohibited and then resumed, but may be a mode in which the supply of power is reduced and then increased. This is for the following reason. As described above with reference to Figures 2 to 4, in the second start process, the amount of compressed air in the cylinder in the compression stroke is reduced, making it easier to successfully start the engine 10. This can be achieved by reducing the amount of compressed air by reversing the crankshaft after the transition condition is established. Therefore, it is not necessary to interrupt the supply of power from the high-voltage battery 26 to the motor generator 12 immediately after the start of the second start process. It is only necessary to reduce the supply of electric power from the high voltage battery 26 to the motor generator 12 immediately after the start of the second starting process so that the crankshaft can be rotated in the reverse direction.

[0057] In the above embodiment, the high voltage battery 26 and the low voltage battery 28 are mounted on the vehicle 100. However, this is merely an example. It is sufficient that the vehicle 100 is mounted with a battery capable of supplying power to the motor generator 12.

[0058] The mode of the combustion cycle can be changed as appropriate. In the above embodiment, the mixture is ignited in the order of cylinder #1, cylinder #3, cylinder #4, and cylinder #2. The mixture may be ignited in the order of cylinder #1, cylinder #2, cylinder #4, and cylinder #3.

[0059] In the above embodiment, the transition condition is a logical OR condition between the engine speed becoming less than 0 and the engine speed being maintained at 0 for a predetermined period or more. Alternatively, the transition condition may be a condition that the engine speed becomes less than 0. In other words, the determination of whether the engine speed is maintained at 0 for a predetermined period or more may be omitted. The transition condition may be a condition that the engine speed is less than the engine speed threshold value after a threshold period from the start of the first start process.

[0060] In the above embodiment, step S30 is executed. That is, the number Cnt of times the second start-up process is executed, which is compared with the judgment threshold value CntTh, is the number Cnt of times the second start-up process is executed consecutively. In other words, the number Cnt of times the second start-up process is executed is reset when the first start-up process is successful. However, this is merely an example. Step S30 may be omitted. That is, the number Cnt of times the second start-up process is executed may be the number Cnt of times the second start-up process is executed discontinuously.

[0061] In the above embodiment, steps S10 and S12 are executed. That is, the control device 34 sets the number of times Cnt to 0 when the engine 10 is started for the first time in a trip. Alternatively, the control device 34 may reset the number of times Cnt to 0 when the trip ends. In this manner, the control device 34 may execute a trip reset process to reset the number of times Cnt when the ignition switch 36 of the vehicle 100 is turned off.

[0062] In the above embodiment, step S10 is executed. That is, the number of times Cnt the second start-up process is executed is the number of times Cnt the second start-up process is executed in one trip. However, this is merely an example. For example, the number of times Cnt the second start-up process is executed may be the number of times Cnt the second start-up process is executed over multiple trips.

[0063] In the above embodiment, the determination threshold CntTh is 2. However, this is merely an example. The determination threshold CntTh may be an integer equal to or greater than 2. In the above embodiment, the judgment threshold CntTh is 2. Alternatively, the judgment threshold CntTh may be 1. If the judgment threshold CntTh is too large, the second start process is more likely to fail. This means that the possibility of starting by the starter 20 occurring increases. In order to suppress the occurrence of starting by the starter 20, it is better for the judgment threshold CntTh to be small. By setting the judgment threshold CntTh to 1, the occurrence of starting by the starter 20 can be suppressed to the greatest extent possible.

[0064] Step S28 may be omitted in a modification in which the determination threshold CntTh is set to 1. If the control device 34 makes a negative determination in step S22, the process may proceed to step S26.

[0065] In the above embodiment, the control device 34 includes a CPU, a ROM, and a RAM, and executes software processing. However, this is merely an example. For example, the control device 34 may include a dedicated hardware circuit (e.g., ASIC, etc.) that processes at least a part of the software processing executed in the above embodiment. That is, the control device 34 may have any of the following configurations (a) to (c). (a) The control device 34 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 34 includes a software execution device. (b) The control device 34 includes a processing device that executes a part of the processing according to a program, and a program storage device. Furthermore, the control device 34 includes a dedicated hardware circuit that executes the remaining processing. (c) The control device 34 includes a dedicated hardware circuit that executes all processing. Here, the software execution device and / or the dedicated hardware circuit may be multiple. That is, the above processing may be executed by a processing circuitry that includes at least one of a software execution device and a dedicated hardware circuit. The software execution device and the dedicated hardware circuit included in the processing circuit may be multiple. Program storage devices or computer-readable media include any available media that can be accessed by a general purpose or special purpose computer. [Explanation of symbols]

[0066] Cnt: Number of times CntTh: Judgment threshold 10…Internal combustion engine 12...Motor generator 16...Belt 20…Starter 34...Control device 36…Ignition switch 100…Hybrid vehicle (vehicle)

Claims

1. A control device for a hybrid vehicle including an engine and a motor generator connected to each other via a belt, a battery configured to supply power to the motor generator, and a starter configured to start the engine, A processing circuit is provided, The processing circuit is configured to execute an engine start process when an execution condition for starting the engine is satisfied; The engine start process includes: a first starting process of supplying electric power from the battery to the motor generator to crank the engine, thereby driving the motor generator; A second start-up process is executed when the first start-up process fails, the second starting process includes reducing a supply of electric power from the battery to the motor generator and then increasing the supply of electric power from the battery to the motor generator to crank the engine, thereby driving the motor generator; The processing circuit is configured to execute a counting process of counting the number of times the first start-up process has failed and the second start-up process has been executed; The processing circuit is configured to prohibit idling stop of the engine even if the second start process is successful when the number of times is equal to or greater than a determination threshold value, The processing circuit is configured to start the engine by the starter and prohibit idling stop of the engine when the second starting process fails. A control device for a hybrid vehicle.

2. The processing circuit is configured to determine that the first starting process has failed when a transition condition is satisfied, the transition condition being a logical OR condition of an engine rotation speed, which is a rotation speed of the engine, becoming less than 0 in the first starting process and the engine rotation speed being maintained at 0 for a predetermined period or more. The control device for a hybrid vehicle according to claim 1.

3. The processing circuit is configured to execute a trip reset process for resetting the number of times when an ignition switch of the hybrid vehicle is turned off. The control device for a hybrid vehicle according to claim 1 or 2.

4. The judgment threshold is an integer equal to or greater than 2, The processing circuit is configured to execute a first start-up reset process to reset the number of times based on the success of the first start-up process. The control device for a hybrid vehicle according to claim 1 or 2.

5. The decision threshold is 2. The control device for a hybrid vehicle according to claim 1 or 2.

6. The judgment threshold is 1. The control device for a hybrid vehicle according to claim 1 or 2.

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