CN112172834A

CN112172834A - Control device for hybrid vehicle

Info

Publication number: CN112172834A
Application number: CN202010540220.9A
Authority: CN
Inventors: 安藤大吾; 小林幸男; 浅见良和; 绳田英和
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2019-06-18
Filing date: 2020-06-15
Publication date: 2021-01-05
Anticipated expiration: 2040-06-15
Also published as: CN112172834B; JP7147694B2; JP2020203606A

Abstract

The control device for a hybrid vehicle includes an engine control unit and a system control unit, wherein the engine control unit includes a diagnosis unit that executes a diagnosis process, and the system control unit includes a stop prohibition unit that executes an intermittent stop prohibition process. The diagnostic unit stores the temporary determination flag in the nonvolatile memory when it is determined that there is an abnormality by the diagnostic processing. On the other hand, the diagnosis unit diagnoses the presence of an abnormality when it is determined that there is an abnormality by the diagnosis process in a state where the temporary determination flag is stored in the nonvolatile memory, and clears the temporary determination flag from the nonvolatile memory. The stop prohibition unit executes the intermittent stop prohibition process when the temporary determination flag is stored in the nonvolatile memory.

Description

Control device for hybrid vehicle

Technical Field

The present invention relates to a control device for a hybrid vehicle.

Background

Japanese patent laid-open No. 2006-266193 discloses a hybrid vehicle provided with an engine and a motor. The hybrid vehicle is capable of stopping the engine and running the vehicle by the motor, and executes intermittent stop control for automatically stopping and restarting the engine.

Disclosure of Invention

When the engine is stopped by the intermittent stop control, it is not possible to diagnose whether or not an abnormality that cannot be detected unless the engine is operating has occurred.

The technical means for solving the above problems and the operational effects thereof are described below. A control device for a hybrid vehicle for solving the above-described problems is applied to a hybrid vehicle including an engine and a motor as a driving force source, and executes intermittent stop control for automatically stopping and restarting an operation of the engine, and includes: a diagnostic unit that executes a diagnostic process for confirming whether or not there is an abnormality in the engine while the engine is operating; and a stop prohibition portion that executes an intermittent stop prohibition process that prohibits stopping of the operation of the engine by the intermittent stop control. In the control device, the diagnosis unit may store the temporary determination flag in the nonvolatile memory when it is determined that there is an abnormality by the diagnosis process in a state where the temporary determination flag is not stored in the nonvolatile memory, and may diagnose that there is an abnormality and clear the temporary determination flag, which is information indicating that there is a possibility of an abnormality, from the nonvolatile memory when it is determined that there is an abnormality by the diagnosis process in a state where the temporary determination flag is stored in the nonvolatile memory. In the control device, the stop prohibition unit may execute the intermittent stop prohibition processing when the temporary determination flag is stored in the nonvolatile memory.

According to the above configuration, the temporary determination flag can be stored in the nonvolatile memory that can be kept even when the power supply is stopped after the system main switch is turned off. Therefore, even if the system main switch of the hybrid vehicle is turned off before the diagnosis of the abnormality is made, the system main switch of the hybrid vehicle can be recognized as being in the middle of the diagnosis based ON the temporary determination flag stored in the nonvolatile memory when the system main switch of the hybrid vehicle is turned ON (ON) next time.

When the temporary determination flag is stored, the stop prohibition unit prohibits stopping the operation of the engine by the intermittent stop control. Therefore, even when the system main switch is turned off during the diagnosis, when the system main switch is turned on next time, the operation of the engine is immediately prohibited from being stopped by the intermittent stop control when the engine operation is started, and the operation of the engine is continued. Therefore, the opportunity to execute the diagnostic process is increased and the diagnosis can be completed quickly as compared with the case where the stop of the operation of the engine by the intermittent stop control is not prohibited.

In one aspect of the control device for a hybrid vehicle, the stop prohibition unit may set a period in which a system main switch of the vehicle is on as one stroke, and when the stroke in which the stop of the engine by the intermittent stop control is prohibited due to the temporary determination flag being stored continues for a predetermined number of times, cancel the prohibition of the stop of the engine due to the temporary determination flag being stored.

When stopping of the operation of the engine by the intermittent stop control is prohibited, the operation of the engine continues, and therefore, the amount of fuel consumption increases. That is, the effect of suppressing the fuel consumption amount that should be obtained by the intermittent stop control may not be obtained. In contrast, according to the above configuration, it is possible to suppress the continuation of the stroke in which the engine stop is prohibited due to the temporary determination flag being stored more than the predetermined number of times. Therefore, it is possible to suppress an excessive increase in the fuel consumption amount by securing the balance between the opportunity of executing the diagnosis and the suppression of the fuel consumption amount.

Drawings

Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and wherein:

fig. 1 is a schematic diagram showing a relationship between a control device and a hybrid vehicle.

Fig. 2 is a schematic diagram showing the configuration of an engine in the hybrid vehicle.

Fig. 3 is a schematic diagram showing the relationship between the engine control unit and the oil pump.

Fig. 4 is a schematic diagram of an engine control unit and a circulation system of cooling water in the engine.

FIG. 5 is a schematic diagram showing the relationship of the crank position sensor and the sensor plate.

Fig. 6 is a timing chart showing a waveform of a crank angle signal output from the crank position sensor.

Fig. 7 is a schematic diagram showing the relationship between the intake-side cam position sensor and the timing rotor.

Fig. 8 is a timing chart showing a waveform of an intake side cam angle signal output from the intake side cam position sensor.

Fig. 9 is a timing chart showing the relationship among the crank angle signal, the cam angle signal, and the crank count.

Fig. 10 is a flowchart showing a flow of processing in the provisional determination routine.

Fig. 11 is a flowchart showing a flow of processing in the truth determination routine.

Fig. 12 is a flowchart showing a flow of the intermittent stop prohibition processing accompanying the diagnosis processing.

Fig. 13 is a flowchart showing a flow of a process of canceling the intermittent stop prohibition associated with the diagnosis process.

Fig. 14 is a flowchart showing a flow of processing for calculating the vehicle speed threshold value.

Fig. 15 is a flowchart showing a flow of the intermittent stop prohibition process based on the vehicle speed.

Fig. 16 is a flowchart showing a flow of processing executed at the time of start-up in a state where the cam position sensor has failed.

Fig. 17 is a flowchart showing a flow of processing executed during operation in a state where the cam position sensor is malfunctioning.

Fig. 18 is a schematic diagram showing a relationship between a control device and a single-motor hybrid vehicle as a modified example.

Fig. 19 is a flowchart showing a flow of processing executed by the control device of the operation period modification example in a state where the cam position sensor has failed.

Detailed Description

An embodiment of a control device for a hybrid vehicle will be described below with reference to fig. 1 to 17. As shown in fig. 1, the hybrid vehicle 10 includes an engine 50. The hybrid vehicle 10 is provided with a battery 30 that stores electric power. Further, the hybrid vehicle 10 includes a 1 st motor generator 11 and a 2 nd motor generator 12. These 1 st motor generator 11 and 2 nd motor generator 12 are motors that generate driving force in accordance with the power supplied from the battery 30, and also function as generators that receive external power and generate electric power charged in the battery 30.

Further, the hybrid vehicle 10 is provided with a planetary gear mechanism 13 having three rotating elements, i.e., a sun gear 14, a carrier 15, and a ring gear 16. A crankshaft 59 as an output shaft of the engine 50 is connected to the carrier 15 of the planetary gear mechanism 13, and the 1 st motor generator 11 is connected to the sun gear 14 of the planetary gear mechanism 13. Further, a counter drive gear (counter drive gear)17 is integrally provided with the ring gear 16 of the planetary gear mechanism 13. A counter drive gear (counter drive gear)18 is engaged with the counter drive gear 17. The 2 nd motor generator 12 is coupled to a reduction gear 19 that meshes with the counter driven gear 18.

A final drive gear (final drive gear)20 is connected to the counter driven gear 18 so as to be integrally rotatable. A final driven gear (final drive gear 2)21 is engaged with the final drive gear 20. A drive shaft 24 of a wheel 23 is coupled to the final driven gear 21 via a differential mechanism 22.

Control device 400 that controls hybrid vehicle 10 is configured from system control unit 100, power control unit 200, and engine control unit 300.

The 1 st motor generator 11 and the 2 nd motor generator 12 are connected to the battery 30 via a power control unit 200 connected to the system control unit 100. The power control unit 200 includes a control unit, an inverter, and a converter, and adjusts the amount of power supplied from the battery 30 to the 1 st motor generator 11 and the 2 nd motor generator 12 and the amount of charge from the 1 st motor generator 11 and the 2 nd motor generator 12 to the battery 30 based on a command from the system control unit 100. The hybrid vehicle 10 is provided with a connector 31 that can be connected to an external power source 40. Therefore, the battery 30 can also be charged with the electric power supplied from the external power supply 40. That is, the hybrid vehicle 10 is a plug-in hybrid vehicle.

An engine control unit 300 that controls engine 50 is also connected to system control unit 100. The engine control unit 300 controls the engine 50 based on an instruction from the system control unit 100.

As shown in fig. 2, engine 50 includes an intake passage 51 through which intake air introduced into combustion chamber 55 flows, and an exhaust passage 60 through which exhaust gas discharged from combustion chamber 55 flows. The engine 50 is provided with a fuel injection valve 54 that injects fuel supplied from a fuel tank 70, and an ignition plug 58 that ignites an air-fuel mixture of the fuel and air injected from the fuel injection valve 54 by spark discharge.

An air cleaner 52, an airflow meter 88, a throttle valve 53, an intake pressure sensor 89, and a fuel injection valve 54 are provided in this order from the upstream side in the intake passage 51. The air cleaner 52 collects dust and the like in the atmosphere sucked into the intake passage 51. The airflow meter 88 detects the intake air amount as the amount of intake air. The throttle valve 53 is driven by a motor as an electric actuator. In the engine 50, the intake air amount is adjusted by increasing or decreasing the area of the flow path through which intake air flows by changing the opening degree of the throttle valve 53. The intake pressure sensor 89 detects the intake pressure, which is the pressure in the portion of the intake passage 51 on the downstream side of the throttle valve 53. The fuel injection valve 54 injects fuel into intake air to form an air-fuel mixture that is burned in the combustion chamber 55.

A fuel pump 71 is disposed in the fuel tank 70. The fuel pump 71 is driven by a motor. The fuel pumped up by the fuel pump 71 is supplied to the fuel injection valve 54 through a fuel supply passage 73 by a filter 72. A fuel pressure sensor 87 that detects the pressure of the fuel is provided in the fuel supply passage 73.

A return passage 75 for returning the fuel pumped up by the fuel pump 71 to the fuel tank 70 is branched from a portion of the fuel supply passage 73 in the fuel tank 70 on the downstream side of the filter 72. An electric relief valve (relief valve)74 is provided midway in the return passage 75. The electric relief valve 74 is opened and closed by an electric actuator. When the electric relief valve 74 is opened, the fuel in the fuel supply passage 73 is discharged into the fuel tank 70 through the return passage 75.

As shown in fig. 2, a spark plug 58 for igniting the air-fuel mixture by an electric spark is provided in the combustion chamber 55. Further, an igniter 57 is provided at the ignition plug 58. The igniter 57 generates the high voltage required to form the spark.

An air-fuel ratio sensor 83, a 1 st three-way catalyst 61, an oxygen sensor 84, and a 2 nd three-way catalyst 62 are provided in the exhaust passage 60 in this order from the upstream side. The air-fuel ratio sensor 83 detects the oxygen concentration of the exhaust gas discharged from the combustion chamber 55 and the air-fuel ratio of the air-fuel mixture burned in the combustion chamber 55. The 1 st three-way catalyst 61 and the 2 nd three-way catalyst 62 purify exhaust gas. The oxygen sensor 84 outputs a signal corresponding to the oxygen concentration of the exhaust gas after passing through the 1 st three-way catalyst 61.

The engine 50 is provided with an intake-side valve timing changing mechanism 56 that changes the opening/closing timing of the intake valve 66, and an exhaust-side valve timing changing mechanism 56 that changes the opening/closing timing of the exhaust valve 67, and the intake valve 66 and the exhaust valve 67 close the intake passage 51 and the combustion chamber 55 and the exhaust passage 60 and the combustion chamber, respectively. Any of the valve timing changing mechanisms 56 is driven by an electric motor, and changes the rotational phase of the camshaft 91 corresponding to the rotational phase of the crankshaft 59.

The engine 50 is also provided with an exhaust gas recirculation system that recirculates a part of the exhaust gas flowing through the exhaust passage 60 to the intake air flowing through the intake passage 51. The exhaust gas recirculation system has an EGR passage 64 connecting the exhaust passage 60 and the intake passage 51. The EGR passage 64 connects a portion of the exhaust passage 60 on the downstream side of the 1 st three-way catalyst 61 to a portion of the intake passage 51 on the downstream side of the throttle valve 53. An EGR cooler 63 that cools the gas recirculated from the exhaust passage 60 to the intake passage 51, and an EGR valve 65 that adjusts the amount of the recirculated gas are arranged in the EGR passage 64. Further, the EGR valve 65 is driven by an electric motor.

As shown in fig. 3, engine 50 is provided with an oil pump 170 that circulates oil (oil) through various portions of engine 50. Further, the oil pump 170 is driven by the power of the crankshaft 59.

The oil pump 170 is a variable-capacity type oil pump capable of changing a discharge amount per one rotation. In the oil pump 170, the discharge amount per one rotation changes according to the control oil pressure controlled by the oil control valve 171. The engine control unit 300 controls the discharge amount of the oil discharged from the oil pump 170 by controlling the oil control valve 171, and controls the oil pressure of the oil circulating through each part of the engine 50.

The oil pump 170 pumps up the oil accumulated in the oil pan 173 via the filter 174. The pumped oil is supplied to each part of the engine 50 through the oil supply passage 175. An oil return passage 176 branches from the oil supply passage 175 midway. The oil return passage 176 is connected to the oil control valve 171. The oil return passage 176 returns a part of the oil discharged from the oil pump 170 to the oil control valve 171.

A discharge passage 178 and a discharge passage 179 connected to the oil pan 173 are connected to the oil control valve 171, and the discharge passage 178 is connected to a control oil chamber that functions as a control oil pressure for changing the discharge amount of the oil pump 170. The oil control valve 171 drives a built-in spool valve (spool valve) by an electric actuator, and supplies oil that has flowed back through the oil return passage 176 to the control oil chamber of the oil pump 170, thereby increasing the control oil pressure in the control oil chamber. Further, the oil control valve 171 drives the spool valve, and discharges the oil in the control oil chamber to the oil pan 173 through the discharge passage 179, thereby reducing the control oil pressure in the control oil chamber. The oil control valve 171 may also close the discharge passage 178 and the discharge passage 179 by a spool valve, and maintain the control oil pressure in the control oil chamber.

The engine control unit 300 controls the oil control valve 171 based on the rotation speed of the crankshaft 59, which has a correlation with the rotation speed of the oil pump 170, and the value of the oil pressure detected by the oil pressure sensor 93, and performs feedback control of the oil pressure of the oil supplied to each part of the engine 50. When the required oil pressure is low, the amount of oil discharged per rotation is reduced, and energy consumption associated with driving the oil pump 170 is suppressed. The required oil pressure is calculated by the engine control unit 300 based on the operating state of the engine 50, the operating conditions of the respective devices that are required for oil, and the like.

As shown in fig. 4, the engine 50 is provided with a water pump 180, and a heat radiation circuit including a radiator 181 is provided with a cooling system for circulating cooling water.

Water pump 180 is provided in the middle of introduction passage 184, and introduction passage 184 introduces the cooling water into the water jacket in engine 50. The cooling water discharged from water pump 180 is discharged to discharge passage 185 through the water jacket in engine 50. The discharge passage 185 is connected to an inlet of the radiator 181. An outlet of the radiator 181 is connected to a suction passage 186 connected to a thermostat (thermo stat) 183.

A fan 182 is provided in the radiator 181, and air drawn by the fan 182 passes through the radiator 181, thereby promoting heat exchange between the cooling water flowing in the radiator 181 and the air. Thus, the heat of the cooling water is radiated by passing through the radiator 181, and the temperature of the cooling water is lowered.

The cooling water having passed through the radiator 181 flows into the introduction passage 184 through the suction passage 186 and the thermostat 183(thermo stat), and is sucked into the water pump 180. A bypass passage 187 branched from the discharge passage 185 is also connected to the thermostat 183. The thermostat 183 operates in accordance with the temperature of the cooling water introduced through the bypass passage 187.

Specifically, when the temperature of the cooling water introduced through the bypass passage 187, that is, the temperature of the cooling water discharged from the water jacket of the engine 50 is lower than the warm-up determination temperature, the thermostat 183 closes the portion connected to the intake passage 186, and causes the bypass passage 187 to communicate with the introduction passage 184. The warm-up determination temperature is a temperature at which it can be determined that warm-up of the engine 50 is completed when the temperature of the cooling water is equal to or higher than the warm-up determination temperature, and is, for example, a value of about 80 ℃.

When the portion of the thermostat 183 to which the intake passage 186 is connected is thus closed, the flow of the cooling water through the radiator 181 does not occur. As a result, the entire amount of the cooling water discharged through the discharge passage 185 flows into the introduction passage 184 through the bypass passage 187 and the thermostat 183, and is introduced into the water jacket of the engine 50 again. This can suppress heat dissipation from the cooling water, and can promote warm-up of the engine 50.

On the other hand, when the temperature of the cooling water introduced through the bypass passage 187 is equal to or higher than the warm-up determination temperature, the thermostat 183 opens the portion connected to the intake passage 186, and causes the intake passage 186 to communicate with the introduction passage 184. When the portion connected to the suction passage 186 is thus opened, the flow of the cooling water through the radiator 181 occurs. As a result, the cooling water discharged through the discharge passage 185 passes through the radiator 181, flows into the introduction passage 184 through the intake passage 186 and the thermostat 183, and is introduced into the water jacket of the engine 50 again. Thereby, the heat of the cooling water is released in the radiator 181, and the cooling water having a lowered temperature is introduced into the water jacket. Therefore, overheating of the engine 50 can be suppressed.

As shown in fig. 4, a water temperature sensor 81 is provided near the outlet of the water jacket to detect the temperature of the cooling water heated through the water jacket. For such an engine 50. Is controlled by the engine control unit 300 according to an instruction from the system control unit 100. Detection signals of various sensors that detect the operating state of engine 50 are input to engine control unit 300. The sensors that input detection signals to the engine control unit 300 also include an air flow meter 88, an intake pressure sensor 89, an air-fuel ratio sensor 83, an oxygen sensor 84, and a fuel pressure sensor 87. In addition, the engine 50 is provided with a crank position sensor 150 that detects the rotation angle of the crankshaft 59, a water temperature sensor 81 that detects the temperature of the cooling water of the engine 50, and an exhaust gas temperature sensor 82 that detects the temperature of the exhaust gas that flows through the exhaust passage 60 and is introduced into the 1 st three-way catalyst 61. Engine 50 is further provided with a knock sensor 90 for detecting occurrence of knocking and a hydraulic pressure sensor 93 for detecting hydraulic pressure. Further, the crank position sensor 150 outputs a crank angle signal corresponding to a change in the rotational phase of the crankshaft 59.

The engine 50 is further provided with two cam position sensors 160, i.e., an intake cam position sensor 160 that detects the rotational phase of the intake camshaft 91 that opens and closes the intake valve 66 and an exhaust cam position sensor 160 that detects the rotational phase of the exhaust camshaft 91 that opens and closes the exhaust valve 67. The cam position sensor 160 outputs a cam angle signal corresponding to a change in the rotational phase of the camshaft 91 of the engine 50.

Detection signals of these sensors are input to the engine control unit 300. The engine control unit 300 calculates the engine speed, which is the rotational speed of the crankshaft 59, based on the detection signal of the rotational angle of the crankshaft 59 input from the crankshaft position sensor 150.

As shown in fig. 1, an accelerator position sensor 85 that detects the amount of operation of an accelerator and a vehicle speed sensor 86 that detects the vehicle speed are connected to the system control unit 100. Then, a detection signal of the accelerator position sensor 85 and a detection signal of the vehicle speed sensor 86 are input to the system control unit 100. The system control unit 100 is also connected to a system main switch 120.

In addition, the current, voltage, and temperature of battery 30 are input to power control unit 200. Based on these current, voltage, and temperature, power control section 200 calculates a state of charge index value SOC, which is the ratio of the remaining charge amount of battery 30 to the charge capacity.

The engine control unit 300 and the power control unit 200 are connected to the system control unit 100, respectively. System control unit 100, power control unit 200, and engine control unit 300 exchange and share information based on the detection signal input from the sensor and/or calculated information with each other.

Based on these pieces of information, system control unit 100 outputs a command to engine control unit 300, and engine control unit 300 controls engine 50. Based on these pieces of information, system control section 100 outputs a command to power control section 200, and power control section 200 controls 1 st motor generator 11 and 2 nd motor generator 12 and controls charging of battery 30. In this way, system control unit 100 outputs commands to power control unit 200 and engine control unit 300 to control hybrid vehicle 10.

Next, the control of hybrid vehicle 10 by control device 400 including system control unit 100, power control unit 200, and engine control unit 300 will be described in detail.

The system control unit 100 calculates a required output, which is a required value of the output of the hybrid vehicle 10, based on the accelerator operation amount and the vehicle speed. The system control unit 100 determines the torque distribution of the engine 50, the 1 st motor generator 11, and the 2 nd motor generator 12 based on the required output and/or the state of charge index value SOC of the battery 30, and the like, and controls the output of the engine 50 and the traction (power running)/regeneration of the 1 st motor generator 11 and the 2 nd motor generator 12. Further, system control unit 100 switches the running mode of hybrid vehicle 10 according to the magnitude of the state of charge index value SOC.

When state of charge index value SOC exceeds a certain level and the remaining charge amount of battery 30 has a sufficient margin, system control section 100 selects an EV running mode which is a mode in which: the engine 50 is not operated, and running is performed by the driving force generated by the 2 nd motor generator 12 and/or the driving force generated by the 1 st motor generator 11.

On the other hand, when the state of charge index value SOC is equal to or lower than a certain level, system control unit 100 selects an HV traveling mode that is a mode in which: the 1 st motor generator 11 and the 2 nd motor generator 12 travel using the engine 50.

Even when the state of charge index value SOC exceeds a certain level, system control unit 100 selects the HV travel mode as follows.

When the vehicle speed exceeds the upper limit vehicle speed of the EV running mode.

A time of sudden acceleration requiring a large instantaneous output, such as a time of rapid acceleration when the accelerator operation amount is large.

When the engine 50 needs to be started. When the HV running mode is selected, the system control unit 100 causes the 1 st motor generator 11 to function as a starter motor when starting the engine 50. Specifically, the system control unit 100 starts the engine 50 by rotating the crankshaft 59 by rotating the sun gear 14 by the 1 st motor generator 11.

When the HV travel mode is selected, system control section 100 switches the control during parking according to the magnitude of the state of charge index value SOC. Specifically, when the state of charge index value SOC is equal to or greater than the threshold value, system control unit 100 stops the operation of engine 50 and does not drive 1 st motor generator 11 and 2 nd motor generator 12. That is, system control unit 100 stops the operation of engine 50 at the time of parking to suppress the idling operation. When the state of charge index value SOC of the battery 30 is smaller than the threshold value, the system control unit 100 operates the engine 50, drives the 1 st motor generator 11 by the output of the engine 50, and causes the 1 st motor generator 11 to function as a generator.

When the HV travel mode is selected, system control section 100 also switches control according to the state of charge index value SOC during travel. When the state of charge index value SOC of the battery 30 is equal to or greater than the threshold value at the time of start and light load running, the system control unit 100 starts and runs the hybrid vehicle 10 using only the driving force of the 2 nd motor generator 12. In this case, the engine 50 is stopped, and the 1 st motor generator 11 also generates electric power. On the other hand, when the state of charge index value SOC of the battery 30 is smaller than the threshold value at the time of start and light load running, the system control unit 100 starts the engine 50, generates power by the 1 st motor generator 11, and charges the generated power to the battery 30. At this time, the hybrid vehicle 10 travels using a part of the driving force of the engine 50 and the driving force of the 2 nd motor generator 12. In steady state running, when the state of charge index value SOC of battery 30 is equal to or greater than the threshold value, system control unit 100 operates engine 50 in a state of high operating efficiency, and causes hybrid vehicle 10 to run mainly with the output of engine 50. At this time, the power of the engine 50 is split between the wheel 23 side and the 1 st motor generator 11 side via the planetary gear mechanism 13. Thus, the hybrid vehicle 10 travels while generating electric power by the 1 st motor generator 11. The system control unit 100 drives the 2 nd motor generator 12 with the generated electric power, and assists the power of the engine 50 with the power of the 2 nd motor generator 12. On the other hand, when the state of charge index value SOC of the battery 30 is smaller than the threshold value during steady-state running, the system control unit 100 increases the engine speed, uses the electric power generated by the 1 st motor generator 11 for driving the 2 nd motor generator 12, and charges the battery 30 with the surplus electric power. At the time of acceleration, system control unit 100 increases the engine speed, uses the electric power generated by 1 st motor generator 11 for driving 2 nd motor generator 12, and accelerates hybrid vehicle 10 using the power of engine 50 and the power of 2 nd motor generator 12. Then, the system control unit 100 stops the operation of the engine 50 at the time of deceleration. The system control unit 100 causes the 2 nd motor generator 12 to function as a generator, and charges the battery 30 with the electric power generated. The hybrid vehicle 10 utilizes the resistance generated by such power generation as a brake. Such power generation control during deceleration is referred to as regeneration control.

As described above, system control unit 100 stops engine 50 when the EV running mode is selected, and stops engine 50 depending on the situation even when the HV running mode is selected. That is, the system control unit 100 executes intermittent stop control for automatically stopping and restarting the engine 50 according to the situation.

As shown in fig. 2, the engine control unit 300 includes a count calculation unit 302, and the count calculation unit 302 calculates a crank count indicating a crank angle as a rotation phase of the crankshaft 59. The count calculation unit 302 calculates a crank count based on the crank angle signal, the intake side cam angle signal, and the exhaust side cam angle signal. The engine control unit 300 controls the timing of fuel injection and ignition for each cylinder with reference to the crank count calculated by the count calculation unit 302, and controls the valve timing changing mechanism 56.

Specifically, the engine control unit 300 calculates a target fuel injection amount, which is a control target value for the fuel injection amount, based on the accelerator operation amount, the vehicle speed, the intake air amount, the engine speed, the engine load factor, and the like. Further, the engine load factor is a ratio of an intake air amount per one combustion cycle of one cylinder with respect to a reference intake air amount. Here, the reference intake air amount is an intake air amount per one combustion cycle of one cylinder when the opening degree of the throttle valve 53 is maximized, and is determined according to the engine speed. The ecu 300 calculates a target fuel injection amount so that the air-fuel ratio becomes substantially the stoichiometric air-fuel ratio. Then, control target values regarding the fuel injection timing and the fuel injection time are calculated. The fuel injection valve 54 is driven to open in accordance with these control target values. Thereby, fuel of an amount commensurate with the operating state of the engine 50 is injected and supplied to the combustion chamber 55.

The engine control unit 300 calculates an ignition timing at which spark discharge is performed by the ignition plug 58, operates the igniter 57, and ignites the air-fuel mixture. The engine control unit 300 calculates a target value of the phase of the camshaft 91 on the intake side with respect to the crankshaft 59 and a target value of the phase of the camshaft 91 on the exhaust side with respect to the crankshaft 59 based on the engine speed and the engine load factor, and operates the intake-side valve timing changing mechanism 56 and the exhaust-side valve timing changing mechanism 56. Thus, the ecu 300 controls the opening/closing timing of the intake valve 66 and the opening/closing timing of the exhaust valve 67. For example, the engine control unit 300 controls the valve overlap, which is a period during which both the exhaust valve 67 and the intake valve 66 are opened.

Next, the crank position sensor 150 and the cam position sensor 160 will be described in detail, and a method of calculating the crank count will be described. First, the crank position sensor 150 will be described with reference to fig. 5 and 6. Fig. 5 shows the relationship between the crank position sensor 150 and a sensor plate 151 attached to the crankshaft 59. The timing chart of fig. 6 shows the waveform of the crank angle signal output from the crank position sensor 150.

As shown in fig. 5, a disk-shaped sensor plate 151 is attached to the crankshaft 59. At the peripheral edge of the sensor plate 151, 34 signal teeth 152 having a width of 5 ° are arranged at an angular interval of 5 °. Therefore, as shown in the right side of fig. 5, the sensor plate 151 is formed with a single-part missing tooth portion 153, and the missing tooth portion 153 makes the interval between the adjacent signal teeth 152 25 ° in terms of angle, and lacks two signal teeth 152 compared with the other portions.

As shown in fig. 5, the crank position sensor 150 is disposed toward the peripheral edge portion of the sensor plate 151 so as to face the signal teeth 152 of the sensor plate 151. The crank position sensor 150 is a magnetoresistive element type sensor including a sensor circuit in which a magnet and a magnetoresistive element are incorporated. When the sensor plate 151 rotates with the rotation of the crankshaft 59, the signal teeth 152 of the sensor plate 151 and the crank position sensor 150 approach and separate from each other. As a result, the direction of the magnetic field of the magnetoresistive element in crank position sensor 150 changes, and the internal resistance of the magnetoresistive element changes. The sensor circuit compares the magnitude relationship between a waveform obtained by converting the change in the resistance value into a voltage and a threshold value, shapes the waveform into a rectangular wave based on a Lo signal (low level signal) as a 1 st signal and a Hi signal (high level signal) as a 2 nd signal, and outputs the rectangular wave as a crank angle signal.

Specifically, as shown in fig. 6, crank position sensor 150 outputs a Lo signal when facing signal teeth 152, and outputs a Hi signal when facing the gap between signal teeth 152. Therefore, when the Hi signal corresponding to the toothless portion 153 is detected, the Lo signal corresponding to the signal tooth 152 is detected thereafter. Then, the Lo signal corresponding to the signal tooth 152 is detected every 10 ° CA from then on. When 34 Lo signals are detected in this way, the Hi signal corresponding to the tooth-missing portion 153 is detected again. Therefore, the rotation angle until the Lo signal corresponding to the next signal tooth 152 of the Hi signal corresponding to the missing tooth portion 153 is detected is 30 ° CA as the crank angle.

As shown in fig. 6, the interval from the detection of the Lo signal corresponding to the signal tooth 152 following the Hi signal corresponding to the tooth-missing portion 153 to the detection of the Lo signal following the Hi signal corresponding to the tooth-missing portion 153 becomes 360 ° CA as the crank angle.

The count calculation unit 302 calculates a crank count by counting edges of the Lo signal that change from the Hi signal. Further, based on the Hi signal corresponding to the tooth-missing portion 153, which is detected to have a longer interval than the other Hi signals, it is detected that the rotational phase of the crankshaft 59 is the rotational phase corresponding to the tooth-missing portion 153.

Next, the cam position sensor 160 will be described with reference to fig. 7. Note that, each of the intake-side cam position sensor 160 and the exhaust-side cam position sensor 160 is a magnetoresistive element type sensor similar to the crank position sensor 150. The intake side cam position sensor 160 and the exhaust side cam position sensor 160 are different only in the detected object, and therefore, the intake side cam angle signal detected by the intake side cam position sensor 160 will be described in detail here.

Fig. 7 shows the relationship between the intake cam position sensor 160 and the timing rotor 161 attached to the intake camshaft 91, and the timing chart of fig. 8 shows the waveform of the intake cam angle signal output from the intake cam position sensor 160.

As shown in fig. 7, the timing rotor 161 is provided with a large protrusion 162, a middle protrusion 163, and a small protrusion 164, which are 3 protrusions having different sizes in the circumferential direction.

The largest large protrusion 162 is formed to spread over 90 ° as an angle in the circumferential direction of the timing rotor 161. On the other hand, the smallest small projection 164 is formed to extend over 30 ° as an angle, and the middle projection 163 smaller than the large projection 162 and larger than the small projection 164 is formed to extend over 60 °.

As shown in fig. 7, in the timing rotor 161, the large projection 162, the middle projection 163, and the small projection 164 are arranged at predetermined intervals. Specifically, the large protrusion 162 and the middle protrusion 163 are disposed at an angular interval of 60 °, and the middle protrusion 163 and the small protrusion 164 are disposed at an angular interval of 90 °. The large protrusions 162 and the small protrusions 164 are arranged at an angular interval of 30 °.

As shown in fig. 7, the cam position sensor 160 is disposed toward the peripheral edge portion of the timing rotor 161 so as to face the large projection 162, the middle projection 163, and the small projection 164 as the timing rotor 161 rotates. Cam position sensor 160 outputs a Lo signal and a Hi signal in the same manner as crank position sensor 150.

Specifically, as shown in fig. 8, the cam position sensor 160 outputs a Lo signal when facing the large projection 162, the middle projection 163, and the small projection 164, and outputs a Hi signal when facing the gap portion between the respective projections. The camshaft 91 makes one revolution during two revolutions of the crankshaft 59. Therefore, the changes in the intake side cam angle signal and the exhaust side cam angle signal are repeated as crank angles at a cycle of 720 ° CA.

As shown in fig. 8, after the Lo signal continuing through 180 ° CA corresponding to large protrusion 162 is output, the Hi signal continuing through 60 ° CA is output, and then the Lo signal continuing through 60 ° CA corresponding to small protrusion 164 is output. Then, after that, the Hi signal continuing through 180 ° CA is output, and then the Lo signal continuing through 120 ° CA corresponding to the middle protrusion 163 is output. Then, after the Hi signal continuing through 120 ° CA is finally output, the Lo signal continuing through 180 ° CA corresponding to the large projection 162 is output again.

Since the intake side cam angle signal changes periodically in a constant change pattern in this way, the engine control unit 300 can detect which rotational phase the camshaft 91 is in by recognizing the change pattern of the cam angle signal. For example, when the Lo signal having a length equivalent to 60 ° CA is output and then the Hi signal is switched, the ecu 300 can detect that the rotation phase of the small projection 164 just before the cam position sensor 160 has passed based on the Lo signal.

In the engine 50, a timing rotor 161 having the same shape is also mounted on the camshaft 91 on the exhaust side. Therefore, the exhaust side cam angle signal detected by the exhaust side cam position sensor 160 also changes periodically in the same change pattern as the intake side cam angle signal shown in fig. 8. Therefore, the engine control unit 300 can detect which rotational phase the exhaust camshaft 91 is located in by recognizing the change pattern of the exhaust cam angle signal output from the exhaust cam position sensor 160.

The timing rotor 161 attached to the exhaust camshaft 91 is attached to the timing rotor 161 attached to the intake camshaft 91 with a phase shift. Specifically, the timing rotor 161 attached to the exhaust camshaft 91 is attached to the intake camshaft 91 with a phase shifted by 30 ° to the advance side from the timing rotor 161 attached to the exhaust camshaft 91.

Thus, as shown in fig. 9, the change pattern of the intake side cam angle signal changes with a delay of 60 ° CA in the crank angle with respect to the change pattern of the exhaust side cam angle signal.

FIG. 9 is a timing diagram showing the relationship between the crank angle signal and the crank count, and the relationship between the crank count and the cam angle signal. In fig. 9, only the edge of the change from the Hi signal to the Lo signal is shown with respect to the crank angle signal.

As described above, count calculation unit 302 of engine control unit 300 counts the edges when the crank angle signal output from crank position sensor 150 changes from the Hi signal to the Lo signal with the operation of engine 50, and calculates the crank count. Further, the count calculation unit 302 performs cylinder determination based on the crank angle signal, the intake side cam angle signal, and the exhaust side cam angle signal.

Specifically, the count calculation unit 302 counts the edges of the crank angle signal output every 10 ° CA as shown in fig. 9, and increments the crank count (count up) every time 3 edges are counted. That is, the count calculation unit 302 increments the crank count, which is the value of the crank count, at every 30 ° CA. Then, engine control unit 300 identifies the current crank angle based on the crank count, and controls the timing of fuel injection and ignition for each cylinder.

The crank count is periodically reset every 720 ° CA. That is, as shown in the center of fig. 9, after "23" corresponding to 690 ° CA is added, at the next increasing timing, the crank count is reset to "0", and from there, the crank count is increased again every 30 ° CA.

When the toothless portion 153 passes in front of the crank position sensor 150, the interval between the detected edges is 30 ° CA. Then, when the interval between the edges is widened, the count calculation unit 302 detects that the tooth-missing portion 153 has passed before the crank position sensor 150 based on the widened interval. Since the missing tooth detection is performed every 360 ° CA, the missing tooth detection is performed 2 times while the crankshaft count is increased by 720 ° CA by 1 cycle.

Further, since the crankshaft 59, the intake-side camshaft 91, and the exhaust-side camshaft 91 are coupled to each other via a timing chain, there is a constant correlation between a change in the crank count and a change in the cam angle signal.

That is, the intake-side camshaft 91 and the exhaust-side camshaft 91 make one rotation while the crankshaft 59 makes two rotations. Therefore, if the crank count is known, the rotational phase of the intake-side camshaft 91 and the exhaust-side camshaft 91 at that time can be estimated. Conversely, if the rotational phases of the intake-side camshaft 91 and the exhaust-side camshaft 91 are known, the crank count can be estimated.

The count calculation unit 302 determines the crank angle that becomes the starting point when the calculation of the crank count is started, and determines the crank count, using the relationship between the intake side cam angle signal and the exhaust side cam angle signal and the crank count, and the relationship between the missing tooth detection and the crank count.

Then, the count calculation unit 302 extracts the crank angle and the value of the crank count as the starting point, and starts incrementing the crank angle using the extracted value of the crank count as the starting point. That is, the crank count is not output unless the crank angle is known or the value of the crank count that becomes the starting point is known. After the value of the crank count that becomes the starting point is found, the crank count starts to be increased and output, starting from the found value of the crank count.

When the intake-side valve timing changing mechanism 56 changes the relative phase of the intake-side camshaft 91 with respect to the crankshaft 59, the relative phase of the sensor plate 151 attached to the crankshaft 59 and the timing rotor 161 attached to the intake-side camshaft 91 also changes. Therefore, the engine control unit 300 grasps the amount of change in the relative phase from the displacement angle, which is the operation amount of the intake-side valve timing changing mechanism 56, and determines the crank count as the starting point in consideration of the influence of the change in the relative phase. The same applies to the change of the relative phase of the exhaust camshaft 91 by the exhaust valve timing changing mechanism 56.

In the engine 50, as shown in fig. 9, the crank angle when the Lo signal that continues from the intake-side cam angle signal over 180 ° CA is switched to the Hi signal that continues over 60 ° CA is set to "0 ° CA". Therefore, as shown by the broken line in fig. 9, the missing tooth detection performed immediately after the Hi signal continuing from the intake cam angle signal over 60 ° CA is switched to the Lo signal is a detection indicating that the crank angle is 90 ° CA. On the other hand, the missing tooth detection performed immediately after the Lo signal continuing from the intake cam angle signal over 120 ° CA is switched to the Hi signal is a detection indicating that the crank angle is 450 ° CA. In this way, engine control unit 300 determines the crank angle, determines the crank count that becomes the starting point, and starts calculation of the crank count when missing tooth portion 153 is detected, using the relationship between detection of missing tooth portion 153 and transition of the intake cam angle signal.

In fig. 9, the value of the crank count is shown below a solid line indicating the transition of the value of the crank count, and the crank angle corresponding to the value of the crank count is shown on the solid line. Fig. 9 shows a state in which both the displacement angle of the intake-side valve timing changing mechanism 56 and the displacement angle of the exhaust-side valve timing changing mechanism 56 are "0".

Control device 400 executes a diagnostic process for confirming the presence or absence of an abnormality in various devices provided in engine 50. Therefore, as shown in fig. 2 to 4, the control device 400 includes a diagnostic unit 301 for executing a diagnostic process in the engine control unit 300.

For example, the diagnosis unit 301 determines that an abnormality has occurred in the fuel system such as the fuel injection valve 54 based on a large deviation between the value detected by the air-fuel ratio sensor 83 and the target value. The diagnosis unit 301 determines that an abnormality has occurred in the air-fuel ratio sensor 83 based on a case where a state in which the learning value learned by the learning process described later coincides with the upper limit value continues and a case where a state in which the learning value coincides with the lower limit value continues.

The diagnostic unit 301 drives the EGR valve 65 to open and close during a fuel cut operation such as deceleration. It is determined that an abnormality has occurred in the EGR valve 65 based on the fact that the pressure detected by the intake pressure sensor 89 does not change with the opening/closing drive.

The diagnostic process performed by the diagnostic unit 301 includes, for example, the following processes.

The diagnosis unit 301 checks whether or not the relationship between the cam angle signal and the crank angle signal changes by an amount appropriate for the driving amount when the valve timing changing mechanism 56 is driven, and determines that an abnormality has occurred in the valve timing changing mechanism 56 based on the fact that the relationship does not change by an amount appropriate for the driving amount.

The diagnosis unit 301 determines that an abnormality has occurred in the oil pump 170 based on a case where there is a large deviation from the required oil pressure detected by the oil pressure sensor 93.

The diagnosis unit 301 determines that an imbalance, which is an abnormality in which the combustion among the cylinders is largely uneven, has occurred based on the variation in the engine speed. Specifically, the diagnosis unit 301 executes a diagnosis process for determining the imbalance on the condition that the warm-up is completed. In this diagnostic process, the diagnostic unit 301 obtains the angular velocity of the crankshaft 59 when the ignition is performed. For example, the diagnostic unit 301 obtains T30, T30 being the time required for the crank angle to change by 30 ° CA as the angular velocity. The diagnosis unit 301 determines that an imbalance has occurred based on the fact that the deviation from the angular velocity obtained when ignition is performed in another cylinder is equal to or greater than the threshold value. Further, the imbalance includes a rich imbalance in which the air-fuel ratio becomes rich and the angular velocity becomes large as compared with the other cylinders, and a lean imbalance in which the air-fuel ratio becomes lean and the angular velocity becomes small as compared with the other cylinders. Further, when the engine control unit 300 executes the imbalance diagnosis process, the ignition timing is retarded and the intake air amount is increased in order to secure the S/N ratio which is the ratio of the signal to the noise.

The diagnosis unit 301 determines that misfire, which is an abnormality of misfiring in the cylinder, has occurred. Specifically, the diagnostic unit 301 executes a diagnostic process for determining misfire on the condition that the engine speed is within a range suitable for diagnosis and the engine load is low. In this diagnostic process, the diagnostic unit 301 obtains the angular velocity of the crankshaft 59 when the ignition is performed. For example, the diagnostic unit 301 obtains T30, T30 being the time required for the crank angle to change by 30 ° CA as the angular velocity. The diagnostic unit 301 determines that misfire occurred based on the fact that the deviation from the angular velocity obtained when the previous ignition was performed in the same cylinder is equal to or greater than the threshold value.

The engine control unit 300 performs the ISC control of feedback-controlling the engine speed to the target idle speed during the idle operation of the engine 50. The target idle rotation speed is corrected at the time of start, corrected for an external load according to an external load of an auxiliary machine such as an air conditioner mounted on the hybrid vehicle 10 and the 1 st and 2 nd motor generators 11 and 12, and corrected for a water temperature according to a temperature of the cooling water. As will be described later in detail, when the state in which the feedback correction amount is large in the ISC control continues, the learning process of converting the feedback correction amount into the learning value is performed. The diagnosis unit 301 determines that an abnormality has occurred in the ISC control based on a case where a state in which the learning value matches the upper limit value continues and a case where a state in which the learning value matches the lower limit value continues.

The diagnosis unit 301 determines that an abnormality has occurred in the thermostat 183 based on the fact that the temperature of the cooling water detected by the water temperature sensor 81 is equal to or higher than the abnormality determination temperature higher than the warm-up determination temperature.

The diagnosis unit 301 opens and closes the throttle valve 53 to check whether or not the intake air amount detected by the airflow meter 88 has varied when the operating state of the engine 50 is stable, such as during steady-state operation. The diagnosis unit 301 determines that an abnormality has occurred in the airflow meter 88 based on the fact that the intake air amount detected by the airflow meter 88 does not vary.

Further, with these diagnostic processes, when the engine 50 is not operating, it is not possible to determine whether there is an abnormality. Then, as shown in fig. 1, in the control device 400, the system control unit 100 is provided with a stop prohibition unit 101, and the stop prohibition unit 101 executes an intermittent stop prohibition process that prohibits stopping the operation of the engine 50 by the intermittent stop control. The stop prohibition unit 101 monitors an intermittent stop prohibition flag, which will be described later, when the system main switch 120 is turned ON (ON), and executes an intermittent stop prohibition process of prohibiting the operation of the engine 50 from being stopped by the intermittent stop control when the intermittent stop prohibition flag is activated (ON). When the intermittent stop prohibition process is executed, system control section 100 keeps operating engine 50 without stopping engine 50 even when there is a request for automatic stop of engine 50 by the intermittent stop control. That is, stopping the operation of the engine 50 by the intermittent stop control is prohibited, and the engine 50 is continuously operated.

Next, the relationship between the diagnostic process executed by the diagnostic unit 301 and the intermittent stop prohibition process executed by the stop prohibition unit 101 will be described with reference to fig. 10 to 13. In the control device 400, the provisional determination routine shown in fig. 10 is executed when the engine 50 is operated and the execution condition of the diagnostic process is satisfied in a state where neither the provisional determination flag nor the true determination flag is stored in the nonvolatile memory 104. The provisional determination routine shown in fig. 10 is executed by the engine control unit 300 by the kind of the diagnostic process. In addition, when the diagnosis process does not determine that an abnormality has occurred, the diagnosis unit 301 does not execute the diagnosis process while the operation of the engine 50 continues.

The temporary determination flag is information indicating that an abnormality is likely to occur. The temporary determination flag is stored in the nonvolatile memory 104 provided in the system control unit 100 and activated as shown in fig. 1. The temporary determination flag is not stored but is inactive (OFF) in the initial state. The temporary determination flag is set for each type of diagnostic processing, and is updated according to the result of the diagnostic processing. The nonvolatile memory 104 is a memory capable of holding a memory even when the system main switch 120 is turned OFF (OFF) and power supply is stopped.

The true determination flag is information indicating that diagnosis of occurrence of an abnormality is made by the diagnosis processing. The true determination flag is also stored in the nonvolatile memory 104 and becomes active (ON). The true determination flag is not stored but becomes inactive (OFF) in the initial state. The authenticity judgment flag is also set for each type of diagnostic processing, and is updated based on the result of the diagnostic processing.

As shown in fig. 10, when starting the routine, the engine control unit 300 first executes the process of step S100. In the process of step S100, the diagnostic portion 301 of the engine control unit 300 executes a diagnostic process. Then, the ecu 300 advances the process to step S110. In the processing of step S110, engine control unit 300 determines whether or not diagnostic unit 301 determines that there is an abnormality in the processing of step S100.

If it is determined by diagnostic unit 301 that there is an abnormality in the processing of step S110 (yes in step S110), engine control unit 300 advances the processing to step S120. In the processing of step S120, the diagnostic unit 301 stores the temporary determination flag in the nonvolatile memory 104 of the system control unit 100, and activates the temporary determination flag. Then, engine control unit 300 temporarily ends the routine.

On the other hand, if the process of step S110 determines that the diagnosis unit 301 has not determined that there is an abnormality (no in step S110), the engine control unit 300 once ends the routine without executing the process of step S120. In other words, in this case, the diagnostic unit 301 does not store the temporary determination flag in the nonvolatile memory 104.

As described above, in the control device 400, when the temporary determination flag and the real determination flag are not activated, the temporary determination flag is stored in the nonvolatile memory 104 on the condition that the diagnosis unit 301 has determined that there is an abnormality by the diagnosis process.

As shown in fig. 1, the hybrid vehicle 10 is provided with a warning display unit 110, and the warning display unit 110 displays information indicating the occurrence of an abnormality and notifies an occupant of the occurrence of the abnormality. When the temporary determination flag is stored in the nonvolatile memory 104, the system control unit 100 causes the warning display unit 110 to display information indicating that an abnormality has occurred.

In the control device 400, the truth determination routine shown in fig. 11 is executed when the engine 50 is operated and the execution condition of the diagnostic process is satisfied in a state where the provisional determination flag is stored in the nonvolatile memory 104. The truth determination routine shown in fig. 11 is executed by the ecu 300 by the kind of diagnostic processing.

As shown in fig. 11, when starting the routine, the engine control unit 300 first executes the process of step S200. In the process of step S200, the diagnostic portion 301 of the engine control unit 300 executes a diagnostic process.

In the case where the diagnostic process for the oil pump 170 is executed in the process of step S200 and the case where the diagnostic process for the valve timing changing mechanism 56 is executed, the diagnostic process is executed after the cancellation operation is executed before the execution of the diagnostic process. The release operation is an operation for reciprocating the actuator to eliminate an abnormality. In the case of the oil pump 170, as a release operation, the spool valve of the oil control valve 171 is reciprocated to eliminate the jamming of foreign matter in the oil control valve 171. In the case of the valve timing changing mechanism 56, the motor is reciprocated to eliminate the sticking of foreign matter.

When the diagnostic unit 301 executes the diagnostic process by the process of step S200, the engine control unit 300 advances the process to step S210. In the processing of step S210, engine control unit 300 determines whether or not diagnostic unit 301 determines that there is an abnormality in the processing of step S200.

If the process of step S210 determines that the diagnosis unit 301 has determined that there is an abnormality (yes in step S210), the engine control unit 300 advances the process to step S220. In the processing of step S220, the diagnostic unit 301 stores the authenticity determination flag in the nonvolatile memory 104 of the system control unit 100, and activates the authenticity determination flag. Then, engine control unit 300 advances the process to step S250. In the processing of step S250, the diagnostic unit 301 clears the temporary determination flag stored in the nonvolatile memory 104 of the system control unit 100, and deactivates the temporary determination flag. Then, engine control unit 300 temporarily ends the routine.

On the other hand, if the process of step S210 determines that the diagnosis unit 301 has not determined that there is an abnormality (no in step S210), the engine control unit 300 advances the process to step S230. Then, in the processing of step S230, the diagnosis unit 301 increments the normal count by one. The normal count is stored in the memory of the engine control unit 300. This memory is not a nonvolatile memory, and the normal count is reset when power supply is stopped. The normal count is "0" in the initial state. Next, the ecu 300 advances the process to step S240. Then, engine control unit 300 determines whether or not the normal count is "3" or more in the process of step S240. If it is determined in the process of step S240 that the count is "3" or more for normality (yes in step S240), ecu 300 advances the process to step S250. In the processing of step S250, the diagnostic unit 301 clears the temporary determination flag stored in the nonvolatile memory 104 of the system control unit 100, and deactivates the temporary determination flag. Then, engine control unit 300 temporarily ends the routine.

On the other hand, if it is determined in the process of step S240 that the count is less than "3" for normality (no in step S240), ecu 300 temporarily ends the routine without executing the process of step S250.

In this way, in the control device 400, when the diagnosis unit 301 determines that there is an abnormality by the diagnosis process in the state where the temporary determination flag is stored in the nonvolatile memory 104, it diagnoses that there is an abnormality and stores the true determination flag in the nonvolatile memory 104. At this time, the diagnostic unit 301 clears the temporary determination flag stored in the nonvolatile memory 104.

Even when the temporary determination flag is cleared and the temporary determination flag is not stored in the nonvolatile memory 104, the system control unit 100 causes the warning display unit 110 to continuously display information indicating the occurrence of an abnormality when the true determination flag is stored in the nonvolatile memory 104.

On the other hand, when the temporary determination flag is cleared, the temporary determination flag is not stored in the nonvolatile memory 104, and the real determination flag is not stored in the nonvolatile memory 104, the system control unit 100 stops the display of the information indicating the occurrence of the abnormality in the warning display unit 110. In this case, the display indicating the occurrence of the abnormality disappears as the provisional determination flag is cleared. That is, in the control device 400, when the state in which the determination of the occurrence of an abnormality is not made in the diagnostic process continues to occur 3 times after the provisional determination flag is activated, the provisional determination flag is cleared, and the display indicating the occurrence of an abnormality is stopped.

Further, the authenticity determination flag is cleared from the nonvolatile memory 104 when an abnormality is eliminated when a repair is performed at a repair factory or the like. Therefore, after the diagnosis of the occurrence of an abnormality is made by the diagnosis process once and the authenticity determination flag is stored in the nonvolatile memory 104, the warning display unit 110 continues to display information indicating the occurrence of an abnormality until the authenticity determination flag is cleared by performing repair or the like.

Fig. 12 is a routine repeatedly executed by the system control unit 100 while the system main switch 120 is turned on and the control device 400 is operating. As shown in fig. 12, when the routine is started, the system control unit 100 first determines whether or not any of the temporary determination flags set for each type of diagnosis process is active in the process of step S300. That is, the system control unit 100 determines whether any temporary determination flag is stored in the nonvolatile memory 104.

If it is determined in the process of step S300 that any of the temporary determination flags is activated (yes in step S300), system control section 100 advances the process to step S310. Then, in the process of step S310, the system control unit 100 stores a 1 st intermittent stop prohibition flag having one of three kinds of intermittent stop prohibition flags in the memory. Thereby, the 1 st intermittent stop prohibition flag becomes active. Note that this memory is not a nonvolatile memory, and the 1 st intermittent stop prohibition flag is inactive when power supply is stopped. When the 1 st intermittent stop prohibition flag is thus made active, the system control unit 100 causes this routine to end temporarily. In the initial state, the 1 st intermittent stop prohibition flag is not stored in the memory and is inactive.

On the other hand, in the case where it is determined in the process of step S300 that the flag is not activated for any provisional determination (no in step S300), system control unit 100 advances the process to step S320. Also, the system control unit 100 clears the 1 st intermittent stop prohibition flag from the memory in the processing of step S320. Thereby, the 1 st intermittent stop prohibition flag becomes inactive. When the 1 st intermittent stop prohibition flag is thus inactivated, the system control unit 100 causes the routine to temporarily end.

As described above, the stop prohibition unit 101 executes the intermittent stop prohibition process when the intermittent stop prohibition flag is activated, and prohibits the operation of the engine 50 from being stopped by the intermittent stop control. As described with reference to fig. 12, when the provisional determination flag is active, system control section 100 activates the 1 st intermittent stop prohibition flag. That is, in the control device 400, when the temporary determination flag is stored in the nonvolatile memory 104, the stop prohibition unit 101 executes the intermittent stop prohibition process.

Fig. 13 shows a flow of processing of a routine executed by the system control unit 100 until the operation of the control device 400 is stopped when the system main switch 120 is turned off in a state where the 1 st intermittent stop prohibition flag is activated.

As shown in fig. 13, when starting this routine, the system control unit 100 first increments the prohibited continuous count in the processing of step S400. The prohibition continuation count is "0" in the initial state, and is incremented one by one each time the process of step S400 is executed. The inhibit duration count is stored in the non-volatile memory 104.

Next, the system control unit 100 determines whether or not the prohibition continuation count is "2" or more in the processing of step S410. If it is determined in the process of step S410 that the continuation count is "2" or more for prohibition (yes in step S410), system control section 100 advances the process to step S420.

Then, in the processing of step S420, system control section 100 deactivates the temporary determination flag. That is, the system control unit 100 clears the temporary determination flag stored in the nonvolatile memory 104.

Next, in the process of step S430, the system control unit 100 deactivates the 1 st intermittent stop prohibition flag. That is, the system control unit 100 clears the 1 st intermittent stop prohibition flag stored in the nonvolatile memory 104. The system control unit 100 resets the prohibition continuation count in the next processing of step S440. Then, the system control unit 100 ends the routine.

On the other hand, when it is determined in the process of step S410 that the continuation count is less than "2" (yes in step S410), system control section 100 does not perform the processes of step S420 to step S440, and ends the routine as it is.

By executing the routine described with reference to fig. 13, the intermittent stop prohibition processing is limited to two strokes in which the temporary determination flag is activated and continues. That is, when the system main switch 120 is turned off for 2 times in a state where the provisional determination flag is activated, the prohibition continuation count becomes "2", and the provisional determination flag and the 1 st intermittent stop prohibition flag are cleared. When the 1 st intermittent stop prohibition flag is cleared, the stop prohibition unit 101 ends the intermittent stop prohibition processing performed because the temporary determination flag is stored. As described above, in the control device 400, when the stroke for prohibiting the stop of the engine 50 by the intermittent stop control continues for 2 times because the provisional determination flag is stored, the stop prohibition unit 101 cancels the prohibition of the stop of the engine 50 because the provisional determination flag is stored.

Here, the stroke refers to a period in which the system main switch 120 of the hybrid vehicle 10 is turned on, that is, a period in which the operation of the control device 400 of the hybrid vehicle 10 is continued, as a unit of a mathematical expression of 1 stroke.

Next, a learning process executed by the control device 400 and an intermittent stop prohibition process associated therewith will be described. The learning process is executed by the engine control unit 300 during operation of the engine 50 and when the execution condition is satisfied.

For example, the engine control unit 300 executes, as one of the learning processes, air-fuel ratio main feedback learning that learns a deviation of the air-fuel ratio in a steady state caused by a deviation of the fuel injection amount injected from the fuel injection valve 54. In this air-fuel ratio main feedback learning, the learning value is updated by calculating the time integral amount of the correction amount of the fuel injection amount in the air-fuel ratio main feedback control, which is feedback control of the fuel injection amount using the detection value of the air-fuel ratio sensor 83, and converting the time integral amount into the learning value at a constant ratio for each fixed time. Further, engine control unit 300 performs air-fuel ratio sub-feedback learning, which learns a steady-state variation in air-fuel ratio due to a variation in the detection value of air-fuel ratio sensor 83, as one of learning processes. In this air-fuel ratio sub-feedback learning, the learning value is updated by calculating the time integral amount of the correction amount of the fuel injection amount in the air-fuel ratio sub-feedback control, which is feedback control of the fuel injection amount using the detection value of the oxygen sensor 84, and converting the time integral amount into the learning value at a constant ratio for each fixed time.

The learning process executed by the engine control unit 300 includes, for example, the following processes.

Engine control unit 300 executes ISC learning for learning a steady-state deviation of the engine speed in ISC control, which is feedback control of the engine speed during idling. In the ISC learning, a time integral amount of a correction amount of a throttle opening degree in the ISC control is calculated, and the time integral amount is converted into a learning value at a constant rate for each fixed time, thereby updating the learning value.

The engine control unit 300 performs KCS learning in KCS control, which is control of ignition timing for suppressing knocking in the engine 50. In KCS learning, when the correction amount of the ignition timing in KCS control becomes equal to or greater than a threshold value, a part of the correction amount is converted into a learning value, and the learning value is updated.

The engine control unit 300 performs throttle learning for learning a deviation between the intake air amount detected by the airflow meter 88 and the intake air amount assumed from the throttle opening degree. In the throttle learning, when the correction amount of the throttle opening in the feedback control of the intake air amount becomes equal to or greater than the threshold value, a part of the correction amount is converted into a learning value, and the learning value is updated.

Each learning value is stored in the nonvolatile memory 104. Therefore, the learned value is also stored in the nonvolatile memory 104 when the system main switch 120 is turned off. Therefore, when learning is completed, control for reflecting the learning value can be executed immediately after the next start of the engine 50. Therefore, it is preferable to quickly complete the update of the learned value.

However, in the above-described learning process, when the engine 50 is operating and the conditions suitable for executing the respective learning processes are not satisfied, the learning processes cannot be executed. Thus, for example, japanese patent application laid-open No. h 11-107834 discloses the following: stopping the operation of the engine 50 by the intermittent stop control is prohibited until the learning process is completed, thereby quickly completing the learning process.

However, when stopping of the operation of the engine 50 by the intermittent stop control is prohibited, the operation of the engine continues, and therefore the fuel consumption increases, and the effect of suppressing the fuel consumption to be obtained by the intermittent stop control cannot be obtained. There is also a case where completion of the learning process does not necessarily need to be prioritized, and therefore, there is room for improvement.

Then, the control device 400 changes the vehicle speed threshold, which is the threshold for determining whether or not to execute the intermittent stop prohibition process, in accordance with the accumulated amount of operation of the engine 50 since the learning of the learning value by the latest learning process is completed, so as to achieve a balance between ensuring the opportunity to update the learning value and suppressing the fuel consumption amount by executing the intermittent stop control. Therefore, as shown in fig. 1, in the control device 400, the system control unit 100 is provided with a workload calculation unit 102 that calculates an index value indicating an integrated workload, and a threshold value calculation unit 103 that calculates a vehicle speed threshold value.

The change of the condition for executing the intermittent stop prohibition process according to the accumulated workload will be specifically described with reference to fig. 14 and 15. Further, the degree of easiness of occurrence of knocking may suddenly change when the properties of the fuel change due to fuel supply. Therefore, the KCS learning is preferably performed per trip. Then, in the control device 400, the intermittent stop prohibition processing is executed until the completion of the KCS learning at the time of the first operation of the engine 50 in each trip, so that the KCS learning is completed quickly.

With the routine shown in fig. 14, when the learning process is completed, it is repeatedly executed by the system control unit 100 while the engine 50 is running. Further, the routine is executed by the kind of learning processing.

As shown in fig. 14, when the routine is started, the system control unit 100 first calculates an index value of the accumulated workload in the processing of step S500. Here, as the index value of the integrated operation amount, the operation amount calculation unit 102 calculates the integrated travel distance of the hybrid vehicle 10 from completion of learning of the learning value by the latest learning process, for example. The longer the cumulative travel distance, the more easily the cumulative operation amount of the engine 50 becomes. Therefore, by calculating the accumulated travel distance from the completion of learning as the index value of the accumulated amount of operation of the engine 50 from the completion of learning, the accumulated amount of operation of the engine from the completion of learning can be estimated based on the calculated index value.

Next, the system control unit 100 advances the process to step S510. In the processing of step S510, the system control unit 100 reads the correction amount in the control of the object for learning the learning value. For example, if the control to be learned of the learned value is the air-fuel ratio main feedback control, the correction amount of the fuel injection amount in the air-fuel ratio main feedback control is read.

Then, in the next step S520, the system control unit 100 calculates a vehicle speed threshold value based on the index value of the integrated workload calculated by the workload calculation unit 102 and the read correction amount. In the processing of step S520, the threshold value calculation unit 103 of the system control unit 100 calculates a smaller value as the vehicle speed threshold value as the index value of the integrated amount of work increases. The threshold value calculation unit 103 calculates a smaller value as the vehicle speed threshold value as the read correction amount is larger.

When the vehicle speed threshold value is thus calculated, the system control unit 100 temporarily ends the routine. The routine shown in fig. 15 is repeatedly executed by system control unit 100 when the HV travel mode is selected and calculation of the vehicle speed threshold value related to a certain learning process is completed.

When this routine is started, first, in the process of step S600, the system control unit 100 compares the minimum vehicle speed threshold value among the calculated vehicle speed threshold values with the vehicle speed detected by the vehicle speed sensor 86, and determines whether or not the vehicle speed is equal to or greater than the vehicle speed threshold value.

If it is determined in the process of step S600 that the vehicle speed is equal to or higher than the vehicle speed threshold (yes in step S600), system control unit 100 advances the process to step S610. Also, in the processing of step S610, the system control unit 100 stores a 2 nd intermittent stop prohibition flag, which is one of the three kinds of intermittent stop prohibition flags, in the memory. Thereby, the 2 nd intermittent stop prohibition flag becomes active. Note that this memory is not a nonvolatile memory, and the 2 nd intermittent stop prohibition flag is inactive when power supply is stopped. When the 2 nd intermittent stop prohibition flag is thus made active, the system control unit 100 causes this routine to end temporarily. In the initial state, the 2 nd intermittent stop prohibition flag is not stored in the memory and is inactive. The 2 nd intermittent stop prohibition flag is set for each type of learning process, and is activated in the process of step S610, and the 2 nd intermittent stop prohibition flag is a flag for the learning process corresponding to the vehicle speed threshold value compared with the vehicle speed in the process of step S600.

On the other hand, when the process of step S600 determines that the vehicle speed is less than the vehicle speed threshold value (no in step S600), system control unit 100 once ends the routine without executing the process of step S610.

As described above, the stop prohibition unit 101 executes the intermittent stop prohibition process when the intermittent stop prohibition flag is activated, and prohibits the operation of the engine 50 from being stopped by the intermittent stop control. As described with reference to fig. 15, system control section 100 activates the 2 nd intermittent stop prohibition flag when the vehicle speed is equal to or higher than the vehicle speed threshold value. Further, in control device 400, the vehicle speed threshold is decreased as the integrated amount of operation increases. Further, the vehicle speed threshold is decreased as the correction amount in the control is larger. Therefore, in this control device 400, the intermittent stop prohibition processing is executed from the lower vehicle speed as the integrated amount of operation increases and the correction amount increases. As a result, the opportunity to execute the intermittent stop prohibition processing increases, and the intermittent stop prohibition processing is easily executed. That is, in control device 400, the opportunity to execute the intermittent stop prohibition processing can be increased and the opportunity to update the learning value can be secured in accordance with the increase in the necessity of updating the learning value accompanying the increase in the integrated operation amount of engine 50.

Further, when the corresponding learning process is completed and the learning value is updated, the 2 nd intermittent stop prohibition flag is reset to inactive. Next, control related to the start of the engine 50 when a failure occurs in the cam position sensor 160 will be described with reference to fig. 16 and 17.

As described above, when the engine 50 is started, the missing tooth portion 153 is detected every time the crankshaft 59 makes one rotation, the cam angle signal output from the cam position sensor 160 is detected, and the cam position sensor 160 detects the arrival of the specific cam angle of the camshaft 91 making two rotations during one rotation of the crankshaft 59. And, it is determined which value of the values of the crank count corresponding to the crank angle of the crank shaft 59 by two revolutions corresponds to the tooth-missing portion 153. Japanese patent application laid-open No. 2015-059469 also discloses a control device for an internal combustion engine that generates a crank count that increases for each fixed crank angle, as in the control device 400.

While the missing tooth portion 153 is detected 2 times by the crank position sensor 150 during two revolutions of the crankshaft 59, when the cam position sensor 160 fails, it is not possible to determine which value of the crank count values corresponding to the crank angle corresponding to the two revolutions of the crankshaft the missing tooth portion 153 detected corresponds to.

Then, in the control device 400, when the cam position sensor 160 fails, for example, when the signal is not output from the cam position sensor 160 on the intake side, the count calculation unit 302 temporarily determines one of the two crank angles corresponding to the tooth-missing portion 153 as the crank angle based on the detection of the tooth-missing portion 153 at the time of starting the engine 50. For example, in the control device 400, the "90 ° CA" of the two crank angles corresponding to the tooth-missing portion 153, i.e., "90 ° CA" and "450 ° CA", as shown in fig. 9, is temporarily determined as the crank angle.

Then, the count calculation unit 302 calculates a value of the crank count based on the temporarily determined crank angle. The engine control unit 300 controls the engine 50 based on the thus calculated crank count to attempt start-up.

The routine shown in fig. 16 is executed by the engine control unit 300 when starting the engine 50 in a state where the cam position sensor 160 is out of order.

As shown in fig. 16, when this routine is started, engine control unit 300 first determines whether or not the start of engine 50 has failed in the process of step S700. The determination as to whether the start has failed is made based on whether the start of the engine 50 is completed within a predetermined time. That is, when the start of the engine 50 is completed within a predetermined time, the engine control unit 300 determines that the start of the engine 50 is successful at the time point when the start of the engine 50 is completed. On the other hand, if the start of engine 50 is not completed even after the elapse of the predetermined time, engine control unit 300 determines that the start of engine 50 has failed.

If it is determined in the process of step S700 that the engine has failed to be started (yes in step S700), engine control unit 300 advances the process to step S710. Then, in the process of step S710, the engine control unit 300 switches the value of the crank count.

Specifically, in the processing of step S710, the count calculation unit 302 determines "450 ° CA", which is not the tentatively determined crank angle, of the two crank angles corresponding to the tooth-missing portion 153, i.e., "90 ° CA" and "450 ° CA", as the correct crank angle, and recalculates the crank count. When the crank count is thus switched, the engine control unit 300 causes the routine to end temporarily. Engine control section 300 then restarts engine 50 based on the newly recalculated crank count.

On the other hand, if it is determined in the process of step S700 that the engine has been successfully started (no in step S700), engine control unit 300 ends the routine without executing the process of step S710. Then, the count calculation unit 302 continues to calculate the crank count based on the temporarily determined crank angle, and the engine control unit 300 controls the engine 50 based on the crank count calculated by the count calculation unit 302.

In this way, in the control device 400, when the cam position sensor 160 fails, one of the two crank angles corresponding to the tooth-missing portion 153 is temporarily determined as the crank angle based on the detection of the tooth-missing portion 153 by the crank position sensor 150, and the value of the crank count is calculated based on the temporarily determined crank angle. The engine 50 is controlled based on the value of the crank count calculated based on the temporarily determined crank angle.

In addition, in the control device 400, when the start-up using the value of the crank count calculated based on the tentatively determined crank angle fails, the crank count is recalculated based on the other crank angle, which is not the tentatively determined crank angle, of the two crank angles corresponding to the tooth-missing portion 153. Then, the controller 400 tries to start the engine 50 again using the recalculated crank count. Therefore, even when the start based on one of the temporarily determined crank angles fails, the start of the engine 50 can be completed by the start using the crank count recalculated based on the other crank angle.

After the start is completed, the count calculation unit 302 counts the edges of the crank angle signal and continues to calculate the crank count. Also, the engine control unit 300 controls the engine 50 based on the crank count.

The crank position sensor 150 cannot detect the crank angle when the rotation speed of the crankshaft 59 is extremely slow. Further, since the rotation direction of the crankshaft 59 cannot be specified, when the crankshaft 59 rotates in the reverse rotation direction due to the compression reaction force of the air in the cylinder immediately before the engine 50 stops, the crank angle cannot be grasped.

In the control device 400, the 1 st motor generator 11 and the 2 nd motor generator 12 are coupled to the crankshaft 59 via the planetary gear mechanism 13, and therefore, the rotation angle of the crankshaft 59 can be estimated based on the rotation angles detected by the resonators (resonators) provided in the 1 st motor generator 11 and the 2 nd motor generator 12.

Then, in the control device 400, when the rotation speed of the crankshaft 59 is extremely slow or when rotation in the reverse rotation direction occurs, the rotation angle of the crankshaft 59 is estimated by referring to the transition of the rotation angle of the 1 st motor generator 11 and the transition of the rotation angle of the 2 nd motor generator 12 detected by the resonator. Then, the count calculation unit 302 calculates a crank count based on the estimated rotation angle of the crankshaft 59. In this way, in control device 400, count calculation unit 302 continues to calculate the crank count even during the period from when the operation of engine 50 is stopped until when engine 50 is started next time.

Then, in the control device 400, the next time the engine 50 is started, the start is performed based on the grasped value of the crank count without waiting for the detection of the missing tooth portion 153. Therefore, even if the cam position sensor 160 fails, the start of the engine 50 can be completed quickly.

However, when the rotation angle of the 1 st motor generator 11 or the rotation angle of the 2 nd motor generator 12 cannot be detected due to a failure of the resonator or the like, the rotation angle of the crankshaft 59 cannot be estimated.

Then, in the control device 400, the routine shown in fig. 17 is repeatedly executed during the operation of the engine 50 in which the cam position sensor 160 is in a failure state and the 3 rd intermittent stop prohibition flag, which is one of the intermittent stop prohibition flags, is inactive. The routine shown in fig. 17 is executed by the system control unit 100.

As shown in fig. 17, when this routine is started, the system control unit 100 first determines whether or not the rotation angle of the 1 st motor generator 11 or the rotation angle of the 2 nd motor generator 12 cannot be detected and the rotation angle is unknown in the processing of step S800. That is, the system control unit 100 determines whether or not the crankshaft count cannot be calculated with reference to the rotation angle of the 1 st motor generator 11 and the rotation angle of the 2 nd motor generator 12 by the processing of step S800.

If it is determined in the process of step S800 that the rotation angle is unknown (yes in step S800), system control section 100 advances the process to step S810. Then, system control section 100 causes nonvolatile memory 104 to store an abnormality flag indicating that an abnormality has occurred in the motor generator whose rotation angle is unknown in the processing of step S810. When the abnormality flag is stored in the nonvolatile memory 104, the system control unit 100 causes the warning display unit 110 to display information indicating that an abnormality has occurred.

Next, the system control unit 100 stores the 3 rd intermittent stop prohibition flag in the nonvolatile memory 104 in the processing of step S820. Thereby, the 3 rd intermittent stop prohibition flag becomes active. When the 3 rd intermittent stop prohibition flag is thus made active, the system control unit 100 causes this routine to temporarily end. In the initial state, the 3 rd intermittent stop prohibition flag is not stored in the nonvolatile memory 104 and is deactivated.

As described above, the stop prohibition unit 101 executes the intermittent stop prohibition process when the intermittent stop prohibition flag is active, and prohibits the operation of the engine 50 from being stopped by the intermittent stop control. As described with reference to fig. 17, when the system control unit 100 is in a state where the crank count cannot be calculated with reference to the rotation angle of the 1 st motor generator 11 and the rotation angle of the 2 nd motor generator 12, the 3 rd intermittent stop prohibition flag is set to active. That is, in the control device 400, when the cam position sensor 160 has failed and the calculation of the crank count cannot be performed with reference to the rotation angle of the motor generator, the stop prohibition unit 101 executes the intermittent stop prohibition process to continue the operation of the engine.

When the operation of the engine 50 is stopped by the intermittent stop control when the cam position sensor 160 has failed, it is necessary to restart the engine by using the crank angle temporarily determined based on the detection of the tooth missing portion 153. The restart in the state where the cam position sensor 160 is malfunctioning may fail. In contrast, in the control device 400, the intermittent stop prohibition process is executed to continue the operation of the engine 50, and therefore, the execution of the restart, which may fail, is suppressed, and the failure of the start can be avoided.

The abnormality flag is cleared from the nonvolatile memory 104 when the abnormality is resolved, such as when the abnormality is repaired in a repair factory. In addition, the 3 rd intermittent stop prohibition flag is also cleared along with the clearing of the abnormality flag.

The operation and effect of the present embodiment will be described.

(concerning intermittent stop prohibition processing accompanying the diagnosis processing)

(1-1) in the control device 400, the temporary determination flag is stored in the nonvolatile memory 104 that can be kept stored even when the power supply is stopped by turning off the system main switch 120. Therefore, even if the system main switch 120 is turned off before the real determination flag is set to active when a diagnosis intended for an abnormality is made, when the system main switch 120 is subsequently turned on, it is possible to recognize that the diagnosis is underway based on the temporary determination flag stored in the nonvolatile memory 104.

When the temporary determination flag is stored, the stop prohibition unit 101 prohibits the stop of the operation of the engine 50 by the intermittent stop control. Therefore, even when the system main switch 120 is turned off during the diagnosis, when the system main switch 120 is turned on next time, the stop of the operation of the engine 50 by the intermittent stop control is immediately prohibited when the operation of the engine 50 is started, and the operation of the engine 50 is continued. Therefore, the opportunity to execute the diagnostic process is increased and the diagnosis can be completed quickly as compared with the case where the stop of the operation of the engine 50 by the intermittent stop control is not prohibited.

(1-2) when stopping of the operation of the engine 50 by the intermittent stop control is prohibited, the operation of the engine 50 continues, and therefore, the amount of fuel consumption increases. That is, the effect of suppressing the fuel consumption amount to be obtained by the intermittent stop control may not be obtained. In contrast, as described with reference to fig. 13, the control device 400 can suppress the case where the stroke in which the stop of the engine 50 is prohibited due to the temporary determination flag being stored continues for more than 2 times. Therefore, it is possible to secure the balance between the opportunity of execution of the diagnosis and the suppression of the fuel consumption amount, and it is possible to suppress an excessive increase in the fuel consumption amount.

(with respect to intermittent stop prohibition processing accompanying learning processing)

(2-1) since the engine 50 is operated using fuel in a less efficient state as the vehicle speed is lower, the fuel consumption amount is increased by executing the intermittent stop prohibition processing as the vehicle speed is lower. Therefore, in order to suppress the fuel consumption, it is preferable to set the vehicle speed threshold to a large value, set the vehicle speed at which the intermittent stop prohibition processing is executed to a high vehicle speed side, and suppress the operation of the engine in an inefficient state by the intermittent stop control.

However, as the operation of the engine 50 continues, a secular change in the control target, for example, accumulation of deposits in the throttle valve 53, etc., is accumulated, and therefore, the necessity of updating the learned value becomes high. In contrast, in control device 400, the vehicle speed threshold becomes smaller as the integrated amount of work of engine 50 from the completion of learning increases, so that the opportunity to execute the intermittent stop prohibition processing increases, and the intermittent stop prohibition processing is easily executed. That is, in control device 400, the opportunity of execution of the intermittent stop prohibition process is increased to secure the opportunity of updating the learning value in accordance with the increase in the necessity of updating the learning value accompanying the increase in the integrated operation amount of engine 50. Therefore, according to the control device 400, it is possible to achieve a balance between ensuring the opportunity to update the learning value and suppressing the fuel consumption amount by the execution of the intermittent stop control.

(2-2) when the correction amount in the control is large, it is preferable to quickly update the learning value. In contrast, in the control device 400, the smaller the vehicle speed threshold value, the greater the correction amount, the greater the chance of execution of the intermittent stop prohibition processing. That is, according to the control device 400, when the correction amount is large, the chance of updating the learning value can be increased, and the control deviation can be quickly eliminated.

(control relating to engine start in the event of failure of the cam position sensor)

(3-1) in the control device 400, when the cam position sensor 160 fails, one of the two crank angles corresponding to the tooth-missing portion 153 is temporarily determined as the crank angle based on the detection of the tooth-missing portion 153 by the crank position sensor 150. Engine control section 300 controls engine 50 based on the value of the crank count calculated from the tentatively determined crank angle. Therefore, even if the cam position sensor 160 malfunctions, the engine 50 can be started with a probability of about 50%.

(3-2) in the control device 400, when the start-up using the value of the crank count calculated based on the crank angle determined at the time fails, the crank count is recalculated based on the other crank angle, which is not the crank angle determined at the time, of the two crank angles corresponding to the tooth-missing portion 153. Then, the start of the engine 50 is attempted again using the recalculated crank count. Therefore, even when the start based on one of the temporarily determined crank angles fails, the start of the engine 50 can be completed by the start using the crank count recalculated based on the other crank angle.

(3-3) in the control device 400, even when the operation of the engine 50 is stopped, the rotation angle of the crankshaft 59 is estimated with reference to the rotation angle of the motor generator, and therefore, the crank angle during the stop of the engine 50 can be grasped. Therefore, the next engine start can be performed based on the grasped crank angle. Therefore, even if the cam position sensor 160 fails, the start of the engine 50 can be completed quickly.

(3-4) in the control device 400, when the crankshaft count cannot be calculated with reference to the rotation angle of the 1 st motor generator 11 and the rotation angle of the 2 nd motor generator 12, the operation of the engine 50 is continued. Therefore, the execution of the restart, which may fail, can be suppressed, and the failure of the start can be avoided.

This embodiment can be modified and implemented as follows. This embodiment and the following modifications can be combined and implemented within a range not technically contradictory to each other.

The control device 400 is applied to a plug-in hybrid vehicle in which the battery 30 can be charged by the external power supply 40, but may be applied to a non-plug-in hybrid vehicle.

Although the engine 50 is provided with the intake-side valve timing changing mechanism 56 and the exhaust-side valve timing changing mechanism 56, the control device 400 may be applied to a hybrid vehicle provided with an engine without the valve timing changing mechanism 56.

Specifically, the present invention can be applied to an engine equipped with only the intake-side valve timing changing mechanism 56, an engine equipped with only the exhaust-side valve timing changing mechanism 56, and a hybrid vehicle equipped with no valve timing changing mechanism 56.

The expression of the value of the crank count is not limited to the expression of "1", "2", "3", … … which are increased one by one. For example, 30 crank angles such as "0", "30", "60", and … … may be increased by 30. Of course, the 30-30 increments may not be the same as the crankshaft angle. For example, 5 may be added by 5, such as "0", "5" and "10".

An example in which the crank count is increased every 30 ° CA is shown, but the manner of increasing the crank count is not limited to such a scheme. For example, the angle may be increased at every 10 ° CA, or may be increased at intervals longer than 30 ° CA. That is, in the above embodiment, the crank count is increased every time 3 edges are counted, and the crank count is increased every 30 ° CA, but the number of edges required for the increase may be changed as appropriate. For example, the following configuration may be adopted: the crank count is incremented every time 1 edge is counted, and is incremented every 10 ° CA.

The valve timing changing mechanism 56 may be a hydraulically driven mechanism. In this case, the oil control valve that controls the hydraulic pressure is reciprocated during the release operation.

All the diagnostic processes described above may not be performed. The diagnostic process to be performed is not limited to the illustrated process. When the intermittent stop prohibition processing is executed when the diagnosis processing that makes it impossible to diagnose the occurrence of an abnormality when the engine 50 is not running is executed, the diagnostic device can obtain the effect that the diagnosis can be completed quickly while ensuring the opportunity to perform the diagnosis, as in the above-described embodiment.

In the case where the learning value reaches the upper limit or the lower limit in the diagnosis process, the abnormality is determined to have occurred, but the method of abnormality diagnosis is not limited to this. For example, it is also possible to provide: when the deviation between the target value and the detection value is large, it is determined that an abnormality occurs.

While an example in which the intermittent stop prohibition processing continues because the temporary determination flag is activated is limited to two strokes has been shown, the number of strokes for which the intermittent stop prohibition processing is permitted to continue is not limited to "2". For example, "3" or more may be used. Further, the configuration for continuing the restriction may be omitted.

As described with reference to fig. 11, in the above embodiment, when the normality count becomes "3" or more after the provisional determination flag is activated, the provisional determination flag is cleared, and the display indicating the occurrence of the abnormality is stopped. In contrast, the threshold value of the normal count which becomes a condition for clearing the provisional determination flag is not limited to "3". For example, the value may be smaller than "3", or may be equal to or larger than "4".

An example is shown as follows: when the determination of abnormality is made by the provisional determination routine and the provisional determination flag is activated, when the determination of abnormality is made by the truth determination routine, a diagnosis of abnormality occurrence is made and the truth determination flag is activated. In contrast, the method of determining the diagnosis in the diagnosis process, that is, the conditions under which the diagnosis is finally made, may be changed as appropriate. For example, the following may be set: when the determination of abnormality by the provisional determination routine is continued a plurality of times, the diagnosis of abnormality occurrence is made, and the true determination flag is made active.

Although an example in which control device 400 is configured by system control unit 100, power control unit 200, and engine control unit 300 is shown, the configuration of the control device is not limited to this configuration. For example, the control device may be physically configured as one device. The control device may be configured by 4 or more units.

While the threshold value calculation unit 10 calculates a smaller value as the vehicle speed threshold value as the correction amount in the control to be learned of the learned value is larger, the process of step S510 may be omitted, and the threshold value calculation unit 103 may calculate the vehicle speed threshold value based on the integrated amount of operation regardless of the correction amount.

Although an example is shown in which the operation amount calculation unit 102 calculates the cumulative travel distance of the hybrid vehicle 10 as the index value of the cumulative operation amount, the index value of the cumulative operation amount is not limited to this. For example, the following configuration may be adopted: the operation amount calculation unit 102 calculates the integrated intake air amount of the engine 50 from the completion of the learning value by the latest learning process as the index value of the integrated operation amount.

It can be said that the greater the integrated intake air amount, the greater the integrated operation amount of the engine 50. Therefore, by calculating the integrated intake air amount of the engine 50 from the completion of learning as the index value of the integrated operation amount of the engine 50 from the completion of learning, the integrated operation amount of the engine 50 from the completion of learning can be estimated based on the calculated index value.

Further, for example, the following configuration may be adopted: the operation amount calculation unit 102 calculates the accumulated operation time of the engine 50 from completion of learning of the learning value by the latest learning process as the index value of the accumulated operation amount.

It can be said that the longer the accumulated operation time, the more the accumulated operation amount of the engine 50. Therefore, by calculating the accumulated operating time of the engine 50 from the completion of learning as the index value of the accumulated amount of operation of the engine 50 from the completion of learning, the accumulated amount of operation of the engine 50 from the completion of learning can be estimated based on the calculated index value.

The following example is shown: the crank angle corresponding to the tooth-missing portion 153 is "90 ° CA" and "450 ° CA", and when the cam position sensor 160 has failed, the crank angle at which the tooth-missing portion 153 is detected is temporarily determined as "90 ° CA". However, the crank angle temporarily determined may be "450 ° CA". In this case, in the processing of step S710, "90 ° CA" is regarded as the correct crank angle, and the crank count is recalculated.

That is, when the crankshaft 59 makes two revolutions, the two crank angles corresponding to the tooth-missing portions 153 are separated by 360 ° CA, and therefore, the other crank angle is a crank angle that is increased or decreased by one revolution with respect to the one crank angle.

Therefore, when the start of the engine 50 has failed, the count calculation unit 302 recalculates the crank count based on the crank angle obtained by increasing or decreasing the crank angle by the amount corresponding to one rotation from the temporarily determined crank angle, and restarts the engine 50 based on the recalculated crank count.

The processing described with reference to fig. 16 for switching the value of the crank count when the start-up based on the temporarily determined crank angle has failed may be omitted. If the start is performed by at least temporarily determining one of the two crank angles corresponding to the tooth-missing portion 153, the start can be successful with a probability of about 50%.

The intermittent stop may be omitted when the crank count cannot be calculated with reference to the rotation angle of the motor generator. In this case, at the time of the next start, the crank angle is temporarily determined, and the process described with reference to fig. 16 is executed to try the start.

The following configuration may be omitted: while the operation of the engine 50 is stopped, the calculation of the crank count is continued with reference to the rotation angle of the motor generator.

Although the example in which the 3 rd intermittent stop prohibition flag is stored in the nonvolatile memory 104 is shown, the 3 rd intermittent stop prohibition flag may be stored in a memory that is cleared when power supply is stopped, instead of the nonvolatile memory 104. In this case, the 3 rd intermittent stop prohibition flag is set to active when the routine described with reference to fig. 17 is executed next time the engine 50 is operated.

When the engine 50 is operated, the engine speed is difficult to stabilize immediately after the change of the driving force by the 2 nd motor generator 12, the change of the power generation amount by the 1 st motor generator 11, or the like. Therefore, the ISC learning may also be prohibited at this time so that the ISC learning is not performed. In addition, the intermittent stop prohibition process for ensuring the execution opportunity of the ISC learning may not be executed at this time. In addition, the ISC learning may not be prohibited, and the intermittent stop prohibition process for ensuring the execution opportunity of the ISC learning may not be executed.

Even when the fuel increase correction is performed at the time of starting the engine 50, the engine speed is difficult to stabilize. Therefore, it is also possible to prohibit the ISC learning without performing the ISC learning at the time of and immediately after the fuel increase correction is performed. In addition, the intermittent stop prohibition process for ensuring the execution opportunity of the ISC learning may not be executed at this time. In addition, the ISC learning may not be prohibited, and the intermittent stop prohibition process for ensuring the execution opportunity of the ISC learning may not be executed.

When the imbalance diagnosis process is executed, the ignition timing is retarded and the intake air amount is increased in order to secure an S/N ratio which is a ratio of the signal to the noise. Therefore, there is a possibility that a deviation occurs in the learning value of the ISC learning. Thus, it is also possible not to perform the ISC learning when the imbalance diagnosis process is executed.

In the case of performing the ISC learning, even when the learning value deviates in consideration of other control, if the magnitude of the deviation due to the influence of the control can be grasped in advance, the deviation can be canceled out and the learning can be performed. Therefore, in the case of performing such cancellation, the learning is performed by performing the intermittent stop prohibition processing as in the above-described embodiment. For example, when a change in the driving force by the 2 nd motor generator 12 or a change in the power generation amount by the 1 st motor generator 11 occurs, the torque related to the crankshaft 59 changes, and therefore, in that case, the ISC learning cannot be accurately performed, but the ISC learning can be performed by canceling the change in the torque in advance. In this case, the learning can be performed by performing the intermittent stop prohibition as in the above-described embodiment.

During idling, moreover, the following results are obtained: the energization of the 1 st motor generator 11 is controlled so that the load generated by the 1 st motor generator 11 does not act on the crankshaft 59. However, in this control, there is an error for each rotation speed of the 1 st motor generator 11. As a result, the learning value in the ISC learning varies. Then, correction amounts may be set for the respective rotation speeds of the 1 st motor generator, and correction may be performed to control the energization of the 1 st motor generator 11, thereby performing ISC learning. Since the rotation speed of the 1 st motor/generator 11 is proportional to the vehicle speed, the correction amount may be calculated based on the vehicle speed.

As an example of determining whether or not the crankshaft count cannot be calculated with reference to the rotation angle of the motor generator, failure of the resonator is exemplified. However, the factor that makes it impossible to calculate the crank count with reference to the rotation angle of the motor generator is not limited to the failure of the resonator. For example, in the case of a single-motor hybrid vehicle as shown in fig. 18, the connection between the crankshaft 59 of the engine 50 and the drive motor 210 is released by the clutch 230, and the crankshaft count cannot be calculated with reference to the rotation angle of the drive motor 210.

An example of control in the case of such a configuration will be described with reference to fig. 18 and 19. As shown in fig. 18, the hybrid vehicle is provided with a drive motor 210 between an engine 50 and a transmission 220. Further, a clutch 230 is interposed between the drive motor 210 and the engine 50. The drive motor 210 is coupled to an input shaft 221 of the transmission 220, and a drive shaft 24 of the wheels 23 is coupled to an output shaft 222 of the transmission via a differential mechanism 22.

The control device 400 includes a stop prohibition unit 101 and a count calculation unit 302. The control device 400 controls the engine 50, the clutch 230, and the drive motor 210. In this control device 400, the routine shown in fig. 19 is executed instead of the routine shown in fig. 17. This routine is repeatedly executed by the control device 400 during the operation of the engine 50 in which the cam position sensor 160 is in a failure state and the 3 rd intermittent stop flag is inactive.

As shown in fig. 19, when this routine is started, the control device 400 first determines whether or not the clutch 230 is in a disconnected (OFF) state in which the connection between the crankshaft 59 and the drive motor 210 is released in the processing of step S900. That is, the control device 400 determines whether or not the rotation angle of the drive motor 210 cannot be referred to and the crank count is in a state by the processing of step S900.

If it is determined in the process of step S900 that the clutch is disengaged (yes in step S900), control device 400 advances the process to step S910. Then, the control device 400 stores the 3 rd intermittent stop prohibition flag in the memory in the process of step S910. Thereby, the 3 rd intermittent stop prohibition flag becomes active. When the 3 rd intermittent stop prohibition flag is thus made active, the control device 400 causes this routine to end temporarily. In the initial state, the 3 rd intermittent stop prohibition flag is not stored in the memory and is deactivated. In the case of this control device 400, the memory storing the 3 rd intermittent stop prohibition flag is not a nonvolatile memory, and therefore, when the power supply is stopped, the 3 rd intermittent stop prohibition flag is cleared.

ON the other hand, if it is determined in the process of step S900 that the clutch is not disengaged and the crankshaft 59 and the drive motor 210 are in the engaged (ON) state, which is the connected state (no in step S900), the control device 400 does not perform the process of step S910 and temporarily ends the routine.

In the case of such a configuration, the stop prohibition unit 101 can continue the operation of the engine by executing the intermittent stop prohibition process when the rotation angle of the motor generator is not referenced and the calculation of the crank count is performed. Therefore, the execution of the restart, which may fail, can be suppressed, and the failure of the start can be avoided.

Technical ideas that can be grasped from the above-described embodiments and modification examples are described. (1) A control device for a hybrid vehicle, applied to a hybrid vehicle including an engine and a motor as a driving force source, the control device executing intermittent stop control for automatically stopping and restarting an operation of the engine and learning processing for learning a learning value used in control of the engine, the control device comprising: a stop prohibition portion that executes an intermittent stop prohibition process that prohibits stopping of operation of the engine by the intermittent stop control; an operation amount calculation unit that calculates an index value indicating an accumulated operation amount of the engine from completion of learning of the learning value by the latest learning process; and a threshold value calculation unit that calculates a vehicle speed threshold value based on the index value calculated by the workload calculation unit, wherein the threshold value calculation unit calculates a smaller value as the vehicle speed threshold value based on the index value as the cumulative workload increases, and the stop prohibition unit executes the intermittent stop prohibition process when the vehicle speed of the hybrid vehicle is equal to or greater than the vehicle speed threshold value.

As the engine operation continues, a secular change in the control target, for example, accumulation of deposits in the throttle valve, etc., is accumulated, and therefore, the necessity of updating the learned value becomes high. In contrast, according to the above configuration, the vehicle speed threshold becomes smaller as the amount of engine operation from the completion of learning increases, so that the opportunity to execute the intermittent stop prohibition processing increases, and the intermittent stop prohibition processing is easily executed. That is, according to the above configuration, the opportunity of executing the intermittent stop prohibition processing is increased in accordance with the increase in the necessity of updating the learning value accompanying the increase in the engine operation amount, and it is possible to ensure the balance between the opportunity of updating the learning value and the suppression of the fuel consumption amount by the execution of the intermittent stop control.

(2) According to the control device for a hybrid vehicle described in (1), the threshold value calculation unit calculates a smaller value as the vehicle speed threshold value as the correction amount in the control to be performed for learning the learning value is larger.

It is preferable to quickly update the learning value when the correction amount in control is large. In contrast, according to the above configuration, the larger the correction amount, the smaller the vehicle speed threshold value, and the greater the opportunity for execution of the intermittent stop prohibition processing. That is, when the correction amount is large, the opportunity of updating the learning value is increased to quickly eliminate the control deviation.

(3) According to the control device for a hybrid vehicle described in (1) or (2), the operation amount calculation unit calculates, as the index value, an accumulated travel distance of the hybrid vehicle from completion of learning of the learning value by the latest learning process.

The longer the accumulated travel distance is, the more easily the accumulated amount of work of the engine becomes. Therefore, by calculating the accumulated travel distance from the completion of learning as the index value of the accumulated amount of operation of the engine from the completion of learning, the accumulated amount of operation of the engine from the completion of learning can be estimated based on the calculated index value.

(4) According to the control device for a hybrid vehicle recited in (1) or (2), the operation amount calculation unit calculates, as the index value, an integrated intake air amount of the engine from completion of learning of the learning value by the latest learning process.

It can be said that the larger the integrated intake air amount, the larger the integrated amount of operation of the engine. Therefore, by calculating the integrated intake air amount of the engine from the completion of learning as the index value of the integrated operation amount of the engine from the completion of learning, the integrated operation amount of the engine from the completion of learning can be estimated based on the calculated index value.

(5) According to the control device for a hybrid vehicle recited in (1) or (2), the operation amount calculation unit calculates, as the index value, an accumulated operation time of the engine from completion of learning of the learning value by the latest learning process.

It can be said that the longer the accumulated operation time, the more the accumulated operation amount of the engine. Therefore, by calculating the accumulated operating time of the engine from the completion of learning as the index value of the accumulated amount of operation of the engine from the completion of learning, the accumulated amount of operation of the engine from the completion of learning can be estimated based on the calculated index value.

(6) A control device for a hybrid vehicle, which is applied to a hybrid vehicle including an engine and a motor as a drive force source, and which executes intermittent stop control for automatically stopping and restarting the operation of the engine, wherein the control device includes a count calculation unit that calculates a value of a crank count corresponding to a crank angle corresponding to two revolutions of a crankshaft of the crankshaft based on detection of a pulse signal output by a crank position sensor for every certain crank angle along with the rotation of the crankshaft of the engine, detection of a tooth missing portion occurring once during one revolution of the crankshaft, and detection of a signal output by a cam position sensor that detects arrival of a specific cam angle of a camshaft that rotates in conjunction with the crankshaft and rotates once during two revolutions of the crankshaft, the count calculation unit temporarily determines a crank angle and calculates a crank count value based on the detection of the missing tooth portion by the crank position sensor when the cam position sensor fails, and controls the engine based on the crank count value calculated by the count calculation unit based on the temporarily determined crank angle when the cam position sensor fails.

Since the missing tooth portion is detected 2 times during two crankshaft revolutions, the crank angle corresponding to the missing tooth portion includes two crank angles of the 1 st revolution and the 2 nd revolution separated by 360 ° CA from the crank angle of the 1 st revolution.

According to the above configuration, when the cam position sensor fails, one of the two crank angles corresponding to the tooth missing portion is provisionally determined as the crank angle based on the detection of the tooth missing portion by the crank position sensor, and the value of the crank count is calculated based on the provisionally determined crank angle. The engine is controlled based on the value of the crank count calculated from the temporarily determined crank angle. Therefore, even if the cam position sensor fails, the engine can be started with a probability of about 50% by controlling the engine based on the value of the crank count calculated from the temporarily determined crank.

(7) According to the control device for a hybrid vehicle recited in (6), when the start of the engine performed based on the value of the crank count calculated based on the tentatively determined crank angle has succeeded, the count calculation unit continues the calculation of the crank count based on the tentatively determined crank angle, and when the start of the engine performed based on the value of the crank count calculated based on the tentatively determined crank angle has failed, the count calculation unit recalculates the crank count based on the crank angle obtained by increasing or decreasing the crank angle by an amount corresponding to one rotation from the tentatively determined crank angle, and restarts the engine based on the recalculated crank count.

According to the above configuration, when the start using the value of the crank count calculated based on the tentatively determined crank angle has failed, the crank count is recalculated based on the other one of the two crank angles corresponding to the tooth-missing portion, which is not the tentatively determined crank angle, and the start of the engine is retried using the recalculated crank count. Therefore, even when the start based on one of the temporarily determined crank angles has failed, the start of the engine can be completed by the start using the crank count recalculated based on the other crank angle.

(8) According to the control device for a hybrid vehicle of (6) or (7), the count calculation unit calculates the crank count with reference to a rotation angle of the motor. The crank position sensor cannot detect the crank angle when the rotational speed of the crankshaft is extremely slow. Further, since the rotation direction of the crankshaft cannot be specified, the crank angle cannot be grasped when the crankshaft rotates in the opposite rotation direction immediately before the engine stops. In contrast, in the case of a hybrid vehicle that travels using a motor and an engine, the rotation angle of the crankshaft can be estimated based on the rotation angle of the motor that assists in driving the engine. In this case, even when the rotation speed of the crankshaft is extremely slow, such as when the engine is stopped, or when rotation in the opposite rotation direction occurs, the rotation angle of the crankshaft can be estimated. Therefore, according to the above configuration, even when the operation of the engine is stopped, the rotation angle of the crankshaft can be estimated with reference to the rotation angle of the motor. If the crank angle during the engine stop can be grasped in this way, the engine can be started based on the grasped crank angle at the next engine start. Therefore, even if the cam position sensor fails, the start of the engine can be completed quickly.

(9) The control device for a hybrid vehicle according to (8) is provided with a stop prohibition unit that prohibits an operation of the engine from being stopped by the intermittent stop control, and the stop prohibition unit continues the operation of the engine by executing the intermittent stop prohibition process when the cam position sensor has failed and the calculation of the crank count cannot be performed with reference to the rotation angle of the motor.

When the operation of the engine is stopped by the intermittent stop control when the cam position sensor fails, it is necessary to perform the start again using the crank angle temporarily determined based on the detection of the missing tooth portion.

The restart in the state where the cam position sensor is failed may fail, and as compared with the case where the operation of the engine is continued, wasteful consumption of fuel and discharge of unburned gas may be caused. In contrast, according to the above configuration, the engine operation is continued, and therefore, the execution of the restart, which may fail, is suppressed, and the failure of the start can be avoided.

Claims

1. A control device for a hybrid vehicle, applied to a hybrid vehicle including an engine and a motor as a driving force source, the control device executing intermittent stop control for automatically stopping and restarting an operation of the engine, the control device comprising:

a diagnostic unit that executes a diagnostic process for confirming whether or not there is an abnormality in the engine while the engine is operating; and

a stop prohibition portion that executes intermittent stop prohibition processing that prohibits stopping of operation of the engine by the intermittent stop control,

the diagnostic unit causes the temporary determination flag to be stored in the nonvolatile memory when it is determined that there is an abnormality by the diagnostic processing in a state where the temporary determination flag is not stored in the nonvolatile memory, and performs a diagnosis of an abnormality and clears the temporary determination flag from the nonvolatile memory when it is determined that there is an abnormality by the diagnostic processing in a state where the temporary determination flag is stored in the nonvolatile memory,

the stop prohibition portion executes the intermittent stop prohibition processing when the temporary determination flag is stored in the nonvolatile memory.

2. The control device of the hybrid vehicle according to claim 1,

the stop prohibition unit sets a period in which a system main switch of a vehicle is on as one stroke, and releases prohibition of stopping the engine due to storage of the provisional determination flag when the stroke in which stopping of the engine by the intermittent stop control is prohibited due to storage of the provisional determination flag continues for a predetermined number of times.