Hybrid vehicle control device

Abstract

To provide a hybrid-vehicular control apparatus with a distance in a limp-home mode secured.SOLUTION: A hybrid-vehicular control apparatus comprises: an engine; a motor disposed in a power transmission path between the engine and wheels; a clutch disposed at a part between the engine and motor in the power transmission path; a battery for charging power generated by the motor; and an auxiliary machine for driving with power charged in the battery. The hybrid-vehicular control apparatus further includes: an abnormality determination part for determining whether or not there is abnormality in the engine: and a fail-safe control part for charging, in a case where it is determined that there is abnormality in the engine, the battery with power generated by the motor driven by the engine while executing limp-home mode control by the engine with the clutch engaged.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Patent Document 1 describes a hybrid vehicle that performs evacuation running using a motor when an abnormality occurs in the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-001531 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, when the vehicle is traveling to an evacuation zone using the motor, the motor cannot generate electricity and therefore cannot charge the battery. Because the charging power of the battery is also used for the hybrid vehicle's auxiliary equipment, there is a risk that the charging power of the battery will be insufficient to drive the auxiliary equipment, which may result in a short driving distance during the evacuation zone.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a control device for a hybrid vehicle that ensures a sufficient distance for evacuation travel. [Means for solving the problem]

[0006] The object of the present invention is to provide an engine, a motor provided in a power transmission path between the engine and wheels, a clutch provided in a portion of the power transmission path between the engine and the motor, a battery that charges the generated power of the motor, and an auxiliary device that is driven by the charged power of the battery. an exhaust gas purification catalyst provided in an exhaust passage of the engine;a fail-safe control unit that, when it is determined that the engine has an abnormality, engages the clutch to execute an evacuation drive control by the engine, while rotating the motor by the engine to charge the battery with power generated by the motor, and the fail-safe control unit limits the amount of charge of the battery by the power generated by the motor to the amount of power consumed by the auxiliary device, stops a motor assist control that assists the engine by the motor, and stops an intermittent operation control that automatically stops and restarts the operation of the engine. This can be achieved by a control device for a hybrid vehicle. Effect of the Invention

[0010] According to the present invention, it is possible to provide a control device for a hybrid vehicle that ensures a sufficient driving distance for evacuation driving. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a hybrid vehicle. [Diagram 2] FIG. 2 is a schematic diagram of the engine. [Diagram 3] FIG. 3 is a flowchart showing an example of the fail-safe control executed by the ECU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [General configuration of hybrid vehicle] FIG. 1 is a schematic diagram of a hybrid vehicle. The hybrid vehicle is equipped with an engine 10 and a motor 15 as driving sources for traveling. The engine 10 is an internal combustion engine, and in this embodiment is a spark-ignition gasoline engine as described below, but is not limited to this and may be, for example, a diesel engine. A transmission unit 11 is provided in a power transmission path from the engine 10 to wheels 13. The transmission unit 11 and the left and right wheels 13 are drivingly connected via a differential 12.

[0013] The transmission unit 11 is provided with a K0 clutch 14 and a motor 15. In the transmission unit 11, the motor 15 is installed so as to be located on a power transmission path from the engine 10 to the wheels 13.

[0014] The K0 clutch 14 is disposed so as to be located between the engine 10 and the motor 15 in the power transmission path. The K0 clutch 14 is supplied with hydraulic pressure and enters an engaged state, connecting the power transmission between the engine 10 and the motor 15. The K0 clutch 14 enters a released state in response to the cessation of the hydraulic pressure supply, and interrupts the power transmission between the engine 10 and the motor 15. The K0 clutch 14 is in a slip state from the start of torque transmission until it is fully engaged. The ECU 50, which will be described later, can control the K0 clutch 14 to any one of a released state, a slip state, and an engaged state by adjusting the hydraulic pressure supplied to the K0 clutch 14 by a hydraulic control mechanism 22.

[0015] The motor 15 is connected to the main battery 16 via an inverter 17. The main battery 16 is a chargeable and dischargeable secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The motor 15 functions as a motor that generates driving force for the vehicle in response to power supplied from the main battery 16, and also functions as a generator that generates electric power to charge the main battery 16 in response to power transmission from the engine 10 and the wheels 13. The electric power exchanged between the motor 15 and the main battery 16 is adjusted by the inverter 17.

[0016] An auxiliary battery 16a is connected to the main battery 16 via a DC / DC converter 17a. The DC / DC converter 17a reduces the high-voltage power of the main battery 16 and outputs low-voltage power to the auxiliary battery 16a. The auxiliary battery 16a is a secondary battery such as a lead-acid battery, and is charged by the low-voltage power output by the DC / DC converter 17a. The auxiliary battery 16a supplies low-voltage power to auxiliary devices 24 of the vehicle. The auxiliary devices 24 include devices having functions necessary during evacuation driving, such as an air conditioner compressor, headlights, a blower fan, wipers, hazard lights, a meter panel, audio, seat heaters, electric power steering, a navigation system, and a brake actuator.

[0017] The transmission unit 11 is provided with a torque converter 18, which is a fluid coupling having a torque amplifying function, and a stepped automatic transmission 19 that switches the gear ratio in multiple stages by changing the gear stage. In the transmission unit 11, the automatic transmission 19 is installed so as to be located at a portion of the power transmission path closer to the wheels 13 than the motor 15. The motor 15 and the automatic transmission 19 are connected via the torque converter 18. The torque converter 18 is provided with a lock-up clutch 20 that is supplied with hydraulic pressure and engages to directly connect the motor 15 and the automatic transmission 19.

[0018] The transmission unit 11 is further provided with an oil pump 21 and a hydraulic control mechanism 22. The hydraulic pressure generated by the oil pump 21 is supplied to the K0 clutch 14, the torque converter 18, the automatic transmission 19, and the lock-up clutch 20 via the hydraulic control mechanism 22. The hydraulic control mechanism 22 is provided with hydraulic circuits for each of the K0 clutch 14, the torque converter 18, the automatic transmission 19, and the lock-up clutch 20, and various hydraulic control valves for controlling the operating hydraulic pressures thereof.

[0019] The hybrid vehicle is provided with an ECU (Electronic Control Unit) 50 as a control device for the vehicle. The ECU 50 is an electronic control unit including a calculation processing circuit that performs various calculation processes related to vehicle driving control, and a memory that stores control programs and data. The ECU 50 is an example of a control device for a hybrid vehicle, and functionally realizes an abnormality determination unit and a fail-safe control unit, which will be described in detail later.

[0020] The ECU 50 controls the operation of the engine 10 and the motor 15. For example, the ECU 50 controls the inverter 17 to adjust the amount of power exchanged between the motor 15 and the main battery 16, thereby controlling the torque of the motor 15. The ECU 50 controls the operation of the K0 clutch 14, the lock-up clutch 20, and the automatic transmission 19 through the control of the hydraulic control mechanism 22. The ECU 50 receives detection signals such as an accelerator pedal opening degree, which is the amount of depression of the accelerator pedal by the driver. In addition, the ECU 50 is connected to a warning light 25 installed in the vehicle cabin, and when an abnormality occurs in the engine 10, for example, the warning light 25 is turned on to notify the driver of the abnormality. The ECU 50 is connected to an SOC sensor 26 that detects the remaining charge of the main battery 16.

[0021] The ECU 50 drives the hybrid vehicle in one of the driving modes of the motor driving mode, the hybrid driving mode, and the engine driving mode. In the motor driving mode, the ECU 50 releases the K0 clutch 14 to rotate the wheels 13 with the power of the motor 15. In the hybrid driving mode, the ECU 50 engages the K0 clutch 14 to rotate the wheels 13 with the power of the engine 10 and the motor 15. In the engine driving mode, the ECU 50 engages the K0 clutch 14 to rotate the wheels 13 with the power of the engine 10. The driving mode is switched based on the required driving force of the vehicle calculated from the vehicle speed and the accelerator pedal opening, the charging state of the main battery 16, and the like.

[0022] [Engine outline] FIG. 2 is a schematic diagram of the engine 10. The engine 10 has cylinders 30, pistons 31, connecting rods 32, a crankshaft 33, an intake passage 35, an intake valve 36, an intake valve timing mechanism 36v, and an exhaust passage 37. The cylinders 30 burn an air-fuel mixture. FIG. 2 shows only one of the multiple cylinders 30 of the engine 10. The pistons 31 are accommodated in the respective cylinders 30 so as to be capable of reciprocating, and are connected to a crankshaft 33, which is an output shaft of the engine 10, via a connecting rod 32. The connecting rods 32 and the crankshaft 33 constitute a crank mechanism that converts the reciprocating motion of the pistons 31 into the rotational motion of the crankshaft 33. The engine 10 is provided with a crank angle sensor 34 that detects the rotation angle of the crankshaft 33.

[0023] The intake passage 35 is an intake passage for intake air, and is connected to each cylinder 30 via an intake valve 36. The exhaust passage 37 is an exhaust passage for exhaust air, and is connected to each cylinder 30 via an exhaust valve 38. The intake valve 36 and the exhaust valve 38 are provided with a hydraulic intake valve timing mechanism 36v and an exhaust valve timing mechanism 38v that change the opening and closing timing of the intake valve 36 and the exhaust valve 38, respectively. The intake passage 35 is provided with an air flow meter 39 that detects the amount of intake air, a throttle valve 40 that is a valve for adjusting the flow rate of intake air, and an intake air temperature sensor 45 that detects the temperature of the intake air.

[0024] Each cylinder 30 is provided with a fuel injection valve 41. The fuel injection valve 41 is an in-cylinder injection valve that directly injects fuel into the cylinder 30, but is not limited thereto. It may be a port injection valve that injects fuel toward an intake port, or both an in-cylinder injection valve and a port injection valve may be provided. Each cylinder 30 is provided with an ignition device 42 that ignites a mixture of intake air introduced through the intake passage 35 and fuel injected by the fuel injection valve 41 by spark discharge. A catalyst 43 for exhaust purification is provided in the exhaust passage 37, and an air-fuel ratio sensor 44 for detecting an air-fuel ratio is provided upstream of the catalyst 43. In addition, the engine 10 is provided with a water temperature sensor 46 for detecting the temperature of cooling water for cooling the engine 10.

[0025] The ECU 50 receives detection signals from the crank angle sensor 34, the air flow meter 39, the air-fuel ratio sensor 44, the intake air temperature sensor 45, and the water temperature sensor 46. The ECU 50 calculates the engine speed from the detection signal from the crank angle sensor 34. The ECU 50 controls the operation of the engine 10 through control of the opening degree of the throttle valve 40, control of fuel injection by the fuel injector 41, control of ignition by the ignition device 42, and control of the opening and closing of the intake valve 36 and the exhaust valve 38 by the intake valve timing mechanism 36v and the exhaust valve timing mechanism 38v.

[0026] [Engine abnormality detection] The ECU 50 determines whether or not there is an abnormality in the engine 10. Specifically, the ECU 50 determines that there is an abnormality in the engine 10 when there is an abnormality in at least one of various devices such as the crank angle sensor 34, the intake valve timing mechanism 36v, the exhaust valve timing mechanism 38v, the air flow meter 39, the throttle valve 40, the fuel injector 41, the intake air temperature sensor 45, the water temperature sensor 46, and the combustion state of the engine 10.

[0027] The ECU 50 judges these abnormalities, for example, as follows. When the detection value of the crank angle sensor 34 is not input to the ECU 50 for a predetermined period while the engine 10 is running, the ECU 50 judges that an abnormality has occurred in the crank angle sensor 34. When the relationship between the cam angle signal and the crank angle signal does not change by an amount corresponding to the amount of drive when the intake valve timing mechanism 36v is driven, the ECU 50 judges that an abnormality has occurred in the intake valve timing mechanism 36v. The same applies to the exhaust valve timing mechanism 38v. When the deviation between the detection value and the target value of the air-fuel ratio sensor 44 is large, the ECU 50 judges that an abnormality has occurred in the fuel injection valve 41. When the intake air amount detected by the air flow meter 39 does not change in response to the opening and closing operation of the throttle valve 40 during steady operation, the ECU 50 judges that an abnormality has occurred in the air flow meter 39. If there is a large difference between the temperatures detected by the intake air temperature sensor 45 and the water temperature sensor 46 immediately after starting the engine 10, the ECU 50 determines that an abnormality has occurred in at least one of the intake air temperature sensor 45 and the water temperature sensor 46. If there is a large amount of rotational fluctuation at a predetermined crank angle corresponding to the combustion stroke of each cylinder, the ECU 50 determines that a misfire has occurred in one of the cylinders. combustion It is determined that an abnormality has occurred in the state. Note that the devices and controls that are the targets of the abnormality determination for the engine 10 are not limited to those described above. Also, the method of abnormality determination described above is one example, and abnormality determination may be performed using other methods.

[0028] [Fail-safe control in the event of engine abnormality] Next, the fail-safe control executed by the ECU 50 when an abnormality occurs in the engine 10 will be described. FIG. 3 is a flow chart showing an example of the fail-safe control executed by the ECU 50. This control is executed repeatedly during system startup of the hybrid vehicle. First, the ECU 50 determines whether or not there is an abnormality in the engine 10 as described above (step S1). Step S1 is an example of a process executed by the abnormality determination unit. If the result in step S1 is No, this control ends.

[0029] If the answer is Yes in step S1, the ECU 50 executes fail-safe control (step S2). Specifically, in the fail-safe control of this embodiment, the ECU 50 executes evacuation travel control by the engine 10, stops the motor assist control of the motor 15, limits the amount of charge to the main battery 16 by the motor 15 to the amount of power consumed by the accessories 24, and stops the intermittent operation control of the engine 10. In the evacuation travel control by the engine 10, the rotation speed and output torque of the engine 10 are limited. Step S2 is an example of a process executed by the fail-safe control unit.

[0030] In the above-mentioned fail-safe control, the K0 clutch 14 is engaged to execute the evacuation travel control by the engine 10. In this case, the motor 15 also rotates with the rotation of the engine 10. In this state, the motor assist control is stopped, that is, the power running by the motor 15 is stopped, so that the power consumption of the main battery 16 by the motor 15 is suppressed. Here, the charging power of the main battery 16 is charged to the auxiliary battery 16a via the DC / DC converter 17a, and the charging power of the auxiliary battery 16a is consumed by the auxiliary equipment 24. Therefore, by suppressing the power consumption of the main battery 16 by the motor 15, the power consumed by the auxiliary equipment 24 can be secured. This makes it possible to secure the distance for evacuation travel by the engine 10. In addition, by stopping the motor assist control, for example, when an abnormality in the combustion state (misfire) occurs, the motor assist control supplies unburned fuel and a large amount of oxygen to the catalyst 43, and the catalyst 43 can be prevented from overheating.

[0031] In the above-mentioned fail-safe control, the charging power to the main battery 16 by the motor 15 is limited to the power consumption by the auxiliary equipment 24, so that the power consumption by the auxiliary equipment 24 is ensured, and it is possible to suppress an increase in the load on the rotation of the engine 10 caused by an increase in the power generated by the motor 15 more than necessary. In addition, since the motor assist control is stopped as described above, the charging power of the main battery 16 is not consumed by the motor 15. Therefore, the decrease in the remaining charge of the main battery 16 after the start of the fail-safe control is almost equivalent to the power consumption of the auxiliary equipment 24. Here, the decrease in the remaining charge of the main battery 16 can be calculated based on the detection value of the SOC sensor 26. The ECU 50 controls the inverter 17 to charge the generated power of the motor 15 to the main battery 16, and controls the DC / DC converter 17a to charge the auxiliary battery 16a with the charging power of the main battery 16 so that the decrease in the remaining charge of the main battery 16 is charged to the main battery 16. This ensures that the auxiliary machinery 24 consumes sufficient power and continues to operate, thereby ensuring the distance required for evacuation travel.

[0032] In the above-mentioned fail-safe control, the intermittent operation control that automatically stops and restarts the engine 10 is stopped. The intermittent operation control is a control that can improve fuel economy, startability, and exhaust emissions at the time of starting by starting fuel injection control and ignition timing control at the time of restarting based on the crank angle at the time the engine 10 was stopped. However, as described above, if there is an abnormality in the crank angle sensor 34, the air flow meter 39, the throttle valve 40, the fuel injection valve 41, etc., it may not be possible to appropriately start fuel injection control and ignition timing control at the time of restarting, and it may not be possible to sufficiently improve fuel economy, etc. For this reason, the intermittent operation control is stopped.

[0033] Next, the ECU 50 turns on the warning light 25 (step S3), thereby making it possible to notify the driver that an abnormality has occurred in the engine 10, and to prompt the driver to inspect or repair the engine 10.

[0034] As described above, in the above fail-safe control, it is possible to ensure a sufficient driving distance during evacuation running using the engine 10. Also, by stopping the motor assist control during evacuation running using the engine 10 and limiting the power generated by the motor 15 to the power consumption of the auxiliary equipment 24, it is possible to realize evacuation running equivalent to that of an engine vehicle. As a result, for example, the engine control method used during evacuation running in an engine vehicle can also be used for evacuation running in the hybrid vehicle of this embodiment.

[0035] In this embodiment, an example has been given of a case where a hybrid vehicle is controlled by a single ECU 50, but this is not limited to this, and the above-mentioned control may be performed by multiple ECUs, such as an engine ECU that controls the engine 10, a motor ECU that controls the motor 15, a clutch ECU that controls the K0 clutch 14, and a battery ECU that controls the main battery 16.

[0036] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0037] 10 Engine 14 K0 clutch 15 Motor 16 Main battery 16a Auxiliary battery 17 Inverter 17a DC / DC converter 24 Auxiliary Equipment 25 Warning light 26 SOC sensor 50 ECU (control unit for hybrid vehicles)

Claims

[Claim 1] A control device for a hybrid vehicle having an engine, a motor provided in a power transmission path between the engine and wheels, a clutch provided in a portion of the power transmission path between the engine and the motor, a battery that charges electric power generated by the motor, accessories that are driven by the charged electric power of the battery, and an exhaust purification catalyst provided in an exhaust passage of the engine, an abnormality determination unit that determines whether or not an abnormality exists in the engine; a fail-safe control unit that, when it is determined that the engine has an abnormality, engages the clutch to execute an evacuation travel control by the engine, while rotating the motor by the engine to charge the battery with power generated by the motor, The fail-safe control unit is a control device for a hybrid vehicle that limits the amount of charging of the battery using the power generated by the motor to the amount of power consumed by the auxiliary equipment, stops motor assist control that assists the engine with the motor, and stops intermittent operation control that automatically stops and restarts the operation of the engine.

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