Hybrid vehicle control device

Abstract

To provide a control device of a hybrid vehicle that can suppress shock and start an internal combustion engine.SOLUTION: A control device of a hybrid vehicle which has an internal combustion engine, a motor, and a clutch provided between the internal combustion engine and the motor, comprises a clutch control part that controls the clutch and a fuel control part that controls supply of fuel to the internal combustion engine. When the clutch is stuck while starting the internal combustion engine, the fuel control part stops the supply of the fuel, and the clutch control part makes the clutch engage more strongly than that when the clutch is not stuck.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Some hybrid vehicles include an internal combustion engine, a motor provided in a power transmission path between the engine and the wheels, and a clutch provided in the power transmission path between the engine and the motor. When a request is made to start the engine, the clutch is slipped to crank the engine using the motor, and the clutch is engaged to start the engine (for example, see Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-111276 A Summary of the Invention [Problem to be solved by the invention]

[0004] If the clutch becomes stuck during start-up of the internal combustion engine, the clutch is tightened to start the engine. However, this increases the torque transmitted from the internal combustion engine, causing shocks. Therefore, the objective of this invention is to provide a control device for a hybrid vehicle that can suppress shocks and start the internal combustion engine. [Means for solving the problem]

[0005] The above object is to provide a control device for a hybrid vehicle having an internal combustion engine, a motor, and a clutch provided between the internal combustion engine and the motor, the control device including a clutch control unit that controls the clutch, and a fuel control unit that controls the supply of fuel to the internal combustion engine, the clutch control unit switches between a state in which the clutch is released and power is not transmitted between the internal combustion engine and the motor and a state in which the clutch is engaged and power can be transmitted between the internal combustion engine and the motor compared to the released state, and the internal combustion engine starts when the clutch is in a state in which power can be transmitted and the power of the motor is transmitted via the clutch, The clutch is stuck during starting of the internal combustion engine and the switch to a state in which the power can be transmitted is stopped.In this case, the fuel control unit stops the supply of the fuel, and the clutch control unit closes the clutch more than before the stack. Increase the force to engage the clutch This can be accomplished by a hybrid vehicle control system that provides hard engagement. Effect of the Invention

[0006] It is possible to provide a control device for a hybrid vehicle that suppresses shock and enables starting of the internal combustion engine. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating a hybrid vehicle. [Diagram 2] FIG. 2 is a flowchart illustrating the processing executed by the ECU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (Hybrid vehicle) FIG. 1 is a schematic diagram illustrating a hybrid vehicle 1. The hybrid vehicle 1 is equipped with an engine 10 (internal combustion engine) and a motor 15 as driving sources. In the hybrid vehicle 1, a K0 clutch 14, a motor 15, a torque converter 18, and an automatic transmission 19 are provided in this order in a power transmission path from the engine 10 to the wheels 13. The engine 10 is, for example, a V-type six-cylinder engine and has six cylinders #1 to #6. The engine 10 may be, for example, a V-type engine or an in-line engine. The engine 10 may be a gasoline engine or a diesel engine. The number of cylinders in the engine 10 may be a plurality of cylinders, for example, four or six, or may be one. The K0 clutch 14, the motor 15, the torque converter 18, and the automatic transmission 19 are provided in a transmission unit 11. The transmission unit 11 and the left and right wheels 13 are drivingly connected via a differential gear 12.

[0009] The K0 clutch 14 is provided between the engine 10 and the motor 15 on the power transmission path. The K0 clutch 14 is switched to any one of a released state, a slip state, and an engaged state according to the supply of hydraulic pressure. In detail, when the K0 clutch 14 is in the released state, the K0 clutch 14 is switched to a slip state or an engaged state by the supply of hydraulic pressure, and the power transmission between the engine 10 and the motor 15 is connected. In addition, the K0 clutch 14 is switched to a released state according to the stop of the hydraulic pressure supply, and the power transmission between the engine 10 and the motor 15 is interrupted. The slip state is a state in which the engagement element of the K0 clutch 14 on the engine 10 side and the engagement element on the motor 15 side are in sliding contact with each other with a predetermined difference in rotation speed. The engaged state is a state in which both engagement elements of the K0 clutch 14 are connected and the engine 10 and the motor 15 have the same rotation speed. The released state is a state in which both engagement elements of the K0 clutch 14 are separated.

[0010] The motor 15 is connected to the battery 16 via an inverter 17. The motor 15 functions as a motor that generates driving force for the vehicle in response to power supplied from the battery 16, and also functions as a generator that generates electric power to charge the 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 battery 16 is adjusted by the inverter 17.

[0011] The inverter 17 is controlled by the ECU 50 described later, and converts the DC voltage from the battery 16 into an AC voltage, or converts the AC voltage from the motor 15 into a DC voltage. In the case of powering operation in which the motor 15 outputs torque, the inverter 17 converts the DC voltage of the battery 16 into an AC voltage and adjusts the power supplied to the motor 15. In the case of regenerative operation in which the motor 15 generates power, the inverter 17 converts the AC voltage from the motor 15 into a DC voltage and adjusts the power supplied to the battery 16.

[0012] The torque converter 18 is a fluid coupling having a torque amplifying function. The automatic transmission 19 is a stepped automatic transmission that switches the gear ratio in multiple stages by switching the gear stage. The automatic transmission 19 is provided between the motor 15 and the wheels 13 on the power transmission path. 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 enters an engaged state to directly connect the motor 15 and the automatic transmission 19.

[0013] 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.

[0014] The hybrid vehicle 1 is provided with an ECU (Electronic Control Unit) 50 as a control device. 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 functions as a clutch control unit that controls the K0 clutch 14, and a fuel control unit that controls the supply of fuel to the engine 10.

[0015] The ECU 50 controls the operation of the engine 10 and the motor 15. For example, the ECU 50 controls the torque and rotation speed of the engine 10 by controlling the throttle opening, ignition timing, and fuel injection amount of the engine 10. The ECU 50 also controls the operation of the K0 clutch 14, the lock-up clutch 20, and the automatic transmission 19 through control of the hydraulic control mechanism 22. The ECU 50 controls the hydraulic pressure applied to the K0 clutch 14 using the hydraulic control mechanism 22, and changes the state of the K0 clutch 14, thereby controlling the cranking torque transmitted from the motor 15 to the engine 10.

[0016] The ECU 50 controls the inverter 17 to adjust the amount of power exchanged between the motor 15 and the battery 16, thereby controlling the rotation speed and torque of the motor 15. As will be described in detail later, the ECU 50 also controls the power supplied by the inverter 17 from the motor 15 to the battery 16 so that the motor braking torque during regenerative operation becomes a target value.

[0017] Signals are input to the ECU 50 from an ignition switch 71, a crank angle sensor 72, a motor revolution speed sensor 73, an airflow meter 74, and an accelerator opening sensor 75. The crank angle sensor 72 detects the rotation speed of the crankshaft of the engine 10. The motor revolution speed sensor 73 detects the rotation speed of the output shaft of the motor 15. The airflow meter 74 detects the amount of intake air of the engine 10. The accelerator opening sensor 75 detects the accelerator pedal opening, which is the amount of depression of the accelerator pedal by the driver.

[0018] The ECU 50 runs the hybrid vehicle in either a motor mode or a hybrid mode. In the motor mode, the ECU 50 releases the K0 clutch 14 and runs the vehicle using the power of the motor 15. In the hybrid mode, the ECU 50 engages the K0 clutch 14 and runs the vehicle using at least the power of the engine 10. The hybrid mode includes a mode in which the vehicle runs using only the power of the engine 10, and a mode in which the motor 15 is powered and the vehicle runs using both the engine 10 and the motor 15 as power sources.

[0019] The driving mode is switched based on the vehicle's required driving force calculated from the vehicle speed and accelerator opening, and the state of charge of the battery 16. For example, when the required driving force is relatively small and the SOC (State Of Charge) indicating the remaining charge of the battery 16 is relatively high, the motor mode in which the engine 10 is stopped is selected to improve fuel efficiency. When the required driving force is relatively large or the SOC of the battery 16 is relatively low, the hybrid mode in which at least the engine 10 is driven is selected.

[0020] In the hybrid mode, the ECU 50 executes intermittent operation control to automatically stop the engine 10 when a predetermined stop condition is satisfied, and to restart the automatically stopped engine 10 when a predetermined restart condition is satisfied. For example, in the hybrid mode, when the accelerator opening becomes zero, the ECU 50 automatically stops the engine 10 assuming that the automatic stop condition is satisfied. In addition, in the hybrid mode, when the accelerator opening becomes greater than zero, the ECU 50 automatically restarts the engine 10 assuming that the restart condition is satisfied. When automatically stopping the engine 10, the ECU 50 releases the K0 clutch 14 to stop fuel injection. When automatically restarting the engine 10, the ECU 50 cranks the engine 10 by the motor 15 via the K0 clutch 14 to start fuel injection and ignition, and then engages the K0 clutch 14.

[0021] During start control, the K0 clutch 14 may become stuck. The K0 clutch 14 being stuck means that the control sequence for the K0 clutch 14 stops midway, and may occur, for example, due to a malfunction of the K0 clutch 14 or a malfunction of a part other than the K0 clutch 14. In this embodiment, when the engine 10 is stuck, the engine 10 is started and a shock is suppressed.

[0022] 2 is a flowchart illustrating a process executed by the ECU 50. In response to a request to start the engine 10, the ECU 50 executes start control of the engine 10. The ECU 50 determines whether the K0 clutch 14 is stuck during start of the engine 10 (step S10). If the determination is negative (No), the ECU 50 executes start control of the engine 10 (step S12). Specifically, the ECU 50 cranks the engine 10 using the motor 15, supplies and burns fuel to the engine 10, and starts the engine 10. Fuel cut is not performed.

[0023] If the determination in step S10 is affirmative (Yes), the ECU 50 stops the supply of fuel to the engine 10 (fuel cut, step S14). After step S14, the ECU 50 increases the oil pressure of the K0 clutch 14, for example, fully engaging the K0 clutch 14 (step S16, backup phase). After step S16, the ECU 50 resumes the supply of fuel and starts the engine 10 (step S12). This ends the process.

[0024] According to this embodiment, if the K0 clutch 14 gets stuck during starting of the engine 10, the ECU 50 cuts off the fuel supply to the engine 10. After the fuel cut, the ECU 50 engages the K0 clutch 14 more strongly than before the clutch 14 gets stuck, for example, by fully engaging the K0 clutch 14. Because the fuel is cut, the torque of the engine 10 is suppressed, and even if the K0 clutch 14 is fully engaged, the torque increase is suppressed. As a result, shock is suppressed. The full engagement of the K0 clutch 14 increases the cranking torque. The crankshaft of the engine 10 is rotated by cranking, and fuel is supplied and burned to start the engine 10. It is possible to start the engine 10 while suppressing shock.

[0025] In the above example, the hybrid vehicle 1 is controlled by a single ECU 50. However, the embodiment is not limited to this, and the above control may be executed by a plurality of ECUs, such as an engine ECU that controls the engine 10, a motor ECU that controls the motor 15, and a clutch ECU that controls the K0 clutch 14.

[0026] Although a preferred embodiment of the present invention has been described in detail above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0027] 1 Hybrid vehicles 10 Engine 11. Gear unit 12 Differential gear 13 wheels 14 K0 clutch 15 Motor 16 Battery 17 Inverter 18 Torque converter 19 Automatic transmission 20 Lock-up clutch 21 Oil pump 22 Hydraulic control mechanism 50 ECU 71 Ignition switch 72 Crank angle sensor 73 Motor speed sensor 74 Air flow meter 75 Accelerator opening sensor

Claims

[Claim 1] A control device for a hybrid vehicle having an internal combustion engine, a motor, and a clutch provided between the internal combustion engine and the motor, A clutch control unit that controls the clutch; A fuel control unit that controls the supply of fuel to the internal combustion engine, the clutch control unit switches between a state in which the clutch is released and power is not transmitted between the internal combustion engine and the motor and a state in which the clutch is engaged and power can be transmitted between the internal combustion engine and the motor, as compared with the released state; the clutch is in a state in which the power can be transmitted, and the power of the motor is transmitted via the clutch to start the internal combustion engine; A control device for a hybrid vehicle in which, when the clutch becomes stuck during start-up of the internal combustion engine and switching to a state in which the power can be transmitted is stopped, the fuel control unit stops the supply of fuel, and the clutch control unit increases the force that engages the clutch compared to before the clutch becomes stuck, thereby engaging the clutch more strongly.

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