Vehicle control device

Abstract

To provide a controller for a vehicle that can execute both temperature raising control and regeneration control over a filter while securing drivability.SOLUTION: The present invention relates to a controller for a vehicle that has an engine as a travel power source, a filter collecting exhausted fine particles from the engine, and a lock-up clutch provided on a power transmission path between the engine and driving wheels. The controller for the vehicle comprises: a determination part which determines whether or not there is a request to raise a temperature of the filter through retardation processing on an ignition period of the engine and a request to regenerate the filter by cutting fuel of the engine; and a control part which releases the lock-up clutch in an accelerator ON state to execute temperature raising control of the filter when there are the request to raise the temperature and the request to regenerate the filter, and engages the lock-up clutch to execute the regeneration control of the filter if the accelerator ON state is switched to an accelerator OFF state after the temperature raising control is completed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] In some cases, filter temperature increase control is performed by retarding the ignition timing of the engine. In this case, by disengaging the lockup clutch, it is possible to prevent engine vibrations caused by the ignition timing retard from being transmitted to the drive wheels (see, for example, Patent Document 1). In other cases, filter regeneration control is performed by cutting fuel to the engine. In this case, by engaging the lockup clutch of the torque converter, power is transmitted from the drive wheels to the engine, which suppresses a decrease in engine speed and prevents the engine from stalling (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-141445 [Patent Document 2] Patent Publication No. 2021-148097 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned patent documents do not disclose a case where both a temperature increase request and a regeneration request are made, and it is desirable to execute both temperature increase control and regeneration control while ensuring drivability.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vehicle control device that can execute both filter temperature increase control and filter regeneration control while ensuring drivability. [Means for solving the problem]

[0006] The above object can be achieved by a vehicle control device that includes an engine as a driving power source, a filter that collects exhaust particulates from the engine, and a torque converter with a lock-up clutch provided on a power transmission path between the engine and drive wheels, the vehicle control device including: a determination unit that determines whether there is a request to increase the temperature of the filter by retarding the ignition timing of the engine, and a request to regenerate the filter by cutting fuel in the engine; and a control unit that, when there is a request to increase the temperature and a request to regenerate the filter, releases the lock-up clutch when the accelerator is on and performs temperature increase control of the filter, and engages the lock-up clutch and performs regeneration control of the filter when the accelerator is switched from on to off after completion of the temperature increase control.

[0007] The control unit may continue the temperature rise control when the accelerator is switched from on to off before the temperature rise control is completed.

[0008] The vehicle may further include a motor serving as a power source for traveling, the motor being provided on a power transmission path between the engine and the torque converter, and a battery for supplying and receiving electric power to and from the motor. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a vehicle control device that can execute both filter temperature increase control and filter regeneration control while ensuring drivability. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a hybrid vehicle. [Figure 2] FIG. 1 is a schematic diagram of an engine. [Figure 3] 4 is a flowchart illustrating temperature rise control and regeneration control. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Hybrid vehicle configuration] FIG. 1 is a schematic diagram of a hybrid vehicle 1. The hybrid vehicle 1 is equipped with an engine 10 and a motor 15 as power sources for traveling. The engine 10 is a gasoline engine with multiple cylinders, but may also be a diesel engine. A transmission unit 11 is provided in a power transmission path from the engine 10 to drive wheels 13. The transmission unit 11 and the left and right drive wheels 13 are drivingly connected via a differential 12.

[0012] The transmission unit 11 is provided with a K0 clutch 14 and a motor 15. The motor 15 is provided on a power transmission path from the engine 10 to the drive wheels 13.

[0013] The K0 clutch 14 is provided between the engine 10 and the motor 15 in the power transmission path. The K0 clutch 14 is engaged when supplied with hydraulic pressure, connecting the power transmission between the engine 10 and the motor 15. The K0 clutch 14 is released when the hydraulic pressure supply is stopped, cutting off the power transmission between the engine 10 and the motor 15. The K0 clutch 14 is in a slip state from when torque transmission begins until it is fully engaged.

[0014] The motor 15 is connected to the battery 16 via an inverter 17. The battery 16 is a rechargeable 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 battery 16. The motor 15 also functions as a generator that generates electric power to charge the battery 16 in response to power transmitted from the engine 10 and the drive wheels 13. The electric power exchanged between the motor 15 and the battery 16 is adjusted by the inverter 17.

[0015] The transmission unit 11 is provided with a torque converter 18 and an automatic transmission 19. The torque converter 18 is a fluid coupling with a torque amplification function. The automatic transmission 19 is a stepped transmission that switches the gear ratio in multiple stages. The torque converter 18 is provided on the power transmission path between the motor 15 and the drive wheels 13. The automatic transmission 19 is provided on the power transmission path between the torque converter 18 and the drive wheels 13. The torque converter 18 is provided with a lock-up clutch (hereinafter referred to as an LU clutch) 20 that receives a supply of hydraulic pressure and engages to directly connect the motor 15 and the automatic transmission 19.

[0016] The LU clutch 20 is engaged when hydraulic pressure is applied, connecting the power transmission between the motor 15 and the drive wheels 13. The LU clutch 20 is released when the hydraulic pressure supply is stopped. The LU clutch 20 is in a slip state from the released state to the engaged state.

[0017] 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 LU 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 LU clutch 20, and various hydraulic control valves for controlling the operating hydraulic pressures thereof.

[0018] The hybrid vehicle 1 is provided with an ECU (Electronic Control Unit) 50 as a control device for the vehicle. The ECU 50 is an electronic control unit that includes a processing circuit that performs various types of calculations related to vehicle driving control, and a memory that stores control programs and data. The ECU 50 is an example of a vehicle control device, and functionally realizes a determination unit and a control unit, which will be described in detail later.

[0019] The ECU 50 receives signals from an ignition switch 61, a crank angle sensor 62, an air flow meter 63, air-fuel ratio sensors 64 and 65, and an accelerator position sensor 66. The ignition switch 61 detects whether the ignition is on or off. The crank angle sensor 62 detects the rotation speed of the crankshaft of the engine 10. The air flow meter 63 detects the amount of intake air introduced into the engine 10. The air-fuel ratio sensors 64 and 65 detect the air-fuel ratio of the exhaust gas from the engine 10. The accelerator position sensor 66 detects the accelerator position operated by the accelerator pedal.

[0020] The ECU 50 controls the operation of the engine 10 and the motor 15. Specifically, the ECU 50 controls the inverter 17 to adjust the amount of electric power exchanged between the motor 15 and the battery 16, thereby controlling the torque of the motor 15. The ECU 50 controls the operation of the K0 clutch 14, the LU clutch 20, and the automatic transmission 19 through the control of the hydraulic control mechanism 22.

[0021] The ECU 50 drives the hybrid vehicle 1 in either the motor driving mode or the hybrid driving mode. In the motor driving mode, the ECU 50 disengages the K0 clutch 14 to rotate the drive wheels 13 using the power of the motor 15. In the hybrid driving mode, the ECU 50 engages the K0 clutch 14 to rotate the drive wheels 13 using the power of at least one of the engine 10 and the motor 15. The motor driving mode is selected when there is a sufficient margin of charge in the battery 16. The hybrid driving mode is selected when the remaining charge of the battery 16 is low, when the vehicle speed exceeds the upper limit in the motor driving mode, or when rapid acceleration occurs.

[0022] [Engine outline] 2 is a schematic diagram of the engine 10. The engine 10 includes a cylinder block 30, a cylinder head 32, a piston 33, a connecting rod 34, a crankshaft 35, an intake passage 36, an intake valve 36v, an exhaust passage 37, and an exhaust valve 37v.

[0023] A cylindrical bore 31 is provided in the cylinder block 30. A piston 33 is housed in the bore 31 so as to be able to reciprocate. A combustion chamber C is defined by the wall surface of the bore 31, the lower surface of the cylinder head 32, and the top surface of the piston 33. The volume of the combustion chamber C increases and decreases as the piston 33 reciprocates.

[0024] The engine 10 is connected to a crankshaft 35, which is the output shaft of the engine 10, via a connecting rod 34. The connecting rod 34 and the crankshaft 35 form a crank mechanism that converts the reciprocating motion of the piston 33 into the rotational motion of the crankshaft 35. The engine 10 is provided with the crank angle sensor 62 described above.

[0025] The intake passage 36 is connected to the combustion chamber C via an intake valve 36v. The exhaust passage 37 is connected to the combustion chamber C via an exhaust valve 37v. The intake passage 36 is provided with the air flow meter 63 described above.

[0026] The cylinder block 30 is provided with an in-cylinder injection valve 41D that injects fuel directly into the combustion chamber C. The intake passage 36 is provided with a port injection valve 41P that injects fuel toward the intake port. The cylinder head 32 is provided with an ignition plug 42 that ignites the mixture of intake air and fuel introduced into the combustion chamber C. Note that only one of the in-cylinder injection valve 41D and the port injection valve 41P may be provided.

[0027] The exhaust passage 37 is provided with a three-way catalyst 43 and a GPF (Gasoline Particulate Filter) 44. The three-way catalyst 43 contains catalytic metal, has oxygen storage capacity, and purifies NOx, HC, and CO. The GPF 44 is a porous ceramic structure that captures exhaust fine particles (hereinafter referred to as PM (Particulate Matter)) in the exhaust gas. The GPF 44 is an example of a filter. Note that, for example, if the engine 10 is a diesel engine, a DPF (Diesel Particulate Filter) is provided instead of the GPF 44.

[0028] An air-fuel ratio sensor 64 is provided between the three-way catalyst 43 and the GPF 44. The air-fuel ratio sensor 64 detects the air-fuel ratio of the exhaust gas discharged from the three-way catalyst 43. An air-fuel ratio sensor 65 is provided downstream of the GPF 44. The air-fuel ratio sensor 65 detects the air-fuel ratio of the exhaust gas discharged from the GPF 44.

[0029] The ECU 50 controls the operation of the engine 10 by controlling the opening of the throttle valve 40, the fuel injection amount of the in-cylinder injection valve 41D and the port injection valve 41P, the ignition timing of the spark plug 42, etc. based on the detection signals of the above-mentioned sensors.

[0030] [Temperature rise control and regeneration control] Next, an example of the temperature increase control and regeneration control of the GPF 44 executed by the ECU 50 will be described. Fig. 3 is a flowchart illustrating the temperature increase control and regeneration control of the GPF 44 in this embodiment. This control is repeatedly executed while the ignition is on.

[0031] The ECU 50 determines whether there is a request to increase the temperature of the GPF 44 (step S1). If the answer is Yes in step S1, the ECU 50 determines whether there is a request to regenerate the GPF 44 (step S2). If the answer is Yes in step S1 and No in step S2, the ECU 50 releases the LU clutch 20 and executes temperature increase control of the GPF 44 (step S3). In the temperature increase control, ignition timing retardation processing is executed. The ignition timing retardation processing increases the amount of exhaust heat, causing the temperature of the GPF 44 to increase. Furthermore, because the LU clutch 20 is released, it is possible to prevent fluctuations in the combustion state of the engine 10 due to the ignition timing retardation processing from being transmitted to the drive wheels 13.

[0032] If the answer is No in step S1, the ECU 50 determines whether or not there is a request to regenerate the GPF 44 (step S4). If the answers are No in both steps S1 and S4, this control ends. If the answer is No in step S1 and Yes in step S4, the ECU 50 executes regeneration control (step S5). In regeneration control, fuel is cut off while the LU clutch 20 is engaged. By cutting fuel, oxygen is supplied to the GPF 44, which can promote the combustion of accumulated PM. Furthermore, because fuel is cut off while the LU clutch 20 is engaged, stalling of the engine 10 can be prevented.

[0033] If the judgment results in steps S1 and S2 are Yes, the ECU 50 judges whether the accelerator is on, i.e., whether the accelerator pedal is depressed, based on the detection value of the accelerator opening sensor 66 (step S6). If the judgment result in step S6 is Yes, the hybrid vehicle 1 can be considered to be accelerating, and the ECU 50 releases the LU clutch 20 and executes temperature rise control (step S7). Temperature rise control can be executed while satisfying the driver's acceleration request. Steps S1 and S2 are an example of processing executed by the judgment unit.

[0034] Next, the ECU 50 executes step S6 again. If the answer is No in step S6, that is, if the accelerator is off and the hybrid vehicle 1 is decelerating, the ECU 50 determines whether the temperature rise control has been completed (step S8). Specifically, it is determined that the temperature rise control has been completed when the temperature of the GPF 44 is equal to or higher than a predetermined value. The temperature of the GPF 44 may be an estimated value calculated based on the engine speed or engine load, a detected value of a temperature sensor provided in the GPF 44, or calculated by any other known method. If the answer is No in step S8, step S7 is executed again.

[0035] If step S6 is No and step S8 is Yes, it is assumed that the hybrid vehicle 1 is decelerating and the temperature increase control is complete, and the ECU 50 engages the LU clutch 20 to perform regeneration control by fuel cut (step S9). Since fuel cut is performed when the accelerator is released, the impact on drivability can also be suppressed. Steps S6 to S9 are an example of processing performed by the control unit.

[0036] In this way, when both a temperature increase request and a regeneration request are present, the temperature increase control and the regeneration control can be executed continuously in response to accelerator pedal ON / OFF, thereby enabling both the temperature increase control and the regeneration control to be executed while minimizing the impact on drivability.

[0037] As described above, the hybrid vehicle 1 includes the motor 15 and the battery 16 in addition to the engine 10. For example, the battery 16 supplies power to the motor 15, which is a driving power source, and charges the motor 15 with regenerative power. Therefore, the battery 16 is heavier than a battery installed in an internal combustion engine vehicle. Thus, the weight of the hybrid vehicle 1 is greater than that of an internal combustion engine vehicle. As a result, the load on the engine 10 in the hybrid driving mode is greater than that of an internal combustion engine vehicle. Therefore, the amount of PM emissions in the hybrid driving mode may be greater than that of an internal combustion engine vehicle. Therefore, the hybrid vehicle 1 may need to perform temperature rise control and regeneration control more frequently than an internal combustion engine vehicle. The above-described embodiment is suitable for the hybrid vehicle 1, which performs temperature rise control and regeneration control more frequently. However, the above-described embodiment can also be applied to a control device for an internal combustion engine vehicle that has only an engine as a driving power source.

[0038] 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 as defined in the claims. [Explanation of symbols]

[0039] 1 Hybrid vehicle 10 Engine 15 motor 16 Battery 18 Torque converter 20 Lock-up clutch 44 GPF (filter) 50 ECU (vehicle control unit, judgment unit, control unit)

Claims

1. A control device for a vehicle including an engine as a driving power source, a filter that collects exhaust particulates from the engine, and a torque converter having a lock-up clutch provided on a power transmission path between the engine and drive wheels, a determination unit that determines whether or not there is a request to increase the temperature of the filter by retarding the ignition timing of the engine and a request to regenerate the filter by cutting fuel in the engine; a control unit that, when there is a temperature increase request and a regeneration request, disengages the lock-up clutch to execute temperature increase control of the filter when the accelerator is on, and engages the lock-up clutch to execute regeneration control of the filter when the accelerator is switched from on to off after completion of the temperature increase control, The control device for a vehicle, when there is a temperature increase request but there is no regeneration request, disengages the lock-up clutch to perform temperature increase control of the filter, and when there is no temperature increase request but there is a regeneration request, engages the lock-up clutch to perform regeneration control of the filter.

2. The vehicle control device according to claim 1 , wherein the control unit continues the temperature rise control when the accelerator is switched from on to off before the temperature rise control is completed.

3. a motor serving as a driving power source provided on a power transmission path between the engine and the torque converter; 3. The vehicle control device according to claim 1, further comprising: a battery for supplying and receiving electric power to and from the motor.

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