Vehicular control device and method

Abstract

When an engine is in operation an ignition switch is turned off by a driver an ECU executes a program including the step of actuating an electric motor driven oil pump.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a configuration of a power train of a hybrid vehicle.

FIG. 2 is a nomographic chart of a power split device.

FIG. 3 is a nomographic chart of a transmission.

FIG. 4 shows a hydraulic control device of a hybrid vehicle.

FIG. 5 is timing plots (1) representing how MG (1) and MG (2) transition in an engine stopping process.

FIG. 6 is a flow chart representing a structure of a program executed by an ECU shown in FIG. 1 for control.

FIG. 7 is timing plots (2) representing how MG (1) and MG (2) transition in an engine stopping process.

Claims

1. A vehicular control device for a vehicle having an engine, a first rotating electric machine connected to an output shaft of said engine, a second rotating electric machine, a transmission hydraulically operated to transmit a torque from said second rotating electric machine to a driving wheel, an electric motor driven oil pump, and a mechanical oil pump driven by said engine, the vehicular control device comprising an operation unit, wherein if an ignition switch is operated to stop said engine, said operation unit allows said transmission to receive hydraulic pressure to engage a friction engagement-element of said transmission and thus control said transmission to be capable of transmitting a torque from said second rotating electric machine;if said ignition switch is operated to stop said engine, said operation unit controls said second rotating electric machine to generate a torque; andif said engine is in operation and said ignition switch is operated to stop said engine, said operation unit controls said electric motor driven oil pump to be actuated.

2. The vehicular control device according to claim 1, wherein; said operation unit determines whether hydraulic pressure generated by said mechanical oil pump before that said ignition switch is operated is detected, can be maintained; andif said hydraulic pressure generated by said mechanical oil pump can be maintained, said operation unit prohibits activating said electric motor driven oil pump.

3. The vehicular control device according to claim 2, wherein said operation unit determines from temperature of hydraulic fluid whether said hydraulic pressure generated by said mechanical oil pump can be maintained.

4. The vehicular control device according to claim 1, wherein if said ignition switch is operated by a driver to stop said engine, said operation unit controls said first rotating electric machine to generate a torque to rotate said output shaft of said engine to stop said engine at a predetermined crank angle.

5. The vehicular control device according to claim 4, wherein: said operation unit controls said first rotating electric machine such that said first rotating electric machine maintains a predetermined torque to allow said engine to have a predetermined number of revolutions for a predetermined period of time, and in that condition, said output shaft of said engine is rotated to attain said predetermined crank angle, and thereafter said torque is reduced to stop said engine at said predetermined crank angle; andafter said electric motor driven oil pump is actuated, said electric motor driven oil pump is stopped as based on a torque of said first rotating electric machine.

6. A method of controlling a vehicle having an engine, a first rotating electric machine connected to an output shaft of said engine, a second rotating electric machine, a transmission hydraulically operated to transmit a torque from said second rotating electric machine to a driving wheel, an electric motor driven oil pump, and a mechanical oil pump driven by said engine, the method comprising the steps of: in response to an ignition switch being operated to stop said engine, feeding said transmission with hydraulic pressure to engage a friction engagement element of said transmission to control said transmission to be capable of transmitting a torque from said second rotating electric machine;in response to said ignition switch being operated to stop said engine, controlling said second rotating electric machine to generate a torque; andif said engine is in operation and said ignition switch is operated to stop said engine, controlling said electric motor driven oil pump to be actuated.

7. The method of controlling a vehicle according to claim 6, further comprising the steps of: determining whether hydraulic pressure generated by said mechanical oil pump before that said ignition switch is operated is detected, can be maintained; andif said hydraulic pressure generated by said mechanical oil pump can be maintained, then prohibiting actuating said electric motor driven oil pump in the step of controlling said pump.

8. The method of controlling a vehicle according to claim 7, wherein the step of determining whether said hydraulic pressure can be maintained includes the step of determining from temperature of hydraulic fluid whether said hydraulic pressure generated by said mechanical oil pump can be maintained.

9. The method of controlling a vehicle according to claim 6, further comprising the step of controlling said first rotating electric machine to stop said engine at a predetermined crank angle by rotating said output shaft of said engine by causing said first rotating electric machine to generate a torque when said ignition switch is operated by a driver to stop said engine.

10. The method of controlling a vehicle according to claim 9, wherein: the step of controlling said first rotating electric machine to stop said engine includes the step of controlling said first rotating electric machine such that said first rotating electric machine maintains a predetermined torque to allow said engine to have a predetermined number of revolutions for a predetermined period of time, and in that condition, said output shaft of said engine is rotated to attain said predetermined crank angle, and thereafter said torque is reduced to stop said engine at said predetermined crank angle; andthe method further comprises the step of stopping said electric motor driven oil pump, as based on a torque of said first rotating electric machine, after said electric motor driven oil pump is actuated.

11. A vehicular control device for a vehicle having an engine, a first rotating electric machine connected to an output shaft of said engine, a second rotating electric machine, a transmission hydraulically operated to transmit a torque from said second rotating electric machine to a driving wheel, an electric motor driven oil pump, and a mechanical oil pump driven by said engine, comprising: means operative in response to an ignition switch being operated to stop said engine, for feeding said transmission with hydraulic pressure to engage a friction engagement element of said transmission to control said transmission to be capable of transmitting a torque from said second rotating electric machine;means operative in response to said ignition switch being operated to stop said engine, for controlling said second rotating electric machine to generate a torque; andmeans operative in response to said ignition switch being operated with said engine in operation to stop said engine, for controlling said electric motor driven oil pump to be actuated.

12. The vehicular control device according to claim 11, further comprising: means for determining whether hydraulic pressure generated by said mechanical oil pump before that said ignition switch is operated is detected, can be maintained; andmeans for prohibiting said means for controlling said pump from actuating said electric motor driven oil pump if said hydraulic pressure generated by said mechanical oil pump can be maintained.

13. The vehicular control device according to claim 12, wherein said means for determining includes means for determining from temperature of hydraulic fluid whether said hydraulic pressure generated by said mechanical oil pump can be maintained.

14. The vehicular control device according to claim 11, further comprising means for controlling said first rotating electric machine to stop said engine at a predetermined crank angle by rotating said output shaft of said engine by causing said first rotating electric machine to generate a torque when said ignition switch is operated by a driver to stop said engine.

15. The vehicular control device according to claim 14, wherein: said means for controlling said first rotating electric machine to stop said engine includes means for controlling said first rotating electric machine such that said first rotating electric machine maintains a predetermined torque to allow said engine to have a predetermined number of revolutions for a predetermined period of time, and in that condition, said output shaft of said engine is rotated to attain said predetermined crank angle, and thereafter said torque is reduced to stop said engine at said predetermined crank angle; andthe vehicular control device further comprises means for stopping said electric motor driven oil pump, as based on a torque of said first rotating electric machine, after said electric motor driven oil pump is actuated.