| 主权项 |
1. A control system for a hybrid vehicle, the vehicle including an engine, an output member, a power split mechanism, a brake mechanism, a first motor, a second motor, a first oil pump and a second oil pump, the power split mechanism including a first rotating element, a second rotating element and a third rotating element, the power split mechanism being configured to carry out differential action, an output torque of the engine being transmitted to the first rotating element, the first motor having a power generation function being coupled to the second rotating element, the output member being coupled to the third rotating element, the brake mechanism being configured to selectively stop rotation of the first rotating element, the second motor being configured to add a driving torque for propelling the vehicle to a torque of the output member, the first oil pump being coupled to the first rotating element, the first oil pump being configured to be driven by the output torque of the engine to supply oil to the power split mechanism, the second oil pump being configured to be driven through energization to supply oil to the power split mechanism,
the control system comprising: an electronic control unit configured to select a second drive mode when any one of the following conditions i), ii) is satisfied,
i) a required driving force is larger than the required driving force at which a first drive mode is selected or a vehicle speed is larger than the vehicle speed at which the first drive mode is selected, andii) the required driving force is lower than the required driving force at which a third drive mode is selected or the vehicle speed is lower than the vehicle speed at which the third drive mode is selected, the electronic control unit being configured to, when any one of the following conditions iii) to vi) is satisfied, activate the second oil pump to start supplying oil from the second oil pump to the power split mechanism,
iii) the required driving force becomes larger than or equal to a first pump changing value when the first drive mode is selected, the first pump changing value being smaller than a first drive changing value at which a drive mode is changed from the first drive mode to the second drive mode,iv) the vehicle speed becomes higher than or equal to a second pump changing value when the first drive mode is selected, the second pump changing value being lower than a second drive changing value at which the drive mode is changed from the first drive mode to the second drive mode,v) the required driving force becomes smaller than or equal to a third pump changing value when the third drive mode is selected, the third pump changing value being larger than a third drive changing value at which the drive mode is changed from the third drive mode to the second drive mode, andvi) the vehicle speed becomes lower than or equal to a fourth pump changing value when the third drive mode is selected, the fourth pump changing value being higher than a fourth drive changing value at which the drive mode is changed from the third drive mode to the second drive mode, the first drive mode being a mode in which fixing of the first rotating element by the brake mechanism is released and the vehicle travels by using the driving torque of the second motor, the second drive mode being a mode in which a torque output from the first motor is transmitted to the output member via the power split mechanism in a state where the first rotating element is fixed by the brake mechanism and the vehicle travels by using the driving torque output from the second motor, the third drive mode being a mode in which the vehicle travels by using the output torque of the engine or the output torque of both the engine and the second motor in a state where fixing of the first rotating element by the brake mechanism is released. |
