A hydraulic actuation device for a motor vehicle friction clutch has a manually actuatable master cylinder, that has a master pressure chamber which, in a rest position, is fluidically connected to a reservoir. The master cylinder is connected to a slave arrangement that is functionally connected to the motor vehicle friction clutch. A pressure line connects the master pressure chamber to the slave arrangement and in which incorporates an electrically actuatable valve arrangement with an electrically actuatable proportional valve and, connected in parallel, a first check valve which blocks in the direction of the master pressure chamber. A motor pump is connected, on the input side, to the reservoir and can be connected, on the output side, to the pressure line between the valve arrangement and the slave pressure chamber through a second check valve that blocks in the direction of the motor pump.

A control method of an electromagnetic clutch in a hybrid power system and a hybrid power system are disclosed. Besides the electromagnetic clutch, the hybrid power system further comprises an engine or motor, a motor, an electromagnetic clutch controller and a power supply system. The power supply system comprises: a low-voltage battery, a standby power supply system and a switching circuit. The electromagnetic clutch is used to control connection of the motor. The control method comprises: monitoring whether a voltage of the low-voltage battery is lower than a target value, and judging whether the low-voltage battery fails; using the switching circuit to switch to the standby power supply system to supply power to the electromagnetic clutch and the electromagnetic clutch controller; using the electromagnetic clutch controller to judge an engaged or disengaged state of the electromagnetic clutch; and further controlling the electromagnetic clutch according to the engaged or disengaged state. When the low-voltage battery power supply fails, the switching circuit switches to the standby power supply system to supply power, thereby ensuring that the electromagnetic clutch is in a reasonable state and make the hybrid power system more safe and reliable.

A gear change control device according to an embodiment includes a detection unit configured to detect the gear stage of a transmission and measure the input rotation rate of the transmission and the rotation rate of an engine and a controller configured to decrease the torque of a clutch to a second reference value from a first reference value when a first time elapses from a time point at which the rotation rate of the engine and the input rotation rate of the transmission become different from each other due to a gear change from a certain gear stage to a gear stage one or a plurality of stages higher than the certain gear stage that is performed by the transmission.

A gear change control device according to an embodiment includes a detection unit configured to detect the gear stage of a transmission and measure the input rotation rate of the transmission and the rotation rate of an engine and a controller configured to decrease the torque of a clutch to a second reference value from a first reference value when a first time elapses from a time point at which the rotation rate of the engine and the input rotation rate of the transmission become different from each other due to a gear change from a certain gear stage to a gear stage one or a plurality of stages higher than the certain gear stage that is performed by the transmission.

A hybrid power system comprises an engine, a motor, an electromagnetic clutch, an electromagnetic clutch controller and a power supply system. The power supply system comprises: a low-voltage battery, a standby power supply system and a switching circuit. The electromagnetic clutch is used to control connection of the motor. A control method comprises: monitoring whether a voltage of the low-voltage battery is lower than a target value, and judging whether the low-voltage battery fails; using the switching circuit to switch to the standby power supply system to supply power to the electromagnetic clutch and the electromagnetic clutch controller; using the electromagnetic clutch controller to judge an engaged or disengaged state of the electromagnetic clutch; and further controlling the electromagnetic clutch according to the engaged or disengaged state. When the low-voltage battery power supply fails, the switching circuit switches to the standby power supply system to supply power.

A vehicle control system configured to carry out an energy saving control is provided. The vehicle control system is applied to a vehicle having an engine, a torque converter, a transmission and a clutch device selectively connecting a turbine runner to the transmission. The vehicle control system executes the energy saving control by controlling both an operating condition of the engine and an engagement condition of the clutch device or only the engagement condition of the clutch device. The vehicle control system comprises a clutch control means configured to increase the torque transmitting capacity of the clutch device using an increasing amount of a speed of the turbine runner as a target value, when bringing the clutch device into engagement being in disengagement during execution of the energy saving control.

This clutch control device includes a clutch device connecting and disconnecting power transmission between a prime mover and an output target, a clutch actuator outputting a driving force for operating the clutch device, a release mechanism operating the clutch device by receiving a driving force of the clutch actuator, a control unit driving and controlling the clutch actuator, a first detection part detecting an output value of the clutch actuator, and second detection parts detecting an amount of operation of the release mechanism, in which the control unit controls an operation of the clutch actuator by selectively using detection information of the first detection part and detection information of the second detection parts.

This clutch control device includes a clutch device connecting and disconnecting power transmission between a prime mover and an output target, a clutch actuator outputting a driving force for operating the clutch device, a release mechanism operating the clutch device by receiving a driving force of the clutch actuator, a control unit driving and controlling the clutch actuator, a first detection part detecting an output value of the clutch actuator, and second detection parts detecting an amount of operation of the release mechanism, in which the control unit controls an operation of the clutch actuator by selectively using detection information of the first detection part and detection information of the second detection parts.