Abstract: A shift control device includes a hydraulic circuit and a control unit. The hydraulic circuit is provided with multiple actuation valves. The control unit is configured to switch positions or states of each of the multiple actuation valves in accordance with a shift position command by a shift operation device. The hydraulic circuit is configured to couples a hydraulic oil supply source to one of travel actuators in an automatic transmission in multiple circuit states where the position or the state of at least one of the multiple actuation valves differs.

Abstract: A hydraulic pressure supply system includes a mechanical oil pump, an electric oil pump, a first flow path, a second flow path, and a cut-off mechanism. The mechanical oil pump is configured to operate by power from an engine. The electric oil pump is configured to operate by power from a motor. In the first flow path, oil supplied from the mechanical oil pump and the electric oil pump flows, the first flow path being coupled to the mechanical oil pump and the electric oil pump. The second flow path branches off from the first flow path and is configured to cause an oil to return to an oil pan via a torque converter. The cut-off mechanism is configured to close off the second flow path by oil delivered from the electric oil pump.

Abstract: A shift control device includes: a hydraulic circuit, an actuation valve, a control unit, and a pressure holding valve. The hydraulic circuit is provided with a supply oil passage coupled to a hydraulic oil supply source, a drain oil passage coupled to a tank, and an actuator oil passage coupled to a travel actuator. The actuation valve is provided in the hydraulic circuit and couples the actuator oil passage to the supply oil passage or the drain oil passage. The control unit switches the actuation valve in accordance with a shift position command of a shift operation device. The pressure holding valve is provided in the drain oil passage and holds a pressure of the drain oil passage at a predetermined pressure.

Abstract: A hydraulic pressure supply system includes a mechanical oil pump, an electric oil pump, a first flow path, a second flow path, and a cut-off mechanism. The mechanical oil pump is configured to operate by power from an engine. The electric oil pump is configured to operate by power from a motor. In the first flow path, oil supplied from the mechanical oil pump and the electric oil pump flows, the first flow path being coupled to the mechanical oil pump and the electric oil pump. The second flow path branches off from the first flow path and is configured to cause an oil to return to an oil pan via a torque converter. The cut-off mechanism is configured to close off the second flow path by oil delivered from the electric oil pump.

Abstract: A shift control device includes a hydraulic circuit and a control unit. The hydraulic circuit is provided with multiple actuation valves. The control unit is configured to switch positions or states of each of the multiple actuation valves in accordance with a shift position command by a shift operation device. The hydraulic circuit is configured to couplesa hydraulic oil supply source to one of travel actuators in an automatic transmission in multiple circuit states where the position or the state of at least one of the multiple actuation valves differs.

Abstract: A shift control device includes: a hydraulic circuit, an actuation valve, a control unit, and a pressure holding valve. The hydraulic circuit is provided with a supply oil passage coupled to a hydraulic oil supply source, a drain oil passage coupled to a tank, and an actuator oil passage coupled to a travel actuator. The actuation valve is provided in the hydraulic circuit and couples the actuator oil passage to the supply oil passage or the drain oil passage. The control unit switches the actuation valve in accordance with a shift position command of a shift operation device. The pressure holding valve is provided in the drain oil passage and holds a pressure of the drain oil passage at a predetermined pressure.