Patent ID: 7041030

Claim:
A hydraulic control apparatus for a hybrid vehicle comprising: an engine and a motor as power sources of the hybrid vehicle; a transmission which is provided for transmitting powers of the engine and the motor to output shafts of the hybrid vehicle, and which includes a torque converter, a starting gear, and a clutch that controls an engagement state of the starting gear by being supplied with oil pressure; a hydraulic control circuit associated with the transmission; a motor-driven oil pump for supplying oil pressure to the hydraulic control circuit and the clutch; an engine automatic stop and start device which is associated with the engine in order to stop and start the engine under predetermined conditions; a control unit which is operatively connected to the engine automatic stop and start device, the motor-driven oil pump, and the hydraulic control circuit; a brake pedal depression detecting device which is provided for detecting whether the brake pedal of the hybrid vehicle is depressed, and which is connected to the control unit; an accelerator pedal depression detecting device which is provided for detecting whether the accelerator pedal of the hybrid vehicle is depressed, and which is connected to the control unit; and an engine revolution rate measuring device which is provided for sensing revolution rate of the engine, and which is connected to the control unit, wherein the control unit is adapted to control the motor-driven oil pump and the hydraulic control circuit so that the oil pressure applied to the clutch is set to be a first oil pressure while the engine is automatically stopped, wherein the control unit is adapted to operate the engine automatic stop and start device so as to start the engine when it is determined by the brake pedal depression detecting device that the brake pedal is released while the engine is automatically stopped, and wherein the control unit is adapted to control the motor-driven oil pump and the hydraulic control circuit so that the oil pressure applied to the clutch is maintained to be the first oil pressure when the engine is automatically started upon detecting release of the brake pedal, it is determined by the accelerator pedal depression detecting device that the accelerator pedal of the hybrid vehicle is not depressed, and it is determined by the engine revolution rate measuring device that the engine revolution rate is equal to or less than an idling revolution rate.