| 摘要 |
PURPOSE:To minimize the dispersion of the engagement time and the engagement shock of a frictional engagement device in switching from the neutral condition to the traveling condition. CONSTITUTION:In a hydraulic pressure control device of an automatic transmission to achieve the engagement of a forward clutch based on the input signal (duty ratio) of a solenoid valve (of normal close type), when the command to switch to the traveling range is generated, the duty ratio is set to SD1 in the first switching step to increase the supply pressure, and the first-quick-fill is executed. When the turbine speed is reduced below the refence value DELTANC0 which is obtained based on the turbine speed when the switching command is generated, the first switching step is completed, and the second switching step is executed, and similarly the supply pressure to the forward clutch is reduced at the reduction ratio equivalent to the prescribed duty change quantity SD2 obtained from the turbine speed when the switching command is generated. Immediately before the complete engagement, the supply pressure is minimized by the duty ratio SD3 obtained based on the engine speed to achieve the complete engagement. |
