| 摘要 |
PURPOSE: A hydraulic pressure discharge time calculating apparatus for learning control of an automatic transmission and a method thereof are provided to enhance shift quality by controlling accurately with detecting fluid discharge time, and to improve reliability by compensating fluid discharge time according to viscosity of fluid. CONSTITUTION: A hydraulic pressure discharge time operating device is composed of an engine RPM(Revolution Per Minute) detecting unit(11) outputting engine RPM; a turbine shaft RPM detecting unit(12) calculating the engine RPM; an output shaft RPM detecting unit(13) outputting travel speed of a vehicle; a throttle valve opening degree detecting unit(14) outputting the opening degree of the throttle valve; a fluid temperature detecting unit(15) outputting temperature of fluid in an automatic transmission; a transmission control unit(2) deciding traveling state of the vehicle and shifting and fluid temperature according to signals; and a timer(31) counting fluid discharge time of frictional factors according to the control signal, and deciding the fluid discharge time. The transmission control unit calculates pressure discharge time in releasing frictional factors according to temperature ranges and stores in a memory in power-on downshifting, and performs learning control by the calculated hydraulic discharge time. Shifting is controlled accurately with measuring the fluid discharge time according to frictional factors, and the life span is extended with reducing shift shock. The fluid discharge time is compensated according to viscosity of fluid with checking fluid discharge time at temperature ranges.
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