VORRICHTUNG ZUR MODULATION VON LEITUNGSDRUCK IN EINEM HYDRAULISCHEN STEUERSYSTEM EINES SELBSTTAETIG SCHALTENDEN GETRIEBES EINES KRAFTFAHRZEUGS

摘要

A line pressure modulating device for use with a hydraulic control system of an automatic power transmission, which device reduces line pressure when a motor vehicle remains at standstill for thereby minimizing shifting shock that would otherwise occur during shifting from neutral to automatic forward drive or reverse drive ranges. The line pressure modulating device includes first and second control valves which cooperates with each other to pass line pressure as a signal pressure to a line pressure regulator valve to move the same in a position to decrease line pressure when an accelerator pedal is released while the motor vehicle remains at standstill.