Shock control arrangement in hydraulic control system

摘要

In an automatic power transmission having a transmission mechanism including fluid operated frictional units to be actuated to select automatic forward drive and reverse drive gear conditions and make a shift between the first and second gear ratios in the automatic forward drive range condition, a shock control arrangement is provided in the hydraulic control system for the transmission mechanism, comprising a pressure accumulator unit which takes up the fluid pressure to be applied to any of the frictional units during selection of the automatic forward drive range or reverse drive gear position or during upshifting between the first and second gear ratios in the automatic forward drive range, the level at which the pressure accumulator unit is to commence taking up of the fluid pressure for one of the frictional units being varied with engine load.