SERVO OIL PRESSURE CONTROL METHOD FOR AUTOMATIC TRANSMISSION

摘要

PURPOSE:To prevent the occurrence of a shift shock during regrasping of the brake of an automatic transmission. CONSTITUTION:Servo oil pressures B-3 and B-2 by which the frictional engaging means of brakes having a relation wherein the one thereof is disengaged and the other thereof is engaged during a shift are engaged with and disengaged from each other are lowered and controlled linearly throughout a range of from the starting of a shift to at least a point of time when a torque phase is completed so that the servo oil pressure B-3 on the frictional engaging element side disengaged by inputting the servo oil pressure B-2 on the frictional engaging element side to be engaged is adapted to an inverse proportion relation between a theoretically determined engaging pressure and a drain pressure.