Line pressure control method for a transmission having a dog clutch

摘要

A method of controlling the system pressure in an automatic transmission having interlocking shifting elements in which, during shifts and gear engagement and gear disengagement processes involving interlocking shifting elements, as a function of the engagement and disengagement times of the interlocking shifting elements involved and the shift conditions of the frictional shifting elements involved, the system pressure is increased to an elevated pressure that enables rapid engagement or disengagement of the interlocking shifting elements, in such manner that the system pressure is increased in at least two phases whose timing depends on the shift conditions of at least one of the shifting elements involved.

主权项

1. A method of controlling a system pressure, in an automatic transmission having interlocking shifting elements, during shifts and gear engagement and gear disengagement processes in which the interlocking shifting elements are involved, the method comprising the steps of:
increasing the system pressure to an elevated pressure which enables either rapid engagement or disengagement of the interlocking shifting elements, increasing the system pressure based on time-points at which the interlocking shifting elements are engaged and disengaged, and shift conditions of frictional shifting elements involved with the shift, and increasing the system pressure via at least two pressure phases, timing of the least two pressure phases depends on the shift conditions of at least one of the interlocking and the frictional shifting elements involved.