Reverse gear control apparatus for an automatic transmission

摘要

In order to improve transmission efficiency of an automatic transmission (T), an engagement brake (B-R) which does not cause drag is used and the surety of its engagement and release, and quick switching between forward maneuver and backward maneuver, is enabled. The automatic transmission comprises a transmission mechanism (T) to achieve forward maneuver and backward maneuver. A backward motion brake (B-R) which stops the rotation element to achieve backward maneuver is the engagement brake (B-R) and an input clutch (C-1) to transfer power by meshing with the rotation element during both forward maneuver and backward maneuver is a friction clutch. The control apparatus ECU executes the control operation to prepare for speedy re-meshing by holding a supply pressure for the clutch hydraulic servo (67) at a sufficient oil pressure to place the pressure in the stand-by condition at the piston stroke position immediately before the start of clutch engagement during the engagement or releasing of engagement of the engagement brake at the time of D->R or R->D shift.