HYDRAULIC CONTROL DEVICE OF AUTOMATIC TRANSMISSION

摘要

PROBLEM TO BE SOLVED: To provide a hydraulic control device of an automatic transmission capable of securing engagement pressure supply to a frictional engagement element even when a fail occurs in a control valve or the like.

SOLUTION: In the hydraulic control device 1, a clutch apply control valve 21 disposed in an oil passage between a control valve 22 and a linear solenoid valve SL1 is switched between a left half position for communicating an input port m with an output port r to supply control pressure I to a control oil chamber s and a right half position for communicating an input port l with the output port r to supply D range pressure (L) through an oil passage 52 instead of the control pressure I to the control oil chamber s.Thus, while securing sufficient responsiveness of a clutch C-1, the control valve 21 can secure supply of engagement pressure to the clutch C-1 even when a fail occurs in the control valve 22 or the like.

COPYRIGHT: (C)2004,JPO