HYDRAULIC CONTROL DEVICE FOR AUTOMATIC TRANSMISSION

摘要

PROBLEM TO BE SOLVED: To provide a simply structured hydraulic control device of an automatic transmission capable of certainly blocking engagement pressure to a frictional engagement element such as a brake at a direct connection stage even when a fail occurs in a linear solenoid valve or the like. SOLUTION: The hydraulic control device 1 of the automatic transmission has a 3-4 shift valve 23 for outputting initial pressure of a first route at a third speed stage lower than a fourth speed stage directly connecting an input shaft 11 and an output shaft 15 of the automatic transmission and a clutch apply control valve 17 for outputting initial pressure of a second route at a fifth speed stage higher than the direct connection stage.Both valves 23 and 17 perform a control to block both initial pressures of the first and second routes at the direct connection stage. COPYRIGHT: (C)2004,JPO