HYDRAULIC CONTROL DEVICE OF AUTOMATIC TRANSMISSION FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To avoid the occurrence of the interlock of an automatic transmission for a vehicle by the minimum quantity of valves in a hydraulic control device of the automatic transmission for selectively supplying a hydraulic oil to a hydraulic frictional engagement device for achieving multiple shift stages of the automatic transmission. SOLUTION: When at least three of control pressures among control pressures PSLC1to PSLB3which are not simultaneously supplied during the normal state are simultaneously supplied when any of first to sixth gear stages is achieved, the supply of the control pressure PSLB3to a brake B3 is cut off by a first operating valve 150 and the supply of a control pressure PSLB1to a brake B1 and the supply of a control pressure PSLB2to a brake B2 by a second operating valve 152 are cut off. Consequently, all combinations by which the automatic transmission 10 is interlocked by the two first operating valve 150 and the second operating valve 152 can be avoided. COPYRIGHT: (C)2008,JPO&INPIT