| 摘要 |
PROBLEM TO BE SOLVED: To restrain generation of a speed change shock by holding the lowest value of control pressure supplied to a pressure regulating valve by a previously set setting value higher than the lowest limit value of its variable range within the time interval of transmissions to release a hydraulic frictional engagement device by a control pressure holding means. SOLUTION: A B3 control valve 92 as a pressure regulating valve to directly regulating pressure of a brake B3 provided with no accumulator, it is provided cocentrically with a spool valve element 104 by sandwiching the spool valve element 104 to open and close a passage between oil passages L01, L02 and a spring 106 and stores a plumger 108 a diameter of which is larger than the spool valve element 104 and the spring 106. Additionally, it is furnished with an oil chamber 110 to receive forward range pressure output from a third speed side when a 2-3 shift valve is changed over to the third speed side and an oil chamber 112 provided on a shaft end of the plunger 108 and to receive control pressure from a linear solenoid valve. |
