PURPOSE: To carry out a speedy clutch operation with least speed change shocks automatically by constituting a hydraulic pump and a valve mechanism connectedly so as to be put under a condition that when delivery pressure of the hydraulic pump becomes high, pressure rising time becomes long, and when the delivery pressure becomes low, the pressure rising time becomes short.
CONSTITUTION: An accumulator 37 as a pressure rising device E and a valve mechanism F are connected to the middle of the second oil passage 18, and the valve mechanism F is constituted of a valve body 39 operated by means of an extending movement of a hydraulic cylinder 38, the first port 41 connecting a large orifice 40 having large resistance, the second port 43 connecting a small orifice 42 having small resistance, and the third port 44 which connects nothing and consists only of an oil passage. Furthermore, the valve body 39 is energized by push-pressing toward the third position S3 side by means of a return spring 55, and the hydraulic cylinder 38 is energized shortly. Thereby, a hydraulic pump 48 and a valve mechanism F are constituted connectedly so as to be put under a condition that when delivery pressure of the hydraulic pump 48 becomes high, pressure rising time becomes long, and when the delivery pressure of the hydraulic pump 48 becomes low, the pressure rising time becomes short.
OKADA MAKOTO
HAMA MASAAKI
KAJINO KATSUJI
