| 摘要 |
PURPOSE:To cross the rise and fall characteristics of operating pressure in the course of speed change operation by transmitting a first operating signal from a first control means on the basis of a speed change command from a speed change operating means, and operating a second control means by a third control means so that a second operating signal is transmitted from the second operating means before the lapse of pressure rise time after the transmission of the first operating signal. CONSTITUTION:On the basis of a speed change command from speed change operating means 61, 62, a first operating signal is transmitted from a first control means for controlling in such a way as to start the supply of an operating current to solenoid operated valves 31b, 32b, 33b, 34b corresponding to the speed change command. Slightly before the lapse of pressure rise time from the transmission of the first operating signal until the operating pressure of hydraulic clutches 21-24 reaches the specified pressure on the transmission state side, a third control means for a first gear speed and a second gear speed clutches 21, 22 controls in such a way that a second operating signal is transmitted from a second control means for operating down to zero from the operating pressure in the transmission state by the solenoid operated valves 31b-34b. The rise and fall characteristics of operating pressure can be thereby crossed successfully in the course of speed change operation. |
