| 摘要 |
PURPOSE:To reduce shocks in speed change without being influenced by a vehicle condition by detecting delivery pressure of a hydraulic pump and one of input and output pressures of a hydraulic motor, and controlling respective speed change clutch oil pressures during speed change by means of these detected signals. CONSTITUTION:A control unit 17 is constituted in such a way that it inputs respective detected signals such as a speed change position Lp from a speed change lever 18, pressure P from a pressure sensor 15, the number of revolutions Ntheta from a rotation sensor 16 and accel opening theta of an accel 2a to detect accel opening of a prime mover 2, and that prescribed signals are outputted to a control unit of clutch control valves 12 and 13 of respective clutches 10 and 11 and control units 1a and 3a of both hydraulic pumps 1 and 3 according to these signals. Under this constitution, transmission torque during speed change is detected, and when its torque value is large, rise inclination of clutch engagement control oil pressure is set large, and when the torque value is small, the rise inclination is set small, so that speed change control with least shocks and least calorific value can be realized without being influenced by a vehicle condition. |
