SPEED CHANGE CONTROL DEVICE FOR VEHICULAR TRANSMISSION

PROBLEM TO BE SOLVED: To provide a speed change control device for a vehicular transmission, which secures the function of an engine brake when a vehicle is abruptly decelerated, prevents the occurrence of engine stall and knocking, and also prevents acceleration responsiveness from being degraded at the time of reacceleration. SOLUTION: When a vehicle is abruptly decelerated, let the swash plate angle of a hydraulic motor be 1/3 of that of a normal operation, and let a stroke for the swash plate angle of a hydraulic pump be 1/3 of that of a normal operation. By this constitution, the responsiveness of the swash plate of the liquid operated motor is enhanced, the change of a stroke for the swash plate of the hydraulic pump when the vehicle is abruptly decelerated can be followed to the change of vehicle speed, the occurrence of troubles such as engine stall and the like caused by the delay in response, can be prevented, and the delay in response at the time of reacceleration can also be prevented.