AUTOMATIC DECELERATION APPARATUS FOR BULLDOZING

摘要

PURPOSE:To reduce the work of a bulldozer operator by allowing the brake and decelerator to be automatically controlled for deceleration simply by operating the change-speed lever without stepping the pedals of the brake and decelerator. CONSTITUTION:A change-speed lever means 30 is operated by using a change- speed lever 33. The first to the fifth change-speed solenoid valves 1-5 provided in a transmission also perform change-over of speeds in forward and reverse movements. A solenoid valve-controlling circuit 32 controls solenoid valves 6 and 7 and the first to the fifth change-speed solenoid valves 1-5 so that a brake and a decelerator automatically operate to change-over speeds when the vehicle speed is above a theoretical vehicle-speed, and the circuit 32 controls the solenoid valves 6 and 7 and 1-5 so that the brake and the decelerator do not operate and the change-over of speeds can be performed immediately when the vehicle speed is below the theoretical vehicle-speed. A comparator 29 compares a set vehicle-speed with the vehicle speed detected by means of a revolution sensor 25 to discriminate the detected speed from the theoretical speed, and outputs a signal corresponding to the discrimination.