Apparatus for controlling revolution speed of prime mover for hydraulically propelled work vehicle

摘要

PCT No. PCT/JP90/01333 Sec. 371 Date May 19, 1993 Sec. 102(e) Date May 19, 1993 PCT Filed Oct. 16, 1990 PCT Pub. No. WO92/07145 PCT Pub. Date Apr. 30, 1992.A prime mover revolution speed control system for a hydraulically propelled vehicle controls the revolution speed of a prime mover to optimize vehicle acceleration in a vehicle propelling mode, and to optimize engine output and economy in a working mode. A vehicle equipped with the control system may include a hydraulic pump for discharging hydraulic fluid, the amount of fluid discharged depending on the revolution speed of the prime mover, a hydraulic motor for vehicle propulsion that is driven by hydraulic fluid discharged from the hydraulic pump, and an actuator for performing work that is also driven by hydraulic fluid discharged from the hydraulic pump. The revolution speed of the prime mover may be controlled according to a depression amount of a revolution speed control pedal. When the control system is in the working mode, the revolution speed of the prime mover is controlled in accordance with revolution speed characteristics suitable for a working operation. When the control system is in the vehicle propelling mode, the revolution speed of the engine is controlled in accordance with revolution speed characteristics suitable for a vehicle propelling operation.