Control device for hydraulically propelled work vehicle

摘要

A control device for a hydraulically propelled work vehicle according to the present invention comprises an engine revolution speed control means (360) which controls the revolution speed of an engine (21); a variable displacement type hydraulic pump (1) which is driven by the engine (21); a displacement variation means (40) which varies the displacement of this variable displacement hydraulic pump (1); a displacement control means (160A) which determines a target displacement according to the operational state of the pump (1), and drive controls the displacement variation means (40); and, a hydraulic motor (4) for vehicle propulsion which is driven by hydraulic fluid ejected from the variable volume type hydraulic pump (1). There is further provided a slope descending detection means (52) which detects when the vehicle is descending down a slope, and, when it is detected by this detection means that the vehicle is descending down a slope, along with a means for engine revolution speed control (360) lowering the revolution speed of the engine (21), a displacement control means (160A) limits the maximum displacement of the hydraulic pump (1) to a value higher than during vehicle propulsion on level ground at a constant speed.