HYDRAULIC CIRCUIT FOR HYDRAULICALLY DRIVEN WORKING VEHICLES

摘要

A hydraulic circuit for hydraulically driven working vehicles that can allow the vehicles to run at an almost constant speed during high-speed running, provides a great digging force during working, does not need charging pressure for preventing cavitation, loses energy little, and is constructed simply. The hydraulic circuit has a running hydraulic pump (2) and a hydraulic pump (4) for a working machine that are driven by the power of an engine (1) and adapted to discharge pressure oil, respectively, of a running HST circuit and a working machine driving hydraulic circuit, wherein pressure oil from the hydraulic pump (4) for the working machine joins pressure oil in the running hydraulic pump (2) to enable high-speed running, while pressure oil from the running hydraulic pump (2) joins pressure oil in the hydraulic pump (4) for the working machine to generate a digging force of a great magnitude to thereby effect digging.