TRAVELING CONTROL DEVICE OF HYDRAULICALLY DRIVEN VEHICLE AND HYDRAULICALLY DRIVEN VEHICLE

摘要

A traveling control device of a hydraulically driven vehicle, comprising a hydraulic pump (10) driven by a prime mover (1), a traveling motor (12) driven by pressure oil supplied from the hydraulic pump (10), a traveling control valve (11) controlling the flow of the pressure oil supplied from the hydraulic pump (10) to the traveling motor (12), a counterbalance valve (13) switched by a motor loading pressure supplied thereto through the control valve (11) and generating a brake pressure in the return side line (L1A) or (L1B) of the traveling motor (12) due to the lowering of the loading pressure, an over- rotation detection means (42) detecting the over-rotation state of the traveling motor (12), and a motor over-rotation suppressing means (50) suppressing the rotation of the traveling motor (12) when the over- rotation state of the traveling motor (12) is detected by the over- rotation detection means (42) until the over-rotation state of the traveling motor (12) is eliminated by the occurrence of the brake pressure by the switching of the counterbalance valve (13).