HYDRAULIC CONTROL VALVE

摘要

PURPOSE: A hydraulic control valve is provided to prevent vibration from a vehicle in returning the hydraulic control valve, and to improve stability of operation by absorbing impact with forming a piston, a ball check valve and an orifice. CONSTITUTION: A spool(5) is moved down with pressing a push rod(4) by a cam(3) in pushing a pedal(2), and a traveling motor is operated with supplying oil from a pump port(P). Repulsive force of a return spring(9) is offset by a buffering unit of a hydraulic vibration preventive chamber(10). The hydraulic vibration preventive chamber is divided into upper and lower parts, and a ball check valve(14) is formed to supply operating oil unidirectionally. An orifice(18) is integrally formed in a piston(13) to flow oil by connecting the hydraulic vibration preventive chambers. The push rod is reciprocated in the piston and the hydraulic vibration preventive chamber. The volume of upper and lower hydraulic vibration preventive chambers is changed according to the diameter of the push rod.