Variable-regeneration directional control valve for constructional vehicles

摘要

A variable-regeneration directional control valve for construction vehicles is disclosed. The control valve has a pressure control means 55 for controlling the opposite pressure caused by elasticity of a valve spring 25. The opposite pressure acts on one end of a regeneration switching spool 22, while a self pressure (hydraulic pressure of pressurized fluid output from a pump) acts on the other end of the regeneration switching spool and thereby moves the spool. In the preferred embodiment, the means is a pressure control pistol 23 which is provided on the tip of the valve spring. The pressure control piston receives an outside control signal through an electronic proportional control valve and thereby continuously moves. The electronic proportional control valve outputs pressurized fluid in proportion to a current amount of the outside control signal.