Pressure control valve

Abstract

A pressure control valve is provided, which can variably control the set pressure of a relief valve in accordance with pilot signal pressure that is controlled in an operator's seat and so on when the set pressure of the relief valve required in a replaced working device is changed. The pressure control valve includes a sleeve having an inlet port and a tank path, a poppet opening/closing a flow path between the inlet port and the tank path, a poppet spring elastically supporting the path between the inlet port and the tank path in a closed state, a valve sheet installed to face the poppet so that a set pressure is formed in a pressure chamber of the sleeve, a pilot poppet draining the hydraulic fluid in the pressure chamber to the hydraulic tank when high pressure that exceeds the set pressure is generated in the pressure chamber, a pilot poppet spring elastically supporting the path of the valve sheet in a closed state, a plug coupled to the sleeve and having a pilot port to receive the pilot signal pressure from an outside, a main piston slidably coupled within a guide coupled to the plug to variably control the set pressure in the pressure chamber in accordance with the pilot signal pressure, and a control plug movably coupled to the guide to control a set pressure of a spring supporting the main piston.

Dependencies are inferred from the claim text.