HYDRO-PNEUMATIC TYPE RELIEF VALVE

摘要

The present invention relates to a relief valve used to prevent damage to a hydraulic device by the over-pressure in the hydraulic system and, more specifically, to a hydro-pneumatic relief valve which allows a valve to be operated by combination of a spring and hydro-pneumatic pressure in a traditional valve opening and closing structure operated by a spring so that a valve can be stably opened and closed. According to the present invention, the relief valve comprises a valve body having an inlet and an outlet; a disc which is installed in the valve body and opens and closes the inlet and the outlet; a valve sheet where the disc is mounted; a spring which opens and closes the disc in accordance with the working fluid pressure in the inlet; a cap equipped to be detached from the upper part of the valve body; a slide axis which is installed to be slid up and down by being fixed o the center of the upper surface of the disc in the lower end; a piston member which is fixed to the upper end of the slide axis and is installed to be slid up and down along the inner wall surface of a cylinder unit of the upper part of the valve body; a compressed fluid which is charged between the bottom of the piston member and the bottom surface of the cylinder unit of the upper part of the valve body; and a sealing member which is arranged in the bottom surface of the cylinder unit of the upper part of the valve body in order to prevent the leakage of the compressed fluid.