Pilot valve

Abstract

A pilot valve comprises valve bodies, valve sleeves, a valve rod, a spring and a plug, wherein the one end of the valve rod is positioned outside each of the valve bodies, and the other end of the valve rod is sleeved in the valve sleeves; one end of the spring is propped against the valve rod, and the other end of the spring is propped against the valve bodies; the valve sleeves and the plug are arranged in the valve bodies; the plug is propped against one ends, which are far away from the spring, of the valve sleeves; an oil inlet, an oil outlet and an oil return port are formed on the valve sleeves; oil passages communicated with the oil inlet, the oil outlet and the oil return port are arranged on the valve bodies respectively; a first liquid cavity and a second liquid cavity are arranged on the valve rod; a first oil port and a second oil port which are communicated with the first liquid cavity as well as a third oil port and a fourth oil port which are communicated with the second liquid cavity are arranged on the valve rod; the first oil port and the second oil port correspond to the oil inlet, the third oil port corresponds to the oil return port, and the fourth oil port corresponds to the oil outlet. The pilot valve has good sealing performance and low requirements for hydraulic medium.

Description

technical field [0001] The invention relates to a valve, in particular to a pilot valve. Background technique [0002] The pilot valve is an auxiliary valve used to control the operation of other valves or components. It is often used in the occasion where a small flow pilot valve controls a large flow main control valve. The opening and closing of the existing pilot valve is generally realized by the steel ball and the conical valve seat. The machining accuracy of the contact surface is relatively high. If the machining accuracy does not meet the requirements, the hydraulic medium will pass through the steel ball and The contact surface of the valve seat leaks, which leads to poor sealing performance and affects the normal operation of the pilot valve; at the same time, when the pilot valve is opened, the diameter of the pilot valve hole formed by the steel ball and the conical valve seat is very small, generally only 2 to 3mm. The hydraulic medium passes through the pilot...

AI Technical Summary

Problems solved by technology

The opening and closing of the existing pilot valve is generally realized by the steel ball and the conical valve seat. The machining accuracy of the contact surface is relatively high. If the machining accuracy does not meet the requirements, the hydraulic medium will pass through the steel ball and The contact surface of the valve seat leaks, which leads to poor sealing performance and affects the normal operation of the pilot valve; at the same time, when the pilot valve is opened, the diameter of the pilot valve hole formed by the steel ball and the conical valve seat is very small, generally only 2 to 3mm. The hydraulic medium passes through the pilot valve hole, which has high requirements on the cleanliness of the hydraulic medium. If the contaminated hydraulic medium or the hydraulic medium that does not meet the requirements enters the pilot valve hole, it is easy to block the pilot valve hole, so that the pilot valve cannot work normally.

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