High-precision discharge pilot valve

Abstract

The invention discloses a high-precision discharge pilot valve, and belongs to the technical field of valves. The high-precision discharge pilot valve comprises a valve body and a valve cover, wherein a control cavity and a pressure relief cavity are arranged in the valve body, the control cavity and the pressure relief cavity are communicated through a conducting hole, the valve body is provided with a control cavity port communicated with the control cavity, the bottom of the pressure relief cavity is provided with a valve front port, a conducting valve sleeve is arranged in the pressure relief cavity in a sliding manner, the lower end of the conducting valve sleeve is communicated with the valve front port, a reset piece is arranged on the conductingvalve sleeve in a sleeved mode, a valve rod is arranged in the conductinghole in a sliding mode, the lower end of the valve rod is opposite to a through hole in the middle of the conductingvalve sleeve, a gap is reserved between the valve rod and the side wall of the conductinghole, and a movable control assembly for controlling the reciprocating motion of the valve rod by controlling the valve rear pressure is arranged in the valve cover. Compared with the prior art, sensitivity and precision of pilot valve control are further improved while empty balance self-locking caused by communication of the upper control cavity of the control valve and the valve rear end of the control valve is avoided. Compared with an existing pilot valve, differential-pressure-free all-pass valve opening of the valve front end and the valve rear end of the control valve can be achieved.

Description

technical field [0001] The invention relates to the technical field of valves, in particular to a high-precision external discharge pilot valve. Background technique [0002] The self-operated control valve is a control valve that relies on the pressure and temperature of the medium flowing through the valve itself to drive the valve to work automatically, without external power supply and secondary instruments. Existing control valves are divided into direct-acting control valves and indirect-acting control valves according to their operating principles. Self-operated control valves with indirect control generally need to add a pilot valve. The pilot valve can amplify the feedback signal, and then through the actuator Drive the disc movement of the control valve to achieve the purpose of changing the valve opening. The control accuracy of the existing pilot valve is low. When used with the control valve, the control valve is more likely to have the problem of air balance s...

AI Technical Summary

Problems solved by technology

The control accuracy of the existing pilot valve is low. When used with the control valve, the control valve is more likely to have the problem of air balance self-locking. The main valve is always fully open and cannot be closed. In order to avoid the problem of air balance self-locking, the control valve There needs to be a pressure difference of 1 bar between the front end of the valve and the rear end of the valve, so a set of springs must be installed on the disc of the main valve for decompression, and the control valve cannot realize full-way opening without pressure difference

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