Compensation device for valve opening and closing mechanism

Abstract

The invention discloses a valve for compensation device for fluid medium control valve opening and closing mechanism. The valve is composed of a valve body, a valve cover, an opening and closing mechanism and a compensation device. The opening and closing mechanism comprises a pressure sensing element, a main spring and a valve plug, and is arranged in the valve body. The pressure sensing elementand the valve cover form a pressure sensing element cavity. The compensation device comprises an upper compensation spring, a lower compensation spring and a piston, and is arranged in the valve body.Pressure on two sides of the pressure sensing element separately acts on two ends of the piston. When P1-(P3+F) is greater than 0, the piston moves to the direction of less pressure, the lower compensation spring is compressed and the valve plug is closed until the P1-(P3+F) is equal to 0, the differential pressure is controlled to be a preset value, and the valve plug is in a balanced state; andwhen the P1-(P3+F) is less than 0, the piston moves to the direction of greater pressure, the upper compensation spring is compressed and the valve plug is opened until the P1-(P3+F) is equal to 0, the differential pressure is controlled to be the preset value, and the valve plug is in a balanced state. The problem in the prior art that control precision error is high is effectively solved.

Description

technical field [0001] The invention relates to the technical field of fluid control valves, in particular to a compensation device for fluid medium control valve opening and closing mechanisms. Background technique [0002] In the field of fluid medium control valves, there are many types of valves that use pressure-sensitive elements and springs as actuators. The pressure-sensitive elements can be piston-type, diaphragm-type, bellows-type. The pressure at both ends of one (or a group) of terminal equipment, install a spring on the small pressure side to help the small pressure work, the ratio of the spring force to the effective working area of ​​the pressure sensing element is the set pressure difference, called the control pressure difference, for For normally open valves, only when the force on both sides of the pressure sensing element is the same, the position of the valve plug (spool) of the opening and closing mechanism will be balanced in the ideal position, contro...

AI Technical Summary

Problems solved by technology

[0007] The present invention provides a compensation device (hereinafter referred to as: compensation device) for the opening and closing mechanism of a fluid medium control valve to solve the problem of large control accuracy errors in the prior art

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