Membrane type flow quantity adjusting valve with circulation

Abstract

The invention discloses a membrane type flow quantity adjusting valve with circulation. A bottom cover is provided with a liquid inlet and a circulatory liquid outlet which are communicated by a liquid flow passage. A liquid cavity is communicated with the liquid flow passage. A first valve block is provided with a conical inner cavity, the lower end is provided with a liquid cavity, and the conical inner cavity is communicated with a flow quantity adjusting outlet on the valve block. A conical valve core is arranged in the conical inner cavity, a large cylinder body on the upper end enters into a second valve block after penetrating through a first membrane hole, the upper end of the conical valve core is butted on the lower end of a support rod of the conical valve core, and the shoulder surface of the conical valve core is butted on the lower end of the first membrane. The second valve block is provided with a gas cavity which is communicated with a control gas inlet on the valve block, and the middle of the second membrane is arranged on the upper part of the gas cavity of the second valve block. The inner hole of a nut in the gas cavity of the second valve block is matched with the upper end of the conical valve core. The lower end of the nut is butted on the upper end of the first membrane, and the upper end is connected with the second membrane. The invention can effectively prevent small particles in liquid from blocking the valve body and has compact structure under the condition of ensuring enough flow quantity adjusting range.

Description

technical field [0001] The invention relates to a flow regulating valve, in particular to a diaphragm type flow regulating valve with circulation. Background technique [0002] Flow regulating valves began to develop in the 1970s. This is because the flow regulating valve can be used not only in closed-loop control, but also in open-loop control systems; in addition, the processing accuracy of the flow regulating valve is much lower than that of the servo valve, which greatly reduces the production cost. In most industrial control systems, its control accuracy and dynamic performance can meet the requirements. [0003] At present, the flow control valves on the market are mainly based on the electromagnetic slide valve structure. It is composed of proportional electromagnet, valve core, valve sleeve, main valve body, base and feedback spring. Its working principle is: in the reset state, the spring type is compressed, and the valve core is pressed against the outlet of th...

AI Technical Summary

Problems solved by technology

The above-mentioned spool type flow regulating valve has the following disadvantages: In order to ensure the sealing of the oil circuit, the gap between the sliding sealing surfaces is very small, which may easily cause the valve core to be stuck and cause the flow regulating valve to fail; the electro-mechanical characteristics of the proportional electromagnet And the mechanical-displacement characteristics of the spring determine the accuracy of the slide valve flow regulating valve, so in the open-loop system, the accuracy of the slide valve flow regulating valve is mainly determined by the electro-mechanical accuracy of the electromagnet; the installation accuracy is high, Not suitable for occasions that require frequent disassembly

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