Valve seat structure of fluid control valve

Abstract

In a valve seat structure of a fluid control valve comprising a valve element(60), a body formed with an inlet port (41) and an outlet port (42), and a valve seat member (50)provided in the body, the fluid control valve being configured to bring the valve element into or out of contact with the valve seat member to control the flow of a fluid, the valve seat member is formed in a ring shape and includes a valve seat portion (51) with which the valve element will come into our out of contact. Assuming that a thickness of the valve seat portion in a radial direction of the valve seat member is a first thickness t1 (0<t1), a second thickness t2 corresponding to a height of the valve seat member in a direction along an axis of the fluid control valve is determined in a range of 0.5 t1<=t2<=1.5 t1.

Description

technical field [0001] The present invention relates to a valve seat structure of a fluid control valve that controls the flow of fluid. More specifically, it relates to a valve seat structure of a diaphragm valve for controlling the flow of a fluid such as a high-temperature gas by abutting or separating a diaphragm valve element from a valve seat in, for example, a semiconductor manufacturing device. Background technique [0002] In the semiconductor manufacturing process or liquid crystal panel manufacturing process, etc., when H 2 When supplying or shutting off high-temperature gas such as gas and Ar gas to semiconductor manufacturing equipment, for example, metal diaphragm valves disclosed in Patent Documents 1 and 2 are used as fluid control valves for controlling the flow of the high-temperature gas. [0003] Figure 6 and Figure 7 A diagram illustrating the metal diaphragm valve of Patent Document 1 is shown. Such as Figure 6 and Figure 7 As shown, Patent Docu...

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Problems solved by technology

[0023] In this way, when the stroke difference between the valve seat 250, 350 and the metal diaphragm 260, 360 occurs after the valve is opened, the flow rate of the fluid flowing in the valve-opened state will be uneven. As the flow control accuracy of the valve, there is a problem that Cv The value drop is suppressed within 0.2 after valve opening, which is required in the field of precision parts manufacturing such as semiconductor manufacturing in recent years.

[0024] In addition, in the conventional metal diaphragm valve in which the second wall thickness t2 is formed at about 2.7 times the first wall thickness t1, although the sealing performance between the valve core and the valve seat member 150 is higher than that of a metal valve seat, it is different from that of the patent. In Documents 1 and 2, similarly, when the valve is in the open state, the flow rate of the flowing fluid becomes uneven, and the fluid cannot flow at a stable flow rate.

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