JPH01153869A - Flat diaphragm - Google Patents

Abstract

PURPOSE:To obtain a product with a smooth action and increase the yield of conforming articles in a diaphragm interposed between a lip and a backup ring by providing steps between sealing portions and a portion on which gas pressure acts. CONSTITUTION:The gas chamber of a valve is formed by pushing and sealing a metal flat diaphragm 1 against backup rings 3, 8 with finely machined lips 2, 7. In the diaphragm 1, steps 13, 14 are provided between sealed portions 11A, 11B and a portion 12 on which gas pressure acts. Thereby, since the portion on which the gas pressure acts can be kept flat, the dispersion of products is small obtaining a product with a smooth action while increasing the yield of conforming articles.

Description

[Detailed description of the invention]

Goriki Oihara

[Industrial application field]

The present invention relates to improvements in planar diaphragms, especially those made of metal, for forming gas chambers in pulps, regulators, etc. (Prior art) A metal flat diaphragm is used in gas chambers such as valves and regulators that adjust the flow rate and pressure of gas. For example, the gas chamber for pulp uses a metal flat diaphragm, as shown in Figure 4. It is formed by pressing a flat diaphragm 1 with precision-machined lips 2 and 7 against backup rings 3 and 8 to form a seal. Both the lips and the backup ring are usually made of metal and are metal-touch seals. is often,
This is done not only around the periphery of the diaphragm but also in the center. When the diaphragm is pressed by the lip and sunk into the backup ring, the deformation of the seal portion affects the entire diaphragm, and the diaphragm tends to deform into a cone shape with the surface in contact with the lip concave. In the case of FIG. 4, this deformation causes the valve body 4 to move upward, causing the clearance between the valve 5 and the valve seat 6 to vary from product to product. The deformed diaphragm has
This stress prevents the valve from operating smoothly and makes delicate valve adjustments difficult, making it impossible to achieve the goal of adjusting minute flow rates and pressures. In order to eliminate these disadvantages, it is important to prevent the diaphragm from deforming and keep it flat.

[Problems to be solved by the invention]

An object of the present invention is to provide a diaphragm whose portion on which gas pressure acts can maintain a flat surface when the diaphragm is incorporated into a valve or the like. [Means for solving the problems] The diaphragm of the present invention, as shown in FIGS. 1 and 2, seals the diaphragm by sandwiching the diaphragm between a lip and a backup ring, thereby sealing the gas chamber. In the diaphragm for forming, there are steps 13 and 14 between the parts 11A, 11B to be sealed and the part 12 on which gas pressure acts.
It is characterized by having the following. The diaphragm of the present invention can be made of materials similar to conventional metal diaphragms, such as stainless steel and Monel metal.

[For use]

As mentioned above, when a conventional planar diaphragm is assembled into a valve or the like, the deformation of the portion that is forced onto the lip and sunk into the backup ring often spreads to the entire diaphragm and deforms into a cone shape. The cone tends to be formed in the direction of the concave side where the lip touches, and by setting the lip directions of the peripheral seal and the center seal to be the same, the amount of deformation can be reduced, but the amount of deformation inside the diaphragm The stress is complex and does not allow for smooth operation. In contrast, when the diaphragm of the present invention is used to assemble a valve, the lip 2
The deformation of the diaphragm that occurs in the seal portion when the diaphragm 1 is pressed onto the backup rings 3 and 8 in steps 1 and 7 is localized only to the seal portion and does not extend beyond the steps 13 and 14 to the portion 12 where gas pressure acts. In this way, the part on which the gas pressure acts can be kept flat, and the valve body 4 of the valve will shift up and down, the clearance between the valve 5 and the valve seat 6 will vary, and the operation of the valve will become stiff. Never.

【Example】

An ultra-high vacuum dynamic minute flow control valve (manufactured by Nippon Fine Ceramics ■) was assembled using the diaphragm of the present invention having the shape shown in FIGS. 1 and 2. The diaphragm is made of Monel metal with a thickness of 0.1 m and an outer diameter of 3
071111. The step height is 0°2an. The variation in the clearance between the valve and the valve seat was ±0.2M when using a conventional diaphragm, but
±0.1711 using the diaphragm of the present invention
It was within the range of 111. When the operation of the valves was examined, all valves using the diaphragm of the present invention operated smoothly. Effects of the Invention When the diaphragm of the present invention is incorporated into a valve, etc., the part on which gas pressure acts can be kept flat, resulting in products with less variation, smooth operation, and a higher yield of good products. can be increased. Therefore, the diaphragm of the present invention can be used not only in the minute flow control valve shown in the example, but also in various devices that provide metal-touch gas sealing, such as regulators, pressure switches, and pressure sensors.

[Brief explanation of the drawing]

1 and 2 show an example of the diaphragm of the present invention, with FIG. 1 being a plan view and FIG. 2 being a sectional view passing through the center. FIG. 3 is a longitudinal cross-sectional view of a minute flow control valve using the diaphragm of the present invention. FIG. 4 is a longitudinal sectional view of the gas chamber of the valve, conceptually showing the deformation of the diaphragm that tends to occur when a conventional diaphragm is used. 1...Diaphragm 11A, 11B...Seal part 12...Part where gas pressure acts 13...Step 2...Lip 3...Backup ring 4...Valve body 5...Valve 6... Valve
Patent Applicant Jun Nishizawa - JGC Corporation Representative Patent Attorney Souo Suga Figure 1 Figure 3 Figure 4

Claims (2)

[Claims] (1) In a diaphragm for forming a gas chamber by sandwiching and sealing the diaphragm between a lip and a backup ring, a flat surface characterized by providing a step between the sealing part and the part on which gas pressure acts. diaphragm. (2) The planar diaphragm according to claim 1, which is used to form a gas chamber of a minute flow control valve.