JPH04366072A - Manufacture of metal gasket - Google Patents

Abstract

PURPOSE:To make matching and welding unnecessary and moreover manufacture plural gaskets at a time. CONSTITUTION:A metal bellows 1 having alternately annular mountain portions 2 and annular valley portions 3 whose sections are of approximate C shapes, is formed. These bellows 1 annular mountain portions 2 or annular valley portions 3 are removed extensively over the whole periphery.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a gasket used for sealing between a valve body and a valve cover, for example,
The present invention relates to a method of manufacturing a metal gasket having a substantially arcuate cross section.

0002

2. Description of the Related Art Conventional methods for manufacturing metal gaskets include the following.

First conventional example [FIGS. 2(A) and 2(B)]. First, as shown in (A), a metal hollow tube 100 is bent into a U-shape, and the end surfaces 101 of the hollow tube 100 are butted and welded to form an annular shape. Thereafter, a part of the hollow tube 100 is removed along the entire circumferential direction as shown in (B), and a gasket 4 having a substantially arcuate cross section, that is, a C shape as shown in (E), is removed.
Get 00.

A second conventional example [FIGS. 2(C) and 2(D)]. (C
The metal plate-shaped base material 200 of ) is bent and formed so that the cross section has a substantially arc shape, that is, a C shape, as shown in (D). Then, the end surfaces 201 are brought together and welded to obtain an annular gasket 400.

The metal gasket manufactured as described above is installed between the valve body 300 and valve cover 301 of a valve, for example as shown in (E). And metal gasket 4
00 ensures the contact pressure of the seal surface 401 against the valve box 300 and valve lid 301 by its elastic force, and exhibits sealing performance.

[0006]

[Problems to be Solved by the Invention] However, the above conventional example has the following problems.

■ In both the first and second conventional examples, the bending process,
Each piece must be manufactured one by one through a welding process. For this reason, the molding time per piece is long, resulting in poor production efficiency.

■ In both the first and second conventional examples, the end face 101
, 201 is difficult to match with accuracy.
There is a possibility that a step portion may be formed on the surface of the metal gasket 400. As a result, the contact pressure of the sealing surface 401 becomes non-uniform, leading to a decrease in sealing performance.

[0009] When the end faces 101, 201 are welded together, there is a possibility that the vicinity of the end faces 101, 201 may be deformed due to heat, or fluctuations in elastic force may occur. Furthermore, welding defects are likely to occur. As a result, the contact pressure of the sealing surface 401 becomes uneven or decreases, leading to a decrease in sealing performance.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing metal gaskets that does not require butting or joining (welding) and can manufacture a plurality of gaskets at once.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the present invention forms a metal bellows having alternating annular ridges and annular troughs each having a substantially arcuate cross section. It is characterized by removing the part or annular valley part all around the circumference.

0012

[Operation] According to the present invention based on the above structure, when the annular ridge or annular trough of the metal bellows is removed, the remaining annular trough or annular ridge is obtained as a gasket having a substantially arcuate cross section.

[0013]

[Example] Next, an example of the present invention will be described. Figure 1 (A
) and (B) show a metal bellows 1. This metal bellows 1 is made by processing a disc-shaped base material (not shown) into a bottomed cylindrical shape by drawing, and then forming a plurality of annular peaks 2 and annular valleys 3 alternately using hydraulic forming. .

[0014] As the material of the base material, Inconel, Waspaloy, copper alloy, stainless steel, etc. are selected. Further, the inner peripheral surface or outer peripheral surface of the bellows 1 may be coated or plated with lead, indium, Teflon, or the like.

The cross section of the annular peak portion 2 and annular valley portion 3 of the bellows 1 formed as described above is approximately arc-shaped, that is, C-shaped.

[0016]The area indicated by the dashed line F in (A),
That is, when the annular valley portion 3 of the bellows 1 is removed over the entire circumference by a processing method such as polishing or cutting, only the plurality of annular peak portions 2 remain. This annular peak portion 2 is a gasket 4 having a C-shaped cross section as shown in (C). When in use, this gasket 4 is used as a so-called internal pressure seal in which the pressure of sealing fluid is applied from the inner peripheral side. In addition, when used as an internal pressure seal, the plating and coating described above are applied to the bellows 1.
It may be applied to the outer peripheral surface of the.

As described above, in the present invention, by removing the annular valley portion 3 of the bellows 1, a plurality of gaskets 4 can be manufactured at once. Therefore, the molding time per piece can be significantly shortened, and productivity is improved.

Furthermore, since the gasket 4 is obtained by simply removing the annular peak portion 2, there is no cut around the entire circumference, and there is no need for butting or joining. Therefore, the surface accuracy is uniform all around, and thermal deformation and elastic force fluctuations do not occur during molding. When such a gasket 4 is installed between the valve body 5 and valve cover 6 of the valve as shown in (E), the contact pressure of the sealing surface 7 against the valve body 5 and valve cover 6 can be uniformly and appropriately. The sealing performance of the sealing surface 7 can be maintained.

(B) shows another embodiment. That is,
In this embodiment, the region G shown by the dashed line of the bellows 1, that is, the annular peak portion 2 is removed over the entire circumference. In this way, the annular valley portion 3 remains, and the gasket 8 shown in (D) is completed.

When in use, this gasket 8 is used as a so-called external pressure seal in which the pressure of sealing fluid is applied from the outer circumferential side. Therefore, the plating or coating described above may be applied to the inner circumferential surface of the bellows 1 in advance. This gasket 8 also has the same effect as the gasket 4.

Although the illustrated embodiment has a C-shaped cross section, it is also possible to manufacture E-shaped and U-shaped gaskets.

[0022]

Since the present invention is constructed as described above, a plurality of metal gaskets can be manufactured at once. Therefore, the molding time per piece can be significantly shortened, and productivity is improved.

Furthermore, the metal gasket has a uniform surface precision over its entire circumference, and no thermal deformation or fluctuation in elastic force occurs during molding. Therefore, the sealability of the sealing surface can be ensured during use.

[Brief explanation of drawings]

1 shows an embodiment of the present invention, (A) is a cross-sectional view when the annular valley part of the bellows is removed, (B) is a cross-sectional view when the annular peak part of the bellows is removed, and (C) is a cross-sectional view when the annular peak part of the bellows is removed. (A) is a half-sectional view of the gasket manufactured by the method, (D) is (B)
(E) is a half-sectional view of the gasket manufactured by the method of (C), and (E) is a cross-sectional view showing the state in which the gasket of (C) is used.

[Fig. 2] (A) and (B) are perspective views showing the manufacturing method of the first conventional example, (C) and (D) are perspective views showing the manufacturing method of the second conventional example, and (E) is a perspective view showing the manufacturing method of the second conventional example. FIG. 3 is a sectional view showing how the gasket is used.

[Explanation of symbols]

1 Bellows 2　Circular mountain part 3 Annular valley 4,8 Gasket

Claims (1)

[Claims] 1. Forming a metal bellows having alternating annular peaks and annular valleys each having a substantially arcuate cross section, and removing the annular peaks or annular valleys of the bellows over the entire circumference. A method for manufacturing a metal gasket characterized by: