JPH028559A - Manufacture of metal bellows - Google Patents

Abstract

PURPOSE:To enable good brazing to be attained by pressing and holding a desired number of sheets of bellows base materials to be combined with their axial line direction horizontally facing. CONSTITUTION:First removing a retaining plate 16 and a nut 15 from a jig 10, connection surfaces 6, 7 of each peripheral edge connection part 3 and internal peripheral edge connection part 4 of a bellows base material 1 are alternately brought into direct contact, further an axial line direction of these connection surfaces is horizontally directed, and the base material is combined in a desired number of sheets, arranging flange members 18, 19 in the both ends. And the base material is supported onto a supporting bar 17 with a bolt 13 and the supporting bar 17 penetrating through circular holes 2, 20, 21. Simultaneously arranging a brazing material in the vicinity of each connection part 3, 4, next mounting the retaining plate 16 to the bolt 13, screwing the nut 15 horizontally pressing the base material 1 and the members 18, 19, adjusting forced adhering force between the connection parts and forming a proper space between the connection surfaces, a position of the plate 16 is determined so as to form the final shape of a bellows product. Under this condition, heating and brazing are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] <Industrial Application Field> The present invention relates to a method of manufacturing metal bellows used in expansion pipe joints, air springs, flexible tubes, etc. by brazing.

<Prior Art> Generally, as the metal bellows, integrally molded bellows or welded bellows are used.

However, molded bellows have a large height when they are in close contact, and the strength of the peaks tends to decrease during processing, and welded bellows are difficult to mass produce, are expensive to manufacture, and are prone to cracks and poor fusion at the joint. There was a problem. Therefore, as disclosed in JP-A-60-61166 and JP-A-61167, for example, there is a method for manufacturing metal bellows in which a plurality of bellows materials are integrally joined together with plate materials connected at both ends by brazing. Proposed.

According to this manufacturing method, a plurality of bellows materials are overlapped with a brazing material interposed between the joining surfaces, heated while pressurized to form a bellows shape, and after cooling, an expansion tension is applied to each bellows material. to complete the desired final bellows shape.

However, in such conventional technology, bellows materials made of thin metal plates are stacked vertically, so when brazing at high temperatures, the yield strength of the bellows materials decreases, resulting in a decrease in crimp force and the creation of gaps at the joint surfaces. There was a problem in that poor bonding etc. occurred. For this reason, it was necessary to increase the flatness of each joint surface to a level below the permeation gap of the brazing material, and to press and hold the joint surfaces with weights or springs. In addition, since the bellows material deforms due to its own weight, there is a risk that non-joint parts of the bellows material will come into contact with each other and join in the lower part where the amount of deformation is large, so it is necessary to apply a joining prevention agent etc. in advance. However, there was a problem in that the upper portion had insufficient crimp force, resulting in poor bonding. Therefore, it was necessary to limit the number of stacked bellows materials to be joined, and to apply expansion processing during brazing to enlarge and correct the spacing between the peaks and troughs of the bellows to form a desired shape.

<Problems to be Solved by the Invention> Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art by applying uniform pressure bonding force to the joining surfaces of each bellows material regardless of the number of bellows materials to be joined. The object of the present invention is to provide a method for producing metal bellows that allows for good brazing and that the brazing process can be formed into the desired final bellows product.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, the above-mentioned object is to form a plurality of metal bellows materials having a predetermined shape by connecting their outer peripheral edge joints and inner peripheral edge joints. A method for manufacturing metal bellows that is joined by alternate brazing, the metal surfaces of the outer peripheral edge joint portion and the inner peripheral edge joint portion of the corresponding bellows materials being brought into direct contact with each other, and a brazing material is provided in the vicinity of the joint portion. The combined bellows materials are pressed and held in the axial direction and heated, and the molten brazing filler metal is infiltrated between the joints at once. This is achieved by providing a method for manufacturing a metal bellows, which is characterized by comprising the steps of brazing and brazing.

<Function> In this way, gravity does not act in the direction in which the bellows materials are combined, and an equal pressure force is applied to each joint by only the pressing force in the axial direction, so the gap between the joints can be adjusted appropriately. It can be adjusted to achieve good brazing.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show examples of bellows materials used in the present invention. The bellows material 1 is formed into a disk shape with a circular hole 2 in the center by punching a thin metal plate, and has a joint portion 3 of a predetermined width formed by bending the inner and outer edges by press working. 4 and a bellows plate portion 5 as a non-joining portion connecting them. As shown in FIG. 2, the bellows materials 1 are arranged alternately in opposite directions so that the joint surfaces 6 of the outer peripheral edge joints 3 and the joint surfaces 7 of the inner peripheral edge joints 4 are in contact with each other. . By bending the joint portion 3.4 and the bellows plate portion 5, a gap is formed between adjacent bellows plate portions 5 near each joint portion. Moreover, flange members are arranged at both ends of the metal bellows as necessary.

Before the brazing process, each bellows material 1 is washed with acid, alkaline or ultrasonic. This cleaning is performed to improve the wettability of the bellows material, and removes the surface treatment layer of the bellows material and dirt such as metal powder, oil, etc. adhering to the surface, exposing the metal surface of the bellows material itself, and waxing. This makes it easier for the material and the bellows material to bond together. Conditions such as the cleaning material and cleaning time are appropriately determined in consideration of the material of the bellows material and the characteristics of the brazing filler metal used. Further, in order to improve the flow of the brazing material, the surface of the bellows material may be scratched with sandpaper or the like in advance. Furthermore, the flange members disposed at both ends of the metal bellows are also cleaned in the same manner.

The brazing process of metal bellows according to the present invention uses a jig 10 as shown in FIGS. 3 and 4, for example. The jig 10 includes a horizontally arranged support stand 11 and a support stand 1.
1 and a fixed plate 12 vertically erected at one end of the fixing plate 1. At the center of the fixing plate 12 is a bolt 1 extending horizontally.
3 is fixed, and a nut 15 is screwed into the threaded portion 14 at its free end. On the bolt 13 is a holding plate 16 that faces the fixing plate 12! It is installed so that it can be spoken and acted upon. bolt 1
Two parallel support rods 17 are provided above the fixing plate 12 and extend horizontally through the holding plate 16 in parallel with the bolts 13.

As shown in FIGS. 3 and 4, the cleaned bellows material 1 is assembled to the jig 10 with flange members 18 and 19 disposed at both ends. The flange members 18 and 19 each have the same outer diameter as the bellows material 1 and have circular holes 20 and 2 of the same diameter.
It is formed into a disk shape with 1. First, jig 10
Remove the presser plate 16 and nut 15 from. Next, a desired number of bellows materials 1 are attached to both ends of the flange member, with the joint surfaces 6.7 of the outer peripheral edge joints 3 and the inner peripheral edge joints 4 in direct contact with each other alternately, and with their axes oriented horizontally. 18
．． 19 are arranged and combined, the bolts 13 and the support rods 17 are passed through the circular holes 2, 20, 21, and the flange members 1
The end face of 8 is brought into contact with the fixed plate 12 and supported on the support rod 17.

At the same time as the bellows material 1 and the flange members 18.19 are assembled, a brazing material is placed near each joint 3.4. As described above, the adjacent bellows plate portion 5 near the joint portion 3.4
A gap 22,23 is formed between them. This gap 22.2
3, as shown in FIG. 5 and FIG. Deploy.

Preferably, the legs of brazing material 24,25 are such that they fill between each joint surface and form a slight fillet on the outside of each joint.

In another embodiment of the invention shown in FIGS. 7 and 8,
Sheet-shaped brazing filler metal 2 instead of linear brazing filler metal 24.25
6.27 is used. The brazing filler metals 26 and 27 are each curved in an arc shape along the outer periphery or inner periphery of the joint, and have a sufficient length in the axial direction to include the flange members 18 and one joint at both ends. The brazing material 26 is placed over the assembled bellows material 1 and flange member 18.19 to cover nearly the upper half of the outer peripheral edge joint 3, and the brazing material 27 is placed in the circular holes 2.20, 21. It is arranged so as to cover the lower half of the inner peripheral edge joint part 4.

Next, attach the presser plate 16 to the bolt 13 and
5 are screwed together to form bellows material 1 and flange material 18.1.
Press 9 horizontally. By tightening the nut 15, the pressure bonding force between each joint can be adjusted appropriately to form an appropriate gap between the joint surfaces, and the peaks and valleys can be adjusted according to the shape of the final bellows product. The position of the presser plate 16 is determined so that the distance is the desired distance. While being pressed and held on the jig 10 in this manner, it is heated and brazed using a well-known vacuum furnace or reduction furnace. The melted brazing filler metal 24.25 is
Due to capillary action, it permeates the entire circumference of each joint and into the slight gap between the joint surfaces, joining the adjacent bellows materials 1 and the flange members 18, 19 at both ends.

At this time, bellows material 1 and flange material 18.19
is held with its axial direction horizontal, so the crimp force acts evenly on each bellows material, and even if the flatness of the joint surface 6.7 is somewhat poor, the gap can be adjusted to ensure good brazing. can be done.

Further, there is no need to apply a brazing prevention material to the bellows plate portion 5, which is a non-joint portion.

Furthermore, since it is possible to braze the shape of the final bellows product, if heat treatment such as hardening of the bellows material is required, heat treatment can be performed as is after brazing is completed. Further, in the case of manufacturing a completely nested type metal bellows in which the bellows are tightly attached, a compression step using a press device may be added to the brazing described above after the brazing step or after heat treatment. The metal bellows brazed in this manner is completed by cleaning and leak testing.

9 to 11 show another embodiment of the bellows material used in the present invention. The bellows material 31 in FIG. 9 is formed into a disk shape with a circular hole 32 in the center by punching a thin metal plate, and is formed by pressing into a generally flat bellows plate portion 33, an outer peripheral edge joint portion 34, and an inner peripheral edge. A joint portion 35 is provided. Each of the joint parts 34 and 35 is connected to the bellows plate part 33 via a bent part 36 and 37 bent in opposite directions, and a linear brazing material is inserted between adjacent bellows plate parts 33 near the joint part. It is adapted to form a relatively large gap sufficient for placement.

In the embodiment shown in FIG. 10, a first bellows material 41 and a second bellows material 42 having the same outer diameter and inner diameter but different cross-sectional shapes are used in alternate combination. The first bellows material 41 has an outer peripheral edge joint part 45 connected to a flat bellows plate part 44 via a bent part 43, and an inner peripheral edge joint part 46 provided on the same plane as the bellows plate part 44. Preparation and second
The bellows material 42 has an inner peripheral edge joint portion 50 connected to the bellows plate portion 47 via an outer peripheral edge joint portion 48 and a bent portion 49 provided on the same plane as the bellows plate portion 47 on the flat plate.
Equipped with. In the embodiment of FIG. 11, the first bellows material 5
The first and second bellows materials 521fi have joint portions 53.54 of different S-shaped surface shapes, and outer peripheral joint portions 55.57 and inner peripheral edges 56.58 are alternately formed on the outer and inner peripheral edges thereof, respectively. are arranged so as to be in contact with each other.

In the embodiments shown in FIGS. 10 and 11 as well, a gap sufficient for arranging the linear brazing filler metal is formed between the non-bonded parts in the vicinity of the respective joined parts that are in contact with each other.

12 and 13 show another embodiment of the jig used in the present invention. This jig 6O, like the jig 10 in FIG. 3, has a support base 61 arranged horizontally and a fixing plate 62 vertically erected at one end of the support base 61. At approximately the center of the fixed plate 62, a supporting vibro 3 having approximately the same diameter as the circular holes 2, 20, and 21 of the bellows material 1 and the flange member 18, 19 is horizontally protruded. A threaded portion 64 is formed at the tip of the support vibro 3, and a presser plate 65 facing the fixing plate 62 is directly screwed into this. By tightening and positioning the presser plate 65, the bellows material 1 and the flange members 17, 18 can be assembled and held under pressure in the same manner as the jig 10 in FIG.

[Effects of the Invention] As described above, according to the present invention, a desired number of bellows materials are combined and held under pressure so that their axes face horizontally, thereby applying equal pressure to each bellows material. Therefore, regardless of the number of bellows materials to be joined, good brazing is always possible, and the shape of the final bellows product can be brazed. Since heat treatment can be performed continuously in the process, it is very advantageous in manufacturing.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a bellows material used in the present invention. FIG. 2 is a sectional view of the bellows material of FIG. 1. FIG. 3 is a partial sectional view showing the bellows material and flange member assembled into the jig used in the present invention. FIG. 4 is a view in the direction of the arrow in FIG. 3. Figures 5 and 6 are the ■-v line and V line of Figure 3, respectively.
This is a view taken along the l-Vl line. FIG. 7 is a partial sectional view similar to FIG. 3 showing another embodiment of the brazing material used in the present invention. FIG. 8 is a view taken along the line ■-■ in FIG. 7. 9 to 11 are cross-sectional views showing other bellows members used in the present invention, respectively. FIG. 12 is a partial sectional view showing another embodiment of the jig used in the present invention. FIG. 13 is a view in the direction of arrow B in FIG. 12. 1... Bellows material 2... Circular hole 3... Outer periphery joint part 4... Inner periphery joint part 5... Bellows plate part 6.7... Joint surface 10... Jig 11
...Support stand 12...Fixing plate 13...Bolt 14...Thread part 15...Nut]6...
- Holder temporary 17...Support rod 18.19...Flange member 20.21...Circular hole 22.23...Gap 24~
27... Brazing metal 31... Bellows material 32...
Circular hole 33... Bellows plate part 34... Outer circumferential edge joint part 35... Inner circumferential edge joint part 36.37... Bent part 41... First bellows material 42... Second bellows material 43 ...Bending portion 44...Bellows plate portion 45
...Outer peripheral edge joint 46...Inner peripheral edge joint 47...
・Bellows plate portion 48...Outer peripheral edge joint part 49...Bending part 50...Inner peripheral edge joint part 51...First bellows material 52...Second bellows material 53.54...Not joined Part 55... Outer periphery joint part 56
...Inner peripheral edge joint 57...Outer peripheral edge joint 58...
・Inner peripheral edge joint 60...Jig 61...Support stand 1
62... Fixed plate 63... Support pipe 64.
... Threaded part 65 ... Holding plate

Claims (3)

[Claims] (1) A method for manufacturing a metal bellows, in which a plurality of metal bellows materials having a predetermined shape are joined by alternately brazing the outer peripheral edge joint portion and the inner peripheral edge joint portion thereof, the corresponding bellows materials being bringing the metal surfaces of the outer circumferential edge joint and the inner circumferential edge bonding part into direct contact with each other, and arranging the brazing material in the vicinity of the joint, and assembling the bellows material horizontally in the axial direction; and the combined bellows material. A method for producing a metal bellows, comprising the steps of: pressing and holding the metal bellows in the axial direction and heating the metal bellows, and infiltrating the molten brazing material between the joint parts to braze them all at once. (2) According to claim 1, a linear brazing material is arranged in a gap formed in the vicinity of each joint of the bellows material that contacts each other and along the joint. manufacturing method of metal bellows. (3) The method for manufacturing a metal bellows according to claim 1, characterized in that a sheet-shaped brazing material is arranged near the joint portion along the axial direction of the bellows material.