JPS61142025A - Preparation of clamp made of shape memory alloy - Google Patents

Abstract

PURPOSE:To facilitate molding work and permit cost cut by preparing a clamp through a series of assembly line operation of cutting work, elongation work, bending work, and welding work for a band-shaped plate. CONSTITUTION:A plate member which is made of shape memory alloy and has a prescribed width is press-cut to the developmentlength of clamp to form a band-shaped plate 1. After said band-shaped plate is applied with the prescribed shape memory treatment, the elongation work to a prescribed elongation rate at the temperature below the martensite deformation temperature is applied. Then, the bending work for the formation of annular clamp corresponding to the pipe body such as the pipe to be connected is applied in the pressurized state. Then, the both butt-joint parts 2 at the both edges are fused by electron beam, laser, or plasma arc welding. In the welding work, almost all the part of the body 3 held by a jig 4 is immersed into the prescribed cooling liquid C, and kept at the temperature below the martensite deformation temperature, and the butt-joint part 2 is welded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method of manufacturing a clamp using a shape memory alloy for fastening and joining tubular bodies such as pipes at their ends.

(Prior Art and its Problems) As a conventional clamp using a shape memory alloy, there is one disclosed, for example, in Japanese Patent Laid-Open No. 123919/1983.

FIG. 9 shows an embodiment of the clamp (coupling device) according to the application, and the clamp 101 consists of an insertion member 102 with a tapered inner surface and a shape memory alloy disposed on the outer surface of the insertion member 102. It is composed of two parts: a suppressing member 103.

However, in the conventional wooden example, the suppression member 103 is formed from the beginning as a tubular body by seamless cutting, and the insertion member 102 is also formed by cutting, and since it is two parts, it is difficult to fit the pipe to be fastened. There is a problem in that high precision is required to mold the shape, making it difficult to manufacture.

Further, as another example, the one disclosed in JP-A-59-166427 is an annular one as shown in FIG. 1O.
In this conventional example, it is a clamp 104 that has been subjected to reversible shape memory processing, and is formed into a cylindrical shape by machine cutting, and the inner diameter is made larger or smaller than the pipe body to be fastened. The tubes 105 and 106 are expanded or contracted by heating and cooling to connect the tubes 105 and 106.

Therefore, heat treatment and shape processing for reversible shape memory processing require a lot of man-hours, and the reliability is insufficient.

(Object of the Invention) The present invention was developed in view of the above-mentioned conventional problems, and provides a shape memory alloy clamp that has sufficient fastening performance, good productivity, and is inexpensive. The purpose is to provide a manufacturing method.

(Means for Solving the Problems) In order to achieve the above object, in the first invention of the present application, a shape memory alloy plate having a predetermined width is press-cut to a clamp development length to form a band-shaped plate, After performing a prescribed shape memory treatment on the strip plate, it is stretched to a prescribed elongation rate at a temperature below the martensitic transformation temperature, and then bent into a clamp shape that corresponds to the pipe body to be fastened. A method for manufacturing a shape memory alloy clamp is characterized in that the abutting portions at both ends are welded and formed while the above is maintained at a temperature below the transformation temperature.

In addition, in order to achieve the above object, in the second invention of the present application, a shape memory alloy plate material having a predetermined width is press-cut to a clamp development length to form a band-shaped plate, and a predetermined shape is formed in the band-shaped plate. After the memory treatment, the pipe is bent into a clamp shape that corresponds to the pipe body to be fastened, and then the abutting portions at both ends are welded, and the material is rolled and expanded at a predetermined elongation rate at a temperature below the martensitic transformation temperature. The present invention is characterized by a method of manufacturing a shape memory alloy clamp that is formed by stretching.

(Example) Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1 to 5 show an embodiment of the first invention of the present application, and in manufacturing the shape memory alloy clamp according to this embodiment, first, as shown in FIG. A plate material made of a shape memory alloy is press-cut to a predetermined clamp development length Ll) to form a band-shaped plate l.

Thus, the belt-like plate l is at the developed length Ll.

For example, shape memory treatment is performed at a temperature of 500° C. for 1 hour.

Thereafter, the strip plate 1 is stretched to the length L2 shown in FIG. 2 using a predetermined jig at a temperature below the martensitic transformation temperature of about -30°C to -20°C.

Stretching is performed at an elongation rate of about 5 to 10%.

Next, as shown in Fig. 3, bending is performed under pressure using an annular mold (not shown) into an annular clamp shape corresponding to the tubular body such as a pipe to be fastened, and then both ends of the clamp are bent. The abutted portions 2 are welded by electron beam, laser, plasma arc welding, or the like.

In addition, during the welding work, if the entire body is heated, the clamp itself will contract and return to the L memorized shape. Therefore, as shown in FIG.
The butt part 2 is welded by immersing most of it in a predetermined cooling liquid C and keeping it below the above-mentioned martensitic transformation temperature.

In this way, as shown in FIG. 5, only the peripheral portion 6 of the welded portion 5 will locally shrink to the memorized shape, but the overall clamp length will not be affected.

Shape memory alloy clamp C manufactured by the method described in 11-
The inner diameter of the pipe is set to be slightly larger than the outer diameter of the pipe to which it is to be fastened.

For example, as shown in FIG. 6, when the clamp C is fitted onto the abutting portion of the ends of the pipes 7 and 8 to be fastened and heated to the above-mentioned transformation temperature or higher, the clamp C memorizes as shown in FIG. Since the inner diameter of the clamp C is set to be slightly smaller than the outer diameter of the pipe 7.8 in the restored state, the restoring force causes the pipe 7.8 to contract and restore its shape.
The joint is made by firmly tightening the abutting portions of 8.

According to the manufacturing method according to this embodiment, the clamp C can be manufactured by simply performing a series of assembly operations such as cutting, stretching, bending, and welding using a strip plate. Therefore, compared to conventional shape memory alloy clamps, the molding work is easier and it can be produced at a lower cost.

Next, an embodiment of the second invention of the present application will be described.

In the manufacturing method according to this embodiment, similarly to the embodiment according to the first invention, as shown in FIG.
x) to form a band-shaped plate 1, and a predetermined shape memory treatment is performed at the developed length L□.

Next, as shown in FIG. 3 of the embodiment described in -1-, the strip plate l is bent into an annular clamp shape, and then the abutting portions 2 at both ends are bent with an electron beam according to the above embodiment. Welding is performed by means such as welding.In this welding operation, the strip plate l remains in its memorized shape, so there is no need to keep the main body below the martensitic transformation temperature during welding.

After that, as shown in FIG. 8, a pair of rollers 9.1
The shape memory alloy clamp C according to the above example was obtained by rolling and expanding the clamp C by pulling the clamps outward while rotating the clamps to an overall elongation rate of about 5 to 10%. It is something to be manufactured.

In addition, during the above-mentioned rolling expansion process, the clamp C shall be kept at a temperature below the martensitic transformation temperature.

The manner of use of the clamp C manufactured according to this example is the same as that of the above-mentioned example, and the operation and effect are also similar to the above-mentioned example, but the main body is heated below the transformation temperature during welding work. Since there is no need to maintain it, a new effect can be achieved in that work can be performed more efficiently.

In addition, the shape memory alloy in each of the examples described in 2.
For example, Ni--i alloy is preferred, but it goes without saying that various changes can be made without departing from the spirit of the invention, such as the use of other alloys if necessary.

(Effects of the Invention) I-As mentioned above, according to the manufacturing method of the present invention, it is possible to manufacture a shape memory alloy clamp with extremely high productivity and sufficient strength, and it is possible to manufacture a clamp made of a shape memory alloy with an extremely high productivity. Without any
It has various useful effects such as providing a lamp that is inexpensive and easy to use.

[Brief explanation of the drawing]

Figures 1 to 7 show an embodiment of the first invention of the present application, Figures 1 to 5 are explanatory diagrams showing the manufacturing process of the clamp, and Figures 6 and 7 show the use of the clamp. FIG. 8 is an explanatory diagram showing an embodiment of the second invention of the present application, and FIGS. 9 and 10 are explanatory diagrams each showing how a conventional clamp is used. DESCRIPTION OF SYMBOLS 1... Band-shaped plate, 2... Butt part, 3... Main body, 5... Welding part, 7.8... Pipe body,
9.10...Roller, C...Shape memory alloy clamp. Patent Applicant Kato Hatsujo Co., Ltd. Agent Patent Attorney Hiroshi Fujiwara

Claims (2)

[Claims] (1) In a method for manufacturing a shape memory alloy clamp for fastening tube bodies such as pipes, a shape memory alloy plate having a predetermined width is press-cut to the clamp development length to form a band-shaped plate, and the band-shaped After applying a specified shape memory treatment to the plate, it is stretched to a specified elongation rate at a temperature below the martensitic transformation temperature, and then bent into a clamp shape that corresponds to the pipe to be fastened, and the main body is A method for manufacturing a shape memory alloy clamp, characterized in that the shape is formed by welding the abutting portions of both ends while maintaining the temperature below the transformation temperature. (2) In a method for manufacturing a shape memory alloy clamp for fastening tube bodies such as pipes, a shape memory alloy plate having a predetermined width is press-cut to the clamp development length to form a band-shaped plate, and the band-shaped After applying a specified shape memory treatment to the plate, it is bent into a clamp shape that corresponds to the pipe body to be fastened, and then the abutting portions at both ends are welded, and the plate is rolled and expanded into the specified shape at a temperature below the martensitic transformation temperature. A method for manufacturing a shape memory alloy clamp, characterized in that the clamp is formed by being stretched at an elongation rate of .