JPH0384292A - Shape memory alloy coupling - Google Patents

Abstract

PURPOSE:To firmly join together minor and major diameter members through the sharp increase of both a joining area between the minor diameter member and a member to be connected and a joining area between the minor diameter member and the major diameter member by a method wherein the minor diameter member is threaded joined with the major diameter member, and a screw member capable of being threaded joined with the member to be connected is formed on the inner peripheral surface of the minor diameter member. CONSTITUTION:Through threaded engagement between an inner cylinder member 1 and an outer cylinder member 2 made of a shape memory alloy and threaded engagement between the inner cylinder member 1 and members 8 and 9 to be connected, each joining area is increased to increase a joining force. Since a coupling is coupled to the members 8 and 9 to be connected by caulking and threaded joining through reduction of the size of the outer cylinder member 2, pull-off resistance is excellent. The outer cylinder member 2 is heated and reduced in size through recovery of a shape produced by means of a shape memory effect to caulk the inner cylinder member 1, and the caulked inner cylinder member 1 is forced into pressure contact with the members 8 and 9 to be connected, which are inserted in the inner member.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a shape memory alloy joint.

[Conventional technology] Pipe joints using shape memory alloys have been known for some time.

As shown in FIG. 5, this pipe joint includes an inner cylinder member 10 formed of a metal cylinder with both ends open, and an outer cylinder member 20 made of a shape memory alloy that is fitted onto the outer peripheral surface of the inner cylinder member 10. , and a resin liquid [13] deposited on the inner circumferential surface of the inner cylinder member 10. The outer cylindrical member 20 is heated and recovers its shape due to the shape memory effect, thereby caulking the inner cylindrical member 10. By this caulking, this pipe joint is inserted into the pipe 80.9 inserted into the inner cylinder member 10.
Junction with 0. Note that the resin coating 30 is melted by the heating and seals the gap between the inner cylinder member 10 and the pipes 80 and 90.

In addition, as shown in FIG. 6, there is another shape memory alloy pipe joint that consists of a diameter-reduced cylindrical member 1Oa made of a shape memory alloy cylinder and a resin coating 30a coated on its inner circumferential surface. . In this pipe joint, the diameter-reduced member 10a is reduced in diameter and joined to the pipe 80.90 via the resin coating 30a.

[Problems to be Solved by the Invention] However, in the conventional pipe joint described above, the outer cylinder member 20
If the bonding area between the inner tube member 10 and the inner tube member 10 is small, the bonding force between the two will be insufficient, and the force with which the inner tube member 10 caulks the pipes 80 and 90 will be insufficient. If the joint area between the pipes 80 and 90 is small, the joint force between the inner cylinder member 10 and the pipes 80 and 90 will be insufficient, and for example, when an external force is applied to the pipes 80 and 90 in the pulling direction, the pipes 80 and 90 will There was a possibility that it would come off the joint, and even if it did not come off, there was a possibility that the internal fluid would leak.

The present invention has been made in view of such problems, and an object to be solved is to provide a shape memory alloy joint that can be firmly joined to a member to be connected.

[Means for Solving the Problems] The shape memory alloy joint of the first invention includes an inner cylindrical member made of a metal cylinder each having an opening into which a connected member can be inserted, and a shape memory alloy joint that is fitted onto the outer circumferential surface of the inner cylindrical member. A shape memory alloy joint having an outer cylinder member made of a shape memory alloy cylinder whose diameter is reduced by shape recovery based on a shape memory effect and caulks the inner cylinder member, wherein the inner cylinder member is screwed together with the outer cylinder member. It is characterized by having a screw portion that fits together with the connecting member, and a screw portion that screws together with the connected member.

The shape memory alloy joint of the second invention has a reduced diameter tube made of a shape memory alloy tube, each having an opening into which a member to be connected can be inserted, and which is reduced in diameter by shape recovery based on a shape memory effect and joined to the member to be connected. In a shape memory alloy joint having a member,
The reduced diameter cylindrical member is characterized in that it has a threaded portion into which the threaded portion of the connected member is screwed.

The inner cylindrical member or the diameter-reduced cylindrical member can be formed into a sleeve shape or an elbow shape with openings at both ends, or can also be formed into a cheese shape, a cross shape, or the like, and have three or more openings.

A temperature-indicating resin film that irreversibly changes color at a temperature higher than the transformation point of the shape memory alloy can be applied to the outer cylinder member and diameter-reducing cylinder member, and in this way, diameter reduction can be confirmed. .

[Function] In the shape memory alloy joint of the first invention (hereinafter also simply referred to as a joint), each joint area is increases, and the bonding force increases. Further, since the joint and the connected member are connected by caulking by reducing the diameter of the outer cylinder member and the above-mentioned screw engagement, the joint has excellent pull-out resistance. Then, the outer cylinder member is heated and reduced in diameter due to shape recovery due to the shape memory effect, and the inner cylinder member is caulked, and the caulked inner cylinder part is pressed into contact with the connected member inserted therein.

In the joint of the second aspect of the invention, the reduced diameter cylindrical member is screwed onto the outer peripheral surface of the member to be connected and then pressed into contact with the outer circumferential surface of the connected member by reducing the diameter, so that the joint area of both increases and the joining force increases. The reduced diameter cylindrical member is then heated and reduced in diameter due to shape recovery due to the shape memory effect, and is pressed into contact with the connected member inserted therein.

[Example] Embodiments of the joint of the present invention will be described below with reference to the drawings.

Note that each figure shows the state after bonding.

(Example 1) An embodiment of the joint of the first invention will be described with reference to FIG.

This joint consists of an inner cylinder member 1 which is formed into a tubular shape with both ends open, and an outer cylinder member 2 which is screwed onto the outer peripheral surface of the inner cylinder member 1.

The inner cylindrical member 1 is made of an aluminum alloy cylindrical member with a predetermined wall thickness, and has threaded portions 1 on the inner and outer peripheral surfaces except for both ends.
a and 1b are formed.

The outer cylindrical member 2 is made of a CLI-Zn-AI shape memory alloy cylinder, and has a threaded portion 2a formed on its inner peripheral surface except for both ends thereof, and is screwed into the threaded portion 1b of the inner cylindrical member 1. There is.

The threaded portion 1a of the inner cylinder member 1 is a threaded portion 8a formed on the outer circumferential surface of a pipe 8.9 that constitutes a connected member in the present invention.
, 9a are screwed together.

Next, the assembly of this joint will be explained.

First, threaded portions 1a and 1b are formed on the inner circumference m and outer circumferential surface of the inner cylinder member 1 using a predetermined jig. Next, a threaded portion 2a is formed on the inner peripheral surface of the outer cylinder member 2. However, the diameter of the root 1C of the threaded portion 1b of the inner cylinder member 1 is approximately 4% smaller than that of the top 2C of the threaded portion 2a of the cylinder member 2.
The top portion 1d of the threaded portion 1b is approximately 4% smaller in diameter than the valley portion 2d of the threaded portion 2a of the outer cylinder member 2.

Next, the inner diameter of the outer cylinder member 2 is set to 7 to 8 over the entire inner circumferential surface.
%, and the expanded outer cylindrical member 2 is screwed onto the outer peripheral surface of the large diameter portion IC of the inner cylindrical member 1. In this way, the %a of the joint is completed.

Next, the joint of the pipe 8.9 using this joint will be explained.

Turn the pipe 8.9 into the joint at room temperature and screw them together, and heat the outer cylinder member 2 at 200' (f).The outer cylinder 8 heated to about 150'C or higher The material 2 recovers its shape memory and shrinks in diameter, and the entire outer peripheral surface of the inner cylinder member 1C is caulked with a uniform compressive force, and the caulked inner cylinder member 1 becomes a pipe 8.
9 is pressed against.

As explained above, in the joint of this embodiment, after the inner cylinder member 1 is screwed together with the outer cylinder member 2 and the pipe 8.9, the joint and the pipe 8.9 are uniformly caulked by reducing the diameter.
It is possible to significantly increase the bonding area with the material, increase the bonding strength, and prevent leakage. Moreover, the pull-out resistance of the pipe can be improved.

In addition, as shown in FIG. 2, a rod member 80. having a threaded portion is provided.
90 can also be screwed onto the inner cylinder member 1.

(Example 2) An embodiment of the joint of the second invention is shown in FIG.

This joint consists of a reduced diameter cylindrical member 6 of a shape memory alloy joint, and a threaded portion 6a is formed on the inner peripheral surface of this reduced diameter cylindrical member 6.

After the diameter of the reduced diameter cylinder member 6 is expanded in the same manner as the outer cylinder member 2 of Example 1, the pipe 8.9 is inserted into the reduced diameter cylinder member 6 while rotating, and the threaded portion of the pipe 8.9 is inserted. 8a and 9a are screwed into the threaded portion 6a of the diameter-reducing cylinder member 6. Thereafter, the reduced diameter cylindrical member 6 is heated and reduced in diameter in the same manner as the outer cylindrical member 2 of Example 1, and is joined to the pipe 8.9.

In this embodiment as well, the diameter-reducing member 6 can produce the same effects as those described in embodiment 1, and although the amount of shape memory alloy increases, the structure of the joint becomes simpler.

In addition, as shown in FIG. 4, a rod member 80. having a threaded portion is provided.
90 can also be screwed onto the inner cylinder member 1.

[Effects of the Invention] In the shape memory alloy joint of the first invention, the inner cylindrical member is threadedly engaged with the outer cylindrical member, and has a threaded portion on its inner peripheral surface that can be threadedly engaged with the connected member. Both the joint area between the member and the connected member and the joint area between the inner diameter member and the outer diameter member can be significantly increased to firmly join the two, and
The pull-out resistance of the connected member can be improved.

In the shape memory alloy joint of the second invention, the diameter-reduced cylindrical member also has a threaded portion that engages with the connected member, so the joint area between the two increases and the joint can be strengthened, and , the pull-out resistance can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the joint of the first invention;
FIG. 2 is a schematic sectional view showing another modification of the joint of the first invention, FIG. 3 is a schematic sectional view showing an embodiment of the joint of the second invention, and FIG. 4 is a schematic sectional view showing another modification of the joint of the second invention. FIGS. 5 and 6 are schematic sectional views of a conventional joint. 1...Inner tube member 2...Outer tube member 6...Reduced diameter tube member

Claims (2)

[Claims] (1) An inner cylindrical member made of a metal cylinder each having an opening into which a connected member can be inserted; In a shape memory alloy joint having an outer cylindrical member made of a shape memory alloy cylinder that caulks the members, the inner cylindrical member has a threaded portion that threadably engages with the outer cylindrical member, and a threaded portion that threadably engages with the connected member. A shape memory alloy joint characterized by having. (2) A shape memory alloy joint having reduced diameter cylindrical members made of shape memory alloy cylinders each having an opening into which a connected member can be inserted, and whose diameter is reduced by shape recovery based on the shape memory effect and joined to the connected member. In the shape memory alloy joint, the diameter-reduced cylindrical member has a threaded portion into which the connected member is threaded.