JPH0655337B2 - Shape memory element manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a shape memory element by molding a shape memory alloy material and performing a shape memory treatment (heat treatment).

[Prior art and its problems]

Shape memory alloys have the property that once a specific shape is memorized, even if it is deformed at low temperature, it will return to its original shape by simply heating it, and it is industrially applied as various sensors and actuators. Is expected.

Since shape memory alloys usually extend the working stroke,
Often used in the form of coil springs, in that case, the process of manufacturing shape memory elements from shape memory alloy materials such as wire rods and plates is almost the same as the spring forming process for piano wires, etc., except for the heat treatment process. Is. In the case of general coiled elements, a wire rod that has been sufficiently work-hardened by cold rolling or wire drawing is formed into a coil shape such as tension, compression, or torsion spring, and then heat treated to suit each application. To obtain a shape memory element having a predetermined characteristic.

The coiled element may be formed by winding a wire around a cylindrical fixing jig in the case of a small amount of prototype, but is usually formed by an automatic coiling machine like an ordinary coil spring. FIG. 4 shows a coiling mechanism by an automatic machine. The shape memory alloy wire 1 is realigned by a realigning roller 2 and then sent out through a guide 4 by a feed roller 3 and predetermined by coiling pins 5A, 5B. Can be bent to a curvature of. The coil diameter is adjusted by moving the coiling pins 5A and 5B with respect to the mandrel 6.
The claw 7 moves in a direction perpendicular to the paper surface to adjust the coil pitch. When a certain length of wire is fed out, the feeding is automatically stopped, and the coil is cut off at the straight portion of the cutting blade 8 and the mandrel 6.

The wire formed into the coil is subjected to a predetermined heat treatment (shape memory processing) to memorize its shape.

For shape memory treatment of Ti-Ni alloy, (1) 400-500 after forming an alloy material sufficiently work-hardened by cold working
Medium temperature treatment that keeps the temperature at ℃ for about 1 hour, and (2) 800 ℃
Normalization annealing is performed at the above high temperature in advance, and after molding in the annealed state, a low temperature treatment is performed at 200 to 300 ° C, and (3) After solution treatment, several times at a temperature of around 400 ° C. There are three types of aging treatment, that is, time aging treatment.However, in any of the treatment methods, the formed shape must be fixed so that the formed coiled element does not change its shape due to heat during processing. I won't.

The shape is fixed by screwing, winding, caulking, etc. using an appropriate fixing jig, but the fixing jig and the labor required for fixing make the shape memory element manufacturing cost high. This is one of the factors that hinder the widespread use of the device.

[Means for solving problems and their effects]

The present invention provides a method for manufacturing a shape memory element, which solves the above-mentioned problems of the prior art.
A shape-memory alloy material is added with a metal material having a shape-retaining function during shape-memory processing of the shape-memory alloy material, and in that state, a desired shape is formed and shape-memory processing is performed. The shape memory element is obtained by separating the memory alloy material from the metal material.

In this way, the fixing jig and its attachment are not required, so that the manufacturing cost can be reduced.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 and 2, 1 is a shape memory alloy wire rod,
Reference numeral 9 is a steel wire attached to it. The steel wire 9 has a groove 10, and the shape memory alloy wire rod 1 housed in the groove 10 is held from both sides. In this way, the composite wire rod 11 is
A groove 10 is previously formed in the steel wire 9 by atypical die drawing, cutting, roll forming, etc., and the shape memory alloy wire rod 1 is superposed thereon, and then the opening of the steel wire 9 is formed by roll forming or caulking. It can be obtained by molding the wire 1 so as to hold it from both sides. This composite process may be continuously performed during the process of supplying the wire rod during the molding process with the automatic coiling machine.

This composite wire rod 11 is fed into an automatic coiling machine as shown in FIG. 1, and the steel wire 9 is formed into a coil shape so that it is on the outer peripheral side of the shape memory alloy wire rod 1. The molded composite wire rod is subjected to the above-mentioned shape memory treatment as it is, and when the end face is polished, the end face polishing is performed as it is, and the shape memory alloy wire rod 1 is removed from the steel wire 9 to obtain a coil-shaped shape memory element. It is one of the advantages of the present invention that the end surface is easily polished.

FIG. 3 shows another embodiment of the present invention, in which the shape memory alloy wire rod 1 is simply inserted into the groove 10 of the steel wire 9 without closing the opening of the steel wire 9.
In the example of performing the same forming and shape memory treatment as described above in a state of being added, it is easier to separate the shape memory alloy wire from the steel wire in a later step as compared with the above embodiment.

In each of the above embodiments, the case of manufacturing the coil-shaped shape memory element has been described, but the present invention can be applied to the case of manufacturing shape memory elements of other shapes. Further, the case where the shape memory alloy material is a wire has been described, but the same can be applied to the case of a plate material or the like. Further, the steel wire is used as the metal material to be added to the shape memory alloy material, but the metal material may be another material as long as it has a shape retaining function during shape memory processing of the shape memory alloy material.

〔The invention's effect〕

As described above, according to the present invention, the shape memory process can be easily performed without using a special shape fixing jig after molding, and thus the manufacturing process of the shape memory element can be simplified and the cost can be reduced. is there.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a method of manufacturing a shape memory element according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a sectional view of the wire portion shown, and FIG. 4 is an explanatory view showing a conventional manufacturing method. 1 to shape memory alloy wire rod, 3 to feed roller, 4 to guide,
5A / 5B ~ coiling pin, 6 ~ mandrel, 9 ~ steel wire, 10
~groove.

Claims (1)

[Claims] 1. A shape memory alloy material is added with a metal material having a shape retaining function at the time of shape memory processing of the shape memory alloy material, and in that state, it is molded into a desired shape, and shape memory processing is performed, Then, the shape memory alloy material is obtained by separating the shape memory alloy material from the metal material.