JPH0118272B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shape memory effect device that performs various functions by utilizing the shape memory effect exhibited by a shape memory alloy.

[Problems to be solved by conventional technology and invention]

Many of the shape memory effect devices proposed so far have used linear shape memory alloys. Therefore, (a) it is not possible to memorize a "surface" in a shape memory alloy.

(b) The force (shape recovery force) when the shape memory alloy attempts to return to its memorized shape due to the shape memory effect is relatively small.

(c) Shape memory alloys cannot be significantly deformed in the compression and tension directions.

There were other drawbacks.

In addition, some shape memory effect devices using plate-shaped shape memory alloys have been proposed in the past;
Because a simple plate-shaped shape memory alloy was used, (d) the selection range of shape change modes of the shape memory alloy was narrow.

(E) Similar to the case of linear shape memory alloys, shape memory alloys cannot be significantly deformed in the tensile and compressive directions.

(F) When attempting to heat the shape memory alloy by direct current flowing through the shape memory alloy using Joule heat, the current distribution will not be uniform, the shape memory alloy will be heated unevenly, and some parts of the shape memory alloy may be heated. may be overheated or not heated to the required temperature range,
It may not be possible to make use of shape recovery power.

There were other drawbacks.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shape memory effect device that can eliminate the various drawbacks of the conventional devices and that can extremely easily manufacture a shape memory alloy having a desired shape.

[Means to solve the problem]

A shape memory effect device according to the present invention includes a plate-shaped shape memory alloy having a plurality of notches and a generally belt-shaped connecting portion formed between these notches, and both ends of the connecting portion are connected to the shape memory alloy. is continuous with other parts of the shape memory alloy, and when the shape memory alloy is deformed in a predetermined manner, the plurality of cuts are opened to form a plurality of openings, and the shape memory alloy The device is characterized in that a shape is stored in which each of the notches is opened and closed in a predetermined state.

[Effect]

In the present invention, the shape memory alloy is deformed into a shape other than the memorized shape (i.e., in a state where each notch is deformed into an open/close state other than the predetermined open/close state) at a predetermined temperature. When heated to a certain extent, the shape memory effect tends to return to the memorized shape (that is, the shape in which each cut is in the predetermined open/closed state). In the case of the present invention, the above object can be achieved by deforming the shape memory alloy from the memorized shape and returning to the memorized shape by deforming and restoring the shape of the approximately band-shaped connecting portion.

〔Example〕

The present invention will be explained in more detail below based on embodiments shown in the drawings.

FIG. 1 shows an embodiment of the present invention, in which a shape memory alloy 1 is formed by forming a large number of cuts 2 in a plate-shaped Ti-Ni shape memory alloy in an alternating manner in the vertical direction as shown in FIG. Become. Roughly band-shaped connecting portions 21 are formed between these cuts 2, and both ends of these connecting portions 21 are continuous with other parts of the shape memory alloy 1. This shape memory alloy 1 is subjected to a predetermined shape memory treatment to memorize the shape in which each notch 2 is closed, as shown in FIG.

In the lateral direction in the figure, one end of the shape memory alloy 1 is fixed to a fixing member 3, and the other end is connected to a driven body 4. A tension spring 6 is interposed between the driven body 4 and the fixed member 5, and this spring 6 pushes the shape memory alloy 1 through the driven body 4 in a direction perpendicular to each notch 2. (towards the right in the diagram). Further, the shape memory alloy 1 can be heated by a heating means (not shown).

Next, the operation of this embodiment will be explained.

At a temperature lower than a certain temperature, the portions of the shape memory alloy 1 near both ends of the connecting portion 21 are particularly bent and torsionally deformed to a large extent by being stretched by the force of the spring 6, as shown in FIG. As shown in b, each cut 2 opens to form a small opening, and the shape memory alloy 1 becomes net-like. As a result, the shape memory alloy 1 as a whole is stretched by a length L in the lateral direction in the figure. Therefore, the driven body 4 is positioned on the right side as shown in FIG.

However, when the shape memory alloy 1 is heated above the certain temperature by the heating means, due to the shape memory effect, the shape memory alloy 1 contracts against the spring 6 and assumes the memorized shape shown in FIG. 1a. Return. Therefore, the driven body 4 is moved to the left by a distance L from the position b in FIG.

Next, when the heating of the shape memory alloy 1 by the heating means is stopped and the shape memory alloy 1 is cooled, the shape memory alloy 1 is heated again as shown in FIG. 1b by the force of the spring 6.
The driven body 4 returns to its original position.

Thereafter, when the above-described heating and cooling of the shape memory alloy 1 is repeated, the shape memory alloy 1 repeats expansion and contraction, and the driven body 4 also moves as shown in FIGS.
It reciprocates between positions.

Note that by maintaining the shape memory alloy 1 at an appropriate temperature, the alloy 1 can also be maintained in an expanded/contracted state intermediate between those shown in FIGS. 1a and 1b.

In this device, since the shape memory alloy 1 is plate-shaped, a "surface" can be memorized in the alloy 1.

Further, in this device, the expansion and contraction of the shape memory alloy 1, that is, the deformation from the memorized shape and the return to the memorized shape, are mainly performed by the deformation and shape recovery of the connecting portion 21, and furthermore, in this case, the connecting portion 21 The deformation of is mainly caused by bending deformation in which small strain causes large deformation. Therefore,
It is possible to increase the expansion/contraction distance L of the shape memory alloy 1 (that is, the deformation of the shape memory alloy 1 in the compression direction and the tension direction when viewed macroscopically), thereby increasing the stroke of the driven body 4. Can be done.

In addition, since the sum of the shape recovery forces of the many connecting parts 21 becomes the shape recovery force of the shape memory alloy 1 as a whole, the shape memory alloy 1 It is possible to greatly increase the shape recovery power.

Furthermore, when an electric current is applied directly to the shape memory alloy to heat the shape memory alloy by Joule heat, the current flows through the approximately strip-shaped connecting portion 21, so that the current distribution becomes uniform, and the shape memory alloy 1 is heated evenly.

Furthermore, the shape memory alloy 1 can be manufactured by simply providing a notch in a plate-shaped shape memory alloy by press working or the like, so it can be manufactured extremely easily.

Figures 2-4 show other embodiments of the invention.

A pair of shape memory alloys 7 are made of Ti as shown in FIG.
- A central part 7 of the Ni shape memory alloy disk.
A suitable number of arc-shaped cuts 8 are provided from the periphery of A toward the peripheral edge 7B. A roughly belt-shaped connection part 22 is formed between these cuts 8,
Both ends of these connecting parts 22 are made of shape memory alloy 7
Continuous to other parts of. These shape memory alloys 7 are subjected to a predetermined shape memory treatment to form a substantially truncated cone with the central portion 7A raised perpendicularly to the peripheral portion 7B as shown in FIGS. 2b and 4. The shape of the figure is memorized.

In this memorized shape, compared to the flat state shown in FIG. 3, the connecting portions 22 of the shape memory alloy 7 are bent and twisted, and each notch 8 opens to form an opening. Alloy central part 7
The portion between A and the peripheral edge 7B has a net shape.

The pair of shape memory alloys 7 are fixed to each other at their peripheral edges 7B. Further, between the central portions 7A of both shape memory alloys 7, there is a
A tension spring 9 is interposed in a direction perpendicular to the shape memory alloy 7, and this spring 9 urges each shape memory alloy 7 to approach the flat disk-like state shown in FIG.

In this embodiment, at a temperature lower than a certain temperature, the force of the spring 9 causes each shape memory alloy 7 to
As shown in Figure a, it has been deformed into a nearly disc-shaped state. However, when heated above a certain temperature,
As shown in Fig. 2b, the device returns to the memorized shape shown in Fig. 4 against the force of the spring 9, so that the entire device roughly has the shape of two truncated cones stacked in opposite directions, as shown in Fig. 2b. Become. Therefore, in this embodiment, the device can be expanded and contracted in the vertical direction in FIG. 2 when viewed macroscopically.

In this manner, the same effects as in the previous embodiment can be obtained in this embodiment as well.

Furthermore, in this embodiment, when the device transitions between the state shown in FIG. 2a and the state shown in FIG. Since it moves, it becomes possible to utilize both this rotational movement and the macroscopic expansion and contraction movement.

5 and 6 show other embodiments of shape memory alloys that can replace the shape memory alloy 7 in the embodiments of FIGS. 2 to 4.

In this embodiment, the shape memory alloy 10 is formed into a disk of Ti-Ni shape memory alloy, as shown in FIG.
A large number of arcuate notches 11 forming part of a concentric circle having a common center with the disk are provided in a staggered manner. Roughly band-shaped connecting portions 23 are formed between these cuts 11, and both ends of these connecting portions 23 are continuous with other parts of the shape memory alloy 10. This shape memory alloy 10 is
By being subjected to a predetermined shape memory process, the sixth
As shown in the figure, a shape approximately forming a truncated cone in which the central portion 10A is lifted from the peripheral portion 10B is memorized.

In addition, in this memory shape, the connecting portions 23 of the shape memory alloy 10 are bent and torsionally deformed compared to the flat state shown in FIG.
1 open to form openings, and the portion between the central portion 10A and the peripheral portion 10B of the alloy 10 has a net shape.

Even if this shape memory alloy 10 is used, the same operation as the embodiment shown in FIGS. 2 to 4 can be performed. However, in this embodiment, no relative rotational movement occurs between the central portion 10A and the peripheral portion 10B of the shape memory alloy 10.

FIG. 7 shows yet another embodiment of the invention.

The shape memory alloy 12 is made of Ti-
It is constructed by providing a large number of notches 13 in the same direction in a staggered manner on a flat plate of Ni shape memory alloy, and further winding this flat plate into a cylindrical shape so that each notch 13 is oriented in the axial direction. Roughly band-shaped connecting portions 24 are formed between these cuts 13, and both ends of these connecting portions 24 are continuous with other parts of the shape memory alloy 12. Then, the shape memory alloy 12 is subjected to a predetermined shape memory treatment, so that the notches 13 are opened to form a net shape and the diameter thereof is enlarged to memorize the shape, as shown in FIG. 7b. ing.

Further, the entire outer periphery of the shape memory alloy 12 is covered with a covering material 14 made of a flexible and highly elastic material such as silicone rubber. This covering material 14 is made of shape memory alloy 12 as shown in FIG. 7a.
Each cut 13 is closed as shown in FIG.
2 is biased so that its diameter is reduced.

In this embodiment, at a temperature lower than a certain temperature, the shape memory alloy 12 is in a small diameter state as shown in FIG. 7a due to the biasing force of the covering material 14.

However, when heated to above the certain temperature, the shape memory alloy 12 resists the covering material 14 and returns to the memorized shape shown in FIG. 7b due to the shape memory effect.
Large diameter.

Further, when the heating is stopped and the shape memory alloy 12 is cooled, its diameter is reduced again by the biasing force of the covering material 14.

Note that by maintaining the shape memory alloy 12 at an appropriate temperature, it is also possible to make the diameter of the alloy 12 intermediate between those shown in FIGS. 7a and 7b.

In this embodiment, the flow rate of the fluid can also be controlled by, for example, changing the diameter of the shape memory alloy 12 as described above while the fluid is flowing through the shape memory alloy 12 and the coating material 14. death,
By locally heating the shape memory alloy 12 and moving this local heating point in the axial direction of the alloy 12, the change in diameter is propagated in the axial direction in the alloy 12. It is also possible to force the fluid to move in the axial direction, i.e. to perform a pumping function.

In addition, in the above embodiment, the shape memory alloy is made to memorize the shape in which the notch is closed.
The shape memory alloy may memorize the state in which the cut is opened to a predetermined extent.

In addition to the above-mentioned Ti-Ni alloy, the shape memory alloy constituting the shape memory alloy in the present invention includes:
Cu−Zn, Cu−Zn−Al, Cu−Zn−Ga, Cu−Zn
−Sn, Cu−Zn−Si, Cu−Al−Ni, Cu−Au−
Zn, Cu-Sn, Au-Cd, Ag-Cd, Ni-Ti-X
(X is a third element), Ni-Al, Fe-Pt, and all other shape memory alloys can of course be used.

〔Effect of the invention〕

As described above, according to the present invention, (a) since the shape memory alloy is planar, it is possible to memorize a "plane" in the shape memory alloy.

(b) By deforming the connecting part between each notch, including bending deformation, shape memory alloy can be
Macroscopically, it can be deformed in the compression and tension directions. Further, since the bending deformation results in a large deformation as a whole with a small strain, the shape memory alloy can be greatly deformed in the compression direction and the tension direction when viewed macroscopically.

(c) By considering the installation location, size, direction, etc. of the notch, it is possible to easily cause the shape memory alloy to change shape in various ways, so it is possible to change the shape of the shape memory alloy in a wide range of ways. can be selected.

(d) The shape-recovery force of the shape-memory alloy as a whole is the sum of the shape-recovery forces of many connected parts, so the shape-recovery force is greater than that of the linear shape-memory alloys that have been commonly used in the past. be able to.

(e) When trying to heat the shape memory alloy by direct current flowing through the shape memory alloy using Joule heat, the current flows through the roughly band-shaped connection, so the current distribution becomes uniform and the shape memory alloy heats up. Heats evenly.

(f) It can be manufactured simply by making notches in a plate-shaped shape memory alloy by press working, etc., so it can be manufactured extremely easily.

It is possible to obtain excellent effects such as.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the shape memory effect device according to the present invention, Fig. 2 is a sectional view showing another embodiment of the present invention, and Fig. 3 is a shape memory alloy in the same embodiment. FIG. 4 is a perspective view showing the shape memory alloy according to the embodiment in a memorized shape state, and FIG. 5 shows another embodiment of the shape memory alloy in a disk shape state. FIG. 6 is a perspective view showing this embodiment in a memorized shape state, and FIG. 7 is a perspective view showing still another embodiment of the present invention. 1, 7, 10, 12...shape memory alloy, 2,
8, 11, 13...notches, 21-24...connections.

Claims (1)

[Scope of Claims] 1. A plate-shaped shape memory alloy having a plurality of notches and a generally belt-shaped connecting portion formed between these notches, wherein both ends of the connecting portion are connected to the shape memory alloy other than the shape memory alloy. , and when the shape memory alloy is deformed in a predetermined manner, the plurality of cuts are opened to form a plurality of openings, and the shape memory alloy A shape memory effect device, characterized in that a shape in which the notch is opened and closed in a predetermined state is memorized.