JPH02205648A - Spring material - Google Patents

Abstract

PURPOSE:To obtain the spring material enduring high loads, necessarily recoverable to the initial shape and having improved response characteristics by forming it with shape memory alloy plurally provided so that rectangular folded parts are alternately arranged in a row. CONSTITUTION:A spring material 20 is composed so that, as shown in a figure A, folded parts 21 of which plural wire rods constituted of shape memory alloy are folded into a rectangular shape are alternately arranged in a row. The shape memory alloy is composed of Ni-Ti series alloy and the folded parts can necessarily be recovered into the initial shape even if both ends 22-22 are drawn and highly bent from the state of memorizing the initial state. Namely, the spring material 20 can necessarily be recovered into the initial state even if drawn and deformed, as shown in a figure B, into the position at which permanent deformation is produced and elastic recovery is made impossible in a conventional spring material. Furthermore, the spring material 20 has the properties of having a superelastic area W where, as shown by an indication line X, loads are made approximately same when the amt. to be folded is made certain or above. Thus, by using the area W, loads at the time of folding the spring material 20 can be certain, so that the elastic recovering power of the spring material 20 can be set to certain loads.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a spring material made of a shape memory alloy.

B9 Summary of the Invention The present invention is a spring material formed by providing a plurality of shape memory alloys alternately in parallel in a rectangular folded part, which resists a large load and always returns to its initial state, and which improves response characteristics. This is an attempt to improve the situation.

C3 Prior Art Various types of spring materials have been proposed in the past, each of which is a wire formed into a spring shape. That is, there are various spring materials in which a wire material such as stainless steel or piano wire is wound into a coil shape.

By the way, in the case of the spring material used to tension and bias the suspenders that press and support the head in the headband of the headphone device, due to the limitations of the storage section, in order to make the spring material smaller and to the F31 type, A spring material 50 has been proposed in which the above-mentioned wire material is formed not in a coil shape but in a so-called quintuple shape in which a plurality of circular arc-shaped folded portions 51 are alternately arranged in parallel as shown in FIG.

D1 Problems to be Solved by the Invention However, when the spring material 50 is formed into a quintuple shape in which the arcuate folded portions 51 are alternately folded in parallel as described above, the conventional wire material such as stainless steel or piano wire is As shown by the solid line in the indicated line y in the figure, the elastic region is narrow and even with a small amount of deflection, it will be permanently deformed and will no longer function as a spring. In addition, the conventional spring material 50 has a large load change with respect to the amount of deflection, and the elastic return force is not constant. Therefore, stainless steel, piano wire, or the like cannot be used as the spring material.

Furthermore, the spring material 50 in the shape of a quincunx, in which the folded portions 51 are simply provided alternately in parallel, has a large hysteresis during elastic displacement when a load is applied and elastic return when the load is unloaded, resulting in poor responsiveness during loading and unloading. There is a difference.

Therefore, for example, when used as a spring material to tension and bias suspenders that press and support the head in a headband of a headphone device, the suspenders are housed in the thin headband and can withstand the large load required to extend the suspenders. In addition, the conventional materials such as stainless steel and piano wire cannot be used as spring materials that can always return to the initial state in a reliable and responsive manner.

Further, the spring material used in the headband of the headphone device needs to quickly absorb sound vibrations generated from the headphone units attached to both ends of the headband to prevent crosstalk from occurring. but,
The above spring materials such as stainless steel and piano wire generally have high resonance sharpness and do not have good acoustic vibration damping characteristics.

Therefore, an object of the present invention is to provide a spring material that achieves the above-mentioned problems.

E6 Means for Solving the Problems In order to achieve the above object, the spring material according to the present invention is made of a shape memory alloy having a plurality of rectangular folded portions arranged alternately in parallel.

F0 action In the present invention, since the spring material is formed of a shape memory alloy, it can withstand a large load and can always return to its initial state. At this time, the load becomes constant in the superelastic region, and the elastic force is made uniform. Further, by forming the folded portion in a rectangular shape, hysteresis can be reduced and response characteristics can be improved.

G. Example Hereinafter, a spring material according to the present invention will be explained with reference to FIGS. 1A and 1B.

As shown in FIG. 1A, the spring material 20 according to the present invention has a folded part 2 formed by folding a wire made of a shape memory alloy into a rectangular shape.
1 are arranged alternately in parallel.

This shape memory alloy is made of a nickel-titanium alloy, and since the initial state in which a plurality of rectangular folded parts 21 are alternately arranged in parallel is memorized, from this state, both ends 2
2. Even if 22 is pulled and bent to a large extent, it can always elastically return to its initial state. That is, even if the conventional spring material 50 shown in FIG. 8 is stretched and displaced to a position as shown in FIG. You can return to

In addition, the shape memory alloy spring material 20 is shown in FIG.
As shown in the figure, when the amount of deflection exceeds a certain level, there is a characteristic of having a superelastic region W in which the load becomes negative. By utilizing the superelastic region W of this shape memory alloy, it is possible to keep the load constant when the spring material 20 is deflected, and it is possible to set the elastic return force of the spring material 20 to a constant load. Become.

Furthermore, since the spring material 20 of the present invention includes a plurality of rectangular folded portions 21 of the shape memory alloy wire in parallel, it is possible to reduce hysteresis during elastic displacement and elastic return.

In other words, the spring material 5 is shaped like a 5-shape as shown in FIG.
0, large hysteresis occurs during elastic displacement and elastic return, as shown by curves c and d in the graph of FIG. 3B, even when the shape memory alloy is used.

On the other hand, the displacement of the rectangular folded portions according to the present invention provided in parallel is the curves a and b of the graph in FIG. 3A.
As shown in Figure 2, we were able to reduce the hysteresis. In Fig. 3 A and B, a and C show the case where the number of turns of the spring material is 18, and b and d show the case where the number of turns is 2.
The case of 4 times is shown, and the solid line shows the loaded state and the broken line shows the unloaded state. In addition, by increasing the number of turns in the spring material, it was possible to further stabilize the load in the superelastic region and reduce hysteresis.

Furthermore, this shape memory alloy is made of a nickel-titanium alloy. Therefore, this shape memory alloy has a large internal loss of acoustic vibration, as shown in FIG. 4A.

As shown in comparison in B, the vibration damping characteristics are better than the spring material made of piano wire.

Next, a spring material 2 according to the present invention having the above-mentioned characteristics will be described.
0 as a spring material for tensioning and biasing the suspenders of a headphone device will be described with reference to FIGS. 5 to 7.

As shown in FIG. 5, the headphone device according to the present invention has an inverted U
Support members 2 are attached to both ends of the headband 1 formed in a letter shape.
A headphone unit 4 is rotatably disposed via a support arm 3.

The headband 1 is made of a plate having spring properties and formed into an inverted U-shape. The reason why the headband 1 is required to have spring properties is to press the headphone units 4 attached to both sides of the headband 1 against the ears with a constant lateral pressure when the headband 1 is worn on the head.

The headband 1 is made of carbon fiber reinforced plastic. The reason why carbon fiber is used as the material for the headband 1 is to attenuate acoustic vibrations so that the acoustic vibrations of one headphone unit 4 do not interfere with the other headphone unit 4, and to reduce the weight of the entire device. .

The headband 1 made of the above-mentioned material is
The headband 1 is formed into a generally U-shaped cross section that is flat toward the inside, and the opening side is closed with a lid 6, and a cavity 7 is provided within the headband 1.

A spring member 9, which connects both ends of suspenders 8 formed in a band-like body, which will be described later, is housed in this gap 7.

Further, the headband 1 has supporting members 2.sub.2 attached to both ends thereof. This support member 2 rotatably supports a support arm 3 around a support shaft I0, and supports a headphone unit 4 attached to the support arm 3. This support member 2 is made of a magnesium-based alloy in order to reduce its weight and to attenuate acoustic vibrations transmitted from the headphone unit 4 that it supports.

Like the headband 1, this support member 2 is made up of an exterior part 12 and an inner plate 13 so that a cavity 11 is provided inside. The inner plate 13 has an opening 14.
is provided.

For the headband 1 configured as described above, the fifth
As shown in the figure, the suspenders 8 are attached. That is, both ends of the suspenders 8 are drawn into the headband 1 through the openings 14.14 of the support members 2.2 attached to both sides of the headband 1, respectively, and connected to the spring members 9, so that the suspenders 8 The hook is passed so that the middle part serves as a head support part 15 and becomes a bowstring inwardly with respect to the headband 1.

As shown in FIG.
is pulled into the headband 1 from both ends with a certain tension. On the other hand, by pulling out the suspenders 8 against the biasing force of the spring member 9, the head support portion 15 of the suspenders 8 can be pulled out.
It is possible to pull it out and extend it.

The suspenders 8 are flexible band-like bodies, and are preferably made of a material that does not stretch in the length direction but stretches to some extent in the width direction and fits the head.

The spring member 9 is a spring member 20 according to the present invention, and is used to constantly tension and bias the suspender 8 in the direction of storing it in the headband 1. A certain tension is applied to the suspenders 8 that are pulled out when the headphone device is worn on the head. This spring member 9 applies a similar tensile force to both ends of the suspender 8, so its center portion is fixedly supported inside the apex of the headband l.

In the headphone device configured as described above, when the headphone device is worn on the user's head, the suspenders 8 are wrapped around the user's head as shown in FIG. It is for supporting the parts. That is, when the headband 1 is worn on the user's head, the headband 1 is pushed out and the head support part 15 of the suspender 8 is pushed inside the headband 1 against the tensile force of the spring member 9. The suspenders 8 press and support the head by wrapping them around the head along the shape of the head.

By supporting the head with the suspenders 8 whose length can be changed in this way, the appropriate amount of air is always drawn out from within the headband 1 without being affected by individual differences in the distance from the top of the user's head to the ears. The head can be pressed and supported with a constant tension by the suspenders 8 having a certain length. Further, the suspenders 8 can contact the head with a uniform pressing force over the entire width of the head between both ears. Furthermore, since the length of the headband 1 itself is not variable at this time, the lateral pressure of the headband 1 against the ear of the headphone unit 4 can always be kept constant, and a good wearing feeling can be obtained. .

The suspenders 8 are automatically pulled out when the headphone device is worn on the head to automatically adjust the height position of the headphone unit 4, so the suspenders 8 are automatically pulled out when the headphone device is attached to the head, and therefore the height position of the headphone unit 4 is automatically adjusted. There is no need to adjust the height position of the headphone unit each time, and operability can be improved.

Further, as explained above, the shape memory alloy spring material has a characteristic of having a superelastic region in which the load becomes negative when the amount of displacement exceeds a certain amount. Therefore, due to the characteristics of the superelastic region W of this shape memory alloy, when the suspenders 8 are pulled out, the tension exerted by the spring member 9 that tries to pull back the suspenders 8 is always a constant tension, and the suspenders are wrapped around the head with a constant tension. This will allow you to support your head. Further, since the shape memory alloy spring material always returns to its initial state, the spring member 9 does not stretch due to fatigue or the like, and the suspenders 8 do not loosen.

When the headphone device is removed from the head, the suspenders 8 are automatically wound up within the headband 1 by the spring member 9, returning to the initial state. At this time, the shape memory alloy spring member 9 has a folded portion bent into a rectangular shape, so the hysteresis as a spring material is small.
It can be returned to its original state by adjusting the tension between when it is pulled out and when it is pulled out.

Note that the spring material according to the present invention is not limited to being used in headphone devices, but can be applied as a spring material used in a variety of electrical devices, such as a return spring for a shutter plate of a disk cartridge. . moreover,
It can be used not only for electrical equipment, but also as a spring material for hanging pants, belts, and other clothing, and has a variety of possible applications.

Effects of the H0 Invention According to the present invention, since the spring material is formed of a shape memory alloy, it can withstand a large load and can always return to its initial state. At this time, the load becomes constant in the superelastic region, and the elastic force is made uniform. Also,
By forming the folded portion into a rectangular shape, hysteresis can be reduced and response characteristics can be improved.

[Brief explanation of the drawing]

1A and 1B are plan views of the spring material according to the present invention, with FIG. 1A showing the normal state and FIG. 1B showing the stretched state. FIG. 2 is a graph showing a comparison of the amount of deflection with respect to load between a shape memory alloy spring material according to the present invention and a conventional piano wire spring material. Furthermore, Fig. 3A is a graph showing the amount of deflection of the spring material against the load when the shape memory alloy wire is bent into a rectangular shape, and Fig. 3B is a graph when the wire is bent into a five-section shape. be. FIGS. 4A and 4B are characteristic diagrams showing a comparison of the vibration damping characteristics of a shape memory alloy spring material and a piano wire spring material. Further, FIG. 5 is a partially exploded perspective view showing a headphone device using a spring member used in the present invention. 6 and 7 are cutaway front views of the headphone spring portion of the headphone device, with FIG. 6 showing the headphone device before it is attached to the head, and FIG.
The figure shows when it is worn on the head. FIG. 8 is a plan view showing a conventional spring member having a general shape. l...Headband 2...Support member 8...Suspenders 9...Spring member 20...Spring material 21...Folded part

Claims (1)

[Claims] A spring material made of a shape memory alloy that has a plurality of rectangular folded parts arranged in parallel alternately.