JPH01230306A - Key holder using shape memory alloy - Google Patents

Abstract

PURPOSE:To open and close a key holder in simple ways when a key is put in or put out by using a specific shape memory alloy for the whole or a part of the key holder and keeping the opened port part for putting-in/out the key in the closed state over the body temperature. CONSTITUTION:As for a key holder which is formed into a closed loop form in ordinary case and holds and stores a key, the shape memory alloy which has an austenite phase over the body temperature and has a martensite phase below 20 deg.C is used in the whole or a part of the key holder, and said key holder is constituted so that an opened port part 2 for putting-in/out the key is in closed state over the body temperature. Below 20 deg.C, the opening/closing of the opening/closing port can be carried out manually even with any shape, and at the body temperature, the opening/closing port is perfectly closed, and can not be opened and closed manually, and further destruction due to the opening and closing in many times can be prevented.

Description

[Detailed description of the invention] [Field overview] The present invention relates to a key chain using a shape memory alloy.

[Contents and problems of conventional technology]

A conventional key chain has a structure shown in FIG.

As shown in Fig. 6 (a), the ring]- is a pipe, and the inner diameter has a small open/close opening 2 that can be further moved, and the protrusion 3 is moved outward along the ring. As a result, as shown in Fig. 6 (b), the opening/closing part 1 opened, creating a gap in the ring, through which the key string or ring could be passed.

Further, as shown in FIGS. 7(a) and 7(b), the cap 10 was opened and closed, and there was a hook 4 therein, and the hook 4 was fitted into the groove 5 to be hooked, thereby forming a key chain. This hook 4 is easily removed from the groove 5 to create an opening and closing opening, and is used as a key chain.

In conventional keychains, the ring 1 of the keychain is cut into some kind of opening and closing 11"2, and a gap is mechanically created in the ring, and the key ring is passed through there to make the keychain, so the opening and closing structure is complicated and can easily break. The drawback was that it could not be used.

For this reason, key chains could only be made in the simple shape of a ring.

[Purpose of the invention]

The present invention does not mechanically create a gap for the key ring to pass through, but even if the key chain does not have an opening/closing opening, the ring can be easily opened and closed when inserting and removing the key. The purpose of the present invention is to provide an unbreakable key chain that can be made into any shape such as a ring, triangle, square, or polygon by utilizing the characteristics of memory alloy.

[Structure of the invention]

The key holder according to the present invention is a key holder in which a shape memory alloy is used for a part or the entirety of the ring, triangular, or variously shaped key holder, and the key holder has a shape memory alloy in at least one part of the key holder of the conventional structure through which keys are taken in and out. The shape memory alloy used in the present invention is completely austenitic at the human body temperature of 36°C, and martensitic at temperatures below 208°C. This is a key chain that can be transformed into.

That is, the present invention provides a key holder which normally has a closed loop shape and holds and stores a key, in which the whole or part of the key holder is in a 1----stenite phase at +111 degrees above body temperature.
This is a key chain characterized by using a shape memory alloy that becomes a martensitic phase at temperatures below 20°C and configured so that the opening for inserting and removing the key remains closed at temperatures above body temperature5. ] The transformation temperature of the austenite phase and martensite phase of a shape memory alloy varies depending on the composition of the alloy and the heat treatment conditions. , it has the characteristic that when it is returned to the austenite phase, it returns to the shape previously memorized in the austenite phase. The temperature at which the transformation to the austenite phase and martenzite phase is exceeded depends on the alloy composition and the heat treatment temperature during processing.
It has the property of changing.

Shape memory alloy is a characteristic that can be seen in various alloys such as Ni-Ti alloy, Fe-Mn-8i alloy, Cu-Zn-Al alloy, etc. in the alloy composition range, but in the present invention, it is the property of human body temperature. At 36°C, the phase is completely austenite, and the
At temperatures below 0°C, a material that becomes a martensitic phase is used. In the Ni-Ti alloy type shape memory alloy, Ni is 50 to 51 at% (atomic %) and Ti is 49 to 5 at%.
0at% alloy at 400°C to 500°C after processing
A material having the above characteristics can be obtained by heat treatment at a temperature of .

On the other hand, when kept at a temperature below body temperature, an austenite phase is formed and the desired shape is obtained, but the shaping of the austenite phase is carried out simultaneously with heat treatment in the temperature range of 400°C to 500°C. .

Therefore, during the heat treatment in the temperature range of 400°C and 500°C, the shape shaping and the austenite/martensite transformation temperature are determined. Ni-Ti-based shape memory alloys have a high expansion force when in the austenite phase and cannot be deformed by human force, but when they enter the martensitic phase, they can be easily changed in shape by human force, and Ni
-Ti alloys have the property of completely returning to their original shape when the temperature at which the austenite phase is reached is reached even if a strain that causes elongation of up to 7% is applied.

Therefore, when the shape memory alloy key chain is cooled down in water below 20°C or by using a spray, etc., the shape of the key chain can be easily changed by hand. can also be made straight,
It is easier to put in and take out keys compared to conventional key chains.

A triangular key chain is shown in FIGS. 1(a) and 1(b).

(a) may be a round bar, or the cross-sectional shape may be square, triangular, or any polygon, and the diameter is less than the key hole diameter, usually about 2 mmφ.

- A diagram of the long lines of a book in the shape of a triangle,
At the temperature of the hand, the opening/closing opening 2 is completely closed as shown in Figure (a). The temperature is lowered to 20°C to bring it into a martensite state, and the part shown at 1 in Figure (b) is opened by hand, the part 2 is released, and the key is taken in and out of the key boulder. When the key chain of the present invention is warmed by hand in the state shown in FIG. 1(b), it returns to the shape shown in FIG. 1(a). Also, normally, unless force is applied to the key chain, the shape shown in (a) is maintained.

Similarly, Figures 2 (a) (b), 3 (a) (b), and 4 (a Hb) are key chains with similar structures,
Figures 2(a), 3(a), and 4(a) show the shape of the keychain when it is in the austenite phase, and are the shape when the keychain is warmed with body temperature. When adding and opening the overlapped part, Figure 2(b), Figure 3(b),
The shape is shown in FIG. 4(b). and Fig. 1(b), Fig. 2
Figure 1 (a), Figure 2 (a), Figure 3 (a), Figure 4 (
Configure it so that it returns to the shape of a).

FIG. 5 shows an example in which a shape memory alloy is used as part of a key chain.

6 is a part of a pipe-shaped ring, and 7 is a part of a ring made of shape-measuring alloy.

When a part of the shape memory alloy ring is inserted into a part of the pipe-like ring and warmed by hand, the shape memory alloy 7 transforms into an austenite phase, and the projections 9 attached to the shape memory alloy ring are inserted into the four parts 8 of the vibro. are fitted to form a key chain (a). When you want to replace the key, heat (a) to 20°C.
Place it in the following water or spray it to lower the temperature to 20°C, and press the shape memory alloy ring part 7 with your fingers to remove the protrusion 9 from the recess 8 to bring it into the state b).

The embodiments of the present invention have been described with respect to a key chain constructed using a Ni-Ti based shape memory alloy, but the shape memory alloy is
In addition to i-Ti alloy, Fe-Mn-3i alloy, Cu-Z
Although other alloy compositions such as the n-A1 alloy are known, when using a shape memory alloy that is in the austenitic phase at human body temperature and becomes martensitic at temperatures below 20°C, the key chain according to the present invention can be used as shown in the examples. Of course, it is possible to complete it in a similar manner.

〔Effect of the invention〕

The key chain using the shape memory alloy according to the present invention has two
At temperatures below 0°C, the opening 11 can be opened and closed by hand in any shape, and at the temperature of the human body, it closes completely and cannot be opened or closed manually, and it will not break even if the mouth is opened and closed many times. Furthermore, by keeping the temperature below 20°C, it is possible to easily open and close the key holder, and it is possible to provide a mechanically strong key chain that is easy to put in and take out keys.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the key chain of the present invention. (a,) (b) are triangle-shaped keychains,
(a) is an austenite phase, and (b) is a martensitic phase at temperatures below 20°C. FIG. 2 is a front view showing another example of the key chain of the present invention. (a Hb) is a ring-shaped keychain, (a) is an austenite phase, and (b) is a martensitic phase at 20°C or less. FIG. 3 is a plan view showing another example of the key holder according to the present invention, and (a Hb) is a key holder with a triangular opening and opening that has a different shape, (a) is an austenite phase, and (1)) is a key holder with a triangular shape. When it is in martensitic phase below 20°C. FIG. 4 is a plan view showing another example of the key chain according to the present invention. (a Hb) is a square key chain, (a) is in austenite phase, (b) is in martensite phase at 20°C or less. FIG. 5 is a diagram showing an example in which a shape memory alloy is used as a part of a key chain. (a) is a plan view of a normal shape. (b) is a plan view showing a state in which the shape memory alloy has been manually deformed and removed at 20° C. or below. FIG. 6 is a front view showing the structure of a conventional key chain. (a) is a diagram showing a state of use. (b) is a front view of the key chain in a state where the opening/closing opening is opened by moving the protrusion. FIG. 7(a) is a plan view showing a cap-type key holder of a conventional key holder, and showing the shape when in use. (b) is a perspective view when the cap is opened. Margin 1 below: Fixed part. 2...Opening/closing mouth. 3... Protrusion. 4...Hikake. 5...Groove. 6... Part of a pipe-shaped ring. 7... Part of the shape memory alloy ring. 8... Concavity. 9... Protrusion. 10... Cap. Patent applicant Tohoku Metal Industry Co., Ltd. Figure 7 (b) (a) Figure 2 (b) (a) Figure 3<b) ((1) Figure 4 (b) (Q,) Figure 5 ( b) 7 q δ 6th (G) 7th (b) (Q) (b) N

Claims (1)

[Claims] Keychains that hold and store keys usually have a closed-loop shape, and the entire or part of the keychain uses a shape memory alloy that changes to an austenitic phase above body temperature and a martensitic phase below 20°C. , a key chain characterized in that the opening for inserting and removing the key is configured to be in a closed state when the temperature exceeds body temperature.