JPS59169025A - Shape memory alloy composite member and current breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a shape memory alloy composite member in which a shape memory alloy having a shape memory effect and a copper alloy are combined in a wire or strip shape over the entire length direction. - The present invention further relates to a current breaker that effectively utilizes the shape memory properties of the shape memory alloy composite member to interrupt the current path when a current of a predetermined value or more flows through the current path.

Description of Prior Art The electrical conductivity and thermal conductivity of NI Tl-based shape memory alloys are about 1150 that of copper, which is extremely low. Therefore, by applying electricity to a material 1 made of a single NlTl-based shape memory alloy whose cross section is shown in Fig. 1, it is heated to a temperature exceeding its austenite phase transition temperature to exhibit a shape memory effect. , giving rise to difficulties. That is, N.I.
If the material made of the Tl-based shape memory alloy is a thin member, it would take a very long time to generate heat by energizing it to a temperature exceeding the austenite phase transition temperature because of its high electrical resistance. To avoid this, high voltage must be used to energize.

Purpose of the Invention Therefore, the main purpose of the present invention is to combine an NI Tl-based shape memory alloy having a shape memory effect and a copper alloy with good electrical conductivity and thermal conductivity into a wire or strip in the entire length direction. It is an object of the present invention to provide a shape memory alloy composite member which has good electrical conductivity and thermal conductivity as a whole.

Another object of the present invention is to ensure that when an overcurrent of a predetermined value or more flows in a current path, the shape memory alloy composite member described above effectively utilizes the shape memory properties to ensure that the
An object of the present invention is to provide a current breaker capable of interrupting a current path.

Still another object of the present invention is to make it possible to repeatedly perform current interruption operations and to achieve long structural life by effectively utilizing the shape memory properties of the shape memory alloy composite member described above. An object of the present invention is to provide a current breaker.

As described above, the first invention is a shape memory alloy composite member in which a shape memory alloy having a shape memory effect and a copper alloy are combined in a wire or strip shape over the entire length direction.

The second invention is arranged between a first connection point and a second connection point that are fixed at a predetermined spaced position in the current path, and when an overcurrent occurs, the first connection point In a current breaker that interrupts a current path leading to a second connection point, at least a portion of the material that electrically connects the first connection point and the second connection point is composed of the above-mentioned shape memory alloy composite member. This is a current breaker. The shape memory alloy composite member is shape memory treated so that its length will shrink when it is heated by an overcurrent above the austenite phase transition temperature of the shape memory alloy. When this shape memory alloy composite member contracts during an overcurrent, the length of the material connecting the first connection point and the second connection point, which are fixed at a certain distance, becomes shorter. The current path from the first connection point to the second connection point is cut off.

A current breaker according to the third invention includes a tubular case made of a conductive material, a first lead wire electrically connected to one end of the tubular case, and a first lead wire connected from the other end of the tubular case into the tubular case. A second lead wire extends and is electrically connected and fixed to the tubular case via an insulator. A fixed contact is provided at the tip of the second lead wire extending and disposed within the tubular case. A movable contact is disposed within the tubular case and is in contact with an inner wall of the tubular case and is movable within the tubular case. The present invention is characterized in that a spring that biases the movable contact so that the fixed contact and the movable contact are always in contact with each other, and a predetermined value or more between the first lead wire and the second lead wire. The above-mentioned shape memory alloy composite member, which has been subjected to shape memory treatment so as to electrically isolate the fixed contact and the movable contact by changing its length when a current flows and generates heat, is arranged in a tubular case. It is.

The above objects and other objects and features of these inventions will become more apparent from the following detailed description with reference to the drawings.

DESCRIPTION OF EMBODIMENTS The first invention comprises a shape memory alloy having a shape memory effect;
This is a shape memory alloy composite member in which copper alloy is composited over the entire length in a track or strip shape. FIGS. 2 to 5 each show an example of a shape memory alloy composite member according to the first invention, and the difference between each figure is the degree of compositing.

The shape memory alloy composite member 2 shown in FIG. 2 is a shape memory alloy composite member 2 in which a copper alloy 4 is composited on the outer circumferential surface of a linearly extending shape memory alloy 3.

The shape memory alloy composite member 5 shown in FIG. 3 is a composite of a copper alloy 4 on the upper surface of a shape memory alloy 3 extending in a strip shape.

The shape-memory alloy composite member 6 shown in FIG. 4 is a shape-memory alloy composite member 6 in which a copper alloy 4 is composited on the upper and lower surfaces of a shape-memory alloy 3 extending in a strip shape.

A shape memory alloy composite member 7 shown in FIG. 5 is a composite member 7 in which a copper alloy 4 is composited onto the outer peripheral surface of a shape memory alloy 3 extending in a strip shape.

The shape memory alloy used in each of the above examples has an N1 of 53 to 57 m! 1% and the remainder is TI, or the above N1 or T117) partially contains C.
The composition is substituted with one or more metals selected from the group consisting of u, V, All, Fe, Go, and the like. Here, N
The reason for setting l to 53 to 57% by weight is that if it is less than 53% by weight, the shape memory effect may not be exhibited, and if it is more than 111%, the shape memory effect may not be exhibited and it may be difficult to process. This is because the sex deteriorates. Also, a part of Nl or TI can be replaced with CO, V, Al, )”e
.

Appropriately made of one or more metals selected from fresh materials including CO, etc.
In other words, it is possible to finely control the austenite phase transition temperature of the shape memory alloy.

Furthermore, the shape memory alloy having the above composition has an austenite phase transition temperature of 0 to 150°C.

Here, the austenite phase transition temperature is set at 0 to 150°C because if it is below 0°C, it will be difficult to cool to a temperature lower than the austenite phase transition temperature, and if it is above 150°C, the shape will change. This is because the memory effect becomes less effective.

The copper alloy used in each of the examples described above is Cu
The composition contains 80% by weight or more of.

Here, copper alloy is used as the material to be combined with N and ITITl-based shape memory alloys because of its high electrical conductivity, and even if Cu does not form in the NI Tj alloy phase during intermediate heat treatment including shape memory treatment. This is because even if it is diffused, it does not adversely affect the shape memory characteristics. Also, Qtl
The reason why 801i is set to 80% by weight or more is because if the content of 801i is less than 1%, the conductivity will be low. In addition, the term "copper alloy" used in this specification means that Cu is 1
Also includes 00ml11%.

As mentioned above, NI has extremely low electrical conductivity and thermal conductivity.
By combining a Tl-based shape memory alloy and a copper alloy with good electrical conductivity, the overall electrical conductivity of the shape memory alloy composite member is significantly higher than that of a member made of a single NlTl-based shape memory alloy. to cover. Therefore, the current carrying capacity of the shape memory alloy composite member can be increased, and in turn, it becomes possible to heat the shape memory alloy composite member to a temperature exceeding the austenite phase transition temperature of the shape memory alloy by energization.

13- The ratio of the NI Tl-based shape memory alloy and the copper alloy constituting the shape memory alloy composite member is appropriately determined depending on the application, but it is preferable that the overall electrical conductivity of the shape memory alloy composite member is It is set to be 20%rAO8 (ratio to universal standard mild steel) or more.This is because if the overall conductivity is less than 20%, there are fewer benefits compared to copper-based shape memory alloys.

As mentioned above, the shape memory alloy composite member according to the first invention has improved electrical conductivity. Therefore, by energizing the shape memory alloy composite member, it becomes easy to heat the composite member to a concentration exceeding the austenite phase transition concentration of the shape memory alloy, thereby exhibiting the shape memory effect. Such shape memory alloy composite members can be effectively used in a wide variety of applications. For example, current breakers that cut off the electric fill path in the event of an overcurrent, shape memory antennas that utilize shape memory effects (in the case of this antenna, high frequency current flows more easily through copper alloy), special wires for robots, or Effectively used for special electric wires for medical equipment. In either application, the first
The shape memory alloy composite member according to the invention not only has electrical conductivity, but also exhibits flexibility and high tensile strength characteristic of shape memory alloys.

Next, the second invention, the current breaker, will be explained using FIGS. 6 to 10. FIG. 6 is a front view showing a conventionally used cylindrical fuse as an example of a current breaker, with a portion of the fuse shown broken. 7 to 110WJ are respective embodiments of the current circuit breaker according to the second invention.

The cylindrical fuse 8 shown in FIG. 6 has a metal cap 9 at its head, a metal cap 10 at its bottom, and is soldered or brazed to the metal caps 9 and 10 as indicated by reference numeral 11. The fuse conductor 12 connected by and the glass that shields the fuse conductor 12 from the outside! It consists of 13. When this cylindrical fuse 8 is inserted into the current path, the metal cap 9 constitutes the first connection point to the fuse conductor 12, and the metal cap 1
0 constitutes the second connection point to the fuse conductor 12. When an overcurrent of a predetermined value or more flows through the current path in which the cylindrical fuse 8 is arranged, the fuse conductor 12 melts, thereby causing the current 211! to flow from the first connection point to the second connection point. road is blocked.

Such a conventional cylindrical fuse 8 is configured to utilize the fusing characteristics of the fuse conductor 12 to interrupt the current path from the first connection point to the second connection point. Therefore, when a current exceeding a predetermined value flows, the current path is not immediately interrupted, but requires a certain amount of time. As a result, there have been drawbacks such as damage to electrical equipment through which overcurrent flows. Furthermore, the fusing characteristics of the fuse conductor 12 tend to vary, and as a result, the fuse conductor 12 may break or not break even at the same current value.

The second invention can eliminate the above-mentioned drawbacks. Current interruption according to the second invention shown in FIG. 7! 11
4 has a cylindrical shape as a whole, and has a metal cap 9 at the head, a metal cap 10 at the bottom, and a shape memory alloy composite member 15 that electrically connects the metal cap 9 and the metal cap 10. and a glass tube 13 that shields the shape memory alloy composite member 15 from the outside. The shape memory alloy composite member 15 is fixed to the metal caps 9 and 10 by soldering, brazing, etc., as indicated by reference numeral 11, while maintaining its straightness. When the illustrated electric island 14 is placed in the current path, the metal cap 9 constitutes the first connection point to the shape memory alloy composite member 15, and the metal cap 10 constitutes the shape memory alloy composite member 15. A second connection point to member 15 is formed.

The shape memory alloy composite member 15 is according to the first invention described above and therefore has good electrical conductivity. This shape memory alloy composite member 15 can cut off current! !
14 is placed in the current path, and the shape memory alloy composite member 15 itself undergoes an austenite phase transition of the shape memory alloy.When the shape memory alloy composite member 15 itself is heated beyond the austenite phase transition degree, its length shrinks. It has been processed with shape memory to make it look like this. The specific method is as follows:
For example, a shape memory alloy composite member containing a shape memory alloy whose composition is set to have an austenite phase transition temperature of 100°C is shaped into a nearly straight bar shape, and then stretched by about 5% at room temperature to determine its length. It is possible to keep it longer.

In this way, when the shape memory alloy composite member is heated beyond the austenite phase transition concentration of the shape memory base metal, its length will shrink by about 5%.

In FIG. 7, the connection strength between the shape memory alloy composite member 15 indicated by the reference number @11 and the metal caps 9 and 10 is made smaller than the shrinkage force of the shape memory alloy composite member 15. Therefore, if the shape memory alloy composite member 15 is heated by an overcurrent to exceed the austenite phase transition temperature of the shape memory alloy and its length contracts, the shape memory alloy composite member 15 and the metal cap 9 and The connection at the connection point 11 with 10 is disconnected, thereby interrupting the current path from the metal cap 9 (first connection point) to the 18-gold LiI cap 10 (second connection point). What should be noted here is that since the shape memory alloy composite member 15 is a composite of copper alloys, it has good electrical conductivity, and therefore has less overcurrent than a member made of a single NI Tl-based shape memory alloy. This means that it can be easily heated due to

In the case of the current breaker 16 shown in FIG. 8, the material that electrically connects the metal cap 9 (first connection point) and the metal cap 10 (second connection point) is the intermediate connection member 17.
It is composed of two shape memory alloy composite members 15 and 15' connected in series via. Here again, the shape memory alloy composite members 15 and 15' are connected to each other while maintaining their straightness. The connection strength of the intermediate connecting member 17 that connects one shape memory alloy composite member 15 and the other shape memory alloy composite member 15', or the shape memory alloy composite members 15 and 15' and the metal caps 9 and 1
The connection strength of the connection portion 11 with the shape memory alloy composite member 15 and 15' is made weaker than the contraction force of the shape memory alloy composite member 15 and 15'. Therefore, the shape memory alloy composite members 15 and 15'
When the material is heated to exceed the austenite phase transition moisture content due to an overcurrent and contracts, the connection at the connection part 11 (or the connection at the intermediate connection member 17) is broken.In this way, the first connection point h1 connects to the second connection point. The current path is 1lIII
I will be treated.

In the case of the current breaker 1B shown in FIG. 9, the material that electrically connects the metal cap 9 (first connection point) and the metal cap 10 (second connection point) is Shape memory alloy composite member 15 and conductive materials 19 and 19' having lower electrical resistance per unit length than shape memory alloy composite member 15 are connected in parallel. The materials 19 and 19' are connected in series via a swaged connection 20, the respective ends of which are fixed at the connection 11 to the metal caps 10 and 9, for example by soldering.Shape memory alloy composite member 15 is fixed at one end to the metal cap 10 (second connection point), and the other end is fixed to the caulking connection part 20.Then, the caulking connection part 20 and the metal cap 9 (the second connection point) The conductive material 19' that connects the shape memory alloy composite member 15 and the shape memory alloy composite member 15 are connected to each other in a tensioned state by adjusting the caulking connection part 20. This current breaker 18 is preferably used when it is desired to increase the current value to be interrupted.Here, the connection between one conductive material 19'□ and the gold 11tll cap 9 (first connection point) Connection strength of part 11, one conductive material 19
The connection strength between the shape memory alloy composite member 15 and the caulked connection portion 20 or the tensile strength of one of the S electrically conductive materials 19
It is considered to be weaker than the contraction force of Then, when the shape memory alloy composite member 15 is heated beyond the austenant phase transition temperature by an overcurrent, the connection part 11't or the caulked connection part 20 (breaks or breaks). One of the conductive materials 19' is disconnected, and the radio wave path from the metal cap 9 (first connection point) to the metal cap 10 (second connection point) is blocked.

In each of the embodiments shown in FIGS. 7 to 9, the shape of the current breaker is cylindrical as a whole, but it is not limited to such a shape.

For example, a claw-shaped current breaker 21 as shown in FIG. 10 may be used. This claw-shaped current breaker 21 consists of two conductive materials 22 connected together via an intermediate connection member 17.
and 23, and a shape memory alloy composite member 15 whose ends are fixed to the intermediate connecting member 17. The end portion of the conductive material 22 is formed with a recess 24 so that it can be conveniently fixed to a first connection point in the current path, while the end portion of the conductive material 23 is formed with a A recess 25 is formed in such a way that it can be conveniently secured to a second connection point within. The other end of the shape memory alloy composite member 15 is fixed to a second connection point in the current path while maintaining its straightness. Here, the tensile strength of the conductive material 22, the unified strength between the conductive material 22 and the first connection point, or the connection strength between the conductive material 22 and the intermediate connection member 17 is determined by the shrinkage of the shape memory alloy composite member 15. considered to be smaller than force. Therefore, when the shape memory alloy composite member 15 is heated beyond its austenite phase transition wettability due to an overcurrent and its length contracts, the current path from the first connection point to the second connection point changes. Be cut off.

Next, the third invention will be explained using FIGS. 11 to 13. FIG. 11 is a sectional view showing a temperature fuse, which is an example of a conventional current breaker. FIG. 12 and FIG. 13 are sectional views showing respective embodiments of the current breaker according to the third invention.

The temperature fuse 26 shown in FIG. and a second lead 1129 extending and disposed within the tubular case. Second lead wire 2
9 has a fixed contact 30 at its tip, and an insulator 3
1 and fixed to the tubular case 27 in an electrically insulated manner. Further, as shown in the figure, there is a portion inside the tubular case 27 that is in contact with the inner wall of the tubular case 27 and that is in contact with the inner wall of the tubular case 27.
A movable contact 32 movable within 7 is arranged. The movable contact 32 is always urged to be in contact with the fixed contact 30 of the second lead wire 29 by a spring 34 disposed on a fusible pellet 33 disposed on the inner wall of one end of the tubular case 27. ing. Furthermore, the second lead 112
The surface of the movable contact 32 facing the 9 side is pressed by a spring 35. The pressing force of the spring 35 is weaker than the pressing force of the spring 34 in the illustrated state.

Here, when a current of a predetermined value or more flows between the first lead wire 28 and the second lead wire 29 and the entire concentration fuse 26 generates heat, the fusible pellet 33 melts. Therefore, the bias applied to the movable contact 32 by the spring 34 disposed on the fusible pellet 33 is released, and the pressure applied to the movable contact 32 by the spring 35 causes the movable contact 32 and the fixed contact 3 to
0 and is electrically isolated. In this way, when a current exceeding a predetermined value flows, the current path is cut off.

In the temperature fuse 26 described above, the movable contact 32
The isolated state between the fixed contact 30 and the fusible pellet 3
Since the structure is achieved by melting 3, the current interrupting operation is less likely to react sensitively to temperature, that is, to the amount of energization. Further, once the fusible pellet 33 is melted, even if the temperature of the temperature fuse 26 drops, it is impossible for the movable contact 32 and the fixed contact 30 to return to a state in which they are in contact with each other again. That is, the illustrated concentration fuse 26 is used for only one current interruption operation. This is economically very disadvantageous.

Current breakers 36 and 37 according to the third invention shown in FIGS. 12 and 13, respectively, eliminate the above-mentioned disadvantages and are capable of repeatedly performing current breaking operations. .

The current breaker 36 shown in FIG. a second lead extending from the end into the tubular case 27, having a fixed contact 325-O at the distal end, and fixed electrically insulated within the tubular case 27 via insulators 31 and 38; line 29. A movable contact 32 that is in contact with the inner wall of the tubular case 27 and is movable within the tubular case 27 is arranged inside the tubular case 27 . As shown in the figure, the fixed contact 30 described above is processed to have a tapered shape, and the movable contact 32 is formed with a central opening 39 corresponding to this shape. The tapered shape of the fixed contact 30 and the central opening 3 of the movable contact 32
9 is not necessarily necessary, but fixed contact 30
This can be said to be preferable in that electrical continuity between the movable contact 32 and the movable contact 32 is ensured.

An insulator 40 is disposed on the inner wall at one end of the tubular case 27, and a spring 41 is disposed between the insulator 40 and the movable contact 32.
is placed. This spring 41 biases the movable contact 32 so that the fixed contact 30 and the movable contact 32 are always in contact with each other. When the fixed contact 30 and the movable contact 32 are in contact, the current is 26-second lead 1$29-fixed contact 30-movable contact 32-
It flows through the tubular case 27 to the first lead [128].

A shape memory alloy composite member 4 formed in a coil shape is disposed between the movable contact 32 and the inner wall on the other end side of the tubular case 27.
2 is arranged so that it can act on the movable contact 32. This shape memory alloy composite member 42 is according to the first invention, and therefore has good electrical conductivity. The shape memory alloy composite part 1142 has a first glue point [1
A current of a predetermined value or more flows between 2B and the second lead wire 29 until the current breaker 36 reaches a temperature higher than the austenite phase transition temperature of the shape memory alloy that constitutes one material of the shape memory alloy composite member 42. Shape memory treatment is applied so that when heat is generated, the length increases due to an austenite phase transition. The amount of elongation must be such that the following actions can be achieved:

That is, as the length of the shape memory alloy composite member 42 increases, the movable contact 32 overcomes the force of the spring 41 and moves to the left in the figure, and as a result, the fixed contact 30 and the movable contact 32 are electrically isolated. be done. In this way, when a current of a predetermined value or more flows between the first lead wire 28 and the second lead wire 29, the current path is interrupted due to the shape memory effect of the shape memory alloy composite member 42.

Next, when the overcurrent abnormality is resolved and the concentration of the current breaker 36 decreases, the shape memory alloy that constitutes one material of the shape memory alloy composite member 42 undergoes a phase transition to a martensitic phase and its length is reduced, so that the spring 41 overcomes the force of the shape memory alloy composite member 42 formed into a coiled shape. As a result, the movable contact 32 moves rightward in the figure and comes into contact with the fixed contact 30 again. Here, the current interrupt 136 is
The state returns to the state before the current was cut off, that is, the state of electrical continuity.

In the current breaker 37 shown in FIG. 13, the fixed contact 30 has a hemispherical shape, and the movable contact 32 has a corresponding recess 43 formed therein.

This is to ensure electrical continuity between the fixed contact 30 and the movable contact 32, similar to the relationship between the tapered shape and the corresponding central opening in FIG. Further, in this embodiment, the spring 41 that biases the movable contact 32 so that the fixed contact 30 and the movable contact 32 are always in contact with each other, and the current breaker 37 that is illustrated when a current exceeding a predetermined value flows therein generate heat. When the shape memory alloy composite member 42 that serves to electrically isolate the fixed contact 30 and the movable contact 32 is placed on one end side of the tubular case 27 to which the movable contact 32 and the first lead wire 28 are connected. and an insulator 40 disposed on the inner wall of. As shown, the shape memory alloy composite member 42 is formed into a coil shape, and both ends of the shape memory alloy composite member 42 are connected to fixing members 44 and 4.
5 to the movable contact 32 and the insulator 40, respectively.

When a current of a predetermined value or less is flowing between the first lead 8128 and the second lead 1129, the spring 41 overcomes the force of the shape memory alloy composite member 42 and moves the movable contact 32.
is brought into contact with the fixed contact 30. The shape memory alloy composite part 29-material 42 used in this embodiment is such that when a current of a predetermined value or more flows between the first lead wire 28 and the second lead wire 29, the current breaker 37 is made of a shape memory alloy. When heat is generated to a temperature higher than the austenite phase transition temperature of the shape memory alloy constituting one material of the composite member 42, its length shrinks due to the austenite phase transition, thereby overcoming the force of the gradient 41 and moving the movable contact 32.
Shape memory processing is applied to separate the contact point 30 from the fixed contact point 30. Therefore, if a current of a predetermined value or more flows between the first lead wire 28 and the second lead wire 29, the current *, W path will be cut off.

Next, when the overcurrent abnormality is resolved and the temperature of the current breaker 37 decreases, the length of the shape memory alloy composite part 1i842 increases, so the spring 41 comes to overcome the force of the shape memory alloy composite member 42. This brings the movable contact 32 into contact with the fixed contact 30.

In this way, the current breaker 37 returns to the electrically conductive state again. - Although the shape memory alloy composite member 42 used in FIGS. 12 and 13 was formed into a coil shape 30-, it is not limited to such a shape, and may be, for example, a rod shape. good.

Effects of the Invention As described above, according to the first invention, a shape in which a Ni Ti-based shape memory alloy having a shape memory effect and a copper alloy are combined with a wire or strip over the entire length direction. Since it is a memory alloy composite member, its overall electrical conductivity is significantly increased compared to a single NiTi-based shape memory alloy. Therefore, by applying electricity at a constant voltage to the shape memory alloy composite member according to the first invention, it becomes easy to heat it to a temperature exceeding the austenite phase transition moisture content of the shape memory alloy. In other words, it can be said that the shape memory effect is sensitive to the value of the current flowing through the shape memory alloy composite member, which serves to heat the shape memory alloy composite member.

According to the second invention, the first connection point and the second connection point in the current path
At least a portion of the material electrically connecting the connecting point of the shape memory alloy composite member according to the first invention is made of a shape memory alloy composite member, and the length of the shape memory alloy composite member contracts when an overcurrent occurs. Because it is processed with shape memory,
When the current flowing in the current path reaches a predetermined value, the current path can be immediately and reliably interrupted. This is due to the good electrical conductivity of the shape memory alloy composite member and the IIr! It can be said that the L-sensitive shape memory property is utilized very effectively.

Furthermore, since the structure of the current breaker according to the second invention is as simple as, for example, a conventional cylindrical fuse, it is advantageous in construction and is expected to be mass-producible. The electricity 11iE''1j111ils according to the third invention can be effectively used in place of fuses conventionally used for household use, fuses used for automobiles, or fuses used for other purposes. can be done.

Furthermore, according to the third invention, the current breaker is configured to move the movable contact by utilizing the shape memory properties of the shape memory alloy composite member and thereby interrupt the current path, so that it can be used in a conventional fuse. It becomes possible to use it repeatedly. This is economically very advantageous. There are other types of circuit breakers that can be used repeatedly, such as magnetic type circuit breakers, but because they use magnets, their structure is complicated.

In comparison, the current breaker according to the third invention is
It has a simpler structure and therefore can be made smaller and lighter if necessary. This in turn leads to a reduction in the cost of the current circuit breaker itself.

Furthermore, in the current breaker according to the third invention, conditions such as the transformation temperature and spring strength of the shape memory alloy constituting one material of the shape memory alloy composite member can be appropriately selected. It is very easy to design a circuit so that the interrupting operation is performed at a predetermined current value.

This third invention, like the second invention, has a structure that effectively utilizes the good conductivity of the shape memory alloy composite member and the shape memory properties of the shape memory alloy, which is sensitive to temperature. Therefore, the current interrupting operation is extremely sensitive to temperature and therefore overcurrent.

33- NI T containing 55% by weight of N1 and the remainder consisting of T1
A composite wire with a diameter of 0.5 mm was manufactured by fitting a 1-alloy track and a Cu pipe and subjecting it to wire drawing and intermediate heat treatment. At this time, the diameter of the core material made of NI T1 alloy is 0.
41 It was foggy. The overall electrical conductivity of the composite wire was 36%lAC3. This composite rod has an outer diameter of 81-
It was wrapped tightly around a rod and heated at 500°C for 10 minutes to undergo shape memory treatment.

This composite rod (approximately 15cm in length) is twisted 30 times into a coiled shape.
When the wire was stretched to a length of 500 mm and a constant voltage of 5 V was applied to the wire, the shape recovered instantly.

For comparison, NI T with the same composition as the core material of this composite rod
When a similar test was carried out using a wire rod of 0.5 and 1.0 mm alloy made of the same shape as a coil, the shape did not recover easily.

A shape memory alloy composite member having the cross-sectional structure shown in FIG. 4 was manufactured. The electrical conductivity of this shape memory alloy composite member as wood was 30% TAC8. As in Example 1, this was used as a linear shape-memory-treated bond and a hot wire (operated by applying electricity) for operating the joints of a robot.
Compared to wire made of alloy, it is more sensitive (reacts and moves more quickly).

"Ai 1" - NI containing 54.8% by weight of Nl and the remainder being TI
Using a Ti alloy strip (thickness 0.2mwxl10.5o+I), when it is heated to 120°C, its length decreases by about 5%.
It was pre-treated with shape memory so that it would shrink.

Then, CLI plating was applied to the surface of the alloy strip so that the overall electrical conductivity was 60% TAC8. As shown in FIG. 14, this alloy strip was fixed to two fixed ends 46 and 47 made of a conductive material by soldering 48 and 49 while maintaining the straightness of the alloy strip. When this was used in place of a conventional fuse, the alloy strip began to shrink when the temperature reached 120°C, and the current was reliably cut off by the time the temperature reached 140°C.

Moreover, in order to manufacture the structure shown in FIG. 14 using a strip made of NI T1 alloy and to produce the same effect as the composite strip described above, it is necessary to use about 30% of the expensive NI T1 alloy. I had to use twice as much.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a wire made of a single NI T1 alloy. ! 2 to 5 are cross-sectional views showing examples of the shape memory alloy composite member according to the first invention, and each figure is different in the mode of composite formation. FIG. 6 is a front view of a conventional cylindrical fuse, with a portion thereof broken away. 7 to 9 are front views showing embodiments of the current circuit breaker according to the second invention, each partially cut away. FIG. 10 is a front view showing still another embodiment of the current breaker according to the second invention. FIG. 11 is a sectional view showing a conventional temperature fuse. FIG. 12 and FIG. 13 are sectional views each showing an embodiment of the current breaker according to the third invention. FIG. 14 is a diagram used to explain Example 3, and shows a shape memory alloy composite member according to the present invention being fixed between two fixed ends made of a conductive material. It is a diagram. In the figure, 2.5.6, 7.15' and 42 are shape memory alloy composite members, 3 is a shape memory alloy, 4 is a copper alloy, 9
and 10 is a metal keyboard, 14°16.1B, 21
．． 36 and 37 are current breakers, 17 is an intermediate connection member,
19 and 19' are III materials, 27 is a tubular case,
On the 2nd, numeral 2 represents the first lead, 29 represents the second lead, 30 represents a fixed contact, 31 represents an insulator, 32 represents a movable contact, and 41 represents a spring. 371

Claims (12)

[Claims] (1) A shape memory alloy composite member in which a shape memory alloy having a shape memory effect and a copper alloy are combined in a heddle or strip shape over the entire length direction, wherein the shape memory alloy has an N1 of 53 ~57% by weight with the remainder being T1, or the above-mentioned NI material, <&tTi 17) Partially substituted with one or more metals selected from the group containing Ctl, V, All, 11 #CO The composition is
A shape memory alloy composite member, wherein the austenite phase transition temperature is 0 to 150°C, and the copper alloy has a composition containing 80 wt % or more of Cu. (2) The shape memory alloy composite member according to claim 1, having an overall electrical conductivity of 20% I AC8 or more. (3) The copper alloy is disposed on the outer circumferential surface of the shape memory alloy extending into a line or strip.
The shape memory alloy composite member according to item 1 or 2. (4) The shape memory alloy composite member according to claim 1 or 2, wherein the copper alloy is disposed on the upper surface of the shape memory alloy extending in a strip shape. (5) The copper alloy is disposed on the upper and lower surfaces of the shape memory alloy extending in a strip shape.
The shape memory alloy composite member according to item 1 or 2. (6) Disposed between a first connection point and a second connection point that are fixed at a certain distance in a current path, and when an overcurrent occurs, the connection point is moved from the first connection point to the second connection point. In a current breaker that interrupts a current path leading to a connection point, at least a portion of the material electrically connecting the first connection point and the second connection point is made of a shape memory material having a shape memory effect. It is composed of a shape memory alloy composite member in which an alloy and a copper alloy are composited in a wire or strip shape throughout the length direction, the shape memory alloy containing 53 to 57% by weight of N1,
The remainder is T1, or the Nl or T
A part of the steel has a composition in which one or more metals selected from the group containing Cu, V, ALFe*CO are substituted, and the austenite phase transition temperature is 0 to 150°C, The alloy has a composition containing 80111% or more of CIJ, and the shape memory alloy composite member shrinks in length when heated above the austenite phase transition temperature of the shape memory alloy by an overcurrent. A material connecting the first connection point and the second connection point is fixed at a predetermined spaced apart position by shrinking the shape memory alloy composite member. mm circuit breaker, wherein the length is reduced, thereby interrupting the current path from said first connection point to said second connection point. (7) The electric current according to claim 6, wherein the material electrically connecting the first connection point and the second connection point is entirely composed of the shape memory alloy composite member. circuit breaker. (8) The material electrically connecting the first connection point and the second connection point is composed of two shape memory alloy composite members connected in series via an intermediate connection member. t[*l[. (9) The material that electrically connects the first connection point and the second connection point is a 1TG shape memory alloy composite member, and a material that has a shape memory alloy composite member that has a higher resistance per unit length than the shape memory alloy composite member. 7. The current breaker according to claim 6, wherein the member having low lightning resistance is connected in parallel. (10) The shape memory alloy composite member is cotton that has been subjected to shape memory treatment in a straight state and then elongated by 5% or more by cold-open wire drawing using a die. The current breaker according to any one of Items 1 to 9. (11) Claims 6 to 7 are characterized in that they are cylindrical as a whole, with the cylindrical head forming the first connection point and the cylindrical bottom forming the second connection point. The current breaker according to any one of Item 10. (12) a tubular case made of a conductive material; a first lead wire electrically connected to one end of the tubular case; and a first lead wire extending from the other end of the tubular case into the tubular case. A second tube having a fixed contact at its tip and fixed to the tubular case through an insulator in an electrically insulated manner.
a lead wire; a movable contact disposed in contact with an inner wall of the tubular case and movable within the tubular case; and a movable contact disposed within the tubular case and constantly connecting the fixed contact and the movable contact. a spring biasing the movable contact into contact; a spring disposed within the tubular case so as to act on the movable contact and between the first lead wire and the second lead wire; a shape memory alloy composite member that has been subjected to shape memory treatment so as to change its length when a current of a predetermined value or more flows through it and generates heat; 5- The shape memory alloy composite member has a shape memory effect. A shape memory alloy and a copper alloy are composited in a wire or strip shape over the entire length direction, and the shape memory alloy has a composition containing 53 to 57% by weight of N1 and the balance consisting of T1, or Part of N1 or T1 is CO, V,
Ajll Fe. The composition is substituted with one or more metals selected from the group containing CO, and the austenite phase transition temperature is 0 to 0.
150°C, and the copper alloy has a CLI of 801! The movable contact moves within the tubular case as the length of the shape memory alloy composite member changes, thereby electrically separating the fixed contact and the movable contact. ,wt
current breaker