JPS63309780A - Shape storage alloy actuator - Google Patents

Abstract

PURPOSE:To make the easy reciprocation of a iron core possible by winding plural shape storage alloys around an iron core, and providing its both ends with a permanent magnet respectively, and utilizing both the expansion action of each shape storage alloy and the attraction and repulsion actions of each permanent magnet. CONSTITUTION:An actuator 1 is provided with a casing 2 fixed to a fixing member 11, plural permanent magnets 12, 13 provided outside both ends of the casing 2 respectively, and a bar-shaped iron core 3 supported through the casing 2. Plural coil-shaped shape storage alloys 4, 5 are severally wound around the bar-shaped iron core 3. In addition to that, each of the shape storage alloys 4, 5 is intermittently and selectively turned on by an electric circuit 6, and the selecting switch 62 of the electric circuit 6 is thereby operated to supply an electric current from a battery 61 to each of the shape storage alloys 4, 5 and to magnetize the bar-shaped iron core 3. Thus, the expansion action of the shape storage alloys 4, 5 and the attraction and repulsion action of the permanent magnets 12, 13 are utilized to make the bar-shaped iron core 3 reciprocate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to an actuator using a shape memory alloy.

[Prior Art] Japanese Patent Application Laid-Open No. 58-214737 describes a combination structure of a coiled shape memory alloy and a plastic deformation spring as an actuator that utilizes the thermal deformation characteristics of a shape memory alloy. There is. In addition to this structure, this actuator may also have a structure in which two coiled shape memory alloys are wound around a piston rod. In this case,
The piston rod can be moved back and forth by alternately heating the shape memory alloy by directly applying electricity to the shape memory alloy.

However, if the first shape memory alloy is energized to cause thermal deformation and the energization is stopped after the piston rod has achieved the first displacement state, the thermal deformation stress is lost as it cools. The second shape memory alloy, which had been compressed and deformed, begins to return to its original shape due to the stored deformation stress. Therefore, in a device in which the piston rod is switched from the first displacement state to the second displacement state by the action of the first shape memory alloy, when heating of one shape memory alloy is stopped, the other shape is changed against the user's will. Due to the action of the memory alloy, a phenomenon occurs in which the piston rod attempts to return to the first displacement state again.

[Problems to be Solved by the Invention] Therefore, in Japanese Patent Application No. 61-141150, the present applicant proposed a first shape memory alloy 110 as shown in FIG.
As the iron core 130, which also serves as a piston rod, contacts the limit switch 141 in the energizing circuit 140 as the iron core 130 expands, the energization to the first shape memory alloy 110 is stopped, and then the first displacement of the iron core 130 occurs. In order to maintain the state, an actuator 100 using a lock spring 150 was proposed.

However, since the above-mentioned actuator 100 is provided with the lock spring 150, the actuator 100 is
In order to displace the iron core 130, the lock spring 15 is
The first shape memory alloy 1 has an extra force to overcome the biasing force of 0.
10 or the second shape memory alloy 120.

Further, although the electrical resistance values of the first shape memory alloy 110 and the second shape memory alloy 120 are very small, there has been no one that utilizes this.

An object of the present invention is to provide a shape memory alloy actuator whose core can be easily reciprocated even if the force generated by the coiled shape memory alloy is small.

[Means for Solving the Problems] The shape memory alloy actuator of the present invention includes a coiled first shape memory alloy and a coiled second shape memory alloy arranged in series with the first shape memory alloy. a shape memory alloy; an energizing means for intermittently and selectively energizing the first shape memory alloy and the second shape memory alloy; comprising a displaceably arranged iron core, one magnet arranged at a predetermined gap from one end of the iron core, and another magnet arranged at a predetermined gap from the other end of the iron core, Magnetizing the iron core by energizing the first shape memory alloy or the second shape memory alloy, and displacing the iron core by transforming the first shape memory alloy or the second shape memory alloy, A configuration is adopted in which one end or the other end of the iron core is polarized so that it is attracted to the one magnet or the other magnet.

[Function] The shape memory alloy actuator of the present invention has the following function due to the above structure.

By energizing the coiled first shape memory alloy, a large current flows through the shape memory alloy having a small electrical resistance value, thereby magnetizing the iron core. The first shape memory alloy is wound so that the magnetized polarity of this iron core is a polarity that repels the polarity of the other magnet (or one magnet). Therefore, the iron core easily separates from the other magnet (or the negative magnet).

Then, the first shape memory alloy is heated and transformed into a pre-memorized shape (e.g., elongated or contracted), thereby displacing the iron core in the first direction and attracting it to one magnet (or the other magnet). . Even if the power supply to the first shape memory alloy is stopped, the iron core remains attracted to the magnet due to the magnetic force of one magnet (or the other magnet).

Next, by energizing the coiled second shape memory alloy, a large current flows through the shape memory alloy having a small electrical resistance value, thereby magnetizing the iron core. Then, the second shape memory alloy is heated and transformed into a pre-memorized shape (for example, elongated or contracted), thereby displacing the iron core in a second direction (opposite to the first direction) and displacing the other core. Attach it to a magnet (or one magnet). Even if the power supply to the second shape memory alloy is stopped, the iron core remains attracted to the magnet due to the magnetic force of the other magnet (or one magnet).

[Effects of the Invention] The shape memory alloy actuator of the present invention has the following effects due to the above configuration and operation.

Therefore, by energizing the first shape memory alloy or the second shape memory alloy, the core can be easily displaced even if the force generated by the shape memory alloy is small.

[Example] An example of the shape memory alloy actuator of the present invention will be described based on FIGS. 1 to 3.

FIG. 1 shows a shape memory alloy actuator to which a first embodiment of the present invention is applied.

The shape memory alloy actuator 1 includes a casing 2 fixed to a fixed member 11, permanent magnets 12 and 13 arranged at a predetermined gap from both ends of the casing 2, and a rod-shaped iron core 3 supported by the casing 2. Equipped with. The shape memory alloy actuator 1 also includes a first shape memory alloy 4 in a coil shape, a second shape memory alloy 5 in a coil shape, and a first shape memory alloy 4 wound around a rod-shaped iron core 3. The second shape memory alloy 5 is provided with an electric circuit 6 which is an energizing means for intermittently and selectively energizing the second shape memory alloy 5.

The permanent magnets 12 and 13 are arranged within the range of the reciprocating movement distance (stroke) of the rod-shaped core 3 of the fixed member 11 so that the inner end (on the rod-shaped core 3 side) where both of them face each other is the S pole and the outer end is the N pole. is fixed.

The casing 2 includes a bottom wall 21 fixed to the fixed member 11,
one support wall 22 which is one support means for the rod-shaped iron core 3;
The other support wall 23, which is the other support means for the rod-shaped iron core 3, is integrally formed. One supporting wall 22 is
A through hole 24 is formed which protrudes from one end of the bottom wall 21 in a direction perpendicular to the bottom wall 21 and through which the rod-shaped iron core 3 passes. The other supporting wall 23 protrudes from the other end of the bottom wall 21 in a direction perpendicular to the bottom wall 21 so as to face the one supporting wall 22 with a predetermined gap therebetween. A through hole 25 is formed through which the through hole 25 passes.

The rod-shaped iron core 3 is a ferromagnetic material, and is made of either shape memory alloy 4.
．． 5 becomes magnetized when energized. When the first shape memory alloy 4 is energized, one end 31 of the rod-shaped iron core 3 becomes a permanent magnet 12.
The first magnet is repelled by the magnet, and the other @32 is attracted to the permanent magnet 13.
is located in a state of displacement. Moreover, when the second shape memory alloy 5 is energized, the rod-shaped iron core 3 is located in a second displacement state in which one end 31 is attracted to the permanent magnet 12 and the other end 32 is repelled by the permanent magnet 13.

Further, one of the penetrating portions 33 of the rod-shaped iron core 3 always penetrates the through hole 24 of one of the support walls 22 of the casing 2 and is slidably supported. The other penetrating portion 34 of the rod-shaped core 3
is always inserted through the through hole 25 of the other support wall 23 of the casing 2 and is slidably supported. Furthermore, a cylindrical member 36 that is an insulating member that electrically insulates the iron core 3, the first shape memory alloy 4, and the second shape memory alloy 5 is fixed to the outer periphery of the central portion 35 of the rod-shaped iron core 3. There is.

The first shape memory alloy 4 and the second shape memory alloy 5 are
- 1-Ni alloy (martenzite transformation starting temperature 50°C to 100°C) with excellent repeated durability and corrosion resistance, Cu-
It is made of an A1-Zn alloy (Martenley 1 to transformation start temperature Knee 180°C to 100°C), and has a shape memory that causes it to elongate when heated to a reverse transformation start temperature near the martenzite transformation start temperature. Further, since the first shape memory alloy 4 and the second shape memory alloy 5 have a small electrical resistance value and a large current flows through them, the rod-shaped iron core 3 can be easily magnetized even if the number of turns is at least.

The first shape memory alloy 4 has one end 41 fixed to one support wall 22 of the casing 2, and the other end 42 fixed to the cylindrical member 36. The first shape memory alloy 4 is wound so that when energized, current flows from the other #a 42 to one end 41, and one end 31 of the rod-shaped iron core 3 becomes an S pole and the other end 32 becomes an N pole.

The second shape memory alloy 5 is arranged in series on the same axis as the first shape memory alloy 4, and has one end 51 fixed to the cylindrical member 36 and the other end 52 supporting the other side of the casing 2. wall 23
is fixed to. The second shape memory alloy 5 is wound so that when energized, a current flows from one end 51 to the other end 52, and one end 31 of the rod-shaped iron core 3 becomes a north pole and the other end 32 becomes a south pole. Therefore, the first shape memory alloy 4 and the second shape memory alloy
The winding directions of the shape memory alloy 5 are the same direction.

The electric circuit 6 includes a battery 61, a selection switch 62, a limit switch 63, 64, a power supply side terminal 65 of the first shape memory alloy 4, a power supply side terminal 66 of the second shape memory alloy 5,
d from the switch side terminal 67 of the first shape memory alloy 4, the switch side terminal 68 of the second shape memory alloy 5, and the electrical wiring 69 connecting these.

The selection switch 62 has an A contact that supplies electricity to the first shape memory alloy 4 and a B contact that supplies electricity to the second shape memory alloy 5. When the rod-shaped iron core 3 is magnetized and attracted to the permanent magnet 13, the limit switch 63 automatically stops energizing the first shape memory alloy 4 when the rod-shaped iron core 3 comes into contact with it. When the rod-shaped iron core 3 is magnetized and attracted to the permanent magnet 12, the limit switch 64 automatically stops energizing the second shape memory alloy 5 when the rod-shaped iron core 3 comes into contact with it. The power supply side terminal 65 of the first shape memory alloy 4 and the power supply side terminal 66 of the second shape memory alloy 5 are connected to the rod-shaped iron core 3, the first shape memory alloy 4, and the second shape memory alloy in the cylindrical member 36. It is buried to prevent short circuit with alloy 5.

The operation of the actuator 1 of this embodiment will be explained based on the drawings.

When the selection switch 62 of the electric circuit 6 is connected to the A contact, the first shape memory alloy 4 is connected to the power supply side terminal 65.
is connected to the rose tee 61. At this time, the first shape memory alloy 4 is heated by electricity, so that one end 31 of the rod-shaped iron core 3 is set to 88i and the other end 32 is set to the north pole, so that the rod-shaped iron core 3 is magnetized. When heated to the reverse transformation start temperature, the first shape memory alloy 4 expands in a direction that opens the space between the one support wall 22 of the casing 2 and the cylindrical member 36. As the first shape memory alloy 4 expands, the magnetized rod-shaped iron core 3 moves in the direction of the arrow shown in the figure.

Further, the other end 32 of the rod-shaped iron core 3, which is set as the north pole, is attracted to the permanent magnet 13 by the attractive force of the inner part of the permanent magnet 13, which is set as the south pole.
The rod-shaped iron core 3 is easily attracted to the first displacement state. When the rod-shaped iron core 3 is attracted to the permanent magnet 13, the limit switch 63 of the electric circuit 6 automatically stops energizing the first shape memory alloy 4 due to the contact of the rod-shaped iron core 3. Therefore, although the magnetic pole of the rod-shaped iron core 3 disappears, the rod-shaped iron core 3 remains attracted to the permanent magnet 13 due to the attractive force of the permanent magnet 13.

In this state, when the selection switch 62 of the electric circuit 6 is connected to the 8 contacts, the second shape memory alloy 5 is connected to the battery 61 via the power supply side terminal 66.

At this time, the second shape memory alloy 5 is heated with electricity, so that one end 31 of the rod-shaped iron core 3 becomes a north pole and the other end 32 becomes a south pole, so that the rod-shaped iron core 3 is magnetized.

Therefore, the rod-shaped iron core 3 is easily separated from the permanent magnet 13 due to the repulsive force of the permanent magnet 13.

When the second shape memory alloy 5 is heated to the reverse transformation start temperature, it expands in a direction that opens the gap between the other support wall 23 of the casing 2 and the cylindrical member 36.

As the second shape memory alloy 5 expands, the magnetized rod-shaped iron core 3 moves in the direction of the broken line arrow shown in the figure.

Furthermore, one end 31 of the rod-shaped iron core 3, which is set as the north pole, is attracted to the permanent magnet 12 by the attractive force of the inner part of the permanent magnet 12, which is set as the south pole.
is easily attracted to the bar-shaped iron core 3, and the rod-shaped iron core 3 is located in the second displacement state. When the rod-shaped iron core 3 is attracted to the permanent magnet 12, the limit switch 64 of the electric circuit 6 automatically stops energizing the second shape memory alloy 5 due to the contact of the rod-shaped iron core 3. Therefore, the magnetic pole of the rod-shaped iron core 3 disappears, but due to the attractive force of the permanent magnet 13, the rod-shaped iron core 3 is attached to the permanent magnet 121C.
Retains the adsorbed state.

By selectively switching the selection switch 62 in this way, the rod-shaped iron core 3 moves back and forth.

Therefore, the magnetized bar-shaped iron core 3 becomes the permanent magnet 12.1.
3, the rod-shaped core 3 can be easily moved back and forth even if the covering force generated by the first shape-memory alloy 4 and the second shape-memory alloy 5 is small. After being attracted to the permanent magnet 12.13, the power supply to the first shape memory alloy 4 and the second shape memory alloy 5 is stopped, thereby preventing abnormal temperature rise of the first shape memory alloy 4.5. The actuator 1 is ideal as a device for applying reciprocating motion to functional parts.

FIG. 2 shows a damper driving actuator 1 to which the first embodiment of the present invention is applied.

Reference numeral 7 indicates an inside/outside air switching box of an air conditioner that forms the inside air introduction lower 1 and the outside air introduction lower 2, and 73 shows an inside/outside air switching damper whose one end is pivotally connected to the inside/outside air switching box 7. Also 7
Reference numeral 4 indicates a drive motor that drives the ventilation fan 75.

Reference numeral 8 denotes a transmission member that converts the reciprocating motion of the rod-shaped iron core 3 into an opening/closing motion of the inside/outside air switching damper 13, together with a coupling member 81 fixed to one end of the inside/outside air switching damper. In this case, the selection switch 62 is provided in the operation panel of the air conditioner and serves as an inside/outside air changeover switch in which the contact Δ is used to introduce inside air and the contact B is used to introduce outside air.

FIG. 3 shows an actuator 1 to which a second embodiment of the present invention is applied.

(The same functional objects as in the first embodiment are given the same numbers.) The coiled first shape memory alloy 9 and the coiled second shape memory alloy 10 of this embodiment are arranged at the reverse transformation start temperature. The shape is memorized so that when heated, it contracts in the direction toward one support wall 22 or the other support wall 23.

The operation of the actuator 1 of this embodiment will be explained.

(Description of the same function as in the first embodiment is omitted) When the selection switch 62 of the electric circuit 6 is connected to the A contact, the first shape memory alloy 9 is connected to the battery 61 via the power supply side terminal 65. be done. At this time, the first shape memory alloy 9 is heated with electricity, so that one end 31 of the rod-shaped iron core 3 is made a north pole (l!! The end 32 is made a south pole, and the rod-shaped iron core 3 is magnetized. When heated to the reverse transformation start temperature, the first shape memory alloy 9 contracts in a direction that shortens the distance between the other support wall 23 of the casing 2 and the cylindrical member 36. As the alloy 9 contracts, the magnetized bar-shaped iron core 3 moves in the direction of the arrow shown in the figure, and the permanent magnet 13
, and the rod-shaped iron core 3 is located in the first displacement state.

In this state, when the selection switch 62 of the electric circuit 6 is connected to the B contact, the second shape memory alloy 10 is connected to the battery 61 via the power supply side terminal 66.

At this time, the second shape memory alloy 10 is electrically heated so that one end 31 of the rod-shaped iron core 3 becomes the S pole and the other end 32
is set to N8i, and the rod-shaped iron core 3 is magnetized.

Therefore, the rod-shaped iron core 3 is easily separated from the permanent magnet 13 due to the repulsive force of the permanent magnet 13. When the second shape memory alloy 10 is heated to the reverse transformation start temperature, it contracts in a direction that shortens the distance between the one support wall 22 of the casing 2 and the cylindrical member 36. As the shape memory alloy 10 contracts, the magnetized rod-shaped core 3 moves in the direction of the broken line arrow shown in the figure and is attracted to the permanent magnet 12, so that the rod-shaped core 3 is positioned in the second displacement state.

In this example, the first shape memory alloy and the second shape memory alloy were separately provided, but if the center is fixed to the insulating member, the first shape memory alloy and the second shape memory alloy can be used. (installed in one piece) is also acceptable.

In this embodiment, a permanent magnet is used as the magnet, but an electromagnet may be used as the magnet, or another magnet may be used.

In this embodiment, an insulating cylindrical member is fixed to the outer periphery of the iron core, but an insulating round bobbin may be provided on the outer periphery of the iron core.

In this embodiment, a casing in which one supporting wall, which is one supporting means of the iron core, and the other supporting wall, which is the other supporting means, are integrally molded is adopted. The supporting wall may be formed separately.

In this embodiment, the shape memory alloy actuator of the present invention was employed as an actuator that drives an internal/external air switching damper, but it may also be employed as an actuator that drives dampers and valve bodies of other devices, and can be used to open and close doors and windows. The present invention may be employed in actuators that perform reciprocating motion on functional components of various devices, or may be employed in actuators that exert reciprocating motion on functional components of various devices, or motions other than reciprocating motion may be exerted on functional components via interlocking members.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a shape memory alloy actuator to which the first embodiment of the present invention is applied, and Fig. 2 is a schematic diagram of an internal/external air switching box equipped with a shape memory alloy actuator to which the first embodiment of the present invention is applied. 3 is a block diagram of a shape memory alloy actuator according to a second embodiment of the present invention, and FIG. 4 is a block diagram of a conventional shape memory alloy actuator. In the figure 1... Shape memory alloy actuator 3... Rod-shaped iron core 4.9... First shape memory alloy 5.10...
Second shape memory alloy 6... Electric circuit (current supply means) 1
2.13... Permanent magnet 22... One support wall (one support means) 23... Other support wall (other support means) 36... Cylindrical member (insulating member) 63.64 ...
Limit switch

Claims (1)

[Scope of Claims] 1) A first shape memory alloy in a coil shape, a second shape memory alloy in a coil shape arranged in series with the first shape memory alloy, and the first shape memory alloy. energizing means for intermittently and selectively energizing the alloy and the second shape memory alloy; an iron core disposed displaceably within the first shape memory alloy and the second shape memory alloy; the iron core; one magnet disposed at a predetermined gap from one end of the iron core, and the other magnet disposed at a predetermined gap from the other end of the iron core, the first shape memory alloy or the second By energizing the shape memory alloy, the iron core is magnetized, the iron core is displaced by transformation of the first shape memory alloy or the second shape memory alloy, and one end or the other end of the iron core is A polarized shape memory alloy actuator that is attracted to one magnet or another. 2) The shape memory alloy actuator according to claim 1, wherein the magnet is a permanent magnet. 3) One part of the iron core is slidably supported by one support means, the other part is slidably supported by the other support means, and the shape memory alloy is electrically connected to the outer periphery of the central part. 3. The shape memory alloy actuator according to claim 1, further comprising an insulating member for electrically insulating the shape memory alloy actuator. 4) The first shape memory alloy has one end fixed to the one supporting means and the other end fixed to the insulating means, and the second shape memory alloy has one end fixed to the insulating member and the other end. 4. The shape memory alloy actuator according to claim 3, wherein the shape memory alloy actuator is fixed to the other supporting means. 5) The energizing means is provided with a switch that automatically stops energizing the shape memory alloy when the iron core is magnetized and attracted to the magnet. The shape memory alloy actuator according to any one of Items 1 to 4.