JP2013096386A - Shape memory alloy actuator and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape memory alloy actuator which improves operational responsiveness of the actuator both when heating and when heat releasing, and has a compact cooling structure, and to provide a manufacturing method thereof.SOLUTION: The shape memory alloy actuator 10 uses a shape recovery action, as a generated force and a generated displacement, of an actuator body 12 which is composed of a woven structure body 12 wherein a shape memory alloy wire 11 is woven, or a fabrication structure body wherein a shape memory alloy material is fabricated into a woven shape or wavy shape. The shape memory alloy actuator 10 has a means for heating the actuator body, a heat pipe 13 on the surface or back of the actuator body 12, and a heat release sheet 14 in the tip end side of the heat pipe 13. The heat pipe 13 has a valve 15 for opening and closing an in-pipe flow channel. Thereby, operational responsiveness of the actuator both when heating and when heat releasing is improved, and a compact cooling structure is achieved.

Description

  The present invention relates to an actuator technology for a shape memory alloy that uses a knitted structure of a shape memory alloy wire (material) to improve operation response during heating and heat dissipation and to obtain a compact cooling structure.

  Shape Memory Alloy (SMA) remembers the shape memorized at high temperature and has the property of returning to its original memorized shape when heated above the transformation point even if it is deformed at room temperature. . A shape memory alloy actuator is known that uses, as an actuator, the force and deformation generated at the time of SMA shape recovery.

  However, since SMA has a narrow elastic range in which the shape can be restored, it is known to use a knitted structure made of wire-like SMA material as an actuator in order to increase the amount of expansion and contraction of the actuator (Patent Document). 1).

  Since an actuator using such an SMA is operated by controlling the temperature of the SMA, it is necessary to increase the heating rate and the heat dissipation rate of the SMA in order to improve the operation response and improve the response.

  As a method for heating the SMA actuator, there are an indirect heating method in which a heat source such as a heater is brought into contact with the actuator, and a method in which electricity is directly supplied to the SMA actuator itself and heated directly by Joule heat.

  On the other hand, as a cooling method for the SMA actuator, a cooling structure in which the cooling performance is improved by combining the actuator with a heat sink or a heat pipe in addition to natural cooling in the atmosphere (Patent Document 1).

  Furthermore, there is a type in which the flow of the heat medium (heating liquid) inside the heat pipe is controlled by an electromagnetic valve so that the heating speed with the actuator is not impaired even when combined with the heat pipe (see Patent Document 2).

  Since the SMA actuator is driven by heating and heat dissipation of the actuator, it is necessary to improve the heat control speed in order to improve the operation response of the actuator. Generally, since it is difficult to make the heat removal amount larger than the heating amount, the cooling response time becomes longer than the heating response time.

JP 2002-48053 A JP 2004-150283 A

  If a conventional SMA actuator is combined with a cooling structure such as a heat sink in order to enhance heat dissipation, heat will be dissipated in parallel even when the actuator is heated, reducing the responsiveness during heating. There was a risk of it.

  The cooling structure of the SMA actuator needs to be attached in close contact with the actuator of the knitting structure that expands and contracts, but there is no technique that shows or suggests a specific cooling structure that can cope with this expansion and contraction operation.

  In addition, the generation force of the actuator can be increased by laminating the knitted structure of the SMA wire. However, in the cooling structure in which the heat sink is in close contact with the surface of the knitted structure, the thickness of the actuator increases. There was a problem that became.

  In consideration of the above-described circumstances, the present invention provides a shape memory alloy actuator capable of improving the operation responsiveness of the actuator both during heating and during heat dissipation and obtaining a compact cooling structure, and a method for manufacturing the same. For the purpose.

  Another object of the present invention is to improve the operation responsiveness of the actuator using the SMA wire (material) braided structure when heating and radiating heat, so that the entire actuator can be made compact and simplified. Another object of the present invention is to provide a shape memory alloy actuator having flexibility and a manufacturing method thereof.

  In order to solve the above-described problems, a shape memory alloy actuator according to an embodiment of the present invention is an actuator body composed of a knitted structure in which an SMA wire is knitted or a processed structure in which an SMA material is processed into a knitted shape or a wavy shape. It is an actuator having a shape restoring action as a generating force and a generated displacement, and includes a heating means for heating the actuator body, a heat pipe on the front surface or the back surface of the actuator body, and a heat dissipation sheet on the tip side of the heat pipe, The heat pipe has a valve for opening and closing the flow path in the pipe.

  In order to solve the above-described problems, a method of manufacturing a shape memory alloy actuator according to an embodiment of the present invention is a process in which a knitted structure or shape memory alloy material knitted from a shape memory alloy wire is processed into a knitted shape or a wavy shape. A sheet-like actuator body made of a structure is created, the actuator body is subjected to shape memory processing by a natural length constant temperature heating process, both side electrodes of the actuator body are connected to a power source, and the surface of the actuator body or It is a manufacturing method characterized in that a heat pipe is provided on the back surface, and an actuator is manufactured by connecting to a heat radiating sheet through a valve on the front end side of the heat pipe.

  According to the present invention, it is possible to improve the operation responsiveness of the actuator both during heating and during heat dissipation, provide a compact cooling structure, have flexibility and flexibility, and maintain the responsiveness of the actuator during heating. It is possible to provide a shape memory alloy (SMA) actuator that can obtain high heat dissipation during cooling and can be driven at high speed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the basic shape state which shows 1st Embodiment of the shape memory alloy actuator which concerns on this invention, (A) is a top view of an actuator, (B) is the front view of an actuator similarly, (C) is the same actuator Side view. BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the expansion | extension shape state which shows 1st Embodiment of the shape memory alloy actuator which concerns on this invention, (A) is a top view of an actuator, (B) is the front view of an actuator similarly, (C) is the same actuator Side view. The figure which shows the knitting structure example of the knitting structure with which a shape memory alloy actuator is equipped. It is a figure which shows the valve structure with which a shape memory alloy actuator is equipped, (A) is a figure which shows the open state (at the time of high temperature) of a valve, (B) is a figure which similarly shows the closed state (at the time of low temperature) of a valve. It is a cross-sectional view showing the connection pipe of the heat pipe and the heat dissipation sheet provided in the shape memory alloy actuator, (A) is an example of a connection pipe having a triangular cross section, (B) is an example of a connection pipe having a square cross section. Each figure. The figure which shows the cross-sectional structure which inserted the wire and the protrusion in the connection pipe. It is a lamination | stacking structural drawing of the actuator which shows 2nd Embodiment of the shape memory alloy actuator which concerns on this invention, (A) is a front view of an actuator, (B) is a side view of an actuator similarly. It is a whole block diagram which shows 3rd Embodiment of the shape memory alloy actuator which concerns on this invention, (A) is a top view of the heat pipe which accommodated the knitted structure in the heat pipe, (B) is a knitted structure in a heat pipe The front view which shows the partial cross section state of the actuator which accommodated the body, (C) is a side view of an actuator similarly.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[First Embodiment]
1 and 2 show a first embodiment of a shape memory alloy actuator. The shape memory alloy actuator 10 includes a knitted structure 12 knitted from a shape memory alloy (SMA) wire (material) 11, a heat pipe 13 provided on the front or back surface of the knitted structure 12, The heat pipe 13 has a heat radiating sheet 14 provided on the front end side, and a valve 15 that opens and closes a flow path of a working fluid such as water or alcohol in the heat pipe 13. The knitting structure 12 constitutes an actuator body.

  SMA shows an example using a general Ni—Ti alloy, but the material may be a Cu—Zn—Al alloy, a Cu—Al—Ni alloy, or the like, and is not limited to a Ni—Ti alloy. For example, a knitted structure 12 as an actuator body is created by knitting an SMA wire 11 having a wire diameter of about 0.15 mm with a metal knitting machine (not shown). In this embodiment, an example is shown in which a sheet-like (planar shape) actuator is constructed using knitting which is a typical knitting method in a metal knitting machine. In knitting, a knitted structure 12 can be created with a single SMA wire (material) 11. FIG. 3 shows an example of the knitting structure of a mesh-shaped knitting structure 12 in which the SMA wire 11 is knitted.

  The SMA constituting the knitted structure 12 is in a martensite phase at a low temperature, and the knitted structure 12 is deformed flexibly and flexibly by an external force. When the SMA of the martensite phase is brought to a high temperature state, it transforms into an austenite phase, and the shape is restored to its natural length state (recovered), and the rigidity as the SMA material (wire) is increased.

  The SMA actuator 10 remembers the shape memorized at a high temperature by controlling the temperature of the SMA (shape memory effect), and functions as an actuator by returning to the memorized shape when heated above the transformation point. Although the strain that can be restored to the SMA shape is several percent, if the knitted structure 12 is formed in a mesh shape with the SMA wire material, the amount of expansion and contraction that can be restored to the shape and the amount of deformation can be increased to about 10 to 30%. .

[Heating structure of knitted structure]
In the SMA actuator 10 of this embodiment, as shown in FIG. 1A, electrodes 17 formed on both sides of an SMA knitted structure 12 as an actuator body are directly connected to a power source 18 or via a switch (not shown). To form a heating structure of the knitted structure 12. With this heating structure, the knitted structure 12 is directly heated by Joule heat. Therefore, heating can be performed more efficiently than indirect heating in which heat from a heat source such as a heater is transmitted to the SMA knitted structure 12.

[Cooling structure of knitted structure]
Further, the SMA actuator 10 forms a cooling structure of the knitted structure 12 by attaching a heat pipe 13 to the front or back surface of the sheet-like knitted structure 12 and providing a heat radiation sheet 14 on the front end side of the heat pipe 13. In this cooling structure, the heat pipe 13 is connected to the heat radiating sheet 14 via the valve 15 and the connecting pipe 20, and a working liquid (fluid: heat medium) such as water or alcohol liquid is interposed between the heat pipe 13 and the heat radiating sheet 14. It is configured to be movable (flowable). The heat dissipation sheet 14 is disposed on one or both sides of the knitted structure 12. The type of the working liquid is appropriately selected according to the SMA control temperature.

  Since the knitted structure 12 is expanded and contracted by the temperature control of the SMA, the heat pipe 13 and the knitted structure 12 are configured to be slidable through thermally conductive grease such as silicon grease, or the heat pipe. By forming 13 with a flexible material and fixing it to the knitted structure 12, the structure can be deformed flexibly and flexibly following the contraction of the knitted structure 12.

  The heat pipe 13 is configured to have a flexible deformation structure that follows the expansion and contraction of the knitted structure 12. The heat pipe 13 is formed of a flexible material in a corrugated shape or a zigzag shape, and is configured to be able to deform following the expansion / contraction deformation of the knitted structure 12. Therefore, the shape memory alloy actuator 10 in which the SMA knitting structure 12 and the heat pipe 13 are combined can be used, for example, as an exercise assisting tool for a human body joint, and can also be applied to an orthopedic instrument.

  The heat pipe 13 and the knitted structure 12 may be fixed by being fixed with a wire or the like at regular intervals. Also in the operation | movement accompanying the deformation | transformation of the heat pipe 13, it is desirable to insert thermal conductive grease in the clearance gap between the heat pipe 13 and the knitted structure 12, and to improve thermal conductivity.

  In the SMA actuator 10 of the present embodiment, the heat pipe 13 evaporates (absorbs latent heat) due to heat transferred from the SMA to cool the knitted structure 12 while the working liquid (fluid) inside the heat pipe 13 cools. The gas) is cooled by the heat dissipation sheet 14 and condensed (release of latent heat) and circulated to obtain the heat removal effect of SMA, and the knitted structure 12 is cooled.

  The heat dissipating sheet 14 disposed on one side or both sides of the SMA actuator 10 can dissipate the heat of the working liquid in the vapor state. The heat dissipating sheet 14 includes an aluminum material or copper having good thermal conductivity. A thin plate of material, silver material or the like is used. The heat dissipating sheet 14 is configured to be deformed in accordance with the contraction operation of the knitted structure 12 by forming a bellows (bellows) shape in which mountain folding and valley folding are repeated.

[Valve open / close operation]
Further, the valve 15 provided in the heat pipe 13 is configured so as to close the flow path of the heat pipe 13 during heat driving so as not to radiate heat from the heat radiating sheet 14. The valve 15 may be an electromagnetic valve that is electromagnetically driven, and may control the opening and closing of the heat pipe flow path in accordance with the timing of heating and heat dissipation.

  In the present embodiment, the valve 15 employs a clip valve structure using SMA as shown in FIG. This valve 15 is a clip-shaped SMA pinch valve and has a structure in which the flow path of the heat pipe 13 is sandwiched. The clip-shaped valve 15 is subjected to shape memory processing in a state where the flow path of the heat pipe 13 is opened, that is, a shape in which the clip 21 is opened. The SMA valve 15 biases (compresses) the open tip side of the clip 21 in the direction to be closed by the spring member 22 and applies a spring force in the direction to close the heat pipe flow path. The clip 21 of the SMA member is subjected to shape memory processing in a shape in which the flow path of the heat pipe 13 is open.

  Thus, the SMA valve 15 provided in the heat pipe 13 is closed when the clip (SMA member) 21 is closed by the spring force of the spring member 22 and sandwiches the flow path of the heat pipe 13 at a low temperature, and the working fluid flows. Disappear. On the other hand, when the temperature is high, the clip 21 opens the valve 15 with the SMA shape restoring force exceeding the spring force, and the working liquid flows. The SMA valve 15 functions as a valve that operates by opening the flow path of the heat pipe 13 at a high temperature. High heat dissipation can be obtained during cooling while maintaining good heat responsiveness during heating. Therefore, the cooling performance of the knitted structure 12 can be kept good. Moreover, since the SMA valve 15 can be operated without a power source or a controller in accordance with the transformation temperature of the SMA actuator 10, a simple configuration can be achieved.

[Heat responsiveness of knitted structure]
The heat pipe 13 can adjust the boiling point of the working liquid by adjusting the type and pressure of the internal working fluid (not shown). In the heat pipe 13, the internal working liquid evaporates due to the heat transmitted from the knitted structure 12, but the heat removal effect cannot be obtained until the working liquid starts to evaporate. For this reason, when the SMA knitted structure 12 is heated in a low temperature state by adjusting the operating temperature, the valve 15 is closed and the knitted structure 12 is not subjected to heat removal (cooling) by the heat pipe 13. The heating responsiveness of can be maintained well.

[Connecting pipe connecting heat pipe and heat dissipation sheet]
The connecting pipe 20 connecting the heat pipe 13 and the heat radiating sheet 14 is configured in a pipe structure having a cross-sectional shape in which an angle formed by an inner wall surface inside the pipe is an acute angle. For example, as shown in FIGS. 5A and 5B, the cross-sectional shape of the connecting tube 20 is configured to be a triangle or a quadrangle, or a star (not shown). The working liquid OL condensed in the heat radiating sheet 14 is moved to the heating portion of the heat pipe 13 by a capillary phenomenon by setting the angle of the inner wall surface of the cross section of the connecting pipe 20 (hereinafter referred to as a cross section angle) to an acute angle. .

  By making the angle of the cross-sectional shape of the connecting pipe 20 an acute angle, the condensed working liquid does not depend on the difference in height between the heating part of the heat pipe 13 and the heat radiation sheet 14 due to the capillary phenomenon, and the heating part of the heat pipe 13 Returned to

  Even when the angle (cross-sectional angle) formed by the cross section of the connecting tube 20 cannot be an acute angle, a similar capillary tube can be obtained by inserting the wire 24 or the uneven member into the connecting tube 20 as shown in FIG. By obtaining the phenomenon, the condensed hydraulic fluid can be returned to the heating portion of the heat pipe 13. In this case, the connecting tube may be polygonal or circular, and various tube shapes are adopted.

[Method of manufacturing shape memory alloy actuator]
In manufacturing a shape memory alloy (SMA) actuator, first, a wire material, which is a thin SMA material, is prepared, and this SMA wire 11 is knitted, for example, using a metal knitting machine (not shown) to form a sheet-like material. A knitted structure 12 is created.

  Next, the knitted structure 12 knitted into a sheet shape is subjected to a shape memory process by a constant temperature heating process for several hours, for example, 2 to 3 hours in a natural length state, thereby storing a shape that functions as an actuator. As a result, the knitted structure 12 is deformed flexibly and flexibly by the external force of the SMA in the martensite phase at a low temperature. When the SMA knitted structure 12 is brought to a high temperature state, it is transformed into an austenite phase, and the shape is restored (recovered) to the natural length state in which the shape is memorized. The SMA wire has an actuator function that increases the rigidity as a wire material while exhibiting a large force with this shape restoration.

  After the shape memory process is performed, the knitted structure 12 is connected to the power source 18 by connecting the electrodes 17 on both sides, and heated by Joule heat by energization from the power source 18, while the surface or back surface of the knitted structure 12 is heated. A pipe 13 is attached, and a heat radiation sheet 14 is provided at each end of the heat pipe 13. The heat pipe 13 is connected to the heat dissipation sheet 14 via the valve 15 and the connecting pipe 20. The heat dissipation sheet 14 is disposed on one or both sides of the knitted structure 12. The heat pipe 13 may be connected to the heat radiating sheet 14 or the power source 18 after being provided on the knitted structure 12 subjected to the shape memory processing.

  In this way, while forming the heating structure of the knitted structure 12 that heats the SMA knitted structure 12 by energization from the power source 18, the heat pipe 13 is provided on one surface of the knitted structure 12. Both ends of the knitted structure 12 are connected to the heat radiating sheet 14 via the valve 15 and the connecting pipe 20, and the working liquid (heat medium) inside the heat pipe 13 is circulated between the heat pipe 13 and the heat radiating sheet 14. A cooling structure is formed, and the shape memory alloy actuator 10 is manufactured.

  In the shape memory alloy (SMA) actuator 10, the SMA knitted structure 12 is heated by Joule heat when energized from the power source 18, and the knitted structure 12 returns to its original shape memory before deformation by this heating. Is done.

  In addition, the working fluid inside the heat pipe 13 provided in the knitted structure 12 is evaporated (absorption of latent heat) by heat transferred from the SMA of the knitted structure 12, cooled by the heat radiating sheet 14 and condensed (latent heat). It is possible to obtain a heat removal effect by circulating it and then cooling the knitted structure 12.

  According to the present embodiment, since the shape memory alloy actuator 10 is directly Joule-heated by the energization heating from the power source 18 in the knitted structure 12, high operation responsiveness during heating can be obtained. Further, it is possible to implement the shape memory alloy actuator 10 that can obtain high heat dissipation during cooling while maintaining responsiveness during heating and can be driven at high speed. In addition, since the heat dissipating sheet 14 is provided on the side of the actuator body in the SMA actuator 10, the actuator body of the SMA knitted structure 12 is combined with the heat pipe 13 and configured in a sheet shape, so that flexibility and flexibility are provided. Can be held.

  Further, when the SMA actuator 10 is used as a movement assist jig for a human body joint part, it is necessary to reduce the size and simplify the entire actuator.

  In the present embodiment, a flexible heat pipe 13 is folded back into a wave shape or a zigzag shape with respect to the actuator driving direction (stretching direction) on the sheet-like actuator body of the SMA knitted structure 12 to form a sheet shape. Since it is fixed, it is possible to prevent the entire actuator from becoming thick, and it is possible to reduce the size, the size and the size of the actuator. Further, the heat dissipation sheet 14 and the valve 15 are arranged beside the actuator body 12. In addition, since the SMA actuator 10 is configured as a flat sheet as a whole by combining the knitted structure 12 and the heat pipe 13, the thickness and the size of the SMA actuator 10 can be reduced. Since the SMA actuator 10 improves the heat removal effect of the actuator and improves the operation responsiveness without using a cooling structure such as a cooling fan, the SMA actuator 10 is suitable as an exercise assisting tool for a human body joint.

[Second Embodiment]
FIG. 7 is a front view and a side view showing a second embodiment of a shape memory alloy (SMA) actuator.

  The shape memory alloy (SMA) actuator 10A shown in the second embodiment has the same planar shape as the SMA actuator 10 shown in FIGS. 1 (A) and 2 (A). The description is omitted or simplified and the plan view of the SMA actuator 10A is omitted.

  As shown in FIGS. 7A and 7B, the SMA actuator 10A of the second embodiment is provided by laminating a plurality of planar or sheet-like knitted structures 12 formed by knitting the SMA wire 11. At the same time, a heat pipe 13 is attached to the front or back surface of each laminated knitted structure 12. Each of the heat pipes 13 is formed in a flat shape having a wave shape or a zigzag shape along one surface of the knitted structure 12. At both ends of the tip of the heat pipe 13, a heat radiating sheet 14 is provided via a valve 15 and a connecting pipe 20.

  Each heat dissipation sheet 14 is arranged in a laminated structure on one or both sides of the knitted structure 12. Each heat dissipation sheet 14 corresponds to each knitted structure 12 and heat pipe 13 having a laminated structure. In this way, a stacked structure is formed in which a plurality of SMA actuators 10 are stacked. Since the configuration of the valve 15 and the connecting pipe 20 is not different from the shape memory alloy actuator 10 shown in the first embodiment, the description thereof is omitted.

  The shape memory alloy actuator 10A of the second embodiment is configured by stacking the SMA actuators 10 having a plurality of knitted structures 12, and can increase the generated force as an actuator, thereby obtaining an actuator with a large operating force. It is done.

  Further, the shape memory alloy actuator 10 </ b> A is shown in FIGS. 7A and 7B by arranging the heat dissipating sheets 14 laminated corresponding to the plurality of knitted structures 12 on the side of the knitted structure 12. As described above, since the heat radiating portion (heat radiating sheet 14) is not sandwiched between the knitted structures 12 as a heat source, good heat radiation characteristics can be obtained, and the knitted structures 12 can have excellent cooling performance.

[Third Embodiment]
FIG. 8 shows a third embodiment of the shape memory alloy actuator.

  In the shape memory alloy (SMA) actuator 10B shown in the third embodiment, the structure of the heat pipe 13A and the mounting / fixing structure of the knitted structure body 12A knitted with the SMA wire 11 are the same as the shape memory alloy ( It is different from the SMA) actuator 10. Since other configurations and operations are not substantially different from the shape memory alloy (SMA) actuator 10 of the first embodiment, the same configurations are denoted by the same reference numerals, and description thereof is omitted or simplified.

  In the SMA actuator 10B shown in FIG. 8, the heat pipe 13A is not a corrugated or zigzag pipe structure, but is a flat bellows (bellows) structure that is rectangular in plan view. The heat pipe 13A has a flat bellows shape so that the knitted structure 12A and the working liquid are enclosed in a flat space in the heat pipe 13A. The knitted structure 12A does not attach the heat pipe 13A to the surface, but accommodates the knitted structure 12A in the flat heat pipe 13A.

  Both ends in the longitudinal direction (stretching direction) of the knitted structure 12A are fixed to the end side of the heat pipe 13A. Since the heat pipe 13A has a bellows structure, the heat pipe 13A can be expanded and contracted in accordance with the expansion and contraction of the knitted structure 12A.

  The heat dissipation sheet 14 is disposed on one side or both sides of the flat heat pipe 13A. The connecting pipe 20 that connects the heat radiation sheet 14 and the heat pipe 13A and the valve 15 that opens and closes the flow path of the working liquid to the connecting pipe 20 are not different from the shape memory alloy (SMA) of the first embodiment.

  The valve 15 is disposed in the heat pipe 13A so as to be able to heat and dissipate heat together with the knitted structure 12A. However, the valve 15 is disposed outside the heat pipe 13A and opens and closes in conjunction with the operation of the knitted structure 12A. An operation may be performed.

  According to the SMA actuator of the third embodiment, since the knitted structure 12A is immersed in the working liquid of the heat pipe 13A, the heat of the knitted structure 12A can be efficiently transferred to the working liquid, The knitted structure 12A can be efficiently cooled.

  In the SMA actuator of each embodiment, an example in which a knitted structure knitted by a metal knitting machine is provided as an actuator body has been described. However, the knitted structure is not limited to this knitted structure, and knitted structures by other knitting methods. It may be a body. Further, instead of a knitted structure using an SMA wire, an SMA plate material may be cut into a net shape and processed to have a stretchable structure. Further, the SMA belt-like material or linear material is bent into a wave shape or a zigzag uneven shape, and the processed structure is formed into a sheet shape or a planar shape by sequentially joining the peak portions and the valley portions of the bent SMA material. The actuator main body may be constituted by the processed structure formed.

  In each embodiment, the example in which the knitted structure of the SMA actuator is directly heated by energization from the power source has been described. However, the present invention is not limited to direct heating by energization, and the actuator body such as the knitted structure is heated in combination with the heater. The heater may be stopped when radiating heat. Further, by combining a Peltier element or the like that can generate a low temperature portion with an actuator body such as a knitted structure, it is possible to further improve heat removal and to further improve the cooling performance of the actuator body.

10, 10A, 10B Shape memory alloy (SMA) actuator 11 Shape memory alloy (SMA) wire (SMA material)
12, 12A Knitted structure (actuator body)
13, 13A Heat pipe 14 Heat radiation sheet 15 Valve 17 Electrode 18 Power supply 20 Connecting pipe 21 Clip (SMA member)
22 Spring member 24 Wire

Claims (10)

It is an actuator that takes the shape return action of the actuator body consisting of a knitted structure knitted from a shape memory alloy wire or a processed structure obtained by processing a shape memory alloy material into a knitted shape or a wavy shape, and a generated displacement.
A heating means for heating the actuator body, a heat pipe on the front or back surface of the actuator body, and a heat dissipation sheet on the tip side of the heat pipe,
A shape memory alloy actuator, wherein the heat pipe has a valve for opening and closing a flow path in the pipe. The valve is configured to have a valve structure in which a shape memory alloy member that is subjected to shape memory processing in a shape in which the flow path of the heat pipe is opened and a spring member that applies a spring force in a direction to close the flow path of the heat pipe,
2. The flow path of the heat pipe is opened when the shape memory alloy member returns to a shape at a high temperature, and the flow path of the heat pipe is closed by a spring force of the spring member at a low temperature. The shape memory alloy actuator described. The valve is configured to sandwich the heat pipe flow path with a clip-shaped shape memory alloy member, while the shape memory alloy member is subjected to shape memory processing in a shape in which the clip is opened,
The shape memory alloy actuator according to claim 1, wherein a spring force is applied to the spring member in a direction in which the clip is closed. 2. The shape memory alloy actuator according to claim 1, wherein the heat dissipating sheet is configured in a bellows structure in which a mountain fold and a valley fold are repeated in an extension / contraction direction of the actuator body, and is disposed on the side of the actuator body. The shape memory alloy actuator according to claim 1, wherein the heat pipe is formed in a wavy shape or a zigzag shape using a flexible material, and is provided in the actuator body. The heat pipe and the heat dissipation sheet are connected by a connecting pipe,
The shape memory alloy actuator according to any one of claims 1 to 5, wherein the connecting pipe has a cross section having an acute angle formed by an inner wall surface. The shape memory alloy actuator according to claim 6, wherein a wire or an uneven shape is inserted into the connecting pipe. A shape memory alloy actuator characterized in that a plurality of the shape memory alloy actuators according to claim 1 are laminated to form a laminated structure. The shape memory alloy actuator according to claim 1, wherein the knitted structure is enclosed with a working fluid in a heat pipe. Create a sheet-like actuator body consisting of a knitted structure knitted from a shape memory alloy wire or a processed structure obtained by processing a shape memory alloy material into a knitted or wavy shape,
The actuator body performs a shape memory process by a natural temperature constant temperature heating process,
The actuator body is manufactured by connecting both electrodes of the actuator body to a power source, and providing a heat pipe on the front or back surface of the actuator body, and connecting a heat dissipating sheet to the front end side of the heat pipe via a valve. A manufacturing method of a shape memory alloy actuator.

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