JP6135523B2 - Plate actuator - Google Patents

Description

  The present invention relates to an actuator for deforming a structure, and more particularly to a plate actuator that is advantageously used for deformation of a structure such as a body of a moving body.

  As one type of actuator for deformation of various structures, a conventional shape memory alloy whose dimensions expand and contract with temperature is used, and part of the structure is deformed or movable parts are driven by expansion and contraction of the shape memory alloy. Various configurations have been proposed. For example, Patent Document 1 proposes an actuator in which a linear elastic body made of a shape memory alloy is embedded in an elastic body formed of a polymer or the like as a small actuator used in a micromachine or the like. This actuator is of a type that deforms a part of a target structure by changing the length of the stretchable body. In Patent Documents 2 and 3, a linear expansion / contraction body made of a shape memory alloy is used as a mesh as an actuator that is supposed to be used for moving parts such as blood pressure measuring instruments and massage machines, and assisting movement of limbs. Or what was arranged in the shape of a cylinder which is arranged in a spiral shape and expands and contracts in length and diameter is disclosed. Furthermore, a shape memory alloy whose size is expanded and contracted as a temperature is used as an actuator for a part of the body of the moving body and other structures, and a part of the structure is deformed or a movable part is driven by the expansion and contraction of the shape memory alloy. Various configurations have been proposed (for example, Patent Documents 4-10). Furthermore, as a structure of a transport pipe such as an artificial esophagus, a band-shaped shape memory alloy is wound around a plurality of locations on the pipe, and the expansion and contraction of the band-shaped shape memory alloy is controlled so as to cause the pipe to move. Therefore, a configuration for moving a substance in a pipe has also been proposed (Patent Document 11).

JP 06-341369 JP-A-2005-98241 JP 2005-48658 A JP 09-257398 A Shokai 62-112971 ACT 59-123674 Japanese Utility Model Sho 61-113174 JP 2002-319343 JP 09-126116 A JP2007-92556A JP-A-2005-104722

  When using a deforming element such as a shape memory alloy that expands or contracts depending on conditions (temperature, voltage, etc.), the deforming element itself can be incorporated as a part of the structure to be deformed, and therefore is occupied by the actuator itself. The space can be made relatively small. However, the amount of displacement per unit length of these deformation elements is generally small, and in order to obtain a large displacement directly from the deformation of the deformation elements, it is necessary to enlarge the deformation elements. That is, the displacement amount of the distance between crystal lattices or the displacement amount of the dimension when the phase structure changes in a typical deformation element is 30% at the maximum, and the maximum displacement δ of the element of length L Is at most about δ = 0.3L, so if the required displacement amount Δ desired to be generated by the actuator is considerably larger than the maximum displacement per unit length of the element, the maximum displacement δ of the element is required. The length L of the element must be increased so that the displacement amount Δ can be sufficiently achieved, and thus the actuator is increased in size. That is, in order to use a conventional actuator as exemplified in the above example for deformation of a structure such as a body of a moving body, generally, when trying to achieve both high load (or high output) and high displacement, The actuator becomes large, and it is difficult to reduce the weight and space.

  In view of this, the inventor of the present invention disclosed in Japanese Patent Application No. 2013-111400 an actuator using a shape memory alloy that can be advantageously used for deformation of a structure such as a body of a moving body. The structure of the plate-like actuator that can give a large displacement in the structure (compared to the past) without increasing the size of the structure is proposed. In short, the plate-like actuator described in the above-mentioned patent application is mounted on the plate-like member having a flexible curved plate-like member 2 ′ as illustrated in FIG. 8A. Deformation element 4 ′ made of a stretchable band-shaped shape memory alloy (in the figure, a plurality of deformation elements 4 ′ are arranged), and the position of deformation element 4 ′ whose length has changed (for example, As shown in FIG. 8B, the plate-like member is caused to swing by being changed (in order from the end). Here, “peristration of the curved plate-like structure” means a portion of the curved plate-like structure that is locally expanded and contracted along the bending direction (a concave region or a curved surface that is recessed inward of the curved surface). Is a movement that moves along a direction substantially perpendicular to the bending direction, and the moving concave region or convex region pushes a part of the structure to be deformed. As a result, the deformation of the structure is achieved. According to such a configuration, first, the portion that generates the force is a concave region or a convex region, and the portion where the force acts is a movable part of the body that is in contact with the concave region or the convex region. The action point substantially coincides with the force, and the force generated at the power point is directly applied to the action point, so that the amount of reduction of the generated force is reduced. In addition, a large displacement can be obtained by configuring the concave region or the convex region to move over a long distance in the curved plate-like structure. Since the shape of the actuator itself is a curved plate, it is not necessary to increase the space occupied by the actuator body, and the actuator can be further reduced in weight and space.

  By the way, the deforming element 4 ′ made of the shape memory alloy exemplified in the embodiment of the above Japanese Patent Application No. 2013-111400 basically has an insulating material as shown in FIG. Electrodes 8 'are provided at both ends of the expansion / contraction element 7' located on the edge 5 of the plate-like member. In this configuration, when an electric current is passed through the expansion element 7 'via the electrode 8', the temperature rises due to the Joule heat generated thereby, and the expansion element 7 'contracts in the length direction, thereby In the plate member, a concave region is locally generated. When the current is cut off, the length of the expansion / contraction element 7 'expands, but the length may not be completely restored. Therefore, in order to ensure the restoration of the length after the energization is stopped, A leaf spring 9 'arranged on the lower or side surface is arranged.

  In the case of the configuration in which the length of the deformation element 4 ′ is contracted to generate the peristalsis as illustrated in FIG. 8, the magnitude of the driving force is determined by the magnitude of the contraction force of the deformation element 4 ′. Therefore, in the configuration shown in the figure, when it is intended to further increase the output, it is necessary to increase the contraction force of the deformation element 4 ′. For this purpose, the thickness of the strip-shaped deformation element 4 ′ is increased. An increase in the number of expansion / contraction elements 7 ′ (the number of superpositions) and an increase in the thickness of the leaf spring 9 ′ are requirements. However, in this case, the shape memory alloy layer close to the leaf spring and the shape memory alloy far from the leaf spring in which the thickness of the plate actuator increases and the curvature of the expansion / contraction element composed of the shape memory alloy layer changes without contracting. There is a shift in shrinkage between the layers due to a shift in curvature. In this regard, in general, adjusting the amount of shrinkage of each of the plurality of layers of shape memory alloy in accordance with the position where each layer is arranged is a cumbersome and costly factor, so usually the same shrinkage A shape memory alloy layer having an amount will be used. However, in the case of the configuration of FIG. 8, the shape memory in contact with the interface with the leaf spring is generated by the occurrence of the shrinkage of the shrinkage amount in the shape memory alloy layer depending on the distance from the surface of the leaf spring as described above. The shrinkage force of the alloy layer is consumed in the shear fracture of the interface with the leaf spring or the layer itself, and is not used for the force acting on the outside as the actuator, and the actuator efficiency can be reduced or broken. In addition, the shape memory alloy has a relatively large operating shrinkage (up to 5%), and it may be difficult to coat the surface of the linear member of the shape memory alloy with the shape memory alloy. In the case of a type in which a current is passed through the linear member itself to generate heat, if multiple layers of shape memory alloy are overlapped, adjacent shape memory alloy wires without an insulating film come into contact with each other, and apparent conduction interruption The area increases, and therefore the electrical resistance decreases. As a result, the amount of heat generated by energization is reduced due to a decrease in electrical resistance, so that it is necessary to distribute a large current in order to obtain a sufficient amount of heat generation. On the other hand, it is very difficult to arrange the wires finely so that the shape memory alloy wires do not contact each other. In other words, there is a certain limit to the increase in the number of arrangements of the expansion / contraction elements 7 'formed of the band-shaped shape memory alloy layer as illustrated in FIG.

  Thus, one object of the present invention is to attach a selectively stretchable linear or belt-like stretchable element made of a shape memory alloy on a plate-like elastic body, and determine the position of the stretchable element whose length has been changed. In the moving plate type actuator, a new configuration capable of further increasing the output is proposed.

  Another object of the present invention is an actuator as described above, which does not use a curved leaf spring for restoring the length of the expansion / contraction element, and uses the shape memory alloy itself as a current circuit for heat generation. It is providing the actuator comprised without using as.

  According to the present invention, the above-described problem is a plate-shaped actuator, which is an elastically deformable elastic plate-shaped member, and at least one of the elastic plate-shaped members disposed along the surface. A linear deformable element, a shrinkable linear stretchable element formed by bundling a shape memory alloy wire and an electric resistance wire in a predetermined arrangement, and surrounding both of the stretchable elements by enclosing at least a part of the stretchable element The elastic plate-shaped member is deformed along with the change in the length of the linear deformation element. This is achieved by a plate-like actuator in which the deformation portion of the elastic plate-like member is changed along with the change of the position of the linear deformation element whose length has changed.

  In this configuration, the “elastic plate-like member” may be any flexible plate-like member, for example, any high-elasticity resin film such as polyurethane (urethane rubber or urethane resin) or thermoplastic elastomer. Etc. may be used. As described above, the “linear deformation element” has a configuration in which a shape memory alloy wire and an electric resistance wire are bundled in a predetermined arrangement, and a plurality of wires are bundled in order to achieve high output. As described above, the “shape memory alloy wire” is a wire whose length changes depending on the temperature (typically, shortens as the temperature rises), and the “electric resistance wire” It is for flowing and generating heat to increase the temperature of the shape memory alloy wire. In that case, preferably, each surface of the electric resistance wire is coated with an insulating film, and in order to increase the electric resistance in order to increase the amount of heat generation, a plurality of electric resistance wires are provided at respective end portions. It may be made conductive only in the case. According to such a configuration, since it is not necessary for the shape memory alloy wire itself to circulate current, the shape memory alloy wires that are not covered with the insulating film may be brought into contact with each other. Thus, the number of wires can be easily increased.

  Furthermore, “an elastic element that surrounds at least a part of the elastic element and elastically deforms the length of both of the elastic elements” means any elastic element for restoring the length of the elastic element whose length has changed. In the case of the present invention, in the case of the present invention, at least a part of the expansion / contraction element is surrounded, and elastic deformation thereof occurs in the length direction, that is, the expansion / contraction direction of the expansion / contraction element. Therefore, since the change in the curvature is not essential in the expansion / contraction of the expansion / contraction element, the problem of the displacement of the expansion / contraction amount of the expansion / contraction element as in the case where the leaf spring is adopted is solved. As such an elastic element, a cylindrical member made of an elastic material such as a helical spring, a disc spring, or a thermoplastic elastomer may be employed. Further, the elastic element and the rigid tube may be alternately arranged in series instead of being surrounded by the elastic element over the entire length of the expansion / contraction element.

  The operation of the plate actuator according to the present invention described above may be basically the same as the actuator described in Japanese Patent Application No. 2013-111400. Since the length of the expansion / contraction element of the linear deformation element contracts when energized, the position of the deformation element with the contracted length is moved by appropriately controlling the energization of the expansion / contraction element, and thereby the elastic plate By changing or moving the deformed portion of the member, the acting force (the pressing force or the traction force due to the deformation) is exerted on the external structure to be driven. In particular, when the elastic plate-like member is bent and used in the same manner as in Japanese Patent Application No. 2013-111400, the deformation element extends along the bending direction, and the length of the deformation element with the contracted length is reduced. The “movement” occurs due to the movement of the position.

  As one mode of changing the position of the deforming element whose length has changed in the plate-like member, a plurality of deforming elements are spaced from each other and attached to the plate-like member, and the length of the plural deforming elements is The peristalsis may be advanced by selectively changing. According to such a configuration, as described in the section of the embodiment described later, the length of the plurality of deformation elements spaced apart from the plate member is selectively set, for example, the length of the adjacent deformation elements. By expanding or contracting the length in order (by shifting the timing for expanding or contracting the length of the deformation element), the deformation portion on the plate-like member moves. Control for selectively expanding and contracting the lengths of the plurality of deformation elements can be achieved by controlling the timing of energization of each deformation element.

  As another mode of changing the position of the deforming element whose length has changed in the plate-like member, in the plate-like actuator, further, two strips extending without intersecting on the plate-like member. A conductive region is provided, the deformation element has a conductive portion extending between both ends thereof, and each of the two strip-shaped conductive regions and each end of the conductive portion of the deformation element are in conduction. The deformation element may be arranged to be movable along the extending direction of the two strip-like conductive regions. In such a configuration, the length is changed by the Lorentz force generated by the magnetic field generated between the two strip-shaped conductive regions by passing a current through the two strip-shaped conductive regions and the conductive portion of the deformation element. The deformation element moves along the extending direction of the two strip-like conductive regions, and accordingly, the deformation portion formed in the portion of the plate-like member adjacent to the deformation element having a changed length moves. . Here, the expansion and contraction of the deformation element can be achieved by controlling energization of the deformation element. In addition, according to this aspect, it should be understood that the movement of the deformation portion on the plate-like member can be generated by one deformation element.

  In the above configuration, after energizing the deformable element, the refrigerant is circulated around the expansion / contraction element for the purpose of cooling the expansion / contraction element whose temperature has once increased in order to turn off the energization and restore the length of the expansion / contraction element. A flow path may be provided. Specifically, for example, the expansion / contraction element may be inserted into the sheath structure, a gap may be provided between the inner surface of the sheath structure and the surface of the expansion / contraction element, and the refrigerant may be circulated using the gap as a flow path.

  Thus, according to the present invention described above, a selectively stretchable linear or belt-like stretchable element made of a shape memory alloy is attached to the plate-like elastic body, and the position of the stretchable element whose length has been changed is determined. In a plate-type actuator to be moved, an actuator constructed without using a curved leaf spring for restoring the length of the expansion / contraction element and without using the shape memory alloy itself as a current circuit for heat generation Is provided. In the present invention, the shape memory alloy wire and the electric resistance wire are separated, and a bundle of these wires is adopted as an expansion / contraction element. Further, the elastic element is surrounded as an elastic body for restoring the length of the expansion / contraction element. By adopting an elastic element that elastically deforms in the length direction, the number of shape memory alloy wire rods can be increased with little consideration of displacement of shrinkage and the configuration of insulation. High output is possible. The plate-like actuator according to the present invention is an actuator used for deformation of an arbitrary structure, so that a large displacement can be obtained without greatly reducing the occupied space of the actuator body and reducing the driving force of the deformation element. Since the actuator has a plate shape, there are devices or equipment for other functions (moving body drive device, control device, seat, etc.) inside the body of the moving body. Even when it is provided, it is advantageous in that the degree to which the actuator protrudes into the space inside the body can be kept small. Since the equipment for controlling the length of the deforming element is basically only an electric circuit, etc., the equipment required for the operation of the actuator is relatively small, and therefore the actuator can be further reduced in weight and space. This is also advantageous.

  Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention.

FIG. 1A is a schematic perspective view of a plate-like actuator according to the present invention, and FIG. 1B is an enlarged schematic perspective view in the vicinity of an end portion of the linear deformation element. FIG. 2A is a schematic perspective view of the end portion of the deformation element in the plate-like actuator according to the present invention, and FIG. 2B is a schematic perspective view of the end portion of the expansion / contraction element. . These figures are partially cut away to show the interior. FIG. 2C is a cross section of the expansion / contraction element, and shows an arrangement of shape memory alloy wire (white circle) and electric resistance wire (black circle). FIG. 3 (A) is a schematic perspective view of a part of a deformation element showing an embodiment in which a disc spring is used as an elastic element in the deformation element of the plate-like actuator according to the present invention. FIG. 4 is a schematic perspective view of a part of a deformation element showing an embodiment using a cylindrical member made of a thermoplastic elastomer as an elastic element in the deformation element of the plate actuator according to the present invention. FIG. 4 is a schematic perspective view of the end portion of the deformation element similar to that in FIG. 2 (A), and is a diagram illustrating the configuration of the flow path through which the refrigerant flows. FIG. 5 is a perspective view schematically showing the state of movement of the deformed portion when the plate-like actuator according to the present invention is developed in a planar shape. FIG. 6 (A) is a diagram schematically showing the deformation of the deformation element when the plate-like actuator according to the present invention is bent, and FIG. 6 (B) is a diagram showing the curve of the plate-like actuator according to the present invention. It is the perspective view which represented typically the mode of the movement of the deformation | transformation site | part at the time of making it do. FIG. 7 is a perspective view schematically showing another embodiment of the plate-like elastic member of the plate-like actuator according to the present invention. FIG. 8A is a schematic perspective view of the actuator described in Japanese Patent Application No. 2013-111400, and FIG. 8B is a schematic diagram illustrating how the peristalsis proceeds. FIG. These are the typical perspective views explaining the structure of the edge part of the deformation | transformation element in Japanese Patent Application No. 2013-111400.

DESCRIPTION OF SYMBOLS 1 ... Plate-shaped actuator 100 ... Elastic plate-shaped member 101 ... Pocket 8 ... Shaft support member 9 ... Support shaft 10 ... Linear deformation element 11 ... Support end 11h ... Shaft through-hole 12a-c ... Screw 13 ... Refrigerant flow path DESCRIPTION OF SYMBOLS 14 ... Holding tube 15 ... Sheath structure 15a ... Refrigerant inflow port 16a ... Tube 16b ... Elastic element (helical spring)
17 ... Electric resistance wire 18 ... Shape memory alloy wire 19 ... Rigid pipe 20 ... Belleville spring 21 ... Elastomer pipe member 200 ... Crevice

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings. In the figure, the same reference numerals indicate the same parts.

Diagram of the plate-shaped actuator 1 (A), with reference to (B), is at the plate-shaped actuator 1 according to the present invention, as illustrated, at the elastic membrane (elastic plate-like member) 100 of arbitrary size Thus, a pocket 101 having a length substantially equal to that of the elastic film 100 for receiving the linear deformation element 10 described in detail later is formed. The elastic film 100 and the pocket 101 may typically be a film-like member made of any highly elastic resin film such as polyurethane (urethane rubber or urethane resin) or thermoplastic elastomer, and the pocket 101 may be bonded or It may be provided on the elastic film 100 at a predetermined interval by welding or the like. The linear deformation element 10 is inserted into each pocket 101 and positioned in a direction perpendicular to the length direction thereof. Further, the end of the linear deformation element 10 has a support end portion having a shaft through hole 11h. 11 is attached. The support shaft 9 is passed through the shaft through-hole 11h, and the support shaft 9 is gripped so as to be covered with the shaft support member 8 on the edge portion 100a of the elastic film 100, whereby the support end portion 11 is supported. The plurality of linear deformation elements 10 may be positioned in the length direction by the support shaft 9 through the support shaft 9.

  As illustrated in FIGS. 2A to 2C, the linear deformation element 10 includes a plurality of shape memory alloy wires 18 and electric resistance wires 17 covered with a flexible holding tube 14. A telescopic element 10a composed of a bundle (17, 18), a cylindrical tube body 16a attached to both ends of the telescopic element (in the drawing, it is drawn to show the inside), and the telescopic element. Are formed of a tubular or cylindrical elastic element 16b surrounding the expansion / contraction element 10a between tube bodies 16a at both ends (only one end is shown in the figure).

  The shape memory alloy wire 18 may be an arbitrary wire made of a shape memory alloy that shrinks in the length direction as the temperature rises, and the electric resistance wire 17 is an arbitrary conductor that generates Joule heat by passing an electric current. The surface which consists of a conductive material may be the wire by which insulation coating was carried out. The shape memory alloy wire 18 and the electric resistance wire 17 may be arranged so as to form a structure such as a close-packed lattice in cross section, as illustrated in FIG. 2C, for example. As illustrated in FIG. 2B, the electric resistance wire 17 may be a single wire folded at the end of the bundle, so that the amount of current flowing through the expansion / contraction element is kept low. It may be. The expansion / contraction element 10a is fitted with rigid pipes 16c (three in the illustrated example) at both ends, and is fixed to the pipe 16a by any fastening means such as screws 12a to 12c. Further, at both ends of the electric resistance wire 17, the terminal 17a is drawn out of the tube body 16a and connected to an external power source (not shown). Thus, when a current is passed through the electrical resistance wire 17 via the terminal 17a, Joule heat is generated, and the temperature of the expansion / contraction element 10a, which is a bundle of the shape memory alloy wire 18 and the electrical resistance wire 17, rises, Since the shape memory alloy wire 18 is contracted, the length of the expansion / contraction element 10a is contracted. And when electricity supply to the electric resistance wire 17 is cut off, the temperature is lowered, and the shape memory alloy wire 18 is restored to its original length. Note that the contraction force of the expansion / contraction element 10a is proportional to the cross-sectional area of the shape memory alloy wire 18 in the bundle and is the sum of the contraction force of each shape memory alloy wire 18, so when increasing the output, The number of the shape memory alloy wires 18 is increased, and the number of the electric resistance wires 17 and the applied voltage are appropriately adjusted in order to quickly and appropriately increase the temperature of the shape memory alloy wire 18 during current flow. Is done. The ratio of the number of the shape memory alloy wire 18 and the electric resistance wire 17 in the bundle of the elastic elements 10a may be determined experimentally. As illustrated in FIG. 2C, according to the configuration of the bundle in which the shape memory alloy wire 18 is arranged in the form of a close-packed lattice around the electric resistance wire 17, the electric resistance wire 17 is formed of the shape memory alloy wire. Therefore, the heat generated in the electric resistance wire 17 is quickly transmitted to the shape memory alloy wire 18, and a rapid shrinkage response of the shape memory alloy wire 18 is expected. The ratio of the number of the shape memory alloy wire 18 and the electric resistance wire 17 in the bundle of the expansion elements 10a and the diameter of the wire may be determined experimentally. In the case of the arrangement illustrated in FIG. 2C, the diameter of the shape memory alloy wire 18 and the diameter of the electric resistance wire 17 are preferably substantially equal, but are not limited thereto.

  Typically, the elastic element 16b may be an elastic body that extends and contracts in the lengthwise direction, such as a helical spring having a hollow cylindrical shape, as illustrated in FIG. The elastic element 10a is received in the cavity. The elastic element 16b is attached and fixed between the tube bodies 16a at both ends of the expansion element 10a, thereby reducing the distance between the tube bodies 16a at both ends due to contraction due to energization of the expansion element 10a. Will be shrunk. When the energization of the expansion / contraction element 10a is cut, the shape memory alloy wire of the expansion / contraction element 10a expands, and the elastic element 16b elastically supports both ends in order to assist in restoring the original length completely. It will act so that it may pull apart between the tube bodies 16a. In addition, the elastic element 16b is made of, in addition to the helical spring, a structure in which a plurality of disc springs 20 are stacked as illustrated in FIG. 3A, or a thermoplastic elastomer material as illustrated in FIG. 3B. A cylindrical member 21 may be used. Further, the elastic element 16b does not need to have a length over the entire length between the pipe bodies 16a at both ends of the expansion / contraction element 10a. For example, as illustrated in FIGS. Further, a structure in which a plurality of elastic bodies shorter than the expansion and contraction element 10a are connected via the rigid tube 19 (for example, a structure in which elastic bodies and rigid tubes are alternately connected in series) may be used. In particular, when a thin actuator is configured, the tube 16a at both ends has a configuration having a long free length with respect to the diameter (a configuration having an extremely high aspect ratio). In order to avoid plastic deformation, a configuration with a rigid tube 19 interposed is advantageous. The elastic coefficient k of each elastic element when n elastic elements are connected through the rigid tube 19 is given by k = nK using the elastic coefficient K required as a whole (all elastic elements Of the same elastic modulus).

  When arranging the linear deformation element 10 on the elastic membrane 100, as already mentioned, it is inserted into the pocket 101, and further, the end 11b of the support end 11 is connected to the tubular body 16a at both ends. Fixed. The support shaft 9 may be inserted into the hole 11 h of the head 11 a of the support end 11. According to such a configuration, the position of each linear deformation element 10 in the length direction is fixed, and the positions of the end portions of the plurality of linear deformation elements 10 are aligned at the edge of the elastic film 100.

  Further, in the linear deformation element 10 described above, the sheath structure 15 may be provided between the protective tube 14 covering the bundle of the wire rods 17 and 18 of the expansion / contraction element 10a and the elastic element 16b (that is, the expansion / contraction element). 10a is inserted into the inside of the sheath structure 15, and in this state, is further inserted into the elastic element 16b). A gap 13 is provided between the inner surface of the sheath structure 15 and the outer surface of the protective tube 14, and the end of the sheath structure 15 may be sealed onto the surface of the protective tube 14 (15b). A hole 15 a is provided in a part of the sheath structure 15. Such holes 15a may be provided in the vicinity of both ends of the sheath structure 15, respectively, using one as a refrigerant inlet and the other as a refrigerant outlet, and through the gap 13, a refrigerant such as air or water is supplied to the expansion element 10a. It may be designed to circulate around. According to the configuration in which such a refrigerant is circulated, the expansion / contraction element 10a whose temperature has been once increased by energization is quickly cooled after the energization is cut off, and the expansion / contraction response of the expansion / contraction element 10a is improved.

  Further, when the deformation element 10 is disposed on the elastic film 100 as shown in FIG. 1A, a part of the contraction energy is consumed for contraction of the elastic film 100 when the deformation element 10 contracts. Will be. In order to reduce the energy consumption, a gap 200 may be provided in the elastic film 100 in a direction perpendicular to the extending direction of the deformation element 10 as shown in FIG. In this case, in order to allow the deformation of the elastic film 100 accompanying the contraction of the deformation element 10, the bonding part between the pocket 101 and the elastic film 100 may be only the part indicated by the arrow in the drawing. In the case of such a configuration, the elastic film can be used even if it is a member having a slightly high surface rigidity such as an FRP thin plate.

Operation of plate actuator In the operation of the above plate actuator, as shown in FIG. 1A, a plurality of linear deformation elements are selectively contracted, and the position of the contracted linear deformation elements is moved. As a result, an acting force is applied to an arbitrary structure to be driven. In the operation of each linear deformation element, as already mentioned, when a current is supplied from the external power source to the electric resistance wire 17, the electric resistance wire 17 generates Joule heat, and the heat causes the shape memory alloy wire 18. Contracts. At this time, since the elastic element 16b contracts in the length direction, the linear deformation element basically contracts and deforms in the length direction. Then, when energization to the electric resistance wire 17 is stopped, Joule heat is no longer generated, so the temperature of the shape memory alloy wire 18 decreases, and the length of the shape memory alloy wire 18 returns to the original length. Elongate. At that time, the elastic element 16b gives a force to elastically extend so as to assist the complete restoration. Moreover, when the refrigerant | coolant distribution mechanism by the sheath structure 15 is provided, the temperature fall of the shape memory alloy wire 18 will be accelerated | stimulated, and the expansion-contraction response will be improved.

  FIG. 5 is a view schematically showing a state in which the plate-like actuator is expanded and operated in a planar shape. In the example shown in the figure, the support shaft 9 is not inserted or a flexible shaft is used. Referring to the figure, in this case, energization is sequentially turned on / off from the linear deformation element 10 on one edge to the linear deformation element 10 on the other edge. Then, when the energized linear deformation element 10 contracts, a recess is formed in the elastic film 100, and when the object to be energized is moved to the adjacent linear deformation element 10, the recess moves in the direction of the arrow. It will be. That is, the occurrence of the wave-like structure movement is achieved at the edge of the plate-like actuator.

  As yet another example, FIG. 6B shows a case where the plate actuator is operated while being bent. In this case, a rigid support shaft 9 is inserted, and the linear deformation element 10 is fixed. In this state, when the linear deformation element 10 is energized, the linear deformation element 10 contracts, so that the curvature of the linear deformation element 10 is schematically illustrated in FIG. It becomes smaller and a local concave region is formed on the curved surface of the plate actuator. Then, when energization is sequentially turned on / off from the linear deformation element 10 on one edge to the linear deformation element 10 on the other edge, a concave is formed in the direction of the arrow as shown in FIG. The area moves and peristalsis occurs.

  Although not shown in the drawing, a direction perpendicular to the length direction of the linear deformation element 10 in a state where one linear deformation element 10 is arranged on the plate-like actuator and the linear deformation element 10 is contracted. In this case, a deformation operation substantially similar to that shown in FIGS. 5 and 6 can be obtained.

  In order to verify the effectiveness of the present invention described above, the following experiment was conducted. It should be understood that the following examples illustrate the effectiveness of the present invention and do not limit the scope of the present invention.

An example of creating the plate actuator will be described. First, a polyurethane film having a thickness of 0.2 mm and a length of 200 mm was used as the elastic film 100, and a pocket 101 made of a polyurethane film having a length of 200 mm was fixed to the surface by thermal welding at intervals of 20 mm. On the other hand, a NiTi shape memory alloy wire 18 having a diameter d1 and a length L of 5% shrinkage and a nichrome wire 17 having a diameter d2 and enamel coating are basically arranged based on the arrangement shown in FIG. Bundled in an expanded configuration as an array. In that case, the diameter d1 and the diameter d2 may be substantially the same. When the shape memory alloy wire 18 having the output stress σi is used to obtain the required output (contraction force) W of the expansion / contraction element 10a, the required number n is:
n = 4W / (πd1 ² σi)
The number m of the nichrome wires 17 is determined by the arrangement configuration of FIG. When σi = about 600 MPa, assuming that n = 42 and m = 19, the wire diameter d1 is about 1.8 mm. Further, in the expansion element of the reference length L in which the shape memory alloy wire 18 having a tension of Si that returns the original shape from the contracted state has n pieces, the contracted state at the contraction rate ε is restored to the original shape. The spring count K is given by K = nSi / (εL). When Si = 5N, L = 200 mm, ε = 4%, and n = 42, the required spring constant is 29 × 10 ³ N / mm. Degree.

  Thus, the bundle of the shape memory alloy wire 18 and the nichrome wire 17 obtained above is a silicon tube (protective tube 14) having an inner diameter of 2 mm and a thickness of 0.5 mm, and a metal tube having an inner diameter of 3 mm and a thickness of 0.2 mm. It was inserted into the interior tube and only the metal tube was pulled out. In addition, when it is difficult to insert and remove the metal tube, an incision slit may be provided in the axial direction over the entire length of the protective tube 14. Next, a heat-shrinkable tube (sheath structure) having an inner diameter of 4 mm, in which a hole 15 a having a diameter of 2 mm is provided on the circumferential side surface near both ends of the protective tube 14 into which the bundle of the shape memory alloy wire 18 and the nichrome wire 17 is inserted. 15) was packaged, and only the ends thereof were heated and shrunk to form a seal (15b). A soft metal tube 16c such as brass having an inner diameter of 3.1 mm and a thickness of 0.5 mm was fitted to the end of the protective tube 14 containing the bundle of the shape memory alloy wire 18 and the nichrome wire 17 (shown in the figure). In the example, there are three at each end.) Further, a steel pipe body 16a having an inner diameter of 8 mm having three M3 through screw holes drilled in a zigzag cross section in a flat cross section with respect to the portion of the soft metal pipe body 16c is sheathed, and M3 is formed in the through screw hole. A hollow screw was screwed in and the tube body 16a was attached to the end of the expansion / contraction element 10a. The screws were tightened in the order of 12a, 12b, and 12c in order to prevent breakage due to disorder of orientation of the wire rods 17 and 18 and over tension (see FIG. 2A). And the support end part 11 was fixed to the pipe body 16a of one end by screw fastening.

  Next, a helical spring 16b or an elastic element in which the disc springs 20 or the elastic bodies 21 and the rigid tubes 16 are alternately arranged in series is mounted around the expansion / contraction element 10a configured as described above. With regard to the specifications of the spring, in the case of the example of this creation procedure, the aspect ratio of the elastic element is excessive, and the helical spring may be buckled. Therefore, in this example, for example, ten elastic bodies 21 made of a thermoplastic elastomer such as a block polymer of polybutylene terephthalate and polyether having a compression elastic modulus of about 240 MPa, and having an outer diameter of 7 mm and a length of 5 mm are used. An elastic element in which an FRP rigid tube 19 having an outer diameter of 7 mm and a length of 17 mm is interposed between the elastic bodies 21 is preferable (the necessary spring constant can be obtained). The expansion / contraction element to which the elastic element is attached, that is, the deformation element is inserted into the pocket 101 of the elastic film 100, and the support end portion is not fastened to the tube body 16a. Part 11 is fastened. Thereafter, the GFRP support shaft 9 is passed through the hole 11h of the support end 11, and fixed to the elastic film 100 that covers the shaft 9 by the FRP shaft support member 8 by heat welding, thereby completing the plate actuator. It was.

  In the above plate actuator, when the resistance wire 17 was repeatedly energized and interrupted at a current of 1 A at room temperature, the temperature of the deformation element repeatedly increased to about 70 ° C., The plate-shaped actuator was locally expanded and contracted at about 8 mm.

  Although the above description has been made in relation to the embodiment of the present invention, many modifications and changes can be easily made by those skilled in the art, and the present invention is limited to the embodiment exemplified above. It will be apparent that the invention is not limited and applies to various devices without departing from the inventive concept.

Claims (1)

A plate actuator,
An elastically deformable elastic plate member;
A shrinkable wire formed by bundling a shape memory alloy wire and an electric resistance wire in a predetermined arrangement, with at least one linear deformation element arranged along the surface of the elastic plate member. A wire that includes an elastic element, an elastic element that surrounds at least a portion of the elastic element, the length of both of the elastic elements being elastically deformable, and an energization means that selectively energizes the electric resistance wire A deformation element,
The elastic plate member is deformed along with the change in the length of the linear deformation element,
A plate-like actuator in which the deformation portion of the elastic plate-like member is changed along with the change in the position of the linear deformation element whose length has changed.

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