JP2005081487A - High polymer actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high polymer actuator, generating output and stroke of enough magnitude both in the extending direction and in the contracting direction. <P>SOLUTION: An actuator element 14 formed of conductive high polymer material extended and contracted by application of voltage is wound round the outer periphery of two plate springs 26, both end parts of which are pivoted on a first casing 21 and a second casing 22 relatively moved in the direction of an axis L by hinges 27, the middle part thereof being curved in the direction of separating from the axis L. The plate springs 26 are deformed in the direction of approaching the axis L by contraction of the actuator element 14 to separate the first and second casings 21, 22 from each other, and the plate springs 26 are deformed in the direction of separating from the axis L by resilient force of the plate springs 16 due to extension of the actuator element 14 to make the first and second casings 21, 22 approach each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polymer actuator using a conductive polymer material that expands and contracts when a voltage is applied.

Such a polymer actuator is known from Patent Document 1 below. The example shown in FIG. 7 of this Patent Document 1 is to form a conductive polymer tube by covering the outer periphery of a coil spring with a conductive polymer material with an electrolyte portion interposed therebetween, and this conductive polymer tube. By applying a voltage between the conductive polymer material and the electrolyte part, the conductive polymer tube expands and contracts in the direction along the axis of the coil spring to exhibit the function as a polymer actuator.
JP 2000-133854 A

  By the way, the expansion / contraction rate of the conductive polymer material is only about 15%, and there is a problem that a sufficient stroke cannot be obtained when the output of the polymer actuator is taken out as a reciprocating motion. In addition, the conductive polymer tube receives a tensile load at the time of contraction and a compressive load at the time of expansion, but the elongated conductive polymer tube has a problem of buckling because it cannot support a large compressive load. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polymer actuator capable of generating a sufficiently large output and stroke in both the extension direction and the contraction direction.

  In order to achieve the above object, according to the first aspect of the present invention, the first output member and the second output member that are relatively movable in the axial direction, and the first and second output members whose end portions are close to the axial line. It is composed of a plurality of driving force conversion members connected to the output member and energized by a resilient force so that the intermediate portion is curved away from the axis, and a conductive polymer material that expands and contracts when a voltage is applied. An actuator element wound around the plurality of driving force conversion members, and the first and second output members are mutually deformed by deforming the plurality of driving force conversion members in a direction approaching the axis by contraction of the actuator element. The first output member and the second output member are moved closer to each other by causing the plurality of driving force conversion members to be deformed in a direction away from the axis by the elastic force by extending the actuator element. Polymer actuator that is proposed.

  According to the invention described in claim 2, in addition to the structure of claim 1, the driving force conversion member is constituted by a leaf spring and generates the elastic force by its own elasticity. A molecular actuator is proposed.

  The first and second casings 21 and 22 of the embodiment correspond to the first and second output members of the present invention, and the leaf spring 26 and the link member 34 of the embodiment correspond to the driving force conversion member of the present invention. .

  According to the configuration of the first aspect, the both ends of the plurality of driving force conversion members biased by the elastic force so that the intermediate portion curves in a direction away from the axis are connected to the first and second output members. Since the actuator element made of a conductive polymer material that expands and contracts when voltage is applied is wound around the plurality of driving force conversion members, the plurality of driving force conversion members approach the axis when the actuator element is contracted The first and second output members can be separated from each other by deforming in the direction, and when the actuator element is extended, the plurality of driving force conversion members are deformed in the direction away from the axis by the elastic force. 1. The 2nd output member can be made to approach mutually.

  By interposing the driving force converting member between the actuator element and the first and second output members, the expansion and contraction amount of the actuator element can be expanded and a large stroke can be given to the first and second output members, In addition, since a sufficiently long actuator element is wound around the outer periphery of the plurality of driving force conversion members, the contraction force of the actuator element can be effectively transmitted to the driving force conversion member to generate a large output. Furthermore, since the driving force conversion member is biased by the elastic force when the actuator element is extended, the first and second output members can be brought close to each other while preventing the actuator element from buckling.

  According to the configuration of the second aspect, since the driving force converting member made of a leaf spring generates the elastic force by its own elasticity, a special elastic member is not required and the number of parts can be reduced.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 6 show a first embodiment of the present invention. FIG. 1 is a view showing a structure of a conductive polymer tube, FIG. 2 is an overall view of an actuator element, and FIG. 4 is an enlarged sectional view, FIG. 4 is a vertical sectional view of the polymer actuator, FIG. 5 is a horizontal sectional view of the polymer actuator, and FIG. 6 is an operation explanatory view corresponding to FIG.

  First, the structure of an actuator element used for a polymer actuator will be described with reference to FIGS.

  The conductive polymer material used for the polymer actuator A is composed of, for example, one or a mixture of polypyrrole, polyaniline, polythiophene and derivatives thereof. When a conductive polymer material is immersed in an electrolytic solution and a positive potential and a negative potential are applied to the conductive polymer material and the electrolytic solution, respectively, negative ions in the electrolytic solution are absorbed and expanded by the conductive polymer material. When a negative potential and a positive potential are applied to the conductive polymer material and the electrolytic solution, negative ions in the electrolytic solution are released from the conductive polymer material and contract. At this time, the conductive polymer material can generate an expansion ratio of about 15% and an output of about 22 MPa by applying a voltage of 1 V to 3 V, and it can be stretched with a response time of about 0.2 seconds. And the contraction state can be switched.

  As shown in FIG. 1, a conductive polymer tube 13 is formed by covering a coil member 11 obtained by winding a thin metal wire in a coil shape with a conductive polymer material 12. By integrating the conductive polymer material 12 with the coil member 11, the expansion and contraction in the axial direction can be promoted by suppressing the expansion and contraction in the radial direction. Since there is a limit to the output generated by one conductive polymer tube 13, a plurality of them are bundled to constitute the actuator element 14.

  As shown in FIGS. 2 and 3, the actuator element 14 of the present embodiment is formed by bundling six conductive polymer tubes 13 and integrally fastening them at both ends thereof. That is, at the end of the actuator element 14, the outer periphery of a cylindrical core material 15 formed of a hard material such as metal is covered with a cushioning material 16 such as rubber, and a plurality of (in the embodiment, six) conductive materials are provided on the outer periphery. After bundling the ends of the conductive polymer tubes 13..., A cylindrical fastening ring 18 formed of metal is fitted to the outer periphery of the ends through a buffer material 17 such as rubber. And by crimping the fastening ring 18 radially inward from the state of FIG. 3 (B) to the state of FIG. 3 (A) at six locations between the adjacent conductive polymer tubes 13. Six conductive polymer tubes 13 are fastened between the fastening ring 18.

  Further, when the one fastening ring 18 is caulked, one electrode wire 20 extending inward is electrically connected to any one of the conductive polymer tubes 13. Since the six conductive polymer tubes 13 are in contact with each other, a voltage can be applied to the six conductive polymer tubes 13 via one electrode wire 20.

  Next, the structure of the polymer actuator A using the actuator element 14 will be described with reference to FIGS.

  A cylindrical member having a bottomed cylindrical first casing 21 and a second casing 22 arranged on the axis L are slidably fitted, and are slidably supported on the inner peripheral surface of the second casing 22. 23 is connected to the first and second casings 21 and 22 by bellows-like boots 24 and 24, so that the electrolyte chamber 25 filled with the electrolyte is defined. Two rectangular leaf springs 26 that are curved in an arc are combined, and both end portions thereof are pivotally supported on the inner surfaces of the end plates 21a and 22a of the first and second casings 21 and 22 via hinges 27. At this time, the intermediate portions of the leaf springs 26 and 26 are curved in directions away from each other across the axis L.

  Both end portions of the actuator element 14 are fixed to both end portions of the cylindrical member 23, and an intermediate portion of the actuator element 14 is spirally wound around the outer periphery of the two leaf springs 26, 26. At this time, a notch for engaging the actuator element 14 is formed on the side edges of the leaf springs 26 and 26 so that the actuator element 14 does not slide in the direction of the axis L. The electrode rod 28 extending into the electrolyte chamber 25 and the electrode wire 20 extending from the actuator element 14 are connected to the battery through the first casing 21.

  Thus, when the negative electrode of the battery is connected to the actuator element 14 via the electrode wire 20 and the positive electrode of the battery is connected to the electrolytic solution via the electrode rod 28, the conductive polymer tube 13 ... enters the electrolytic solution. When the negative ions are released, the conductive polymer tubes 13, that is, the actuator elements 14 are contracted. Then, as shown in FIG. 6, the two leaf springs 26, 26, which are bent in the direction in which the actuator element 14 contracts and separates from each other, are deformed in a direction approaching each other, and the bay extreme is reduced. By approaching the straight line, the distance between both ends of the leaf springs 26 and 26 increases, and the first and second casings 21 and 22 are driven to extend in the axis L direction. At this time, the boots 24 and 24 that define a part of the electrolyte chamber 25 are stretched in the direction of the axis L, and at the same time bend in the direction of approaching the axis L, so that the volume of the electrolyte chamber 25 is kept constant. .

  On the contrary, when the positive electrode of the battery is connected to the actuator element 14 via the electrode wire 20 and the negative electrode of the battery is connected to the electrolyte solution via the electrode rod 28, the negative ions in the electrolyte solution become conductive polymer tubes. The actuator elements 14 are extended by being absorbed by 13. When the actuator element 14 is extended, the two leaf springs 26 and 26 are restored to their original curved shape by their own elasticity, whereby the distance between both ends of the leaf springs 26 and 26 is reduced and the first and second casings 21 are reduced. , 22 are driven to contract in the direction of the axis L. At this time, the boots 24 and 24 that define a part of the electrolyte chamber 25 contract in the direction of the axis L and bend in a direction away from the axis L, so that the volume of the electrolyte chamber 25 is kept constant.

  As described above, even if the expansion / contraction ratio of the actuator element 14 itself is small, the entire length is increased by winding the actuator element 14 around the outer periphery of the leaf springs 26, 26, and the curved leaf springs 26, 26 are linearly formed. By extending the length, an expansion / contraction stroke is generated in the polymer actuator A. Therefore, a large stroke can be generated while using the actuator element 14 having a limited contraction rate.

  Further, the actuator elements 14... Transmit only the tensile load and cannot transmit the compressive load. However, the leaf springs 26 and 26 return to the original curved shape by their own elasticity, so that the actuator elements 14 do not buckle. The molecular actuator A can be driven to contract. Furthermore, since the polymer actuator A can be operated at an extremely low voltage of 1V to 3V, the power consumption is small and noise is not generated, so that it can be operated silently.

  The actuator element 14 itself has the following excellent characteristics. That is, when the ends of the six conductive polymer tubes 13... Are bundled, the outer periphery of the conductive polymer tubes 13. Since they are fastened together by tightening, the six conductive polymer tubes 13 can be bundled in an orderly shape and fixed to the cylindrical member 23 with high accuracy.

  Next, a second embodiment of the present invention will be described with reference to FIGS.

  In the first embodiment, a pair of leaf springs 26 that are curved in an arc shape are used as power conversion members. In the second embodiment, however, the center portion is composed of two link plates 32 and 33 pivotally supported by a hinge 31. These link members 34 are used, and both end portions of each link member 34 are pivotally supported by end plates 21a and 22a of the first and second casings 21 and 22 via hinges 27 and 27, respectively. Both link members 34 and 34 are formed in a rhombus shape as a whole, and their intermediate portions are biased by the compression coil spring 35 in a direction away from each other. Other configurations of the second embodiment are the same as those of the first embodiment described above.

  According to the second embodiment, the first and second casings 21 and 22 are separated by flattening the link members 34 and 34 while compressing the compression coil spring 35 by contraction of the actuator element 14, so that the actuator element 14 The first and second casings 21 and 22 approach each other by returning the link members 34 and 34 to the original shape by the elastic force of the compression coil spring 35 due to the extension of. Also according to the second embodiment, it is possible to achieve the same operation and effect as the first embodiment described above.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the six conductive polymer tubes 13 are bundled to constitute the actuator element 14, but the number of the conductive polymer tubes 13 to be bundled is arbitrary.

  In the first embodiment, the two leaf springs 26 are combined, but three or more leaf springs 26 may be arranged so as to surround the axis L.

  In the first embodiment, the two leaf springs 26 and 26 curved in an arc are combined in a spindle shape, but the two leaf springs 26 and 26 in which a flat plate is bent at a predetermined angle at the center are combined in a diamond shape. May be.

Diagram showing the structure of a conductive polymer tube Overall view of actuator element 3-3 enlarged sectional view of FIG. Vertical section of polymer actuator Horizontal section of polymer actuator Action explanatory diagram corresponding to FIG. Vertical sectional view of the polymer actuator according to the second embodiment Action explanation diagram corresponding to FIG.

Explanation of symbols

12 Conductive polymer material 14 Actuator element 21 First casing (first output member)
22 Second casing (second output member 26 leaf spring (driving force conversion member)
34 Link member (driving force conversion member)
L axis

Claims (2)

A first output member (21) and a second output member (22) capable of relative movement in the direction of the axis (L);
Both ends are connected to the first and second output members (21, 22) in the vicinity of the axis (L), and the intermediate portion is biased by a resilient force so as to bend in a direction away from the axis (L). A plurality of driving force conversion members (26, 34);
An actuator element (14) composed of a conductive polymer material (12) that expands and contracts when a voltage is applied, and is wound around a plurality of driving force conversion members (26, 34);
With
While the actuator element (14) contracts, the plurality of driving force conversion members (26, 34) are deformed in a direction approaching the axis (L) to separate the first and second output members (21, 22) from each other. The first and second output members (21, 22) are formed by deforming the plurality of driving force converting members (26, 34) away from the axis (L) by the elastic force by the extension of the actuator element (14). Polymer actuators characterized in that they are close to each other. The polymer actuator according to claim 1, wherein the driving force conversion member (26) is formed of a leaf spring and generates the elastic force by its own elasticity.

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