JP2005086981A - Polymer actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise the reliability of a clamped part when ends of a plurality of conductive polymer tubes of a polymer actuator are bundled and clamped. <P>SOLUTION: The polymer actuator includes a conductive polymer tube 13 constituted by covering a coil member with a conductive polymer material expanded and contracted by applying a voltage, and an actuator element 14 constituted by bundling ends of a plurality of the conductive polymer tubes 13 to surround the outer periphery of a core material 15, clamping the outer peripheries of the ends of the plurality of the bundled conductive polymer tues 15 by a clamping ring 18 to clamp the core material 15, and fixing the clamped part by a synthetic resin. The plurality of the conductive polymer tubes 13 are not only bundled in an order shape to be realized to be accurately fixed to an output transmission member, but also a twist or a bent of the conductive polymer tube 13 is prevented at its clamped part to raise the reliability of the clamped part, and an output generated from the conductive polymer tube 13 can be effectively transmitted. <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, since the output which one electroconductive polymer tube can generate | occur | produce is small, it is possible to obtain a high output polymer actuator by couple | bonding many electroconductive polymer tubes in parallel. In this case, simply bundling and fixing the ends of a large number of conductive polymer tubes is low in reliability, and the conductive polymer tubes are loosened or tilted at the fixed portions so that the output is effectively transmitted to the output transmission member. There is a problem that transmission cannot be performed, or the shape of the ends of many bundled conductive polymer tubes collapses and cannot be correctly fixed to the output transmission member.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to increase the reliability of the fastening portions when the ends of a plurality of conductive polymer tubes of a polymer actuator are bundled and fastened.

  In order to achieve the above object, according to the invention described in claim 1, a conductive polymer tube is formed by covering a coil member with a conductive polymer material that expands and contracts when a voltage is applied. The ends of the conductive polymer tube are bundled so as to surround the outer periphery of the core material, and the outer periphery of the ends of the plurality of bundled conductive polymer tubes are fastened with a fastening ring to be fastened between the core material, A polymer actuator is proposed in which the fastening portion is hardened with a synthetic resin.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, an electrode wire for energizing each conductive polymer tube is embedded in the synthetic resin. An actuator is proposed.

  According to the third aspect of the invention, in addition to the configuration of the first or second aspect, the spherical bearing through which the bundled conductive polymer tube passes is attached so as to contact the fastening ring, and the output is transmitted. A polymer actuator is proposed in which the spherical bearing is supported on a spherical seat formed on a member.

  In addition, the lower base member 44 and the upper base member 46 of an Example respond | correspond to the output transmission member of this invention.

  According to the configuration of claim 1, the ends of the plurality of conductive polymer tubes are bundled around the core material, and the outer periphery thereof is fastened and fastened with the fastening ring, so that the plurality of conductive polymer tubes are in an orderly shape. In addition to being able to bind to the output transmission member with high accuracy, the conductive polymer tube can be prevented from being twisted or bent at the fastening portion to improve the reliability of the fastening portion, and the output generated by the conductive polymer tube can be increased. Can communicate effectively. In addition, by solidifying the fastening portion with a synthetic resin, the conductive polymer tube can be prevented from loosening and coming off, and the reliability can be further enhanced.

  According to the configuration of the second aspect, since the electrode wire for energizing each conductive polymer tube is embedded in the synthetic resin, it is possible to prevent the occurrence of disconnection, short circuit, contact failure, etc. of the electrode wire and reliability. Can be further increased.

  According to the configuration of the third aspect, since the bundled conductive polymer tube is passed through the inside of the spherical bearing in contact with the fastening ring, and this spherical bearing is supported by the spherical seat portion formed on the output transmission member, The contraction load of the polymer tube can be reliably transmitted from the fastening ring to the output transmission member via the spherical bearing. Moreover, by positioning the spherical bearing with respect to the spherical seat by the tension of the conductive polymer tube, it is possible to prevent the bending load from being applied to the end of the conductive polymer tube and increase the output transmission efficiency. .

  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 8 show an 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. 3 is a line 3-3 in FIG. FIG. 4 is a front view of a vehicle suspension device, FIG. 5 is a longitudinal sectional view of a vehicle height adjusting actuator, FIG. 6 is a sectional view taken along line 6-6 in FIG. 5, and FIG. FIG. 8 and FIG. 8 are explanatory diagrams of operations corresponding to FIG.

  In this embodiment, a polymer actuator is applied to a vehicle height adjustment device for an automobile suspension. First, the structure of an actuator element used in the polymer actuator will be described with reference to FIGS.

  The conductive polymer material used for the polymer actuator 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.

  Before the fastening ring 18 is caulked, six conductive polymer tubes 13 are inserted in advance into a through hole 19a that penetrates the center of the hemispherical spherical bearing 19. Further, when the 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.

  FIG. 4 shows an automobile suspension device. A knuckle 32 that rotatably supports a wheel 31 is supported by a vehicle body 34 via a suspension arm 33 so as to be movable up and down. A coil is provided between the suspension arm 33 and the vehicle body 34. The spring 35 and the vehicle height adjusting actuator 36 are arranged coaxially and in series. The damper 37 that connects the knuckle 32 and the vehicle body 34 includes a cylinder 38 that is supported at the lower end by the knuckle 32 and a piston rod 39 that protrudes upward from the cylinder 38 and is supported by the vehicle body 34. Therefore, the impact input from the road surface to the wheel 31 is buffered by the coil spring 35 and attenuated by the damper 37, and the vehicle height is adjusted by the expansion and contraction of the vehicle height adjusting actuator 36.

  Next, the structure of the vehicle height adjusting actuator 36 will be described with reference to FIGS.

  The vehicle height adjusting actuator 36 includes a bottomed cylindrical lower casing 41 fixed to the vehicle body 34, and an upper casing 43 having the same diameter connected to the upper end of the lower casing 41 via a retractable boot 42. . A large-diameter piston 45 projects upward from a lower base member 44 fixed to the bottom surface of the lower casing 41, and a large-diameter cylinder 48 formed coaxially from an upper base member 46 fixed to the bottom surface of the upper casing 43 faces downward. The large-diameter piston 45 is slidably fitted into the large-diameter cylinder 48.

  The lower end of the small diameter piston 49 slidably fitted to the small diameter cylinder 47 penetrating the lower base member 44 and the large diameter piston 45 is supported on the upper surface of the spring seat 40 that supports the upper end of the coil spring 35. The large-diameter cylinder 48, the upper base member 46, and the upper casing 43 are separated from the large-diameter piston 45, the lower base member 44, and the lower casing 41 by a return spring 50 disposed between the large-diameter piston 45 and the large-diameter cylinder 48. It is biased upward. The first oil chamber 51 defined by the large diameter piston 45 and the large diameter cylinder 48 and the second oil chamber 52 defined by the small diameter cylinder 47 and the small diameter piston 49 are in communication with each other. Oil chambers 51 and 52 are filled with oil.

  The lower base member 44 and the upper base member 46 are connected by a plurality of (20 in the embodiment) actuator elements 14 arranged at predetermined intervals in the circumferential direction. An electrolyte chamber 53 defined by a lower base member 44, a lower casing 41, a boot 42, an upper casing 43, an upper base member 46, a large diameter piston 45 and a large diameter cylinder 48 is filled with an electrolyte solution. The actuator elements 14 accommodated in the chamber 53 are in contact with the electrolytic solution.

  As shown in detail in FIG. 7, in order to fix each actuator element 14 to the upper base plate 46, one annular groove 46a, 20 spherical seat portions 46b,. Through-holes 46c are formed. In a state where the six conductive polymer tubes 13 of the actuator element 14 pass through the through-hole 46c loosely, the spherical bearing 19 is slidably fitted into the spherical seat portion 46b. Then, by applying tension to the conductive polymer tubes 13..., The composite melted in the annular groove 46a in a state where the actuator element 14 extends linearly due to the slip between the spherical bearing 19 and the spherical seat 46b. The resin 54 is poured and cured.

  The structure for fixing the upper end of each actuator element 14 to the upper base member 46 has been described above, but the structure for fixing the lower end to the lower base member 44 is also the same. However, the difference is that the electrode wire 20 is not provided at the lower end of the actuator element 14.

  An annular first electrode plate 55 and an annular second electrode plate 56 are concentrically fixed to the upper surface of the upper base plate 46. Twenty electrode wires 20 extending upward from the twenty actuator elements 14 are connected to the first electrode plate 55 disposed on the radially outer side. Further, four platinum electrode rods 57 arranged at intervals of 90 ° extend from the second electrode plate 56 arranged on the inner side in the radial direction into the electrolyte chamber 53, and the lower ends thereof are large-diameter cylinders. It is supported by a support member 58 fixed to the outer periphery of 48.

  Next, the operation of the first embodiment having the above configuration will be described.

  The first electrode plate 55 connected to the conductive polymer tubes 13 of the actuator elements 14 through the electrode wires 20 is connected to the negative electrode of the battery and is immersed in the electrolyte in the electrolyte chamber 53. When the second electrode plate 56 connected to the rods 57 is connected to the positive electrode of the battery, the negative ions absorbed in the conductive polymer tubes 13 are discharged into the electrolytic solution, so that the conductive polymer tubes 13 are discharged. ... contracts in the axial direction. Then, as shown in FIG. 8, the actuator elements 14 contract in the axial direction, and the upper base member 46 is pulled down with respect to the lower base member 44, so that the large diameter cylinder 48 is relative to the large diameter piston 45. When the oil is lowered to push out the oil in the first oil chamber 51 to the second oil chamber 52, the small-diameter piston 49 smaller in diameter than the large-diameter piston 45 protrudes downward from the lower base member 44 with a large stroke, and the upper base member 46 The distance from the upper surface to the lower end of the small-diameter piston 49 increases. As a result, the suspension arm 33 is pushed down with respect to the vehicle body 34, so that the vehicle height is adjusted in the increasing direction.

  Further, when each actuator element 14 contracts, the contraction load is transmitted from the fastening ring 18 to the lower base member 44 and the upper base member 46 via the spherical bearing 19, so that the contraction load is efficiently transmitted with high reliability. can do.

  Conversely, when the first electrode plate 55 is connected to the positive electrode of the battery and the second electrode plate 56 is connected to the negative electrode of the battery, the negative ions in the electrolyte are absorbed by the conductive polymer tube 13. Thus, the conductive polymer tubes 13, that is, the actuator elements 14 extend in the axial direction. Although the actuator elements 14 only transmit a tensile load and cannot transmit a compressive load, as shown in FIG. 5, the actuator elements 14 are large with respect to the large-diameter piston 45 by the elastic force of the return spring 50 housed in the first oil chamber 51. As the diameter cylinder 48 rises relatively and the volume of the first oil chamber 51 increases, the small-diameter piston 49 having a smaller diameter than the large-diameter piston 45 lowers with a large stroke to reduce the volume of the second oil chamber 52. Retreating upward from the base member 44, the distance from the upper surface of the upper base member 46 to the lower end of the small diameter piston 49 decreases. As a result, the suspension arm 33 rises with respect to the vehicle body 34, so that the vehicle height is adjusted in the decreasing direction.

  When the upper base member 46 moves up and down relative to the lower base member 44, the volume of the electrolyte chamber 53 increases or decreases. However, the increase or decrease of the volume is caused by elastic deformation of the boot 42 connecting the lower casing 41 and the upper casing 43. Can be absorbed.

  As described above, in this embodiment, the polymer actuator having high responsiveness is applied to the vehicle height adjusting actuator 36, so that the vehicle height is quicker than that of the conventional vehicle height adjusting actuator 36 that employs hydraulic or pneumatic pressure. Not only can adjustment be made, but large-scale equipment such as a hydraulic pump, an air compressor, and an accumulator can eliminate the need for equipment and contribute to cost and space reduction. Further, since the polymer actuator can be operated at an extremely low voltage of 1V to 3V, the power consumption is small and no noise is generated, so that the vehicle height can be adjusted quietly.

  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 fastening, the six conductive polymer tubes 13 can be bundled in an orderly shape and fixed to the lower base member 44 and the upper base member 46 with high accuracy. Moreover, since the conductive polymer tubes 13 are prevented from being twisted or bent at the fastening portion, the output can be effectively transmitted to the lower base member 44 and the upper base member 46. Further, by solidifying the fastening portion with the synthetic resin 54, it is possible not only to prevent looseness and disconnection of the conductive polymer tubes 13.. By embedding in, it can prevent generation | occurrence | production of a disconnection, a short circuit, contact failure, etc. of the electrode wire 20 ..., and can improve reliability further.

  Further, when each actuator element 14 is fixed to the lower base member 44 and the upper base member 46, both end portions of the actuator element 14 are correctly aligned in the axial direction by sliding between the spherical bearing 19 and the spherical seat portions 44b and 46b. The problem that the actuator element 14 bends in the vicinity of the end portion and a sufficient output cannot be transmitted to the lower base member 44 and the upper base member 46 can be solved.

  As described above, the first oil chamber 51 defined by the large-diameter piston 45 and the large-diameter cylinder 48 and the second oil chamber 52 defined by the small-diameter piston 49 and the small-diameter cylinder 47 are communicated with each other, thereby providing a plurality of actuators. The volume of the first oil chamber 51 and the volume of the second oil chamber 52 are changed by relatively moving the large-diameter piston 45 and the large-diameter cylinder 48 by expansion and contraction of the elements 14. Since the relative movement of the small-diameter piston 49 and the small-diameter cylinder 47 is extracted as an output, the output stroke can be arbitrarily increased in the vehicle height adjusting actuator 36 by changing the diameter ratio of the large-diameter piston 45 and the small-diameter piston 49.

  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, although the actuator element 14 is applied to the vehicle height adjusting actuator 36 in the embodiment, the polymer actuator of the present invention can be applied to any other application.

  Further, 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.

Diagram showing the structure of a conductive polymer tube Overall view of actuator element 3-3 enlarged sectional view of FIG. Front view of automobile suspension system Longitudinal sectional view of vehicle height adjustment actuator 6-6 sectional view of FIG. 7 enlarged view of FIG. Action explanatory diagram corresponding to FIG.

Explanation of symbols

11 Coil member 12 Conductive polymer material 13 Conductive polymer tube 15 Core material 18 Fastening ring 19 Spherical bearing 20 Electrode wire 44 Lower base member (output transmission member)
44b Spherical seat 46 Upper base member (output transmission member)
46b Spherical seat 54 Synthetic resin

Claims (3)

  A conductive polymer tube (13) is formed by covering the coil member (11) with a conductive polymer material (12) that expands and contracts when voltage is applied, and ends of the plurality of conductive polymer tubes (13) are formed. The core material (15) is bundled so as to surround the outer periphery, and the outer periphery of the end portions of the bundled conductive polymer tubes (13) is fastened with the fastening ring (18) to the space between the core material (15). A polymer actuator characterized in that the fastening portion is fastened with a synthetic resin (54).   The polymer actuator according to claim 1, characterized in that an electrode wire (20) for energizing each conductive polymer tube (13) is embedded in the synthetic resin (54). A spherical bearing (19) through which the bundled conductive polymer tube (13) passes is attached so as to be in contact with the fastening ring (18), and the spherical seat portion (44b, 46b) formed on the output transmission member (44, 46). The polymer actuator according to claim 1 or 2, wherein the spherical bearing (19) is supported on the polymer actuator.

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