JP6046981B2 - Actuator - Google Patents

Description

  The present invention relates to an actuator that obtains a driving force by utilizing a property of contracting when a current is applied to a shape memory alloy or heated.

  Conventionally, various actuators using a heat-shrinking action of a shape memory alloy have been proposed for a moving mechanism of a portable device such as a mobile phone with a camera or a wristwatch camera, for example, a moving mechanism of a lens for focusing a camera. (For example, Patent Document 1).

In recent years, this type of actuator is not only used for the above-mentioned moving mechanism, but also has a tactile function that gives a tactile sensation when a user operates an operation unit in an electronic device such as a touch panel that does not have a tactile sensation of a pressing operation. Is also attracting attention as being available.
Against this background, various proposals have been made regarding the joint structure of shape memory alloys for performing electromechanical joining without impairing the characteristics of the shape memory alloy (for example, Patent Document 2). ).

  Here, in Patent Document 1, one or more support portions and recesses are provided on a flat support base, and the shape memory alloy wire is slackened by the recesses so as to intersect with them, and both ends are fixed. A configuration is described in which a plate-like movable element is fixed from above, and a flat plate-like movable element is arranged from above so that its protruding portion enters the slack portion of the shape memory alloy wire of the concave portion, and a bias force is applied by a spring or the like.

  Patent Document 2 is an invention relating to a joint structure between a shape memory alloy coil and an electrode. In Patent Document 2, a copper thin film and a substrate, for example, an electrode patterned on the substrate, directly formed on a position different from the direction of action of the elastic force for restoring the shape on one end side of the shape memory alloy coil In addition, a structure is described in which the electrode is electrically contacted via a contact or eutectic solder and is mechanically fixed.

Japanese Patent Laying-Open No. 2005-226456 (FIGS. 1 to 3 of Patent Document 1) JP 2004-237349 A (FIG. 1 of Patent Document 2, etc.)

  By the way, portable devices such as mobile phones and cameras, and electronic devices such as smartphones and touch panels are originally intended for portability, so that they must be small and light. Therefore, the installation space of the actuator added to such a device is further reduced.

  Therefore, this actuator needs to be small and lightweight according to the installation space. However, such a small actuator has small components and is assembled manually by one unit. There is a concern that there will be a difference in assembly man-hours between skilled and beginners, and that productivity will deteriorate in terms of production technology.

  In particular, linear shape memory alloys have a small wire diameter and are difficult to assemble, and assembly man-hours and durability vary depending on the level of skill of the assembly operator. It is regarded as a problem that a plurality of products cannot be manufactured.

  By the way, when the shape memory alloy wire is fixed with a screw, the position of the shape memory alloy wire deviates from the center of the screw, so that the position of the shape memory alloy wire fixed with the screw is displaced from a desired position. Further, when the shape memory alloy wire is tightened, loosening of the screw becomes a problem.

  Patent Document 1 does not describe the position of the shape memory alloy wire to be screwed and the looseness of the screw when the shape memory alloy wire is fixed with the screw.

  Although Patent Document 2 describes that the shape memory alloy coil is fixed or the end of the linear shape memory alloy wire is formed in an arc shape and engaged, the linear shape memory alloy wire is fixed with a screw as it is. There is no description to do. Moreover, there is no description about the position of the linear shape memory alloy wire fixed with the screw in this case.

  An object of the present invention is to provide an actuator that is easy to assemble and has high reliability.

In order to achieve the above object, the actuator according to claim 1 is a case in which a shape memory alloy, a movable element having a protruding first protruding part or a recessed hollow part, and the moving element has the first protruding part. Has a hollow portion arranged to face the first protrusion of the moving element, or arranged to face the hollow portion of the moving element when the moving element has the hollow portion. And a stator having a pair of electrodes for energizing the shape memory alloy, and the shape memory alloy is fixed to each of the electrodes from its center. by a pair of mounting members having eccentric center respectively, stretched portion is fixed to a predetermined direction.

According to the actuator of claim 1, the shape memory alloy is fixed so that the stretched portion is in a predetermined direction by the pair of attachment members fixed to each electrode and having a center eccentric from the center. Therefore, the stretched portion of the shape memory alloy fixed to the electrode can be arranged in a predetermined direction.
In addition, since the shape memory alloy is fixed to the electrode, the shape memory alloy can be reliably energized and the operation reliability is high.

The actuator according to claim 2 includes a shape memory alloy, a movable element having a convex first protrusion or a concave depression, and the movable element has a first protrusion when the movable element has the first protrusion. It has a hollow part arranged facing one projection part, or when the slider has the hollow part, it has a first projection part arranged facing the depression part of the slider around a stator, the stator, the shape memory alloy pair of electrodes for energizing is provided, the electrode, the shape memory alloy is, that the not eccentric from the center is fixed to the electrode Are fixed by a pair of attachment members each having a shape, and are disposed at positions decentered from the predetermined direction so that the stretched portion of the shape memory alloy is in a predetermined direction.

According to the actuator of the second aspect, since the electrode is disposed at an eccentric position, the stretched portion of the shape memory alloy fixed to the electrode can be disposed in a predetermined direction.
In addition, since the shape memory alloy is fixed to the electrode, the shape memory alloy can be reliably energized and the operation reliability is high.

  In the actuator according to claim 3, in the actuator according to claim 1 or 2, when the first protrusion is formed repeatedly, and the movable element has the recess, the movable element is When the stator has second protrusions that are alternately formed with respect to the first protrusions of the stator, and the stator has the recesses, the stator is the first of the mover. A second protrusion formed alternately with respect to the protrusion; and a concave groove is formed in at least one of the first protrusion and the second protrusion, and the shape memory alloy spans the groove. Has been.

  According to the actuator of the third aspect, since the shape memory alloy is disposed in the concave groove portion, it is possible to prevent the shape memory alloy from being damaged.

The actuator of claim 4, in the actuator according to any one of claims 1 to 3, before Symbol mounting member is a male screw, and contraction direction of the shape memory alloy and clamping direction of the external thread It is the same direction.

According to the actuator of the fourth aspect , since the contraction direction of the shape memory alloy and the tightening direction of the male screw for fixing the shape memory alloy are the same direction, loosening of the male screw for fixing the shape memory alloy can be prevented.

According to a fifth aspect of the present invention, in the actuator according to any one of the first to fourth aspects, a through hole or a notch is formed at a location facing the electrode of the moving element.

According to the actuator of claim 5, since a through hole or a notch is formed at a position facing the electrode of the moving element, after assembling the moving element to the stator by applying a desired tension to the shape memory alloy, The shape memory alloy can be fixed to the stator.

According to a sixth aspect of the present invention, in the actuator according to any one of the first to fourth aspects, the electrode is disposed outside the end of the moving element.

According to the actuator of claim 6 , since the electrode provided on the stator is arranged outside the end portion of the mover, after assembling the mover to the stator by applying a desired tension to the shape memory alloy, The shape memory alloy can be fixed to the stator.

  According to the present invention, it is possible to achieve an actuator that is easy to assemble and has high reliability.

(a) is a perspective view which shows the actuator of embodiment based on this invention, (b) is the sectional view on the AA line of (a), (c) is the B section enlarged view of (b). (a) is a perspective view showing a stator, (b) is a front view of the stator, (c) is a plan view of the stator, and (d) is a bottom view of the stator. (a) is a perspective view showing a movable element, (b) is a front view of the movable element, (c) is a plan view of the movable element, and (d) is a bottom view of the movable element. (a) is a front view which shows a stepped screw, (b) is a top view which shows a stepped screw. (a) is a front view which shows a compression coil spring, (b) is a top view which shows a compression coil spring. The figure which abbreviate | omitted the slider of the actuator of FIG.1 (b), and looked at the shape memory alloy wire 4 of the actuator from the C direction. The schematic diagram which shows the positional relationship of the shape memory alloy wire shown in FIG. 6, an electrode, and the external thread for fixation. The schematic diagram which shows the positional relationship of the shape memory alloy wire of the comparative example 1, an electrode, and the external thread for fixation. The schematic diagram which shows the positional relationship of the shape memory alloy wire of the comparative example 2, an electrode, and the external thread for fixation. (a)-(c) is a perspective view which shows the assembly process of an actuator. The front view which shows the assembly process of an actuator. The front view which shows the assembly process of an actuator. The front view which shows the assembly process of an actuator. (a) is a perspective view showing an actuator when the shape memory alloy wire is energized, and (b) is a perspective view showing the actuator when the energization to the shape memory alloy wire is stopped. The top view which shows the actuator of the modification 1. FIG. The top view which shows the actuator of the modification 2. FIG. FIG. 10 is a view of the shape memory alloy wire, the stator, and the like of the actuator viewed from the direction C shown in FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1A is a perspective view showing an actuator 1 according to an embodiment of the present invention, FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A, and FIG. These are the B section enlarged views of FIG.1 (b).
The actuator 1 according to the embodiment is used for, for example, one that gives a tactile sensation to the user when the user touches the touch panel when the movable element 3 is displaced as indicated by an arrow α1 in FIG. .

The actuator 1 includes a stator 2, a mover 3, and a shape memory alloy wire 4 that is arranged in a wave shape between the stator 2 and the mover 3.
The moving element 3 is provided with a plurality of moving side protrusions 3t. A plurality of fixed-side protrusions 2t are provided at positions alternately with the movement-side protrusions 3t on the stator 2 disposed to face the mover 3.

  Further, the moving side protrusion 3t of the moving element 3 is fitted into the fixed side depression 2k formed between the adjacent fixed side protruding parts 2t of the stator 2, and the moving element 3 is adjacent to the moving side protrusion 2t. The fixed-side protrusion 2t of the stator 2 is fitted into the moving-side depression 3k formed between the moving-side protrusions 3t.

  With this configuration, the shape memory alloy wire 4 is disposed between the stator 2 and the movable element 3, and the distal end portion of the movable protrusion 3 t of the movable element 3 is brought into contact with the fixed-side depression 2 k of the stator 2. At the same time, by fitting the distal end portion of the fixed-side protrusion 2t of the stator 2 to the moving-side depression 3k of the mover 3, the shape memory alloy wire 4 fixed at both ends and arranged in a wave shape is fixed to the shape memory alloy wire 4 Tension is applied.

As shown in FIG. 1 (c), one end of the moving element 3 is screwed into a female screw 2a1 in which a stepped screw 5a at one end is screwed into the stator 2, thereby forming a stepped screw 5a. The compression coil spring 6a inserted into the compression coil spring 6a is compressed and attached to the stator 2 by the elastic force F1 due to the compression deformation x1 of the compression coil spring 6a.
The compression deformation x1 of the compression coil spring 6a is represented by F1 = k1 × x1. k1 is a spring constant of the compression coil spring 6a, and F1 is an elastic force due to compression deformation of the compression coil spring 6a.

Similarly, the other end of the mover 3 is screwed into a female screw 2b1 in which the stepped screw 5b at the other end is screwed into the stator 2, so that the compression coil spring 6b is inserted into the stepped screw 5b. Is compressed and attached to the stator 2 by the elastic force F2 due to the compression deformation x2 of the compression coil spring 6b.
The compression deformation x2 of the compression coil spring 6b is represented by F2 = k2 × x2. k2 is a spring constant of the compression coil spring 6b, and F2 is an elastic force due to compression deformation of the compression coil spring 6b.

  The shape memory alloy wire 4 is attached at one end by a male screw n1 screwed to an electrode 7a fixed to the stator 2, and the other end is screwed to an electrode 7b fixed to the stator 2. It is attached by a male screw n2. Here, since the shape memory alloy wire 4 is arranged in a desired direction of the actuator 1, here, in the longitudinal direction of the center of the actuator 1, the shape memory alloy wire 4 is eccentric from the centers 7 a 0 and 7 b 0 of the cylindrical electrodes 7 a and 7 b (see FIG. 2 (c)) (see below for details).

  Further, after the movable element 3 is overlaid on the stator 2, the both ends of the movable element 3 are penetrated to positions facing the electrodes 7a and 7b, respectively, so that the shape memory alloy wire 4 can be screwed to the electrodes 7a and 7b. Holes 3c1 and 3c2 are provided therethrough.

  The shape memory alloy wire 4 attached to the electrodes 7a and 7b has a predetermined tension due to the attachment tension t1 (see FIG. 10C) upon attachment, the elastic force F1 of the compression coil spring 6a, and the elastic force F2 of the compression coil spring 6b. A tension T (see FIG. 1B) is applied.

  With the above configuration, the shape memory alloy wire 4 is brought close (close) to the stator 2 by the mover 3 by the elastic forces F1 and F2 of the compression coil springs 6a and 6b inserted through the stepped screws 5a and 5b, respectively. Is pressed.

  The actuator 1 is connected to the shape memory alloy wire 4 arranged in the shape of a wave, spanning the plurality of moving side protrusions 3t of the mover 3 and the fixed side protrusion 2t of the stator 2 via electric connection lines c1 and c2. By energizing, the shape memory alloy wire 4 contracts and becomes a shape that stretches linearly. As a result, the shape memory alloy wire 4 presses the mover 3 away from the stator 2, and the mover 3 is displaced as indicated by α1 in FIG.

Hereinafter, each component of the actuator 1 will be described in detail.
<Stator 2>
2 (a) is a perspective view showing the stator 2, FIG. 2 (b) is a front view of the stator 2, and FIG. 2 (c) is a plan view of the stator 2. FIG. 2 (d) is a bottom view of the stator 2.
The stator 2 is formed in an elongated rectangular parallelepiped shape by aluminum die casting using aluminum.

The stator 2 needs to be insulated in order to make the shape memory alloy wire 4 through which an electric current flows, and the surface is anodized. Further, since the shape memory alloy wire 4 is energized and contracted by heat, it is necessary to dissipate heat. In this respect, aluminum is preferable because it has high thermal conductivity and good heat dissipation. In addition, aluminum has the advantage of good workability. As long as the stator 2 can be insulated, a method other than the alumite treatment may be adopted.
The stator 2 has a plurality of protruding fixed-side protruding portions 2t and recessed fixed-side recessed portions 2k formed in a wave shape alternately at the center.

  A stepped hole 2a having a small diameter on one side and a large diameter on the other side is provided through one end edge of the stator 2. The small diameter portion of the stepped hole 2a has a female screw 2a1 threaded with a tap or the like. As the large diameter portion of the stepped hole 2a, an enlarged diameter hole 2a2 having a diameter larger than the female screw 2a1 is formed with a stepped portion 2a3 with respect to the female screw 2a1.

A through hole 2c1 is provided in the center side of the stepped hole 2a of the stator 2, and an electrode 7a is fixed to the through hole 2c1 by press-fitting or an adhesive. The electrode 7 a is for applying a voltage (flowing current) to the shape memory alloy wire 4.
The electrode 7a is formed in a cylindrical shape using brass or the like. An internal thread 7a1 for fixing the shape memory alloy wire 4 is screwed into the electrode 7a at a position eccentric from the center 7a0. A male screw n1 is screwed onto the female screw 7a1 of the electrode 7a, and one end of the shape memory alloy wire 4 is fixed.

  Similarly, a stepped hole 2b having a small diameter on one side and a large diameter on the other side is provided through the other end edge of the stator 2. The small diameter portion of the stepped hole 2b has a female screw 2b1 threaded with a tap or the like. As the large diameter portion of the stepped hole 2b, an enlarged diameter hole 2b2 having a diameter larger than the female screw 2b1 is formed with a stepped portion 2b3 with respect to the female screw 2b1.

A through hole 2c2 is provided in the center side of the stepped hole 2b of the stator 2, and an electrode 7b is fixed to the through hole 2c2 by press-fitting or an adhesive. The electrode 7b is for applying a voltage (flowing current) to the shape memory alloy wire 4 together with the electrode 7a.
The electrode 7b is formed in a cylindrical shape using brass or the like. An internal thread 7b1 for fixing the shape memory alloy wire 4 is screwed into the electrode 7b at a position eccentric from the center 7b0. A male screw n2 is screwed onto the female screw 7b1 of the electrode 7b, and the other end of the shape memory alloy wire 4 is fixed.

<Mover 3>
3A is a perspective view showing the movable element 3, FIG. 3B is a front view of the movable element 3, and FIG. 3C is a plan view of the movable element 3. FIG. 3 (d) is a bottom view of the movable element 3.
Since the movable element 3 is disposed so as to face the stator 2, the movable element 3 is formed in an elongated rectangular parallelepiped shape by aluminum die casting or the like using aluminum, like the stator 2.

  The mover 3 must be insulated so as to face the shape memory alloy wire 4 through which a current flows, facing the stator 2, and anodized on the surface. In addition, like the stator 2, the mover 3 is energized through the shape memory alloy wire 4 and contracted by heat, so that heat dissipation is required. In this respect, aluminum is preferable because it has high thermal conductivity and good heat dissipation. In addition, aluminum has the advantage of good workability.

The mover 3 has a central portion with a plurality of protruding movement-side projections 3t fitted into the fixed-side depression 2k of the stator 2 and a depression with which the fixed-side projection 2t of the stator 2 is fitted. The moving side depressions 3k are formed in a wave shape alternately. Here, the height of the projecting moving projection 3t of the movable element 3 is formed higher than the depth of the stationary recess 2k of the stator 2, and serves as a stopper for the stator 2 of the movable element 3. Yes.
At the center in the width direction of each moving side protrusion 3t of the mover 3, a groove 3m formed lower than the height of the moving side protrusion 3t is provided.

A stepped hole 3 a is provided through one end edge of the movable element 3. In the stepped hole 3a, a small diameter hole 3a1 is formed on one side facing the stator 2, and a large diameter hole 3a2 larger in diameter than the small diameter hole 3a1 is formed on the other side with respect to the small diameter hole 3a1. Attached portion 3a3 is formed.
On the center side of the stepped hole 3a of the mover 3, when the shape memory alloy wire 4 is fixed to the electrode 7a of the stator 2, the through hole 3c1 having a larger diameter than the male screw n1 through which the fixing male screw n1 is inserted. Is penetrated.

  Similarly, a stepped hole 3 b is provided through the other end edge of the moving element 3. In the stepped hole 3b, a small diameter hole 3b1 is formed on one side facing the stator 2, and a large diameter hole 3b2 larger in diameter than the small diameter hole 3b1 is formed on the other side with respect to the small diameter hole 3b1. Attached portion 3b3 is formed.

On the center side of the stepped hole 3b of the mover 3, when the shape memory alloy wire 4 is fixed to the electrode 7b of the stator 2, the through hole 3c2 having a diameter larger than that of the male screw n2 through which the fixing male screw n2 is inserted. Is penetrated.
Since the through holes 3c1, 3c2 are screwed with the fixing male screws n1, n2 at positions eccentric from the centers 7a0, 7b0 of the electrodes 7a, 7b (see FIG. 2C), the male screws n1, n2 The through holes 3c1 and 3c2 may be formed at positions eccentric from the centers 7a0 and 7b0 of the electrodes 7a and 7b.

  In addition, although the case where the stator 2 and the mover 3 are each made of aluminum is illustrated, if other conditions such as insulation, heat dissipation, workability (mass productivity) are satisfied, other materials other than aluminum May be used. Of course, a method other than the alumite treatment may be adopted as long as the stator 2 and the mover 3 can be insulated.

<Stepped screws 5a, 5b>
FIG. 4A is a front view showing the stepped screws 5a and 5b, and FIG. 4B is a plan view showing the stepped screws 5a and 5b.
The stepped screw 5a includes a male screw portion 5a1 having a small diameter, an enlarged diameter portion 5a2 having a diameter larger than that of the male screw portion 5a1, and a screw head 5a3 having a minus (−) hole into which a minus driver is inserted. Yes.

Similarly, the stepped screw 5b includes a male screw portion 5b1 having a small diameter, an enlarged diameter portion 5b2 having a diameter larger than that of the male screw portion 5b1, and a screw head 5b3 having a minus (−) hole into which a minus driver is inserted. Have.
The stepped screws 5a and 5b are manufactured by cutting, die, rolling or the like.

<Compression coil springs 6a and 6b>
Fig.5 (a) is a front view which shows the compression coil springs 6a and 6b, and FIG.5 (b) is a top view which shows the compression coil springs 6a and 6b.
The compression coil spring 6a has an inner diameter s1 larger than the outer diameter of the enlarged diameter portion 5a2 of the stepped screw 5a, and has an outer diameter s2 larger than the inner diameter of the half through hole 2a2 of the stepped hole 2a of the stator 2. Yes. Further, as shown in FIG. 1C, the compression coil spring 6a has a larger diameter than the small diameter hole 3a1 of the stepped hole 3a of the moving element 3, and the stepped portion 3a3 of the stepped hole 3a of the moving element 3 And abutted against the screw head 5a3 of the stepped screw 5a.

The compression coil spring 6a is attached to the enlarged diameter portion 5a2 against the screw head 5a3 of the stepped screw 5a, and the male threaded portion 5a1 of the stepped screw 5a is connected to the stepped hole of the stator 2 as shown in FIG. It is screwed onto the female screw 2a1 of 2a. Thereby, the elastic force due to the compression of the compression coil spring 6a works so that the movable element 3 and the stator 2 are brought close to (in close contact with).
At this time, the spring constant k1 of the compression coil spring 6a is selected so that a predetermined elastic force F1 is obtained by the compression deformation x1 of the compression coil spring 6a.

  Similarly, the compression coil spring 6b has an inner diameter s3 larger than the outer diameter of the enlarged diameter portion 5b2 of the stepped screw 5b, and an outer diameter s4 larger than the inner diameter of the half-through hole 2b2 of the stepped hole 2b of the stator 2. Have. Further, as shown in FIG. 1C, the compression coil spring 6b has a larger diameter than the small diameter hole 3b1 of the stepped hole 3b of the moving element 3, and the stepped portion 3b3 of the stepped hole 3b of the moving element 3 And abutted against the screw head 5b3 of the stepped screw 5b.

The compression coil spring 6b is mounted on the diameter-expanded portion 5b2 against the screw head 5b3 of the stepped screw 5b, and the male screw portion 5b1 of the stepped screw 5b is connected to the stepped hole of the stator 2 as shown in FIG. It is screwed onto the 2b female screw 2b1. Thereby, the elastic force due to the compression of the compression coil spring 6b works so that the moving element 3 and the stator 2 are close (close).
At this time, the spring constant k2 of the compression coil spring 6b is selected so that a predetermined elastic force F2 is obtained by the compression deformation x2 of the compression coil spring 6b.

<Shape memory alloy wire 4>
As the shape memory alloy wire 4, for example, a wire rod having a thin wire diameter is used.

<Features of actuator 1>
A characteristic part of the actuator 1 according to the embodiment is a fixing method of the shape memory alloy wire 4 and the electrodes 7 a and 7 b provided on the stator 2.
As described above, when the both ends of the shape memory alloy wire 4 are fixed to the electrodes 7a and 7b provided on the stator 2, the actuator 1 has the male screw n1 at positions eccentric from the centers 7a0 and 7b0 of the electrodes 7a and 7b, respectively. , N2 is fixed.
Further, through holes 3c1 and 3c2 are formed at positions facing the respective electrodes 7a and 7b of the movable element 3, respectively.

FIG. 6 is a view of the shape memory alloy wire 4 of the actuator 1 as viewed from the C direction with the mover 3 of the actuator 1 of FIG.
FIG. 7 is a schematic diagram showing the positional relationship between the shape memory alloy wire 4, the electrodes 7a and 7b, and the fixing male screws n1 and n2 shown in FIG.

  As shown in FIG. 7, the male screws n1 and n2 screwed to the electrodes 7a and 7b provided on the stator 2 are provided with their centers decentered from the centers 7a0 and 7b0 of the electrodes 7a and 7b. These are arranged along the longitudinal direction of the stator 2. Specifically, the shape memory alloy wire 4 is disposed so as to be positioned at the center of the groove 3m (see FIGS. 3A and 3C) of each moving side protrusion 3t formed on the moving element 3. .

The shape memory alloy wire 4 is wound around the fixing male screws n1 and n2 and screwed (screwed) to the pair of electrodes 7a and 7b. When the shape memory alloy wire 4 contracts, the male screw The contraction force of the shape memory alloy wire 4 is applied in the direction in which n1 and n2 are tightened.
Thus, the male screws n1 and n2 are loosened so that the shape memory alloy wire 4 does not come off from the electrodes 7a and 7b.

FIG. 8 is a schematic diagram showing the positional relationship between the shape memory alloy wire 4, the electrodes 7a and 7b, and the fixing male screws n1 and n2 of the first comparative example.
The reason why the fixing male screws n1 and n2 are eccentric with respect to the centers 7a0 and 7b0 of the electrodes 7a and 7b, respectively, will be described with reference to FIGS.

For example, as shown in FIG. 8 of the comparative example, when the shape memory alloy wire 4 is fixed by screwing (screwing) concentrically with the electrodes 7 a and 7 b, the shape memory alloy wire 4 extends in the longitudinal direction of the actuator 1. On the other hand, it tilts with respect to the concave groove 3m (see FIG. 3 (a)) formed in the longitudinal direction of the movable element 3, and crawls diagonally.
In this case, when the actuator 1 is assembled or actually used, one end of the shape memory alloy wire 4 comes into contact with the groove 3m and an excessive external force is applied, and the shape memory alloy wire 4 may be damaged.

  Therefore, in the actuator 1 of the embodiment, as shown in FIG. 7, the shape memory alloy wire 4 is screwed (screwed) at a position eccentric from the centers 7a0 and 7b0 of the electrodes 7a and 7b, thereby shape memory. The alloy wire 4 runs parallel to or along the concave groove 3m of the mover 3.

FIG. 9 is a schematic diagram showing the positional relationship between the shape memory alloy wire 4, the electrodes 7a and 7b, and the fixing male screws n1 and n2 of the second comparative example.
Further, as shown in FIG. 9 of Comparative Example 2, when the shape memory alloy wire 4 is screwed (screwed) to the electrodes 7a and 7b with male screws n1 and n2, the tightening direction of the male screws n1 and n2 (arrows in FIG. 9) The direction of contraction (the direction of arrow β1 in FIG. 9) when the shape memory alloy wire 4 is energized is in the opposite direction.

In this case, every time the shape memory alloy wire 4 is energized, a force is applied to the male screws n1 and n2 in the direction of loosening the screws (in the direction of arrow β1 in FIG. 9). Therefore, the male screws n1 and n2 fastened to the electrodes 7a and 7b are easily loosened.
Therefore, in the actuator 1 of the embodiment, as shown in FIG. 7, the shape memory alloy wire 4 is screwed (screwed) to the electrodes 7a, 7b with male screws n1, n2 (arrow α2 in FIG. 7) and the shape. The direction in which the memory alloy wire 4 contracts when energized (the direction of the arrow β1 in FIG. 7) is the same direction.

  As a result, each time the shape memory alloy wire 4 is energized, force is applied to the male screws n1 and n2 in the direction in which the screws are tightened (in the direction of arrow β1 in FIG. 7). Therefore, it is possible to prevent the male screws n1 and n2 fastened to the electrodes 7a and 7b from being tightened and loosened.

  As features other than the above, as shown in FIGS. 1 (a) and 1 (b), movement is achieved by opening through-holes 3c1 and 3c2 at positions of the mover 3 at positions facing the electrodes 7a and 7b of the stator 2. Even after the child 3 and the stator 2 are assembled and fixed, the shape memory alloy wire 4 can be fixed to the electrodes 7a, 7b by screwing (screwing) with male screws n1, n2.

  As a result, when the actuator 1 is assembled, the shape memory alloy wire 4 can be sandwiched between the stator 2 and the mover 3 and the shape memory alloy wire 4 can be assembled while applying a certain initial stress T.

<Other features of actuator 1>
The other characteristic part of the actuator 1 is the method of fixing the moving element 3 and the stator 2.
In the actuator 1, the stepped screws 5a and 5b and the cylindrical compression coil springs 6a and 6b connect the moving element 3 and the stator 2 with the elastic force of the compression coil springs 6a and 6b with the shape memory alloy wire 4 interposed therebetween. The shape memory alloy wire 4 is fixed and pulled with a constant tension.

Further, in the actuator 1, the height of the moving side protrusion 3 t of the mover 3 is formed to be higher than the depth of the fixed side recess 2 k of the stator 2, thereby reliably moving the moving side protrusion 3 t of the mover 3. Is configured to abut against the fixed-side depression 2k of the stator 2.
Further, by forming the recessed groove 3m of the moving side protrusion 3t of the moving element 3 deeper than the wire diameter, width or thickness of the shape memory alloy wire 4, the shape memory alloy wire 4 can be It has a structure that is less likely to fall off from the outside of 1.

On the other hand, the shape memory alloy wire 4 needs to be used by generating a certain initial stress.
Therefore, the initial stress of the shape memory alloy wire 4 is controlled by the tension when the shape memory alloy wire 4 is attached to the electrodes 7a and 7b.

In the operation of the actuator 1, the mover 3 moves away from the stator 2 (see FIG. 1 (a)). To realize this, a cylindrical compression coil spring is used by using stepped screws 5a and 5b. The mover 3 is fixed to the stator 2 by the elastic force of 6a and 6b.
In other words, the actuator 1 is assembled using the stepped screws 5a and 5b and the cylindrical compression coil springs 6a and 6b with the shape memory alloy wire 4 sandwiched between the mover 3 and the stator 2.

The initial tension T of the shape memory alloy wire 4 is the tension t1 applied when the shape memory alloy wire 4 is attached, the spring constants k1 and k2 of the two compression coil springs 6a and 6b, and the elastic forces F1 and F2 due to the displacements x1 and x2. Generate a certain force based on.
That is, the tension T1 of the shape memory alloy wire 4 is determined by the tension t1 applied when the shape memory alloy wire 4 is attached and the spring constants k1 and k2 of the compression coil springs 6a and 6b and the elastic forces F1 and F2 due to the displacements x1 and x2. Structure to control.

  With such a structure, the movement of the actuator 1 having the mover 3 and the stator 2 is not hindered, and the mover 3 and the stator 2 are provided with stepped screws 5a and 5b and a compression coil spring. Since it is fixed by 6a, 6b, it is possible to realize a structure that is not easily disassembled by vibration and / or impact and is not easily disassembled.

<Assembly method of actuator 1>
Next, a method for assembling the actuator 1 will be described.
10A to 10C, 11, 12, and 13 are a perspective view and a front view showing the assembly process of the actuator 1.

(1) First, as shown in FIG. 10 (a), the electrodes 7a and 7b are respectively fixed to the pair of through holes 2c1 and 2c2 formed at both ends of the stator 2 by press-fitting or using an adhesive. To do.
The electrodes 7a and 7b are fixed to the stator 2 by screwing female screws into the through holes 2c1 and 2c2, and by screwing male screws around the outer periphery of the electrodes 7a and 7b. 2 may be screwed, and the method of fixing the electrodes 7a and 7b to the stator 2 can be arbitrarily selected.

(2) Subsequently, as shown in FIG. 10B, one end of the shape memory alloy wire 4 is engaged with the fixing male screw n1, and the fixing male screw n1 is fixed to the stator 2. The other end of the shape memory alloy wire 4 is attached to the electrode 7a by being screwed onto the female screw 7a1 of the other electrode 7a.

(3) Then, as shown in FIG. 10 (c), the shape memory alloy wire 4 is hung over the recessed groove 3m formed on the moving side projection 3t of the moving element 3 with a predetermined tension t1. Then, alignment is performed such that the tip of the moving side protrusion 3t of the moving element 3 comes into contact with the fixed side recess 2k of the stator 2. Then, the shape memory alloy wire 4 is placed along the groove 3m of the moving side protrusion 3t of the mover 3 and the fixed side protrusion 2t and the fixed side depression 2k of the stator 2, so that the stator 2 and the mover 3 are aligned. And pinch.

(4) Subsequently, as shown in FIG. 11, compression coil springs are provided in the stepped holes 3 a, 3 b of the mounting holes formed in the movable body 3 and the stepped holes 2 a, 2 b of the stator 2 opposed to the mounting holes, respectively. The stepped screws 5a and 5b to which 6a and 6b are attached are accommodated.

(5) The stepped screws 5a and 5b to which the compression coil springs 6a and 6b are attached are fixed to the enlarged diameter portions 5a2 and 5b2 of the stepped screws 5a and 5b, respectively, as shown in FIG. 1 (c). Screw onto the female threads 2a1 and 2b1 until they contact the stepped portions 2a3 and 2b3 of the stepped holes 2a and 2b of the child 2. Thereby, the mover 3 is attached to the stator 2 by the elastic forces F1 and F2 due to the compression deformations x1 and x2 of the compression coil springs 6a and 6b.

(6) Subsequently, as shown in FIG. 12, the other end of the shape memory alloy wire 4 sandwiched between the stator 2 and the mover 3 is fixed to the fixing male screw n2 and the through hole 3c2 of the mover 3. Is inserted into the female screw 7b1 of the other electrode 7b fixed to the stator 2, and the other end of the shape memory alloy wire 4 is attached to the other electrode 7b.
Thereby, the tension t1 at the time of passing and the force by the elastic forces F1 and F2 of the compression coil springs 6a and 6b are applied to the shape memory alloy wire 4 as a predetermined tension T.

(7) Finally, the wire rod at the other end of the excess shape memory alloy wire 4 is cut. Then, as shown in FIG. 13, the electrical connection lines c <b> 1 and c <b> 2 are respectively connected to the electrodes 7 a and 7 b protruding below the stator 2 by soldering or the like, thereby completing the actuator 1.

<Operation method of actuator 1>
Next, an operation method of the actuator 1 will be described.
(1) A power drive circuit (not shown) is connected to both ends of the shape memory alloy wire 4 of the actuator 1 shown in FIG. 13 via electrical connection lines c1 and c2 connected to the electrodes 7a and 7b. When this power supply driving circuit is turned on, a current flows from the electrical connection lines c1 and c2 to the shape memory alloy wire 4, and the shape memory alloy wire 4 is energized.

(2) By this energization, the shape memory alloy wire 4 of the actuator 1 generates heat and contracts, and changes from a wavy shape to a linear shape. Due to the shape change of the shape memory alloy wire 4, the mover 3 is lifted away from the stator 2 against the elastic force of the compression coil springs 6a and 6b, as indicated by an arrow α3 in FIG.

  14A is a perspective view showing the actuator 1 when the shape memory alloy wire 4 is energized, and FIG. 14B is the actuator 1 when the energization of the shape memory alloy wire 4 is stopped. FIG.

(3) When the energization from the power source drive circuit is completed, the shape memory alloy wire 4 is de-energized and dissipated, and the shape memory alloy wire 4 returns to its original shape, and the mover 3 has compression coil springs 6a and 6b. As shown by an arrow α4 in FIG. 14B, the original state of being pressed against the stator 2 is restored.

As described above, the actuator 1 of the present embodiment has the following effects.
(1) With respect to the centers 7a0 and 7b0 of the electrodes 7a and 7b, the male screws n1 and n2 for fixing the shape memory alloy wire 4 are arranged eccentrically and shifted so that the shape memory alloy wire 4 It can arrange | position along the groove part 3m.
Therefore, the shape memory alloy wire 4 can be reliably disposed in the groove portion 3m of the movable element 3, and the shape memory alloy wire 4 can be prevented from being displaced or dropped from the groove portion 3m. Further, since the shape memory alloy wire 4 is surely stored in the groove portion 3m of the movable element 3, it is avoided that the shape memory alloy wire 4 hits the groove portion 3m and the shape memory alloy wire 4 is crushed and damaged by overload. it can.

(2) Since the shape memory alloy wire 4 is surely stored in the groove 3m of the moving element 3, the assemblability is good, the assembling cost is low, and the productivity is high.

(3) Since the shape memory alloy wire 4 is fixed to the electrodes 7a and 7b, the shape memory alloy wire 4 can be reliably energized, and the operation reliability of the actuator 1 is high.

(4) Since the screw tightening (screwing) direction of the male screws n1 and n2 for fixing the shape memory alloy wire 4 and the contraction direction of the shape memory alloy wire 4 are the same direction, the shape memory alloy wire 4 is energized. Each time it contracts, the fixing male screws n1 and n2 are tightened, and the male screws n1 and n2 are prevented from loosening.

(5) By providing through-holes 3c1 and 3c2 in the mover 3, after the mover 3 and the stator 2 are assembled, the electrodes 7a and 7b are respectively applied to the shape memory alloy wire 4 while applying a constant tension T. Since it can be screwed, it is excellent in assemblability.
From the above, it is possible to realize the actuator 1 that is easy to assemble and has high reliability.

Next, a modified example will be described.
<< Modification 1 >>
FIG. 15 is a plan view showing the actuator 11 of the first modification.
The actuator 11 of Modification 1 is formed with notches 13c1 and 13c2 instead of the through holes 3c1 and 3c2 of the movable element 3 through which the fixing male screws n1 and n2 are inserted. Since other configurations are the same as those of the embodiment, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the actuator 11 of the first modification, the through hole 2c1 of the stator 2 to which the electrode 7a is fixed and the stepped hole 2a are arranged side by side in the short direction of the actuator 1 and the electrode 7b is fixed to be fixed. The through hole 2 c 2 of the child 2 and the stepped hole 2 b are arranged side by side in the short direction of the actuator 1.

  That is, the electrode 7a fixed to the through hole 2c1 of the stator 2 and the stepped screw 5a inserted through the movable element 3 and screwed to the stator 2 are arranged side by side in the short direction. Similarly, an electrode 7b fixed to the through hole 2c2 of the stator 2 and a stepped screw 5b inserted through the movable element 3 and screwed to the stator 2 are arranged side by side in the lateral direction.

Thus, by providing the movable element 3 with the cutouts 13c1 and 13c2, the movable element 3 and the stator 2 are assembled, and then fixed to the electrodes 7a and 7b while applying a constant tension T to the shape memory alloy wire 4. Since the male screws n1 and n2 for use can be respectively screwed, the assemblability is excellent.
Further, by arranging the stepped screws 5 a and 5 b at the end of the actuator 11, the through holes 3 c 1 and 3 c 2 of the embodiment can be replaced with the notches 13 c 1 and 13 c 2 of the moving element 3, and the design freedom of the moving element 3 Will improve.

<< Modification 2 >>
FIG. 16 is a plan view showing the actuator 21 of the second modification.
The actuator 21 of Modification 2 has a configuration in which the electrodes 7a and 7b are arranged outside the stepped screws 5a and 5b. Since other configurations are the same as those of the embodiment, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the actuator 21 of the second modification, the through holes 2c1 of the stator 2 to which the electrodes 7a are fixed are arranged outside the stepped holes 2a so that the stepped screws 5a and 5b do not interfere with the shape memory alloy wire 4. ing. Similarly, the through hole 2c2 of the stator 2 to which the electrode 7b is fixed is disposed outside the stepped hole 2b.

  With this configuration, the electrode 7 a fixed to the through-hole 2 c 1 of the stator 2 is arranged outside the stepped screw 5 a that is inserted through the mover 3 and screwed to the stator 2. Similarly, the electrode 7b fixed to the through hole 2c2 of the stator 2 is disposed outside the stepped screw 5b that is inserted through the movable element 3 and screwed to the stator 2.

According to the second modification, it is not necessary to form through holes or notches for screwing the fixing male screws n1 and n2 in the moving element 3 by shortening the length of the moving element 3.
Further, by arranging the electrodes 7a and 7b outside the stepped screws 5a and 5b, a constant tension T is applied to the shape memory alloy wire 4 after the mover 3 and the stator 2 are assembled. However, the electrodes 7a and 7b can be screwed to each other, so that the assemblability is excellent.

In addition, since the length of the mover 3 can be shortened, the raw material cost is reduced and the cost can be reduced.
Furthermore, since it is not necessary to form a through-hole and a notch in the moving element 3, the shape of the moving element 3 is simple, and the manufacturing cost and assembly cost of the moving element 3 are reduced.

<< Modification 3 >>
FIG. 17 is a view of the shape memory alloy wire 4 and the stator 2 of the actuator 31 as viewed from the direction C shown in FIG. 1B, omitting the mover 3 of FIG. is there.
The actuator 31 of Modification 3 is arranged with the positions of the electrodes 7a and 7b decentered with respect to the desired direction so that the shape memory alloy wire 4 is in the desired direction (the longitudinal direction of the actuator 31 in FIG. 17). doing.
By doing so, the fixing male screws n1 and n2 are configured without being eccentric from the centers 7a0 and 7b0 of the electrodes 7a and 7b, respectively. Since other configurations are the same as those of the embodiment, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

In the actuator 31 of the third modification, in the configuration of the actuator 1 of the embodiment, the electrode 7a is fixed so that the shape memory alloy wire 4 is in a desired direction in the center of the groove 3 (the longitudinal direction of the actuator 31 in FIG. 17). A through hole 2c1 of the stator 2 to be fixed and a through hole 2c2 of the stator 2 to which the electrode 7b is fixed are arranged.
Further, the female screw 7a1 of the electrode 7a to which the fixing male screw n1 is screwed is screwed concentrically with the center 7a0 of the electrode 7a. The female screw 7b1 of the electrode 7b to which the fixing male screw n2 is screwed is screwed concentrically with the center 7b0 of the electrode 7b.

  Then, one end of the shape memory alloy wire 4 is fixed by screwing the male screw n1 into the female screw 7a1 of the electrode 7a fixed to the through hole 2c1 of the stator 2. Further, the other end of the shape memory alloy wire 4 is fixed by screwing the male screw n2 into the female screw 7b1 of the electrode 7b fixed to the through hole 2c2 of the stator 2.

Thus, the shape memory alloy wire 4 is in a desired direction (the longitudinal direction of the actuator 31 in FIG. 17) without decentering the fixing male screws n1 and n2 with respect to the centers 7a0 and 7b0 of the electrodes 7a and 7b. Can be arranged as follows.
Note that the configurations of the first and second modifications can also be applied to the third modification.

<< Other Modifications >>
(1) In the first to third modified examples, when the shape memory alloy wire 4 is attached to the electrodes 7a and 7b, the case where the fixing male screws n1 and n2 are used is exemplified. The shape memory alloy wire 4 may be attached to the electrodes 7a and 7b by pressing a pin having a portion into an attachment hole formed in the electrodes 7a and 7b and fixing it with an adhesive or the like. As described above, a part (attachment member) for attaching the shape memory alloy wire 4 to the electrodes 7a and 7b may be other than the external thread.

(2) In the embodiment and the modification, the case where the through hole, the cutout, and the space of the moving element 3 are arranged above the electrodes 7a and 7b is exemplified. However, the electrode 7a that fixes the shape memory alloy wire 4 lastly. 7b may have a through hole, a notch, or a space. If a through hole, a notch, or a space is arranged above the electrodes 7a and 7b, the direction of the mover 3 is lost, and the handleability and assembly workability of the mover 3 are improved. .
Therefore, in terms of handling and workability, as illustrated, it is preferable to arrange the through hole, notch, and space of the moving element 3 above the electrodes 7a and 7b.

(3) In the above embodiment, the case where the linear shape memory alloy wire 4 is stretched over the hollow groove 3m formed on the moving side protrusion 3t of the moving element 3 is illustrated, but the present invention is not limited to this. In addition, a recessed groove portion may be formed in the fixed-side protrusion 2t of the stator 2. In this case, in order to make it easier to transmit the contraction force of the shape memory alloy wire 4 to the moving element 3, it is preferable that the fixed-side protrusion 2t is higher than the moving-side protrusion 3t. Or you may form the hollow-shaped groove part 3m in both the movement side and fixed side protrusion part 3t, 2t.

(4) In the above-described embodiment, the moving-side protrusion 3t, the groove 3m, and the moving-side depression 3 are formed on the moving element 3, and the fixed-side protruding part 2t and the fixing-side depression 2k are formed on the stator 2. As illustrated, the stator 2 is formed with a projecting movement-side projection 3t, a depression-shaped groove 3m, and a depression-like movement-side depression 3k. The projection 3 has a projection-like stationary-side projection 2t and a depression. The fixed-side depression 2k may be formed. That is, the shape of the protrusion and the groove may be switched between the moving element 3 and the stator 2 and applied.
In this case as well, a recessed groove portion may be formed in the fixed-side protruding portion 2t. Moreover, you may form the recessed groove part 3m in both the movement side and fixed side protrusion parts 3t and 2t similarly to the above.

(5) The shape memory alloy wire 4 may be a strip-shaped wire, and the shape of the shape memory alloy wire 4 is not limited as long as it has the effect of the present invention.

(6) In the above embodiment, the compression coil springs 6a and 6b are exemplified as the elastic member. However, any elastic member other than the compression coil spring, such as other springs or rubber, may be used as long as it is an elastic member that generates an elastic force by being compressed and deformed. May be.

(7) In the above-described embodiment, the configuration in which the stepped screws 5a and 5b are brought into contact with the stator 2 and screwed is illustrated. However, the stator 2 and the mover 3 are made elastic such as compression coil springs 6a and 6b. Since it may be attached with the elastic force of the member, the configuration of the stator 2 and the mover 3 may be changed, and the stepped screws 5a and 5b may be brought into contact with the mover 3 and screwed.

(8) In the above-described embodiment and modification, the shapes of the stator 2 and the mover 3 have been described by exemplifying elongate shapes. However, other rectangular parallelepipeds and columnar shapes may be used, and the effects of the present invention. The shape of the stator 2 and the mover 3 can be arbitrarily selected.

(9) In the above embodiment, the stepped screws 5a and 5b are exemplified as the attaching means. However, if the attaching means is stepped, it may be fixed by press-fitting or adhesive without being fixed by screwing. A stepped pin other than the stepped screws 5a and 5b may be used.

  Further, if the stator 2 and the mover 3 are attached by elastic force and fixed to either the stator 2 or the mover 3, attachments other than the stepped screws 5a and 5b and the stepped pins are provided. Means may be applied. For example, an elastic member such as the compression coil springs 6a and 6b is pressed so that the stator 2 and the mover 3 are in close contact with each other, and press-fitting, adhesive, screwing, etc. into either the stator 2 or the mover 3 A fixing member other than a stepped screw and a stepped pin may be used.

(10) Although various configurations have been described in the above-described embodiments and modifications, the configurations may be arbitrarily selected and combined.

  Although various embodiments and modifications of the present invention have been described above, the description is intended to be exemplary. Accordingly, various modifications and changes can be made within the scope of the present invention. That is, the present invention can be changed without departing from the spirit of the invention.

1, 11, 21, 31 Actuator 2 Stator 2k Fixed side indentation (indentation)
2t Fixed side protrusion (second protrusion)
DESCRIPTION OF SYMBOLS 3 Mover 3c1, 3c2 Through-hole 3m Groove part 3t 1st projection part 4 Shape memory alloy wire (shape memory alloy)
7a, 7b electrode 7a0, 7b0 center of electrode 7a1 female screw (mounting hole, screw hole)
7b1 female screw (mounting hole, screw hole)
13c1, 13c2 Notch n1, n2 Male thread (attachment member)

Claims (6)

A shape memory alloy,
A mover having a protruding first protrusion or a hollowed portion;
When the moving element has the first protrusion, the moving element has a hollow portion disposed to face the first protruding portion of the moving element, or when the moving element has the hollow portion. A stator having a first protrusion disposed opposite to the recess of the movable element,
The stator is provided with a pair of electrodes for energizing the shape memory alloy,
Wherein the shape memory alloy actuator, characterized in that said a pair of mounting members each having the eccentric center from the center is fixed to the respective electrodes, stretched portion is fixed to a predetermined direction . A shape memory alloy,
A mover having a protruding first protrusion or a hollowed portion;
When the moving element has the first protrusion, the moving element has a hollow portion disposed to face the first protruding portion of the moving element, or when the moving element has the hollow portion. A stator having a first protrusion disposed opposite to the recess of the movable element,
The stator is provided with a pair of electrodes for energizing the shape memory alloy,
The electrode, wherein the shape memory alloy is, by a pair of mounting members having a center that the not eccentric from the center is fixed to the electrodes, respectively, is fixed, stretched portion of said shape memory alloy is given The actuator is arranged at a position eccentric from the predetermined direction so as to be in a direction. The first protrusion is formed repeatedly a plurality of times,
When the mover has the hollow portion, the mover has second protrusions that are alternately formed with respect to the first protrusions of the stator,
When the stator has the recess, the stator has second protrusions that are alternately formed with respect to the first protrusions of the mover,
The actuator according to claim 1 or 2, wherein a concave groove is formed in at least one of the first protrusion and the second protrusion, and the shape memory alloy is stretched over the groove. Before Symbol attachment member is a male thread,
The actuator according to any one of claims 1 to 3, wherein a contraction direction of the shape memory alloy and a tightening direction of the male screw are the same direction. The actuator according to any one of claims 1 to 4 , wherein a through hole or a notch is formed at a location facing the electrode of the moving element. The actuator according to any one of claims 1 to 4 , wherein the electrode is disposed outside an end portion of the moving element.

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