JP7653869B2 - Actuator - Google Patents

Description

The present invention relates to an actuator.

The following Patent Document 1 discloses an actuator that includes a mounting member with a coil, and a mover that is supported on the mounting member via an elastic support and displaces when electricity is passed through the coil. The elastic support described in this document includes a mounting member-side fixed part that is fixed to the mounting member, a mover-side fixed part that is fixed to the mover, and a deformation part that connects the mounting member-side fixed part and the mover-side fixed part. The deformation part flexes and deforms to allow the mover to be displaced relative to the mounting member.

International Publication No. 2020/184439

From the standpoint of ensuring the durability of the elastic support, it is preferable to ensure the length of the deformation portion, but the configuration described in Patent Document 1 leaves room for improvement in this regard.

The present invention takes the above facts into consideration and aims to obtain an actuator that can ensure the length of the deformation part.

The actuator of the first aspect comprises an attachment member including a coil, a movable element having a magnet arranged opposite to the coil and displaced relative to the attachment member when current is applied to the coil, and an elastic support having an attachment member-side fixed part fixed to the attachment member, a movable element-side fixed part fixed to the movable element, and a deformation part connecting the attachment member-side fixed part and the movable element-side fixed part, the deformation part having an arm extending between the movable element-side fixed part to the attachment member-side fixed part, and when the displacement direction in which the movable element is displaced is defined as the ±Z direction, and the directions perpendicular to each other among the directions in a plane perpendicular to the ±Z direction are defined as the X direction and the Y direction, the arm extends from the movable element-side fixed part side to the outside in the X direction. The movable member includes a first X-direction outer extension portion that extends from the first X-direction outer extension portion toward the fixed portion on the mounting member side, a first folded portion that is formed closer to the fixed portion on the mounting member side than the first X-direction outer extension portion and whose extension direction is folded back from the outside in the X-direction to the inside in the X-direction, an X-direction inner extension portion that extends inward in the X-direction from the first folded portion, a second folded portion that is formed closer to the fixed portion on the movable member side than the X-direction inner extension portion and whose extension direction is folded back from the inside in the X-direction to the outside in the X-direction, a second X-direction outer extension portion that extends outward in the X-direction from the second folded portion, a third folded portion that is formed closer to the fixed portion on the mounting member side than the second X-direction outer extension portion and whose extension direction is folded back from the outside in the X-direction to the outside in the Y-direction, and a Y-direction outer extension portion that extends outward in the Y-direction from the third folded portion and is connected to the fixed portion on the mounting member side.

In the actuator of the first aspect, when electricity is applied to the coil, the movable element having the magnet is displaced relative to the mounting member. Also, when the movable element is displaced relative to the mounting member, the deformation portion of the elastic support is flexed and deformed. Here, the arm of the deformation portion of the elastic support has a first X-direction outer extension portion, a first turn-back portion, an X-direction inner extension portion, a second turn-back portion, a second X-direction outer extension portion, a third turn-back portion, and a Y-direction outer extension portion. This allows the length of the arm of the deformation portion to be longer than a configuration without the third turn-back portion and the Y-direction outer extension portion. By increasing the length of the arm, the resonant frequency can be lowered. This allows the load on the elastic support to be reduced, the load applied to the fixed portion to be reduced, and metal fatigue to be less likely to occur.

The actuator of the second aspect is the actuator of the first aspect, in which the elastic support comprises four of the mounting member side fixed parts and four of the arms, two of the four arms are disposed on one side in the X direction with respect to the movable member side fixed parts and are formed symmetrically in the Y direction, and the other two of the four arms are disposed on the other side in the X direction with respect to the movable member side fixed parts and are formed symmetrically in the Y direction.

In the actuator of the second embodiment, two of the four arms are disposed on one side in the X direction relative to the fixed part on the movable member side and are formed symmetrically in the Y direction. The other two of the four arms are disposed on the other side in the X direction relative to the fixed part on the movable member side and are formed symmetrically in the Y direction. This makes it possible to increase the ratio of the length of the four arms to the area occupied by the elastic support when viewed from the Z direction.

The actuator of the third aspect is the actuator of the second aspect, in which the deformation portion is formed in a plate shape, and includes a Y-direction connection portion that connects in the Y direction the third folded portions of the two arms arranged on one side in the X direction relative to the movable member fixed portion, and a Y-direction connection portion that connects in the Y direction the third folded portions of the two arms arranged on the other side in the X direction relative to the movable member fixed portion.

The actuator of the third aspect is provided with a Y-direction connection part that connects the third folded part of the arm in the Y direction, and as a result, the flatness of the deformation part formed in a plate shape can be improved compared to a configuration without a Y-direction connection part. In addition, because the flatness of the deformation part is maintained, individual differences between parts are less likely to occur, and the variation in the spring constant (variation in hardness and stiffness) can be suppressed.

The actuator of the fourth aspect is an actuator of any one of the first to third aspects, in which the mounting member-side fixed portion is fixed to the mounting member via a welded portion so as not to be separated from the mounting member.

In the actuator of the fourth aspect, the mounting member side fixed portion is fixed to the mounting member via a welded portion so as not to be separated from the mounting member. This makes it possible to suppress changes in the contact state between the mounting member side fixed portion and the mounting member at the fixed portion. This makes it possible to suppress a shift in the resonance point of the elastic support body that would occur due to a change in the contact state between the two.

The actuator of the present invention has the excellent effect of ensuring the length of the deformation portion.

FIG. FIG. 2 is an exploded perspective view showing the actuator. FIG. FIG. 3B is a plan view corresponding to FIG. 3A, in which the cover member is omitted. 4 is a cross-sectional view showing a cross section of the actuator taken along line 4-4 shown in FIG. 3A. FIG. FIG. 11 is a perspective view showing another type of elastic support; FIG. 11 is a plan view showing another embodiment of the elastic support body. FIG. 11 is a plan view showing another embodiment of the elastic support body.

The actuator 10 according to the embodiment of the present invention will be described with reference to Figures 1 to 5. Note that the arrow X direction, arrow Y direction, and arrow Z direction shown in the figures indicate the respective directions of the actuator 10. In the following description, the +Z direction shown in each figure is referred to as the upward direction, and the -Z direction is referred to as the downward direction. However, this is a directional concept based on the actuator, and does not limit the mounting posture of the actuator. In addition, an axis parallel to the Z direction and passing through the center of gravity of the mover 14 described later is referred to as the center of gravity axis AX of the mover 14. In addition, the direction approaching the center of gravity axis AX of the mover 14 in the X direction is referred to as the inner side in the X direction, and the direction moving away from it is referred to as the outer side in the X direction, and in the Y direction, the direction approaching the center of gravity axis AX of the mover 14 is referred to as the inner side in the Y direction, and the direction moving away from it is referred to as the outer side in the Y direction. In addition, the +X direction is referred to as one side in the X direction, the -X direction is referred to as the other side in the X direction, the +Y direction is referred to as one side in the Y direction, the -Y direction is referred to as the other side in the Y direction, the +Z direction is referred to as one side in the Z direction, and the -Z direction is referred to as the other side in the Z direction.

As shown in Figs. 1 to 4, the actuator 10 of this embodiment is an actuator that is attached to a display unit such as a liquid crystal panel configured as a touch panel, or to various controllers, and vibrates the display unit or controller. By controlling the flow of electricity to this actuator 10, it is possible to give various tactile sensations to the fingers of a user touching the touch panel, controller, etc.

As shown in Figures 1 and 2, the actuator 10 comprises a mounting member 12 that is attached to an object to be mounted, such as the display unit of a tablet terminal, a mover 14 that is displaced relative to the mounting member 12, and an elastic support 16 that elastically supports the mover 14 relative to the mounting member 12. The actuator 10 also comprises two cushioning materials 18 that dampen the vibration of the elastic support 16, and two cover members 20 that are attached to the elastic support 16 and cover one side of the cushioning material 18.

(Configuration of mounting member 12)
As shown in FIG. 2, the mounting member 12 includes a box-shaped frame 22, a coil 24 formed by winding a conductive electric wire in a circular shape, an adhesive sheet 26 for mounting, and a pair of terminals 28.

The frame 22 is formed, for example, using a resin material, and is formed in a box shape with one side in the Z direction open. The frame 22 has a bottom wall portion 30 formed in a rectangular shape with the Z direction as the thickness direction, the X direction as the longitudinal direction when viewed from the Z direction, and the Y direction as the short side direction. As shown in Figures 2 and 4, a circular opening 32 penetrating in the Z direction is formed in the center of the bottom wall portion 30 in the X and Y directions. The frame 22 also has an annular rib 34 protruding in the Z direction from the edge of the opening 32 of the bottom wall portion 30.

The frame 22 also has a pair of first side wall portions 36 that rise from the ends of the bottom wall portion 30 on one side in the X direction and the other side toward one side in the Z direction, and a pair of second side wall portions 38 that rise from the ends of the bottom wall portion 30 on one side in the Y direction and the other side toward one side in the Z direction.

As shown in FIG. 2, two pedestal portions 40 formed in a rectangular block shape protrude toward one side in the Z direction from the ends of one side and the other side in the Y direction of the end faces on one side in the Z direction of the pair of first side wall portions 36. In addition, from the two pedestal portions 40, a welding boss portion 42 (welded portion) formed in a cylindrical shape before welding, which will be described later, protrudes toward one side in the Z direction.

The frame 22 also has a central protrusion 44 that protrudes from the center in the Y direction of one first side wall 36 toward the other first side wall 36. The frame 22 also has a central protrusion 44 that protrudes from the center in the Y direction of the other first side wall 36 toward the one first side wall 36. In this embodiment, these central protrusions 44 have a plurality of recesses 44A that are open on one side in the Z direction. Here, the end face on one side in the Z direction of one central protrusion 44 and the Y direction central portion of the end face on one side in the Z direction of one first side wall 36 are cushioning material attachment surfaces 46 to which one cushioning material 18 described later is attached. In addition, the end face on one side in the Z direction of the other central protrusion 44 and the Y direction central portion of the end face on one side in the Z direction of one first side wall 36 are cushioning material attachment surfaces 46 to which the other cushioning material 18 described later is attached.

(Configuration of coil 24)
2 and 4, the coil 24 is formed by winding a conductive electric wire in a circular shape around a coil base 48 that is formed in a circular shape with the Z direction as its axial direction. The coil 24 is supported by the frame 22 together with the coil base 48. In addition, when the coil 24 is supported by the frame 22 together with the coil base 48, the coil 24 abuts against the rib 34 of the frame 22. A pair of end portions 24A of the coil 24 are connected to a pair of terminals 28 supported by the frame 22, respectively.

(Configuration of mounting adhesive sheet 26)
The mounting adhesive sheet 26 is a member for mounting the actuator 10 to an object to which the actuator 10 is to be mounted. The mounting adhesive sheet 26 is an adhesive sheet with adhesive surfaces on both sides. The mounting adhesive sheet 26 is adhered to the lower surface side of the bottom wall portion 30 of the frame 22. The mounting adhesive sheet 26 has a circular opening 26A formed therein, which corresponds to the opening 32 formed in the bottom wall portion 30 of the frame 22.

(Configuration of the mover 14)
The mover 14 includes a yoke 50, a magnet 52, and a pole piece 54.

The yoke 50 is made of a soft magnetic material. The yoke 50 has a top wall portion 50A formed in a disk shape with the thickness direction in the Z direction, and a peripheral wall portion 50B extending downward from the outer periphery of the top wall portion 50A. The yoke 50 also has a fixed convex portion 50C that protrudes from the center of the surface on one side in the Z direction of the top wall portion 50A toward one side in the Z direction.

The magnet 52 is formed in a disk shape with its axial direction in the Z direction. The magnet 52 is fixed to the underside of the top wall portion 50A of the yoke 50 while being disposed inside the peripheral wall portion 50B of the yoke 50.

The pole piece 54 is made of a soft magnetic material. This pole piece 54 is formed in a disk shape with its axial direction in the Z direction, and is fixed to the underside of the magnet 52.

In the mover 14 described above, a magnetic circuit is formed by the yoke 50, the magnet 52, and the pole piece 54. A space is formed between the magnet 52 and the pole piece 54 and the peripheral wall portion 50B of the yoke 50, and the coil 24 is disposed in this space. The lower end of the peripheral wall portion 50B of the yoke 50 is flush with the lower end of the pole piece 54. Note that the pole piece 54 may have a height that protrudes downward beyond the lower end of the peripheral wall portion 50B.

(Configuration of Elastic Support 16)
3 and 5, the elastic support 16 is formed, for example, by using a metal plate formed into a plate shape (flat shape). In the free state (when no external force is acting), the elastic support 16 is entirely formed into a plate shape along a direction perpendicular to the Z direction.

The elastic support 16 is partially fixed to the mounting member 12 and partially fixed to the movable element 14. The portion of the elastic support 16 between the portion fixed to the mounting member 12 and the portion fixed to the movable element 14 is a deformation portion 60, and this deformation portion 60 is a portion that deforms when the movable element 14 is displaced (vibrates). In other words, the elastic support 16 is composed of four mounting member side fixed portions 56 fixed to the mounting member 12, a movable element side fixed portion 58 fixed to the movable element 14, and a deformation portion 60 that connects between the mounting member side fixed portions 56 and the movable element side fixed portions 58.

The four mounting member side fixed parts 56 are formed in a rectangular shape corresponding to the four base parts 40 of the frame 22 when viewed from the Z direction. The four mounting member side fixed parts 56 each have a circular fixing hole 56A penetrating in the Z direction. The four welding boss parts 42 of the frame 22 are inserted into the fixing holes 56A of the four mounting member side fixed parts 56. The four mounting member side fixed parts 56 are fixed to the four base parts 40 of the frame 22 by welding (thermal crimping) the ends of the welding boss parts 42 of the frame 22 on one side in the Z direction. In addition, when the four mounting member side fixed parts 56 are fixed to the four base parts 40 of the frame 22, the four mounting member side fixed parts 56 are inseparable from the four base parts 40 of the frame 22. Note that each figure shows the state after the welding boss parts 42 have been thermally crimped.

The movable member side fixed portion 58 is formed in a circular shape with a smaller diameter than the top wall portion 50A of the yoke 50 that constitutes part of the movable member 14 when viewed from the Z direction. A circular fixing hole 58A is formed in the center of this movable member side fixed portion 58. The fixing protrusion 50C of the yoke 50 is inserted into the fixing hole 58A of the movable member side fixed portion 58. Furthermore, the end of one side of the fixing protrusion 50C of the yoke 50 in the Z direction is deformed (crimped) with a punch or the like, thereby fixing the movable member side fixed portion 58 to the yoke 50. Note that the deformed state of the fixing protrusion 50C is not shown in each figure.

The deformation section 60 has, from the starting point 62 to the terminal end 64, a starting point portion 66A on one side and a starting point portion 66B on the other side, and four arms 68A, 68B, 68C, and 68D. In the following description, the four arms 68A, 68B, 68C, and 68D may be referred to as a first arm 68A, a second arm 68B, a third arm 68C, and a fourth arm 68D, respectively.

The starting end 62 here refers to the beginning of the deformation portion 60 when the deformation portion 60 is defined as a portion extending from the movable member side fixed portion 58 side toward the mounting member side fixed portion 56 side. Specifically, the starting end 62 coincides with the boundary between the movable member side fixed portion 58 and the deformation portion 60. In addition, in this embodiment, there are two starting ends 62, one on one side in the Y direction and the other on the other side in the Y direction.

The terminus 64 refers to the end of the deformation section 60 when the deformation section 60 is defined as the section extending from the movable member side fixed section 58 side toward the mounting member side fixed section 56 side. Specifically, it coincides with the boundary between the deformation section 60 and the mounting member side fixed section 56. In this embodiment, there are four termini 64 corresponding to the four mounting member side fixed sections 56 and the four arms 68A, 68B, 68C, 68D.

The one-side starting point portion 66A and the other-side starting point portion 66B are both adjacent to the movable member-side fixed portion 58 in the Y direction. The one-side starting point portion 66A is located on one side of the movable member-side fixed portion 58 in the Y direction, and the other-side starting point portion 66B is located on the other side of the movable member-side fixed portion 58 in the Y direction.

The deformation section 60 branches out from the starting point on one side 66A towards one side and the other side in the X direction, and is connected to a first arm 68A and a second arm 68B, respectively. The deformation section 60 also branches out from the starting point on the other side 66B towards one side and the other side in the X direction, and is connected to a third arm 68C and a fourth arm 68D, respectively. When there is no particular distinction between the starting point on one side 66A and the starting point on the other side 66B, they are simply referred to as starting points 66.

Here, the deformation portion 60 of this embodiment is symmetrical in both the X direction and the Y direction, and the four arms 68A, 68B, 68C, and 68D have the same shape. In detail, the first arm 68A and the third arm 68C are disposed on one side in the X direction with respect to the movable member side fixed portion 58, and are formed symmetrically in the Y direction. The second arm 68B and the fourth arm 68D are disposed on the other side in the X direction with respect to the movable member side fixed portion 58, and are formed symmetrically in the Y direction. Furthermore, the first arm 68A and the second arm 68B are formed symmetrically in the X direction. Furthermore, the third arm 68C and the fourth arm 68D are formed symmetrically in the X direction.

Each arm 68A, 68B, 68C, 68D has, in this order from the starting point 66 toward the respective mounting member side fixed portion 56, a first X-direction outer extension portion 70a, a first folded portion 70b, an X-direction inner extension portion 70c, a second folded portion 70d, a second X-direction outer extension portion 70e, a third folded portion 70f, and a Y-direction outer extension portion 70g.

The first X-direction outer extension portion 70a is a portion that extends outward in the X-direction from the movable member side fixed portion 58 side. The extension direction of the first X-direction outer extension portion 70a is parallel to the X-direction.

The first folded portion 70b is formed closer to the attachment member side fixed portion 56 than the first X-direction outer extension portion 70a, and this first folded portion 70b is folded back so that the extension direction of the arms 68A, 68B, 68C, and 68D is directed inward in the Y-direction.

The X-direction inner extension portion 70c is a portion that extends inward in the X-direction from the first folded portion 70b. The extension direction of the X-direction inner extension portion 70c is parallel to the X-direction.

The second folded portion 70d is formed closer to the movable member fixed portion 58 than the X-direction inner extension portion 70c, and at this second folded portion 70d, the extension direction of the arms 68A, 68B, 68C, and 68D is folded back toward the inside in the Y-direction.

The second X-direction outer extension portion 70e is a portion that extends from the second folded portion 70d toward the outside in the X-direction. The second X-direction outer extension portion 70e has a curved shape such that the inclination angle of its extension direction with respect to the X-direction gradually decreases as it extends toward the outside in the X-direction.

The third folded portion 70f is formed closer to the attachment member side fixed portion 56 than the second X-direction outer extension portion 70e, and at this third folded portion 70f, the extension direction of the arms 68A, 68B, 68C, and 68D is folded from the outer side in the X direction to the outer side in the Y direction.

The Y-direction outer extension portion 70g extends outward in the Y-direction from the third folded portion 70f, and the side opposite the third folded portion 70f is connected to the mounting member side fixed portion 56. The extension direction of the Y-direction outer extension portion 70g is parallel to the Y direction.

The elastic support 16 of this embodiment also includes a Y-direction connection portion 72 that connects the third folded portion 70f of the first arm 68A to the third folded portion 70f of the third arm 68C in the Y direction, and also includes a Y-direction connection portion 72 that connects the third folded portion 70f of the second arm 68B to the third folded portion 70f of the fourth arm 68D in the Y direction. Each Y-direction connection portion 72 extends in the Y direction at the same position in the X direction as each Y-direction outer extension portion 70g.

(Configuration of the cushioning material 18)
2, 3B, and 4, the cushioning material 18 is formed into a plate shape using a viscoelastic material, with the Z direction as the thickness direction and formed into a rectangular shape when viewed from the Z direction. Specifically, the cushioning material 18 is formed into a rectangular shape with the Y direction as the longitudinal direction and the X direction as the short side direction when viewed from the Z direction. The dimensions of the cushioning material 18 in the Y direction and the X direction are set to correspond to the dimensions of the cushioning material attachment surface 46 of the frame 22 in the Y direction and the X direction.

The surface (lower surface) of the cushioning material 18 on the other side in the Z direction is a first adhesive surface 18A that can be bonded to other members. The surface (upper surface) of the cushioning material 18 on one side in the Z direction is a second adhesive surface 18B that can be bonded to other members. Only one of the upper and lower surfaces of the cushioning material 18 may be an adhesive surface, or both the upper and lower surfaces of the cushioning material 18 may not be adhesive surfaces. Furthermore, the thickness dimension T of the cushioning material 18 in its component state (before it is sandwiched between the cushioning material attachment surface 46 of the frame 22 and the elastic support 16 and deformed) is set to a dimension larger than the clearance between the cushioning material attachment surface 46 of the frame 22 and the elastic support 16.

The first adhesive surface 18A of one of the cushioning materials 18 is then attached to one of the cushioning material attachment surfaces 46 of the frame 22. As a result, one of the cushioning materials 18 is attached to one of the cushioning material attachment surfaces 46 of the frame 22. Similarly, the first adhesive surface 18A of the other of the cushioning materials 18 is attached to the other of the cushioning material attachment surfaces 46 of the frame 22. As a result, the other of the cushioning materials 18 is attached to the other of the cushioning material attachment surfaces 46 of the frame 22. Note that in a configuration in which the first adhesive surface 18A is not provided on the cushioning material 18, it is advisable to provide a holding portion such as a recess that holds the position of the cushioning material 18 in a portion that corresponds to the cushioning material attachment surface 46 of the frame 22.

Next, the four welded bosses 42 of the frame 22 are inserted into the fixing holes 56A of the four mounting member side fixed parts 56 of the elastic support 16, and the ends of the welded bosses 42 on one side in the Z direction are welded. This attaches the elastic support 16 to the frame 22.

Here, when the elastic support 16 is attached to the frame 22, one of the cushioning materials 18 is arranged along the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the first arm 68A and the third arm 68C, and one of the Y-direction connecting portions 72. Also, when the elastic support 16 is attached to the frame 22, the second adhesive surface 18B of one of the cushioning materials 18 is attached to the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the first arm 68A and the third arm 68C, and the surface (lower surface) on the other side in the Z direction of the one of the Y-direction connecting portions 72. Furthermore, when the elastic support 16 is attached to the frame 22, one of the cushioning materials 18 is crushed (compressed) between the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the first arm 68A and the third arm 68C, as well as one of the Y-direction connection portions 72 and one of the cushioning material attachment surfaces 46 of the frame 22.

Similarly, when the elastic support 16 is attached to the frame 22, the other cushioning material 18 is arranged along the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the second arm 68B and the fourth arm 68D, and the other Y-direction connection portion 72. Also, when the elastic support 16 is attached to the frame 22, the second adhesive surface 18B of the other cushioning material 18 is attached to the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the second arm 68B and the fourth arm 68D, and the other Z-direction side surface (lower surface) of the other Y-direction connection portion 72. Furthermore, when the elastic support 16 is attached to the frame 22, the other cushioning material 18 is crushed (compressed) between the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the second arm 68B and the fourth arm 68D, as well as the other Y-direction connection portion 72 and the other cushioning material attachment surface 46 of the frame 22.

Note that each figure does not reflect the state in which the cushioning material 18 is crushed between the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each arm 68A, 68B, 68C, 68D and the other cushioning material attachment surface 46 of the frame 22.

Figure 3B shows a plan view of the actuator 10 before the two cover members 20 described below are attached. The portion of the cushioning material 18 shown in this figure where the second adhesive surface 18B is visible will be referred to as the excess portion 18C of the cushioning material 18. In other words, the portion of the cushioning material 18 shown in this figure that does not overlap in the Z direction with the second X-direction outer extension portion 70e, the third folded portion 70f, the Y-direction outer extension portion 70g, and the Y-direction connection portion 72 of each arm 68A, 68B, 68C, 68D will be referred to as the excess portion 18C of the cushioning material 18.

(Configuration of Cover Member 20)
The cover member 20 is formed in a plate shape using a viscoelastic material, with the Z direction as the thickness direction and formed in a rectangular shape when viewed from the Z direction. Specifically, the cover member 20 is formed in a rectangular shape with the Y direction as the longitudinal direction and the X direction as the short side direction when viewed from the Z direction. The dimensions of the cover member 20 in the Y direction and the X direction are set to correspond to the dimensions of the cushioning material 18 in the Y direction and the X direction.

The surface (lower surface) of the cover member 20 on the other side in the Z direction is an adhesive surface 20A that can be attached to other members. The surface (upper surface) of the cover member 20 on one side in the Z direction is not an adhesive surface. As shown in Figures 3A and 3B, the adhesive surface 20A of one cover member 20 is attached to the second adhesive surface 18B of the excess portion 18C of one cushioning material 18, and is attached to the surface (upper surface) of one side in the Z direction of the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the first arm 68A and the third arm 68C, and one Y-direction connection portion 72. Then, between one cushioning material 18 and one cover member 20, the second X-direction outer extension portion 70e, the third folded portion 70f, and one Y-direction connection portion 72 of each of the first arm 68A and the third arm 68C are arranged. Similarly, the adhesive surface 20A of the other cover member 20 is attached to the second adhesive surface 18B of the excess portion 18C of the other cushioning material 18, and is attached to the surface (upper surface) of the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the second arm 68B and the fourth arm 68D, and the other Y-direction connection portion 72 on one side in the Z direction. Then, the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each of the second arm 68B and the fourth arm 68D, and the other Y-direction connection portion 72 are arranged between the other cushioning material 18 and the other cover member 20. Note that each figure does not show the state in which the adhesive surface 20A of the cover member 20 is attached to the second adhesive surface 18B of the excess portion 18C of the cushioning material 18.

(Actions and Effects of the Present Embodiment)
Next, the operation and effects of this embodiment will be described.

As shown in Figures 1, 2 and 4, in the actuator 10 described above, the mover 14 is supported by the elastic support 16, and when no current is applied to the coil 24, the mover 14 is in the origin position shown in Figure 4. In the actuator 10 of this embodiment, the coil 24 is fixed to the frame 22, and the magnet 52 and the like are provided on the mover 14. Therefore, when current is applied to the coil 24, a thrust force is generated in the mover 14 as a reaction force to the force generated by the coil 24. Then, when an alternating current is applied to the coil 24, the mover 14 vibrates in the vertical direction along the center axis AX.

Here, when the movable member 14 is displaced relative to the mounting member 12, the deformation portion 60 of the elastic support 16 is flexibly deformed. When the deformation portion 60 of the elastic support 16 is flexibly deformed, the two buffer materials 18 provided between the mounting member 12 and the deformation portion 60 of the elastic support 16 are deformed. This allows the vibration of the elastic support 16 to be damped. Here, in this embodiment, the buffer material 18 is provided between the mounting member 12 and the deformation portion 60 of the elastic support 16. As a result, in this embodiment, the amount of buffer material 18 used can be reduced compared to a configuration in which the elastic support 16 is configured to include a pair of spring materials, and a buffer material formed into a shape corresponding to the pair of spring materials is bonded to one spring material and the other spring material.

In addition, in this embodiment, the first adhesive surface 18A and the second adhesive surface 18B of the cushioning material 18 are respectively adhered to the cushioning material attachment surface 46 of the frame 22 and the elastic support body 16. This allows the damping effect of the cushioning material 18 to be increased even if the area of the cushioning material 18 as viewed in the thickness direction is reduced.

In addition, in this embodiment, the cushioning material 18 is provided on the side of the mounting member side fixed portion 56 in the deformation portion 60 of the elastic support 16. That is, the cushioning material 18 is provided on the side of the deformation portion 60 of the elastic support 16 with a smaller amplitude. In detail, as shown in FIG. 3B and FIG. 5, the cushioning material 18 is provided only in the portion corresponding to the second X-direction outer extension portion 70e, the third folded portion 70f, the Y-direction outer extension portion 70g, and the Y-direction connecting portion 72 of each arm 68A, 68B, 68C, 68D. As a result, the amount of deformation of the cushioning material 18 can be suppressed compared to a configuration in which the cushioning material 18 is provided on the movable member side fixed portion 58 side from the corresponding portion. As a result, deterioration due to repeated deformation of the cushioning material 18 can be suppressed. Furthermore, by suppressing deterioration due to repeated deformation of the cushioning material 18, changes in the resonance frequency of the vibration system including the elastic support 16 can be suppressed.

In this embodiment, as shown in Figs. 3A and 3B, the cover member 20 is attached to the second adhesive surface 18B of the excess portion 18C of the cushioning material 18, the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g of each arm 68A, 68B, 68C, and 68D, and the surface (upper surface) on one side in the Z direction of the Y-direction connection portion 72. In this configuration, the excess portion 18C of the cushioning material 18 can be covered by the cover member 20. As a result, it is possible to prevent foreign matter such as dust from adhering to the second adhesive surface 18B of the excess portion 18C of the cushioning material 18. In addition, a damping effect can be obtained by the cover member 20. This can enhance the damping effect compared to a configuration in which only the cushioning material 18 is provided.

In addition, in this embodiment, the second X-direction outer extension portion 70e, the third folded portion 70f, the Y-direction outer extension portion 70g, and the Y-direction connection portion 72 of each of the arms 68A, 68B, 68C, and 68D are sandwiched between the cushioning material 18 and the cover member 20. This provides an effect of damping the vibration of the elastic support 16 by the cover member 20 in addition to the effect of damping the vibration of the elastic support 16 by the cushioning material 18. Furthermore, since vibration can be damped by both the cushioning material 18 and the cover member 20, the durability of the cushioning material 18 can be improved compared to the case where only the cushioning material 18 is provided.

Furthermore, in this embodiment, the cushioning material 18 is in a crushed (compressed) state between the second X-direction outer extension portion 70e, the third folded portion 70f, the Y-direction outer extension portion 70g, and the Y-direction connection portion 72 of each arm 68A, 68B, 68C, 68D and the cushioning material attachment surface 46 of the frame 22. As a result, even when the second X-direction outer extension portion 70e, the third folded portion 70f, the Y-direction outer extension portion 70g, and the Y-direction connection portion 72 of each arm 68A, 68B, 68C, 68D are deformed toward the opposite side to the mounting member 12 (one side in the Z direction), the contact state between the cushioning material 18 and the elastic support 16 and the contact state between the cushioning material 18 and the mounting member 12 can be maintained.

In addition, in this embodiment, each arm 68A, 68B, 68C, 68D of the deformation part 60 of the elastic support 16 has a first X-direction outer extension part 70a, a first folded part 70b, an X-direction inner extension part 70c, a second folded part 70d, a second X-direction outer extension part 70e, a third folded part 70f, and a Y-direction outer extension part 70g. As a result, the length of each arm 68A, 68B, 68C, 68D of the deformation part 60 can be increased compared to a configuration without the third folded part 70f and the Y-direction outer extension part 70g. As a result, the load on each arm 68A, 68B, 68C, 68D can be reduced, and the load applied to the movable member side fixed part 58 and the mounting member side fixed part 56 can also be reduced, making it difficult for metal fatigue to occur. Therefore, the durability of each arm 68A, 68B, 68C, 68D can be improved. In addition, the resonance frequency of the vibration system including the elastic support 16 can be lowered compared to a configuration without the third folded portion 70f and the Y-direction outer extending portion 70g.

In addition, the cushioning material is provided along the second X-direction outer extension portion 70e, the third folded portion 70f, and the Y-direction outer extension portion 70g. In this way, by providing the third folded portion 70f and the Y-direction outer extension portion 70g, the cushioning material 18 can be easily positioned between the mounting member 12 and each arm 68A, 68B, 68C, and 68D at a position where the deformation of the arms is small.

Furthermore, in this embodiment, the first arm 68A and the third arm 68C having the third folded portion 70f and the Y-direction outer extension portion 70g are arranged on one side in the X direction with respect to the movable member side fixed portion 58 and are formed symmetrically in the Y direction. Also, the second arm 68B and the fourth arm 68D having the third folded portion 70f and the Y-direction outer extension portion 70g are arranged on the other side in the X direction with respect to the movable member side fixed portion 58 and are formed symmetrically in the Y direction. Furthermore, the first arm 68A and the second arm 68B are formed symmetrically in the X direction. Also, the third arm 68C and the fourth arm 68D are formed symmetrically in the X direction. This makes it possible to increase the ratio of the length of the four arms 68A, 68B, 68C, and 68D to the area occupied by the elastic support 16 when viewed from the Z direction.

Furthermore, in this embodiment, two cushioning materials 18 are provided for each of the four arms 68A, 68B, 68C, and 68D. This allows the number of cushioning materials 18 to be reduced compared to a configuration in which four cushioning materials 18 are provided for each of the four arms 68A, 68B, 68C, and 68D.

In addition, in this embodiment, the elastic support 16 has a Y-direction connection portion 72 that connects the third folded portion 70f of the first arm 68A and the third folded portion 70f of the third arm 68C in the Y direction, and also has a Y-direction connection portion 72 that connects the third folded portion 70f of the second arm 68B and the third folded portion 70f of the fourth arm 68D in the Y direction. This makes it possible to increase the flatness of the deformation portion 60 of the elastic support 16 formed in a plate shape in the free state compared to a configuration without the Y-direction connection portion 72. In particular, it is possible to increase the flatness of the deformation portion 60 when the elastic support 16 is press-molded. In addition, since the flatness of the deformation portion 60 is maintained, individual differences between parts are unlikely to occur, and the variation in the spring coefficient (variation in hardness and stiffness) can be suppressed.

Furthermore, in this embodiment, when the four mounting member side fixed parts 56 of the elastic support 16 are respectively fixed to the four pedestal parts 40 of the frame 22, the four mounting member side fixed parts 56 are respectively unable to be separated from the four pedestal parts 40 of the frame 22. This makes it possible to suppress changes in the contact state between the mounting member side fixed parts 56 and the pedestal parts 40 at the fixed parts between them. This makes it possible to suppress a shift in the resonance point of the elastic support 16 that would occur due to a change in the contact state between them.

In the above example, the elastic support 16 is provided with a Y-direction connecting portion 72 that connects the third folded portion 70f of the first arm 68A and the third folded portion 70f of the third arm 68C in the Y direction, and also has a Y-direction connecting portion 72 that connects the third folded portion 70f of the second arm 68B and the third folded portion 70f of the fourth arm 68D in the Y direction, but the present invention is not limited to this. For example, the elastic support 80 shown in Figures 6 and 7 may be configured without the Y-direction connecting portion 72. In addition, the parts of the elastic support 80 shown in Figures 6 and 7 that correspond to the elastic support 16 described above are given the same reference numerals as the parts that correspond to the elastic support 16 described above.

In the above-described example, the elastic support 16 has both sides entirely planar, but the present invention is not limited to this. For example, as in the elastic support 82 shown in FIG. 8, a configuration in which step portions 84 are formed at four locations corresponding to the end 64 of the deformation portion 60 may be used. Although not shown, a configuration in which step portions are formed at two locations corresponding to the beginning of the deformation portion of the elastic support may be used. In the configuration shown in FIG. 8, the movable member side fixed portion 58 and the deformation portion 60 are offset to one side in the Z direction relative to the four mounting member side fixed portions 56. Thus, in FIG. 8, the step portion 84 is formed, and the movable member side fixed portion 58 and the deformation portion 60 are offset to one side in the Z direction relative to the mounting member side fixed portion 56, but they may be offset to the other side in the Z direction. By providing the step portion 84, the step portion can be used as the base point of the deformation portion 60, and the stress applied to the mounting member side fixed portion 56 can be reduced. Also, as shown in FIG. 8, by offsetting the movable member side fixed portion 58 and the deformation portion 60 to one side in the Z direction relative to the mounting member side fixed portion 56, it is possible to increase the degree of freedom in the thickness dimension of the buffer material while suppressing an increase in the height of the entire actuator, and to increase the adjustment range of the damping effect of the buffer material. Note that the parts of the elastic support 82 shown in FIG. 8 that correspond to the elastic support 16 described above are given the same reference numerals as the parts that correspond to the elastic support 16 described above.

In the above example, the four mounting member side fixed parts 56 are fixed to the four base parts 40 of the frame 22 by welding, but the present invention is not limited to this. For example, the four mounting member side fixed parts 56 may be removably fixed to the four base parts 40 of the frame 22 by using screws or the like.

In addition, in the above example, a configuration in which two cushioning materials 18 are provided for four arms 68A, 68B, 68C, and 68D has been described, but the present invention is not limited to this. The number of arms 68A, 68B, 68C, and 68D and the number of cushioning materials 18 may be set appropriately taking into consideration the vibration characteristics required of the actuator 10, etc.

In the above-described example, the cushioning material 18 is provided only in the portion corresponding to the second X-direction outer extension portion 70e, the third folded portion 70f, the Y-direction outer extension portion 70g, and the Y-direction connection portion 72 of each arm 68A, 68B, 68C, and 68D, but the present invention is not limited to this. For example, the cushioning material 18 may be provided on the movable member side fixed portion 58 side from the position. In this way, the position where the cushioning material 18 is provided may be appropriately set in consideration of the durability required for the cushioning material 18. In addition, for example, the resonance frequency of the vibration system including the elastic support 16 may be adjusted by adjusting the dimension of the cushioning material 18 in the X direction or the like. For example, as shown by the two-dot chain line in FIG. 3B, the dimension of the cushioning material 18 in the Y direction from the end opposite the movable member side fixed portion 58 may be set to 1/2W, which is half the dimension of the above-described example, or 2/3W, which is 2/3 of the dimension of the above-described example. In this case, the shorter the dimension in the Y direction from the end of the cushioning material 18 opposite the movable member side fixed part 58, the lower the resonant frequency of the vibration system including the elastic support 16.

In addition, in the above-described example, the cover member 20 is provided, but the present invention is not limited to this. Whether or not to provide the cover member 20 can be determined appropriately taking into consideration the type and size of foreign matter expected to adhere to the second adhesive surface 18B of the cushioning material 18, the vibration damping effect of the elastic support 16 required for the cover member 20, etc.

In the above example, the entire surface of one side of the cover member 20 is an adhesive surface, but the present invention is not limited to this. For example, even if the cover member does not have an adhesive surface, it can be attached to the adhesive surface of the cushioning material. In this case, the damping effect can be enhanced by arranging a deformation portion between the cushioning material and the cover member. It is also possible to provide an adhesive surface partially on one side of the cover member. For example, an adhesive surface can be provided only on the contact portion with the deformation portion, and this can be set appropriately taking into consideration the damping effect of the vibration of the elastic support body.

In the above example, the cushioning material 18 is provided, but the present invention is not limited to this. Whether or not to provide the cushioning material 18 can be determined appropriately taking into account the vibration damping characteristics of the elastic support 16, etc.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it is of course possible to implement the invention in various other modified forms without departing from the spirit of the invention.

10 actuator 12 mounting member 14 mover 16 elastic support 24 coil
42 Welded boss part (welded part)
52 Magnet 56 Mounting member side fixed part 58 Mover side fixed part 60 Deformed part 68A Arm 68B Arm 68C Arm 68D Arm 70a First X direction outer extension part 70b First folded part 70c X direction inner extension part 70d Second folded part 70e Second X direction outer extension part 70f Third folded part 70g Y direction outer extension part 72 Y direction connection part 80 elastic support

Claims (2)

A mounting member including a coil;
a mover having a magnet arranged opposite to the coil and displaced relative to the mounting member when current is applied to the coil;
an elastic support having a mounting member-side fixed portion fixed to the mounting member, a mover-side fixed portion fixed to the mover, and a deformation portion connecting the mounting member-side fixed portion and the mover-side fixed portion;
Equipped with
the deformation portion has an arm extending between the movable member side fixed portion and the mounting member side fixed portion,
When the displacement direction of the mover is defined as ±Z direction, and the directions perpendicular to each other among the directions in a plane perpendicular to the ±Z direction are defined as X direction and Y direction, the arm has a first X-direction outer extension portion extending outward in the X direction from the mover-side fixed portion side, a first folded portion formed on the mounting member-side fixed portion side relative to the first X-direction outer extension portion and whose extension direction is folded back from the outer side in the X direction to the inner side in the X direction, an X-direction inner extension portion extending inward in the X direction from the first folded portion, and a second folded portion extending inward in the X direction from the first folded portion. a second folded portion formed closer to the movable member fixed portion than the inner extension portion and whose extension direction is folded back from the inner side in the X direction to the outer side in the X direction, a second X-direction outer extension portion extending outward in the X direction from the second folded portion, a third folded portion formed closer to the mounting member fixed portion than the second X-direction outer extension portion and whose extension direction is folded back from the outer side in the X direction to the outer side in the Y direction, and a Y-direction outer extension portion extending outward in the Y direction from the third folded portion and connected to the mounting member fixed portion ,
The elastic support body includes four mounting member side fixed portions and four arms,
Two of the four arms are disposed on one side in the X direction with respect to the movable element side fixed portion and are formed symmetrically in the Y direction,
The other two of the four arms are disposed on the other side in the X direction with respect to the movable element side fixed portion and are formed symmetrically in the Y direction,
The deformation portion is formed in a plate shape,
a Y-direction connection portion that connects in a Y direction the third folded-back portions of the two arms that are arranged on one side in the X direction with respect to the movable member-side fixed portion, and a Y-direction connection portion that connects in a Y direction the third folded-back portions of the two arms that are arranged on the other side in the X direction with respect to the movable member-side fixed portion,
one of the Y-direction connecting portions is deformable in the ±Z direction together with the third folded-back portions and the Y-direction outer extending portions of the two arms arranged on one side in the X direction with respect to the movable member-side fixed portion,
An actuator in which the other Y-direction connection portion is deformable in the ±Z direction together with the third folded portion and the Y-direction outer extension portion of the two arms arranged on the other side of the X-direction relative to the movable member side fixed portion. 2. The actuator according to claim 1 , wherein the mounting member-side fixed portion is fixed to the mounting member via a welded portion so as not to be separated from the mounting member.