Linear vibration motor

Abstract

To provide a linear vibration motor configured so as to suppress stress from concentrating accompanying vibration of an elastic member.SOLUTION: A linear vibration motor comprises an actuator having a movable element having a magnet and a back yoke and a stator, and an elastic member 40 supporting the movable element so that the element can vibrate with respect to the housing. The elastic member has a pair of first extending parts 410 and 411 extending along a first direction, a pair of second extending parts 412 and 413 extending along a second direction, and a fixed part 42 that is connected to the first extending parts. The fixed part is positioned between the pair of first extending parts and the pair of second extending parts and is provided at a position overlapping a central part of the elastic member. The fixed part is fixed to the back yoke, at a plurality of fixing points. The plurality of fixing points are formed at a position that is symmetric with a first referenced line parallel to the first direction through the central part and is formed at a position that is symmetric with a second referenced line parallel to the second direction through the central part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a linear vibration motor. [Background technology]

[0002] 2. Description of the Related Art Linear vibration motors are known that are provided in switches or the like that are operated by a user, and generate vibrations when operated by the user.

[0003] Patent Document 1 discloses a linear vibration motor in which an elastic support that elastically supports a mover is provided on the upper part of a frame. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-88960 Summary of the Invention [Problem to be solved by the invention]

[0005] However, depending on the connection between the elastic support and the movable element, stress may be concentrated at a specific point on the elastic support during vibration, which may result in damage to the elastic support. [Means for solving the problem]

[0006] A linear vibration motor according to an embodiment of the present invention includes an actuator having a mover having a magnet and a back yoke and a stator, a housing that accommodates the actuator, and an elastic member fixed to the mover and the housing and supporting the mover so that it can vibrate relative to the housing. The elastic member has a pair of first extension portions extending along a first direction that intersects with a vibration direction in which the mover vibrates, a pair of second extension portions extending along a second direction that intersects with both the first direction and the vibration direction, and a fixed portion connected to the first extension portions. The fixed portion is located between the pair of first extension portions and the pair of second extension portions and is provided at a position overlapping with a center portion of the elastic member. The fixed portion is fixed to the back yoke at a plurality of fixed points. The multiple fixed points are provided at positions symmetrical with respect to a first reference line that passes through the center portion and is parallel to the first direction, and at positions symmetrical with respect to a second reference line that passes through the center portion and is parallel to the second direction. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to suppress the concentration of stress caused by vibration of the elastic member. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of the appearance of a linear vibration motor according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the linear vibration motor. [Figure 3] FIG. 3 is an external perspective view of the housing. [Figure 4] FIG. 4 is a plan view of the elastic member. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Embodiment> Hereinafter, linear vibration motors according to embodiments will be described in detail with reference to the drawings.

[0010] Linear vibration motors are provided, for example, in various operation switches operated by users. Examples of operation switches that can be provided with linear vibration motors include switch panels for air conditioners and power window operation switches located inside automobiles. When a user operates one of these switches, the linear vibration motor vibrates, causing the switch to vibrate. In other words, when the user operates the switch, the linear vibration motor provides feedback to the user through vibration.

[0011] <Overall structure> Fig. 1 is a perspective view of the appearance of a linear vibration motor 10 according to an embodiment. Fig. 2 is an exploded perspective view of the linear vibration motor 10. The linear vibration motor 10 includes a housing 20, an actuator 30, and an elastic member 40.

[0012] <Housing 20> 3 is a perspective view of the exterior of the housing 20. The housing 20 is made of a metal material such as stainless steel (SUS). The housing 20 has a bottom plate 201, first side wall plates 202 and 203, second side wall plates 204 and 205, and connecting plates 206 and 207.

[0013] The bottom plate 201 is rectangular or approximately rectangular having a pair of long sides and a pair of short sides. In the following description, the direction along the long sides of the bottom plate 201 is referred to as the X direction, and the direction intersecting (orthogonal to) the X direction and along the short sides of the bottom plate 201 is referred to as the Y direction. The direction intersecting (orthogonal to) the X and Y directions is referred to as the Z direction. The X direction may also be referred to as the first direction, and the Y direction may also be referred to as the second direction.

[0014] A double-sided adhesive tape 51 is attached to the negative surface in the Z direction of the bottom plate 201 (see FIG. 2). By attaching the double-sided adhesive tape 51 to the operation switch, the linear vibration motor 10 is fixed to the operation switch.

[0015] The first side wall plates 202, 203 and the second side wall plates 204, 205 are connected to the respective sides of the bottom plate 201 at their ends (one ends) on the negative side in the Z direction. Specifically, the first side wall plate 202 is connected to one long side (positive side in the Y direction) of the bottom plate 201, and the first side wall plate 203 is connected to the other long side (negative side in the Y direction) of the bottom plate 201. In other words, the first side wall plates 202, 203 extend along the X direction (first direction).

[0016] The second side wall plate 204 is connected to one short side (positive side in the X direction) of the bottom plate 201, and the second side wall plate 205 is connected to the other short side (negative side in the X direction) of the bottom plate 201. In other words, the second side wall plates 204, 205 extend along the Y direction (second direction).

[0017] The length (height) of the first side wall plates 202, 203 in the Z direction is shorter (lower) than the length (height) of the second side wall plates 204, 205 in the Z direction. That is, the height of the first side wall plates 202, 203 from the bottom plate 201 is shorter than the height of the second side wall plates 204, 205 from the bottom plate 201. In other words, the first side wall plates 202, 203 and the second side wall plate 204 are connected to each other with a step D1 on the positive side in the Z direction. Similarly, the first side wall plates 202, 203 and the second side wall plate 205 are connected to each other with a step D2 on the positive side in the Z direction. These step portions D1, D2 have a size (length) of about 0.8 mm to 1.2 mm along the Z direction, and more preferably a size (length) of about 1 mm.

[0018] An actuator 30, which will be described later, is accommodated in a space S surrounded by the bottom plate 201, first side wall plates 202 and 203, and second side wall plates 204 and 205. That is, the housing 20 accommodates the actuator 30. An opening 204a is formed in the second side wall plate 204, penetrating the space S and the outside of the housing 20. A flexible printed circuit board (FPC) 50, which supplies power to the actuator 30, is inserted into the space S from the outside of the housing 20 through this opening 204a. The opening 204a can be made large as long as the strength of the second side wall plate 204 can be maintained.

[0019] A protruding surface 201a is formed at the positive end of the bottom panel 201 in the X direction, i.e., below the opening 204a formed in the second side wall panel 204, and protrudes further toward the positive X direction than the positive end of the bottom panel 201 in the X direction. Therefore, the protruding surface 201a has a size along the X direction that corresponds to the size of the opening 204a in the X direction. The FPC 50 is fixed to the upper surface (the surface on the positive Z direction side) of this protruding surface 201a by adhesive or the like. Since the opening 204a can be made large within a range that maintains the strength of the second side wall panel 204, the size of the protruding surface 201a in the X direction can be increased, thereby ensuring the area of ​​the protruding surface 201a. This increases the fixing strength of the FPC 50, thereby preventing the FPC 50 from peeling off.

[0020] The connecting plate 206 is formed at the end (other end) of the second side wall plate 204 on the + side in the Z direction. The connecting plate 206 has a surface that intersects with the Z direction, i.e., is parallel to the XY plane. The connecting plate 206 protrudes further toward the + side in the X direction than the second side wall plate 204. In other words, the end of the connecting plate 206 on the - side in the X direction is connected to the end of the second side wall plate 204 on the + side in the Z direction.

[0021] The connecting plate 207 is formed at the end (other end) of the second side wall plate 205 on the + side in the Z direction. The connecting plate 207 has a surface that intersects with the Z direction, i.e., is parallel to the XY plane. The connecting plate 207 protrudes further toward the - side in the X direction than the second side wall plate 205. In other words, the end of the connecting plate 207 on the + side in the X direction is connected to the end of the second side wall plate 205 on the + side in the Z direction.

[0022] The connecting plates 206, 207 are connected to the elastic member 40, which will be described later, to support the elastic member 40. In this case, the connecting plates 206, 207 and the elastic member 40 are joined by welding. That is, the elastic member 40 is fixed to the end (the other end) of the second side wall plates 205, 204 on the + side in the Z direction.

[0023] The amount by which the connecting plates 206, 207 protrude beyond the second side wall plates 204, 205 in the X direction is greater than the welding diameter of 0.8 mm and is an amount that can prevent excessive enlargement of the housing 20 in the X direction. The amount by which the connecting plates 206, 207 protrude is, for example, about 1.0 mm each.

[0024] As described above, the height in the Z direction of the first side wall plates 202, 203 is lower than the height in the Z direction of the second side wall plates 204, 205. For this reason, the connecting plates 206, 207 connected to the second side wall plates 204, 205 are provided on the positive side in the Z direction relative to the first side wall plates 202, 203.

[0025] <Actuator 30> 2 has a stator 31 and a mover 32. The actuator 30 is housed in a space S of the housing 20 in a state where it is joined to an elastic member 40, which will be described later.

[0026] <Stator 31> The stator 31 is fixed by adhesive or the like to the surface on the positive side in the Z direction of the bottom plate 201 of the housing 20. The stator 31 is an air-core coil formed into a cylindrical shape by winding an electric wire. The stator 31 is arranged so that the coil axis direction coincides or nearly coincides with the Z direction. A magnet 321 and a pole piece 322, which will be described later, are housed inside the cylindrical stator 31. The stator 31 is electrically connected to the FPC 50. As a result, power is supplied to the stator 31 from an external source.

[0027] When the stator 31 is energized, the mover 32 is configured to be able to move (vibrate) in the positive and negative Z directions relative to the stator 31. Specifically, the mover 32 has a back yoke 320, a magnet 321, a pole piece 322, and a weight 323. In the following description, the Z direction may be referred to as the vibration direction in which the mover 32 vibrates. In other words, the first direction, which is the X direction, is a direction intersecting the vibration direction, and the second direction, which is the Y direction, is a direction intersecting the first direction and the vibration direction.

[0028] <Back yoke 320> Back yoke 320 is a flat plate-shaped member made of a magnetic material such as ferritic stainless steel. Back yoke 320 is rectangular with two long sides along the X direction and two short sides along the Y direction. Magnet 321 is fixed by adhesive or the like to the surface of back yoke 320 on the negative side in the Z direction.

[0029] <Magnet 321> Magnet 321 is formed in a columnar shape with an axis along the Z direction. Although magnet 321 is shown as a cylinder in Fig. 2, magnet 321 may also be a square pillar. The end face of magnet 321 on the +Z direction side is fixed to the surface of back yoke 320 on the -Z direction side by adhesive or the like.

[0030] The diameter of magnet 321 is smaller than the inner diameter of cylindrical stator 31. Therefore, magnet 321 is housed within stator 31 so as to be able to vibrate along the Z direction.

[0031] <Pole piece 322> Pole piece 322 is formed in a disk shape with an outer diameter smaller than that of magnet 321. Pole piece 322 is fixed to the end face of magnet 321 on the negative side in the Z direction by adhesive or the like. Therefore, pole piece 322 is housed in stator 31 so as to be able to vibrate together with magnet 321 along the Z direction. Note that pole piece 322 is not limited to being disk-shaped, and may also be in the shape of a polygonal plate.

[0032] <Weight 323> Weight 323 is a rectangular prism having a rectangular bottom surface with long sides along the X direction and short sides along the Y direction. Weight 323 is fixed to the surface of back yoke 320 on the negative side in the Z direction by adhesive or the like.

[0033] A through hole 324 is formed in the weight 323, penetrating the weight 323 along the Z direction. The through hole 324 has a diameter larger than the outer diameter of the cylindrical stator 31. Therefore, the stator 31, the magnet 321, and the pole piece 322 are housed inside the through hole 324. In other words, the through hole 324 is an accommodation portion that houses the stator 31, the magnet 321, and the pole piece 322.

[0034] Since the stator 31 is housed in the through hole 324, the weight 323 connected to the magnet 321 via the back yoke 320 can also vibrate in the Z direction relative to the stator 31. Since the stator 31 is fixed to the bottom plate 201, the back yoke 320, the magnet 321, the pole piece 322, and the weight 323 can vibrate in the space S relative to the housing 20 in the Z direction.

[0035] <Elastic member 40> 4 is a plan view of the elastic member 40. The elastic member 40 is made of a metal material such as stainless steel. The elastic member 40 is in the form of a plate parallel to the XY plane. As described above, the elastic member 40 is fixed to the housing 20. A film 52 made of, for example, a resin material is provided on the surface of the elastic member 40 on the positive side in the Z direction.

[0036] The back yoke 320 described above is joined by welding or the like to the surface of the elastic member 40 on the negative side in the Z direction. That is, the mover 32 including the back yoke 320 is fixed to the elastic member 40. As described above, the mover 32 vibrates in the Z direction relative to the housing 20, and therefore it can be said that the elastic member 40 fixed to the housing 20 supports the mover 32 so that it can vibrate relative to the housing 20. The elastic member 40 deforms (vibrates) in response to the vibration of the mover 32.

[0037] In the following description, a virtual line that passes through the center C (the center point and its periphery) of the elastic member 40 and is parallel to the X direction is referred to as a first reference line RL1. A virtual line that passes through the center C (the center point and its periphery) of the elastic member 40 and is parallel to the Y direction is referred to as a second reference line RL2.

[0038] The elastic member 40 has a frame portion 41 and a fixing portion 42. In the elastic member 40, the frame portion 41 and the fixing portion 42 are integrally formed.

[0039] The frame body 41 is composed of a pair of first extending portions 410, 411 extending along the X direction (first direction) and a pair of second extending portions 412, 413 extending along the Y direction (second direction). The end of the first extending portion 410 on the positive side in the X direction is connected to the end of the second extending portion 412 on the positive side in the Y direction. The end of the first extending portion 410 on the negative side in the X direction is connected to the end of the second extending portion 413 on the positive side in the Y direction. The end of the first extending portion 411 on the positive side in the X direction is connected to the end of the second extending portion 412 on the negative side in the Y direction. The end of the first extending portion 411 on the negative side in the X direction is connected to the end of the second extending portion 413 on the negative side in the Y direction.

[0040] The lengths of the first extensions 410, 411 along the X direction are equal to or approximately equal to the lengths of the first side wall plates 202, 203 of the housing 20 along the X direction. The lengths of the second extensions 412, 413 along the Y direction are equal to or approximately equal to the lengths of the second side wall plates 204, 205 of the housing 20 along the Y direction.

[0041] The width of the first extending portions 410, 411 in the Y direction is smaller than the width of the fixed portion 42, which will be described later, in the Y direction. Specifically, the width of the first extending portions 410, 411 is, for example, 0.73 mm. However, the width of the first extending portions 410, 411 is not limited to the above value, and may be larger than the above value depending on the size of the linear vibration motor, etc.

[0042] A protrusion 412a is formed at the end on the positive X-direction side of the second extending portion 412, protruding further in the positive X-direction than the positive X-direction ends of the first extending portions 410, 411. Furthermore, a protrusion 413a is formed at the end on the negative X-direction side of the second extending portion 413, protruding further in the negative X-direction than the negative X-direction ends of the first extending portions 410, 411. The length along the X-direction between the end edge on the positive X-direction side of protrusion 412a and the end edge on the negative X-direction side of protrusion 413a is equal to or approximately equal to the length along the X-direction between the end edge on the positive X-direction side of connecting plate 206 of housing 20 and the end edge on the negative X-direction side of connecting plate 207.

[0043] As described above, in the X direction, the length of the first extending portions 410, 411 is equal to or approximately equal to the length of the first side wall plates 202, 203. Therefore, when the elastic member 40 is placed in the housing 20, the protruding portions 412a, 413a are located on the connecting plates 206, 207. The protruding portions 412a, 413a are joined to the connecting plates 206, 207 by welding or the like, thereby fixing the elastic member 40 to the housing 20.

[0044] As described above, the protrusions 412a, 413a are formed on the second extending portions 412, 413, and the connecting plates 206, 207 are formed on the second side wall plates 204, 205. For this reason, it can be said that the elastic member 40 is fixed to the end portions (other ends) on the +Z direction side of the second side wall plates 204, 205 by the second extending portions 412, 413.

[0045] As described above, the amount by which the connecting plates 206, 207 protrude beyond the second side wall plates 204, 205 in the X direction is greater than the welding diameter. This provides strength to the joint between the connecting plates 206, 207 and the elastic member 40. This prevents the elastic member 40 from falling off the housing 20 even when the elastic member 40 vibrates to the positive and negative sides in the Z direction in response to vibration of the mover 32, as will be described later.

[0046] Arc-shaped curved portions 44 are formed at the locations where the first extending portions 410, 411 and the second extending portions 412, 413 are connected, i.e., at the four corners of the frame portion 41. That is, the first extending portions 410, 411 are connected to the second extending portions 412, 413 via the curved portions 44. Therefore, the positive and negative X-direction ends of the first extending portions 410, 411 are not parallel to the X direction, and the positive and negative Y-direction ends of the second extending portions 412, 413 are not parallel to the Y direction. In addition, the protruding portions 412a, 413a of the second extending portions 412, 413 are connected to the curved portions 44 via arc-shaped curved portions 45.

[0047] The fixed portion 42 is formed between the first extending portion 410 and the first extending portion 411, and between the second extending portion 412 and the second extending portion 413. More specifically, the inside of the fixed portion 42 on the XY plane includes the central portion C of the elastic member 40. In other words, the fixed portion 42 is provided at a position overlapping with the central portion C of the elastic member 40. The fixed portion 42 is joined to the back yoke 320 of the mover 32 by welding or the like, as will be described in detail later.

[0048] The length in the X direction of the fixed portion 42 is shorter than the length in the X direction of the first extending portions 410, 411. Furthermore, the length (width) in the Y direction of the fixed portion 42 is smaller than the distance between the first extending portion 410 and the first extending portion 411, and is larger than the width in the Y direction of the first extending portions 410, 411 described above. In other words, the width in the Y direction of the first extending portions 410, 411 is smaller than the width in the Y direction of the fixed portion 42. This prevents stress from concentrating at a specific location and damaging the elastic member 40 when the elastic member 40 vibrates together with the mover 32, as will be described later.

[0049] The fixed portion 42 is connected to the pair of first extending portions 410, 411. Specifically, the fixed portion 42 has a main fixed portion 421 and a pair of connecting portions 422, 423. The main fixed portion 421 is formed in a rectangular shape with a center C as the center and long sides along the X direction. In other words, the main fixed portion 421 extends along the first direction. Note that the shape of the main fixed portion 421 is not limited to a rectangle, and may be a circle or an ellipse.

[0050] The pair of connecting portions 422, 423 extend along the Y direction and connect the main fixing portion 421 to the pair of first extending portions 410, 411, respectively. Specifically, the connecting portion 422 connects the +Y direction side of the main fixing portion 421 to the first extending portion 410. The connecting portion 423 connects the -Y direction side of the main fixing portion 421 to the first extending portion 411. Note that, as shown in FIG. 4, the length of the connecting portions 422, 423 in the X direction is shorter than the length of the main fixing portion 421 in the X direction.

[0051] Arc-shaped curved portions 46 are formed at the locations where the first extending portions 410, 411 and the connecting portions 422, 423 are connected. In other words, near the second reference line RL2, the first extending portions 410, 411 are not parallel to the X direction, and the end portion of the connecting portion 422 on the +Y direction side and the end portion of the connecting portion 423 on the -Y direction side are not parallel to the Y direction. For this reason, in the range other than the curved portions 46 of the first extending portions 410, 411, the width (length along the Y direction) is smaller than the width (length along the Y direction) of the curved portions 46.

[0052] A notch 414 is formed at a position where the outer edges 410a, 411a of the first extending portions 410, 411 intersect with the second reference line RL2. This notch 414 is a curved portion formed in an arc shape. By forming the curved portions 44, 45, 46 and the notch 414, when the elastic member 40 vibrates together with the mover 32 as described below, stress is prevented from concentrating at a specific location, which would otherwise cause damage to the elastic member 40.

[0053] The elastic member 40 having the above-described shape is joined and fixed to the back yoke 320 by welding. Specifically, the elastic member 40 is joined to the surface of the back yoke 320 on the +Z direction side. That is, the elastic member 40 is disposed above the back yoke 320. In this embodiment, the fixing portion 42 of the elastic member 40 is spot-welded to the back yoke 320 at six fixing points WP1 to WP6 shown in FIG. 4, thereby fixing the fixing portion 42 and the back yoke 320. Note that the number of fixing points is not limited to six.

[0054] <Fixed points WP1~WP6> As shown in Fig. 4, fixed points WP1 and WP2 are provided at connecting portion 422 of fixed portion 42, fixed points WP3 and WP4 are provided at main fixed portion 421 of fixed portion 42, and fixed points WP5 and WP6 are provided at connecting portion 423. In Fig. 4, fixed points WP1 to WP6 are represented as circles with dots inside for convenience of illustration.

[0055] Of the multiple fixed points WP1 to WP6, the two fixed points WP1 and WP2 provided along the X direction are included in a first fixed point group G1, the two fixed points WP3 and WP4 provided along the X direction are included in a second fixed point group G2, and the two fixed points WP5 and WP6 provided along the X direction are included in a third fixed point group G3. The first fixed point group G1, the second fixed point group G2, and the third fixed point group G3 are provided on fixed portion 42 along the Y direction (second direction). More specifically, fixed point groups are provided on each of main fixed portion 421 and the pair of connecting portions 422, 423.

[0056] Fixed points WP1 and WP2 included in first fixed point group G1 are provided on connecting portion 422. Fixed points WP1 and WP2 are provided at positions symmetrical with respect to second reference line RL2. That is, fixed points WP1 and WP2 are provided at positions on connecting portion 422 at equal or approximately equal distances from second reference line RL2 along the X direction. More specifically, fixed point WP1 is provided on the positive X-direction side of second reference line RL2, and fixed point WP2 is provided on the negative X-direction side of second reference line RL2. In other words, the distance between fixed point WP1 and end edge 422a of connecting portion 422 on the positive X-direction side and the distance between fixed point WP2 and end edge 422b of connecting portion 422 on the negative X-direction side are equal or approximately equal.

[0057] Fixed points WP3 and WP4 included in second fixed point group G2 are provided on first reference line RL1 in main fixed portion 421. Fixed points WP3 and WP4 are provided at positions symmetrical with respect to second reference line RL2. That is, fixed points WP3 and WP4 are provided at positions on main fixed portion 421 at equal or approximately equal distances from second reference line RL2. More specifically, fixed point WP3 is provided on the positive X-direction side of second reference line RL2, and fixed point WP4 is provided on the negative X-direction side of second reference line RL2. In other words, the distance between fixed point WP3 and end edge 421a of main fixed portion 421 on the positive X-direction side and the distance between fixed point WP4 and end edge 421b of main fixed portion 421 on the negative X-direction side are equal or approximately equal.

[0058] Fixed points WP5 and WP6 included in third fixed point group G3 are provided at positions on connecting portion 423 that are symmetrical with respect to second reference line RL2. That is, fixed points WP5 and WP6 are provided at positions on connecting portion 423 that are spaced the same or approximately the same distance from second reference line RL2 along the X direction. More specifically, fixed point WP5 is provided on the positive X-direction side of second reference line RL2, and fixed point WP6 is provided on the negative X-direction side of second reference line RL2. In other words, the distance between fixed point WP5 and end edge 423a of connecting portion 423 on the positive X-direction side and the distance between fixed point WP6 and end edge 423b of connecting portion 423 on the negative X-direction side are equal or approximately equal.

[0059] As described above, in each of the fixed point groups G1, G2, and G3, the distance between one of the fixed points WP1, WP3, and WP5 and one end side 421a, 422a, and 423a of the fixed portion 42 (on the positive side in the X direction) is equal to or substantially equal to the distance between the other of the fixed points WP2, WP4, and WP6 and the other end side 421b, 422b, and 423b of the fixed portion 42 (on the negative side in the X direction). This prevents stress from concentrating at specific locations on the coupling portions 422 and 423 when the mover 32 including the back yoke 320 joined to the elastic member 40 vibrates along the Z direction. This prevents damage to the elastic member 40. Furthermore, since the fixed points WP3 and WP4 of the second fixed point group G2 are arranged to have the above-described positional relationship, the positive side and the negative side in the X direction of the main fixed portion 421 are prevented from vibrating in opposite directions to each other along the Z direction due to secondary resonance.

[0060] Furthermore, fixed point WP1 and fixed point WP5 are located symmetrically with respect to first reference line RL1. That is, fixed point WP1 and fixed point WP5 are located at equal or approximately equal distances from first reference line RL1 along the Y direction. More specifically, fixed point WP1 is located on the +Y side of first reference line RL1, and fixed point WP5 is located on the -Y side of first reference line RL1.

[0061] Fixed point WP2 and fixed point WP6 are located symmetrically with respect to first reference line RL1. That is, fixed point WP2 and fixed point WP6 are located at equal or approximately equal distances from first reference line RL1 along the Y direction. More specifically, fixed point WP2 is located on the +Y side of first reference line RL1, and fixed point WP6 is located on the -Y side of first reference line RL1 in the Y direction.

[0062] As described above, fixed points WP3 and WP4 are located on the first reference line RL1. For this reason, fixed point WP3 can be considered to be located at a position symmetrical to fixed point WP3 with respect to the first reference line RL1, and fixed point WP4 can be considered to be located at a position symmetrical to fixed point WP3 with respect to the first reference line RL1.

[0063] As described above, the multiple fixing points WP1 to WP6 are provided on the fixed portion 42 at positions that are symmetrical with respect to the first reference line RL1 and symmetrical with respect to the second reference line RL2. Therefore, when the mover 32 including the back yoke 320 joined to the elastic member 40 vibrates along the Z direction, stress is prevented from concentrating at a specific location on the elastic member 40. As a result, damage such as breaking of the elastic member 40 caused by vibration of the mover 32 is prevented. In other words, the durability of the elastic member 40 can be improved.

[0064] <Operation of the linear vibration motor 10> When a current flows through the FPC 50, the stator 31 is excited and generates a magnetic field that acts on the magnet 321. As described above, the stator 31 is arranged so that the coil axis direction and the Z direction coincide or approximately coincide. Therefore, the direction of the magnetic field generated by the stator 31 is either the positive side or the negative side along the Z direction. Due to the action of this magnetic field, the mover 32 including the magnet 321 and the elastic member 40 joined to the back yoke 320 move to either the positive side or the negative side along the Z direction.

[0065] When the direction of the current flowing through the stator 31 is switched, the direction of the magnetic field generated by the stator 31 switches to the other of the positive and negative sides along the Z direction. As a result, the direction of the magnetic field acting on the magnet 321 switches, and the movement directions of the mover 32 and the elastic member 40 switch. Each time the direction of the current flowing through the stator 31 is switched, the movement directions of the mover 32 and the elastic member 40 switch, causing the mover 32 and the elastic member 40 to vibrate along the Z direction.

[0066] As described above, the length along the X direction of the first extension portions 410, 411 of the elastic member 40 is equal to or approximately equal to the length along the X direction of the first side wall plates 202, 203 of the housing 20 described above. The length along the Y direction of the second extension portions 412, 413 is equal to or approximately equal to the length along the Y direction of the second side wall plates 204, 205 of the housing 20. However, the height along the Z direction of the first side wall plates 202, 203 is shorter than the height along the Z direction of the second side wall plates 204, 205.

[0067] Therefore, even when the elastic member 40 vibrates together with the movable element 32 to the positive and negative sides in the Z direction, the first extension portions 410, 411 are prevented from colliding with the first side wall plates 202, 203 of the housing 20. That is, the elastic member 40 can vibrate without being hindered by the housing 20. In other words, the lengths of the step portions D1, D2 in the Z direction are formed to be greater than the maximum amplitude of the vibration of the elastic member 40 in the Z direction. That is, the length of the step portions D1, D2, which is approximately 1.0 mm, is a value determined according to the maximum amplitude of the elastic member 40.

[0068] Although various embodiments and modifications have been described above, the present disclosure is not limited to these. Other embodiments that are conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present disclosure.

[0069] In the fixed portion 42, the main fixed portion 421 is connected to the first extending portions 410, 411 via the connecting portions 422, 423. However, the fixed portion 42 may not be formed with the connecting portions 422, 423, and the main fixed portion 421 may be connected to the first extending portions 410, 411. In this case, the main fixed portion 421 and the first extending portions 410, 411 are connected via the curved portion 46. Furthermore, even in this case, the multiple fixed points WP1 to WP6 are provided on the main fixed portion 421 with the above-described positional relationship.

[0070] According to the above-described embodiment, at least one of the following advantageous effects can be obtained.

[0071] (1) The linear vibration motor 10 includes a housing 20 that accommodates an actuator 30, a mover 32 that constitutes the actuator 30, and an elastic member 40 that is fixed to the housing 20 and supports the mover 32 so that the mover 32 can vibrate relative to the housing 20. The elastic member 40 has a pair of first extending portions 410, 411 that extend along a first direction (X direction), a pair of second extending portions 412, 413 that extend along a second direction (Y direction), and a fixed portion 42 that connects the first extending portions 410, 411. The fixed portion 42 is located between the pair of first extending portions 410, 411 and the pair of second extending portions 412, 413, and is provided at a position that overlaps with a center portion C of the elastic member 40, and is fixed to a back yoke 320 at multiple fixing points WP1 to WP6. The multiple fixed points WP1 to WP6 are provided at positions symmetrical with respect to a first reference line RL1 that passes through the central portion C and is parallel to the first direction, and are also provided at positions symmetrical with respect to a second reference line RL2 that passes through the central portion C and is parallel to the second direction.

[0072] This prevents stress from concentrating on a specific location of the elastic member 40 when the mover 32, including the back yoke 320 joined to the elastic member 40, vibrates along the Z direction. This prevents damage such as breaking of the elastic member 40 caused by vibration of the mover 32. As a result, it is possible to improve the durability of the elastic member 40 and extend the product life of the linear vibration motor 10.

[0073] (2) Fixed portion 42 is provided with a plurality of fixed point groups G1 to G3 along the second direction (Y direction), each of which includes two fixed points provided along the first direction (X direction). This makes it possible to prevent stress from concentrating near the positions where fixed portion 42 and first extension portions 410 and 411 are connected.

[0074] (3) The distance between one of the fixed points WP1, WP3, WP5 and one end side 421a, 422a, 423a (on the positive side in the X direction) of the fixed portion 42 is equal to or approximately equal to the distance between the other of the fixed points WP2, WP4, WP6 and the other end side 421b, 422b, 423b (on the negative side in the X direction) of the fixed portion 42. This prevents stress from concentrating at a specific location on the fixed portion 42 when the mover 32 including the back yoke 320 joined to the elastic member 40 vibrates along the Z direction. As a result, damage to the elastic member 40 is prevented.

[0075] (4) Fixed point groups are provided on main fixed portion 421 of fixed portion 42 and on pair of connecting portions 422, 423, respectively. This prevents stress from concentrating on specific locations on connecting portions 422, 423 when mover 32 including back yoke 320 joined to elastic member 40 vibrates along the Z direction. As a result, damage to elastic member 40 is prevented. Furthermore, by providing fixed points WP3, WP4 of second fixed point group G2 with the above-described positional relationship, secondary resonance is prevented from causing the positive X-direction side and the negative X-direction side of main fixed portion 421 to vibrate in opposite directions to each other along the Z direction.

[0076] (5) The first extending portions 410, 411 are connected to the second extending portions 412, 413 and the connecting portions 422, 423 via the curved portions 44, 46. This prevents stress from concentrating at a specific location and damaging the elastic member 40 when the elastic member 40 vibrates together with the movable element 32.

[0077] (6) The outer edges 410a, 411a of the first extending portions 410, 411 are provided with arc-shaped notches 414 at positions where they intersect with the second reference line RL2. This reduces the concentration of stress caused by vibration of the elastic member 40, and prevents damage to the elastic member 40.

[0078] (7) The width of the first extending portions 410, 411 in the second direction (Y direction) is smaller than the width of the fixed portion 42 in the second direction. This suppresses the concentration of stress due to vibration of the elastic member 40, and prevents damage to the elastic member 40.

[0079] The present technology can be configured as follows.

[0080] (1) A linear vibration motor comprising: an actuator having a movable element having a magnet and a back yoke, and a stator; a housing that accommodates the actuator; and an elastic member fixed to the movable element and the housing and supporting the movable element so that it can vibrate relative to the housing, wherein the elastic member has a pair of first extension portions extending along a first direction that intersects with a vibration direction in which the movable element vibrates, a pair of second extension portions extending along a second direction that intersects with the first direction and the vibration direction, and a fixed portion connecting to the first extension portions, wherein the fixed portion is located between the pair of first extension portions and the pair of second extension portions and is provided at a position overlapping with a center of the elastic member, and the fixed portion is fixed to the back yoke at a plurality of fixed points, wherein the plurality of fixed points are provided at positions symmetrical with respect to a first reference line that passes through the center and is parallel to the first direction, and are provided at positions symmetrical with respect to a second reference line that passes through the center and is parallel to the second direction.

[0081] (2) The linear vibration motor described in (1), wherein the fixed portion has a plurality of fixed point groups arranged along the second direction, each group including two of the fixed points arranged along the first direction.

[0082] (3) The linear vibration motor described in (2), wherein the fixed portion has a pair of end edges along the second direction, and the distance between one of the fixed points included in the fixed point group and one of the end edges of the fixed portion is equal to the distance between the other of the fixed points included in the fixed point group and the other of the end edges of the fixed portion.

[0083] (4) The linear vibration motor described in (3), wherein the fixed portion has a main fixed portion extending along the first direction centered on the central portion, and a pair of connecting portions connecting the main fixed portion to each of the pair of first extension portions, and the main fixed portion and each of the pair of connecting portions are provided with the fixed point group.

[0084] (5) The linear vibration motor according to (4), wherein the first extension portion is connected to the second extension portion and the connecting portion via a curved portion.

[0085] (6) The linear vibration motor according to any one of (1) to (5), wherein an arc-shaped notch is provided on the outer edge of the first extending portion at a position where the first extending portion intersects with the second reference line.

[0086] (7) A linear vibration motor according to any one of (1) to (6), wherein the width of the first extension portion along the second direction is smaller than the width of the fixed portion along the second direction. [Explanation of symbols]

[0087] 10 Linear vibration motor, 20 Housing, 30 Actuator, 31 Stator, 32 Movable element, 40 Elastic member, 41 Frame body portion, 42 Fixed portion, 44, 45, 46 Bending portion, 50 Flexible printed circuit board (FPC), 201 Bottom plate, 202, 203 First side wall plate, 204, 205 Second side wall plate, 206, 207 Connection plate, 320 Back yoke, 321 Magnet, 322 Pole piece, 323 Weight, 410, 411 First extension portion, 410a, 411a Outer edge, 412, 413 Second extension portion, 412a, 413a Protrusion portion, 414 Notch portion, 421 Main fixing portion, 421a, 421b, 422a, 422b, 423a, 423b Edges, 422,423 Connections, C Center, D1, D2 Steps, G1 1st fixed point group, G2 2nd fixed point group, G3 3rd fixed point group, RL1 1st reference line, RL2 2nd reference line, WP1,WP2,WP3,WP4,WP5,WP6 Fixed points

Claims

1. an actuator having a mover having a magnet and a back yoke, and a stator; a housing that accommodates the actuator; an elastic member fixed to the mover and the housing, and supporting the mover so as to be able to vibrate relative to the housing; the elastic member has a pair of first extending portions extending along a first direction intersecting a vibration direction in which the movable element vibrates, a pair of second extending portions extending along a second direction intersecting the first direction and the vibration direction, and a fixing portion connected to the first extending portions, the fixing portion is located between the pair of first extending portions and the pair of second extending portions, and is provided at a position overlapping with a central portion of the elastic member; the fixing portion is fixed to the back yoke at a plurality of fixing points, A linear vibration motor, wherein the multiple fixed points are arranged at positions symmetrical with respect to a first reference line that passes through the central portion and is parallel to the first direction, and are arranged at positions symmetrical with respect to a second reference line that passes through the central portion and is parallel to the second direction.

2. 2. The linear vibration motor according to claim 1, A linear vibration motor, wherein the fixed portion has a plurality of fixed point groups arranged along the second direction, each group including two of the fixed points arranged along the first direction.

3. 3. The linear vibration motor according to claim 2, the fixing portion has a pair of end sides along the second direction, A linear vibration motor in which the distance between one of the fixed points included in the fixed point group and one of the end edges of the fixed part is equal to the distance between the other of the fixed points included in the fixed point group and the other end edge of the fixed part.

4. 4. The linear vibration motor according to claim 3, the fixing portion includes a main fixing portion extending along the first direction with the central portion as a center, and a pair of connecting portions connecting the main fixing portion to each of the pair of first extending portions, The linear vibration motor, wherein the main fixed portion and the pair of connecting portions are each provided with the fixed point group.

5. 5. The linear vibration motor according to claim 4, The first extension portion is connected to the second extension portion and the connecting portion via a curved portion.

6. 6. The linear vibration motor according to claim 5, A linear vibration motor, wherein an arc-shaped notch is provided on the outer edge of the first extension portion at a position where the first extension portion intersects with the second reference line.

7. 7. The linear vibration motor according to claim 1, A linear vibration motor, wherein the width of the first extension portion along the second direction is smaller than the width of the fixed portion along the second direction.

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