Linear vibration motor and method for manufacturing linear vibration motor
Patent Information
- Application Number
- PCT/JP2024/027856
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-08-09
- Filing Date
- 2024-08-05
- Publication Date
- 2025-02-13
Smart Images
Figure JP2024027856_13022025_PF_FP_ABST
Abstract
Description
Linear vibration motor and method for manufacturing the same
[0001] The present invention relates to a linear vibration motor, a method for manufacturing a linear vibration motor, and a linear vibration motor.
[0002] Patent Document 1 describes a vibration actuator. The vibration actuator includes a hollow cylindrical shaft.
[0003] Fixed magnets are disposed on both axial ends of the shaft, and a movable magnet that is movable in the axial direction of the shaft is disposed inside the shaft between the magnets at both ends.
[0004] The vibration actuator realizes a magnetic spring mechanism by utilizing the repulsive force generated between a fixed magnet and a moving magnet.
[0005] Japanese Patent Application Laid-Open No. 2019-195787
[0006] However, in the conventional configuration including the linear vibration motor vibration actuator shown in Patent Document 1, a set screw or the like is provided as an adjustment member for adjusting the position of the fixed magnet in the axial direction of the shaft, so the axial length of the bracket is longer than that of the shaft, making it difficult to reduce the size in the axial direction.
[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a linear vibration motor with a magnetic spring mechanism that is compact in the axial direction.
[0008] A linear vibration motor according to one embodiment of the present invention comprises a cylindrical body having a through hole with one end in a first direction being a first opening end and the other end in the first direction being a second opening end, a movable magnet housed in the through hole of the cylindrical body and movable between the first opening end and the second opening end, a first stator magnet arranged closer to the first opening end in the first direction than the movable magnet so as to generate a magnetic repulsive force against the movable magnet, a second stator magnet arranged closer to the second opening end in the first direction than the movable magnet so as to generate a magnetic repulsive force against the movable magnet, a winding conductor arranged on the outer surface of the cylindrical body, and a case housing the cylindrical body housing the movable magnet, the first stator magnet, the second stator magnet, and the winding conductor.
[0009] The length A of the cylindrical body in the first direction, the length B of the case in the first direction, and the lengths C of the first stator magnet and the second stator magnet in the first direction satisfy the relationship A<B<A+2C. The case includes a side wall extending in the first direction, a first end wall connected to the side wall, and a second end wall connected to the side wall. The first end wall, the second end wall, a first portion of the side wall connected to the first end wall and having a predetermined length, and a second portion of the side wall connected to the second end wall are made of magnetic material. The first stator magnet is attracted to the first end wall by magnetic force and is positioned by the first end of the cylindrical body that forms the first open end. The second stator magnet is attracted to the second end wall by magnetic force and is positioned by the second end of the cylindrical body that forms the second open end.
[0010] Moreover, a linear vibration motor according to one embodiment of the invention comprises a cylindrical body having a through hole in which one end in a first direction is a first opening end and the other end in the first direction is a second opening end, a movable magnet housed in the through hole of the cylindrical body and movable between the first opening end and the second opening end, a first stator magnet arranged closer to the first opening end in the first direction than the movable magnet so as to generate a magnetic repulsive force against the movable magnet, a second stator magnet arranged closer to the second opening end in the first direction than the movable magnet so as to generate a magnetic repulsive force against the movable magnet, a winding conductor arranged on the outer surface of the cylindrical body, and a case that houses the cylindrical body in which the movable magnet is housed, the first stator magnet, the second stator magnet, and the winding conductor.
[0011] The length A of the cylindrical body in the first direction, the length B of the case in the first direction, and the length C of the first stator magnet and the second stator magnet in the first direction satisfy the relationship A + 2C < B. The case includes a side wall extending in the first direction, a first end wall connected to the side wall, and a second end wall connected to the side wall. The first end wall, the second end wall, a first portion of the side wall connected to the first end wall and having a predetermined length, and a second portion of the side wall connected to the second end wall are made of magnetic material. The first end wall includes a first recess that opens to the first open end, and the second end wall includes a second recess that opens to the second open end. At least a portion of the first stator magnet is accommodated in the first recess and is attracted to the first end wall by magnetic force. At least a portion of the second stator magnet is accommodated in the second recess and is attracted to the second end wall by magnetic force.
[0012] In these configurations, the first stator magnet and the second stator magnet are reliably positioned relative to the case at positions that allow them to continue to apply an appropriate magnetic force that causes the mover magnet to move (vibrate) in the through-hole of the cylindrical body.
[0013] According to this invention, a linear vibration motor with a magnetic spring mechanism that is compact in the axial direction can be realized.
[0014] FIG. 1(A) is an external perspective view of a linear vibration motor according to a first embodiment, and FIG. 1(B) is an external perspective view of a cylindrical body according to the first embodiment. FIG. 2 is an exploded perspective view of the linear vibration motor according to the first embodiment. FIGS. 3(A) and 3(B) are cross-sectional views of the linear vibration motor according to the first embodiment. FIG. 4 is a diagram illustrating the concept of a magnetic flux loop generated by a stator magnet and a mover magnet. FIGS. 5(A), 5(B), 5(C), and 5(D) are cross-sectional views showing the state at each step in a manufacturing method for the linear vibration motor according to the first embodiment. FIGS. 6(A) and 6(B) are cross-sectional views showing the state at each step in a manufacturing method for the linear vibration motor according to the first embodiment. FIG. 7 is a side cross-sectional view of a linear vibration motor according to a second embodiment. FIG. 8 is a side cross-sectional view of a linear vibration motor according to a third embodiment. FIG. 9 is a side cross-sectional view of a linear vibration motor according to a fourth embodiment. FIGS. 10(A) and 10(B) are side cross-sectional views of a linear vibration motor according to a fifth embodiment. FIG. 11 is a side cross-sectional view of a linear vibration motor according to a sixth embodiment. Fig. 12 is a cross-sectional view showing the state at each step in the manufacturing method for the linear vibration motor according to the sixth embodiment. Fig. 13 is a cross-sectional view showing the state at each step in the manufacturing method for the linear vibration motor according to the sixth embodiment. Fig. 14 is a side cross-sectional view of the linear vibration motor according to the seventh embodiment. Fig. 15 is a cross-sectional view showing the state at each step in the manufacturing method for the linear vibration motor according to the seventh embodiment.
[0015] First Embodiment A linear vibration motor and a method for manufacturing a linear vibration motor according to a first embodiment of the present invention will be described with reference to the drawings.
[0016] (Configuration of linear vibration motor 10) Fig. 1(A) is an external perspective view of a linear vibration motor according to the first embodiment, and Fig. 1(B) is an external perspective view of a cylindrical body according to the first embodiment. Fig. 2 is an exploded perspective view of the linear vibration motor according to the first embodiment. Figs. 3(A) and 3(B) are cross-sectional views of the linear vibration motor according to the first embodiment. Fig. 3(A) shows the A-A cross section shown in Fig. 1(A), which is a cross section parallel to the longitudinal direction of the linear vibration motor. Fig. 3(B) shows the B-B cross section shown in Fig. 3(A), which is a cross section perpendicular to the longitudinal direction of the linear vibration motor.
[0017] As shown in Figures 1(A), 1(B), 2, 3(A), and 3(B), the linear vibration motor 10 includes a case 20, a cylindrical body 30, winding conductors 41, 42, stator magnets 51, 52, a mover magnet 60, and a flexible wiring board 70.
[0018] One of the stator magnets 51 and 52 corresponds to the first stator magnet, and the other corresponds to the second stator magnet. In the following description, it is assumed that the stator magnet 51 corresponds to the first stator magnet, and the stator magnet 52 corresponds to the second stator magnet.
[0019] The case 20 has a rectangular parallelepiped shape and is made of a magnetic material. The case 20 includes a main body 21 and a lid 22.
[0020] The main body 21 is a rectangular parallelepiped box with one side open along the longitudinal direction (the X-axis direction in the drawing). More specifically, the main body 21 includes side walls 211, 212, 213, end walls 214, and end walls 215, each of which is made of a flat plate.
[0021] The side walls 211, 212, and 213 have main surfaces parallel to the longitudinal direction. The main surface of the side wall 213 is perpendicular to the main surfaces of the side walls 211 and 212. The side wall 213 is connected to the side walls 211 and 212.
[0022] The end walls 214 and 215 have main surfaces perpendicular to the longitudinal direction. The end wall 214 is connected to one longitudinal end of the side walls 211, 212, and 213. The end wall 215 is connected to one longitudinal end of the side walls 211, 212, and 213.
[0023] The lid 22 is a flat plate. The lid 22 has substantially the same shape as the side walls 211, 212, and 213. The lid 22 is arranged to close the opening of the main body 21. As a result, the case 20 has a substantially rectangular parallelepiped case internal space 210 surrounded by the main body 21 and the lid 22.
[0024] An opening 229 is formed in the lid 22. The opening 229 allows the case internal space 210 to communicate with the external space of the case 20.
[0025] The cylindrical body 30 includes a cylindrical main body 31, a flange 321, and a flange 322. The cylindrical body 30 is made of a non-magnetic material. The main body 31 has a first end E311 and a second end E312, and has a through hole 310 that communicates between an opening (first open end) of the first end E311 and an opening (second open end) of the second end E312.
[0026] Flange portions 321 and 322 are flat plates with a generally polygonal shape. Flange portions 321 and 322 are arranged on the outer peripheral surface of cylindrical main body 31. The flat surface of flange portion 321 and the flat surface of flange portion 322 are perpendicular to the extension direction of main body 31 (the extension direction of through hole 310). Flange portions 321 and 322 are arranged on main body 31 in a shape that protrudes outward from the outer peripheral surface of main body 31.
[0027] The flanges 321 and 322 are disposed at midpoints in the longitudinal direction of the main body 31. More specifically, the flanges 321 and 322 are disposed at approximately the same distance on the first end E311 side and the second end E312 side, with the center of the main body 31 in the longitudinal direction as a reference.
[0028] In this case, the flange portions 321 and 322 are positioned so that the winding conductors 41 and 42 (described later) are positioned at a predetermined position relative to the main body 31 (for example, a position that does not overlap the stator magnets 51 and 52 in the longitudinal direction).
[0029] The length of flanges 321 and 322 in one direction perpendicular to the longitudinal direction (Y direction in the figure) is approximately the same as the distance between side wall 213 and lid 22 of case 20. The length of flanges 321 and 322 in another direction perpendicular to the longitudinal direction (Z direction in the figure) is approximately the same as the distance between side wall 211 and side wall 212 of case 20.
[0030] The surfaces of the flanges 321 and 322 that are close to or in contact with the side walls 211, 212, 213 and the lid 22 are flat.
[0031] The winding conductors 41 and 42 each have a cylindrical shape formed by winding a linear conductor. The winding conductors 41 and 42 are arranged along the outer circumferential surface of the main body 31 of the cylindrical body 30. In other words, the main body 31 passes through the central opening of the winding conductor 41 and the central opening of the winding conductor 42.
[0032] The winding conductor 41 is disposed closer to the first end E311 than the flange 321 of the main body 31 and abuts against the flange 321. The winding conductor 42 is disposed closer to the second end E312 than the flange 322 of the main body 31 and abuts against the flange 322.
[0033] The stator magnets 51, 52, and mover magnet 60 are made of permanent magnets having ferromagnetic properties. For example, the stator magnets 51, 52, and mover magnet 60 are made of neodymium magnets.
[0034] The stator magnet 51, the stator magnet 52, and the mover magnet 60 are cylindrical. The height of the stator magnet 51 and the height of the stator magnet 52 are shorter than the height of the mover magnet 60.
[0035] The shapes of the stator magnets 51, 52, and mover magnet 60 when viewed along their respective height directions are substantially the same as the shape of the through-hole 310 of the main body 31 of the cylindrical body 30 when viewed in the axial direction. The sizes of the stator magnets 51, 52, and mover magnet 60 when viewed along their respective height directions are such that they can be accommodated in the through-hole 310.
[0036] The mover magnet 60 is housed in the through-hole 310 of the cylindrical body 30. The mover magnet 60 is housed in a state in which it can move between a first end E311 (first opening end) and a second end E312 (second opening end).
[0037] The stator magnet 51 is arranged in a position overlapping the first end E311 in the longitudinal direction of the main body 31 of the cylindrical body 30, with a portion of the stator magnet 51 in the height direction housed in the through-hole 310.
[0038] The stator magnet 52 is arranged in a position overlapping the second end E312 in the longitudinal direction of the main body 31 of the cylindrical body 30, with a portion of the stator magnet 52 in the height direction housed in the through-hole 310.
[0039] In this case, the stator magnet 51 and the mover magnet 60 are arranged so that the same magnetic poles face each other. Furthermore, the stator magnet 52 and the mover magnet 60 are arranged so that the same magnetic poles face each other.
[0040] For example, specifically as shown in Figures 2 and 3(A), the mover magnet 60 is arranged so that the north pole face 60N faces the first end E311 and the south pole face 60S faces the second end E312.
[0041] The stator magnet 51 is arranged so that its north pole face 51N faces the mover magnet 60 and its south pole face 51S faces outward in the longitudinal direction from the first end E311 of the main body 31. In this way, the stator magnet 51 is arranged so as to generate a repulsive force due to magnetic force with respect to the mover magnet 60.
[0042] The stator magnet 52 is arranged so that its south pole face 52S faces the mover magnet 60 and its north pole face 52N faces outward along the longitudinal direction from the second end E312 of the main body 31. In this way, the stator magnet 52 is arranged so as to generate a repulsive force due to magnetic force with respect to the mover magnet 60.
[0043] Flexible wiring board 70 has a conductor pattern and is connected to winding conductors 41 and 42 through wiring 400. Wiring 400 is formed from the tip portions of winding conductors 41 and 42.
[0044] The cylindrical body 30, in which the mover magnet 60 is housed and in which the plurality of winding conductors 41, 42 are arranged, the stator magnets 51, 52, and the flexible wiring board 70 are housed in the case internal space 210 of the case 20. In this case, the extending direction of the cylindrical body 30 is parallel to the longitudinal direction of the case 20. The extending direction of the cylindrical body 30 is the longitudinal direction of the cylindrical body 30, which is the direction connecting the first end E311 and the second end E312 of the cylindrical body 30.
[0045] The cylindrical body 30 is disposed at a position where the center of the cylindrical body 30 in the extending direction substantially coincides with the center of the case 20 in the longitudinal direction.
[0046] The stator magnet 51 is arranged so that the south pole surface 51S abuts against the inner wall surface of the end wall 214 of the case 20. Furthermore, a portion of the stator magnet 51 on the north pole surface 51N side in the height direction is accommodated in the through hole 310 of the main body 31 of the cylindrical body 30.
[0047] The stator magnet 52 is arranged so that the north pole surface 52N abuts against the inner wall surface of the end wall 215 of the case 20. Furthermore, a portion of the stator magnet 52 on the south pole surface 52S side in the height direction is accommodated in the through hole 310 of the main body 31 of the cylindrical body 30.
[0048] The flexible wiring board 70 is inserted through the opening 229 of the lid 22 , with one part of the flexible wiring board 70 being disposed in the case internal space 210 and the other part protruding to the outside of the case 20 .
[0049] In this configuration, an AC drive signal is applied to the winding conductors 41 and 42. This excites an electromagnetic field in the winding conductors 41 and 42. This electromagnetic field acts on the mover magnet 60, causing it to move in the longitudinal direction of the cylindrical body 30.
[0050] At this time, the mover magnet 60 receives a magnetic repulsive force from the stator magnets 51 and 52 at both ends in the longitudinal direction, causing the mover magnet 60 to vibrate along the longitudinal direction. Therefore, the linear vibration motor 10 can generate vibrations using a magnetic spring mechanism.
[0051] This vibration is transmitted to the case 20, and the linear vibration motor 10 can apply vibration to an object or person that comes into contact with the case 20.
[0052] In this configuration, since the case 20 is made of a magnetic material, the stator magnet 51 is attracted to the end wall 214 by magnetic force. Furthermore, the stator magnet 52 is fixed to the end wall 215 by magnetic force.
[0053] Specifically, Fig. 4 is a diagram showing the concept of magnetic flux loops generated by the stator magnet and the mover magnet. Note that Fig. 4 shows the stator magnet 52 as an example, but the stator magnet 51 can also generate similar magnetic flux loops.
[0054] As shown in Figure 4, the magnetic field (magnetic lines of force) originating from the stator magnet 52 passes through the end wall 215 of the case 20, which is made of a magnetic material and is located nearby, and then returns to the stator magnet 52 through the side walls 211, 212, and 213 (not shown), and the lid 22 (not shown).
[0055] In this case, the mover magnet 60 is located toward the center in the longitudinal direction of the case 20. The stator magnet 52 and the mover magnet 60 are in a relationship in which they generate a repulsive magnetic force. As a result, the magnetic field generated by the stator magnet 52 is less likely to leak toward the mover magnet 60, and is confined to the periphery of the stator magnet 52.
[0056] Therefore, the magnetic flux loop of the stator magnet 52 has a shape that passes through the end wall 215 of the case 20, the side walls 211, 212, and 213 (not shown), and a predetermined length of the side of the lid 22 (not shown) that is connected to the end wall 215. As a result, the stator magnet 52 is attracted to the end wall 215 that it abuts on in a planar manner.
[0057] Similarly, the stator magnet 51 is attracted to the end wall 214 that contacts it in a planar manner.
[0058] As a result, the stator magnets 51 and 52 are reliably fixed to the case 20 in a position that allows them to continue to apply an appropriate magnetic force to the mover magnet 60 to move (vibrate) in the through-hole 310 of the cylindrical body 31. In this case, no other members that would significantly increase the size of the positioning are required, so the linear vibration motor 10 can be made smaller. Furthermore, the stator magnets 51 and 52 can be fixed to the case 20 without using adhesive. Therefore, a linear vibration motor 10 with a magnetic spring mechanism that is easy to manufacture can be realized.
[0059] 3A , with the longitudinal direction of case 20 and the extension direction of cylindrical body 30 defined as a first direction, the length L31 in the first direction of cylindrical body 30 (length A in the first direction), the length L21i in the first direction of case 20 (length B in the first direction), the length L51 in the first direction of stator magnet 51 (length C in the first direction), and the length L52 in the first direction of stator magnet 52 (length C in the first direction) satisfy the following relationship: Note that length L21i of case 20 is the distance between the inner wall surface of end wall 214 and the inner wall surface of end wall 215.
[0060] L31<L21i<(L31+L51+L52) That is, the length L21i of the case 20 is longer than the length L31 of the cylindrical body 30. Moreover, the length L21i of the case 20 is shorter than the total length of the length L31 of the cylindrical body 30, the length L51 of the stator magnet 51, and the length L52 of the stator magnet 52.
[0061] Here, if the length L51 and the length L52 are the same and are taken as the length L50, the following relationship is satisfied: L31<L21i<(L31+2L50) This corresponds to A<B<A+2C in the present application.
[0062] With this relationship, when the longitudinal center of the case 20 and the center of the cylindrical body 30 in the extension direction are substantially aligned, the stator magnet 51 is housed in a portion of the cylindrical body 30 that is a predetermined length on the first end E311 side. Similarly, the stator magnet 52 is housed in a portion of the cylindrical body 30 that is a predetermined length on the second end E312 side.
[0063] This makes it possible to more reliably position the stator magnets 51 and 52 in a plane perpendicular to the longitudinal direction (the YZ plane in the figure). Therefore, it is possible to easily manufacture the linear vibration motor 10 with a magnetic spring mechanism that allows for more stable positioning of the stator magnets 51 and 52.
[0064] It is more preferable that the linear vibration motor 10 satisfy the relationship L31<L21i<(L31+L50). This ensures that the stator magnets 51 and 52 are always inside the through-holes 310 of the cylindrical body 30, even if the cylindrical body 30 moves in the longitudinal direction of the case 20. Therefore, the linear vibration motor 10 can more reliably achieve stable positioning of the stator magnets 51 and 52.
[0065] 3B, in the linear vibration motor 10, the outer surfaces (circumferential surfaces) of the flanges 321 and 322 of the cylindrical body 30 are in planar contact with the inner wall surfaces of the side walls 211, 212, and 213 of the case 20 and the lid 22. This makes it possible to prevent the cylindrical body 30 from rotating around an axis corresponding to the direction in which the cylindrical body 30 extends.
[0066] (Manufacturing method of linear vibration motor 10) Figures 5(A), 5(B), 5(C), 5(D), 6(A), and 6(B) are cross-sectional views showing the state at each step in the manufacturing method of the linear vibration motor according to the first embodiment.
[0067] First, a cylindrical body 30 having a through hole 310 and flanges 321 and 322 on its outer circumferential surface is prepared.
[0068] 5A, the winding conductor 41 is moved from the first end E311 of the cylindrical body 30 along the outer circumferential surface of the cylindrical body 30 (main body 31). The winding conductor 42 is moved from the second end E312 of the cylindrical body 30 along the outer circumferential surface of the cylindrical body 30 (main body 31). The winding conductor 41 is brought into contact with the flange portion 321, and the winding conductor 41 is positioned relative to the cylindrical body 30. The winding conductor 42 is brought into contact with the flange portion 322, and the winding conductor 42 is positioned relative to the cylindrical body 30.
[0069] 5(B), 5(C), and 5(D), while closing the opening at one end (second end E312) of the through-hole 310 in the main body 31 of the cylindrical body 30, the stator magnet 52, the mover magnet 60, and the stator magnet 51 are inserted into the through-hole 310 in this order from the opening at the other end (first end E311). At this time, the mover magnet 60 is inserted so that the magnetic poles of the stator magnets 51 and 52 are arranged to repel each other, i.e., so that they generate a repulsive magnetic force.
[0070] Next, as shown in Figure 6 (A), the winding conductors 41 and 42 are positioned, and the cylindrical body 30 into which the stator magnet 52, the mover magnet 60, and the stator magnet 51 have been inserted is inserted through an opening into a rectangular parallelepiped case 20 made of a magnetic material and having an opening on one of its longitudinal sides.
[0071] The cylindrical body 30 is inserted until the flanges 321 and 322 abut against the side wall 213 .
[0072] When the cylindrical body 30 is inserted into the case 20, the stator magnet 51 is attracted to the end wall 214 by magnetic force, and the stator magnet 52 is attracted to the end wall 215 by magnetic force (see FIG. 6B).
[0073] Next, the ends of the winding conductors 41 and 42 are pulled out through the opening of the case 20 via a flexible wiring board 70 (not shown), and the opening is sealed with a magnetic cover 22 as shown in FIG. 6B.
[0074] By using the manufacturing method described above, the linear vibration motor 10 can be easily manufactured without using adhesive to fix the stator magnets 51 and 52 together.
[0075] Second Embodiment A linear vibration motor and a method for manufacturing a linear vibration motor according to a second embodiment of the present invention will be described with reference to the drawings.
[0076] (Configuration of linear vibration motor 10A) Figure 7 is a side cross-sectional view of a linear vibration motor according to the second embodiment. As shown in Figure 7, the linear vibration motor 10A according to the second embodiment differs from the linear vibration motor 10 according to the first embodiment in the configuration of the case 20A and the positional relationship of the stator magnets 51 and 52 with respect to the cylindrical body 30. The other configuration of the linear vibration motor 10A is the same as that of the linear vibration motor 10, and a description of similar parts will be omitted.
[0077] The case 20A includes a main body 21A and a lid 22. The main body 21A differs from the main body 21 of the case 20 according to the first embodiment in that the main body 21A includes a recess C214A and a recess C215A.
[0078] The recess C214A is formed in the end wall 214. The recess C214A is recessed outward from the case 20A. The recess C214A is formed at a position facing the opening of the first end E311 of the cylindrical body 30.
[0079] The recess C215A is formed in the end wall 215. The recess C215A is recessed outward from the case 20A. The recess C215A is formed at a position facing the opening of the second end E312 of the cylindrical body 30.
[0080] The stator magnet 51 is housed in the recess C214A. The stator magnet 51 does not enter the through-hole 310 of the cylindrical body 30.
[0081] The stator magnet 52 is housed in the recess C215A. The stator magnet 52 does not enter the through-hole 310 of the cylindrical body 30.
[0082] In this configuration, with the longitudinal direction of case 20A and the extension direction of cylindrical body 30 defined as a first direction, the length L31 in the first direction of cylindrical body 30 (length A in the first direction), the length L21i in the first direction of case 20A (length B in the first direction), the length L51 in the first direction of stator magnet 51 (length C in the first direction), and the length L52 in the first direction of stator magnet 52 (length C in the first direction) satisfy the following relationship: Note that length L21i of case 20A is the distance between the inner wall surface of the portion of end wall 214 where recess C214A is not formed and the inner wall surface of the portion of end wall 215A where recess C215A is not formed.
[0083] (L31+L51+L52)<L21i Here, if the length L51 and the length L52 are the same and are taken as the length L50, the relationship (L31+2L50)<L21i is satisfied, which corresponds to A+2C<B in the present application.
[0084] Even with this configuration, the stator magnet 51 is housed in the recess C214A (first recess) and is attracted by magnetic force to the end wall 214. The stator magnet 52 is housed in the recess C215A (second recess) and is attracted by magnetic force to the end wall 215.
[0085] This makes it possible to easily manufacture the linear vibration motor 10C with a magnetic spring mechanism that allows for more stable positioning of the stator magnets 51 and 52.
[0086] Therefore, the linear vibration motor 10A can achieve the same effects as the linear vibration motor 10.
[0087] Third Embodiment A linear vibration motor according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 8 is a side cross-sectional view of the linear vibration motor according to the third embodiment.
[0088] As shown in FIG. 8, the linear vibration motor 10B according to the third embodiment differs from the linear vibration motor 10 according to the first embodiment in that it additionally includes a spacer SP51 and a spacer SP52.
[0089] The spacers SP51 and SP52 are plate-shaped and made of a magnetic material. The spacer SP51 is disposed between the stator magnet 51 and the inner wall surface of the end wall 214 and abuts against the stator magnet 51 and the inner wall surface of the end wall 214. The spacer SP52 is disposed between the stator magnet 52 and the inner wall surface of the end wall 215 and abuts against the stator magnet 52 and the inner wall surface of the end wall 215.
[0090] By using such magnetic spacers SP51 and SP52, the linear vibration motor 10B can achieve the same effects as the linear vibration motor 10. Furthermore, in the linear vibration motor 10B, the positions of the stator magnets 51 and 52 relative to the mover magnet 60 in the direction parallel to the vibration direction of the mover magnet 60 can be adjusted to appropriate positions by the spacers SP51 and SP52.
[0091] The linear vibration motor 10B can achieve the same effects as the linear vibration motor 10.
[0092] [Fourth embodiment] A linear vibration motor according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 9 is a side cross-sectional view of the linear vibration motor according to the fourth embodiment.
[0093] 9, the linear vibration motor 10C according to the fourth embodiment differs from the linear vibration motor 10 according to the first embodiment in the configuration of the case 20F. The other configuration of the linear vibration motor 10C is the same as that of the linear vibration motor 10, and a description of the same parts will be omitted.
[0094] The case 20C includes a main body 21C. The main body 21C includes a side wall 211C, a side wall 212C, and a side wall 213C (not shown).
[0095] The side wall 211C includes a magnetic material portion 211Cd and a non-magnetic material portion 211Ci. The magnetic material portion 211Cd is located at the end of the side wall 211C that connects to the end wall 214 and the end wall 215, and the non-magnetic material portion 211Ci is located between the magnetic material portions 211Cd at both ends. The magnetic material portion 211Cd corresponds to the "first portion" and "second portion" of the present invention, and the non-magnetic material portion 211Ci corresponds to the "third portion" of the present invention.
[0096] The side wall 212C includes a magnetic material portion 212Cd and a non-magnetic material portion 212Ci. The magnetic material portion 212Cd is located at the end of the side wall 212C that connects to the end wall 214 and the end wall 215, and the non-magnetic material portion 212Ci is located between the magnetic material portions 212Cd at both ends.
[0097] The side wall 213C and the lid 22, which are not shown, have the same configuration as the side wall 211C and the side wall 212C.
[0098] It is preferable that the length L21Cd in the first direction of one end of the magnetic material portion 211Cd and the magnetic material portion 212Cd is greater than or equal to the length L51 of the stator magnet 51 and the length L52 of the stator magnet 52 (L21Cd ≧ L51, L52: corresponding to C or greater in the present application).
[0099] With this configuration, the linear vibration motor 10C can achieve the same effects as the linear vibration motor 10.
[0100] When a configuration in which the case 20A includes recesses C214A and C215A, such as the linear vibration motor 10A according to the second embodiment, is applied to a configuration in which the non-magnetic material portion 211Ci is used in the case 20C, such as the linear vibration motor 10C according to the fourth embodiment, the following dimensions are preferable: The length L21Cd in the first direction of one end of the magnetic material portion 211Cd and the magnetic material portion 212Cd is preferably equal to or greater than the value obtained by subtracting the depth L214A of the recess C214A from the length L51 of the stator magnet 51 (corresponding to equal to or greater than (C-D) in the present application) and the value obtained by subtracting the depth L215C of the recess C215C from the length L52 of the stator magnet 52 (corresponding to equal to or greater than (C-D) in the present application).
[0101] The linear vibration motor 10C can achieve the same effects as the linear vibration motor 10.
[0102] Fifth Embodiment A linear vibration motor according to a fifth embodiment of the present invention will be described with reference to the drawings. Figures 10(A) and 10(B) are side cross-sectional views of the linear vibration motor according to the fifth embodiment.
[0103] As shown in Fig. 10A, the linear vibration motor 10D1 according to the fifth embodiment differs from the linear vibration motor 10 according to the first embodiment in the configuration of the lid 22G1. As shown in Fig. 10B, the linear vibration motor 10D2 according to the fifth embodiment differs from the linear vibration motor 10 according to the first embodiment in the configuration of the lid 22D2. The other configurations of the linear vibration motors 10D1 and 10D2 are similar to those of the linear vibration motor 10, and descriptions of similar parts will be omitted.
[0104] 10A, the lid 22D1 has a groove G22D into which the flanges 321 and 322 of the main body 31 of the cylindrical body 30 are housed or fitted. By housing or fitting the flanges 321 and 322 in the groove G22D, the position of the main body 31 of the cylindrical body 30 relative to the case 20D1 in the vibration direction of the mover magnet 60 is fixed.
[0105] 10(B), the lid 22D2 has a protrusion P22D that is sandwiched between the flanges 321 and 322 of the main body 31 of the cylindrical body 30. By sandwiching the protrusion P22D between the flanges 321 and 322, the position of the main body 31 of the cylindrical body 30 relative to the case 20D2 in the vibration direction of the mover magnet 60 is fixed.
[0106] As a result, the linear vibration motor 10D1 and the linear vibration motor 10D2 can produce the same effects as the linear vibration motor 10, and can also generate vibrations more effectively.
[0107] In this embodiment, the groove or protrusion is formed on the lid, but the groove or protrusion may be formed on the side wall of the main body of the case.
[0108] Sixth Embodiment A linear vibration motor according to a sixth embodiment of the present invention will be described with reference to the drawings. Fig. 11 is a side cross-sectional view of the linear vibration motor according to the sixth embodiment.
[0109] 11, the linear vibration motor 10E according to the sixth embodiment differs from the linear vibration motor 10 according to the first embodiment in that an adhesive ADH is used. The other configurations of the linear vibration motor 10E are the same as those of the linear vibration motor 10, and a description of the same parts will be omitted.
[0110] In the linear vibration motor 10E, the stator magnet 51 is adhered and fixed to the end wall 214 using the adhesive ADH. The stator magnet 52 is adhered and fixed to the end wall 215 using the adhesive ADH. The adhesive ADH may also be adhered to the cylindrical body 31.
[0111] 12 and 13 are cross-sectional views showing the state at each step in a method for manufacturing a linear vibration motor according to the sixth embodiment. The manufacturing method shown in FIG. 12 is different from the manufacturing method shown in FIG. 13.
[0112] 12, the adhesive ADH is applied to the first end E311 and the second end E312 of the cylindrical body 31 with the stator magnets 51 and 52 inserted into the cylindrical body 31. At this point, the adhesive ADH is in an uncured state.
[0113] When the cylindrical body 31 coated with the adhesive ADH is inserted in this manner, the cylindrical body 31 is placed in a predetermined position in the case 20, as shown in the first embodiment. After this, the stator magnet 51 is attracted to the end wall 214 by magnetic force, and the stator magnet 52 is attracted to the end wall 215 by magnetic force. Here, because the adhesive ADH is applied to the first end E311 and the second end E312 of the cylindrical body 31, the adhesive ADH adheres to the stator magnet 51 and the end wall 214, and to the stator magnet 52 and the end wall 215. After this, as the adhesive ADH hardens, the stator magnet 51 is adhered to the end wall 214, and the stator magnet 52 is adhered to the end wall 215.
[0114] 13 , first, the cylindrical body 31 is placed in a predetermined position in the case 20, with the stator magnet 51 attached to the end wall 214 and the stator magnet 52 attached to the end wall 215. In this state, the adhesive ADH is applied by a nozzle to the positions of the stator magnets 51 and 52. Thereafter, the adhesive ADH hardens, bonding the stator magnet 51 to the end wall 214 and bonding the stator magnet 52 to the end wall 215.
[0115] With this configuration, the linear vibration motor 10E can achieve the same effects as the linear vibration motor 10.
[0116] Seventh Embodiment A linear vibration motor according to a seventh embodiment of the present invention will be described with reference to the drawings. Fig. 14 is a side cross-sectional view of the linear vibration motor according to the seventh embodiment.
[0117] 14, the linear vibration motor 10F according to the seventh embodiment differs from the linear vibration motor 10A according to the second embodiment in that an adhesive ADH is used. The other configurations of the linear vibration motor 10F are the same as those of the linear vibration motor 10A, and a description of the same parts will be omitted.
[0118] The linear vibration motor 10F has an adhesive ADH on at least the wall surfaces of the recess C214F and the wall surfaces of the recess C215F in the case 20F.
[0119] The stator magnet 51 is housed in the recess C214F and is adhered and fixed to the wall surface of the recess C214F by adhesive ADH.
[0120] The stator magnet 52 is housed in the recess C215F and is adhered and fixed to the wall surface of the recess C215F by adhesive ADH.
[0121] (Manufacturing Method of Linear Vibration Motor 10F) FIGS. 15A to 15C are cross-sectional views showing the state of each step in the manufacturing method of the linear vibration motor according to the seventh embodiment.
[0122] 15, the adhesive ADH is applied to the recesses C214F and C215F in the main body 21F of the case 20F. At this point, the adhesive ADH is in an uncured state.
[0123] Next, the cylindrical body 31 with the stator magnets 51 and 52 inserted therein is inserted into the main body 21F.
[0124] When the cylindrical body 31 reaches a position where it overlaps with the recesses C214F and C215F, the stator magnet 51 is attracted into the recess C214F and housed in the recess C214F to which the adhesive ADH is applied. Similarly, the stator magnet 52 is attracted into the recess C215F and housed in the recess C215F to which the adhesive ADH is applied.
[0125] Thereafter, the adhesive ADH hardens, so that the stator magnet 51 adheres to the end wall 214 within the recess C214F, and the stator magnet 52 adheres to the end wall 215 within the recess C215F.
[0126] With this configuration, the linear vibration motor 10F can achieve the same effects as the linear vibration motor 10.
[0127] 14, in the linear vibration motor 10F, the stator magnets 51 and 52 are fixed with adhesive ADH, and portions of the stator magnets 51 and 52 are inserted into the through-holes 310 of the cylindrical body 31. This allows the stator magnets 51 and 52 to be fixed in the appropriate positions more reliably.
[0128] <1> A linear vibration motor comprising: a cylinder having a through hole, one end of which in a first direction is a first opening end and the other end in the first direction is a second opening end; a mover magnet housed in the through hole of the cylinder and movable between the first opening end and the second opening end; a first stator magnet arranged closer to the first opening end in the first direction than the mover magnet so as to generate a magnetic repulsive force against the mover magnet; a second stator magnet arranged closer to the second opening end in the first direction than the mover magnet so as to generate a magnetic repulsive force against the mover magnet; winding conductors arranged on an outer circumferential surface of the cylinder; and a case that houses the cylinder that houses the mover magnet, the first stator magnet, the second stator magnet, and the winding conductors, wherein a length A of the cylinder in the first direction, a length B of the case in the first direction, and a length C of the first stator magnet and the second stator magnet in the first direction satisfy the relationship A<B<A+2C, the case comprises a side wall extending in the first direction, a first end wall connected to the side wall, and a second end wall connected to the side wall and facing the first end wall; the first end wall, the second end wall, a first portion of the side wall connected to the first end wall and having a predetermined length, and a second portion of the side wall connected to the second end wall are made of magnetic material; the first stator magnet is attracted to the first end wall by magnetic force and is positioned by a first end of the cylinder that forms the first open end; and the second stator magnet is attracted to the second end wall by magnetic force and is positioned by a second end of the cylinder that forms the second open end.
[0129] <2> The linear vibration motor of <1>, wherein a length A of the cylindrical body in the first direction, a length B of the case in the first direction, and a length C of the first stator magnet and the second stator magnet in the first direction satisfy the relationship A<B<A+C.
[0130] <3> The linear vibration motor of <1> or <2>, wherein the case includes a third portion disposed between the first portion and the second portion on the side wall and connecting the first portion and the second portion, the third portion being made of a non-magnetic material, and the lengths of the first portion and the second portion in the first direction are equal to or greater than C.
[0131] <4> The linear vibration motor according to any one of <1> to <3>, wherein the first end wall is open to the first opening end and has a first recess facing the first opening end, the second end wall is open to the second opening end and has a second recess facing the second opening end, the first stator magnet is housed in the first recess, and the second stator magnet is housed in the second recess.
[0132] <5> A linear vibration motor comprising: a cylinder having a through hole, one end of which in a first direction is a first opening end and the other end in the first direction is a second opening end; a mover magnet housed in the through hole of the cylinder and movable between the first opening end and the second opening end; a first stator magnet arranged closer to the first opening end in the first direction than the mover magnet so as to generate a magnetic repulsive force against the mover magnet; a second stator magnet arranged closer to the second opening end in the first direction than the mover magnet so as to generate a magnetic repulsive force against the mover magnet; winding conductors arranged on an outer circumferential surface of the cylinder; and a case that houses the winding conductors, wherein a length A of the cylinder in the first direction, a length B of the case in the first direction, and a length C of the first stator magnet and the second stator magnet in the first direction satisfy the relationship A + 2C < B, the case comprises a side wall extending in the first direction, a first end wall connected to the side wall, and a second end wall connected to the side wall and facing the first end wall; the first end wall, the second end wall, a first portion of the side wall of a predetermined length connected to the first end wall, and a second portion of the side wall of a predetermined length connected to the second end wall are made of magnetic material; the first end wall comprises a first recess that opens to the first opening end side; the second end wall comprises a second recess that opens to the second opening end side; at least a portion of the first stator magnet is accommodated in the first recess and is attracted to the first end wall by magnetic force; and at least a portion of the second stator magnet is accommodated in the second recess and is attracted to the second end wall by magnetic force.
[0133] <6> The linear vibration motor of <5>, wherein the case includes a third portion disposed between the first portion and the second portion on the side wall and connecting the first portion and the second portion, the third portion being made of a non-magnetic material, and the length of the first portion and the second portion in the first direction is equal to or greater than (C-D), where D is the depth of the first recess and the second recess.
[0134] <7> The linear vibration motor according to any one of <1> to <6>, wherein the case has a rectangular parallelepiped shape, the cylindrical body has a flange portion that positions the winding conductor, the flange portion has a polygonal shape when viewed in the first direction, and the side wall of the case and the polygonal outer surface of the flange portion are in surface contact.
[0135] <8> The linear vibration motor according to any one of <1> to <7>, wherein the first stator magnet and the second stator magnet are fixed to the case by adhesive.
[0136] <9> A step of preparing a cylinder having a through hole and a polygonal flange on its outer circumferential surface; a step of moving a winding conductor from an end of the cylinder along the outer circumferential surface of the cylinder and positioning the winding conductor by the flange; a step of inserting a first stator magnet, a mover magnet, and a second stator magnet into the through hole from the other end of the cylinder while closing one end of the through hole in that order, so that the magnetic poles of the mover magnet are aligned such that the first stator magnet and the second stator magnet repel each other; a step of inserting the cylinder, in which the winding conductor has been positioned and the first stator magnet, the mover magnet, and the second stator magnet have been inserted, into a rectangular parallelepiped case made of a magnetic material and one of its longitudinal sides is opened, through the opening; a step of drawing out the end of the winding conductor from the opening of the case and sealing the opening with a magnetic cover; a longitudinal length A of the cylinder, a longitudinal length B of the case, and a length C of the first stator magnet and the second stator magnet in the insertion direction satisfying the relationship A<B<A+2C; a polygonal flange is brought into contact with an inner wall surface of the case to restrict rotation of the cylinder within the case; and movement of the first stator magnet and the second stator magnet in a plane perpendicular to the longitudinal direction is restricted by the cylinder, and movement in the longitudinal direction is restricted by a repulsive magnetic force between the first stator magnet and the second stator magnet.
[0137] DESCRIPTION OF SYMBOLS 10, 10A, 10B, 10C, 10D, 10E, 10F: Linear vibration motor 20, 20A, 20C, 20D, 20F: Case 21, 21A, 21C, 21F: Main body 22, 22A: Lid 30: Cylinder 31: Main body 41, 42: Winding conductor 51, 52: Stator magnet 60: Mover magnet 51N, 52N, 60N: North pole surface 51S, 52S, 60S: South pole surface 70: Flexible wiring board 210: Case internal space 211, 212, 213: Side wall 214, 215: End wall 229: Opening 310: Through hole 400: Wiring C214C, C214F, C215C, C215F, C22B: Recess E311: First end E312: Second end F214, F215: Storage walls
Claims
1. A linear vibration motor comprising: a cylinder having a through hole, one end of which in a first direction is a first opening end and the other end in the first direction is a second opening end; a mover magnet housed in the through hole of the cylinder and movable between the first opening end and the second opening end; a first stator magnet arranged closer to the first opening end in the first direction than the mover magnet so as to generate a magnetic repulsive force against the mover magnet; a second stator magnet arranged closer to the second opening end in the first direction than the mover magnet so as to generate a magnetic repulsive force against the mover magnet; a winding conductor arranged on the outer circumferential surface of the cylinder; and a case that houses the cylinder in which the mover magnet is housed, the first stator magnet, the second stator magnet, and the winding conductor, wherein a length A of the cylinder in the first direction, a length B of the case in the first direction, and a length C of the first stator magnet and the second stator magnet in the first direction satisfy the relationship A<B<A+2C, the case comprises a sidewall extending in the first direction, a first end wall connected to the sidewall, and a second end wall connected to the sidewall and facing the first end wall; the first end wall, the second end wall, a first portion of the sidewall connected to the first end wall and of a predetermined length, and a second portion of the sidewall connected to the second end wall are made of magnetic material; the first stator magnet is attracted to the first end wall by magnetic force and is positioned by a first end of the cylinder that forms the first open end; and the second stator magnet is attracted to the second end wall and of a predetermined length, and is positioned by a second end of the cylinder that forms the second open end.
2. The linear vibration motor as described in claim 1, wherein the length A of the cylindrical body in the first direction, the length B of the case in the first direction, and the length C of the first stator magnet and the second stator magnet in the first direction satisfy the relationship A<B<A+C.
3. A linear vibration motor as described in claim 1 or claim 2, wherein the case is provided with a third portion arranged between the first portion and the second portion of the side wall and connecting the first portion and the second portion, the third portion being made of a non-magnetic material, and the length in the first direction of the first portion and the second portion being equal to or greater than C.
4. A linear vibration motor as described in any one of claims 1 to 3, wherein the first end wall opens towards the first opening end and has a first recess facing the first opening end, the second end wall opens towards the second opening end and has a second recess facing the second opening end, the first stator magnet is housed in the first recess, and the second stator magnet is housed in the second recess.
5. A linear vibration motor comprising: a cylinder having a through hole, one end of which in a first direction is a first opening end and the other end in the first direction is a second opening end; a mover magnet housed in the through hole of the cylinder and movable between the first opening end and the second opening end; a first stator magnet arranged closer to the first opening end in the first direction than the mover magnet so as to generate a magnetic repulsive force against the mover magnet; a second stator magnet arranged closer to the second opening end in the first direction than the mover magnet so as to generate a magnetic repulsive force against the mover magnet; a winding conductor arranged on the outer circumferential surface of the cylinder; and a case that houses the cylinder in which the mover magnet is housed, the first stator magnet, the second stator magnet, and the winding conductor, wherein a length A of the cylinder in the first direction, a length B of the case in the first direction, and a length C of the first stator magnet and the second stator magnet in the first direction satisfy the relationship A + 2C < B, the case comprises a side wall extending in the first direction, a first end wall connected to the side wall, and a second end wall connected to the side wall and facing the first end wall; the first end wall, the second end wall, a first portion of the side wall connected to the first end wall and of a predetermined length, and a second portion of the side wall connected to the second end wall and of a predetermined length are made of magnetic material; the first end wall has a first recess opening to the first opening end side; the second end wall has a second recess opening to the second opening end side; at least a portion of the first stator magnet is accommodated in the first recess and is attracted to the first end wall by magnetic force; and at least a portion of the second stator magnet is accommodated in the second recess and is attracted to the second end wall by magnetic force.
6. A linear vibration motor as described in claim 5, wherein the case comprises a third portion disposed between the first portion and the second portion on the side wall and connecting the first portion and the second portion, the third portion being made of a non-magnetic material, and the length of the first portion and the second portion in the first direction is equal to or greater than (C-D), with respect to a depth D of the first recess and the second recess.
7. A linear vibration motor as described in any one of claims 1 to 6, wherein the case is rectangular parallelepiped in shape, the cylinder is provided with a flange portion that positions the winding conductor, the flange portion is polygonal in shape when viewed in the first direction, and the side wall of the case and the polygonal outer surface of the flange portion are in surface contact.
8. A linear vibration motor according to any one of claims 1 to 7, wherein the first stator magnet and the second stator magnet are fixed to the case by an adhesive.
9. A process of preparing a cylinder having a through hole and a polygonal flange on its outer circumferential surface; a process of moving a winding conductor from an end of the cylinder along the outer circumferential surface of the cylinder and positioning the winding conductor by the flange; a process of inserting a first stator magnet, a mover magnet, and a second stator magnet into the through hole from the other end of the cylinder while blocking one end of the through hole in the cylinder in the order of a first stator magnet, a mover magnet, and a second stator magnet, so that the magnetic poles of the mover magnet are arranged such that the first stator magnet and the second stator magnet repel each other; a process of inserting the cylinder in which the winding conductor has been positioned and in which the first stator magnet, the mover magnet, and the second stator magnet have been inserted, into a rectangular parallelepiped case made of a magnetic material and one of its longitudinal sides is opened, through the opening; a process of drawing out the end of the winding conductor from the opening of the case and sealing the opening with a magnetic cover; a longitudinal length A of the cylinder, a longitudinal length B of the case, and a length C of the first stator magnet and the second stator magnet in the insertion direction satisfy the relationship A<B<A+2C; a polygonal flange is abutted against an inner wall surface of the case to restrict rotation of the cylinder within the case; and movement of the first stator magnet and the second stator magnet in a plane perpendicular to the longitudinal direction is restricted by the cylinder, and movement in the longitudinal direction is restricted by a repulsive magnetic force between the first stator magnet and the second stator magnet.
Citation Information
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