Vibration motor

Abstract

A vibration motor (10) comprises one movable element magnet (40), a cylindrical holder (30), drive windings (61, 62), a cylindrical case (20), and two stator magnets (51, 52). The cylindrical holder (30) has a through-hole (300) in which both ends are open, the movable element magnet (40) being stored in the through-hole (300), and the cylindrical holder (30) also has a flange (32) at the central portion of the outer surface thereof. The drive windings (61, 62) are wound on both sides on the outer periphery of the cylindrical holder (30), with the flange (32) interposed therebetween. The cylindrical holder (30) and the drive windings (61, 62) are accommodated in the cylindrical case (20). The two stator magnets (51, 52) are respectively disposed at the two ends of the cylindrical holder (30), with the movable element magnet (40) interposed therebetween, so as to generate magnetic force that repulses the movable element magnet (40) in a first direction, which is the direction in which the movable element magnet (40) can move. At least a portion of each of the two stator magnets (51, 52) is stored in the cylindrical holder (30). The cylindrical case (20) is provided with a step portion that faces the end portion of the cylindrical holder (30). The cylindrical holder (30) is disposed in the cylindrical case (20) in a state in which both end portions are in contact with the side surface of the step portion in the radial direction of the through-hole.

Description

Vibration motor

[0001] The present invention relates to a structure of a vibration motor.

[0002] Patent Document 1 describes a resonant motor. The resonant motor includes a housing, a stator magnet, and a mover magnet. The mover magnet is housed in the housing. The stator magnets are arranged on both ends of the housing.

[0003] In a motor having such a configuration, in order to increase the acceleration of the mover magnet within the limited dimensions, it is conceivable to configure the drive coil disposed on the outer surface of the housing as close as possible to the mover magnet.

[0004] The configuration of Patent Document 1 uses two permanent magnets as the mover magnet, and the two permanent magnets are glued together with a spacer or the like in a mutually repulsive orientation. In this case, a recess is provided on the outer surface at approximately the center of the direction in which the housing extends (the direction in which the mover magnet vibrates), and the drive coil is placed in the recess. This brings the drive coil and mover magnet closer together.

[0005] Japanese Patent Application Laid-Open No. 2014-223014

[0006] When the configuration of Patent Document 1 is used, two permanent magnets are used as the mover magnet, which increases the number of components of the motor and lengthens the length of the housing.

[0007] On the other hand, if the mover magnet is configured with a single permanent magnet, it is necessary to place the drive coils at both ends of the housing in the extension direction, and to provide recesses at both ends of the housing to bring the drive coils closer to the mover magnet.

[0008] In this case, the end of the housing becomes thinner, reducing its mechanical strength. If the mechanical strength of the housing cannot be ensured, there will be resistance when the mover magnet slides, which can result in lower acceleration and increased noise.

[0009] Therefore, an object of the present invention is to suppress the deterioration of the characteristics as a vibration motor and to suppress noise while suppressing an increase in size.

[0010] The vibration motor of this invention includes one mover magnet, a cylindrical holder, a drive winding, a cylindrical case, and two stator magnets. The cylindrical holder has a through hole with open ends, the mover magnet is housed in the through hole, and has a flange portion in the center of its outer surface. The drive winding is wound on both sides of the outer periphery of the cylindrical holder, sandwiching the flange portion. The cylindrical case houses the cylindrical holder and the drive winding. The two stator magnets are arranged at both ends of the cylindrical holder, sandwiching the mover magnet between them, so that each stator magnet generates a magnetic force that repels the mover magnet in a first direction, which is the moving direction of the mover magnet. At least a portion of each of the two stator magnets is housed within the cylindrical holder. The cylindrical case has a step portion facing the end of the cylindrical holder. The cylindrical holder is arranged in the cylindrical case with both ends in contact with the side surfaces of the step portion in the radial direction of the through hole.

[0011] In this configuration, both ends of the cylindrical holder that houses the mover magnet are thin sections, and the drive windings are disposed in these thin sections. The thin sections of the cylindrical holder are then disposed in the recesses of the cylindrical case. In this case, the outer surface of the thin sections of the cylindrical holder contacts the side surfaces of the recesses of the cylindrical case, and the inner surface of the thin sections of the cylindrical holder contacts the outer peripheral surfaces of the stator magnets. This fixes the cylindrical holder to the cylindrical case in a state that makes it difficult for the cylindrical holder to deform.

[0012] According to this invention, it is possible to suppress the deterioration of the characteristics as a vibration motor and to suppress noise while suppressing an increase in size of the motor.

[0013] FIG. 1 is an exploded perspective view of a vibration motor according to a first embodiment. FIG. 2 is a side cross-sectional view of the vibration motor according to the first embodiment. FIG. 3 is a side cross-sectional view of the vibration motor according to the first embodiment with the cylindrical case removed. FIG. 4(A) is a plan view of a second portion of the cylindrical case of the vibration motor according to the first embodiment, and FIG. 4(B) is a side cross-sectional view of the second portion. FIGS. 5(A), 5(B), 5(C), and 5(D) are side cross-sectional views showing the respective steps of an example of a manufacturing method for the vibration motor according to the first embodiment. FIG. 6 is a side cross-sectional view of a vibration motor according to a second embodiment. FIGS. 7(A), 7(B), 7(C), and 7(D) are side cross-sectional views showing the manufacturing steps of a second case member according to the second embodiment. FIG. 8 is an exploded perspective view of a vibration motor according to a third embodiment. FIG. 9 is a side cross-sectional view of the vibration motor according to the third embodiment. 10(A), 10(B), and 10(C) are plan views showing the arrangement of the stator magnet, the cylindrical holder, and the main body on the second cover member. Fig. 11 is an exploded perspective view of a vibration motor according to a fourth embodiment. Fig. 12 is a side cross-sectional view of the vibration motor according to the fourth embodiment.

[0014] [First embodiment] A vibration motor according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an exploded perspective view of the vibration motor according to the first embodiment. Fig. 2 is a side cross-sectional view of the vibration motor according to the first embodiment. Fig. 3 is a side cross-sectional view of the vibration motor according to the first embodiment with the cylindrical case removed. Fig. 4(A) is a plan view of a second part of the cylindrical case of the vibration motor according to the first embodiment, and Fig. 4(B) is a side cross-sectional view of the second part.

[0015] 1 to 4(A) and 4(B) described in each embodiment may have portions where dimensions are appropriately emphasized to make the configuration easier to understand. Also, although the order of reference numerals may vary, the specific configuration will be described starting from the center of the vibration motor 10.

[0016] The vibration motor 10 includes a cylindrical case 20 , a cylindrical holder 30 , a mover magnet 40 , a plurality of stator magnets 51 and 52 , and a plurality of drive windings 61 and 62 .

[0017] The mover magnet 40 and the multiple stator magnets 51, 52 are permanent magnets, such as neodymium magnets, that have strong magnetic force. The mover magnet 40 and the multiple stator magnets 51, 52 are cylindrical. The mover magnet 40 and the multiple stator magnets 51, 52 have approximately the same diameter.

[0018] The mover magnet 40 has an N pole face N40 and an S pole face S40. The stator magnet 51 has an N pole face N51 and an S pole face S51. The stator magnet 52 has an N pole face N52 and an S pole face S52.

[0019] The cylindrical holder 30 includes a main body 31 and a flange 32. The cylindrical holder 30 is made of a material that allows a magnetic field to pass through, such as an insulating resin. The main body 31 and the flange 32 are molded integrally.

[0020] The main body 31 has a cylindrical shape extending in the first direction and has a first end face E31, a second end face E32, an outer surface SO31, and an inner surface SI30. The main body 31 has a through hole 300 that penetrates between the first end face E31 and the second end face E32. The through hole 300 forms the inner surface SI30. The diameter of the through hole 300 is approximately the same as the diameters of the mover magnet 40 and the multiple stator magnets 51, 52, to the extent that the mover magnet 40 and the multiple stator magnets 51, 52 can be accommodated. The through hole 300 has the same diameter at any position in the first direction.

[0021] The flange 32 is cylindrical and protrudes outward in the circumferential direction from the outer surface SO31 of the main body 31. The flange 32 is disposed so as to include the center of the main body 31 in the first direction. As a result, the cylindrical holder 30 has thin portions on both sides of the flange 32 in the first direction.

[0022] The mover magnet 40 is housed in the through-hole 300 of the cylindrical holder 30. At this time, the mover magnet 40 is housed so that the north pole face N40 faces the first end face E31 and the south pole face S40 faces the second end face E32.

[0023] The cylindrical case 20 includes a first case member 21 and a second case member 22. The first case member 21 and the second case member 22 each extend in a first direction and have a three-dimensional shape with an outer circumferential surface parallel to the first direction.

[0024] The first case member 21 (the three-dimensional portion thereof) is provided with a recess 21C0, a recess 21C1, and a recess 21C2.

[0025] The recess 21C0 is recessed from one end face of the first case member 21 in the first direction, and has a circular shape when viewed from the first direction. The diameter of the recess 21C0 (the diameter of the circle when viewed from the first direction) is approximately the same as the diameter of the flange 32 of the cylindrical holder 30.

[0026] The recess 21C2 is recessed from the bottom surface of the recess 21C0, and has a circular shape when viewed from the first direction. The diameter of the recess 21C2 (the diameter of the circle when viewed from the first direction) is approximately the same as the diameter of the main body 31 (thin portion) of the cylindrical holder 30.

[0027] The recess 21C1 is recessed from the bottom surface of the recess 21C2, and has a circular shape when viewed from the first direction. The diameter of the recess 21C1 (the diameter of the circle when viewed from the first direction) is approximately the same as the diameter of the stator magnet 51.

[0028] The second case member 22 (the three-dimensional portion thereof) is provided with recesses 22C0, 22C1, and 22C2.

[0029] The recess 22C0 is recessed from one end face of the second case member 22 in the first direction, and has a circular shape when viewed from the first direction. The diameter of the recess 22C0 (the diameter of the circle when viewed from the first direction) is approximately the same as the diameter of the flange 32 of the cylindrical holder 30.

[0030] The recess 22C2 is recessed from the bottom surface of the recess 22C0, and has a circular shape when viewed from the first direction. The diameter of the recess 22C2 (the diameter of the circle when viewed from the first direction) is approximately the same as the diameter of the main body 31 (thin portion) of the cylindrical holder 30.

[0031] The recess 22C1 is recessed from the bottom surface of the recess 22C2, and has a circular shape when viewed from the first direction. The diameter of the recess 22C1 (the diameter of the circle when viewed from the first direction) is approximately the same as the diameter of the stator magnet 52.

[0032] The first case member 21 and the second case member 22 are arranged side by side in the first direction and connected together so that the surfaces on which the recessed portions 21C0 and 22C0 open face each other.

[0033] As a result, the cylindrical case 20 has an internal space formed by the recesses 21C0, 21C1, and 21C2 formed in the first case member 21 and the recesses 22C0, 22C1, and 22C2 formed in the second case member 22. With this configuration, the cylindrical case 20 has stepped portions on both ends in the first direction.

[0034] A first opening 29 is provided at the end where the first case member 21 and the second case member 22 are connected, so as to include a dividing line that divides the cylindrical case 20 into the first case member 21 and the second case member 22. The first opening 29 connects the internal space of the cylindrical case 20 with the outside.

[0035] The plurality of drive windings 61, 62 are made of wound linear conductors coated with an insulating film and are wound around the outer periphery of the cylindrical holder 30 on both sides of the flange 32.

[0036] More specifically, the drive winding 61 is disposed on the outer surface SO31 of the main body 31 of the cylindrical holder 30, which is closer to the first end face E31 than the flange 32. In this case, the drive winding 61 is disposed at a position spaced a predetermined distance from the first end face E31.

[0037] The drive winding 62 is disposed on the outer surface SO31 of the main body 31 of the cylindrical holder 30, closer to the second end face E32 than the flange 32. In this case, the drive winding 62 is disposed at a position spaced a predetermined distance from the second end face E32.

[0038] The circumferential height of the drive windings 61, 62 is lower than the height of the flange portion 32. An annular shield member SH is disposed on the outer circumferential surface of the drive windings 61, 62. The shield member SH is made of metal and shields the magnetic field radiated from the drive windings 61, 62 to the outside.

[0039] The stator magnet 51 is accommodated and arranged in the recess 21C1. The stator magnet 51 is arranged so that its south pole face S51 is adjacent to and faces the bottom face B211 of the recess 21C1. The stator magnet 51 is fixed in the recess 21C1 with an adhesive or the like. The depth of the recess 21C1 is smaller than the height of the stator magnet 51, so that the stator magnet 51 is fixed with a portion of its height protruding from the recess 21C1.

[0040] The stator magnet 52 is housed and arranged in the recess 22C1. The stator magnet 52 is arranged so that its north pole face N52 is adjacent to and faces the bottom surface B221 of the recess 22C1. The stator magnet 52 is fixed in the recess 22C1 with an adhesive or the like. The depth of the recess 22C1 is smaller than the height of the stator magnet 52, so that the stator magnet 52 is fixed with a portion of its height protruding from the recess 22C1.

[0041] The end of the cylindrical holder 30 housing the mover magnet 40 on the first end face E31 side is housed and arranged in the recess 21C2. At this time, the first end face E31 abuts against the bottom surface B212 of the recess 21C2. The outer surface SO31 of the end (thin portion) of the cylindrical holder 30 on the first end face E31 side abuts against the side surface S212 of the recess 21C2. The outer surface SO31 of the end (thin portion) of the cylindrical holder 30 on the first end face E31 side abuts against the outer peripheral surface of the stator magnet 51.

[0042] The end of the cylindrical holder 30 housing the mover magnet 40 on the second end face E32 side is housed and arranged in the recess 22C2. At this time, the second end face E32 abuts against the bottom surface B222 of the recess 22C2. The outer surface SO31 of the end (thin portion) of the cylindrical holder 30 on the second end face E32 side abuts against the side surface S222 of the recess 22C2. The outer surface SO31 of the end (thin portion) of the cylindrical holder 30 on the second end face E32 side abuts against the outer peripheral surface of the stator magnet 52.

[0043] With this configuration, the two stator magnets 51, 52 are arranged at both ends of the cylindrical holder 30 with the mover magnet 40 sandwiched between them so that they each generate a magnetic force that repels the mover magnet 40 in the first direction, which is the moving direction of the mover magnet 40. Therefore, the vibration motor 10 can realize a magnetic spring type actuator by passing a drive current through the drive windings 61, 62.

[0044] With this configuration, both ends of the cylindrical holder 30 that houses the mover magnet 40 become thin sections, and the multiple drive windings 61, 62 are arranged in these sections. This reduces the distance between the mover magnet 40 and the multiple drive windings 61, 62, and the vibration motor 10 can increase the acceleration of the mover magnet 40.

[0045] Furthermore, the main body 31 (thin portion) of the cylindrical holder 30 is disposed in the recesses 21C1, 22C1 of the cylindrical case 20. At this time, the outer surface SO31 of the main body 31 (thin portion) of the cylindrical holder 30 abuts against the side surfaces S212, S222 of the recesses 21C2, 22C2 of the cylindrical case 20, and the inner surface SI30 of the cylindrical holder 30 abuts against the outer peripheral surface of the stator magnet. This allows the cylindrical holder 30 to be fixed to the cylindrical case 20 in a state where it is difficult to deform. Therefore, the cylindrical holder 30 is difficult to deform due to sliding of the mover magnet 40 along the first direction, and the vibration motor 10 can suppress deterioration of its characteristics as a vibration motor and suppress noise.

[0046] In this way, the vibration motor 10 can suppress deterioration of the characteristics as a vibration motor and suppress noise while suppressing an increase in size.

[0047] The ends of the drive windings 61, 62 are drawn out to the outside of the cylindrical case 20 through the first opening 29 and connected to a circuit board (e.g., a flexible circuit board) arranged outside the cylindrical case 20. The external electrode ET of the vibration motor 10 is formed by this circuit board. The structure for drawing the drive windings 61, 62 out of the cylindrical case 20 is not limited to this, and through holes may be formed at appropriate positions in the cylindrical case 20 and the drive windings 61, 62 may be drawn through the through holes. Alternatively, terminal pins may be inserted into the through holes and the drive windings 61, 62 may be connected to the terminal pins inside the cylindrical case 20.

[0048] 5A, 5B, 5C, and 5D are side cross-sectional views showing states in each step of an example of a method for manufacturing the vibration motor according to the first embodiment.

[0049] 5A, adhesive is applied to the recess 22C1 of the second case member 22 of the cylindrical case 20, and the stator magnet 52 is arranged and fixed therein. Although not shown in the figure, adhesive is also applied to the recess 21C1 of the first case member 21 of the cylindrical case 20, and the stator magnet 51 is arranged and fixed therein.

[0050] 5(B), the mover magnet 40 is accommodated in the through-hole 300 of the cylindrical holder 30, and the cylindrical holder 30 is inserted into the second case member 22 of the cylindrical case 20. At this time, the cylindrical holder 30 is inserted into the second case member 22 so that the end of the cylindrical holder 30 on the second end face E32 side is accommodated in the recess 22C2, and the portion of the stator magnet 52 protruding from the recess 22C1 is accommodated in the through-hole 300.

[0051] As a result, as shown in FIG. 5C, the cylindrical holder 30 containing the mover magnet 40 is fixed to the cylindrical case 20 to which the stator magnet 51 is fixed.

[0052] 5(D), the first case member 21 of the cylindrical case 20 to which the stator magnet 51 is fixed is placed over the cylindrical holder 30. At this time, the first case member 21 is placed over the cylindrical holder 30 so that the end of the cylindrical holder 30 on the first end face E31 side is housed in the recess 21C2 and the portion of the stator magnet 51 protruding from the recess 21C1 is housed in the through-hole 300.

[0053] The vibration motor 10 is formed by fixing the first case member 21 and the second case member 22 together.

[0054] In this manufacturing method, recess 22C1 can be used to position stator magnet 52, and recess 21C1 can be used to position stator magnet 51. Furthermore, recess 22C2 and recess 21C2 can be used to position cylindrical holder 30. This allows for easy assembly while maintaining accurate positional relationships between the components that make up vibration motor 10.

[0055] Second Embodiment A vibration motor according to a second embodiment of the present invention will be described with reference to the drawings. Fig. 6 is a side cross-sectional view of the vibration motor according to the second embodiment.

[0056] 6, the vibration motor 10A according to the second embodiment differs from the vibration motor 10 according to the first embodiment in that it includes a cylindrical case 20A. The other configuration of the vibration motor 10A according to the second embodiment is the same as that of the vibration motor 10 according to the first embodiment, and a description of the same parts will be omitted.

[0057] The vibration motor 10A includes a cylindrical case 20A. The cylindrical case 20A includes a first case member 21A and a second case member 22A. The first case member 21A and the second case member 22A are made of metal. The basic shape of the first case member 21A and the basic shape of the second case member 22A are similar.

[0058] The first case member 21A has recesses 21C0 and 21C2. In other words, the first case member 21A has the same shape as the first case member 21 according to the first embodiment but does not have the recess 21C1.

[0059] The second case member 22A has recesses 22C0 and 22C2. In other words, the second case member 22A has the same shape as the second case member 22 according to the first embodiment but does not have the recess 22C1.

[0060] The stator magnet 51 and the end of the cylindrical holder 30 on the first end face E31 side are housed in the recess 21C2. The outer peripheral surface of the stator magnet 51 abuts against the inner surface SI30 of the cylindrical holder 30. The outer surface SO31 of the cylindrical holder 30 abuts against the side surface S212 of the recess 21C2. The stator magnet 51 is attracted to the bottom surface B211 of the recess 21C2 by magnetic force.

[0061] The stator magnet 52 and the end of the cylindrical holder 30 on the second end face E32 side are housed in the recess 22C2. The outer peripheral surface of the stator magnet 52 abuts against the inner surface SI30 of the cylindrical holder 30. The outer surface SO31 of the cylindrical holder 30 abuts against the side surface S222 of the recess 22C2. The stator magnet 52 is attracted by magnetic force to the bottom surface B221 of the recess 22C2.

[0062] With this configuration, the vibration motor 10A can achieve the same effects as the vibration motor 10.

[0063] The first case member 21A and the second case member 22A having such shapes are manufactured as follows. Figures 7(A), 7(B), 7(C), and 7(D) are side cross-sectional views showing the manufacturing process of the second case member according to the second embodiment. Figures 7(A), 7(B), 7(C), and 7(D) show the manufacturing process of the second case member 22A, but the first case member 21A is manufactured in the same manner.

[0064] First, as shown in Fig. 7(A), a flat plate N22 is prepared, and a punch having an outer shape corresponding to the shape of the recess 22C0 is pressed against the flat plate N22 to perform drawing, thereby forming an intermediate member NA22 of the second case member 22A having the recess 22C0 as shown in Fig. 7(B).

[0065] Next, as shown in Fig. 7C, the excess portion is removed, and a punch having an outer shape corresponding to the shape of the recess 22C2 is pressed against the bottom wall of the intermediate member NA22 to perform drawing.

[0066] The second case member 22A can be manufactured by this manufacturing method.

[0067] [Third embodiment] A vibration motor according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 8 is an exploded perspective view of the vibration motor according to the third embodiment. Fig. 9 is a side cross-sectional view of the vibration motor according to the third embodiment. Figs. 10(A), 10(B), and 10(C) are plan views showing the arrangement of the stator magnet, cylindrical holder, and main body portion on the second cover member.

[0068] 8 and 9, the vibration motor 10B according to the third embodiment differs from the vibration motor 10 according to the first embodiment in the configuration of the cylindrical case 20B and in that the cylindrical holder 30 includes fitting recesses C311 and C312. The other configuration of the vibration motor 10B according to the second embodiment is the same as that of the vibration motor 10 according to the first embodiment, and a description of similar parts will be omitted.

[0069] The cylindrical holder 30 has a plurality of fitting recesses C311 recessed in a first direction from the first end face E31. The plurality of fitting recesses C311 are formed at equal intervals in the extension direction of the ring that forms the first end face E31.

[0070] The cylindrical holder 30 has a plurality of fitting recesses C312 recessed in the first direction from the second end face E32. The plurality of fitting recesses C312 are formed at equal intervals in the extension direction of the ring that forms the second end face E32.

[0071] Cylindrical case 20B includes main body 23, first lid member 241, and second lid member 242. Main body 23, first lid member 241, and second lid member 242 are made of metal. However, main body 23, first lid member 241, and second lid member 242 do not have to be made of metal only, as long as they are made of a material that blocks magnetic fields.

[0072] The main body portion 23 is cylindrical and has a through hole 230. The first cover member 241 is disposed at one end of the main body portion 23 in the first direction and closes one opening of the through hole 230. The second cover member 242 is disposed at the other end of the main body portion 23 in the second direction and closes the other opening of the through hole 230.

[0073] The first cover member 241 has a plurality of protrusions 2410 protruding from a surface F241 on the side where the first cover member 241 is disposed on the main body portion 23. The plurality of protrusions 2410 are formed by half-punching the plate-shaped first cover member 241.

[0074] The plurality of protrusions 2410 are formed in a shape where the annular protrusion is partially missing (arc-shaped), and are formed at approximately equal angular intervals with the center of the first cover member 241 as viewed in the first direction as a reference point.

[0075] Each of the multiple convex portions 2410 includes a first portion 2411 and a second portion 2412. The height of the first portion 2411 and the height of the second portion 2412 are the same. The first portion 2411 is arc-shaped when viewed in the first direction, and includes a first outer peripheral surface F2410 and a first inner peripheral surface F2411. The diameter of the circle formed by the multiple first outer peripheral surfaces F2410 is approximately the same as the diameter of the inner surface of the main body portion 23 on the through-hole 230 side. The diameter of the circle formed by the multiple first inner peripheral surfaces F2411 is approximately the same as the diameter of the outer surface SO31 of the cylindrical holder 30.

[0076] The second portion 2412 has a shape that protrudes from the first inner circumferential surface F2411 of the first portion 2411 toward the center of the circle formed by the multiple first portions 2411. The second portion 2412 has a second inner circumferential surface F2412 at the protruding tip. The diameter of the circle formed by the multiple second inner circumferential surfaces F2412 is approximately the same as the diameter of the stator magnet 51.

[0077] The length of the arc of the second portion 2412 is shorter than the length of the arc of the first portion 2411. The center of the arc of the second portion 2412 and the center of the arc of the first portion 2411 are substantially the same.

[0078] The first cover member 241 further includes a through-hole TH241. The through-hole TH241 is formed at a position that does not overlap with the plurality of protrusions 2410. The through-hole TH241 corresponds to the "second opening" of the invention.

[0079] The second cover member 242 has the same configuration as the first cover member 241, except that no through-holes are formed.

[0080] Specifically, second cover member 242 has a plurality of protrusions 2420 protruding from surface F242 on the side where second cover member 242 is disposed on main body portion 23. The plurality of protrusions 2420 are formed by half-punching plate-shaped second cover member 242.

[0081] The plurality of protrusions 2420 are formed in a shape where the annular protrusion is partially missing (arc-shaped), and are formed at approximately equal angular intervals with the center of the second cover member 242 when viewed in the first direction as a reference point.

[0082] Each of the multiple protrusions 2420 includes a first portion 2421 and a second portion 2422. The height of the first portion 2421 and the height of the second portion 2422 are the same. The first portion 2421 is arc-shaped when viewed in the first direction, and includes a first outer peripheral surface F2420 and a first inner peripheral surface F2421. The diameter of the circle formed by the multiple first outer peripheral surfaces F2420 is approximately the same as the diameter of the inner surface of the main body portion 23 on the through-hole 230 side. The diameter of the circle formed by the multiple first inner peripheral surfaces F2421 is approximately the same as the diameter of the outer surface SO31 of the cylindrical holder 30.

[0083] The second portion 2422 has a shape that protrudes from the first inner circumferential surface F2421 of the first portion 2421 toward the center of a circle formed by the plurality of second portions 2422. The second portion 2422 has the second inner circumferential surface F2422 at its protruding tip. The diameter of the circle formed by the plurality of second inner circumferential surfaces F2422 is approximately the same as the diameter of the stator magnet 52.

[0084] The length of the arc of the second portion 2422 is shorter than the length of the arc of the first portion 2421. The center of the arc of the second portion 2422 and the center of the arc of the first portion 2421 are substantially the same.

[0085] The cylindrical holder 30, which houses the mover magnet 40 and has multiple drive windings 61, 62 arranged therein, and the multiple stator magnets 51, 52 are arranged in an internal space surrounded by the main body 23, the first cover member 241, and the second cover member 242.

[0086] More specifically, the stator magnet 51 is disposed in a space surrounded by the plurality of second portions 2412 of the plurality of protrusions 2410 of the first cover member 241. The main surface (circular surface) of the stator magnet 51 abuts against the surface F241 of the first cover member 241. The circumferential surface of the stator magnet 51 abuts against the second inner circumferential surfaces F2412 of the plurality of second portions 2412.

[0087] The stator magnet 52 is disposed in a space surrounded by the plurality of second portions 2422 of the plurality of protrusions 2420 of the second cover member 242. The main surface (circular surface) of the stator magnet 52 abuts against the surface F242 of the second cover member 242. The peripheral surface of the stator magnet 52 abuts against the second inner peripheral surfaces F2422 of the plurality of second portions 2422.

[0088] The cylindrical holder 30 is disposed so that the first end surface E31 abuts against the surface F241 of the first cover member 241 and the plurality of fitting recesses C311 fit into the second portions 2412 of the plurality of protrusions 2410. At this time, the outer surface SO31 of the cylindrical holder 30 abuts against the first inner circumferential surface F2411 of the first portion 2411.

[0089] Furthermore, the cylindrical holder 30 is disposed so that the second end surface E32 abuts against the surface F242 of the second cover member 242 and the plurality of fitting recesses C312 fit into the second portions 2422 of the plurality of protrusions 2420. At this time, the outer surface SO31 of the cylindrical holder 30 abuts against the first inner circumferential surface F2421 of the first portion 2421.

[0090] With this configuration, the vibration motor 10B achieves the same effects as the vibration motor 10.

[0091] Furthermore, the vibration motor 10B can prevent the cylindrical holder 30 from rotating by having the multiple mating recesses C311 of the cylindrical holder 30 engage with the second parts 2412 of the multiple protrusions 2410, and having the multiple mating recesses C312 engage with the second parts 2422 of the multiple protrusions 2420.

[0092] Furthermore, in the vibration motor 10B, the cylindrical case 20B is made of metal, so the shielding member SH shown in the first embodiment can be omitted. As a result, the vibration motor 10B can have a larger number of turns of the drive windings 61, 62 than the vibration motor 10, while still having the same size as the vibration motor 10.

[0093] Furthermore, in the vibration motor 10B, the ends of the drive windings 61 and 62 are drawn out to the outside of the cylindrical case 20B through the through holes TH241. In this way, in the vibration motor 10B, the ends of the drive windings 61 and 62 can be drawn out from the end faces of the cylindrical case 20B.

[0094] In this embodiment, the number of the plurality of convex portions 2410 and the number of the plurality of convex portions 2420 are four, but the number is not limited to this.

[0095] [Fourth embodiment] A vibration motor according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 11 is an exploded perspective view of the vibration motor according to the fourth embodiment. Fig. 12 is a side cross-sectional view of the vibration motor according to the fourth embodiment.

[0096] 11 and 12, the vibration motor 10C according to the fourth embodiment differs from the vibration motor 10B according to the third embodiment in the configuration of the cylindrical case 20C. The other configuration of the vibration motor 10C according to the fourth embodiment is the same as that of the vibration motor 10B according to the third embodiment, and a description of the same parts will be omitted.

[0097] The cylindrical case 20C includes a main body 23C, a first lid member 241C, and a second lid member 242. The first lid member 241C has a configuration in which the through-hole TH241 is omitted from the first lid member 241 according to the second embodiment.

[0098] The main body portion 23C is a plate member having a circumferential shape with one end and the other end close to each other when viewed from the first direction, and a circumferential surface in the extension direction. In other words, the main body portion 23C is formed by bending a flat plate member into a cylindrical shape with both ends close to each other or connected to each other.

[0099] Notches 29C are formed on both ends of the main body 23C, and through the notches 29C, a through-hole 230C, which is the space inside the main body 23C, communicates with the space outside.

[0100] The cylindrical holder 30, which houses the mover magnet 40 and has the plurality of drive windings 61, 62 arranged therein, a portion of the stator magnet 51, and a portion of the stator magnet 52 are housed in the through-hole 230C of the main body portion 23C.

[0101] The ends of the drive windings 61, 62 are drawn out to the outside of the cylindrical case 20C through the notch 29C and connected to a circuit board (for example, a flexible circuit board) arranged outside the cylindrical case 20C. The external electrode ET of the vibration motor 10C is formed by this circuit board.

[0102] The configurations of the above-described embodiments can be combined as appropriate, and effects according to each combination can be achieved.

[0103] <1> A vibration motor comprising: one mover magnet; a cylindrical holder having a through hole with both ends open, the mover magnet being housed in the through hole, and having a flange portion in the center of the outer surface; a drive winding wound on both sides of the outer periphery of the cylindrical holder, sandwiching the flange portion; a cylindrical case that houses the cylindrical holder and the drive winding; and two stator magnets arranged on both ends of the cylindrical holder, sandwiching the mover magnet therebetween, so that each stator magnet generates a magnetic force that repels the mover magnet in a first direction that is a moving direction of the mover magnet, wherein at least a portion of each of the two stator magnets is housed within the cylindrical holder, and the cylindrical case has a step portion facing an end of the cylindrical holder, and the cylindrical holder is arranged in the cylindrical case with both ends in contact with side surfaces of the step portion in the radial direction of the through hole.

[0104] <2> The vibration motor according to <1>, wherein the cylindrical case includes a first case member and a second case member that are divided using a dividing line on a plane perpendicular to the first direction, a first opening is provided in a side wall that includes the dividing line, and the drive winding is drawn out from the first opening.

[0105] <3> The vibration motor according to <1>, wherein the cylindrical case includes: a main body portion having openings at both ends in an extension direction; and two cover members disposed at both ends of the main body portion, one of the cover members being provided with a second opening, and the drive winding being drawn out from the second opening.

[0106] <4> The vibration motor according to <3>, wherein the cover member has a shape that protrudes from a surface on the side where the cover member is placed on the main body portion and includes an annular protrusion, and when the cover member is viewed in a plan view, the annular protrusion has a shape that follows the outer shape of the stator magnet and the outer shape of the cylindrical case.

[0107] <5> The vibration motor described in <4>, wherein the convex portion includes: a first portion having a first inner circumferential surface that conforms to the outer shape of the cylindrical case; and a second portion having a second inner circumferential surface that conforms to the outer shape of the stator magnet, the first portion and the second portion having a shape divided into a plurality of portions in the circumferential direction of the annular shape, and the circumferential length of the plurality of second portions is shorter than the circumferential length of the first portion.

[0108] <6> The vibration motor according to <5>, wherein the cylindrical case has a plurality of fitting recesses at an end in an extension direction, and the plurality of fitting recesses of the cylindrical case are fitted into the first portion.

[0109] <7> The vibration motor according to <1>, wherein the cylindrical case comprises: a main body portion having openings at both ends in the extension direction; and two cover members respectively arranged at both ends of the main body portion; the main body portion is a plate member having a circumferential shape with one end and the other end close to each other and having a peripheral surface parallel to the extension direction; the peripheral surface has a notch portion that connects the inside and outside of the main body portion; and the drive winding is drawn out from the notch portion.

[0110] 10, 10A, 10B, 10C: vibration motor 20, 20A, 20B, 20C: cylindrical case 21, 21A: first case member 22, 22A: second case member 21C0, 21C1, 21C2, 22C0, 22C1, 22C2: recess 23, 23C: main body 29: first opening 29C: notch 30: cylindrical holder 31: main body 32: flange 40: mover magnet 51, 52: stator magnet 61, 62: drive winding 230, 230C: through hole TH241: through hole 241, 241C: first cover member 242: second cover member 300: through hole 2410, 2420: convex portion 2411, 2421: first portion 2412, 2422: Second portion B211, B212, B221, B222: Bottom surface C311, C312: Fitting recess E31: First end surface E32: Second end surface ET: External electrode F241, F242: Surface F2410, F2420: First outer peripheral surface F2411, F2421: First inner peripheral surface F2412, F2422: Second inner peripheral surface S212, S222: Side surface N40, N51, N52: North pole surface S40, S51, S52: South pole surface SH: Shielding member SI30: Inner surface SO31: Outer surface TH241: Through hole

Claims

1. A vibration motor comprising: a movable magnet; a cylindrical holder having a through-hole with both ends open, the movable magnet being housed in the through-hole and having a flange portion at the center of the outer surface; drive windings wound around both sides of the cylindrical holder across the flange portion on the outer periphery of the cylindrical holder; a cylindrical case housing the cylindrical holder and the drive windings; two stator magnets respectively arranged at both ends of the cylindrical holder with the movable magnet sandwiched therebetween so as to generate magnetic forces that repel the movable magnet in a first direction which is the movable direction of the movable magnet; at least a part of each of the two stator magnets being housed in the cylindrical holder; the cylindrical case having a stepped portion facing the end of the cylindrical holder; and the cylindrical holder being arranged in the cylindrical case with both ends in contact with the side surface of the stepped portion in the radial direction of the through-hole.

2. The vibration motor according to claim 1, wherein the cylindrical case includes a first case member and a second case member divided by a dividing line on a plane orthogonal to the first direction, a first opening being provided in a side wall including the dividing line, and the drive winding being drawn out from the first opening.

3. The vibration motor according to claim 1, wherein the cylindrical case includes a main body portion with both ends open in the extending direction and two lid members respectively arranged at both ends of the main body portion, a second opening being provided in one of the lid members, and the drive winding being drawn out from the second opening.

4. The vibration motor according to claim 3, wherein the lid member has a shape protruding from a surface on the side where the lid member is arranged on the main body portion and includes an annular convex portion, and in a plan view of the lid member, the annular convex portion has a shape conforming to the outer shape of the stator magnet and the outer shape of the cylindrical case.

5. The vibration motor according to claim 4, wherein the convex portion includes a first portion having a first inner peripheral surface conforming to the outer shape of the cylindrical case and a second portion having a second inner peripheral surface conforming to the outer shape of the stator magnet, the first portion and the second portion being divided into a plurality of parts in the circumferential direction of the annular shape, and the circumferential length of the plurality of second portions being shorter than the circumferential length of the first portion.

6. The cylindrical case is provided with a plurality of fitting recesses at the end portions in the extending direction, and the plurality of fitting recesses of the cylindrical case are fitted to the first portion. The vibration motor according to claim 5.

7. The cylindrical case includes a main body portion having both ends in the extending direction opened, and two lid members respectively disposed at both ends of the main body portion. The main body portion is a plate member having a circumferential shape in which one end and the other end are close to each other and having a circumferential surface parallel to the extending direction. The circumferential surface is provided with a notch portion communicating the inside and the outside of the main body portion. The drive winding is drawn out from the notch portion. The vibration motor according to claim 1.

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