Vibration motor

Abstract

The invention provides a vibration motor. The vibration motor (1A) is provided with: a housing (10); a vibrating body (50) which is housed in the housing (10) and which reciprocates in the left-right direction inside the housing (10); and a pair of elastic members (60) that support the vibrating body (50) inside the housing (10) so that the vibrating body (50) can reciprocate in the left-right direction. Each of the elastic members (60) is a metal plate including a first fixing portion (63) fixed to the vibrating body (50) and a second fixing portion (64) fixed to the housing (10). The first fixing part (63) and the second fixing part (64) bend in the same direction and face each other in the front-rear direction. In addition, the first fixing part (63) and the second fixing part (64) are provided with a pair of bent parts extending towards the inner side, and the pair of bent parts face each other in the vertical direction.

Description

Technical Field

[0001] The invention relates to a vibration motor. Background Art

[0002] Nowadays, vibration motors are built into various electronic devices such as smartphones and tablet terminals. Patent document 1 describes an example of a vibration motor built into an electronic device. The vibration motor described in patent document 1 is a linear vibration motor in which a vibration body vibrates linearly. The vibration body of the vibration motor described in patent document 1 is housed in a housing and supported by an elastic member so as to be able to vibrate.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-176688

[0004] In order to improve the reliability of the vibration motor, it is desired to improve the durability of the elastic member. Summary of the invention

[0005] A vibration motor in one embodiment comprises: a housing; a vibrating body housed in the housing and reciprocating in a first direction inside the housing; and a pair of elastic components that support the vibrating body inside the housing so that it can reciprocate in the first direction. Each of the elastic components is a metal plate including a first fixing portion fixed to the vibrating body, a second fixing portion fixed to the housing, and an intermediate portion connecting the first fixing portion and the second fixing portion. The first fixing portion and the second fixing portion are bent in the same direction relative to the intermediate portion and are opposed to each other in a second direction perpendicular to the first direction. At least one of the first fixing portion and the second fixing portion has a pair of bent portions extending toward one side or the other side of the second direction, and the pair of bent portions are opposed to each other in a third direction perpendicular to the first direction and the second direction.

[0006] According to the present invention, it is possible to realize a vibration motor with improved durability of an elastic member and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a perspective view showing the appearance of a vibration motor.

[0008] Figure 2 It is a perspective view showing the structure of a vibration motor.

[0009] Figure 3 It is an exploded perspective view showing the structure of the vibration motor.

[0010] Figure 4 It is an exploded perspective view showing the structure of the housing.

[0011] Figure 5It is a plan view showing a state in which the elastic member supports the vibrating body.

[0012] Fig. 6A It is a perspective view showing an elastic member in an enlarged manner.

[0013] Figure 6B It is a perspective view showing another elastic member in an enlarged manner.

[0014] Figure 7 It is along Figure 5 An enlarged cross-sectional view of line AA in FIG.

[0015] Figure 8 It is along Figure 5 An enlarged cross-sectional view of line BB in FIG.

[0016] Fig. 9 It is a plan view showing a modified example of the arrangement of the elastic member.

[0017] Description of symbols

[0018] 1A: vibration motor; 10: housing; 11: top wall; 11a, 11b: limiting portion; 12: bottom wall; 13: front wall; 14: rear wall; 15: right side wall; 16: left side wall; 17: peripheral wall; 30: substrate; 33: connecting terminal; 40: coil; 50: vibrating body; 51: counterweight; 52: magnet group; 53: side; 54: upper surface; 55: lower surface; 56: magnet storage portion; 57: back yoke; 58: pole piece; 59: recess; 60, 61, 62: elastic component; 63: first fixing portion; 64: second fixing portion; 65: middle portion; 66a, 66b, 67a, 67b: bending portion. DETAILED DESCRIPTION

[0019] Hereinafter, an example of an embodiment will be described in detail with reference to the accompanying drawings. In addition, in all the drawings used to illustrate the embodiment, the same reference numerals are used for the same or substantially the same structures and elements. In addition, in principle, the structure and elements described once will not be described repeatedly.

[0020] <Overview of Vibration Motor>

[0021] Figure 1 It is a perspective view showing the appearance of a vibration motor 1A according to the present embodiment. Figure 2 It is a perspective view showing the structure of the vibration motor 1A. Figure 3 It is an exploded perspective view showing the structure of the vibration motor 1A.

[0022] The vibration motor 1A has a housing 10 forming the outer shell of the vibration motor 1A. The housing 10 is a metal box having a substantially rectangular planar shape. The housing 10 contains components of the vibration motor 1A such as a substrate 30, a coil 40, and a vibrator 50.

[0023] The vibrating body 50, which is one of the components of the vibration motor 1A, reciprocates inside the housing 10. More specifically, the vibrating body 50 reciprocates inside the housing 10 along the long side direction (length direction) of the housing 10. In other words, the vibrating body 50 generates vibrations in the long side direction of the housing 10. That is, the vibration motor 1A is a horizontally driven linear vibration motor that generates vibrations in the long side direction of the housing 10.

[0024] Here, the long side direction of the housing 10 is defined as the "left-right direction", and the short side direction of the housing 10 is defined as the "front-back direction". In addition, the direction perpendicular to both the left-right direction and the front-back direction is defined as the "up-down direction". According to this definition, the vibrator 50 generates vibration in the left-right direction.

[0025] In other words, the left-right direction is the reciprocating direction of the vibrator 50, which is equivalent to the first direction of the present invention. The front-back direction is one of the directions perpendicular to the left-right direction, which is equivalent to the second direction of the present invention. The up-down direction is a direction perpendicular to the front-back direction and the left-right direction, which is equivalent to the third direction of the present invention.

[0026] <Housing>

[0027] Figure 4 1 is an exploded perspective view showing the structure of the housing 10. The housing 10 has a top wall portion 11 and a bottom wall portion 12 opposed in the up-down direction, a front wall portion 13 and a rear wall portion 14 opposed in the front-back direction, and a right side wall portion 15 and a left side wall portion 16 opposed in the left-right direction. That is, the vibrating body 50 vibrating along the long side direction (left-right direction) of the housing 10 vibrates between the right side wall portion 15 and the left side wall portion 16 in their opposing directions. In the following description, the front wall portion 13, the rear wall portion 14, the right side wall portion 15, and the left side wall portion 16 are sometimes collectively referred to as the "peripheral wall portion 17".

[0028] The housing 10 is formed of sheet metal (for example, stainless steel sheet). However, the top wall 11, the bottom wall 12, and the peripheral wall 17 are formed of different sheet metals. In other words, the housing 10 is formed of a plurality of integrated sheet metals.

[0029] The peripheral wall portion 17 is formed into a square tube shape by a strip-shaped sheet metal whose ends are fixed to each other. The two ends of the sheet metal forming the peripheral wall portion 17 are located on the rear wall portion 14. More specifically, the two ends of the sheet metal forming the peripheral wall portion 17 are located at the center in the longitudinal direction (the center in the vibration direction) of the rear wall portion 14. By arranging the two ends of the sheet metal fixed to each other on the rear wall portion 14, the impact resistance performance of the vibration motor 1A can be improved.

[0030] For example, when the vibration motor 1A (housing 10) is impacted by being dropped or the like, the vibrating body 50 is unlikely to come into contact with both ends (fixing portions) of the sheet metal forming the peripheral wall portion 17. In addition, both ends of the sheet metal forming the peripheral wall portion 17 are fixed by caulking, but may be fixed by welding or other fixing methods.

[0031] The top wall 11 and the bottom wall 12 are each formed of a flat sheet metal punched into a substantially rectangular shape. The top wall 11 closes the opening at one end of the peripheral wall 17, and the bottom wall 12 closes the opening at the other end of the peripheral wall 17. The periphery of the sheet metal forming the top wall 11 is welded to one end of the sheet metal forming the peripheral wall 17. In addition, the periphery of the sheet metal forming the bottom wall 12 is welded to the other end of the sheet metal forming the peripheral wall 17.

[0032] A pair of restricting parts 11a and 11b are provided on the left and right sides of the top wall 11. The restricting parts 11a and 11b are located on the left and right sides of the vibrator 50 and restrict the reciprocating motion of the vibrator 50 within a predetermined range. In other words, the vibrator 50 can vibrate between the restricting parts 11a and 11b.

[0033] However, in a normal vibration state, the vibrating body 50 does not contact the limiting portion 11a or the limiting portion 11b. If the vibrating body 50 vibrates (moves) more than usual for some reason, the vibrating body 50 contacts the limiting portion 11a or the limiting portion 11b. As a result, excessive vibration (movement) of the vibrating body 50 is prevented. In addition, a limiting portion similar to the limiting portions 11a and 11b may be provided on the bottom wall portion 12.

[0034] <Substrate>

[0035] Refer again Figure 3 The substrate 30 is a flexible printed circuit board having electrical wiring for supplying power to the coil 40 shown in the figure. The substrate 30 is arranged on the bottom wall portion 12 of the housing 10. Most of the substrate 30 is arranged inside the housing 10, but a part of the substrate 30 is led out of the housing 10.

[0036] In the following description, most of the substrate 30 disposed inside the housing 10 may be referred to as a “main body portion”, and a portion of the substrate 30 led out of the housing 10 may be referred to as a “connection portion” for distinction.

[0037] The connection portion of the substrate 30 is provided with a connection terminal 33 that is electrically connected to the input end of the electrical wiring formed in the main body. The connection portion crosses one short side (left side) of the housing 10 and extends to the outside of the housing 10 (see Figure 1 , Figure 2 Specifically, the connection portion is formed by Figure 4The connecting portion is led out to the left side of the housing 10 between the bottom wall portion 12 and the left side wall portion 16 shown in the figure. However, the leading direction of the connecting portion can be changed appropriately.

[0038] <Coil>

[0039] Figure 2 , Figure 3 The coil 40 shown is formed by a conductive wire wound around a plate-shaped iron core. The coil 40 is connected to the output end of the electrical wiring formed on the main body of the substrate 30. Therefore, when a voltage is applied to the connection terminal 33 of the substrate 30, a voltage is applied to the coil 40 via the electrical wiring. In addition, the coil 40 can also be replaced by an air-core coil.

[0040] <Vibrating body>

[0041] The vibrating body 50 has a counterweight 51 and two magnet groups 52. The counterweight 51 is a block of a metal alloy (e.g., a tungsten alloy). The counterweight 51 is surrounded by the peripheral wall portion 17 of the housing 10 and has a side surface 53 opposite to the peripheral wall portion 17. The counterweight 51 also has an upper surface 54 connected to one peripheral edge of the side surface 53 and a lower surface 55 connected to the other peripheral edge of the side surface 53.

[0042] A magnet housing portion 56 is formed at the center of the weight 51 and penetrates the weight 51 in the up-down direction. The magnet housing portion 56 houses the magnet groups 52. Each magnet group 52 includes three plate-shaped permanent magnets arranged in the left-right direction.

[0043] The two magnet groups 52 face each other from front to back across the coil 40 in the magnet housing 56. A back yoke 57 is disposed behind each magnet group 52, and pole pieces 58 are disposed on both sides of the coil 40 in the axial direction.

[0044] When a voltage is applied to the coil 40 via the electrical wiring provided on the substrate 30, the coil 40 is magnetized to generate magnetic flux. Then, due to the magnetic interaction between the magnetic flux generated around the coil 40 and the magnetic flux generated around the magnet group 52, the vibrating body 50 including the weight 51 and the magnet group 52 reciprocates (vibrates) in the left-right direction.

[0045] <Elastic components>

[0046] The vibrating body 50 is supported by a pair of elastic members 60 so as to be capable of reciprocating motion. In the following description, the elastic member 60 disposed on one side (right side) of the vibrating body 50 in the left-right direction is sometimes referred to as "elastic member 61", and the elastic member 60 disposed on the other side (left side) of the vibrating body 50 in the left-right direction is sometimes referred to as "elastic member 62" to distinguish them. However, this distinction is only for the convenience of description.

[0047] Figure 5It is a plan view showing a state in which the elastic member 60 supports the vibrating body 50 . Fig. 6A is a perspective view showing an enlarged view of the elastic member 61, Figure 6B It is a perspective view showing the elastic member 62 in an enlarged manner.

[0048] The elastic member 60 is a metal plate having a thickness of 1.0 mm or less. In other words, the elastic member 60 is a leaf spring having a thickness of 1.0 mm or less. However, the thickness of the metal plate as the elastic member 60 is not limited to 1.0 mm or less. In addition, the material of the metal plate is not limited to a specific material.

[0049] A first fixing portion 63 is provided at one end of the elastic member 60 , and a second fixing portion 64 is provided at the other end of the elastic member 60 . The first fixing portion 63 and the second fixing portion 64 are connected via an intermediate portion 65 .

[0050] However, the distinction between the first fixing portion 63, the second fixing portion 64, and the middle portion 65 is only for the convenience of explanation. In other words, the first fixing portion 63 is a part of a metal plate, the second fixing portion 64 is another part of a metal plate, and the middle portion 65 is another part of a metal plate.

[0051] The first fixing portion 63 and the second fixing portion 64 are bent at right angles or substantially right angles in the same direction with respect to the intermediate portion 65, and face each other in the front-rear direction. As a result, the elastic member 60 has a substantially U-shaped planar shape.

[0052] The middle portion 65 of the elastic member 60 tapers gradually from both outer sides in the longitudinal direction toward the inner side. In other words, the dimension (width) of the middle portion 65 in the vertical direction tapers gradually from both outer sides in the longitudinal direction toward the inner side.

[0053] The first fixing portion 63 has a pair of bent portions 66a and 66b extending toward one side (front side) in the front-rear direction. The second fixing portion 64 has a pair of bent portions 67a and 67b extending toward the other side (rear side) in the front-rear direction.

[0054] In other words, the first fixing portion 63 includes a pair of bent portions 66 a and 66 b bent inwardly, and the second fixing portion 64 also includes a pair of bent portions 67 a and 67 b bent inwardly.

[0055] The curved portion 66a and the curved portion 66b of the first fixing portion 63 are bent inwardly by 90 degrees. As a result, the curved portion 66a and the curved portion 66b are opposed to each other (face to each other) in the vertical direction. Similarly, the curved portion 67a and the curved portion 67b of the second fixing portion 64 are bent inwardly by 90 degrees. As a result, the curved portion 67a and the curved portion 67b are opposed to each other (face to each other) in the vertical direction.

[0056] As described above, the elastic members 61 and 62 have the same shape and structure and are common in that the first fixing portion 63 is fixed to the weight 51 of the vibrating body 50 and the second fixing portion 64 is fixed to the peripheral wall portion 17 of the housing 10 .

[0057] However, the first fixing portion 63 of the elastic member 61 is welded to the right side of the counterweight 51, while the first fixing portion 63 of the elastic member 62 is welded to the left side of the counterweight 51. More specifically, the first fixing portion 63 of the elastic member 61 is welded to the right side of the back surface of the counterweight 51 facing the rear wall portion 14 of the housing 10. On the other hand, the first fixing portion 63 of the elastic member 62 is welded to the left side of the back surface of the counterweight 51 facing the rear wall portion 14 of the housing 10. In addition, the second fixing portion 64 of the elastic member 61 is welded to the right side of the inner surface of the front wall portion 13 of the housing 10, while the second fixing portion 64 of the elastic member 62 is welded to the left side of the inner surface of the front wall portion 13 of the housing 10.

[0058] Figure 7 It is along Figure 5 The enlarged cross-sectional view of line AA in the figure is as follows: Figure 8 It is along Figure 5 An enlarged cross-sectional view of line BB in FIG.

[0059] like Figure 7 As shown, the first fixing portion 63 of the elastic member 61 has a pair of bent portions 66a and 66b that face each other in the vertical direction with the weight 51 interposed therebetween. Figure 8 As shown, the pair of bent portions 66 a and 66 b included in the first fixing portion 63 of the elastic member 62 also face each other in the up-down direction with the weight 51 interposed therebetween.

[0060] As described above, each first fixing portion 63 is fixed to the counterweight 51 by welding. However, the bent portions 66a and 66b, which are part of the first fixing portion 63, are not welded to the counterweight 51. In other words, the portion of each first fixing portion 63 other than the bent portions 66a and 66b (the portion facing the back surface of the counterweight 51) is welded to the counterweight 51.

[0061] In addition, a concave portion 59 which is lower than other portions is formed on the upper surface 54 and the lower surface 55 of the counterweight 51. The curved portion 66a overlaps with the bottom surface of the concave portion 59 formed on the upper surface 54 of the counterweight 51, and the curved portion 66b overlaps with the bottom surface of the concave portion 59 formed on the lower surface 55 of the counterweight 51.

[0062] As a result, the upper surface of the curved portion 66a is flush with or substantially flush with the upper surface 54 of the counterweight 51, and the lower surface of the curved portion 66b is flush with or substantially flush with the lower surface 55 of the counterweight 51. That is, the thickness of the curved portions 66a and 66b is absorbed by the recess 59. As a result, the size (height / thickness) of the housing 10 in the vertical direction does not increase due to the provision of the curved portions 66a and 66b.

[0063] In the present embodiment, the first fixing portion 63 of the elastic member 60 fixed to the vibrating body 50 is provided with bent portions 66a and 66b extending in a direction perpendicular to the vibration direction (left-right direction) of the vibrating body 50. In addition, the second fixing portion 64 of the elastic member 60 fixed to the housing 10 is also provided with bent portions 67a and 67b extending in a direction perpendicular to the vibration direction (left-right direction) of the vibrating body 50.

[0064] As a result, the stress generated in the elastic member 60 is dispersed as the vibrating body 50 moves. More specifically, the stress concentration at the base and the vicinity of the first fixing portion 63 and the second fixing portion 64 is suppressed. Therefore, even if the vibrating body 50 moves more than usual, the damage or deformation of the elastic member 60 can be suppressed or prevented.

[0065] That is, the elastic member 60 in this embodiment has excellent durability compared with other elastic members without the curved portions 66a, 66b, 67a, 67b. As a result, it is not necessary to improve the durability of the elastic member 60 by using reinforcing members, limiting members, etc., and the number of parts and assembly man-hours can be reduced.

[0066] The present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the scope of the present invention. For example, as long as at least one of the first fixing portion 63 and the second fixing portion 64 is provided with a bent portion, the stress generated by the elastic member 60 is dispersed, thereby suppressing or preventing the elastic member 60 from being damaged or deformed.

[0067] In other words, any one of the bent portions 66a, 66b and the bent portions 67a, 67b may be omitted. However, from the viewpoint of more reliably suppressing or preventing damage or deformation of the elastic member 60, it is preferred to provide a bent portion on the first fixing portion 63 fixed to the vibrating body 50. In addition, it is preferred to provide a reinforcing plate on the second fixing portion 64 from which the bent portion is omitted.

[0068] The curved portions 66a, 66b and the curved portions 67a, 67b may extend in the opposite direction to that in the above-described embodiment. For example, the curved portions 66a, 66b may extend toward the rear side, and the curved portions 67a, 67b may extend toward the front side.

[0069] In addition, the bending angle of the bent portions 66a, 66b, 67a, 67b is not limited to 90 degrees, and may be greater than 90 degrees or less than 90 degrees. By not limiting the bending angle of the bent portions 66a, 66b, 67a, 67b to 90 degrees, the required bending accuracy is reduced, so that processing and assembly can be facilitated.

[0070] In addition, the bending angle of the curved portions 66a, 66b may be the same as or different from the bending angle of the curved portions 67a, 67b. For example, the bending angle of one of the curved portions 66a, 66b and the curved portions 67a, 67b may be set to be greater than 90 degrees, and the bending angle of the other may be set to be less than 90 degrees.

[0071] However, by bending the bent portions 66a, 66b and the bent portions 67a, 67b inward by 90 degrees, it is possible to prevent the housing 10 from being enlarged, and further, it is possible to prevent the vibration motor 1A from being enlarged. On the other hand, if the bending angle of the bent portions 66a, 66b is made smaller than 90 degrees, it is easy to arrange the counterweight 51 between the bent portions 66a, 66b, and the workability of assembly can be improved.

[0072] Either one of the elastic members 61 and 62 may be reversed. Fig. 9 It is a plan view showing a modified example of the arrangement of the elastic members 61 and 62 . Fig. 9 The elastic member 61 shown is relative to Figure 5 The elastic member 61 is shown rotated 180 degrees. In this case, the first fixing portion 63 of the elastic member 61 is welded to the right side of the front surface of the counterweight 51 opposite to the front wall 13 of the housing 10, and the second fixing portion 64 is welded to the right side of the inner surface of the rear wall 14 of the housing 10.

[0073] In addition, the present invention can adopt the following structures.

[0074] (1) A vibration motor comprising: a housing; a vibration body housed in the housing and reciprocating in a first direction inside the housing; and a pair of elastic members, the pair of elastic members supporting the vibration body inside the housing so that it can reciprocate in the first direction, each of the elastic members being a metal plate including a first fixing portion fixed to the vibration body, a second fixing portion fixed to the housing, and an intermediate portion connecting the first fixing portion and the second fixing portion, the first fixing portion and the second fixing portion being bent in the same direction relative to the intermediate portion and facing each other in a second direction perpendicular to the first direction,

[0075] At least one of the first fixing portion and the second fixing portion has a pair of bent portions extending toward one side or the other side of the second direction, and the pair of bent portions face each other in a third direction perpendicular to the first direction and the second direction.

[0076] (2) The vibration motor according to (1), wherein the first fixing portion and the second fixing portion each include a pair of the bent portions, and the pair of the bent portions included in the first fixing portion are opposed to each other with the vibrating body interposed therebetween.

[0077] (3) The vibration motor according to (1) or (2), wherein one of the elastic members is arranged on one side of the vibration body in the first direction, and the other of the elastic members is arranged on the other side of the vibration body in the first direction.

[0078] (4) In the vibration motor according to any one of (1) to (3), each of the first fixing portions is welded to a weight included in the vibration body, and each of the second fixing portions is welded to the housing.

[0079] (5) A vibration motor according to (4), wherein each of the second fixing parts is welded to a peripheral wall portion of the shell surrounding the counterweight, each of the first fixing parts is welded to a side surface of the counterweight opposite to the peripheral wall portion of the shell, one of the bent parts of each of the first fixing parts overlaps with a lower surface of the counterweight, and the lower surface of the counterweight is connected to the side surface of the counterweight, and another of the bent parts of each of the first fixing parts overlaps with an upper surface of the counterweight, and the upper surface of the counterweight is connected to the side surface of the counterweight.

Claims

1. A vibration motor, comprising: case; a vibrator housed in the housing and reciprocating in a first direction inside the housing; and a pair of elastic members that support the vibrating body inside the housing so that the vibrating body can reciprocate in the first direction, Each of the elastic members is a metal plate including a first fixing portion fixed to the vibrating body, a second fixing portion fixed to the housing, and an intermediate portion connecting the first fixing portion and the second fixing portion. The first fixing portion and the second fixing portion are bent in the same direction relative to the middle portion and are opposed to each other in a second direction perpendicular to the first direction. At least one of the first fixing portion and the second fixing portion has a pair of bent portions extending toward one side or the other side of the second direction, The pair of bent portions face each other in a third direction perpendicular to the first direction and the second direction.

2. The vibration motor according to claim 1, wherein: The first fixing portion and the second fixing portion each have a pair of the bent portions. The pair of bent portions included in the first fixing portion are opposed to each other with the vibrating body interposed therebetween.

3. The vibration motor according to claim 1, wherein: One of the elastic members is disposed on one side of the vibrator in the first direction, and the other of the elastic members is disposed on the other side of the vibrator in the first direction.

4. The vibration motor according to claim 3, wherein: Each of the first fixing parts is welded to a weight of the vibrating body. Each of the second fixing parts is welded to the shell.

5. The vibration motor according to claim 4, wherein: Each of the second fixing parts is welded to a peripheral wall of the housing surrounding the counterweight, Each of the first fixing portions is welded to a side surface of the counterweight that is opposite to the peripheral wall portion of the housing. One of the bent portions of each of the first fixing portions overlaps with a lower surface of the counterweight, and the lower surface of the counterweight is connected to the side surface of the counterweight. The other bent portion of each of the first fixing portions overlaps with an upper surface of the weight, and the upper surface of the weight is connected to the side surface of the weight.

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