Vibration actuator and method of manufacturing the same

Abstract

The invention provides a vibration actuator and a manufacturing method thereof. The vibration actuator has a stator housing with a stator plate and a stator cover. The vibration actuator has a mover unit which is housed in the stator housing and has a first facing surface facing the stator plate and a second facing surface facing the stator cover. The vibration actuator has a first connection structure that connects the stator housing and the mover unit to each other and that has a first elastic body that is attached to the stator plate and the first facing surface. The vibration actuator has a second connection structure that connects the stator housing and the mover unit to each other and that has a second elastic body attached to the stator cover and the second facing surface. The rigidity of the first connection structure and the rigidity of the second connection structure are different from each other.

Description

Technical Field

[0001] The present invention relates to a vibration actuator and a method for manufacturing the same. Background Art

[0002] Devices such as smartphones, tablet computers, and touchpads have a feedback function that provides users with a tactile sense through vibration. To achieve this feedback function, a vibration generator that vibrates a vibrator supported by an elastic body has been proposed (see Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-94561

[0004] However, the physical properties of elastomers made of rubber and the like vary not only depending on the raw materials but also sometimes depending on the manufacturing batch. Thus, variations in the physical properties of the elastomer assembled into the vibration generator are the primary cause of variations in the resonant frequency of the vibration generator, i.e., the vibration actuator. Furthermore, deviations in the resonant frequency of the vibration actuator are the primary cause of performance deviations in the vibration actuators produced in batches. Therefore, there is a need to suppress deviations in the resonant frequency of the vibration actuator. Summary of the Invention

[0005] According to the present invention, the vibration actuator has a stator housing having a stator plate and a stator cover. The vibration actuator has a mover unit, which is housed in the stator housing and has a first opposing surface opposite to the stator plate and a second opposing surface opposite to the stator cover. The vibration actuator has a first connecting structure, which connects the stator housing and the mover unit to each other, and has a first elastic body installed on the stator plate and the first opposing surface. The vibration actuator has a second connecting structure, which connects the stator housing and the mover unit to each other, and has a second elastic body installed on the stator cover and the second opposing surface. The rigidity of the first connecting structure is different from the rigidity of the second connecting structure.

[0006] According to the present invention, the manufacturing method of the vibration actuator has the following stator assembly process: assembling a stator assembly consisting of a stator plate and a coil mounted on the stator plate. The manufacturing method of the vibration actuator has the following mover assembly process: assembling a mover assembly consisting of a mover plate and a magnet mounted on the mover plate. The manufacturing method of the vibration driver has the following semi-finished product assembly process: assembling a semi-finished product consisting of the stator assembly and the mover assembly mounted on the stator assembly via a first elastic body. The manufacturing method of the vibration actuator has the following frequency measurement process: vibrating the mover assembly of the semi-finished product, and measuring the resonant frequency of the semi-finished product. The manufacturing method of the vibration actuator has the following cover installation process: mounting a stator cover on the mover assembly via a second elastic body, and mounting the stator cover on the stator plate.

[0007] According to the present invention, it is possible to suppress variations in the resonance frequency of the vibration actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a perspective view showing a smartphone including a vibration actuator according to an embodiment of the present invention.

[0009] Figure 2 It is a perspective view showing a vibration actuator.

[0010] Figure 3 It is an exploded perspective view showing a vibration actuator.

[0011] Figure 4 It is an exploded perspective view showing the stator unit.

[0012] Figure 5 It is an exploded perspective view showing the mover unit.

[0013] Figure 6 It is along Figure 2 Line AA shows a cross-sectional view of the vibration actuator.

[0014] Figure 7 It shows Figure 6 A cross-sectional view of an exploded state of the vibration actuator shown.

[0015] Figure 8 This is a perspective view of the vibration actuator showing a state where the stator cover and the mover plate are removed.

[0016] Figure 9 It is a diagram showing the operating state of the vibration actuator.

[0017] Figure 10 It is a diagram showing the operating state of the vibration actuator.

[0018] Figure 11 It is a figure which shows the manufacturing method of the vibration actuator which concerns on one embodiment of this invention.

[0019] Figure 12A This is a perspective view showing an example of a stator assembly.

[0020] Figure 12B It is a perspective view showing an example of a movable element assembly.

[0021] Figure 12C It is a perspective view showing an example of a semi-finished product.

[0022] Figure 13 This is a diagram showing an example of a frequency measurement process.

[0023] Figure 14 It is a figure which shows an example of a cover mounting process.

[0024] Description of labels

[0025] 10: Vibration actuator; 20: Stator unit; 21, 22: Plate-shaped coil (coil); 23: Stator plate; 24: Stator cover; 25: Stator housing; 30: Mover unit; 31, 32, 33: Plate-shaped magnet (magnet); 34: Mover plate; 51: First opposing surface; 52: Second opposing surface; 53: First connecting structure; 54: Main damper (first elastic body); 55: Second connecting structure; 56, 56A, 56B, 56C: Adjustment damper (second elastic body); 60: Stator assembly; 70: Mover assembly; 80: Semi-finished product. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, identical or substantially identical structures and elements will be denoted by identical reference numerals, and repeated description will be omitted.

[0027] <Equipment with a vibration actuator>

[0028] Figure 1 1 is a perspective view showing a smartphone 11 having a vibration actuator 10 according to an embodiment of the present invention. Figure 1 As shown, a vibration actuator 10 is mounted on a display 12 of a smartphone 11. By controlling the vibration pattern of the display 12 using the vibration actuator 10, a tactile sensation such as a click feeling based on vibration can be given to a user touching the display 12.

[0029] In the example shown in the figure, the vibration actuator 10 is installed on the display 12, but is not limited to this. The vibration actuator 10 can also be installed on the housing 13 of the smart phone 11. In this case, the vibration actuator 10 can be used to control the vibration mode of the housing 13, and the user who touches the housing 13 can be given a tactile sense based on vibration. Such vibration feedback technology is also referred to as tactile technology. In addition, the vibration actuator 10 is also referred to as a linear vibration motor.

[0030] In addition, the vibration actuator 10 is connected to an unillustrated electronic control unit consisting of a microcontroller and a drive circuit. By using this electronic control unit to control the energized current of the plate-shaped coils 21 and 22 described later, the vibration actuator 10 can be vibrated in a specified vibration mode. In addition, in the illustrated example, the vibration actuator 10 is assembled on a smart phone 11, but is not limited to this, and the vibration actuator 10 can also be assembled on other devices. For example, the vibration actuator 10 can be assembled on mobile devices such as tablet computers, or the vibration actuator 10 can be assembled on a touchpad of a notebook computer. In addition, the vibration actuator 10 can also be assembled on a car-mounted display mounted on a vehicle.

[0031] <Structure of a Vibration Actuator>

[0032] Figure 2 is a perspective view showing the vibration actuator 10, Figure 3 It is an exploded perspective view showing the vibration actuator 10 . Figure 4 is an exploded perspective view showing the stator unit 20, Figure 5 : is an exploded perspective view showing the mover unit 30. Figure 6 It is along Figure 2 The AA line shows a cross-sectional view of the vibration actuator 10, Figure 7 It shows Figure 6 The sectional view of the vibration actuator 10 in the exploded state is shown. Figure 8 It is a perspective view showing the vibration actuator 10 in a state where the stator cover and the mover plate are removed.

[0033] like Figure 2 and Figure 3 As shown, the vibration actuator 10 includes a stator unit 20 having plate-shaped coils 21 and 22 as air-core coils, and a mover unit 30 having plate-shaped magnets 31, 32, and 33 as permanent magnets. The stator unit 20 includes a stator housing 25 composed of a stator plate 23 and a stator cover 24. The mover unit 30 is housed within the stator housing 25 of the stator unit 20.

[0034] like Figure 4As shown, the stator unit 20 includes a stator plate 23, a flexible printed circuit board 26 mounted on the stator plate 23, and two plate-shaped coils 21 and 22 mounted on the stator plate 23 and the flexible printed circuit board 26. Furthermore, the stator unit 20 includes a stator cover 24 mounted on the stator plate 23. The plate-shaped coils 21 and 22 and the flexible printed circuit board 26 are mounted on the stator plate 23 by bonding or the like, and the stator cover 24 is mounted on the stator plate 23 by welding or the like.

[0035] Plate-shaped coil 21 has a pair of parallel straight portions 40, 41 and a pair of curved portions 42 connecting straight portions 40, 41. Similarly, plate-shaped coil 22 has a pair of parallel straight portions 44, 45 and a pair of curved portions 46 connecting straight portions 44, 45. Plate-shaped coils 21, 22 are air-core coils formed by winding an electric wire. Air-core portions 43, 47, which are elongated, hole-shaped spaces, are provided in the center of plate-shaped coils 21, 22.

[0036] like Figure 5 As shown, the mover unit 30 includes a mover plate 34, three plate-shaped magnets 31, 32, and 33 mounted on the mover plate 34, and three pole pieces 35, 36, and 37 mounted on the plate-shaped magnets 31, 32, and 33. Furthermore, the mover unit 30 includes a frame-shaped counterweight 38 mounted on the mover plate 34. The plate-shaped magnets 31, 32, and 33 and the counterweight 38 are mounted on the mover plate 34 by bonding or the like, and the pole pieces 35, 36, and 37 are mounted on the plate-shaped magnets 31, 32, and 33 by bonding or the like.

[0037] Furthermore, the stator plate 23, the mover plate 34, and the pole pieces 35, 36, and 37 are formed of a ferromagnetic material. Examples of such ferromagnetic materials include ferritic stainless steels such as SUS 430 and martensitic stainless steels such as SUS 410. Furthermore, ferromagnetic materials are not limited to ferritic stainless steels and martensitic stainless steels; iron, nickel, and the like may also be used to form the mover plate 34 and the stator plate 23. Furthermore, to improve the magnetic circuit of the vibration actuator 10, a plurality of slits 48 are formed in the mover plate 34 and the stator plate 23.

[0038] like Figure 6 and Figure 7 As shown, the mover unit 30 has a first opposing surface 51 opposing the stator plate 23 and a second opposing surface 52 opposing the stator housing 24. Four main dampers (first elastic bodies) 54 constituting a first connecting structure 53 are attached to the stator plate 23 and the first opposing surface 51 by bonding or the like. Specifically, the first connecting structure 53, consisting of the main dampers 54, connects the mover unit 30 to the stator plate 23 of the stator housing 25. The main dampers 54 are made of a polymeric elastomer such as silicone rubber, butyl rubber, or natural rubber.

[0039] An adjustment damper (second elastic body) 56 constituting the second connection structure 55 is installed on the stator cover 24 and the second opposing surface 52 by bonding or the like. That is, the second connection structure 55 consisting of the adjustment damper 56 connects the mover unit 30 and the stator cover 24 of the stator housing 25 to each other. In addition, a through hole 39 is formed on the mover plate 34 of the mover unit 30, and the adjustment damper 56 is mounted on the plate-shaped magnet 32 ​​of the mover unit 30 through the through hole 39. In this way, the thickness dimension of the vibration actuator 10 can be reduced. In addition, as the adjustment damper 56, an elastomer such as a polymer object such as silicone rubber, butyl rubber, or natural rubber is used.

[0040] As described above, the stator housing 25 and the mover unit 30 are connected via the main damper 54 and the adjustment damper 56. Therefore, the mover unit 30 can be displaced relative to the stator housing 25 by a stroke corresponding to the elastic deformation of the main damper 54 and the adjustment damper 56. In addition, the number of adjustment dampers 56 constituting the second connection structure 55 is set to be smaller than the number of main dampers 54 constituting the first connection structure 53. In addition, the diameter of the adjustment damper 56 is smaller than the diameter of the main damper 54, and the rigidity of the adjustment damper 56 is lower than the rigidity of the main damper 54. Due to these various factors, the rigidity of the second connection structure 55 composed of the adjustment damper 56 is lower than the rigidity of the first connection structure 53 composed of the main damper 54. In other words, the rigidity of the first connection structure 53 and the rigidity of the second connection structure 55 are different from each other.

[0041] The rigidity of the second connection structure 55 is lower than that of the first connection structure 53. The second connection structure 55 is softer and more easily deformed than the first connection structure 53. The rigidity of the second connection structure 55 is lower than that of the first connection structure 53, which means that the deformation amount when a predetermined load is input to the second connection structure 55 alone is greater than the deformation amount when a predetermined load is input to the first connection structure 53 alone. For example, in a state where only the second connection structure 55 is removed from the vibration actuator 10, it is assumed that when a predetermined load W is applied to the movable element 30 in the vibration direction, the movable element 30 moves by a movement amount S1. Alternatively, in a state where only the first connection structure 53 is removed from the vibration actuator 10, it is assumed that when a predetermined load W is applied to the movable element 30 in the vibration direction, the movable element 30 moves by a movement amount S2. In this case, the rigidity of the second connection structure 55 is lower than that of the first connection structure 53, which means that the movement amount S2 is greater than the movement amount S1.

[0042] The fact that the rigidity of the adjusting damper 56 is lower than that of the main damper 54 means that the adjusting damper 56 is softer than the main damper 54. The softness of the main damper 54 and the adjusting damper 56 can be measured using a hardness test standardized in, for example, JISK 6253 or ISO 48-4.

[0043] like Figure 6 and Figure 8 As shown, the plate-shaped magnet 31 is positioned adjacent to the straight portion 40 of the plate-shaped coil 21, and the plate-shaped magnet 32 ​​is positioned adjacent to the straight portion 41 of the plate-shaped coil 21. Similarly, the plate-shaped magnet 32 ​​is positioned adjacent to the straight portion 44 of the plate-shaped coil 22, and the plate-shaped magnet 33 is positioned adjacent to the straight portion 45 of the plate-shaped coil 22. In other words, the plate-shaped coil 21 is accommodated in the space between the plate-shaped magnet 31 and the plate-shaped magnet 32, and the plate-shaped coil 22 is accommodated in the space between the plate-shaped magnet 32 ​​and the plate-shaped magnet 33.

[0044] That is, Figure 6 and Figure 7 As shown, in the thickness direction D1 of the vibration actuator 10, the plate-shaped magnets 31, 32, 33 and the front surfaces of the plate-shaped coils 21, 22 are arranged so as not to face each other. Figure 6 As shown, when the stator unit 20 and the mover unit 30 are combined, the front surfaces 31a, 32a, and 33a of the plate-shaped magnets 31, 32, and 33 are located closer to the stator plate 23 than the front surfaces 21a and 22a of the plate-shaped coils 21 and 22. In other words, the front surfaces 21a and 22a of the plate-shaped coils 21 and 22 are located closer to the mover plate 34 than the front surfaces 31a, 32a, and 33a of the plate-shaped magnets 31, 32, and 33.

[0045] As described above, by arranging the plate-shaped magnets 31, 32, 33 and the plate-shaped coils 21, 22 in the thickness direction D1 of the vibration actuator 10, the thickness of the vibration actuator 10 can be reduced, and the vibration actuator 10 can be made thinner. Furthermore, it is possible to achieve miniaturization and thinning of various devices incorporating the vibration actuator 10. The thickness direction D1 of the vibration actuator 10 is a direction perpendicular to the front surfaces of the mover plate 34 and the stator plate 23.

[0046] <Operation of the Vibration Actuator>

[0047] Figure 9 and Figure 10 1 is a diagram showing the operating state of the vibration actuator 10. Figure 9 and Figure 10 Shown in Figure 6 In addition, in order to facilitate the description of the operation of the vibration actuator 10, Figure 9 and Figure 10 FIG shows a vibration actuator 10 magnified in the thickness direction. Figure 9 The plate coils 21 and 22 are shown in FIG. Figure 8 When the power is supplied in the direction of arrow A1, Figure 10 The plate coils 21 and 22 are shown in FIG. Figure 8 The situation where power is flowing in the direction of arrow A2.

[0048] like Figure 9 As shown, the plate-shaped magnets 31 and 33 at the ends are magnetized so that their front surfaces 31a and 33a have north poles, while the plate-shaped magnet 32 ​​at the center is magnetized so that its front surface 32a has south poles. Thus, the plate-shaped magnets 31 and 33 at the ends and the plate-shaped magnet 32 ​​at the center are magnetized to opposite polarities. Alternatively, the plate-shaped magnets 31 and 32 may be magnetized so that their front surfaces 31a and 33a have south poles, while the plate-shaped magnet 32 ​​may be magnetized so that its front surface 32a has north poles.

[0049] like Figure 9 As shown, by magnetizing the plate-shaped magnets 31, 32, and 33, a magnetic field H1 is generated from the stator plate 23 toward the mover plate 34 at the straight portion 40 of the plate-shaped coil 21, and a magnetic field H2 is generated from the mover plate 34 toward the stator plate 23 at the straight portion 41 of the plate-shaped coil 21. Furthermore, a magnetic field H3 is generated from the mover plate 34 toward the stator plate 23 at the straight portion 44 of the plate-shaped coil 22, and a magnetic field H4 is generated from the stator plate 23 toward the mover plate 34 at the straight portion 45 of the plate-shaped coil 22.

[0050] In the state where magnetic fields H1 to H4 are generated, when the current is as Figure 8 When the flow passes through the straight sections 40, 41, 44, and 45 of the plate-shaped coils 21 and 22 as indicated by the arrow A1, Figure 9 As shown, a Lorentz force F1a is generated on the straight portion 40, which, through reaction, generates a thrust F1b on the plate-shaped magnet 31 in a direction toward the straight portion 40. Furthermore, a Lorentz force F2a is generated on the straight portion 41, which, through reaction, generates a thrust F2b on the plate-shaped magnet 32 ​​in a direction away from the straight portion 41. Furthermore, a Lorentz force F3a is generated on the straight portion 44, which, through reaction, generates a thrust F3b on the plate-shaped magnet 32 ​​in a direction toward the straight portion 44. Furthermore, a Lorentz force F4a is generated on the straight portion 45, which, through reaction, generates a thrust F4b on the plate-shaped magnet 33 in a direction away from the straight portion 45. Thus, the thrusts F1b, F2b, F3b, and F4b act on the mover unit 30, causing the mover unit 30 to displace in the direction of arrow X1 while deforming the main damper 54 and the adjustment damper 56.

[0051] On the other hand, when the current is Figure 8 When the flow passes through the straight sections 40, 41, 44, and 45 of the plate-shaped coils 21 and 22 as indicated by the arrow A2, Figure 10As shown, a Lorentz force F1c is generated on the straight portion 40, which, through reaction, generates a thrust F1d on the plate-shaped magnet 31 in a direction away from the straight portion 40. Furthermore, a Lorentz force F2c is generated on the straight portion 41, which, through reaction, generates a thrust F2d on the plate-shaped magnet 32 ​​in a direction toward the straight portion 41. Furthermore, a Lorentz force F3c is generated on the straight portion 44, which, through reaction, generates a thrust F3d on the plate-shaped magnet 32 ​​in a direction away from the straight portion 44. Furthermore, a Lorentz force F4c is generated on the straight portion 45, which, through reaction, generates a thrust F4d on the plate-shaped magnet 33 in a direction toward the straight portion 45. Thus, the thrusts F1d, F2d, F3d, and F4d act on the mover unit 30, causing the mover unit 30 to displace in the direction of arrow X2 while deforming the main damper 54 and the adjustment damper 56.

[0052] That is, by switching the direction of power supply of the plate-shaped coils 21 and 22, the thrust acting on the mover unit 30 can be switched to the direction of the arrow X1 and the direction of the arrow X2. As a result, the mover unit 30 can be reciprocated with a specified stroke, and the vibration actuator 10 can be vibrated. By using the vibration actuator 10 to control the vibration mode of the display 12, for example, it is possible to give a tactile sensation such as a click feeling based on vibration to the user of the touch display 12. In addition, the rigidity of the first connecting structure 53 is higher than the rigidity of the second connecting structure 55, so the vibration characteristics of the vibration actuator 10 are mainly determined by the main damper 54 constituting the first connecting structure 53.

[0053] <Method for Manufacturing a Vibration Actuator>

[0054] Figure 11 It is a figure which shows the manufacturing method of the vibration actuator 10 which concerns on one embodiment of this invention. Figure 12A 1 is a perspective view showing an example of the stator assembly 60. Figure 12B 1 is a perspective view showing an example of a movable element assembly 70. Figure 12C : is a perspective view showing an example of a semi-finished product 80. Figure 13 1 is a diagram showing an example of the frequency measurement step S130. Figure 14 It is a figure which shows an example of the cover attachment process S140.

[0055] like Figure 11As shown, the manufacturing method of the vibration actuator 10 has the following stator assembly step S100: assembling a stator assembly 60 composed of a stator plate 23 and plate-shaped coils (coils) 21 and 22 mounted on the stator plate 23. In addition, the manufacturing method of the vibration actuator 10 has the following mover assembly step S110: assembling a mover assembly 70 composed of a mover plate 34 and plate-shaped magnets (magnets) 31, 32, and 33 mounted on the mover plate 34. Furthermore, the manufacturing method of the vibration actuator 10 has the following semi-finished product assembly step S120: assembling a semi-finished product 80 composed of the stator assembly 60 and the mover assembly 70 mounted on the stator assembly 60 via the main damper (first elastic body) 54.

[0056] like Figure 12A As shown, the stator assembly 60 assembled in the stator assembly step S100 is an assembly obtained by removing the stator cover 24 from the stator unit 20. Figure 12B As shown in FIG. 1 , the movable assembly 70 assembled in the movable assembly step S110 is the same assembly as the movable unit 30 described above. Figure 12C As shown, the semi-finished product 80 assembled in the semi-finished product assembling step S120 is an assembly obtained by removing the stator cover 24 and the adjustment damper 56 from the vibration actuator 10 as a finished product.

[0057] like Figure 11 As shown, the manufacturing method of the vibration actuator 10 includes the following frequency measurement step S130: vibrating the movable assembly 70 of the semi-finished product 80 to measure the resonant frequency of the semi-finished product 80. In addition, the manufacturing method of the vibration actuator 10 includes the following cover mounting step S140: mounting the stator cover 24 to the movable assembly 70 via the adjustment damper (second elastic body) 56, and mounting the stator cover 24 to the stator plate 23.

[0058] like Figure 13 As shown, in the frequency measurement step S130, the semi-finished product 80 is placed on a measuring table 91 having an acceleration sensor 90, and a measuring device 92 for measuring the resonant frequency is connected to the flexible printed circuit board 26 of the semi-finished product 80. The measuring device 92 is composed of a microcontroller, a drive circuit, etc., and is connected to the acceleration sensor 90 that detects the acceleration of the measuring table 91. The measuring device 92 can control the current flowing through the plate-shaped coils 21 and 22 of the stator assembly 60 and can vibrate the movable assembly 70 assembled with the semi-finished product 80. In addition, the measuring device 92 can calculate the natural vibration frequency, that is, the resonant frequency, of the semi-finished product 80 based on the acceleration of the measuring table 91 when the movable assembly 70 is vibrated.

[0059] In this way, in the frequency measuring step S130, when the resonance frequency of the semi-finished product 80 is measured, the cover mounting step S140 is entered to mount the adjustment damper 56 and the stator cover 24 on the semi-finished product 80. Figure 14 As shown, in the cover mounting step S140, the adjustment damper 56 is mounted on the movable assembly 70 of the semi-finished product 80 by bonding or the like, and the stator cover 24 is mounted on the stator plate 23 of the semi-finished product 80 by welding or the like. Figure 14 As indicated by reference numerals 56A, 56B, and 56C, in addition to the reference adjusting damper 56, adjusting dampers 56A, 56B, and 56C having different elastic characteristics from those of adjusting damper 56 are prepared as adjusting dampers to be assembled into the semi-finished product 80. Then, in a cover mounting step S140, one of the adjusting dampers 56, 56A, 56B, and 56C is selected based on the resonant frequency of the semi-finished product 80, and the selected adjusting damper 56, 56A, 56B, and 56C is mounted between the mover assembly 70 and the stator cover 24.

[0060] That is, the resonant frequency of the semi-finished product 80 is primarily determined by the physical properties of the main damper 54, namely, its elasticity and attenuation characteristics. However, the physical properties of the main damper 54, which is made of silicone rubber or the like, may vary depending on the manufacturing batch. Therefore, in the vibration actuator 10 of the present invention, the dampers 56, 56A, 56B, and 56C are selected and adjusted based on the resonant frequency of the semi-finished product 80, thereby adjusting the resonant frequency of the vibration actuator 10 toward a predetermined target frequency. This suppresses variations in the resonant frequency of the vibration actuator 10, and stabilizes the performance of the vibration actuator 10 as a mass-produced product.

[0061] That is, when the resonant frequency of the semi-finished product 80 is within the specified target range, the adjustment damper 56 serving as the reference is selected. In contrast, when the resonant frequency of the semi-finished product 80 is lower than the specified target range, adjustment dampers 56A and 56B having higher rigidity than the adjustment damper 56 are selected from the perspective of increasing the resonant frequency of the vibration actuator 10. On the other hand, when the resonant frequency of the semi-finished product 80 is higher than the specified target range, adjustment damper 56C having lower rigidity than the adjustment damper 56 is selected from the perspective of reducing the resonant frequency of the vibration actuator 10. This suppresses the deviation of the resonant frequency of the vibration actuator 10 and stabilizes the performance of the vibration actuator 10 as a mass-produced product.

[0062] In other words, the vibration actuator 10 includes a first connection structure 53 that connects the stator housing 25 and the mover unit 30 to each other, and a second connection structure 55 that connects the stator housing 25 and the mover unit 30 to each other. In addition, the rigidity of the first connection structure 53 and the rigidity of the second connection structure 55 are different from each other. Thus, as a connection structure connecting the mover unit 30 to the stator housing 25, in addition to the first connection structure 53 composed of the main damper 54, a second connection structure 55 having a different rigidity from the first connection structure 53 is provided, that is, the second connection structure 55 composed of the adjustment damper 56. Thus, the resonant frequency of the vibration actuator 10 can be adjusted by adjusting the damper 56, thereby suppressing the deviation of the resonant frequency in the vibration actuator 10.

[0063] Other Modifications

[0064] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. Figure 14 In the illustrated example, adjustment dampers 56A are increased in number compared to adjustment damper 56, adjustment dampers 56B are increased in diameter (i.e., increased in end surface area) compared to adjustment damper 56, and adjustment dampers 56C are decreased in diameter (i.e., decreased in end surface area) compared to adjustment damper 56, but the present invention is not limited thereto. For example, adjustment dampers with altered properties from adjustment damper 56 by changing the material of adjustment damper 56 may also be used. Alternatively, adjustment dampers with altered properties from adjustment damper 56 by changing the shape of adjustment damper 56 may also be used.

[0065] In the above description, the rigidity of the second connection structure 55 is lower than that of the first connection structure 53. However, this is not limiting. The rigidity of the second connection structure 55 may also be higher than that of the first connection structure 53. Furthermore, in the illustrated example, the first connection structure 53 is composed of four main dampers 54, and the second connection structure 55 is composed of one adjustable damper 56. However, this is not limiting. That is, the first connection structure 53 may be composed of one or more main dampers 54, and the second connection structure 55 may be composed of one or more adjustable dampers 56. Furthermore, in the illustrated example, the main dampers 54 and the adjustable dampers 56 are cylindrical, but this is not limiting. The main dampers 54 and the adjustable dampers 56 may also be formed in other shapes. For example, the main dampers 54 and the adjustable dampers 56 may be cylindrical, prismatic, or square.

[0066] In the example shown in the figure, the vibration actuator 10 is formed using two plate-shaped coils 21, 22 and three plate-shaped magnets 31, 32, 33, but the present invention is not limited to this. The number of plate-shaped magnets 31, 32, 33 and plate-shaped coils 21, 22 that form the vibration actuator 10 may be changed. In addition, in the example shown in the figure, a counterweight 38 is installed on the movable plate 34, but the present invention is not limited to this. If the movable plate 34 and the plate-shaped magnets 31, 32, 33 have sufficient mass, the counterweight 38 may be removed from the movable plate 34. In addition, in the example shown in the figure, pole pieces 35, 36, 37 are installed on the plate-shaped magnets 31, 32, 33, but the present invention is not limited to this. The pole pieces 35, 36, 37 may be removed from the plate-shaped magnets 31, 32, 33.

[0067] In addition, the present technology can adopt the following configurations.

[0068] [1] A vibration actuator comprising: a stator housing having a stator plate and a stator cover; a mover unit housed in the stator housing and having a first opposing surface opposing the stator plate and a second opposing surface opposing the stator cover; a first connecting structure connecting the stator housing and the mover unit to each other, the first elastic body being mounted on the stator plate and the first opposing surface; and a second connecting structure connecting the stator housing and the mover unit to each other, the second elastic body being mounted on the stator cover and the second opposing surface, wherein the rigidity of the first connecting structure and the rigidity of the second connecting structure are different from each other.

[0069] [2] The vibration actuator according to [1], wherein the rigidity of the second connecting structure is lower than the rigidity of the first connecting structure.

[0070] [3] The vibration actuator according to [1] or [2], wherein the first coupling structure includes a plurality of the first elastic bodies, and the second coupling structure includes a single second elastic body.

[0071] [4] The vibration actuator according to [1] or [2], wherein the first coupling structure includes a plurality of the first elastic bodies, and the second coupling structure includes a plurality of the second elastic bodies.

[0072] [5] The vibration actuator according to any one of [1] to [4], wherein the number of the second elastic bodies constituting the second coupling structure is smaller than the number of the first elastic bodies constituting the first coupling structure.

[0073] [6] The vibration actuator according to any one of [1] to [5], wherein the second elastic body is smaller than the first elastic body.

[0074] [7] The vibration actuator according to any one of [1] to [6], wherein the rigidity of the second elastic body is lower than the rigidity of the first elastic body.

[0075] [8] A method for manufacturing a vibration actuator, wherein the manufacturing method comprises the following steps: a stator assembly step of assembling a stator assembly consisting of a stator plate and a coil mounted on the stator plate; a mover assembly step of assembling a mover assembly consisting of a mover plate and a magnet mounted on the mover plate; a semi-finished product assembly step of assembling a semi-finished product consisting of the stator assembly and the mover assembly mounted on the stator assembly via a first elastic body; a frequency measuring step of vibrating the mover assembly of the semi-finished product and measuring the resonance frequency of the semi-finished product; and a cover mounting step of mounting a stator cover on the mover assembly via a second elastic body and mounting the stator cover on the stator plate.

Claims

1. A vibration actuator comprising: a stator housing having a stator plate and a stator cover; a mover unit housed in the stator housing and having a first facing surface facing the stator plate and a second facing surface facing the stator cover; a first connecting structure connecting the stator housing and the mover unit to each other, comprising a first elastic body attached to the stator plate and the first facing surface; as well as The second connecting structure connects the stator housing and the mover unit to each other and includes a second elastic body attached to the stator cover and the second facing surface. The rigidity of the first connecting structure and the rigidity of the second connecting structure are different from each other.

2. The vibration actuator according to claim 1, wherein The rigidity of the second connecting structure is lower than the rigidity of the first connecting structure.

3. The vibration actuator according to claim 1, wherein The first connecting structure includes a plurality of first elastic bodies. The second connecting structure includes one second elastic body.

4. The vibration actuator according to claim 1, wherein The first connecting structure includes a plurality of first elastic bodies. The second coupling structure includes a plurality of second elastic bodies.

5. The vibration actuator according to claim 1, wherein The number of the second elastic bodies constituting the second coupling structure is smaller than the number of the first elastic bodies constituting the first coupling structure.

6. The vibration actuator according to claim 1, wherein The second elastic body is smaller than the first elastic body.

7. The vibration actuator according to claim 1, wherein The second elastic body has lower rigidity than the first elastic body.

8. A method for manufacturing a vibration actuator, wherein: The manufacturing method has the following steps: a stator assembly step of assembling a stator assembly consisting of a stator plate and a coil mounted on the stator plate; A mover assembly step of assembling a mover assembly consisting of a mover plate and a magnet mounted on the mover plate; a semi-finished product assembling step of assembling a semi-finished product consisting of the stator assembly and the mover assembly mounted on the stator assembly via a first elastic body; a frequency measuring step of vibrating the movable element assembly of the semi-finished product to measure the resonance frequency of the semi-finished product; and The cover mounting step includes mounting a stator cover to the movable element assembly via a second elastic body, and mounting the stator cover to the stator plate.

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