Vibration actuator

Abstract

The invention provides a vibration actuator. The vibration actuator has a first plate and a second plate facing the first plate. The first plate has a magnet mounting surface on which the back surface of the magnet is mounted, and a coil facing surface facing the front surface of the coil. The second plate has a coil mounting surface on which the back surface of the coil is mounted, and a magnet facing surface facing the front surface of the magnet. The distance between the coil mounting surface and the coil facing surface is narrower than the distance between the magnet mounting surface and the magnet facing surface.

Description

Technical Field

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

[0002] Devices such as smartphones, tablet computers, and game controllers have a function of giving haptic feedback based on vibration to a user. In order to realize this feedback function, a linear vibration actuator that vibrates a mover using electromagnetic force has been proposed (see Patent Document 1).

[0003] Patent Document 1: International Publication No. 2019 / 151232

[0004] However, since devices such as smartphones are required to be thinner, vibration actuators such as linear vibration actuators are also required to be thinner. However, thinning of the vibration actuator is a main cause of reducing the vibration torque, and thus it is required to increase the vibration torque of the vibration actuator. Summary of the Invention

[0005] According to the present invention, a vibration actuator includes a first plate and a second plate opposed to the first plate. The vibration actuator includes a plate-shaped magnet having a magnet back surface mounted on the first plate and a magnet front surface located on the opposite side of the magnet back surface and opposed to the second plate. The vibration actuator includes a plate-shaped coil having a coil back surface mounted on the second plate and a coil front surface located on the opposite side of the coil back surface and opposed to the first plate. The vibration actuator includes an elastic member having a first end mounted on the first plate and a second end mounted on the second plate. The first plate has a magnet mounting surface for mounting the magnet back surface and a coil opposing surface opposed to the coil front surface. The second plate has a coil mounting surface for mounting the coil back surface and a magnet opposing surface opposed to the magnet front surface. The interval between the coil mounting surface and the coil opposing surface is narrower than the interval between the magnet mounting surface and the magnet opposing surface.

[0006] According to the present invention, it is possible to increase the vibration torque of the vibration actuator. Brief Description of the Drawings

[0007] Figure 1 is a perspective view of a smartphone having a vibration actuator according to an embodiment of the present invention.

[0008] Figure 2 is a perspective view of the vibration actuator.

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

[0010] Figure 4 is along Figure 2The A-A line shows a cross-sectional view of the vibration actuator.

[0011] Figure 5 shows Figure 4 A cross-sectional view showing the disassembled state of the vibration actuator shown.

[0012] Figure 6 A perspective view of the vibration actuator showing the state where the movable plate has been removed.

[0013] Figure 7 A diagram showing the positional relationship between the slits formed in the movable plate and the fixed plate and the plate-shaped magnet and the plate-shaped coil.

[0014] Figure 8 A diagram showing the operating condition of the vibration actuator.

[0015] Figure 9 A diagram showing the operating condition of the vibration actuator.

[0016] Figure 10 [[ID=2~6]]A cross-sectional view showing the vibration actuator of Modification 1.

[0017] Figure 11 A cross-sectional view showing the vibration actuator of Modification 2.

[0018] Figure 12 A partially disassembled perspective view showing the vibration actuator of Modification 3.

[0019] Figure 13 A cross-sectional view showing the vibration actuator of Modification 3.

[0020] Reference numeral description

[0021] 10: Vibration actuator; 21: Movable plate (first plate); 22, 23, 24: Plate-shaped magnets; 22a, 23a, 24a: Magnet back surfaces; 22b, 23b, 24b: Magnet front surfaces; 25: Counterweight; 31: Fixed plate (second plate); 33, 34: Plate-shaped coils; 33a, 34a: Coil back surfaces; 33b, 34b: Coil front surfaces; 40, 41: Straight portions; 43: Hollow portion; 44, 45: Straight portions; 47: Hollow portion; 48: Rubber damper (elastic member); 48a: First end portion; 48b: Second end portion; 50, 51, 52: Magnet mounting surfaces; 53, 54: Coil opposing surfaces; 55: Plate main body portion; 56, 57: Stamping portions; 60, 61: Coil mounting surfaces; 62, 63, 64: Magnet opposing surfaces; 65: Plate main body portion; 66, 67: Stamping portions; 70, 71: Coil side seams (openings); 80: Vibration actuator; 82: Movable plate (first plate); 90: Vibration actuator; 93: Movable plate (first plate); 94: Plate main body; 95a, 95b: Auxiliary plates; 96: Fixed plate (second plate); 97: Plate main body; 98a, 98b: Auxiliary plates; 100: Vibration actuator; G1, G2, G3, G4: Spacings; W3, W4: Width dimensions. Detailed Description of the Embodiment

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or substantially the same structures and elements are denoted by the same reference numerals and repeated descriptions are omitted.

[0023] <Portable Electronic Device with Vibration Actuator>

[0024] Figure 1 is a perspective view of a smartphone 11 having a vibration actuator 10 according to an embodiment of the present invention. As Figure 1 shown, the vibration actuator 10 is mounted on a display 12 or the like of the smartphone 11 as an electronic device. By using the vibration actuator 10 to control the vibration mode of the display 12, it is possible to give a user who touches the display 12 a tactile sensation such as a vibration-based click feeling.

[0025] In the illustrated example, the vibration actuator 10 is mounted on the display 12, but it is not limited thereto, and the vibration actuator 10 may also be mounted on a housing 13 of the smartphone 11. In this case, the vibration actuator 10 can be used to control the vibration mode of the housing 13, and a user who touches the housing 13 can be given a vibration-based tactile sensation. These vibration feedback technologies are also referred to as haptic technologies. In addition, the vibration actuator 10 is also referred to as a linear vibration actuator, a linear vibration motor, etc.

[0026] In addition, an electronic control unit (not shown) composed of a microcontroller, a drive circuit, etc. is connected to the vibration actuator 10. By controlling the energizing current of the plate-shaped coil described later using this electronic control unit, the vibration actuator 10 can be vibrated in a specified vibration mode. In the illustrated example, the vibration actuator 10 is assembled in the smartphone 11, but it is not limited thereto, and the vibration actuator 10 can also be assembled in other devices. For example, the vibration actuator 10 can be assembled in a mobile device such as a tablet computer, can be assembled in an in-vehicle display mounted on a vehicle, and can also be assembled in an operating device such as a game controller or a joystick.

[0027] <Structure of Vibration Actuator>

[0028] Figure 2 is a perspective view showing the vibration actuator 10, Figure 3 is an exploded perspective view showing the internal structure of the vibration actuator 10. In addition, Figure 4 is along Figure 2 sectional view of the vibration actuator 10 taken along line A-A, Figure 5 is showing Figure 4 sectional view of the vibration actuator 10 shown in the exploded state. And, Figure 6 is a perspective view of the vibration actuator 10 with the movable plate 21 removed.

[0029] As Figure 2 and Figure 3 shown, the vibration actuator 10 includes: a mover unit 20 having plate-shaped magnets 22, 23, 24; and a stator unit 30 having plate-shaped coils 33, 34. As Figure 3 and Figure 5 shown, the mover unit 20 has a movable plate (first plate) 21 made of a ferromagnetic material, three plate-shaped magnets 22, 23, 24 mounted on the movable plate 21, and a frame-shaped weight 25 mounted on the movable plate 21. In addition, the stator unit 30 has a fixed plate (second plate) 31 made of a ferromagnetic material, a flexible printed circuit board 32 mounted on the fixed plate 31, and two plate-shaped coils 33, 34 mounted on the fixed plate 31 and the flexible printed circuit board 32. As Figure 3 , Figure 4 and Figure 5 shown, the movable plate 21 and the fixed plate 31 face each other.

[0030] In addition, as the ferromagnetic materials constituting the movable plate 21 and the fixed plate 31, for example, ferritic stainless steels such as SUS 430 and martensitic stainless steels such as SUS 410 can be used. In addition, as the ferromagnetic material, not limited to ferritic stainless steels and martensitic stainless steels, iron, nickel, etc. can also be used to form the movable plate 21 and the fixed plate 31. In addition, the plate magnets 22, 23, 24 and the counterweight 25 are mounted on the movable plate 21 by bonding or the like, and the plate coils 33, 34 and the flexible printed circuit board 32 are mounted on the fixed plate 31 by bonding or the like.

[0031] As Figure 5 shown, the plate magnets 22, 23, 24, which are permanent magnets provided in the mover unit 20, have magnet back surfaces 22a, 23a, 24a mounted on the movable plate 21 and magnet front surfaces 2,b, 23b, 24b located on the opposite sides of the magnet back surfaces 22a, 23a, 24a and facing the fixed plate 31. In addition, the width dimension W1 of the plate magnet 23 disposed in the center is set to be larger than the width dimension W2 of the plate magnets 22, 24 disposed at both ends. That is, the magnetic force of the plate magnet 23 disposed in the center is stronger than the magnetic forces of the plate magnets 22, 24 disposed at both ends.

[0032] The plate coils 33, 34 provided in the stator unit 30 have coil back surfaces 33a, 34a mounted on the fixed plate 31 and coil front surfaces 33b, 34b located on the opposite sides of the coil back surfaces 33a, 34a and facing the movable plate 21. As Figure 3 shown, the plate coil 33 has a pair of straight portions 40, 41 parallel to each other and a pair of bent portions 42a, 42b connecting the straight portions 40, 41. In addition, the plate coil 34 has a pair of straight portions 44, 45 parallel to each other and a pair of bent portions 46a, 46b connecting the straight portions 44, 45. The plate coils 33, 34 are air-core coils formed by winding a wire, and a long-hole-shaped space, i.e., an air-core portion 43, 47, is provided in the center of the plate coils 33, 34. That is, the plate coil 33 has an air-core portion 43 divided by a pair of straight portions 40, 41, and the plate coil 34 has an air-core portion 47 divided by a pair of straight portions 44, 45.

[0033] As Figure 5As shown, the movable plate 21 has magnet mounting surfaces 50, 51, 52 for mounting the back surfaces 22a, 23a, 24a of the magnets, and coil opposing surfaces 53, 54 opposing the front surfaces 33b, 34b of the coils. Similarly, the fixed plate 31 has coil mounting surfaces 60, 61 for mounting the back surfaces 33a, 34a of the coils, and magnet opposing surfaces 62, 63, 64 opposing the front surfaces 22b, 23b, 24b of the magnets. In addition, the movable plate 21 and the fixed plate 31 are stamping parts formed by stamping. The movable plate 21 has: a plate main body portion 55 having magnet mounting surfaces 50, 51, 52; and stamping portions 56, 57 provided on the plate main body portion 55 and having coil opposing surfaces 53, 54. Similarly, the fixed plate 31 has: a plate main body portion 65 having magnet opposing surfaces 62, 63, 64; and stamping portions 66, 67 provided on the plate main body portion 65 and having coil mounting surfaces 60, 61.

[0034] As Figure 4 shown, the coil opposing surfaces 53, 54 of the movable plate 21 protrude toward the fixed plate 31 side more than the magnet mounting surfaces 50, 51, 52 of the movable plate 21. In addition, the coil mounting surfaces 60, 61 of the fixed plate 31 protrude toward the movable plate 21 side more than the magnet opposing surfaces 62, 63, 64 of the fixed plate 31. Here, the distance between the coil mounting surface 60 and the coil opposing surface 53 is "G1", and the distance between the coil mounting surface 61 and the coil opposing surface 54 is "G1". In addition, the distance between the magnet mounting surface 50 and the magnet opposing surface 62 is "G2", the distance between the magnet mounting surface 51 and the magnet opposing surface 63 is "G2", and the distance between the magnet mounting surface 52 and the magnet opposing surface 64 is "G2". Moreover, the distance G1 between the coil mounting surfaces 60, 61 and the coil opposing surfaces 53, 54 is set to be narrower than the distance G2 between the magnet mounting surfaces 50, 51, 52 and the magnet opposing surfaces 62, 63, 64.

[0035] As Figure 3 and Figure 5 shown, the vibration actuator 10 has four rubber dampers (elastic members) 48 connecting the movable plate 21 and the fixed plate 31. The rubber damper 48 has a first end portion 48a mounted on the movable plate 21 by adhesion or the like and a second end portion 48b mounted on the fixed plate 31 by adhesion or the like. Thus, since the movable plate 21 and the fixed plate 31 are connected via the rubber damper 48, the movable plate 21 can be displaced relative to the fixed plate 31 by a stroke corresponding to the elastic deformation amount of the rubber damper 48.

[0036] As Figure 4 and Figure 5As shown, in the thickness direction D1 of the vibration actuator 10, the plate-shaped magnets 22, 23, 24 and the plate-shaped coils 33, 34 are arranged such that the front faces 22b, 23b, 24b of the magnets and the front faces 33b, 34b of the coils do not face each other. That is, as Figure 4 and Figure 6 shown, the plate-shaped coil 33 is housed in the space between the plate-shaped magnet 22 and the plate-shaped magnet 23, and the plate-shaped coil 34 is housed in the space between the plate-shaped magnet 23 and the plate-shaped magnet 24. That is, the front faces 22b, 23b, 24b of the plate-shaped magnets 22, 23, 24 are located on the side of the back faces 33a, 34a of the coils with respect to the front faces 33b, 34b of the plate-shaped coils 33, 34. In other words, the front faces 33b, 34b of the plate-shaped coils 33, 34 are located on the side of the back faces 22a, 23a, 24a of the magnets with respect to the front faces 22b, 23b, 24b of the plate-shaped magnets 22, 23, 24. Further, the front faces 22b, 23b, 24b of the plate-shaped magnets 22, 23, 24 are located on the side of the fixing plate 31 with respect to the front faces 33b, 34b of the plate-shaped coils 33, 34. In other words, the front faces 33b, 34b of the plate-shaped coils 33, 34 are located on the side of the movable plate 21 with respect to the front faces 22b, 23b, 24b of the plate-shaped magnets 22, 23, 24.

[0037] As described above, by arranging the plate-shaped magnets 22, 23, 24 and the plate-shaped coils 33, 34 in the thickness direction D1 of the vibration actuator 10, the thickness dimension of the vibration actuator 10 can be reduced, and thus the vibration actuator 10 can be made thinner. Furthermore, miniaturization and thinning of various devices equipped with the vibration actuator 10 can be achieved. In addition, the thickness direction D1 of the vibration actuator 10 is a direction perpendicular to the surfaces of the movable plate 21 and the fixing plate 31.

[0038] As Figure 4 and Figure 6 shown, the plate-shaped magnet 22 is arranged adjacent to the straight portion 40 of the plate-shaped coil 33, and the plate-shaped magnet 23 is arranged adjacent to the straight portion 41 of the plate-shaped coil 33. Similarly, the plate-shaped magnet 23 is arranged adjacent to the straight portion 44 of the plate-shaped coil 34, and the plate-shaped magnet 24 is arranged adjacent to the straight portion 45 of the plate-shaped coil 34. In addition, the side face 22c of the plate-shaped magnet 22 faces the side face 40a of the straight portion 40, and the side face 23c of the plate-shaped magnet 23 faces the side face 41a of the straight portion 41. Similarly, the side face 23d of the plate-shaped magnet 23 faces the side face 44a of the straight portion 44, and the side face 24c of the plate-shaped magnet 24 faces the side face 45a of the straight portion 45.

[0039] Here, Figure 7FIG. is a view showing the positional relationship between the slits 70, 71, 72, 73 formed in the movable plate 21 and the fixed plate 31 and the plate-shaped magnets 22, 23, 24 and the plate-shaped coils 33, 34. As Figure 3 and Figure 7 shown, the movable plate 21 and the fixed plate 31 have coil-side slits (openings) 70, 71 that open into the hollow portions 43, 47 of the plate-shaped coils 33, 34. In addition, the coil-side slits 70, 71 not only open into the hollow portions 43, 47 of the plate-shaped coils 33, 34, but also extend so as to overlap with the bent portions 42a, 42b, 46a, 46b of the plate-shaped coils 33, 34. In addition, the movable plate 21 and the fixed plate 31 have magnet-side slits 72, 73 that open near the plate-shaped magnets 22, 24.

[0040] As Figure 5 shown, the width dimension W3 of the coil-side slits 70, 71 and the width dimension W4 of the hollow portions 43, 47 are set to be in agreement with each other. In the illustrated example, the width dimensions W3, W4 are made to agree with each other, but this is not limiting, and the width dimension W3 of the coil-side slits 70, 71 may be set to be larger than the width dimension W4 of the hollow portions 43, 47. That is, the width dimension W3 of the coil-side slits 70, 71 is preferably set to be equal to or greater than the width dimension W4 of the hollow portions 43, 47. In addition, the width direction D2 when defining the width dimensions W3, W4 refers to the direction perpendicular to the length direction D3 of the straight portion.

[0041] <Operation of the Vibration Actuator>

[0042] Figure 8 and Figure 9 FIG. is a view showing the operating state of the vibration actuator 10. In addition, FIGS. Figure 8 and Figure 9 show the same portions as those shown in Figure 4 FIG. In addition, in order to facilitate the explanation of the operation of the vibration actuator 10, FIGS. Figure 8 and Figure 9 show the vibration actuator 10 magnified in the thickness direction. In addition, FIG. Figure 8 shows the state in which the plate-shaped coils 33, 34 are energized in the direction of arrow A1 along Figure 6 FIG., and FIG. Figure 9 shows the state in which the plate-shaped coils 33, 34 are energized in the direction of arrow A2 along Figure 6 FIG.

[0043] As Figure 8As shown, the plate-shaped magnets 22 and 24 arranged at both ends are magnetized so that the N poles appear on the front surfaces 22b and 24b of the magnets, and the plate-shaped magnet 23 arranged in the center is magnetized so that the S pole appears on the front surface 23b of the magnet. In this way, the plate-shaped magnets 22 and 24 arranged at both ends and the plate-shaped magnet 23 arranged in the center are magnetized to have opposite polarities to each other.

[0044] In this way, by magnetizing the plate-shaped magnets 22, 23, and 24, a magnetic field H1 from the fixed plate 31 toward the movable plate 21 is generated in the straight portion 40 of the plate-shaped coil 33, and a magnetic field H2 from the movable plate 21 toward the fixed plate 31 is generated in the straight portion 41 of the plate-shaped coil 33. In addition, a magnetic field H3 from the movable plate 21 toward the fixed plate 31 is generated in the straight portion 44 of the plate-shaped coil 34, and a magnetic field H4 from the fixed plate 31 toward the movable plate 21 is generated in the straight portion 45 of the plate-shaped coil 34. In addition, the width dimension W1 of the plate-shaped magnet 23 arranged in the center is larger than the width dimension W2 of the plate-shaped magnets 22 and 24 arranged at both ends. Thereby, the magnetic force of the plate-shaped magnet 23 can be increased, and sufficient magnetic fields H2 and H3 can be generated in the two straight portions 41 and 44.

[0045] In a state where the magnetic fields H1 to H4 are generated, as Figure 6 indicated by the arrow A1 in, when current flows through the straight portions 40, 41, 44, and 45 of the plate-shaped coils 33 and 34, as Figure 8 shown, a Lorentz force F1a is generated in the straight portion 40, and therefore, a thrust F1b in the direction approaching the straight portion 40 is generated in the plate-shaped magnet 22 by reaction. In addition, since a Lorentz force F2a is generated in the straight portion 41, a thrust F2b in the direction away from the straight portion 41 is generated in the plate-shaped magnet 23 by reaction. In addition, since a Lorentz force F3a is generated in the straight portion 44, a thrust F3b in the direction approaching the straight portion 44 is generated in the plate-shaped magnet 23 by reaction. In addition, since a Lorentz force F4a is generated in the straight portion 45, a thrust F4b in the direction away from the straight portion 45 is generated in the plate-shaped magnet 24 by reaction. In this way, the thrusts F1b, F2b, F3b, and F4b act on the mover unit 20, and therefore, the mover unit 20 is displaced in the direction of the arrow X1 while deforming the rubber damper 48.

[0046] On the other hand, as Figure 6 indicated by the arrow A2 in, when current flows through the straight portions 40, 41, 44, and 45 of the plate-shaped coils 33 and 34, as Figure 9As shown, a Lorentz force F1c is generated in the straight portion 40, and thus a thrust F1d in the direction away from the straight portion 40 is generated in the plate-shaped magnet 22 by reaction. Further, since a Lorentz force F2c is generated in the straight portion 41, a thrust F2d in the direction approaching the straight portion 41 is generated in the plate-shaped magnet 23 by reaction. Further, since a Lorentz force F3c is generated in the straight portion 44, a thrust F3d in the direction away from the straight portion 44 is generated in the plate-shaped magnet 23 by reaction. Further, since a Lorentz force F4c is generated in the straight portion 45, a thrust F4d in the direction approaching the straight portion 45 is generated in the plate-shaped magnet 24 by reaction. Thus, the thrusts F1d, F2d, F3d, and F4d act on the mover unit 20, and thus the mover unit 20 is displaced in the direction of the arrow X2 while deforming the rubber damper 48.

[0047] That is, by switching the energization directions of the plate-shaped coils 33 and 34, the thrust acting on the mover unit 20 can be switched between the direction of the arrow X1 and the direction of the arrow X2. Thereby, the mover unit 20 can reciprocate with a specified stroke, and the vibration actuator 10 can be vibrated. By using this vibration actuator 10 to control, for example, the vibration mode of the display 12, a tactile sensation such as a vibration-based click feeling can be imparted to the user of the touch display 12.

[0048] <Vibration torque enhancement 1>

[0049] As Figure 4 shown, the intervals G1 between the coil mounting surfaces 60 and 61 and the coil opposing surfaces 53 and 54 are narrower than the intervals G2 between the magnet mounting surfaces 50, 51, 52 and the magnet opposing surfaces 62, 63, 64. Thereby, the movable plate 21 can be brought closer to the plate-shaped coils 33 and 34, and the air gaps between the coil front surfaces 33b and 34b and the coil opposing surfaces 53 and 54 can be narrowed. Further, since the magnetic flux hardly flows in the air, the magnetic flux easily flows by narrowing the air gap, and the magnetic flux acting on the straight portions 40, 41, 44, and 45 can be increased, thereby improving the vibration torque of the mover unit 20. That is, from the viewpoint of thinning the vibration actuator 10, the plate-shaped magnets 22, 23, 24 and the plate-shaped coils 33, 34 are arranged and disposed in the thickness direction D1 of the vibration actuator 10, but even with such a configuration, the vibration torque of the mover unit 20 can be sufficiently ensured.

[0050] In addition, as described above, the width dimension W3 of the coil side seams 70 and 71 is set to be equal to or greater than the width dimension W4 of the hollow portions 43 and 47. Thereby, substantially all of the coil opposing surfaces 53 and 54 can be opposed to the coil front surfaces 33b and 34b, and thus the magnetic flux perpendicular to the coil front surfaces 33b and 34b can be increased. That is, the magnetic flux toward the hollow portions 43 and 47 can be reduced, and the magnetic flux toward the straight portions 40, 41, 44, and 45 can be increased. Thereby, the thrust acting on the plate magnets 22, 23, and 24 can be increased, and thus the vibration torque of the mover unit 20 can be increased.

[0051] <Modified Example 1>

[0052] In Figure 4 the example shown, the stamping portions 56, 57, 66, and 67 are provided on both the movable plate 21 and the fixed plate 31, but it is not limited thereto. For example, the stamping portions 56 and 57 may be provided only on the movable plate 21, or the stamping portions 66 and 67 may be provided only on the fixed plate 31. Here, Figure 10 is a cross-sectional view showing the vibration actuator 80 of Modified Example 1. In Figure 10 the same portions as those shown in Figure 4 and Figure 8 are shown.

[0053] As Figure 10 shown, the vibration actuator 80 includes: a mover unit 81 having plate magnets 22, 23, and 24; and a stator unit 30 having plate coils 33 and 34. The mover unit 81 has a flat plate-shaped movable plate (first plate) 82 made of a ferromagnetic material. In addition, the stator unit 30 has a fixed plate (second plate) 31 made of a ferromagnetic material having stamping portions 66 and 67. Thus, even when the stamping portions 66 and 67 are formed only on the fixed plate 31, the interval G3 between the coil mounting surfaces 60 and 61 and the coil opposing surfaces 53 and 54 can be made narrower than the interval G2 between the magnet mounting surfaces 50, 51, and 52 and the magnet opposing surfaces 62, 63, and 64.

[0054] Thereby, the movable plate 82 can be brought closer to the plate coils 33 and 34, and the air gap between the coil front surfaces 33b and 34b and the coil opposing surfaces 53 and 54 can be narrowed. Furthermore, the magnetic flux acting on the straight portions 40, 41, 44, and 45 can be increased, and the vibration torque of the mover unit 81 can be increased. In Figure 10 the example shown, the stamping portions 66 and 67 are provided only on the fixed plate 31, but it is not limited thereto, and the stamping portions 56 and 57 may be provided only on the movable plate 21. In addition, since the plate magnets 22, 23, and 24 are not in contact with the fixed plate 31, in order to efficiently improve the magnetic circuit, it is preferable to provide the stamping portions 66 and 67 on the fixed plate 31.

[0055] <Modified Example 2>

[0056] In Figure 4 In the example shown, both the movable plate 21 and the fixed plate 31 have stamping portions 56, 57, 66, 67, but it is not limited thereto. For example, an auxiliary plate may be provided on the movable plate 21 instead of the stamping portions 56, 57, or an auxiliary plate may be provided on the fixed plate 31 instead of the stamping portions 66, 67. Here, Figure 11 is a cross-sectional view showing the vibration actuator 90 of the modified example 2. In Figure 11 is shown the same part as the part shown in Figure 4 and Figure 8 shown.

[0057] As Figure 11 shown, the vibration actuator 90 has: a rotor unit 91 having plate-shaped magnets 22, 23, 24; and a stator unit 92 having plate-shaped coils 33, 34. The rotor unit 91 has a movable plate (first plate) 93 made of a ferromagnetic material. The movable plate 93 has: a plate main body 9X having magnet mounting surfaces 50, 51, 52; and auxiliary plates 95a, 95b mounted on the plate main body 94 and having coil opposing surfaces 53, 54. In addition, the stator unit 92 has a fixed plate (second plate) 96 made of a ferromagnetic material. The fixed plate 96 has: a plate main body 97 having magnet opposing surfaces 62, 63, 64; and auxiliary plates 98a, 98b mounted on the plate main body 97 and having coil mounting surfaces 60, 61.

[0058] In this way, even when the auxiliary plates 95a, 95b are used to form the movable plate 93 and the auxiliary plates 98a, 98b are used to form the fixed plate 96, the interval G4 between the coil mounting surfaces 60, 61 and the coil opposing surfaces 53, 54 can be made narrower than the interval G2 between the magnet mounting surfaces 50, 51, 52 and the magnet opposing surfaces 62, 63, 64. Thereby, the movable plate 93 can be brought closer to the plate-shaped coils 33, 34, and the air gap between the coil front surfaces 33b, 34b and the coil opposing surfaces 53, 54 can be narrowed. Furthermore, the magnetic flux acting on the straight portions 40, 41, 44, 45 can be increased, and the vibration torque of the rotor unit 91 can be improved.

[0059] In Figure 11In the example shown, auxiliary plates 95a, 95b, 98a, and 98b are installed on both the movable plate 93 and the fixed plate 96, but it is not limited to this. That is, the auxiliary plates 95a and 95b can be installed only on the movable plate 93, or the auxiliary plates 98a and 98b can be installed only on the fixed plate 96. In addition, since the plate-shaped magnets 22, 23, and 24 are not in contact with the fixed plate 96, in order to efficiently improve the magnetic circuit, it is preferable to install the auxiliary plates 98a and 98b on the fixed plate 96.

[0060] <Vibration torque enhancement 2>

[0061] As Figure 3 and Figure 7 shown, coil-side slits 70 and 71 and magnet-side slits 72 and 73 are formed on the movable plate 21 and the fixed plate 31. In this way, by forming the slits 70, 71, 72, and 73 on the movable plate 21 and the fixed plate 31, the magnetic circuit of the vibration actuator 10 can be improved. That is, as Figure 7 shown, since the slits 70 and 72 are arranged around the plate-shaped magnet 22 and the straight portion 40, the magnetic flux from the plate-shaped magnet 22 toward the straight portion 40 can be increased. In addition, since the slits 70 and 71 are arranged around the plate-shaped magnet 23 and the straight portions 41 and 44, the magnetic flux from the plate-shaped magnet 23 toward the straight portions 41 and 44 can be increased. And since the slits 71 and 73 are arranged around the plate-shaped magnet 24 and the straight portion 45, the magnetic flux from the plate-shaped magnet 24 toward the straight portion 45 can be increased.

[0062] As described above, by forming the slits 70, 71, 72, and 73 on the movable plate 21 and the fixed plate 31, the magnetic circuit of the vibration actuator 10 can be improved. That is, the magnetic resistance of the slits 70, 71, 72, and 73 in the movable plate 21 and the fixed plate 31 is higher than that of other parts, so the magnetic flux toward the slits 70, 71, 72, and 73 can be reduced and the magnetic flux toward the straight portions 40, 41, 44, and 45 can be increased. As a result, the thrust acting on the plate-shaped magnets 22, 23, and 24 can be increased, and thus the vibration torque of the mover unit 20 can be increased. That is, from the viewpoint of making the vibration actuator 10 thinner, in the thickness direction D1 of the vibration actuator 10, the plate-shaped magnets 22, 23, and 24 and the plate-shaped coils 33 and 34 are arranged, but even with such a configuration, the vibration torque of the mover unit 20 can be sufficiently ensured.

[0063] In addition, in Figure 3 and Figure 7In the example shown, coil side slits 70 and 71 and magnet side slits 72 and 73 are formed on the movable plate 21 and the fixed plate 31, but it is not limited thereto. That is, when sufficiently ensuring the vibration torque of the mover unit 20, the magnet side slits 72 and 73 can be cut from the movable plate 21, or the coil side slits 70 and 71 and the magnet side slits 72 and 73 can be cut from the movable plate 21. Similarly, the magnet side slits 72 and 73 can be cut from the fixed plate 31, or the coil side slits 70 and 71 and the magnet side slits 72 and 73 can be cut from the fixed plate 31.

[0064] <Deformation Example 3>

[0065] In Figure 4 the example shown, the magnet fronts 22b, 23b, and 24b of the plate magnets 22, 23, and 24 are exposed, but it is not limited thereto, and pole pieces made of a ferromagnetic material can also be installed on the magnet fronts 22b, 23b, and 24b. Here, Figure 12 is an exploded perspective view showing a part of the vibration actuator 100 of Deformation Example 3. In addition, Figure 13 is a cross-sectional view showing the vibration actuator 100. In Figure 13 the same parts as those shown in Figure 4 and Figure 8 are shown.

[0066] As Figure 12 shown, the vibration actuator 100 has a mover unit 101, and the mover unit 101 has plate magnets 22, 23, and 24. The mover unit 101 has a movable plate 21 made of a ferromagnetic material, three plate magnets 22, 23, and 24 mounted on the movable plate 21, three pole pieces 102, 103, and 104 mounted on the plate magnets 22, 23, and 24, and a frame-shaped counterweight 25 mounted on the movable plate 21. The pole pieces 102, 103, and 104 are flat plates made of a ferromagnetic material such as ferritic stainless steel or martensitic stainless steel.

[0067] As Figure 13 shown, by mounting the pole pieces 102, 103, and 104 on the plate magnets 22, 23, and 24, a magnetic attractive force M1 in a direction inclined with respect to the magnet fronts 22b, 23b, and 24b can be generated. Thereby, the magnetic attractive force M2 in the vertical direction between the magnet fronts 22b, 23b, and 24b and the fixed plate 31 can be reduced, and the operation of the vibration actuator 100 can be stabilized. That is, the situation where the plate magnets 22, 23, and 24 of the movable plate 21 stay on the fixed plate 31 due to the magnetic attractive force M2 in the vertical direction can be avoided, and the operation of the vibration actuator 100 can be stabilized.

[0068] <Other Deformation Examples>

[0069] The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof. In Figure 3 In the example shown, the vibration actuator 10 is constituted by using three plate-shaped magnets 22, 23, 24 and two plate-shaped coils 33, 34, but it is not limited thereto, and the number of plate-shaped magnets and plate-shaped coils constituting the vibration actuator can also be changed. For example, the vibration actuator can also be constituted by using one plate-shaped magnet and one plate-shaped coil. In addition, the vibration actuator can be constituted by using two plate-shaped magnets and one plate-shaped coil, or can be constituted by using one plate-shaped magnet and two plate-shaped coils. Further, the vibration actuator can be constituted by using four or more plate-shaped magnets, or can be constituted by using three or more plate-shaped coils.

[0070] In Figure 3 In the example shown, the plate-shaped magnets 22, 23, 24 are mounted on the movable plate 21, and the plate-shaped coils 33, 34 are mounted on the fixed plate 31, but it is not limited thereto. For example, the plate-shaped magnets 22, 23, 24 can also be mounted on the fixed plate 31, and the plate-shaped coils 33, 34 can be mounted on the movable plate 21. In addition, a weight 25 is mounted on the movable plate 21, but it is not limited thereto. When the movable plate 21, the plate-shaped magnets 22, 23, 24 have sufficient mass, the weight 25 can also be removed from the movable plate 21.

[0071] In Figure 3 In the example shown, a rubber damper 48 is used as the elastic member for connecting the movable plate 21 and the fixed plate 31, but it is not limited thereto, and a spring can also be used as the elastic member. In addition, in the illustrated example, four rubber dampers 48 are provided in the vibration actuator 10, but it is not limited thereto. As long as the mover unit 20 can be appropriately supported, the number of rubber dampers 48 of the vibration actuator 10 can also be set to three or less. Of course, five or more rubber dampers 48 can also be provided in the vibration actuator 10. In addition, in the illustrated example, the rubber damper 48 is formed in a cylindrical shape, but it is not limited thereto, and the rubber damper 48 can also be formed in other shapes. For example, the rubber damper 48 can be formed in a cylindrical shape, or can be formed in a prismatic shape or a square tube shape.

[0072] In Figure 8 In the example shown, the plate-shaped magnets 22, 24 disposed at both ends are magnetized so that the N poles appear on the magnet fronts 22b, 24b, and the plate-shaped magnet 23 disposed at the center is magnetized so that the S pole appears on the magnet front 23b, but it is not limited thereto. That is, the plate-shaped magnets 22, 24 disposed at both ends can also be magnetized so that the S poles appear on the magnet fronts 22b, 24b, and the plate-shaped magnet 23 disposed at the center can be magnetized so that the N pole appears on the magnet front 23b. In addition, inFigure 5 In the example shown, the width dimension W1 of the plate-shaped magnet 23 disposed at the center is set to be larger than the width dimensions W2 of the plate-shaped magnets 22 and 24 disposed at both ends, but it is not limited thereto. For example, the width dimension W1 of the plate-shaped magnet 23 disposed at the center may be made to coincide with the width dimensions W2 of the plate-shaped magnets 22 and 24 disposed at both ends.

[0073] In addition, the present technology may adopt the following structure.

[0074] [1]. A vibration actuator having a first plate and a second plate opposed to the first plate, wherein the vibration actuator includes: a plate-shaped magnet having a magnet back surface mounted on the first plate and a magnet front surface located on the opposite side of the magnet back surface and opposed to the second plate; a plate-shaped coil having a coil back surface mounted on the second plate and a coil front surface located on the opposite side of the coil back surface and opposed to the first plate; and an elastic member having a first end mounted on the first plate and a second end mounted on the second plate, the first plate having a magnet mounting surface for mounting the magnet back surface and a coil opposing surface opposed to the coil front surface, the second plate having a coil mounting surface for mounting the coil back surface and a magnet opposing surface opposed to the magnet front surface, and the interval between the coil mounting surface and the coil opposing surface being narrower than the interval between the magnet mounting surface and the magnet opposing surface.

[0075] [2]. The vibration actuator according to [1], wherein the coil opposing surface of the first plate is located on the side closer to the second plate than the magnet mounting surface of the first plate.

[0076] [3]. The vibration actuator according to [1] or [2], wherein the coil mounting surface of the second plate is located on the side closer to the first plate than the magnet opposing surface of the second plate.

[0077] [4]. The vibration actuator according to any one of [1] to [3], wherein the first plate includes: a plate main body portion having the magnet mounting surface; and a stamping portion provided on the plate main body portion and having the coil opposing surface.

[0078] [5]. The vibration actuator according to any one of [1] to [4], wherein the second plate includes: a plate main body portion having the magnet opposing surface; and a stamping portion provided on the plate main body portion and having the coil mounting surface.

[0079] [6]. The vibration actuator according to any one of [1] to [5], wherein the first plate includes: a plate main body having the magnet mounting surface; and an auxiliary plate mounted on the plate main body and having the coil opposing surface.

[0080] [7] The vibration actuator according to any one of [1] to [6], wherein the second plate has: a plate main body having the magnet facing surface; and an auxiliary plate mounted on the plate main body and having the coil mounting surface.

[0081] [8] The vibration actuator according to any one of [1] to [7], wherein the coil front surface of the plate-shaped coil is located on the side closer to the magnet back surface than the magnet front surface of the plate-shaped magnet.

[0082] [9] The vibration actuator according to any one of [1] to [8], wherein the first plate and the second plate are made of a ferromagnetic material and have an opening portion that opens in the hollow portion of the plate-shaped coil.

[0083]

[10] The vibration actuator according to any one of [1] to [9], wherein the plate-shaped coil has a pair of straight portions that divide the hollow portion, and when the direction perpendicular to the length direction of the straight portion is set as the width direction, the width dimension of the opening portion is equal to or greater than the width dimension of the hollow portion.

[0084]

[11] The vibration actuator according to any one of [1] to

[10] , wherein the plate-shaped magnet is disposed adjacent to the straight portion of the plate-shaped coil.

[0085]

[12] The vibration actuator according to any one of [1] to

[11] , wherein the vibration actuator has a weight mounted on the first plate.

Claims

1. A vibration actuator having a first plate and a second plate opposed to the first plate, wherein, the vibration actuator has: a plate-shaped magnet having a magnet back surface mounted on the first plate and a magnet front surface located on the opposite side of the magnet back surface and opposed to the second plate; a plate-shaped coil having a coil back surface mounted on the second plate and a coil front surface located on the opposite side of the coil back surface and opposed to the first plate; and an elastic member having a first end mounted on the first plate and a second end mounted on the second plate, the first plate has a magnet mounting surface for mounting the magnet back surface and a coil opposing surface opposed to the coil front surface, the second plate has a coil mounting surface for mounting the coil back surface and a magnet opposing surface opposed to the magnet front surface, the interval between the coil mounting surface and the coil opposing surface is narrower than the interval between the magnet mounting surface and the magnet opposing surface.

2. The vibration actuator according to claim 1, wherein, the coil opposing surface of the first plate is located on the side closer to the second plate than the magnet mounting surface of the first plate.

3. The vibration actuator according to claim 1 or 2, wherein, the coil mounting surface of the second plate is located on the side closer to the first plate than the magnet opposing surface of the second plate.

4. The vibration actuator according to claim 1, wherein, the first plate has: a plate main body portion having the magnet mounting surface; and a stamping portion provided on the plate main body portion and having the coil opposing surface.

5. The vibration actuator according to claim 1 or 4, wherein, the second plate has: a plate main body portion having the magnet opposing surface; and a stamping portion provided on the plate main body portion and having the coil mounting surface.

6. The vibration actuator according to claim 1, wherein, the first plate has: a plate main body having the magnet mounting surface; and an auxiliary plate mounted on the plate main body and having the coil opposing surface.

7. The vibration actuator according to claim 1 or 6, wherein, the second plate has: a plate main body having the magnet opposing surface; and an auxiliary plate mounted on the plate main body and having the coil mounting surface.

8. The vibration actuator according to claim 1, wherein, the coil front surface of the plate-shaped coil is located on the side closer to the magnet back surface than the magnet front surface of the plate-shaped magnet.

9. The vibration actuator according to claim 1, wherein, the first plate and the second plate are made of a ferromagnetic material and have an opening portion opening in the hollow portion of the plate-shaped coil.

10. The vibration actuator according to claim 9, wherein, the plate-shaped coil has a pair of straight portions dividing the hollow portion, when the direction perpendicular to the length direction of the straight portion is set as the width direction, the width dimension of the opening portion is equal to or greater than the width dimension of the hollow portion.

11. The vibration actuator according to claim 1, wherein, the plate-shaped magnet is disposed adjacent to the straight portion of the plate-shaped coil.

12. The vibration actuator according to claim 1, wherein the vibration actuator has a counterweight mounted on the first plate.

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