Vibration actuator and electric device

Abstract

Provided is a vibration actuator including: a movable body having a disk-like magnet, a pair of weight parts that are magnetic bodies fixed to both surfaces of the magnet in an axial direction, and a pair of spring connection parts that are provided at both ends in the axial direction; and a fixed body that has a case, and a cylindrical body that has an annular coil arranged on the outer periphery thereof and accommodates the movable body so as to be capable of reciprocating in the axial direction by a pair of elastic support parts that are separated in the axial direction and are respectively connected to the pair of spring connection parts. The case has a pair of bottomed cylindrical cases each having a case lid part at one end and a case opening part at the other end. The pair of bottomed cylindrical cases are respectively made to cover the cylindrical body from both sides in the axial direction, and the case opening parts of the pair of bottomed cylindrical cases are joined to each other to accommodate the cylindrical body. The pair of bottomed cylindrical cases are common members having the same shape.

Description

Vibration actuator and electrical device

[0001] The present invention relates to a vibration actuator and an electrical device equipped with the same.

[0002] Conventionally, electronic devices with vibration functions are equipped with vibration actuators as vibration generation sources. By driving the vibration actuators to transmit vibrations to the user, electronic devices can provide stimulation to the user, notify the user of incoming calls, and improve the sense of operation and realism. Electronic devices are primarily handheld electrical devices, including portable game consoles, controllers (gamepads) for stationary game consoles, mobile communication terminals such as mobile phones and smartphones, and personal digital assistants such as tablet PCs. Vibration actuators are also sometimes installed in wearable devices that are attached to clothing, the arm, etc.

[0003] As a vibration actuator having a structure that can be miniaturized and mounted in a portable device, for example, a vibration actuator used in a pager or the like is known, as disclosed in Patent Document 1.

[0004] This vibration actuator has a pair of elastic plates arranged facing each other and supported by the opening edges of a cylindrical frame. In addition, this vibration actuator has a yoke with a magnet attached fixed to the raised central portion of one of the pair of elastic plates, which has a spiral shape, and the yoke is supported within the frame.

[0005] The yoke and the magnet form a ring-shaped magnetic field generator, and the coil is attached to the other elastic plate and placed within the magnetic field of this magnetic field generator. By alternately applying currents of different frequencies to the coils through an oscillator circuit, the pair of elastic plates are selectively resonated to generate vibrations, and the yoke vibrates within the frame in the direction of the frame's centerline.

[0006] In this vibration actuator, the distance between the magnet and coil, and between the yoke and coil, is greater than the distance between the yoke and the inner peripheral wall of the frame. As a result, in the event of an external impact, the yoke will collide with the inner peripheral wall of the frame first, preventing the yoke or magnet from coming into contact with the coil and preventing damage to the coil.

[0007] Patent No. 3748637

[0008] Incidentally, vibration actuators as vibration generators are required to have small design dimensional errors, be thin, and ensure high output, and are also required to have a structure that can withstand external impacts such as those caused by being dropped. In a configuration in which a yoke is vibrated within a frame, as in Patent Document 1, if a plate-shaped elastic body is provided to close one opening of the frame, when the vibration actuator is dropped and receives an external impact, the plate-shaped elastic body may collide with the yoke, which is a movable body, in addition to colliding with the outside. This can damage the plate-shaped elastic body itself, resulting in problems such as in an insufficient level of vibration and high output.

[0009] An object of the present invention is to provide a vibration actuator and an electrical device that are highly robust, thin, and can be manufactured at low cost.

[0010] One aspect of the vibration actuator of the present invention comprises: a movable body having a disk-shaped magnet, a pair of weight portions which are magnetic bodies fixed to both sides of the magnet in the axial direction, and a pair of spring connection portions provided at both ends in the axial direction; a cylindrical body having an annular coil arranged on its outer periphery and which houses the movable body so that it can vibrate back and forth in the axial direction by a pair of elastic support portions which are spaced apart in the axial direction and connected to the pair of spring connection portions; and a fixed body having a case, wherein the case has a pair of bottomed cylindrical cases, each of which has a case lid portion at one end and a case opening at the other end, and each of the pair of bottomed cylindrical cases is placed over the cylindrical body from both sides in the axial direction and the case openings of the pair of bottomed cylindrical cases are joined to house the cylindrical body, and the pair of bottomed cylindrical cases are configured to be common members of the same shape.

[0011] One aspect of the electrical device of the present invention is a handheld or wearable electrical device, which has a configuration in which the vibration actuator having the above-described configuration is mounted on a portion that comes into contact with a user.

[0012] According to the present invention, it is possible to achieve high robustness, a thinner design, and reduced manufacturing costs.

[0013] 11. FIG. 12 is an external perspective view of a vibration actuator according to an embodiment of the present invention. FIG. 13 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 14 is an exploded perspective view showing a case and drive unit of a vibration actuator according to an embodiment of the present invention. FIG. 15 is an external perspective view of the drive unit. FIG. 16 is an exploded perspective view of the drive unit. FIG. 17 is an exploded perspective view showing a movable body and an elastic support part in the drive unit. FIG. 18 is a view showing a state in which an outer yoke has been removed from a coil assembly in fixing the drive unit. FIG. 19 is an exploded perspective view of the case. FIG. 19 is a schematic diagram showing a magnetic circuit configuration of the vibration actuator. FIG. 19 is a perspective view showing a modified spacer in the vibration actuator. FIG. 19 is a longitudinal cross-sectional view of a vibration actuator comprising a modified spacer. FIG. 19 is an enlarged view of the X portion in FIG. 11. FIG. 19 is a diagram showing an example of an electrical device in which a vibration actuator according to the present embodiment is implemented. FIG. 19 is a diagram showing an example of an electrical device in which a vibration actuator according to the present embodiment is implemented.

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0015] [Overall Configuration of Vibration Actuator] Fig. 1 is an external perspective view of a vibration actuator according to one embodiment of the present invention, Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, and Fig. 3 is an exploded perspective view showing the case and drive unit of a vibration actuator according to one embodiment of the present invention. Note that the terms "upper" and "lower" in this embodiment are given for the sake of convenience to make it easier to understand, and refer to one side and the other side of the vibration direction of the movable body in the vibration actuator. In other words, when the vibration actuator is mounted in an electrical device (see Figs. 13 and 14), it does not matter if it is mounted upside down or left and right.

[0016] The vibration actuator 1 is mounted as an electrical device as a vibration generating source in electronic devices such as portable game terminal devices (for example, the game controller GC shown in FIG. 13 ), and realizes the vibration function of the electronic device. Such electronic devices also include mobile devices such as smartphones (for example, the mobile terminal M shown in FIG. 14 ). The vibration actuator 1 is mounted in each device such as a portable game terminal device or a mobile device, and vibrates when driven to notify the user of an incoming call or to provide a sense of operation or realism.

[0017] 1, the vibration actuator 1 is a vibrating body formed into a cylindrical shape as a whole and having a case 10. The diameter of the case 10 is longer than the length in the axial direction (vibration direction).

[0018] 2 and 3, in this embodiment, the case 10 is a hollow cylindrical body formed by combining a first case section (hereinafter also referred to as the "first case") 11-1 and a second case section (hereinafter also referred to as the "second case") 11-2. A detailed description of the case 10 will be given later.

[0019] 2 and 3, the vibration actuator 1 is constructed by housing a drive unit 15 having a vibrating movable body 20 inside a case 10. When the movable body 20 moves, the vibration actuator 1 itself functions as a vibrator. In this embodiment, the drive unit 15 is cylindrical, corresponding to the case 10, and its central axis (not shown) is parallel to or coaxial with the central axis (not shown) of the case 10, which is also cylindrical. The vibration direction of the movable body 20 is a linear direction extending along the extension direction of the central axis of the cylindrical drive unit 15, including the F direction and the −F direction (see FIG. 9).

[0020] The vibration actuator 1 has a movable body 20 having a magnet 21, a first weight portion 23 and a second weight portion 25, a fixed body 40 having a coil (a pair of coils 61, 62), and plate-shaped elastic support portions 81, 82 that support the movable body 20 so that it can vibrate back and forth relative to the fixed body 40.

[0021] Fig. 4 is an external perspective view of the drive unit 15. Specifically, Fig. 4 is a view of the drive unit 15 as seen from the terminal binding portion (which may be referred to as the "terminal connection portion" together with the terminal lead-out portion) side. Fig. 5 is an exploded perspective view of the drive unit, showing the coil holding portion, the movable body, and the elastic support portion.

[0022] 2 to 5 includes a coil holding portion 42, an outer yoke 50, a movable body 20, and elastic support portions 81 and 82. The coil holding portion 42, together with the coils 61 and 62, constitutes a coil assembly that is a part of the fixed body, and the coil assembly, together with the outer yoke 50, constitutes a part of the fixed body.

[0023] The drive unit 15 supports the movable body 20 arranged within the coil holding portion 42 so that it can vibrate freely while being suspended from the coil holding portion 42 via elastic support portions 81 and 82 arranged opposite each other and spaced apart in the axial direction (vibration direction).

[0024] The drive unit 15 is connected to an external device via a terminal connection portion (wire connection portion) 43 arranged on the outer circumferential surface thereof, and receives power from the external device.

[0025] <Movable body 20> As shown in Figures 2 and 5, the movable body 20 is arranged inside the cylindrical coil holding portion 42 of the fixed body 40 with a circumferential gap between them. The movable body 20 is columnar, and the outer dimensions of both ends (upper and lower ends) that are separated in the axial direction, i.e., the vibration direction, are smaller than the outer dimension of the center portion. Both ends of the movable body 20 are connected to the inner peripheries of the elastic support portions 81 and 82. The elastic support portions 81 and 82 cover both open ends (corresponding to the open end faces 427a and 428a) of the cylindrical coil holding portion 42. The movable body 20 is supported along the inner periphery 42a of the coil holding portion 42 so as to be able to move back and forth in the axial direction (vibration direction).

[0026] FIG. 6 is an exploded perspective view showing the movable body and the elastic support portion in the drive unit.

[0027] As shown in Figures 2 and 5 to 6, the movable body 20 has a pair of weight portions (e.g., a first weight portion 23 and a second weight portion 25) and a pair of connecting portions (a first spring connecting portion 31 and a second spring connecting portion 33) arranged on both sides of the magnet 21.

[0028] In this embodiment, magnet 21 is disposed in the center of movable body 20 in the vibration direction, i.e., at the center of movable body 20. On both sides of magnet 21 in the vibration direction (on front surface 21a and back surface 21b, i.e., up and down in each drawing), first weight portion 23, second weight portion 25, and spring connecting portions 31, 33 are disposed symmetrically around magnet 21. First weight portion 23 and second weight portion 25 are provided on both sides of magnet 21 in the vibration direction, with spring connecting portion 31 inserted into and joined to first weight portion 23, and connecting portion 33 inserted into and joined to second weight portion 25.

[0029] <Magnet 21> As shown in Figures 5 and 6, the magnet 21 is a solid columnar (including plate-shaped) magnetized in the vibration direction. For example, the magnet 21 has the vibration direction as its magnetization direction, and the front and back surfaces 21a and 21b, which are spaced apart in the vibration direction, have different polarities. The magnet 21 is also formed, for example, in the shape of a cylinder (which may also be called a flat disk or disk shape) whose diameter (width) is longer than its length (height) in the vibration direction. The magnet 21 is, for example, a neodymium sintered magnet.

[0030] The magnet 21 is disposed so as to be spaced apart from the coils (a pair of coils 61, 62) (details of which will be described later) held by the coil holding portion 42, on the radially inner side of the coils (a pair of coils 61, 62). Here, the "radial direction" also refers to a direction perpendicular to the axial direction (vibration direction) of the coils (a pair of coils 61, 62). In other words, the magnet 21 is disposed so as to face the center position in the vibration direction on the inner peripheral surface of the coil holding portion 42, on the radially outer side. The pair of coils 61, 62 will also be referred to as "coils 61, 62" hereinafter.

[0031] This "spacing" in the radial direction is the spacing between the magnet 21 and the coils 61, 62 when the cylindrical main body 422 around which the coils 61, 62 are wound is positioned radially inside the coils 61, 62, between the coils 61, 62 and the magnet 21. This spacing is also set to allow movement without contacting each other in the vibration direction of the movable body 20. The "spacing" in the embodiment refers to the predetermined spacing between the coil holding portion 42 (particularly the cylindrical main body 422) and the magnet 21 shown in FIG. 2.

[0032] The magnet 21 may have a shape other than a solid column, such as a cylindrical shape or a plate shape, as long as it is disposed inside the coils 61 and 62 with its two magnetized surfaces facing in the direction of extension (vibration direction) of the axes of the coils 61 and 62. It is also desirable that the axial center of the magnet 21 coincides with the axial center of the movable body 20.

[0033] <First Weight Portion 23 and Second Weight Portion 25> The first weight portion 23 and the second weight portion 25 each function as a weight that increases the vibration output of the movable body 20, and also function as a yoke.

[0034] The first weight portion 23 and the second weight portion 25 are formed in the same shape and are common annular members having weight openings 232 and 252, and are arranged so as to sandwich the magnet 21 in the vibration direction, and are fixed to the front and back surfaces 21a and 21b of the magnet 21, respectively.

[0035] The first weight portion 23 and the second weight portion 25 are preferably made of a material with a high specific gravity (metal material). The first weight portion 23 and the second weight portion 25 are preferably made of, for example, tungsten (19.3 g / cm ３ The first weight portion 23 and the second weight portion 25 are made of a material with a high specific gravity (for example, a specific gravity of 16 to 19 g / cm ３ It is preferable that the surface is formed by a method of forming the surface of the substrate.

[0036] Since the first weight portion 23 and the second weight portion 25 are made of a material with a high specific gravity as a weight, the mass of the movable body 20 can be increased relatively easily even if the external dimensions of the movable body 20 are set in the design, etc.

[0037] The first weight portion 23 and the second weight portion 25 are made of, for example, tungsten that has been ferromagnetically treated, so that a single component can function as both a weight and a yoke, and by increasing the weight of the moving part, stronger vibrations can be obtained, improving vibration characteristics.

[0038] Furthermore, since the first weight portion 23 and the second weight portion 25 are made of ferromagnetic material, together with the magnet 21, coil (a pair of coils 61, 62) and outer yoke 50 as a yoke, they form a magnetic circuit having an appropriate magnetic path with little magnetic flux leakage and high magnetic efficiency.

[0039] The first weight portion 23 and the second weight portion 25 concentrate the magnetic flux of the magnet 21, allowing it to flow efficiently without leakage, and effectively distribute the magnetic flux flowing between the magnet 21 and the coil (a pair of coils 61, 62).

[0040] The first weight portion 23 and the second weight portion 25 have large diameter portions 234 and 254 that have the same outer diameter and surface shape as the magnet 21 , and small diameter portions 236 and 256 that have smaller outer diameters than the large diameter portions 234 and 254 .

[0041] The first weight portion 23 and the second weight portion 25 are fixed to the magnet 21 so that the outer surfaces of the large diameter portions 234, 254 are flush with the outer surface of the magnet 21, and the outer surfaces of the large diameter portions 234, 254, together with the outer surface of the magnet 21, form the outer surface of the movable body 20.

[0042] In the first weight portion 23 and the second weight portion 25, the small diameter portions 236, 256 are formed so as to be stacked coaxially on the large diameter portions 234, 254, and the small diameter portions 236, 256 form a shape in which the corners (outer peripheral portions) of both end portions that are separated in the vibration direction as the movable body 20 are cut out.

[0043] The shape of the corners (outer peripheral portions) of the upper end portion formed by the small diameter portion 236 of the first weight portion 23 ensures a deformation area for the elastic support portion 81, and ultimately a movable area for the movable body 20, so that the elastic support portion 81, which deforms when the movable body 20 moves, does not come into contact with the elastic support portion 81.

[0044] The shape of the corners (outer peripheral portions) of the lower end portion of the small diameter portion 256 of the second weight portion 25 ensures a deformation area for the elastic support portion 82, and therefore a movable area for the movable body 20, so that the elastic support portion 82, which deforms when the movable body 20 moves, does not come into contact with the elastic support portions 82. As a result, when the movable body 20 vibrates, the movable body 20 is less likely to come into contact with the elastic support portions 81, 82, and can vibrate favorably. This makes it possible to ensure high vibration output while miniaturizing the vibration actuator 1.

[0045] The first weight portion 23 and the second weight portion 25 are positioned inside (radially inside) the coil (pair of coils 61, 62) so as to face each of the coils (pair of coils 61, 62) in a direction perpendicular to the axial direction of the coil (pair of coils 61, 62).

[0046] When the movable body 20 is not vibrating, it is preferable that the first weight portion 23 and the second weight portion 25 are each positioned inside (radially inside) the pair of coils 61, 62, in a direction perpendicular to the vibration direction, and facing the center of the vibration direction of the pair of coils 61, 62.

[0047] Furthermore, the first weight portion 23 and the second weight portion 25 are preferably arranged such that the height position of the upper surface of the large diameter portion 234 of the first weight portion 23 on the upper side of the magnet 21 is located lower (closer to the center) than the upper end of the upper coil 61. In addition, the height position of the lower surface of the large diameter portion 254 of the second weight portion 25 on the lower side of the magnet 21 is preferably located higher (closer to the center) than the lower end of the lower coil 62.

[0048] The first weight portion 23 and the second weight portion 25 may be fixed to the magnet 21 by being attracted to the magnet 21 by the large diameter portions 234, 254, or may be fixed to the magnet 21 by a thermosetting adhesive such as epoxy resin or an anaerobic adhesive.

[0049] The spring connecting portions 31, 33 (also referred to as the first spring connecting portion 31 and the second spring connecting portion 33) are inserted into the weight openings 232, 252. For example, the spring connecting portions 31, 33 may be fitted into the weight openings 232, 252, or may be joined after insertion.

[0050] The weight openings 232, 252 are provided so that the axes of the spring connection portions 31, 33, in other words, the central axes of the elastic support portions 81, 82 described below, are positioned on the central axis of the movable body 20. Note that the weight openings 232, 252 are formed with dimensions that fit corresponding to the outer shapes of the spring connection portions 31, 33, but are not limited to this. The weight openings 232, 252 may contact the outer peripheral surfaces of the inserted spring connection portions 31, 33 at three or four points to be positioned on the axis of the movable body 20 and fixably support the spring connection portions 31, 33. Furthermore, the weight openings 232, 252 may not penetrate in the axial direction, but may be formed in a recessed shape that closes the magnet side to which the spring connection portions 31, 33 are fixed in the axial direction, and the spring connection portions 31, 33 may be joined into this recessed shape.

[0051] The mass of the first weight portion 23 and the second weight portion 25 can be adjusted by changing the sizes of the large diameter portions 234, 254 and the small diameter portions 236, 256 to an extent that they do not interfere with the elastic support portions 81, 82 when the movable body 20 vibrates, depending on the vibration output of the movable body 20. The sizes of the large diameter portions 234, 254 and the small diameter portions 236, 256 refer to the height dimension, which is the length in the vibration direction, and the radial dimension, which is perpendicular to the vibration direction.

[0052] In the movable body 20, the outer peripheral surface 20a of the central portion (the outer peripheral surfaces of the magnet 21, the first weight portion 23, and the second weight portion 25) faces the inner peripheral surface 42a of the coil holding portion 42 at a predetermined distance inside.

[0053] In addition, the first weight portion 23 and the second weight portion 25 may have the function of serving as a weight and as part of the magnetic circuit, as well as the function of serving as the main body portion of the movable body 20 and the function of positioning and fixing the spring connection portions 31 and 33 relative to the magnet 21.

[0054] <Spring Connection Portions 31 and 33> The spring connection portions 31 and 33 connect the magnet 21, the first weight portion 23, and the second weight portion 25 to the elastic support portions 81 and 82.

[0055] The spring connection portions 31, 33 are sleeves and are provided at both ends in the vibration direction (both axial ends) of the movable body 20. The spring connection portions 31, 33 constitute the ends of the movable body 20 that are located apart from the magnet 21 on both sides in the vibration direction.

[0056] The spring connecting portions 31, 33 are cylindrical bodies arranged along the central axis of the movable body 20, and are arranged so as to protrude along the axial direction from the center of each of the front and back surfaces 21 a, 21 b of the magnet 21, penetrating the first weight portion 23 and the second weight portion 25. The spring connecting portions 31, 33 are fixed to the first weight portion 23 and the second weight portion 25, respectively. The spring connecting portions 31, 33 may also be fixed to the magnet 21.

[0057] The spring connection portions 31, 33 have connection bodies 312, 332 provided on the other axial end side and inserted into the first weight portion 23 and the second weight portion 25, and support fixing portions 314, 334 provided on one end side and protruding from one end of the connection bodies 312, 332.

[0058] The connecting bodies 312, 332 are formed into a cylindrical shape with an outer diameter (the same diameter) that allows them to be inserted into the weight openings 232, 252 of this embodiment. The connecting bodies 312, 332 may be fixed to both the first weight portion 23 and the second weight portion 25 by press-fitting them into both. The spring connecting portions 31, 33 may be bonded to the first weight portion 23 and the second weight portion 25 using, for example, a thermosetting adhesive such as epoxy resin or an anaerobic adhesive.

[0059] The connection bodies 312, 332 may be joined by abutting against the magnet 21 at one end surface facing the magnet 21. The connection bodies 312, 332 are arranged so that the axis of the movable body 20 and their central axes coincide with each other.

[0060] The support fixing portions 314 and 334 join the movable body 20 to the elastic support portions 81 and 82 via the connection bodies 312 and 332 of the spring connection portions 31 and 33 .

[0061] The support fixing portions 314, 334 are protruding portions that protrude from the surface of one end of the connection main bodies 312, 332 in the axial direction (vibration direction) and have an outer diameter smaller than the outer diameter of the connection main bodies 312, 332. Annular recesses 316, 336 are provided around these protruding portions, and function as reservoirs for adhesive or welding material, portions to be engaged during crimping, etc., in order to firmly join the support fixing portions 314, 334 to the inner peripheries of the elastic support portions 81, 82.

[0062] Specifically, support fixing part 314 constitutes one end of movable body 20 in the vibration direction, i.e., the upper end of movable body 20, and is joined to inner circumferential part 802, which is the end on the inner diameter side of the upper leaf spring, which is elastic support part 81. On the other hand, support fixing part 334 constitutes the other end of movable body 20 in the vibration direction, i.e., the lower end of movable body 20, and is joined to inner circumferential part 802, which is the end on the inner diameter side of the lower leaf spring, which is elastic support part 82.

[0063] When the support / fixing portions 314, 334 are fitted into and joined to the inner peripheries 802, 802 of the elastic support portions 81, 82, the peripheral surfaces of the support / fixing portions 314, 334, and the surfaces of the connection bodies 312, 332 on one end side thereof, are disposed opposite the inner peripheries 802, 802. The connection bodies 312, 332 may be joined at one end thereof to the elastic support portions 81, 82 joined to the support / fixing portions 314, 334 at the peripheral portions of the support / fixing portions 314, 334. For example, the connection bodies 312, 332 and the elastic support portions 81, 82 may be joined via adhesive, welding, or the like. Furthermore, the connection bodies 312, 332 may be joined to the elastic support portions 81, 82 by sandwiching the elastic support portions 81, 82 between them using other members such as rivets. This allows the connection bodies 312, 332 and the inner circumferential portions 802, 802 to be reliably joined to each other, and the elastic support portions 81, 82 and the movable body 20 to be joined more reliably.

[0064] Furthermore, the elastic support portions 81, 82 and the support fixing portions 314, 334 may be connected by crimping or by a combination of welding, adhesive, and crimping. The spring connecting portions 31, 33 are formed, for example, from a sintered copper material. The spring connecting portions 31, 33 may be made of a non-magnetic material or a magnetic material. If the spring connecting portions 31, 33 are made of a magnetic material, leakage magnetic flux can be prevented.

[0065] 2 , the fixed body 40 has a pair of coils 61, 62, and accommodates the movable body 20 having the magnet 21 radially inside the pair of coils 61, 62. The fixed body 40 supports the movable body 20 via elastic support portions 81, 82 so as to be movable in the axial direction of the movable body 20 (which is the vibration direction and also the coil axial direction).

[0066] FIG. 7 is a diagram showing the fixed body of the drive unit with the outer yoke removed from the coil assembly.

[0067] 2 to 5 and 7, the fixed body 40 includes a case 10, spacers (a first spacer 13-1 and a second spacer 13-2), and coils (a pair of coils 61 and 62), as well as a coil holding portion 42 that holds the coils 61 and 62, and an outer yoke 50. The coil assembly that includes the coils 61 and 62 and the coil holding portion 42, together with the outer yoke 50, the movable body 20, and the elastic support portions 81 and 82, constitutes the drive unit 15.

[0068] The coil holding portion 42 is a cylindrical body made of a resin such as a phenol resin or polybutylene terephthalate (PBT). In this embodiment, the coil holding portion 42 is made of a material containing a phenol resin, such as Bakelite, which has high flame retardancy.

[0069] Furthermore, by constructing the coil holding portion 42 from a material containing phenolic resin, flame retardancy is enhanced, and safety during operation can be improved even if heat is generated by Joule heat when a current flows through the holding coil (a pair of coils 61, 62). Furthermore, improved dimensional accuracy and positional accuracy of the coils (a pair of coils 61, 62) can reduce variations in vibration characteristics.

[0070] As shown in Figures 2 and 7, the coil holding portion 42 has a cylindrical main body portion 422, flange portions 426 to 428 protruding radially from the outer peripheral surface of the cylindrical main body portion 422, a routing portion 41 having a terminal pull-out portion (terminal connection portion) 46 and a connecting groove portion 47, and engaging protrusions 44 and 45.

[0071] The coil holding portion 42 has coils 61, 62 arranged on the outer periphery of the cylindrical main body portion 422. The coil holding portion 42 is formed into a coil bobbin shape by the cylindrical main body portion 422 and flange portions 426 to 428.

[0072] The cylindrical main body 422 is located radially inside the pair of coils 61, 62, and has an inner circumferential surface 42a that faces the outer circumferential surface of the movable body 20 at a predetermined interval. This predetermined interval is a distance that allows the movable body 20 to move in the vibration direction without coming into contact with the inner circumferential surface 42a.

[0073] The cylindrical main body 422 is positioned between the magnet 21 and the pair of coils 61, 62, thereby preventing contact between the magnet 21 and the pair of coils 61, 62. The cylindrical main body 422 guides the movable body 20 so that the movable body 20 can move back and forth along the inner circumferential surface 42 a.

[0074] That is, the cylindrical main body 422 functions as a protective wall that protects the pair of coils 61 and 62 from collision with the movable body 20 when the movable body 20 is driven.

[0075] The coil holding portion 42 has coils (a pair of coils 61, 62) arranged on coil attachment portions 42b, 42c (see FIGS. 2 and 7) provided on the outer periphery of the cylindrical main body portion 422. The coil attachment portions 42b, 42c (see FIGS. 2 and 7) are formed by the outer periphery of the cylindrical main body portion 422 and flange portions 426 to 428 in a concave shape that opens radially outward from the outer periphery of the cylindrical main body portion 422. The pair of coils 61, 62 are arranged between flange portions (also referred to as "end flange portions") 427, 428 so as to sandwich the central flange portion (hereinafter also referred to as "central flange portion") 426 in the vibration direction.

[0076] The coils 61 and 62 are positioned side by side in the coil axis direction so as to surround the outer circumferential surfaces of the first weight portion 23 and the second weight portion 25 of the movable body 20 .

[0077] The central flange portion 426 is provided in an annular shape and protrudes radially outward from the outer circumferential surface of the cylindrical main body portion 422 .

[0078] The diameter of the central flange portion 426 excluding the terminal lead-out portion 46, i.e., the diameter of the outer peripheral portion 426 a, is shorter than the maximum diameter of the other flange portions (end flange portions 427, 428). As a result, a recessed portion 420 is formed on the outer peripheral surface of the coil holding portion 42, located in the center in the vibration direction, and at the open ends of the coil mounting portions 42 b, 42 c (see FIGS. 2 and 7).

[0079] As a result, the outer yoke 50 fits into the recessed portion 420, and the outer yoke 50 covers the coil mounting portions 42b, 42c on which the coils 61, 62 are arranged, with its outer surface positioned flush with the outer surfaces of the end flange portions 427, 428.

[0080] The routing portion 41 is provided on a part of the outer periphery of the central flange portion 426, and is used to route the windings that make up the coils 61, 62. The routing portion 41 is disposed in the central portion in the axial direction (vibration direction) on the outer periphery of the drive unit 15 or the coil assembly.

[0081] The routing portion 41 projects outward to pass through the outer yoke 50, and processes the ends (windings 63) of the coils 61, 62 so that they can be connected to external devices via the terminal draw-out portion 46, which has a flat tip surface, and the connecting groove portion 47 guides the coil winding 64. In this way, the coil winding (e.g., winding 64) is routed so that the coil holding portion 42 can appropriately hold the coils 61, 62.

[0082] The terminal lead-out portion 46 has a terminal entangling portion 43 protruding from the flat surface. As shown in Fig. 7, the terminal entangling portion 43 entangles the windings 63 at the ends of the windings connecting the pair of coils 61, 62, and functions as a connector connecting portion for connecting to an external device. The terminal entangling portion 43 connects the pair of coils 61, 62 to an external device (for example, a power supply unit such as a drive control unit), enabling power to be supplied from the external device to the pair of coils 61, 62. The terminal entangling portion 43 is conductive and has a rod-shaped body for entangling the coil windings.

[0083] The base end of the terminal binding portion 43 is press-fitted into the terminal lead-out portion 46 that protrudes from the outer periphery of the coil holding portion 42. The windings 63 at the ends of the windings that make up the coils 61 and 62 are bound and connected to the terminal binding portion 43, and this connection is securely joined with a ferrule 432 formed by solder.

[0084] Terminal lead-out portion 46 protrudes from the outer circumferential surface of central flange portion 426 and is provided at central flange portion 426 with a predetermined radial length, a thickness in the vibration direction, and a width along the circumferential direction, thereby ensuring a press-fit margin for terminal binding portion 43. The horizontal side of the tip surface of terminal lead-out portion 46 is parallel to a tangent to the outer periphery of central flange portion 426, and here, both ends of coils 61, 62 connected to terminal binding portion 43 protrude from the tip surface of terminal lead-out portion 46.

[0085] The terminal pull-out portion 46 has a sufficient press-fitting margin for the terminal entanglement portion 43, so that the terminal entanglement portion 43 can be firmly held, and the terminal entanglement portion 43 can be stably fixed when assembled to the coil holding portion 42.

[0086] The terminal lead-out portion 46 leads the ends of the windings of the coils (pair of coils 61, 62) out of the vibration actuator 1 via the terminal binding portion 43 and connects them to a power supply. The terminal lead-out portion 46 passes through the outer yoke 50, exposing the terminal binding portion 43 to the outside of the outer yoke 50 and, ultimately, to the outside of the case 10.

[0087] Because the terminal binding portion 43 is provided on the terminal lead-out portion 46, even if the outer yoke 50 comes into contact with the terminal binding portion 43 and applies a load to the outer yoke 50 when the terminal binding portion 46 is inserted through the outer yoke 50, the load can be received by the terminal lead-out portion 46. This prevents the load applied when the outer yoke 50 is attached from being applied to the terminal binding portion 43, preventing deformation of the terminal binding portion 43 due to the load, and enabling stable manufacture of vibration actuators.

[0088] A coil winding 64 that connects the coils (a pair of coils 61, 62) is inserted into the communication groove 47. In the communication groove 47 of this embodiment, the winding directions of the coil windings that form the coils 61 and 62 are reversed above and below the communication groove 47.

[0089] The communication groove 47 is formed to open radially outward at the outer periphery of the central flange 426 and to penetrate along the vibration direction. Specifically, the communication groove 47 has a bottom wall 47a that forms the bottom of the groove, and a side wall 47b (one side wall) of the bottom wall 47a that is far from the terminal binding portion 43.

[0090] The communication groove 47, even when covered by the outer yoke 50, connects the coil mounting portions 42b and 42c in the vibration direction at the central flange portion 426. The communication groove 47 is disposed close to or adjacent to the terminal lead-out portion 46. The notched portion functions to lock the windings to prevent them from coming off when, after winding and placing one of the coils 61 and 62, the winding direction is reversed and the other coil is wound and placed. The communication groove 47 in this embodiment is formed in a U-shape in plan view, with the bottom wall portion 47a as the bottom surface and both side walls extending upright at both ends spaced apart in the circumferential direction. Therefore, when the pair of coils 61 and 62 are placed by winding the coil windings around the coil mounting portions 42b and 42c in upside-down directions, the coil winding 64 is securely engaged with and retained in the communication groove 47 to prevent it from coming off.

[0091] The wiring portion 41 has a coil guide portion 412 in the central flange portion 426 (see FIG. 7 ). The coil guide portion 412 guides the coil winding 63 from the terminal binding portion 43 to the first turn position (e.g., a corner) in the coil winding portion of the coil holding portion 42 (one of the coil mounting portions 42 b, 42 c).

[0092] The coil guide portion 412 is formed in a stepped shape on at least one of the upper and lower surfaces (surfaces separated in the vibration direction) of the central flange portion 426, on the upper surface portion of the connecting groove portion 47 adjacent to one side of the terminal pull-out portion 46 in the circumferential direction, and on the lower surface portion of the terminal pull-out portion 46.

[0093] The coil guide portion 412 is an inclined portion formed by steps on the upper and lower surfaces (surfaces in the vibration direction) of the central flange portion 426, and guides the coil winding from the terminal binding portion 43 so that it can be pulled in to the bottom side of the coil mounting portions 42b and 42c, that is, to the outer peripheral surface side of the cylindrical main body portion 422.

[0094] The end flanges 427 and 428 are provided at both ends of the cylindrical main body 422 that are spaced apart in the axial direction, and constitute the upper and lower ends of the coil holding portion 42 .

[0095] The end flanges 427, 428 (collectively referred to as "end flanges") are provided so as to protrude radially from the outer periphery of the cylindrical main body 422 to both ends in the vibration direction. The outer peripheries of the end flanges 427, 428 each have a portion with the same diameter as the outer periphery 426a of the central flange 426. These same-diameter portions form the recessed portion 420 including the recessed coil mounting portions 42b, 42c, and this same-diameter portion abuts against the inner circumferential surface of the outer yoke 50.

[0096] By placing outer yoke 50 in this recessed portion 420, outer yoke 50 is positioned in a position surrounding the pair of coils 61, 62. Furthermore, outer yoke 50 is stably fixed to coil holding portion 42 by abutting outer periphery 426a against the same diameter portions of end flange portions 427, 428. As a result, even if the height dimension (length in the vibration direction) of outer yoke 50 increases, it can be stably fixed using an attachment method that corresponds to that increase.

[0097] The end flange portions 427, 428 are formed in a cylindrical shape that opens in a direction (vertical direction in this embodiment) away from the central flange portion 426. The elastic support portions 81, 82 are fixed to the open ends of the end flange portions 427, 428, i.e., the upper and lower ends.

[0098] The engaging protrusions 44, 45 are protrusions protruding in the vibration direction (vertical direction) at the upper and lower ends of the coil holding portion 42, i.e., at the upper and lower annular opening end faces (also referred to as the "upper end face" and the "lower end face") 427a, 428a of the end flange portions 427, 428, respectively.

[0099] 2 and 3, the engaging protrusions 44, 45 sandwich the elastic support portions 81, 82 together with the first spacer 13-1 and the second spacer 13-2 within the first case 11-1 and the second case 11-2, and engage with the engaging recesses 134 of the first spacer 13-1 and the second spacer 13-2. Note that by engaging with the engaging recesses 134, the engaging protrusions 44, 45 position the first case 11-1, the second case 11-2, and the coil holding portion 42 in the radial direction and vibration direction. In addition, together with the first spacer 13-1 and the second spacer 13-2, they also position the elastic support portions 81, 82 sandwiched between them in the radial direction.

[0100] <Coils 61, 62> In the vibration actuator 1, the pair of coils 61, 62, together with the magnet 21, the first weight portion 23 and the second weight portion 25, form a magnetic circuit used to generate a driving source, with the axial direction of the pair of coils 61, 62 (the magnetization direction of the magnet 21) being the vibration direction.

[0101] The pair of coils 61, 62 are energized when driven (when vibrating) and constitute a voice coil motor together with the magnet 21. Although a pair of coils 61, 62 is used in this embodiment, one coil or three or more coils may be used as long as they constitute a magnetic circuit that is driven in the same way, but it is desirable to use an even number of coils so that they are symmetrical in the vibration direction.

[0102] The pair of coils 61, 62 are arranged in positions symmetrical in the vibration direction with respect to the magnet 21 as the center of the movable body 20, which includes the magnet 21, the first weight portion 23, and the second weight portion 25. It is preferable that the center position of the length of the coils in the vibration direction, that is, the center position of the length between the upper end of coil 61 and the lower end of coil 62, be the same position (including approximately the same position) in the vibration direction as the center position of the length of the movable body 20 (particularly the magnet 21) in the vibration direction.

[0103] In this embodiment, the pair of coils 61, 62 is formed by winding a single coil in opposite directions, and when energized, current flows in opposite directions in the coils 61, 62. The ends of the pair of coils 61, 62, i.e., both ends of the windings of the coils constituting the pair of coils 61, 62, are wound and connected to the terminal winding portion 43 of the flange portion 426.

[0104] The coils (pair of coils 61, 62) are connected to a power supply unit (e.g., the drive control unit 203 shown in FIGS. 13 and 14 ) via the terminal fastening unit 43. For example, each end of the coils (pair of coils 61, 62) is connected to an AC supply unit via the terminal fastening unit 43, and AC power (AC voltage) is supplied from the AC supply unit to the coils (pair of coils 61, 62). This allows the coils (pair of coils 61, 62) to generate a thrust between the magnet and the coils (pair of coils 61, 62) that moves them toward and away from each other in their axial directions. The coils 61, 62 can be assembled without using self-fusing wire, which reduces the cost of the coils (pair of coils 61, 62) themselves and, ultimately, the cost of the entire vibration actuator.

[0105] 2 to 5 and 7, the outer yoke 50 is a cylindrical magnetic body that surrounds the outer peripheral surface of the coil holding portion 42 and is positioned so as to cover the radially outer side of the pair of coils 61, 62. As described above, the outer yoke 50 constitutes a magnetic circuit on the fixed body side together with the pair of coils 61, 62, and also constitutes a magnetic circuit on the movable body side, that is, a magnetic circuit together with the magnet 21, the first weight portion 23, and the second weight portion 25. The outer yoke 50 prevents leakage of magnetic flux from the magnetic circuit to the outside of the vibration actuator 1.

[0106] The outer yoke 50 increases the thrust constant in the magnetic circuit, thereby improving electromagnetic conversion efficiency. The outer yoke 50 is positioned so that the center of the length of the outer yoke 50 in the vibration direction is at the same height as the center of the vibration direction of the magnet 21 placed inside. The shielding effect of this outer yoke 50 can reduce leakage magnetic flux to the outside of the vibration actuator.

[0107] It is preferable that the ends of outer yoke 50 that are separated in the vibration direction are configured to a length that does not cover both ends of the movable range in the vibration direction of the laminate formed by stacking magnet 21, first weight portion 23, and second weight portion 25, regardless of whether movable body 20 is vibrating or not. Outer yoke 50 has a yoke body 51 and a plurality of openings (first opening 53, second opening 55) that are provided at the same position in the vibration direction of yoke body 51 and distributed circumferentially.

[0108] The yoke body 51 is formed in a cylindrical shape and is made of, for example, SECC (electro-galvanized steel sheet), which has excellent weldability and corrosion resistance.

[0109] The yoke body 51 is flexible and has, for example, a slit parallel to the axial direction in a portion of the peripheral wall. The yoke body 51 is formed into a C-shaped cylinder in a planar cross section. When the yoke body 51 is attached to the outer periphery of the coil holding portion 42, the ends 52 constituting the slit are widened to position the coil holding portion 42 inside the yoke body 51. Next, the deformation of the yoke body 51 is restored, and the yoke body 51 is fitted into the recessed portion 420 on the outer periphery of the coil holding portion 42, thereby fitting the yoke body 51 onto the exterior of the coil holding portion 42.

[0110] The multiple openings 53, 55 are all provided in the yoke body 51 at positions that are equally spaced apart in the circumferential direction around the axis of the outer yoke 50. The multiple openings 53, 55 are also provided at the center of the vibration direction, which is the height direction, of the yoke body 51. The multiple openings 53, 55 open, for example, in the yoke body 51 at positions that face each other around the axis of the outer yoke 50.

[0111] In this embodiment, the multiple openings 53, 55 are formed in a rectangular shape in the yoke body 51, separated in the circumferential direction by parallel sides spaced apart in the circumferential direction, and separated in the vibration direction by upper and lower sides that are spaced apart in the vibration direction and are formed symmetrically around the center point of the vibration direction.

[0112] The plurality of openings 53, 55 include a first opening 53 for passing wiring connecting an external device to coils 61, 62, and a second opening 55 provided at a predetermined position based on the position of first opening 53. Opening 53 is provided in the center of the slit portion of yoke body 51 so as to extend in the circumferential direction.

[0113] Terminal lead-out portion 46 is inserted into opening 53. As a result, terminal entanglement portion (wiring) 43 connected to coils 61 and 62 passes through opening 53, and terminal entanglement portion (wiring) 43 is disposed in an exposed state protruding outside outer yoke 50 so as to be connectable to an external device.

[0114] Furthermore, the opening 53 functions as a stopper for preventing the outer yoke 50 from rotating in the circumferential direction relative to the coil holding portion 42 by fitting into the terminal lead-out portion 46 .

[0115] Opening 53 has cutouts 533 formed on diagonally arranged edges of left and right sides that separate opening 53. The cutouts 533 are shaped to widen a part of opening 53 in the circumferential direction. That is, opening 53 has a cutout shape such that the positions of the edges extending along the vibration direction are shifted in the circumferential direction.

[0116] The end of the winding connected to the terminal binding portion 43 is wired inside the cutout portion 533. When fitting the outer yoke 50 into the recessed portion 420 of the coil holding portion 42 and positioning the terminal lead-out portion 46 inside the opening 53, the winding connecting the terminal binding portion 43 of the terminal lead-out portion 46 and the coils 61, 62 inside the outer yoke 50 is wired inside the cutout portion 533. This allows the outer yoke 50 to be suitably attached to the coil holding portion 42 without the coil winding getting in the way.

[0117] In outer yoke 50, the left and right side portions that circumferentially divide opening 53 may be formed to sandwich terminal lead portion 46. In this case, the protruding side portions adjacent to cutout portion 533 can press terminal lead portion 46 from both sides in the circumferential direction to hold terminal lead portion 46. This allows outer yoke 50 to be securely attached to coil holding portion 42 with terminal lead portion 46 sandwiched in the circumferential direction.

[0118] Furthermore, the opening 53 is divided into two regions spaced apart in the vibration direction by the terminal pull-out portion 46, and band-shaped open regions extending in the circumferential direction and communicating with the cutout portions 533 are formed on both sides (up and down) of the terminal pull-out portion 46 in the vibration direction. The windings connecting the terminal binding portion 43 and the coil mounting portions 42b, 42c are suitably arranged in the band-shaped regions including the cutout portions 533.

[0119] Opening (second opening) 55 is provided at a position facing opening 53 with respect to the radial center. Opening 55 is formed, for example, in yoke body 51 at a position facing opening 53. Opening 55 has substantially the same shape as opening 53, and is formed in a rectangular shape extending in the circumferential direction and bounded by top, bottom, left, and right sides.

[0120] The widths in the vibration direction of the upper and lower side portions 55a, 55b that separate the opening 55 are formed to be approximately the same as the widths in the vibration direction of the upper and lower side portions of the opening 53.

[0121] The openings 53 and 55 form a magnetic path in the magnetic circuit that is symmetrical about the axis, ensuring a balance of the generated magnetism. That is, the openings 53 and 55 allow the movable body 20 and the fixed body 40 to attract each other equally in the vibration direction and in the direction perpendicular to the vibration direction (radial direction), i.e., up, down, left, and right. As a result, the movable body 20 vibrates in a state where they are attracted equally to each other in the radial direction relative to the fixed body, and the vibration actuator 1 maintains a good balance, minimizing imbalances in the magnetic attractive forces and leakage magnetic flux in the magnetic circuit.

[0122] In this embodiment, each of the upper and lower side portions that separate the opening 53 is divided in the circumferential direction by a slit sandwiched between the ends 52, which differs from a configuration in which the upper and lower sides have no slits. However, because the division of the upper and lower side portions at the opening 53 results in a short distance between the ends 52 that face each other in the circumferential direction via the cutout, the division has the same function as upper and lower side portions without a slit, and provides the same effect in terms of the magnetic circuit.

[0123] In this embodiment, the openings 53 and 55 are configured to be provided at two locations facing each other in the center of the outer yoke 50 in the vertical direction (vibration direction), but two or more openings may be provided as long as they are spaced equally apart around the axis of the outer yoke 50.

[0124] <Elastic Supporting Portions 81, 82> As shown in FIGS. 2 to 6, the elastic supporting portions 81, 82 support the movable body 20 so that it can move back and forth relative to the fixed body 40 in the vibration direction.

[0125] The elastic support parts 81 and 82 sandwich the movable body 20 in the vibration direction of the movable body 20 and are installed across both the movable body 20 and the fixed body 40 so as to intersect with the vibration direction.

[0126] In this embodiment, as shown in Figures 2 to 6, the elastic support portions 81 and 82 are attached parallel to each other across both ends (upper and lower ends) of the coil holding portion 42 that are spaced apart in the vibration direction and both ends of the movable body.

[0127] The elastic support members 81 and 82 are each a plurality of flat leaf springs formed into a spiral disk shape. The elastic support members 81 and 82 have a shape in which an annular inner peripheral portion 802, which is the inner spring end, and an annular outer peripheral portion 806, which is the outer spring end, are joined by a deformation arm 804 that is elastically deformable and has an arc-like shape in a plan view.

[0128] The deforming arms 804 are arranged in a spiral shape connecting the inner circumferential portion 802 and the outer circumferential portion 806, and deformation of the deforming arms 804 causes the inner circumferential portion 802 and the outer circumferential portion 806 to be displaced relative to each other in the axial direction.

[0129] The elastic support portions 81 and 82 support the movable body 20 so that it is movable in the axial direction (vibration direction) without coming into contact with the fixed body 40 .

[0130] The inner peripheral portion 802 has a connection hole 802a disposed at the center of the elastic support portions 81 and 82. Both ends of the movable body 20 that are separated in the vibration direction (the support fixing portions 314 and 334 of the spring connection portions 31 and 33) are fitted into and connected to this connection hole 802a.

[0131] On the other hand, the outer peripheral portion 806 is attached to the upper and lower ends of the coil holding portion 42, i.e., the opening end faces 427a, 428a of the end flange portions 427, 428, in a state where it is sandwiched between the first spacer 13-1 and the second spacer 13-2. The outer peripheral portion 806 is fixed in a state where it is positioned by engaging the engaging protrusions 44, 45 with the positioning groove portion 808. The outer peripheral portion 806 may be fixed to the opening end faces 427a, 428a of the end flange portions 427, 428 by being adhered to the opening end faces 427a, 428a with an adhesive or the like.

[0132] The leaf springs serving as elastic support members 81, 82 may be made of any material that is elastically deformable, and may be formed by sheet metal processing using stainless steel plate, phosphor bronze, etc. In this embodiment, elastic support members 81, 82 are thin, flat, disc-shaped spiral springs made of phosphor bronze, which has high workability, excellent corrosion resistance, tensile strength, and wear resistance.

[0133] In this embodiment, the multiple elastic support parts 81, 82 are joined to the coil holding part 42 and the movable body 20 in such a way that the spiral direction is the same, and even if the movement amount of the movable body 20 becomes large, they can move smoothly along the vibration direction, i.e., can deform.

[0134] Furthermore, the outer peripheral portion 806 of the elastic support portion 81 is positioned and fixed on the annular opening end face 427a of the end flange portion 427 at a location that avoids the engaging protrusion 44. On the other hand, the outer peripheral portion 806 of the elastic support portion 82 is positioned and fixed on the annular opening end face 428a of the end flange portion 428 at a location that avoids the engaging protrusion 45.

[0135] In this way, the elastic support portions 81 and 82 are sandwiched between the opening end faces 427a and 428a of the upper and lower opening edge portions of the coil holding portion 42 and the first spacer 13-1 and second spacer 13-2, while being arranged in a direction perpendicular to the vibration direction.

[0136] In addition, the elastic support portions 81, 82 are attached to the coil holding portion 42 and to the movable body 20 accommodated inside the coil holding portion 42 so as to be able to vibrate back and forth, so as to close the upper and lower openings of the coil holding portion 42 around which a pair of coils 61, 62 are wound on the outer periphery.

[0137] <Case 10> FIG. 8 is an exploded perspective view of the case.

[0138] The case 10 includes a first case 11-1 and a second case 11-2 shown in FIGS. 1 to 3 and 8. The first case 11-1 and the second case 11-2 have the same shape and are made of the same material, and are common components. The first case 11-1 and the second case 11-2 are formed in the same cylindrical shape with a bottom. Notches 116-1 and 116-2 are provided in portions of the opening edges of the case openings 111-1 and 111-2 of the peripheral wall portions 114-1 and 114-2. The notches 116-1 and 116-2 are positioned so that the wiring portion 41 is exposed to the outside when the drive unit 15 is housed in the case 10 together with the spacers 13-1 and 13-2. That is, the notches 116-1 and 116-2 are joined together to form a notched opening, through which the terminal connection portion (wiring portion 41) of the cylindrical body is inserted. The first case 11-1 and the second case 11-2 are joined to each other, for example, by welding.

[0139] The first case 11-1 and the second case 11-2 have peripheral wall portions 114-1 and 114-2 that rise from disk-shaped case lid portions 112-1 and 112-2, and the internal corners do not have steps or the like for arranging the drive unit 15. Note that the case lid portions 112-1 and 112-2 can also function as case bottoms instead of case lids depending on the arrangement positions of the first case 11-1 and the second case 11-2. For convenience, the bottoms of the bottomed cylindrical first case 11-1 and second case 11-2 will be referred to as case lid portions 112-1 and 112-2, but they also function as case bottoms.

[0140] The first case 11-1 and the second case 11-2 may be made of a non-magnetic material or a magnetic material, and may function as a magnetic shield by being made of a magnetic material. The first case 11-1 and the second case 11-2 are, for example, metal cases that are magnetic materials formed by drawing a metal plate such as SUS.

[0141] The case lids 112-1 and 112-2 of the first case 11-1 and the second case 11-2 are made of thin plate-like bodies and define the range of movement of the movable body 20 in the drive unit 15 inside the case 10. The back surfaces of the first case 11-1 and the second case 11-2 may each be shaped so that their thickness decreases toward the center (the axis).

[0142] The first case 11-1 and the second case 11-2 have positioning holes 118-1 and 118-2, through which a jig can be inserted to position the first case 11-1 and the second case 11-2 while preventing rotation when assembling the vibration actuator 1. This makes it easy to position one or both of the first case 11-1 and the second case 11-2 when inserting the drive unit 15 inside the case 10, and assemble the two after inserting the drive unit 15 inside. When housing the drive unit 15 inside the first case 11-1 and the second case 11-2, the cutouts 116-1 and 116-2 are used to allow the windings of the coils 61 and 62 to escape and to install them so that they are not pinched.

[0143] Because the first case 11-1 and the second case 11-2 are metal cases formed by processing metal plates, component precision is improved compared to cases where they are formed by resin molding. Furthermore, the first case 11-1 and the second case 11-2 are common components with the same shape. As a result, the case 10 is constructed by connecting the respective case lids 112-1 and 112-2 facing the pair of elastic support members 81 and 82, with the case openings 111-1 and 111-2 aligned and closed to each other. In this state, the dimension between the case lids 112-1 and 112-2 is defined. Based on this, when manufacturing the vibration actuator 1, the dimension of the range of motion of the movable body 20, i.e., the length in the vibration direction that corresponds to the range of movement of the movable body 20 within the case 10, is formed to a stable length.

[0144] This ensures stable vibration, thereby stabilizing vibration characteristics and realizing a vibration actuator 1 with a larger input voltage.

[0145] <First spacer 13-1, second spacer 13-2> The first spacer 13-1 and the second spacer 13-2 are attached to the upper and lower ends of the drive unit 15 so as to sandwich the drive unit 15, and stably accommodate the drive unit 15 within the case 10 while allowing the movable body 20 of the drive unit 15 to vibrate.

[0146] The first spacer 13-1 and the second spacer 13-2 ensure a separation length between the case lids 112-1 and 112-2 and the elastic support members 81 and 82. This ensured separation length is the displacement length of the movable space of the movable body 20, and is a space within a range in which the elastic support members 81 and 82 do not undergo plastic deformation. Even if a force exceeding a predetermined vibration range is applied to the movable body 20 due to, for example, a drop impact, the elastic support members 81 and 82 will not undergo plastic deformation and will come into contact with the fixed body 40 (at least one of the case lids 112-1 and 112-2). This prevents damage to the elastic support members 81 and 82, thereby improving the reliability of the vibration actuator 1.

[0147] The first spacer 13-1 and the second spacer 13-2 are disposed and fixed in the first case 11-1 and the second case 11-2.

[0148] More specifically, the first spacer 13-1 and the second spacer 13-2, together with both end portions (end flange portions 427, 428) of the coil holding portion 42, sandwich and fix the outer circumferential portions 806 of the elastic support portions 81, 82 in the vibration direction. The first spacer 13-1 and the second spacer 13-2 may be made of a magnetic or non-magnetic material, for example, a metal such as SUS.

[0149] The first spacer 13-1 and the second spacer 13-2 have the same shape and are made of the same material, making them a common component. This eliminates the need to manufacture the first spacer 13-1 and the second spacer 13-2 individually, and allows them to be manufactured as a common component.

[0150] The first spacer 13-1 and the second spacer 13-2 are arranged inside the case 10 and have a main body portion 132 having a thickness that separates the elastic support portions 81 and 82 from the case lid portions 112-1 and 112-2 so that they can be displaced, and an engagement recess 134 into which the engagement protrusions 44 and 45 engage.

[0151] The main body 132 is, for example, annular, and has an outer diameter similar to the outer diameter of the upper and lower ends of the drive unit 15 (coil holding portion 42).

[0152] The engaging recesses 134 are formed in the main body 132 at positions corresponding to the engaging protrusions 44, 45, respectively, and are engaged with the engaging protrusions 44, 45 in the axial direction to restrict their movement in the circumferential direction.

[0153] The drive unit 15 disposed inside the case 10 can be accommodated so as to be freely positioned in the circumferential direction.

[0154] <Operation of Vibration Actuator 1> The operation of the magnetic circuit configuration of the vibration actuator 1 will be described with reference to Fig. 9. Fig. 9 is a diagram showing a schematic diagram of the magnetic circuit configuration of the vibration actuator.

[0155] The operation of the vibration actuator 1 will be described using as an example a case in which the magnet 21 is magnetized so that the front surface 21a on one side of the magnetization direction (the upper side in this embodiment) is the north pole and the back surface 21b on the other side of the magnetization direction (the lower side in this embodiment) is the south pole.

[0156] In the vibration actuator 1, the movable body 20 is considered to correspond to the mass portion in a vibration model of a spring-mass system, so when the resonance is sharp (has a steep peak), the steep peak is suppressed by damping the vibration. By damping the vibration, the resonance becomes less steep, and the maximum amplitude value and maximum movement amount of the movable body 20 at resonance do not vary, and vibration with an appropriate, stable maximum movement amount is output.

[0157] When the vibration actuator 1 is in a non-driven state, the magnetic flux flow mf is formed so as to be emitted from the surface 21a side of the magnet 21, radiated from the first weight portion 23 toward the coil 61 side, and pass through the outer yoke 50. The magnetic flux flow mf is then formed so as to be incident on the magnet 21 from the second weight portion 25 below the magnet 21 via the coil 62.

[0158] As shown in FIG. 9 , when current is applied, the magnetic field of the magnet 21 interacts with the current flowing through the coils (the pair of coils 61 and 62), generating a Lorentz force in the −f direction in the pair of coils 61 and 62 according to Fleming's left-hand rule. A force opposite to this −f-direction Lorentz force is generated in the movable body 20 having the magnet 21 as a thrust in the F direction, causing the movable body 20 having the magnet 21 to move in the F direction, i.e., toward the case lid 112-1 of the first case 11-1. Furthermore, when the current flow direction of the pair of coils 61 and 62 is reversed and current is applied to the pair of coils 61 and 62, a Lorentz force in the opposite f direction is generated. According to the law of action and reaction, a force opposite to this f-direction Lorentz force is generated in the movable body 20 as a thrust (thrust in the −F direction). As a result, the movable body 20 moves in the −F direction, i.e., toward the case lid 112-2 of the second case 11-2. When not energized and not vibrating, a magnetic attractive force acts between the magnet 21 and the outer yoke 50, causing them to function as magnetic springs. The magnetic attractive force generated between the magnet 21 and the outer yoke 50 and the restoring forces of the elastic support portions 81 and 82 that attempt to return them to their original shapes cause the movable body 20 to return to its original position.

[0159] According to this embodiment, the exterior of the vibration actuator 1 is a metal case made of a common material and divided into two upper and lower halves, the first case 11-1 and the second case 11-2. This ensures the strength of the vibration actuator 1, making it more durable than a resin case and improving the strength and reliability of the vibration actuator.

[0160] Furthermore, in the movable body 20, the first weight portion 23 and the second weight portion 25 are made of ferromagnetic material such as tungsten, and have the functions of both a weight and a yoke in one component, and by increasing the weight of the movable portion, the vibration characteristics can be improved.

[0161] Furthermore, the vibration actuator 1 is constructed using common materials for both the upper and lower parts, except for the coil holding portion 42 and the magnet 21. Therefore, when manufacturing the vibration actuator 1, there is no need to manufacture separate parts for the upper and lower parts, which reduces costs.

[0162] <Modification> FIG. 10 is a perspective view showing a modification of the spacer in the vibration actuator of this embodiment.

[0163] 10 has a circular main body 132A similar to that of the spacer 13, an engaging recess 134A formed in the same shape as the engaging recess 134 and having the same function, and also has a cone-shaped spacer lid 1360 on the inner diameter side of the circular main body 132A. The spacer 13A is made of, for example, resin. Note that the spacer lid 1360 also functions as a bottom depending on its position in the vibration actuator 1A.

[0164] Figure 11 is a vertical cross-sectional view of a vibration actuator equipped with a modified spacer, and Figure 12 is an enlarged view of part X in Figure 11. Note that the vibration actuator 1A shown in Figure 11 is configured in such a way that the first spacer 13-1 and the second spacer 13-2 are replaced with spacers 13A (first spacer 13A-1, second spacer 13A-2), respectively, in the configuration of the vibration actuator 1, but the rest of the configuration is similar. Therefore, similar members are given the same names and symbols and their explanations will be omitted.

[0165] The spacer lid portion 1360 has a tapered inner surface that is inclined so that it becomes thinner toward the center. An opening 138A is provided in the center of the spacer lid portion 1360. The outer surface of the spacer lid portion 1360 is flat as shown in Figures 11 and 12, and abuts against the case lid portions 112-1 and 112-2 of the first case 11-1 and the second case 11-2. Figure 12 shows the normal movable area of ​​the movable body 20 (the area indicated by hatching surrounded by a dotted line) and the dead space DS (the area surrounded by a dotted line).

[0166] By making the spacer lid portion 1360 tapered, when the spacer 13A is placed together with the drive unit 15 in the first case 11-1 and the second case 11-2, the spacer lid portion 1360 can be provided in the dead space DS within the case 10. As a result, even if the vibration actuator 1 is subjected to an external force such as a drop impact, the elastic support portions 81, 82 come into contact with the spacer lid portion 1360 of the spacer 13A, thereby restricting the movement of the elastic support portions 81, 82 and further preventing plastic deformation of the elastic support portions 81, 82. Note that at this time, the support fixing portions 314, 334 of the spring connecting portions 31, 33 are inserted into the opening 138A and are not in contact with the spacer lid portion 1360.

[0167] In this way, the spacer is configured to be placed in the dead space DS, and may have any configuration as long as it has the same basic configuration as the spacers 13 and 13A.

[0168] The vibration actuator 1 is driven by an AC wave input from a power supply unit (for example, the drive control unit 203 shown in FIGS. 13 and 14) to a pair of coils 61, 62. In other words, the direction of current flow through the pair of coils 61, 62 switches periodically, and a thrust in the F direction on the case lid 112-1 side of the first case 11-1 and a thrust in the -F direction on the case lid 112-2 side of the second case 11-2 act alternately on the movable body 20, as shown in FIG. 9. This causes the movable body 20 to vibrate in the vibration direction.

[0169] The following is a brief description of the driving principle of the vibration actuator 1. In the vibration actuator 1 of this embodiment, the mass of the movable body 20 is m [kg], the spring constant of the spring (elastic support portions 81 and 82 which are springs) is K ｓｐ In this case, the movable body 20 has a resonance frequency F ｒ It vibrates at [Hz].

[0170]

[0171] Since the movable body 20 is considered to constitute a mass part in a vibration model of a spring-mass system, the coils (a pair of coils 61 and 62) are set to have a resonance frequency F ｒ When an AC wave having a frequency equal to the resonant frequency F of the movable body 20 is input, the movable body 20 enters a resonant state. ｒ By inputting an AC wave having a frequency substantially equal to the frequency of the input, the movable body 20 can be vibrated efficiently.

[0172] Below are shown the equation of motion and the circuit equation that show the driving principle of the vibration actuator 1. The vibration actuator 1 is driven based on the equation of motion shown in the following equation (2) and the circuit equation shown in the following equation (3).

[0173]

[0174]

[0175] That is, the mass m [kg], displacement x(t) [m], thrust constant K f [N / A], current i(t) [A], spring constant K sp [N / m], damping coefficient D [N / (m / s)], etc. can be changed as appropriate within the range that satisfies formula (2). ｅ [V / (rad / s)] can be changed as appropriate within a range that satisfies formula (3).

[0176] In this way, in the vibration actuator 1, the mass m of the movable body 20 and the spring constant K of the elastic support members 81 and 82, which are leaf springs, ｓｐThe resonant frequency F is determined by ｒ When the coils 61 and 62 are energized with an AC wave corresponding to the above, a large vibration output can be obtained efficiently.

[0177] Furthermore, the vibration actuator 1 satisfies equations (2) and (3) and is driven by a resonance phenomenon using the resonance frequency shown in equation (1). This allows the vibration actuator 1 to be driven with low power consumption, that is, the movable body 20 to vibrate back and forth in a linear manner with low power consumption. Furthermore, by increasing the damping coefficient D, it is possible to generate vibrations over a wide frequency range.

[0178] According to this embodiment, the vibration actuator 1 can stably drive the movable body 20 in the vertical direction, and at the same time, can efficiently distribute the magnetic flux of the pair of coils 61, 62 from the upper and lower elastic support parts 81, 82 of the magnet 21. This allows the vibration actuator 1 to achieve high-output vibration.

[0179] 13 and 14 are diagrams showing examples of mounting forms of the vibration actuator 1. Fig. 13 shows an example in which the vibration actuator 1 is mounted on a game controller GC, and Fig. 14 shows an example in which the vibration actuator 1 is mounted on a mobile terminal M.

[0180] The game controller GC is connected to the game console via wireless communication, for example, and is used by being held or grasped by the user. The game controller GC here has a rectangular plate shape, and is operated by the user grasping the left and right sides of the game controller GC with both hands.

[0181] The game controller GC notifies the user of commands from the game console by vibration. Although not shown, the game controller GC also has functions other than command notification, such as an input operation unit for the game console.

[0182] The mobile terminal M is, for example, a mobile communication terminal such as a mobile phone, a smartphone, etc. The mobile terminal M notifies the user of an incoming call from an external communication device by vibration, and also realizes various functions of the mobile terminal M (for example, functions that provide a sense of operation and a sense of realism).

[0183] The game controller GC and the mobile terminal M each have a communication unit 201, a processing unit 202, a drive control unit 203, and vibration actuators 204, 205, and 206, which are vibration actuators 1 serving as drive units. Note that the game controller GC is equipped with a plurality of vibration actuators 204 and 205.

[0184] In the game controller GC and the portable terminal M, the vibration actuators 204 to 206 are preferably mounted, for example, so that the main surface of the terminal is parallel to a plane perpendicular to the vibration direction of the vibration actuators 204 to 206. In this case, the plane perpendicular to the main surface of the terminal and the vibration direction of the vibration actuators 204 to 206 is the surface of the case lids (bottoms) 112-1 and 112-2 of the first and second cases 11-1 and 11-2.

[0185] The main surface of the terminal is the surface that comes into contact with the user's body surface, and in this embodiment, it means the vibration transmission surface that comes into contact with the user's body surface and transmits vibrations. Note that the main surface of the terminal and case lids (bottoms) 112-1 and 112-2 of vibration actuators 204, 205, and 206 may be arranged so as to be perpendicular to each other.

[0186] Specifically, in the game controller GC, vibration actuators 204 and 205 are mounted so that their vibration direction is perpendicular to the surface that comes into contact with the fingertips, finger pads, or back of the hand of the operating user, or the surface on which the operation unit is provided. Also, in the case of the portable terminal M, vibration actuator 206 is mounted so that its vibration direction is perpendicular to the display screen (touch panel surface). As a result, vibrations in a direction perpendicular to the main surfaces of the game controller GC and portable terminal M are transmitted to the user.

[0187] The communication unit 201 is connected to an external communication device via wireless communication, receives signals from the communication device, and outputs the signals to the processing unit 202. In the case of a game controller GC, the external communication device is a game console main body as an information communication terminal, and communication is performed in accordance with a short-range wireless communication standard such as Bluetooth (registered trademark). In the case of a portable terminal M, the external communication device is, for example, a base station, and communication is performed in accordance with a mobile communication standard.

[0188] The processing unit 202 converts the input signal into a drive signal for driving the vibration actuators 204, 205, and 206 using a conversion circuit unit (not shown), and outputs the drive signal to the drive control unit 203. In the mobile terminal M, the processing unit 202 generates the drive signal based on the signal input from the communication unit 201 as well as signals input from various functional units (not shown, for example, an operation unit such as a touch panel).

[0189] The drive control unit 203 is connected to the vibration actuators 204, 205, and 206, and is equipped with circuits for driving the vibration actuators 204, 205, and 206. The drive control unit 203 supplies drive signals to the vibration actuators 204, 205, and 206.

[0190] The vibration actuators 204, 205, and 206 are driven in accordance with drive signals from the drive control unit 203. Specifically, in the vibration actuators 204, 205, and 206, the movable body 20 vibrates in a direction perpendicular to the main surfaces of the game controller GC and the mobile terminal M.

[0191] The user can be given a sufficient bodily sensation of vibration because vibrations are transmitted in a direction perpendicular to the body surface to the surface of the user's body that is in contact with the game controller GC or the mobile terminal M. The game controller GC can impart bodily sensation of vibration to the user by one or both of the vibration actuators 204, 205, and can impart highly expressive vibrations, such as selectively imparting at least strong and weak vibrations.

[0192] The invention made by the inventor has been specifically described above based on an embodiment, but the present invention is not limited to the above embodiment and can be modified within the scope of the gist thereof.

[0193] Furthermore, the vibration actuator according to the present invention may be mounted on a user contact portion of a portable device other than a game controller GC or a portable terminal M (for example, a portable information terminal such as a tablet PC, a portable game terminal, etc.). That is, the vibration actuator 1 may be mounted on a user contact portion of a handheld electrical device such as a portable terminal or an electric beauty appliance such as a facial massager. The vibration actuator 1 may be mounted on a user contact portion of a wearable terminal that is worn by the user. In the case of a handheld electrical device such as a game controller GC, the user contact portion is, for example, a handle portion that the user grips during use. In the case of a wearable electrical device such as a facial massager, the user contact portion is, for example, a pressure applying portion that applies pressure to the surface of the user's body.

[0194] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2023-168527, filed on September 28, 2023, are incorporated herein by reference in their entirety.

[0195] The vibration actuator according to the present invention can generate a suitable vibration output while being miniaturized, and is useful for being mounted in electronic devices such as game console terminals or mobile terminals, and electrical devices such as electric beauty and hairdressing appliances.

[0196] DESCRIPTION OF SYMBOLS 1, 1A, 204, 205, 206 Vibration actuator 10 Case 11-1 First case 11-2 Second case 13 Spacer (spacer portion) 13-1, 13A-1 First spacer 13-2, 13A-2 Second spacer 15 Drive unit 20 Movable body 20a Outer peripheral surface 21 Magnet 21a Front surface 21b Back surface 23 First weight portion 25 Second weight portion 31, 33 Spring connection portion 40 Fixed body 41 Leading portion 42 Coil holding portion (cylindrical body) 42a Inner peripheral surface 42b, 42c Coil attachment portion 43 Terminal binding portion 44, 45 Engaging protrusion 46 Terminal lead-out portion 47 Communication groove portion 50 Outer yoke 51 Yoke body 52 End portion 53, 55 Opening 55a Upper side portion 55b Lower side portion 61, 62 Coil 63, 64 Winding 81, 82 Elastic support portion 111-1, 111-2 Case opening 112-1, 112-2 Case lid portion 114-1, 114-2 Peripheral wall portion 116-1, 116-2 Notch portion 118-1, 118-2 Positioning hole 134 Engagement recess 201 Communication portion 202 Processing portion 203 Drive control portion 232, 252 Weight opening (opening) 312 Connection body 313, 333 Spring fixing portion 314 Support fixing portion 332 Connection body 334 Support fixing portion 412 Coil guide portion 420 Recessed portion 422 Cylindrical main body portion 426, 427, 428 Flange portion 426a Outer periphery 427a, 428a Open end surface 432 Ferret 533 Notch 802 Inner periphery 802a Connection hole 804 Deformable arm 806 Outer periphery 808 Positioning groove

Claims

1. A vibration actuator comprising: a movable body having a disk-shaped magnet, a pair of weight portions which are magnetic bodies fixed to both sides of the magnet in the axial direction, and a pair of spring connection portions provided at both ends in the axial direction; a cylindrical body having an annular coil arranged on the outer periphery and which houses the movable body so that it can vibrate back and forth in the axial direction by a pair of elastic support portions which are spaced apart in the axial direction and connected to the pair of spring connection portions; and a fixed body having a case, wherein the case has a pair of bottomed cylindrical cases each having a case lid portion at one end and a case opening at the other end, each of the pair of bottomed cylindrical cases is placed over the cylindrical body from both sides in the axial direction, and the case openings of the pair of bottomed cylindrical cases are joined together to house the cylindrical body, and the pair of bottomed cylindrical cases are common members having the same shape.

2. A vibration actuator as described in claim 1, wherein each of the pair of bottomed cylindrical cases has a notch on the edge of the case opening, and the terminal connection portion of the cylindrical body is inserted into the notch opening formed by joining the notches together.

3. A vibration actuator as described in claim 1, wherein the elastic support part is disc-shaped, its central part is connected to the spring connection part, and its outer periphery is sandwiched between the open end of the cylindrical body and a spacer part, and is fixed at a distance from the case lid part via the spacer part.

4. A vibration actuator as set forth in claim 3, wherein both open ends of said cylindrical body are provided with protrusions which protrude axially from the respective open ends, pass through said elastic support parts and engage with said spacer parts.

5. A vibration actuator according to claim 4, wherein the spacer portion has a recess with which the protrusion engages to restrict mutual circumferential movement.

6. A handheld or wearable electrical device, comprising a vibration actuator according to any one of claims 1 to 5 mounted on a part that comes into contact with a user.

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