Vibration actuator and electric device

Abstract

This vibration actuator comprises: a movable body having a pillar-shaped magnet and a pair of plate-shaped yokes which are fixed to a rear surface of the magnet in the axial direction; and a fixed body having a pair of annular coils which are disposed radially outward of the movable body and a cylindrical coil holding part which accommodates the movable body, in which the pair of coils are disposed between a pair of flange parts that are provided so as to protrude radially outward from an outer peripheral surface, in which a pair of elastic support parts respectively support both ends of the movable body that are separate from each other in the axial direction, and which accommodates the movable body so as to enable reciprocating vibration in the axial direction. The fixed body has: a cylindrical outer yoke that is disposed between the pair of flange parts and that entirely covers the pair of coils from the radially outer side; and a terminal part that is provided to one of the pair of flange parts so as to protrude radially outward and that is connected to the pair of coils.

Description

Vibration actuator and electrical equipment

[0001] The present invention relates to a vibration actuator and an electrical equipment including the same.

[0002] Conventionally, in electronic devices having a vibration function as electrical equipment, a vibration actuator is mounted as a vibration source. By driving the vibration actuator to transmit vibration to the user for physical sensation, the electronic device can give a stimulus, notify an incoming call, or improve the operation feeling and sense of presence. The electronic device mainly includes portable electrical equipment such as a portable game terminal, a controller (game pad) of a stationary game machine, a portable communication terminal such as a mobile phone or a smart phone, and a portable information terminal such as a tablet PC. In addition, the vibration actuator may be mounted on a wearable terminal or the like that is worn on clothes or arms.

[0003] As a vibration actuator having a miniaturizable structure mounted on a portable device, for example, the configurations shown in Patent Documents 1 to 3 are known.

[0004] Patent Document 1 is a vibration actuator used for a pager or the like. Inside a cylindrical frame body, a movable body is accommodated, and a pair of disk-shaped elastic bodies are respectively attached to the upper and lower openings of the frame body so as to face each other. The movable body is an annular magnetic field generating body having a magnet and a yoke, and is connected at the raised central portion of one of the pair of plate-shaped elastic bodies having a spiral shape. The movable body vibrates in the direction of the center line of the frame body by energizing a coil provided on the other plate-shaped elastic body.

[0005] The vibration actuators of Patent Documents 2 and 3 have multiple coils arranged around a movable part with a magnet in the center, and the movable part is supported via an elastic support so as to move axially by energizing the coils. In particular, these vibration actuators have a yoke or electromagnetic shield arranged around the outer circumference of the multiple coils, in addition to the multiple coils. The yoke of Patent Document 2 increases the horizontal component of the magnetic flux of the magnet, and the electromagnetic shield of Patent Document 3 prevents leakage of magnetic flux to the outside, thereby forming an efficient magnetic circuit. As a result, the vibration actuators of Patent Documents 2 and 3 can ensure higher output vibration than the vibration actuator of Patent Document 1.

[0006] Japanese Patent Publication No. 3748637, Japanese Unexamined Patent Publication No. 2020-54018, Japanese Patent Publication No. 6750825

[0007] Incidentally, there is a need for vibration actuators that can be made smaller while ensuring high output, and that are easy to assemble. In conventional vibration actuators, the vibration actuators shown in Patent Documents 2 and 3 can vibrate with higher output compared to the vibration actuator in Patent Document 1.

[0008] However, in Patent Document 2, when connecting a coil to a terminal that connects the coil to the outside, the coil is placed inside the yoke, a case is attached to the outside of the yoke, and a substrate is placed on the outer surface of the case, and the coil is connected to the placed substrate, which makes the work time-consuming.

[0009] Furthermore, in Patent Document 3, the terminal portion is located on the bottom surface that is attached to the bobbin from below. Therefore, when the bobbin is assembled to the bottom surface, it is necessary to position the coil connection portion on the bobbin, to which the ends of the coil are connected, and the projection on the bottom surface where the terminals are located, so that they are in the same position vertically, which presents a problem as it is a time-consuming process.

[0010] The objective of the present invention is to provide a vibration actuator and electrical equipment that can generate strong vibrations even when miniaturized and are easy to assemble.

[0011] One aspect of the vibration actuator of the present invention comprises: a movable body having a columnar magnet and a pair of plate-shaped yokes fixed to the front and back surfaces of the magnet in the axial direction; a pair of annular coils arranged radially outward of the movable body; and a fixed body having a cylindrical coil holding portion that houses the movable body, wherein the pair of coils are arranged between a pair of flange portions projecting radially outward from the outer peripheral surface, and both ends of the movable body, which are spaced apart in the axial direction by a pair of elastic support portions, the fixed body having a coil holding portion that houses the movable body so as to be able to reciprocate in the axial direction; wherein the fixed body has a cylindrical outer yoke arranged between the pair of flange portions and covering the pair of coils radially outward across their entire surface; and a terminal portion projecting radially outward from one of the flange portions of the pair and connected to the pair of coils.

[0012] One embodiment of the electrical device of the present invention adopts a configuration in which the vibration actuator having the above configuration is implemented.

[0013] According to the present invention, strong vibrations can be generated even when miniaturized, and assembly is highly efficient with high assembly flexibility.

[0014] Figure 1 is an external perspective view of a vibration actuator according to one embodiment of the present invention, viewed from the front. Figure 2 is a front view of the vibration actuator. Figure 3 is a rear view of the vibration actuator. Figure 4 is a top view of the vibration actuator. Figure 5 is a bottom view of the vibration actuator. Figure 6 is a right side view of the vibration actuator. Figure 7 is a left side view of the vibration actuator. Figure 8 is a cross-sectional view taken along line A-A in Figure 2. Figure 9 is an exploded perspective view of the main components of the vibration actuator. Figure 10 is a front view of the drive unit with the cover and bracket removed from the vibration actuator. Figure 11 is an exploded view of the movable body. Figure 12 is a front view of the coil holder where the coil is arranged. Figure 13 is an upper perspective view of the coil holder. Figure 14 is a partial cross-sectional view taken along line B-B in Figure 12. Figure 15 is a front view of the coil holder where the coil is not arranged. Figure 16 is a partial cross-sectional view taken along line C-C in Figure 15. Figure 17 is a schematic diagram showing the magnetic circuit configuration and operation of the vibration actuator. Figures 18A, 18B, and 18C illustrate the flow of magnetic flux in the vibration actuator of this embodiment when it is not moving and when it is moving. Figures 19A, 19B, and 19C illustrate the flow of magnetic flux in the vibration actuator when it is not moving and when it is moving as a reference example. Figure 20 is a diagram showing the winding pattern of the coil in the vibration actuator. Figure 21 is a diagram showing the winding pattern of the coil in the vibration actuator. Figure 22 is a diagram showing the winding pattern of the coil in the vibration actuator. Figure 23 is a diagram showing the winding pattern of the coil in the vibration actuator. Figure 24 is a diagram showing the winding pattern of the coil in the vibration actuator. Figures 25A and 25B illustrate modified examples of the winding path from the terminal to the coil in the vibration actuator. Figures 26A and 26B are diagrams showing modified examples of the coil holding part in the vibration actuator. Figure 27 is a diagram showing an example of the vibration actuator being mounted on electrical equipment. Figure 28 is a diagram showing an example of the vibration actuator being mounted on electrical equipment.

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0016] [Overall Configuration of Vibration Actuator] Figure 1 is an external perspective view of a vibration actuator according to one embodiment of the present invention, viewed from the front. Figure 2 is a front view of the vibration actuator, Figure 3 is a rear view of the vibration actuator, and Figure 4 is a top view of the vibration actuator. Figure 5 is a bottom view of the vibration actuator, Figure 6 is a right side view of the vibration actuator, Figure 7 is a left side view of the vibration actuator, and Figure 8 is a cross-sectional view taken along line A-A in Figure 2. Figure 9 is an exploded perspective view of the main components of the vibration actuator.

[0017] In this embodiment, the terms "upper" and "lower" are merely added for ease of understanding and refer to the axial direction of the movable body in the vibration actuator, i.e., the direction of vibration. In other words, when the vibration actuator is mounted on electrical equipment (for example, the electronic equipment shown in Figures 27 and 28), the orientation (upper and lower) may be reversed or reversed (left and right).

[0018] The vibration actuator 1 is implemented as an electrical device in electronic devices such as portable game terminals (see Figure 27) as a vibration source, realizing the vibration function of the electronic device. This electronic device also includes portable devices such as smartphones (see Figure 28). The vibration actuator 1 is implemented in portable game terminals or other portable devices, and when driven, it vibrates to notify the user of incoming calls or to provide a sense of operation and realism.

[0019] As shown in Figures 1 to 7, the vibration actuator 1 is a columnar vibrating body, and is formed, for example, in a cylindrical shape.

[0020] The vibration actuator 1 is constructed by attaching a lid 4 and a bracket 6 to the upper and lower ends of a drive unit 2, which has a movable body movably housed within a cylindrical body. The vibration actuator 1 is a covered cylindrical body and is formed to correspond to the shape of the mounting position of the electrical equipment on which the actuator 1 is mounted. However, the vibration actuator 1 is not limited to a covered cylindrical body configuration; it may be formed to close both the upper and lower ends of the drive unit 2, or it may have an open shape at both the upper and lower ends.

[0021] Figure 8 is a cross-sectional view taken along line A-A in Figure 2, and Figure 9 is an exploded perspective view of the main components of the same vibration actuator.

[0022] The cover portion 4 closes the upper opening of the drive unit 2 and restricts the movement of the movable body 20 inside the drive unit 2 beyond the range in which the elastic support portions 81 and 82 can be elastically deformed when the movable body 20 moves in the axial direction.

[0023] Bracket 6 is annular in shape and is positioned on the outer circumference of the lower end of the drive unit 2. Bracket 6 is attached to the drive unit 2 so as to surround the opening at the lower end of the drive unit 2 and is formed to correspond to the shape of the mounting position of the electronic equipment on which the vibration actuator 1 is mounted.

[0024] The drive unit 2 includes a columnar movable body 20 having a magnet 22, a cylindrical coil assembly having coils (a pair of coils 61, 62) arranged on the outer circumference of the movable body 20, and plate-shaped elastic support parts 81, 82. The elastic support parts 81, 82 are attached so as to cover both openings (opening ends 461, 471) of the coil holding part 40. In addition to the coils 61, 62, the coil assembly includes a cylindrical bobbin part (cylindrical body part) 42 on which the coils 61, 62 are wound around the outer circumference, and an outer yoke 70 that covers the coils 61, 62. Within the coil assembly, the movable body 20 moves in the axial direction of the movable body 20, which is the direction of vibration, so that the vibration actuator 1 itself functions as a vibrating body.

[0025] In the drive unit 2, the movable body 20 is supported by the coil holding portion 40 via elastic support portions 81 and 82 so as to be able to vibrate in the axial direction, with an annular gap G provided between the inner circumferential surface 42a of the coil holding portion 40 and the outer circumferential surface 20a of the movable body 20.

[0026] Figure 10 is a front view of the drive unit with the cover and bracket removed in the vibration actuator. In the drive unit 2, the outer yoke 70 is arranged to surround the outer circumference of the cylindrical coil holding portion 40.

[0027] The drive unit 2 has terminal portions 5 that protrude from terminal block portions 464 on its outer circumferential surface (outer circumferential surface of coil holding portion 40, outer circumferential surface of flange portion 46) at a portion adjacent to the outer yoke 70 in the axial direction. The windings of coils 61 and 62 (see Figures 8 and 9) are wound around the terminal portions 5, and the terminal portions 5 and the windings are electrically joined by ferrets 610 formed by solder.

[0028] In the drive unit 2, the coils 61 and 62 (see Figures 8 and 9) are connected to an external device via a terminal section (connection section) 5 and receive power from the external device. Details of the terminal section 5 will be described later.

[0029] <Movable body 20> As shown in Figures 8 and 9, the movable body 20 is a columnar body positioned within the coil holding portion 40 of the coil assembly. Within the coil holding portion 40, the movable body 20 is connected to the inner circumference 802 of the elastic support portions 81 and 82 at both ends (upper and lower ends) that are spaced apart in the axial direction, i.e., the vibration direction.

[0030] The movable body 20 is supported so as to be able to reciprocate in the axial direction along the inner circumferential surface 42a of the coil holding portion 40. The movable body 20 can have any planar cross-sectional shape as long as it is columnar. Preferably, the movable body 20 is formed in a cylindrical shape or a polygonal shape that approximates a cylinder, and is shaped in a way that makes it easy to create a gap of a constant width around the entire circumference between it and the inner circumferential surface 42a of the coil holding portion 40 (cylindrical main body portion 42). The outer circumferential surface 20a of the movable body 20 is a smooth surface that has a length that protrudes from the inner circumferential surface 42a of the coil holding portion 40 on both sides in the axial direction over the entire range of motion of the movable body 20.

[0031] Figure 11 is an exploded view of the movable body. The movable body 20 shown in Figure 11 has a magnet 22, a pair of spring retainers 26a and 26b, and a pair of yokes (yokes 24a and 24b) positioned between the magnet 22 and the pair of spring retainers 26a and 26b.

[0032] In this embodiment, the magnet 22 is positioned in the center of the movable body 20 in the direction of vibration, which is the axial direction of the movable body 20, that is, at the center of the movable body 20. On both sides of the magnet 22 in the direction of vibration (the front surface 22a side and the back surface 22b side shown in Figure 8, and the vertical direction in Figure 10), the yokes 24a, 24b and spring retainers 26a, 26b are positioned symmetrically around the magnet 22.

[0033] Specifically, a yoke 24a and a spring retainer 26a are stacked in order on the upper side of the magnet 22 in the direction of vibration, and a yoke 24b and a spring retainer 26b are stacked in order on the lower side of the magnet 22 in the direction of vibration. The magnet 22, yokes 24a and 24b, together with the coils (a pair of coils 61 and 62) and the outer yoke 70, constitute a magnetic circuit that drives the movable body 20 with the axial direction of the pair of coils 61 and 62 (the magnetization direction of the magnet 22) as the direction of vibration.

[0034] In the movable body 20, the outer diameters of the magnet 22, the yokes 24a and 24b, and the large-diameter portions 262 (see Figure 11) of the spring retaining portions 26a and 26b are configured to be the same or approximately the same diameter.

[0035] The outer circumferential surfaces of the magnet 22, the yokes 24a and 24b, and the large-diameter portions 262 of the spring retaining portions 26a and 26b constitute an outer circumferential surface 20a that is flat in the axial direction. As a result, in the movable body 20, the outer circumferential surface 20a facing the inner circumferential surface 42a of the coil holding portion 40 is flush or nearly flush, and has a flat circumferential surface without irregularities.

[0036] The outer diameters of both ends are smaller than the outer diameter of the central part of the movable body. The ends with smaller outer diameters are positioned to protrude vertically in the axial direction from the upper and lower ends of the inner circumferential surface 42a of the coil holding part 40 (cylindrical main body part 42). In other words, both ends of the movable body 20 in the direction of vibration are composed of the small diameter portions 264 of the spring stopper parts 26a and 26b, respectively, and when not in motion, they are located outward in the direction of vibration from both ends of the inner circumferential surface 42a of the coil holding part 40 in the direction of vibration.

[0037] Furthermore, when the movable body 20 is at its maximum amplitude position on both sides in the vibration direction, one of the spring retaining portions 26a and 26b is configured to be located outside the range where it faces the outer yoke 70 in the radial direction.

[0038] The outer circumferential surfaces of the large-diameter portions of the magnet 22, yokes 24a and 24b, and spring retaining portions 26a and 26b face each other at a predetermined distance inside the inner circumferential surface 42a of the coil holding portion 40, even at the drive reference position and the maximum amplitude position. The drive reference position is the reference position when the movable body 20 moves in the direction of vibration, and is, for example, the position located in the center of the vibration direction when the power is not supplied.

[0039] <Magnet 22> The magnet 22 is a solid columnar body (including plate-shaped bodies) that is magnetized in the direction of vibration. For example, in the magnet 22, the front and back surfaces 22a and 22b, which are separated in the direction of vibration, each have different polarities.

[0040] In this embodiment, the magnet 22 is formed in a cylindrical shape (which may also be called a disc shape) in which the diameter (width) is longer than the length (height) in the direction of vibration. The magnet 22 may be processed to have recesses or the like, but if it is a solid cylindrical shape, it can be manufactured at a lower cost compared to a magnet that has recesses or the like. The magnet 22 is, for example, a neodymium sintered magnet. As for processing the magnet 22, the yokes 24a and 24b are joined to the front and back surfaces 22a and 22b by adhesive or the like.

[0041] The magnet 22 is positioned at a distance from the coil (a pair of coils 61, 62) held in the coil holding portion 40 (details will be described later), on the radially inner side of the coil (a pair of coils 61, 62). Here, "radial direction" also refers to the direction perpendicular to the axial direction (vibration direction) of the coil (a pair of coils 61, 62). The magnet 22 is positioned such that the center position of the vibration direction on its radially outer surface and the center position of the vibration direction on the inner circumferential surface 42a of the coil holding portion 40 are opposite each other in the radial direction. The pair of coils 61, 62 will also be referred to as "coils 61, 62" below.

[0042] Note that the interval in the radial direction is the interval between the coils 61 and 62 and the magnet 22 in a state where the cylindrical main body 42 around which the coils 61 and 62 are wound is located inside the coils 61 and 62 in the radial direction and between them and the magnet 22. Also, this interval should be such that the coils 61 and 62 can move without contacting each other in the vibration direction of the movable body 20.

[0043] The magnet 22 may have a shape other than a solid columnar shape such as a cylindrical shape or a plate shape as long as it is arranged inside the coils 61 and 62 with two magnetization surfaces facing the extending direction of the axis of the coils 61 and 62 respectively. Also, it is desirable that the center of the magnet 22 in the axial direction coincides with the center of the movable body 20 in the axial direction.

[0044] <Yokes 24a and 24b> The yokes 24a and 24b are magnetic bodies and are arranged on the front and back surfaces 22a and 22b of the magnet 22 so as to sandwich the magnet 22. The yokes 24a and 24b are formed in a columnar shape (may also be plate-shaped) having a thickness in the axial direction. The yokes 24a and 24b are, for example, formed in a cylindrical shape (may be referred to as a disc shape) having the same diameter as the magnet 22 and each have an outer peripheral surface flush with the outer peripheral surface of the magnet 22. The yokes 24a and 24b are fixed to the front and back surfaces of the magnet 22.

[0045] The yokes 24a and 24b concentrate the magnetic flux of the magnet 22, allow it to flow efficiently without leakage, and effectively distribute the magnetic flux flowing between the magnet 22 and the coils (pair of coils 61 and 62). The yokes 24a and 24b are preferably formed of a metal magnetic body such as SECC (bonded steel sheet).

[0046] Also, in addition to the function as a part of the magnetic circuit, the yokes 24a and 24b may have the function as the main body part of the movable body 20 and the function as a weight in the movable body 20. Further, when joining the spring stoppers 26a and 26b having the same outer diameter, the yokes 24a and 24b have the function of positioning the spring stoppers 26a and 26b with respect to the magnet 22 by aligning the outer diameters.

[0047] In this embodiment, the yokes 24a and 24b are members of the same shape formed in the same manner. The yokes 24a and 24b may be fixed to the magnet 22 by being attracted by the magnet 22, or the yokes 24a and 24b may be fixed to the magnet 22 by a thermosetting adhesive or an anaerobic adhesive such as an epoxy resin. The yokes 24a and 24b are fixed to the spring stoppers 26a and 26b with the above-mentioned adhesive.

[0048] When the movable body 20 is not moving, the yokes 24a and 24b are preferably located inside (radially inward) of the pair of coils 61 and 62, in a direction orthogonal to the vibration direction, and facing the center of the vibration direction of the pair of coils 61 and 62.

[0049] Also, in this embodiment, it is preferable that the height position of the upper surface of the upper yoke 24a of the magnet 22 is located below (toward the center) the position of the upper end of the upper coil 61. In addition, it is preferable that the height position of the lower surface of the lower yoke 24b of the magnet 22 is located above (toward the center) the position of the lower end of the lower coil 62. With this configuration, the yokes 24a and 24b, together with the magnet 22, the coils 61 and 62, and the outer yoke 70, form a suitable magnetic path with less magnetic flux leakage and high magnetic efficiency.

[0050] <Spring stoppers 26a and 26b> The spring stoppers 26a and 26b, also referred to as sleeves, join the movable body 20 to the elastic support portions 81 and 82. The spring stoppers 26a and 26b are provided so as to sandwich the yokes 24a and 24b in the axial direction, respectively, on the front and back surfaces of the magnet 22 in the vibration direction (the magnetization direction of the magnet 22). The spring stoppers 26a and 26b are formed in a cylindrical shape, but are not limited thereto, and may be formed in a frustum shape, a polygonal frustum shape, or a polygonal shape.

[0051] The spring stoppers 26a and 26b are arranged symmetrically in the vibration direction with respect to the center in the vibration direction of the movable body 20.

[0052] The spring retaining portions 26a and 26b are preferably made of a non-magnetic material, such as aluminum, but may also be made of a material with a high specific gravity. If the spring retaining portions 26a and 26b are made of a non-magnetic material, the expansion of the magnetic circuit configuration in the direction of vibration can be suppressed, and the magnetic circuit can be made compact.

[0053] The spring retaining portions 26a and 26b each have a large-diameter portion 262 that is joined to the yokes 24a and 24b, and a small-diameter portion 264 that has a spring joint portion 266 at its tip that is joined to the elastic support portions 81 and 82. Note that the spring retaining portions 26a and 26b are, for example, identical in shape and configuration.

[0054] In the spring retaining portions 26a and 26b, the large-diameter portion 262 and the small-diameter portion 264 are formed continuously in the axial direction and are each formed in a cylindrical shape. The outer diameter of the large-diameter portion 262 is the same as or approximately the same as the yokes 24a and 24b. The small-diameter portions 264 constitute the ends of the movable body 20 that are separated in the direction of vibration, and the outer diameter of these small-diameter portions 264 is smaller than that of the large-diameter portion 262 and smaller than the outer diameter of the central portion of the movable body 20 itself.

[0055] Since the outer diameters of both ends of the movable body 20 are smaller than the outer diameter of the central part, when the movable body 20 moves axially due to the deformation of the elastic support parts 81 and 82, a relief portion is formed for the deformed elastic support parts 81 and 82. This avoids interference between the moving movable body 20 and the elastic support parts 81 and 82, thereby ensuring a suitable range of motion for the movable body 20 and enabling high vibration output.

[0056] The spring joint portion 266 protrudes from the tip of the small-diameter portion 264 and is inserted into and joined to the opening of the inner circumference portion 802, which is the inner diameter end of the elastic support portions 81 and 82. The spring joint portion 266 is joined to the elastic support portions 81 and 82 by crimping, using adhesive, or the like.

[0057] A groove 268 is formed around the protruding spring joint 266 on the tip surface of the small diameter portion 264. Since the spring joint 266 is joined with the spring joint 266 inserted into the opening of the inner circumference portion 802, the inner circumference portion 802 is placed on the tip surface of the small diameter portion during joining. The groove 268 forms an adhesive reservoir when adhesive is used to join the spring stoppers 26a, 26b and the elastic support portions 81, 82.

[0058] Although the spring retaining portions 26a and 26b and the elastic support portions 81 and 82 are joined (fixed to each other) by crimping the spring joint portion 266 to the inner circumference portion 802, they may also be joined to each other by a method that combines welding, bonding, and crimping.

[0059] <Coil Holding Section 40> Figure 12 is a front view of the coil holding section with the coils arranged therein, Figure 13 is an upper perspective view of the same coil holding section, and Figure 14 is a partial cross-sectional view taken along line B-B in Figure 12. Also, Figure 15 is a front view of the coil holding section without the coils arranged therein, and Figure 16 is a partial cross-sectional view taken along line C-C in Figure 15.

[0060] The coil holding portion 40 is formed in a cylindrical shape and holds a pair of coils 61 and 62 with its outer circumferential surfaces 421 and 422 (see Figure 15). The coil holding portion 40 has terminal portions 5 for supplying current to the coils 61 and 62 and supports the internal movable body 20 so that it can move freely via elastic support portions 81 and 82.

[0061] The coil holder portion 40 is a non-magnetic material and is formed from a resin such as phenolic resin or polybutylene terephthalate (PBT). In this embodiment, the coil holder portion 40 is formed from a material containing phenolic resin, such as highly flame-retardant bakelite.

[0062] Since the coil holding portion 40 is made of a material containing phenolic resin, its flame retardancy is enhanced, and even if it generates heat due to Joule heating when current flows through the pair of coils 61 and 62 it holds, safety during operation can be improved. Furthermore, since the coil holding portion 40 can be formed from phenolic resin, dimensional accuracy is improved, and the positional accuracy of the pair of coils 61 and 62 is improved, thereby reducing variations in vibration characteristics.

[0063] The coil holding portion 40 has a cylindrical main body portion 42 arranged on the inner circumference of the coil 61, flange portions 44, 46, and 47, a terminal portion 5, and an engaging projection portion 48. The flange portions 44, 46, and 47 are arranged at predetermined intervals on the outer surface of the cylindrical main body portion 42 and protrude radially from the outer surface.

[0064] The coil holding portion 40 is formed in the shape of a coil bobbin that holds coils 61 and 62, by a cylindrical body portion 42 and flange portions 44, 46, and 47. The coil holding portion 40 has coil arrangement portions 401 and 402 on the outer surface of the cylindrical body portion 42, and between the flange portions 44, 46, and 47, where a pair of coils 61 and 62 are respectively arranged.

[0065] The cylindrical body portion 42 is cylindrical in shape, located radially inward of the pair of coils 61 and 62, and has an inner circumferential surface 42a that faces the outer circumferential surface 20a of the movable body 20 at a predetermined distance (gap G). The inner circumferential surface 42a is the inner circumferential surface of the coil assembly or drive unit 2, and is a flat circumferential surface without irregularities in the axial direction (vibration direction) so that the gap G is maintained at a constant width in the axial direction whether the movable body 20 is moving or not. The gap G is a distance that allows the movable body 20 to move without contact between the outer circumferential surface 20a and the inner circumferential surface 42a when the movable body 20 moves in the vibration direction. The cylindrical body portion 42 guides the movable body 20 so that it can reciprocate along the inner circumferential surface 42a.

[0066] The cylindrical body portion 42 is positioned between the magnet 22 and the pair of coils 61 and 62, preventing contact between the magnet 22 and the pair of coils 61 and 62. In other words, the cylindrical body portion 42 functions as a protective wall to prevent collisions between the movable body 20 and the pair of coils 61 and 62 when the movable body 20 is in motion.

[0067] The coil arrangement sections 401 and 402 are formed on the outer circumferential surfaces 421 and 422 of the cylindrical main body 42, separated by flange sections 44, 46, and 47, and open radially outward from the outer circumferential surfaces 421 and 422 of the cylindrical main body 42. The coil arrangement sections 401 and 402 have a concave shape that extends along the outer circumference of the outer circumferential surfaces 421 and 422 of the cylindrical main body 42.

[0068] A pair of coils 61 and 62 are arranged in a wound state in the concave coil arrangement sections 401 and 402. The coils 61 and 62 in the coil arrangement sections 401 and 402 are arranged to surround the outer surfaces of the yokes 24a and 24b of the movable body 20 (the outer surface of a part of the magnet 22, the outer surface of the yoke 24a, and the outer surface of the yoke 24b). When not energized, the width of the bottom of the coil arrangement sections 401 and 402, i.e., the length in the direction of vibration, is longer than the length in the direction of vibration of the yokes 24a and 24b that sandwich the magnet 22, and the pair of coils 61 and 62 are arranged to cover them.

[0069] <Flange portions 44, 46, 47> Of the flange portions 44, 46, and 47, the central flange portion 44 is formed to protrude radially outward from the outer circumferential surface of the central part of the cylindrical main body portion 42. The flange portion 44 is an annular body having a hollowed-out portion 444. The hollowed-out portion 444 allows the axial length of the coil holding portion 40 itself to be adjusted according to the positional relationship of the coils 61 and 62. In addition, the hollowed-out portion 444 can be made lighter and costs can be reduced.

[0070] The outer diameter of the central flange portion 44 is shorter than the maximum diameter of the other flange portions (flange portions 46 and 47). That is, the outer diameter of the central flange portion 44 is smaller than the outer diameter of the flange portions 46 and 47, and it is positioned recessed from the outer end faces of the flange portions 46 and 47. As a result, recessed portions 462a and 472a are formed on the outer circumference of the coil holding portion 40, recessed radially inward between the outer circumferences of the flange portions 44 and 46. The outer yoke 70 is positioned so that it fits into these recessed portions 462a and 472a. The coil arrangement portions 401 and 402 and the coils 61 and 62 arranged in the coil arrangement portions 401 and 402 are covered by the outer yoke 70.

[0071] The flange portions 46 and 47 (collectively referred to as "flange portions at both ends") are provided at both ends of the cylindrical main body portion 42 that are spaced apart in the axial direction, and constitute the upper and lower ends of the coil holding portion 40.

[0072] The flange portions 46 and 47 each have flange bodies 462 and 472 that protrude radially from the outer circumference of both ends of the cylindrical main body portion 42 in the direction of vibration.

[0073] On the outer circumferences of the respective flange bodies 462 and 472, the opposing and circumferentially extending outer edges 462a and 472a (see Figure 15) have steps formed that are the same diameter as the outer circumference of the central flange portion 44. Preferably, the stepped surfaces of these steps have the same outer diameter as the outer diameter of the outer surface of the flange portion 44. Together with the outer surface of the flange 44, the stepped surfaces form a recessed portion into which the outer yoke 70 is fitted.

[0074] The flange bodies 462 and 472 of the flange portions 46 and 47 are formed in a cylindrical shape with openings in a direction away from the central flange portion 44, for example, in the vertical direction. Elastic support portions 81 and 82 are fixed at the opening ends of the flange portions 46 and 47, that is, at the upper and lower ends.

[0075] As shown in Figures 12 to 16, the flange portions 44, 46, and 47 each have a terminal block portion 464 on which the terminal portion 5 is arranged, a guide groove portion 468 for guiding the winding extending from the terminal portion 5, and a groove-shaped connecting groove portion 446 for guiding the winding between the coils 61 and 62.

[0076] A terminal block portion 464 and a guide groove portion 468 are provided on the outer circumferential surface of one of the flange portions 46 and 47 at both ends of the coil holding portion 40. In addition, a connecting groove portion 446 is provided on the central flange portion 44.

[0077] Multiple terminal block sections 464 are formed projecting radially outward from the outer circumferential surface of the annular flange body 462 of the flange 46. The terminal block sections 464 are formed, for example, as rectangular parallelepipeds with their width parallel to the tangent to the outer circumference of the flange section 44. Terminal sections 5 (5a, 5b) are provided projecting from the tip surface (protruding end surface) of each terminal block section 464.

[0078] The terminal block section 464 has a recessed portion (press-fit area) for fixing the terminal section 5, so the terminal section 5 can be firmly held and can be stably fixed when the terminal section 5 is assembled to the coil holding section 40.

[0079] Each of the terminal portions 5 (5a, 5b) is a conductive pin-shaped terminal, and is arranged so that its base end is embedded in the flange 46 and its tip end protrudes. The terminal portions 5 (5a, 5b) may be provided in the flange portion 46 by press-fitting, or they may be provided in the flange portion 46 by insert molding into the coil holding portion 40.

[0080] The terminal sections 5 (5a, 5b) function as connector connection sections for connecting to external equipment. The terminal sections 5 (5a, 5b) connect the coils 61, 62 to external equipment that functions as an AC power supply unit, etc. (other than the main body of the vibration actuator, for example, a power supply unit such as a drive control unit), enabling the supply of power (for example, AC voltage, etc.) from the external equipment to the coils 61, 62. As a result, the pair of coils 61, 62 can generate thrust between themselves and the magnet, allowing them to move toward and away from each other in their respective axial directions.

[0081] The terminals 5 (5a, 5b) are connected to the windings 602 and 604 at both ends of a single winding that constitutes coils 61 and 62, respectively, by being intertwined. As described above, the terminals 5 and the windings 602 and 604 at both ends of the winding are electrically connected via a ferret 610 (see Figures 1 and 10).

[0082] The guide groove 468 is a groove that opens axially between the terminal block sections 464 and is formed continuously above the flange body 462 and the coil arrangement section 401.

[0083] The upper part of the flange portion 46 is provided with a notch 467, which is formed by cutting out a section from near the base end of the terminal portion 5 in a direction perpendicular to the protruding direction of the terminal portion 5.

[0084] A protruding piece 465 is provided adjacent to the notch 467, and the protruding piece 465, together with the terminal block portion 464, partitions the guide groove portion 468. The winding is hooked onto the notch 467 (more specifically, the corner portion formed by the notch 467 and the protruding piece 465), and the winding is hooked onto it in a direction different from the direction of extension toward the terminal portion 5. That is, the notch 467 hooks onto the windings of the coils 61 and 62 connected to the terminal portion 5, changes the direction of extension of the winding, and guides the winding to the coil arrangement portion 401 (or coil arrangement portion 402, connecting groove portion 446, guide groove portion 468, etc.). Note that the corners of the notch 467 (467a, 467b) are rounded.

[0085] The notch 467 passes through the portion of the winding 602 at the terminal, which is joined by wrapping its tip 602a around the terminal portion 5a. The notch 467 and the corner of the protruding piece 465 engage with the passed winding 602, and guide the base end side portion 602b of the winding into the guide groove portion 468. In this way, the guide groove portion 468 is located in the flange portion 46, adjacent to the notch 467 in the circumferential direction, penetrates vertically, and is provided continuously with the lower coil arrangement portion 401.

[0086] The base end portion 602b of the winding, which passes through the guide groove portion 468, is guided to the coil arrangement portion 401 and forms the coil 61 within the coil arrangement portion 401.

[0087] The connecting groove 446 is formed on the outer circumference of the central flange portion 44, opening radially outward and penetrating along the vibration direction (axial direction). The connecting groove 446 functions as a positioning element for the outer yoke 70 on the flange portion 44 and is covered by the outer yoke 70.

[0088] The connecting groove 446 is formed in the central flange portion 44 directly below the guide groove 468 and on the extension of the guide groove 468, and opens in the same direction as the guide groove 468. Tapered edges 442 are formed on the upper and lower opening edges of the connecting groove 446. The tapered edges 442 suitably guide the windings connecting the coil arrangement portions 401 and 402 into the connecting groove 446 so as not to become loose.

[0089] In this way, in the coil holding section 40, the terminal windings 602 and 604, which are wrapped around and connected to the terminal sections 5a and 5b, are each passed through the notch 467 and routed to the back of the protruding piece 465, and then passed through the guide groove 468 and positioned on the coil 61. As a result, the terminal windings 602 and 604 are wired so that the load of the windings is applied to the protruding piece 465, etc., until they are connected to the terminal section 5.

[0090] When the coil 61 (62) is arranged by winding the windings within the coil arrangement section 401 (402), the winding 602 (or winding 604) at the end that is wrapped around the terminal section 5 will be pulled. However, the winding that is being pulled has its direction of extension changed by being caught on corners or protruding pieces 465 by the notches 467, etc., before reaching the terminal section 5, so the pulling force is not transmitted to the terminal section 5 itself. As a result, no pulling force is applied to the terminal sections 5a and 5b via the windings.

[0091] Within the coil arrangement sections 401 and 402, the windings forming coils 61 and 62 are led out through the connecting groove section 446 into the lower coil arrangement section 402, forming coil 62. The tip 608 of the winding extending from the portion forming coil 62 passes through the connecting groove section 446 of the flange section 44 and is hooked onto the edge portion of the connecting groove section 446 (the edge portion in the winding direction), extending circumferentially (in the winding direction) along the outer circumference of coil 61 from above the taper 442. The tip 608 on coil 61 moves upward and is connected to the terminal section 5b as the terminal winding 604.

[0092] In this embodiment, the winding direction of the coil windings forming coils 61 and 62 is reversed in the connecting groove 446 so that it is in opposite directions above and below the connecting groove 446. Then, in the coil arrangement sections 401 and 402, the coil windings are wound in the inverted direction above and below to arrange the pair of coils 61 and 62. At this time, the windings 606 and 608 (see Figure 13) are securely engaged with the connecting groove 446 to form coils 61 and 62, so that they do not come off the connecting groove 446, with a portion of them remaining engaged. As a result, the windings 606 and 608 are suitably guided by the connecting groove 446 from one coil arrangement section 401 and 402 to the other. Therefore, the pair of coils 61 and 62 can be easily assembled to the coil holding section 40 using the windings of a single coil.

[0093] The engaging projection 48 positions and engages the drive unit 2 with the cover portion 4 and the bracket 6. The engaging projection 48 is provided protruding in the vibration direction (vertical direction) at the upper and lower ends of the coil holding portion 40, that is, at the upper and lower annular opening ends 461 and 471 of the flange portions 46 and 47 (referred to as the "openings of the coil holding portion 40," respectively).

[0094] As shown in Figure 9, the engaging projections 48 engage with the recesses of the lid 4 and the recess 6b of the bracket 6 (see Figure 9), respectively. Multiple engaging projections 48 are provided at equal intervals around the axis of the coil holding portion 40, corresponding to the recesses of the lid 4 and the bracket 6.

[0095] The engaging projection 48 positions the drive unit 2 radially and in the vibration direction relative to the cover 4 and bracket 6, and also positions the elastic support portions 81 and 82 that are sandwiched between the drive unit 2 and the cover 4, and between the drive unit 2 and the bracket 6, in the radial direction.

[0096] The engaging projection 48 engages with the positioning groove 809 (see Figure 9) of the elastic support parts 81 and 82, thereby positioning the elastic support parts 81 and 82 relative to the coil holding part 40. This allows for a uniform and stable positioning of the elastic support parts 81 and 82 relative to the coil holding part 40 in each individual drive unit 2. As a result, the movement of the elastic support parts 81 and 82 in the rotational direction is restricted, suppressing variations in the elastic support parts 81 and 82 in the product and achieving stable characteristics.

[0097] <Coils 61, 62> The pair of coils 61 and 62 are energized when the vehicle is moving (vibrating) and together with the magnet 22, they constitute a voice coil motor. The pair of coils 61 and 62 are provided in the coil arrangement sections 401 and 402 and are positioned symmetrically with respect to the magnet 22 in the direction of vibration with respect to the movable body 20 which has the magnet 22, yoke 24a and yoke 24b, etc.

[0098] It is preferable that the center position of the length of coils 61 and 62 in the direction of vibration, that is, the center position of the length between the upper end of coil 61 and the lower end of coil 62, is the same position (including approximately the same position) in the direction of vibration as the center position of the length of the movable body 20 (especially the magnet 22) in the direction of vibration.

[0099] Furthermore, coils 61 and 62 are constructed by winding the wire of a single coil in opposite directions to each other, and when energized, current flows in opposite directions through coils 61 and 62.

[0100] <Outer Yoke 70> The outer yoke 70 is a cylindrical magnetic material and, as shown in Figures 1 to 3 and Figures 6 to 10, is positioned to surround the outer circumferential surface of the coil holding portion 40 and to cover the pair of coils 61 and 62 radially outward.

[0101] As described above, the outer yoke 70, together with the pair of coils 61 and 62, constitutes the magnetic circuit on the stationary side, and together with the magnetic circuit on the movable side, that is, the magnet 22, yoke 24a, and yoke 24b, constitutes the magnetic circuit.

[0102] The outer yoke 70 is formed in a cylindrical shape without any notches. The outer yoke 70 is formed, for example, from SECC (electro-galvanized steel sheet), which has excellent weldability and corrosion resistance.

[0103] The outer yoke 70 is formed from a conductive plate-like material into a cylindrical shape, with engaging portions (dovetail groove portion 762, dovetail tenon portion 764) and engaged portions (dovetail tenon portion 742, dovetail groove portion 744, dovetail tenon portion 746) formed at both ends. As a result, the outer yoke 70 is a cylindrical magnetic body with upper and lower sides and no openings.

[0104] The outer yoke 70 is positioned between a pair of flange portions 46 and 47 and covers the pair of coils 61 and 62 radially outward, with a cylindrical body that has no openings and covers the entire surface.

[0105] The outer yoke 70 is fitted into the recessed portions 462a and 472a between the flanges 46 and 47 in the coil holding portion 40, covering the coils 61 and 62 from the outer circumference. The outer yoke 70 can increase the thrust constant in the magnetic circuit and improve the electromagnetic conversion efficiency. The outer yoke 70 functions as a magnetic spring together with the magnet 22, utilizing the magnetic attraction force of the magnet 22. The outer yoke 70 can reduce the stress on the elastic support portions 81 and 82 when they are made into mechanical springs, thereby improving the durability of the elastic support portions 81 and 82.

[0106] The vertical height of the outer yoke 70 is positioned above the upper end of the coil 61 and below the height of the lower end of the coil 62. Furthermore, when the movable body 20 moves, the vertical height of the outer yoke 70 is positioned higher and lower, respectively, than the upper and lower surfaces of the pair of yokes 24a and 24b fixed to the front and back surfaces of the magnet 22 of the movable body 20. The outer yoke 70 is configured to have a length that covers both ends of the movable area in the vibration direction of the laminate formed by stacking the magnet 22, yoke 24a, and yoke 24b.

[0107] <Elastic support parts 81, 82> The elastic support parts 81 and 82 shown in Figures 8 and 9 support the movable body 20 so that it can reciprocate in the vibration direction relative to the fixed body 40. The elastic support parts 81 and 82 are mounted parallel to each other, spanning both ends (upper and lower ends) of the coil holding part 40 that are spaced apart in the vibration direction of the movable body 20 and both ends of the movable body.

[0108] The elastic support parts 81 and 82 are spiral-shaped springs formed in a disc shape, with an annular inner circumference 802 which is the inner spring end and an annular outer circumference 804 which is the outer spring end, joined together by a deformable arm 806 which is an arc shape in plan view and is elastically deformed and arranged in a spiral shape.

[0109] Due to the deformation of the deformable arm 806, the elastic support portions 81 and 82 are displaced relatively in the axial direction, with the inner circumference 802 and the outer circumference 804 being displaced.

[0110] In this embodiment, the pair of elastic support parts 81 and 82 are arranged so that the directions of rotation of the vortices are opposite to each other. Furthermore, the pair of elastic support parts 81 and 82 are identical components having similar configurations.

[0111] The inner circumference 802 has a connecting hole located in the center of the elastic support portions 81 and 82, into which the spring joint portion 266 of the movable body 20 is fitted and joined.

[0112] The outer periphery 804 is fixed to the upper and lower ends of the coil holding portion 40, that is, the open ends 461 and 471 of the flange portions 46 and 47, with the engaging projection 48 engaged in the positioning recess 809, for example by bonding with an adhesive. Alternatively, the outer periphery 804 may be fixed in a state where the engaging projection 48 is engaged in the positioning groove 809 and the outer periphery 804 is sandwiched between the open ends 461 and 471 and the internal stepped portion 4a of the lid portion and the internal stepped portion 6a of the bracket 6.

[0113] The elastic support parts 81 and 82 are made of thin, flat, disc-shaped spiral springs formed from phosphor bronze, which has high workability, excellent corrosion resistance, and high tensile strength and wear resistance. However, they may be made from any material that is elastically deformable. Furthermore, if they are made from a non-magnetic material such as phosphor bronze, the flow of magnetic flux in the magnetic circuit will not be disturbed at all. In this embodiment, the pair of elastic support parts 81 and 82 may be joined to the coil holding part 40 and the movable body 20 in a direction in which the spiral direction is the same.

[0114] <Operation of Vibration Actuator 1> The operation of the vibration actuator 1 based on its magnetic circuit configuration will be explained with reference to Figure 17. Figure 17 is a schematic diagram showing the magnetic circuit configuration of the vibration actuator.

[0115] The operation of the vibration actuator 1 will be explained using the example of a case where the magnet 22 is magnetized such that the surface 22a on one side in the magnetization direction (upper side in this embodiment) is the north pole, and the back surface 22b on the other side in the magnetization direction (lower side in this embodiment) is the south pole.

[0116] In the vibration actuator 1, the movable body 20 is considered to correspond to the mass portion in a spring-mass vibration model. Therefore, if 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 position (maximum amplitude value) and maximum displacement of the movable body 20 at the time of resonance do not vary, resulting in the output of a vibration with a suitable and stable maximum displacement.

[0117] In the vibration actuator 1, a magnetic flux flow mf is formed when it is not in operation and no power is supplied. The magnetic flux flow mf is emitted from the surface 22a side of the magnet 22, radiated from the yoke 24a towards the coil 61 side, passes through the outer yoke 70, passes through the coil 62 and the yoke 24b, and enters the magnet 22 from the back surface 22b side.

[0118] Therefore, as shown in Figure 17, when current is applied, the interaction between the magnetic field of the magnet 22 and the current flowing through the coils (a pair of coils 61 and 62) generates a Lorentz force in the -f direction on the pair of coils 61 and 62 according to Fleming's left-hand rule. Since the coils (a pair of coils 61 and 62) are fixed to the stationary body 40 (coil holder 40), according to the law of action and reaction, a force opposite to this -f direction Lorentz force is generated as a thrust in the F direction on the movable body 20 having the magnet 22. As a result, the movable body 20 moves in the F direction, that is, towards the lid 4.

[0119] Furthermore, when the energizing direction of the pair of coils 61 and 62 is switched to the opposite direction and energized, a Lorentz force in the opposite direction f is generated. When a Lorentz force in the direction f is generated, according to the law of action and reaction, a force opposite to this Lorentz force in the direction f is generated as a thrust (a thrust in the -F direction) on the movable body 20, and the movable body 20 moves in the -F direction, that is, towards the bracket 6 side of the case body 11. In addition, in the vibration actuator 1, when it is not moving and energized, a magnetic attractive force acts between the magnet 22 and the outer yoke 70, and they function as magnetic springs. Due to this magnetic attractive force generated between the magnet 22 and the outer yoke 70, and the restoring force of the elastic support parts 81 and 82 that tries to return to their original shape, the movable body 20 returns to its original position.

[0120] The vibration actuator 1 is driven by an alternating current wave input from a power supply unit (for example, the drive control unit 203 shown in Figures 27 and 28) to a pair of coils 61 and 62. In other words, the direction of current flow in the pair of coils 61 and 62 is periodically switched, and the movable body 20 is subjected to alternating thrusts in the F direction on the lid 4 side and in the -F direction on the bracket 6 side.

[0121] As a result, the movable body 20 vibrates in the direction of vibration. Regarding the driving of the movable body 20 by generating a resonance phenomenon in the vibration actuator 1, for example, the driving principle is explained in Patent Document 3, using equations of motion and circuit equations. This driving principle is applicable to this embodiment.

[0122] <Effect> In the vibration actuator 1, the magnet 22 and yokes 24a and 24b are surrounded radially outward by coils 61 and 62, and a cylindrical outer yoke 70 without an opening is positioned radially outward of these coils 61 and 62, surrounding the coils 61 and 62.

[0123] The outer yoke 70 is a cylindrical magnetic body with upper and lower edges and no openings, and completely covers the coils 61 and 62 from the radially outer side. As a result, the outer yoke 70 functions as an electromagnetic shield, preventing leakage of magnetic flux to the outside in the magnetic circuit, reducing magnetic flux leakage, and enabling efficient driving of the movable body.

[0124] Figures 18A, 18B, and 18C illustrate the magnetic flux flow in the immobile and moving states of the vibration actuator of this embodiment. Specifically, Figure 18A is the outer yoke 70 of this embodiment, Figure 18B shows the magnetic distribution in the immobile state, and Figure 18C shows the magnetic (magnetic flux) distribution in the moving state (when the movable body 20 has moved upward). Furthermore, Figures 19A, 19B, and 19C illustrate the magnetic flux flow in the immobile and moving states of a vibration actuator as a reference example. Specifically, Figure 19A shows an example of an outer yoke with an opening, and Figure 19B shows the magnetic (magnetic flux) distribution in the immobile state when the outer yoke of Figure 19A is used in the configuration of the vibration actuator. Furthermore, Figure 19C shows the magnetic distribution in the moving state (when the movable body 20 has moved upward) in the same case.

[0125] As shown in Figure 18, in both the immobile and mobile states, the magnet 22 of the vibration actuator 1 attracts the outer yoke 70 equally on both sides, resulting in a balanced state. As a result, in the vibration actuator 1, the movable body 20 moves in the direction of vibration, that is, in the axial direction, i.e., moves back and forth in a linear fashion parallel to the inner circumferential surface 42a, and vibrates appropriately.

[0126] In contrast, Figures 19B and 19C show the magnetic flux distribution in the immobile and mobile states of a vibration actuator using the outer yoke 700 shown in Figure 19A. When using an outer yoke 700 with an opening, as shown in Figure 19B, even in the immobile state, the magnetic circuit is unbalanced because the area with the opening 701 and the other areas attract each other unevenly (uneven left-right in the figure).

[0127] As shown in Figure 19B, when the opening 701 is present, there is less magnetic flux intersecting the coils 61 and 62. Furthermore, as shown in Figure 19C, when in a movable state, it is less balanced than in a non-movable state and moves in a tilted position. In Figure 19C, when the opening 701 is present, the flow of magnetic flux is weaker only on the lower side of the hole. For this reason, the gap G between the movable body 20 and the inner surface of the coil holding part 40 on its outer circumference needs to be wider than when an outer yoke without a hole is used, and the actuator itself also becomes larger.

[0128] Thus, in the vibration actuator 1, the outer yoke 70 that receives the magnetic force generated by the magnet 22 does not have an opening, and the pair of coils 61 and 62 are completely covered from the radially outer side.

[0129] This increases the efficiency of the magnetic circuit, enabling strong vibrations over a wide frequency range. Furthermore, magnetic balance can be maintained whether the vibration actuator 1 is stationary or in motion, causing the movable body 20 to move perpendicular to the vibration direction, and making it less likely for the outer diameter (outer surface 20a) of the movable body 20 to come into contact with the inner diameter (inner surface 42a) of the fixed body.

[0130] Therefore, the gap between the magnet 22 of the movable body 20, that is, between the outer surface 20a and the inner surface 42a of the movable body 20, can be reduced. This also reduces the distance between the magnet 22 and the coils 61, 62 and outer yoke 70 of the fixed body, allowing for strong vibrations to be obtained over a wide frequency range. Furthermore, the volume of the movable body 20 can be increased, allowing for even stronger vibrations to be obtained.

[0131] <Example of coil assembly> In the vibration actuator 1, the terminal portion 5 is located at the end (upper end) of the coil holding portion 40, so there are several possible patterns for forming multiple coils 61 and 62 in the coil holding portion 40.

[0132] Figures 20 to 24 show the winding patterns 1 to 5 of the coil in a vibration actuator.

[0133] For example, in winding pattern 1 shown in Figure 20, in the coil holding section 40, the end of the winding is first wrapped around (or temporarily fixed somewhere) one of the terminal sections 5 and passed through the guide groove section 468. Next, in the coil arrangement section 401, the winding is wound around the outer surface 421 until it becomes N-1 layers, which is one less layer than the multiple N layers (composed of N turns) that form the coil 61. After that, the winding is passed through the connecting groove section 446 and guided to the coil arrangement section 402 below.

[0134] The winding is wound in N layers on the outer surface 422 at the coil arrangement section 402 to form a coil 62 (N layers) in the coil arrangement section 402. Next, the winding is wound in one layer at the coil arrangement section 401 through the connecting groove section 446 to form a coil 61, and then wrapped around the terminal section 5.

[0135] Alternatively, as shown in winding pattern 2 in Figure 21, the coil may be formed starting from the lower coil 62 in the coil holding section 40. In Figure 21, after wrapping one end of the winding around the terminal section 5, the winding 601 is wound once in the coil arrangement section 401 and passed through the connecting groove section 446 to the lower coil arrangement section 402 (2 phases). The winding is wound in N layers within the coil arrangement section 402 to form coil 62, and then the winding is passed through the connecting groove section 446 and wound in N layers in the coil arrangement section 401 to form coil 61, and the other end is wrapped around the remaining terminal section 5.

[0136] As shown in winding pattern 3 in Figure 22, the winding 601 wrapped around one terminal portion 5 extends downward along the axial direction from the guide groove portion 468, crosses the coil arrangement portion 401, passes through the connecting groove portion 446, and reaches the coil arrangement portion 402 (2 phase). Next, the winding that has been passed to the 2 phase portion, i.e., the coil arrangement portion 402, is wound in N layers within the coil arrangement portion 402 to form a coil 62, and is led out to the coil arrangement portion 401 through the connecting groove portion 446. In the coil arrangement portion 401, a coil 61 is formed by winding in N layers, and the end extending from the coil 61 is wrapped around the remaining terminal portion.

[0137] As shown in winding pattern 4 in Figure 23, in the coil holding section 40, the end of the winding is wrapped around the terminal section 5, passes through the guide groove section 468, and is wound in N layers within the coil arrangement section 401 to form coil 61. The winding leading out from coil 61 passes through the connecting groove section 446 and reaches the two-phase coil arrangement section 402, where it is wound in N layers around the outer surface 422 to form coil 62. After that, the winding passes through the connecting groove section 446 and is wound once on the outer surface of coil 61 within the coil arrangement section 401 (indicated by winding 609) and wrapped around the terminal section 5.

[0138] Furthermore, as shown in the winding pattern in Figure 24, in the coil holding section 40, the ends of the windings are wrapped around the terminal section 5, passed through the guide groove section 468, and wound in N layers within the coil arrangement section 401 to form coil 61. The windings leading out from coil 61 pass through the connecting groove section 446 and reach the two-phase coil arrangement section 402, where they are wound in N layers around the outer surface 422 to form coil 62. After that, the windings extend linearly upward through the connecting groove section 446 and are wrapped around the terminal section 5.

[0139] In the vibration actuator 1, the guide groove 468 formed in the flange portion 46 of the coil holding portion 40 is configured such that the windings from the terminals wrapped around the terminal portions 5 (5a, 5b) extend straight down and are parallel to each other, but this is not limited to this configuration.

[0140] In the vibration actuator 1, the ends of the windings are wired in parallel within the connecting groove 446, so even if the movable body 20 vibrates, they do not interfere with each other, thus improving durability.

[0141] Figures 25A and 25B illustrate a modified example of the winding path from the terminal to the coil in a vibration actuator.

[0142] As shown in Figures 25A and 25B, the windings extending downward from the upper end of the guide groove 468 may be arranged in paths that cross each other, as indicated by the dashed line Y1. This allows the windings forming coils 61 and 62 to be easily wound in layers or around in any direction in the circumferential direction within the coil arrangement section 401, regardless of whether they are led out from the terminal sections 5a or 5b.

[0143] Specifically, the winding 604, which is wrapped around the terminal portion 5a and led out upward from the terminal portion 5a, passes through the notch portion 467a and the back surface of the protruding piece 465a, and is locked into the corner formed by the notch portion 467a and the protruding piece 465a, and extends downward. The extended winding 604 is guided through the guide groove portion 468 to the opening edge on the other terminal portion 5b side, and is locked at the opening edge before reaching the coil arrangement portion 401.

[0144] The terminal winding 602, which is wrapped around the terminal portion 5b and leads out upward from the terminal portion 5b, passes through the notch portion 467b and the back surface of the protruding piece 465b, locks into the notch portion 467b, and extends downward. The extended winding 604 extends through the guide groove portion 468 to the opening edge on the other terminal portion 5b side, and, while being locked at the opening edge, reaches into the coil arrangement portion 401.

[0145] <Modified Coil Holding Part> Figures 26A and 26B show modified coil holding parts in a vibration actuator.

[0146] As shown in Figures 26A and 26B, the coil holding portion 40A may be arranged such that the guide groove portion 468 (indicated by portion X1) and the connecting groove portion 446 (indicated by portion X2) are 180 degrees opposite each other (opposite sides on the front and back surfaces) with respect to the axis.

[0147] <Electronic Devices> Figures 27 and 28 show examples of mounting configurations for the vibration actuator 1. Figure 27 shows an example of the vibration actuator 1 being mounted on a game controller GC, and Figure 28 shows an example of the vibration actuator 1 being mounted on a mobile terminal M.

[0148] The Game Controller GC is connected to the game console, for example, via wireless communication, and is used by the user by gripping or holding it. In Figure 27, the Game Controller GC has a rectangular plate shape, and the user operates it by grasping both sides of the Game Controller GC with both hands.

[0149] The Game Controller GC notifies the user of commands from the game console via vibration. Although not shown in the diagram, the Game Controller GC also includes functions other than command notification, such as an input control unit for the game console.

[0150] Mobile device M is, for example, a mobile communication device such as a cell phone or a smartphone. Mobile device M notifies the user of incoming calls from external communication devices through vibration, and also enables various functions of mobile device M (for example, functions that provide a sense of operation and realism).

[0151] As shown in Figures 27 and 28, 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 acting as drive units. In the game controller GC, multiple vibration actuators 204 and 205 are implemented.

[0152] In the game controller GC and the portable terminal M, it is preferable that the vibration actuators 204 to 206 are mounted such that, for example, the main surface of the terminal and the surface perpendicular to the vibration direction of the vibration actuators 204 to 206, in this case the bottom surface of the bracket 6, are parallel. The main surface of the terminal is the surface that contacts the user's body surface, and in this embodiment, it means the vibration transmission surface that contacts the user's body surface and transmits vibrations. Alternatively, the main surface of the terminal and the bottom surface of the bracket 6 of the vibration actuators 204, 205, and 206 may be arranged perpendicular to each other.

[0153] Specifically, in the Game Controller GC, vibration actuators 204 and 205 are mounted so that the vibration direction is perpendicular to the surface that the user's fingertips, fingertips, and hand make contact with, or the surface on which the control unit is located. In the case of the mobile terminal M, vibration actuator 206 is mounted so that the vibration direction is perpendicular to the display screen (touch panel surface). As a result, vibrations perpendicular to the main surface of the Game Controller GC and the mobile terminal M are transmitted to the user.

[0154] The communication unit 201 is connected to an external communication device via wireless communication and receives signals from the communication device, outputting them to the processing unit 202. In the case of the Game Controller GC, the external communication device is the game console itself, which acts as an information communication terminal, and communication is performed according to a short-range wireless communication standard such as Bluetooth®. In the case of the mobile terminal M, the external communication device is, for example, a base station, and communication is performed according to a mobile communication standard.

[0155] 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 it to the drive control unit 203. In the mobile terminal M, the processing unit 202 generates the drive signal based on signals input from the communication unit 201 as well as signals input from various functional units (not shown, for example, operation units such as a touch panel).

[0156] The drive control unit 203 is connected to the vibration actuators 204, 205, and 206, and has circuits implemented to drive the vibration actuators 204, 205, and 206. The drive control unit 203 supplies drive signals to the vibration actuators 204, 205, and 206.

[0157] The vibration actuators 204, 205, and 206 are driven according to the 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 surface of the game controller GC and the mobile terminal M.

[0158] Since vibrations perpendicular to the body surface are transmitted to the user's body surface when they come into contact with the game controller GC or mobile device M, sufficient tactile vibrations can be provided to the user. With the game controller GC, tactile vibrations can be provided to the user by one or both of the vibration actuators 204 and 205, and highly expressive vibrations can be provided, such as selectively applying vibrations of varying strengths.

[0159] Although the present invention has been specifically described above based on embodiments, the present invention is not limited to the above embodiments and can be modified without departing from its spirit.

[0160] Furthermore, the vibration actuator according to the present invention may be implemented in the user contact area of ​​portable devices other than the game controller GC and the mobile terminal M (for example, portable information terminals such as tablet PCs, portable game terminals, etc.). That is, the vibration actuator 1 may be implemented in the user contact area of ​​handheld electrical devices such as mobile terminals and electric beauty and grooming devices such as facial massagers. The vibration actuator 1 may also be implemented in the user contact area of ​​a wearable terminal that is worn and used by the user. In the case of handheld electrical devices such as the game controller GC, the user contact area is, for example, the handle that the user grips when using it. In the case of wearable electrical devices such as facial massagers, the user contact area is, for example, the pressure area that applies pressure to the user's body surface.

[0161] All disclosures in the specification, drawings, and abstract contained in the Japanese application No. 2024-218924, filed on 13 December 2024, are incorporated herein by reference.

[0162] The vibration actuator according to the present invention generates strong vibrations even when miniaturized, is easy to assemble and can be assembled efficiently, and is useful for mounting in electronic devices such as game consoles that provide vibrations to the user, exciters that produce sound as vibration devices, or mobile terminals.

[0163] 1 Vibration actuator, 2 Drive unit, 4 Cover, 4a, 6a Internal stepped section, 5, 5a, 5b Terminal section, 6 Bracket, 6b Recess, 11 Case body, 20 Movable body, 20a Outer surface, 22 Magnet, 22a Front surface, 22b Back surface, 24a, 24b Yoke, 26a, 26b Spring stopper section, 40, 40A Coil holding section, 42 Cylindrical body section, 42a Inner surface, 44, 46, 47 Flange section, 48 Engaging projection, 61, 62 Coil, 70 Outer yoke, 81, 82 Elastic support section, 201 Communication section, 202 Processing section, 203 Drive control section, 262 Large diameter section, 264 Small diameter section, 266 Spring joint section, 268 Groove section, 401, 402 Coil arrangement section, 421, 422 Outer surface, 442 Taper, 444 Hollow section, 446 Connecting groove section, 461, 471 Open end, 462, 472 Flange body, 462a Outer edge section, 464 Terminal block section, 465, 465a, 465b Projecting piece, 467, 467a, 467b Notch section, 468 Guide groove section

Claims

1. A vibration actuator comprising: a movable body having a columnar magnet and a pair of plate-shaped yokes fixed to the front and back surfaces of the magnet in the axial direction; a pair of annular coils arranged radially outward of the movable body; and a fixed body having a cylindrical coil holding portion that houses the movable body, wherein the pair of coils are arranged between a pair of flange portions projecting radially outward from the outer peripheral surface, and both ends of the movable body, which are spaced apart in the axial direction by a pair of elastic support portions, the fixed body having a cylindrical outer yoke arranged between the pair of flange portions and covering the pair of coils radially outward and on their entire surface; and a terminal portion projecting radially outward from one of the flange portions of the pair and connected to the pair of coils.

2. The vibration actuator according to claim 1, wherein one flange portion has a notch that hooks onto the winding of the coil connected to the terminal portion, changes the direction of extension of the winding, and guides the winding to the coil arrangement portion.

3. The vibration actuator according to claim 2, wherein the notch is provided in one flange portion above the terminal portion, and a groove is provided adjacent to the notch in the circumferential direction, penetrating vertically and continuous with the coil arrangement portion below.

4. A recessed portion is formed between the pair of flange portions, into which the outer yoke fits so as to cover the pair of coils, as described in claim 1.

5. An electrical device equipped with the vibration actuator described in claim 1.

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