Vibration actuator and electronic apparatus

Abstract

The invention provides a vibration actuator and an electronic apparatus including the same. The vibration actuator includes: a fixed body having a coil; a movable body having a disc-shaped magnet disposed on the inside in the radial direction of the coil so as to be relatively movable in an oscillation direction orthogonal to the radial direction; and an upper plate spring and a lower plate spring which are elastic support parts that support the movable body so that the movable body is movable with respect to the fixed body. And an upper-side plate spring and a lower-side plate spring which are provided between the fixed body and the movable body so as to sandwich the movable body in the vibration direction, and in the vibration actuator, the movable body vibrates with respect to the fixed body by the cooperative operation of the coil to which power is supplied and the disc-shaped magnet.

Description

[0001] This application is a divisional application of the Chinese invention patent application with the application date of August 28, 2019, application number 201980056702.2, invention name “Vibration actuator and electronic device”, and the applicant being MinebeaMitsumi Co., Ltd. Technical Field

[0002] The present invention relates to a vibration actuator and an electronic device having the same. Background Art

[0003] In the past, a vibration actuator was installed in an electronic device with a vibration function as a vibration source. The electronic device can make the user feel the vibration personally by driving the vibration actuator and transmitting the vibration to the user, thereby notifying the incoming call or enhancing the sense of operation or sense of presence. Here, the electronic device includes: portable game terminals, controllers (game handles) of fixed game consoles, portable communication terminals such as portable phones or smart phones, portable information terminals such as tablet personal computers (PCs), and portable devices such as wearable terminals worn on clothes or arms.

[0004] As a vibration actuator having a miniaturized structure that can be mounted on a portable device, for example, as shown in Patent Document 1, there is known a vibration actuator used in a pager or the like.

[0005] In the vibration actuator, a pair of plate-like elastic bodies are supported in an opposing manner at the opening edge of a cylindrical frame, respectively, and a yoke with a magnet mounted thereon is fixed to a central portion of a protrusion in a spiral-shaped plate-like elastic body of the pair of plate-like elastic bodies, and the yoke is supported in the frame.

[0006] The yoke and the magnet together constitute a magnetic field generator, and the coil is installed on another plate-like elastic body and arranged in the magnetic field of the magnetic field generator. The oscillation circuit switches and applies currents of different frequencies to the coil, so that the pair of plate-like elastic bodies are selectively resonated and vibrate, and the yoke vibrates in the frame in the direction of the center line of the frame.

[0007] In the vibration actuator, the distance between the magnet and the coil and the distance between the yoke and the coil are set to be greater than the distance between the yoke and the inner peripheral wall of the frame. Thus, when the yoke is impacted from the outside, the yoke first collides with the inner peripheral wall of the frame, so that the yoke or the magnet does not contact the coil, thereby preventing the coil from being damaged.

[0008] However, in reality, since the yoke having the magnet collides with the frame, the pair of plate-like elastic bodies that elastically support the movable body having the yoke may be impacted and damaged.

[0009] Therefore, in Patent Document 1, as a second embodiment, a structure is disclosed in which a shaft for slidingly moving a movable body in a vibration direction is provided on a fixed body. Thus, even if an impact is received from the outside, the yoke as a movable body will not move to the inner peripheral surface of the frame due to the shaft, thereby preventing collision with the frame.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Patent No. 3748637 Summary of the invention

[0013] Problem that the invention aims to solve

[0014] However, in the structure of the conventional vibration actuator in which the shaft on which the movable body slides is provided on the fixed body, although the movement of the movable body can be restricted by the shaft to improve the impact resistance, there is a possibility that the movable body slides on the shaft during driving and generates sliding noise.

[0015] There is a problem that the generation of noise caused by contact, such as vibration sound, reduces the amplitude of the vibration actuator itself. Therefore, for the vibration actuator that vibrates as a vibrating body by driving a movable body, it is required to output vibration in a state of increasing the amplitude without vibration noise, and transmit it to the user so that the user can fully feel the vibration in person, that is, it is required to output appropriate vibration.

[0016] An object of the present invention is to provide a vibration actuator and an electronic device, which have impact resistance and generate appropriate vibrations with high output as an example of a subject.

[0017] Solutions to the problem

[0018] One aspect of the vibration actuator of the present invention adopts the following structure, having:

[0019] a fixed body having a coil;

[0020] a movable body having a disk-shaped magnet disposed radially inward of the coil so as to be relatively movable in a vibration direction orthogonal to the radial direction; and

[0021] an upper leaf spring and a lower leaf spring, the upper leaf spring and the lower leaf spring being elastic supporting parts for supporting the movable body in a manner that allows the movable body to be movable relative to the fixed body, and the upper leaf spring and the lower leaf spring being spanned between the fixed body and the movable body in a manner that sandwiches the movable body in the vibration direction,

[0022] In the vibration actuator,

[0023] The movable body vibrates relative to the fixed body through the cooperation between the coil to which power is supplied and the disk-shaped magnet.

[0024] The movable body comprises the disc-shaped magnet, a pair of flat cores and a pair of spring fixings, the pair of flat cores being arranged on the front and back sides of the disc-shaped magnet, one end of each of the pair of spring fixings in the vibration direction is embedded in the central part of the pair of flat cores to be positioned and connected to the pair of flat cores, the other end of each of the pair of spring fixings in the vibration direction is connected to the radial inner end of the upper leaf spring or the lower leaf spring, and the weight main body of each of the pair of spring fixings is arranged between the one end and the other end of each of the pair of spring fixings in the vibration direction of the movable body,

[0025] The fixed body has a coil protection wall portion, which is arranged in a manner to surround the movable body and hold the coil, and the coil protection wall portion is arranged at a distance from the disc-shaped magnet on the radial inner side of the coil to prevent the disc-shaped magnet from contacting the coil.

[0026] The fixed body supports the movable body by means of the upper leaf spring and the lower leaf spring in such a manner that the movable body having the disc-shaped magnet, the flat core and the spring fixing part can vibrate along the axial direction of the coil on the radial inner side of the coil and the movable body does not contact the fixed body when the movable body is not vibrating and when it is vibrating.

[0027] One aspect of the vibration actuator of the present invention adopts the following structure, having:

[0028] a fixed body having a coil;

[0029] a movable body having a magnet disposed radially inward of the coil, the magnet being disposed radially inward of the coil so as to be relatively movable in a vibration direction orthogonal to the radial direction; and

[0030] an elastic support portion for supporting the movable body in such a manner that the movable body is movable relative to the fixed body,

[0031] Through the cooperation of the powered coil and the magnet, the movable body vibrates relative to the fixed body. In the above-mentioned vibration actuator,

[0032] The fixed body has a coil holding portion, which is arranged to surround the movable body and holds the coil.

[0033] The coil holding portion has a coil protection wall portion on the inner diameter side of the coil, the coil protection wall portion being arranged at a distance from the magnet to prevent contact between the magnet and the coil.

[0034] The elastic support portion includes at least two leaf springs, and the at least two leaf springs are arranged between the coil holding portion and the movable body so as to sandwich the movable body in the vibration direction.

[0035] The leaf spring supports the movable body movably in the vibration direction so that the movable body does not come into contact with the coil holding portion when the movable body is not vibrating and when the movable body is vibrating.

[0036] One form of the electronic device of the present invention adopts the following structure:

[0037] The vibration actuator of the above structure is installed therein.

[0038] Effects of the Invention

[0039] According to the present invention, it is possible to have impact resistance and generate appropriate vibration at a high output. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a perspective view showing the appearance of the vibration actuator according to the first embodiment of the present invention.

[0041] Figure 2 It is a longitudinal sectional view showing the vibration actuator according to the first embodiment of the present invention.

[0042] Figure 3 This is an exploded perspective view of the vibration actuator.

[0043] Figure 4 It is a perspective view showing a movable body and an elastic support portion of the vibration actuator.

[0044] Figure 5A , Figure 5B It is a diagram showing a coupled state of the elastic support portion and the movable body.

[0045] Fig. 6A , Figure 6B It is a diagram showing a modified example of the connection state between the elastic support portion and the movable body.

[0046] Figure 7 is a top view of an elastic support portion having a damping portion.

[0047] Figure 8 It is a partial cross-sectional view of an elastic support portion having a damping portion.

[0048] Fig. 9 It is a top view of an elastic support portion including a damping portion as a modified example.

[0049] Fig.10 It is a partial cross-sectional view of an elastic support portion including a damping portion as a modified example.

[0050] Fig.11 This is a diagram schematically showing the magnetic circuit structure of the vibration actuator.

[0051] Fig.12 It is a diagram schematically showing the balanced position of the coil and the magnet.

[0052] Fig.13 It is a diagram schematically showing the relative movement state of the coil and the magnet.

[0053] Fig.14 It is a longitudinal sectional view showing a vibration actuator according to Embodiment 2 of the present invention.

[0054] Fig.15 It is an exploded perspective view of a vibration actuator according to Embodiment 2 of the present invention.

[0055] Fig.16 The figure shows an example of an electronic device in which the vibration actuator is mounted.

[0056] Fig.17 The figure shows an example of an electronic device in which the vibration actuator is mounted. DETAILED DESCRIPTION

[0057] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0058] (Implementation Method 1)

[0059] [Overall structure of vibration actuator]

[0060] Figure 1 1 is a perspective view showing the appearance of a vibration actuator according to Embodiment 1 of the present invention. Figure 2 1 is a longitudinal sectional view showing a vibration actuator according to Embodiment 1 of the present invention, Figure 3 is an exploded perspective view of the vibration actuator. Figure 4 1 is a three-dimensional diagram showing the movable body and elastic support portion of the vibration actuator. In addition, the "upper" side and the "lower" side in this embodiment are directions given for ease of understanding and convenience, and refer to one side and the other side of the vibration direction of the movable body 20 in the vibration actuator 10. That is, when the vibration actuator 10 is mounted on an electronic device (see Fig.16 and Fig.17 ), you can reverse it up and down, or left and right.

[0061] Figure 1 to Figure 4The vibration actuator 10 shown is installed in an electronic device, specifically a portable game terminal device (for example, Fig.16 GC), or a portable device such as a smartphone (e.g., Fig.17 The portable terminal 24 shown in the figure realizes the vibration function of each device. In addition, the vibration actuator 10 can also have the function of generating sound by vibration. The vibration actuator 10 is driven, for example, when notifying the user of an incoming call or giving a sense of operation or a sense of presence, etc.

[0062] like Figure 1 As shown, in the vibration actuator 10 of this embodiment, a movable body 20 (see Figure 2 ) The movable body 20 is accommodated in a manner that allows the movable body 20 to vibrate in the axial direction of the column shape. As the movable body 20 moves, the vibration actuator 10 itself becomes a vibrating body.

[0063] like Figure 2 to Figure 4 As shown, the vibration actuator 10 includes a movable body 20 having a magnet 30 and movable body cores 41 , 42 , a fixed body 5σ having coils 61 , 62 , and plate-shaped elastic support parts 81 , 82 that support the movable body 20 so that the movable body 20 can reciprocate freely relative to the fixed body 50 .

[0064] In the vibration actuator 10, the coils 61, 62, the magnet 30, and the movable body cores 41, 42 constitute a magnetic circuit for vibrating the movable body 20. In the vibration actuator 10, the coils 61, 62 are connected to the movable body 20 through a power supply unit (for example, Fig.16 and Fig.17 The movable body 20 is energized by power supplied by the drive control unit 203 shown in FIG. 1 , whereby the coils 61 and 62 cooperate with the magnet 30 , and the movable body 20 reciprocates in the vibration direction relative to the fixed body 50 .

[0065] In the vibration actuator 10 of the present embodiment, the movable body 20 reciprocates along the axial direction of the coils 61, 62, that is, the vibration direction, on the inner side of the coils 61, 62 held in the coil holding portion 52. Specifically, the movable body 20 can reciprocate on the inner side of the inner body portion (coil protection wall portion) 522 arranged between the coils 61, 62 and the movable body 20. The inner body portion 522 is a part of the coil holding portion 52, and the details of the coil holding portion 52 will be described later. In addition, the axial direction of the coils 61, 62 is the vibration direction of the movable body 20, and is the magnetization direction of the magnet 30 or the axial direction of the coil holding portion 52.

[0066] In the vibration actuator 10, when the movable body 20 is immovable and non-vibrating, the movable body 20 is arranged at a predetermined interval on the inner side of the fixed body 50 (more specifically, the inner body 522 of the coil holding part 52) ​​at the center of the length in the vibration direction of the fixed body 50 (specifically, the coil holding part 52) ​​and along the direction orthogonal to the axial direction of the movable body 20 by means of the elastic support parts 81 and 82. At this time, it is preferred that the movable body 20 is located at a position that maintains balance between the coils 61 and 62 in a manner that does not contact the inner body 522 of the coil holding part 52. Specifically, it is preferably configured so that the center of the length in the vibration direction of the magnet 30 and the movable body core 41 and 42 and the center of the length in the vibration direction between the coils 61 and 62 are opposite in a direction orthogonal to the vibration direction.

[0067] When movable (when vibrating), the movable body 20 reciprocates in the vibration direction along the inner peripheral surface 522a of the inner body portion 522. In addition, a magnetic fluid may be interposed between the inner body portion 522 and the movable body 20.

[0068] <Movable body 20>

[0069] like Figure 2 to Figure 4 As shown, the movable body 20 is supported by the elastic support parts 81 and 82 on the inner side of the cylindrical coil holding part 52 of the fixed body 50 so as to be able to reciprocate along the inner peripheral surface 522a of the inner main body part 522. The direction in which the reciprocating movement can be performed is the direction in which the housing (hereinafter referred to as the "upper housing" for ease of understanding) 54 and the housing (hereinafter referred to as the "lower housing" for ease of understanding) 56 that seal the opening of the coil holding part 52 are opposite.

[0070] The movable body 20 has a magnet 30, movable body cores 41, 42, and spring fixing members 22, 24. In the present embodiment, the movable body cores 41, 42 and the spring fixing members 22, 24 are continuously arranged on both sides of the vibration direction with the magnet 30 as the center. In the movable body 20, the outer peripheral surface 20a of the magnet 30 and the movable body cores 41, 42 is located inside the inner peripheral surface 522a of the inner body portion 522, and faces the inner peripheral surface 522a with a predetermined interval therebetween.

[0071] When the movable body 20 moves in the vibration direction, the outer peripheral surface 20 a reciprocates along the inner peripheral surface 522 a without contact.

[0072] The magnet 30 is arranged radially inside the coils 61, 62 in such a manner that it can move relative to the vibration direction that is radially orthogonal to the coils 61, 62. The magnet 30 is arranged so as to be located at a position with a gap in the radial inside of the coils 61, 62 relative to the coils 61, 62. Here, "radial" refers to a direction that is orthogonal to the axis of the coils 61, 62, and is also a direction that is orthogonal to the vibration direction. The "gap" in the radial direction is the gap between the magnet 30 and the coils 61, 62, including the inner body portion 522, and is a gap that allows the movable body 20 to move without contact with each other in the vibration direction. In the present embodiment, the gap between the coils 61, 62 and the magnet 30 refers to the gap between the inner body portion 522 on the coil 61, 62 side and the magnet 30.

[0073] In addition, in the present embodiment, the magnet 30 is arranged so as to be opposed to the center of the inner body portion 522 on the radially outer side of the magnet 30. In addition, the magnet 30 can be any shape other than a disc shape such as a cylindrical shape or a plate shape, as long as it is arranged on the inner side of the coils 61 and 62 so that the two magnetized surfaces are respectively oriented in the extending direction of the axis of the coils 61 and 62.

[0074] In the present embodiment, the magnet 30 is a disk-shaped magnet, and its axial direction is the vibration direction and the magnetization direction. It is preferable that the axial center of the magnet 30 coincides with the axial center of the movable body 20 .

[0075] The magnet 30 is magnetized in the vibration direction, and the front surface 30 a and the back surface 30 b spaced apart in the vibration direction each have a different polarity.

[0076] Movable cores 41 and 42 are provided on the front surface 30 a and the back surface 30 b of the magnet 30 , respectively.

[0077] Movable cores 41 and 42 are magnetic bodies and constitute a magnetic circuit together with magnet 30 and coils 61 and 62 to function as a yoke. Movable cores 41 and 42 collect the magnetic flux of magnet 30 and efficiently flow it without leakage, and effectively distribute the magnetic flux flowing between magnet 30 and coils 61 and 62.

[0078] In addition, the movable body cores 41 and 42 function as a part of the magnetic circuit and also function as a main body portion of the movable body 20 and as a counterweight in the movable body 2σ.

[0079] In the present embodiment, the movable body cores 41 and 42 are formed in annular flat plate shapes, and are arranged so that their outer peripheral surfaces are aligned with the outer peripheral surface of the magnet 30 , and together with the outer peripheral surface of the magnet 30 , they constitute the outer peripheral surface 20 a of the movable body 20 .

[0080] The movable cores 41 and 42 are respectively laminated cores, for example, formed by laminating silicon steel plates. In the present embodiment, the movable cores 41 and 42 are identical components formed in the same manner and are symmetrically arranged with the magnet 30 as the center. In addition, the movable cores 41 and 42 are attracted to the magnet 30 and fixed to the magnet 30 using, for example, a thermosetting adhesive such as epoxy resin or an anaerobic adhesive.

[0081] The openings 412 and 422 formed in the center of each of the movable body cores 41 and 42 indicate the axial position of the movable body 20 and function as joints with the spring fixing members 22 and 24 .

[0082] In the present embodiment, when the movable body 20 is not vibrating, the movable body cores 41 and 42 are located inside (radially inside) the coils 61 and 62 and facing the coils 61 and 62 in a direction perpendicular to the axial direction of the coils 61 and 62 .

[0083] Furthermore, movable body cores 41 and 42 constitute a movable body side magnetic circuit portion of the magnetic circuit together with magnet 30 .

[0084] The spring fixtures 22 and 24 have the function of fixing the movable body side magnetic circuit portion to the elastic support portions 81 and 82. The spring fixtures 22 and 24 are also weight portions, and function as a counterweight for the movable body 20 to increase the vibration output of the movable body 20.

[0085] In the present embodiment, the spring fixing members 22 and 24 include the joint portions 222 and 242 to be joined to the movable cores 41 and 42 , the weight main body portions 224 and 244 , and the spring fixing portions 226 and 246 .

[0086] In this embodiment, the spring fixing members 22 and 24 are respectively provided with the joint parts 222 and 242, the weight main body parts 224 and 244, and the spring fixing parts 226 and 246 continuously in the vibration direction, and are formed into a cylindrical shape having a through hole opened in the vibration direction. In addition, a weight can be added to the through hole, whereby the through hole can function as a weight adjustment part together with the weight. By adding a weight to the through hole, the movable body 20 can be weighted to increase the vibration output of the movable body 20.

[0087] The joints 222 and 242 are respectively joined to the movable cores 41 and 42. Specifically, the joints 222 and 242 are respectively inserted and fitted into the openings 412 and 422 of the movable cores 41 and 42. The joints 222 and 242 are respectively bonded and fixed in the openings 412 and 422 using, for example, a thermosetting adhesive such as epoxy resin or an anaerobic adhesive.

[0088] The weight body parts 224 and 244 are cylindrical bodies having an outer diameter larger than that of the joint parts 222 and 242 and the spring fixing parts 226 and 246 , and also having a larger mass than that of the joint parts 222 and 242 and the spring fixing parts 226 and 246 .

[0089] In addition, the weight main body parts 224 and 244 are provided at two ends of the movable body 20 spaced apart in the vibration direction, and are not provided on the outer peripheral side of the movable body 20. Therefore, the weight main body parts 224 and 244 do not limit the configuration space of the coil located on the outer peripheral side of the movable body 20, so that the efficiency of electromagnetic conversion is not reduced. As a result, the weight of the movable body 20 can be appropriately increased, and high vibration output can be achieved.

[0090] The spring fixing portion 226 is disposed at one end of the movable body 20 in the vibration direction, that is, at the upper end of the movable body 20, and is connected to the inner peripheral portion 802 of the elastic support portion 81, that is, the inner diameter side end of the upper leaf spring (see Figure 4 On the other hand, the spring fixing portion 246 is connected to the inner peripheral portion 802 (see FIG. 1 ) of the elastic support portion 82, i.e., the inner diameter side end of the lower leaf spring, at the other end of the movable body in the vibration direction, i.e., the lower end of the movable body 20. Figure 4 ) are joined. In addition, details about the elastic support parts 81 and 82 will be described later.

[0091] The spring fixing parts 226 and 246 protrude from the weight main body parts 224 and 244 in the vibration direction, respectively, and are respectively connected with the inner peripheral parts 802 and 802 of the elastic support parts 81 and 82 at their front ends. Thus, the elastic support parts 81 and 82 are fixed to the front ends of the spring fixing parts 226 and 246, which protrude from the weight main body parts 224 and 244 and form a step relative to the weight main body parts 224 and 244. Through the step, a gap is ensured as a region where the elastic support parts 81 and 82 are elastically deformed in the vibration direction, and the elastic support parts 81 and 82 extend from the inner peripheral parts 802 and 802 to the outside in the outer peripheral direction.

[0092] The spring fixing members 22 and 24 can be used as fixing parts for fixing weights (counterweights) or springs. That is, the spring fixing members 22 and 24 respectively play the function of weights (counterweights) and the function of fixing the elastic support members 81 and 82, that is, the spring fixing function, so there is no need to assemble the parts that play each function. As long as the spring fixing members 22 and 24 are set on the movable body side magnetic circuit part, the elastic support members 81 and 82, that is, the upper leaf spring and the lower leaf spring, can be easily assembled to the movable body 20 in a state where the weight function and the spring fixing function are played, which can improve the assemblability.

[0093] In addition, the spring fixing members 22 and 24 may be made of a magnetic material, but are preferably made of a non-magnetic material. If the spring fixing members 22 and 24 are made of a non-magnetic material, the magnetic flux from the movable core 41 does not flow upward, and the magnetic flux from the movable core 42 does not flow downward, so that the magnetic flux can efficiently flow to the coils 61 and 62 located on the outer peripheral side of the movable cores 41 and 42.

[0094] In addition, the spring fixing members 22 and 24 are preferably formed of a material having a higher specific gravity (for example, a specific gravity of about 16 to 19) than a material such as a silicon steel plate (the specific gravity of the steel plate is 7.7σ to 7.98). Tungsten can be used as a material for the spring fixing members 22 and 24, for example. Thus, even when the outer dimensions of the movable body 20 are set during design, the mass of the movable body 20 can be increased relatively easily, and the desired vibration output that is sufficient for the user to feel the vibration can be achieved.

[0095] <Fixed body 50>

[0096] The fixed body 50 supports the movable body 20 via elastic support parts 81 and 82 inside the coils 61 and 62 so that the movable body 20 can move in the vibration direction (the same direction as the coil axial direction and the magnetization direction).

[0097] In this embodiment, the fixed body 50 has, in addition to the coils 61 and 62 , a coil holding portion 52 , an upper shell (also referred to as a “first shell”) 54 , a lower shell (also referred to as a “second shell”) 56 , and an electromagnetic shielding portion 58 .

[0098] The coil holding portion 52 holds the coils 61 and 62 arranged at a predetermined interval so as to surround the magnet 30 , and guides the movement of the movable body 20 .

[0099] The coil holding portion 52 is a cylindrical body formed of resin or the like, and has an inner body portion 522, which is arranged radially inward of the coils 61, 62 and provided between the coils 61, 62 and the magnet 30. The inner body portion 522 is arranged on the inner diameter side of the coils 61, 62 at a distance from the magnet 30. The inner body portion 522 prevents contact between the magnet 30 and the coils 61, 62.

[0100] In addition to the inner main body portion 522, the coil holding portion 52 also has an outer main body portion 524 and a central annular portion 526 connecting the inner main body portion 522 and the outer main body portion 524. The outer main body portion 524 is a concentric cylindrical body arranged in a manner that is spaced apart from the outer peripheral side of the inner main body portion 522 and surrounds the inner main body portion 522.

[0101] The outer body portion 524 is arranged in a manner to surround the coils 61 and 62 arranged on the outer peripheral surface of the inner body portion 522, and the outer peripheral surface of the outer body portion 524 is covered by the cylindrical electromagnetic shielding portion 58. The outer body portion 524 clamps the outer peripheral portion 806 of the elastic support portions 81 and 82 together with the upper shell 54 and the lower shell 56 at two open ends (upper end and lower end), and is respectively closed by the upper shell 54 and the lower shell 56. By using the upper shell 54 and the lower shell 56 to respectively close the two ends of the outer body portion 524, a hollow housing of the vibration actuator is formed.

[0102] The central annular portion 526 is formed in a disk shape extending between the inner body portion 522 and the outer body portion 524 at the center position in the axial direction (vibration direction).

[0103] That is, in the coil holding portion 52, the outer body portion 524, the inner body portion 522 and the central annular portion 526 respectively form pockets (coil insertion portions) with circular openings and concave cross-sections at both ends of the axial direction. The central annular portion 526 constitutes the bottom of the pocket. The coils 61 and 62 are fixed in a state of being respectively accommodated in the concave pockets.

[0104] The inner body portion 522 is a cylindrical body, and the movable body 20 is arranged so as to be able to reciprocate axially on the inner circumference side of the inner body portion 522 . The coils 61 , 62 are arranged side by side in the axial direction (coil axial direction) so as to surround the outer circumference of the inner body portion 522 .

[0105] The inner circumferential surface 522a of the inner body portion 522 is arranged to face the outer circumferential surface of the movable body 20 at a predetermined interval. The predetermined interval is an interval that allows the movable body 20 to move in the vibration direction, i.e., the axial direction, without contacting the inner circumferential surface 522a when the movable body 20 moves in the vibration direction. The movable body 20 moves along the inner circumferential surface 522a without contacting the inner circumferential surface 522a.

[0106] The thickness of the inner body portion 522 is preferably thinner than the thickness of the outer body portion 524, and is a thickness that achieves the following strength: even if it contacts the moving movable body 20, it will not have any effect on the coils 61 and 62 on the outer peripheral side. That is, the durability of the coil holding portion 52 that holds the coils 61 and 62 is ensured mainly by the radial thickness of the inner body portion 522, the axial length of the central annular portion 526, and the radial thickness of the outer body portion 524.

[0107] In addition, the coil wire connecting the coils 61 and 62 held axially spaced apart by the coil holding portion 52 is provided in the coil holding portion 52 and guided by a guide groove (not shown) that connects the pockets (slits) with concave cross-sections. The coils 61 and 62 are connected to the outside via the coil connecting portion 521 at the bottom of the coil holding portion 52. The coil connecting portion 521 is located on the protrusion 564 of the lower housing 56. In addition, the guide groove is provided, for example, at the outer periphery of the central annular portion 526.

[0108] In the coil holding portion 52, the coils 61 and 62 are inserted into a concave bag (slit) formed by the inner body portion 522, the outer body portion 524 and the central annular portion 526 and opened on both sides of the axial direction, and fixed by bonding or sealing. In the present embodiment, the coils 61 and 62 are fixed to the inner body portion 522, the outer body portion 524 and the central annular portion 526 by bonding. Thus, the coils 61 and 62 can increase the bonding strength between the coil holding portion 52, and even if a large impact is applied, the coils 61 and 62 will not be damaged compared to the structure in which the movable body directly contacts the coil.

[0109] In the vibration actuator 10, the coils 61 and 62 use the axial direction of the coils 61 and 62 (the magnetization direction of the magnet 30) as the vibration direction, and are used together with the magnet 30 and the movable cores 41 and 42 to generate the driving source of the vibration actuator 10. The coils 61 and 62 are energized during driving, and together with the magnet 30, form a voice coil motor.

[0110] In the present embodiment, the coils 61 and 62 are formed of self-fusible wire coils. Thus, when assembled to the coil holding portion 52, they can be inserted into and held in the concave bag portion as the slit in a cylindrical state, so that the coil wire will not loosen, thereby improving the assemblability of the vibration actuator 10.

[0111] It is preferable that the coil axes of the coils 61 and 62 are arranged on the same axis as the axis of the coil holding portion 52 or the axis of the magnet 30 .

[0112] The coils 61 and 62 are held in the coil holding portion 52 in such a manner that the center position of the length in the axial direction (vibration direction) of the coils and the center position of the length in the vibration direction of the movable body 20 (specifically, the vibration direction of the magnet 30) are located at substantially the same position (including the same position) in the vibration direction. In addition, the coils 61 and 62 of the present embodiment are wound in opposite directions to each other, thereby being configured so that currents flow in opposite directions when energized.

[0113] The two ends of the coils 61 and 62 are connected to a power supply unit (for example, Fig.16 and Fig.17For example, both ends of the coils 61 and 62 are connected to an AC supply unit, and an AC power supply (AC voltage) is supplied from the AC supply unit to the coils 61 and 62. Thus, the coils 61 and 62 can generate thrust between the coils 61 and 62 and the magnets to move in directions toward or away from each other in the axial direction.

[0114] In the magnet 30, when the front surface 30a side on one side (the upper side in the present embodiment) of the magnetization direction is magnetized to be the N pole and the back surface 30b side on the other side (the lower side in the present embodiment) of the magnetization direction is magnetized to be the S pole, a magnetic flux is formed which is radiated from the movable core 41 on the front surface 30a side of the magnet 30 and is incident on the movable core 42 on the back surface 30b side of the magnet 30. Specifically, a flow of magnetic flux is formed in which the magnetic flux is emitted from the front surface side of the magnet 30, radiated from the movable core 41 on the upper side of the magnet 30 toward the coil 61 side, passes through the electromagnetic shield 58, and is incident on the magnet 30 from the movable core 42 on the lower side of the magnet 30 via the coil 62. In this way, the magnetic flux crosses the coils 61 and 62 in the radial direction with respect to any part of the coils 61 and 62 arranged so as to surround the magnet 30 and the movable cores 41 and 42. Thus, when the coils 61 and 62 are energized, the Lorentz force acts in the same direction (for example, Fig.11 -f direction as shown).

[0115] The upper shell 54 and the lower shell 56 are formed into bottomed cylindrical shapes, respectively, and their respective bottoms 541 and 561 constitute the top and bottom surfaces of the vibration actuator 10 in this embodiment. In addition, the upper shell 54 and the lower shell 56 can also be formed into a concave shape by deep drawing of metal plates.

[0116] The electromagnetic shielding portion 58 is a cylindrical magnetic body arranged in a manner covering the outer periphery of the coil holding portion 52. The electromagnetic shielding portion 58 functions as an electromagnetic shield to prevent the magnetic flux from leaking to the outside of the vibration actuator 10. The electromagnetic shielding effect of the electromagnetic shielding portion 58 can reduce the leakage magnetic flux toward the outside of the vibration actuator.

[0117] Electromagnetic shield 58 also functions as a magnetic circuit together with coils 61 and 62, magnet 30, and movable cores 41 and 42, thereby increasing the thrust constant and improving electromagnetic conversion efficiency. Electromagnetic shield 58 utilizes the magnetic attraction force of magnet 30 and functions as a magnetic spring together with magnet 30.

[0118] The magnet 30 is arranged inside the electromagnetic shielding portion 58 so that the center of the magnet 30 in the vibration direction is located at the center of the length of the electromagnetic shielding portion 58 in the vibration direction. Fig.12As shown in FIG. 1 , when not driven, the magnetic attraction force F1 acts between the magnet 30 and the electromagnetic shielding portion 58. Fig.13 As shown, even when movable body 20 excessively moves in one of the vibration directions, magnetic attraction force F2 is generated between magnet 30 and electromagnetic shielding portion 58 , and movable body 20 returns to its original position by the force of thrust F3 .

[0119] The overall spring constant includes not only the spring constant of the leaf springs serving as the elastic support portions 81 and 82, but also the spring constant of the magnetic spring formed by the magnet 30 and the electromagnetic shielding portion 58. This can reduce the spring constant of the leaf spring, and as a result, the stress of the leaf spring is reduced, and the adverse effect on the life is suppressed, thereby improving the reliability of the vibration actuator 10.

[0120] The bottom 541 of the upper housing 54 and the bottom 561 of the lower housing 56 are disc-shaped bodies, and an annular step extending in the circumferential direction is provided at a position closer to the bottom 541, 561 than the opening edge on the inner side of the cylindrical peripheral wall portion 542, 562 rising from the outer peripheral edge of each bottom 541, 561 (see Figure 2 ).

[0121] Furthermore, in the present embodiment, the outer surfaces of the peripheral wall portions 542 and 562 are arranged to be aligned with the outer surface of the electromagnetic shielding portion 58 surrounding the coils 61 and 62. Thus, the vibration actuator 10 is formed into a substantially cylindrical (barrel-shaped) shape having a flat outer peripheral surface, which is a small and simple shape, and thus its installation space can be formed in a simple cylindrical shape.

[0122] The upper housing 54 and the lower housing 56 are respectively fitted with the two open ends of the coil holding portion 52 at the step portion, and the outer peripheral portion 806 of the elastic support portion 81, 82 is clamped and fixed with the open ends. The length from the bottom 541, 561 to the step portion can respectively define the movable range of the movable body 20. The movable range of the movable body 20 is configured so that the movable body 20 vibrates within the movable range by deformation of the elastic support portions 81, 82.

[0123] With the movable body space of the length from the bottom 541, 561 to the step portion of the fixed elastic support parts 81, 82, the upper shell 54 and the lower shell 56 of the fixed body 50 function as a movable range suppression mechanism of the hard stop (limited movable range) HS. That is, the movable body space is defined as the length of the range in which the elastic support parts 81, 82 will not be plastically deformed. Thus, even when a force exceeding the movable range is applied to the movable body 20, the elastic support parts 81, 82 do not contact the fixed body 50 without plastic deformation, so the elastic support parts 81, 82 will not be damaged, and reliability can be improved.

[0124] <Elastic Supporting Parts 81, 82>

[0125] The elastic support parts 81 and 82 sandwich the movable body 20 in the vibration direction of the movable body 20 and are bridged between the movable body 20 and the fixed body 50 in a manner perpendicular to the vibration direction to support the movable body 20 so that the movable body 20 can reciprocate freely relative to the fixed body 50 in the vibration direction.

[0126] In this embodiment, if Figure 2 to Figure 4 As shown, both ends of the elastic support portions 81 , 82 spaced apart in the vibration direction in the movable body 20 are spaced apart from each other and connected to the fixed body 50 .

[0127] The inner circumference 802 of the elastic support parts 81 and 82 are respectively correspondingly embedded in the two end parts (spring fixing parts 226 and 246) separated in the axial direction (vibration direction) of the movable body 20, and the elastic support parts 81 and 82 are installed on the movable body 20 in a manner that the outer circumference 806 extends radially outward (radial direction).

[0128] When the movable body 20 is not vibrating or vibrating, the elastic support parts 81 and 82 support the movable body 20 in a manner that the movable body 20 does not contact the fixed body 50. In addition, when the elastic support parts 81 and 82 are driven, even if the movable body 20 contacts the inner peripheral surface 522a of the inner body part 522, the magnetic circuit, specifically the coils 61 and 62, will not be damaged. The elastic support parts 81 and 82 may be of any structure as long as they can elastically support the movable body 20 in a manner that allows the movable body 20 to move freely.

[0129] The elastic support parts 81 and 82 may be non-magnetic or magnetic (specifically, ferromagnetic). If the elastic support parts 81 and 82 are leaf springs of non-magnetic material, they may be formed of stainless steel plates such as SUS304 and SUS316. In addition, if the elastic support parts 81 and 82 are magnetic, they may be formed of stainless steel plates such as SUS301.

[0130] When the elastic support parts 81 and 82 are arranged in the vibration actuator at a position that is not easily affected by the magnetic field of the magnetic circuit in the movable body 20, the material of the elastic support parts 81 and 82 may be a non-magnetic material or a magnetic material. In addition, when the elastic support parts 81 and 82 are arranged at a position that is easily affected by the magnetic field of the magnetic circuit in the movable body 20, it is preferred that the material of the elastic support parts 81 and 82 is a non-magnetic material, thereby being set as a non-magnetic body.

[0131] As a material of the elastic supporting parts 81 and 82 , for example, it is known that a magnetic material (for example, SUS301) has higher durability and is inexpensive than a non-magnetic material (for example, SUS304 or SUS316).

[0132] In the vibration actuator 10 of the present embodiment, the elastic support parts 81 and 82 are arranged at positions that are not easily affected by the magnetic field of the magnetic circuit in the movable body 20, so the material of the elastic support parts 81 and 82 is, for example, a magnetic material (ferromagnetic material) such as SUS301. Therefore, in the present embodiment, compared with the case of using non-magnetic materials, the elastic support parts 81 and 82 are more durable and inexpensive, so that the vibration actuator 10 with excellent durability can be realized at a low cost.

[0133] like Figure 4 As shown, the elastic support parts 81 and 82 are respectively a plurality of planar leaf springs. Alternatively, the movable body 20 may include the plurality of elastic support parts 81 and 82 as three or more leaf springs. The plurality of leaf springs are attached in a direction perpendicular to the vibration direction.

[0134] The elastic support parts 81 and 82 as leaf springs have a shape in which an annular inner peripheral part 802 as an inner spring end and an outer peripheral part 806 as an outer spring end are joined by an elastically deformed arc-shaped deformation arm 804. By deformation of the deformation arm 804, the inner peripheral part 802 and the outer peripheral part 806 are relatively displaced in the axial direction.

[0135] In the elastic support parts 81 and 82 , the outer peripheral part 806 is joined to the fixed body 50 , and the inner peripheral part 802 is joined to the movable body 20 .

[0136] In the present embodiment, the leaf springs serving as the elastic support parts 81 and 82 are formed by sheet metal processing using a stainless steel plate, and more specifically, are thin, flat disc-shaped spiral springs. The elastic support parts 81 and 82 are flat, and thus, compared with conical springs, the position accuracy, that is, the processing accuracy, can be improved.

[0137] In this embodiment, the spiral directions of the plurality of elastic support portions 81 and 82 are the same, and the outer peripheral portion 806 at one end on the outer peripheral side is fixed to the fixed body 50 , and the inner peripheral portion 802 at the other end on the inner peripheral side is fixed to the movable body 20 .

[0138] Thus, in the present embodiment, a plurality of spiral leaf springs are used as the plurality of elastic support portions 81 and 82, and the leaf springs are respectively mounted on two ends of the movable body 20 spaced apart in the vibration direction. Thus, in the vibration actuator 10, when the movable body 20 is elastically supported relative to the fixed body 50, if the amount of movement of the movable body 20 is large, the movable body 20 rotates slightly and moves in the translation direction (here, the direction on the plane perpendicular to the vibration direction). If the vortex directions of the plurality of leaf springs are opposite, the plurality of leaf springs move in the bending direction or the stretching direction to each other, thereby hindering smooth movement.

[0139] The elastic support parts 81 and 82 of this embodiment are fixed to the movable body 20 so that the spiral directions are the same. Therefore, even if the movable body 20 moves a large amount, it can move smoothly, that is, deform, and can achieve a larger amplitude and improve the vibration output.

[0140] The ends of the elastic support parts 81 and 82 spaced apart in the vibration direction (in the present embodiment, the up-down direction) of the movable body 20 are fixed to the front ends of the spring fixing parts 226 and 246, and the spring fixing parts 226 and 246 protrude from the weight main body parts 224 and 244 in a manner that a step is formed at the peripheral part. The elastic support parts 81 and 82 are configured in a manner that extends from the front ends of the spring fixing parts 226 and 246 in a direction orthogonal to the vibration direction, so that the elastic deformation area is ensured by the step. Thus, the elastic support parts can be made at low cost, and the reliability of the vibration actuator itself using the elastic support parts can be improved.

[0141] In the present embodiment, the elastic support portions 81 , 82 are firmly joined to the movable body 20 via the fixing pins 26 , 28 , respectively, so as not to be separated due to vibration of the movable body 20 .

[0142] Figure 2 to Figure 4 The fixing pins 26 and 28 shown have flanges 264 and 284 at the opening edge portions on one end sides of cylindrical pin bodies 262 and 282 that can be press-fitted into the spring fixing portions 226 and 246, respectively.

[0143] Figure 5A , Figure 5B 1 and 2 are diagrams showing a coupled state of the elastic support portions 81 and 82 and the movable body 20 .

[0144] like Figure 5AAs shown, when the plate-shaped elastic support parts 81, 82 are fixed to the movable body 20, the inner peripheral parts 802 of the elastic support parts 81, 82 are overlapped with the spring fixing parts 226, 246 constituting the end parts in the vibration direction of the movable body 20. Next, the pin bodies 262, 282 of the fixing pins 26, 28 are respectively pressed into the through holes opened in the spring fixing parts 226, 246 through the openings of the inner peripheral parts 802, 802 of the plate-shaped elastic support parts 81, 82.

[0145] Therefore, if Figure 5B As shown, the flanges 264 , 284 and the spring fixing portions 226 , 246 clamp the inner circumferential portions 802 of the elastic supporting portions 81 , 82 , so that the elastic supporting portions 81 , 82 are firmly joined to the spring fixing portions 226 , 246 .

[0146] When the movable body 20 reciprocates, the spring fixing portions 226 and 246 will not come off even if a large force is applied to them. In addition, for example, compared with the case where the movable body 20 is fixed only by bonding, it is more able to withstand repeated vibrations.

[0147] Alternatively, the inner peripheral portion 802 of the elastic support portion 81 , 82 and the spring fixing portion 226 , 246 may be joined by welding, bonding, riveting, or a combination of welding, bonding, or riveting.

[0148] Fig. 6A , Figure 6B It is a diagram showing a modified example of the connection state between the elastic support parts 81 and 82 and the movable body 20 .

[0149] Compared with the structure of the movable body 20, Fig. 6A , Figure 6B In the illustrated movable body 20 , spring fixing portions 226 , 246 of spring fixing members 22A, 24A having the same structure as the spring fixing members 22 , 24 include cylindrical caulking portions 228 , 248 protruding from the periphery of a through hole opened in the vibration direction.

[0150] like Fig. 6A As shown, the rivet parts 228 and 248 are inserted into the openings of the inner peripheral parts 802 of the elastic support parts 81 and 82. Preferably, the outer periphery of the cylindrical rivet parts 228 and 248 has a diameter that is embedded in the inner peripheral parts 802 of the elastic support parts 81 and 82. In addition, the protruding length of the rivet parts 228 and 248 from the surface on which the inner peripheral part 802 is placed is longer than the thickness of the elastic support parts 81 and 82.

[0151] like Fig. 6AAs shown in FIG. 5 , the rivet portions 228, 248 are inserted into the inner peripheral portions 802, 802, and the rivet portions 228, 248 are crushed or the like to be riveted, so that the elastic support portions 81, 82 are firmly joined to the spring fixing portions 226, 246. Compared with the structure using the fixing pins 26, 28 shown in FIG. 5 , this structure can reduce the number of components, can reduce the assembly man-hours, and is easy to manufacture. In addition, the joining of the elastic support portions 81, 82 and the spring fixing portions 226, 246 can also be performed by welding or bonding in addition to riveting.

[0152] On the other hand, Figure 2 As described above, the outer peripheral portion 806 of the elastic support portion 81 is clamped on the radially outer side by the inner peripheral side portion (the step portion on the inner peripheral side) of the opening portion in the peripheral wall portion 542 of the upper shell 54 and the opening end of the outer main body portion 524 in the coil holding portion 52, thereby being fixed to the fixed book 50.

[0153] like Figure 2 As shown, the outer peripheral portion 806 of the elastic support portion 82 is clamped radially outward by the opening end of the outer main body portion 524 in the coil holding portion 52 and the step portion inside the opening portion in the peripheral wall portion 562 of the lower shell 56, thereby being fixed to the fixed body 50.

[0154] In this way, the elastic support parts 81 and 82 are arranged in a direction perpendicular to the vibration direction and are sandwiched by the upper and lower opening ends of the outer body part 524 of the coil holding part 52 and the upper and lower shells 54 and 56 that fit and close these opening ends.

[0155] In the present embodiment, in the elastic support parts 81 and 82, an attenuation part (shock absorber) 72 as an attenuation unit for attenuating vibration generated in the elastic support parts 81 and 82 is installed on the deformable arm 804 or the deformable arm 804 and the outer peripheral part 806. The attenuation unit suppresses the resonance peak in the elastic support parts 81 and 82 and generates stable vibration over a wide range.

[0156] Figure 7 is a top view of the elastic support portion 81 having the attenuation portion, Figure 8 It is a partial cross-sectional view of the elastic support portion including the attenuation portion 72. The elastic support portion 82 also includes the attenuation portion 72, but since it has the same structure as the elastic support portion 81, the description thereof will be omitted.

[0157] like Figure 7 and Figure 8As shown in FIG. 1 , the attenuation part 72 of this embodiment is an elastic member such as an elastic body having an H-shaped cross section, in which the central parts of a pair of flanges 722 arranged in parallel and opposite to each other are connected by a convex ridge (insertion part) 724. In the attenuation part 72, the elastic body is inserted between the bridge part of the elastic support part 81 as a leaf spring, in this embodiment, the outer peripheral part 806 and the deformation arm 804, and is arranged in contact with both. A plurality of attenuation parts 72 are mounted on the elastic support part 81 in a non-fixed manner.

[0158] The attenuation portion 72 as the attenuation means attenuates the strong spring resonance in the elastic support portion 81 to prevent the vibration near the resonance frequency from becoming significantly larger, thereby preventing the vibration difference due to the frequency difference from becoming larger. As a result, the movable body 20 vibrates in a manner that does not contact the bottoms 541 and 561 before plastic deformation, and abnormal noise is not generated due to contact.

[0159] The damping portion 72 may be formed of any shape, material, or the like as long as it can prevent the occurrence of strong vibration in the elastic support portion 81 ( 82 ).

[0160] Fig. 9 and Figure 1 σ is a plan view and a partial cross-sectional view of an elastic support portion including a damping portion 72A as a modified example.

[0161] Fig. 9 and Fig.10 The damping portion 72A shown is an elastic body having a T-shaped cross section, and has a plate-like flange 722 and a plug portion 724A provided to protrude from the center portion of the flange 722 .

[0162] In the attenuation part 72A, the insertion part 724A is inserted from one side of the elastic support part 81 between the spring parts, specifically between the outer peripheral part 806 and the deformable arm 804, and the flange 722 is located at a position spanning between the spring parts. The mounting part 73 is a thermosetting resin or an adhesive that is not fixed to the elastic support part 81, and is fixed to the insertion part 724A on the back side of the elastic support part 81 in a shape that prevents the insertion part 724A from being separated from the spring parts.

[0163] With this structure, the damping portion 72A can reduce component costs compared to the damping portion 72 having an H-shaped cross section, achieve the same damping effect as the damping portion 72 , suppress the resonance peak, and generate stable vibration over a wide range.

[0164] That is, in the vibration actuator 10, the movable body 20 is considered to be equivalent to the mass part in the vibration model of the spring-mass system, so when the resonance is strong (with a steep peak), the steep peak is suppressed by attenuating the vibration. By reducing the vibration so that the resonance is no longer steep, the maximum amplitude value and the maximum movement amount of the movable body 20 during resonance will not be uneven, and a suitable and stable vibration with the maximum movement amount is output.

[0165] In the vibration actuator 10, Fig.11 In the vibration actuator 10, the coils 61 and 62 are arranged so that the coil axes are orthogonal to the magnetic flux from the movable cores 41 and 42, which sandwich the magnet 30 in the vibration direction. Fig.11 When the coils 61 and 62 are energized as shown, a Lorentz force in the −f direction is generated in the coils 61 and 62 based on the interaction between the magnetic field of the magnet 30 and the current flowing through the coils 61 and 62 according to Fleming's left-hand law.

[0166] The Lorentz force in the -f direction is a direction orthogonal to the direction of the magnetic field and the direction of the current flowing through the coils 61 and 62. The coils 61 and 62 are fixed to the fixed body 50 (coil holding portion 52), so according to the law of action and reaction, a force opposite to the Lorentz force in the -f direction is generated in the movable body 20 having the magnet 30 as a thrust in the F direction. As a result, the movable body 20 having the magnet 30 moves laterally in the F direction, that is, to the bottom 541 side of the upper housing 54.

[0167] In addition, if the energization direction of the coils 61 and 62 is switched to the opposite direction and the coils 61 and 62 are energized, a Lorentz force in the opposite direction F is generated. By generating the Lorentz force in the F direction, according to the law of action and reaction, a force opposite to the Lorentz force in the F direction is generated in the movable body 20 as a thrust (thrust in the -F direction), and the movable body 20 moves in the -F direction, that is, to the bottom 561 side of the lower housing 56 of the fixed body 50.

[0168] The vibration actuator 10 comprises: a fixed body 50 having coils 61, 62; a movable body 20 having a magnet 30, which is magnetized in the axial direction of the coils 61, 62 and is arranged radially inward of the coils 61, 62; and flat-plate-shaped elastic support parts 81, 82, which elastically hold the movable body 20 in a manner that the movable body 20 can move freely in the vibration direction.

[0169] In addition, the inner body portion 522 is provided between the outer peripheral surface 30 a of the movable body 20 and the coils 61 , 62 , and the elastic support portions 81 , 82 support the movable body 20 so that the movable body 20 does not contact the inner body portion 522 when the movable body 20 is not vibrating or vibrating.

[0170] Thus, the movable body 20 is supported with a gap between the fixed body 50 and the inner main body portion 522 when in an immovable non-vibrating state and when in a movable, i.e., vibrating state, so that the movable body 20 does not come into contact with the fixed body 50 when in a movable, i.e., vibrating state.

[0171] In addition, only when the vibration actuator 10 itself is impacted, such as when the vibration actuator 10 falls, the movable body 20 contacts the inner body portion 522. That is, only when there is an impact, the movable body 20 and the inner body portion 522 move relatively in the range between the outer peripheral surface 20a of the movable body 20 and the inner peripheral surface 522a of the inner body portion 522, and the movable body 20 contacts the inner body portion 522, so that the movement is restricted.

[0172] Like this, according to the vibration actuator 10, different from the previous vibration actuator, by applying impact to the vibration actuator 10, the movable body 20 is displaced and contacts with the inner wall of the fixed body, and no impact is brought. That is to say, the coil 61,62 of the fixed body 50 will not be damaged by impact. In addition, along with the impact, the movement of the movable body 20 is limited by the inner main body 522, so that the elastic support parts 81,82 themselves will not be deformed by the impact, and the undesirable conditions such as the immovable movable body 20 caused by the deformation of the elastic support parts 81,82 can be eliminated. In addition, the vibration actuator 10 is a structure that enables the movable body 20 to reciprocate in a non-sliding manner along the axis, so when the movable body 20 moves, there will certainly be no sliding sound between the axis.

[0173] As described above, according to the vibration actuator 10 , it is possible to output appropriate body-felt vibration having high vibration expression while having impact resistance.

[0174] Here, the power supply unit (for example, Fig.16 and Fig.17 The vibration actuator 10 is driven by an AC wave inputted to the coils 61 and 62 by a drive control unit 203 shown in FIG. 1 . That is, the energizing direction of the coils 61 and 62 is periodically switched, and the thrust in the F direction on the bottom 541 side of the upper housing 54 and the thrust in the -F direction on the bottom 561 side of the lower housing 56 are alternately applied to the movable body 20. As a result, the movable body 20 vibrates in the vibration direction (the winding axial direction orthogonal to the radial direction of the coils 61 and 62, or the magnetization direction of the magnet 30).

[0175] Next, the driving principle of the vibration actuator 10 is briefly described. In the vibration actuator 10 of the present embodiment, the mass of the movable body 20 is set to m [kg], and the spring constant of the spring (the elastic support parts 81 and 82 as the spring) is set to K sp In the case of , the movable body 20 is relative to the fixed body 50 at a resonance frequency f calculated by the following formula (1):r [Hz] vibration.

[0176]

Mathematical formula 1

[0177]

[0178] The movable body 20 is considered to constitute the mass part in the vibration model of the spring-mass system. If the resonance frequency f r The movable body 20 is in a resonant state. That is, when the power supply unit inputs an AC wave of the same frequency as the resonant frequency f of the movable body 20 to the coils 61 and 62, r The AC waves of substantially equal frequency can efficiently vibrate the movable body 20 .

[0179] The motion equation and circuit equation representing the driving principle of the vibration actuator 10 are as follows: The vibration actuator 10 is driven based on the motion equation represented by the following equation (2) and the circuit equation represented by the following equation (3).

[0180]

Mathematical formula 2

[0181]

[0182] m: mass [kg]

[0183] x(t): displacement [m]

[0184] K f :Thrust constant [N / A]

[0185] i(t): current [A]

[0186] K sp : Spring constant [N / m]

[0187] D: Attenuation coefficient [N / (m / s)]

[0188]

Mathematical formula 3

[0189]

[0190] e(t): voltage [V]

[0191] R: resistance [Ω]

[0192] L: Inductance [H]

[0193] K e : Back electromotive force constant [V / (rad / s)]

[0194] That is, the mass m [kg], displacement x (t) [m], and thrust constant K in the vibration actuator 10 can be appropriately changed within the range satisfying equation (2).f [N / A], current i(t)[A], spring constant K sp [N / m], attenuation coefficient D [N / (m / s)], etc. In addition, the voltage e(t) [V], resistance R [Ω], inductance L [H], back electromotive force constant K can be appropriately changed within the range satisfying equation (3). e [V / (rad / s)].

[0195] Thus, in the vibration actuator 10, the resonance frequency f r When the corresponding AC wave is energized to the coils 61 and 62, a large vibration output can be obtained efficiently. The resonance frequency f r The mass m of the movable body 20 and the spring constant K of the elastic support parts 81 and 82 as leaf springs are sp decided.

[0196] In addition, the vibration actuator 10 is driven by a resonance phenomenon that satisfies equations (2) and (3) and uses the resonance frequency shown in equation (1). Thus, in the vibration actuator 10, the power consumed in a stable state is only the loss at the attenuation portion 72, so that it can be driven with low power consumption, that is, the movable body 20 can be made to perform linear reciprocating vibration with low power consumption.

[0197] According to the present embodiment, the plate-shaped elastic support parts 81 and 82 are arranged above and below (in the vibration direction) the movable body 20, so that the movable body 20 can be stably driven in the up and down directions while the magnetic flux of the coils 61 and 62 can be efficiently distributed from the upper and lower elastic support parts 81 and 82 of the magnet 30. As a result, high-output vibration can be achieved as a vibration motor.

[0198] In addition, the fixed body 50 has a coil holding portion 52, which has both the function of holding the coils 61 and 62 and the function of protecting the coils 61 and 62 from the movable body 20. Thus, even when the vibration actuator 10 is impacted, the fixed body 50 can withstand the impact and will not cause damage such as deformation to the elastic support portions 81 and 82. In addition, for the coils 61 and 62, the impact is transmitted via the inner main body portion 522 made of resin, so it is possible to suppress damage and realize a vibration actuator 10 with high reliability.

[0199] (Implementation Method 2)

[0200] Fig.14 2 is a longitudinal sectional view showing a vibration actuator according to a second embodiment of the present invention. Fig.15 It is an exploded perspective view of a vibration actuator according to Embodiment 2 of the present invention.

[0201] Fig.14 and Fig.15 The vibration actuator 10A shown has Figures 1 to 13 The same basic structure as the vibration actuator 10 corresponding to the embodiment 1 shown is that only the coil holding portion 52A is changed in the structure of the vibration actuator 10. In the vibration actuator 10A, the same structure as the vibration actuator 10 has the same effect. Below, the same reference numerals are used for the same components, and repeated descriptions are omitted.

[0202] Right now, Fig.14 and Fig.15 In the vibration actuator 10A shown, the movable body 20A is housed in a cylindrical fixed body 50A so that the movable body 20A can vibrate in the axial direction of the cylindrical shape. When the movable body 20A moves, the vibration actuator 10A itself becomes a vibrating body.

[0203] The vibration actuator 10A includes a movable body 20A having a magnet 30 and movable body cores 41 , 42 , a fixed body 50A having coils 61 , 62 , and plate-shaped elastic support parts 81 , 82 that support the movable body 20A so that the movable body 20A can reciprocate relative to the fixed body 50A.

[0204] In the vibration actuator 10A, in the cylindrical coil holding portion 52A disposed so as to surround the outer periphery of the magnet 30 , the coils 61 and 62 are held on the outer periphery side of the coil holding portion 52A.

[0205] The coil holding portion 52A is cylindrical, and has a concave coil mounting portion 522A on the outer peripheral side that opens radially outward and arranges the coils 61 and 62. The coil mounting portion 522A is formed by convex ridges 528A, 528A, and 526A that protrude from the outer surface of the cylindrical portion in the axial direction at intervals. The coils 61 and 62 arranged in the coil mounting portion 522A are fixed in the coil mounting portion by bonding or the like in a state surrounded and sealed by the electromagnetic shielding portion 58 that surrounds the outer peripheral surface of the coil holding portion 52A. In addition, the coil mounting portion 522A is formed in a concave shape that extends circumferentially and opens radially outward on the outer periphery of the coil holding portion 52A, and therefore also functions as a coil insertion portion that can insert the coils 61 and 62 from the radial outside.

[0206] The coils 61 and 62 are wound around the coil wires from the outside of the coil holding portion 52A and are arranged in a winding manner on the coil holding portion 52A. Thus, in order to maintain the cylindrical coils 61 and 62, it is possible to assemble without using self-fusing wires, and the same effect as that of the first embodiment can be achieved, and the cost of the coils 61 and 62 themselves can be reduced, and the overall cost of the vibration actuator 10A can also be reduced.

[0207] (Electronic equipment example)

[0208] Fig.16 and Fig.17 It is a figure which shows an example of the mounting form of the vibration actuator 10, 10A. Fig.16 An example in which the vibration actuator 10 is mounted on the game controller GC is shown. Fig.17 An example in which the vibration actuator 10 is mounted on a portable terminal M is shown.

[0209] The game controller GC is connected to the game machine body by wireless communication, and is held or grasped by the user for use. Here, the game controller GC has a rectangular plate shape, and the user grasps the left and right sides of the game controller GC with both hands for operation.

[0210] The game controller GC notifies the user of the command from the game console body by vibration. In addition, although not shown, the game controller GC has functions other than the command notification, such as an input operation unit for the game console body.

[0211] The portable terminal M is a portable communication terminal such as a mobile phone or a smartphone. The portable terminal M notifies the user of an incoming call from an external communication device by vibration and realizes various functions of the portable terminal M (for example, a function of providing an operational sense or a sense of presence).

[0212] like Fig.16 and Fig.17 As shown, the game controller GC and the portable terminal M respectively have: a communication unit 201, a processing unit 202, a drive control unit 203, and a vibration actuator 10 as a drive unit, that is, vibration actuators 10B, 10C, and 10D. In addition, a plurality of vibration actuators 10B and 10C are installed in the game controller GC.

[0213] In the game controller GC and the portable terminal M, the vibration actuators 10B, 10C, and 10D are installed, for example, in such a manner that the main surface of the terminal is parallel to a surface orthogonal to the vibration direction of the vibration actuators 10B, 10C, and 10D, and in this case, the main surface of the terminal is installed in such a manner that the main surface of the terminal is parallel to the bottom surface of the lower housing 56. The main surface of the terminal is a surface in contact with the body surface of the user. In the present embodiment, the main surface of the terminal refers to a vibration transmission surface that contacts the body surface of the user and transmits vibration.

[0214] Specifically, in the game controller GC, the vibration actuators 10B and 10C are installed in a manner that the vibration direction of the vibration actuators 10B and 10C is orthogonal to the surface that the fingertips, finger pulps, palms, etc. of the user who performs the operation contact, or the surface provided with the operating portion. In addition, in the case of the portable terminal M, the vibration actuator 10D is installed in a manner that the vibration direction of the vibration actuator 10D is orthogonal to the display screen (touch panel surface). Thus, the vibration in the direction perpendicular to the main surface of the game controller GC and the portable terminal M is transmitted to the user.

[0215] The communication unit 201 is connected to an external communication device through wireless communication, receives a signal from the communication device and outputs it to the processing unit 202. In the case of a game controller GC, the external communication device is a game console body as an information communication terminal, and communicates according to 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 communicates according to a mobile communication standard.

[0216] The processing unit 2σ2 converts the input signal into a drive signal for driving the vibration actuators 10B, 10C, and 10D through a conversion circuit unit (not shown) and outputs the signal to the drive control unit 203. In addition, in the portable terminal M, the processing unit 202 generates a drive signal based on signals input from various functional units (not shown, such as operating units such as a touch panel) in addition to the signal input from the communication unit 201.

[0217] The drive control unit 203 is connected to the vibration actuators 10B, 10C, and 10D, and is provided with a circuit for driving the vibration actuators 10B, 10C, and 10D. The drive control unit 203 supplies a drive signal to the vibration actuators 10B, 10C, and 10D.

[0218] The vibration actuators 10B, 10C, and 10D are driven based on the drive signal from the drive control unit 203. Specifically, in the vibration actuators 10B, 10C, and 10D, the movable body 20 vibrates in a direction perpendicular to the main surface of the game controller GC and the portable terminal M.

[0219] It is also possible that the movable body 20 contacts the bottom 541 of the upper housing 54 or the bottom 561 of the lower housing 56 via the shock absorber each time it vibrates. In this case, the impact on the bottom 541 of the upper housing 54 or the bottom 561 of the lower housing 56 caused by the vibration of the movable body 20, that is, the impact on the housing, is directly transmitted to the user as vibration. In particular, a plurality of vibration actuators 10B and 10C are installed in the game controller GC, so that one of the plurality of vibration actuators 10B and 10C can be driven or two can be driven simultaneously in response to the input drive signal.

[0220] Since the vibration in the direction perpendicular to the body surface is transmitted to the body surface of the user in contact with the game controller GC or the portable terminal M, sufficient somatosensory vibration can be provided to the user. In the game controller GC, one or both of the vibration actuators 10B and 10C can be used to impart somatosensory vibration to the user, and at least a highly expressive vibration such as selectively imparting strong or weak vibration can be imparted.

[0221] As mentioned above, the invention completed by the present inventors has been specifically described based on the embodiments, but the present invention is not limited to the above-mentioned embodiments and can be modified within the scope not departing from the gist thereof.

[0222] In addition, for example, the vibration actuator 10, 10A of the present invention is suitable for application to portable devices other than the game controller GC and the portable terminal M shown in the embodiment (for example, portable information terminals such as tablet PCs, portable game terminals, and wearable terminals that users wear on their bodies for use). In addition, it is also possible that the vibration actuator 10, 10A of the present invention is used as an exciter, which is a vibration device that emits sound by vibration. The exciter is, for example, a vibration speaker having the following function: making the vibration surface contact with the object without using a conical vibration plate (cone) to emit sound. In addition, it is also possible that the vibration actuator 10, 10A of the present invention is an exciter that cancels and reduces external noise such as road noise by emitting sound. In addition, the vibration actuator 10, 10A of the present invention can also be used as a vibration generator. In addition, in addition to the above-mentioned portable devices, the vibration actuator 10, 10A of this embodiment can also be used for electric beauty instruments such as beauty massagers that require vibration.

[0223] The disclosure of Japanese Patent Application No. 2018-159790 filed on August 28, 2018, including the specification, drawings, and abstract, is incorporated herein by reference in its entirety.

[0224] Industrial Applicability

[0225] The vibration actuator of the present invention has impact resistance and can output appropriate body-felt vibration, and is useful as a component mounted on the following electronic devices: a game terminal that imparts vibration to a user, an exciter or a portable terminal that is a vibration device that emits sound, etc.

[0226] Description of Reference Numerals

[0227] 10, 10A, 10B, 10C, 10D Vibration actuator

[0228] 20, 20A movable body

[0229] 20a Outer surface

[0230] 22, 22A, 24, 24A Spring retainer

[0231] 30 Magnet

[0232] 30a Front

[0233] 30b Back

[0234] 41, 42 movable core (yoke)

[0235] 50, 50A fixed body

[0236] 52, 52A Coil holding part

[0237] 54 Upper shell

[0238] 56 Lower housing

[0239] 58 Electromagnetic shielding part

[0240] 61, 62 Coil

[0241] 72, 72A Attenuation section

[0242] 73 Installation

[0243] 81, 82 elastic support part

[0244] 201 Ministry of Communications

[0245] 202 Processing Department

[0246] 203 Drive control unit

[0247] 226, 246 Spring fixing part

[0248] 522a Inner Surface

[0249] 522 Inner body part (coil protection wall)

[0250] 522A Coil Mounting Section

[0251] 524 Outer body

[0252] 526 Central Ring

[0253] 541, 561 bottom

[0254] 542, 562 surrounding wall

[0255] 722 Flange

[0256] 724 ridge (stuffed part)

[0257] 802 Inner Periphery

[0258] 804 Deformed Arm

[0259] 806 Peripheral part

Claims

1. A vibration actuator, characterized in that: have: a fixed body having a coil; a movable body having a disk-shaped magnet disposed radially inward of the coil so as to be relatively movable in a vibration direction orthogonal to the radial direction; and an upper leaf spring and a lower leaf spring, the upper leaf spring and the lower leaf spring being elastic supporting parts for supporting the movable body in a manner that allows the movable body to be movable relative to the fixed body, and the upper leaf spring and the lower leaf spring being spanned between the fixed body and the movable body in a manner that sandwiches the movable body in the vibration direction, In the vibration actuator, The movable body vibrates relative to the fixed body through the cooperation between the coil to which power is supplied and the disk-shaped magnet. The movable body comprises the disc-shaped magnet, a pair of flat cores and a pair of spring fixings, the pair of flat cores being arranged on the front and back sides of the disc-shaped magnet, one end of each of the pair of spring fixings in the vibration direction is embedded in the central part of the pair of flat cores to be positioned and connected to the pair of flat cores, the other end of each of the pair of spring fixings in the vibration direction is connected to the radial inner end of the upper leaf spring or the lower leaf spring, and the weight main body of each of the pair of spring fixings is arranged between the one end and the other end of each of the pair of spring fixings in the vibration direction of the movable body, The fixed body has a coil protection wall portion, which is arranged in a manner to surround the movable body and hold the coil, and the coil protection wall portion is arranged at a distance from the disc-shaped magnet on the radial inner side of the coil to prevent the disc-shaped magnet from contacting the coil. The fixed body supports the movable body by means of the upper leaf spring and the lower leaf spring in such a manner that the movable body having the disc-shaped magnet, the flat core and the spring fixing part can vibrate along the axial direction of the coil on the radial inner side of the coil and the movable body does not contact the fixed body when the movable body is not vibrating and when it is vibrating.

2. The vibration actuator according to claim 1, wherein: The fixed body has an electromagnetic shielding portion, which is arranged radially outside the coil and is longer than the interval between the two ends of the pair of flat cores in the vibration direction and shorter than the interval between the upper leaf spring and the lower leaf spring in the vibration direction.

3. The vibration actuator according to claim 1, wherein: The upper leaf spring and the lower leaf spring are flat plate disc-shaped coil springs provided with a damping portion that damps vibration due to elastic deformation.

4. An electronic device, characterized in that: The vibration actuator according to claim 1 is installed.

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