Vibration actuators and electrical equipment

Abstract

To generate suitable vibration output in a wide frequency band according to a use environment or the like while achieving miniaturization.SOLUTION: A vibration actuator includes: a movable body which has a columnar magnet; and a fixed body which has a coil and a body section which has an inner peripheral surface surrounding the movable body with a gap between the inner peripheral surface and an outer peripheral surface of the movable body inside the coil and supports the movable body so as to be vibrated in an axial direction of the movable body through an elastic support section. The vibration actuator is configured to cause the gap to generate a flow of fluid in a direction opposite to a moving direction of the movable body and generate pipeline resistance with respect to the fluid.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vibration actuator and an electrical device equipped therewith. [Background technology]

[0002] Traditionally, electronic devices with vibration functionality have incorporated vibration actuators as vibration sources. These devices utilize vibration actuators to transmit vibrations to the user, providing stimulation, notifying of incoming calls, and enhancing tactile feedback and a sense of realism. Electronic devices primarily include handheld electronic devices such as portable game consoles, controllers (gamepads) for home game consoles, mobile communication devices like mobile phones and smartphones, and personal information devices like tablet PCs. Vibration actuators are also sometimes incorporated into wearable devices attached to clothing or arms.

[0003] As a vibration actuator with a structure that can be miniaturized for implementation in portable devices, for example, as shown in Patent Document 1, vibration actuators used in pagers and the like are known.

[0004] This vibration actuator consists of a pair of plate-shaped elastic bodies arranged opposite each other, each supported by the open edge of a cylindrical frame. In addition, this vibration actuator has a yoke with a magnet attached fixed to the raised central portion of one of the spiral-shaped plate-shaped elastic bodies, and the yoke is supported within the frame.

[0005] The yoke, together with the magnet, forms a ring-shaped magnetic field generator. Within the magnetic field of this generator, the coil is positioned attached to the other plate-shaped elastic body. By applying currents of different frequencies to the coil through an oscillation circuit, the pair of plate-shaped elastic bodies resonate selectively and generate vibrations, causing the yoke to vibrate within the frame in the direction of the frame's centerline.

[0006] In this vibration actuator, the distance between the magnet and the coil, and between the yoke and the coil, is greater than the distance between the yoke and the inner wall of the frame. This prevents damage to the coil by ensuring that, in the event of an external impact, the yoke first collides with the inner wall of the frame, preventing the yoke and magnet from contacting the coil. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 3748637 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Incidentally, vibration actuators, as vibration generators, are being miniaturized while maintaining high output, in line with the miniaturization of the products they are installed in. In this miniaturized structure, it is desirable to generate vibrations across a wide frequency range depending on the environment in which it is used.

[0009] This invention has been made in view of the above, and aims to provide a vibration actuator and electrical equipment that can be miniaturized and generate suitable vibration output over a wide frequency range depending on the environment in which it is used. [Means for solving the problem]

[0010] One embodiment of the vibration actuator of the present invention is: A movable body having a columnar magnet, The coil and the inside of the coil It is set up in A gap is created between the outer surface of the movable body and the outer surface of the movable body. form Having an inner circumferential surface surrounding the movable body, and Main body portion that supports the movable body via an elastic support portion so that it can vibrate in the axial direction of the movable body Equipped with A fixed body and It has, The outer circumferential surface of the movable body has a length that protrudes from the inner circumferential surface of the main body on both sides in the axial direction, and this length is configured such that the gap formed between the inner circumferential surface and the movable body, both when the movable body is not moving and when it is moving, has a uniform width in the radial direction and extends with that uniform width along the axial direction. It is configured to cause a fluid flow in a direction opposite to the moving direction of the movable body in the gap and to generate a pipe resistance against the fluid.

[0011] One aspect of the electrical device of the present invention is a handheld or wearable electrical device, and adopts a configuration in which the vibration actuator having the above configuration is mounted on a contact portion with a user.

Advantages of the Invention

[0012] According to the present invention, while achieving miniaturization, it is possible to generate a suitable vibration output in a wide frequency band according to the environment in which it is used and the like.

Brief Description of the Drawings

[0013] [Figure 1] It is an external perspective view of a vibration actuator according to an embodiment of the present invention as viewed from the front side. [Figure 2] It is a plan view of the vibration actuator. [Figure 3] It is a sectional view taken along line A-A of FIG. 2. [Figure 4] It is a view showing a state in which a case and a drive unit inside thereof are disassembled in the same vibration actuator. [Figure 5] In the drive unit, it is a view showing an outer surface of a coil assembly with an outer yoke removed from the coil assembly. [Figure 6] It is an exploded perspective view showing a coil assembly and a movable body. [Figure 7] It is a perspective view showing a movable body and an elastic support portion. [Figure 8] It is an exploded perspective view of a movable body and an elastic support portion. [Figure 9] It is an exploded perspective view of a coil assembly. [Figure 10] It is a perspective view showing an internal structure of a case. [Figure 11] It is a perspective view showing a back surface of a lid body. [Figure 12] It is a partially enlarged sectional view for explaining a gap and a movable space. [Figure 13] This is a left side view of the vibration actuator used to explain the wire holding mechanism. [Figure 14] Figures 14A and 14B are diagrams illustrating the wire holding mechanism. [Figure 15] This diagram illustrates a modified example of the wire-holding section. [Figure 16] This diagram schematically shows the magnetic circuit configuration of the vibration actuator. [Figure 17] Figures 17A and 17B are diagrams illustrating the operation of the actuator body. [Figure 18] This diagram illustrates the difference in resonant frequency in a vibration actuator depending on whether or not air damping is present. [Figure 19] This figure shows an example of a vibration actuator being implemented in a game controller. [Figure 20] This figure shows an example of a vibration actuator being implemented in a mobile device. [Modes for carrying out the invention]

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

[0015] [Overall configuration of the vibration actuator] Figure 1 is a front perspective view of a vibration actuator according to one embodiment of the present invention, Figure 2 is a plan view of the vibration actuator, and Figure 3 is a cross-sectional view taken along line AA in Figure 2. Figure 4 shows the vibration actuator disassembled, with the case and the drive unit inside it separated. Figure 5 shows the outer surface of the coil assembly with the outer yoke removed from the coil assembly in the drive unit, and Figure 6 is an exploded perspective view showing the coil assembly and the movable body.

[0016] In this embodiment, the terms "upper" and "lower" are 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 19 and 20), the orientation can be reversed (upper and lower) or reversed (left and right). Note that the lead wires shown in Figure 1 are omitted from Figures 3 to 6 and Figure 9 for convenience.

[0017] The vibration actuator 1 is implemented as an electrical device in electronic devices such as portable game terminals (see Figure 19) as a vibration source, realizing the vibration function of the electronic device. This electronic device also includes portable devices such as smartphones (see Figure 20). 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.

[0018] As shown in Figure 1, the vibration actuator 1 is a vibrating body having a columnar case 10, and is formed, for example, in a cylindrical shape.

[0019] In this embodiment, as shown in Figures 1 to 4, case 10 is a hollow cylindrical body composed of multiple case sections, including a case body 11 as the first case and a lid 12 as the second case. Note that case 10 does not have ventilation holes connecting the outside and inside. A detailed description of case 10 will follow later.

[0020] As shown in Figures 1 to 4, the vibration actuator 1 is constructed by housing a drive unit 15 having a vibrating movable body 20 within a case 10. The vibration actuator 1 itself functions as a vibrating body as the movable body 20 moves in the axial direction of the movable body 20, which is the direction of vibration.

[0021] In this embodiment, the drive unit 15 is cylindrical overall, and its central axis (not shown) is parallel to or coaxial with the central axis (not shown) of the case 10, which is also cylindrical. In this embodiment, the vibration direction of the movable body 20 is a linear direction including the F direction and the -F direction (see Figure 16), which extends along the direction of the central axis of the cylindrical drive unit 15.

[0022] The vibration actuator 1 includes a movable body 20 having a magnet 21, a first yoke 23, a second yoke 25, and weights (first weight 27 and second weight 29), a fixed body 40 having coils (a pair of coils 61 and 62), a coil holder 42, and a case, and plate-shaped elastic support parts 81 and 82.

[0023] In the vibration actuator 1, as shown in Figure 3, an annular gap G (see Figure 3; hereinafter simply referred to as "gap G") is provided between the inner circumferential surface 42a of the coil holding portion 42 of the fixed body 40 and the outer circumferential surface 20a of the movable body 20, and the movable body 20 is supported by the fixed body 40 via elastic support portions 81 and 82 so as to be able to vibrate in the axial direction. In this vibration actuator 1, the movable body 20, together with the coil holding portion 42, is included in a drive unit 15 housed in a case 10.

[0024] The vibration actuator 1 is configured to generate fluid flow in the gap G in the direction opposite to the direction of movement of the movable body 20, thereby creating pipeline resistance to the fluid. Details of the gap G will be described later along with the explanation of pipeline resistance.

[0025] The drive unit 15 shown in Figures 3 to 6 includes a coil holding part 42 that, together with the coils 61 and 62, constitutes a coil assembly which is part of the fixed body, an outer yoke 50, a movable body 20, and elastic support parts 81 and 82.

[0026] The drive unit 15 supports the movable body 20, which is positioned within the coil holding portion 42 with a gap G between it and the inner circumferential surface 42a of the coil holding portion 42, via elastic support portions 81 and 82 that are spaced apart and facing each other in the axial direction (vibration direction), so that it can reciprocate freely in the vibration direction while suspended from the coil holding portion 42.

[0027] The drive unit 15 is connected to an external device via a terminal connection portion (connection portion) 43 exposed on its outer circumferential surface (outer circumferential surface of the coil holding portion 42), and receives power from the external device.

[0028] As shown in Figures 3 to 6, the coil assembly is a cylindrical body that, together with the outer yoke 50, constitutes part of the fixed body, and movably houses the movable body 20 inside via elastic support parts 81 and 82.

[0029] <Movable body 20> As shown in Figure 3, the movable body 20 is positioned inside the cylindrical coil holding portion 42 of the fixed body 40, spaced apart in the circumferential direction. The movable body 20 is columnar and connected to the inner circumference 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. The elastic support portions 81 and 82 are attached so as to cover both openings (open ends 427a and 428a) of the cylindrical coil holding portion 42.

[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 42. 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 42 (cylindrical main body portion 422). The outer circumferential surface 20a of the movable body 20 has a length that protrudes from the inner circumferential surface 42a of the coil holding portion 42 on both sides in the axial direction throughout the entire range of motion of the movable body 20, and maintains the generation of pipe resistance that results in an air damping effect throughout the entire range of motion of the movable body 20.

[0031] Figure 7 is a perspective view of the movable body to which the elastic support is attached, and Figure 8 is an exploded perspective view of the movable body to which the elastic support is attached.

[0032] As shown in Figures 6 to 8, the movable body 20 includes a magnet 21, a pair of weights (weight 27, weight 29), and a pair of movable yokes (first yoke 23 and second yoke 25) positioned between the magnet 21 and the pair of weights 27 and 29.

[0033] In this embodiment, as shown in Figures 3, 7, and 8, a magnet 21 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 vibration direction of the magnet 21 (the front surface 21a side and the back surface 21b side shown in Figure 8, which are in the vertical direction in each figure), the first yoke 23 and the second yoke 25, the weight portion 27 and the weight portion 29 are arranged symmetrically around the magnet 21. Specifically, the first yoke 23 and the weight portion 27, and the second yoke 25 and the weight portion 29 are stacked in order on both sides of the vibration direction of the magnet 21.

[0034] In the movable body 20, the outer diameters of the magnet 21, the first yoke 23, the second yoke 25, the weight portion 27, and the weight portion 29 are all the same or approximately the same. The magnet 21, the first yoke 23, the second yoke 25, the weight portion 27, and the weight portion 29 form an axially flat outer surface 20a. As a result, the outer surface 20a of the movable body 20 is flush or approximately flush, and is a flat surface without irregularities.

[0035] When not in operation, the ends of the movable body 20 in the direction of vibration (weight portions 27 and 29) are located outward in the direction of vibration than the ends of the inner circumferential surface 42a of the fixed portion 40 (coil holding portion 42) in the direction of vibration.

[0036] Furthermore, when the movable body 20 is at its maximum amplitude position on both sides of the vibration direction (see Figures 17A and 17B), one of the weights 27 and 29 is configured to be located outside the range where it faces the outer yoke 50 in the radial direction. The weights 27 and 29 are joined to the first yoke 23 and the second yoke 25, which are stacked on the magnet 21, in the axial direction of the magnet, so that the outer circumferential surface 20a of the movable body 20 protrudes on both sides of the vibration direction (axial direction) beyond the inner circumferential surface 42a of the coil holding portion 42 of the fixed body 40 throughout the entire range of motion of the movable body 20.

[0037] In the movable body 20, the nearly flat outer surface 20a without irregularities is specifically the outer surface of the magnet 21, the first yoke 23, the second yoke 25, and a portion of the weights 27 and 29 (weight bodies 272 and 292). These outer surfaces of the magnet 21, the first yoke 23, the second yoke 25, and a portion of the weights 27 and 29 (weight bodies 272 and 292) face each other at a predetermined distance inside the inner surface 42a of the coil holding portion 42, 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 middle of the direction of vibration when the power is not supplied. As shown in Figure 3, the movable body 20 has a stroke length of T × 2, which is the sum of the length T from position K to the inner surface 42a and the length T in the direction away from the inner surface 42a by length T from position K.

[0038] <Magnet 21> As shown in Figures 7 and 8, the magnet 21 is a solid columnar body (including plate-shaped) magnetized in the direction of vibration. For example, in the magnet 21, the front and back surfaces 21a and 21b, which are separated in the direction of vibration, have different polarities. Also, in this embodiment, the magnet 21 is formed in a cylindrical shape (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 21 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 magnets that have recesses or the like. The magnet 21 is, for example, a neodymium sintered magnet. As for processing the magnet 21, grooves may be provided on the front and back surfaces 21a and 21b to hold adhesive when joining the first yoke 23 and the second yoke 25 by adhesive or the like.

[0039] The magnet 21 is positioned at a distance from the coils (a pair of coils 61 and 62) held by the coil holding portion 42 (details will be described later), on the radially inner side of the coils (a pair of coils 61 and 62). Here, "radial direction" is also the direction perpendicular to the axial direction (vibration direction) of the coils (a pair of coils 61 and 62). In other words, the magnet 21 is positioned radially outward, facing the center position in the vibration direction on the inner circumferential surface 42a of the coil holding portion 42. The pair of coils 61 and 62 will also be referred to as "coils 61 and 62" below.

[0040] This radial spacing is the distance between the coils 61 and 62 and the magnet 21 when the cylindrical main body 422 around which the coils 61 and 62 are wound is located radially inward of the coils 61 and 62 and between the coils 61 and 62 and the magnet 21. Furthermore, this spacing is such that the movable body 20 can move without contacting each other in the direction of vibration.

[0041] The magnet 21 may be cylindrical, plate-shaped, or any other shape other than a solid columnar shape, as long as it is positioned inside the coils 61 and 62 with its two magnetization surfaces facing the direction of extension of the coils 61 and 62's axes. Furthermore, it is desirable that the axial center of the magnet 21 coincides with the axial center of the movable body 20.

[0042] <First York 23rd and Second York 25th> The first yoke 23 and the second yoke 25 are magnetic materials and are arranged on the front and back surfaces 21a and 21b of the magnet 21, respectively, to optimize the magnetic circuit of the magnetic flux of the magnet 21. The first yoke 23 and the second yoke 25 are formed in a columnar shape (or plate shape) with thickness in the axial direction and have the same outer diameter as the magnet 21.

[0043] The first yoke 23 and the second yoke 25 are columnar in shape, for example, formed in the shape of a cylinder (which may also be called a disc) with the same diameter as the magnet 21, and each has an outer surface that is flush with the outer surface of the magnet 21. The first yoke 23 and the second yoke 25 are fixed to the front and back surfaces of the magnet 21, and their outer surfaces, together with the outer surface of the magnet 21 and parts of the weight portions 27 and 29, constitute the flat outer surface 20a of the movable body 20.

[0044] The first yoke 23 and the second yoke 25, together with the magnet 21, the coils (a pair of coils 61 and 62), and the outer yoke 50, constitute the magnetic circuit of the vibration actuator 1. The first yoke 23 and the second yoke 25 concentrate the magnetic flux of the magnet 21, allowing it to flow efficiently without leakage, and effectively distribute the magnetic flux flowing between the magnet 21 and the coils (a pair of coils 61 and 62). Preferably, the first yoke 23 and the second yoke 25 are formed from a metallic magnetic material such as SECC (bonderized steel sheet).

[0045] Furthermore, the first yoke 23 and the second yoke 25 may, in addition to functioning as part of the magnetic circuit, also function as the main body of the movable body 20 and as weights. Moreover, the first yoke 23 and the second yoke 25 have the function of positioning the weights 27 and 29 relative to the magnet 21 by aligning their outer diameters when joining weights 27 and 29 with the same outer diameter.

[0046] In this embodiment, the first yoke 23 and the second yoke 25 are the same member formed in the same way, and are symmetrically provided on the front and back surfaces 21a and 21b (upper and lower surfaces) of the magnet 21, sandwiching the magnet 21. The first yoke 23 and the second yoke 25 may be fixed by attraction to the magnet 21, or they may be fixed to the magnet 21 by a thermosetting adhesive such as epoxy resin or an anaerobic adhesive. The first yoke 23 and the second yoke 25 are fixed to the weight portions 27 and 29 by the adhesive described above.

[0047] The joints between the magnet 21 and the first yoke 23 and the second yoke 25 are provided with grooves (not shown) and grooves 252, which serve as reservoirs for adhesive or welding material. The joints between the first yoke 23 and the weight portion 27, and the joints between the second yoke 25 and the weight portion 29 are provided with grooves 232 and grooves (not shown), which serve as reservoirs for adhesive or welding material.

[0048] The grooves 232 and 252 are provided along the circumferential direction on the outer circumference of the front and back surfaces of the first yoke 23 and the second yoke 25, respectively. The grooves 232 and 252 are designed to hold adhesive or welding material used to join members that are laminated and fixed to the first yoke 23 and the second yoke 25, preventing it from spilling radially outward beyond the grooves 232 and 252. In other words, adhesive or welding material will not leak out to the outer circumference from the joints between the magnet 21 and the first yoke 23 and the second yoke 25, or from the joints between the first yoke 23 and the second yoke 25.

[0049] In other words, the grooves 232 and 252 store adhesive that is sandwiched between the objects to be joined and moves radially outward when the magnet 21 and weights 27 and 29 are joined to the front and back surfaces of the first yoke 23 and the second yoke 25, respectively, via adhesive. As a result, the adhesive does not protrude outward from the respective joining portions of the first yoke 23 and the magnet 21, the first yoke 23 and the weight 27, the second yoke 25 and the magnet 21, and the second yoke 25 and the weight 29, and the two are joined together.

[0050] Therefore, the outer surface of the movable body 20, which is formed by joining the magnet 21, the first yoke 23, the second yoke 25, and the weights 27 and 29, can be made smooth.

[0051] The grooves 232 and 252 only need to be provided on at least one of the surfaces that are joined together, and may be provided on the magnet 21 side or the weights 27 and 29 side.

[0052] The grooves 232 and 252 only need to be provided on at least one surface of the front and back surfaces of the first yoke 23 and the second yoke 25, respectively. Since the first yoke 23 and the second yoke 25 have grooves 232 and 252 on their respective front and back surfaces, they can be joined to the magnet 21 and the weights 27 and 29 without having to set their orientation. When the first yoke 23 and the second yoke 25 are formed from SECC or the like, they can be manufactured by press working, making it easy to form the grooves 232 and 252.

[0053] When not vibrating, the first yoke 23 and the second yoke 25 are positioned inside (radially inward) the coil (pair of coils 61, 62), in a direction perpendicular to the axial direction of the coil (pair of coils 61, 62), and facing each of the coils (pair of coils 61, 62).

[0054] Preferably, when the movable body 20 is not vibrating, the first yoke 23 and the second yoke 25 are positioned inside (radially inward) of the pair of coils 61 and 62, in a direction perpendicular to the vibration direction, and facing the center of the vibration direction of the pair of coils 61 and 62.

[0055] Furthermore, in this embodiment, it is preferable that the height of the upper surface of the first yoke 23, which is above the magnet 21, is located below (towards the center) the position of the upper end of the upper coil 61. In addition, it is preferable that the height of the lower surface of the second yoke 25, which is below the magnet 21, is located above (towards the center) the position of the lower end of the lower coil 62. With this configuration, the first yoke 23 and the second yoke 25, together with the magnet 21, coils 61 and 62, and the outer yoke 50, constitute a suitable magnetic path with low magnetic flux leakage and high magnetic efficiency.

[0056] <Weight 27, 29> The weights 27 and 29 are provided on the first yoke 23 and the second yoke 25, respectively, which are joined to the front and back surfaces of the magnet 21 in the direction of vibration (the direction of magnetization of the magnet 21), so as to sandwich the first yoke 23 and the second yoke 25.

[0057] The weights 27 and 29 are positioned symmetrically in the direction of vibration with respect to the center of the vibration direction on the first yoke 23 and the second yoke 25, respectively, increasing the vibration output of the movable body 20. The weights 27 and 29 constitute the ends on both sides of the movable body 20 in the direction of vibration, that is, the ends that are spaced apart from the magnet 21 on both sides in the direction of vibration.

[0058] The weights 27 and 29 are preferably made of a material with a high specific gravity. The weights 27 and 29 are formed of a material with a higher specific gravity than the first yoke 23 and the second yoke 25, and are formed, for example, by copper sintering. The weights 27 and 29 are made of silicon steel sheet (the specific gravity of the steel sheet is 7.70 to 7.98 g / cm³). 3 Materials with a higher specific gravity than those mentioned above (for example, materials with a specific gravity of 16-19 g / cm³) 3 It is preferable that it be formed by tungsten (19.3 g / cm³) to a certain extent. 3 ) may be formed from the like. This makes it possible to increase the mass of the movable body 20 relatively easily, even when the external dimensions of the movable body 20 are set in the design, and to achieve the desired vibration output that provides sufficient vibration for the user to feel.

[0059] The outer diameters of the weight sections 27 and 29 are the same as or approximately the same as the outer diameters of the first yoke 23 and the second yoke 25.

[0060] Each weight portion 27 and 29 has a weight body 272 and 292 having the same or approximately the same diameter as the outer diameter of the first yoke 23 and the second yoke 25, and a spring fixing portion 274 and 294 protruding from the weight body 272 and 292 and connected to the elastic support portions 81 and 82. The weight bodies 272 and 292 are formed in a columnar shape (may also be called plate-shaped) and have a length in the direction of vibration.

[0061] The weights 27 and 29 are formed in a cylindrical shape with end faces spaced apart in the direction of vibration, and are similarly constructed, for example, of the same shape. The weights 27 and 29 are fixed to the first yoke 23 or the second yoke 25 at the end face (one end face) on the magnet 21 side, and elastic support parts 81 and 82 are connected to the other end face (separated from the magnet 21) via spring fixing parts 274 and 294.

[0062] Chamfered portions 276 and 296 are provided at the corners of the other end faces of the weight portions 27 and 29, and spring fixing portions 274 and 294 are provided protruding from the center of the other end faces.

[0063] The chamfered portions 276 and 296 form relief portions that accept the deformation of the elastic support portions 81 and 82, which are connected to the spring fixing portions 274 and 294 and extend radially, when the movable body 20 vibrates, and prevent the deformed elastic support portions 81 and 82 from coming into contact with the movable body 20. This allows the movable body 20 to vibrate appropriately, enabling miniaturization of the vibration actuator 1 while ensuring high vibration output.

[0064] Furthermore, if the weights 27 and 29 are made of non-magnetic material, the expansion of the magnetic circuit configuration of the vibration actuator 1 in the direction of vibration can be suppressed, and the magnetic circuit can be made more compact.

[0065] Since the weights 27 and 29 are made of non-magnetic materials such as sintered copper that do not affect the size of the magnetic circuit, the design freedom of the weights 27 and 29 can be increased in order to obtain the desired vibration characteristics of the movable body 20.

[0066] The spring fixing parts 274 and 294 fix the movable body 20 to the elastic support parts 81 and 82. The spring fixing parts 274 and 294 are arranged along the axis of the weight body 272 and 292 (the central axis of the movable body 20) and have a frustoconical portion and a protruding end.

[0067] The spring fixing parts 274 and 294 constitute both ends of the movable body in the direction of vibration. In the spring fixing parts 274 and 294, the tip protrudes from the center of the frustum-shaped part, and the tip is joined to the inner circumference 802 of the elastic support parts 81 and 82, respectively. The tip has a crimped part formed in the shape of a flange at its tip, and the crimped part is crimped to the inner circumference 802 to fix it to the elastic support parts 81 and 82. Note that the frustum-shaped part does not have to be a frustum-shaped part; it may be a cylinder, a polygonal trapezoid, or a polygon.

[0068] The spring fixing portions 274 and 294 have an outer diameter smaller than the outer diameter of the weight bodies 272 and 292. The spring fixing portion 274 constitutes one end of the movable body 20 in the direction of vibration, that is, the upper end of the movable body 20, and is joined to the inner circumference portion 802, which is the inner diameter side end of the upper leaf spring, which is the elastic support portion 81. The spring fixing portion 294 constitutes the other end of the movable body 20 in the direction of vibration, that is, the lower end of the movable body 20, and is joined to the inner circumference portion 802 of the lower leaf spring, which is the elastic support portion 82.

[0069] When the spring fixing parts 274 and 294 are fitted and joined to the inner circumference parts 802, 802 of the elastic support parts 81 and 82, the inner circumference parts 802, 802 are held between the flange-shaped tip and the upper surface of the conical part, and are securely held by the weight parts 27 and 29.

[0070] The spring fixing parts 274 and 294 are fixed to the elastic support parts 81 and 82 by crimping or the like at their flange-shaped tips (protruding ends). The spring fixing parts 274 and 294 may also be joined to the elastic support parts 81 and 82 by a method combining welding, bonding, and crimping.

[0071] The spring fixing parts 274 and 294 are positioned on the movable body 20 away from the magnetic circuit on the movable body side, which includes the magnet 21 and the first yoke 23 and second yoke 25. This does not restrict the space for the pair of coils 61 and 62 to be placed, meaning that the distance between the magnetic circuit on the movable body side (magnet 21, first yoke 23 and second yoke 25) and the pair of coils 61 and 62 is not increased, and the efficiency of electromagnetic conversion is not reduced. Therefore, the weight of the movable body 20 can be suitably increased, and high vibration output can be achieved.

[0072] <Fixed body 40> Figure 9 is an exploded perspective view of the coil assembly. The fixed body 40 shown in Figures 3 to 6 and 9 houses the movable body 20 having the magnet 21, with a gap G between its inner circumferential surface 42a and the outer circumferential surface 20a of the movable body 10, radially inward of the pair of coils 61 and 62. The fixed body 40 supports the movable body 20 so that it can move freely in the axial direction (which is the vibration direction and also the coil axis direction) via elastic support parts 81 and 82.

[0073] The fixed body 40 includes a case 10, a coil assembly, and an outer yoke 50. The coil assembly includes a coil (a pair of coils 61 and 62) and a coil holding part 42 that holds the coils 61 and 62. The coil assembly, together with the movable body 20, the outer yoke 50, and the elastic support parts 81 and 82, constitutes the drive unit 15.

[0074] The fixed body 40 may not include the case 10, as long as the coil holding portion 42, which holds a pair of coils 61 and 62, supports the movable body 20 movably via elastic support portions 81 and 82.

[0075] The coil holding portion 42 is where the coil 60 (a pair of coils 61 and 62) is arranged, and is made of a non-magnetic material. The coil holding portion 42 may be formed in the shape of a bobbin for holding the coils 61 and 62, for example. The coil holding portion 42 is a cylindrical body made of a resin such as phenolic resin or polybutylene terephthalate (PBT). In this embodiment, the coil holding portion 42 is made of a material containing phenolic resin such as bakelite, which has high flame retardancy.

[0076] Since the coil holding section 42 is made of a material containing phenolic resin, its flame retardancy is enhanced, and even if heat is generated by Joule heating when current flows through the coils it holds (a pair of coils 61 and 62), safety during operation can be improved. In addition, dimensional accuracy is improved, and the positional accuracy of the coils (a pair of coils 61 and 62) is improved, so variations in vibration characteristics can be reduced.

[0077] As shown in Figures 5 and 9, the coil holding portion 42 has a cylindrical body portion 422, flange portions 426 to 428, a routing portion 41 having a terminal lead-out portion 46 and a connecting groove portion 47, and engaging protrusions 44 and 45. The flange portions 426 to 428 are arranged at predetermined intervals on the outer circumferential surface of the cylindrical body portion 422 and protrude radially from the outer circumferential surface.

[0078] The coil holding portion 42 is formed in the shape of a coil bobbin by a cylindrical body portion 422 and flange portions 426-428. The coil holding portion 42 has coil mounting portions 42b and 42c between the flange portions 426-428, around which a coil (a pair of coils 61 and 62) is wound.

[0079] The cylindrical body portion 422 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 flat in the axial direction (vibration direction) and can be described as a flat circumferential surface without irregularities, so that the gap G is maintained at a constant width in the axial direction whether the movable body 20 is moving or not. In other words, the gap G is a distance that allows the movable body 20 to move without contacting the inner circumferential surface 42a when it moves in the vibration direction.

[0080] The inner circumferential surface 42a, together with the outer circumferential surface 20a of the movable body 20, is configured to be axially flat in order to maintain the occurrence of straight pipe losses to the fluid throughout the entire range of motion of the movable body 20.

[0081] The cylindrical body portion 422 is positioned between the magnet 21 and the pair of coils 61 and 62, thereby preventing contact between the magnet 21 and the pair of coils 61 and 62. The cylindrical body portion 422 guides the movable body 20 so that it can reciprocate along its inner circumferential surface 42a.

[0082] In other words, the cylindrical body portion 422 functions as a protective wall portion that protects the movable body 20 from collisions with the pair of coils 61 and 62 when the movable body 20 is driven. The thickness of the cylindrical body portion 422 is such that even if the moving movable body 20 comes into contact with it, it will not have any effect on the pair of coils 61 and 62 on the outer circumference.

[0083] The coil mounting portions 42b and 42c are provided in a concave shape on the outer circumferential surface of the cylindrical main body portion 422.

[0084] Specifically, the coil mounting portions 42b and 42c (see Figure 9) are formed by the outer circumferential surface of the cylindrical body portion 422 and the flange portions 426 to 428, so as to open radially outward from the outer circumferential surface of the cylindrical body portion 422.

[0085] The coil mounting sections 42b and 42c are provided so as to be separated by flange sections 426 to 428. A pair of coils 61 and 62 are wound around the coil mounting sections 42b and 42c. The pair of coils 61 and 62 are wound between the flange sections (also referred to as "end flange sections") 427 and 428 so as to sandwich the central flange section (hereinafter also referred to as "central flange section") 426 in the direction of vibration.

[0086] The coils 61 and 62 within the coil mounting sections 42b and 42c are positioned in a coil-axial direction so as to surround the outer surfaces of the first yoke 23 and second yoke 25 of the movable body 20 (a portion of the outer surface of the magnet 21, the outer surface of the first yoke 23, and the outer surface of the second yoke 25). In other words, when not energized, the length of the pair of coils 61 and 62 in the direction of vibration is longer than the length of the first yoke 23 and second yoke 25 that sandwich the magnet 21 in the direction of vibration, and the pair of coils 61 and 62 are positioned to cover them.

[0087] The central flange portion 426 is formed in an annular shape, projecting radially outward from the outer circumferential surface of the cylindrical main body portion 422, and has an annular outer circumference. A routing portion 41 for routing the winding is provided on a part of the outer circumference of the central flange portion 426.

[0088] In the central flange portion 426, the diameter of the portion excluding the terminal lead-out portion 46, that is, the diameter of the outer peripheral portion 426a, is shorter than the maximum diameter of the other flange portions (end flange portions 427 and 428). In other words, the outer peripheral surface, which is the end face of the outer peripheral portion 426a of the central flange portion 426, has a smaller diameter than the outer peripheral surfaces of the end flange portions 427 and 428, and is positioned further back than the outer ends of the end flange portions 427 and 428. As shown in Figures 5, 6, and 9, the outer peripheral surface of the central flange portion 426, together with a part of the end flange portions 427 and 428, constitutes a concave portion 420 (details will be described later) into which the outer yoke 50 is fitted. The coil mounting portions 42b and 42c are covered by the outer yoke 50.

[0089] The routing section 41 processes the ends (windings 63) of the coils 61 and 62 so that they can be connected to external equipment via the terminal lead-out section 46, and the connecting groove section 47 guides the coil windings 64 into the coil mounting sections 42b and 42c. As a result, the coil windings (for example, windings 64) are routed into the coil mounting sections 42b and 42c so that the coil holding section 42 can suitably hold the coils 61 and 62.

[0090] The terminal lead-out section 46 has a terminal entanglement section 43. As shown in Figures 5 and 9, the terminal entanglement section 43 entangles the windings 63 at the ends of the windings connecting the pair of coils 61 and 62, and functions as a connector connection section for connecting to external equipment. The terminal entanglement section 43 connects the pair of coils 61 and 62 to external equipment (other than the main body of the vibration actuator, for example, a power supply unit such as a drive control unit), enabling power supply from the external equipment to the pair of coils 61 and 62.

[0091] The terminal-binding portion 43 is a conductive member that protrudes from the outer circumference of the coil-holding portion 42, specifically the cylindrical main body portion 422. The terminal-binding portion 43 has a rod-shaped body for wrapping the coil windings.

[0092] The terminal entanglement portion 43 is provided by press-fitting its base end into the terminal lead-out portion 46, which is projected from the outer circumferential surface of the central flange portion 426 of the coil holding portion 42, specifically onto the outer circumferential surface of the central flange portion 426 of the coil holding portion 42. The windings 63 at the ends of the windings constituting the coils 61 and 62 are entangled and connected to the terminal entanglement portion 43, and are electrically and reliably joined via a ferret 432 formed by solder.

[0093] The terminal lead portion 46 is provided on the central flange portion 426 by protruding from the outer circumferential surface of the central flange portion 426, having a predetermined length in the radial direction, a thickness in the vibration direction, and a width along the circumferential direction, thereby ensuring a press-fit allowance for the terminal binding portion 43. The width of the terminal lead portion 46 is parallel to the tangent to the outer circumference of the central flange portion 426. In this embodiment, the terminal lead portion 46 is formed as a rectangular parallelepiped, with the terminal binding portion 43, that is, both ends of the coils 61 and 62, protruding from its tip surface.

[0094] The terminal lead-out section 46 has a press-fit allowance for fixing the terminal binding section 43 by press-fitting, so the terminal binding section 43 can be firmly held and stably fixed when the terminal binding section 43 is assembled to the coil holding section 42.

[0095] The terminal lead-out section 46, via the terminal entanglement section 43, leads the ends of the coil windings forming the coil (a pair of coils 61, 62) to the outside of the vibration actuator 1 and connects them to the power supply. The terminal lead-out section 46 passes through the outer yoke 50, exposing the terminal entanglement section 43 to the outside of the outer yoke 50, and consequently to the outside of the case 10.

[0096] Since the terminal engagement portion 43 is provided on the terminal lead-out portion 46, even when the outer yoke 50 comes into contact with the terminal lead-out portion 46 and a load is applied to it when the outer yoke 50 is inserted through the terminal lead-out portion 46, the load can be received by the terminal lead-out portion 46. This prevents the load when the outer yoke 50 is attached from being applied to the terminal engagement portion 43, prevents deformation of the terminal engagement portion 43 due to the load, and enables the stable manufacture of the vibration actuator. Alternatively, adhesive portions may be provided on the outer circumferential surfaces of the flange portions 426 to 428 with the same outer diameter, and the outer yoke 50 may be fixed to each of the flange portions 426 to 428 via the adhesive portions. This can achieve more stable vibration characteristics.

[0097] A coil winding 64 connecting a pair of coils (coils 61 and 62) is inserted into the connecting groove 47. In the connecting groove 47 of this embodiment, the winding direction of the coil windings forming coils 61 and 62 is reversed so that it is in opposite directions above and below the connecting groove 47.

[0098] The connecting groove 47 is formed to open radially outward on the outer circumference of the central flange portion 426 and to penetrate along the direction of vibration. Specifically, the connecting groove 47 has a bottom wall portion that forms a groove-shaped bottom and a side wall portion (one side wall portion) that is far from the terminal entanglement portion 43 on the bottom wall portion.

[0099] The connecting groove 47 is covered by the outer yoke 50 at the central flange portion 426. Even when covered by the outer yoke 50, the connecting groove 47 connects the coil mounting portions 42b and 42c in the vibration direction radially inward of the outer yoke 50. The connecting groove 47 is located in close proximity to or adjacent to the terminal lead-out portion 46.

[0100] As shown in Figures 5 and 9, the connecting groove 47 is a notched portion formed adjacent to the terminal lead-out portion 46, having a bottom surface that slopes between parallel walls. The notched portion has the function of locking the windings in place so that they do not come off when winding and positioning one of the coils 61 or 62 after winding and positioning it, and then winding and positioning the other coil in the reverse winding direction. In this embodiment, the connecting groove 47 is formed in a U-shape in plan view, with the bottom wall serving as the bottom surface and both side walls erected at both ends that are spaced apart in the circumferential direction.

[0101] Therefore, when winding the coil windings around the coil mounting portions 42b and 42c in an inverted direction to position the pair of coils 61 and 62, the coil windings 64 are securely engaged with the connecting groove portion 47 and remain in place so as not to come off. As a result, the coil windings 64 are suitably guided by the connecting groove portion 47 from one coil mounting portion 42b and 42c to the other. Thus, the pair of coils 61 and 62 can be easily assembled to the coil holding portion 42 using a single coil winding.

[0102] The routing section 41 has a coil guide section 412 on at least one of the upper and lower surfaces (surfaces separated in the direction of vibration) of the central flange section 426. The coil guide section guides the coil winding 63 from the terminal wrapping section 43 to the position of the first turn (for example, a corner) in the coil winding portion of the coil holding section 42 (one of the coil mounting sections 42b, 42c). In this embodiment, the coil guide section is formed in a stepped manner on the upper and lower surfaces of the central flange section 426, on the upper surface portion up to the connecting groove section 47 adjacent to the terminal lead-out section 46 in the circumferential direction, and on the lower surface portion of the terminal lead-out section 46. The coil guide section is a step provided on the upper and lower surfaces (surfaces in the direction of vibration) of the central flange section 426, and this step is formed to guide the coil winding from the terminal wrapping section 43 so that it can be pulled in to the bottom side of the coil mounting sections 42b, 42c, that is, to the outer peripheral surface side of the cylindrical main body section 422.

[0103] The end flange portions 427 and 428 are provided at both ends of the cylindrical main body portion 422 that are spaced apart in the axial direction, and constitute the upper and lower ends of the coil holding portion 42.

[0104] The end flange portions 427 and 428 (collectively referred to as the "end flange portions") are provided extending radially from the outer circumference of the cylindrical main body portion 422 to both ends in the direction of vibration. The outer circumferences of the end flange portions 427 and 428 each have a portion with the same diameter as the outer circumference 426a of the central flange portion 426. In other words, the upper opening edge in the direction of vibration of the coil mounting portion 42b formed by the end flange portion 427 and the lower opening edge in the direction of vibration of the coil mounting portion 42c formed by the end flange portion 428 are provided with a step that is flush with the outer surface of the central flange portion 426.

[0105] Since the stepped surface of the step lies on the same plane as the outer surface of the central flange portion 426, the end flange portions 427 and 428 constitute portions of the same diameter as the outer surface 426a of the central flange portion 426.

[0106] These stepped surfaces and the outer circumferential surface of the coil holding portion 42 form a concave portion 420 that opens radially outward. When the outer yoke 50 is fitted into the concave portion 420, the outer yoke 50 is positioned on the coil holding portion 42 such that the outer surface of the outer yoke 50 and the outer surfaces of the end flange portions 427 and 428 are flush.

[0107] By positioning the outer yoke 50 in the concave portion 420, the outer yoke 50 is positioned to surround the pair of coils 61 and 62. Furthermore, the outer yoke 50 is stably fixed to the coil holding portion 42 by contacting the outer circumference 426a and the portion of the end flanges 427 and 428 that has the same diameter as the outer diameter of the central flange portion 426. This allows the outer yoke 50 to be stably fixed using a mounting method that accommodates its increased height (length in the direction of vibration).

[0108] The end flange portions 427 and 428 are formed in a cylindrical shape, each opening in a direction away from the central flange portion 426, for example, in the vertical direction. Elastic support portions 81 and 82 are fixed at the open ends of the end flange portions 427 and 428, i.e., the upper and lower ends.

[0109] The end flange portions 427 and 428 have an opening that opens in the vertical direction, a horizontal annular surface extending radially outward from the upper end of the cylindrical main body portion 422, a circumferential surface rising inclined from the outer edge of the annular surface, and an outer peripheral portion rising parallel to the axial direction from the radially outward end of the circumferential surface. The outer peripheral portion rising parallel to the axial direction from the radially outward end of the circumferential surface is a wall portion that separates the opening ends 427a and 428a.

[0110] The engaging protrusions 44 and 45 are protruding portions that protrude in the direction of vibration (vertical direction) at the upper and lower ends of the coil holding portion 42, that is, at the upper and lower annular opening ends of the end flange portions 427 and 428 (also referred to as "openings of the coil holding portion 42") 427a and 428a, respectively.

[0111] As shown in Figures 3 and 4, the engaging projections 44 and 45 engage with the engaging recess 127 of the lid 12 of the case 10 and the engaging recess 117 of the case body 11 (see Figures 10 and 11). By engaging with the engaging recesses 127 and 117, the engaging projections 44 and 45 position the coil holding portion 42 radially and in the vibration direction relative to the lid 12 and the case body 11, and also position the elastic support portions 81 and 82 that are sandwiched between them radially.

[0112] The engaging protrusions 44 and 45 are positioned to face the top surface 122 of the lid 12 and the bottom surface 114 of the case body 11, respectively, and the end flanges 427 and 428 receive the top surface 122 and bottom surface 114, respectively, with the elastic support parts 81 and 82 in between.

[0113] The elastic support parts 81 and 82 are positioned relative to the coil holding part 42 by fitting the engaging protrusions 44 and 45 into the positioning grooves 808. This allows the positions of the elastic support parts 81 and 82 to be uniformly set for each individual drive unit 15, enabling stable positioning of the elastic support parts 81 and 82 relative to the coil holding part 42. 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.

[0114] Multiple engaging protrusions 44 and 45 are provided at equal intervals around the axis of the coil holding portion 42.

[0115] Furthermore, multiple engaging protrusions 44 and 45 engage with the positioning grooves 808 of the elastic support parts 81 and 82. This reduces snagging and friction when inserting the movable body 20 into the coil holding part 42 of the elastic support parts 81 and 82, allowing for easy assembly and facilitating the positioning of the movable body 20 and the coil holding part 42.

[0116] Furthermore, the coil holding portion 42 is housed and fixed within the case by engaging the engaging protrusions 44 and 45 at its upper and lower ends with the engaging recesses 127 and 117 of the case 10, so that it faces the edge of the lid portion 12 and the edge of the bottom portion 114.

[0117] When not in operation, the coil holding portion 42 supports the movable body 20 via the elastic support portions 81 and 82 such that both edges of the outer circumferential surface of the movable body 20 in the direction of vibration protrude more in the direction of vibration than both edges of the inner circumferential surface 42a in the direction of vibration. Furthermore, even when in operation, the coil holding portion 42 supports the movable body 20 such that the cylindrical outer circumferential surface 20a of the movable body 20 forms a gap G of a certain length (width) extending in the direction of vibration relative to the inner circumferential surface 42a.

[0118] <Coils 61, 62> In the vibration actuator 1, the pair of coils 61 and 62, along with the magnet 21, the first yoke 23, and the second yoke 25, constitute a magnetic circuit used to generate a drive source, with the axial direction of the pair of coils 61 and 62 (the magnetization direction of the magnet 21) being the direction of vibration.

[0119] The pair of coils 61 and 62 are energized during operation (vibration) and, together with the magnet 21, constitute a voice coil motor. In this embodiment, one pair of coils 61 and 62 are used, but one or more coils may be used as long as they constitute a magnetic circuit that drives in a similar manner. However, it is desirable that the number of coils be even so that they are symmetrical in the direction of vibration.

[0120] The pair of coils 61 and 62 are positioned symmetrically with respect to the magnet 21 in the direction of vibration with respect to the movable body 20, which has the magnet 21, the first yoke 23 and the second yoke 25, etc. Preferably, the center position of the length of the coils 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 21) in the direction of vibration.

[0121] In this embodiment, the pair of 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.

[0122] Each end of the pair of coils 61 and 62, that is, both ends of the windings of the coils that make up the pair of coils 61 and 62, are connected by being wrapped around the terminal wrapping portion 43 of the flange portion 426.

[0123] The pair of coils 61 and 62 are connected to a power supply unit (for example, the drive control unit 203 shown in Figures 19 and 20) via a terminal connection section 43. For example, each end of the pair of coils 61 and 62 is connected to an AC power supply unit via the terminal connection section 43, and AC power (AC voltage) is supplied from the AC power supply unit to the pair of coils 61 and 62. As a result, the pair of coils 61 and 62 can generate thrust between themselves and the magnet, allowing them to move toward and away from each other in their respective axial directions.

[0124] In this embodiment, as shown in Figure 9, the pair of coils 61 and 62 are connected to one end of the terminal wrapping portion 43, and the other end of the coil winding is guided by a step in the coil guide portion 412 on the coil mounting portion 42b to the position where the first winding is formed at the coil mounting portion 42b. At this first winding position, the winding is wound counterclockwise to form the first winding, and then the coil 62 is formed by winding sequentially counterclockwise.

[0125] Next, the winding on the other end of coil 62 is guided to the coil mounting portion 42c in the connecting groove portion 47 as described above, and the winding direction is reversed within the connecting groove portion 47 to position it at the first winding position of the coil mounting portion 42c. After that, it is wound in the opposite direction to that of the coil mounting portion 42b, and in this embodiment, it is wound clockwise to form coil 61 within the coil mounting portion 42c. In this embodiment, the coil (a pair of coils 61, 62) is made from a single winding, but it is not limited to this, and it may be made using separate coils (a pair of coils 61, 62). In this configuration, if the separate coils are made by winding the wire in the same direction, they will each be supplied with current in different directions when driven.

[0126] Furthermore, it is preferable that the coil shafts of the pair of coils 61 and 62 be arranged coaxially with the shaft of the coil holder 42 or the shaft of the magnet 21.

[0127] In the vibration actuator 1, the pair of coils 61 and 62 are formed into a cylindrical shape by winding the coil windings around the coil mounting parts 42b and 42c from the outside of the coil holding part 42. As a result, the coils 61 and 62 can be assembled without using self-fusing wire, thereby reducing the cost of the coils (the pair of coils 61 and 62) themselves, and ultimately reducing the cost of the entire vibration actuator.

[0128] <Outer Yoke 50> The outer yoke 50 is a cylindrical magnetic material and, as shown in Figures 3 to 5, is positioned to surround the outer circumferential surface of the coil holding portion 42 and to cover the pair of coils 61 and 62 radially outward.

[0129] As described above, the outer yoke 50, 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 21, the first yoke 23, and the second yoke 25, constitutes the magnetic circuit. The outer yoke 50 prevents leakage magnetic flux from the vibration actuator 1 to the outside in the magnetic circuit.

[0130] The outer yoke 50 can increase the thrust constant in the magnetic circuit, thereby improving electromagnetic conversion efficiency. The outer yoke 50 utilizes the magnetic attraction force of the magnet 21 and functions as a magnetic spring together with the magnet 21, which can reduce the stress on the elastic support parts 81 and 82 when they are made into mechanical springs, thereby improving the durability of the elastic support parts 81 and 82.

[0131] In the vibration actuator 1, the coils 61 and 62 are energized via the terminal connection part 43, causing the coils 61 and 62 and the magnet 21 to cooperate, resulting in the movable body 20 reciprocating in the vibration direction within the case 10.

[0132] The outer yoke 50 is positioned such that the center of its length in the direction of vibration is at the same height as the center of vibration of the magnet 21 located inside it. This shielding effect of the outer yoke 50 helps to reduce the leakage magnetic flux to the outside of the vibration actuator.

[0133] The outer yoke 50, which is separated in the direction of vibration, is positioned lower than the respective ends of the movable body 20 in the direction of vibration when the movable body 20 is moving. In other words, the outer yoke 50 is configured to have a length that covers both ends of the movable region in the direction of vibration of the laminate formed by stacking the magnet 21, the first yoke 23, and the second yoke 25.

[0134] The outer yoke 50 has a yoke body 51 and an opening 53 provided in the center of the yoke body 51 in the direction of vibration.

[0135] The yoke body 51 is a cylindrical magnetic material, and is formed from, for example, SECC (electro-galvanized steel sheet) which has excellent weldability and corrosion resistance.

[0136] In this embodiment, the yoke body 51 is flexible and has a slit parallel to the axial direction in a part of its peripheral wall. The yoke body 51 is formed in a C-shaped cylindrical form when viewed in plan. When attaching the yoke body 51 to the outer circumference of the coil holding portion 42, the space between the ends 52 that constitute the slit portion is widened to position the coil holding portion 42 inside the yoke body 51. Then, the deformation of the yoke body 51 is returned to its original state and the yoke body 51 is fitted into the concave portion 420 on the outer circumference of the coil holding portion 42, thereby attaching the yoke body 51 to the coil holding portion 42.

[0137] The opening 53 allows wiring connecting external equipment to coils 61 and 62 to pass through. The opening 53 is provided in the center of the slit portion of the yoke body 51, extending in the circumferential direction. The upper and lower edges that partition the opening 53 are formed by end portions 52 that extend circumferentially from each other and face each other in the circumferential direction on the yoke body 51.

[0138] A terminal lead-out section 46 is inserted into the opening 53. This positions the terminal entanglement section (wiring section) 43, which is connected to the coils 61 and 62, within the opening 53. In the drive unit 15, the terminal entanglement section (wiring) 43 is positioned to protrude and be exposed outside the outer yoke 50 so that it can be connected to external equipment.

[0139] Furthermore, the opening 53, when fitted into the terminal lead-out portion 46, functions as a stopper for the outer yoke 50 to rotate circumferentially relative to the coil holding portion 42.

[0140] In the outer yoke 50, the left and right sides that partition the opening 53 in the circumferential direction may be formed to sandwich the terminal lead-out portion 46.

[0141] <Elastic support parts 81, 82> The elastic support parts 81 and 82 shown in Figures 3 to 7 support the movable body 20 so that it can reciprocate in the vibration direction relative to the fixed body 40.

[0142] The elastic support parts 81 and 82 are installed so as to sandwich the movable body 20 in the direction of vibration of the movable body 20, and so as to intersect the direction of vibration between the movable body 20 and the fixed body 40.

[0143] In this embodiment, as shown in Figures 3 and 7, the elastic support parts 81 and 82 are mounted parallel to each other across both ends (upper and lower ends) of the coil holding part 42 that are separated in the direction of vibration, and across both ends of the movable body.

[0144] The elastic support portions 81 and 82 are formed in a disc shape, and have a shape in which an annular inner circumference portion 802, which is the inner spring end, and an annular outer circumference portion 806, which is the outer spring end, are joined by an elastically deformable, arc-shaped deformable arm 804 in plan view.

[0145] The deformable arm 804 is arranged in a spiral shape connecting the inner circumference 802 and the outer circumference 806, and the deformation of the deformable arm 804 causes the inner circumference 802 and the outer circumference 806 to be displaced relative to each other in the axial direction.

[0146] The elastic support parts 81 and 82 support the movable body 20 so that it can move axially (in the direction of vibration) without contacting the fixed body 40.

[0147] The elastic support parts 81 and 82 are each a plurality of flat leaf springs. The movable body 20 is supported by a pair of elastic support parts 81 and 82, but it may also be supported by three or more leaf springs. These multiple leaf springs are mounted along a direction perpendicular to the direction of vibration.

[0148] The elastic support parts 81 and 82 are protected from damage when the movable body 20 is driven (vibrated) or subjected to external impact, as the movable body 20 contacts the inner circumferential surface 42a of the cylindrical main body 422 but does not contact the pair of coils 61 and 62. Furthermore, the elastic support parts 81 and 82 can be made of any material that elastically supports the movable body 20 in a movable manner. In this embodiment, the elastic support parts 81 and 82 are the same members having the same configuration.

[0149] The inner circumference 802 has a connection hole 802a located in the center of the elastic support parts 81 and 82. The two ends of the movable body 20 that are spaced apart in the direction of vibration are connected to this connection hole 802a by fitting. Specifically, the spring fixing parts 274 and 294 of the weight parts 27 and 29 are inserted into the inner circumference 802 and are sandwiched between the weight part and the flange part of the spring fixing part.

[0150] On the other hand, the outer peripheral portion 806 is attached to the upper and lower ends of the coil holding portion 42, that is, the open ends 427a and 428a of the end flange portions 427 and 428. The outer peripheral portion 806 may be fixed to the open ends 427a and 428a of the end flange portions 427 and 428 by bonding them with an adhesive or the like. Alternatively, the outer peripheral portion 806 may be fixed by sandwiching it between the open ends 427a and 428a and the positioning stepped portions 128 and 118 on the case 10 side, with the engaging projections 44 and 45 engaged with the positioning grooves 808. In this embodiment, the outer peripheral portion 806 is fixed by sandwiching it between the open ends 427a and 428a and the positioning stepped portions 128 and 118 on the case 10 side.

[0151] The leaf springs serving as elastic support parts 81 and 82 can be made from any material that is elastically deformable, and may be formed by sheet metal processing using stainless steel plates, phosphor bronze, etc. In this embodiment, the elastic support parts 81 and 82 are thin, flat, disc-shaped spiral springs made of phosphor bronze, which has high workability, excellent corrosion resistance, and high tensile strength and wear resistance. Furthermore, if they are made of a non-magnetic material such as phosphor bronze, the flow of magnetic flux in the magnetic circuit will not be disturbed at all. The elastic support parts 81 and 82 may also be made of resin, as long as they support the movable body 20 in a vibratory manner. In addition, since the elastic support parts 81 and 82 are flat, their positional accuracy, i.e., processing accuracy, can be improved compared to conical springs.

[0152] In this embodiment, the multiple elastic support parts 81 and 82 are joined to the coil holding part 42 and the movable body 20 in a direction in which the spiral direction is the same.

[0153] In this embodiment, the elastic support parts 81 and 82 are equipped with damping parts 88 attached to the deformable arm 804 or to the deformable arm 804 and its outer circumference 806 to dampen vibrations generated in the elastic support parts 81 and 82.

[0154] Thus, in this embodiment, multiple spiral-shaped leaf springs are used as multiple elastic support parts 81 and 82, with the same spiral orientation, and are attached to the movable body 20 at both ends that are separated in the direction of vibration, thereby elastically supporting the movable body 20 with respect to the fixed body 40.

[0155] As a result, when the amount of movement of the movable body 20 increases, the movable body moves in the translational direction (for example, in a direction perpendicular to the direction of vibration) while rotating slightly. If the vortices of the multiple leaf springs are in opposite directions, the multiple leaf springs will move relative to each other in the buckling or tensile direction, hindering smooth movement.

[0156] In this embodiment, the elastic support parts 81 and 82 are fixed to the movable body 20 so that their spiral directions are the same. Therefore, even if the amount of movement of the movable body 20 increases, they can move smoothly along the vibration direction, that is, they can deform. As a result, it is possible to achieve a larger amplitude and increase the vibration output. However, depending on the desired range of motion of the movable body 20, the design may also involve aligning the spiral directions of multiple elastic support parts 81 and 82 in opposite directions.

[0157] The plate-shaped elastic support parts 81 and 82 are joined to the movable body 20 by fitting their respective inner circumferences 802 to spring fixing parts 274 and 294 that constitute the ends of the movable body 20 in the direction of vibration. Alternatively, adhesive or the like may be applied to the spring fixing parts 274 and 294 to join them to the inner circumference 802. In this case, the spring fixing parts 274 and 294 may be firmly joined to the inner circumference 802 via adhesive that accumulates in arc-shaped notches formed around the inner circumference 802.

[0158] Furthermore, the outer periphery 806 of the elastic support portion 81 is positioned and fixed on the annular open end 427a of the end flange portion 427, avoiding the engaging projection 44. On the other hand, the outer periphery 806 of the elastic support portion 82 is positioned and fixed on the annular open end face 428a of the end flange portion 428, avoiding the engaging projection 45.

[0159] In this manner, the elastic support portions 81 and 82 are held between the open ends 427a and 428a of the upper and lower opening edges of the coil holding portion 42 and the lid portion 12 and bottom portion 114 of the case 10, arranged in a direction perpendicular to the vibration direction.

[0160] Furthermore, the elastic support parts 81 and 82 are attached to the coil holding part 42 and the movable body 20 housed inside the coil holding part 42 so as to close the upper and lower openings of the coil holding part 42 around which the pair of coils 61 and 62 are wound on the outer circumference.

[0161] The elastic support parts 81 and 82 are joined to the movable body 20 by crimping the connection hole 802a of the inner circumference 802 to the spring fixing parts 274 and 294 of the weight parts 27 and 29 at the upper and lower ends of the movable body 20. The positioning groove 808 is engaged with the engaging projections 44 and 45, and the outer circumference 806 is fixed in contact with the open ends 427a and 428a of the coil holding part 42. This configures the drive unit 15 with a defined positional relationship between the coil (a pair of coils 61 and 62) and the movable body 20, making it easier to place inside the case 10.

[0162] <Damping section (damper) 88> The damping section 88 is attached to the elastic support sections 81 and 82, suppressing the resonance peaks caused by the elastic support sections 81 and 82, and generating stable vibrations over a wide range.

[0163] If the movable body 20, which is supported via the elastic support parts 81 and 82, is positioned with a misaligned central axis within the coil holding part 42, that is, if it is misaligned, the gap G will narrow, and it is expected that the gap G will not be a constant width in the radial direction around the entire circumference of the movable body 20. However, by attaching the damping part 88 to the elastic support parts 81 and 82, the misalignment can be adjusted, allowing the movable body 20 to move in a suitable manner.

[0164] The damping section 88 is formed in an H-shaped cross-section and has, for example, a pair of flanges arranged parallel to each other, sandwiching the elastic support sections 81 and 82, and a rib (indentation section) connecting the central parts of the flanges. It is made of an elastic material such as an elastomer. The damping section 88 is positioned in contact with both the bridge portion of the elastic support section 81, which is a leaf spring, in this embodiment, by inserting the elastomer between the outer circumference 806 and the deformable arm 804. Multiple damping sections 88 are attached to the elastic support section 81 without being fixed to it.

[0165] The damping section 88 dampens the sharp spring resonance in the elastic support sections 81 and 82, preventing the vibration near the resonance frequency from becoming significantly larger and thus preventing large differences in vibration depending on the frequency.

[0166] As a result, even when the movable body 20 vibrates in a way that causes plastic deformation of the elastic support parts 81 and 82, it can vibrate without contacting the top surface 122 and bottom surface 114 before plastic deformation occurs, and no abnormal noise is generated due to contact between the movable body 20 and the top surface 122 and bottom surface 114. The damping part 88 may be formed in any shape, material, etc., as long as it prevents the generation of sharp vibrations in the elastic support parts 81 and 82.

[0167] <Case 10> Figure 10 is a top-side perspective view of the case body 11, and Figure 11 is a bottom-side perspective view of the lid 12.

[0168] As shown in Figures 1 to 3, 10 and 11, the case 10 houses the drive unit 15 by closing the opening 115 of the bottomed cylindrical case body 11 with the lid 12. The case 10 is formed from a resin such as PBT. The case body 11 and the lid 12 may be molded from a resin such as PBT.

[0169] The case body 11 has a cylindrical peripheral wall portion 112, a bottom portion 114 that closes one opening of the peripheral wall portion 112, and a wire holding portion 18. The peripheral wall portion 112 is provided with a notch portion 113 that is cut out on the other opening side, which is the opening 115.

[0170] The lid portion 12 and bottom portion 114 of case 10 constitute the top portion 122 and bottom portion (bottom portion 114) of the vibration actuator 1 in this embodiment, and are positioned opposite the movable body 20 of the drive unit 15 at a predetermined distance in the vibration direction of the movable body 20. The lid portion 12 is provided hanging down from a part of the outer circumference of the top portion 122 and has a hanging portion 124 that engages with the notch portion 113 of the case body 11. Since case 10 is made of resin, the lid portion 12 is joined to the case body 11 by welding and riveting the opening edge of the case body 11. In Figure 10, the opening edge of the case body 11 is shown in its bent shape after riveting.

[0171] The lid 12 and bottom 114 define the maximum range of motion of the movable body 20 within the drive unit 15. The top surface 122 of the lid 12 and the back surface of the bottom 114 of the case body 11 are provided with mortar-shaped (inverted truncated cone) recesses 122b and 114b, respectively. The inclined circumferential surfaces of the recesses 122b and 114b are formed to conform to the deformed state of the elastic support parts 81 and 82.

[0172] The recesses 122b in the top surface 122 and 114b in the bottom surface 114 define the internal space of the lid 112 and bottom surface 114 within the case 10, that is, the movement space outward in the direction of vibration from the elastic support parts 81 and 82 that sandwich the movable body 20, thereby preventing plastic deformation of the elastic support parts 81 and 82.

[0173] Therefore, even when a force exceeding the range of motion is applied to the movable body 20, the elastic support parts 81 and 82 will come into contact with the fixed body 40 (at least one of the lid 12 and the bottom 114) before undergoing plastic deformation. The range of motion is wider in the axial direction (vibration direction) than the range of motion of the movable body 20.

[0174] Recesses 122b and 114b, together with the internal spaces of the lid portion 112 and the bottom portion 114 and the internal spaces of the end flange portions 427 and 428 of the drive unit 15, define the movable spaces GS1 and GS2 of the movable body 20 and the elastic support portions 81 and 82. The movable spaces GS1 and GS2 have a shape that is symmetrical with respect to a cross section perpendicular to the axis passing through the axial center position. That is, the fluid storage capacity of the movable spaces GS1 and GS2 is configured to be approximately the same.

[0175] Furthermore, although the movable spaces GS1 and GS2 are sealed spaces, a minimum number of holes may be provided to eliminate the pressure difference between the inside and outside of the vibration actuator 1, thereby exhibiting an air damping effect due to flow resistance. Such minimum holes may be formed in the joints between the outer circumference 806 of the elastic support parts 81 and 82 and the coil holding part 42 or the positioning step parts 128 and 118 by adhesive bonding.

[0176] Preferably, the volume occupied by the movable body 20 is approximately 50% of the total volume, which includes the movable spaces GS1 and GS2 and the internal space inside the cylindrical body 422 of the fixed body 40. More preferably, the movable body 20 occupies slightly more than 50% of the total volume.

[0177] The movable spaces GS1 and GS2 are formed within the internal space of the case 10 between the outer circumferential surface 20a of the movable body 20 and the inner circumferential surface 42a of the coil holding portion 42, and are connected to both ends of a cylindrical gap G of constant width around the entire circumference of the outer circumferential surface 20a. The movable spaces GS1 and GS2 are a pair of fluid storage chambers in the fixed body 40 that communicate with the gap G at both axial ends of the movable body 20, and store and contain air, which is the fluid.

[0178] As shown in Figure 3, the movable spaces GS1 and GS2 are provided so as to expand in diameter steeply relative to the inner circumferential surface 42a.

[0179] Figure 12 is a partially enlarged cross-sectional view illustrating the gap G and the movable spaces GS1 and GS2. As shown in Figure 12, the movable space GS1 is formed so that the inner circumferential surface on the fixed body side is located at a position where the diameter is steeply expanded (indicated by D1) from the width of the gap G.

[0180] As a result, within the case 10, movable spaces GS1 and GS2, which have a larger outer diameter than gap G, are connected to both ends of a cylindrical gap G that extends in the axial direction, thereby forming the range of motion of the movable body 20. Note that the movable spaces GS1 and GS2 also have a diameter portion (the diameter portion of space S1) that is greater than the length of the outer diameter D1. During travel Details regarding the functions of the movable spaces GS1 and GS2, along with gap G, will be described later.

[0181] As shown in Figure 12, the space S1 between the chamfered portion 276 and the opening (open end 427a) of the coil holding portion 42, which faces the chamfered portion 276 radially outward (in a direction perpendicular to the axial direction), is larger than the diameter of the recess 112b of the movable space GS1. As a result, space S1 expands outward from the movable body 20, and when the weight portion 27 of the movable body 20 moves toward the recess 114b, the air that was in the recess 114b can be released and stored.

[0182] Furthermore, the gap G is the movable body 20 Non-moving In this configuration, the length S2 of the portion of the outer circumferential surface 20a of the movable body 20 that protrudes toward the opening side from the inner circumferential surfaces 42a which are arranged parallel to each other is smaller than the length S2 of the portion of the outer circumferential surface 20a of the movable body 20 that protrudes toward the opening side.

[0183] As shown in Figure 10, a positioning step 118 is provided on the inner surface of the bottom portion 114 from the outer circumference of the recess 114b, and an engaging recess 117 is provided adjacent to the positioning step 118. On the other hand, as shown in Figure 11, a positioning step 128 is provided on the back surface of the top portion 122 from the outer circumference of the top portion 122, and an engaging recess 127 is provided adjacent to the positioning step 128.

[0184] In this embodiment, the terminal lead-out portion 46 and the hanging portion 124 of the coil holding portion 42 are arranged within the notch 113 of the case 10. The terminal lead-out portion 46 is located in the central part of the case 10 within the notch 113 and is surrounded by the peripheral wall portion 112 and the hanging portion 124, thus closing the notch 113. As a result, the terminal entanglement portion 43 is positioned to protrude outward from the outer circumferential surface of the case 10, and the vibration actuator 1 facilitates connection to external equipment via the terminal entanglement portion 43.

[0185] The thickness of the bottom portion 114 and the top portion 122 are formed to be greater than the thickness of the peripheral wall portion 112. This allows the structure to withstand collisions with the movable body or external components due to drops or other events. Furthermore, it can withstand sudden pressure changes in the internal space when the movable body 20 moves, thereby improving durability.

[0186] <Gap G and movable spaces GS1, GS2> As shown in Figure 3, within the case 10, the outer circumferential surface 20a of the movable body 20 is longer on both sides in the axial direction than the inner circumferential surface 42a of the coil holding portion 42, across the entire range of motion of the movable body 20 (the movable spaces GS1, GS2 and the central movable body housing space including the gap G). As a result, the gap G between the outer circumferential surface 20a of the movable body 20 and the inner circumferential surface 42a of the coil holding portion 42 is a constant width in the axial direction when the movable body 20 is not moving, and is maintained constant in the axial direction when the movable body 20 is moving. The gap G is, for example, the movable body 20 Non-moving and moving It is configured to maintain the same width.

[0187] In other words, the gap G is a cylindrical space having a radial length (width) that is equal in length around the entire circumference of the movable body 20 so as to surround the outer circumference of the movable body 20, and this annular width extends uniformly in the axial direction (vibration direction).

[0188] The pipe resistance generated within this gap G is caused by the movement of the movable body 20 inside the coil holding portion 42, that is, inside the inner circumferential surface 42a. In this embodiment, the pipe through which the fluid flows due to the pipe resistance corresponds to the wall surface surrounding the gap G, such as the inner circumferential surface 42a of the coil holding portion 42 and the outer circumferential surface 20a of the movable body 20.

[0189] Due to the pipe resistance, the movement of air in the movable spaces GS1 and GS2 at both ends of the vibration direction of the movable body 20 within the case 10, that is, the movement of air (fluid) flowing through the movable spaces GS1 and GS2 via the gap G, is suppressed. The pipe resistance exerts an air damping effect on the air throughout the entire range of motion of the movable body within the case 10, thereby damping the vibration of the movable body 20.

[0190] Pipe resistance generally includes straight-pipe losses, which are the loss of kinetic energy due to friction between the pipe and the fluid, as well as inlet losses, outlet losses, flow contraction losses, and flow separation losses due to differences in pipe shape (changes in flow path shape).

[0191] Inlet loss is the loss of kinetic energy that occurs when a fluid flows into a pipe from a wide area. In the case of the vibration actuator 1, this loss is thought to occur when air flows into the gap G from the movable spaces GS1 and GS2.

[0192] Furthermore, outlet loss is the loss of kinetic energy that occurs when fluid flows out of the pipe over a wide area, and in the case of the vibration actuator 1, it is considered to be the loss that occurs when air flows out from the gap G into the movable spaces GS1 and GS2.

[0193] The contraction loss (shrinkage loss) is the loss of kinetic energy that occurs when a fluid flows through a pipe whose cross-section rapidly narrows, causing the flow to contract and generate a vortex, resulting in a contracted flow (also called compressed flow). In the vibration actuator 1, this loss is thought to occur when air flows from the movable spaces GS1 and GS2 into the gap G.

[0194] Separation flow loss is the loss of kinetic energy that occurs when a fluid flows through a pipe whose cross-section rapidly expands, resulting in a large separation region that does not conform to the shape, and the generation of separation flow along with vortices. In the vibration actuator 1, this loss is thought to occur when air flows into the movable spaces GS1 and GS2 from the gap G.

[0195] The movable body 20 and the fixed body 40, in particular the outer surface 20a and the inner surface 42a, are configured to generate conduit resistance including at least one of these.

[0196] <Line holding part 18> Figure 13 is a left side view of the vibration actuator used to explain the wire holding part, Figures 14A and 14B are diagrams used to explain the wire holding part, Figure 14A is an enlarged perspective view of the wire holding part, and Figure 14B is a diagram showing the wire holding part 18 before it holds the lead wire 16.

[0197] The wire holding section 18 shown in Figures 1 to 3, 13 and 14 holds the lead wires 16 that are electrically connected to the coils 61 and 62 of the drive unit 15 housed in the case 10, so that no external load is applied to the connection portion with the coils 61 and 62.

[0198] Specifically, the wire holding portion 18 is introduced from the outside and holds the lead wires 16 connected to the windings of the coils 61 and 62 at the terminal entanglement portion 43. Since the wire holding portion 18 is integrally molded with the case body 11 of the case 10, it is made of the same material as the case body 11, for example, a resin such as PBT.

[0199] The wire holding portion 18 is provided on the outer surface of the case 10, projecting radially outward from a position along the opening edge surrounding the notch portion 113.

[0200] The wire holding portion 18 is positioned adjacent to the terminal entanglement portion 43 of the drive unit 15 in the circumferential direction.

[0201] As shown in Figure 14A, the wire holding portion 18 has a concave wire insertion portion 182 for fitting and holding the lead wire 16, and a wire fixing portion 184. The wire insertion portion 182 is formed so that the inserted lead wire 16 faces in a straight line without putting any load on the terminal entanglement portion 43.

[0202] The wire fixing portion 184 is formed to surround the lead wire 16 inserted into the wire insertion portion 182. The wire fixing portion 184 is welded and deformed. That is, as shown in Figure 14B, before deformation, it forms a concave portion through which the lead wire 16 can be inserted together with the wire insertion portion 182. By inserting the lead wire 16 into this concave portion and applying the jig J and heating it, it deforms and welds together to hold the lead wire 16 together with the wire insertion portion 182.

[0203] This allows the lead wire 16 to be easily held in place simply by inserting it into the recessed portion and heating the wire fixing portion 184.

[0204] The wire holder 18 holds the lead wire 16 so that it does not move due to welding, or at least restricts its movement in the radial direction. However, the configuration is not limited to this, and as shown in Figure 15, the lead wire 16 may also be held using adhesive 187.

[0205] Figure 15 illustrates a modified example of the wire holding portion, showing a wire holding portion 180 provided on the outer surface of the peripheral wall portion 112 of the case body 11 in place of the wire holding portion 18. The wire holding portion 180 is a T-shaped wire holding portion 180 that protrudes from the outer surface of the peripheral wall portion 112 of the case body 11, and has a concave hooking portion 186 that opens laterally between itself and the outer surface. The wire holding portion 180 is secured by inserting two lead wires 16 through the concave parts of the hooking portion 186.

[0206] The wire holding portion 180 is secured by inserting the lead wire 16 into the latching portion 186. At this time, the lead wire 16 is partially secured to the latching portion 186, extends to the terminal wrapping portion 43, and its tip is connected to the terminal wrapping portion 43. The wire holding portion 180 and the lead wire 16 are fixed in contact with each other by adhesive 187.

[0207] <Operation of Vibration Actuator 1> The operation of the vibration actuator 1 based on its magnetic circuit configuration will be explained with reference to Figures 16 and 17. Figure 16 is a schematic diagram showing the magnetic circuit configuration of the vibration actuator. Figure 17 is a diagram used to explain the operation of the actuator body, and Figure 17A shows the vibration state at the maximum amplitude position on the top surface of the movable body. Figure 17B is a diagram used to explain the operation of the actuator body, and shows the vibration state at the maximum amplitude position on the bottom surface of the movable body.

[0208] The operation of the vibration actuator 1 will be explained using the example of a case where the magnet 21 is magnetized such that the surface 21a on one side in the magnetization direction (upper side in this embodiment) is the north pole, and the back surface 21b on the other side in the magnetization direction (lower side in this embodiment) is the south pole.

[0209] 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 vibration with a suitable and stable maximum displacement.

[0210] In the vibration actuator 1, the pair of coils 61 and 62 are arranged such that their coil axes are perpendicular to the magnetic flux from the first yoke 23 and the second yoke 25 that sandwich the magnet 21 in the direction of vibration.

[0211] Specifically, in the non-vibration state when no power is applied, a magnetic flux flow mf is formed, which is emitted from the surface 21a side of the magnet 21, radiated from the first yoke 23 towards the coil 61 side, passes through the outer yoke 50, through the coil 62, through the second yoke 25, and incident on the magnet 21 from the back surface 21b side.

[0212] Therefore, as shown in Figure 16, when current is applied, the interaction between the magnetic field of the magnet 21 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.

[0213] The Lorentz force in the -f direction is perpendicular to the direction of the magnetic field and the direction of the current flowing through the coils (a pair of coils 61 and 62). Since the coils (a pair of coils 61 and 62) are fixed to the stationary body 40 (coil holder 42), according to the law of action and reaction, a force opposite to this Lorentz force in the -f direction is generated as a thrust in the F direction on the movable body 20 having the magnet 21. As a result, the movable body 20 having the magnet 21 moves in the F direction, that is, towards the lid 12 (top surface 122 of the lid 12) (see Figure 17A).

[0214] 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 (see Figure 16). Due to the generation of this Lorentz force in the direction f, according to the law of action and reaction, a force opposite to this Lorentz force in the direction f is generated as a thrust (thrust in the -F direction) on the movable body 20, and the movable body 20 moves in the -F direction, that is, towards the bottom 114 side of the case body 11 (see Figure 17B).

[0215] In the vibration actuator 1, when no power is supplied and no vibration is occurring, magnetic attractive forces act between the magnet 21 and the outer yoke 50, respectively, causing them to function as magnetic springs. Due to the magnetic attractive force generated between the magnet 21 and the outer yoke 50, and the restoring force of the elastic support parts 81 and 82 returning to their original shapes, the movable body 20 returns to its original position.

[0216] 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 19 and 20) 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 as shown in Figure 16, the movable body 20 is subjected to alternating thrusts in the F direction on the top surface 122 side of the lid 12 and thrusts in the -F direction on the bottom 114 side. As a result, the movable body 20 vibrates in the vibration direction.

[0217] As shown in the SK section of Figures 17A and 17B, the two edges of the inner circumferential surface 42a (the flat cross-section) of the coil holding portion 42, which are separated in the direction of vibration, do not face the chamfered portions 276 and 296 radially outward, even when the movable body 20 is positioned at the maximum amplitude position on both sides in the direction of vibration. The chamfered portions 276 and 296 are located outside the inner circumferential surface 42a, and the inner circumferential surface 42a faces the flat outer circumferential surface 20a of the movable body 20.

[0218] As the movable body 20 moves, an airflow is generated in the gap G in the opposite direction to the direction of movement, creating pipe resistance against the air. This causes a pressure loss in the air in the gap G, increasing the air damping within the case 10, which in turn dampens the vibration of the movable body 20 and allows for the optimal generation of vibration of the movable body 20.

[0219] This allows for effective damping of vibrations in the movable body 20 without providing ventilation holes in the case 10 or increasing the weight of the movable body 20.

[0220] As a result, the vibration actuator 1 can generate suitable vibrations by damping the movement of the movable body 20 through the pressure loss caused by the air flowing through the gap G due to the movement of the movable body 20.

[0221] Figure 18 is a diagram illustrating the air damping in the vibration actuator 1 of this embodiment.

[0222] Figure 18 shows the resonant frequencies of the movable body 20, comparing the resonant frequency f0 of a vibration actuator 1 that uses air damping with an actuator that does not use air damping, for example, one that has ventilation holes. According to this, the vibration actuator 1 with air damping can suppress only the G value (K1) at the peak of the resonant frequency f0. As a result, the vibration actuator 1 can increase the overall G value other than the resonant frequency f0 by applying a voltage that makes the frequency peaks equivalent, and can generate suitable vibrations in a wider frequency band.

[0223] Thus, the vibration actuator 1 is configured to generate fluid flow in the gap G in the direction opposite to the direction of movement of the movable body 20, and to generate pipeline resistance against the air. This pipeline resistance against the air provides air damping to the vibration, thereby broadening the vibration bandwidth. The vibration actuator 1 allows for miniaturization while generating suitable vibration output over a wide frequency range, depending on the environment in which it is used.

[0224] Furthermore, the outer circumferential surface 20a of the movable body 20 has a length that protrudes axially from the inner circumferential surface of the cylindrical main body (main body) 422 of the coil holding part 42 over the entire range of motion of the movable body 20. This allows the generation of pipe resistance, which provides an air damping effect, to be maintained throughout the entire range of motion.

[0225] The outer circumferential surface 20a of the movable body 20 and the inner circumferential surface 42a of the cylindrical main body portion 422 are both flat in the axial direction, such that the gap G is a constant width in the axial direction when the movable body 20 is not moving and is maintained constant in the axial direction when the movable body 20 is moving, thereby maintaining the occurrence of straight pipe loss to air throughout the entire range of motion. This makes it possible to stabilize air damping.

[0226] The fixed body 40 has a pair of movable spaces (fluid containment chambers) GS1 and GS2 that communicate with the gap G at both ends in the axial direction. The pair of movable spaces GS1 and GS2 expand steeply in diameter relative to the inner circumferential surface 42a so that losses due to changes in the flow path shape at the inlet and outlet of the gap G occur throughout the entire range of motion of the movable body 20, thereby ensuring an air damping effect throughout the entire range of motion. Furthermore, since the movable spaces GS1 and GS2 have a shape that is symmetrical with respect to a cross section perpendicular to the axis passing through the axial center position, the reciprocating movement of air can be made symmetrical, and the air damping effect can be stabilized.

[0227] The driving principle of the vibration actuator 1 is briefly described below. In the vibration actuator 1 of this embodiment, the mass of the movable body 20 is m [kg], and the spring constant of the springs (elastic support parts 81, 82, which are springs) is K. sp In this case, the movable body 20 has a resonant frequency F calculated by the following equation (1) relative to the fixed body 40. r It vibrates at [Hz].

[0228]

number

[0229] Since the movable body 20 is considered to constitute the mass portion in the spring-mass vibration model, the coil (a pair of coils 61 and 62) is set to the resonant frequency F of the movable body 20. r When an AC wave with a frequency equal to F is input to the movable body 20, the movable body 20 enters a resonant state. That is, the power supply unit inputs the resonant frequency F of the movable body 20 to the coils (a pair of coils 61 and 62). r By inputting an AC wave with approximately the same frequency, the movable body 20 can be vibrated efficiently.

[0230] The equations of motion and circuit equations illustrating the driving principle of the vibration actuator 1 are shown below. The vibration actuator 1 is driven based on the equation of motion shown in equation (2) and the circuit equation shown in equation (3) below.

[0231]

number

[0232] [Number]

[0233] That is, the mass m [kg], displacement x(t) [m], thrust constant K f [N / A], current i(t) [A], spring constant K sp [N / m], damping coefficient D [N / (m / s)], etc. can be appropriately changed within the range that satisfies Equation (2). Also, voltage e(t) [V], resistance R [Ω], inductance L [H], back electromotive force constant K e [V / (rad / s)] can be appropriately changed within the range that satisfies Equation (3).

[0234] Thus, in the vibration actuator 1, when energizing the coils 61 and 62 with an alternating current corresponding to the resonance frequency F sp determined by the mass m of the movable body 20 and the spring constants K of the elastic support portions 81 and 82 which are leaf springs, r it is possible to efficiently obtain a large vibration output.

[0235] Also, the vibration actuator 1 satisfies Equations (2) and (3) and is driven by a resonance phenomenon using the resonance frequency shown in Equation (1). As a result, in the vibration actuator 1, it can be driven with low power consumption, that is, the movable body 20 can be linearly reciprocated with low power consumption. Also, if the damping coefficient D is increased, vibration can be generated over a high band.

[0236] According to this embodiment, plate-shaped elastic support portions 81 and 82 are arranged in the vertical direction (vibration direction) of the movable body 20. Thereby, the vibration actuator 1 can stably drive the movable body 20 in the vertical direction, and at the same time, efficiently distribute the magnetic fluxes of the pair of coils 61 and 62 from the upper and lower elastic support portions 81 and 82 of the magnet 21. As a result, high-output vibration can be realized as the vibration actuator 1.

[0237] Furthermore, the vibration actuator 1 is configured to have a gap G, and the gap G (more specifically, the width (radial length) of the gap G) is set to satisfy the following equation (4).

number

[0238] In the above formula, the pipe corresponds to the inner circumferential surface 42a and outer circumferential surface 20a that define the gap G. The pressure loss ΔP [Pa] is the phenomenon in which the pressure drops when the fluid flows between the inner circumferential surface 42a of the coil holding part 42 and the outer circumferential surface of the movable body 20, due to resistance to the flow caused by friction with the wall surface and the shape of the wall surface. The pipe friction coefficient (friction coefficient of the members surrounding the gap G (inner circumferential surface 42a, outer circumferential surface 20a)) λ, the length of the pipe (length in the direction of vibration of the members surrounding the gap G (inner circumferential surface 42a, outer circumferential surface 20a)) Li [m], the air gap (length in the radial direction of the gap G) h [m], and the density of the fluid (air) ρ [kg / m³] 3 The flow velocity u [m / s], etc., can be appropriately changed within the range that satisfies equation (4). In particular, by increasing the length Li in the direction of vibration of the gap G and narrowing the air gap h, that is, by shortening the radial length of the gap G, the pressure loss, i.e., air damping, can be increased. For example, a predetermined threshold can be set for Li / h, and the gap G can be set to satisfy that equation.

[0239] (electronic equipment) Figures 19 and 20 show examples of implementation configurations of the vibration actuator 1. Figure 19 shows an example of the vibration actuator 1 being implemented in a game controller GC, and Figure 20 shows an example of the vibration actuator 1 being implemented in a mobile terminal M.

[0240] 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 19, 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.

[0241] 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.

[0242] Mobile device M is, for example, a mobile communication device such as a cell phone or 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).

[0243] As shown in Figures 19 and 20, 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.

[0244] In the game controller GC and the mobile 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 are parallel, in this case the bottom surface of the bottom 114.

[0245] The main surface of the terminal is the surface that contacts the user's body surface, and in this embodiment, it refers to the vibration transmission surface that contacts the user's body surface and transmits vibrations. The main surface of the terminal and the bottom surface of the bottom portion 114 of the vibration actuators 204, 205, and 206 may be arranged perpendicular to each other.

[0246] Specifically, in the Game Controller GC, vibration actuators 204 and 205 are implemented so that the vibration direction is perpendicular to the surface that the user's fingertips, fingertips, or hand contacts, or the surface on which the control unit is located. In the case of the mobile device M, vibration actuator 206 is implemented 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 device M are transmitted to the user.

[0247] 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 (registered trademark). 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.

[0248] 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, such as an operation unit like a touch panel).

[0249] 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.

[0250] 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.

[0251] Furthermore, the movable body 20 may be configured to contact the top surface 122 or bottom surface 114 of the lid 12 via a damper each time it vibrates. In this case, the impact on the top surface 122 or bottom surface 114 of the lid 12, i.e., the impact on the housing, caused by the vibration of the movable body 20, is directly transmitted to the user as vibration.

[0252] Since vibrations in a direction perpendicular to the body surface are transmitted to the body surface of the user who touches the game controller GC or the mobile terminal M, sufficient tactile vibrations can be given to the user. In the game controller GC, tactile vibrations for the user can be applied by one or both of the vibration actuators 204 and 205, and vibrations with high expressiveness such as selectively applying at least strong and weak vibrations can be applied.

[0253] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments and can be modified without departing from the gist thereof.

[0254] In addition, the vibration actuator according to the present invention may be mounted on a contact portion with a user of a portable device other than the game controller GC and the mobile terminal M (for example, a portable information terminal such as a tablet PC, a portable game terminal), etc. That is, the vibration actuator 1 may be mounted on a contact portion with a user in a handheld electric device such as a mobile terminal or an electric beauty massager. The vibration actuator 1 may be mounted on a contact portion with a user in a wearable terminal used by the user. The contact portion with the user is, for example, a handle portion that the user grips during use in the case of a handheld electric device such as the game controller GC, and is, for example, a pressing portion that presses against the body surface of the user in the case of a wearable electric device such as an electric beauty massager.

Industrial Applicability

[0255] The vibration actuator according to the present invention can generate a suitable vibration output in a wide frequency band according to the environment in which it is used while achieving miniaturization, and is useful as being mounted on an electronic device such as a game machine terminal or a mobile terminal or an electric device such as an electric beauty massager.

Explanation of Reference Numerals

[0256] 1, 204, 205, 206 Vibration actuator 10 Case 11 Case body 12 Lid part 15 Drive unit 16 Lead wire 18 Wire holding part 20 Movable body 20a Outer peripheral surface 21 Magnet 21a Surface 21b Back surface 23 First yoke 25 Second yoke 27, 29 Weight part 40 Fixed body 41 Winding part 42 Coil holding part (main body part) 42a Inner peripheral surface 42b, 42c Coil mounting part 43 Terminal bundling part 44, 45 Engaging projection 46 Terminal lead-out part 47 Communication groove part 50 Outer yoke 51 Yoke body 52 End part 53 Opening part 60, 61, 62 Coil 63, 64 Winding 81, 82 Elastic support part 88 Damping part 112 Peripheral wall part 113 Notch part 114 Bottom part 118, 128 Step part 122 Top surface part 122b Concave part 124 Hanging part 127 Engaging concave part 180 Wire holding part 182 Wire insertion part 184 Wire fixing part 186 Hooking part 187 Adhesive 201 Communication part 202 Processing part 203 Drive control part 232, 252 Groove part 272, 292 Weight body 274, 294 Spring fixing part 276, 296 Chamfered section 420 Concave part 422 Cylindrical main body 426 Central flange section 426a Outer periphery 427, 428 End flange section 427a, 428a open end 432 Ferrets 802 Inner circumference 802a Connection hole 804 Transforming Arm 806 Outer perimeter 808 Groove

Claims

1. A movable body having a columnar magnet, A fixed body comprising a coil, and a main body portion provided inside the coil, having an inner circumferential surface that surrounds the movable body by forming a gap between itself and the outer circumferential surface of the movable body, and supporting the movable body so as to be vibrable in the axial direction of the movable body via an elastic support portion, It has, The outer circumferential surface of the movable body has a length that protrudes from the inner circumferential surface of the main body on both sides in the axial direction, and this length is configured such that the gap formed between the inner circumferential surface and the movable body, both when the movable body is not moving and when it is moving, has a uniform width in the radial direction and extends with that uniform width along the axial direction. The system is configured to generate fluid flow in the gap in the direction opposite to the direction of movement of the movable body and to generate pipeline resistance to the fluid, Vibration actuator.

2. The movable body has the magnet in the central part in the axial direction, a pair of weights at both ends in the axial direction, and a pair of yokes between the magnet and the pair of weights. The magnet, the pair of yokes, and the pair of weights are each formed in the shape of a cylinder of the same diameter, and are joined in the axial direction such that their outer surfaces are flush with each other. The vibration actuator according to claim 1.

3. A reservoir for accumulating adhesive or welding material is provided at the joint between the magnet and each of the pair of yokes, or at the joint between each of the pair of yokes and each of the pair of weights. The vibration actuator according to claim 2.

4. The outer circumferential surface of the movable body and the inner circumferential surface of the main body are both flat in the axial direction. The vibration actuator according to claim 1.

5. The fixed body has a pair of fluid-retaining chambers that communicate with the gap at both ends in the axial direction, The pair of fluid-containing chambers are designed to widen sharply relative to the inner circumferential surface so that losses due to changes in flow path shape occur at the inlet and outlet of the gap throughout the entire range of motion of the movable body. The vibration actuator according to claim 1.

6. The pair of fluid-containing chambers are a pair of sealed spaces having a shape that is symmetrical with respect to a cross-section perpendicular to the axis passing through the central position in the axial direction. The vibration actuator according to claim 5.

7. Handheld or wearable electrical devices, The configuration includes a vibration actuator as described in claim 1 mounted at the part that comes into contact with the user. Electrical equipment.

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