Vibration actuator

Abstract

To obtain strong vibration in a wide frequency range.SOLUTION: The vibration actuator is a vibration actuator that elastically vibrates a movable part supported on a fixed part by an elastic member by a driving force of a driving part, and the driving part includes a magnet included in the fixed part and disposed to form a pair facing each other via a space, and a coil included in the movable part and disposed in the space, and generates the driving force by an interaction between a magnetic field by the magnet and a current flowing through the coil. The movable portion further includes a conductive plate-shaped portion disposed in the space, and the plate-shaped portion generates an eddy current therein with movement of the movable portion in the magnetic field and damps vibration of the movable portion by interaction between the magnetic field and the eddy current.SELECTED DRAWING: Figure 11

Description

[Technical Field]

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

[0002] BACKGROUND ART A vibration actuator is known in which a movable part is elastically supported by a fixed part, and the movable part is elastically vibrated relative to the fixed part by a magnetic drive circuit using a coil and a magnet (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-013086 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional vibration actuators such as those described in Patent Document 1, the vibration acceleration peaks at the resonant frequency of the moving part, and this peak is steep. For this reason, it is difficult for conventional vibration actuators to produce strong vibrations over a wide frequency range.

[0005] An object of the present invention is to provide a vibration actuator that can obtain strong vibrations over a wide frequency range. [Means for solving the problem]

[0006] The vibration actuator according to the present invention comprises: A vibration actuator that elastically vibrates a movable part supported by a fixed part by an elastic member using a driving force from a driving part, the driving unit has magnets included in the fixed unit and arranged to form a pair facing each other across a space, and a coil included in the movable unit and arranged in the space, and generates the driving force by interaction between a magnetic field generated by the magnets and a current flowing through the coil; The movable part further includes a conductive plate-shaped part arranged in the space, and the plate-shaped part generates eddy currents inside as the movable part moves within the magnetic field, and the interaction between the magnetic field and the eddy currents damps the vibration of the movable part. [Effects of the Invention]

[0007] According to the present invention, strong vibrations can be obtained over a wide frequency range. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of the appearance of a vibration actuator according to an embodiment of the present invention. [Figure 2] 2 is an exploded perspective view of a fixed portion that constitutes the vibration actuator shown in FIG. 1. FIG. [Figure 3] FIG. 2 is a perspective view of a movable part that constitutes the vibration actuator shown in FIG. [Figure 4] FIG. 4 is an exploded perspective view of the movable part shown in FIG. 3. [Figure 5] 2 is a diagram illustrating the internal configuration of the vibration actuator shown in FIG. 1. FIG. [Figure 6] 4 is a perspective view showing a plate-shaped portion and a weight that constitute the movable portion shown in FIG. 3. FIG. [Figure 7] 7 is a view of the plate-shaped portion and the weight shown in FIG. 6 as viewed from the X direction. [Figure 8] 7 is a view of the plate-shaped portion and the weight shown in FIG. 6 as viewed from the Y direction. [Figure 9] 2 is a diagram illustrating the inside of the vibration actuator shown in FIG. 1, and is a top view showing the configuration of the vibration actuator with the upper cover, upper yoke, and upper magnet removed. FIG. [Figure 10] FIG. 10 is a development view of the wiring portion shown in FIG. [Figure 11] 2A to 2C are diagrams illustrating the operation of the vibration actuator shown in FIG. [Figure 12] 2 is a graph showing the relationship between drive frequency and vibration acceleration for a conventional vibration actuator and the vibration actuator shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0010] In this embodiment, a description will be given using a Cartesian coordinate system (X, Y, Z). Here, the description will be given assuming that the vibration direction of a movable part 30 (described later) is the X direction. Also, the Z direction may be described as the up-down direction.

[0011] [Vibration Actuator 10] A vibration actuator 10 according to this embodiment will be described with reference to FIGS.

[0012] Fig. 1 is a perspective view of the appearance of a vibration actuator 10 according to this embodiment. Fig. 2 is an exploded perspective view of a fixed part 20 that constitutes the vibration actuator 10. Fig. 3 is a perspective view of a movable part 30 that constitutes the vibration actuator 10. Fig. 4 is an exploded perspective view of the movable part 30.

[0013] The vibration actuator 10 is a box-shaped vibration actuator, and here, as an example, is shaped like a rectangular parallelepiped. The vibration actuator 10 vibrates the vibration target to which the vibration actuator 10 is attached by vibrating the movable part 30 arranged inside. By vibrating the vibration target, the vibration actuator 10 imparts vibration to, for example, a person in contact with the vibration target.

[0014] The vibration actuator 10 mainly comprises a fixed part 20, a movable part 30, an elastic member 41, wiring parts 51 and 52, and the like.

[0015] [Fixed part 20] The fixed part 20 has a side cover 21, an upper cover 22, and a lower cover 23 that form a box-shaped housing that houses the movable part 30. The side cover 21, the upper cover 22, and the lower cover 23 are connected to one another to close the inside of the housing, and a notch 21a is formed in a part of one side surface of the side cover 21. Here, as an example, the notch 21a is formed on the lower end side in the Z direction of one side surface in the X direction. The wiring part 51 is arranged so as to pass through the notch 21a and be drawn from inside the housing to outside the housing.

[0016] An upper yoke 24 and an upper magnet 26 are attached to the inside of the upper cover 22 in this order from the top. A lower yoke 25 and a lower magnet 27 are attached to the inside of the lower cover 23 in this order from the bottom. Here, as an example, the upper yoke 24, the upper magnet 26, and the lower magnet 27 are each shaped like a rectangular parallelepiped, and the lower yoke 25 is shaped like a roughly rectangular parallelepiped.

[0017] The upper magnets 26 and the lower magnets 27 are arranged to form pairs facing each other across a space S (see FIG. 11 described later). As an example, the upper magnets 26 and the lower magnets 27 are each magnetized with four poles. The upper magnets 26 and the lower magnets 27 magnetized with four poles are referred to as upper magnets 26a to 26d and lower magnets 27a to 27d from left to right in FIG. 2. The same applies to FIG. 11 described later. The upper magnets 26a to 26d and the lower magnets 27a to 27d are arranged in pairs with opposite opposing poles, and the north and south poles are arranged alternately along the X direction.

[0018] The upper magnet 26 and the lower magnet 27 are made of, for example, sintered powder of neodymium magnet material, and as described above, are magnetized into four poles. The upper magnet 26 and the lower magnet 27 are not limited to this configuration, and may be, for example, four magnets integrated together.

[0019] The upper magnet 26 and the lower magnet 27 are arranged as described above to form a magnetic field along the Z direction (hereinafter referred to as a magnetic field) in the space S. The side cover 21, the upper cover 22, the lower cover 23, the upper yoke 24, and the lower yoke 25 are made of a magnetic material, and are configured to form a magnetic circuit by the upper magnet 26 and the lower magnet 27.

[0020] The magnetic material for the side cover 21, the upper cover 22, and the lower cover 23 may be, for example, ferritic stainless steel (e.g., SUS430). The magnetic material for the upper yoke 24 and the lower yoke 25 may be, for example, electro-galvanized steel sheet (SECC). These magnetic materials are merely examples and can be changed as appropriate.

[0021] Protruding support portions 25a that protrude outward in the X direction are formed on both ends of lower yoke 25 in the X direction. First mounting portions 41a of elastic member 41, which will be described later, are attached to protruding support portions 25a. With this configuration, lower yoke 25 supports elastic member 41, and lower yoke 25, i.e., fixed portion 20, supports movable portion 30 via elastic member 41 in a manner that allows it to elastically vibrate.

[0022] [Movable part 30] As described above, the movable part 30 is supported by the fixed part 20 via the elastic member 41 so as to be capable of elastic vibration. The movable part 30 has a coil 31, a plate-like part 32, an upper weight 33, and a lower weight .

[0023] The movable section 30 will be described with reference to Figs. 5 to 8. Fig. 5 is a diagram illustrating the internal configuration of the vibration actuator 10. Fig. 6 is a perspective view showing the plate-shaped section 32, upper weight 33, and lower weight 34 that make up the movable section 30. Fig. 7 is a diagram of the plate-shaped section 32, upper weight 33, and lower weight 34 as viewed from the X direction. Fig. 8 is a diagram of the plate-shaped section 32, upper weight 33, and lower weight 34 as viewed from the Y direction.

[0024] Coil 31 is disposed in space S between upper magnet 26 and lower magnet 27, which face each other. The windings of coil 31 are wound so as to be perpendicular to the direction of the magnetic field of the magnet (here, the Z direction) in space S. Coil 31 is also configured so that its longitudinal direction is the Y direction, which is perpendicular to the X direction, which is the direction of movement.

[0025] Therefore, the main direction of the current flowing in coil 31 is the Y direction, which is perpendicular to the direction of the magnetic field of the magnet (Z direction) (see FIG. 11 described later). Therefore, when a current flows through coil 31, the interaction between the current flowing through coil 31 and the magnetic field of the magnet generates a Lorentz force (driving force), which causes the movable part 30 to move in the X direction, as will be explained later in FIG. 11. With this configuration, upper magnet 26, lower magnet 27, and coil 31 function as a driving part that drives the movable part 30.

[0026] The coils 31 are arranged in three rows along the X direction corresponding to the upper magnet 26 and lower magnet 27, which are magnetized into four poles, and are attached to the plate-shaped portion 32. The three coils 31 are numbered 31a to 31c from left to right in Figs. 3 and 4. The same applies to Fig. 5 and Fig. 11, which will be described later. The lead wires of the coils 31a to 31c are connected so that the directions of current flow are opposite between adjacent coils, as shown in Fig. 11.

[0027] The plate-shaped portion 32 is a rectangular plate member to which three coils 31a to 31c are attached. Here, as an example, the three coils 31a to 31c are arranged side by side in the X direction on the upper surface side of the flat portion 32a of the plate-shaped portion 32.

[0028] The plate-shaped portion 32 is also disposed in the space S between the opposing upper magnet 26 and lower magnet 27. The flat surface portion 32a of the plate-shaped portion 32 extends in the space S in a direction perpendicular to the direction of the magnetic field of the magnet (here, in the XY plane direction).

[0029] The plate-like portion 32 is made of a conductive material, and is preferably made of a material with high conductivity, such as copper, aluminum, or an alloy containing these.

[0030] As described above, when a current flows through the coil 31, the movable part 30 moves in the X direction due to the force of the magnetic field of the magnet, and at this time, the plate-shaped part 32 also moves. As the plate-shaped part 32 moves, a change in magnetic flux occurs in the plate-shaped part 32, and eddy currents are generated in the plate-shaped part 32 to cancel out the change in magnetic flux. At this time, the eddy currents generate a magnetic field in the same direction as the magnetic field of the magnet on the side of the direction of movement, and a magnetic field in the opposite direction to the magnetic field of the magnet on the side opposite to the direction of movement. The interaction between the magnetic field due to such eddy currents and the magnetic field of the magnet generates a force acting in a direction that brakes the movement due to the Lorentz force described above, thereby braking the movable part 30. With this configuration, the upper magnet 26, the lower magnet 27, and the plate-shaped part 32 function as a braking part that brakes the movable part 30.

[0031] Furthermore, bent portions 32b are disposed at both ends of the flat portion 32a in the X direction, and are bent to stand upward (in the Z direction) from the flat portion 32a. The bent portions 32b are provided to improve the rigidity of the plate-like portion 32 itself and suppress bending of the plate-like portion 32. An end portion 33a of an upper weight 33, which will be described later, is attached to the bent portions 32b.

[0032] Furthermore, recesses 32c (positioning portions in the present invention) are formed at both ends of the flat portion 32a in the Y direction. The recesses 32c are portions into which protrusions 33b (positioning portions in the present invention) of the upper weight 33, which will be described later, are fitted. The recesses 32c and the protrusions 33b make it easy to position the upper weight 33 relative to the plate-like portion 32, facilitating the assembly work.

[0033] In addition, in the Y direction, the flat portion 32a extends longer than the upper yoke 24, the lower yoke 25, the upper magnet 26, the lower magnet 27, and the coil 31. In the Y direction, the upper weight 33 is attached to the upper surface side of the flat portion 32a so as to be located in the gap between the upper yoke 24 and the upper magnet 26 and the side cover 21 (see FIG. 5). Similarly, the lower weight 34 is attached to the lower surface side of the flat portion 32a so as to be located in the gap between the lower yoke 25 and the lower magnet 27 and the side cover 21.

[0034] Although not indicated by symbols, the plate-shaped portion 32 has through holes corresponding to the lead wires of the three coils 31a to 31c, and by accommodating the lead wires in the through holes, the thickness of the coils 31 and the plate-shaped portion 32 in the Z direction does not become too large.

[0035] The upper weight 33 and the lower weight 34 (weight members in the present invention) are provided to increase the weight of the movable part 30.

[0036] The upper weight 33 is a substantially rectangular parallelepiped member extending in the XZ plane direction. The upper weight 33 has end portions 33a at both ends in the X direction attached to the bent portions 32b of the plate-like portion 32 described above.

[0037] The upper weight 33 also has a protruding portion 33b that protrudes downward. The protruding portion 33b is fitted into the recessed portion 32c described above, and the upper weight 33 is attached to the upper surface side of the flat portion 32a.

[0038] The lower weight 34 is also a substantially rectangular parallelepiped member extending in the XZ plane direction. The lower weight 34 has support ends 34a at both ends in the X direction. Second mounting portions 41b of the elastic member 41, which will be described later, are attached to the support ends 34a.

[0039] The lower weight 34 also has a fitting portion 34b (a positioning portion in the present invention) that corresponds to the protruding portion 33b of the upper weight 33. The protruding portion 33b is fitted into the fitting portion 34b, and the lower weight 34 is attached to the underside of the flat portion 32a. The protruding portion 33b and the fitting portion 34b make it easy to position the lower weight 34 relative to the plate-like portion 32 and the upper weight 33, facilitating the assembly work.

[0040] Here, the upper weight 33 has a protrusion 33b and the lower weight 34 has a fitting portion 34b, but the reverse is also possible, with the upper weight 33 having the fitting portion and the lower weight 34 having the protrusion.

[0041] At the Y-direction end of the flat portion 32a, an upper weight 33 is attached to the upper surface side of the flat portion 32a, and a lower weight 34 is attached to the lower surface side of the flat portion 32a. In other words, the flat portion 32a is sandwiched between the upper weight 33 and the lower weight 34 at the Y-direction end. By sandwiching the end of the flat portion 32a between the two pairs of upper weights 33 and lower weights 34 in this way, the rigidity of the plate-like portion 32 is further improved, and bending of the plate-like portion 32 is suppressed.

[0042] By improving the rigidity of the plate-shaped portion 32 in this way, it is no longer necessary to make the plate-shaped portion 32 thicker, and therefore the vibration actuator 10 can be made thinner.

[0043] The upper weight 33 and the lower weight 34 are connected to the plate-shaped portion 32 in a manner that allows thermal conductivity. For example, the upper weight 33 and the lower weight 34 are connected to the plate-shaped portion 32 at their connecting portions with a material that has high thermal conductivity. The plate-shaped portion 32 generates heat due to eddy currents, but the upper weight 33 and the lower weight 34 function as heat sinks, thereby suppressing a rise in the temperature of the plate-shaped portion 32. Furthermore, the upper weight 33 and the lower weight 34 can dissipate not only the heat generated by eddy currents in the plate-shaped portion 32, but also the heat generated by the coils 31a to 31c that is transferred via the plate-shaped portion 32.

[0044] In addition, as will be described later, the plate-shaped portion 32, the upper weight 33, and the lower weight 34 vibrate as the movable portion 30, that is, they move through the air, so to speak, blowing air onto the plate-shaped portion 32, the upper weight 33, and the lower weight 34. As a result, the plate-shaped portion 32, the upper weight 33, and the lower weight 34 are cooled more than if they were not moving.

[0045] The upper weight 33 and the lower weight 34 are preferably made of a material with high density and high heat dissipation properties, such as tungsten or a tungsten alloy. By using a material with high density, it is possible to obtain strong vibrations without increasing the size of the vibration actuator 10, and it is possible to make the vibration actuator 10 smaller and thinner.

[0046] In order to increase the weight of the movable part 30, the sizes of the related members may be changed within the housing consisting of the side cover 21, the upper cover 22, and the lower cover 23. In this embodiment, for example, as shown in Fig. 5, the width of the lower yoke 25 and the lower magnet 27 is made smaller in the Y direction compared to the width of the upper yoke 24 and the upper magnet 26. This allows the width of the lower weight 34 to be increased within the housing, and the weight of the lower weight 34 to be increased.

[0047] In this way, by changing the size of the components inside the housing, it is possible to obtain strong vibrations without increasing the size of the vibration actuator 10, and it is possible to make the vibration actuator 10 smaller and thinner.

[0048] [Elastic member 41] The elastic member 41 is a member that supports the movable part 30 so that it can elastically vibrate relative to the fixed part 20. In this embodiment, the movable part 30 is configured to be able to vibrate in the X direction, and therefore the elastic members 41 are disposed on both ends of the movable part 30 in the X direction.

[0049] The elastic member 41 is formed, for example, from a leaf spring. When viewed from the X direction, the elastic member 41 has a shape that is line-symmetrical with respect to a center line along the Z direction. The elastic member 41 has a first mounting portion 41a disposed at the center, second mounting portions 41b disposed at both ends, and a deformation portion 41c that connects the first mounting portion 41a and the second mounting portion 41b and is elastically deformable.

[0050] As described above, the first mounting portion 41a is attached to the protruding support portion 25a of the lower yoke 25. That is, the first mounting portion 41a is attached to the fixed portion 20 side. Furthermore, as described above, the second mounting portions 41b are attached to the support ends 34a of the lower weights 34. That is, the second mounting portions 41b are attached to the movable portion 30 side. In this manner, the elastic member 41 connects the fixed portion 20 and the movable portion 30, and the deforming portion 41c is elastically deformed by the driving force of the driving portion described above, causing the movable portion 30 to vibrate in the X direction.

[0051] Since the first mounting portion 41a and the protruding support portion 25a, and the second mounting portion 41b and the support end portion 34a are subjected to a force due to vibration, it is desirable that they be fixed by welding, for example.

[0052] The deformable portion 41c is formed in a meandering shape, so that even if the range in which it can be placed is limited, the deformable portion 41c can be made to have a desired length, thereby achieving desired vibration characteristics.

[0053] [Wiring section 51, 52] The wiring sections 51 and 52 will be described with reference to Figures 9 and 10. Figure 9 is a diagram illustrating the inside of the vibration actuator 10, and is a top view showing the configuration with the upper cover 22, upper yoke 24, and upper magnet 26 removed from the vibration actuator 10. Figure 10 is a development view of the wiring sections 51 and 52.

[0054] The wiring portions 51 and 52 are members that function as wiring to the coil 31 in the vibration actuator 10. The wiring portions 51 and 52 are formed by an FPC (Flexible Printed Circuit).

[0055] The wiring section 51 is a wire that connects the wiring section 52 to an external device that controls the vibration actuator 10. The wiring section 51 has an internal connection section 51a, an external connection section 51b, and an intermediate wire 51c.

[0056] The internal connection portion 51a is fixed to one bent portion 32b of the plate-shaped portion 32, and is connected to a relay connection portion 52a of the wiring portion 52, which will be described later (see FIG. 9). The external connection portion 51b is fixed to one side surface of the side cover 21 in the X direction, and is connected to an external device.

[0057] The intermediate wiring 51c connects between the internal connection portion 51a and the external connection portion 51b. That is, the intermediate wiring 51c connects between the movable portion 30 side and the fixed portion 20 side. Because the wiring portion 51 is formed of an FPC, the intermediate wiring 51c is deformable and can accommodate deformation caused by vibration of the movable portion 30. Furthermore, because the intermediate wiring 51c is deformable, it can be drawn from inside the housing to outside the housing through the notch 21a of the side cover 21 described above.

[0058] The wiring portion 52 is a wire that connects the wiring portion 51 and the coil 31. The wiring portion 52 has a relay connection portion 52a, a connection terminal 52b, and an intermediate wire 52c.

[0059] Similar to the internal connection portion 51a, the relay connection portion 52a is fixed to one bent portion 32b of the plate-shaped portion 32 and connected to the internal connection portion 51a (see FIG. 9). Two connection terminals 52b are provided corresponding to the terminals on both ends of the coil 31. The two connection terminals 52b are fixed to the plate-shaped portion 32 and connected to the terminals on both ends of the coil 31, respectively. The intermediate wiring 52c connects between the relay connection portion 52a and the connection terminals 52b. In other words, the wiring portion 52 is arranged on the movable portion 30 side.

[0060] When an alternating current is supplied to the coil 31 using the wiring sections 51 and 52 configured as described above, the movable section 30 vibrates in the X direction.

[0061] [Operation of vibration actuator 10] The operation of the vibration actuator 10, specifically the vibration of the movable part 30, will be described with reference to Fig. 11. Fig. 11 is a diagram illustrating the operation of the vibration actuator 10.

[0062] When the coils 31a to 31c are not energized, no current flows through the coils 31a to 31c, which interacts with the magnetic fields formed by the upper magnet 26 and the lower magnet 27. Therefore, the driving force described above is not generated, and the movable part 30 does not move.

[0063] When the coils 31a to 31c are energized, a current flows through the coils 31a to 31c. For convenience, the currents flowing through the coils 31a to 31c are designated as currents i1 and i2, taking into consideration the direction of the current flow, as shown in Fig. 11. Current i1 flows toward the front side of the paper, and current i2 flows toward the back side of the paper.

[0064] The magnetic fields formed between upper magnet 26a and lower magnet 27a, and between upper magnet 26c and lower magnet 27c, are magnetic fields directed upward in the Z direction. Current i1 flows in the direction toward the front of the page through the portion of coil 31a located between upper magnet 26a and lower magnet 27a, and through the portions of coils 31b and 31c located between upper magnet 26c and lower magnet 27c. In this case, the interaction between current i1 and the magnetic fields generates a Lorentz force (driving force) in the direction of arrow F, and movable part 30 moves in the X direction.

[0065] Similarly, the magnetic fields formed between upper magnet 26b and lower magnet 27b and between upper magnet 26d and lower magnet 27d are magnetic fields directed downward in the Z direction. Current i2 flows into the page through the portion of coils 31a and 31b located between upper magnet 26b and lower magnet 27b, and through the portion of coil 31c located between upper magnet 26d and lower magnet 27d. In this case, the interaction between current i2 and the magnetic fields generates a Lorentz force (driving force) in the direction of arrow F, and movable part 30 moves in the X direction.

[0066] In this way, the movable part 30 moves in the X direction indicated by the arrow F due to the interaction between the magnetic fields formed by the upper magnets 26a to 26d and the lower magnets 27a to 27d and the currents flowing through the coils 31a to 31c.

[0067] When the direction of the current flowing through coils 31a to 31c is reversed, a Lorentz force (driving force) is generated in the opposite direction to the direction of arrow F, and movable part 30 moves in the X direction, which is the opposite direction to the direction of arrow F. Supplying alternating current to coils 31a to 31c changes the direction of the current flowing through coils 31a to 31c, causing movable part 30 to vibrate in the X direction.

[0068] In this embodiment, the movable part 30 has the plate-like part 32 in which eddy currents are generated as the movable part 30 vibrates (moves), and therefore a braking force also acts to brake the movable part 30. The technical effect of this braking force will be described with reference to FIG.

[0069] Fig. 12 is a graph showing the relationship between drive frequency and vibration acceleration for a conventional vibration actuator and vibration actuator 10. In Fig. 12, the dashed line is a graph showing the relationship between drive frequency and vibration acceleration for the conventional vibration actuator, and the solid line is a graph showing the relationship between drive frequency and vibration acceleration for vibration actuator 10.

[0070] In conventional vibration actuators, the vibration acceleration peak is steep at the resonant frequency F0 of the moving part, as shown in Figure 12. For this reason, it was difficult to obtain strong vibrations over a wide frequency range with conventional vibration actuators.

[0071] On the other hand, as described above, the vibration actuator 10 has a movable part 30 that has a plate-like part 32 in which eddy currents are generated as the movable part 30 vibrates (moves), and therefore a braking force acts on the movable part 30, and this braking force becomes larger near the resonance frequency F0 where the vibration acceleration becomes large. Therefore, as shown in Figure 12, it is possible to make the change in vibration acceleration near the resonance frequency F0 gentler. Therefore, for example, if the peak of the vibration acceleration in the vibration actuator 10 is made the same as the peak of the vibration acceleration in a conventional vibration actuator, strong vibration (vibration acceleration) can be obtained over a wide range of drive frequencies.

[0072] As explained above, vibration actuator 10 has plate-like portion 32, in which eddy currents are generated as movable portion 30 vibrates (moves), thereby damping the vibration of movable portion 30. Damping the vibration of movable portion 30 makes it possible to smooth out changes in vibration acceleration near resonance frequency F0, enabling vibration actuator 10 to obtain strong vibrations (vibration acceleration) over a wide range of drive frequencies.

[0073] Furthermore, the movable part 30 has an upper weight 33 and a lower weight 34 that are heat-dissipating and thermally conductively connected to the plate-like part 32, so that it is possible to obtain strong vibrations (vibration acceleration) and dissipate heat generated by eddy currents. Furthermore, the movable part 30 can dissipate heat generated by the coils 31a to 31c as well as heat generated by eddy currents in the plate-like part 32, thanks to the upper weight 33 and the lower weight 34.

[0074] <Modification> In the above embodiment, the elastic member 41 is exemplified as being formed from a leaf spring, but it is not limited to a leaf spring and may be formed from a gel that can be elastically changed or a plate-like body having a nonwoven fabric structure or a woven fabric structure.

[0075] Furthermore, in the above embodiment, the movable part 30 has been described as having a moving coil configuration with the coil 31, but the present invention may also have a moving magnet configuration.

[0076] The embodiments of the present invention have been described above. Note that the above description is an example of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this. In other words, the description of the configuration of the above device and the shape of each part is one example, and it is clear that various modifications and additions to these examples are possible within the scope of the present invention. [Industrial Applicability]

[0077] The vibration actuator according to the present invention is useful as a vibration actuator that imparts strong vibrations over a wide range of drive frequencies even when it is small. For example, the vibration actuator according to the present invention is suitable for installation in game controllers, game machines, vehicle seats, mobile devices (e.g., portable game terminals, portable information terminals, wearable devices, etc.), gaming machines such as pachinko, home appliances, etc. By installing the vibration actuator according to the present invention in these devices, it is possible to provide the user with haptic feedback through vibrations, for example, instead of a physical switch. Furthermore, it is also possible to impart vibrations from the vibration actuator according to the present invention to the user as haptic or bodily vibrations, as one means of transmitting information (e.g., warnings) from the device to the user. [Explanation of symbols]

[0078] 10 Vibration Actuator 20 Fixed part 21 Side cover 22 Upper cover 23 Lower cover 24 Upper Yoke 25 Lower Yoke 26, 26a~26d Upper magnet 27, 27a~27d Lower magnet 30 Moving parts 31, 31a to 32c Coil 32 Plate-shaped part 32a Flat part 32b Bending section 32c recess 33 Upper weight 33a end 33b Protrusion 34 Lower Weight 34a Support end 34b Mating part 41 Elastic member 51, 52 Wiring section

Claims

1. A vibration actuator that elastically vibrates a movable part supported by a fixed part by an elastic member using a driving force from a driving part, the driving unit has magnets included in the fixed unit and arranged to form a pair facing each other across a space, and a coil included in the movable unit and arranged in the space, and generates the driving force by interaction between a magnetic field generated by the magnets and a current flowing through the coil; the movable part further includes a conductive plate-like part disposed in the space, the plate-like part generates an eddy current therein as the movable part moves within the magnetic field, and damps vibration of the movable part through interaction between the magnetic field and the eddy current. Vibration actuator.

2. the movable portion further includes a weight having heat dissipation properties and connected to the plate-shaped portion in a thermally conductive manner; The vibration actuator according to claim 1 .

3. the plate-shaped portion extends so that an end portion is located outside the space, The weight is connected to the end. The vibration actuator according to claim 2 .

4. The weight comprises two pairs of weight members, The plate-shaped portion has a rectangular shape, and two opposing ends are sandwiched between a pair of the weight members. The vibration actuator according to claim 3 .

5. The plate-shaped portion and the weight have positioning portions that are fitted together to position them. The vibration actuator according to claim 2 .

6. The weight is made of tungsten. The vibration actuator according to claim 2 .

7. The elastic member is made of any one of a leaf spring, gel, and a plate-like body having a nonwoven fabric structure or a woven fabric structure. The vibration actuator according to claim 2 .

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