Vibration actuator

Abstract

Provided is a vibration actuator that elastically vibrates a movable part supported by a fixed part via an elastic member by a driving force of a drive unit. The drive unit comprises: magnets included in the fixed part and disposed as opposing pairs across a space; and a coil included in the movable part and disposed in the space. The drive unit generates the driving force through interaction between a magnetic field produced by the magnets and a current flowing in the coil. The movable part further includes a conductive plate-like part disposed in the space. The plate-like part generates eddy currents internally as the movable part moves within the magnetic field, and controls vibration of the movable part through interaction between the magnetic field and the eddy currents.

Description

Vibration Actuator

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

[0002] 2. Description of the Related 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).

[0003] Japanese Patent Application Laid-Open No. 2019-013086

[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 to obtain strong vibrations over a wide frequency range with conventional vibration actuators.

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

[0006] The vibration actuator of the present invention is a vibration actuator that elastically vibrates a movable part supported by a fixed part by an elastic member using the driving force of a driving part, wherein the driving part has magnets included in the fixed part and arranged to form a pair facing each other across a space, and a coil included in the movable part and arranged in the space, and the driving force is generated by the interaction between the magnetic field of the magnets and the current flowing in the coil, and 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.

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

[0008] 1. is an external perspective view of a vibration actuator according to an embodiment of the present invention. FIG. 1 is an exploded perspective view of a fixed part that constitutes the vibration actuator shown in FIG. 1. FIG. 2 is a perspective view of a movable part that constitutes the vibration actuator shown in FIG. 1. FIG. 3 is an exploded perspective view of the movable part shown in FIG. 4. FIG. 5 is a diagram explaining the internal configuration of the vibration actuator shown in FIG. 1. FIG. 6 is a perspective view of a plate-shaped part and weight that constitute the movable part shown in FIG. 3. FIG. 7 is a diagram showing the plate-shaped part and weight that constitute the movable part shown in FIG. 6 from the X direction. FIG. 8 is a diagram showing the plate-shaped part and weight shown in FIG. 6 from the Y direction. FIG. 9 is a diagram explaining the internal configuration 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. 10 is an exploded view of the wiring part shown in FIG. 1. FIG. 11 is a diagram explaining the operation of the vibration actuator shown in FIG. 1. FIG. 12 is a graph showing the relationship between drive frequency and vibration acceleration for a conventional vibration actuator and the vibration actuator shown in FIG. 1.

[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, the description will be made using a Cartesian coordinate system (X, Y, Z). Here, the description will be made assuming that the vibration direction of the movable part 30 (described later) is the X direction. Also, the description will sometimes be made assuming that the Z direction is 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 portion 20 that constitutes the vibration actuator 10. Fig. 3 is a perspective view of a movable portion 30 that constitutes the vibration actuator 10. Fig. 4 is an exploded perspective view of the movable portion 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 a vibration target to which the vibration actuator 10 is attached by vibrating a movable part 30 arranged inside the vibration actuator 10. By vibrating the vibration target, the vibration actuator 10 imparts vibrations to, for example, a person in contact with the vibration target.

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

[0015] [Fixed portion 20] The fixed portion 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 portion 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 portion 51 is arranged 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 top to bottom. A lower yoke 25 and a lower magnet 27 are attached to the inside of the lower cover 23 in this order from bottom to top. 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 in pairs facing each other across a space S (see FIG. 11 described below). 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 below. 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 with 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), etc. The magnetic material for the upper yoke 24 and the lower yoke 25 may be, for example, electro-galvanized steel sheet (SECC), etc. These magnetic materials are merely examples and may be changed as appropriate.

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

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

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

[0024] The coil 31 is disposed in the space S between the upper magnet 26 and the lower magnet 27, which face each other. The windings of the coil 31 are wound so as to be perpendicular to the direction of the magnetic field of the magnet (here, the Z direction) in the space S. The 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 the 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 the coil 31, the interaction between the current flowing through the 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 described later in FIG. 11. With this configuration, the upper magnet 26, the lower magnet 27, and the 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 designated coils 31a to 31c from left to right in Figures 3 and 4. The same applies to Figure 5 and Figure 11, which will be described later. The lead wires of the coils 31a to 31c are connected so that the current flows in opposite directions between adjacent coils, as shown in Figure 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 planar 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 from 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 caused by 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 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 according to 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 according to 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 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 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. Ends 33a of the upper weight 33 at both ends in the X direction are 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, 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. 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 (positioning portion in the present invention) that corresponds to the protrusion 33b of the upper weight 33. The protrusion 33b is fitted into the fitting portion 34b, and the lower weight 34 is attached to the underside of the flat portion 32a. The protrusion 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 heat generated by eddy currents in the plate-shaped portion 32, but also 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, move through the air, so to speak, blowing air onto the plate-shaped portion 32, the upper weight 33, and the lower weight 34. Therefore, 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 elastically deformable deformation portions 41c that connect the first mounting portion 41a and the second mounting portion 41b.

[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 driving force of the driving portion described above elastically deforms the deformation portion 41c, 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 deformation portion 41c is formed in a serpentine shape, so that even if the range in which it can be placed is limited, the deformation portion 41c can be made to the desired length, and the desired vibration characteristics can be obtained.

[0053] [Wiring Sections 51, 52] The wiring sections 51, 52 will be described with reference to Figures 9 and 10. Figure 9 is a diagram illustrating the interior 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 an exploded view of the wiring sections 51, 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 (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 in 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] Like 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 parts 51 and 52 configured as described above, the movable part 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 for explaining 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. Taking into consideration the direction of the current flow, the currents flowing through the coils 31a to 31c are designated as currents i1 and i2 for the sake of convenience, as shown in Figure 11. Current i1 flows toward the front side of the page, and current i2 flows toward the back side of the page.

[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 toward the front of the page in the portion of coil 31a located between upper magnet 26a and lower magnet 27a, and in 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 the 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 the 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. 12 .

[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 at the resonant frequency F0 of the moving part, and this peak is steep, as shown in Figure 12. For this reason, it has been 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 described above, the vibration actuator 10 has a plate-like portion 32 in which eddy currents are generated as the movable portion 30 vibrates (moves), thereby damping the vibration of the movable portion 30. Damping the vibration of the movable portion 30 makes it possible to smooth out changes in vibration acceleration near the resonance frequency F0, and therefore the vibration actuator 10 can 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] <Modifications> In the above embodiment, the elastic member 41 is formed from a leaf spring, but it is not limited to a leaf spring and may be formed from a gel that is elastically variable 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.

[0077] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2024-108876, filed on July 5, 2024, are incorporated herein by reference in their entirety.

[0078] 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 machines, home appliances, etc. By installing the vibration actuator according to the present invention in these devices, it is possible to provide haptic feedback to the user through vibrations, for example, instead of physical switches. Furthermore, it is also possible to provide the user with haptic or bodily vibrations by using the vibration actuator according to the present invention as a means of transmitting information (e.g., warnings) from the device to the user.

[0079] 10 vibration actuator, 20 fixed part, 21 side cover, 22 upper cover, 23 lower cover, 24 upper yoke, 25 lower yoke, 26, 26a to 26d upper magnet, 27, 27a to 27d lower magnet, 30 movable part, 31, 31a to 31c coil, 32 plate-shaped part, 32a flat part, 32b bent part, 32c recess, 33 upper weight, 33a end, 33b protruding part, 34 lower weight, 34a support end, 34b fitting part, 41 elastic member, 51, 52 wiring part

Claims

1. A vibration actuator that elastically vibrates a movable part supported on a fixed part by an elastic member using the driving force of a driving part, wherein the driving part has magnets included in the fixed part and arranged to form a pair facing each other across a space, and a coil included in the movable part and arranged in the space, and the driving force is generated by the interaction between the magnetic field of the magnets and the current flowing in the coil, and 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.

2. The vibration actuator according to claim 1, wherein the movable portion further includes a weight having heat dissipation properties and connected to the plate portion in a manner that allows thermal conduction.

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

4. A vibration actuator as described in claim 3, wherein the weight is made up of two pairs of weight members, and the plate-like portion is rectangular, with each of the two opposing ends being sandwiched between a pair of the weight members.

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

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

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

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