Vibration generating device

Abstract

A vibration generating device (101) comprises: a housing (HS), a vibrator (VB) housed in the housing (HS), an elastic support member (ES) that supports the vibrator (VB) so as to be capable of vibrating along the X-axis direction, a coil (12) having a bundle wire part extending along the Y-axis direction, and a magnet (15) that generates a magnetic flux passing through the bundle wire part along the Z-axis direction. In addition, the vibration generating device (101) is configured such that the coil (12) is fixed to the housing (HS) and the magnet (15) is fixed to the vibrator (VB). Moreover, the vibration generating device (101) comprises a bracket (11) as a conductive member fixed to the coil (12), extending along the X-axis direction across the magnetic flux, and configured to generate an eddy current and reduce the acceleration of the vibrator (VB) when the vibrator (VB) moves along the X-axis direction.

Description

Vibration Generator

[0001] The present disclosure relates to a vibration generating device.

[0002] Conventionally, an actuator (vibration generator) that generates vibrations has been known (see Patent Document 1). This actuator is configured to vibrate a movable body relative to a support body using a magnetic drive circuit equipped with a coil and a magnet. This actuator is also configured to suppress resonance of the movable body using a viscoelastic member, which is a gel-like damper member, disposed between the support body and the movable body.

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

[0004] However, the above-mentioned viscoelastic member may have a problem in terms of durability.

[0005] Therefore, it is desirable to provide a vibration generator that is more durable.

[0006] A vibration generating device according to one embodiment of the present disclosure comprises a housing, a movable body accommodated within the housing, a support member that supports the movable body so that it can vibrate along a first direction, a coil having a flux portion extending along a second direction perpendicular to the first direction, and a magnetic flux generating member that generates magnetic flux that passes through the flux portion along a third direction that is perpendicular to both the first direction and the second direction, wherein one of the coil and the magnetic flux generating member is fixed to the housing and the other of the coil and the magnetic flux generating member is fixed to the movable body, and further comprises a conductive member that is fixed to the coil, extends along the first direction so as to cross the magnetic flux, and is configured to generate an eddy current when the movable body moves along the first direction, thereby reducing the acceleration of the movable body.

[0007] The above measures provide a more durable vibration generating device.

[0008] 1 is a perspective view of a vibration generator; 2 is an exploded perspective view of a vibration generator; 3 is an exploded perspective view of a vibration section and a non-vibration body; 4 is a perspective view of a non-vibration body; 5 is a diagram showing an example of the configuration of a base member and an elastic support member; 6 is a perspective view of a vibration section; 7 is a perspective view of components of a driving means; 8 is a perspective view of a leaf spring; 9 is a perspective view of a base member and a bracket; 10 is a cross-sectional view of a vibration body; 11 is a perspective view of each member that constitutes a vibration generator; 12 is a perspective view of each member that constitutes a vibration generator; 13 is a graph showing the relationship between the drive frequency of a vibration body and vibration acceleration;

[0009] A vibration device VE including a vibration generator 101 according to an embodiment of the present disclosure will now be described with reference to the drawings. Fig. 1 is a perspective view of the vibration device VE including the vibration generator 101 and a control unit CTR. Specifically, the upper view of Fig. 1 is a perspective view of the vibration generator 101 connected to the control unit CTR, and the lower view of Fig. 1 is a perspective view of the vibration generator 101 with the cover member 1 removed. Fig. 2 is an exploded perspective view of the vibration generator 101.

[0010] In each of FIGS. 1 and 2 , X1 represents one direction of the X axis constituting a three-dimensional orthogonal coordinate system, and X2 represents the other direction of the X axis. Furthermore, Y1 represents one direction of the Y axis constituting the three-dimensional orthogonal coordinate system, and Y2 represents the other direction of the Y axis. Similarly, Z1 represents one direction of the Z axis constituting the three-dimensional orthogonal coordinate system, and Z2 represents the other direction of the Z axis. In this embodiment, the X1 side of the vibration generator 101 corresponds to the front side (front face side) of the vibration generator 101, and the X2 side of the vibration generator 101 corresponds to the rear side (rear face side) of the vibration generator 101. Furthermore, the Y1 side of the vibration generator 101 corresponds to the left side of the vibration generator 101, and the Y2 side of the vibration generator 101 corresponds to the right side of the vibration generator 101. The Z1 side of the vibration generator 101 corresponds to the upper side of the vibration generator 101, and the Z2 side of the vibration generator 101 corresponds to the lower side of the vibration generator 101. The same applies to the other figures.

[0011] The vibration device VE has a control unit CTR and a vibration generator 101. The vibration generator 101 has a housing HS and a vibration unit VP accommodated in the housing HS.

[0012] As shown in Fig. 1, the housing HS has a substantially rectangular parallelepiped outer shape. In this embodiment, the housing HS is made of a non-magnetic material such as austenitic stainless steel. The housing HS is composed of a cover member 1 and a base member 2.

[0013] 2, the cover member 1 is configured to form the side and top surfaces of the housing HS, and the base member 2 is configured to form the bottom surface of the housing HS. In the illustrated example, the base member 2 is configured to function as a base that supports the vibration unit VP.

[0014] In this embodiment, the cover member 1 has a generally rectangular cylindrical outer wall portion 1A and a flat top plate portion 1T provided so as to be continuous with the upper end (the end on the Z1 side) of the outer wall portion 1A.

[0015] The outer peripheral wall 1A has four side plate portions formed in a flat plate shape. Specifically, as shown in Fig. 2, the outer peripheral wall 1A has a first side plate portion 1A1 and a third side plate portion 1A3 that face each other, and a second side plate portion 1A2 and a fourth side plate portion 1A4 that are perpendicular to the first side plate portion 1A1 and the third side plate portion 1A3 and face each other.

[0016] The control unit CTR is configured to realize the movement of the vibration unit VP. In this embodiment, the control unit CTR includes an electronic circuit and is configured to supply an alternating current to the vibration unit VP to vibrate the vibration unit VP. Note that although the control unit CTR is installed outside the housing HS in this embodiment, it may also be installed inside the housing HS. In this case, the control unit CTR may be one of the components of the vibration generator 101.

[0017] The vibration part VP is configured to be able to vibrate the housing HS by vibrating itself. In this embodiment, the vibration part VP is configured to be attached inside the housing HS and to be able to vibrate the housing HS.

[0018] Next, details of the vibration part VP will be described with reference to Fig. 3. Fig. 3 is an exploded perspective view of the vibration part VP. The vibration part VP is configured to include a vibrating body VB, a driving means DM, and an elastic support member ES.

[0019] The vibrating body VB as a movable body has a predetermined natural frequency and is configured to be able to vibrate relative to the housing HS along a vibration axis VA (see FIG. 2) extending in a predetermined direction. In this embodiment, the vibrating body VB has a predetermined natural frequency and is configured to be able to vibrate relative to the base member 2 along the vibration axis VA (see FIG. 2) extending in the X-axis direction (front-back direction).

[0020] The driving means DM is an example of a vibration force generating unit, and is configured to vibrate the vibrating body VB along the vibration axis VA. In this embodiment, the driving means DM is configured to vibrate the vibrating body VB, which is elastically supported by the elastic support member ES, along the vibration axis VA in response to an AC current supplied through the control unit CTR.

[0021] The elastic support member ES is an example of a support member, and is configured to be interposed between the housing HS and the vibrating body VB so as to elastically support the vibrating body VB.

[0022] Specifically, the vibrating part VP, which includes the vibrating body VB, driving means DM, and elastic support member ES, is composed of a yoke 10, a bracket 11, a coil 12, a wiring board 13, a magnet 15, and a leaf spring 17. The vibrating body VB is composed of the yoke 10 and the magnet 15, the driving means DM is composed of the coil 12 and the magnet 15, and the elastic support member ES is composed of the leaf spring 17. The bracket 11, the coil 12, and the wiring board 13 form a non-vibrating body NV that does not vibrate together with the vibrating body VB. The non-vibrating body NV vibrates together with the housing HS, but does not vibrate together with the vibrating body VB.

[0023] The yoke 10 is a component that constitutes a magnetic circuit. In this embodiment, the yoke 10 is made of a magnetic material such as iron. In the illustrated example, the yoke 10 is composed of two components, an upper yoke 10U and a lower yoke 10D, and is made of cold-rolled steel plate (SPCC). The upper yoke 10U constitutes the upper surface of the vibrating body VB and includes a left plate portion LW, a right plate portion RW, and a top plate portion TW. Specifically, a protrusion PR is formed on the Z2-side end surface of each of the left plate portion LW and the right plate portion RW so as to engage with the recess RC formed in the lower yoke 10D. The lower yoke 10D constitutes the lower surface of the vibrating body VB and includes a bottom plate portion BW. Specifically, a recess RC is formed on each of the Y1-side (left) end surface and the Y2-side (right) end surface of the lower yoke 10D so as to engage with the protrusion PR formed in the upper yoke 10U.

[0024] The bracket 11 is an example of a conductive member and is configured to support the coil 12 while the coil 12 faces the magnet 15 without contacting the magnet 15. That is, the bracket 11 is configured to function as a coil holder that supports the coil 12. The bracket 11 is also fixed to the base member 2 so as not to come into contact with the vibrating body VB. In this embodiment, the bracket 11 is a plate-shaped member formed of a non-magnetic material such as copper, aluminum, or an alloy thereof, and has a connecting portion 11A and a plate-shaped portion 11B. Specifically, the bracket 11 is fixed to the base member 2 by fastening members, welding, adhesive, crimping, or the like via four connecting portions 11A protruding outward from the plate-shaped portion 11B at positions where the bracket 11 and the coil 12 do not come into contact with the vibrating body VB even when the vibrating body VB vibrates. That is, the bracket 11 to which the coil 12 is attached is configured not to vibrate together with the vibrating body VB.

[0025] The coil 12 is configured to generate a magnetic field when supplied with current. In the example shown in FIG. 3 , the coil 12 includes three coil winding portions (a first coil winding portion 12A, a second coil winding portion 12B, and a third coil winding portion 12C) connected in series. The first coil winding portion 12A, the second coil winding portion 12B, and the third coil winding portion 12C each have a substantially elliptical shape (a rounded rectangle) with a major axis along the Y-axis direction. The coil 12 has a first end portion 12S at the winding start side and a second end portion 12E at the winding end side. The coil 12 is fixed to the Z2 side (lower side) of the bracket 11 with an adhesive or the like. The conductive wire (a wire made of copper or a copper alloy, etc.) constituting the coil 12 has an insulating coating on its surface. For clarity, the coil 12 is illustrated in a simplified form in FIG. 3 , and detailed winding details are omitted. This is also true for other figures.

[0026] The wiring board 13 is a member to which the first end 12S and the second end 12E of the coil 12 are connected. In this embodiment, the wiring board 13 is fixed to the Z2 side (lower side) surface of the bracket 11 with an adhesive, as shown in the lower view of Fig. 4. Fig. 4 is a perspective view of the non-vibrating body NV. Specifically, the upper view of Fig. 4 is a top perspective view of the non-vibrating body NV, and the lower view of Fig. 4 is a bottom perspective view of the non-vibrating body NV.

[0027] In the illustrated example, the wiring board 13 is a flexible wiring board having flexibility and includes a left wiring board 13L and a right wiring board 13R. The left wiring board 13L and the right wiring board 13R are fixed to the X1 side (front side) end of the bracket 11 with an adhesive or the like. As shown in the lower diagram of FIG. 4 , a first end 12S of the coil 12 is connected to the inner conductor pattern PI of the right wiring board 13R with solder or a conductive adhesive or the like, and a second end 12E of the coil 12 is connected to the inner conductor pattern PI of the left wiring board 13L with solder or a conductive adhesive or the like. The outer conductor patterns PE on each of the left wiring board 13L and the right wiring board 13R are connected to conductors from the control unit CTR with solder or a conductive adhesive or the like.

[0028] Each of the first coil winding portion 12A, the second coil winding portion 12B, and the third coil winding portion 12C has an air-core portion AC. The first end portion 12S, the first coil winding portion 12A, the second coil winding portion 12B, the third coil winding portion 12C, and the second end portion 12E are connected by a conductor portion CP. Specifically, the conductor portion CP includes a first conductor portion CP1 to a fourth conductor portion CP4. The first end portion 12S and the first coil winding portion 12A are connected by a first conductor portion CP1, the first coil winding portion 12A and the second coil winding portion 12B are connected by a second conductor portion CP2, the second coil winding portion 12B and the third coil winding portion 12C are connected by a third conductor portion CP3, and the third coil winding portion 12C and the second end portion 12E are connected by a fourth conductor portion CP4.

[0029] The coil 12 also includes bundled wire portions extending along the Y-axis direction. Specifically, the first coil winding portion 12A has a front bundled wire portion 12A1 and a rear bundled wire portion 12A2, the second coil winding portion 12B has a front bundled wire portion 12B1 and a rear bundled wire portion 12B2, and the third coil winding portion 12C has a front bundled wire portion 12C1 and a rear bundled wire portion 12C2. In the lower diagram of Figure 4, the bundled wire portions of the coil 12 are indicated with a dot pattern for clarity.

[0030] The magnet 15 is an example of a magnetic flux generating member and, together with the coil 12, constitutes the driving means DM. In this embodiment, the magnet 15 includes an upper magnet 15U and a lower magnet 15D. Each of the upper magnet 15U and the lower magnet 15D is an eight-pole magnetized permanent magnet having a substantially rectangular parallelepiped outer shape. Specifically, the upper magnet 15U includes a first upper magnet portion 15U1 to a fourth upper magnet portion 15U4, and the lower magnet 15D includes a first lower magnet portion 15D1 to a fourth lower magnet portion 15D4. Each of the first upper magnet portion 15U1 to the fourth upper magnet portion 15U4 and the first lower magnet portion 15D1 to the fourth lower magnet portion 15D4 includes one north pole portion and one south pole portion. In the illustrated example, the top surfaces of the first upper magnet portion 15U1, the third upper magnet portion 15U3, the first lower magnet portion 15D1, and the third lower magnet portion 15D3 are north poles, and the top surfaces of the second upper magnet portion 15U2, the fourth upper magnet portion 15U4, the second lower magnet portion 15D2, and the fourth lower magnet portion 15D4 are south poles. For clarity, in FIG. 3 , a dot pattern is applied to the north pole of the eight-pole magnetized permanent magnet, and a cross pattern is applied to the south pole. This is the same in other figures. Each of the upper magnet 15U and the lower magnet 15D may be a combination of four two-pole magnetized permanent magnets, or a combination of two four-pole magnetized permanent magnets.

[0031] The leaf spring 17 is an example of an elastic support member ES that is interposed between the housing HS and the vibrating body VB and is configured to elastically support the vibrating body VB. In this embodiment, the leaf spring 17 is made of a non-magnetic material such as austenitic stainless steel, and has a connecting portion 17A, a vibrating body support portion 17B, and an elastic arm portion 17C, as shown in FIG.

[0032] Specifically, the leaf spring 17 is formed by punching and bending a metal plate made of austenitic stainless steel with a thickness of, for example, 0.2 mm. More specifically, as shown in Fig. 5, the connection portion 17A of the leaf spring 17 is welded to the bottom plate portion 2B of the base member 2. The leaf spring 17 is attached to the base member 2 only via the connection portion 17A, with a gap GP formed between the bottom plate portion 2B of the base member 2 and the vibrating body support portion 17B so that the vibrating body support portion 17B and the elastic arm portion 17C do not come into contact with the base member 2.

[0033] Fig. 5 is a diagram showing an example of the configuration of the base member 2 and the elastic support member ES (leaf spring 17). Specifically, the upper view of Fig. 5 is a perspective view of the base member 2 to which the elastic support member ES (leaf spring 17) is attached. The lower view of Fig. 5 is a front view of the base member 2 to which the elastic support member ES (leaf spring 17) is attached, and corresponds to an enlarged view of the area R1 surrounded by the dashed line in the upper view of Fig. 5. Note that in Fig. 5, a dot pattern is applied to the elastic support member ES (leaf spring 17) for clarity.

[0034] In this embodiment, the connection portion 17A of the leaf spring 17 includes a first connection portion 17A1 to a fourth connection portion 17A4, as shown in the upper diagram of Figure 5, and the elastic arm portion 17C of the leaf spring 17 includes a first elastic arm portion 17C1 to a fourth elastic arm portion 17C4.

[0035] As shown in the upper diagram of FIG. 5, each of the first connecting portion 17A1 to the fourth connecting portion 17A4 is fixed to the bottom plate portion 2B of the base member 2 by welding. Furthermore, as shown in FIG. 6, the vibrating body VB is welded to the vibrating body support portion 17B of the leaf spring 17. FIG. 6 is a perspective view of the vibrating portion VP. Specifically, the upper diagram of FIG. 6 is a perspective view of the vibrating portion VP (elastic support member ES and vibrating body VB) with the non-vibrating body NV (bracket 11, coil 12, and wiring board 13) omitted, and the lower diagram of FIG. 6 is a perspective view of the vibrating portion VP with the non-vibrating body NV shown. Note that in the lower diagram of FIG. 6, a dot pattern is applied to the vibrating portions (vibrating body VB and elastic support member ES) for clarity. The presence or absence of a dot pattern indicates that the non-vibrating body NV, which does not have a dot pattern, is fixed to the base member 2 (not shown in the lower diagram of FIG. 6) so as not to come into contact with the vibrating body VB, which has a dot pattern. Note that the lower diagram of FIG. 1 shows the non-vibrating body NV fixed to the base member 2 so as not to come into contact with the vibrating body VB.

[0036] Specifically, the vibrating body VB is composed of an upper yoke 10U, an upper magnet 15U, a lower magnet 15D, and a lower yoke 10D, as shown in the upper diagram of Fig. 6. The Z2 side (lower side) surface of the bottom plate portion BW of the lower yoke 10D is welded to the Z1 side (upper side) surface of the vibrating body support portion 17B of the leaf spring 17.

[0037] When an AC current is applied to the coil 12 via the wiring board 13 in the state shown in the lower diagram of FIG. 6, the vibrating body VB vibrates along the vibration axis VA.

[0038] Here, referring to FIG. 7 , the positional relationship of the components of the driving means DM when the vibrating body VB vibrates along the vibration axis VA will be described. FIG. 7 is a perspective view of the components of the driving means DM. Specifically, the upper diagram of FIG. 7 shows the positional relationship between the non-vibrating body NV (coil 12) and the vibrating body VB (magnet 15) when current flows in one direction through the coil 12 and the vibrating body VB (magnet 15) moves all the way to the X2 side (rear side). The center diagram of FIG. 7 shows the positional relationship between the non-vibrating body NV (coil 12) and the vibrating body VB (magnet 15) when no current flows through the coil 12. The lower diagram of FIG. 7 shows the positional relationship between the non-vibrating body NV (coil 12) and the vibrating body VB (magnet 15) when current flows in the other direction through the coil 12 and the vibrating body VB (magnet 15) moves all the way to the X1 side (front side).

[0039] When no current flows through the coil 12, the coil 12 does not generate a magnetic field, and therefore no repulsive or attractive force occurs between the coil 12 and the magnet 15. Therefore, the magnet 15 is positioned in a neutral position so that its center faces the center of the coil 12 (second coil winding portion 12B), as shown in the center of Figure 7. Specifically, the vibrating body VB (magnet 15) in a position other than the neutral position is urged by the elastic support member ES (leaf spring 17) to return to the neutral position.

[0040] When current flows from the first end 12S to the second end 12E of the coil 12, the first coil winding portion 12A generates a magnetic field such that the Z1 side is a north pole and the Z2 side is a south pole, the second coil winding portion 12B generates a magnetic field such that the Z2 side is a north pole and the Z1 side is a south pole, and the third coil winding portion 12C generates a magnetic field such that the Z1 side is a north pole and the Z2 side is a south pole. As a result, the north pole portion of the second upper magnet portion 15U2 is moved away from the first coil winding portion 12A and attracted toward the second coil winding portion 12B, the south pole portion of the third upper magnet portion 15U3 is moved away from the second coil winding portion 12B and attracted toward the third coil winding portion 12C, the south pole portion of the second lower magnet portion 15D2 is moved away from the first coil winding portion 12A and attracted toward the second coil winding portion 12B, and the north pole portion of the third lower magnet portion 15D3 is moved away from the second coil winding portion 12B and attracted toward the third coil winding portion 12C, and as a result, the vibrating body VB (magnet 15) moves toward the X2 side (rear side) as shown by the arrow AR1 in the upper diagram of Figure 7.

[0041] Conversely, when current flows from the second end 12E of the coil 12 to the first end 12S, the first coil winding portion 12A generates a magnetic field such that the Z1 side is a south pole and the Z2 side is a north pole, the second coil winding portion 12B generates a magnetic field such that the Z2 side is a south pole and the Z1 side is a north pole, and the third coil winding portion 12C generates a magnetic field such that the Z1 side is a south pole and the Z2 side is a north pole. As a result, the north pole portion of the second upper magnet portion 15U2 is moved away from the second coil winding portion 12B and attracted toward the first coil winding portion 12A, the south pole portion of the third upper magnet portion 15U3 is moved away from the third coil winding portion 12C and attracted toward the second coil winding portion 12B, the south pole portion of the second lower magnet portion 15D2 is moved away from the second coil winding portion 12B and attracted toward the first coil winding portion 12A, and the north pole portion of the third lower magnet portion 15D3 is moved away from the third coil winding portion 12C and attracted toward the second coil winding portion 12B, causing the vibrating body VB (magnet 15) to move toward the X1 side (front side) as shown by arrow AR2 in the lower diagram of Figure 7.

[0042] The control unit CTR can alternately reverse the direction of the magnetic field generated by the coil 12 by alternately reversing the direction of the current flowing through the coil 12, and thus can vibrate the vibrating body VB (magnet 15) along the vibration axis VA (X-axis direction).

[0043] Next, the movement of the elastic arm 17C when the vibrating body VB vibrates will be described with reference to Fig. 8. Fig. 8 is a perspective view of the leaf spring 17. Specifically, the upper diagram of Fig. 8 shows the state of the leaf spring 17 when no current flows through the coil 12, i.e., when the vibrating body VB is in a neutral position (not vibrating). The lower diagram of Fig. 8 shows the state of the leaf spring 17 when the vibrating body VB moves to the X2 side (rear side).

[0044] 8, the elastic arm portion 17C is provided between the connection portion 17A and the vibrating body support portion 17B. Specifically, the first elastic arm portion 17C1 is provided between the first connection portion 17A1 and the vibrating body support portion 17B, the second elastic arm portion 17C2 is provided between the second connection portion 17A2 and the vibrating body support portion 17B, the third elastic arm portion 17C3 is provided between the third connection portion 17A3 and the vibrating body support portion 17B, and the fourth elastic arm portion 17C4 is provided between the fourth connection portion 17A4 and the vibrating body support portion 17B.

[0045] When the vibrator VB (not shown in FIG. 8) is moved in the direction indicated by the arrow AR3 by the driving means DM, the elastic arm 17C bends as shown in the lower diagram of FIG. 8, allowing the vibrator VB to translate in the X2 direction. Note that in FIG. 8, for clarity, dot patterns are added to the parts of the elastic arm 17C that are bent relatively greatly.

[0046] Conversely, when the vibrator VB is moved by the driving means DM in the direction opposite to the direction indicated by the arrow AR3 (X2 direction) (X1 direction), the elastic arm portion 17C bends in the direction opposite to the bending direction shown in the lower diagram of Figure 8, allowing the vibrator VB to move in the X1 direction.

[0047] Referring again to FIG. 3, the upper yoke 10U will be described in detail. The upper yoke 10U has a top plate portion TW, a right plate portion RW, and a left plate portion LW. Specifically, a left plate portion LW extending in the Z2 direction is formed at the Y1-side end of the top plate portion TW, and a right plate portion RW extending in the Z2 direction is formed at the Y2-side end of the top plate portion TW. Furthermore, a protrusion PR is formed at the lower end of each of the left plate portion LW and the right plate portion RW so as to engage with a recess RC formed in the lower yoke 10D. The upper diagram of FIG. 6 shows the recess RC formed in the lower yoke 10D engaged with the protrusion PR of the upper yoke 10U.

[0048] When assembling the vibrating body VB, the upper magnet 15U is attached to the top plate portion TW (see FIG. 3) of the upper yoke 10U, the lower magnet 15D is attached to the bottom plate portion BW (see FIG. 3) of the lower yoke 10D, and further, the protrusion PR of the upper yoke 10U is engaged with the recess RC of the lower yoke 10D. In this way, in this embodiment, the upper yoke 10U and the lower yoke 10D surrounding the magnet 15 are separate members to simplify assembly of the vibrating body VB.

[0049] 6, the Z1-side (upper) surface of upper magnet 15U is magnetically joined to the Z2-side (lower) surface of top plate portion TW of upper yoke 10U, and the Z2-side (lower) surface of lower magnet 15D is magnetically joined to the Z1-side (upper) surface of bottom plate portion BW of lower yoke 10D. Furthermore, in the space surrounded by upper yoke 10U and lower yoke 10D, as shown in the lower diagram of FIG. 6, coil 12 fixed to bracket 11 is installed on the Z2 side of upper magnet 15U and on the Z1 side of lower magnet 15D, without contacting upper magnet 15U or lower magnet 15D.

[0050] As shown in Fig. 9, the bracket 11 is attached to the base member 2 by engaging a connecting portion 11A provided on the bracket 11 with a support portion 2P provided on the base member 2. Fig. 9 is a diagram showing an example of the configuration of the base member 2 and the bracket 11. Specifically, the upper diagram in Fig. 9 is a perspective view of the bracket 11, the center diagram in Fig. 9 is a perspective view of the base member 2, and the lower diagram in Fig. 9 is a perspective view of the bracket 11 attached to the base member 2.

[0051] As shown in FIG. 9 , the connecting portion 11A includes a first connecting portion 11A1 to a fourth connecting portion 11A4. The support portion 2P includes a first supporting portion 2P1 to a fourth supporting portion 2P4. The first connecting portion 11A1 is engaged with the first supporting portion 2P1, the second connecting portion 11A2 is engaged with the second supporting portion 2P2, the third connecting portion 11A3 is engaged with the third supporting portion 2P3, and the fourth connecting portion 11A4 is engaged with the fourth supporting portion 2P4. In the illustrated example, the connecting portion 11A and the support portion 2P are joined by welding. However, the connecting portion 11A and the support portion 2P may also be joined by a fastening member, an adhesive, caulking, or the like.

[0052] Next, the magnetic flux generated by the magnet 15 will be described with reference to FIG. 10 . FIG. 10 is a cross-sectional view of the vibrating body VB. Specifically, FIG. 10 shows the vibrating body VB, which is configured with an upper yoke 10U, an upper magnet 15U, a lower magnet 15D, and a lower yoke 10D, and the coil 12 installed inside the space surrounded by the upper yoke 10U and the lower yoke 10D (the space sandwiched between the upper magnet 15U and the lower magnet 15D). The magnet 15 generates magnetic flux represented by magnetic field lines MF, as shown by dotted lines in FIG. 10 . In the example shown in FIG. 10 , the magnetic field lines MF include first to sixth magnetic field lines MF1 to MF6.

[0053] Specifically, when no current is flowing through the coil 12, the first magnetic field line MF1 exits from the north pole portion of the first lower magnet portion 15D1 of the lower magnet 15D, passes through the front bundle portion 12A1 of the first coil winding portion 12A, and enters the south pole portion of the first upper magnet portion 15U1 of the upper magnet 15U. The second magnetic field line MF2 exits from the north pole portion of the second upper magnet portion 15U2 of the upper magnet 15U, passes through the rear bundle portion 12A2 of the first coil winding portion 12A, and enters the south pole portion of the second lower magnet portion 15D2 of the lower magnet 15D. The third magnetic field line MF3 exits from the north pole portion of the second upper magnet portion 15U2 of the upper magnet 15U, passes through the front bundle portion 12B1 of the second coil winding portion 12B, and enters the south pole portion of the second lower magnet portion 15D2 of the lower magnet 15D. The fourth magnetic field line MF4 exits from the north pole portion of the third lower magnet portion 15D3 of the lower magnet 15D, passes through the rear bundle portion 12B2 of the second coil winding portion 12B, and enters the south pole portion of the third upper magnet portion 15U3 of the upper magnet 15U. The fifth magnetic field line MF5 exits from the north pole portion of the third lower magnet portion 15D3 of the lower magnet 15D, passes through the front bundle portion 12C1 of the third coil winding portion 12C, and enters the south pole portion of the third upper magnet portion 15U3 of the upper magnet 15U. The sixth magnetic field line MF6 exits from the north pole portion of the fourth upper magnet portion 15U4 of the upper magnet 15U, passes through the rear bundle portion 12C2 of the third coil winding portion 12C, and enters the south pole portion of the fourth lower magnet portion 15D4 of the lower magnet 15D.

[0054] Therefore, in the space surrounded by upper yoke 10U and lower yoke 10D, magnetic field lines are concentrated in the partial space between upper magnet 15U and lower magnet 15D, increasing the magnetic flux density, and coil 12 is installed in this partial space. Therefore, with this configuration, by passing a current between first end 12S and second end 12E of coil 12, a Lorentz force can be efficiently generated, and vibrating body VB can be efficiently vibrated along the X-axis direction.

[0055] For example, when a current flows from the first end 12S to the second end 12E of the coil 12, the vibrating body VB moves toward the X2 side (rear side). Also, when a current flows from the second end 12E to the first end 12S of the coil 12, the vibrating body VB moves toward the X1 side (front side). Therefore, the control unit CTR can vibrate the vibrating body VB along the vibration axis VA by passing a current through the coil 12 so that the direction of the current alternates. Note that the bracket 11 to which the coil 12 is attached is fixed to the base member 2, but not to the vibrating body VB, and therefore the bracket 11 and the coil 12 do not vibrate together with the vibrating body VB.

[0056] Furthermore, when the vibrating body VB vibrates along the vibration axis VA, the magnetic flux (hereinafter referred to as "effective magnetic flux") extending in the Z-axis direction generated between the upper magnet 15U and the lower magnet 15D included in the vibrating body VB also vibrates along the vibration axis VA. That is, the effective magnetic flux that crosses the bracket 11, which serves as a conductive member located between the upper magnet 15U and the lower magnet 15D, vibrates along the vibration axis VA while maintaining its cross-sectional relationship across the bracket 11. As a result, eddy currents flow in the plate-like portion 11B of the bracket 11. In the illustrated example, the upper magnet 15U, the lower magnet 15D, and the bracket 11 are arranged so that the effective magnetic flux and the plate-like portion 11B are perpendicular to each other.

[0057] The vibrating body VB is constantly subjected to a damping force, which is a force caused by eddy currents and acts in the direction opposite to the vibration direction. Specifically, while the vibrating body VB is vibrated by the Lorentz force generated by the driving means DM, it is subjected to a damping force that acts to slow down the vibration. The damping force increases in proportion to the vibration velocity of the vibrating body VB. Therefore, the vibration acceleration at the natural frequency of the vibrating body VB and frequencies nearby is reduced by the damping force.

[0058] The braking force caused by eddy currents increases as the eddy currents increase. The eddy currents also increase as the resistivity of the conductive member (bracket 11) decreases, as the conductivity of the conductive member (bracket 11) increases, and as the thickness of the conductive member (bracket 11) (thickness of plate-like portion 11B) increases. Therefore, the material and thickness of bracket 11 are selected so as to obtain a desired braking force. In the illustrated example, bracket 11 is made of tough-pitch copper, the same material as the wire material of coil 12, and has a thickness of approximately 0.3 mm.

[0059] This configuration improves the durability of the vibration generator 101 compared to when a viscoelastic member for generating a braking force is attached between the vibrating body VB and the non-vibrating body NV. This is because the bracket 11 is less susceptible to the effects of viscoelastic members, such as ambient temperature, dimensional variations, deterioration, peeling, or tearing.

[0060] 4, the bracket 11 is formed to have a plurality of openings (three first openings H1, three second openings H2, and six third openings H3), at least one of which may be a notch.

[0061] The first opening H1 is a non-circular (approximately teardrop-shaped) opening that prevents the upper surface of the coil 12 from tilting relative to the lower surface of the plate-shaped portion 11B when the coil 12 is attached to the lower surface of the plate-shaped portion 11B of the bracket 11 due to interference between the plate-shaped portion 11B and the conductor portion CP.

[0062] The second opening H2 is a substantially circular opening for receiving a jig (not shown) used to position the air-core portion AC of the coil 12. The jig (not shown) is, for example, a cylindrical rod member. In the illustrated example, the first opening H1 also functions as an opening for receiving the jig.

[0063] The third opening H3 is an approximately circular opening formed for inserting a jig to maintain an appropriate clearance between the bracket 11 and the coil 12 when supplying adhesive between the lower surface of the plate-shaped portion 11B of the bracket 11 and the upper surface of the coil 12.

[0064] In the illustrated example, the first opening H1 to the third opening H3 are all formed at positions that avoid the locus TR. The locus TR is the locus on the plate-shaped portion 11B through which the central axis of the effective magnetic flux passes when the vibrating body VB vibrates. In other words, the vibration generator 101 is configured so that the central axis of the effective magnetic flux extending along the Z-axis direction moves in the X-axis direction along the linear locus TR. In the illustrated example, the central axis of the effective magnetic flux includes the central axes of the effective magnetic flux generated by the first lower magnet portion 15D1, the second upper magnet portion 15U2, the third lower magnet portion 15D3, and the fourth upper magnet portion 15U4, as indicated by the magnetic field lines MF in FIG. 10 . Furthermore, the locus TR is located on the vibration axis VA when viewed from above. Note that the central axis of the effective magnetic flux may be interpreted as the coil axes of the first coil winding portion 12A, the second coil winding portion 12B, and the third coil winding portion 12C.

[0065] In other words, the first opening H1 to the third opening H3 are all formed at positions that avoid the central region CR. The central region CR is a region in the center of the plate-shaped portion 11B that includes the locus TR. Specifically, the central region CR is a region through which eddy currents flow, which are generated by the effective magnetic flux generated by the magnet 15 and the conductive member (bracket 11) that is installed across the effective magnetic flux. In the upper diagram of Figure 4, a dot pattern is added to the central region CR for clarity.

[0066] In the illustrated example, the vibration generator 101 has no openings such as the first opening H1 to the third opening H3 in the rectangular central region CR of the plate-like portion 11B, which results in an effect of allowing eddy currents to flow more easily than when openings are formed in the central region CR. Also, the vibration generator 101 has a rectangular central region CR of the plate-like portion 11B that is flat and does not have any recesses, protrusions, or the like, which results in an effect of allowing eddy currents to flow more easily than when recesses, protrusions, or the like are formed in the central region CR and it is not flat.

[0067] In addition, the central region CR is symmetrical in the top view with respect to the vibration axis VA, and is also symmetrical in the front-rear direction with respect to a line segment L1 (see the upper diagram in FIG. 4 ) that represents the left-right axis passing through the center point of the bracket 11. This configuration brings about the effect that the magnitude of the braking force when the vibrating body VB moves forward (in the X1 direction) is the same as the magnitude of the braking force when the vibrating body VB moves backward (in the X2 direction).

[0068] Next, a method for assembling the electromagnetic exciter 101 will be described with reference to Fig. 11 and Fig. 12. Fig. 11 and Fig. 12 are perspective views of the components constituting the electromagnetic exciter 101. Note that in Fig. 11 and Fig. 12, newly attached components are indicated by dot patterns for clarity.

[0069] Specifically, the upper view of Figure 11 is a perspective view of the leaf spring 17, the central view of Figure 11 is a perspective view of the leaf spring 17 with the lower yoke 10D attached, and the lower view of Figure 11 is a perspective view of the base member 2 with the leaf spring 17 attached in the state shown in the central view of Figure 11.

[0070] The top figure in Figure 12 is an oblique view of the base member 2 to which a lower magnet 15D is further attached, the second figure from the top in Figure 12 is an oblique view of the base member 2 to which a bracket 11 and a coil 12 are further attached, the third figure from the top in Figure 12 is an oblique view of the base member 2 to which an upper yoke 10U and a wiring board 13 are further attached, and the bottom figure in Figure 12 is an oblique view of the base member 2 to which a cover member 1 is further attached.

[0071] First, as shown in the center diagram of Fig. 11, the lower yoke 10D is placed on the upper surface of the vibrating body support portion 17B of the leaf spring 17. In the illustrated example, the bottom plate portion BW of the lower yoke 10D is placed on the upper surface of the vibrating body support portion 17B without applying any adhesive. Note that a vibration-damping steel plate (not shown) may be attached to the outer surface of the standing portion EP of the elastic arm portion 17C of the leaf spring 17 as a reinforcing material to suppress deflection of the standing portion EP.

[0072] Thereafter, the leaf spring 17 with the lower yoke 10D placed thereon is placed on the upper surface of the bottom plate portion 2B of the base member 2, as shown in the lower diagram of Fig. 11. Then, the lower yoke 10D and the leaf spring 17 are joined, and the base member 2 and the leaf spring 17 are joined. In the illustrated example, the bottom plate portion BW of the lower yoke 10D is joined to the upper surface of the vibrating body support portion 17B of the leaf spring 17 by laser welding, and the connection portion 17A of the leaf spring 17 is joined to the upper surface of the bottom plate portion 2B of the base member 2 by laser welding.

[0073] Then, as shown in the top diagram of Fig. 12, a lower magnet 15D is placed on the upper surface of the bottom plate portion BW of the lower yoke 10D. In the illustrated example, the lower yoke 10D and the lower magnet 15D are attracted to each other by magnetic force, and therefore are not joined by laser welding or adhesive. However, the lower yoke 10D and the lower magnet 15D may also be joined by laser welding or adhesive.

[0074] Thereafter, the non-vibrating body NV is attached to the base member 2, as shown in the second diagram from the top in Fig. 12. In the illustrated example, the non-vibrating body NV is composed of a bracket 11, a coil 12, and a wiring board 13. The support portion 2P of the base member 2 and the connecting portion 11A of the bracket 11 are joined by a fastening member, caulking, laser welding, an adhesive, or the like. In the illustrated example, the support portion 2P and the connecting portion 11A are joined by an adhesive. Note that before the non-vibrating body NV is attached to the base member 2, the coil 12 is joined to the bracket 11 by an adhesive, and the wiring board 13 is joined to the bracket 11 by double-sided tape.

[0075] Thereafter, the upper yoke 10U, to which the upper magnet 15U is attached, is joined to the lower yoke 10D at a position where it does not come into contact with the non-vibrating body NV, as shown in the third diagram from the top of Figure 12. Specifically, the upper yoke 10U and the lower yoke 10D are joined by welding, adhesive, or the like at the portion where the recessed portion RC formed in the lower yoke 10D and the protruding portion PR of the upper yoke 10U engage with each other. In the illustrated example, the upper yoke 10U and the lower yoke 10D are joined by laser welding.

[0076] The upper magnet 15U is placed on the lower surface of the top plate portion TW of the upper yoke 10U in the same way that the lower magnet 15D is placed on the upper surface of the bottom plate portion BW of the lower yoke 10D before the upper yoke 10U is joined to the lower yoke 10D. Because the upper yoke 10U and the upper magnet 15U are attracted to each other by magnetic force, they are not joined by laser welding or adhesive. However, the upper yoke 10U and the upper magnet 15U may be joined by laser welding or adhesive.

[0077] 12, the cover member 1 is attached so as to cover the components other than the base member 2 and the wiring board 13. In the illustrated example, the lower end of the outer peripheral wall portion 1A of the cover member 1 and the peripheral edge of the bottom plate portion 2B of the base member 2 are joined by laser welding. The cover member 1 and the base member 2 may also be joined by a fastening member, an adhesive, caulking, or the like.

[0078] In this manner, the vibration generator 101 is assembled. The adhesive used in the above-described assembly process may be a thermosetting adhesive, a light-curing adhesive, a moisture-curing adhesive, or a hybrid adhesive that is a combination of these. In the illustrated example, the adhesive is a thermosetting adhesive.

[0079] Next, referring to FIG. 13 , the relationship between the drive frequency and vibration acceleration of the vibrator VB will be described. FIG. 13 is a graph showing the relationship between the drive frequency and vibration acceleration of the vibrator VB, with the drive frequency [Hz] on the horizontal axis and the vibration acceleration [G p-p] on the vertical axis. The solid graph line in FIG. 13 shows the relationship between the drive frequency [Hz] and vibration acceleration [G p-p] when a copper bracket 11 is used, while the dashed graph line in FIG. 13 shows the relationship between the drive frequency and vibration acceleration when a stainless steel bracket is used instead of the copper bracket 11. The copper bracket 11 and the stainless steel bracket are formed to have the same size and shape. The thickness of the copper bracket 11 and the thickness of the stainless steel bracket are both 0.2 mm. The drive frequency value f0 corresponds to the resonant frequency (natural frequency) of the vibrator VB. Vibrating the vibrator VB at a drive frequency of value f0 means vibrating the vibrator VB at the resonant frequency. Similarly, the drive frequency value 2f0 corresponds to twice the resonant frequency of the vibrating body VB, and vibrating the vibrating body VB at a drive frequency of 2f0 means vibrating the vibrating body VB at twice the resonant frequency. The same is true for drive frequency values ​​3f0 (three times the resonant frequency) and 4f0 (four times the resonant frequency).

[0080] In the case of the copper bracket 11, as represented by the solid graph line, when the drive frequency is f0, the vibration acceleration of the vibrating body VB is 1.0, and when the drive frequency is 2f0, the vibration acceleration is 0.6. In other words, the vibration acceleration of 1.0 when the vibrating body VB vibrates at the resonant frequency is less than twice (approximately 1.67 times) the vibration acceleration of 0.6 when the vibrating body VB vibrates at a frequency twice the resonant frequency.

[0081] On the other hand, in the case of a stainless steel bracket, as represented by the dashed graph line, when the drive frequency is f0, the vibration acceleration of vibrating body VB is 1.4, and when the drive frequency is 2f0, the vibration acceleration is 0.6. In other words, the vibration acceleration value of 1.4 when vibrating body VB vibrates at the resonant frequency is greater than twice the vibration acceleration value of 0.6 when vibrating body VB vibrates at a frequency twice the resonant frequency, or approximately 2.33 times.

[0082] In this way, when a copper bracket 11 is used, the vibration generator 101 can suppress the value of the vibration acceleration when the vibrating body VB vibrates at the resonant frequency to less than twice the value of the vibration acceleration when the vibrating body VB vibrates at a frequency twice the resonant frequency. Therefore, this configuration has the effect of suppressing the vibration of the vibrating body VB at and near the resonant frequency, compared to when the bracket is made of stainless steel. The same applies when the bracket 11 is made of aluminum, an alloy containing copper, an alloy containing aluminum, or the like.

[0083] 1 to 3 , the electromagnetic exciter 101 according to one embodiment of the present disclosure includes a housing HS, a movable body (vibrator VB) accommodated in the housing HS, a support member (elastic support member ES) that supports the movable body (vibrator VB) so that it can vibrate along a first direction (X-axis direction), a coil 12 having a bundled portion extending along a second direction (Y-axis direction) perpendicular to the first direction (X-axis direction), and a magnetic flux generating member (magnet 15) that generates magnetic flux that passes through the bundled portion along a third direction (Z-axis direction) perpendicular to both the first direction (X-axis direction) and the second direction (Y-axis direction). The electromagnetic exciter 101 is configured such that one of the coil 12 and the magnetic flux generating member (magnet 15) is fixed to the housing HS, and the other of the coil 12 and the magnetic flux generating member (magnet 15) is fixed to the movable body (vibrator VB). The vibration generating device 101 also includes a conductive member (bracket 11) that is fixed to the coil 12, extends along a first direction (X-axis direction) so as to cross the magnetic flux, and is configured to generate eddy currents when the movable body (vibrator VB) moves along the first direction (X-axis direction), thereby reducing the acceleration (vibration acceleration) of the movable body (vibrator VB).

[0084] In this configuration, the magnetism generating member (magnet 15) and the conductive member (bracket 11) can generate a damping force (a force that suppresses vibration) in the same way as a gel-like damper member that generates viscous resistance. Furthermore, this configuration can suppress the resonance of the vibrating body VB by the damping force. Note that in this configuration, the damping force is generated by eddy currents. Therefore, this configuration, which does not include a deforming part or sliding part like a gel-like damper member, has the effect of improving the durability of the vibration generator 101.

[0085] Furthermore, in a typical vibration generating device, the braking force due to eddy currents can be an undesirable force that reduces vibration acceleration, but the vibration generating device 101 according to the present disclosure is configured to suppress resonance of the vibrating body VB by actively utilizing the braking force due to eddy currents.

[0086] The conductive member (bracket 11) may be made of a non-magnetic metal. This configuration prevents magnetic force (attraction) from acting between the conductive member and the magnet 15, as occurs when the conductive member (bracket 11) is made of a magnetic metal, and prevents such attraction from interfering with efficient use of the driving force of the driving means DM. In the illustrated example, the conductive member (bracket 11) is made of tough pitch copper and is housed in a housing HS made of austenitic stainless steel, which has a lower conductivity than tough pitch copper. This configuration prevents eddy currents from leaking out of the housing HS.

[0087] Furthermore, the conductive member (bracket 11) may be formed of a material with a higher conductivity than iron and iron alloys. This configuration has the effect of increasing the damping force (force that suppresses vibration) due to eddy currents. This is because the greater the conductivity, the greater the damping force due to eddy currents. Therefore, this configuration has the effect of suppressing resonance of, for example, a heavier vibrating body VB.

[0088] The conductive member (bracket 11) may be preferably made of copper, aluminum, or an alloy thereof, which has the advantage of reducing material costs compared to when the conductive member is made of a precious metal such as silver or an alloy thereof.

[0089] Furthermore, the conductive member (bracket 11) may be provided between the magnetic flux generating member (magnet 15) and the coil 12. This configuration allows the conductive member (bracket 11) to be located closer to the magnetic flux generating member (magnet 15) than when the coil 12 is located between the conductive member (bracket 11) and the magnetic flux generating member (magnet 15), thereby providing the effect of increasing the braking force (the force that suppresses vibration). This is because the closer the conductive member (bracket 11) is to the magnetic flux generating member (magnet 15), the higher the magnetic flux density passing through the conductive member (bracket 11), and therefore the higher the magnetic flux density passing through the conductive member (bracket 11), the greater the braking force.

[0090] The vibration generator 101 may also include a magnetic flux attracting member that attracts magnetic flux and is positioned away from the magnetic flux generating member (magnet 15) along the third direction (Z-axis direction). In this case, the conductive member (bracket 11) may be disposed between the magnetic flux generating member (magnet 15) and the magnetic flux attracting member. In the illustrated example, the magnet 15 functions as both the magnetic flux generating member and the magnetic flux attracting member, and the yoke 10 functions as the magnetic flux attracting member. Specifically, when the upper magnet 15U functions as the magnetic flux generating member, the lower yoke 10D and the lower magnet 15D function as the magnetic flux attracting member. When the lower magnet 15D functions as the magnetic flux generating member, the upper yoke 10U and the upper magnet 15U function as the magnetic flux attracting member. Note that one of the upper magnet 15U and the lower magnet 15D may be omitted. When the upper magnet 15U is omitted, the lower magnet 15D functions as the magnetic flux generating member, and the upper yoke 10U functions as the magnetic flux attracting member. The same applies when the lower magnet 15D is omitted. This configuration makes the angle (hereinafter referred to as the "magnetic flux angle") formed between the extension direction (X-axis direction or Y-axis direction) of the conductive member (bracket 11) and the direction of the magnetic flux from the magnetic flux generating member (magnet 15) toward the magnetic flux attracting member (Z-axis direction) approximately a right angle, thereby providing the effect of increasing the braking force (the force that suppresses vibration) compared to when the magnetic flux angle is an angle other than a right angle. This is because, for the same magnetic flux density, the closer the magnetic flux angle is to a right angle, the greater the braking force.

[0091] For example, the magnetic flux generating member may be an upper magnet 15U serving as a first permanent magnet, and the magnetic flux attracting member may be a lower magnet 15D serving as a second permanent magnet. In this case, the first permanent magnet (upper magnet 15U) and the second permanent magnet (lower magnet 15D) may be arranged so that the opposing surfaces have opposite polarities, as shown in Fig. 7. This configuration brings the magnetic flux angle closer to a right angle, thereby further increasing the braking force (the force that suppresses vibration).

[0092] As shown in FIG. 4 , the vibration generator 101 may include a bracket 11 having a plate-shaped portion 11B extending along planes parallel to the first direction (X-axis direction) and the second direction (Y-axis direction) and to which the coil 12 is attached, and a connecting portion 11A extending from the plate-shaped portion 11B and fixed to the housing HS. In this case, the coil 12 may be fixed to the housing HS (base member 2) via the bracket 11, and the magnetic flux generating member (magnet 15) may be fixed to the movable body (vibrator VB). The plate-shaped portion 11B may be formed of copper, aluminum, or an alloy thereof and configured to function as a conductive member. This configuration has the advantage of reducing the number of parts compared to when a member separate from the bracket 11 (plate-shaped portion 11B) functions as a conductive member.

[0093] Furthermore, the conductive member (bracket 11) may be configured not to have an opening at a position corresponding to the locus TR (see the upper diagram in Figure 4) of the center of the magnetic flux when the movable body (vibrating body VB) vibrates. In other words, the conductive member (bracket 11) may be configured to always intersect with the magnetic flux at least in the central region CR when the movable body (vibrating body VB) is vibrating. This configuration has the effect of making it easier for eddy currents to flow compared to when there is an opening that intersects with the locus TR.

[0094] Furthermore, the coil 12 may have an air-core portion AC, which is the innermost portion of the coil winding portion, and a conductor portion CP extending outward from the air-core portion AC. The conductive member (bracket 11) may have an opening (see the first opening H1 in the upper diagram of FIG. 4 ) that prevents interference with the conductor portion CP when the coil 12 is attached. In this case, the opening (first opening H1) may be formed at a position that avoids the locus TR. That is, the opening (first opening H1) may be formed at a position that avoids the central region CR. This configuration prevents interference between the conductor portion CP and the conductive member (bracket 11), while allowing eddy currents to flow more easily than when an opening (first opening H1) that intersects with the locus TR is provided.

[0095] As shown in the lower diagram of Fig. 4 , the air core portion AC may be formed in the shape of an elongated hole extending along the second direction (Y-axis direction). In this case, as shown in the upper diagram of Fig. 4 , the conductor portion CP may be configured to extend outward from an end of the air core portion AC in the second direction (Y-axis direction). In the example shown in the upper diagram of Fig. 4 , the conductor portion CP is configured to extend forward (in the X1 direction) from the right end (end on the Y2 side) of the air core portion AC. This configuration has the advantage of allowing an opening (first opening) to be formed at a position farther away from the locus TR than when the conductor portion CP is configured to extend outward from a portion other than the end of the air core portion AC (e.g., the center).

[0096] 13, the vibration generator 101 may be configured so that the acceleration (value of vibration acceleration) when the movable body (vibrator VB) vibrates at the resonant frequency is equal to or less than twice the acceleration (value of vibration acceleration) when the movable body (vibrator VB) vibrates at a frequency twice the resonant frequency. This configuration has the effect of suppressing vibration of the vibrator VB at the resonant frequency and in the vicinity thereof.

[0097] The preferred embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions may be applied to the above-described embodiments without departing from the scope of the present invention. Furthermore, the features described with reference to the above-described embodiments may be combined as appropriate unless technically inconsistent.

[0098] For example, in the above embodiment, the magnet 15 is a component of the vibrating body VB and the coil 12 is a component of the non-vibrating body NV, but the magnet 15 may be a component of the non-vibrating body NV and the coil 12 may be a component of the vibrating body VB. That is, the vibration generator 101 may be configured such that the magnet 15 is fixed to the cover member 1 or the base member 2, and the bracket 11 and the coil 12 vibrate together with the yoke 10.

[0099] Furthermore, in the above-described embodiment, the vibrating body VB includes the yoke 10 and the magnet 15, but the yoke 10 may be a component of the non-vibrating body NV. In this case, the yoke 10 may be fixed to the inner surface of the housing HS. Also, in this case, the coil 12 may be fixed to the inner surface of the conductive member (bracket 11), and the conductive member (bracket 11) may be fixed to the inner surface of the yoke 10. That is, the coil 12 may be disposed between the vibrating body VB (magnet 15) and the conductive member (bracket 11), or may be disposed between the yoke 10 and the conductive member (bracket 11).

[0100] Furthermore, in the above-described embodiment, the magnet 15 includes the upper magnet 15U and the lower magnet 15D, but one of the upper magnet 15U and the lower magnet 15D may be omitted. For example, the lower magnet 15D may be omitted. In this case, the yoke 10 may be a component of the non-vibrating body NV. For example, the upper yoke 10U may be omitted, and the lower yoke 10D may be fixed to the base member 2. In this case, a conductive member such as the bracket 11 may be disposed on the opposite side of the coil 12 from the upper magnet 15U and fixed to the base member 2 or the lower yoke 10D.

[0101] The conductive member (bracket 11) may also be a cylindrical member. In this case, the coil 12 may be wound around the cylindrical conductive member. The magnet 15 may be configured to vibrate inside the cylindrical conductive member in the axial direction of the cylindrical conductive member. In this configuration, the coil 12 wound around the outer peripheral surface of the cylindrical conductive member may be fixed to the inner peripheral surface of a cylindrical yoke 10 disposed outside the cylindrical conductive member. The outer peripheral surface of the cylindrical yoke 10 may then be fixed to a housing HS located further outside the coil 12.

[0102] Alternatively, the bracket 11 may be configured with a base made of a non-conductive material and a conductive material (conductive film) attached to the base. In this case, the conductive film may be a film made of, for example, copper, aluminum, or an alloy thereof.

[0103] Furthermore, in the above-described embodiment, the vibration generator 101 is configured to include the magnet 15 magnetized with eight poles and the coil 12 having three coil winding portions (six bundled wire portions), but it may also be configured to include the magnet 15 magnetized with a number of magnetic poles other than eight, such as two, four, six, ten, or twelve poles, and the coil 12 having the corresponding number of bundled wire portions. In other words, the coil 12 may be configured to have one, two, four or more coil winding portions.

[0104] This application claims priority based on Japanese Patent Application No. 2022-123572, filed on August 2, 2022, the entire contents of which are incorporated herein by reference.

[0105]

Claims

1. Housing and A movable body accommodated in the housing; a support member that supports the movable body so that the movable body can vibrate along a first direction; a coil having a bundled wire portion extending along a second direction perpendicular to the first direction; a magnetic flux generating member that generates a magnetic flux passing through the bundled portion along a third direction perpendicular to each of the first direction and the second direction, one of the coil and the magnetic flux generating member is fixed to the housing; the other of the coil and the magnetic flux generating member is fixed to the movable body, A vibration generating device comprising a conductive member fixed to the coil, extending along the first direction so as to cross the magnetic flux, and configured to generate eddy currents when the movable body moves along the first direction, thereby reducing the acceleration of the movable body.

2. The conductive member is made of a non-magnetic metal. The vibration generating device according to claim 1 .

3. The conductive member has a higher electrical conductivity than iron and iron alloys. The vibration generating device according to claim 1 .

4. The conductive member is formed of copper, aluminum, or an alloy thereof. The vibration generating device according to claim 1 .

5. The conductive member is disposed between the magnetic flux generating member and the coil. The vibration generating device according to any one of claims 1 to 4.

6. a magnetic flux attracting member that attracts the magnetic flux at a position spaced apart from the magnetic flux generating member along the third direction, The conductive member is disposed between the magnetic flux generating member and the magnetic flux attracting member. The vibration generating device according to any one of claims 1 to 4.

7. The magnetic flux generating member is a first permanent magnet, The magnetic flux attracting member is a second permanent magnet, The first permanent magnet and the second permanent magnet are arranged such that opposing surfaces have different polarities. The vibration generating device according to claim 6.

8. a bracket including a plate-shaped portion extending along a plane parallel to each of the first direction and the second direction and to which the coil is attached, and a connecting portion extending from the plate-shaped portion and fixed to the housing, The coil is fixed to the housing via the bracket, The magnetic flux generating member is fixed to the movable body, The plate-shaped portion is formed of copper, aluminum, or an alloy thereof and functions as the conductive member. The vibration generating device according to claim 1 .

9. the conductive member does not have an opening at a position corresponding to a locus of the center of the magnetic flux when the movable body vibrates; The vibration generating device according to claim 1 .

10. The coil has an air core portion and a conductor portion extending outward from the air core portion, the conductive member has an opening for preventing interference with the conductor portion when the coil is attached, The opening is formed at a position avoiding the locus. The vibration generating device according to claim 9.

11. The hollow core portion is formed in a long hole shape extending along the second direction, The conductor portion extends outward from an end portion of the air-core portion in the second direction. The vibration generating device according to claim 10.

12. the acceleration when the movable body is driven at a resonant frequency is equal to or less than twice the acceleration when the movable body is driven at a frequency twice the resonant frequency; The vibration generating device according to claim 1 .