Vibration generation device and production method for vibration generation device

Abstract

A vibration generation device (101) comprises a plate-shaped base member (2) that is to be held on an installation destination member so as to be immobile, a vibrating body (VB), a plate spring (17) that supports the vibrating body (VB) on the base member (2) to allow vibration along the X-axis direction, and a drive means (DM) that includes a permanent magnet (15) that is attached to the vibrating body (VB) and a coil (12) that is attached to the base member (2) via a bracket (11). The plate spring (17) has a fixed-side connection part (17A1) that is connected to the base member (2), a mobile-side connection part (17B) that is connected to the vibrating body (VB) (lower yoke (10D)), and an elastic arm part (17C) that connects the fixed-side connection part (17A) and the mobile-side connection part (17B). The surface of the elastic arm part (17C) has undergone conditioning processing that forms a plurality of recesses (RS).

Description

Vibration generator and method for manufacturing the same

[0001] The present disclosure relates to a vibration generator and a method for manufacturing a vibration generator.

[0002] Conventionally, a vibration generating device has been known that includes a plate-shaped fixed body that is held so as not to move relative to an attached member such as a touchpad, a movable body, an elastic support member that supports the movable body so that it can vibrate in a predetermined direction relative to the fixed body, a permanent magnet attached to the movable body, and a magnetic drive unit that includes a coil attached to the fixed body (see Patent Document 1).

[0003] JP 2023-047774 A

[0004] In recent years, vibration generators have come to be used in a variety of applications, and there are cases where vibration generators are required to have a longer lifespan than those used in conventional applications.

[0005] Therefore, it is desired to provide a vibration generator that can achieve a longer life.

[0006] A vibration generating device according to one embodiment of the present disclosure comprises a plate-shaped fixed body that is held so as not to move relative to the attached member, a movable body, an elastic support member that supports the movable body relative to the fixed body so that it can vibrate along a first direction, and a magnetic drive unit that includes a permanent magnet attached to one of the fixed body and the movable body, and a coil attached to the other of the fixed body and the movable body, wherein the elastic support member has a fixed side connection portion connected to the fixed body, a movable side connection portion connected to the movable body, and an elastic arm portion that connects the fixed side connection portion and the movable side connection portion, and the surface of the elastic arm portion is subjected to a recessing process that forms multiple recesses.

[0007] The above-described vibration generator can achieve a further longer life.

[0008] 14 is a perspective view of a vibration device including a vibration generator according to an embodiment of the present disclosure. FIG. 14 is an exploded perspective view of the vibration generator shown in FIG. 1. FIG. 14 is an exploded perspective view of a vibrating unit and a non-vibrating body constituting the vibration generator shown in FIG. 1. FIG. 14 is a perspective view of a non-vibrating body constituting the vibration generator shown in FIG. 1. FIG. 14 is a diagram showing an example of a configuration of a base member and an elastic support member constituting the vibration generator shown in FIG. 1. FIG. 14 is a perspective view of a vibrating unit and a non-vibrating body constituting the vibration generator shown in FIG. 1. FIG. 14 is a perspective view of a driving means constituting the vibration generator shown in FIG. 1. FIG. 14 is a perspective view of an elastic support member constituting the vibration generator shown in FIG. 1. FIG. 14 is a perspective view of a base member and a bracket constituting the vibration generator shown in FIG. 1. FIG. 14 is a top view and a cross-sectional view of a base member, a bracket, a coil, and a vibrating body constituting the vibration generator shown in FIG. 1. FIG. 14 is a perspective view of each member constituting the vibration generator shown in FIG. 1. FIG. 14 is a perspective view of each member constituting the vibration generator shown in FIG. 1. FIG. 14 is a four-sided view of a leaf spring constituting the vibration generator shown in FIG. 1. FIG. 14 is a front view and a partial cross-sectional view of a leaf spring constituting the vibration generator shown in FIG. 1. FIG. 14 is a perspective view of a punch member used to form recesses in the surface of the leaf spring shown in FIG. 15A and 15B are diagrams illustrating the positional relationship between the leaf spring and a punch member when forming recesses on the surface of the leaf spring shown in Fig. 14. Fig. 15A and 15B are diagrams illustrating a method for manufacturing the leaf spring shown in Fig. 14.

[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 device VE, the center view of FIG. 1 is a perspective view of the vibration device VE in a state where the adhesive AD covering the connection between the wiring board 13 and the conductor wires 14 of the vibration generator 101 is omitted, and the lower view of FIG. 1 is a perspective view of the vibration device VE in a state where the solder SD joining the wiring board 13 and the conductor wires 14 of the vibration generator 101 is omitted. FIG. 2 is a perspective view of the vibration generator 101. Specifically, the upper view of FIG. 2 (the view above the block arrow) is an assembled perspective view of the vibration generator 101, and the lower view of FIG. 2 (the view below the block arrow) 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] As shown in FIG. 1, the vibration device VE includes a lead wire 14, a connector CN, a control unit CTR, and a vibration generator 101.

[0012] The conductor 14 is a member for supplying current to the coil 12 (see FIG. 3 ). In the illustrated example, a portion of the conductor 14 is disposed on the Z1 side (upper side) of the wiring board 13 and is electrically connected to the coil 12 via the wiring board 13. Specifically, the conductor 14 includes a front conductor 14F electrically connected to the first end 12S of the coil 12 and a rear conductor 14B electrically connected to the second end 12E of the coil 12.

[0013] 1 , one end 14S of the front conducting wire 14F is connected by solder SD to an upper end 13FU of the front conductor pattern 13F on the Z1 side (upper side) of the wiring board 13, and one end 14E of the rear conducting wire 14B is connected by solder SD to an upper end 13BU of the rear conductor pattern 13B on the Z1 side (upper side) of the wiring board 13. The solder SD is covered with adhesive AD. The adhesive AD is, for example, an ultraviolet-curing adhesive.

[0014] The other ends of the rear conducting wire 14B and the front conducting wire 14F are connected to a connector CN, and are connected to a control unit CTR via the connector CN.

[0015] As shown in FIG. 2, the vibration generator 101 has a housing HS and a vibration part VP accommodated in the housing HS.

[0016] The housing HS has a substantially rectangular parallelepiped outer shape. In the illustrated example, 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, which serve as fixed members.

[0017] 2, the cover member 1 is configured to form the top surface of the housing HS, and the base member 2 is configured to form the side and bottom surfaces 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.

[0018] Specifically, the base member 2 has a substantially rectangular cylindrical outer wall portion 2A and a flat bottom plate portion 2B provided so as to be continuous with the lower end (the end on the Z2 side) of the outer wall portion 2A.

[0019] The outer peripheral wall 2A has four side plate portions formed in a flat plate shape. Specifically, as shown in the lower diagram of Figure 2, the outer peripheral wall 2A has a first side plate portion 2A1 and a third side plate portion 2A3 that face each other, and a second side plate portion 2A2 and a fourth side plate portion 2A4 that are perpendicular to the first side plate portion 2A1 and the third side plate portion 2A3 and face each other.

[0020] The control unit CTR is configured to realize the movement of the vibration unit VP. In the illustrated example, 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 in the illustrated example, the control unit CTR is installed outside the housing HS, but 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.

[0021] The vibration part VP is configured to be able to vibrate the housing HS by vibrating itself. In the illustrated example, the vibration part VP is configured to be attached inside the housing HS and to be able to vibrate the housing HS.

[0022] Next, details of the vibrating part VP will be described with reference to Fig. 3. Fig. 3 is an exploded perspective view of the vibrating part VP. The vibrating part VP is configured to include a vibrating body VB, a driving means DM, and an elastic support member ES.

[0023] The vibrating body VB as a movable body has a predetermined natural frequency corresponding to the mass of the vibrating body VB and the spring constant of the elastic support member ES, 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 the illustrated example, 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).

[0024] 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 the illustrated example, 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 under the control of the control unit CTR.

[0025] The elastic support member ES is configured to be interposed between the housing HS and the vibrating body VB and to elastically support the vibrating body VB.

[0026] Specifically, the vibration section VP, which includes the vibration body VB, the driving means DM, and the elastic support member ES, is composed of a yoke 10, a bracket 11, a coil 12, a wiring board 13, a permanent magnet 15, and a leaf spring 17. The vibration body VB is composed of the yoke 10 and the permanent magnet 15, the driving means DM is composed of the coil 12 and the permanent 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 vibration body VB. The non-vibrating body NV is integrally held by the housing HS, so it vibrates together with the housing HS when the housing HS vibrates. However, because it is connected to the vibration body VB via the leaf spring 17, it does not vibrate integrally with the vibration body VB. 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] The yoke 10 is a component that constitutes a magnetic circuit. In the illustrated example, the yoke 10 is made of a magnetic material such as iron. Specifically, 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 lower yoke 10D constitutes the side and bottom surfaces of the vibrating body VB and includes a rear plate portion BW, a front plate portion FW, and a bottom plate portion DW. Specifically, a protrusion PR is formed on the Z1-side end surface of each of the rear plate portion BW and the front plate portion FW so as to engage with the recess RC formed on the upper yoke 10U. The upper yoke 10U constitutes the top surface of the vibrating body VB and includes a top plate portion TW. Specifically, a recess RC is formed on each of the X1-side (front) end surface and the X2-side (rear) end surface of the upper yoke 10U so as to engage with the protrusion PR formed on the lower yoke 10D.

[0028] The bracket 11 is an example of a conductive member that functions as a coil bracket for holding the coil 12 and is configured to support the coil 12 while facing the permanent magnet 15 without contacting it. In other words, the bracket 11 is configured to function as a coil holder for supporting 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 the illustrated example, the bracket 11 is a plate-shaped member formed of a non-magnetic material such as copper, aluminum, or an alloy thereof, and includes a mounting plate portion 11A and a main body plate portion 11B. Specifically, the bracket 11 is fixed to the housing HS via four mounting plate portions 11A protruding outward from the main body plate 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. In other words, the bracket 11 to which the coil 12 is attached is configured not to vibrate together with the vibrating body VB.

[0029] 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 two coil winding portions (a first coil winding portion 12A and a second coil winding portion 12B) connected in series. Each of the first coil winding portion 12A and the second coil winding portion 12B has a generally elliptical shape (a rounded rectangular shape) 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 via a wiring board 13 using an adhesive or the like. The conductor wire (a wire made of copper, a copper alloy, or the like) 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.

[0030] 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 the illustrated example, 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 diagram of FIG.

[0031] In the illustrated example, the wiring board 13 is a flexible wiring board having flexibility and includes a rear conductor pattern 13B and a front conductor pattern 13F. The wiring board 13 is fixed to the Z2 side (lower side) 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 a lower end 13FD of the front conductor pattern 13F with solder or a conductive adhesive or the like, and a second end 12E of the coil 12 is connected to a lower end 13BD of the rear conductor pattern 13B with solder or a conductive adhesive or the like. Note that, as shown in the lower diagram of FIG. 1 , an upper end 13BU of the rear conductor pattern 13B is connected to a rear conductor wire 14B with solder SD, and an upper end 13FU of the front conductor pattern 13F is connected to a front conductor wire 14F with solder SD.

[0032] Each of the first coil winding portion 12A and the second coil winding portion 12B has an air-core portion AC. The first end portion 12S, the first coil winding portion 12A, the second coil winding portion 12B, and the second end portion 12E are connected by a conductor portion CP. Specifically, as shown in FIG. 3 , the conductor portion CP includes a first conductor portion CP1 to a third conductor portion CP3. The first end portion 12S and the first coil winding portion 12A are connected by the first conductor portion CP1, the first coil winding portion 12A and the second coil winding portion 12B are connected by the second conductor portion CP2, and the second coil winding portion 12B and the second end portion 12E are connected by the third conductor portion CP3.

[0033] 4, the coil 12 includes a main bundle wire portion MW extending along the Y-axis direction and a sub-bundle wire portion SW connecting two adjacent main bundle wire portions MW. In the illustrated example, the main bundle wire portion MW has a rectangular shape in top view and includes multiple conductor wires extending in the Y-axis direction (left-right direction), while the sub-bundle wire portion SW has a substantially semicircular shape in top view and includes multiple conductor wires extending concentrically. Specifically, the first coil winding portion 12A includes a front main bundle wire portion 12A1, a rear main bundle wire portion 12A2, a left sub-bundle wire portion 12A3, and a right sub-bundle wire portion 12A4, and the second coil winding portion 12B includes a front main bundle wire portion 12B1, a rear main bundle wire portion 12B2, a left sub-bundle wire portion 12B3, and a right sub-bundle wire portion 12B4. The main bundle wire portion MW includes a front main bundle wire portion 12A1, a rear main bundle wire portion 12A2, a front main bundle wire portion 12B1, and a rear main bundle wire portion 12B2. The sub-bundle wire portion SW includes a left sub-bundle wire portion 12A3, a right sub-bundle wire portion 12A4, a left sub-bundle wire portion 12B3, and a right sub-bundle wire portion 12B4. In the lower diagram of Fig. 4, for clarity, a dot pattern is added to the main bundle wire portion MW of the coil 12.

[0034] The permanent magnet 15 is an example of a magnetic flux generating member and, together with the coil 12, constitutes the driving means DM. In the illustrated example, the permanent magnet 15 includes an upper permanent magnet 15U and a lower permanent magnet 15D, as shown in FIG. 3 . Each of the upper permanent magnet 15U and the lower permanent magnet 15D is a six-pole magnetized permanent magnet having a substantially rectangular parallelepiped outer shape. Specifically, the upper permanent magnet 15U includes a first upper magnet portion 15U1 to a third upper magnet portion 15U3 formed (arranged side by side) along the X-axis direction, and the lower permanent magnet 15D includes a first lower magnet portion 15D1 to a third lower magnet portion 15D3 formed (arranged side by side) along the X-axis direction. Each of the first upper magnet portion 15U1 to the third upper magnet portion 15U3 and the first lower magnet portion 15D1 to the third lower magnet portion 15D3 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 each a north pole, and the top surfaces of the second upper magnet portion 15U2 and the second lower magnet portion 15D2 are each a south pole. For clarity, in FIG. 3 , a cross pattern is applied to the north pole portion of the six-pole magnetized permanent magnet, and a dot pattern is applied to the south pole portion. This is the same in the other figures. Each of the upper permanent magnet 15U and the lower permanent magnet 15D may be a combination of three two-pole magnetized permanent magnets, or a combination of a four-pole magnetized permanent magnet and a two-pole magnetized permanent magnet.

[0035] 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 the illustrated example, the leaf spring 17 is made of a non-magnetic material such as austenitic stainless steel, and has a fixed-side connecting portion 17A, a movable-side connecting portion 17B, and an elastic arm portion 17C, as shown in Figures 3 and 5.

[0036] 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 diagram of Fig. 5 is a perspective view of the base member 2 to which the leaf spring 17 is attached. The lower diagram of Fig. 5 is a cross-sectional view of the base member 2 to which the leaf spring 17 is attached, showing the cross section of the base member 2 and the leaf spring 17 on an imaginary plane parallel to the YZ plane including the cutting line L1 in the upper diagram of Fig. 5, as viewed from the X1 side.

[0037] Specifically, the leaf spring 17 is formed by punching (outline 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 the lower diagram of Figure 5, the fixed-side 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 fixed-side connection portion 17A, with a gap GP formed between the bottom plate portion 2B of the base member 2 and the movable-side connection portion 17B so that the movable-side connection portion 17B and the elastic arm portion 17C do not come into contact with the base member 2.

[0038] As shown in FIG. 3, the fixed side connection portion 17A of the leaf spring 17 includes a rear fixed side connection portion 17AB and a front fixed side connection portion 17AF, and the elastic arm portion 17C of the leaf spring 17 includes a rear elastic arm portion 17CB and a front elastic arm portion 17CF.

[0039] The rear fixed-side connection portion 17AB and the front fixed-side connection portion 17AF are each 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 movable-side connection portion 17B of the leaf spring 17. FIG. 6 is a perspective view of the vibrating body VP. Specifically, the upper view of FIG. 6 is a perspective view of the vibrating body 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 view of FIG. 6 is a perspective view of the vibrating body VP with the non-vibrating body NV shown. Note that in the lower view of FIG. 6 , a cross pattern is applied to the non-vibrating body NV for clarity. The presence or absence of a cross pattern indicates that the non-vibrating body NV, which has a cross pattern, is fixed to the base member 2 (not shown in the lower view of FIG. 6 ) so as not to come into contact with the vibrating body VB, which does not have a cross pattern.

[0040] Specifically, as shown in the upper diagram of Fig. 6, the vibrating body VB is composed of an upper yoke 10U, an upper permanent magnet 15U, a lower permanent magnet 15D, and a lower yoke 10D. The Z2-side (lower) surface of the bottom plate portion DW of the lower yoke 10D is welded to the Z1-side (upper) surface of the movable-side connecting portion 17B of the leaf spring 17. 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.

[0041] 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 (permanent magnet 15) when current flows in one direction through the coil 12 and the vibrating body VB (permanent magnet 15) moves toward 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 (permanent 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 (permanent magnet 15) when current flows in the other direction through the coil 12 and the vibrating body VB (permanent magnet 15) moves toward the X1 side (front side).

[0042] When no current flows through the coil 12, the coil 12 is not subjected to the Lorentz force. Therefore, the permanent magnet 15 is positioned in a neutral position so that its center faces the center of the coil 12, as shown in the center of Fig. 7. Specifically, the vibrating body VB (permanent 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.

[0043] When a current flows from the first end 12S of the coil 12 to the second end 12E, the current flows through the first coil winding portion 12A and the second coil winding portion 12B in the direction DR1 indicated by the dashed arrow in the central diagram of Figure 7, and the vibrating body VB (permanent magnet 15) receives a reaction force of the Lorentz force and moves toward the X2 side (rear side) as indicated by the arrow AR1 in the upper diagram of Figure 7.

[0044] Conversely, when current flows from the second end 12E of the coil 12 toward the first end 12S, current flows through the first coil winding portion 12A and the second coil winding portion 12B in the direction DR2 indicated by the dashed arrow in the central diagram of Figure 7, and the vibrating body VB (permanent magnet 15) is subjected to a reaction force of the Lorentz force and moves toward the X1 side (front side) as indicated by the arrow AR2 in the lower diagram of Figure 7.

[0045] The control unit CTR can alternately reverse the direction of the Lorentz force that the main flux portion MW of the coil 12 receives by alternately reversing the direction of the current flowing through the coil 12 (for example, by passing a sinusoidal wave current or a rectangular wave current), and thus can vibrate the vibrating body VB (permanent magnet 15) along the vibration axis VA (X-axis direction).

[0046] Next, the movement of the elastic arm portion 17C when the vibrating body VB vibrates will be described with reference to Fig. 8. Fig. 8 is a top view of the leaf spring 17. Specifically, the upper view 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 view of Fig. 8 shows the state of the leaf spring 17 when the vibrating body VB moves to the X2 side (rear side).

[0047] 8, the elastic arm portion 17C is provided between the fixed-side connection portion 17A and the movable-side connection portion 17B. Specifically, the rear elastic arm portion 17CB is provided between the rear fixed-side connection portion 17AB and the movable-side connection portion 17B, and the front elastic arm portion 17CF is provided between the front fixed-side connection portion 17AF and the movable-side connection portion 17B.

[0048] When the vibrator VB (not shown in Figure 8) is moved by the driving means DM by a distance DS in the direction indicated by the arrow AR3, the elastic arm portion 17C bends as shown in the lower diagram of Figure 8, allowing the vibrator VB to translate toward the X2 side.

[0049] Conversely, when the vibrator VB is moved by the driving means DM in the direction opposite (X1 direction, forward) to the direction indicated by the arrow AR3 (X2 direction, backward), 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 parallel to the X1 side.

[0050] Referring again to FIG. 3, the details of the lower yoke 10D will be described. The lower yoke 10D has a rear plate portion BW, a bottom plate portion DW, and a front plate portion FW. Specifically, a front plate portion FW extending in the Z1 direction is formed at the X1-side end of the bottom plate portion DW, and a rear plate portion BW extending in the Z1 direction is formed at the X2-side end of the bottom plate portion DW. Furthermore, a protrusion PR is formed at the upper end of each of the rear plate portion BW and the front plate portion FW to engage with a recess RC formed in the upper yoke 10U. The upper view of FIG. 6 shows the recess RC formed in the upper yoke 10U engaged with the protrusion PR of the lower yoke 10D.

[0051] When assembling the vibrating body VB, the upper permanent magnet 15U is attached to the top plate portion TW (see FIG. 3) of the upper yoke 10U, the lower permanent magnet 15D is attached to the bottom plate portion DW (see FIG. 3) of the lower yoke 10D, and further, the recessed portion RC of the upper yoke 10U is engaged with the protruding portion PR of the lower yoke 10D. In this way, in the illustrated example, the upper yoke 10U and the lower yoke 10D surrounding the permanent magnet 15 are separate members to simplify assembly of the vibrating body VB.

[0052] 6, the Z1-side (upper) surface of the upper permanent magnet 15U is magnetically joined to the Z2-side (lower) surface of the top plate portion TW of the upper yoke 10U, and the Z2-side (lower) surface of the lower permanent magnet 15D is magnetically joined to the Z1-side (upper) surface of the bottom plate portion DW of the lower yoke 10D. In the space surrounded by the upper yoke 10U and the lower yoke 10D, as shown in the lower diagram of FIG. 6, a coil 12 fixed to the bracket 11 is installed on the Z2 side of the upper permanent magnet 15U and on the Z1 side of the lower permanent magnet 15D, without contacting the upper permanent magnet 15U and the lower permanent magnet 15D.

[0053] As shown in Fig. 9 , the bracket 11 is attached to the base member 2 by engaging a mounting plate 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 view of Fig. 9 (the view above the block arrow) is an exploded perspective view of the base member 2 and the bracket 11, and the lower view of Fig. 9 (the view below the block arrow) is an assembled perspective view of the base member 2 and the bracket 11.

[0054] As shown in FIG. 9 , the mounting plate 11A includes a first mounting plate 11A1 to a fourth mounting plate 11A4. The support portion 2P includes a first supporting portion 2P1 to a fourth supporting portion 2P4. The first mounting plate 11A1 is engaged with the first supporting portion 2P1, the second mounting plate 11A2 is engaged with the second supporting portion 2P2, the third mounting plate 11A3 is engaged with the third supporting portion 2P3, and the fourth mounting plate 11A4 is engaged with the fourth supporting portion 2P4. Specifically, a through hole 11H is formed in each of the first mounting plate 11A1 to the fourth mounting plate 11A4, and a protrusion 2Q that protrudes upward is formed in each of the first supporting portion 2P1 to the fourth supporting portion 2P4. The engagement between the first mounting plate 11A1 and the first support portion 2P1 is achieved when the underside of the first mounting plate 11A1 is in contact with the two protruding support portions 2D of the first support portion 2P1 and the protruding portion 2Q of the first support portion 2P1 is inserted into the through-hole 11H in the first mounting plate 11A1. The same applies to the engagement between the second mounting plate 11A2 and the second support portion 2P2, the engagement between the third mounting plate 11A3 and the third support portion 2P3, and the engagement between the fourth mounting plate 11A4 and the fourth support portion 2P4. The bracket 11 may be attached to the housing HS so that the mounting plate 11A is placed on the support portion 2P with the mounting plate 11A positioned on the support portion 2P and is sandwiched between the support portion 2P and the cover member 1.

[0055] Next, the magnetic flux generated by the permanent magnet 15 will be described with reference to FIG. 10 . FIG. 10 is a diagram illustrating an example configuration of the base member 2, bracket 11, coil 12, and vibrating body VB. Specifically, the upper view of FIG. 10 is a top view of the base member 2, bracket 11, and vibrating body VB. In the upper view of FIG. 10 , a dot pattern is applied to the bracket 11 for clarity. The lower view of FIG. 10 is a cross-sectional view of the base member 2, bracket 11, coil 12, and vibrating body VB. Specifically, the lower view of FIG. 10 is a cross-sectional view of the base member 2, bracket 11, coil 12, and vibrating body VB taken on an imaginary plane parallel to the XZ plane including the cutting line L2 in the upper view of FIG. 10 , as viewed from the Y2 side. More specifically, the lower diagram of Fig. 10 shows a vibrating body VB configured by an upper yoke 10U, an upper permanent magnet 15U, a lower permanent magnet 15D, and a lower yoke 10D, and a coil 12 installed inside a space surrounded by the upper yoke 10U and the lower yoke 10D (the space sandwiched between the upper permanent magnet 15U and the lower permanent magnet 15D). The permanent magnet 15 generates magnetic flux represented by magnetic flux lines MF shown by dotted lines in the lower diagram of Fig. 10. In the example shown in the lower diagram of Fig. 10, the magnetic flux lines MF include first magnetic flux line MF1 to fourth magnetic flux line MF4.

[0056] Specifically, when no current flows through the coil 12, the first magnetic flux line MF1 exits from the north pole portion of the first lower magnet portion 15D1 of the lower permanent magnet 15D, passes through the front main flux line 12A1 of the first coil winding portion 12A, and enters the south pole portion of the first upper magnet portion 15U1 of the upper permanent magnet 15U. The second magnetic flux line MF2 exits from the north pole portion of the second upper magnet portion 15U2 of the upper permanent magnet 15U, passes through the rear main flux line 12A2 of the first coil winding portion 12A, and enters the south pole portion of the second lower magnet portion 15D2 of the lower permanent magnet 15D. The third magnetic flux line MF3 exits from the north pole portion of the second upper magnet portion 15U2 of the upper permanent magnet 15U, passes through the front main flux line 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 permanent magnet 15D. The fourth magnetic flux line MF4 exits from the north pole portion of the third lower magnet portion 15D3 of the lower permanent magnet 15D, passes through the rear main flux line 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 permanent magnet 15U.

[0057] Therefore, in the space surrounded by the upper yoke 10U and the lower yoke 10D, magnetic flux lines are concentrated in the partial space between the upper permanent magnet 15U and the lower permanent magnet 15D, resulting in a high magnetic flux density, and the coil 12 is installed in this partial space. Therefore, with this configuration, by passing a current between the first end 12S and the second end 12E of the coil 12, a Lorentz force can be efficiently generated, and the vibrating body VB can be efficiently vibrated along the X-axis direction.

[0058] 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.

[0059] 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 permanent magnet 15U and the lower permanent 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 permanent magnet 15U and the lower permanent 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 main body plate portion 11B of the bracket 11. In the illustrated example, the upper permanent magnet 15U, the lower permanent magnet 15D, and the bracket 11 are arranged so that the effective magnetic flux and the main body plate portion 11B are perpendicular to each other.

[0060] Therefore, the vibrating body VB is subjected to a braking force, which is a force caused by eddy currents and acts in the direction opposite to the direction of vibration. Specifically, while the vibrating body VB is vibrated by the Lorentz force generated by the driving means DM, it is not only subjected to a braking force that acts to damp the vibration, but also to a braking force that acts to damp residual vibration after the supply of current to the coil 12 is stopped. The braking force increases in proportion to the vibration velocity of the vibrating body VB. Therefore, the vibration acceleration of the vibrating body VB is reduced by the braking force.

[0061] The braking force caused by eddy currents increases as the eddy currents increase. The eddy currents also increase as the resistivity (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 main body plate 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.

[0062] 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.

[0063] As shown in the upper diagram of Fig. 4, the bracket 11 is formed to have a plurality of openings H1. At least one of the plurality of openings H1 may be a notch. The opening H1 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 opening H1 also functions as an opening for receiving the jig.

[0064] In the illustrated example, each of the multiple openings H1 is formed at a position that avoids the locus TR. The locus TR is a locus on the main body plate portion 11B through which the central axis of the effective magnetic flux passes when the vibrating body VB vibrates. That is, 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, and the third lower magnet portion 15D3, as shown by the magnetic flux 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 and the second coil winding portion 12B.

[0065] In other words, each of the multiple openings H1 is formed at a position that avoids the central region CR. The central region CR is a region in the center of the main body plate 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 permanent 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 opening such as opening H1 in the rectangular central region CR of the main body plate 11B, which results in an effect of allowing eddy currents to flow more easily than if an opening were formed in the central region CR. Also, the vibration generator 101 has a rectangular central region CR in the main body plate 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 if the central region CR were not flat and had recesses, protrusions, or the like.

[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 L3 (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 (toward the X1 side) is the same as the magnitude of the braking force when the vibrating body VB moves rearward (toward the X2 side).

[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 topmost figure in Figure 11 is a perspective view of leaf spring 17, the second figure from the top in Figure 11 is a perspective view of leaf spring 17 with lower yoke 10D attached, the third figure from the top in Figure 11 is a perspective view of base member 2 with leaf spring 17 attached in the state shown in the second figure from the top in Figure 11, and the bottommost figure in Figure 11 is a perspective view of base member 2 with lower permanent magnet 15D further attached.

[0070] Furthermore, the topmost figure in Figure 12 is an oblique view of the base member 2 to which a non-vibrating body NV (bracket 11, coil 12, and wiring board 13) is further attached, the second figure from the top in Figure 12 is an oblique view of the base member 2 to which an upper yoke 10U and an upper permanent magnet 15U are further attached, and the bottommost figure in Figure 12 is an oblique view of the base member 2 to which a cover member 1 is further attached, i.e., an oblique view of the vibration generating device 101.

[0071] First, as shown in the second drawing from the top of Fig. 11, the lower yoke 10D is placed on the upper surface of the movable connecting portion 17B of the leaf spring 17. In the illustrated example, the bottom plate portion DW of the lower yoke 10D is placed on the upper surface of the movable connecting portion 17B without applying any adhesive. Note that a vibration-damping steel plate (not shown) may be attached to the outer surface of the first upright portion EP1 of the elastic arm portion 17C of the leaf spring 17 as a reinforcing material to suppress deflection of the first upright portion EP1.

[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 third diagram from the top in 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 DW of the lower yoke 10D is joined to the upper surface of the movable side connection portion 17B of the leaf spring 17 by laser welding, and the fixed side 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 bottom diagram of Fig. 11, a lower permanent magnet 15D is placed on the upper surface of the bottom plate portion DW of the lower yoke 10D. In the illustrated example, the lower yoke 10D and the lower permanent 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 permanent 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 top diagram of 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. Before the non-vibrating body NV is attached to the base member 2, the coil 12 is bonded to the wiring board 13 with an adhesive or the like, and the wiring board 13 with the coil 12 bonded thereto is bonded to the bracket 11 with double-sided tape or the like.

[0075] Thereafter, the upper yoke 10U, to which the upper permanent 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 second diagram from the top in Figure 12. Specifically, the upper yoke 10U and the lower yoke 10D are positioned 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, and are joined at the portion where the recessed portion RC and the protruding portion PR engage by welding, adhesive, or the like. In the illustrated example, the upper yoke 10U and the lower yoke 10D are joined by laser welding.

[0076] The upper permanent 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 permanent magnet 15D is placed on the upper surface of the bottom plate portion DW 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 permanent 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 permanent 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 upper end of the outer peripheral wall portion 2A of the base member 2 and the peripheral edge of the top plate portion 1T of the cover member 1 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, details of the leaf spring 17 serving as the elastic support member ES will be described with reference to Figures 13 and 14. Figure 13 is a four-view diagram (top view, front view, rear view, and right side view) of the leaf spring 17. Figure 14 is a front view and a partial cross-sectional view of the leaf spring 17. Specifically, the upper view of Figure 14 is a front view of the leaf spring 17, the center view of Figure 14 is an enlarged view of the area R1 surrounded by the dashed line in the upper view of Figure 14, and the lower view of Figure 14 is a cross-section of the U-shaped curved portion EP3 of the front elastic arm portion 17CF of the leaf spring 17, viewed from the Y1 side, on an imaginary plane parallel to the XZ plane including the cutting line L4 in the center view of Figure 14.

[0080] Specifically, as shown in FIG. 13 , the leaf spring 17 has fixed-side connection portions 17A (rear fixed-side connection portions 17AB and front fixed-side connection portions 17AF) and movable-side connection portions 17B extending parallel to the XY plane, and elastic arm portions 17C (rear elastic arm portions 17CB and front elastic arm portions 17CF) extending parallel to the YZ plane. The rear fixed-side connection portions 17AB and front fixed-side connection portions 17AF have the same size and shape, and the rear elastic arm portions 17CB and front elastic arm portions 17CF have the same size and shape. That is, the combination of the rear fixed-side connection portion 17AB and rear elastic arm portion 17CB and the combination of the front fixed-side connection portion 17AF and front elastic arm portion 17CF have the same size and shape. In other words, the leaf spring 17 is configured to be point-symmetric with respect to the center point 17P when viewed from above.

[0081] Each of the rear elastic arm portion 17CB and the front elastic arm portion 17CF has a first standing portion EP1, a first extending portion EP2, a U-shaped curved portion EP3, a second extending portion EP4, and a second standing portion EP5. For clarity, cross patterns are applied to the first standing portion EP1, the U-shaped curved portion EP3, and the second standing portion EP5 in Figures 13 and 14.

[0082] Specifically, the rear elastic arm portion 17CB has a first upright portion EP1 extending upward from the rear end of the rear fixed side connection portion 17AB, a second upright portion EP5 extending upward from the rear end of the movable side connection portion 17B, a first extension portion EP2 extending leftward from the left end of the first upright portion EP1, a second extension portion EP4 extending leftward from the left end of the second upright portion EP5, and a U-shaped curved portion EP3 connecting the left end of the first extension portion EP2 and the left end of the second extension portion EP4. Similarly, the front elastic arm portion 17CF has a first upright portion EP1 extending upward from the front end of the front fixed side connection portion 17AF, a second upright portion EP5 extending upward from the front end of the movable side connection portion 17B, a first extension portion EP2 extending to the right from the right end of the first upright portion EP1, a second extension portion EP4 extending to the right from the right end of the second upright portion EP5, and a U-shaped curved portion EP3 connecting the right end of the first extension portion EP2 and the right end of the second extension portion EP4.

[0083] 14, on both surfaces (outer surface SF1 and inner surface SF2) of the elastic arm portion 17C, quadrangular pyramidal recesses RS are arranged side by side at a predetermined distance WD. Specifically, the recesses RS are arranged side by side at a distance WD1 in the Y-axis direction and a distance WD2 in the Z-axis direction. In the illustrated example, the distance WD1 and the distance WD2 are the same. However, the distances WD1 and WD2 may be different from each other. The recesses RS may also be arranged randomly.

[0084] Each of the multiple recesses RS has a rectangular opening with a length LT1 in the Y-axis direction and a length LT2 in the Z-axis direction, and is formed to have a depth DP in the X-axis direction (see the lower diagram in FIG. 14 ). In the illustrated example, the lengths LT1 and LT2 are the same. However, the lengths LT1 and LT2 may be different from each other. As shown in the lower diagram in FIG. 14 , the recesses RS are quadrangular pyramidal recesses with an apex angle θ of 80 to 120 degrees, and are arranged so that the apex of the recesses RS formed on the outer surface SF1 and the apex of the recesses RS formed on the inner surface SF2 face each other in the X-axis direction. However, the apex of the recesses RS formed on the outer surface SF1 and the apex of the recesses RS formed on the inner surface SF2 may be arranged so as not to face each other (be offset) in the X-axis direction. In the illustrated example, each of the recesses RS is formed to have the same length LT1, length LT2, depth DP, and apex angle θ, but at least one of the length LT1, length LT2, depth DP, and apex angle θ may be different from each other. For example, the apex angle θ of the recesses RS formed on the outer surface SF1 may be different from the apex angle θ of the recesses RS formed on the inner surface SF2.

[0085] The recesses RS may be cylindrical recesses, polygonal pillar-shaped recesses, hemispherical recesses, conical recesses, polygonal pyramidal recesses, etc. The polygonal pyramidal recesses are, for example, triangular pyramidal recesses or hexagonal pyramidal recesses. The recesses RS may be formed only on the outer surface SF1 or only on the inner surface SF2.

[0086] Furthermore, the leaf spring 17 may be formed so that the density (distribution density) of the multiple recesses RS varies depending on the location. For example, the leaf spring 17 may be formed so that the distribution density of the recesses RS in the U-shaped curved portion EP3 is higher than the distribution density of the recesses RS in each of the first upright portion EP1, the first extending portion EP2, the second extending portion EP4, and the second upright portion EP5. Alternatively, the leaf spring 17 may be formed so that the distribution density of the recesses RS in a region close to the outer edge of the surface of the elastic arm portion 17C is higher than the distribution density of the recesses RS in a region far from the outer edge of the surface of the elastic arm portion 17C.

[0087] 15 and 16, a punch member PM for forming the recesses RS on the surface of the leaf spring 17 will be described. Fig. 15 is a perspective view of the punch member PM, and Fig. 16 is a diagram showing the positional relationship between the leaf spring 17 and the punch member PM when forming the recesses RS on the surface of the leaf spring 17.

[0088] Specifically, as shown in FIG. 15, the punch member PM is a plate-shaped member formed of a metal material harder than the material constituting the leaf spring 17, and is configured to have a machining surface provided with a plurality of protrusions VT and a flat support surface.

[0089] 16, the punch member PM is disposed so that, when forming the recesses RS on the surface of the leaf spring 17, the processed surface on which the plurality of protrusions VT are provided is pressed against the surface of the leaf spring 17. In the example shown in Fig. 16, the punch member PM includes an upper punch member PMU that is pressed against the outer surface SF1 of the leaf spring 17, and a lower punch member PMD that is pressed against the inner surface SF2 of the leaf spring 17. Note that the block arrow in Fig. 16 indicates the direction in which the punch member PM is pressed.

[0090] Next, a method for manufacturing the leaf spring 17 will be described with reference to Fig. 17. Fig. 17 is a diagram for explaining the method for manufacturing the leaf spring 17. Specifically, the top diagram in Fig. 17 is a top view of the metal plate MP before punching (outer shape punching), the second diagram from the top in Fig. 17 is a top view of the leaf spring 17 after outer shape punching (before smoothing) is performed, the third diagram from the top in Fig. 17 is a top view of the leaf spring 17 after smoothing (before bending) is performed, and the bottom diagram in Fig. 17 is a top view of the leaf spring 17 after bending.

[0091] Specifically, as shown in the top diagram of Fig. 17, the leaf spring 17 is formed by punching (outline punching) a flat metal plate MP. In the illustrated example, the metal plate MP is a non-magnetic material such as austenitic stainless steel, and may be subjected to a process to remove internal stress, such as tension annealing. The punching line DC, represented by a dashed line, represents the shape punched out by the punching process, i.e., the shape of the leaf spring 17.

[0092] The plate spring 17 punched out as a press hoop by punching is then subjected to a leveling process in the portion (encircled by the dashed line) shown in the second diagram from the top in Figure 17. The dashed-line rear punch area ZB represents the size of the punch member PM used to form the recesses RS in the surface of the rear elastic arm portion 17CB, and the dashed-line front punch area ZF represents the size of the punch member PM used to form the recesses RS in the surface of the front elastic arm portion 17CF. In the illustrated example, the leveling process is a seven-point leveling process, and the recesses RS, which are square pyramidal recesses, are formed on both surfaces (outer surface SF1 and inner surface SF2) of the elastic arm portion 17C of the plate spring 17 so as to have a predetermined distribution density.

[0093] The flattened leaf spring 17 is then bent along the bend line FL in the third diagram from the top of FIG. 17 . Specifically, the bend line FL includes a first bend line FL1 located on the boundary line between the movable-side connection portion 17B and the second upright portion EP5 of the elastic arm portion 17C, and a second bend line FL2 located on the boundary line between the fixed-side connection portion 17A and the first upright portion EP1 of the elastic arm portion 17C. In the illustrated example, the first bend is performed along the first bend line FL1, and then the second bend is performed along the second bend line FL2. However, the first bend may be performed along the second bend line FL2, and then the second bend may be performed along the first bend line FL1. Alternatively, the bending along the first bend line FL1 and the bending along the second bend line FL2 may be performed simultaneously. In the illustrated example, the recess RS is not formed in the region where the bending line FL is located in order to prevent problems such as breakage of the leaf spring 17 at the portion where the bending line FL is located.

[0094] In the illustrated example, the punching, leveling, and bending are each one of the processes constituting the progressive press working and are performed by the same device (press machine). However, the punching, leveling, and bending may each be performed by a separate device.

[0095] 2 and 3, the vibration generator 101 according to an embodiment of the present disclosure includes a plate-shaped fixed body (base member 2) that is held immovable relative to a support member such as a touchpad, a movable body (vibrator VB), an elastic support member ES (leaf spring 17) that supports the movable body relative to the fixed body so that it can vibrate along a first direction (X-axis direction), and a magnetic drive unit (drive means DM) that includes a permanent magnet 15 attached to one of the fixed body and the movable body (vibrator VB) and a coil 12 attached to the other of the fixed body and the movable body (base member 2). As shown in FIG. 13, the leaf spring 17 serving as the elastic support member ES includes a fixed-side connection portion 17A connected to the fixed body (base member 2), a movable-side connection portion 17B connected to the movable body (vibrator VB), and an elastic arm portion 17C that connects the fixed-side connection portion 17A and the movable-side connection portion 17B. The surface of the elastic arm portion 17C is subjected to a recessing process, which is a process for forming a plurality of recesses RS, as shown in FIG. 14 . The recessing process may be a leveling process, or the leveling process may be a coining process. Preferably, the plurality of recesses RS are cone-shaped recesses, and the recessing process is a seven-point leveling process. The seven-point leveling process is also called a star-shaped process, bumping, or dot ring. Preferably, the recesses RS may be cylindrical recesses, polygonal prism-shaped recesses, hemispherical recesses, conical recesses, polygonal pyramid-shaped recesses, or the like.

[0096] This configuration has the effect of forming recesses RS on the surface of the leaf spring 17 formed by punching, thereby alleviating residual stress on the shear surface of the outer edge of the leaf spring 17 caused by the punching process, thereby further extending the life of the vibration generator 101. Therefore, this configuration can increase the number of vibrations until the leaf spring 17 breaks. In the illustrated example, the number of vibrations until the leaf spring 17 breaks can be increased by 10 times or more (for example, from several million to tens of millions). Note that, typically, the life of the leaf spring 17 becomes longer as the weight of the vibrating body VB becomes smaller.

[0097] The contour of the surface of the elastic arm portion 17C includes a curved portion, as shown in the upper diagram of FIG. 14 . The smoothing process is performed on the surface portion along the curved portion. Specifically, the front elastic arm portion 17CF includes a curved portion BP located inside the U-shaped curved portion EP3. For clarity, the curved portion BP located inside the U-shaped curved portion EP3 is indicated by a thick solid line in the upper diagram of FIG. 14 . The seven-point smoothing process is performed on the surface portion along the curved portion BP. In the illustrated example, the seven-point smoothing process is performed on substantially the entire surface of the elastic arm portion 17C, but it may be performed only on a region within a predetermined distance from the curved portion BP.

[0098] This configuration has the effect of realizing a further longer lifespan for the vibration generating device 101, since the residual stress on the shear surface of the outer edge of the portion where stress is concentrated when the vibrating body VB vibrates and the leaf spring 17 is elastically deformed (for example, the inner curved portion BP of the U-shaped curved portion EP3) can be alleviated by the recess RS.

[0099] 10 , the permanent magnet 15 preferably has a magnet surface 15S extending in a first direction (X-axis direction) and a second direction (Y-axis direction) perpendicular to the first direction, and is disposed so that the magnet surface 15S faces the coil 12 in a third direction (Z-axis direction) perpendicular to both the first and second directions. Specifically, the upper permanent magnet 15U has an upper magnet surface 15SU facing the upper surface of the coil 12, and the lower permanent magnet 15D has a lower magnet surface 15SD facing the lower surface of the coil 12. The elastic arm portion 17C is preferably a flat portion extending in the second and third directions (extending in an imaginary plane along the YZ plane), as shown in Figure 13, and has a first upright portion EP1 extending from the fixed side connection portion 17A to one side in the third direction (Z1 side, upward), a first extending portion EP2 extending from the first upright portion EP1 to one side in the second direction, a U-shaped curved portion EP3 extending from the first extending portion EP2, a second extending portion EP4 extending from the U-shaped curved portion EP3 to the other side in the second direction, and a second upright portion EP5 extending from the second extending portion EP4 to the other side in the third direction (Z2 side, downward) (the second upright portion EP5 extending from the movable side connection portion 17B to one side in the third direction (Z1 side, upward)). The surface of the U-shaped curved portion EP3 is smoothed.

[0100] This configuration has the effect of further extending the lifespan of the vibration generating device 101, because the recess RS can alleviate residual stress on the shear surface of the outer edge of the part where stress is concentrated (for example, the U-shaped curved part EP3) when the vibrating body VB vibrates and the leaf spring 17 is elastically deformed.

[0101] Furthermore, the depth DP of the recess RS (see the lower diagram of FIG. 14) is preferably 5 / 1000 to 1 / 10 of the thickness TK of the elastic arm portion 17C, and more preferably 1 / 100 to 5 / 100 of the thickness TK of the elastic arm portion 17C. In the illustrated example, the depth DP of the recess RS is 3 / 100 of the thickness TK of the elastic arm portion 17C. Specifically, the thickness TK of the elastic arm portion 17C is 0.2 mm, and the depth DP of the recess RS is 6 μm. Note that in the lower diagram of FIG. 14, for clarity, the depth DP of the recess RS is drawn deeper than its actual depth.

[0102] This configuration has the effect of realizing a longer lifespan for the leaf spring 17 without impairing the spring characteristics of the leaf spring 17 compared to when a deeper recess RS is formed, and ultimately realizing an even longer lifespan for the vibration generating device 101.

[0103] Furthermore, the distance WD between two adjacent recesses RS (see the center diagram in FIG. 14) is preferably at least half the thickness TK of the elastic arm portion 17C and not more than twice the thickness TK of the elastic arm portion 17C. In the illustrated example, the distance WD between two adjacent recesses RS is the same as the thickness TK of the elastic arm portion 17C.

[0104] This configuration has the effect of realizing a longer lifespan of the leaf spring 17 without impairing the spring characteristics of the leaf spring 17, compared to when the recesses RS are formed with an excessively high distribution density or an excessively low partial density, and ultimately realizing a further longer lifespan of the vibration generating device 101.

[0105] The recess RS is preferably a cone-shaped recess, and the apex angle θ (see the lower diagram in FIG. 14) of the cone is 80 to 120 degrees. In the illustrated example, the apex angle θ is 90 degrees.

[0106] This configuration has the effect of realizing a longer lifespan of the leaf spring 17 without impairing the spring characteristics of the leaf spring 17, compared to when a recess RS having an excessively large or small apex angle θ is formed, and ultimately realizing a further longer lifespan of the vibration generating device 101.

[0107] The recesses RS are preferably formed on both surfaces (outer surface SF1 and inner surface SF2) of the flat elastic arm portion 17C as shown in the lower diagram of Fig. 14. The position of the recesses RS on one of the surfaces corresponds to the position of the recesses RS on the other surface.

[0108] Compared to when a recess RS is formed on one side of the flat elastic arm portion 17C, this configuration can efficiently relieve residual stress at the center of the shear surface of the outer edge of the leaf spring 17 caused by punching, thereby achieving an even longer life for the vibration generator 101. Note that the center of the shear surface of the outer edge of the leaf spring 17 is the center of the thickness of the leaf spring 17, and is an area where residual stress is particularly likely to concentrate.

[0109] In addition, the manufacturing method of the vibration generating device according to an embodiment of the present disclosure includes a step of producing the elastic support member ES (leaf spring 17) by outline punching processing, and a step of performing smoothing processing, which is processing to form multiple recesses RS, on the surface of the elastic arm portion 17C of the elastic support member ES (leaf spring 17).

[0110] This manufacturing method has the effect of forming a recess RS on the surface of the leaf spring 17 formed by punching, thereby alleviating the residual stress on the shear surface of the outer edge of the leaf spring 17 caused by the punching process, thereby achieving a further longer lifespan of the vibration generating device 101.

[0111] 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.

[0112] For example, in the above-described embodiment, the vibration generator 101 is configured to include a permanent magnet 15 magnetized with six poles and a coil 12 having two coil winding portions (four main bundle portions MW), but it may also be configured to include a permanent magnet 15 magnetized with a number of magnetic poles other than six, such as 2, 4, 8, 10, or 12 poles, and a coil 12 having a corresponding number of bundle portions. In other words, the coil 12 may be configured to have one, or three or more coil winding portions.

[0113] Furthermore, in the above-described embodiment, the multiple recesses RS on the surface of the leaf spring 17 are formed simultaneously by pressing the punch member PM against the surface of the leaf spring 17, but each of the multiple recesses RS may be formed separately at different times.

[0114] This application claims priority based on Japanese Patent Application No. 2024-104360, filed on June 27, 2024, the entire contents of which are incorporated herein by reference.

[0115]

Claims

1. A vibration generating device comprising: a plate-shaped fixed body that is held so as not to move relative to a workpiece to which it is attached; a movable body; an elastic support member that supports the movable body relative to the fixed body so that it can vibrate along a first direction; and a magnetic drive unit comprising a permanent magnet attached to one of the fixed body and the movable body, and a coil attached to the other of the fixed body and the movable body, wherein the elastic support member has a fixed-side connecting part that is connected to the fixed body, a movable-side connecting part that is connected to the movable body, and an elastic arm part that connects the fixed-side connecting part and the movable-side connecting part, and the surface of the elastic arm part is subjected to a recessing process that forms a plurality of recesses.

2. The vibration generator according to claim 1, wherein the contour of the surface of the elastic arm includes a curved portion, and the recess is formed on the surface portion along the curved portion.

3. The vibration generating device described in claim 1, wherein the permanent magnet has a magnet surface extending in the first direction and a second direction perpendicular to the first direction, and is arranged so that the magnet surface faces the coil in a third direction perpendicular to both the first direction and the second direction, and the elastic arm portion is a flat portion extending in the second direction and the third direction, and has an erect portion extending from the fixed side connection portion to one side in the third direction, a first extending portion extending from the erect portion to one side in the second direction, a U-shaped curved portion extending from the first extending portion, and a second extending portion extending from the U-shaped curved portion to the other side in the second direction, and the recessed portion is formed on the surface of the U-shaped curved portion.

4. The vibration generator according to claim 1, wherein the recess is a quadrangular pyramidal recess.

5. The vibration generator according to claim 1, wherein the depth of the recess is 1 / 100 to 5 / 100 of the thickness of the elastic arm portion.

6. The vibration generator according to claim 1, wherein the distance between two adjacent recesses is at least half the thickness of the elastic arm portion and is not more than twice the thickness of the elastic arm portion.

7. The vibration generator according to claim 1, wherein the recess is a cone-shaped recess, and the apex angle of the cone is 80 to 120 degrees.

8. The vibration generator according to claim 1, wherein the recesses are formed on both sides of the flat elastic arm portion, and the position of the recesses on one of the two sides corresponds to the position of the recesses on the other of the two sides.

9. A method for manufacturing a vibration generating device comprising: a plate-shaped fixed body that is held so as not to move relative to a workpiece to which it is attached; a movable body; an elastic support member that supports the movable body so that it can vibrate in a first direction relative to the fixed body; a permanent magnet attached to one of the fixed body and the movable body; and a magnetic drive unit that includes a coil attached to the other of the fixed body and the movable body, the method comprising the steps of: producing the elastic support member by outline punching, the elastic support member having a fixed-side connecting portion fixed to the fixed body, a movable-side connecting portion fixed to the movable body, and an elastic arm portion that connects the fixed-side connecting portion and the movable-side connecting portion; and performing recess processing, which is processing to form multiple recesses in the surface of the elastic arm portion.

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