JP2021035009A - Actuator and panel speaker - Google Patents

Abstract

To provide an actuator and a panel speaker capable of suppressing temperature rise in a coil even when the coil constituting a magnetic driving mechanism is covered by a yoke of a movable body.SOLUTION: In an actuator 1, flat plate sections 521 of a first yoke 51 and a second yoke 52 are respectively superposed on both sides of a magnet 50 magnetized in a Z axis direction in a movable body 5. A cylindrical trunk section 522 of the second yoke 52 faces the first yoke 51 via the coil 60 in a direction crossing the Z axis direction. A vent hole 523 is arranged at a position overlapping the coil 60 in the Z axis direction in the second yoke 52. Consequently, when the movable body 5 oscillates in the Z axis direction, air going into and out of the vent hole 523 of the second yoke 52 can cool the coil 60 so as to prevent the temperature rise of the coil 60.SELECTED DRAWING: Figure 5

Description

The present invention relates to an actuator that generates various vibrations and a panel speaker.

As a device that generates vibration by a magnetic drive mechanism, an actuator having a support that holds a tubular coil and a movable body that is supported by a gel-like damper member with respect to the support has been proposed (patented). Reference 1). In such an actuator, the movable body includes a permanent magnet located inside the radial direction of the coil, a first yoke fixed to the permanent magnet on one side in the axial direction inside the radial direction of the coil, and an axis line with respect to the permanent magnet. A second yoke fixed on the other side of the direction is provided. The second yoke includes a side plate portion extending to a position facing the first yoke in a direction intersecting the axial direction via a coil, and supports the second yoke facing the first yoke in a direction intersecting the axial direction. A gel-like damper member is arranged between the body and the body.

JP-A-2017-60207

In the configuration described in Patent Document 1, since the radial outer side of the coil is covered with the second yoke, the heat dissipation of the coil is low. Therefore, when the actuator is operated, the temperature of the coil tends to rise. Therefore, when the actuator is operated for a long time, there is a problem that the vibration characteristic output from the actuator tends to deteriorate.

In view of the above problems, an object of the present invention is to provide an actuator and a panel speaker capable of suppressing a temperature rise of the coil even when the coil constituting the magnetic drive mechanism is covered with a yoke of a movable body. To provide.

In order to solve the above problems, the actuator according to the present invention includes a support, a movable body supported by the support via an elastic member, and an axial direction extending along the central axis of the movable body. It has a magnetic drive mechanism that displaces the movable body with respect to the support, and the magnetic drive mechanism has a coil held by the support and a magnet held by the movable body. The coil is a tubular coil wound around the central axis, the magnet is a permanent magnet arranged inside the coil, and the permanent magnet is magnetized in the axial direction. From the first yoke that overlaps the permanent magnet from one side in the axial direction inside the coil, the flat plate portion that overlaps the permanent magnet from the other side in the axial direction, and the flat plate portion. A second yoke having a tubular body extending to a position facing the first yoke in a direction intersecting the axial direction via the coil, and the second yoke includes a second yoke. It is characterized in that a plurality of through holes are provided at positions overlapping the coil when viewed from the axial direction.

In the present invention, the coil used for the magnetic drive mechanism is covered from the outside in the radial direction by the second yoke of the movable body, but a plurality of ventilation holes are provided at positions where the coil overlaps the coil in the axial direction in the second yoke. ing. Therefore, when the coil is energized and the movable body is vibrated in the axial direction, the air inside the second yoke enters and exits through the through hole. Therefore, the coil can be cooled by the air entering and exiting the through hole of the second yoke, so that the temperature rise of the coil can be suppressed.

In the present invention, it is possible to adopt an embodiment in which the support is provided with a window that opens the flat plate portion toward the other side in the axial direction. According to this aspect, when the coil is energized and the movable body is vibrated in the axial direction, air enters and exits from the inside of the support through the window. Therefore, since the coil can be cooled by the through hole of the support and the air entering and exiting from the through hole of the second yoke, the temperature rise of the coil can be suppressed.

In the present invention, the elastic member extends so as to surround the tubular body portion over the entire circumference between the tubular body portion and the wall portion of the support that faces the tubular body portion radially outward. A mode in which the existing tubular viscoelastic member can be adopted. In such an embodiment, the length of air between the tubular body portion of the second yoke and the wall portion of the support is blocked by the viscoelastic member, but even in such a case, the air enters and exits through the through hole of the second yoke. Since the coil can be cooled by the air, the temperature rise of the coil can be suppressed.

In the present invention, it is possible to adopt an embodiment in which a through hole is provided at the center of the movable body so as to penetrate the movable body in the axial direction. According to this aspect, when the movable body is vibrated in the axial direction, air moves through the through hole, so that the movable body can be smoothly vibrated in the axial direction. Further, the heat of the coil can be released by moving the air through the through hole.

In the present invention, it is possible to adopt an embodiment in which the end plate portion located on one side of the support in the axial direction is provided with an opening penetrating the end plate portion at a position where the central axis passes. it can. According to this aspect, when the movable body is vibrated in the axial direction, the air moves through the opening, so that the movable body can be smoothly vibrated in the axial direction. In addition, the heat of the coil can be dissipated by moving the air through the opening.

The actuator according to the present invention can be used for a panel speaker, in which case the support is fixed to the diaphragm. In the present invention, the diaphragm can adopt an aspect of being a display panel.

In the present invention, the coil used for the magnetic drive mechanism is covered from the outside in the radial direction by the second yoke of the movable body, but the second yoke has a plurality of ventilation holes at positions overlapping the coil in the axial direction. It is provided. Therefore, when the coil is energized and the movable body is vibrated in the axial direction, the air inside the second yoke enters and exits through the through hole. Therefore, the coil can be cooled by the air entering and exiting the through hole of the second yoke, so that the temperature rise of the coil can be suppressed.

The perspective view of the actuator to which this invention is applied. The exploded perspective view which separated the support and the movable body from the state shown in FIG. A perspective view of the actuator shown in FIG. 1 when viewed from different directions. The exploded perspective view which separated the support and the movable body from the state shown in FIG. FIG. 5 is a YZ cross-sectional view of the actuator shown in FIG. An exploded perspective view of a state in which a viscoelastic member or the like is removed from the actuator shown in FIG. Explanatory drawing of the panel speaker provided with the actuator shown in FIG. An explanatory view showing an enlarged portion of a fixed portion between the actuator and the diaphragm shown in FIG. 7. FIG. 6 is an enlarged explanatory view showing another aspect of the fixed portion between the actuator and the diaphragm shown in FIG. 7.

Embodiments of the present invention will be described with reference to the drawings. In the following description, the three directions intersecting each other will be described as the Z-axis direction (first direction), the X-axis direction (second direction), and the Y-axis direction (third direction), respectively. Further, the Z-axis direction (first direction), the X-axis direction (second direction), and the Y-axis direction (third direction) are directions orthogonal to each other. Further, Z1 is attached to one side in the Z-axis direction, Z2 is attached to the other side in the Z-axis direction, X1 is attached to one side in the X-axis direction, and X2 is attached to the other side in the X-axis direction. Y1 will be attached to one side in the Y-axis direction, and Y2 will be attached to the other side in the Y-axis direction. The central axis of the movable body 5 is simply referred to as the axis L, L1 is attached to one side in the axis L direction in which the axis L extends, and L2 is attached to the other side in the axis L direction.

(overall structure)
FIG. 1 is a perspective view of an actuator 1 to which the present invention is applied. FIG. 2 is an exploded perspective view in which the support 2 and the movable body 5 are separated from the state shown in FIG. FIG. 3 is a perspective view of the actuator 1 shown in FIG. 1 when viewed from different directions. FIG. 4 is an exploded perspective view in which the support 2 and the movable body 5 are separated from the state shown in FIG. FIG. 5 is a YZ cross-sectional view of the actuator 1 shown in FIG.

As shown in FIGS. 1, 2, 3, and 4, the actuator 1 of the present embodiment has a flat rectangular parallelepiped shape in which the dimensions in the Z-axis direction are smaller than the dimensions in the X-axis direction and the dimensions in the Y-axis direction. Have. The actuator 1 is a support 2 that holds a tubular coil 60 wound around an axis L extending in the Z-axis direction, and a movable body that is supported by the support 2 via a viscoelastic member 80. The movable body 5 holds a coil 60, a magnet 50 and the like constituting the magnetic drive mechanism 6. Therefore, the movable body 5 can be vibrated in the Z-axis direction by the drive current supplied from the outside to the coil 60 via the terminal 28.

(Structure of support 2)
FIG. 6 is an exploded perspective view of the actuator 1 shown in FIG. 1 with the viscoelastic member 80 and the like removed. In FIGS. 1 to 6, the support 2 has a first support member 3 that overlaps the movable body 5 from one side L1 in the axis L direction, and a second support member that overlaps the first support member 3 from the other side L2 in the axis L direction. Has 4 and. The first support member 3 and the second support member 4 are made of, for example, resin.

The first support member 3 has a substantially quadrangular end plate portion 31 at the end portion of one side L1 in the axis L direction. A circular recess 32 is formed on the surface of the end plate portion 31 on the other side L2 in the axis L direction, and the periphery of the recess 32 is surrounded by a first wall portion 33 formed of a circumferential surface. Here, on the inner peripheral surface of the first wall portion 33, the convex portions 331 for positioning protruding inward in the radial direction extend in the axis L direction at three locations at equal angular intervals.

In the first support member 3, a first outer edge portion 34 extending along the outer edge of the first support member 3 is provided on the radial outer side of the first wall portion 33, and the first outer edge portion 34 is provided with the first outer edge portion 34. It has four corners 35 protruding outward from the first wall 33. In each of the four corners 35, a hole 351 for fixing the bolt 29 is opened toward the other side L2 in the axis L direction, and the hole 351 penetrates the corner 35 to one side L1 in the axis L direction. ing. Around the hole 351 is a cylindrical portion 352, and around the cylindrical portion 352, a recess 353 is opened toward the other side L2 in the axis L direction. The recess 353 is a bottomed recess having a bottom on one side L1 in the axis L direction, and is a meat stealing portion for improving molding accuracy when the first support member 3 is resin-molded.

An opening 325 formed of a circular through hole is formed in the center of the bottom 320 of the recess 32. The bottom 320 of the recess 32 extends concentrically with the annular first rib 321 extending along the opening 325 and the opening 325 and the first rib 321 radially outward of the first rib 321. An annular second rib 322 and a plurality of third ribs 323 extending radially between the first rib 321 and the second rib 322 and connecting the first rib 321 and the second rib 322. Is formed. Further, in the bottom portion 320, through holes 326 are formed at six positions at equal angular intervals at positions adjacent to the second rib 322 on the outer side in the radial direction.

As shown in FIGS. 3 and 4, in the end surface 310 located on one side L1 of the end plate portion 31 in the axis L direction, a long hole extending in the radial direction is provided at a position overlapping each of the plurality of through holes 326. A shaped recess 311 is formed, and the through hole 326 is opened slightly radially outside the center of the recess 311 in the radial direction.

The end surface 310 of the end plate portion 31 is formed with a flat surface portion 315 orthogonal to the axis L and a protruding portion 316 protruding from the flat surface portion 315 on one side L1 in the axis L direction. In this embodiment, the protrusion 316 is arranged so as to surround the axis L. For example, a plurality of projecting portions 316 may be arranged so as to surround the axis L, or may extend so as to surround the axis L. In this embodiment, the protrusion 316 extends along the edge of the opening 325. Therefore. The protruding portion 316 is formed in a rib shape extending in an annular shape so as to surround the axis L, and a flat surface portion 315 is provided on the radial outer side of the protruding portion 316.

The first support member 3 is provided with plate-shaped convex portions 38 on both sides in the X-axis direction, which can be used for positioning when assembling the actuator 1 and as a connecting portion when mounting the actuator 1 on various devices. ing.

Again, in FIGS. 1 to 6, the second support member 4 has a substantially quadrangular planar shape. A window 41 formed of a circular through hole is formed in the center of the second support member 4, and the second support member 4 has a frame shape. Therefore, of the movable body 5, the flat plate portion 521 of the second yoke 52, which will be described later, is in an open state toward the other side L2 in the axis L direction by the window 41.

The second support member 4 is formed with a cylindrical portion 42 extending along the edge of the window 41, and the inner peripheral surface of the cylindrical portion 42 constitutes the second wall portion 43. The cylindrical portion 42 projects from the edge of the window 41 to both one side L1 and the other side L2 in the Z-axis direction.

In the second support member 4, a plate-shaped second outer edge portion 44 extending along the outer edge of the second support member 4 is provided on the radial outer side of the second wall portion 43, and the second outer edge portion 44 has four flange-shaped corners 45 that project outward in the radial direction. In the present embodiment, each of the four corner portions 45 is formed with a hole 451 through which the bolt 29 is passed, and the hole 451 penetrates the corner portion 45 up to one side L1 in the axis L direction.

Here, on the outer peripheral surface of the cylindrical portion 42, a portion located on one side L1 in the axis L direction from the second outer edge portion 44 has positioning recesses 421 recessed inward in the radial direction at three equiangular intervals. It extends in the L direction of the axis.

(Combined structure of the first support member 3 and the second support member 4)
The height of the end portion 340 of the other side L2 of the first outer edge portion 34 of the first support member 3 in the axial direction L direction is constant including the corner portion 35 and the side portion 36, and the end portion of the first outer edge portion 34. 340 is located in a virtual plane orthogonal to the axis L. On the other hand, in the second outer edge portion 44 of the second support member 4, the portion corresponding to the corner portion 45 is a protrusion protruding from the side portion 46 located between the corner portions 45 toward one side L1 in the axis L direction. It is a department. Therefore, the side portion 46 is recessed from the corner portion 45 on the other side L2 in the axis L direction.

In this embodiment, when the support 2 is constructed, the second support member 4 is overlapped with the first support member 3, and the cylindrical portion of the second support member 4 is inside the first wall portion 33 of the first support member 3. Fit 42. At that time, with respect to the concave portion 421 formed on the outer peripheral surface of the cylindrical portion 42 of the second support member 4, the convex portion 331 formed on the inner peripheral surface of the first wall portion 33 of the first support member 3 is aligned with the axis L. The first support member 3 and the second support member 4 are aligned in the circumferential direction by fitting from one side L1 in the direction. As a result, the hole 351 formed in the corner portion 35 of the first support member 3 and the hole 451 formed in the corner portion 45 of the second support member 4 overlap in the axis L direction. Therefore, when the bolt 29 made of the tapping screw is fixed to the holes 351 and 451 from the other side L2 in the axis L direction, the first support member 3 and the second support member 4 are connected.

In this state, as shown in FIGS. 1, 3, and 5, a plurality of first outer edge portions 34 and second outer edge portions 44 are coupled to each other in a surface contact with each other in the L direction of the axis. A first portion 21 and a second portion 22 that are separated from each other in the axis L direction are provided between the plurality of first portions 21. More specifically, the four corners 35 of the first support member 3 and the four corners 45 of the second support member 4 are joined by bolts 29 in a state of surface contact in the L direction of the axis, and the first portion. 21 constitutes. On the other hand, since the side portion 46 extending between the four corner portions 45 is a recess, between the side portion 36 extending between the four corner portions 35 and the four corner portions 45. The extending side portion 46 constitutes a second portion 22 that is separated in the axis L direction, and the second portion 22 forms a gap 220 that opens toward both sides in a direction orthogonal to the axis L.

As described above, in the present embodiment, between the first outer edge portion 34 of the first support member 3 and the second outer edge portion 44 that overlaps the first outer edge portion 34 in the second support member 4 in the axis L direction, the axis L direction Since a plurality of first portions 21 that are bonded to each other in surface contact with each other are provided, the first outer edge portion 34 and the second outer edge portion 44 can be efficiently and easily used regardless of whether a bolt 29 or an adhesive is used. Can be combined with.

Further, between the first outer edge portion 34 and the second outer edge portion 44, a second portion 22 is provided which is separated from the plurality of first portions 21 in the axis L direction. Therefore, even if the first support member 3 and the second support member 4 vibrate when the movable body 5 is vibrated in the Z-axis direction, the second portion 21 between the first portions 21 firmly fixed by the bolt 29 is used. In the portion 22, the state in which the first outer edge portion 34 and the second outer edge portion 44 are separated from each other is maintained, so that the generation of abnormal noise can be suppressed.

(Composition of coil 60, etc.)
The coil 60 has a cylindrical shape wound around the axis L. In providing the coil 60 on the support 2, in the present embodiment, the coil holder 61 having the annular portion 611 extending around the axis L is fixed to the first support member 3. The coil holder 61 is formed by processing a non-magnetic metal plate, and the annular portion 611 is formed by bending a strip-shaped extending portion into an arc shape, and the coil holder 61 has a cylindrical shape on the outer peripheral surface of the annular portion 611. Coil 60 is held. The coil holder 61 includes six claw-shaped convex portions 612 protruding from the annular portion 611 on one side Z1 in the Z-axis direction.

Therefore, after the convex portion 612 is inserted into the through hole 326 of the first support member 3 from the other side L2 in the axis L direction, one of the convex portions 612 from the end plate portion 31 of the first support member 3 in the axis L direction. When the portion protruding toward the side L1 is bent inward in the radial direction in the recess 311, the coil holder 61 is fixed to the first support member 3.

One of the four corners 35 of the first support member 3 is a terminal block 37 protruding outward in the radial direction, and the terminal block 37 holds the terminal 28. The terminal block 37 is provided with two round bar-shaped protrusions 371 that protrude toward the other side L2 in the axis L direction. The terminal block 37 is surrounded by a side wall 372. A slit 373 is formed in a portion of the side wall 372 located between the side wall 372 and the recess 32. Therefore, the end portion (not shown) of the coil 60 can be routed to the protrusion 371 through the slit 373. Further, if the end portion of the coil 60 is entwined with the root of the protrusion 371 and soldered in this state, the terminal 28 and the end portion of the coil 60 can be electrically connected. Therefore, if a wiring member such as a flexible wiring board or a lead wire is electrically connected to the terminal 28, power can be supplied to the coil 60 via the terminal 28. In the second support member 4, one of the four corner portions 45 is a lid portion 47 that projects outward in the radial direction and covers the terminal block 37.

(Structure of movable body 5)
In the present embodiment, the magnetic drive mechanism 6 has a coil 60 held by the support 2 and a magnet 50 held by the movable body 5. The coil 60 is a tubular coil wound around the central axis, and in the movable body 5, the magnet 50 is a permanent magnet arranged inside the coil 60. The permanent magnet is magnetized in the L direction of the axis, and the S pole and the N pole are arranged in the L direction of the axis.

The movable body 5 has a first yoke 51 that overlaps the magnet 50 from one side L1 in the axis L direction inside the coil 60, and a side opposite to the first yoke 51 in the axis L direction with respect to the magnet 50 (in the axis L direction). It has a flat plate portion 521 that overlaps from the other side L2), and a second yoke 52 having a tubular body portion 522 extending from the edge of the flat plate portion 521 toward one side L1 in the axis L direction. In the present embodiment, the tubular body portion 522 extends to a position facing the first yoke 51 via the coil 60 in a direction intersecting the axis L direction (outward in the radial direction). The coil 60 has a cylindrical shape, the flat plate portion 521 of the first yoke 51, the magnet 50, and the second yoke 52 has a disc shape, and the tubular body portion 522 has a cylindrical shape.

Here, at the boundary between the flat plate portion 521 and the tubular body portion 522 of the second yoke 52, a plurality of ventilation holes 523 are provided at positions overlapping the coil 60 when viewed from the axis L direction. In this embodiment, the flat plate portion 521 is provided with ventilation holes 523 at eight locations at equal angle intervals. Further, in the flat plate portion 521, through holes 524 are provided at three positions at equal angular intervals at substantially intermediate positions in the radial direction.

Further, holes 515, 505, and 525 are formed in the center of the flat plate portion 521 of the first yoke 51, the magnet 50, and the second yoke 52, and the holes 515, 505, and 525 overlap in the axis L direction. There is. Therefore, at the center of the movable body 5, a through hole 55 that penetrates the movable body 5 in the axis L direction is provided by the holes 515, 505, and 525, respectively.

(Structure of elastic member 8)
In the present embodiment, the elastic member 8 is a viscoelastic member 80 provided between the outer peripheral surface 56 of the movable body 5 and the second wall portion 43 of the second support member 4. In the present embodiment, the viscoelastic member 80 has a tubular shape extending between the outer peripheral surface 56 of the movable body 5 and the second wall portion 43 of the second support member 4 so as to surround the movable body 5 over the entire circumference. ..

Viscoelasticity is a property that combines both viscosity and elasticity, and is a property that is prominently found in polymer substances such as plastics and rubber. Therefore, various gel members can be used as the viscoelastic member 80. Further, as the viscoelastic member 80, natural rubber, diene rubber (for example, styrene / butadiene rubber, isoprene rubber, butadiene rubber), chloroprene rubber, acrylonitrile / butadiene rubber, etc.), non-diene rubber (for example, butyl rubber, ethylene / Various rubber materials such as propylene rubber, ethylene / propylene / diene rubber, urethane rubber, silicone rubber, fluororubber, etc., and thermoplastic elastomers, and modified materials thereof may be used.

In this embodiment, a gel-like member 81 (gel-like damper member) such as a silicone gel is used as the viscoelastic member 80. Silicone gels with a needle insertion degree of 80 to 110 degrees are used. The degree of needle insertion is defined by JIS-K-2207 and JIS-K-2220, and the smaller this value is, the harder it is.

In the present embodiment, the outer peripheral surface 56 of the movable body 5 is the tubular body portion 522 of the second yoke 52. Therefore, the viscoelastic member 80 extends so as to surround the movable body 5 between the tubular body portion 522 of the second yoke 52 and the second wall portion 43 of the second support member 4. Further, since the tubular body portion 522 of the second yoke 52 and the second wall portion 43 of the second support member 4 each have a circumferential surface, the viscoelastic member 80 is cylindrical. In this embodiment, the center of gravity of the movable body 5 and the center of the viscoelastic member 80 in the Z-axis direction coincide with each other in the Z-axis direction. Therefore, there is an advantage that the movable body 5 is difficult to tilt.

Here, the viscoelastic member 80 is joined to the tubular body portion 522 of the second yoke 52 and the second wall portion 43 of the second support member 4 by the adhesiveness of the viscoelastic member 80 itself. That is, in the present embodiment, a viscoelastic member is formed between the outer peripheral surface 56 of the movable body 5 and the second wall portion 43 of the support 2, and at that time, the viscoelastic member 80 itself causes the movable body 5 to adhere. It is assumed that the viscoelastic member 80 is joined to the outer peripheral surface 56 (cylindrical body portion 522) and the second wall portion 43 of the support body 2. More specifically, a material for forming a silicone gel is filled between the outer peripheral surface 56 of the movable body 5 and the second wall portion 43 of the support 2, and then cured to form the viscoelastic member 80. .. At that time, due to the adhesiveness of the viscoelastic member 80 itself, the viscoelastic member 80 is joined to the outer peripheral surface 56 (cylindrical body portion 522) of the movable body 5 and the second wall portion 43 of the support body 2. It will be in a state of being. Therefore, since it is not necessary to bond with an adhesive, the viscoelastic member 80 can be easily joined to the movable body 5 and the support 2 between the movable body 5 and the support 2.

In this embodiment, the tubular body portion 522 and the second support member 4 of the second yoke 52 are in the state of the second yoke 52 before assembling the movable body 5 and the second support member 4 before assembling the support 2. After forming the viscoelastic member 80 with the second wall portion 43, the actuator 1 is assembled. Therefore, the viscoelastic member 80 can be easily molded.

Further, as shown in FIG. 5, the end portion 526 of one side L1 of the tubular body portion 522 in the axis L direction, the end portion 86 of one side L1 of the viscoelastic member 80 in the axis L direction, and the second wall portion 43. The end portion 436 of one side L1 in the axis L direction has the same position in the axis L direction and overlaps when viewed from the radial direction. Therefore, when the viscoelastic member 80 is molded, the gap between the tubular body portion 522 and the second wall portion 43 that opens toward one side L1 in the axis L direction can be easily closed with a flat plate or the like. Therefore, the viscoelastic member 80 can be easily molded.

In the elastic member 8 (viscoelastic member 80) configured in this way, the gel-like member 81 has linear or non-linear expansion / contraction characteristics depending on the expansion / contraction direction. For example, when the plate-shaped gel-like member 81 is pressed in the thickness direction and compressed and deformed, the non-linear component has a larger expansion and contraction characteristic than the linear component, while the plate-shaped gel-like member 81 is pulled and stretched in the thickness direction. Has a stretch characteristic in which the linear component is larger than the non-linear component. Also, when deforming in the direction intersecting the thickness direction (shearing direction), the linear component has a larger deformation characteristic than the non-linear component. In this embodiment, the viscoelastic member 80 is configured to be deformed in the shearing direction when the movable body 5 vibrates in the Z-axis direction. Therefore, since the viscoelastic member 80 is deformed in a range of high linearity, it is possible to obtain vibration characteristics with good linearity.

(Heat dissipation structure of coil 60)
When power is supplied to the coil 60 in the actuator 1, the coil 60 generates heat. In particular, in the present embodiment, the coil 60 is covered from the outside in the radial direction by the tubular body portion 522 of the second yoke 52 of the movable body 5. Further, on the radial outer side of the tubular body portion 522, the space between the tubular body portion 522 and the second wall portion 43 of the second support member 4 is closed by the viscoelastic member 80 over the entire circumference. Even in this case, since a plurality of ventilation holes 523 are provided at positions where the coil 60 overlaps the coil 60 in the axis L direction in the second yoke 52, the inside of the second yoke 52 when the movable body 5 is vibrated in the axis L direction. Air enters and exits through the ventilation hole 523. Therefore, since the coil 60 can be cooled by the air entering and exiting the ventilation hole 523 of the second yoke 52, the temperature rise of the coil 60 can be suppressed.

Further, in the support body 2, the second support member 4 is provided with a window 41 that opens the flat plate portion 521 of the second yoke 52 of the movable body 5 toward the other side L2 in the axis L direction. Therefore, when the movable body 5 is vibrated in the L direction of the axis, air enters and exits from the inside of the support 2 through the window 41. Further, the movable body 5 is provided with a through hole 55. Therefore, when the movable body 5 is vibrated in the L direction of the axis, air enters and exits through the through hole 55 and the window 41. Therefore, since the coil 60 can be cooled, the temperature rise of the coil 60 can be suppressed.

Further, in the support body 2, an opening 325 is provided in the end plate portion 31 of the first support member 3. Therefore, when the movable body 5 is vibrated in the axis L direction, air enters and exits from the inside of the support 2 through the opening 325. Therefore, since the coil 60 can be cooled, the temperature rise of the coil 60 can be suppressed. However, when the actuator 1 is used as a panel speaker described later, the opening 325 is in a closed state, and in this case, the opening 325 does not contribute to heat dissipation.

(basic action)
In the actuator 1 of the present embodiment, when an alternating current is applied to the coil 60, the movable body 5 vibrates in the Z-axis direction, so that the center of gravity of the actuator 1 fluctuates in the Z-axis direction. Therefore, the user who holds the actuator 1 as a tactile device can experience the vibration in the Z-axis direction. At that time, by adjusting the AC waveform applied to the coil 60, the acceleration at which the movable body 5 moves to one side Z1 in the Z-axis direction and the acceleration at which the movable body 5 moves to the other side Z2 in the Z-axis direction are different. Then, the user can experience the directional vibration in the Z-axis direction.

Further, as described below, the panel speaker can be configured by fixing the actuator 1 to the diaphragm and applying a signal having a predetermined waveform to the coil 60.

(First configuration example of panel speaker 100)
FIG. 7 is an explanatory view of the panel speaker 100 provided with the actuator 1 shown in FIG. FIG. 8 is an enlarged explanatory view showing a fixed portion between the actuator 1 and the diaphragm 110 shown in FIG. 7.

As shown in FIGS. 7 and 8, the panel speaker 100 is configured by fixing the end plate portion 31 of the support 2 of the actuator 1 in the Z-axis direction to the back surface 111 of the diaphragm 110. Therefore, since a chassis or the like for fixing the actuator 1 is not required on the back surface 111 side of the diaphragm 110, the panel speaker 100 can be made thinner.

In such a panel speaker 100, when an alternating current is applied to the coil 60 of the actuator 1, the movable body 5 vibrates in the Z-axis direction, and the reaction force is transmitted to the diaphragm 110. Therefore, as a result of the diaphragm 110 vibrating, a sound corresponding to the alternating current applied to the coil 60 is generated from the front surface 112 of the diaphragm 110. Here, the diaphragm 110 is a display panel such as an organic electroluminescence display panel, and the sound corresponding to the displayed image is emitted from the diaphragm 110.

In this embodiment, as shown in FIG. 8, the end plate portion 31 of the support 2 of the actuator 1 is fixed via an adhesive layer or the like, and the protruding portion 316 is mainly brought into contact with the diaphragm 110. For example, the end plate portion 31 is fixed to the diaphragm 110 by the double-sided tape 150 provided with the adhesive layers 152 and 153 on both sides of the sheet 151. Therefore, of the end plate portions 31, the protruding portion 316 mainly comes into contact with the diaphragm 110 via the double-sided tape 150. That is, the protruding portion 316 abuts on the diaphragm 110 via the crushed double-sided tape 150, while the flat surface portion 315 passes through the thicker double-sided tape 150 between the protruding portion 316 and the diaphragm 110. It will come into contact with the diaphragm 110. Therefore, variations in the shape of the end plate portion 31 such as the flatness of the protruding portion 316 and the surface state of the flat surface portion 315 do not easily affect the characteristics of the panel speaker 100, so that the sound pressure in the high frequency range of the panel speaker 100 It is unlikely that the level will drop.

Further, since the protruding portion 316 is arranged so as to surround the axis L (central axis) of the movable body 5, such as being formed in an annular shape extending along the edge of the opening 325, the end plate portion When the 31 and the diaphragm 110 are fixed, the protruding portion 316 comes into contact with the diaphragm 110 in a stable state. Therefore, it is unlikely that the sound pressure level of the panel speaker 100 in the high frequency range will be lowered.

Further, in the center of the movable body 5, through holes 55 that penetrate the movable body 5 in the Z-axis direction by holes 515, 505, and 525 provided in the first yoke 51, the magnet 50, and the second yoke 52, respectively. Is provided. Therefore, when the movable body 5 vibrates in the Z-axis direction, the through hole 55 functions as an air vent hole, so that the movable body 5 can be vibrated smoothly.

(Second configuration example of panel speaker 100)
FIG. 9 is an enlarged explanatory view showing another aspect of the fixed portion between the actuator 1 and the diaphragm 110 shown in FIG. 7. As shown in FIG. 9, also in this embodiment, the end plate portion 31 of the support 2 of the actuator 1 in the Z-axis direction is fixed to the back surface 111 of the diaphragm 110, as in the configuration example shown in FIG.

In the present embodiment, the flat surface portion 315 of the end plate portion 31 is fixed to the diaphragm 110 via an adhesive layer or the like, and the protruding portion 316 is directly brought into contact with the diaphragm 110. For example, the flat surface portion 315 is fixed to the diaphragm 110 by the double-sided tape 150 provided with the adhesive layers 152 and 153 on both sides of the sheet 151. Therefore, of the end plate portions 31, only the protruding portion 316 comes into contact with the diaphragm 110, so that the contact area between the end plate portion 31 and the diaphragm 110 is narrow. Therefore, the variation in the flatness of the protruding portion 316 and the like is unlikely to affect the characteristics of the panel speaker 100, so that a situation such as a decrease in the sound pressure level in the high frequency range of the panel speaker 100 is unlikely to occur.

Further, since the protruding portion 316 is arranged so as to surround the axis L (central axis) of the movable body 5, when the end plate portion 31 and the diaphragm 110 are fixed, the protruding portion 316 is in a stable state. It touches 110. Therefore, it is unlikely that the sound pressure level of the panel speaker 100 will be lowered in the high frequency range, and the same effect as that of the configuration example shown in FIG. 8 will be obtained.

(Another configuration example of the panel speaker 100)
Although FIG. 7 illustrates an embodiment in which the diaphragm 110 is provided with two actuators 1, one actuator 1 or three or more actuators 1 may be provided depending on the magnitude of the sound to be output.

1 ... Actuator, 2 ... Support, 3 ... 1st support member, 4 ... 2nd support member, 5 ... Movable body, 6 ... Magnetic drive mechanism, 8 ... Elastic member, 21 ... 1st part, 22 ... 2nd part , 31 ... end plate part, 33 ... first wall part, 34 ... first outer edge part, 35, 45 ... corner part, 36, 46 ... side part, 41 ... window, 352 ... cylindrical part, 43 ... second wall part , 44 ... 2nd outer edge, 50 ... magnet, 51 ... 1st yoke, 52 ... 2nd yoke, 55 ... through hole, 56 ... outer peripheral surface, 60 ... coil, 61 ... coil holder, 80 ... viscoelastic member, 81 ... Gel-like member, 100 ... Panel speaker, 110 ... Diaphragm, 150 ... Double-sided tape, 151 ... Sheet, 152, 153 ... Adhesive layer, 220 ... Gap, 315 ... Flat part, 316 ... Protruding part, 320 ... Bottom, 321 ... 1st rib, 322 ... 2nd rib, 323 ... 3rd rib, 325 ... Opening, 331 ... Convex part, 521 ... Flat plate part, 522 ... Cylindrical body part, 523 ... Vent hole, 611 ... Ring part, L ... axis, L1 ... one side, L2 ... other side

Claims (7)

With the support
A movable body supported by the support via an elastic member,
A magnetic drive mechanism that displaces the movable body with respect to the support along an axis direction in which the central axis of the movable body extends.
Have,
The magnetic drive mechanism has a coil held by the support and a magnet held by the movable body.
The coil is a tubular coil wound around the central axis.
The magnet is a permanent magnet arranged inside the coil.
The permanent magnet is magnetized in the axial direction and
The movable body includes a first yoke that overlaps the permanent magnet from one side in the axial direction inside the coil, a flat plate portion that overlaps the permanent magnet from the other side in the axial direction, and the flat plate portion. It has a second yoke having a tubular body extending to a position facing the first yoke in a direction intersecting the axial direction via a coil.
An actuator characterized in that the second yoke is provided with a plurality of through holes at positions overlapping the coil when viewed from the axial direction. The actuator according to claim 1, wherein the support is provided with a window that opens the flat plate portion toward the other side in the axial direction. In the actuator according to claim 1 or 2.
The elastic member has a tubular shape that extends so as to surround the tubular body portion between the tubular body portion and a wall portion that faces the tubular body portion on the outer side in the radial direction in the support. An actuator characterized by being a viscoelastic member of. In the actuator according to any one of claims 1 to 3,
An actuator characterized in that a through hole that penetrates the movable body in the axial direction is provided at the center of the movable body. In the actuator according to any one of claims 1 to 4.
An actuator characterized in that an end plate portion located on one side of the support in the axial direction is provided with an opening penetrating the end plate portion at a position where the central axis passes. A panel speaker including the actuator according to any one of claims 1 to 5.
A panel speaker characterized in that the support is fixed to a diaphragm. In the panel speaker according to claim 6,
The diaphragm is a panel speaker characterized by being a display panel.

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