JP2012071215A - Vibration actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration actuator allowing a spring to be reliably welded to a case.SOLUTION: On the vibration actuator 1, a laser welding hole 26 for exposing part of the spring 17 outside is formed on a spring seating wall part 11a of an upper case part 11 of the case 2. Adopting such a laser welding hole 26 enables the spring seating wall part 11a of the upper case part 11 and the spring 17 to be reliably welded each other with laser beams, even if there is a gap between the upper case part 11 and the spring 17, by emitting laser beams aiming at part of the spring 17 exposed out of the laser welding hole 26. Further, in inspection of the vibration actuator 1, welding quality can be easily determined from outside, and as in the past, a case can be avoided in which the coupling state of the spring and the case cannot be confirmed from outside.

Description

  INDUSTRIAL APPLICABILITY The present invention is used as a vibration generation source for notifying a user of an incoming call of a mobile wireless device such as a mobile phone, a vibration generation source for transmitting a touch feeling of a touch panel or a realistic feeling of a gaming machine to a finger or hand. It relates to a small vibration actuator.

  Conventionally, there is JP, 2010-104864, A as a technique of such a field. In the vibration actuator described in this publication, an annular weight is accommodated in a flat cylindrical case, and an annular magnet is fixed to the inner peripheral surface of the weight. A coil is fixed to the support fixed to the center of the case so as to face the inner peripheral surface of the magnet. Further, an annular leaf spring is accommodated in the case so as to sandwich the weight. One end of the leaf spring is spot welded to the case, and the weight is held in the case by the leaf spring fixed to the case. Yes. The weight is linearly vibrated in the case by passing an alternating current having a predetermined frequency through the coil.

JP 2010-104864 A

  In order to spot weld the leaf spring for holding the weight to the case, the case and the leaf spring are melted by laser light to join both members. However, when a gap is generated between the leaf spring and the case, if this portion is irradiated with laser light from the case side, the leaf spring is not melted and the leaf spring and the case may not be reliably welded. There is a problem that the leaf spring is easily detached from the case and affects the durability of the vibration actuator.

  It is an object of the present invention to provide a vibration actuator in which a spring is securely welded to a case.

The present invention includes a magnet disposed in a case,
A coil arranged in the case to drive the magnet;
A spring that is disposed between the spring seating wall portion of the case and the magnet, abuts against the spring seating wall portion of the case, and biases the magnet in the vibration axis direction;
A laser welding hole for exposing a part of the spring to the outside is formed in the spring seating wall portion of the case.

  In the vibration actuator, when laser welding the case and the spring, it is desirable that there is no gap between the spring seating wall portion of the case and the spring. In particular, in the case of a small vibration actuator, each part is very small and dimensional control is very difficult. At the same time, there is a limit to improvement in dimensional accuracy, and due to dimensional variation between parts, there is a gap between the case and the spring. A gap is likely to occur. Therefore, in the vibration actuator according to the present invention, a laser welding hole that exposes a part of the spring to the outside is formed in the spring seating wall portion of the case. When such a laser welding hole is employed, a part of the case and the spring can be reliably welded with the laser beam by irradiating the laser beam aiming at a part of the spring exposed from the laser welding hole. In addition, in the inspection of the vibration actuator, it is possible to easily determine whether the welding is good or bad from the outside, and it is possible to avoid a situation in which the joining state between the spring and the case cannot be confirmed from the outside as in the prior art.

Further, it is preferable that the spring is formed with a protrusion that is inserted into the laser welding hole.
By inserting the protrusion of the spring into the laser welding hole, the welded portion of the spring can be surely matched with the laser welding hole. As described above, when the vibration actuator is assembled, it is possible to prevent displacement of the welded portion of the spring, and further, the protrusion can facilitate the laser welding and enlarge the welding area. Especially useful.

The spring includes a first ring portion that contacts the spring seating wall portion of the case, a second ring portion that contacts the mover having the magnet, and a plate that connects between the second ring portion and the first ring portion. A spring portion, and the first ring portion is provided with a plurality of connecting portions between the leaf spring portion and the first ring portion, and between the connecting portions, the first ring portion has an extension for welding. It is preferable that the portion is formed.
By adopting such a configuration, since the extended portion that becomes the welded portion can be separated from the connecting portion between the leaf spring portion and the first ring portion, the spring characteristics of the leaf spring portion are unlikely to change due to heat during welding. Thus, adverse effects on the leaf spring portion can be suppressed.

In addition, it is preferable that the extended portion is formed with a protrusion that is inserted into the laser welding hole.
By adopting the extended portion, the protruding portion can be easily formed even with a small spring in which the forming of the protruding portion is difficult.

  According to the present invention, the spring can be reliably welded to the case.

It is a disassembled perspective view which shows 1st Embodiment of the vibration actuator which concerns on this invention. It is the disassembled perspective view which looked at the vibration actuator of FIG. 1 from another angle. It is sectional drawing of the vibration actuator which concerns on 1st Embodiment. It is a perspective view which shows the spring applied to the vibration actuator which concerns on 1st Embodiment. It is a perspective view which shows the state which removed the upper case part and exposed the upper side spring. It is the perspective view which looked at the vibration actuator from the upper part. It is a perspective view which shows the state which removed the lower case part and exposed the lower side spring. It is the perspective view which looked at the vibration actuator from the lower part. It is a perspective view which shows the other spring applied to the vibration actuator which concerns on 1st Embodiment. It is a perspective view which shows 2nd Embodiment of the vibration actuator which concerns on this invention. It is the perspective view which looked at the vibration actuator of Drawing 10 from another angle. It is sectional drawing of the vibration actuator which concerns on 2nd Embodiment. It is a perspective view which shows the spring applied to the vibration actuator which concerns on 2nd Embodiment. It is a perspective view which shows the other spring applied to the vibration actuator which concerns on 2nd Embodiment. It is a perspective view which shows 3rd Embodiment of the vibration actuator which concerns on this invention. It is the perspective view which looked at the vibration actuator of FIG. 15 from another angle. It is sectional drawing of the vibration actuator which concerns on 3rd Embodiment. It is a perspective view which shows the spring applied to the vibration actuator which concerns on 3rd Embodiment. It is a perspective view which shows the other spring applied to the vibration actuator which concerns on 3rd Embodiment.

  Hereinafter, preferred embodiments of a vibration actuator according to the present invention will be described in detail with reference to the drawings. In various embodiments, the same or equivalent components are denoted by the same reference numerals, and description thereof is omitted.

[First Embodiment]
As shown in FIGS. 1 to 3, the small vibration actuator 1 is incorporated in a mobile communication device (for example, a mobile phone) and used as a vibration generation source of a calling function, and has a diameter of about 10 mm and a thickness of about 3 mm. It is a type.

  The case 2 of the vibration actuator 1 has a cup-shaped upper case portion 11 made of a nonmagnetic material (for example, stainless steel) and a disk shape made of a nonmagnetic material (for example, stainless steel) to close the open side of the upper case portion 11. The circular open end of the upper case portion 11 is welded to the lower case portion 12.

  A cylindrical magnet 13 is accommodated in the case 2, a plate-like yoke 14 is fixed to the lower flat portion of the magnet 13 with an adhesive, and a cylindrical cup is placed on the upper flat portion of the magnet 13. The yoke 16 is fixed with an adhesive.

  A donut-shaped weight 15 is fixed to the peripheral wall 16b of the yoke 16 with an adhesive. These magnet 13, yokes 14, 16 and weight 15 constitute a mover. An upper spring 17 that forms a ring-shaped leaf spring is fixed to the closing wall 16a of the yoke 16 by welding, and a lower spring 18 that forms a ring-shaped leaf spring is attached to the open end 16c of the peripheral wall 16b of the yoke 16. Is fixed by welding.

  A cylindrical coil 20 is fixed to the flexible circuit board 19 so as to surround the magnet 13, and the flexible circuit board 19 is fixed on the lower case portion 12 with an adhesive or the like. The extension portion 19b extending in the radial direction from the flexible circuit board 19 is provided with a power supply terminal 19a and fixed to a protruding piece 12b provided on the lower case portion 12.

  As shown in FIG. 4, the upper spring 17 is configured to close the outer ring portion (first ring portion) 21 that contacts the flat spring seating wall portion 11 a provided in the upper case portion 11 and the cylindrical yoke 16. It has the inner ring part (2nd ring part) 22 contact | abutted to the wall 16a, and the leaf | plate spring part 23 which connects between the inner ring part 22 and the outer ring part 21. FIG.

  Three arc-shaped leaf spring portions 23 are provided between the inner ring portion 22 and the outer ring portion 21, and the outer ring portion 21 and the inner ring portion 22 are arranged so as to be vertically displaced in the vibration axis L direction. Are connected. Each leaf spring portion 23 is connected to a first connecting portion that protrudes radially outward at the inner ring portion 22 from a first extended portion 21a that protrudes radially outward at the outer ring portion 21. It extends to the two extended portions 22a.

  The outer ring portion 21 is provided with three connecting portions between the leaf spring portion 23 and the outer ring portion 21 at equal intervals. For example, in the center between the adjacent first extension portions 21a. The outer ring portion 21 is formed with an expansion portion 21b for welding protruding radially inward. A claw-like protrusion 24 that is bent in the direction of the vibration axis L toward the spring seating wall 11a is formed at the free end of each expansion portion 21b. In this way, since the extended portion 21b serving as a welding location is separated from the connection portion between the leaf spring portion 23 and the outer ring portion 21, the spring characteristics of the leaf spring portion 23 are unlikely to change due to heat during welding. Thus, adverse effects on the leaf spring portion 23 can be suppressed. Further, by adopting the extended portion 21b, the protruding portion 24 can be easily formed even with the small upper spring 17.

  As shown in FIG. 5, rectangular laser welding holes 26 are formed at three locations on the spring seating wall portion 11 a of the upper case portion 11 corresponding to the claw-like protrusions 24. Then, by aligning the upper case portion 11 with the lower case portion 12, as shown in FIG.

  In this way, by inserting the protrusion 24 of the upper spring 17 into the laser welding hole 26, when the vibration actuator 1 is assembled, the welding position of the upper spring 17 is surely matched with the laser welding hole 26, and the upper spring 17. Prevents misalignment. Furthermore, the protrusion 24 can facilitate laser welding and increase the welding area, which is particularly useful for the small vibration actuator 1.

  Further, when the laser welding hole 26 is employed, if laser light is irradiated aiming at the protrusion 24 inserted into the laser welding hole 26, there is a gap between the upper case portion 11 and the extended portion 21b. In addition, the protrusion 24 melted by the laser beam and a part of the upper case portion 11 can be reliably welded. Moreover, in the inspection of the vibration actuator 1, it is possible to easily determine whether the welding is good or bad from the outside, and it is possible to avoid a situation where the joining state between the spring and the case cannot be confirmed from the outside as in the prior art. .

  In addition, the inner ring portion 22 is provided with three connection portions between the leaf spring portion 23 and the inner ring portion 22, and between the connection portions, for example, at the center between the adjacent second expansion portions 22a, The inner ring portion 22 is formed with an extended portion 22b for welding extending radially outward. The welding extension 22b and the closing wall 16a of the yoke 16 are laser-welded. Thus, since the extended part 22b used as a welding location is separated from the connection part of the leaf | plate spring part 23 and the inner side ring part 22, the spring characteristic of the leaf | plate spring part 23 becomes difficult to change with the heat at the time of welding. The adverse effect on the leaf spring portion 23 can be suppressed.

  As described above, in the small vibration actuator 1, the width of the inner ring portion 22 and the outer ring portion 21 is less than 1 mm and is very susceptible to heat during welding. Providing the extended portions 21b and 22b is very effective as a measure for preventing the spring characteristics from changing.

  As shown in FIGS. 7 and 8, since the welding of the lower case portion 12 and the lower spring 18 is the same as the welding of the upper case portion 11 and the upper spring 17 described above, the description thereof is omitted and the same. The symbol is attached. The upper spring 17 and the lower spring 18 share parts. An extension 22b for welding in the inner ring portion 22 of the lower spring 18 is fixed to the open side end portion 16c of the peripheral wall 16b of the yoke 16 by laser welding, and is formed on the spring seating wall portion 12a of the lower case portion 12. After the protrusion 24 of the lower spring 18 is inserted into the laser welding hole 26, laser welding is performed.

  As shown in FIG. 9, as other upper and lower springs 17 </ b> A and 18 </ b> A, a claw-shaped protrusion 24 </ b> A may be formed on the outer side of the first extended portion 21 a for connecting the outer ring portion 21.

  It goes without saying that the present invention is not limited to the embodiment described above.

[Second Embodiment]
As shown in FIGS. 10 to 13, in the vibration actuator 30, the upper and lower springs 17 </ b> B and 18 </ b> B are formed with cylindrical protrusions 24 </ b> B on the expansion portions 21 b for welding of the outer ring portion 21. Further, in order to fit these cylindrical protrusions 24B, circular laser welding holes 26B are formed at three locations in the spring seating wall portion 11a of the upper case portion 11. Then, by aligning the upper case portion 11 with the lower case portion 12, as shown in FIG. 10, the top portions of the protruding portions 24B are exposed from the laser welding holes 26B.

  Such a protruding portion 24B is exposed from the upper case portion 11 so as to close the laser welding hole 26B, and aims at the boundary between the protruding portion 24B inserted into the laser welding hole 26B and the spring seating wall portion 11a. The laser beam is irradiated. In this case, even if there is a gap between the upper case 11 and the extended portion 21b, the protrusion 24B melted by the laser beam and a part of the upper case 11 can be reliably welded. In addition, the welded portion can be easily observed from the outside, and in the inspection of the vibration actuator 30, it can be very easily determined from the outside whether the welding is good or bad.

  As shown in FIG. 14, as other upper and lower springs 17 </ b> C and 18 </ b> C, a cylindrical protrusion 24 </ b> C may be formed on the first extended portion 21 a for connecting the outer ring portion 21.

[Third Embodiment]
As shown in FIGS. 15 to 18, in the vibration actuator 40, the upper and lower springs 17 </ b> D and 18 </ b> D are not formed with welding projections. In addition, circular laser welding holes 26D are formed in three locations on the spring seating wall portion 11a of the upper case portion 11 at positions corresponding to the welding expansion portions 21b. And by aligning the upper case part 11 with the lower case part 12, as shown in FIG. 15, a part of the extended part 21b for welding is exposed from within each laser welding hole 26D.

  In this case, the laser beam is irradiated to aim at the boundary between the wall surface forming the laser welding hole 26D and the expansion portion 21b for welding, so that welding can be reliably performed. And the welding location in that case can judge the quality of welding from the outside by looking in the laser welding hole 26D.

  As shown in FIG. 19, as the other upper and lower springs 17E, 18E, the outer ring portion 21 is not formed with an expansion portion for welding between adjacent expansion portions 21a. And the expansion part 21a for connection is utilized for welding, and this expansion part 21a is aligned with the laser welding hole 26D.

  In the first to third embodiments described above, the outer ring portion (second ring portion) 21 contacts the mover, and the inner ring portion (first ring portion) 22 contacts the spring seating wall portions 11a and 12a. May be. In this case, the protrusions 24, 24A, 24B, and 24C may be provided on the inner ring portion (first ring portion) 22, and the outer ring portion 21 and the weight 15 may be fixed by an adhesive.

  DESCRIPTION OF SYMBOLS 1,30,40 ... Vibration actuator, 2 ... Case, 11 ... Upper case part, 11a ... Spring seating wall part, 12 ... Lower case part, 12a ... Spring seating wall part, 13 ... Magnet, 16 ... Yoke, 17, 18 , 17A-17E, 18A-18E ... spring, 20 ... coil, 21 ... outer ring part (first or second ring part), 21a, 21b ... expansion part, 22 ... inner ring part (first or second ring part) ), 23... Leaf spring, 24, 24A, 24B, 24C... Projection, 26, 26B, 26D .. Laser welding hole, L.

Claims (4)

A magnet placed in the case;
A coil disposed in the case for driving the magnet;
A spring disposed between a spring seating wall portion of the case and the magnet, abutting the spring seating wall portion of the case and biasing the magnet in a vibration axis direction;
The vibration actuator according to claim 1, wherein a laser welding hole for exposing a part of the spring to the outside is formed in the spring seating wall portion of the case.   The vibration actuator according to claim 1, wherein the spring is formed with a protrusion inserted into the laser welding hole. The spring includes a first ring portion that contacts the spring seating wall portion of the case, a second ring portion that contacts a mover having the magnet, and a space between the second ring portion and the first ring portion. And a leaf spring portion for connecting
The first ring portion is provided with a plurality of connecting portions between the leaf spring portion and the first ring portion, and an extension portion for welding is formed in the first ring portion between the connecting portions. The vibration actuator according to claim 1, wherein the vibration actuator is provided.   The vibration actuator according to claim 3, wherein a protrusion that is inserted into the laser welding hole is formed in the extension portion.

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