JPH11275846A - Vibrating actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable, long product life, and small-sized vibrating actuator. SOLUTION: A coil 5 is arranged in the gap of a magnetic circuit formed using a permanent magnet 2. The magnetic circuit is supported softly with respect to the coil 5 through the use of a damper 8. If an electric signal is inputted to the coil 5, the magnetic circuit vibrates. It is preferable that an acting part 6 made of resin be added to the damper 8. In addition, it is desirable that the damper 8 should be made of at least one kind of metallic spring material made of SUS304, SUS301, nickel silver, phosphor bronze, and Be-Cu alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration actuator which is mounted on a mobile communication device such as a portable telephone and has a function of generating a ringing sound, voice or vibration.

[0002]

2. Description of the Related Art A vibration actuator of this type is described, for example, in Japanese Patent Application No. 8-324997 (vibration actuator for pager). As shown in FIG. 4, the vibration actuator includes a magnetic circuit composed of a permanent magnet 2, a yoke 1, and a plate 3. The magnetic circuit is supported on a ring-plate-shaped support base 10 by a support rubber 12 as a flexible structure. Between the plate 3 and the support 10, an action portion 17 on the outer peripheral portion is provided.
And a resin damper 19 having a central portion in contact with the plate 3 is interposed. The center shaft 4 is inserted through the center hole at the center of the damper 19 and the center hole of the magnetic circuit. A bobbin 13 is integrally formed on an outer peripheral portion of the damper 8 via an action portion 17, and the coil 5 wound around the bobbin 13 is arranged in a gap of a magnetic circuit. On the outer edge of the support 10,
A claw-shaped protrusion 11 having a small cross-sectional area is provided, and a support rubber 12 is engaged with the claw-shaped protrusion 11. Support base 10
A cushioning material 9 is interposed between the shaft and the yoke 1. When a drive current is applied to the coil 5, the magnetic circuit vibrates in a direction approaching or moving away from the support table 10, that is, in a vertical direction, and transmits the vibration to the outside via the action section 17 and the support table 10.

[0003]

In such a conventional structure, since bending stress is continuously applied to the damper 19 during vibration, if the fatigue resistance of the material of the damper 19 is low, the reliability is liable to decrease and the product life is shortened. There was a problem that it became short. Further, when the damper 19 and the bobbin 13 are integrally formed of resin, it is difficult to form a thin wall having a thickness of 0.2 mm or less, so that the thickness of the bobbin 13 is increased, which makes it difficult to miniaturize the product. .

It is therefore an object of the present invention to provide a vibration actuator which has high reliability, has a long product life, and can be easily miniaturized.

[0005]

According to the present invention, there is provided a magnetic circuit formed by using permanent magnets, a coil disposed in a gap of the magnetic circuit, and a flexible support of the magnetic circuit with respect to the coil. And a vibration actuator which receives an electric signal into the coil and causes the magnetic circuit to vibrate, wherein the damper is formed of metal.

[0006] Preferably, the damper is made of SUS30.
4. Made of at least one metal spring material of SUS301, nickel silver, phosphor bronze, and Be-Cu alloy.

[0007] Preferably, a coil bobbin is formed integrally with the damper by drawing or the like, and the coil is mounted on the coil bobbin.

[0008] Preferably, a resin working portion is added to the outer periphery of the damper, and the vibration of the magnetic circuit is transmitted to the outside via the working portion.

Preferably, a deep center hole is formed at the center of the damper by drawing.

[0010] Preferably, the magnetic circuit includes a central axis of a metal connecting the magnetic circuit to the damper, and the central axis and the damper are fixed by welding.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vibration actuator according to a first embodiment of the present invention will be described with reference to FIGS.

The vibration actuator shown in FIGS. 1 and 2 is mounted on a mobile communication device such as a portable telephone, and is constituted by sandwiching a disk-shaped permanent magnet 2 between a yoke 1 and a plate 3. Includes a magnetic circuit. The magnetic circuit is supported on the support base 10 by a support rubber 12 as a flexible structure. An annular working portion 6 made of resin is also fixed to the support base 10 by bonding. The action portion 6 is a portion formed integrally with the outer peripheral portion of the damper 8 by insert molding or the like. A bobbin 13 is formed on the outer periphery of the damper 8 by drawing or the like. The coil 5 is wound and supported on the bobbin 13. The coil 5 is inserted in the gap of the magnetic circuit. The magnetic circuits are connected by a central shaft 4 via a damper 8. The center shaft 4 has a shape like a bolt, penetrates a center hole in the center of the damper 8, and is fitted into the center hole of the magnetic circuit. That is, the magnetic circuit and the damper 8 are positioned coaxially by the center shaft 4.

The damper 8 is made of SUS304, SUS301,
At least one of metal spring materials such as nickel-white, phosphor bronze, and Be-Cu alloy is formed to have a plurality of spiral shapes. When the bobbin 13 is formed by resin molding, it is difficult to reduce the thickness to 0.2 mm or less, which is an obstacle to miniaturization. However, when metal is used, a thin plate of 0.2 mm or less is formed by cold rolling or the like. It is easy to manufacture, and since the damper 8 can be processed into a predetermined shape by drawing and punching using the thin plate, the bobbin 13 that is extremely thin and has high strength can be integrally formed. Bobbin 1
The adhesive strength between the coil 3 and the coil 5 is also improved.

The center shaft 4 and the damper 8 are fixed by press-fitting, bonding, caulking, or the like. However, if the center shaft 4 and the damper 8 are made of the same material, welding can be performed. It is preferable that the center hole of the damper 8 is formed deep by drawing.

The action portion 6 attached to the outer peripheral portion of the damper 8
Is directly or reinforced with a resin mold.
Adhered to. In this case, it is also effective to interpose an elastic material between the support base 10 and the action section 6. Further, the working portion 6 and the support base 10 may be directly insert-molded.

The support base 10 has a plurality of claw-like projections 11 on the outer peripheral portion 7 thereof.
2 is assembled. The support rubber 12 is assembled so as to flexibly support the magnetic circuit so that the magnetic circuit does not separate from the support base 10.

The cushioning member 9 is interposed between the magnetic circuit and the support base 10 and is bonded to the support base 10 so as to prevent the magnetic circuit from hitting the support base 10 and generating unnecessary sound. ing.

When a drive current is applied to the coil 5, the magnetic circuit flexibly supported by the damper 8 and the support rubber 12 vibrates. At this time, since the bending stress is repeatedly applied to the damper 8 continuously, it is inevitable that the damper 8 is broken due to fatigue after a certain number of repetitions. However, the fatigue strength of metal is 250 MPa for phosphor bronze and SUS30.
4 is 600 MPa, and the fatigue strength of the resin is 10 to 30.
It has ten times or more the strength of MPa, and the reliability is greatly improved by forming the damper 8 with a metal.

FIG. 3 shows a vibration actuator according to a second embodiment of the present invention. The same parts as those of the vibration actuator shown in FIG. 1 and FIG. In the vibration actuator of FIG. 3, the magnetic circuit is flexibly supported only by the metal damper 18. That is, by making the damper 18 of a metal material, the support base 10 and the support rubber 12 in the vibration actuator shown in FIGS. 1 and 2 become unnecessary. Therefore, the resin working portion 16 inserted into the damper 18 is exposed to the outside. The cushioning material 9 is held by the action section 16.

The same operation and effect can be obtained by this vibration actuator.

[0021]

As described above, according to the present invention, since the material of the damper is made of metal, it is possible to provide a vibration actuator having improved fatigue resistance as compared with resin and having high reliability. Was. In addition, because it can be integrated with a thin bobbin, the size of the product can be easily reduced, the reliability of fixing to the coil and the central shaft is improved, and a vibration actuator having high heat resistance can be provided. .

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a vibration actuator according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the vibration actuator of FIG. 1;

FIG. 3 is a longitudinal sectional view of a vibration actuator according to a second embodiment of the present invention.

FIG. 4 is a partially cutaway perspective view of an example of a conventional vibration actuator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Yoke 2 Permanent magnet 3 Plate 4 Central axis 5 Coil 6,16,17 Working part 7 Outer peripheral part of support stand 8,18,19 Damper 9 Buffer material 10 Support stand 11 Claw-like projection 12 Support rubber 13 Bobbin

Claims (6)

[Claims] A magnetic circuit configured by using a permanent magnet; a coil disposed in a gap of the magnetic circuit; and a damper which flexibly supports the magnetic circuit with respect to the coil. A vibration actuator for inputting an electric signal to cause vibration in the magnetic circuit, wherein the damper is formed of metal. 2. The SUS 304, SUS 3
2. The vibration actuator according to claim 1, wherein the vibration actuator is formed of at least one metal spring material selected from the group consisting of 01, nickel silver, phosphor bronze, and Be-Cu alloy. 3. The vibration actuator according to claim 1, wherein a coil bobbin is formed integrally with the damper by drawing or the like, and the coil is mounted on the coil bobbin. 4. The vibration according to claim 1, wherein a resin working portion is added to an outer peripheral portion of the damper, and vibration of the magnetic circuit is transmitted to the outside via the working portion. Actuator. 5. The vibration actuator according to claim 1, wherein a deep center hole is formed at the center of said damper by drawing. 6. The vibration actuator according to claim 1, further comprising a central axis of a metal connecting the magnetic circuit to the damper, wherein the central axis and the damper are fixed by welding.