JPH11341780A - Oscillatory actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise the fatigue resistance by forming a damper out of a stack of resin or meal and rubber, and also, to raise the reliability on an actuator by preventing the transformation caused by the occurrence of permanent distortion. SOLUTION: A damper 8 is made of a stack of a metallic section 14 such as stainless steel SUS304, phosphoric bronze, or the like and a resin part 15 so that it may have a plurality of spiral forms, and it has a bobbin 13 for supporting a coil 5 integrally by drawing or the like at the periphery of the metallic section 14. Then, when a drive current is applied to the coil 5, the damper 8 and a magnetic circuit supported by supporting rubber vibrate, and repeated bending stress works continuously on the damper 8, but the reliability improves sharply by making the damper 8 of metal. But, in the case that axial external force adds to the magnetic circuit, the quantity of displacement of the magnetic circuit becomes large, and with metal by itself, this is transformed largely due to the occurrence of permanent distortion, so this is made in stack structure with resin so as to prevent the transformation of metal with elasticity of resin. As a result, high reliability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration actuator mounted on a mobile communication device such as a portable telephone and having a function of generating a ringing sound, a sound and a 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 includes a damper 19 formed by injection molding of a resin and a support base 1.
A support rubber 12 which is a flexible structure attached to the claw-shaped protrusion 11 provided on the support member 0 is supported so as to be vertically movable. When an oscillating current is applied to the coil 5, the magnetic circuit moves up and down in the axial direction, and the coil 5 causes the outer peripheral portion 1 of the damper to move.
Vibration is transmitted to the outside via the support 7 and the support 10.

[0003]

In such a conventional structure, a bending stress is continuously applied to the damper 19 at the time of vibration. Therefore, if the material of the damper 19, such as a resin, has low fatigue resistance, the product life is shortened. There was the problem of being short. Further, when metal is used as the material of the damper 19 to prolong the product life, a large amount of deflection cannot be obtained, so that a small amount of displacement causes permanent distortion, which causes the damper 19 to be deformed. was there.

[0004] Therefore, an object of the present invention is to provide a vibration actuator provided with a damper having high fatigue resistance and hardly causing permanent distortion.

[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 for inputting an electric signal to the coil to generate vibration in the magnetic circuit, wherein the damper is formed of a laminate of metal and resin or metal and rubber. A vibration actuator is obtained.

Preferably, the damper is formed by molding the periphery of a metal with a resin.

Preferably, the metal part of the damper is SU
S304, SUS301, nickel silver, phosphor bronze, and Be-
It is formed of at least one metal spring material of a Cu alloy.

[0008] Preferably, a coil bobbin is formed integrally with the metal part of the damper by drawing or the like.

Preferably, an annular collision portion of resin is provided on the outer periphery of the damper by insert molding or the like.

Preferably, a resin rib is provided in a center hole of the damper.

Preferably, the center hole of the damper is deepened by drawing or the like.

[0012]

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.

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 sectional view of the same. This vibration actuator is mounted on a mobile communication device such as a mobile phone,
A magnetic circuit is formed by the yoke 1 and the plate 3 so as to sandwich the disk-shaped permanent magnet 2. 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, phosphor bronze, Be-
A laminated product of a metal portion 14 such as a Cu alloy and a resin portion 15 is formed so as to have a plurality of spiral shapes, and a bobbin 13 for supporting the coil 5 is formed integrally on the outer peripheral portion of the metal portion 14 by drawing or the like. doing. In FIGS. 1 and 2, the damper 8 is mainly made of metal, and the resin is only partially laminated. However, the entire metal may have a laminated structure with resin.

The center shaft 4 and the damper 8 are fixed by press-fitting, bonding, caulking or the like.
If 4 is made of the same material, welding is also possible. Alternatively, a resin may be molded on the inner peripheral portion of the damper 8 to provide a rib, and the central shaft 4 may be press-fitted or bonded thereto.

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

The support base 10 has a plurality of claw-shaped protrusions 11 at the outer edge thereof, and a support rubber 12 is attached to the claw-shaped protrusions 11. 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 material 9 includes a magnetic circuit,
The magnetic circuit is adhered to the support base 10 between the magnetic circuit and the support base 10 so as to suppress generation of unnecessary sound due to collision with the magnetic circuit.

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, a bending stress is continuously applied to the damper 8, so that a certain number of repetitions , The damper 8 breaks due to fatigue. The fatigue strength of the metal is 250 MPa for phosphor bronze and 600 MPa for SUS304, which is ten times or more the fatigue strength of the resin of 10 to 30 MPa. , Greatly improve the reliability. However, when an external axial force such as a drop impact is applied to the magnetic circuit,
Since the amount of displacement of the magnetic circuit becomes large and the damper 8 is greatly deformed by the permanent deformation of metal alone, in FIGS. 1 and 2, the damper 8 is formed in a laminated structure by bonding metal and resin, and the elasticity of the resin is increased. This prevents deformation of the metal. Alternatively, the periphery of the metal may be molded with a resin to form a multilayer structure of the metal and the resin.

FIG. 3 is a sectional view of a vibration actuator according to another embodiment of the present invention. In this vibration actuator, the magnetic circuit is flexibly supported only by the damper 18, and the supporting rubber and the supporting base are omitted. Also,
The coil uses a bobbin-less coil, and the bobbin is omitted.

The damper 18 is formed by insert molding so that the metal portion 20 is inserted into the center of the resin portion 21.

[0021]

As described above, according to the present invention, the damper has a multilayer structure of a metal and a resin or a metal and a rubber, thereby improving the fatigue resistance of the damper and extending the life of the product. In addition, the deformation of the damper due to the generation of permanent distortion can be suppressed, and a change in characteristics is small, and a highly reliable vibration actuator 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 Center shaft 5 Coil 6,16,17 Peripheral part of damper 7 Peripheral part of support 8,18,19 Damper 9 Buffer material 10 Support base 11 Claw-like projection 12 Support rubber 13 Bobbin 14,20 Damper Metal part of 15,21 Resin part of damper

Claims (7)

[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 which receives an electric signal and causes vibration in the magnetic circuit, wherein the damper is formed of a laminate of metal and resin or metal and rubber. 2. The vibration actuator according to claim 1, wherein the damper is formed by molding a periphery of a metal with a resin. 3. The metal part of the damper is SUS304,
The vibration actuator according to claim 1, wherein the vibration actuator is formed of at least one metal spring material of SUS301, nickel silver, phosphor bronze, and Be—Cu alloy. 4. The vibration actuator according to claim 1, wherein a coil bobbin is formed integrally with the metal part of the damper by drawing or the like. 5. The vibration actuator according to claim 1, wherein an annular collision portion of resin is provided on an outer periphery of the damper by insert molding or the like. 6. The vibration actuator according to claim 1, wherein a rib of resin is provided in a center hole of said damper. 7. The vibration actuator according to claim 1, wherein a center hole of the damper is deepened by drawing or the like.