JP2000069710A - Vibration actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of performance due to contact of a coil with a magnetic circuit by arranging a damper on the plate side of the magnetic circuit and a supporting plate on the yoke side while coupling with the central part of the magnetic circuit and supporting the magnetic circuit flexibly at two points thereby suppressing inclination of the axis of the magnetic circuit at the time of oscillation. SOLUTION: A magnetic circuit 20, a damper 8 and a supporting plate 7 are positioned coaxially by a central shaft 4. The damper 8 is formed into a plurality of spirals in order to support the center of the magnetic circuit 20 on the plate 3 side flexibly and integrated with a bobbin 13 for supporting a coil 5. The supporting plate 7 is formed into a plurality of spirals in order to support the center of the magnetic circuit 20 on the yoke 3 side flexibly and secured, at the outer fringe part, to a supporting base 10. The magnetic circuit 20 vibrates upon application of a driving current to the coil 5 but since the axis of the magnetic circuit 20 is supported at two points above and below the central shaft 4, inclination of the axis of the magnetic circuit 20 can be suppressed at the time of vibration.

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 tone, 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). This conventional vibration actuator includes a magnetic circuit 20 composed of a permanent magnet 2, a yoke 1, and a plate 3, as shown in FIG. This magnetic circuit is supported by a support rubber 12 which is a flexible structure attached to a damper 8 and a claw-like projection 11 provided on a support base 14 so as to be vertically movable. When a drive current is applied to the coil 5, the magnetic circuit 20
Has a structure in which it moves vertically in the axial direction and transmits vibrations to the outside through the damper outer peripheral portion 6 and the support base 14 by the coil 5. The center shaft 4 is a shaft connected to the yoke 1 and the permanent magnet 2 and connected to the damper 8, and the elastic member 9 is for preventing the yoke 1 from directly colliding with the support base 14. .

[0003]

However, in the above-described conventional vibration actuator having such a structure, since the magnetic circuit and the damper are supported only by the center axis, there is a possibility that the magnetic circuit is inclined during vibration. is there. Therefore, the inclination of the axis of the magnetic circuit is suppressed by the support rubber. However, when the assembly accuracy is poor, the support is insufficient, and the coil is inclined, there is a possibility that the coil and the magnetic circuit may come into contact with each other or abnormal stress may be applied to the damper.

Accordingly, the present invention employs a structure in which the magnetic circuit does not tilt when vibrating, and does not cause performance degradation due to contact between the coil and the magnetic circuit or abnormal stress applied to the damper. It is to provide.

[0005]

According to the present invention, to solve these problems, a damper is provided on a plate side of a magnetic circuit, and a support plate is provided on a yoke side, and each is connected to a central portion of the magnetic circuit. By flexibly supporting the magnetic circuit at two points, the inclination of the axis of the magnetic circuit during vibration is suppressed as much as possible. It is a vibration actuator without any.

That is, according to the present invention, a magnetic circuit constituted 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. Having an electric signal input to the coil;
In a vibration actuator that generates vibration by moving the circuit up and down, a damper is arranged on a plate side of the magnetic circuit, a support plate is arranged on a yoke side, and each is connected to a central portion of the magnetic circuit, thereby forming a magnetic circuit. A vibration actuator characterized by being flexibly supported is obtained.

[0007]

Embodiments of the present invention will be described below.

FIG. 1 is a sectional view of a vibration actuator according to an embodiment of the present invention. In FIG. 1, a magnetic circuit 20 is formed such that a disk-shaped permanent magnet 2 is sandwiched between a yoke 1 and a plate 3. The center shaft 4 is shaped like a bolt, penetrates the center hole at the center of the damper 8,
Further, it is fitted in the center hole of the magnetic circuit 20 and the support plate 7.

That is, the magnetic circuit 2 is controlled by the central shaft 4.
0, damper 8, and support plate 7 are positioned coaxially. The damper 8 is formed to have a plurality of spiral shapes so as to flexibly support the center of the magnetic circuit 20 on the plate 3 side, and integrally has a bobbin 13 that supports the coil 5.

The support plate 7 is formed to have a plurality of spiral shapes so as to flexibly support the center of the magnetic circuit 20 on the yoke 1 side, and its outer edge is fixed to the support base 10.

The elastic member 9 is bonded to the support 10 between the yoke 1 and the support 10 in order to suppress a collision sound when the magnetic circuit 20 collides with the support 10.

In such a configuration, when a drive current is applied to the coil 5, the magnetic circuit 20 flexibly supported by the damper 8 and the support plate 7 vibrates.

At this time, since the axis of the magnetic circuit 20 is supported at two points above and below the central axis 4, the inclination of the axis of the magnetic circuit during vibration can be suppressed.

Therefore, the coil contacts the magnetic circuit,
It is possible to prevent an abnormal stress from being applied to the damper and to cause performance degradation.

[0015]

As described above, according to the present invention, the damper is arranged on the plate side of the magnetic circuit, the support plate is arranged on the yoke side, and the magnetic circuit is connected to the center of the magnetic circuit. Flexible support at two points reduces the inclination of the axis of the magnetic circuit during vibration, preventing the coil from contacting the magnetic circuit and applying extraordinary stress to the damper. Provision is now possible.

[Brief description of the drawings]

FIG. 1 is a sectional view of a vibration actuator according to an embodiment of the present invention.

FIG. 2 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 Damper outer peripheral part 7 Support plate 8 Damper 9 Elastic material 10, 14 Support stand 11 Claw-like projection 12 Support rubber 13 Bobbin 20 Magnetic circuit

Claims (1)

[Claims] A magnetic circuit configured by using a permanent magnet, a coil disposed in a gap of the magnetic circuit, and a damper that flexibly supports the magnetic circuit with respect to the coil;
In a vibration actuator that inputs an electric signal to the coil and generates vibration by moving the circuit up and down, a damper is disposed on a plate side of the magnetic circuit, a support plate is disposed on a yoke side, and each of the magnetic circuit is provided with a magnetic circuit. A vibration actuator, which is connected to a central portion to flexibly support a magnetic circuit.