JP2003145045A - Multifunctional vibrating actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multifunctional vibrating actuator in which power is raised by reducing causes to obstructs the vibration of a vibrating body. SOLUTION: An air vent 309 for passing air is provided in a magnetic circuit constructed by using a permanent magnet 302. A coil 306 is arranged in the space of the magnetic circuit. The magnetic circuit is flexibly supported by a suspension 304 to a vibration transmission part 307.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration actuator, and more particularly to a so-called multi-function vibration actuator having a function of generating ringing sound, voice and vibration.

[0002]

2. Description of the Related Art An example of a multifunctional vibration actuator of this type is shown in FIG. Referring to FIG. 1, a magnetic circuit including a yoke 101, a permanent magnet 102, and a plate 103 is flexibly supported by an arcuate spiral leaf spring suspension 104 fixed to a vibration transmitting portion 107. The suspension 104 is fixed to the outer peripheral portion of the yoke 101 of the magnetic circuit and the vibration transmitting portion 107. Vibrating body 105
The coil 106 fixedly attached to is disposed in the air gap of the magnetic circuit. The vibrating body 105 is fixed to the vibration transmitting unit 107 like the suspension 104.

When a drive current is passed through the coil 106, the magnetic circuit or the coil 106 moves vertically in the axial direction. The vibration transmitting portion 107 becomes a fixed portion at a low frequency, and becomes an elastic body at a high frequency to become a part of the vibrating body 105 and vibrate.
5 operates while interfering with each other and transmits vibration to the outside.

The vibration transmitting portion 107 has a stopper 1
08 is provided. The stopper 108 has a role of preventing the porcelain circuit and the vibrating body from colliding with each other when excessive power is applied to the vibrating actuator.

[0005]

In this type of multifunctional vibration actuator, it is desired that a larger sound pressure can always be output per unit input than the conventional multifunctional vibration actuator.

In the conventional multifunctional vibration actuator of FIG. 1, sound output is generated by vibration of the vibrating body 105. Therefore, a structure that allows the vibrating body 105 to vibrate more is desirable.

When the vibrating body 105 vibrates, it is desirable that the air on both sides of the vibrating body 105 can freely move in and out. This is because if the air in this portion cannot freely move in and out, it acts as an acoustic load and inhibits the vibration of the vibrating body 105.

Vibrating body 1 of the multifunctional vibration actuator of FIG.
FIG. 2 is a diagram schematically showing the flow of air to both sides of the central part of 05. In FIG. 2, reference numeral 201 represents air in and out of the side of the vibrating body facing the magnetic circuit, and 202 represents air in and out of the side of the vibrating body not facing the magnetic circuit.

From FIG. 2, it can be seen that the air inflow and outflow 202 on the side of the vibrating body 105 that does not face the magnetic circuit is performed with almost no load. However, in the air inflow / outflow 201 to the side of the vibrating body 105 facing the magnetic circuit, between the coil 106 and the plate 103, the coil 10 is not provided.
6 and the yoke 101, and between the yoke 102 and the vibration transmitting portion 107 must pass through three narrow passages, and the length of the entire passage through which air flows in and out is also large.
Air in and out on the side not facing the magnetic circuit of 05 202
It has become longer than the one in. Therefore, a large load is applied to the air inflow / outflow 201 of the side of the vibrating body 105 facing the magnetic circuit. This load hinders the vibration of the vibrating body 105 and reduces the output of the multifunctional vibration actuator.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a multifunctional vibration actuator capable of increasing the output by reducing the cause of obstructing the vibration of the vibrating body.

[0011]

According to the present invention, a magnetic circuit formed by using a permanent magnet, a coil arranged in a gap of the magnetic circuit, a vibration transmission section, and the vibration transmission section are provided with A multifunctional vibration actuator including a suspension that flexibly supports a magnetic circuit, wherein the magnetic circuit has a hole for allowing air to pass therethrough.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, referring to FIG. 3 and FIG.
A multifunctional vibration actuator according to an embodiment of the present invention will be described.

First, the structure of the multifunctional vibration actuator will be described with reference to FIG. In this multifunctional vibration actuator, a disk-shaped permanent magnet 302 having a hole in the center is sandwiched between a yoke 301 having a hole in the center and a plate 303 having a hole in the center to form a magnetic circuit or a magnetic path member. It has a formed inner magnet type structure. Yoke 301, permanent magnet 30
2 and the plate 303 are coaxially arranged and bonded to each other, so that the magnetic circuit has a central air hole 309.

The above-mentioned magnetic circuit is flexibly supported by the vibration transmitting portion 307 via the ring plate-shaped suspension 304. The suspension 304 is a single arc-shaped spiral leaf spring. The suspension 304 may have a plurality of leaf spring portions extending in a spiral shape between the inner peripheral edge and the outer peripheral edge. The inner peripheral end of the suspension 304 is fixed to the outer peripheral portion of the yoke 301 by using an elastic material such as an adhesive, an adhesive or a resin, or by caulking. The outer peripheral end of the suspension 304 is fixed to the vibration transmitting portion 307. For example, the suspension 30
4 and the vibration transmitting portion 307 are integrated by insert molding, welding, bonding, or the like.

In the above magnetic circuit, a gap is formed between the yoke 301 and the plate 303. A coil 306 is inserted in the air gap of the magnetic circuit. Coil 30
6 is held by the vibrating body 305, and is fixed to the vibrating body 305 by an adhesive or the like as necessary.

The vibrating body 305 has a plate shape, a dish plate shape, a curved surface shape, a corrugation, or a combination thereof, and has an arbitrary plate thickness. For example, when the vibrating body 305 has a curved shape, a predetermined acoustic characteristic is obtained by a single curvature or a combination of different curvatures. Further, in order to obtain a larger amplitude of the vibrating body 305, the outer peripheral portion of the vibrating body 305 is fixed to the vibration transmitting section 307 through an elastic material such as an adhesive, an adhesive, or a resin as necessary.

The vibration transmitting portion 307 has a stopper 3
08 is provided. The stopper 308 has a role of preventing the porcelain circuit and the vibrating body 305 from colliding with each other when excessive power is applied to the vibration actuator.

The operation of the above-mentioned multifunctional vibration actuator will be described with reference to FIG.

By energizing the coil 306, the multifunctional vibration actuator is put into operation. During operation, the air holes 30 are provided on the side of the vibrating body 305 that faces the magnetic circuit.
Air will flow through 9. It will be understood from a comparison between FIG. 4 and FIG. 2 that the air flows on the sides of the vibrating bodies 305 and 105 facing the magnetic circuit are significantly different. That is, the air flow 402 on the side facing the magnetic circuit of the vibrating body 305 in FIG. 4 is smoother than the air flow 202 on the side facing the magnetic circuit of the vibrating body 105 in FIG. This is because in FIG. 4, the cross-sectional area of the flow path for the air flow is large and the length of the flow path is also short. As a result, the vibrating body 30
The load that impedes the vibration of No. 5 is significantly reduced by the air holes 309 of the magnetic circuit.

The sound pressure characteristics of the multifunctional vibration actuator will be compared and described with reference to FIG.

The difference between the multifunctional vibration actuators used for comparison is only whether or not there is a hole in the magnetic circuit, and there is no difference in other parts. The input is a 1 Vp-p sine wave. The outer diameter of the multifunctional vibration actuator is 18 mm, and the diameter of the air hole provided in the magnetic circuit is 1.5 mm.

In FIG. 5, the solid line shows the sound pressure characteristic of the one corresponding to the multifunctional vibration actuator shown in FIG. 3, and the broken line shows the sound pressure characteristic of the one corresponding to the multifunctional vibration actuator shown in FIG. Comparing the two sound pressure characteristics, there is a difference of 2.25 dB at the average sound pressure of 1 kHz to 2 kHz. Therefore, it can be seen that the air hole has a very large effect in increasing the sound pressure per unit input.

The following various modifications are possible.

The number of air holes provided in the magnetic circuit is one in FIG. 3, but a plurality of air holes may be provided.

The structure of the magnetic circuit may be an outer magnet type or a radial structure in addition to the inner magnet type structure of FIG.

It is desirable that the tip of the yoke of the magnetic circuit has a shape such as a protrusion or an unevenness so as to easily generate a high magnetic flux density in both the inner magnet type and the outer magnet type.

The magnetic poles of the permanent magnet may be oriented in either direction.

[0028]

As described above, according to the present invention,
It is possible to provide a multifunctional vibration actuator capable of increasing the output by reducing the cause of obstructing the vibration of the vibrating body.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an example of a conventional multifunctional vibration actuator.

FIG. 2 is a diagram schematically showing the flow of air inside the multifunctional vibration actuator of FIG.

FIG. 3 is a cross-sectional view showing a multifunctional vibration actuator according to an embodiment of the present invention.

FIG. 4 is a diagram schematically showing a flow of air inside the multifunctional vibration actuator of FIG.

5 is a diagram showing output sound pressure characteristics of the multifunctional vibration actuator of FIG. 1 and the multifunctional vibration actuator of FIG.

[Explanation of symbols]

101 York 102 permanent magnet 103 plate 104 suspension 105 vibrating body 106 coils 107 Vibration transmission unit 108 Stopper 201 Air flow 202 Air flow 301 York 302 permanent magnet 303 plate 304 suspension 305 vibrating body 306 coil 307 Vibration transmitter 308 stopper 309 air holes 401 air flow 402 Air flow

Claims (2)

[Claims] 1. A magnetic circuit configured by using a permanent magnet, a coil arranged in a gap of the magnetic circuit, a vibration transmitting section, and a suspension in which the magnetic circuit is flexibly supported by the vibration transmitting section. A multifunctional vibration actuator comprising: a magnetic circuit having a hole for allowing air to pass therethrough. 2. The multifunctional vibration actuator according to claim 1, further comprising a vibrating body that supports the coil and is fixed to the vibration transmitting unit, and the magnetic circuit is on one side of the vibrating body.