JP2002336780A - Vibration actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration actuator wherein the positioning and the mounting of a coil can be easily carried out and the coil is hardly unstuck from a diaphragm. SOLUTION: This vibration actuator having an electroacoustic transducer is provided with a magnetic circuit consisting of a permanent magnet 32, a coil 36 disposed in a space of the magnetic circuit, a vibrator 35 to which the coil 36 is attached and to which driving force can be given by the coil 36, and a vibration transmitting part 38 supporting the magnetic circuit flexibly through a suspension 34 consisting of a flexible spring. The vibrator 35 is equipped with a concave coil fixing part 39, and the coil 36 is embedded in the coil fixing part 39 to be fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration actuator having a function of generating a ringing tone, voice, vibration, and the like.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view of a conventional vibration actuator. As shown in FIG. 6, the magnetic circuit including the yoke 101, the permanent magnet 102, and the plate 103 is flexibly supported by an arc-shaped helical leaf spring suspension 104 fixed to the vibration transmission unit 108. 104 is fixed to the outer periphery of the yoke 101 of the magnetic circuit and to the vibration transmitting unit 108. Vibrator 105
The coil fixing portion 109 provided in the coil 1 has a concave shape, and the coil 106 is fixed by an adhesive or the like.
Reference numeral 06 is disposed in the gap of the magnetic circuit.

The vibrating body 105 is fixed to a vibration transmitting unit 108, like the suspension 104. When a driving current is applied to the coil 106, the magnetic circuit or the coil 106 moves up and down in the axial direction. At a fixed portion, and at a high frequency into an elastic body,
And the magnetic circuit and the vibrating body 105 operate in each mode of vibration and sound while interfering with each other to transmit vibration to the outside. Reference numeral 107 denotes a central shaft that is inserted through the central hole of the magnetic circuit.
Further, the vibration transmitting unit 108 is provided with a stopper 110. The stopper 110 is provided with a magnetic circuit and the vibrating body 105 when excessive power is applied to the vibration actuator.
Has the role of preventing collision.

By the way, the magnetic flux density in the air gap of the magnetic circuit is:
It becomes the largest on the straight line connecting the yoke and the plate in the shortest distance, and decreases rapidly as the distance from the straight line increases. Therefore, it is ideal that the coils are concentrated and arranged in a straight line connecting the yoke and the plate in the shortest time. In this case, the driving force is the largest. However, in the case of the vibration actuator shown in FIG. 6, one end of the coil 106 is arranged at a portion where the magnetic flux density is large, but one end is arranged at a portion where the magnetic flux density is small. A part of the coil arranged in the portion where the magnetic flux density is small not only contributes little to the improvement of the driving force but also reduces the vibration of the vibrating body due to its mass, thereby deteriorating the characteristics of the vibration actuator.

Therefore, the performance of the conventional vibration actuator shown in FIG. 6 has been improved. FIG. 7 shows a cross-sectional view of another conventional vibration actuator. The yoke 201, the permanent magnet 202, and the plate 20 of the vibration actuator of FIG.
3, suspension 204, coil 206, central axis 20
7, the vibration transmitting unit 208, the coil fixing unit 209, and the stopper 210 are the yoke 10 of the vibration actuator of FIG.
1, permanent magnet 102, plate 103, suspension 104, coil 106, center shaft 107, vibration transmission unit 10
8, has the same configuration and functions as the coil fixing portion 109 and the stopper 110. The coil fixing portion 209 provided on the vibrating body 205 has a convex shape.
By fixing 06, the entire coil 206 can be arranged in a portion where the magnetic flux density is large. Therefore,
The vibration of the vibrating body 205 can be made larger than that of the vibration actuator of FIG.

However, since the coil 206 is fixed to the vibrating body 205 with an adhesive or the like, it is difficult to position the coil 206, and there is a problem that it takes a long time to use a mounting jig. In addition, when the actuator is miniaturized, the current molding technology requires that the convex coil fixing portion 2 be used.
Since it is difficult to make the fixed position of the coil 206 at 09 a perfect plane, there is a problem that the vibrating body 205 and the coil 206 are likely to be in point contact, and the coil 206 is easily peeled off from the vibrating body 205.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a vibration actuator in which the coil can be easily positioned and mounted and the coil is not easily detached from the vibrating body.

[0008]

According to the present invention, there is provided a magnetic circuit formed by using a permanent magnet, a coil disposed in a gap of the magnetic circuit, and a vibration provided with a driving force by the coil. In a vibration actuator having an electroacoustic transducer including a plate and a vibration transmitting unit that flexibly supports the magnetic circuit via a suspension made of a flexible spring, a concave coil fixing unit is provided on the vibrator, A vibration actuator, wherein the coil is embedded and fixed in the coil fixing portion.

Further, in the present invention, the coil is fixed to the vibrating body by inserting the coil into the coil fixing portion, filling the coil fixing portion with a filler, and curing the coil. Is a vibration actuator.

Further, the present invention is the above-mentioned vibration actuator, wherein the coil is completely covered with the filler.

Further, the present invention is the above-described vibration actuator, wherein the filler is filled so that the filler does not touch the lead wire lead-out portion of the coil.

Further, the present invention is the above-mentioned vibration actuator, wherein the coil fixing portion is almost completely filled with the filler.

Further, the present invention is the above-mentioned vibration actuator, wherein the filler is an ultraviolet curing resin.

That is, the vibration actuator of the present invention is characterized in that the vibrating body is provided with a concave portion, and the coil is embedded and fixed in the concave portion so that the conducting wire portion of the coil can be arranged at a position where the magnetic flux density is large. I do.

More specifically, the vibration actuator according to the present invention is characterized in that the coil is buried in the concave portion of the vibrator so that the coil is effectively arranged at the gap position of the magnetic circuit.

Further, when the coil is embedded and fixed in a concave coil fixing portion provided at an arbitrary position in the radial direction of the vibrating body, the positioning of the coil is easy, and the adhesion is higher than in the method in which the coil is fixed to the convex portion. High strength. Further, it is easy to adjust the adhesive strength by adjusting the amount of the filler such as an adhesive to be poured into the coil fixing portion. Adhesive strength can be increased most if the coil is completely covered by a poured filler such as an adhesive.

On the other hand, one of the most frequent causes of failure of the electro-dynamic type vibration actuator is a break in a lead wire extending from a coil. In order to increase the input to the input power of the vibration actuator, rather than completely covering the coil with a filler such as an adhesive and solidifying the lead wire lead portion of the coil, instead of hardening the lead wire lead portion of the coil, A structure in which the lead wire can flexibly vibrate with respect to the vibration of the vibrator is more advantageous.

When the coil fixing portion of the vibrating body is almost completely filled with a filler such as an adhesive, the rigidity of the vibrating body can be increased, and the sound pressure output from the vibration actuator can be increased.

When a method of fixing a coil to a projection of a vibrating body is used, the magnetic circuit and the coil are adjacent to each other with a space therebetween. If a strong impact such as a drop is applied to the vibration actuator in such a state, the magnetic circuit may collide with the coil and the coil may be damaged, and a mechanism for preventing the collision is required. On the other hand, in the case of the method in which the coil is embedded in the concave coil fixing portion of the vibrating body, since the magnetic circuit and the coil are separated by the vibrating body, there is little danger of damaging the coil even if the magnetic circuit collides with the vibrating body. .

When the adhesive is poured as a filler after the coil is inserted into the coil fixing portion of the vibrating body, the smaller the viscosity of the adhesive before curing, the more the adhesive can spread over the entire coil fixing portion. . Further, depending on the shape of the coil fixing portion and the size of the coil, it takes time for the adhesive to spread, and therefore, it is preferable that the adhesive does not cure without applying external energy. In particular, an ultraviolet curable adhesive is suitable for pouring into a concave portion of a vibrating body after inserting a coil.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

FIG. 1 is a sectional view of the vibration actuator according to the first embodiment of the present invention. As shown in FIG. 1, the vibration actuator according to the first embodiment of the present invention has a magnetic circuit formed of a yoke 31 and a plate 33 so as to sandwich a disk-shaped permanent magnet 32, and has an internal magnet type structure. A central shaft 37 having a shape such as a bolt or a pin penetrates a central hole of the magnetic circuit and is fitted therein.
2. The plate 33 is positioned coaxially. The suspension 34 is a single arc-shaped helical leaf spring and flexibly supports the magnetic circuit. The suspension 34 is fixed to the outer periphery of the yoke 31 by an elastic material such as an adhesive, an adhesive or a resin, or by caulking. One end is fixed to the vibration transmitting section 38. On the other hand, the coil 36 has a concave coil fixing portion 39.
Is fixed to the vibrating body 35 formed with the above, and is fixed by an adhesive or the like as necessary, and is disposed in the gap of the magnetic circuit.

The vibration transmitting part 38 has a stopper 40.
The stopper 40 has a role of preventing the magnetic circuit from colliding with the vibrating body when excessive power is applied to the vibration actuator.

The structure of the magnetic circuit may be either an external magnet type or a radial structure in addition to the internal structure shown in FIG. Further, the tip of the yoke 31 of the magnetic circuit is formed in a shape such as a protrusion or an unevenness so that a high magnetic flux density is easily generated even in an inner magnet type or an outer magnet type. The direction of the magnetic pole of the permanent magnet 32 may be any direction.

The suspension 34 is integrated with the vibration transmitting section 38 by insert molding, welding, bonding or the like.

The vibrating body 35 has a flat shape, a plate shape, a curved shape,
A predetermined acoustic characteristic can be obtained by corrugation or a combination of the respective plates having an arbitrary thickness and a curved surface having a single curvature or a combination of different curvatures. Further, the outer peripheral portion of the vibrating body 35 is fixed to the vibration transmitting section 38 via an elastic material such as an adhesive, an adhesive, or a resin as necessary in order to obtain a larger amplitude of the vibrating body 35.

The vibration transmitting portion 38 is made of a resin or the like that provides an elastic action, and is provided with a sound emitting hole arbitrarily so as to satisfy the principle of the Helmholtz resonator. There is no provision.

FIG. 2 is a sectional view showing a vibration actuator according to a second embodiment of the present invention. The yoke 41, the permanent magnet 42, the plate 43, the suspension 44, the vibrating body 45, the coil 46, and the central axis 4 of the vibration actuator of FIG.
7, vibration transmitting section 48, coil fixing section 49, stopper 5
0 denotes a yoke 31, a permanent magnet 32, a plate 33, a suspension 34, and a vibrating body 3 of the vibration actuator of FIG.
5, have the same configuration and function as the coil 36, the central shaft 37, the vibration transmitting section 38, the coil fixing section 39, and the stopper 40.

The coil fixing portion 49 of the vibrating body 45 is filled with a filler 71, and the filler 71 completely covers the coil 46. By completely covering the coil 46 with the filler 71, the adhesive strength between the vibrating body 45 and the coil 46 can be improved.

FIG. 3 is a sectional view showing a vibration actuator according to Embodiment 3 of the present invention. The yoke 51, the permanent magnet 52, the plate 53, the suspension 54, the vibrating body 55, the coil 56, and the central axis 5 of the vibration actuator of FIG.
7, vibration transmitting part 58, coil fixing part 59, stopper 6
0 denotes a yoke 31, a permanent magnet 32, a plate 33, a suspension 34, and a vibrating body 3 of the vibration actuator of FIG.
5, has the same configuration and function as the coil 36, the central shaft 37, the vibration transmitting section 38, the coil fixing section 39, and the stopper 40.

The coil fixing portion 59 of the vibrating body 55 is filled with a filler 81, but the filler 81 does not cover the lead wire lead-out portion 56 a of the coil 56. By completely covering the coil 56 with the filler 81, the adhesive strength between the vibrating body 55 and the coil 56 can be improved.
If the lead wire lead-out portion 56a of the coil 56 is hardened, the flexibility of the lead wire near the filler interface is lost, and the tension or shear load on the lead wire due to the vibration of the vibrator is limited to the limit near the filler interface. It concentrates on the point that was given. Therefore, when the resistance of the lead wire of the coil 56 must be considered, it is more effective not to cover the lead wire lead-out portion 56a of the coil 56 with the filler.

FIG. 4 is a sectional view showing a vibration actuator according to a fourth embodiment of the present invention. 4, the yoke 61, the permanent magnet 62, the plate 63, the suspension 64, the vibrator 65, the coil 66, and the central shaft 6 of the vibration actuator of FIG.
7, vibration transmitting section 68, coil fixing section 69, stopper 7
0 denotes a yoke 31, a permanent magnet 32, a plate 33, a suspension 34, and a vibrating body 3 of the vibration actuator of FIG.
5, has the same configuration and function as the coil 36, the central shaft 37, the vibration transmitting section 38, the coil fixing section 39, and the stopper 40.

The coil fixing portion 69 of the vibrating body 65 is filled with a filler 91. The filling material 91 almost completely fills the coil fixing portion 69 of the vibrating body 65. Filler 91
By filling the coil fixing portion 69 almost completely, the rigidity of the vibrating body can be improved, and the sound pressure of a sound such as a ringing sound or a sound of the vibration actuator can be improved.

The filler of the vibration actuator shown in FIGS. 2 to 4 may be silica-based, urethane-based, epoxy-based, silicon-based or any other filler. Further, a rubber-based material or another filler may be used. In particular, a filler having a small initial viscosity and having a property of being cured by injecting energy such as ultraviolet rays is effective in production. Further, a filler generally called an adhesive may be used.

Next, the conventional vibration actuator shown in FIG. 6 and the vibration actuator according to the first embodiment of the present invention shown in FIG. 1 were manufactured, and the results of evaluating the magnitude of the audio output are shown in FIG.
Shown in The two vibration actuators produced for evaluation have only the vibrating body and the coil, and have the same configuration with the other common components. In addition, the applied power at the time of evaluation and the distance from the actuator to the evaluation microphone are common. As can be seen from FIG. 5, the vibration actuator of FIG.
An increase of about 6 dB is seen at an average of kHz, which indicates that the vibration actuator of the present invention has a very large effect in improving output sound pressure characteristics.

[0036]

As described above, according to the present invention, by fixing a coil inside a concave coil fixing portion formed on a vibrating body, a lightweight small coil can be effectively placed at a gap position of a magnetic circuit. And the output sound pressure of the sound output from the vibration actuator having the function of generating a sound or vibration before calling can be improved.

Further, as compared with a method in which a lightweight and small coil is pasted on the convex portion of the vibrating body, the coil can be easily positioned, the bonding strength can be increased, and the contact between the coil and the magnetic circuit can be prevented. be able to. The vibration actuator of the present invention has a very large effect in terms of productivity and reliability.

When the coil fixing portion of the vibrating body is filled with the filler to fix the coil, the characteristics of the vibration actuator can be adjusted by the amount of the filler. By completely covering the coil with the filler, the adhesive strength between the vibrator and the coil can be increased. Also, by filling the filler with avoiding the position where the lead wire of the coil is pulled out, the durability of the vibration actuator can be improved. Further, by substantially filling the coil fixing portion of the vibrating body with the filler, the rigidity of the vibrating body can be improved, and a sound with a higher sound pressure can be output.

As described above, the present invention has a great effect on the output characteristics, reliability, and productivity of a vibration actuator.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a vibration actuator according to a second embodiment of the present invention.

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

FIG. 4 is a sectional view showing a vibration actuator according to a fourth embodiment of the present invention.

FIG. 5 is a diagram comparing output characteristics of the first embodiment of the present invention and a conventional vibration actuator.

FIG. 6 is a sectional view showing an example of a conventional vibration actuator.

FIG. 7 is a sectional view showing another example of a conventional vibration actuator.

[Explanation of symbols]

31, 41, 51, 61, 101, 201 Yoke 32, 42, 52, 62, 102, 202 Permanent magnets 33, 43, 53, 63, 103, 203 Plates 34, 44, 54, 64, 104, 204 Suspension 35 , 45, 55, 65, 105, 205 Vibrators 36, 46, 56, 66, 106, 206 Coils 36a, 46a, 56a, 66a, 106a, 206a
Lead wire lead-out part 37, 47, 57, 67, 107, 207 Central axis 38, 48, 58, 68, 108, 208 Vibration transmission part 39, 49, 59, 69, 109, 209 Coil fixing part 40, 50, 60 , 70, 110, 210 Stoppers 71, 81, 91 Filler A Vibration actuator according to Embodiment 1 of the present invention B Conventional vibration actuator

Claims (6)

[Claims] 1. A magnetic circuit comprising a permanent magnet, a coil disposed in a gap of the magnetic circuit, a diaphragm to which the coil is attached and a driving force is given by the coil, and a flexible spring. In a vibration actuator having an electroacoustic transducer including a vibration transmitting unit that flexibly supports the magnetic circuit via a suspension, a concave coil fixing unit is provided on the vibrator, and the coil is attached to the coil fixing unit. A vibration actuator characterized by being embedded and fixed. 2. The coil according to claim 1, wherein the coil is fixed to the vibrating body by inserting the coil into the coil fixing part, filling the coil fixing part with a filler, and curing the filler. Vibration actuator. 3. The vibration actuator according to claim 2, wherein the coil completely covers the coil. 4. The vibration actuator according to claim 2, wherein the filler is filled so that the filler does not touch the lead wire lead-out portion of the coil. 5. The vibration actuator according to claim 2, wherein the coil fixing portion is almost completely filled with the filler. 6. The vibration actuator according to claim 2, wherein the filler is an ultraviolet curable resin.