JPH0739197U - Speaker - Google Patents

Abstract

(57) [Abstract] [Purpose] The object is to eliminate the adhesion failure of the dust cap without impairing the braking of the speaker with a simple configuration. A diaphragm 6 is fixed to the front surface of a frame 5, a voice coil 7 is attached to the center of the diaphragm 6, and the voice coil 7 is filled with a magnetic fluid 9 to form a magnetic circuit 4.
Placed in the magnetic gap of. Then, the opening area of 0.8 mm ² ～2.4Mm dust gap 10 having a small hole 11 of ² bonded and fixed to the distal end of the voice coil 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a speaker having a magnetic gap filled with a magnetic fluid.

[0002]

[Prior art]

 Conventionally, as this type of speaker, it has been proposed to fill the magnetic gap of the magnetic circuit with a magnetic fluid for the purpose of braking the speaker, improving heat dissipation of the voice coil, and improving the magnetic flux density.

However, in this speaker, the space formed by the diaphragm, the dust cap, and the magnetic fluid is hermetically sealed. Therefore, when the dust cap is bonded and fixed to the central portion of the diaphragm, the dust cap floats or is displaced due to the enclosed space, resulting in adhesion failure.

Further, there is a problem that the dust cap is deformed when the atmospheric pressure in the space is smaller than the outside.

Therefore, as a solution to this problem, a speaker in which a diaphragm is provided with a hole for eliminating the airtightness of the space has been proposed.

Although this speaker solves the above problem, it has a large hole because it is aimed only at eliminating the above-mentioned airtightness. Therefore, this speaker has a structure in which the vibration of the vibration plate is less likely to be damped, which causes a problem that the voice coil comes into contact with the magnetic circuit at the time of a large input.

[0007]

[Problems to be solved by the device]

 The present invention has been made in order to easily solve the problems described above, and an object thereof is to maintain the initial performance without impairing the braking of the speaker, and to prevent the adhesion failure and the deformation of the dust cap. To do.

[0008]

[Means for Solving the Problems]

According to the present invention, a diaphragm is fixed to the front surface of a frame, a voice coil is attached to the center of the diaphragm, and the voice coil is placed in a magnetic gap of a magnetic circuit filled with magnetic fluid. to the spin chromatography mosquitoes fitted with dust cap, an opening area to the dust cap is to provide a loudspeaker having a small hole of 0.8mm ² ~2.4mm ^2.

[0009]

[Action]

Opening area dust cap by providing the small hole of 0.8mm ² ~2.4mm ^2, joined by moderate braking to the amplitude of the vibration plate, preventing contact with the magnetic circuit of the voice coil. Moreover, since the airtightness of the space is hindered, the dust cap is prevented from floating when adhering and fixing the dust cap.

[0010]

【Example】

 An embodiment of the speaker of the present invention will be described with reference to FIG.

In FIG. 1, 1 is an upper plate, 2 is a donut-shaped magnet, 3 is a bottom plate, and these constitute a magnetic circuit 4. Reference numeral 5 is a frame made of metal, and the diaphragm 6 is fixed to the outer peripheral portion of the frame 5 with an adhesive. A voice coil 7 is fixed to the center of the diaphragm 6 with a rubber adhesive, and is connected to the bottom of the frame 5 via a damper 8 and inserted in the magnetic gap of the magnetic circuit 4. Further, the magnetic fluid 9 is injected into the magnetic gap of the magnetic circuit 4, and plays the role of radiating the voice coil 7 and improving the magnetic flux density of the magnetic circuit 4.

Reference numeral 10 is a dust cap that contributes to dust emission as well as sound emission, and this dust cap 10 is provided with four small holes 11.

Next, Table 1 shows experimental results regarding the size of the small holes 11 and the adhesiveness of the dust cap 10.

In the experiment, a speaker with a diameter of 10 cm was used.

[0015]

[Table 1]

From Table 1, the evaluation of the adhesiveness of the dust cap 10 among Examples A to P is good in Examples D, F, G, H, I, J, K, L, M, N, O, and P. Adhesion could be performed, but in other examples, adhesion failure such as eccentricity of the dust cap 10 occurred.

Further, Table 2 shows the results of the durability test under the condition of 100 w for 96 hours.

[0018]

[Table 2]

From Table 2, good results were obtained in Examples C, D, F, I, J, and K, but in other examples, the magnetic fluid 9 was scattered due to the excessive amplitude of the diaphragm 6, and The temperature rise of the voice coil 7 was recognized.

From these facts, among the experimental ones, the effects were recognized in Examples D, F, I, J, and K. Therefore, the opening area of the small holes 11 of the dust cap 10 was 0.8 mm ² to A range of 2.4 mm ² is considered suitable.

It should be noted that, although the number of the small holes 11 was up to four in this experiment, the present invention is not limited to this number.

[0022]

[Effect of device]

According to the present invention, a diaphragm is fixed to the front surface of a frame, a voice coil is attached to the center of the diaphragm, and the voice coil is placed in a magnetic gap of a magnetic circuit filled with magnetic fluid. to the spin chromatography mosquitoes fitted with dust cap, since the opening area to the dust cap is provided a speaker having a small hole of 0.8mm ² ~2.4mm ^2, with a simple configuration, it can impair the braking speaker In addition, the adhesion failure of the dust cap can be eliminated.

[Brief description of drawings]

FIG. 1 is a diagram showing a speaker of the present invention.

[Explanation of symbols] 1 top plate 2 magnet 3 bottom plate 4 magnetic circuit 5 frame 6 diaphragm 7 voice coil 8 damper 9 magnetic fluid 10 dust cap 11 small hole

Claims (1)

[Scope of utility model registration request] 1. A vibration plate is fixed to a front surface of a frame, a voice coil is attached to a central position of the vibration plate, and the voice coil is arranged in a magnetic gap of a magnetic circuit filled with a magnetic fluid. the speaker fitted with a dust cap to the tip, the speaker, characterized in that the opening area on the dust cap is provided with a small hole of 0.8mm ² ~2.4mm ^2.