JPS622872Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a reinforcing structure for a rectangular voice coil bobbin that drives a plane diaphragm.

The rectangular voice coil bobbin has a rectangular pipe shape, and one end of the rectangular voice coil bobbin is fixed to the center of the flat diaphragm to form a thin speaker. In this case, the shape of the voice coil bobbin is required because the outer shape of the flat diaphragm is square, but as a characteristic of the shape itself, the strength at the corners is high, but the strength at each side is extremely weak. It becomes a thing. For this reason, in the conventional rectangular voice coil bobbin, as shown in the plan view and cross-sectional view of the main part in FIGS. 1a and 1b,
Small pieces of reinforcing members 2a, 2b, 3a, 3 are attached to the inner and outer surfaces of a part of the central portion of each side 2 to 5 of the rectangular voice coil bobbin 1 having a regular square shape.
b, 4a, 4b, 5a, 5b for reinforcement, or as shown in Figure 2 a, b, each side 2~
Reinforcing members 2a, 2b, 3a, 3b, 4 provided in 5
A, 4b, 5a, and 5b each extending over substantially the entire length of each side 2 to 5 are used. Note that 6 is a voice coil wound around the lower end of the rectangular voice coil bobbin 1.

However, in the above-mentioned conventional rectangular voice coil bobbin, since the inner and outer reinforcing members have the same shape, if the reinforcing members are short with respect to the side length of the bobbin, as shown in FIG. In addition, as shown in FIGS. 2a and 2b, if the reinforcing member becomes long, the weight will increase significantly and the sensitivity will decrease. Furthermore, if a reinforcing member is provided only on one side in order to solve the weight problem, it has the disadvantage of producing the opposite effect.

Therefore, an object of this invention is to provide a rectangular voice coil bobbin that can reduce the weight of the reinforcing member and sufficiently increase the strength of the bobbin.

In order to achieve this purpose, this idea
The reinforcing members provided along the inside and outside of the rectangular voice coil bobbin have different lengths.

Hereinafter, the rectangular voice coil bobbin according to this invention will be explained in detail with reference to the drawings.

FIGS. 3a and 3b are a plan view and a cross-sectional view of essential parts showing an embodiment of the rectangular voice coil bobbin according to this invention, and the same parts as in FIGS. 1a and 1b are indicated using the same symbols. In the same figure, 2c, 3
c, 4c, and 5c are reinforcing members provided along the inner part of each side 2 to 5, and the difference from Fig. 1 a, b is that only the inner reinforcing members are made longer. It is.

In this way, short reinforcing members 2a, 3a, 4a, 5a are provided on the outside of each side constituting the rectangular bobbin 1, and long reinforcing members 2c, 3c, 4c, 5c are provided on the inside.
By providing this, sufficient reinforcing strength can be obtained and generation of abnormal mode vibrations can be prevented. In other words, the outer short reinforcing members 2a, 3a, 4a, 5a
If it is made of only one material, the weight will be reduced as described above, but the reinforcing strength will be insufficient and it will not be able to withstand large input signals. Further, if a reinforcing member is provided only on one side, an abnormal vibration mode will occur in the bobbin 1 as shown by the dotted line, and the voice coil 6 will come into contact with a plate (not shown) and generate abnormal noise. On the other hand, as described above, the reinforcing member 2 is long along the inside of each side 2 to 5 of the bobbin 1.
By providing a, 3a, 4a, and 5a, the bobbin 1 is sufficiently reinforced and can withstand even when a large input is supplied. Furthermore, since the reinforcing members are provided on both the inner and outer sides of each side, the vibration modes cancel each other out, as shown in FIG. 5, and the bobbin 1 is prevented from vibrating in an abnormal mode. The problem of contact with a plate (not shown) is completely solved. Furthermore, in the above configuration, each outer reinforcing member 2a, 3a,
Since 4a and 5a are short, the overall weight is sufficiently lighter compared to the case shown in FIGS. 2a and 2b, and there is no problem of deterioration of characteristics.
In the embodiment of this invention, it was optimal to select the length of the inner reinforcing member to be 40 to 50% of the side length of the bobbin. Furthermore, in the above embodiment,
Although the cross-sectional shapes of the reinforcing members provided on the inside and outside are the same, this invention is not limited to this.
It goes without saying that the shape and cross-sectional dimensions of the inner and outer reinforcing members may be different.

As explained above, the rectangular voice coil bobbin according to this invention has reinforcing members along the inside and outside of each piece, and the lengths of the inside and outside reinforcing members are different, so it is lightweight yet large. Provides sufficient strength to withstand input. Further, according to this invention, it is possible to prevent abnormal vibrations of the bobbin, and there are various excellent effects such as no generation of abnormal noise caused by the voice coil contacting the plate.

[Brief explanation of the drawing]

1a, b and 2 a, b are a plan view and a sectional view showing an example of a conventional rectangular voice coil bobbin. FIGS. The sectional views, FIGS. 4 and 5, are sectional views of main parts showing vibration modes of the bobbin. 1...Bobbin, 2-5...Side, 2a, 2c, 3
a, 3c, 4a, 4c, 5a, 5c...Reinforcement member, 6...Voice coil.

Claims (1)

[Scope of utility model registration request] In a rectangular voice coil bobbin used in a speaker having a flat diaphragm, reinforcing members are provided along the inner and outer surfaces of each side constituting the rectangular voice coil bobbin, and the length of the reinforcing members provided on the inner and outer surfaces in the side length direction is A rectangular voice coil bobbin characterized by different shapes.