JPH0753356Y2 - Electromagnetic sound transducer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electromagnetic acoustic transducer used for pagers and the like, and more particularly to a structure for preventing sound leakage from the side opposite to the sound outlet.

(Prior Art) An electromagnetic acoustic transducer includes a lower case 1 and an upper case 2 having an opening 2a which is a sound outlet, as shown in an exploded perspective view of FIG. 3 and a sectional view of FIG. A permanent magnet 3 and a lower case element body 4 which are incorporated in the lower case 1, and an upper case 2
And the diaphragm 5 made of a magnetic material. The lower case body 4 includes a resin base 7 having a terminal pin 6 fixed therethrough, a yoke 8 integral with the base 7, a pole 9 made of a magnetic material fixed to the yoke 8, and the pole 9 And a winding 10 whose both ends are fixed to both side protruding portions 6a of the terminal pin 6. Permanent magnet 3 and lower case body 4
Is fixed to the lower case 1 with an adhesive or the like.
The upper case 2 and the upper case 2 are bonded to each other with an adhesive 12. York 8
The base 7 has a shape in which both side portions a corresponding to the projecting portions 6a of the terminal pins 6 are linearly removed in order to entangle both ends of the winding 10.

When manufacturing such an electromagnetic acoustic transducer, the base 7, that is, the lower case element body 4 is fixed to the lower case 1. Therefore, in the state where the terminal pin 6 side shown in FIG. The base 7 is fixed to the lower case 1 by filling the curable resin 11 on the base 7 and heating to cure it, and the resin 11 is filled in the gap to prevent sound leakage.

(Problems to be solved by the invention) However, according to the above conventional structure, the thermosetting resin
However, due to the gap between the base 7 and the lower case 1, the terminal pin 6
There is a problem in that the end portion of the winding 10 made of a thin wire may be disconnected due to thermal expansion of the terminal pin 6 or the yoke 8 due to heat reaching the end portion 6a.

The present invention has been made in view of the above problems, and an object thereof is to provide an electromagnetic acoustic transducer having a structure capable of preventing the occurrence of wire breakage of a winding due to a thermosetting resin that fixes a base and fills a gap.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a resin case with a base on which a winding pole and a yoke integral with the pole are mounted and terminal pins are fixed. Housed inside,
One end of the terminal pin is projected from the outer surface of the base, the end of the winding is fixed to the other end of the terminal pin inside the outer surface of the base, and a thermosetting resin is filled in the gap between the resin case and the base. In an electromagnetic acoustic transducer having a structure for preventing sound from leaking from the opposite side of the sound outlet, a resin sheet fitted to the inner surface of the resin case is overlaid on the outer surface of the base, and the outer surface of the resin sheet The thermosetting resin for fixing the base is applied.

(Operation) In the present invention, since the resin sheet is stacked on the base as described above, the sheet prevents the thermosetting resin in a fluid state from infiltrating into the winding fixing portion of the terminal pin.

(Embodiment) FIG. 1 is an exploded perspective view showing an electromagnetic acoustic transducer according to an embodiment of the present invention before assembly, and FIG. 2 is a longitudinal sectional view showing a structure of a product after assembly. The same reference numerals as those in FIG. 4 and FIG. 4 indicate the same constituent members. Reference numeral 13 denotes a resin sheet provided by the present invention. The sheet 13 has a circular shape having a diameter substantially matching the inner diameter of the lower case 1, and is attached to the base 7 so as to close the opening of the lower case 1. .
The sheet 13 is provided with holes b through which the terminal pins 6 pass.
14 is a thermosetting resin.

When fixing housing parts such as the base 7 to the lower case 1,
The lower case body 4 is housed in the lower case 1, and the terminal pin 6 is turned upside down. The sheet 13 is put on the base 7 through the holes b and c in the terminal pin 6, and the thermosetting resin 14 is applied. To heat. As a result, the thermosetting resin 14 is cured. When the thermosetting resin 14 is in a fluid state, the presence of the sheet 13 prevents the thermosetting resin in the fluid state from penetrating into the interior, and the thermal expansion of the terminal pins 6 and the resin 14 causes the winding to be wound.
It is possible to prevent the end portion of 10 from being broken.

Although the resin case is divided into the upper case 2 and the lower case 1 and combined with each other in the above-described embodiment, these may be formed with the molding material.

(Effect of the Invention) According to the present invention, the resin sheet is placed on the outer surface of the base of the electromagnetic acoustic transducer to prevent the resin from leaking into the interior when the base is fixed by the thermosetting resin. It is possible to prevent disconnection in the vicinity of the fixed portion of the winding to the terminal pin when fixing the base with resin.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an electromagnetic acoustic transducer according to the present invention before assembly, FIG. 2 is a longitudinal sectional view of the product, and FIG. 3 is an example of a conventional electromagnetic acoustic transducer. FIG. 4 is an exploded perspective view showing a state before assembly, and FIG. 4 is a longitudinal sectional view of the product. 1: Lower case, 2: Upper case, 3: Permanent magnet, 4: Lower case body, 5: Vibration plate, 6: Terminal pin, 7: Base, 8: Yoke, 9: Pole, 10: Winding, 12 : Adhesive, 13: Resin sheet, 14: Thermosetting resin

Claims (1)

[Scope of utility model registration request] 1. A base on which a pole having a winding and a yoke integral with the pole are mounted and a terminal pin is fixed is housed in a resin case, and one end of the terminal pin is projected from the outer surface of the base. , Fixing the end of the winding to the other end of the terminal pin inside the outer surface of the base, filling the gap between the resin case and the base with a thermosetting resin, and removing the sound from the opposite side of the sound outlet. In an electromagnetic acoustic transducer having a structure for preventing leakage, a resin sheet fitted to the inner surface of the resin case is laid on the outer surface of the base, and the thermosetting resin for fixing the base is applied to the outer surface of the resin sheet. An electromagnetic acoustic transducer characterized by the above.