JPS6238345Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a noise filter used as a power line filter that is inserted into a power line to remove noise.

Generally, in this type of noise filter, a box-shaped metal case is often used to shield filter elements such as coils and capacitors. In this case, the structure for attaching the metal case lid to the box-shaped metal case becomes a problem.

Conventionally, a box-shaped metal case and a metal case lid have been generally soldered-sealed over the entire surface or integrated with screws. However, solder sealing is a very time-consuming process, and screwing increases the number of parts and requires tapping, which has the disadvantage that shavings from tapping remain inside the case.

In consideration of this point, the applicant has proposed that the box-shaped metal case and the metal case lid be integrated by spot welding.

FIG. 1 shows an example of a case structure using conventional spot welding. In this figure, a terminal plate 3 having terminals 2 is fitted into a box-shaped metal case 1, and a metal case lid 4 has a raised bottom structure with its peripheral edge folded back so as to be in contact with the inner surface of the box-shaped metal case 1. The mounting portions 5 at both ends have mounting holes 6, respectively. In this case, the box-shaped metal case 1 and the metal case lid 4 are integrated by spot-welding the sides of the box-shaped metal case 1 and the folded portion of the metal case lid 4 using a spot welding machine at multiple locations. integrated by.

However, with the structure shown in FIG. 1, the metal case lid 4 has a raised bottom structure, so the mounting holes 6
When mounted on an electronic device, etc., the heat generated from the coils and capacitors housed inside the case cannot be sufficiently released to the mounting device chassis. Therefore, the structure shown in FIG. 1 is inappropriate when a component that generates a large amount of heat is housed inside the case.

In view of the above points, the present invention has been developed with a box-shaped metal case 1.
The present invention aims to provide a noise filter that can be welded together by spot welding and that also has good heat dissipation by adding some innovation to the structure of the metal case lid that closes the opening of the metal case.

Embodiments of the noise filter according to the present invention will be described below with reference to the drawings.

In Figures 2 and 3, a box-shaped metal case 1
Notches 12 are formed on both end surfaces of the terminal board 1, and terminal plate holding claws 13 are formed adjacent to the notches 12. Here, the notch 12 has the shape of an inverted trapezoid that expands from the bottom side toward the opening side, and both sides 14 thereof are tapered sides. Insulating paper 15 is provided inside such a box-shaped metal case 11. On the other hand, the terminal plate 16A made of insulating resin,
16B has an inverted trapezoidal shape with the top side longer than the bottom side and tapered sides on both sides, and the terminal board 1
6A has lead terminals 17A and 17B, and terminal board 1
Lead terminals 17C and 17D are inserted through 6B, respectively. Here, a groove 18 having a U-shaped cross section is formed at the bottom and both sides of the terminal plates 16A, 16B. An interline capacitor 19 is connected between lead terminals 17A and 17B, and lead terminals 17C and
Line bypass capacitor 20A between 17D,
A series connection of 20B is provided, and a capacitor 20
The connection point between A and 20B is grounded to the metal case 11. Lead terminals 17A, 17
A winding 21A and a coil 22A of a common mode chiyoke coil 21 are connected between the lead terminals 17B and 17D, and a winding 21B and a coil 22B of the common mode chiyoke coil are similarly connected between the lead terminals 17B and 17D. The terminal plates 16A and 16B are attached to the notch 1 with a sealing material 23 such as rubber or heat-welding resin interposed between the notch 12 and the groove 18 on the case side.
2, and at the same time capacitors 19 and 2.
Filter elements 0A, 20B and coils 21, 22A, 22B are housed in the box-shaped metal case 1, and with the terminal plates 16A and 16B securely fitted, bend the terminal plate holding claw 13 toward the inside of the case. Fix the terminal plates 16A and 16B so that they do not float up. The metal case lid 24 is integrally formed with linear hollow protrusions 25 that can come into contact with opposing inner surfaces of the box-shaped metal case 11 in the longitudinal direction. Attachment holes 26 are formed at both ends of the metal case lid 24. Such a metal case lid 24 is welded to the case 11 by casting the inside of the box-shaped metal case 11 with insulating resin and then spot-welding, for example, a point P on the side surface of the box-shaped metal case 11.

As explained above, according to the present invention, a metal case lid is formed into a box-shaped metal case by forming a linear hollow protrusion on the metal case lid that can come into contact with one of the inner surfaces of the box-shaped metal case. It is possible to obtain a noise filter that can be welded and that can improve heat radiation from the metal case lid. In this case, the metal case lid can be easily processed by drawing, making it easy to manufacture and improving mass productivity.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing the case structure when performing conventional spot welding, Fig. 2 is an exploded perspective view showing an embodiment of the noise filter according to the present invention, and Fig. 3 is an exploded perspective view showing the case structure when performing conventional spot welding.
The figure is a perspective view of the same. 1, 11... Box-shaped metal case, 3, 16A to 16C... Terminal board, 4, 24... Metal case lid,
6, 26...Mounting hole, 19, 20A, 20B...
Capacitor, 21, 22A, 22B...Coil,
25...Straight hollow protrusion.

Claims (1)

[Scope of utility model registration request] A terminal plate is fitted into a notch of a box-shaped metal case that houses the filter element, and a metal case lid having a linear hollow protrusion that can come into contact with one of the inner surfaces of the box-shaped metal case is attached to the box. A noise filter characterized by being welded to the opening edge of a molded metal case.