JPS6238342Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a noise filter, and more particularly to a structure of a ground connection terminal of a noise filter in which filter components are housed in a cylindrical metal case.

A noise filter for noise prevention consists of a circuit constructed by connecting a lead wire such as a chiyoke coil or capacitor to a plate-shaped terminal embedded in an insulating terminal holding plate that also serves as a cover plate, and a cylindrical shaped terminal that also serves as a support for the terminal holding plate. The insulating plate wrapped around the insulating plate is stored in a bottomed cylindrical metal case attached to the inner wall, and the ground end is directly connected to the case.After filling the case with the required amount of insulating resin, connect the open end of the case to the terminal. It is made by constricting along the outer edge of the retaining plate.

If the case is made of aluminum, it is difficult to solder the ground end to the case, so for example, as shown in Figure 1, a small hole 2 is made in the side wall of the case 1 and a bolt 3 is inserted through the case to connect the ground end to the case. 4
Connect the case 1 and the ground end 4 by passing the connecting terminal 5, which has a circular hole connected to the bolt 3, through the bolt 3 and tightening it with the nut 6, or by connecting the ground end 4 to the previously attached connection terminal 5 by soldering. are connected. However, in this case, there is a problem in that the work of attaching the connection terminals and the soldering work inside the case 1 requires a lot of man-hours and time, and it is difficult to check the progress afterwards.

The present invention aims to eliminate the above-mentioned drawbacks, and aims to provide a noise filter that can efficiently and reliably connect the ground end to the case.

The present invention is a noise filter in which the circuit elements constituting the filter circuit are housed in a cylindrical aluminum case, and the cover body is an insulating terminal holding plate in which plate-shaped terminals for external connection are embedded. A ground end connection terminal is planted near the outer edge of the case, and a projecting piece extending in the axial direction from the upper open edge of the case is provided integrally with the case, and this projecting piece is bent and connected to the ground end connection terminal on the outside of the case. It is characterized by

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a side view of one embodiment of the noise filter according to the present invention, and FIGS. 3a and 3b are exploded perspective views thereof.

The insulating terminal holding plate 7 has a truncated conical shape with an outer peripheral edge inclined toward the axis, and also serves as a cover plate for the cylindrical case 1 .

In Fig. 3a, four external connection plate terminals 8
is mounted on the terminal holding plate 7, and a plate-shaped terminal 9 for ground end connection is mounted at a required position near the outer periphery.

The plate-shaped terminals 8 and 9 protrude below the holding plate 7 and are bent into an L shape (not shown), and in this part there are provided a check coil 10, which constitutes a filter circuit.
A lead wire and a ground end of the capacitor 11 and the like are connected below the terminal holding plate 7.

The cylindrical case 1 shown in FIG. 2 is made of aluminum and has a mounting bolt 12 integrally provided on its bottom surface, and this bolt is attached to a chassis or the like and grounded. As shown in FIG. 3b, a projecting piece 13 extending in the axial direction is integrally provided on a part of the upper opening edge of the case 1. An elliptical through hole 14 is provided near the tip of the protruding piece 13.

First, the circuit element 1 is placed inside the case 1 fitted with the insulating inner case 15 which is also a support member for the terminal holding plate 7.
0 and 11 are injected, and then the circuit elements 10 and 11 are assembled and connected to the filter circuit, and the terminal holding plate 7 is connected to the earth end connection terminal 9 and the projecting piece 13 of the case 1. After the insulating resin is solidified, the terminal holding plate 7 is fixed to the open end of the case 1 along the outer periphery of the terminal holding plate 7. Bend the protruding piece 13 into an L shape in the middle, and then bend the protruding piece 13 near its base so that this bent part comes into contact with the ground end connection terminal 9.
is bent inward, and the earth end connecting terminal 9 and the protruding piece 13 are joined using the screw 16 and nut 17 to make a noise filter.

As is clear from the above description, the noise filter according to the present invention has a ground end connection terminal provided on the terminal holding plate at a location where there is no problem in connection between the external connection plate terminal and the external circuit, and a protrusion provided on the case. This makes it possible to reliably connect the case and the ground end on the outside of the case, which is useful in reducing costs and improving reliability.

[Brief explanation of the drawing]

Fig. 1 shows a sectional view of the ground end connection structure of a conventional noise filter, Fig. 2 is a side view of an embodiment of the noise filter according to the present invention, and Fig. 3a shows the noise filter circuit before being housed in a case. Fig. 3b shows a perspective view of the case. 1... Aluminum cylindrical case, 3... Bolt, 4
...Earth end, 7...Insulating terminal holding plate, 8...
Plate terminal for external connection, 9...Terminal for earth end connection, 10...Chiyoke coil, 11...Capacitor, 12...Mounting bolt, 13...Protrusion piece, 15...
...insulating paper, 16...screw, 17...nut.

Claims (1)

[Scope of utility model registration request] External connection terminals are planted on the lid plate of the cylindrical case that houses the electronic components that make up the noise filter.
A grounding terminal is embedded in the peripheral edge of the cover plate, a protruding piece extending from the opening edge of the cylindrical case in the axial direction of the case is provided integrally with the case and close to the grounding terminal, and the protruding piece is provided integrally with the case and close to the grounding terminal. A noise filter consisting of one piece and a ground terminal connected.