JPH023290B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a capacitor.

Some of the above capacitors have a structure in which a dielectric material with a substrate of film, paper, etc. is wrapped around a synthetic resin tube or a core made of a cylindrical core made of a film, paper, etc. In order to take out the electrodes, a so-called metallization process is performed in which a conductive metal is thermally sprayed on both sides of the dielectric.

However, in this case, the sprayed metal is deposited not only on the side surfaces of the dielectric but also on the end surfaces and inner and outer surfaces of the winding core, which has the drawback of impairing insulation and voltage resistance.

In view of this, the present invention makes it possible to remove the sprayed metal attached to the end of the winding core, and aims to increase the electrical insulation resistance between both electrodes by removing the sprayed metal, and to ensure that there is no abnormality in the withstand voltage. It is something.

Hereinafter, embodiments of the method of the present invention will be described based on the drawings.

Example 1 This example uses a molded synthetic resin tube as the winding core, and is shown in FIGS. 1 to 4. A capacitor element A1 is formed by winding the dielectric material 2, whose substrate is plastic film or paper, on the winding core 1 a required number of times using well-known means.

(FIG. 1) Next, a conductive metal is thermally sprayed on both sides of the capacitor element A1 to take out the electrodes to form a thermally sprayed metal layer 3. (FIG. 2) After the thermal spraying process, the winding core is The end surfaces 1a, 1a of
Remove the sprayed metal layer attached to (Figure 3),
As a result, a capacitor A shown in FIG. 4 is obtained.

According to the experimental results, when the sprayed metal remains attached to the end face of the winding core 1, there is a short circuit between the two electrodes, and by removing the sprayed metal from both end faces, the insulation resistance, withstand voltage, etc. A predetermined value can be obtained. In addition, almost the same results were obtained even when only one side of the winding core 1 was removed.

Embodiment 2 This embodiment uses a winding core in which a thin film-like material such as paper or film is wound, and is shown in FIGS. 5 to 8.

When the winding core 11 is used, grinding as in Example 1 will only crush the end face of the winding core, making it difficult to reliably remove the sprayed metal, and the metal may enter the gaps between the layers and remain. This may cause damage to the insulation resistance.

Therefore, in this embodiment, the dielectric material 2 is wound around the winding core 11 to form the capacitor element B1. (Fig. 5) Next, both ends 11a, 11a of the winding core 11 are impregnated with a penetrating hardening agent, such as an epoxy resin, to form a penetrating hardening layer 12 (Fig. 6). Insertion into the interlayer is prevented, and the end face is hardened. After that, conductive metal is thermally sprayed in the same manner as in the previous example to form the thermally sprayed metal layer 13.
(Fig. 7), and then grinding both end faces of the winding core 11 with an appropriate grinding tool (not shown) to remove the sprayed metal layer adhering to the end faces of the winding core 11.
Capacitor B shown in the figure is obtained.

In this case, the permeable hardened layer 1 on the winding core 11
The forming process 2 may be performed before the dielectric 2 is wound.

Example 3 In the previous example, one method of manufacturing a capacitor was explained in which a film such as paper or a synthetic resin film was wound to form a core, but this example shows another manufacturing method, in which a film such as a synthetic resin film is wound. A winding core 21 formed by winding a film such as a membrane is wound around a dielectric 2 to form a capacitor element C1 (FIG. 9), as in each of the above examples. Next, both end surfaces 21a, 21a are welded using a heater or the like to form a welding layer 21 on the end surfaces.
b, 21b (FIG. 10) to securely fill in the gap between the film layers on the end face. A conductive metal is thermally sprayed on both sides of the capacitor element C1 which has been subjected to the welding treatment to form a thermally sprayed metal layer 22 (FIG. 11), and then the end surfaces are ground with a grinding tool in the same manner as in Example 1. (not shown) and grind the winding core 21.
A capacitor C is obtained by removing the sprayed metal layer attached to the end face of the capacitor C.

In this case as well, the above welding process may be performed before the dielectric 2 is wound around the winding core 21.

As described above, according to the present invention, after a sprayed metal layer is formed on both end faces of the capacitor element by metal spraying treatment for electrode extraction, the sprayed metal layer attached to the end of the winding core is removed. , it is possible to prevent a short circuit between the two poles of the capacitor.

By making the winding core protrude from the dielectric layer formed by the winding and lamination, it is easier to remove the sprayed metal layer on the end of the winding core, which improves productivity.
This has the advantage of being able to provide a capacitor with excellent electrical characteristics at a low cost.

[Brief explanation of drawings]

The figures illustrate embodiments of the present invention, and Figures 1 to 4 relate to Example 1. Figure 1 is a longitudinal cross-sectional view of a capacitor element, and Figure 2 is an explanatory diagram of a metal thermal spraying process. , Fig. 3 is an explanatory diagram of the procedure for grinding the end face of the winding core, Fig. 4 is a longitudinal sectional view of the capacitor, Figs. 5 to 8 relate to Example 2, and Fig. 5 is a longitudinal sectional view of the capacitor element. FIG. 6 is an explanatory diagram showing how to apply a peeling member, and FIG. 7 is an explanatory diagram showing a process of metal spraying. FIG. 8 is a longitudinal sectional view of the capacitor, FIGS. 9 to 12 relate to Example 3, FIG. 9 is a longitudinal sectional view of the capacitor element, and FIG. 10 shows a state in which a welding layer is formed on the end face of the winding core. An explanatory diagram, FIG. 11 is an explanatory diagram showing the metal sprayed, and FIG. 12 is a longitudinal sectional view of the capacitor. 1, 11, 21... core, 2... dielectric, 3,
13, 22...sprayed metal layer, A1, B1, C1...
...Capacitor element, A, B, C...Capacitor.

Claims (1)

[Claims] 1. A method for manufacturing a capacitor formed by using a synthetic resin cylinder or wound film, paper, etc. as a core, and winding and laminating a dielectric material on the core, in which the dielectric material is wound on the core. , forming a capacitor element protruding from the side surface of the wound dielectric material at the end of the winding core, performing metal spraying treatment on both sides of the capacitor element for taking out the electrodes, and then spraying metal adhering to the end face of the winding core. A method for manufacturing a capacitor, characterized in that the layer is removed by grinding.