JPS5930512Y2 - film capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a film capacitor that improves the load strength of a leader wire and is easy to manufacture.

Conventionally, in so-called lead-insertion type film containers, in which a lead wire is attached to an electrode foil narrower than the dielectric film by welding or the like and then wound, the lead wire may come off due to a slight load on the lead wire, or the welding point may break. In some cases, the capacitor may become detached and lose its function.

This phenomenon is especially true for styrene capacitors, which are self-sealing capacitors that utilize the shrinkage and fusing properties of dielectric films by heating without a resin exterior, or polypropylene films or polyfluoride films stretched at an appropriate stretching ratio. This problem often occurs in capacitors that use vinylidene film as a dielectric film and have a hard exterior by selecting a heat treatment temperature.

As a measure to improve the load strength of the leader wire of this type of capacitor, (1) In the invention of Japanese Patent Publication No. 35-8370, as shown in FIGS. 4 and 5, the leader wire has a flattened head during winding operation. (a) Apply conductive resin 16 to both sides of the flat part at the tip of the leader line 14 in advance, and (b) Glue a protective film piece 12 made of resin to one side of the flat part of the leader line 14. (C) Next, the flat part of this leader wire 14 is inserted between the electrode foil 13 and the dielectric film 11, and the flat part 1
The side where the protective film piece 12 of No. 5 is not attached is attached to the electrode foil 13.
The dielectric film 11 is adhered to the film and then rolled or heated to fuse the dielectric film 11.

However, although this method improves the load strength of the leader wire, it adds the troublesome work steps (a) and (b) above, and this work is difficult because it is prone to unevenness and mistakes. However, the cost was also high.

The present invention aims to improve the drawbacks of these conventional self-sealing capacitors, and will be described below with reference to the drawings showing embodiments.

In Figure 1, 1, 1' are the main dielectric films, 3, 3'
4 is a narrower electrode foil than the main dielectric film 1, 1';
, 4' are lead wires made of conductive metal that are connected and fixed on the electrode foil 3.3' at their flat portions by spot welding or the like.

2, 2' are suitably stretched, and the main dielectric films 1,
1' shrinks and melts at a lower temperature than the main dielectric film 1,
1', an auxiliary plastic film piece that has good adhesion when heated and melted to the electrode foils 3, 3' and lead wires 4, 4', and can be inserted above or below each lead wire 4, 4'. be.

The auxiliary plastic pieces 2, 2' are the main dielectric films 1, 1
At least 1m in the direction of the lead line 4, 4' with respect to
The base of the leader line of the element is exposed by exposing the element for more than 100 m and then being rolled up together with the main dielectric films 1, 1' and the electrode foils 3, 3', and then heat-treated at a temperature higher than the melting point of the auxiliary plastic films 2, 2'. By shrinking and solidifying the auxiliary plastic films 2, 2', a container as shown in FIG. 2 is obtained.

The leading lines 4 and 4' are drawn in the same direction as shown in Figure 2.
Alternatively, it may be in the opposite direction as shown in FIG.

With this configuration, the auxiliary plastic films 2, 2' are melted and bonded around the lead wires 4, 4', and are also bonded over a wide area to the electrode foil 3 and the main dielectric films 1, 1'. The load strength of 4 and 4' increases dramatically.

Note that only one of the plastic film pieces 2 and 2' may be inserted, and its width is the same as that of the main dielectric films 1 and 1.
Even if the width is made to match the width of , the load strength of the leader line is improved to some extent.

As an embodiment of the present invention, the main dielectric films 1 and 1' are polypropylene 6μ films (Torefan BO-2300 manufactured by Toshi Co., Ltd.) with a melting temperature of 170°C, and the electrode foils 3°3' are aluminum foils with a thickness of 6.0°C. Use 5μ, leader line is 0.5φm
m solder plated CP wire, the auxiliary plastic film is a 50 μ thick styrene film (Mitsubishi Plastics Co., Ltd. Styrex, Type C) with a melting temperature of 120°C.
As a result of heat treatment at 35℃ for 1 hour, the size was 9φ×2.
A capacitor of 2 mm and a capacitance of about 0.047 μm was obtained.

Film capacitor and plastic piece according to the present invention 2,
When a load is applied to each of the lead wires 4 and 4' of a conventional film capacitor that does not use 2', the load value at the point in time when the lead wires are removed was tested for each of 10 samples (lead φ = Q, 5 mm). As a result, plastic film pieces 2,2
0.5 kg of the one that does not use 4
．． An average value of 11 kg was obtained.

The same average weight for the capacitors in which the plastic film pieces 2, 2' were not exposed to the outside was 1.58 kg.

As explained above, in order to improve the load strength of the lead wire, the present invention applies conductive resin to both sides of the flat part of the lead wire, and individually adheres a piece of protective film to one side of the flat part of the lead wire. Since there is no troublesome work such as drying, production is easy and costs are low.

In addition, unlike conventional methods, there is no need to apply a resin exterior or apply adhesive to the base of the leader line, and this can be done during the winding process, contributing to improved efficiency and cost reduction. However, it is large.

[Brief explanation of the drawing]

FIG. 1 is an exploded view of the main parts of a film capacitor according to the present invention, and FIGS. 2 and 3 are completed views thereof. Figures 4 and 5 show conventional examples. Figure 4 is a perspective view of a lead wire joint during capacitor manufacturing, and Figure 5 shows a state in which the lead wire is inserted between the electrode foil and the dielectric. Cross-sectional view. 1.1': main dielectric film, 2.2': auxiliary plastic film piece, 3.3': electrode foil, 4.4': leader wire.

Claims (1)

[Claims for Utility Model Registration] Electrode foils 3 and 3' provided with lead wires 4 and 4', respectively, and a main dielectric material having heat-shrinkable properties, heat-fusion properties, or both, which is wider than the electrode foils. In a film container in which films 1 and 1' are alternately stacked and wound and solidified by heat treatment, auxiliary plastic films 2 and 2', which shrink and melt at a lower temperature than the main dielectric films 1 and 1', are pulled out, respectively. line 4,
Electrode foils 3, 3' and main dielectric film 1 to cover 4'.
, 1', intervening in a fused state with both of them, and
Each negative side is 1 mm from the side of the main dielectric film.
The leader line extends and protrudes in the direction of the leader line 4.4'
A film capacitor characterized by being fused and bonded to the surrounding area.