JPS58114413A - Condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacitor, in which an electrode foil of a round-circle-wound type capacitor is improved by combining an electrical foil and a dielectric material.

Round edge electrode foils with bent ends of the electrode foils, as shown in FIGS. 1 and 2, have already been used as electrode foils to sandwich the dielectric material of wound type capacitors in order to improve withstand voltage.

Both Figures 1 and 2 show cross sections of these electrode foils.
In FIG. 1, the bent part 1 is formed by continuously bending both ends of the electrode foil in the width direction inward by a certain width.
Therefore, the thickness of the bent portion is doubled.

In addition, in Fig. 2, the bent part l is the electrode foil that is continuously bent inward in order to have a wider width 9, and both bent end surfaces are in contact with each other at the center in the width direction. Therefore, it is formed to have a cross section exactly like that of two stacked electrode foils.

By the way, in the example shown in Fig. 1, the thickness of the bent portion is twice as large in some areas, which makes it difficult to manage assembly dimensions, capacity management, processing management, etc. After immersion in oil, an oil layer is formed, but the thicker the oil layer, the lower the dielectric breakdown voltage, so this portion becomes the weak point of the capacitor's withstand voltage.

The example shown in Fig. 2 is an example of solving the drawbacks of the electrode foil with a bent part shown in Fig. 1.The bent part is wide and the processing becomes difficult. Katana Roe is difficult.

Therefore, in order to eliminate the above-mentioned problem between the electrode foils, the present invention bends both ends of the electrode foil in the width direction, and furthermore, this part is made so that there is no overlap due to the bending of the electrode foil. Round edged electrode foil with the bent end rolled so that it has approximately the same thickness as the part, or only both ends in the width direction rolled to a certain width and half the thickness in the width direction. A capacitor element is formed using a round edged electrode foil or the like which is bent at this portion so that it has approximately the same thickness as the non-overlapping portion.

The implementation of the present invention will be described below.

The embodiment shown in FIG. 3 is a sectional view of a laminated foil processed from the conventional electrode foil of FIG. 1.

In this case, the electrode foil with both ends in the width direction bent is further rolled with a roller to be rolled to the same thickness as the part of the electrode foil 2 that does not overlap due to bending, thereby forming the bent portion 1'. Ru.

In this case, it is necessary to maintain a round edge R on the bending line.

In the embodiment shown in FIG. 4, rolling is carried out by applying roller processing to the thickness of the saliva by the width located inside in the width direction from both ends in the width direction,
Approximately 10 parts of this thickness are bent toward the processing surface to form a bent part 11 having the same thickness as the part of the electrode foil 2 that does not overlap due to bending.

Of course, it is necessary to maintain a round edge R on the bent edge.

In the embodiment shown in FIG. 5, the bent portion 11 is formed by processing the inner side in the width direction from both ends in the width direction so as to be sloped by a certain width, and by bending approximately 100 mm of this sloped surface portion. It is.

Aluminum foil is usually used as the electrode foil.

FIG. 6 shows an embodiment of the present invention, and FIG. 7 shows a partial cross section of the capacitor shown in FIG.

In the figure, 2 is an electrode foil as explained in FIGS. 3, 4, and 5, and 3 is a dielectric material such as paper or plastic film, which is assembled and rolled as shown in the figure. The wound capacitor element 4 is formed by winding.

As shown in Figure 7, the electrode foil is placed only on one side, and as shown in Figures 3 and 4.
Although the electrode foil 2 as shown in the figure or FIG. 5 is used,
The electrode foil 2 shown in FIG. 3 or 4 can also be used as the counter electrode foil 5 with the dielectric 3 in between.

If the capacitor elements 4 wound in this manner are assembled to form a capacitor element assembly and assembled by a widely known conventional method, an oil-immersed capacitor can be obtained. In this case, the capacitor element assembly is as follows. Due to the following reasons, miniaturization is possible.

FIG. 8 shows a partial cross section of a conventional capacitor element in which the widthwise end of the electrode foil is bent inward to form a round edge for the purpose of explaining the formula.

In the figure, the electrode foil thickness is te, and the dielectric thickness is td.

If the thickness of the oil 1 is to, and the total thickness of the electrode foil and dielectric is TD, the capacitor volume Vo41' = k capacitor element thickness.

According to the above formula, the capacitor volume (%) and to/
The relationship t・e (4) is expressed as te=td/10. t
d15. te/2 is shown in the graph of FIG.

As is clear from FIG. 9, for example, t from the indicated line of te=td15. If =0, the volume of the capacitor element assembly will be reduced by about 15%, but considering the actual electrode foil processing accuracy, it is difficult to make to zero. However, even if to/le is about 80%, it is about 10
It can be seen that the volume can be reduced by about 10%, which greatly contributes to miniaturization.

As explained above, according to the present invention, the ends of the electrode foil in the width direction are folded and bent more neatly than those shown in FIG. Since the electrode foil part uses round edged electrode foil processed to the same thickness, it goes without saying that the partial discharge inception voltage at the end can be increased, which is an advantage of bent electrode foil capacitors. This eliminates the oil layer that forms in the non-overlapping part of the folded electrode foil, which is a disadvantage of folded electrode foil capacitors, and improves the dielectric breakdown voltage in this part. By reducing the electrode thickness, the volume of the capacitor element can be reduced.

In addition, it is easier to manage the collective size and capacity, and it is also easier to perform drying and impregnation treatments.

[Brief explanation of the drawing]

FIGS. 1 and 2 each show a cross section of a conventional round edged electrode foil. FIGS. 3, 4, and 5 each show a cross section of a round edged electrode foil according to the present invention. FIG. 6 shows an embodiment of the present invention, and FIG. 7 is a partial sectional view of the capacitor shown in FIG. FIG. 8 is a partial cross-sectional view of a conventional capacitor element, without explanation of mathematical formulas. Figure 9 shows how the capacitor volume changes when the oil layer thickness changes with respect to the electrode foil thickness.
, 1 #, 1 ///... bending part of electrode foil,
2... Electrode foil, 3... Dielectric, 4... Capacitor element, 5... Counter electrode foil. Cold 8 figures 9 figures ζ〉1-shishiku%)

Claims (1)

[Claims] (1) Electrode foil with round edges, which is made by bending both ends of the electric foil and processing the folded part so that it has almost the same thickness as the part without the overlapped part, or only the two ends. Round edged electrode foil or electrode foil that has been processed to have a certain width and half the thickness in the width direction, and then bent this part so that it has approximately the same thickness as the non-overlapping part. It is characterized by using a round edged electrode foil which has been bent to create a sloped surface at the end of the electrode foil, and this sloped surface is bent so that it has approximately the same thickness as the part that does not overlap due to bending. capacitor.