JPH0356036Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention relates to a sealing plate for an electrolytic capacitor that uses a hard insulating plate and selectively uses an elastic body in the sealing portion.

[Prior Art] Conventionally, when a sealing plate that seals the exterior case of an electrolytic capacitor is made of a hard synthetic resin such as phenolic resin, the sealing plate is made of a hard synthetic resin such as a phenol resin, and the inner wall of a through hole bored in the sealing plate and a hole fixed to the through hole are used. In order to maintain close contact with the electrode rivet, an elastic material such as rubber is interposed in the contact portion. FIG. 1 shows a sealing plate mainly made of synthetic resin. The sealing plate 2 is processed into a shape that matches the opening of the exterior case that encloses the electrolytic capacitor element. Two through holes 4 are formed in the sealing plate 2 at regular intervals, through which electrode rivets (not shown) are inserted and held. The opening of the through hole 4 is stepped and has a large diameter, and an elastic body 6 such as rubber is embedded in the large diameter part, and the electrode rivet of the elastic body 6 and the inner wall surface of the sealing plate 2 are connected to each other. It fills the gap between the two. As a result, since the elastic body 6 is embedded in the inner wall surface of the through hole 4, the gap between the outer peripheral surface of the electrode tab and the inner wall surface of the through hole 4 is filled by the elastic body 6, and the outer case is closed. This allows airtightness to be maintained.

[Problem that the idea aims to solve]

By the way, in such a sealing plate 2, the elastic body 6
Since the electrode rivet is inserted only into a large portion of the diameter of the through hole 4, problems such as movement, deformation, and protrusion may occur when inserting the electrode rivet for fixing the external terminal. In addition, since the elastic body 6 is formed only on a part of the inner wall of the through hole 4, the degree of airtightness is low, and there are also drawbacks such as the inability to maintain the electrical characteristics of the electrolytic capacitor for a long time. It was hot. Therefore, this idea was developed to strengthen the retention of the elastic layer inside the through hole, thereby preventing problems such as movement, deformation, and popping out when inserting the electrode rivet. It is.

[Means to solve the problem]

The sealing plate of the electrolytic capacitor of this invention is the exterior case 2 in which the capacitor element 26 is enclosed and sealed.
a hard insulating plate having a shape corresponding to the opening of No. 4;
A first through hole 8 formed in this hard insulating plate has a large diameter portion 81 on its outer surface and a small diameter portion 83 on its inner surface.
The large-diameter side is attached to the thick wall part 12, and the small-diameter side is connected to the thin wall part 13.
an elastic layer 10 in which a second through hole 15 is formed, and the large diameter portion side protrudes from the hard insulating plate;
An external terminal is attached to the second through hole of the elastic layer, and crimping parts are provided at both ends, and an external terminal is installed on the outer surface side of the hard insulating plate, and an external terminal is installed on the inner surface side of the hard insulating plate. The tabs of the capacitor element to be installed (electrode tabs 28, 30) are sandwiched between the front and back sides of the hard insulating plate and the caulking portion, compressing the elastic layer and tightening the external terminals and the tabs. It is characterized by comprising an electrode rivet 36 for electrically connecting the electrode.

[Effect]

With this configuration, the elastic layer forming the thick part and the thin part is attached to the inner wall part of the large diameter part and the small diameter part of the first through hole formed in the hard insulating plate. Since a second through hole corresponding to the electrode rivet is formed inside the hard insulating plate, in addition to the shape of the first through hole and the elastic layer, the hard insulating plate is The fixing strength between the through hole and the elastic layer is increased, and the adhesion is also improved, and the elastic layer can be prevented from coming out when attaching the electrode rivet. Furthermore, since the elastic layer protrudes from the outer surface of the hard insulating plate, this protrusion is compressed by the electrode rivet, thereby maintaining necessary and sufficient airtightness.

Embodiment FIGS. 2 and 3 show an embodiment of the sealing plate for an electrolytic capacitor of this invention. The sealing plate 2 is a hard insulating plate such as a phenolic resin plate and is formed by molding or the like to fit the opening of the outer case. First through holes 8 are formed in the sealing plate 2 at a constant insulating interval, through which rivets for fixing terminals are passed through and attached. At this time, the through hole 8 is formed on the outer surface side of the sealing plate 2 at the large diameter portion 8.
1, a stepped portion 82 is provided inside the sealing plate 2, and a small diameter portion 83 is formed on the inner surface of the sealing plate 2. Then, an elastic layer 10 covering the entire inner wall of the through hole 8 is formed of an elastic insulator such as rubber, and attached by a fixing method such as baking. This elastic layer 10 has a thick wall portion 1 on the large diameter portion 81 side of the through hole 8.
2. A second through hole 15 corresponding to the electrode rivet is formed in the thin wall portion 13 on the side of the small diameter portion 83. In this case, a protrusion 14 is formed on the upper surface of the elastic layer 10 so as to slightly protrude from the upper surface of the sealing plate 2. Further, a recess 16 is formed around the entire circumference of the upper surface side of the sealing plate 2, leaving the edge.
6, a ring-shaped elastic layer 18 having a circularly protruding upper surface is fixed by a fixing method such as baking. Furthermore, a protrusion 20 formed around the through hole 8 is formed on the back surface of the sealing plate 2, and an upright wall 22 having a diameter smaller than the diameter of the sealing plate 2 is formed around the entire circumference. Next, the sealing plate 2 formed in this way is
As shown in the figure, the exterior case 2 of the electrolytic capacitor
It is attached to the opening of 4. Then, the electrode tabs 28 and 30 of the capacitor element 26 housed in the outer case 24 and the plate terminals 32 and 34 arranged on the upper surface of the sealing plate 2 are inserted into the through hole 8 covered with the elastic layer 10. The electrode rivet 36 is passed through and fixed to establish an electrical connection. In this case, the electrode rivet 3
The gap between the sealing plate 6 and the sealing plate 2 is filled with the elastic layer 10, and the airtightness of the outer case 24 is maintained at a high level. In particular, the protrusion 14 formed on the upper surface of the elastic layer 10 is formed by pressure forming between the crimped parts formed at both ends by crimping the electrode rivet 36. Compressed. As a result,
The elastic layer 10 is pressed against the inner wall of the through hole 8, and it is necessary to maintain airtightness between the electrode rivet 36 on the sealing plate 2 and the elastic layer 10, and between the elastic layer 10 and the through hole 8. and to a sufficient degree. Furthermore, thick portions 12 and thin portions 13 are formed in the elastic layer 10 in correspondence with the large diameter portion 81, step portion 82, and small diameter portion 83 of the through hole 8 formed in the hard insulating plate of the sealing plate 2. Moreover, since the elastic layer 10 is firmly fixed to the inner wall of the through-hole 8 by baking or the like, the joint inside the sealing plate 2 is strong, and the large-diameter portion 81 and the thick-walled portion are tightly bonded. 12. From the shape structure of the small diameter portion 83 and the thin wall portion 13, the electrode rivet 3
It is possible to overcome the stress caused by the insertion of the capacitor 6 and avoid inconveniences such as movement, deformation, and protrusion, and it is possible to improve the efficiency of the electrolytic capacitor assembly work. Furthermore, since the protrusion 20 is formed on the inner surface of the sealing plate 2 and the through hole 8 is formed in the center thereof, the width of the elastic layer 10 is larger than the thickness of the sealing plate 2. There is. As a result, it is possible to increase the bonding area with the outer surface of the electrode rivet 36, and in addition to reducing the amount of synthetic resin material and weight, it is possible to improve the degree of airtightness.

[Effect of the idea]

As explained above, according to this invention, the outer surface side of the hard insulating plate is the large diameter part and the inner surface side thereof is the small diameter part in the first through hole formed in the hard insulating plate.
Corresponding to the shape of the through hole, an elastic layer with a thick wall on the large diameter side and a thin wall on the small diameter side is attached to the inner wall of the through hole, so that the hard insulating plate and the elastic layer are It is tightly bonded, the bond strength is dramatically increased, and the deterioration of sealing strength and airtightness can be reliably prevented.
In addition to strongly maintaining airtightness between the inner wall surface of the elastic layer forming the second through hole and the electrode rivet penetrated into the through hole, when inserting the electrode rivet, It is possible to overcome the stress associated with the insertion and prevent the elastic layer from curling up, moving, deforming, and popping out, improving assembly work efficiency. As a result of being compressed by the electrode rivet through the capacitor, the sealing strength can be increased to reliably prevent a decrease in airtightness, and the reliability of the electrolytic capacitor can be improved.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a conventional sealing plate, Figure 2 is a sectional view of a sealing body showing an embodiment of the sealing plate for an electrolytic capacitor of this invention, and Figure 3 is an implementation of the sealing plate for an electrolytic capacitor of this invention. FIG. 2 is a partial cross-sectional view showing an example electrolytic capacitor. 2... Sealing plate, 8... First through hole, 10... Elastic layer, 12... Thick wall portion, 13... Thin wall portion, 15
...Second through hole, 24...Exterior case, 26...
Capacitor element, 28, 30... Electrode tab, 3
6...Rivet for electrode, 81...Large diameter portion, 83...
...small diameter part.

Claims (1)

[Scope of Claim for Utility Model Registration] A hard insulating plate having a shape corresponding to the opening of an exterior case in which a capacitor element is to be sealed and sealed; a first through hole whose side has a small diameter part; and a second through hole which is installed in the first through hole and has the large diameter part side as a thick wall part and the said small diameter part side as a thin wall part.
an elastic layer having a through hole formed therein, the large diameter portion side protruding from the hard insulating plate; and the elastic layer is attached to the second through hole, and crimping portions are provided at both ends. and an external terminal installed on the outer surface side of the hard insulating plate and a tab of a capacitor element installed on the inner side of the hard insulating plate are sandwiched between the front and back sides of the hard insulating plate and the crimping part. A sealing plate for an electrolytic capacitor, comprising: an electrode rivet that compresses the elastic layer and electrically connects the external terminal and the tab.