JPH0331071Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a sealing structure for an electrolytic capacitor using a hard synthetic resin plate as a sealing body.

[Conventional technology]

Conventionally, when the sealing body that seals the exterior case of an electrolytic capacitor is made of hard synthetic resin such as phenol resin, the inner wall of a through hole drilled in the sealing body and the electrode rivet fixed to this through hole are In order to maintain a close contact state, an elastic body such as rubber is interposed in the contact portion.

FIG. 1 shows a sealing body mainly made of synthetic resin. The sealing body 2 has a shape that matches the opening of the outer case that encloses the electrolytic capacitor element. Two through holes 4 are formed at regular intervals in the sealing body 2, 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 this elastic body 6 connects the electrode rivet and the sealing body 2. It is possible to fill the gap between the inner wall surface and the inner wall surface.

[Problem that the invention attempts to solve]

By the way, in such a sealing body 2, 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 with the interposition of the elastic body 6, and the airtightness of the outer case is maintained. be able to. However, since the elastic body 6 is inserted in a flat shape 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.

In addition, since the elastic body 6 is not formed on a part of the inner wall of the through hole 4, the degree of airtightness is lowered.
There were also drawbacks such as the inability to maintain the electrical characteristics of electrolytic capacitors over a long period of time.

For this reason, in the part where the electrode rivet is fixed, an elastic layer is installed over the entire contact area between the sealing body and the electrode rivet, and the diameter of the opening part of the through hole for fixing the electrode rivet is reduced. By increasing the size and making part of the elastic layer thicker,
A sealing structure has been proposed in which the fixing strength of the elastic layer to the sealing body is increased.

Therefore, the purpose of this invention is to provide a sealing structure for an electrolytic capacitor that uses a hard synthetic resin plate as a sealing body, which increases the sealing strength and improves the volumetric efficiency of the electrolytic capacitor.

[Means for solving problems]

That is, the sealing structure of an electrolytic capacitor of this invention is, as shown in FIGS. a first concave portion 16 with a large diameter portion 8 on the outer surface side of the sealing body;
1. A first through hole 8 formed with a small diameter portion 83 on its inner surface, a second recess 21 formed at the edge of the lower surface of the sealing body, and a The large diameter portion side is the thick wall portion 12, and the small diameter portion is the thin wall portion 23.
A second hole of the same diameter is fixed to the inner wall of the through hole.
a first elastic layer 10 forming a through hole 15; and a second elastic layer 18 installed in the first recess and having a protruding outer surface. An electrode rivet 3 is inserted into the second through hole formed.
6 and insert the outer case 24 into the second recess.
The sealing body is attached to the outer case with the crimped portion thereof facing, and the curled open end of the outer case is bitten into the second elastic layer.

[Effect]

With this configuration, the inner wall of the first through-hole has a large diameter part on the outer surface side of the sealing body, and a thick part on the inner wall side with a step part in the middle, and a small diameter part on the inner surface side. ,
A first elastic layer having a thinner portion on the side of the small diameter portion is fixed, and a second elastic layer is installed in the first recess formed in the peripheral wall of the sealing body, and the portion necessary for sealing is fixed. Since an elastic layer is formed on the outer case, the first elastic layer ensures adhesion to the electrode rivet, and the second elastic layer has a curled open end of the outer case. The outer case is sealed by biting into the outer case. Then, the protrusion formed on the outer case by crimping is made to face the second recess of the sealing body, and a substantial thickness of the sealing body is ensured, thereby improving the volumetric efficiency of the electrolytic capacitor.

〔Example〕

2 and 3 show an embodiment of the sealing structure of the electrolytic capacitor of this invention.

The sealing body 2 is formed of a hard insulating plate such as a phenolic resin plate by molding or the like. First through holes 8 for passing electrode rivets 36 through the sealing body 2 are formed at a constant insulation interval.
The through hole 8 is formed by forming a large diameter portion 81 on the outer surface of the sealing body 2, providing a stepped portion 82 inside, and forming a small diameter portion 83 on the inner surface of the sealing body 2.

A first elastic layer 10 covering the entire inner wall of the through hole 8 is formed of an elastic insulator such as rubber. This elastic layer 10 has a thick part 12 on the large diameter part 81 side of the through hole 8 and a thin part 13 on the small diameter part 83 side, and has a second part of the same diameter corresponding to the electrode rivet 36. A through hole 15 is formed. In this embodiment, 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 body 2 .

Further, a first recess 16 is formed around the entire circumference of the upper surface side of the sealing body 2 except for the edge thereof, and a ring-shaped second elastic layer 18 is formed in this recess 16. The elastic layer 18 is fixed by a fixing means such as baking, and a protrusion 19 having a semicircular cross section is formed on the upper surface of the elastic layer 18 for biting into the open end of the outer case 24 to be curled.

Furthermore, a protrusion 20 formed around the through hole 8 is formed on the back surface of the sealing body 2, and an upright wall 22 having a diameter smaller than the diameter of the sealing body 2 is formed around the entire circumference.

A thin portion 23 having a constant width is formed at the peripheral edge of the sealing body 2.

With the above structure, as shown in FIG. 3, the opening of the exterior case 24 of the electrolytic capacitor is sealed by inserting the sealing body 2, and the elastic layer 1
The open end thereof is curled and bit into the protrusion 19 of 8. And outer case 2
The electrode tabs 28 and 30 of the electrolytic capacitor element 26 housed inside the capacitor 4 are different from the plate-shaped terminals 32 and 34 arranged on the upper surface of the sealing body 2, and the electrode tabs 28 and 30 of the electrolytic capacitor element 26 housed inside the capacitor 4 are connected to the electrodes in the through hole 8 covered with the elastic layer 10. It is firmly fixed through the rivet 36 and electrically connected. In this case, the gap between the electrode rivet 36 and the sealing body 2 is filled with the elastic layer 10, and the airtightness of the outer case 24 is maintained at a high level.

In particular, since the protrusion 14 formed on the upper surface of the elastic layer 10 is compressed and pressed against the inner wall of the through hole 8 as the electrode rivet 36 is press-molded, airtightness is strongly maintained. Become something. moreover,
Since the elastic layer 10 is formed with a thick wall portion 12 that matches the large diameter portion formed on the hard insulator of the sealing body 2, the joint inside the sealing body 2 is strong, and the electrode rivet 36 is formed. Inconveniences such as movement, deformation, and protrusion caused by insertion can be avoided, and assembly work can be made more efficient.

Furthermore, since the protrusion 20 is formed on the inner surface of the sealing body 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 body 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.

Since the sealing body 2 has a stepped portion and a thin wall portion 23 on its peripheral edge, a protrusion 25 is formed by crimping in order to fix the sealing body 2 to the inner wall of the outer case 24. is fixed with the thick part facing the space. For this reason, without damaging the substantial thickness of the sealing body 2, the outer case 24
The utilization rate of the space is increased. In other words,
When the protrusions 25 are formed by crimping, the protrusions 25 fit into the recesses formed by the thin-walled portions 23, and there is also an advantage in processing that the corners of the sealing body 2 can be prevented from being damaged during crimping.

[Effect of idea]

As explained above, according to this invention, since the elastic layer is installed in the first through hole and the first recess formed in the sealing body to ensure the necessary airtightness, the flatness of the sealing body can be reduced. At the same time, the protrusion formed by additional tightening on the outer case can be inserted into the second part of the sealing body.
Since it faces the concave part of the cap, it maintains the original thickness of the sealing body, improves the volumetric efficiency of the electrolytic capacitor, and prevents damage to the sealing body when tightening the outer case, making it possible to realize a highly reliable electrolytic capacitor. .

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional sealing body, Figure 2 is a sectional view of a sealing body that is an embodiment of the sealing structure of an electrolytic capacitor of this invention, and Figure 3 is a sectional view of an electrolytic capacitor that is an embodiment of this invention. FIG. 2... Sealing body, 8... First through hole, 10... First elastic layer, 12... Thick part, 23... Thin wall part, 15... Second through hole, 16... First 1 recess, 1
8...Second elastic layer, 21...Second recess, 2
4...Exterior case, 36...Rivet for electrode, 8
1... Large diameter part, 83... Small diameter part.

Claims (1)

[Claims for Utility Model Registration] A sealing structure for an electrolytic capacitor using a hard insulating plate as a sealing body, comprising: a first recess formed in a peripheral wall of the sealing body; and an outer surface of the sealing body having a larger diameter. a first through hole formed with a small diameter portion on the inner surface thereof; a second recess formed in the edge of the lower surface side of the sealing body; and the large diameter portion of the first through hole. a first elastic layer whose side is a thick wall part and whose small diameter part is a thin wall part and which is fixed to the inner wall of the through hole to form a second through hole having the same diameter; and installed in the first recess. a second elastic layer having an outer surface protruding from the first elastic layer; an electrode rivet is passed through the second through hole formed in the first elastic layer;
The sealing body is attached to the outer case with the caulked part of the outer case facing the recess, and the curled open end of the outer case is bitten into the second elastic layer. Sealing structure of electrolytic capacitor.