JPH07153651A - Case for capacitor - Google Patents

Abstract

PURPOSE:To prevent a capacitor element from protruding to the outside of a case, from being ignited and from damaging other components. CONSTITUTION:The case for a capacitor is provided with a first groove 2 which passed through the center 4 of the bottom face 3 and with a second groove 5 which crossed the first groove 2 so as to be symmetric by being bent toward the center 4 in a part other than the center 4 and which is deeper than the first groove 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor case, and more particularly to a metal capacitor case.

[0002]

2. Description of the Related Art A capacitor such as an aluminum electrolytic capacitor uses a capacitor element formed by laminating an electrode foil for an anode and an electrode foil for a cathode via insulating paper for a capacitor and winding the electrode foil. The capacitor element impregnated with the electrolytic solution is housed in a case made of metal such as aluminum, the case is sealed with a lid, and the terminal is pulled out from the lid.

However, in this type of capacitor, hydrogen gas and the like are generated by the reaction of the electrolytic solution during use. Therefore, the gas pressure in the case rises and the capacitor explodes.

Conventionally, in order to prevent this explosion and the like,
For example, as shown in FIG.
In addition, an explosion-proof mechanism including a substantially S-shaped first groove 13 passing through the center 12 and a short linear second groove 14 intersecting the first groove 13 at the center 12 is provided. Also, FIG.
As shown in (b), there is also a case 18 provided with an explosion-proof mechanism composed of ten grooves 17 intersecting at the center 16 on the bottom surface 15.

In these conventional cases 10 and 18, when the gas pressure rises, the bottom surfaces 11 and 15 first expand.
When the gas pressure is further increased, the first groove 1 is used in the former case.
The bottom surface 11 opens from the center 12 which is the intersection of 3 and the second groove 14 toward the ends of the first groove 13 and the second groove 14. In the latter case, the bottom surface 15 opens from the intersecting center 16 of the groove 17 toward the end. As a result, the gas in the cases 10 and 18 is released to the outside.

[0006]

However, in the conventional cases 10 and 18, the bottom surfaces 11 and 15 are largely expanded by the gas pressure, and the first groove 13 and the like are opened thereafter, so that the opening is large. Therefore, there is a drawback that the capacitor element housed inside the case tends to protrude outside the case with the core portion at the head due to the pressure of gas. Then, at this time, there is a drawback that the electrode foil for the anode and the electrode foil for the cathode are short-circuited by the pointed portion such as the opened first groove 13 to cause a spark, and the capacitor element is ignited. Further, there is a drawback that other electronic components are damaged by the protruding capacitor element or by the ignition of the capacitor element.

An object of the present invention is to improve the above drawbacks and to provide a capacitor case capable of preventing the capacitor element from protruding outside the case to ignite or damage other electronic parts. .

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides, in a capacitor case, a first groove that passes through the center of the bottom surface and a portion that is symmetrical with respect to the first groove and other than the center. And a second groove deeper than the first groove, which is bent and intersects toward the center at the point.

The angle at which the second groove intersects the first groove is preferably 70 to 80 degrees. That is, when the intersecting angle is within this range, the first groove and the second groove are likely to operate as the explosion-proof mechanism.

[0010]

[Function] When the gas pressure in the case rises, the bottom surface expands. At this time, according to the present invention, the first groove passing through the center is relatively shallow, and the second groove intersects with the first groove outside the center, so that the expansion thereof is small. Therefore, when the gas pressure further rises, the bottom surface opens along the second groove and the first groove from the intersection of the first groove and the second groove, but the opening method becomes smaller. Therefore, the capacitor element does not project outside the case from the bottom surface.

[0011]

EXAMPLES The present invention will be described below based on examples.
In FIGS. 1 (a) and 1 (b), reference numeral 1 denotes a cylindrical case for a metal capacitor. Reference numeral 2 is a linear first groove provided outside the bottom surface 3 of the case 1 through the center 4. Reference numeral 5 is a second groove provided at a position other than the first groove 2 and the center 4 so as to be bent symmetrically and intersect at a predetermined angle θ. In particular, the second groove 5 is formed as a groove deeper than the first groove 2. Explosion-proof mechanism has these first grooves 2
And second groove 5.

Next, the case 1 of the embodiment of FIG. 1 and FIG.
Regarding the aluminum electrolytic capacitors using the cases 10 and 18 of the conventional examples of (a) and (b), R of the EIAJ standard
An explosion-proof structure test was conducted by the AC voltage method of C-3807. The aluminum electrolytic capacitor has a rating of 400V,
The size is 470 μF, the diameter is 35 mm, and the length is 50 mm. Further, in the case 1 of the embodiment, the thickness of the side surface is 0.3 mm, the thickness of the bottom surface is 0.45 mm, the first groove 2 is 0.1 mm wide, and the length is 2 mm.
0 mm, wall thickness 0.2 mm, second groove 5 has width 0.1 mm, overall length 24 mm, wall thickness 0.1 mm, and second groove 5 has outer diameter of first groove 2 and case 1. 2: 1 point angle θ = 15
It intersects with each other. The case 10 of the conventional example has a side wall thickness of 0.3 mm, a bottom wall thickness of 0.45 mm, an S-shaped first groove 13 having a width of 0.1 mm, a length of 50.2 mm, and a wall thickness of 0. ．
The width of the second groove 14 is 1 mm, the width is 0.1 mm, the length is 6.0 mm, and the wall thickness is 0.1 mm. Further, in the case 18 of the conventional example, the thickness of the side surface is 0.3 mm, the thickness of the bottom surface is 0.45 mm, the groove 17 is 0.1 mm wide, 16 mm long, and 0.1 mm thick.

As a result of this explosion-proof structure test, in the case 1 of the embodiment, the deformation amount l of the bottom surface 3 of the case 1 shown in FIG. 2 is 0.6 to 1.2 mm when the bottom surface 3 is expanded. And the first
The grooves 2 and the second grooves 5 of No. 2 were opened to release the gas, but none of the capacitor elements protruded.
In the case 10 of the conventional example, the deformation amount of the bottom surface 11 is 4.3.
At about 6.4 mm, 25% of the sample capacitor elements popped out. Furthermore, in the case 18 of the conventional example, the amount of deformation of the bottom surface 15 was 1.8 to 3.9 mm, and 35% of the capacitor elements of the sample were protruding. That is, according to the example, the amount of deformation of the bottom surface can be reduced to about 9.4 to 66.7% as compared with the conventional example, and an accident caused by the capacitor element popping out can be prevented.

The working pressure of the explosion-proof mechanism was measured using a hydraulic tester for an aluminum electrolytic capacitor using the case 1 of the embodiment of FIG. 1 in which the angle θ was variously changed. The case 1 has a diameter of 35 mm and the side wall thickness is 0.3 mm.
mm, and the bottom wall thickness is 0.5 mm. And the first groove 2
Has a width of 0.1 mm, a length of 20 mm and a wall thickness of 0.2 mm.
The second groove 5 has a width of 0.1 mm and an overall length of 24 mm.
The measurement result is shown in FIG. 3 in which the thickness is 0.1 mm, the wall thickness is 0.1 mm, and the first groove 2 intersects with the outer diameter of the case 1 at a point of 2: 1.

As is apparent from FIG. 3, the angle θ is 70
In the range of -80 degrees, the explosion-proof mechanism has an operating pressure of 1
It becomes less than 0.1 kgf / cm ² and operates at lower pressure. Therefore, the angle θ at which the second groove 5 intersects the first groove 2
In this range, it is clear that the explosion-proof mechanism is easy to operate and the safety of the capacitor is high.

[0016]

As described above, according to the present invention, the first groove passing through the center of the bottom surface and the first groove are symmetrically intersected with the first groove at a position other than the center by bending toward the center. Deeper second
By providing the groove with, it is possible to reduce the expansion of the bottom surface due to the gas pressure, the capacitor element protrudes,
As a result, ignition or the like can be prevented, and a highly safe capacitor case can be obtained.

[Brief description of drawings]

FIG. 1 shows a bottom view and a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view showing a state where a bottom surface of the embodiment of the present invention is expanded.

FIG. 3 is a graph showing the operating pressure of the explosion-proof mechanism when the angle at which the second groove intersects with the first groove in the embodiment of the present invention is changed.

FIG. 4 shows a bottom view of a conventional example.

[Explanation of symbols]

1 ... Case, 2 ... 1st groove | channel, 3 ... Bottom surface, 4 ... Center, 5 ... 2nd groove | channel.

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[Procedure amendment]

[Submission date] May 25, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 4]

[Figure 3]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location 9174-5E H01G 1/02 P

Claims (1)

[Claims] 1. A capacitor case, wherein the first groove passing through the center of the bottom surface and the first groove are bent symmetrically with respect to the first groove and intersect with a portion other than the center toward the center. And a second groove deeper than the groove.