JP2002110481A - Capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor realizing a sealing structure suitable for an electric double layer capacitor requiring high hermetic sealing. SOLUTION: The capacitor realizing high hermetic sealing suitable for an electric double layer capacitor comprises a tubular case section (2) for containing a capacitor element (8), e.g. an electric double layer capacitor element, a sealing plate (6) made of a conductor, e.g. a metal, an external terminal part (10) comprising the sealing plate itself, an insulating member (insulating ring 24) for insulating the sealing plate and the tubular case section electrically, and a sealing member (sealing ring 26) for sealing the gap between the sealing plate and the opening of the tubular case section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor, such as an electric double layer capacitor, which requires a high airtightness in a sealing structure.

[0002]

2. Description of the Related Art There are various types of sealing structures, such as electrolytic capacitors and electric double layer capacitors, which require high airtightness, such as Japanese Utility Model Publication No. 6-22222.

In an electric double layer capacitor using a non-aqueous electrolytic solution, even if the electrolytic solution contains about 70 ppm of water, the water reacts on the surface of the activated carbon electrode to cause gas generation. When the generated gas fills the outer case, the safety valve is opened and the use of the condenser becomes impossible. For this reason, in the electric double layer capacitor, the moisture is reduced as much as possible, which is why the capacitor element is sufficiently dried at the time of manufacturing.

[0004] The drying process of the capacitor element is performed by leaving the tab of the capacitor element connected to the rivet of the sealing plate at a high temperature. Although it is possible to dry the capacitor element alone, if the step of connecting the dried capacitor element tab to the rivet of the sealing plate is performed in an open atmosphere, the capacitor element may absorb moisture from the air in this step. . Further, the connection between the tab of the capacitor element and the rivet of the sealing plate can be performed while maintaining a dry state in a sealed space atmosphere, but such an atmosphere formation requires a large-scale manufacturing apparatus.

[0005]

However, if the tab of the capacitor element and the rivet of the sealing plate are connected before drying, the adhesion between the sealing plate and the rivet may be deteriorated in the drying process. This is because the material of the sealing plate and the material of the rivet each have a specific coefficient of thermal expansion. Therefore, if the material is exposed to a high temperature state in the drying step, a difference occurs in the coefficient of thermal expansion, so that the contact surface between the sealing plate and the rivet is distorted. This distortion causes deterioration of the adhesion between the sealing plate and the rivet. Deterioration of the adhesion between the sealing plate and the rivet causes not only leakage of the electrolyte solution inside the electric double layer capacitor but also intrusion of moisture from outside into the case, and the life of the electric double layer capacitor. It also causes deterioration of characteristics.

Accordingly, an object of the present invention is to provide a capacitor which realizes a sealing structure suitable for an electric double layer capacitor or the like which requires high airtightness.

[0007]

According to the present invention, there is provided a capacitor comprising:
A cylindrical case part (2) for accommodating a capacitor element (8) such as an electric double-layer capacitor element; a sealing plate (6) made of a good conductor such as a metal;
0), an insulating member (insulating ring 24) for electrically insulating the sealing plate and the cylindrical case portion, and a sealing member (sealing ring 26) for sealing between the sealing plate and the opening of the cylindrical case portion. ) To realize a highly airtight sealing structure suitable for electric double layer capacitors and the like.

The capacitor according to the first aspect of the present invention is formed of a cylindrical case portion (2) for accommodating a capacitor element (8) such as an electric double layer capacitor element, and a good conductor such as metal. A sealing plate (6) for sealing the opening of the case-like portion, an external terminal (10) formed of the sealing plate itself, and electrically connected to the capacitor element;
An insulating member (insulating ring 2) installed around the sealing plate to electrically insulate the sealing plate from the cylindrical case portion.
4) and a sealing member (sealing ring 26) provided between the sealing plate and the opening of the cylindrical case portion for sealing.

That is, in this capacitor, the sealing plate itself made of a good conductor constitutes the external terminal portion, and the conventional sealing structure between the sealing plate and the external terminal portion is unnecessary.
Further, the sealing plate is formed of a metal plate or the like, and high airtightness at a molecular level is realized. By installing an insulating member around the sealing plate, electrical insulation is achieved between the sealing plate and the cylindrical case portion forming the external terminal portion, and a rubber or the like provided separately from the insulating member is provided. The airtightness between the cylindrical case portion and the external terminal portion is enhanced by the sealing member. As a result, a high degree of airtightness suitable for a capacitor which dislikes moisture, such as an electric double layer capacitor, is obtained, the penetration of moisture can be prevented for a long time, and the capacitor characteristics can be stabilized and good life characteristics can be obtained.

A capacitor according to a second aspect of the present invention is characterized in that the insulating member is formed by integrally molding a synthetic resin around the sealing plate. That is, since the insulating sealing plate is formed using an integral molding technique such as insert molding of the sealing plate in a synthetic resin, the number of parts in the assembly process can be reduced.

According to a third aspect of the capacitor of the present invention, the sealing member is formed of an elastic annular body, and the elastic annular body is provided in a peripheral recess (a supporting step portion 34) of the sealing plate. It is characterized in that the opening edge of the case portion is swaged by caulking. That is, since a concave portion is formed around the sealing plate, and the sealing member made of an elastic annular body is installed in the concave portion, the sealing member does not protrude from the sealing plate, and the sealing member is placed in the surface thereof. For example, it is possible to unify the external shape such as installation. Since the opening of the cylindrical case portion is swaged into the sealing member, the two members are tightly connected to each other, and a high degree of airtightness is realized.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to embodiments shown in the drawings.

1 to 3 show an embodiment of a capacitor according to the present invention. FIG. 1 shows a sealing structure, FIG. 2 shows an enlarged sealing structure, and FIG. 3 shows components used for a sealing structure and the like. .

A cylindrical case portion 2 is formed of a metal material such as aluminum into a cylindrical shape such as a cylindrical shape, and a supporting step portion 4 is formed on the inner peripheral surface of each opening side of the cylindrical case portion 2 by caulking. Is formed. Each sealing plate 6 inserted into the opening of the cylindrical case portion 2 is horizontally supported by the supporting step portion 4.

The sealing plate 6 is made of a metal material such as aluminum which is a good conductor. In this embodiment, the sealing plate 6 is made of the same material as that of the cylindrical case portion 2 and has a shape corresponding to the shape of the opening, for example, a disk shape. Have been. The sealing plate 6 constitutes an external terminal of a capacitor element 8 such as an electric double layer capacitor element housed inside the cylindrical case part 2, and an external terminal part 10 is formed in a central part and is not shown. A screw hole 12 is formed as means for connecting to a wiring member. A pair of screw holes 20 and 22 for fixing rivets 16 and 18 to be connected to the tab 14 of the capacitor element 8 are formed on the inner surface side of the sealing plate 6.

On the peripheral wall surface of the sealing plate 6, an insulating ring 24 as an insulating member for electrically insulating the sealing plate 6 from the cylindrical case portion 2, and a seal for maintaining airtightness with the cylindrical case portion 2. A sealing ring 26 as a member is provided. That is, on the peripheral wall surface of the sealing plate 6, as shown in FIG. 2, a constraining projection 28 for fixing the insulating ring 24 is formed integrally with the sealing plate 6. Narrow first
A second flange portion 32 having a width increased in the thickness direction of the sealing plate 6 is formed on the edge side of the flange portion 30.
The insulating ring 2 is formed so as to cover these flange portions 30 and 32.
In this embodiment, the insulating ring 24 is formed by insert molding. The height of the insulating ring 24 is determined by the height of the supporting step 34 as a peripheral recess formed in the sealing plate 6 as a means for supporting the insulating ring 24, that is, the supporting step 34 in the thickness direction of the sealing plate 6.
And this height is set to be larger than half the thickness of the sealing plate 6.

Further, the supporting step 34 is wrapped around the peripheral edge of the sealing plate 6 at the same height, and a locking projection 36 having a triangular cross section is formed on the outer edge side thereof. A sealing ring 26 is provided on the upper surfaces of the supporting step portion 34 and the insulating ring 24, and a distal end portion of a curling portion 38 of the cylindrical case portion 2 bites into an outer surface of the sealing ring 26. The sealing ring 26 is provided in the plane of the sealing plate 6, and cuts into the tip of the curling portion 38,
Sealing plate 6 supported by supporting step 4 of cylindrical case 2
And, it is sandwiched between the insulating ring 24 and the curling portion 38 in a compressed state, and high airtightness is obtained.

In this capacitor, as shown in FIG. 3, a cylindrical case portion 2 having both ends opened is used, and the same sealing structure is applied to each opening.
That is, the same sealing plate 6 is used, and the same insulating ring 2 is used.
4 and a sealing ring 26 are used to seal each opening with the same sealing structure. In this case, each sealing plate 6
For example, when the tab 14 on the anode side of the capacitor element 8 is connected to the upper sealing plate 6, the tab 14 on the cathode side is connected to the lower sealing plate 6, and each sealing plate 6 6
Are set to different polarities.

The sealing plate 6 has through holes 4 penetrating in and out.
0 is formed, and a safety valve 42 that opens when the internal pressure rises is attached to the through hole 40. FIG. 4 shows an embodiment of the structure of the through hole 40 and the safety valve 42, and the sealing plate 6
Of the through hole 40 as a retaining means in the middle thereof.
Is formed, and a tapered surface 46 is formed on the opening side. The safety valve 42 is a cap body formed of an elastic material such as rubber, and has a concave portion 48 at the center portion and a large-diameter taper portion 50 at the side of the cylindrical case portion 2 for preventing slippage under normal pressure. A thin portion 52 is formed on the top side of the safety valve 42. When the internal pressure of the condenser is abnormally increased, the safety valve 42 is opened, thereby preventing the abnormal increase of the internal pressure.

With this configuration, in this capacitor, the sealing plate itself made of a good conductor forms the external terminal portion, and the conventional sealing structure between the sealing plate and the external terminal portion becomes unnecessary. Since the sealing plate is formed of a metal plate or the like, high airtightness at a molecular level is maintained. In addition, by installing an insulating member on the periphery of the sealing plate, high-level electrical insulation between the sealing plate and the cylindrical case portion constituting the external terminal portion is maintained, and at the same time, the insulating plate is installed separately from this insulation. Airtightness between the cylindrical case portion and the external terminal portion is maintained by a sealing member such as rubber.

Therefore, a high degree of airtightness suitable for a capacitor which dislikes moisture, such as an electric double layer capacitor, can be obtained, and it is possible to prevent moisture from entering for a long period of time, and to stabilize the capacitor characteristics and obtain a good life characteristic. Can be planned.

FIG. 5 shows another embodiment of the structure of the through hole 40 and the safety valve 42. A cap-shaped safety valve 42 is fitted into the through hole 40 of the sealing plate 6 similarly formed. ing. In this case, the safety valve 42 is formed with a flange portion 54 as a stopper at normal pressure.

[0023]

As described above, according to the present invention,
The following effects are obtained. a. Since the sealing member formed of an elastic member is provided between the sealing plate formed of a good conductor such as metal and the cylindrical case portion, a capacitor having a sealing structure with high sealing performance can be realized. b By caulking the opening end of the cylindrical case portion and biting into the sealing member, it is possible to improve the adhesion or sealing strength between the sealing member and the cylindrical case portion, and to achieve high airtightness. Can be realized. c Since the sealing plate is insulated from the cylindrical case by the insulating member, the sealing plate can be configured as an external terminal portion, and the external electrode structure having high mechanical strength can be realized in combination with the simplification of the sealing structure. If the external terminal and the sealing plate are separate members, the stress acting between them when connecting with the wiring member may impair the airtightness, but such inconvenience can be avoided and the characteristics can be stabilized. As a result, good life characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a sealing structure of a capacitor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a sealing structure in which a part of a capacitor is enlarged.

FIG. 3 is an exploded perspective view showing a component configuration for realizing a sealing structure of the capacitor.

FIG. 4 is a cross-sectional view showing one embodiment of a safety valve structure for a condenser.

FIG. 5 is a cross-sectional view showing another embodiment of the safety valve structure of the condenser.

[Explanation of symbols]

 2 Cylindrical case part 6 Sealing plate 10 External terminal part 24 Insulating ring (insulating member) 26 Sealing ring (sealing member) 34 Support step (peripheral recess)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masayuki Mori 1-1167 Higashi-Ome, Ome-shi, Tokyo 1 Inside Nippon Chemi-Con Corporation (72) Inventor Eiji Okumura 8 Clayshrine, Fujisawa City, Kanagawa Prefecture CIR Corporation (72) Inventor Toshikazu Takeda 8 clay bowls in Fujisawa City, Kanagawa Prefecture

Claims (3)

[Claims] 1. A tubular case for accommodating a capacitor element such as an electric double-layer capacitor element, a sealing plate formed of a good conductor such as metal and sealing an opening of the cylindrical case, An external terminal portion formed of a plate itself and electrically connected to the capacitor element; and an insulating member installed around the sealing plate to electrically insulate the sealing plate and the cylindrical case portion. A sealing member provided between the sealing plate and the opening of the cylindrical case portion to seal. 2. The capacitor according to claim 1, wherein the insulating member is formed by integrally molding a synthetic resin around the sealing plate. 3. The sealing member is constituted by an elastic annular body, and the elastic annular body is installed in a peripheral concave portion of the sealing plate, and the opening edge of the cylindrical case portion is swaged and bitten. The capacitor according to claim 1, wherein: