JPH0433323A - Aluminum electrolytic capacitor - Google Patents

Abstract

PURPOSE:To prevent gas of driving electrolytic solution from flowing to the outside by arranging a porous absorbing material having a function to absorb driving electrolytic solution to an outside of an explosion-proof valve provided to a sealing member. CONSTITUTION:A capacitor element 1 is impregnated with driving electrolytic solution and the capacitor element 1 is mounted inside a tubular metallic case 2 with a bottom. A pair of leads 3, 3a consisting of aluminum are led out of the capacitor element 1, and a pair of external connecting terminals 4, 4a are connected to the leads 3, 3a by calking at a part of a sealing member 5 which consists of a terminal board. The sealing member 5 is arranged at an opening part of the metallic case 2 and seals the opening and of the metallic case 2. An explosion-proof valve 6 is formed in the sealing member 5, and a permeable absorbing material 7 having a function to absorb the driving electrolytic solution is provided to the outside. The absorbing material 7 passes through a pair of external connecting terminals 4, 4a and is fixed to the metallic case 2 by use of a fixing jig 8.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an aluminum electrolytic capacitor.

Conventional technology Conventional aluminum electrolytic capacitors are made by forming a dielectric oxide film on the surface of a roughened aluminum foil, and winding this together with a separator to form a capacitor element. It was constructed by enclosing it in an aluminum case.

When an overvoltage higher than the rated voltage is applied to this aluminum electrolytic capacitor, the temperature of the driving electrolyte impregnated in the capacitor element rises and vaporizes, so that the internal pressure of the aluminum case rises. In this case, if the internal pressure of the aluminum case exceeds the sealing force of the sealing member of the aluminum case,
This is extremely dangerous as the capacitor element may come off the aluminum case and fly out of the aluminum case, or the aluminum case may fly off.

Therefore, in this type of aluminum electrolytic capacitor, a weak point is usually provided in the sealing member, and when the pressure inside the aluminum case increases abnormally, the weak point in the sealing material breaks and the inside of the aluminum case is broken. Since the gas from the driving electrolyte flows outside, a large explosion will not occur.

Problems to be Solved by the Invention However, in the above-mentioned conventional aluminum electrolytic capacitor, the gas of the driving electrolyte leaks out of the capacitor, so the inside of the equipment in which the aluminum electrolytic capacitor is set becomes dirty. The problem was that it was difficult to distinguish from smoke caused by flames.

The present invention solves these problems and aims to provide an aluminum electrolytic capacitor that can prevent the gas of the driving electrolyte from flowing out.

Means for Solving the Problems In order to achieve the above object, the aluminum electrolytic capacitor of the present invention includes a capacitor element impregnated with a driving electrolyte;
A bottomed cylindrical metal case containing the capacitor element, a pair of lead wires led out from the capacitor element, a pair of external connection terminals connected to the pair of lead wires, and an opening in the metal case. and a sealing member for sealing the valve, and an absorbent material having air permeability and having the function of absorbing the driving electrolyte is installed on the outside of the explosion-proof valve provided in the sealing member.

Effects According to the above structure, an absorbent material that is breathable and has the function of absorbing the drive electrolyte is installed on the outside of the explosion-proof valve provided in the sealing member, so that no overvoltage is applied to the aluminum electrolytic capacitor. Even if the explosion-proof valve is activated and gas from the internal drive electrolyte is blown out from the explosion-proof valve part due to abnormal stress such as This makes it possible to reliably prevent the driving electrolyte from leaking to the outside.

EXAMPLE Hereinafter, an example of the present invention will be explained based on the accompanying drawings. In the drawings, 1 is a capacitor element, and this capacitor element 1 has a dielectric oxide film formed on the surface of a roughened aluminum foil. , is constructed by winding this together with a separator. This capacitor element 1 is impregnated with a driving electrolyte and is installed in a bottomed cylindrical metal case 72 made of aluminum. A pair of aluminum lead wires 3.32L are led out from the capacitor element 1, and a pair of external connection terminals 4 are connected to the pair of lead wires 3.3B.
, 4a are connected by caulking at a sealing member 50 portion made of a terminal plate. The sealing member 5 made of the terminal plate is disposed at the opening of the metal case 2 and seals the open end of the metal case 2. Further, the sealing member 6 is formed with an explosion-proof valve 6 made of a thin-walled part that is a weak point, and the outside of this explosion-proof valve has air permeability and a function of absorbing the driving electrolyte. This absorbent material 7 penetrates the pair of external connection terminals 4.4a, and this absorbent material 7 is fixed to the metal case 2 using a fixing jig 8. It is something. As the material for the absorbent material 7, for example, glass fibers, porous polymers, filter paper, non-woven fabrics, etc. can be used; however, the filter paper and non-woven fabrics may be used after being subjected to a heat-resistant treatment.

The operation in the above configuration will be explained. When an overvoltage higher than the rated voltage is applied to this aluminum electrolytic capacitor, the internal pressure of the metal cane 2 increases, which causes the explosion-proof valve 6 provided in the sealing member 6 to operate and the internal drive electrolyte to be discharged from the explosion-proof Valve 6
It will gush out from the part. In this case, the driving electrolytic solution is absorbed by the absorbent material 7 installed outside the explosion-proof valve 6, so that the gas of the driving electrolytic solution does not leak to the outside. Thereby, the gas of the driving electrolyte can be prevented from flowing out of the aluminum electrolytic capacitor.

Effects of the Invention As is clear from the description of the above embodiments, according to the aluminum electrolytic capacitor of the present invention, the outside of the explosion-proof valve provided in the sealing member has air permeability and absorbs the driving electrolyte. Because an absorbing material with an action is installed, even if an abnormal strain such as overvoltage is applied to the aluminum electrolytic capacitor and the explosion-proof valve is activated and gas from the internal drive electrolyte blows out from the explosion-proof valve part, The driving electrolyte can be absorbed by the absorbent material placed outside the explosion-proof valve, thereby reliably preventing the driving electrolyte from leaking to the outside.

[Brief explanation of drawings]

Figure 1 is a sectional view of an aluminum electrolytic capacitor showing one embodiment of the present invention. 1...Capacitor element, 2...Metal case, 33IL...-Pair of lead wires, 4, 4a
. . . A pair of external connection terminals, 5 . . . Sealing member, 6 . . . Explosion-proof valve, 7 . . . Absorbent material.

Claims (1)

[Claims] A capacitor element impregnated with a driving electrolyte, a bottomed cylindrical metal case containing the capacitor element, a pair of lead wires led out from the capacitor element, and a pair connected to the pair of lead wires. an external connection terminal, and a sealing member that seals the opening of the metal case, and the sealing member has air permeability on the outside of the explosion-proof valve and has a function of absorbing the driving electrolyte. An aluminum electrolytic capacitor characterized by having an absorbing material installed therein.