JPH0433318A - Aluminum electrolytic capacitor - Google Patents

Abstract

PURPOSE:To prevent gas of driving electrolytic solution from flowing to the outside by providing a space part above an explosion-proof valve provided to a top board part of a metallic case, by providing a buffer board having a small hole inside the space part and by providing an absorbing material for absorbing driving electrolytic solution to the outside. CONSTITUTION:Fiberglass, porous hypolymer, etc., are used as an absorbing material 10. When an excessive voltage over rated value is applied to an aluminum electrolytic capacitor, an internal pressure of a metallic case 2 rises, thereby allowing an explosion-proof valve 6 provided to a top board part 2a of the metallic case 2 to start, and driving electrolytic solution in the inside ejects from the explosion-proof valve 6. In the process, most of gas of driving electrolytic solution falls on a buffer board 9, cooled and liquefied, and drops on the top board part 2a of the metallic case. The remaining gas goes outside through a small hole 9a provided to the buffer board 9. The gas of driving electrolytic solution which goes outside is absorbed by an absorbing material 10 which is positioned and provided to the outside of the buffer board 9 and prevents gas of driving electrolytic solution from flowing outside the capacitor.

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 inside 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, the aluminum case usually has a weak point, and when the internal pressure of the aluminum case rises abnormally, the weak point breaks and the driving electrolyte gas inside the aluminum case. This does not result in a large explosion, as the water will flow outside.

Problems to be Solved by the Invention However, in the above-mentioned conventional aluminum electrolytic capacitors, gas from the driving electrolyte leaks out of the capacitor, which may cause the inside of the equipment in which the aluminum electrolytic capacitor is installed to become dirty or cause flames to ignite. The problem was that it was indistinguishable from smoke caused by smoke.

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 derived from the capacitor element;
A space is provided above the explosion-proof valve provided on the top plate of the metal case, and includes a pair of external connection terminals connected to the pair of lead wires and a sealing member that seals the opening of the metal case. A buffer plate with small holes is installed in this space, and the buffer plate is placed outside of this buffer plate. An absorbent material is installed to absorb the driving electrolyte.

Function According to the above configuration, a space is provided above the explosion-proof valve provided on the top plate of the metal case, a buffer plate having small holes is installed in this space, and the buffer plate is located outside of this buffer plate. Because an absorbing material is installed to absorb the drive electrolyte, abnormal stress such as overvoltage is applied to the aluminum electrolytic capacitor, causing the explosion-proof valve to operate and the gas from the drive electrolyte inside to reach the explosion-proof valve in the metal case. Even if the gas of the driving electrolyte is ejected from the space, most of it will be cooled and liquefied upon hitting the buffer plate with small holes installed in the space, and the driving electrolyte gas that has passed through the small holes of the buffer plate will be cooled and liquefied. Since this gas is absorbed by the absorbent material, there is no possibility that the driving electrolyte leaks to the outside.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the accompanying drawing numbers. In FIG. 1, reference numeral 1 denotes a capacitor element, and this capacitor element 1 is constructed by forming a dielectric oxide film on the surface of a roughened aluminum foil and 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 2 made of aluminum. A pair of lead wires 3.3a made of aluminum are led out from the capacitor element, and the pair of lead wires 3.3a,
A pair of external connection terminals 4, 4a are connected to 3a by caulking at a portion of a sealing member 5 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 opening of the metal case 2 by sealing the open end of the metal case 2. Further, the top plate portion 2a of the metal case 2 is formed with an explosion-proof valve 6 made of a thin portion which is a weak point.

A space 8 is provided above the explosion-proof valve 6 by fixing a fixing jig 7 to the top plate 2a side of the metal case 2.
A buffer plate 9 having small holes 9a is positioned in this space 8 integrally with the fixing jig 7, and a drive electrolyte is placed outside of the buffer plate 9. A collection material 10 is installed to absorb the water. This absorbent material 10
Examples of the material used include glass fiber, porous polymer, filter paper, and nonwoven fabric. Note that filter paper and nonwoven fabric may be used after being subjected to flame retardant 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 case 2 increases, which causes the explosion-proof valve 6 provided on the top plate 2a of the metal case 2 to operate, causing the internal drive electrolyte to rise. The liquid will be ejected from this explosion-proof valve 6 section. In this case, most of the driving electrolyte gas hits the buffer plate 9, and when it hits the buffer plate 9, it is cooled and liquefied, and falls onto the top plate portion 2a of the metal case 2. The remaining gas exits outside through the small hole 9a provided in the buffer plate 9.
The gas of the driving electrolyte discharged to the outside is absorbed by an absorbing material 10 placed outside the buffer plate 9. Thereby, the gas of the driving electrolyte can be prevented from flowing out of the capacitor.

FIG. 2 shows another embodiment of the present invention. In the embodiment shown in FIG. On the other hand, in the other embodiment shown in FIG. 2, the buffer plate 9 and the absorbent material 10 are arranged at right angles to the top plate 2a of the metal case 2, and the other structure and operating principle are the same. This embodiment is exactly the same as the embodiment shown in FIG.

Effects of the Invention As is clear from the description of the embodiments above, the aluminum electrolytic capacitor of the present invention has a space above the explosion-proof valve provided on the top plate of the metal case, and a buffer having a small hole in the space. Because a board is installed and an absorbing material is installed outside of this buffer board to absorb the driving electrolyte, excessive stress such as overvoltage is applied to the capacitor, causing the explosion-proof valve to operate and causing internal damage. Even if the drive electrolyte gas blows out from the metal case, most of the drive electrolyte gas will hit the buffer plate with small holes installed in the space and be cooled and liquefied, and the buffer plate Since the gas of the driving electrolyte that has passed through the small holes is absorbed by the absorbing material, there is no possibility that the driving electrolyte leaks to the outside.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of aluminum electrolytic capacitors showing respective embodiments of the present invention. ■・・・Capacitor element, 2・Old・Metal case, 2a・・・・Top plate part, 3, 3a・Old・Pair of lead wires, 4.4a・・・・A pair of external connection terminals,
5. Old... Sealing member, 6... Explosion-proof valve, 8...
...Space part, 9...Buffer plate, 9a...
・Small hole, 1o...absorbent material. Name of agent Patent attorney Shigetaka Awano Haka 1 person 3.3a 4.4a qσ゛Capacitor element Takarao case - Cross 1 lead Peel - One stroke external cover sealing member for hand sale + R2i explosion valve space Part m* Denko hole singing @Material 2 Capacitor element 1171 Case - support 1 ret) Katsu-uchi 9F section Cotton sealing member IrB Hari 1 # All M Sokuunagi 1 piece Yuko hole σg rotation 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. and a sealing member for sealing the opening of the metal case, a space is provided above the explosion-proof valve provided on the top plate of the metal case, and a small hole is provided in the space. An aluminum electrolytic capacitor characterized by having a buffer plate and an absorbing material positioned outside the buffer plate to absorb driving electrolyte.