JPH0474411A - Aluminum electrolytic capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

Conventional technology In conventional aluminum electrolytic capacitors, a dielectric oxide film is formed on the surface of an anode foil made of roughened aluminum foil, and the anode foil and cathode foil are wound together with a separator to form a capacitor element. It was constructed by impregnating the capacitor element with a driving electrolyte and enclosing the capacitor element in a metal case made of aluminum.

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 turns brown, causing the internal pressure of the metal case to rise. In this case, if the internal pressure of the metal case exceeds the sealing force of the metal case's sealing member, the capacitor element may come off from the metal case and fly out of the metal case, or the metal case may jump, which is extremely dangerous. It is.

Therefore, in this type of aluminum electrolytic capacitor, a weak point consisting of a thin wall is usually provided on the top plate of the metal case, and when the internal pressure of this metal case rises abnormally, the weak point breaks and the metal case The gas from the driving electrolyte inside the tank will flow out to the outside, so a major explosion will not occur.

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, resulting in the inside of equipment containing this aluminum electrolytic capacitor becoming dirty and causing flames to ignite. The problem was that it was indistinguishable from smoke caused by smoke.

The present invention has been made to solve these problems, and an object of the present invention is to provide an aluminum electrolytic capacitor that can prevent the gas of the driving electrolyte from leaking to the outside.

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 pair of external connection terminals connected to the pair of lead wires and a sealing member sealing the opening of the metal case are provided above the explosion-proof valve provided on the top plate of the metal case.
An absorbent material that is breathable and has the function of absorbing the driving electrolyte is provided, and the absorbent material is sandwiched and fixed between the exterior sleeve and the metal case. .

Function: According to the aluminum electrolytic capacitor having the above structure, an absorbent material that has ventilation and has the function of absorbing the driving electrolyte is disposed above the explosion-proof valve provided on the top plate of the metal case.
Moreover, since this absorbent material is fixed by being sandwiched between the outer sleeve and the metal case, the absorbent material is also easily and accurately fixed above the explosion-proof valve provided on the top plate of the metal case. Compared to the method of fixing the absorbent material to the top plate of a metal case with adhesive or the like, it is extremely easy to work with and has high productivity.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. In FIG. 1, 1 is a capacitor element, and this capacitor element l is made by forming a dielectric oxide film on the surface of an anode foil made of roughened aluminum foil, and winding this anode foil and cathode foil together with a separator. It is composed of: This capacitor element 1 is impregnated with a driving electrolyte, and is installed in a bottomed cylindrical metal case 2 made of aluminum.

Further, a pair of lead wires 3, 3 are connected from the capacitor element 1.
A is led out, and a pair of external connection terminals 4.4a are connected to the pair of lead wires 3, 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 in the opening of the metal case 2,
The opening of the metal case 2 is sealed by curling the open end of the metal case 2. Further, an explosion-proof valve 6 made of a thin weak point is formed on the top plate portion 2a of the metal case 2.

Furthermore, an exterior sleeve 7 made of insulating material such as vinyl chloride is installed on the outside of the metal case 2, and the upper part of the explosion-proof valve 6 provided on the top plate 2a of the metal case 2 has ventilation. In addition, an absorbent material 8 having the function of absorbing the driving electrolyte is disposed, and by covering the absorbent material 8 with the exterior sleeve 7 and heat-shrinking it, the absorbent material 8 becomes the exterior sleeve. 7 and the metal case 2 so as to be sandwiched and fixed. Note that, as the material of the absorbent material 8, for example, glass fiber, porous polymer, filter paper, nonwoven fabric, etc. are used. In this case, the filter paper and nonwoven fabric may be used after being subjected to flame retardant treatment.

The operation in the above configuration will be explained. Even if an abnormal voltage or the like is applied to this aluminum electrolytic capacitor and the internal pressure rises, and the explosion-proof valve 6 provided on the top plate 2a of the metal case 2 is activated and the internal drive electrolyte spouts out, the drive The gas of the electrolytic solution is absorbed by the absorbent material 8 and is therefore not released to the outside.

Effects of the Invention As is clear from the description of the above embodiments, 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, and The top of the metal case includes 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 a sealing member that seals the opening of the metal case. An absorbent material that is breathable and has the function of absorbing the driving electrolyte is provided above the explosion-proof valve provided on the plate, and this absorbent material is sandwiched between the exterior sleeve and the metal case. Because it is fixed in this way, the absorbent material can be easily and accurately fixed above the explosion-proof valve installed on the top plate of the metal case, and when the explosion-proof valve is activated, the absorbent material can be easily and accurately fixed above the explosion-proof valve. The gas in the drive electrolyte can be absorbed by the absorbent material fixed above the explosion-proof valve in the metal case, so it is possible to prevent the drive electrolyte gas from leaking outside. be.

[Brief explanation of drawings]

FIG. 1... Capacitor element, 2... Metal case, 33a... Pair of lead wires, 4, 4a...
... Pair of external connection terminals, 5 ... Sealing member, 6 ... Explosion-proof valve, 7 ... Exterior sleeve, 8 ... Absorption 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. external connection terminal,
and a sealing member that seals the opening of the metal case,
An absorbent material that is breathable and has the function of absorbing the driving electrolyte is provided above the explosion-proof valve provided on the top plate of the metal case, and this absorbent material is attached to the outer sleeve and the metal case. An aluminum electrolytic capacitor that is fixed by being sandwiched between.