JPH0433316A - Aluminum electrolytic capacitor - Google Patents

Abstract

PURPOSE:To prevent outflow of gas of driving electrolytic solution to the outside by attaching an temperature sensing element to one of a pair of external connecting terminals and by arranging an insulating material case to cover an attaching part of the temperature sensing element and the external connecting terminal. CONSTITUTION:As a temperature sensing element 6, a temperature fuse, thermistor, etc., are used. When an overvoltage above the rated value is applied to an aluminum electrolytic capacitor, leakage current increases, thereby making a temperature of a capacitor element 1 rise by Joule heat due to resistance of driving electrolytic solution or a dielectric oxide film. In the process, since lead lines 3, 3a led out of the capacitor element 1 have very good heat conductivity, external connecting terminals 4, 4a connected thereto generate heat approximately simultaneously with an inside temperature of the metallic case 2. The heat generation is detected by the temperature sensing element 6, and an electric circuit of a capacitor is cut off rapidly by a detection signal from a connector 7 for connection which is connected to the temperature sensing element 6. Since an attaching part of the external connecting terminal 4 and the temperature sensing element 6 is covered with an insulating material case 8 and protected, an operation temperature of the temperature sensing element 6 is also stable.

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, this type of aluminum electrolytic capacitor element usually has a weak point in the aluminum case, and when the internal pressure of this 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 decomposed 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 for sealing the opening of the metal case are provided, a temperature sensing element is attached to one of the pair of external connection terminals, and the temperature sensing element is attached to one of the pair of external connection terminals. A connector for connection is attached to the end of the lead wire of the thermal element, and an insulating material case is arranged to cover the attachment part between the temperature sensing element and the external connection terminal, and the inside of the metal case is removed in the event of an abnormality. The temperature sensing element detects the heat generated by the external connection terminal due to the temperature rise, and the detection signal from the temperature sensing element is transmitted to the outside through the connection connector.
The signal is used to interrupt the capacitor's electrical circuit.

Function According to the aluminum electrolytic capacitor configured as described above, a temperature sensing element is attached to one of the pair of external connection terminals, a connector for connection is attached to the end of the lead wire of this temperature sensing element, and an insulating material case is attached. , because it is arranged so as to cover the attachment part between the temperature sensing element and the external connection terminal, so if an overvoltage higher than the rated value is applied to this aluminum electrolytic capacitor,
Leakage current increases, and the temperature of the capacitor element inside the metal case rises due to Joule heat due to the resistance of the driving electrolyte and dielectric oxide film. In this case, the lead wire led out from the capacitor element has very good thermal conductivity, so
The external connection terminal connected to this lead wire generates heat approximately equal to the internal temperature of the metal case. This heat generation is detected by the temperature sensing element, and the electric circuit of the capacitor is immediately interrupted by the detection signal from the connector connected to the temperature sensing element, which reduces the internal pressure of the metal case. Activation of safety devices such as an explosion-proof valve due to the rise can also be prevented, thereby preventing the gas of the driving electrolyte from leaking to the outside of the aluminum electrolytic capacitor.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. 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 membrane electrolyte, and the capacitor element 1 is formed into a metal case 2 made of aluminum and having a cylindrical shape with a bottom.
Equipped inside. Further, from the capacitor element 1, a pair of aluminum leads M3. :311 is derived,
A pair of external connection terminals 4 and 4L are connected to the pair of lead wires 3.3a by caulking at a portion of a sealing member 6 made of a terminal plate.

The sealing member 6 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 curling the open end of the metal case 2. Also, among the pair of external connection terminals 4.41,
A temperature sensing element 6 is attached to one external connection terminal 4, and a connector 7 for outputting signals to the outside is connected to the end of the lead wire of this temperature sensing element 6. ing. Further, the attachment portion between the external connection terminal 4 and the temperature sensing element 6 is covered and protected by an insulating material case 8 whose opening end is fixed to the opening side of the metal case 2 .

Note that as the temperature sensing element 6, a temperature fuse, a thermistor, a thermocouple, a bimetal, a temperature sensing reed switch, etc. are normally used.

The operation in the above configuration will be explained. When an overvoltage higher than the rated voltage is applied to this aluminum electrolytic capacitor, leakage current increases, and the temperature of the capacitor element 1 inside the metal case 2 rises due to Joule heat due to the resistance of the driving electrolyte and dielectric oxide film. . In this case, since the lead wire 3.3a led out from the capacitor element 1 has very good thermal conductivity, the external connection terminal 4.4a connected to the lead wire 3.3 is inside the metal case 2. It generates heat almost equal to the temperature. This heat generation is detected by the temperature sensing element 6, and the electric circuit of the capacitor is promptly interrupted by a detection signal from the connector 7 connected to the temperature sensing element 6.

In addition, the attachment part between the external connection terminal 4 and the temperature sensing element 6 is
Since it is covered and protected by the insulating material case 8, it is not affected by wind from external fans, etc.
The temperature of the mounting portion is stable, and as a result, the operating temperature of the temperature sensing element 6 is also stable.

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 pair of external connection terminals includes a pair of lead wires led out from a 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. Attach a temperature sensing element to one of the terminals, attach a connector for connection to the end of the lead wire of this temperature sensing element, and cover the attachment part of the temperature sensing element and the external connection terminal with an insulating material case. The temperature sensing element detects the heat generated by the external connection terminal due to the rise in temperature inside the metal cake in the event of an abnormality.
The detection signal of the temperature-sensitive element is transmitted to the outside through the connector, and the signal interrupts the capacitor's electrical circuit, so safety devices such as explosion-proof valves are not activated due to an increase in the internal pressure of the metal case. This makes it possible to reliably prevent the drive electrolyte from flowing out of the gas-powered aluminum electrolytic capacitor.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an aluminum electrolytic capacitor showing one embodiment of the present invention. 1...Capacitor element, 2...Metal case, 3゜3IL...Pair of lead wires, 4,4
a...Pair of external connection terminals, 6...
Sealing member, 6...Temperature sensing element, 7...Connector for connection, 8...Insulating material case. Name of agent: Patent attorney Shigetaka Awano and 1 other person 1st
figure

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 an opening of the metal case, and a temperature sensing element is attached to one of the pair of external connection terminals,
A connector for connection is attached to the end of the lead wire of this temperature-sensing element, and an insulating material case is arranged to cover the attachment part of the temperature-sensing element and the external connection terminal, and the metal case is used in case of an abnormality. A temperature sensing element detects heat generation at the external connection terminal due to a rise in internal temperature, and the detection signal from the temperature sensing element is transmitted to the outside through the connection connector, and the signal interrupts the capacitor's electrical circuit. An aluminum electrolytic capacitor characterized by: