JPH0410517A - Aluminum electrolytic capacitor - Google Patents

Abstract

PURPOSE:To prevent occurrence of buckling in the vicinity of winding core part toward the center part even when the internal pressure of a capacitor take-up element is increased in case of an abnormal condition by a method wherein a metal rod is provided in the cavity part of the winding core of the capacitor take-up element, the capacitor take-up element is inserted into an aluminum case, and the open end of the aluminum case is sealed by a sealing material. CONSTITUTION:Anode foil is connected to a cathode lead terminal 13 through the intermediary of separator paper, it is wound together with cathode foil, and the center part of the external circumference of the above-mentioned material is fixed by the roll-fastening tape 14 consisting of Mylar and polypropylene. Also, a metal rod is provided on the winding core cavity part 15 of a capacitor take-up element 11. The capacitor take-up element 11 is inserted into a bottomed cylindrical aluminum case 17 together with a driving electrolyte, the open end of the aluminum case 17 is curling-sealed using a sealing material, and an aluminum electronic capacitor is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an aluminum electrolytic capacitor, and more specifically, to an aluminum electrolytic capacitor for power supplies used in switching power supplies and the like.

Conventional technology Conventional aluminum electrolytic capacitors, as shown in Figure 3,
A dielectric oxide film is formed on the surface of the roughened anode foil, an anode lead terminal is connected to the anode foil, and a cathode lead terminal 2 is connected to the anode foil through a separator paper.
The capacitor winding element 4 is formed by winding it together with a roughened shade 8i foil, and fixing this winding with a winding tape 3 made of Mylar or polypropylene. The liquid was inserted into a cylindrical aluminum case (not shown) with a bottom, and the open end of the aluminum case was sealed with a sealing material (not shown).

Problems to be Solved by the Invention When abnormal stress such as overvoltage is applied to the above-mentioned conventional aluminum electrolytic capacitor, leakage current increases, and reaction gas with the driving electrolyte due to electrolysis is generated in the capacitor winding element 4. Internal pressure is generated from within and increases, exerting forces that tend to deform the capacitor winding element 4 inwardly and outwardly.

In this case, since the outer side is fixed with a winding tape 3 made of Mylar or polypropylene, outward deformation can be prevented.

However, since the center of the winding core of the capacitor winding element 4 is a hollow part 5, when gas is generated from the capacitor winding element 4 and its internal pressure increases, the capacitor winding The area around the winding core of the element 4 could not withstand the internal pressure, and buckling 6a, 6b occurred in the cavity 5 toward the center as shown in FIG. When such buckling 6a, 6b occurs,
In this case, the anode foil or cathode foil cracks or cracks, and the pieces of foil that occur at this time break through the separator paper and cause a short circuit.
If a short circuit occurs at the capacitor winding element 4, the spark will ignite the driving electrolyte, causing the aluminum electrolytic capacitor to catch fire.

The present invention solves these problems by providing an aluminum electrolytic capacitor that does not buckle near the winding core toward the center even if the internal pressure of the capacitor winding element increases during abnormal conditions. The purpose is to provide

Means for Solving the Problems In order to achieve the above object, the aluminum electrolytic capacitor of the present invention has a capacitor winding element formed by winding an anode foil and a cathode foil together with a separator paper and impregnating a driving electrolyte. A metal rod is disposed in the core cavity, this capacitor winding element is inserted into an aluminum case, and the open end of the aluminum case is sealed with a sealing material.

Effects According to the above configuration, since the metal rod is arranged in the winding core cavity of the capacitor winding element, when abnormal stress such as overvoltage is applied to the aluminum electrolytic capacitor, gas from the capacitor winding element is removed. Even if the internal pressure of the capacitor winding element increases due to the increase in generation, and a force acts to deform the anode foil, cathode foil, and separator paper near the winding core toward the center, the force is It can be supported by a metal rod placed in the winding core cavity of the capacitor winding element, and as a result, the anode foil, cathode foil, and separator paper do not buckle toward the center as in the past. Therefore, no cracks or cracks occur in the anode foil or the cathode foil, and short circuits can be reliably prevented.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings. In FIGS. 1 and 2, 11 is a capacitor winding element, which forms a dielectric oxide film on the surface of the roughened anode foil, and connects the anode lead terminal 12. This anode foil is connected to the cathode lead terminal 13 via a separator paper, and is wound together with the roughened cathode foil, and the center of the outer periphery of the wound product is fixed with a winding tape 14 made of mylar or polypropylene. It is composed of: In addition, the winding core cavity 1 of the capacitor winding element 11
5 is provided with a metal rod. Reference numeral 17 denotes an aluminum case with a cylindrical bottom. The capacitor winding element 11 is inserted into the aluminum case 17 along with the driving electrolyte, and the open end of the aluminum case 17 is inserted through a sealing material (not shown). By curling and sealing, an aluminum electrolytic capacitor is constructed.

If abnormal stress such as overvoltage is applied to the aluminum electrolytic capacitor configured as described above, leakage current increases, and reaction gas with the driving electrolyte due to electrolysis is generated from inside the capacitor winding element 11, causing internal pressure to rise. increases, and a force acts to deform the capacitor winding element 11 inwardly and outwardly.

In this case, since the outer side is fixed with a winding stopper 13 made of Mylar or polypropylene, outward deformation can be prevented. Furthermore, due to the increase in the internal pressure of the capacitor winding element 11, the force that tends to deform the anode foil, cathode foil, and separator paper near the winding core toward the center is exerted on the winding core cavity of the capacitor winding element 11. It can be supported by the metal rod 16 disposed at the winding core 15, and as a result, buckling toward the center near the winding core can be reliably prevented. This prevents cracks and cracks from occurring in the anode foil and the cathode foil, thereby preventing short circuits.

Effects of the Invention As is clear from the description of the above embodiments, the aluminum electrolytic capacitor of the present invention has a metal rod in the winding core cavity of the capacitor winding element, so that the aluminum electrolytic capacitor is protected against abnormalities such as overvoltage. When stress is applied, gas generation from the capacitor winding element increases and the internal pressure of the capacitor winding element increases, deforming the anode foil, cathode foil, and separator paper near the winding core toward the center. Even if a force is applied to the capacitor winding element, the force can be supported by the metal rod installed in the winding core cavity of the capacitor winding element, and as a result, the anode foil, cathode foil, and separator paper Since the metal will not buckle toward the center, there will be no cracks or cracks in the anode or cathode foils, and short circuits can be reliably prevented. This can be achieved by configuring.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a separated state of the capacitor winding element and aluminum case of an aluminum electrolytic capacitor in an embodiment of the present invention, and FIG. 2 is a partially enlarged perspective view of the capacitor winding element in the same aluminum electrolytic capacitor. Third
The figure is a partially enlarged perspective view of a capacitor stripping element in a conventional aluminum electrolytic capacitor. 11... Capacitor winding element, 15...
... Winding core cavity, 16 ... Metal rod, 17.
·····aluminum case. Name of agent: Patent attorney Shigetaka Awano 1 person/f-Conte/Puketori 1! Child 15゛-Now take a breath, take the police. 2nd Figure tr-11 Contempt respect element 15-Keep your heart with grace 11-'Take 1 offering

Claims (1)

[Claims] Wrap the anode foil and cathode foil together with separator paper,
A metal rod is placed in the winding core cavity of a capacitor winding element impregnated with a driving electrolyte, the capacitor winding element is inserted into an aluminum case, and the open end of the aluminum case is sealed with a sealing material. An aluminum electrolytic capacitor characterized by being sealed through a capacitor.