JP2000030980A - Outer packaging structure of electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer packaging structure of an electrolytic capacitor which can avoid defective phenomena, such as the damage of an outer packaging member and 'squeaking', which are caused by small vibratrion such as noise when there is a little space between the outer surface of an outer packaging case and the outer packaging member. SOLUTION: The outer surface of an outer packaging case 3 for storing a capacitor element 2 is covered with a tubular outer packaging member 6 made of thermal shrinking resin. The outer packaging member 6 is airtightly attached to the outer surface of the outer packaging case 3 due to thermal shrinkage. Over the entire outer surface of the tubular outer packaging member 6, a resin layer 7 is formed. Due to this structure, most of mechanical vibration and stress from outside is absorbed by the resin layer formed on the outer surface of the outer packaging member and therefore inside of the capacitor element is not influenced by those external factors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an electrolytic capacitor, and more particularly to a structure for improving the seismic performance of an electrolytic capacitor.

[0002]

2. Description of the Related Art As shown in FIGS.
In a normal electrolytic capacitor 1, a capacitor element 2 in which an electrode foil and electrolytic paper are wound is housed in a bottomed cylindrical outer case 3 made of aluminum or the like, and the open end surface of the outer case 3 is made of elastic rubber or the like. It has a configuration sealed with a sealing body 5.
From the capacitor element 2, a lead wire 4 electrically connected to the electrode foil penetrates the sealing body 5 and is guided to the outside, and connects the electrode of the electrolytic capacitor 1 to the outside. The outer case 3 is covered with a tubular outer member 6 made of a heat-shrinkable resin.

[0003]

The connection between the electrode foil and the lead wire 4 is usually made by means such as crimping and crimping. This connecting means has the disadvantage that its mechanical strength decreases as it becomes finer. Alternatively, if the electrode foil is subjected to a high-magnification etching process, the mechanical strength of the electrode foil itself becomes extremely weak, which makes the connection process with the lead wire difficult. In some cases, it became defective. Therefore, the electrical characteristics such as tan δ of the electrolytic capacitor are deteriorated, and inconveniences such as a short circuit accident may occur. Alternatively, the distance between the electrode foils is minutely changed due to vibration, and the capacitance is slightly changed.

Further, the electrolytic capacitor uses a tubular outer member made of a heat-shrinkable resin on the outer surface of the outer case, and is adhered to the outer surface of the outer case by heat shrinkage. Nothing could be coated. Therefore, although the outer surface of the outer case and the outer member are in close contact due to the heat shrinkage of the outer member,
A small gap may be generated, or an instantaneous gap may be generated due to vibration such as sound. In particular, in electrolytic capacitors used for acoustic products, minute vibration noise caused by a slight gap between the outer surface of these outer cases and the outer members becomes a so-called "squeal" phenomenon, which affects sound quality characteristics. Had an effect. In addition, since a thin tube-shaped exterior member made of a heat-shrinkable resin is used, it may be damaged by external mechanical stress, and the insulation of the exterior case may be damaged.

[0005] The color of the exterior member is the ground color of the exterior member itself.
After arranging exterior members of each color, it is necessary to install them in a predetermined manufacturing apparatus, and replacement work in the manufacturing process is complicated.

[0006]

According to the electrolytic capacitor of the present invention, the outer surface of an outer case for housing a capacitor element is covered with a tubular outer member made of a heat-shrinkable resin, and the outer surface of the outer case is shrunk by heat shrinkage. Wherein a resin layer is formed on the entire outer surface of the tubular exterior member.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawing shown in FIG. FIG. 1 is a partial sectional view showing an embodiment of the present invention. The same reference numerals used in FIGS. 1 and 2 indicate the same components. In FIG. 1, the capacitor element 2 is formed by winding both electrode foils (not shown) and electrolytic paper. An electrode lead wire 4 made of aluminum or the like is electrically connected to the electrode foil by means such as crimping, and leads the electrode to the outside. Capacitor element 2
Is housed together with the electrolytic solution in a bottomed cylindrical outer case 3 made of aluminum or the like. And the outer case 3
A sealing body 5 made of elastic rubber or the like is attached to the opening end face of the opening. Lead wire 4 projected from capacitor element 2
Is projected through the sealing body 5 to the outside. The opening end of the outer case 3 to which the sealing body 5 is attached is
The inside of the outer case 3 is sealed by being fitted to the sealing body 5 by means such as tightening.

[0008] A tube-shaped exterior member 6 made of a heat-shrinkable resin is placed on the outside of the exterior case 3, and is heat-shrinked by heat treatment so as to adhere to the outer surface of the exterior case.
The exterior member 6 formed of a heat-shrinkable resin tube is
The outer surface of the exterior member 6 is coated with a resin, and a resin layer 7 is formed on the outer surface.

The electrolytic capacitor thus formed is
Tube-shaped exterior member 6 made of heat-shrinkable resin as the exterior
Are arranged, and the exterior member 6 has a resin layer 7 formed on the outer surface. Therefore, even when a thin heat-shrinkable resin tube is used for the exterior of the electrolytic capacitor, vibration such as sound is absorbed by the resin layer 7 and a failure phenomenon such as "squeal" hardly occurs.

In addition, since various colors can be applied by adding a pigment to the resin layer 7 to be coated, even if exteriors of various colors are required, the common exterior member 6 can make up for various colors. Therefore, it is not necessary to use the exterior member, and the manufacturing process is simplified.

[0011]

As described above, according to the present invention, the outer surface of the outer case housing the capacitor element is covered with the tubular outer member made of a heat-shrinkable resin, and a resin layer is formed on the outer surface of the outer member. Since it is characterized by being formed, most of the mechanical vibration and stress from the outside will be absorbed by the resin layer formed on the outer surface of the exterior member, eliminating the influence on the internal capacitor element. be able to.

Therefore, the connection state between the lead wire and the electrode foil can be maintained in good condition, and the electrical characteristics such as tan δ can be maintained for a long time. Further, since external vibrations are absorbed by the resin layer formed on the outer surface of the exterior member, fine changes between the electrode foils are reduced, and the reliability is improved.

[0013] Even when a thin tube-shaped exterior member is used, by forming a resin layer on the outer surface of the exterior member,
With this resin layer, vibration can be suppressed, and the effect on sound quality characteristics can be suppressed.

Further, since the resin layer is formed on the outer surface of the exterior member, even if a thin tube-shaped exterior member is used, damage to the exterior member due to external mechanical stress can be reduced, and the exterior case can be reduced. It is practical because the number of accidents that impair the insulation is reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electrolytic capacitor showing a first embodiment of the present invention.

FIG. 2A is a perspective view of a conventional electrolytic capacitor. (B) is a sectional view of the conventional electrolytic capacitor shown in (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrolytic capacitor 2 Capacitor element 3 Metal case 4 Terminal 5 Sealing body 6 Exterior member 7 Resin layer

Claims (1)

[Claims] 1. An electrolytic capacitor in which a tubular outer member made of a heat-shrinkable resin is coated on an outer surface of an outer case for housing a capacitor element, and is adhered to an outer surface of the outer case by heat shrinkage. An exterior structure for an electrolytic capacitor, wherein a resin layer is formed on the entire outer surface of the exterior member.