JPS60224212A - Aluminum electrolytic condenser - 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 Field of the Invention The present invention relates to electrolytic capacitors, and more particularly to improving the sealing portion of electrolytic capacitors.

Conventional Structure and Problems A conventional aluminum electrolytic capacitor using aluminum foil as an electrode is constructed as shown in FIG. That is, the surface area is expanded by electrochemically roughening the aluminum foil, and then a dielectric oxide film is formed on this surface by anodizing to form an anode body, and this anode body is placed facing each other with a separator in between. The capacitor element 1 is formed by winding the cathode foil together with the cathode foil and impregnating it with a driving electrolyte, and then housing the capacitor element 1 in a cylindrical metal case 2 with a bottom. An elastic sealing body 4 made of rubber through which a lead wire 3 passes is inserted into the metal case 2, and the open end of the metal case 2 is sealed by drawing and curling.

To describe the elastic sealing body 4 in more detail, the conventional elastic sealing body 4 has a lead extraction hole 6 formed in the elastic sealing body 4, as shown in FIG. Such an elastic sealing body 4
When the drawing process was performed using the elastic sealing member 4, as shown in FIG. 3, a slight gap 6 was created on the upper and lower surfaces of the elastic sealing member 4 because force was applied from both sides of the elastic sealing member 4. In such a case, for example, the driving electrolyte may enter the gap 6 on the lower surface, resulting in further problems of electrolyte leakage. On the other hand, organic solvent for cleaning (organic chloride for cleaning the semicircular flux) remains in the gap 6 on the top surface.
This caused corrosion of the lead wire 3.

OBJECTS OF THE INVENTION The present invention is intended to eliminate such conventional drawbacks, and aims to provide an aluminum electrolytic capacitor that is free from electrolyte leakage defects and has improved detergent resistance.

Structure of the Invention To achieve this object, the present invention uses an elastic sealing member for an aluminum electrolytic capacitor in which the shape of the lead extraction hole is thicker at the center in the direction of lead extraction and narrower at the upper and lower ends. .

With this configuration, when an aluminum electrolytic capacitor is sealed, no gap is created between the upper and lower surfaces of the elastic sealing body, so it is possible to prevent electrolyte leakage and flux retention.

Description of examples An embodiment of the present invention will be described below.

Since the structure of the aluminum electrolytic capacitor is substantially the same as that shown in FIG. 1, the explanation here will be omitted.

The feature of the present invention lies in the elastic sealing body.
To explain with reference to FIG. 6, the elastic sealing body 4 made of rubber is provided with a lead extraction hole 6 through which the lead wire 3 is inserted.
The shape of the lead extraction hole 5 is thick at the center and narrow at the upper and lower ends.

That is, the shape of this lead extraction hole 6 is an entasis shape.

When such an elastic sealing body 4 is assembled and subjected to a drawing process 9, the result will be as shown in FIG. 6, and no gap will be created between the elastic sealing body 4 and the lead wire 3 inserted therethrough.

Next, specific examples will be described.

Rated value 16V3300/'F (16φX31')
400 capacitor elements were prepared, these were divided into two parts, and 200 products using elastic sealing bodies with different lead extraction holes were used as products of the present invention, and 200 products using elastic sealing bodies with the same lead extraction holes were used as conventional products. The number of products was 200.

These were visually inspected for electrolyte leakage defects after the thermal shock test. The results are shown in Table 1. The conditions for the thermal shock test were -40°C for 30 minutes, then 85'Cso for 1 cycle, and 50 cycles were performed.

From the results shown in the table, it is clear that the elastic sealant according to the present invention is effective in preventing electrolyte leakage.

Next, as another evaluation method, the above-mentioned 16V330oμF
100 capacitor elements were prepared, and these were divided into two to produce 60 products using elastic sealing bodies with different lead extraction holes as products of the present invention, and products using conventional elastic sealing bodies with the same lead extraction holes as conventional products. was set to 60. These were visually inspected for corrosion defects after the solvent test. The results are shown in Table 2. The conditions for the solvent resistance test were 40°C.
It was left in a Freon TK (manufactured by Mitsui Fluorochemical Co., Ltd.) solution for 20 minutes, and then subjected to a high temperature load test at 86°C for 2000 hours.

＼ As described in detail, according to the present invention, the shape of the lead wire extraction hole of the conventionally used elastic sealing body is made thinner on the upper and lower surfaces of the elastic sealing body than in the center part, so that the electrolyte solution can be easily removed. This has the effect of providing an aluminum electrolytic capacitor that does not suffer from leakage defects or corrosion defects.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a conventional aluminum electrolytic capacitor, Fig. 2 is a cross-sectional view of a conventional elastic sealing body, Fig. 3 is a cross-sectional view of the same in a squeezed state, and Fig. 4 is a cross-sectional view of an aluminum electrolytic capacitor of the present invention. A sectional view of the elastic sealing body in the example, and FIG. 5 is a sectional view showing the elastic sealing body at the time of sealing. 1... Capacitor element, 2... Old metal case, 3... Lead wire, 4... Elastic sealing body, 6... Lead drawer. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3

Claims (1)

[Claims] A capacitor element made by winding an anode foil and a cathode foil together with a separator and impregnating them with a driving electrolyte is housed in a bottomed cylindrical metal case, and the open end is sealed with an elastic sealing body, and the leads of this elastic sealing body are sealed. An aluminum electrolytic capacitor characterized by a lead-out hole that is thicker at the center in the lead-out direction and narrower at the top and bottom ends.