JPS6012283Y2 - Electrolytic capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an external lead terminal in an electrolytic capacitor.

Generally, as shown in Fig. 1, an electrolytic capacitor is manufactured by connecting a lead plate 1 to electrode foils for anodes and cathodes by crimping, etc., and then winding the capacitor element 2 through electrolytic paper.
form.

Next, after impregnating the capacitor element 2 with an electrolytic solution, the drawer lead plate 1 is connected to the aluminum rivet 3 on the back side of the sealing plate 5 to which the external terminal 4 has been previously attached using the aluminum rivet 3, and the element fixing material 6 is attached. It is inserted into the injected capacitor case 7, and the opening of the case 7 is sealed tightly.

As shown in FIG. 2, the electrolytic capacitor constructed as described above is generally manufactured by attaching the aluminum rivet 3 to the lead plate 1 and the aluminum washer 8 so as to penetrate it, and pressing the aluminum rivet 3 to the lead plate. 1 and aluminum rivet 3 are connected.

Further, the external terminal 4 is connected by passing an aluminum rivet 3 through the sealing body 5 and pressing the aluminum rivet 3.

Therefore, the electrical connection between the lead plate 1 and the external terminal 4 is via the aluminum rivet 3 and the aluminum washer 8, and when the resistance between the lead plate 1 and the external terminal 4 is measured, the resistance between the lead plate 1 and the external terminal 4 is The respective contact resistances between the aluminum washers 8, between the aluminum washers 8 and the aluminum rivets 3, and between the aluminum rivets 3 and the external terminals 4 become a large sum.

Especially in the case of acoustic electrolytic capacitors, it is known and confirmed by many experts who evaluate sound quality that the magnitude of contact resistance, including the caulking part between the lead lead and the electrode foil, has a large effect on sound quality. It is.

When we experimentally inserted a conventional electrolytic capacitor into the power supply section of an audio device and compared the sound quality when the external connection position of the capacitor terminal was external terminal 4 and aluminum rivet 3, there was a clear difference in sound quality. In this case, there is a lack of volume and power in the midrange and bass range, a decrease in transparency in the high range, resolution,
The fact that the expressive power of the sound field becomes poor also indicates that the resistance of the connection part has an effect.

The present invention aims to eliminate the above-mentioned drawbacks and provide an electrolytic capacitor in which the contact resistance between the lead plate and the external terminal is significantly reduced.

The present invention will be described below with reference to an embodiment shown in FIG.

FIG. 3 shows a cross-sectional view of the main terminal connection part of an electrolytic capacitor. Powdered aluminum such as alumina is sprayed onto the aluminum rivet 3' and the aluminum washer 8' in advance to coat the surfaces of the aluminum rivet 3' and the aluminum washer 8'. Using a plate with unevenness 9 formed by grinding, connect the lead plate 1 led out from the capacitor element 2 and the external terminal 4 to the aluminum rivet 3' and the aluminum washer through the sealing plate 5 in the same manner as shown in FIG. 8' are crimped and connected, and the capacitor case 7 is inserted into the capacitor case 7, and the opening of the case 7 is tightened and sealed. The oxidized film is removed, the hardness of the connection surface is improved, and the contact area is increased.

In addition, other methods of increasing the contact area include etching by electrolytic polishing, mechanical grinding, and forming irregularities on the surface, but although etching by electrolytic polishing increases the surface area, the irregularities are too fine. , the convex portion is weak in strength and the concave and convex portions are crushed by pressing, resulting in no increase in the contact area.

In addition, there is a limit to the size of the unevenness when using mechanical grinding or molding, and mechanical grinding in particular is not suitable for mass production, and when using molding, the unevenness becomes rough, making it impossible to increase the contact area. .

The electrolytic capacitor of this invention sprays powder such as alumina onto aluminum rivets and aluminum washers to grind the surface and create unevenness 9, so conventional aluminum rivets and washers can be used as is, and can be processed in large quantities. , and the contact resistance of the terminal portion is significantly reduced.

When used in audio equipment, it has the effect of improving sound quality.

Lead 1 of an electrolytic capacitor manufactured based on the present invention
The contact resistance between the external terminal 4 and the external terminal 4 was 0.3 mΩ using the conventional method, but it can be reduced to 0.09 rmΩ.
It was proven that the sound quality was also improved.

Further, the unevenness 9 may be formed by sandblasting at least one of an aluminum rivet and an aluminum washer.

As described above, the electrolytic capacitor of the present invention significantly reduces the contact resistance of the terminal portion, greatly contributes to improving the sound quality of audio equipment, and has great practical value.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a general electrolytic capacitor, Fig. 2 is a cross-sectional view of the main terminal connection part of a conventional electrolytic capacitor, and Fig. 3 is a cross-section of the main terminal connection part of an embodiment of the electrolytic capacitor of the present invention. It is a diagram. 1...Drawer lead plate, 2...Capacitor element, 3'...Aluminum rivet, 4...
...External terminal, 5...Sealing plate, 8'...
...Aluminum washer, 9...Irregularities.

Claims (1)

[Scope of utility model registration request] In an electrolytic capacitor in which a lead plate led out from a capacitor element and an external terminal are crimped and connected with an aluminum rivet and an aluminum washer through a sealing plate, at least one of the aluminum rivet and the aluminum washer has irregularities formed by sandblasting. An electrolytic capacitor is formed by crimping the unevenness on a lead plate.