JPH0330976B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a so-called tubular electrolytic capacitor having a structure in which external connection terminals protrude in opposite directions, and in particular improves and strengthens the connection between the cathode terminal and the exterior case. The present invention also relates to a method for connecting the cathode of an electrolytic capacitor that easily realizes miniaturization of the electrolytic capacitor.

In conventional tubular electrolytic capacitors, the first
As shown in the figure, the cathode terminal 6 is led out from the capacitor element 1 and electrically connected to the inner bottom surface of the outer case 9 by ultrasonic welding, spot welding, or the like.

In the conventional connection method as described above, the cathode terminal 6, which is longer than the outer case 9, occupies a larger volume inside the outer case 9. Therefore, it has become difficult to miniaturize electrolytic capacitors, especially tubular electrolytic capacitors.

Moreover, the cathode terminal 6 stored inside the exterior case 9 is easily folded to form a bent part.
There was a risk that the bent portion would break through the electrolytic paper 4 of the capacitor element 1 and bring the anode foil 2 and cathode foil 3 into contact, inducing an electrical short circuit accident.

In addition, the manufacturing method is such that the cathode terminal 6 is installed at the tip of a welding jig, and the outer case 9 is integrated with the welding jig.
After sliding into the welding jig, ultrasonic waves, electric current, etc. were applied to the welding jig to connect the exterior case 9 and the cathode terminal 6. In this case, the cathode terminal 6 simply installed at the tip of the welding jig often falls off from the welding jig during the connection process, making the manufacturing process complicated.

The present invention aims to overcome the above-mentioned drawbacks, improve the reliability of electrolytic capacitors, especially tubular electrolytic capacitors, and simplify the manufacturing process.

The present invention provides at least one perforation in a part of the tip of a cathode terminal led out from a capacitor element formed by winding an anode foil and a cathode foil together with electrolytic paper, and also provides a hole in one of the welding jigs. a protrusion having a shape that matches the shape of the perforation is provided in the part;
After the perforation is hooked to the protrusion, the cathode terminal and welding jig are inserted into the outer case together and brought into contact with the inner surface of the outer case, and the other welding jig is inserted into the outer surface of the outer case. The exterior case and the cathode terminal are brought into contact with each other, and the exterior case and the cathode terminal are welded while being sandwiched between the two welding jigs.

Next, the present invention will be explained according to the drawings.

FIG. 2 is an explanatory diagram showing a method for connecting the cathode of an electrolytic capacitor according to the present invention.

In the drawing, a capacitor element 1 has an anode foil 2
and cathode foil 3 are wound together with electrolytic paper 4. The capacitor element 1 is housed in an exterior case 9 after being impregnated with an electrolyte. When the capacitor element 1 is housed in the outer case 9, the cathode terminal 7 led out from the capacitor element 1 is connected to a part of the side surface of the outer case 9. At this time, cathode terminal 7
The cathode terminal 7 is slid into the exterior case 9 integrally by anchoring a hole 8 previously provided at the tip of the cathode terminal 7 to a protrusion 14 provided at the end of the welding jig 12.

Cathode terminal 7 slid in together with welding jig 12
is electrically connected to the exterior case 9 by a method such as ultrasonic welding or spot welding by the other welding jig 13 that comes into contact with the outer surface of the exterior case 9.

Welding jig 12 inserted into exterior case 9 after welding
is pulled out, a sealing member 10 made of rubber, synthetic resin, etc. is inserted into the anode terminal 5, and the sealing portion of the outer case 9 is crimped to seal the electrolytic capacitor.

Note that a protrusion 14 provided at the tip of the welding jig 12
may be two or more, and the shape of the projection 14 may be any shape as long as it can grip the cathode terminal 7.

In addition, a protrusion 1 provided on one welding jig 12
4 may be provided at any location as long as the cathode terminal 7 can be gripped.

Furthermore, a welding jig 1 that slides into the exterior case 9
The welding jig 12 may be easily pulled out after welding by providing an inclined portion at the tip of the welding jig 12.

As described above, the method for connecting an electrolytic capacitor according to the present invention involves forming at least one hole in a part of the tip of a cathode terminal led out from a capacitor element formed by winding an anode foil and a cathode foil together with electrolytic paper. At the same time, a part of one welding jig is provided with a protrusion having a shape that matches the shape of the perforation, and after the perforation is hooked to the protrusion, the cathode terminal and the welding jig are integrated into an exterior case. At the same time, the other welding jig is brought into contact with a part of the outer surface of the outer case, and the outer case and the cathode terminal are held between the two welding jigs. Because it is welded, the cathode terminal does not fall off during the electrolytic capacitor manufacturing process.
The manufacturing process can be simplified.

In addition, the cathode terminals inside the completed electrolytic capacitor are housed in a regular manner, which prevents electrical short-circuit accidents where the bent portions penetrate the capacitor element and short-circuit the anode foil and cathode foil, unlike in conventional capacitors. It can be prevented.

In addition, in the cathode terminal connection process, it is sufficient that there is a minimum length between the opening of the outer case and the joint between the side surface of the outer case, and therefore, the volume occupied by the cathode terminal inside the electrolytic capacitor is Since this can be minimized, the electrolytic capacitor as a whole can be easily miniaturized.

Furthermore, the protrusion provided at the tip of the welding jig reliably holds the cathode terminal and guides it to the joint, making it easy to perform a reliable connection process and improving reliability.

In summary, the present invention is a useful invention that easily downsizes an electrolytic capacitor and simplifies the manufacturing process while maintaining a good connection between the cathode terminal and the exterior case.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the structure of a conventional tubular electrolytic capacitor, Fig. 2 is a cross-sectional view explaining the manufacturing process according to the present invention, and Fig. 3 is a completed state of the tubular electrolytic capacitor according to the present invention. FIG. 1... Capacitor element, 2... Anode foil, 3...
Cathode foil, 4... Electrolytic paper, 5... Anode terminal, 6, 7
... Cathode terminal, 8 ... Perforation part, 9 ... Exterior case, 10 ... Sealing body, 11 ... Cathode external terminal, 1
2, 13...Welding jig, 14...Protrusion.

Claims (1)

[Claims] 1 At least one or more perforation is provided in a part of the tip of the cathode terminal led out from the capacitor element formed by winding an anode foil and a cathode foil together with electrolytic paper, and at least one perforation is provided in a part of one of the welding jigs. After providing a protrusion with a shape that matches the shape of the perforation and hooking the perforation to the protrusion, the cathode terminal and the welding jig are integrally inserted into the exterior case and brought into contact with the inner surface of the exterior case. A method for connecting an electrolytic capacitor, characterized in that the other welding jig is brought into contact with a part of the outer surface of the outer case, and the outer case and the cathode terminal are sandwiched and welded between the two welding jigs.