JPH0468516A - Caulking method of aluminum rivet for connection of inside terminal of electrolytic capacitor - Google Patents

Abstract

PURPOSE:To reduce and stabilize contact resistance by using three-stage caulking method including primary caulking for pressing to enlarge an end part of an aluminum rivet, secondary caulking for shaping the aluminum rivet by riveting thereafter and tertiary caulking for further pressing. CONSTITUTION:An aluminum rivet 11 which is provided with brim part 11a to support an terminal board 15 in the middle is attached to the terminal board 15. After a lower part 11b of the aluminum rivet 11 is inserted to a connection hole of an inside terminal 13 led out of a capacitor element, primary caulking is carried out for pressing to enlarge a part of the lower part 11b. Then, the lower part 11b of the aluminum rivet 11 is shaped to a configuration of the 11c by secondary caulking. Tertiary caulking is further carried out to lower the dimension A of a caulking height. The aluminum rivet 11 is adequately enlarged, thereby realizing adequate contact between the aluminum rivet 11 and a connection hole of the inside terminal 13. Connection resistance thereby lowers and stabilizes.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for caulking aluminum rivets for connecting internal terminals of electrolytic capacitors used in general electronic equipment.

2. Description of the Related Art Conventional electrolytic capacitors of this type have a flange 1a in the middle, as shown in FIG. Using the aluminum rivet 1, as shown in FIG. , Figure 7 (al
As shown in Figure 7, the lower part 1b of the aluminum rivet 1 is pressed to the extent that it swells to perform primary caulking, and then, as shown in Figure 7fbl, the lower part 1b of the aluminum rivet 1 is IC-shaped by riveting (secondary caulking).
The internal terminal 3 pulled out from the capacitor element 2 is held between the caulked part IC at the bottom of the cut 1 and the collar part 1a, and the external terminal 6 is inserted into the upper part of the aluminum rib 1. It had a structure in which the caulking portion 1d and the terminal plate 5 were sandwiched and fixed together.

Problems to be Solved by the Invention However, in the conventional method of caulking an aluminum rivet for connecting an internal terminal of an electrolytic capacitor, the contact resistance at the connection part between the internal terminal 3 drawn out from the capacitor element 2 and the aluminum rivet 1 becomes unstable. Something happened. That is, when we investigated the cause, we found that the contact between the internal terminal 3 and the aluminum rivet 1 was due to the bulge of the aluminum rivet 1 due to caulking, as shown in Fig. 6. The bulge of the aluminum rib 1 is difficult to bulge at the base of the flange 1a, as shown in FIG. It was determined whether the contact resistance was unstable due to insufficient contact with the inner surface of No. 4.

In view of such conventional problems, the present invention aims to provide a method for caulking an aluminum rivet for connecting internal terminals of an electrolytic capacitor, which stabilizes the contact resistance of the connecting portion between the aluminum rivet and the internal terminal. It is.

Means for Solving the Problems In order to achieve the above objects, the present invention provides a terminal plate for sealing the opening of a bottomed cylindrical metal case in which a capacitor element is housed, and an aluminum terminal plate for connecting external terminals to the terminal plate. The aluminum rivet has a rivet and an internal terminal pulled out from the capacitor element, a flange supporting the terminal plate is provided in the middle part of the aluminum rivet, the internal terminal is brought into contact with the lower surface of the flange, and the aluminum In a method for caulking an aluminum rivet for internal terminal connection of an electrolytic capacitor, in which the internal terminals are caulked and connected by caulking the ends of the rivets, the aluminum rivet caulking method includes a primary pressing process in which the ends of the aluminum rivets are pressed to the extent that they bulge. This method uses a three-step caulking method: caulking, secondary caulking in which the aluminum rivet is shaped by riveting, and tertiary caulking in which the aluminum rivet is then further pressed.

Function According to the above caulking method, the aluminum rivet for internal terminal connection is caulked by primary caulking in which the head of the aluminum rivet is pressed to the extent that it bulges, and then secondary caulking in which the aluminum rivet is shaped by reshaping.
After this, we use a three-step caulking method with tertiary caulking, which is followed by further pressing, so that the connection between the internal terminal drawn out from the capacitor element and the aluminum rivet is fully expanded by the tertiary caulking, and the internal terminal Sufficient contact with the inner surface of the connection hole is maintained, and as a result, contact resistance is reduced and stable contact is obtained.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings. In FIG. 1, reference numeral 11 denotes an aluminum rivet having a flange 11a that supports a terminal plate 15 in the middle thereof.This aluminum rivet 11 is attached to the terminal plate 15 and is pulled out from the capacitor element 12. Insert the lower part 1 of the aluminum rivet 11 into the connection hole 14 of the internal terminal 13.
1b), and then, as shown in FIG. 2(a), primary caulking is performed by pressing the lower part 11b of the aluminum rivet 11 to the extent that it bulges, and then, as shown in FIG. 2(ib), rehenoting ( The lower part 11b of the aluminum rivet 11 is shaped into a llc shape by secondary caulking, and then, as shown in FIG. Then, as shown in FIG. 1, the internal terminal 13 pulled out from the capacitor element 12 is held between the caulking part 11c and the collar part 11a of the lower part of the aluminum rivet 11.
Connect the external terminal 16 to the caulking part 1 on the top of the aluminum rivet 11.
1d and the terminal plate 15 and are firmly fixed together.

FIG. 3 shows the overall structure of an electrolytic capacitor according to an embodiment of the present invention. The capacitor element 12 is housed in a metal case 17 made of aluminum and has a cylindrical shape with a bottom. Terminal board 1
5 is attached to seal the metal case 17, and an exterior sleeve 18 made of vinyl chloride is attached to the outer peripheral surface of the metal case 17 to form an electrolytic capacitor.

According to the method for caulking the aluminum rivet 11 in the embodiment of the present invention, the lower part 11b of the aluminum rivet 11 is tightened by riveting (secondary caulking) shown in FIG.
After shaping the part into the llc shape, as shown in FIG. and internal terminal 13
Since the contact with the inner surface of the connecting hole 14 is sufficient,
Contact resistance becomes low and stable.

Figure 4 shows the results of comparing the contact resistance of an electrolytic capacitor using the crimping method of this embodiment, which performs tertiary crimping by pressing, with the contact resistance of an electrolytic capacitor using the crimping method shown in the conventional example. As is clear from FIG. 4, the contact resistance of the electrolytic capacitor in this example is significantly improved compared to the conventional example.

Effects of the Invention As is clear from the description of the above embodiments, according to the present invention,
The method of caulking aluminum rivets for internal terminal connections involves three stages: primary caulking, in which the head of the aluminum rivet is pressed to the extent that it swells, secondary caulking, in which the aluminum rivet is then shaped by riveting, and tertiary caulking, in which further pressing is performed. Since the caulking method is used, the connection between the internal terminal drawn out from the capacitor element and the aluminum rivet is made by tertiary caulking, which allows the aluminum rivet to swell sufficiently and to maintain sufficient contact with the inner surface of the connection hole of the internal terminal. As a result, the contact resistance becomes low and stable. Furthermore, since the height of the caulking of the aluminum rivet is lower than before, the gap between the terminal plate and the capacitor element when the capacitor element is housed in a metal case is also reduced, contributing to the miniaturization of the electrolytic capacitor.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the main parts of an electrolytic capacitor that employs the caulking method of aluminum rivets for internal terminal connection in one embodiment of the present invention, and Figures 2 (a), (bl, and c) are the order of the same caulking method. 3 is a longitudinal sectional view of an electrolytic capacitor of the present invention adopting the same crimping method, and FIG. 4 is a characteristic diagram showing a comparison of contact resistance between the electrolytic capacitor of the present invention and a conventional electrolytic capacitor. Fig. 5 is a cross-sectional view showing a conventional aluminum rivet, Fig. 6 is a cross-sectional view of the main part of an electrolytic capacitor that adopts the conventional caulking method of aluminum rivets for internal terminal connection, Fig. 7 (a), (bl is a conventional It is a partial sectional view showing the order of the caulking method. 11... Aluminum rivet, 11a...
Flange portion, 11b... lower part, llc... caulking part, 12... capacitor element, 13...
...Internal terminal, 15...Terminal board, 16...
...External terminal, 17...Metal case. Name of agent: Patent attorney Shigetaka Awano (1 person) Figure 1 Aluminum Ribe °II/F- Tsuba lower 1 door D1 υ sound β 16 Outer pigeon work diagram Figure 71 Remime T seat Figure 7

Claims (1)

[Claims] It has a terminal plate that seals the opening of a bottomed cylindrical metal case that houses a capacitor element, an aluminum rivet that connects an external terminal to this terminal plate, and an internal terminal that is drawn out from the capacitor element, An electrolytic capacitor in which a flange supporting the terminal plate is provided in the middle part of the aluminum rivet, the internal terminal is brought into contact with the lower surface of the flange, and the internal terminal is caulked and connected by caulking the end of the aluminum rivet. In the method of caulking an aluminum rivet for internal terminal connection, the method of caulking the aluminum rivet includes a primary caulking in which the end portion of the aluminum rivet is pressed to the extent that it bulges, a secondary caulking in which the aluminum rivet is then shaped by riveting, and a subsequent caulking. A method for caulking an aluminum rivet for internal terminal connection of an electrolytic capacitor, characterized by using a three-step caulking method including tertiary caulking, which further involves pressing.