JPS6348116Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolytic capacitor that prevents winding of a capacitor element formed by winding aluminum foil and a spacer, and a short circuit between a lead terminal drawn out from the capacitor element and a case.

Conventionally, a capacitor element in which anode and cathode lead terminals are connected to aluminum foil with a roughened surface and a chemical conversion film formed thereon and wound through capacitor paper is wrapped with resin tape, and then the anode and cathode lead terminals are were connected by welding or caulking to rivets attached to the terminal board and housed in a metal case. However, in order to connect the anode and cathode lead terminals to the above-mentioned rivets by welding or caulking, a sufficient area is required for the welding chip or caulking mold to come into contact with the connection part. The length of the capacitor element becomes considerably longer than the distance between the end face of the capacitor element and the connection part of the terminal plate when the terminal plate to which the capacitor element is connected is fitted into the opening of the metal case and the opening is tightened. Therefore, since the anode and cathode lead terminals are folded and housed between the capacitor element and the terminal board, there is a problem that the folded part of the anode lead terminal comes into contact with the metal case which is the cathode, causing a short circuit. . In order to prevent this short circuit, methods are used to fix and insulate the anode lead terminal, such as covering the anode lead terminal with an insulating tube or filling the folded part with compound or adhesive polypropylene. Both of these methods require insulating tubes, adhesive polypropylene, etc., and require special work as described above to prevent short circuits, and have the disadvantage that such work is inefficient.

The present invention has been devised in view of the above points, and provides an electrolytic capacitor that can prevent short-circuit accidents in which the anode lead terminal comes into contact with the metal case by winding the capacitor element. This will be explained below using examples. As shown in Figures 1 and 2, the anode and cathode lead terminals are connected to the anode and cathode foils, respectively, which are made by roughening aluminum foil and forming a chemical conversion film, and the anode and cathode foils are connected using spacers such as capacitor paper. The capacitor element 1 is constructed by winding the capacitor element 1 through the capacitor. After winding, the capacitor element 1 is wrapped around the capacitor element 1 with an adhesive insulating tape 2, and the edge of the insulating tape 2 is configured to protrude from the end surface of the capacitor element 1 as shown in the figure.
The dimensions of this protruding portion 3 will be described later, but since it is intended to prevent the folded portion of the anode lead terminal 4 from coming into contact with the metal case 5, the dimensions of the protruding portion 3 are determined by the outer diameter, height, terminal plate and capacitor element surface of the capacitor element. Determined by requirements such as the gap with the end face. Note that 6 is a cathode lead terminal. The anode lead terminal 4 and the cathode lead terminal 6 of the capacitor element 1 configured in this way
is caulked and connected to the rivet 8 attached to the terminal plate 7. Since this connection is made in the state shown in FIG. 1, the anode and cathode lead terminals 4 and 6 have a considerable length as described in the conventional example. The capacitor element 1 connected to the terminal plate 7 is housed in a metal case 5, and the vicinity of the bottom surface of the terminal plate 7 is pressed to form a groove portion 9, and the opening edge is tightened to form a tightened portion 10 and sealed. . At this time, the anode and cathode lead terminals 4 and 6 are folded and positioned in the gap between the capacitor element 1 and the terminal plate 7. In the electrolytic capacitor produced in this way, the insulating tape 2 used to secure the capacitor element 1 protrudes above the end surface of the capacitor element 1, so the second
As shown in the figure, the gap formed between the terminal plate 7 and the end face of the capacitor element 1 is divided approximately by the outer diameter of the capacitor element 1. Therefore, the anode and cathode lead terminals 4 and 6 are connected to the protruding portion 3 of this insulating tape 2.
In particular, the anode lead terminal 4
Since they do not come into direct contact with the metal case 5 due to the insulating tape 2, a short circuit occurs. According to the inventor's experiments, the case outer diameter was 35 mmφ, the capacitor element outer diameter was 28 mmφ, the terminal gap on the terminal board was 16 mm, and the lead terminal width was 5 mm. In the conventional example described above, a short circuit of 0.8% occurred, but in the case of the present invention, there was no short circuit. It did not occur. In addition, the work is simple because the wrapping of the capacitor element 1, which was conventionally done, is simply done using the insulating tape 2 with a wider tape width. This eliminates the need for filling polypropylene or the like and fixing the lead-out terminals, which allows the process to be omitted.
In the above embodiments, the case where the anode and cathode lead terminals and the rivets are connected by caulking has been described, but welding (electrical, ultrasonic, etc.) may also be used. In addition, although the insulating tape 2 is wound to form the winding stop and the protruding part 3, the same effect can be obtained by, for example, covering the capacitor element after winding with an insulating tube with a protruding part at the tip and shrinking it by heat. I can do it. Further, in the embodiment, the case of two terminals has been described, but it is also effective for electrolytic capacitors having three or more terminals.

[Brief explanation of drawings]

The drawings all show embodiments of the present invention, and FIG. 1 is a front view showing a state in which a capacitor element and a terminal plate are connected, and FIG. 2 is a side sectional view showing an electrolytic capacitor. 1... Capacitor element, 2... Insulating tape, 3... Protruding portion, 4... Anode lead terminal, 5... Metal case,
6... Cathode lead-out terminal, 7... Terminal board, 8... Rivet,
9... Groove portion, 10... Sealing portion.

Claims (1)

[Scope of utility model registration request] A capacitor element in which an anode foil and a cathode foil connected to an anode lead-out terminal and a cathode lead-out terminal are wound with a spacer, and an insulating tape or covered insulation wrapped around the outer periphery of the capacitor element protruding from the end face of the capacitor element. A tube, a terminal plate to which a rivet connected to the anode extraction terminal and the cathode extraction terminal are attached, and a metal case housing the terminal plate and the capacitor element, the anode extraction terminal and the cathode extraction terminal protruding. Electrolytic capacitor folded inside the section.