JP2003197473A - Electrolytic capacitor with terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower the contact resistance value at fixing of lead foil to a rivet by caulking the foil to the rivet through a washer and, in addition, to make the presence/absence of the washer confirmable easily and visually, even after the foil is caulked to the rivet in an electrolytic capacitor with terminal. <P>SOLUTION: At fixing of the lead foil to the rivet of a sealing plate by caulking the foil to the rivet through the washer 10, the washer 10 is made to have at least one rugged surface, containing a plurality of recessed sections and/or projecting sections. In addition, the side face of the washer 10 is formed to a rugged surface to reflect light irregularly. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic capacitor with a terminal such as a lug terminal type electrolytic capacitor and a screw terminal type electrolytic capacitor. More specifically, a lead foil drawn from a capacitor element is provided on a sealing plate. The present invention relates to a washer used when caulking and fixing to a rivet that is being used.

[0002]

2. Description of the Related Art Since an electrolytic capacitor with a terminal handles a large amount of electricity, the lead-out lead of the capacitor element is a ribbon-shaped lead foil, and a sealing plate made of a hard resin plate is used as a sealing member. There is. A pair of rivets are provided through the sealing plate, and the extraction lead foil is pulled out to the outside by being connected to the rivets inside the case.

An example of its general configuration is shown in FIG. According to this, the electrolytic capacitor with a terminal is provided with the bottomed cylindrical metal case 1, and the capacitor element 2 is provided in the metal case 1.
Are stored and fixed by a fixing member 3 such as a pitch.

The capacitor element 2 is formed by spirally winding an anode foil and a cathode foil made of aluminum through a separator paper, and impregnating the electrolytic solution. The anode foil and the cathode foil are made of aluminum ribbon pieces. Lead-out lead foils 4 and 5 are respectively drawn out. The opening of the metal case 1 is sealed by a sealing plate 6.

Usually, a hard resin plate 6a such as Bakelite having a rubber plate 6b laminated on the upper surface is used as the sealing plate 6, and the sealing plate 6 is penetrated by a pair of rivets (aluminum tacks) 7,8. It is set up. Lug terminals 7a and 8a are attached to the outer ends of the cases of the rivets 7 and 8, respectively. In the case of the screw terminal type, female screws are provided at the case outer ends of the rivets 7 and 8.

The lead-out lead foils 4 and 5 have neck portions 7b and 8b inside the case of the rivets 7 and 8 corresponding to their polarities.
It is fixed by crimping. That is, a hole is made in the end of each of the lead foils 4 and 5, and the hole is formed in the neck 7 of the rivet.
While being inserted through b and 8b, a washer 9 is inserted and overlapped to prevent foil breakage, and then the necks 7b and 8b are crushed and fixed by caulking.

According to this caulking fixing, high reliability is obtained in terms of mechanical strength and there is no problem in terms of vibration resistance, but not only the contact resistance value increases due to the interposition of the washer, but also caulking. The contact resistance value may vary depending on the pressure.

Further, since the rivet, the lead foil and the washer are all made of an aluminum material and have the same color, it becomes difficult to visually confirm the presence or absence (forgetting to insert) of the washer, especially after caulking.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to lower the contact resistance value when caulking and fixing a lead foil to a rivet via a washer, and to stabilize the variation of the contact resistance value. It is to make it possible to easily visually confirm the presence or absence of a washer even after caulking.

[0010]

In order to solve the above-mentioned problems, the present invention comprises a capacitor element in which an anode foil and a cathode foil made of aluminum are wound around a separator paper, and the anode foil and the cathode foil. A ribbon-shaped anode lead foil and cathode lead foil that have been pulled out, a bottomed cylindrical metal case that houses the capacitor element, and a pair of rivets that penetrates through and seals the opening of the metal case. In an electrolytic capacitor with a terminal, wherein the anode lead foil and the cathode lead foil are each caulked and fixed to a neck portion inside each of the rivets by a washer, at least one surface of the washer has a plurality of recesses. and/
Alternatively, it is characterized in that it is formed as a non-flat surface including a convex portion.

According to this structure, the surface area of the washer is larger than that of the flat surface, and the washer comes into contact with the lead foil over a wider surface. Therefore, the contact resistance value is correspondingly reduced and the contact resistance value is reduced. It also becomes possible to stabilize the fluctuations of. Also, the mechanical strength is increased. Preferably, both the front and back surfaces of the washer are non-flat surfaces. The shape of the unevenness is arbitrary. Conical or quadrangular pyramid-shaped depressions or projections are preferably employed, but annular ribs or grid-shaped ribs may be used.

Even if only the surface of the washer is a non-flat surface,
Normally, the washer is larger than the head of the rivet after being swaged, so that the outer edge of the washer can be visually recognized. However, according to a preferred embodiment of the present invention, not only the front surface and / or the back surface of the washer but also the side surface of the washer is a non-flat surface. Formed as. This non-flat surface is for facilitating visual confirmation of the presence or absence of the washer.

In this sense, it is preferable that the non-flat surface on the side surface is formed by unevenness that diffusely reflects light. It should be noted that the present invention also includes non-flat surface treatment (for example, a satin-finished treatment having fine unevenness) for diffused reflection on only the side surface of the washer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an enlarged perspective view of a washer used in the present invention, and FIG. 2 is an explanatory view showing a procedure for caulking and fixing a lead foil to an anode side rivet, but caulking to a cathode side rivet is similar to that on the anode side. Is done. For the basic configuration of the electrolytic capacitor with terminal itself, refer to the overall configuration diagram of FIG.

First, referring to the enlarged perspective view of FIG. 1, a washer 10 used in the present invention is made of an aluminum material and has a non-flat surface processing. Non-planar surface processing means forming either a concave portion or a convex portion, or both a concave portion and a convex portion on a flat surface.

As an example, the surface can be made non-planar by making a large number of holes in the aluminum material with a tool such as a cone or a die, but a sand blast method, a chemical etching method or the like may be used.

In order to increase the contact area with respect to the lead foil and reduce the contact resistance value, it is preferable to form a hole by using a cone or the like, but to obtain a rough surface that diffusely reflects light, a die, sandblast method or chemical etching method is used. Can be said to be preferable.

In order to lower the contact resistance value with respect to the lead foil, the non-planar surface processing may be performed on at least either the front surface or the back surface of the washer 10. However, since the contact resistance value is further lowered, this embodiment is used. Then washer 1
Both the front and back of No. 0 have been subjected to non-flat surface processing. Further, after crimping, the side surface (peripheral surface) of the washer 10 is also processed to have a non-flat surface in order to easily visually confirm the presence or absence of the washer.

Next, the caulking fixing of the lead foil to the rivet will be described with reference to FIG. First, FIG.
As shown in (a), a hole 4a is made in the end portion of the lead foil 4. In this example, the tip portions of the three lead foils 4 are overlapped and joined by ultrasonic welding, and then the hole 4a is formed.

Then, the hole 4a is formed in the neck portion 7 of the rivet 7.
2a, and then the washer 10 is inserted into the neck portion 7a and overlapped with the lead foil 4, and then, as shown in FIG.
The lead foil 4 is washer 1 by crushing the neck portion 7a by caulking.
Fix with 0 to rivet 7.

According to this, since the front and back surfaces of the washer 10 are formed with concavities and convexities, the contact area with respect to the lead foil 4 is increased during caulking, the contact resistance value is reduced, and variations in the contact resistance value are suppressed.

Further, since the side surface of the washer 10 is a diffused reflection surface, even if the lead foil 4 and the rivet 7 are made of the same aluminum material, the washer 10 can be easily visually identified from them, and the sensor is automatically identified. Even easier.

As a concrete example, a washer having an outer diameter of 5.0 mm, an inner diameter of 2.7 mm and a thickness of 0.8 mm is provided with a square pyramidal hole having a side of 0.2 mm and a depth of 0.05 mm per side. When about 50 pieces were formed, the contact resistance value could be reduced by about 0.4 mΩ compared to a washer of the same size with a flat surface. Moreover, the width between the maximum and minimum contact resistance values could be reduced from 0.159 mΩ to 0.139 mΩ.

Further, a large number of finer holes (recesses) having an average diameter of 0.1 mm are formed on the side surface of the washer to provide a good light-diffusing reflection surface. Even after caulking, the presence or absence of the washer can be easily checked visually. I was able to.

[0025]

As described above, according to the present invention,
In the electrolytic capacitor with terminals, when caulking and fixing the lead foil to the rivet of the sealing plate via the washer,
By using a washer whose at least one surface is a non-flat surface including a plurality of recesses and / or protrusions, it is possible to reduce the contact resistance of the washer to the lead foil and stabilize the variation in the contact resistance value. Can be made.

Further, by making the side surface of the washer a light diffuse reflection surface which is a non-flat surface, the presence or absence of the washer can be visually checked more easily even after caulking.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view showing an embodiment of a washer included in an electrolytic capacitor with a terminal of the present invention.

FIG. 2 is an explanatory view showing a procedure of crimping and fixing a lead foil to a rivet.

FIG. 3 is a sectional view showing an electrolytic capacitor with a terminal as a conventional example.

[Explanation of symbols]

1 metal case 2 Capacitor element 4,5 lead foil 6 sealing plate 7,8 rivets 7a, 8a lug terminal 7b, 8b neck 10 washers

Claims (3)

[Claims] 1. A capacitor element in which an anode foil and a cathode foil made of aluminum are wound around a separator paper, a ribbon-shaped anode lead foil and a cathode lead foil drawn from the anode foil and the cathode foil, A cylindrical metal case having a bottom, in which the capacitor element is housed, and a pair of rivets that penetrates, and includes a sealing plate that seals the opening of the metal case, the neck portion inside the case of each of the rivets, In an electrolytic capacitor with a terminal, in which an anode lead foil and a cathode lead foil are each caulked and fixed via a washer, at least one surface of the washer is formed as a non-flat surface including a plurality of recesses and / or projections. An electrolytic capacitor with a terminal characterized in that 2. The electrolytic capacitor with a terminal according to claim 1, wherein a side surface of the washer is also formed as a non-flat surface. 3. A capacitor element in which an anode foil and a cathode foil made of aluminum are wound around a separator paper, a ribbon-shaped anode lead foil and a cathode lead foil drawn from the anode foil and the cathode foil, A cylindrical metal case having a bottom, in which the capacitor element is housed, and a pair of rivets that penetrates, and includes a sealing plate that seals the opening of the metal case, the neck portion inside the case of each of the rivets, In an electrolytic capacitor with a terminal, in which an anode lead foil and a cathode lead foil are each caulked and fixed via a washer, a side surface of the washer is formed as a non-flat surface for diffused light reflection including a plurality of concave portions and / or convex portions. Electrolytic capacitor with terminal characterized by