JP4139941B2 - Electrolytic capacitor with terminal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrolytic capacitor with a terminal such as a lug terminal type electrolytic capacitor or a screw terminal type electrolytic capacitor. More specifically, the lead foil drawn from a capacitor element is caulked and fixed to a rivet provided on a sealing plate. This is related to the washer used in the process.
[0002]
[Prior art]
Since the terminal-attached electrolytic capacitor handles a large amount of electricity, the lead lead of the capacitor element is a ribbon-like lead foil, and a sealing plate made of a hard resin plate is used as the sealing member. A pair of rivets are provided through the sealing plate, and the lead-out lead foil is pulled out by being connected to the rivets inside the case.
[0003]
An example of the general configuration is shown in FIG. According to this, the terminal-equipped electrolytic capacitor includes a bottomed cylindrical metal case 1 in which the capacitor element 2 is housed and fixed by a fixing material 3 such as a pitch.
[0004]
Capacitor element 2 consists of an aluminum foil made of aluminum and a cathode foil wound in a spiral through separator paper and impregnated with an electrolytic solution, and a lead made of an aluminum ribbon piece from the anode foil and the cathode foil. Lead foils 4 and 5 are drawn out respectively. The opening of the metal case 1 is sealed with a sealing plate 6.
[0005]
Normally, a hard resin plate 6a such as a bakelite having a rubber plate 6b laminated on the upper surface is used for the sealing plate 6, and a pair of rivets (aluminum ridges) 7 and 8 are provided through the sealing plate 6. Yes. 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, a female screw is provided on the outer end of the case of each rivet 7, 8.
[0006]
Each of the lead lead foils 4 and 5 is fixed by caulking to neck portions 7b and 8b inside the case of the rivets 7 and 8 corresponding to the polarity. That is, a hole is made in the end portion of each lead lead foil 4, 5, the hole is inserted into the neck portion 7 b, 8 b of the rivet, and the washer 9 is inserted and stacked to prevent foil breakage, and then the neck portion 7 b 8b are crushed and fixed by caulking.
[0007]
With this caulking, high reliability is obtained in terms of mechanical strength and there is no problem in terms of vibration resistance, etc., but not only the contact resistance value increases due to the presence of the washer, but also the contact is caused by caulking pressure. The resistance value may vary.
[0008]
Further, since all of the rivets, the lead foil and the washer are made of an aluminum material and exhibit the same color, it is difficult to visually confirm the presence or absence of the washer (forgetting to put it), particularly after caulking.
[0009]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to reduce the contact resistance value when the lead foil is caulked and fixed to the rivet via the washer, to stabilize the variation of the contact resistance value, and even after caulking, The purpose is to make it easy to visually confirm the presence or absence.
[0010]
[Means for Solving the Problems]
To solve the above problems, the present invention comprises a capacitor element formed by winding an anode foil consisting of an aluminum material and a cathode foil via a separator sheet, aluminum material drawn from the above anode foil and cathode foil ribbon Jo of the anode lead foil and cathode lead foil, a bottomed cylindrical metal case the capacitor element is accommodated, a pair of rivets made of aluminum material is pierced, the sealing plate for sealing an opening of the metal case wherein the door, the neck portion of the case inside the rivet, in the electrolytic capacitor with terminals which are fixed by respective caulking through a washer which the anode lead foil and cathode lead foil made of aluminum material, at least one of the surfaces of the washer but with are formed as non-planar surface including a plurality of recesses and / or protrusions, the side of the washer Also, it is characterized in that non-planar surface for light diffuse reflection including a plurality of recesses and / or protrusions for enabling check for the washer visually are formed.
[0011]
According to this configuration, the surface area of the washer is increased as compared with a flat surface, and the lead foil is brought into contact with a wider surface, so that the contact resistance value is reduced by that amount, and the contact resistance value also varies. It becomes small and can be stabilized. Also, the mechanical strength is increased. Preferably, both front and back surfaces of the washer are non-flat surfaces. The shape of the unevenness is arbitrary. Conical or quadrangular pyramid depressions or projections are preferably employed, but may be annular ribs or lattice ribs.
[0012]
Even only non-planar surface surface of the washer, generally washer can visually recognize the outer edge of the washer is larger than the head after the crimping of the rivet, in the present invention, not only the surface and / or back surface of the washer, the washer the side surface of the well, the non-planar surface for light diffuse reflection including a plurality of recesses and / or protrusions for enabling confirm the presence of the washer at visually Ru is formed. According to this, it is possible to easily confirm visually that the washer is forgotten after the caulking.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. 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. Done. For the basic configuration of the terminal-equipped electrolytic capacitor itself, refer to the overall configuration diagram of FIG.
[0014]
First, referring to the enlarged perspective view of FIG. 1, the washer 10 used in the present invention is made of an aluminum material and is subjected to non-flat surface processing. Non-planar surface processing means forming either a concave portion or a convex portion, or both concave and convex portions on a flat surface.
[0015]
As an example, by making a large number of holes in an aluminum material with a tool such as a cone or a mold, the surface can be made non-planar, but it may also be a sand blast method or a chemical etching method.
[0016]
In order to increase the contact area with the lead foil and lower the contact resistance value, drilling with a cone or the like is preferable, but in order to obtain a rough surface that irregularly reflects light, a mold, sandblasting method or chemical etching method is preferable. I can say that.
[0017]
In order to reduce the contact resistance value with respect to the lead foil, it is sufficient that the non-flat surface processing is performed on at least one of the front surface and the back surface of the washer 10. In this embodiment, the washer is used to further reduce the contact resistance value. Non-flat surface processing is given to both front and back 10 surfaces. In addition, after the caulking, the side surface (circumferential surface) of the washer 10 is also subjected to non-flat surface processing in order to make it easy to visually confirm the presence or absence of the washer.
[0018]
Next, the caulking and fixing of the lead foil to the rivet will be described with reference to FIG. First, as shown in FIG. 2A, a hole 4a is formed in the end portion of the lead foil 4. In this example, the tips 4 of the three lead foils 4 are overlapped and joined by ultrasonic welding, and then the holes 4a are formed.
[0019]
Then, the hole 4a is inserted into the neck portion 7a of the rivet 7, and then the washer 10 is inserted into the neck portion 7a and superimposed on the lead foil 4, and then the neck portion 7a is caulked as shown in FIG. 2 (b). The lead foil 4 is crushed and fixed to the rivet 7 together with the washer 10.
[0020]
According to this, since unevenness is formed on both the front and back surfaces of the washer 10, the contact area with the lead foil 4 is increased during caulking, the contact resistance value is lowered, and variations in the contact resistance value are also suppressed.
[0021]
Further, since the side surface of the washer 10 is an irregular 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 identified visually, and automatic identification by a sensor is also easier. It becomes possible.
[0022]
As a specific example, for a washer having an outer diameter of 5.0 mm, an inner diameter of 2.7 mm, and a thickness of 0.8 mm, about 50 square pyramid holes having a side of 0.2 mm and a depth of 0.05 mm per side. As a result, the contact resistance value was reduced by about 0.4 mΩ compared to a washer having the same surface and 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.
[0023]
In addition, when a large number of fine holes (recesses) with an average diameter of 0.1 mm are formed on the side surface of the washer, a good light irregular reflection surface is obtained, and even after caulking, the presence or absence of the washer can be easily confirmed visually. It was.
[0024]
【The invention's effect】
As described above, according to the present invention, in the electrolytic capacitor with a terminal, when the lead foil is caulked and fixed to the rivet of the sealing plate via the washer, at least one surface includes a plurality of concave portions and / or convex portions. By using a washer having a non-flat surface, the contact resistance of the washer with respect to the lead foil can be lowered, and variations in the contact resistance value can be stabilized.
[0025]
In addition, since the side surface of the washer is also a non-flat light diffuse reflection surface, the presence or absence of the washer can be confirmed more easily even after caulking.
[Brief description of the drawings]
FIG. 1 is an enlarged perspective view showing an embodiment of a washer provided in an electrolytic capacitor with a terminal according to the present invention.
FIG. 2 is an explanatory diagram showing a procedure for caulking 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]
DESCRIPTION OF SYMBOLS 1 Metal case 2 Capacitor element 4,5 Lead foil 6 Sealing plate 7,8 Rivet 7a, 8a Lug terminal 7b, 8b Neck part 10 Washer

Claims (1)

A capacitor element with an anode foil and a cathode foil made of aluminum material wound with a separator sheet, and the anode lead foil and cathode lead foil ribbon made of aluminum material drawn from the above anode foil and cathode foil, a bottomed cylindrical metal case the capacitor element is accommodated, a pair of rivet disposed through made of aluminum material, and a sealing plate for sealing an opening of the metal case, inside the case of the rivet In the electrolytic capacitor with a terminal in which the anode lead foil and the cathode lead foil are respectively fixed to the neck by caulking through a washer made of an aluminum material .
At least one surface of the washer is formed as a non-flat surface including a plurality of concave portions and / or convex portions, and the presence or absence of the washer can be visually confirmed on the side surface of the washer. An electrolytic capacitor with a terminal, wherein a non-flat surface for light irregular reflection including a plurality of concave portions and / or convex portions is formed .

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