JP3002701U - Aluminum electrolytic capacitor - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the electrolyte from leaking to the outside from the gap between the through hole of the rubber sealing body and the round bar of the terminal that penetrates the rubber sealing body.
To provide an aluminum electrolytic capacitor using a graded salt electrolytic solution. [Structure] A bottomed outer case 2 in which a capacitor element 3 formed by winding an aluminum anode foil and a cathode foil with separator paper impregnated with a quaternary salt electrolyte is sealed with a rubber sealing body 5. In the aluminum electrolytic capacitor 1 in which the terminals 4 fixed to the anode foil and the cathode foil of the capacitor element are pulled out of the outer case 2 through the through holes 6 of the rubber sealing body 5, the terminals 4 are pulled out from the capacitor element 3. At least the terminal 4 on the cathode side has a through hole 6 in the rubber sealing body 5.
A diameter-expanded portion 7 is provided in the through hole at the entrance.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an aluminum electrolytic capacitor.

[0002]

[Prior art]

 As shown in FIG. 3, in the aluminum electrolytic capacitor 10, a capacitor element 14 formed by winding an aluminum anode foil 11 and an aluminum cathode foil 12 with a separator paper 13 in between is impregnated with a driving electrolytic solution, and this capacitor is formed. After the element is housed in a bottomed outer case 15 made of aluminum having an opening on one side, a rubber sealing body 16 is placed and closed inside the opening of the outer case to seal the periphery 17 of the opening of the outer case. It has a closed structure by being processed. In FIG. 3, the aluminum electrolytic capacitor 10 is shown in a used state, and is turned upside down during manufacturing.

To the anode foil and the cathode foil, the board 18a of the terminal 18 (only the terminal on the cathode side is shown in FIG. 3) is fixed by caulking or the cold weld method, and the other end of the terminal 18 is Each of them is drawn out to the outside through the through hole 19 of the rubber sealing body 16.

As an electrolyte for driving, a quaternary ammonium salt of o-phthalic acid or a quaternary ammonium salt of maleic acid is dissolved as a solute in a solvent such as γ-butyrolactone or ethylene glycol in recent years. A quaternary salt electrolyte is used.

[0005]

[Problems to be solved by the device]

 The electrolytic solution is impregnated into the capacitor element under vacuum and is retained on the rolled aluminum anode foil and cathode foil or separator paper, but the retained amount varies somewhat. If the amount of holding is large, the electrolytic solution may ooze out to the surface of the capacitor element 14 facing the rubber sealing body 16 in use, and the surface of the rubber sealing body may be wet.

In particular, in the case of using the electrolytic solution containing the quaternary salt as a solute as described above, when an electric field is applied, the terminal 18 on the cathode side enters the through hole 19 of the rubber sealing body 16 in the vicinity thereof. 21, it is known that the pH of the electrolytic solution becomes a strong alkali. Therefore, the round bar portion 20 and the rubber sealing body 16 near the terminal 18 on the cathode side entering the through hole 19 of the rubber sealing body 16 are eroded, and the through hole 19 of the rubber sealing body 16 and this In some cases, a gap was formed between the round rod portion 20 of the terminal 18 on the cathode side which was in intimate contact with and penetrated, and the electrolytic solution sometimes leaked to the outside from here.

The present invention is directed to aluminum electrolysis using a quaternary salt electrolyte solution so that the electrolyte solution does not leak to the outside between the through hole of the rubber sealing body and the round bar portion of the terminal penetrating the rubber sealing body. It is intended to provide a capacitor.

[0008]

[Means for Solving the Problems]

 A capacitor element made by winding an aluminum anode foil and a cathode foil with separator paper impregnated with a quaternary salt electrolyte is housed in a bottomed outer case sealed with a rubber sealing body, and In an aluminum electrolytic capacitor in which the terminals fixed to the anode foil and cathode foil of the element are pulled out to the outside of the outer case through the through holes of the rubber sealing body, at least the terminal on the cathode side pulled out from the capacitor element is rubber sealed. It is configured such that a diameter-expanded portion is provided in the through hole of the body that enters the through hole.

[0009]

[Action]

 The diameter of the through hole is large so that at least the terminal on the cathode side that is pulled out from the capacitor element that is impregnated with the electrolyte enters the through hole of the rubber sealing body. Even if the electrolytic solution oozes out to the side of the plug, the electrolytic solution enters the round bar of the terminal or the terminal into the through hole of the rubber sealing body without wetting the place where the terminal enters into the through hole of the rubber sealing body. It does not erode the area around the through holes.

[0010]

Example In FIG. 1, an aluminum electrolytic capacitor 1 has a capacitor element 3 which is placed in an outer case 2 having a bottomed cylindrical shape and impregnated with an electrolytic solution. The capacitor element 3 is an aluminum anode foil and aluminum. It is constructed by winding the cathode foil of and a separator paper. A terminal 4 is fixed to each of the anode foil and the cathode foil (only the terminal on the cathode side is shown in FIG. 1), the terminal 4 is pulled out from the capacitor element 3, and the round bar portion 4a of the terminal 4 is a rubber sealing body. The CP wire 4b of the terminal 4 which is penetrated through the through hole 6 and welded to the round bar portion 4a is drawn out of the outer case 2. The portion 2a of the outer case 2 near the rubber sealing body 5 is caulked to fix the rubber sealing body 5.

An enlarged diameter portion 7 having a large diameter is provided in the through hole 6 where the terminal 4 drawn out from the capacitor element 3 enters the through hole 6 of the rubber sealing body 5. The expanded diameter portion may have a stepped portion as shown in FIG. 1, or may be tapered like the expanded diameter portion 8 in FIG. 2 so that the large diameter gradually decreases.

With the enlarged diameter portion 7, even if the electrolytic solution oozes out to the surface of the capacitor element facing the rubber sealing body, the electrolytic solution does not wet the place where the terminal enters the through hole of the rubber sealing body, and the electrolytic solution is formed. The liquid does not erode the round bar of the terminal or the vicinity of the through hole where the terminal enters the through hole of the rubber sealing body.

An aluminum electrolytic capacitor according to the present invention (rated 10V 1800 μF, diameter 12.5 mm, height 20 mm) provided with a stepwise expanded portion having a diameter of 2.5 mm and a depth of 1.0 mm as the expanded portion, and After making a conventional product with the same rating and size as the above and applying the rated voltage for up to 2000 hours at different times, between the round bar part of the terminal on the cathode side and the through hole of the rubber sealing body penetrating this The leakage of the electrolytic solution in the gap was checked with a 20x stereoscopic microscope, and the results shown in Table 1 were obtained.

[0014]

[Table 1]

In the table, 2/200 means that electrolyte leakage was found in two of 200 aluminum electrolytic capacitors.

From these results, it can be seen that the aluminum electrolytic capacitor according to the present invention has an excellent effect on leakage of electrolytic solution.

[0017]

[Effect of device]

 According to the present invention, in an aluminum electrolytic capacitor using a quaternary salt as an electrolytic solution, at least the terminal on the negative electrode side, which is pulled out from the capacitor element impregnated with the electrolytic solution, enters the through hole of the rubber sealing body. Since the diameter of the through hole is large, even if the electrolytic solution oozes out on the surface of the capacitor element that faces the rubber sealing body, the terminal does not get wet in the place where the terminal enters the through hole of the rubber sealing body. The alkaline electrolyte does not corrode the round bar of the terminal or the vicinity of the through hole where the terminal enters the through hole of the rubber sealing body, and the electrolyte leakage can be prevented.

Therefore, the γ-butyrolactone / quaternary ammonium salt-based electrolytic solution having the highest conductivity can be used as the electrolytic solution of the aluminum electrolytic capacitor, and the secondary smoothing capacitor can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional view showing a part of an aluminum electrolytic capacitor of the present invention.

FIG. 2 is a sectional view showing a part of another aluminum electrolytic capacitor of the present invention.

FIG. 3 is a sectional view showing a part of a conventional aluminum electrolytic capacitor.

[Explanation of symbols]

 1 Aluminum Electrolytic Capacitor 2 Exterior Case 3 Capacitor Element 4 Terminal 4a Round Bar Part 4b CP Wire 5 Rubber Seal 6 Through Hole 7 Expanded Portion 8 Expanded Portion

Claims (1)

[Scope of utility model registration request] 1. A capacitor element obtained by winding an aluminum anode foil and a cathode foil via separator paper and impregnating a quaternary salt electrolyte in a bottomed outer case sealed with a rubber sealing body. In an aluminum electrolytic capacitor in which the terminals housed and fixed to the anode foil and cathode foil of the capacitor element are pulled out of the outer case through the through holes of the rubber sealing body, at least the terminal on the cathode side pulled out from the capacitor element is made of rubber. An aluminum electrolytic capacitor characterized in that a diameter-expanded portion is provided in a through hole of a sealing body that enters the through hole.