JPH07201685A - Method and apparatus for producing electrolytic capacitor sealing closure - Google Patents

Abstract

PURPOSE:To completely shield a part of a sealing closure main body in contact with electrolytic solution by shaping a hole whose diameter is smaller than that of a lead insertion hole in a fluoro-resin film which is overlapped with a sealing closure material and by driving a pin into the shaped hole part and forming a bridge. CONSTITUTION:A laminated sealing closure material is inserted between a top force 6 and a bottom force 7 of a split mold with an ethylene tetrafluoride film 4 up. A small hole is shaped by a tip of an acute angle of a pin 8 in the polytetrafluoroethylene film of the sealing closure material inserted between the top force 6 and the bottom force 7. A diameter of the small hole is smaller than that of a lead insertion hole. Furthermore, when a clearance between the top force 6 and the bottom force 7 is made narrow and a pressure is applied, the pin 8 reaches 11R ground 5 and a tapered surface 12 formed at a tip of the pin 8 is inserted to the through hole 11 little by little. A molded item is obtained by matching the top force 6 and the bottom force 7 and by finishing bridge-formation and molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a sealing plug for an electrolytic capacitor.

[0002]

2. Description of the Related Art In order to improve the characteristics of an electrolytic capacitor, particularly the temperature characteristics and tan δ characteristics, dimethylformamide (hereinafter referred to as DMF) or γ-is used as a solvent for a driving electrolyte.
Butyrolactone (hereinafter referred to as GBL) is used. However, by adopting these as solvents, conventionally used sealing plugs such as styrene butadiene rubber, ethylene propylene rubber or ethylene propylene terpolymer have a phenomenon of permeation of the electrolytic solution, and cannot be used. . The use of butyl rubber (hereinafter referred to as IIR) containing a third component such as isobutylene / isoprene and divinylbenzene instead of these sealing plugs was also examined, but it was not possible to prevent permeation of the electrolytic solution. Therefore, IIR is laminated with a fluorine-based resin film, for example, a film of ethylene trifluoride, ethylene tetrafluoride, ethylene hexafluoride, or the like is used, and a sealing stopper made of IIR laminated with this fluorine-based resin film is used. As a manufacturing method, for example, a technique described in Japanese Patent Publication No. 62-36377 is known. However, the technique disclosed in Japanese Patent Publication No. 62-36377 is to laminate the entire surface of the plug body as a sealing plug structure, and mainly treats the joint surface, the composition and crosslink density of the constituent material of the plug body, and the crosslink / It describes the manufacturing sequence of some processes such as molding and laminating at the same time, but when making a sealing plug based on this technology,
Actually, there is a drawback that the electrolyte solution permeates through the exposed portion of the main body of the sealing plug caused by the fitting of the lead wire terminal and the insertion hole provided in the sealing plug, and the slight gap.

Further, FIG. 3 of Japanese Utility Model Laid-Open No. 55-63151 shows a structure in which the electrode through hole of the fluororesin film is smaller than the diameter of the electrode through hole of the sealing plug body. After inserting the lead wire terminal of this structure, the result is as shown in FIG. 4. However, in this structure, the insertion of the lead wire terminal becomes very tight, and there is a problem that smooth work cannot be performed.

No. 8 of the same Japanese Utility Model Application Laid-Open No. 55-63151
The figure shows a structure in which at least a part of the periphery of the electrode through hole is molded with a fluorine-based resin material, but regarding how to mold and manufacture the sealing plug of this structure, Neither the method nor the manufacturing equipment is described.

As described above, according to the technique disclosed in Japanese Patent Publication No. 62-36377, it is difficult for the fluororesin film of the laminated sealing plug to completely cover the cap body through the manufacturing process of the sealing cap itself and the manufacturing process of the capacitor. There is a problem that the permeation of the electrolytic solution cannot be prevented.
In the technology described in Japanese Patent No. 151, there is no description about how to manufacture the sealing plug, the manufacturing method and the manufacturing apparatus, and it is impossible to actually manufacture.

[0006]

SUMMARY OF THE INVENTION The present invention is a method and an apparatus for manufacturing a sealing plug for an electrolytic capacitor, which is capable of completely shielding a portion of the sealing plug body that comes into contact with an electrolytic solution.
The use of this sealing plug is intended to prevent leakage of the electrolytic solution.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and in a method of manufacturing a sealing plug for an electrolytic capacitor, which has lead wire insertion holes and is laminated with a fluororesin film, a sealing plug material is used. The step of overlapping the fluororesin film and the step of inserting the overlapping sealing plug material between the split molds and punching the fluororesin film from the fluororesin film side to a diameter smaller than the lead wire insertion hole A sealing plug for an electrolytic capacitor, comprising: a step of driving a pin provided in a mold into the perforated portion and compressing the split mold to perform cross-linking / molding; and a step of separating a molded product from an outer diameter part thereof. And a pin for forming a lead wire insertion hole is provided in one of the split molds, and a manufacturing device for a sealing plug for an electrolytic capacitor in which a tip of the pin is formed at an acute angle. It is made of.

[0008]

According to the present invention, it is possible to easily obtain a sealing plug for an electrolytic capacitor in which a fluorine-based resin film is formed on the outer peripheral surface of the sealing plug and in the lead wire insertion hole, and by using this sealing plug. This has the effect of preventing leakage of the electrolytic solution and achieving a longer life.

[0009]

Embodiments of the present invention will be described with reference to the drawings.
First, FIG. 1 shows the structure of a sealing plug for an electrolytic capacitor which is to be obtained in the present invention. That is, the lead wire insertion hole 2 is provided in the sealing plug body 1 made of, for example, IIR, and the lead wire insertion hole 2 is provided in the outer peripheral surface 3 of the sealing plug body 1 and the lead wire insertion hole 2, for example.
The resin film 4 made of ethylene fluoride is laminated. The tetrafluoroethylene film 4 is laminated at the same time as molding as described later, but is laminated to the length from the insertion side in the lead wire insertion hole 2 to the middle thereof. The manufacturing method and manufacturing apparatus will be described below.

First, IIR is carbon black, a filler,
A sheet-shaped uncrosslinked IIR fabric 5 is prepared by kneading a crosslinking agent and other materials that impart necessary properties for capacitors without deteriorating the properties of the capacitor, and the ethylene tetrafluoride film 4 is superposed on this. . The surface of the tetrafluoroethylene film 4 to be laminated on the IIR cloth is preferably subjected to plasma treatment or primer treatment in order to strengthen the adhesion. As shown in FIG. 2, the sealing plug material thus stacked is inserted between the upper mold 6 and the lower mold 7 of the split mold with the ethylene tetrafluoride film 4 facing upward. The upper die 6 is provided with a pin 8 at a position matching the lead wire insertion hole 2 of the sealing plug body 1, and the tip of the pin 8 is formed at an acute angle, for example, 60 degrees. Further, a dug portion 9 is formed so as to match the outer diameter of the sealing plug body 1, and the depth of the dug portion 9 is 4 times larger than the outer peripheral surface 3 of the sealing plug body 1. It is related to the laminated height of the ethylene oxide film 4.

On the other hand, the lower die 7 is provided with a dug portion 10 corresponding to the dug portion 9 of the upper die 6, and a through hole 11 for receiving the pin 8 is formed.

In the sealing plug material inserted between the upper mold 6 and the lower mold 7 as described above, the gap between the upper mold 6 and the lower mold 7 is narrowed due to the molding, but first, the sharp tip of the pin 8 is 4. Make a small hole in the ethylene fluoride film 4. This small hole has a smaller diameter than the lead wire insertion hole 2. Upper mold 6 and lower mold 7
The pin 8 reaches the IIR cloth 5 by narrowing the gap between the pin 8 and the taper surface 12 formed at the tip of the pin 8.
Is gradually inserted into the through-hole 11 while pushing out the ethylene tetrafluoride film 4 and the sealing plug material. A product obtained by combining the upper mold 6 and the lower mold 7 and completing the cross-linking and molding becomes a molded product 13 as shown in FIG. 3, which is connected by a connecting portion 14 formed between the upper mold 6 and the lower mold 7. The molded product 13 is separated from the outer diameter portion by punching to form the sealing plug body 1 having the lead wire insertion hole 2.

In the above-mentioned manufacturing process, the tetrafluoroethylene film 4 is handled by the digging portion 9 while being stretched by heat and pressure applied at the time of molding, so that the outer peripheral surface 3 of the sealing plug body 1 is treated. It is formed at a height corresponding to the dug portion 9.

In addition, the formation of the tetrafluoroethylene film 4 in the lead wire insertion hole 2 is carried out by using a sharp-edged pin 8 to make a hole having a diameter smaller than that of the lead wire insertion hole 2.
Is pushed into the IIR cloth 5, and while the taper surface 12 formed on the pin 8 and the heat at the time of molding are used to extend the ethylene tetrafluoride film 4, the ethylene tetrafluoride film is inserted into the lead wire insertion hole 2. It can be formed by pushing in 4. The tetrafluoroethylene film 4 is laminated in the lead wire insertion hole 2 in a stretched state,
Bonding is performed in the lead wire insertion hole 2 by pressure and heating during molding.

In the above embodiment, the pin 8 having the shape as shown in FIG. 2 was used. However, as shown in FIG. 4, a pin 15 having a root portion larger in diameter than the lead wire insertion hole may be used, or the pin 8 shown in FIG. If the tapered pin 16 is used, the inner diameter of the laminated tetrafluoroethylene film can be made substantially the same as that of the lead wire insertion hole, or an insertion hole having an opening can be formed. It is possible to provide a sealing plug having an effect and an effect of easily inserting a wire terminal.

In the examples, the case where IIR and tetrafluoroethylene film are used as the rubber or fluororesin film has been described, but other rubbers such as ethylene propylene terpolymer and trifluoroethylene film or Other fluororesin films such as ethylene hexafluoride film can also be used.

Further, in the embodiment, the method and apparatus for perforating and cross-linking and forming by using a pin having an acute tip have been described, but the cross-linking and forming may be performed in another step after only perforating. Good. Furthermore, the relationship between the upper mold and the lower mold of the embodiment may be reversed as long as the relationship with the fluorine-based resin film, that is, the relationship of punching from the fluorine-based resin film side.

[0018]

According to the present invention, it is possible to easily obtain a sealing plug for an electrolytic capacitor in which a fluorine-based resin film is laminated on the outer peripheral surface of the sealing plug and inside the lead wire insertion hole, and the sealing plug is used. As a result, leakage of the electrolytic solution can be prevented, which can contribute to reliability and longer life of the electrolytic capacitor.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a sealing plug made according to the present invention.

FIG. 2 shows an embodiment of the present invention and is a front sectional view showing a state before molding of the upper die, the lower die and the sealing plug material.

FIG. 3 is a front sectional view showing a molded product molded according to an example of the present invention.

FIG. 4 is a front sectional view showing another embodiment of the pin provided on the upper die.

FIG. 5 is a front sectional view showing another embodiment of the pin provided on the upper mold.

[Explanation of symbols]

 1 Sealing Plug Main Body 2 Lead Wire Insertion Hole 3 Sealing Plug Outer Surface 4 4 Fluoroethylene Film 5 IIR Fabric 6 Upper Die 7 Lower Die 8 Pins 9 Die Upper Die 10 Die Die Lower Die 11 Lower Die Through hole 12 Tapered surface of pin 13 Molded product

Claims (6)

[Claims] 1. A method of manufacturing a sealing plug for an electrolytic capacitor, which has a lead wire insertion hole and is laminated with a fluororesin film, wherein a step of stacking the sealing plug material and the fluororesin film, and a stacked sealing plug material. Inserting between the split molds and making a hole having a diameter smaller than the lead wire insertion hole in the fluorine-based resin film from the fluorine-based resin film side,
A sealing die for an electrolytic capacitor, comprising: a step of driving a pin provided in a split die into the perforated portion and compressing the split die for crosslinking / molding; and a step of separating a molded product from an outer diameter portion thereof. Method of manufacturing stopper. 2. The method for producing a sealing plug for an electrolytic capacitor according to claim 1, wherein the sealing plug material and the fluorine-based resin film are adhered to each other in the step of superposing them. 3. The method for producing a sealing plug for an electrolytic capacitor according to claim 1, wherein the perforating and the crosslinking / molding are performed in one step. 4. A sealing plug for an electrolytic capacitor according to claim 1, wherein a root portion of the pin has a diameter larger than that of a lead wire insertion hole or is tapered. Manufacturing method. 5. An apparatus for producing a sealing plug for an electrolytic capacitor, wherein one of the split molds is provided with a pin for forming a lead wire insertion hole, and the tip of the pin is formed at an acute angle. 6. The manufacturing apparatus for a sealing plug for an electrolytic capacitor according to claim 5, wherein a root portion of the pin has a diameter larger than that of the lead wire insertion hole or is tapered.