JPS6339091B2 - - Google Patents

Description

[Detailed Description of the Invention] In an abnormal situation such as when a load voltage higher than the rated voltage is applied, a short circuit occurs inside the capacitor before the outer case explodes, and an appropriate protection device for the external circuit is activated. By operating the
This relates to electrolytic capacitors, which are intended to maintain the safety of equipment that uses capacitors.

As shown in Figure 1, conventional electrolytic capacitors have a so-called explosion-proof structure in which the fragile parts of the exterior case 1 or sealing plate 2 of the capacitor element 3 are destroyed when the pressure due to internally generated gas reaches a predetermined level or higher. Normally, consideration is given to prevent dangerous situations such as explosion or generation of capacitors in the event of an abnormality. This method has disadvantages such as contamination of the circuit board and the inside of the set due to gas blowout and leakage of the electrolyte impregnated therein, as well as the risk of secondary disasters such as tracking.

The present invention eliminates these drawbacks, and provides a capacitor in which a capacitor element is housed in a container, and a sealing plate is fitted into the opening of the container to seal the capacitor. This electrolytic capacitor is characterized in that a material that dissolves or whose insulation is reduced by an electrolytic solution is interposed between the leads provided between the capacitor and the plate.

The present invention will be described below with reference to an embodiment shown in FIG.

FIG. 2 is a cross-sectional view of one embodiment of an electrolytic capacitor, in which 1 is a cylindrical container made of aluminum or the like, 2 is an external sealing plate for airtightly sealing the opening of the container 1, and is an elastic plate made of rubber or the like. 2a and an insulating plate 2b made of phenol resin or the like are laminated.

3 is a capacitor element housed in the container 1, from which an anode lead 4 and a cathode lead 5 are led out for connection to external terminals. Reference numerals 6 and 7 denote external terminals for anode and cathode, which are fixed to sealing plate 2 in advance by molding or rivets 8. 10 is the external sealing plate 2
It is an internal sealing plate provided on the inside of the insulating plate 10 made of an elastic plate 10a made of rubber or the like and a phenol resin or the like.
b, and the sealing plate for the opening is composed of the external sealing plate 2 and the internal sealing plate 10,
Small holes 9 and 11 for explosion-proof valves are provided in the center, respectively.

Lead plates 4 and 5 drawn out from capacitor element 3 are connected to external terminals 6 and 7 via intermediate leads 12 and 13 with rivets 8 or the like. Either one of the intermediate leads 12 or 13 has a hygroscopic separator paper for electrolytic capacitors, a porous sheet made of a polymer such as polypropylene, polyester, polyvinyl alcohol, or polyethylene, a nonwoven fabric, or a tube-shaped insulating material. Separator 14
In addition to insulating the intermediate leads 12 and 13 so that they do not become short even if they come into contact with each other, they are tied together.

Since the capacitor of the present invention is constructed as described above, when an abnormal current flows through the capacitor in the event of an abnormality such as application of a reverse voltage or deterioration of the capacitor element, heat is generated internally and the temperature of the capacitor element 3 rises. When gas is generated, the internal pressure of the container 1 housing the capacitor element 3 increases, the explosion-proof valve provided in the internal sealing plate 10 operates, and the electrolytic solution impregnated in the capacitor element 3 flows through the small hole 11 into the container. When it flows into the gap between the sealing plate 10 and the external sealing plate 2 and is adsorbed by the highly hygroscopic insulating separator 14, the insulating separator 14 loses its insulation properties, and the anode intermediate lead 12 and the cathode intermediate lead 13, a short circuit occurs, and the current flowing at this time can activate a suitable protection device such as a fuse breaker provided in the external circuit, and the capacitor can be reliably electrically disconnected from the circuit.

This prevents the capacitor from exploding and catching fire, and prevents electrolyte from leaking, making it possible to manufacture safe and pollution-free electronic devices. On the other hand, in recent years, most electrolytic solutions for electrolytic capacitors are made mainly from organic solvents, and when cellulose plastics such as vinyl acetate or celluloid are used as the material for the insulating separator 14, the inner sealing plate 10 When the provided explosion-proof valve is operated, it is ejected and dissolved by the organic solvent-based electrolyte, and the anode intermediate lead 12 and the cathode intermediate lead 13 come into contact with each other and become short-circuited, providing a double safety function. becomes possible.

Furthermore, the material interposed between the electrodes of the adjacent intermediate leads 12 and 13 is electrolytic paper, polymer film, or non-woven fabric, as well as a paint such as methyl cellulose that is applied to the intermediate leads 12 or 13 in advance.
A similar effect can be expected by applying the coating to insulate it and then gluing it.

In addition, although the above embodiment described a polar electrolytic capacitor, the same effect can be obtained for wound type or laminated type capacitors such as non-polar, AC electrolytic capacitors, and the structure of the sealing part can also be implemented. It is not limited to this example.

Further, the insulating separator 14 is not limited to being used for either the intermediate lead 12 or the intermediate lead 13, and may be used for both intermediate leads without any problem.

As mentioned above, the electrolytic capacitor of the present invention is extremely advantageous in terms of safety and has great industrial and practical value.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional electrolytic capacitor, Figure 2 is a cross-sectional view of a conventional electrolytic capacitor.
The figure is a sectional view of an embodiment of the electrolytic capacitor of the present invention. 1: Container, 2: Internal sealing plate, 3: Capacitor element, 9, 11: Explosion-proof hole, 10: External sealing plate, 1
2, 13: intermediate lead, 14: separator.

Claims (1)

[Claims] 1. In an electrolytic capacitor in which a capacitor element is housed in a container and a sealing plate is fitted to the opening of the container to seal it, there is a gap between the leads provided between the internal sealing plate having an explosion-proof valve and the external sealing plate. An electrolytic capacitor characterized in that it is constructed by interposing a material whose insulation is degraded or dissolved by an electrolytic solution.