JPH0236264Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacitor equipped with a safety device. As shown in Figure 1, capacitors are generally made of plastic films such as polypropylene films and polyester films with Zn and Al.
A capacitor element 1 is formed by winding a metallized plastic film coated with vapor-deposited materials, and the capacitor element 1 is housed and sealed in a case made of aluminum or resin.

When these capacitors are used for a long period of time, the dielectric material deteriorates, and eventually the dielectric material breaks down, and the case 2 may burst due to the gas generated at that time. For this reason, one method is to use the deformation stress of the capacitor's top cover 3 due to the gas pressure generated when the dielectric breaks down, to cut the lead wire 4 from the terminal 5 before the case ruptures, and to stop the gas generated from the dielectric. It is being

2 is a resin case, 6 is a filler, 7 is a lead wire 4
This is a metal plate connected between the terminal 5 and the terminal 5.

Fillers used in these capacitors6
In many cases, a liquid such as polybdenum, diocluphthalate (DOP), or polyethylene glycol is used, or a solid substance is used, such as a single microcrystalline wax or a mixture of the above-mentioned liquid and microcrystalline wax. Also, because even solid materials have a low melting point, the gas generated when the dielectric material breaks down can be easily removed from the upper lid 3.
The weld between the lead wire 4 and the terminal 5, that is, between the terminal 5 and the metal plate 7, can be cut by pushing up the upper cover 3. However, if a thermosetting resin such as epoxy or a thermoplastic resin such as low-density polyethylene or atactic polypropylene is used as a filler to improve heat resistance, the dielectric may break. , a very high gas pressure is required to further break these fillers and allow the gas to reach the top lid. For this reason, more pressure than necessary is suddenly applied to cause the safety function of cutting between the lead wire 4 and the terminal 5 mentioned above at the same time as the destruction of the filler.
As the side surface of the container expands, there is a very high probability that the top lid 3 will open, resulting in disadvantages such as the contents spilling out and peripheral equipment being damaged. The present invention eliminates the above-mentioned drawbacks and provides a capacitor that can safely and reliably operate a safety device. below,
The present invention will be explained with reference to the embodiment shown in FIGS. 2 and 3. FIG. 2 is a sectional view of the capacitor, and the safety device between the lead wire 4 and the terminal 5 is the same as in FIG. 1. However, in the present invention, a resin cylinder 8 which is relatively thinner than the resin case 2 and which is molded integrally with the resin case 2 is provided within the resin case 2.
The capacitor element 1 is inserted therein, filled with a filler 9 such as epoxy resin, and the capacitor element 1 is covered.

Since the capacitor of the present invention is constructed as described above, the gas generated from the capacitor element 1 due to breakdown of the dielectric easily breaks through the filler 9 and the resin cylinder 8 even at relatively low pressure, and As shown by the arrow in the figure, the upper lid 3 is reached through the gap 10 between the resin case 2 and the resin cylinder 8, and the safety device is activated safely and reliably, preventing the upper lid 3 from opening and the contents from spilling out, or peripheral equipment. Accidents such as damage to can be completely eliminated.

Note that the above-mentioned safety device is not limited to the embodiment, and can be similarly applied as long as it disconnects between the lead wire 4 and the terminal 5 when the gas pressure rises to the vicinity of the upper lid 3.

As described above, the capacitor of the present invention is extremely advantageous in terms of safety and heat resistance, and has extremely high practical value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional capacitor, and FIGS. 2 and 3 are sectional views of an embodiment of the capacitor of the present invention. 1: Capacitor element, 2: Resin case, 3: Top cover, 4: Lead wire, 5: Terminal, 8: Resin tube, 9:
Filling material.

Claims (1)

[Scope of utility model registration request] A capacitor element having a vapor-deposited electrode is housed and sealed in a resin case, and due to the increase in internal pressure, the upper cover of the case or a part of the case deforms, cutting the terminal provided on the upper cover and the lead wire drawn out by the capacitor element. A capacitor comprising a safety device that includes a resin cylinder formed integrally with the resin case, and a capacitor element and a filler filled in the resin cylinder.