JPS5831402Y2 - Electrolytic capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electrolytic capacitor, particularly an explosion-proof structure, which is formed by fitting and sealing an elastic sealing body into which a lead wire terminal is inserted into the open end of a metal case.

Conventionally, the explosion-proof structure of electrolytic capacitors sealed using lead wire terminals and elastic sealing bodies is to provide a non-penetrating explosion-proof hole with a thin wall left in the thickness direction of the rubber stopper, and use this as an explosion-proof valve. In the event of an abnormality, the thin-walled part expands and ruptures to discharge gas to prevent an explosion, or a part of the metal case has an extremely thin-walled part that ruptures due to the internal gas pressure when an abnormality occurs to discharge gas. There are some that do this.

However, in electrolytic capacitors in which a rubber stopper is provided with an explosion-proof valve, there is a large variation in the dimensions of the thin wall portion, which results in a difference in the operating pressure of the explosion-proof valve.

In addition, for electrolytic capacitors that have an ultra-thin wall part in a part of the metal case, the thickness of this ultra-thin wall part needs to be approximately 0.1 to 0.2 mm, but it is easy to crack or dent due to external force. There was a problem.

The present invention was developed in view of the above points, and by forming longitudinal grooves on the rod-shaped part of the lead wire terminal, these grooves are used for gas discharge, making it easy to process and inexpensive. The purpose is to provide capacitors.

This will be explained below using examples. As shown in FIG. 1, a condenser element 2 is housed in a metal case 1, and the condenser element 2 has a lead wire formed with a longitudinal groove 4 at the other end of a rod-shaped part 3 that communicates with the inside of the metal case 1. Terminal 5 is pulled out.

Reference numeral 6 denotes a lead wire, which is connected to the rod-shaped portion 3 by welding or the like, and the rod-shaped portion 3 is made of aluminum or the like.

The lead wire terminal 5 is inserted into an insertion hole of an elastic sealing body 7 made of rubber or the like.

Then, the capacitor element 2 is sealed in the metal case 1 by tightening the opening edge of the metal case 1 and pressing the body portion in the vicinity thereof.

The sealing means also seals the grooves 4 of the rod-shaped portion 3 and the elastic sealing body 7.
Although the contact strength between the groove 4 and the elastic sealing body 7 is slightly lower than that of other contact surfaces, if an abnormality occurs in the condenser element 2 and the internal pressure increases, the contact strength between the groove 4 and the elastic sealing body 7 cannot withstand. When the gas is discharged from the groove 4 and the internal pressure decreases, it is sealed again.

Therefore, the electrolytic capacitor of the present invention has excellent airtightness when there is no abnormality in the capacitor, and when an abnormality occurs, gas is discharged to prevent an explosion.

In addition, in FIG. 1, the grooves 4 formed in the rod-shaped part 3 reach the end surface of the rod-shaped part 3, but as shown in FIG.
It is also possible to form longitudinal grooves 14 that do not reach the end faces of the grooves.

Further, the rod-shaped portion does not necessarily have to be a perfect circle, and the same effect can be obtained by using an elliptical shape or a cross-section in which a part of a circle is flattened as shown in FIG. 3 in combination with grooves.

As described above, according to the present invention, by forming the grooves on the rod-shaped portion of the lead wire terminal, even if an abnormality occurs in the capacitor element housed in the metal case, gas can be discharged from the grooves, thereby preventing an explosion. Moreover, since the grooves are easy to process, it is possible to provide an inexpensive electrolytic capacitor with excellent explosion protection.

[Brief explanation of the drawing]

The drawings all show embodiments of the present invention; Fig. 1 is a front sectional view of an electrolytic capacitor, Fig. 2 is a perspective view of one embodiment of the lead wire terminal, and Fig. 3 is a perspective view of another embodiment of the lead wire terminal. It is a perspective view showing an example. DESCRIPTION OF SYMBOLS 1... Metal case, 2... Capacitor element, 3... Rod-shaped part, 4... Groove, 5
...Lead wire terminal, 6...Lead wire,
7...Elastic sealing body.

Claims (2)

[Scope of utility model registration request] (1) In an electrolytic capacitor consisting of a capacitor element housed in a metal case, a lead wire terminal having a rod-shaped part connected to the capacitor element, and an elastic sealing body into which the lead wire terminal is inserted, the rod-shaped part has a longitudinal direction. An electrolytic capacitor characterized by forming grooves. (2) The electrolytic capacitor according to claim 1, wherein the longitudinal groove does not reach the end surface of the rod-shaped portion.