JPS5943727Y2 - Explosion-proof device for electrolytic capacitors - Google Patents

Description

[Detailed description of the invention] This invention relates to an explosion-proof device for electrolytic capacitors.
This is a short/open shade explosion-proof device that shorts the inside of the electrolytic capacitor and blows out the fuse installed outside when an abnormality occurs.

If a voltage higher than the rated voltage is applied to an electrolytic capacitor, if the polarity is reversed, or if alternating current is applied, the internal elements will be damaged, gas will be generated, and the capacitor will be destroyed explosively.

For this reason, electrolytic capacitors are usually equipped with explosion-proof equipment.

Explosion-proof devices are known to have a mechanically weak part in the electrolytic capacitor case or sealing part, and have an explosion-proof valve that ruptures the weak part by internal gas pressure and releases the internal gas. It is being

However, with this mechanism, when the explosion-proof part is activated, the contents eject with a popping sound and smoke, which can surprise the equipment user.
There is a drawback that electrolyte may splash onto nearby electronic components.

Another explosion-proof device has been devised in which a fuse is inserted inside an electrolytic capacitor, and the fuse blows due to internal heat generation or overcurrent, cutting off the circuit.

This mechanism is superior in that it does not emit smoke or spill out the contents, or the fuse may not blow if the current does not suddenly increase but gradually heats up and the internal pressure rises.

Furthermore, during aging, the aging current may cause the fuse to blow out.

This invention relates to an explosion-proof device for electrolytic capacitors that improves these shortcomings.It features a mechanism that short-circuits the inside of the electrolytic capacitor in the event of an abnormality, fuses the externally connected fuse with an instantaneous large current, and opens the circuit. This will be explained in detail below according to the drawings. First, as shown in FIG.
A separator paper 2 is placed in between, and from each electrode foil 1, an external connection lead 3 and connection leads 4, 4' connected to the anode and cathode electrode foils 1 on the opposite side are drawn out. , this is wound to form the capacitor element 5,
After impregnating this capacitor element 5 with an electrolyte, a second
As shown in the figure, the heat-melting sheet 6 is sandwiched between a pair of contact leads 4 and 4' pulled out from the capacitor element 5 and bent to the end surface of the capacitor element 5, and then the third
As shown in the figure, the capacitor element 5 with the external connection lead 3 connected to the terminal portion of the sealed terminal board 7 is enclosed in a bottomed cylindrical capacitor case 9 with an elastic plate 8 laid on the bottom.
A pair of contact leads 4, 4' with a heat-melting sheet 6 sandwiched between them are arranged so as to be pressed between the lower end face of the capacitor element 5 and the elastic plate 8, and the open end of the capacitor case 9 is connected to a sealed terminal plate. It is closed and sealed with I.

In the explosion-proof device of the present invention, when an abnormal voltage is applied to the electrolytic capacitor and heat is generated in the capacitor element 5, the heat is transmitted to the contact leads 4, 4', melts the heat-melting sheet 6, and connects the pair of contact υ- leads 4. , 4' contact and become shorted.

At this time, if fuse 10 is inserted in series with the electrolytic capacitor circuit, the large current at the time of short circuit will cause fuse 1 to
0 melts, opening the circuit and preventing the electrolytic capacitor from exploding.

The elastic plate 8 is inserted to constantly press the pair of contact leads 4, 4', and when the heat-melting sheet 6 melts, it serves to quickly and reliably bring the contact leads 4, 4' into contact with each other. .

The heat-melting sheet 6 may be made of any material that melts at 100 to 200 degrees Celsius, such as polyethylene or polypropylene, and the operating temperature can be changed by appropriately selecting the material and thickness of the sheet.

Further, in order to prevent the heat-melting sheet 6 from shifting from between the contact leads 40, a structure may be adopted in which an adhesive is applied to one side of the sheet 6 and the sheet 6 is affixed to either of the contact leads 4, 4'.

The explosion-proof device of the present invention configured in this way does not cause explosion noise, smoke, or even the contents to fly out, unlike the explosion-proof operation using an explosion-proof valve. There is no need to worry about secondary short circuits or fires.

In addition, it is easier to assemble than a structure with an internal fuse, and it does not cause the fuse to blow out during aging, resulting in defective products, making it an extremely excellent explosion-proof device for electrolytic capacitors. be.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the internal structure of the capacitor element of the present invention, FIG. 2 is a perspective view of the completed capacitor element, and FIG. 3 is a sectional view showing the electrolytic capacitor of the present invention. 4.4'... Contact lead, 5... Capacitor element, 6... Heat melting sheet, 10...
...scold you.

Claims (1)

[Scope of utility model registration request] A pair of contact leads are pulled out from each of the electrode foils on the anode and cathode sides on the side opposite to the lead pullout side for external terminal connection of the electrolytic capacitor element, and a thermofusible sheet is sandwiched between the pair of connection leads. The contact lead is bent to the end face of the electrolytic capacitor element and inserted into a bottomed cylindrical case with an elastic plate laid on the bottom so that the contact lead drawer side is in contact with the elastic plate at the bottom of the case, and the case is opened. An explosion-proof device for an electrolytic capacitor consisting of an electrolytic capacitor body sealed with a sealed terminal plate to which the external terminal connection lead on the end side is connected, and a fuse connected in series to the outside of the electrolytic capacitor.