JPS5938048Y2 - Explosion-proof device for electrolytic capacitors - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an explosion-proof device for electrolytic capacitors, and is a short-open mode explosion-proof device that shorts the inside of the electrolytic capacitor and blows out the fuse attached to the outside when an abnormality occurs.

When an electrolytic capacitor is applied with the rated ground voltage, reversely connected due to its polarity, or applied with alternating current, the internal elements generate heat, gas is generated, and the capacitor explodes.

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

A known explosion-proof device is one that has a mechanically weak part in the case or sealing part of an electrolytic capacitor, and has an explosion-proof valve that ruptures the weak part by internal gas pressure and releases the internal gas. .

However, with this mechanism, when the explosion-proof part operates, the contents eject with a bursting sound and smoke, which can surprise the equipment user.
The drawback is that nearby electronic components may be splashed with electrolyte.

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 excellent in that it does not emit smoke or the contents fly out, but if the current does not suddenly increase the power but gradually heats up and the internal pressure rises, the fuse may not blow.

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

The present invention relates to an explosion-proof device for electrolytic capacitors that improves these shortcomings.It has a mechanism that short-circuits the inside of the electrolytic capacitor when an abnormality occurs, and uses this instantaneous large current to melt the fuse connected to the outside and open the circuit. This invention is characterized by A cathode lead 5 is connected to the anode lead 4 for external connection of the electrode foil iK, and a cathode lead 5 is similarly connected to the cathode side electrode foil 2, and the surface of the anode side electrode foil 1 is coated with a heat-melting resin (for example, polyethylene). , polypropylene, etc.), the contact drawer 7 is brought into close contact with the sheet 6, and this is wound to form the capacitor element 8. After being impregnated with an electrolytic solution, the capacitor element 8 is wrapped as shown in FIG. Connect the anode drawer lead 4 pulled out from the sealing terminal plate 9 to the anode side terminal 10 of the sealing terminal plate 9, overlap the cathode drawer lead 5 and the contact drawer lead 7, and connect it to the cathode side terminal 11 of the sealing terminal plate 9. Connect and outer case 12
It has a structure in which a capacitor element 8 is enclosed in a capacitor element 8, and an opening of an exterior case 12 is sealed with a sealing terminal plate 9.

In the present invention, the contact lead 7 is in contact with the anode electrode foil 1 via the heat-melting resin sheet 6, and the contact lead 7 is connected to the cathode terminal 11Vc.
When an abnormality occurs in the capacitor and it generates heat, the heat-melting resin sheet 6 melts, and the anode side electrode foil 1 and the insertion lead 7 come into direct contact.
A short circuit occurs, and a large current flows through the capacitor, blowing out the fuse 13 connected to the outside of the capacitor, opening the capacitor circuit, and preventing an explosion.

In this embodiment, a thermofusible resin sheet 6 is attached to the anode side electrode foil 1.
The structure is such that the contact lead I is sandwiched between the contact lead 7 and the cathode electrode foil 2 via the thermofusible resin sheet 7, and the insertion lead 7 connected to the anode terminal. 1
The structure may be connected to 0.

In this invention, the heat generated due to an abnormality in the electrolytic capacitor melts the heat-melting sheet and performs explosion-proof operation, so unlike the explosion-proof operation using a conventional explosion-proof valve, gas is generated inside due to the heat generated.
Furthermore, it operates faster and more reliably than a mechanism that opens when the pressure of the gas increases.

In addition, since there is no explosion noise or contents flying out during operation, there is no need to frighten equipment users, and there is no risk of secondary short circuits or fires caused by electrolyte scattering, making this an extremely excellent explosion-proof device for electrolytic capacitors. It is.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing the internal structure of an electrolytic capacitor element, and FIG. 2 is a sectional view showing the internal structure of the completed electrolytic capacitor of the present invention. 6... Hot-melt resin sheet, 7... Contact pull-out lead, 8... Capacitor element, 13... Fuse.

Claims (1)

[Scope of utility model registration request] An external drawer IJ-de is connected to the anode electrode foil and cathode electrode foil pots, and a contact drawer lead is closely attached to the surface of either one of the electrode strips 0 via a heat-melting synthetic resin sheet, and a separator paper is attached. A capacitor element which is wound between two electrodes is impregnated with an electrolytic solution, and then sealed in a cylindrical case, and the external lead is connected to the terminal part of the sealed terminal board, and the contact lead is tightly attached. The electrolytic capacitor body has an internal structure in which the opening of the cylindrical case is sealed with the sealed terminal plate, and the fuse connected in series to this T4 capacitor. Explosion-proof device for electrolytic capacitors consisting of.