JPS6017886Y2 - cylindrical capacitor - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a cylindrical capacitor with a safety device.

Cylindrical capacitors (tubular capacitors) with a relatively small volume have a small absolute value of heat generation even if the capacitor generates abnormally, and the heat is only generated locally, so even if a temperature fuse is built-in, the temperature fuse will not blow out. It was not possible to open the circuit reliably, and the lack of reliability made it unsuitable for practical use.

In addition, it is impossible to mechanically open the circuit by utilizing the deformation of the capacitor case, and if we try to use this method, the protection device will require a larger volume than the capacitor element itself, so this method is practically adopted. I couldn't do it.

As shown in FIG. 3, a conventional tubular capacitor is housed in a case 1 with a capacitor element 2 being pressed by a chrysanthemum washer 3 attached to a cover plate 4, and both ends of the case 1 are attached to the cover plate 4. It was a swaged structure and no safety device was used.

For this reason, no safety device was installed, but safety requirements are increasing even in this field, and it is now required that capacitors at the end of their life or defective products be disconnected from the circuit as quietly as possible. Became.

The present invention satisfies this requirement by providing a cylindrical capacitor with a safety device that electrically opens the circuit in the event of an abnormality.

An embodiment of the present invention will be described with reference to FIG. 1. A convex portion 1A is provided on a part of the inner circumference of a capacitor case 1, and a capacitor element 2 and safety devices such as a protective resistor 8 are connected to the inside of the capacitor case 1. Separate into two rooms for separate storage.

In one chamber, a capacitor element 2 with a foil protruding from a dielectric material such as a film, or a capacitor element 2 with a metallized dielectric film provided with a metallicon layer on both end faces, is pressed with a chrysanthemum washer 3 or the like, and the leads are pressed. After inserting the lid plate 4 integrated with the eyelet 5 with the wire 6, the caulking 7 is fixed.

The other room has a built-in security device.

A protective resistor 8 or the like is used as the safety device, and the lead wire 6 from the capacitor element 2 and the lead wire of the protective resistor 8 are connected to the crimp terminal 1.
Connect by caulking, soldering, or spot welding using 1.

One external lead wire 13 of the protective resistor 8 is led out from the capacitor case 1 through the hole in the eyelet 9 of the lid 12, and the hole in the eyelet 9 is sealed by soldering 10.

The lid 12 is fixed by caulking 14.

In addition, if the capacitor is used in a place with low humidity or dust, the soldering 10 of the eyelet 9 can be omitted, and the lid plate 1 can be omitted.
In some cases, it may be sufficient to simply cover the protective resistor 8 with an insulating sleeve without using the resistor 2.

Further, a current fuse may be used instead of the protective resistor 8.

The capacitor element 2 may be a composite capacitor for noise prevention or the like as shown in FIG. 2, but it can also be applied to a single-element rolled-up capacitor.

Next, to explain the protection circuit, if the capacitor is operating normally, the resistor and capacitor connected in series are divided into voltages, and if the constant is determined so that the most voltage is applied to the capacitor, then If an abnormality occurs and the capacitor is short-circuited, the full voltage will be applied to the resistor, so the resistor will burn out and the circuit will be in an open state, meaning that the capacitor will be disconnected from the circuit.

The same result can be obtained by using a current fuse.

As a specific example, a 220VAC0, 1μF oil tubular capacitor was manufactured.

At this time, two sheets of paper with a thickness of 10μ were used, and the aluminum foil was 6μ and impregnated with polybutene oil.

Five conventional products and five products of the present invention were manufactured, and 1500 VAC and 50 Hz were applied between the terminals using a 5QKVA AC power source.

A 2.2Ω 1/8W carbon film resistor was used as the protective resistor.

As a result, in the conventional product as shown in FIG. 3, all the elements were ejected and some were burned.

However, with the present invention, no abnormality was observed in the appearance of all cases, and the circuit was able to be shut off.The present invention has the structure described above, so it is a simple structure, and it does not become too large, ensuring safety. This is a very useful idea.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the cylindrical capacitor of the present invention, Figure 2
The figure is a circuit diagram showing a circuit to which the present invention can be applied, and FIG. 3 is a sectional view of a conventional product. 1... Capacitor case, IA... Case recess, 2... Capacitor element, 6...
...Lead wire, 8...Protection resistor.

Claims (1)

[Scope of utility model registration request] A convex groove is provided on a part of the inner circumference of the cylindrical capacitor case to position the lid plate that divides the inside of the case into two, and a lid plate is provided to seal both ends to separate the inside of the case into two chambers. A capacitor element is housed in the chamber, lead wires crimped to both end faces of the capacitor element are led out, and the other chamber houses a safety device connected between the lead wire and the external lead. A cylindrical capacitor.