JPS5818283Y2 - Explosion-proof capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an explosion-proof capacitor with a built-in safety device.

Conventionally, explosion-proof capacitors with built-in safety devices were
For example, Utility Model Application Publication No. 48-34840, Utility Model Application Publication No. 48-3
No. 6343, Japanese Utility Model Application No. 49-96434, Japanese Utility Model Application No. 49-117435, or Japanese Utility Model Application No. 1987-932
As proposed in Publication No. 42, all of these are provided with an insulating support plate 3a and 3b as shown in FIG. 2 near the opening of the case body 2 housing the capacitor element 1 as shown in FIG. By arranging a safety device with a metal piece 4 connected to it, and connecting the lead wire 6 led out from the capacitor element 1 to the external terminal 7 via the metal piece 4,
In the case of an increase in internal pressure caused by deterioration of the capacitor element 1, the expansion force of the case body 2 cuts the metal piece 4 and disconnects it from the power source, thereby preventing an explosion.

In addition, 8 is a case upper lid.

However, these structures have the following drawbacks.

That is, after storing the capacitor element 1 in the case body 2,
The top cover of the case is soldered before impregnation, but soldering must be done upside down due to soldering properties, and if the impregnating agent is liquid, it may be difficult to carry the case after assembly. Not only will the capacitor element 1 become loose and thereby damage it, but also if the metal piece 4 is damaged or cut, it will lose its function as a capacitor before it can be set in a circuit and function as a capacitor. There are risks such as

This tendency is particularly noticeable in large capacitors made up of a plurality of capacitor elements.

Therefore, a structure has been considered in which an element fixing plate 13 is disposed between the capacitor element 11 and the safety device 12, as shown in FIG. 3, to prevent the capacitor element 11 from wobbling due to various causes. This method has drawbacks such as being expensive due to an increase in the number of points and man-hours, and is therefore undesirable in practice.

The present invention was developed in view of the above points, and by elongating one of the pair of insulating support plates that make up the safety device so that it also serves as a capacitor element fixing plate, it is possible to avoid damage to metal pieces during the manufacturing process. Another object of the present invention is to provide an explosion-proof capacitor that is easy to manufacture, inexpensive, and suitable for particularly large capacitors, which can reliably exhibit an explosion-proof effect without cutting.

An embodiment of the present invention will be described below with reference to the drawings.

That is, as shown in FIGS. 4 and 5, a pair of insulating support plates 2 having different lengths are connected between a pair of mounting brackets 21a and 2Ib.
2a and 22b are arranged, and the insulating support plates 22a and 22
b Attach one end of each to each of the mounting fittings 21a and 21b, and partially overlap so that the shorter insulating support plate 22a is on top of the longer insulating support plate 22b,
A metal piece 23 is disposed on the overlapping upper surface of the pair of insulating support plates 22a and 22b with one end fixed to one insulating support plate 22a and the other end fixed to the other insulating support plate 22b to provide a safety device c. Form.

Next, the longer insulating support plate 2 that constitutes the safety device L1
As shown in FIG. 6, the lower surface of the mounting bracket 21a is brought into contact with a capacitor element 26 which is a unit of one or more capacitor elements housed in the case body 25.

21b are fixed to both inner surfaces of the case body 25 by soldering or the like.

Then, the lead wire 27 drawn out from the capacitor element 26 is connected to one end of the metal piece 23, and the metal piece 2
3 is connected to an external terminal 29 integrally fixed to the case top cover 28.

Due to the presence of the insulating support plate 22b, the explosion-proof capacitor configured as described above prevents the capacitor element 22 from being damaged by the soldering of the case top cover 28 being turned upside down during work, or by various vibrations or falling sideways during transportation after the capacitor is completed. The metal piece 23 will not shake and at the same time
If the capacitor element 26 reaches a dielectric breakdown point due to deterioration of its characteristics, excessive rise in ambient temperature, application of overvoltage, etc., the case body 25 expands due to the increase in internal pressure as shown in FIG.

As a result, the mounting brackets 21 a and 21 b are pulled, the metal piece 23 is cut, and the case body 25
And, the electric circuit is promptly cut off before the case top lid 28 explodes.

The dimensions of the pair of insulating support plates constituting the safety device are determined based on the premise that they can withstand supporting the capacitor element 26 and at the same time are easily cut by the expansion of the metal piece or case body. As shown in FIG. 8, the tip of the longer insulating support plate 30a should be long enough to reach the bottom of the opposing mounting bracket 31, and the shorter insulating support plate 30b should be set as shown in FIG. The metal piece 32 is attached to the pair of fittings 31a so that the distance between the fittings 31a and 3Ib is less than half.

If you position it almost in the middle between 3Ib, metal piece 3
This has the effect of further increasing the force supporting the capacitor element 26 without damaging the capacitor element 26.

Furthermore, if a notch 33 is provided in the metal piece 32 as shown in FIG. 9, the effect of interrupting the circuit in the event of an abnormality can be further enhanced.

As described above, according to the present invention, one end of a pair of insulating support plates of different lengths is attached between a pair of mounting brackets, and a part of the insulating support plate is placed so that the shorter one is above the longer one. A special capacitor element fixing plate is formed by stacking the two paper edge support plates and placing a metal piece on the upper surface of the overlapping paper edge support plates to make contact with the capacitor element housed in the case body. It is possible to provide an inexpensive and easy-to-manufacture explosion-proof capacitor that can fix an element without needing it, and can quickly interrupt a circuit in the event of an abnormality without damaging or cutting metal pieces during the process.

[Brief explanation of the drawing]

Figures 1 to 3 relate to conventional examples, where Figure 1 is a sectional view showing an explosion-proof capacitor, Figure 2 is a perspective view showing a safety device, Figure 3 is a sectional view showing an explosion-proof capacitor, and Figure 4 is a sectional view showing an explosion-proof capacitor. 9 to 9 relate to an embodiment of the present invention, FIG. 4 is a perspective view showing a safety device, FIG. 5 is a sectional view showing a safety device, and FIGS. 6 to 7 show an explosion-proof capacitor. 8 is a sectional view showing another modification of the safety device, and FIG. 9 is a perspective view showing a metal piece constituting the safety device. 21 a, 2 l b, 31 a, 3 l
b-=-Mounting bracket, 22a, 22b, 30a,
:3ob---Insulating support plate, 23.32...Bent metal piece, 24...Bending safety device, 25...Case body, 26...Capacitor element, 28...・・・・・・
・Case top cover, external terminal between 29, 33...
Notch part.

Claims (4)

[Scope of utility model registration request] (1) A case body housing a capacitor element, a pair of mounting brackets fixed to the inner surface of the case body, and a pair of long and short insulating support plates mounted between the mounting brackets with the short side on top and partially overlapping. , a metal piece having one end fixed to one insulating support plate and the other end fixed to the other insulating support plate on the overlapping upper surface of the pair of insulating support plates, and one end of the metal piece is fixed to the capacitor. An explosion-proof capacitor characterized in that the other end of the long insulating support plate is connected to an external terminal, and the lower surface of the longer insulating support plate is in contact with the capacitor element. (2) The explosion-proof codenser according to claim 1), characterized in that the tip of the longer insulating support plate has a length that reaches the lower part of the opposing mounting bracket. (3) An explosion-proof capacitor according to claim 1 or 2 of the utility model registration claim, characterized in that the tip of the shorter insulating support plate is less than half the distance between the pair of mounting brackets. . (4) The explosion-proof capacitor according to any one of claims (1) to (3) of the utility model registration, characterized in that a notch is provided in the metal piece.