JPH10326721A - Film capacitor contained in case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a conductive matter from scattering even if a capacitor element breaks greatly when an excessive surge voltage is applied, improve safety thereof and realize compactness thereof, by using a gel state silicone material as filler. SOLUTION: A capacitor element 2 is manufactured by winding an aluminum deposition polyester film (8 μm-thick). Then, the manufactured capacitor element 2 is put in a place wherein a gel state silicone material 4 is injected inside a resin (PBT) case 1. An upper surface of the gel state silicone material 4 of the case 1 is sealed by urethane resin 5 of high hardness (hardness of about ASTMD 35) and a film capacitor contained in a case is thereby manufactured. A lead 3 is attached to both end parts of the capacitor element 2. The gel state silicone material 4 used here is formed by partially crosslinking reactive silicone oil and has polysiloxane skeleton -(R2 SiO)2 -1} as a basic structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case in which a capacitor element formed by winding or laminating a metallized film is accommodated in a case, and a filler is injected into a gap between the capacitor element and the case. The present invention relates to a film capacitor.

[0002]

2. Description of the Related Art Even if an excessive surge voltage is applied to a capacitor, the capacitor does not emit smoke or fire, and does not adversely affect surrounding parts, so that there is no scattering of conductive material. Has been requested.

For this reason, for example, as shown in FIG. 2, a capacitor element 2 is accommodated in a case 1 and a soft, low-hardness (hardness of about ASTM D 25) urethane is filled in a gap between the case 1 and the capacitor element 2. Resin 4 is injected, and a high hardness (hardness ASTM D 35)
It is known that the urethane resin 5 is injected into a two-layer structure. In FIG. 2, reference numeral 3 denotes a lead wire.

[0004]

However, in order to reduce the size of the film capacitor in the case described above, if the film forming the capacitor element 2 is made thin, the film capacitor may be destroyed when an excessive surge voltage is applied. However, the soft urethane resin 4 cannot absorb the impact, and has a problem that the conductive material is scattered.

The present invention has been made in view of the above points, and has as its object the purpose of preventing the conductive material from scattering even if the capacitor element is greatly damaged when an excessive surge voltage is applied. An object of the present invention is to provide a film capacitor in a case that can enhance safety and can be reduced in size.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a capacitor element formed by winding or laminating a metallized film in a case, and filling a gap between the capacitor element and the case. In the case-filled film capacitor in which the agent was injected, a gel silicone material was used as the filler, thereby preventing the conductive material from scattering.

Here, the gel silicone material is obtained by partially cross-linking a reactive silicone oil, and has a polysiloxane skeleton {-(R ₂ SiO) _n- } as a basic structure,
It features high flexibility.

Therefore, as compared with the conventional urethane resin, it absorbs a large impact, and as is clear from the following embodiment, there is no scattering of the conductive material in the dump test.
A more secure film capacitor in a case can be manufactured.

This gel-like silicone material is not suitable as a sealant because of its flexibility (external pressure and lead wire holding strength are low). The problem can be solved by sealing with a stopper.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing the structure of a cased film capacitor according to one embodiment of the present invention. As shown in the figure, the film capacitor in the case is made of an aluminum-evaporated polyester film (thickness: 8).
μm) to form a capacitor element 2,
Next, the prepared capacitor element 2 is placed in a place where the gel-like silicone material 4 is injected into a case 1 made of resin (PBT), and the upper surface of the gel-like silicone material 4 of the case 1 is further hardened (hardness ASTM D). It is created by sealing with a urethane resin 5 of about 35). Lead wires 3 are attached to both ends of the capacitor element 2.

The gel silicone material 4 used here is:
It is a product obtained by partially cross-linking a reactive silicone oil and having a polysiloxane skeleton {-(R ₂ SiO) _n- } as a basic structure. Specifically, for example, “αGEL” manufactured by Siegel Co., Ltd. "(Registered trademark).

FIG. 3 is a diagram showing the results of a dump test (test in UL and CSA which is an overseas safety standard) of the film capacitor in a case according to the above embodiment and Comparative Examples 1 and 2 for comparison. Each of the film capacitors in the case used in this dump test had a capacity of 1
(ΜF) and a rated voltage of 250 (VAC) were used.

Here, Conventional Example 1 uses a urethane resin having a one-layer hardness of ASTM D 35 for all the fillers, and Conventional Example 2 uses the same structure as the conventional example shown in FIG. Are manufactured under the same manufacturing conditions using the same parts as those used in the above embodiment.

FIG. 4 is a diagram showing a circuit configuration of a dump test. In the figure, Ct is a capacitor under test, S is a high-voltage switch, Cd is a dump capacitor, Vdc is a variable DC voltage, Vac is a 250 V AC voltage, F is a plug fuse, and L is a reactor.

In the above dump test circuit, the dump test is performed by winding a gauze around the capacitor under test Ct in a single layer and applying an AC voltage (Vac) of 250 V to the capacitor Ct.
The electric charge charged in the dump capacitor Cd is discharged to the capacitor under test Ct four times at intervals of seconds. afterwards,
250V AC voltage (Vac) applied to the capacitor under test Ct
While applying for 30 seconds. However, if there is smoke, check for ignition for 10 seconds.

In the above dump test, it is determined that the capacitor under test Ct or the gauze does not burn and that the main body of the capacitor under test Ct does not come off the lead wires or that the entire internal element does not jump out.

As is apparent from FIG. 3, all of the film capacitors in the case according to the present embodiment have passed.

That is, according to the present invention, the safety against destruction of the capacitor element due to the application of an excessive surge voltage can be higher than that of the conventional example, and it is possible to sufficiently pass the overseas safety standards UL and CSA. It could be confirmed.

[0019]

As described in detail above, the present invention has the following excellent effects. Even if the capacitor element is severely damaged when an excessive surge voltage is applied, the gel silicone material as a filler can absorb this, so the conductive material will not scatter and it will be in a more secure case A film capacitor can be configured.

Further, since the safety can be ensured even if the capacitor element is greatly destroyed, the thickness of the film can be reduced and the thickness of the filler can be reduced correspondingly, so that a smaller film capacitor in a case can be constructed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a cased film capacitor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of a conventional film capacitor in a case.

FIG. 3 is a diagram showing a result of a dump test of a film capacitor in a case.

FIG. 4 is a diagram showing a circuit configuration of a dump test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Capacitor element 3, 3 Lead wire 4 Gel-like silicone material 5 Urethane resin

Claims (2)

[Claims] 1. A film capacitor in a case in which a capacitor element formed by winding or laminating a metallized film is accommodated in a case, and a filler is injected into a gap between the capacitor element and the case. A film capacitor in a case characterized by using a gel-like silicone material. 2. The film capacitor in a case according to claim 1, wherein an upper surface of the gel-like silicone material is sealed with a sealant such as urethane resin.