JPS5914628A - Wire-wound condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in a wound capacitor which is provided with a safety function in the event of dielectric breakdown by dividing a metal vapor deposited electrode.

Conventional configuration and its problems Capacitors formed by dividing and winding metal vapor-deposited electrodes have a structure of a collection of microcapacitors connected by a sprayed metal layer. When dielectric breakdown occurs, the divided electrodes involved in the dielectric breakdown are electrically disconnected from the capacitor body and released, thereby reducing the negative impact on other microcapacitor groups.

Because of this function, even if an unexpected situation occurs such as an abnormal voltage being applied to the capacitor or the surrounding environment becoming abnormally high temperature, the capacitance will simply decrease, avoiding the worst case scenario of smoke or fire. be able to. Hereinafter, this function will be referred to as the security function.

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The safety function is basically a dielectric material 1.1' as shown in Figure 1.
This is obtained by dividing at least one of the vapor-deposited electrodes of the opposing electrodes to form the divided electrode 2. In order to further enhance the function, the electrode edge is coated with metal spray as shown in Figure 2. The present inventor has proposed a method of forming a small current capacity portion 3 having a smaller current capacity than other deposited film portions along the edge in a band shape, a line shape, or an intermittent shape.

Furthermore, the present inventor has proposed a method of using a pressure cushioning material such as plastic foam in the winding core in order to make this safety function work more reliably. It was found that the capacity reduction inside was relatively large. The reason for this is that since the winding core is made of a material that is soft at room temperature, such as sponge, when electricity is applied, the dielectric material around the winding core vibrates, which further weakens the winding tension, and the winding tension is the lowest in this area. I understand.

OBJECTS OF THE INVENTION An object of the present invention is to provide a highly reliable wound capacitor with a safety function in which the safety function is easily activated and the capacitance decreases little during charging.

Structure of the Invention In order to achieve this object, the present invention provides a winding core of a wound type capacitor with a heat deformation temperature (hereinafter abbreviated as HDT) of 4.
According to this configuration, which uses materials with a temperature of 0°C to 140°C, the temperature of the winding core of this capacitor under normal operation is low, so the winding core is hard, making it difficult for corona discharge and self-healing to occur. A situation is brought to light, while
In an abnormal situation, that is, when exposed to abnormally high voltage or temperature, the temperature of the winding core increases abnormally due to self-heating of the capacitor, and if it exceeds the HDT of the material of the winding core, the winding core will becomes soft and the safety function is easily activated.

In other words, by using a material for the winding core that is hard at normal operating temperatures and softens at the capacitor's breakdown temperature,
There is little capacity loss during normal operation, and safety functions are easily activated in the event of destruction in the event of an abnormality.

Materials for the winding core with an HDT of 40°C to 140°C include:
A suitable type of resin such as epoxy, polyethylene, polypropylene, polybutylene, polystyrene, acrylic polyvinyl chloride, polyethylene terephthalate snylon, phenol, etc. is used to form a cylindrical winding core bobbin 4 as shown in FIG. Shape and use. What is important here is the HDT of the material of the winding core, not the material. For example, HDT of polyethylene terephthalate resin is 5
The temperature is 0'Q~86°C, but if it is filled with 18 layers of glass fiber, the HDT becomes 201°C~214°C. Furthermore, it is known that in the case of epoxy resins, the HDT ranges over a wide range from 46°C to 288°C even with the same bisphenol type without a filler.

In such cases, in the present invention, the EDT is 40°C to 14°C.
The key point is to use a material of a grade within the 0°C range, and is not related to the material.

Furthermore, a cylindrical bobbin made of paper, plastic nonwoven fabric, or kraft paper impregnated with the above resin may be used.

Description of examples The present invention will be specifically described below using Examples.

Example 1 Polyethylene terephthalate (hereinafter referred to as PIC) with a thickness of 6μ
When obtaining a double-sided vapor-deposited film of the film (abbreviated as T), a vapor-deposited electrode (segmented electrode) 2 in the pattern shown in FIG. 4 was provided on one side of the film by masking. At this time, the vapor-deposited metal was aluminum, and the vapor-deposited film resistance was 3.0'10 on average. Also, the width W1 of one divided electrode is 361 m, and the width W2 of the fuse portion 60 is 2.41 m! It is I. Note that the width W3'Je2ymx of the double-sided vapor-deposited film was 1·oig, and the width W4 of the dividing groove was 1·oig. On the other hand, as a laminating film, polypropylene (hereinafter referred to as PP) with a width of 60 mm and a thickness of 6 μm was used.
A film was prepared. As the core bobbin, epoxy, polyethylene, polybutylene, acrylic,
A molded bobbin as shown in FIG. 3 made of resin such as polyvinyl chloride, polyethylene terephthalate, or nylon was prepared. For further comparison, the HDT is 20°C at 205°C.
% glass fiber reinforced polybutylene terephthalate (hereinafter P
A molded bobbin made by (abbreviated as BT) was prepared.

Two prepared films were layered and wound around these bobbins, metal spraying was applied to both sides of the element, leads were attached after heating and aging, and the exterior was treated with epoxy resin.

Each of these capacitors had a value of 50 μF, and 20 capacitors were produced for each capacitor. 10 of them are 80°
A safety function test was conducted by forcibly destroying the battery by applying 300vAa in a C atmosphere, and observing whether smoke or ignition occurred at that time. The results are shown in the table below.

For the other 10 batteries, a voltage of 1.2 times the rated voltage was applied at each ambient temperature, and the capacity reduction (μF) after 1000 hours was investigated. The results are also shown in the same table. Heat distortion temperature is STM-D-64
8.

From these results, it can be seen that by using a core bobbin material with a DT of 40° C. to 140° C., it is possible to obtain a capacitor with a reliable safety function and a small decrease in capacitance when energized.

Example 2 A polypropylene nonwoven fabric with a thickness of 100 μm is wound 10 turns to form a core bobbin as shown in Fig. 3 (outer diameter 10 mm).
A capacitor element of 60 μF was obtained by winding the same film as in Example 1 using the bobbin. After that, metal spraying was applied to both sides of the element, and after heat aging, leads were attached, and the element was heated at 10 T in a vacuum impregnation tank.
Exterior treatment was carried out by impregnating and casting with epoxy resin and curing it under reduced pressure of 0.45 mm. Through this impregnation process, the epoxy resin is fully impregnated into the nonwoven fabric.
Moreover, the HDT of the nonwoven fabric impregnated with this epoxy resin (after curing) was 82°C. When this capacitor was subjected to a safety function test, it was found that there was no smoke or ignition at all, and it was found to have sufficient safety functions.The capacitor was also tested under the same conditions as Example 1 in the capacitance reduction test i. However, in an atmosphere of 60°C, the O-62L% was very small.

Example 3 A winding bobbin (outer diameter 13 mm) as shown in FIG. 3 was made by winding 80 μm thick kraft paper in 15 turns, and the film shown in Example 1 was wound on the winding bobbin as shown in FIG. A capacitor element of 30 μF was obtained. After that, metal spraying is applied to both sides of the element, leads are attached after heat aging, and exterior treatment is performed by impregnating and casting epoxy resin in a vacuum impregnating tank under a reduced pressure of 1 o Torr and hardening. did.

Through this impregnation step, the epoxy resin was sufficiently impregnated into the kraft paper. Moreover, the HINT of the kraft paper impregnated with this epoxy resin (after curing) was 90°C. child,
When we conducted a safety function test on this capacitor, it was found that there was no smoke or fire at all, and that it had sufficient safety functions.Also, the capacity reduction test was conducted under the same conditions as in Example 1. However, in an atmosphere of 65°C, -o was very small at 41%.

In Examples 2 and 3, an example was shown in which nonwoven fabric or kraft paper was impregnated with epoxy resin, but in this case, it is not necessary to impregnate all 100 pores of the nonwoven fabric or kraft paper; Impregnation can actually provide the same effect. Further, in these embodiments, examples were shown in which the core bobbin was impregnated with resin when packaging the capacitor, but it is of course possible to use a bobbin in which the core bobbin alone is impregnated and hardened. Further, instead of a bobbin made by winding six turns of nonwoven fabric or kraft paper, it may be a bobbin that is integrally molded using these materials. In addition to non-woven fabrics and kraft paper, polyethylene terephthalate film,
Embossed sheets or films of polypropylene film can also be used.

In addition, in the above example, a PP film was used as a matching film to a PET double-sided vapor deposited film, but
This is not necessarily limited to this configuration, and as the thin dielectric material used, in addition to pic'r and pp, polycarbonate, polystyrene, polyethylene paper, etc. can be used alone or in combination. As described above, according to the present invention, a highly reliable capacitor having reliable safety functions can be provided, and its industrial efficiency is great.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a wound capacitor with a safety function when it is wound, FIG. 2 is a perspective view of another example of a wound capacitor with a security function when it is wound, and FIG. 3 is a perspective view of the winding capacitor of the present invention. FIG. 4 is a perspective view of a winding core bobbin used in a winding capacitor, and a plan view showing a portion of a vapor-deposited film used in the winding winding capacitor of the present invention. 2... Vapor deposition electrode (divided electrode), 4...
Winding core bobbin, 5...fuse part. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3v1 Figure 4

Claims (1)

[Claims] (1) At least one of the vapor-deposited electrodes facing each other with a dielectric interposed therebetween is divided into a plurality of parts, and the winding core is provided with a member having a heat deformation temperature of 40°C to 140°C. A wound capacitor characterized by: (b)) At least one of the divided electrodes has an evaporation electrode part whose flow capacity is set to be smaller than the other evaporation electrode parts in a strip, line, or intermittently along the electrode edge where the metal is sprayed. A wound capacitor according to claim (1). (3) The wound capacitor according to claim (1) or claim Q), wherein the core member is a molded plastic product. G4) The wound capacitor according to claim (1) or claim 4), wherein the core member is made of a plastic nonwoven fabric impregnated with resin. (5) The wound capacitor according to claim 1 or 2, wherein the core member is made of kraft paper impregnated with resin.