JP2632536B2 - SH capacitor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an SH capacitor, and more particularly, to a technique for removing metallikon particles attached to an outer peripheral surface of an SH capacitor.

2. Description of the Related Art In an SH capacitor, a capacitor element is formed by winding an element dielectric material. The element dielectric material is formed by combining a plastic film having a deposition electrode, a capacitor paper, or a plastic film having no deposition electrode or a capacitor paper.

In such an SH capacitor, metallicon (metal spraying) is applied to the end face of the capacitor element, and a lead wire is connected to the metallicon portion as an electrode lead-out portion.

As the metal used for the metallikon, zinc, solder, aluminum, other special metals, or a mixture of these metals is used. Further, as a method of spraying metal, a method of blowing molten metal with a high-pressure air or an inert gas or the like using a gas burner, an electric discharge arc, an electric lamp, or the like is used.

By the way, in the metallikon as described above, no matter which metal is used and whichever thermal spraying method is employed, the metal is blown at high speed in the form of melted fine particles, so of course, the end face requiring the metallikon, Metallicon particles are firmly attached to the outer peripheral portion of the element where metallikon is unnecessary.

In this case, if the metallikon particles adhering to the outer periphery of the capacitor element are left unattended, the particles will be in a conductive state, resulting in a short-circuit failure or an increase in surface leak current.
There is a problem that characteristics are deteriorated. As a method for removing the strongly adhered metallikon particles, it is conceivable to first remove the metallikon element by brushing the element. However, this method is disadvantageous because it may damage the exterior of the capacitor element.

On the other hand, as a method of removing metallikon particles actually implemented, for example, there are a capacitor masking device disclosed in JP-B-61-281514 and a metallized film capacitor disclosed in JP-A-60-244015. . In these methods, the element is masked in advance, and after the metallikon, the masking tape is removed.

Another example of masking is disclosed in
There is a method for manufacturing a film capacitor disclosed in Japanese Patent No. 6920. In this method, a heat-shrinkable tube with perforations is cut from the perforations after coating shrinkage, and the tube is removed.

However, in the above-described masking method, there is a problem that the invasion of metallikon particles cannot be avoided even if a slight gap is generated between the element and the mask due to element variation. In addition, for large capacitors for heavy electrical equipment, the equipment becomes enormous, making it difficult to implement.In the case of flat elements that require heat treatment after masking, the heat treatment bends the end face film, There are problems such as deterioration of later characteristics. In addition, all of them require a step of removing the exterior sheet, and since it is difficult to automate this step, the exterior sheet must be removed manually and there is a problem that the workability is low.

In addition to the above masking method, there are still other methods for removing metallikon particles, such as a method of winding a plastic film around the element and a method of winding a capacitor paper around the element.

However, although the surface of the plastic film is microscopically smooth and has no irregularities such that the metallicon particles mesh with each other, when the metallicon particles are sprayed at a high temperature, the film microscopically melts due to the particles, and the plastic film partially melts. There is a possibility that the metallikon particles may stick to the film in such a manner as to bite into the film. In contrast, capacitor paper is
Although it has heat resistance for a short time, it does not melt even if it hits with metallikon particles, but its seemingly smooth surface has microscopic irregularities of about 1 to 3 μm, so the metallicon particles mesh with these irregularities May stick.
In order to avoid such a problem, similar to the masking method described above, a step of removing these exterior sheets is required, and the exterior sheets must be removed manually, resulting in low workability. .

[Problems to be Solved by the Invention] The present invention has been proposed in order to solve the above-mentioned problems of the prior art, and the problem is that metallikon particles are difficult to adhere, and An object of the present invention is to improve the characteristics of the SH capacitor by attaching an exterior sheet to the capacitor element such that the metallikon particles can be easily removed when adhered.

[Means for Solving the Problems] In the SH capacitor of the present invention, cellophane is attached as an exterior sheet to the outer periphery of the SH capacitor element, and in this state, metallikon is applied to both end faces of the element, and lead wires are connected to the metallikon surface. Later, it is housed in a case and formed.

Instead of cellophane, it is also possible to use a lacquer paper obtained by applying cellulosic lacquer to a capacitor paper, and to mount the lacquer with the lacquer surface on the outside.

[Function] First, cellophane is formed into a film using slits when viscose is extruded into a coagulation bath to produce regenerated cellulose, and has a high tensile strength and a small elongation as compared with a general plastic film.

Excellent organic solvent resistance and oil resistance.

No heat softening property.

It is mainly used for packaging, decoration, cellophane tape and the like. (References:
The present invention focuses on the characteristic of such cellophane that it has no heat-softening property. That is, if a capacitor element with a cellophane exterior is subjected to metallikon, the metallikon particles do not bite into or fuse with cellophane, but are merely attached, and even if attached, the amount is limited to capacitor paper or plastic. It is 1/10 or less compared to the film. Therefore, it is not necessary to apply excessive force when removing the metallikon particles, and the metallikon particles can be easily removed without damaging the element by gently wiping with a soft cloth or the like.
Therefore, there is no insulation problem due to the metallikon particles, and the characteristics of the capacitor can be improved.

Further, the lacquer layer of the cellulose lacquer has heat resistance comparable to that of the capacitor paper, and can cover and smooth the microscopic irregularities on the capacitor paper. Therefore, if such a lacquer layer is externally mounted on the device, the metallikon particles do not fuse to the lacquer surface, but merely adhere, and even if adhered, the amount is small, As with cellophane, it can be easily wiped off with a soft cloth.

Examples Examples of the present invention will be specifically described below with reference to the drawings.

* First Embodiment * FIG. 1 is a sectional view showing an SH capacitor according to a first embodiment. An SH capacitor element 1 has metallikon portions 2 formed at both ends thereof and is housed in a case 3. Metallicon sections 2 at both ends of the SH capacitor element 1 are connected via lead wires 4 to external lead-out terminals 5 fixed to the upper part of case 3.
It is connected to the.

In this embodiment, the manufacturing process of the SH capacitor is the second process.
As shown in the figure, the element dielectric material 7 is wound around the core 6 to form the SH capacitor element 1 by the usual method.
A cellophane 8 having the same width as the element 1 is wound around the outer periphery of the SH capacitor element 1 for one or more turns, and metallikon is applied in this state. As shown in FIG. 3, the metal capacitor is arranged by aligning the SH capacitor elements 1 in the axial direction and the end faces thereof, and covering the upper and lower sides. The method of spraying the particles 11 is adopted.

In this case, in this embodiment, since the surface is smooth in micro units and the outer periphery of the SH capacitor element 1 is covered with the cellophane 8 having excellent heat resistance, the metallikon particles 11 are not fused to the cellophane 8. No, it only adheres to the surface, and even if it does, its amount is
Very few. Therefore, by wiping with a soft cloth or the like, the metallikon particles can be easily formed without damaging the element 1.
11 can be removed. Accordingly, the problem of insulation caused by the metallikon particles 11 can be solved, and the capacitor can have stable and good characteristics. In addition, since the removal operation such as simply wiping can be easily performed by mechanization and automation, workability can be improved.

As a modified example of this embodiment, for example, as cellophane, an adhesive cellophane tape coated with an adhesive on one side and a substance having no affinity with the adhesive is applied on the back side. Thereby, there are advantages such as being secondarily fixed with an adhesive tape and preventing loosening during work. Further, it is sufficient that the width of the cellophane is about half the width of the element.

* Second Embodiment * FIG. 4 is a developed perspective view showing a second embodiment of the present invention. In this embodiment, a lacquer paper 14 is used as an exterior sheet of the SH capacitor element 1 by applying a cellulose lacquer to a capacitor paper 12 and using a lacquer coating layer 13, and the lacquer paper 14 is coated with the lacquer coating 13. The capacitor is wound one turn or more around the SH capacitor element 1 with the side facing outward.

In this case, a high-density capacitor paper having a density of 1.1 or more is used as the capacitor paper. That is, in the low-density capacitor paper, since the surface smoothness is low and the absorption amount of the lacquer is large, there is a problem that the formed lacquer coating layer also has a low smoothness.
High-density capacitor paper with high surface smoothness and high lacquer coating layer smoothness is adopted.

When the thickness of the capacitor paper is less than 9 μm, the holding force of the planar shape is low, and the workability is deteriorated. When the thickness exceeds 17 μm, it becomes hard, the flexibility is reduced, and it is difficult to wind the element around the element. Therefore, the range of 9 to 17 μm is appropriate.
Further, the width of the capacitor paper is made substantially equal to the width of the element 1.

Further, as the cellulose lacquer, for example, acetyl cellulose, ethyl cellulose, nitrocellulose and the like are used. Lacquer coating thickness is 0.5
When the thickness is less than μm, the effect is low. When the thickness is 2 μm or more, there is a problem that cracks easily occur due to bending.
An appropriate range is from 2 μm to 2 μm.

Then, under the above conditions, a cellulose lacquer dissolved in a solvent such as acetone is uniformly applied to the capacitor paper 12 and dried, and the lacquer coating layer is formed.
When the lacquer coating layer 13 is formed, the lacquer coating layer 13 has heat resistance almost equivalent to that of the capacitor paper, covers irregularities on the capacitor paper, and realizes a smooth surface equivalent to a plastic film.

Therefore, if the lacquer paper 14 is wound around the outer periphery of the element 1 with the lacquer coating layer 13 as the outer side, even if the metallicon particles are scattered by the metallikon, the metallicon particles do not adhere to the outer periphery of the element 1 but simply. It only adheres, and if so, the amount is very small. Therefore, similarly to the above-described first embodiment, the metallikon particles 11 can be easily removed without damaging the element 1 by wiping with a soft cloth or the like, and the insulation problem due to the metallikon particles 11 can be solved. Stable and good characteristics can be provided. In addition, since mechanization and automation can be easily performed, there is an advantage that workability can be improved.

As a modified example of the present embodiment, a configuration in which a lacquer coating layer is formed on both sides of the capacitor paper to form lacquer paper, and the capacitor paper is used regardless of the front and back sides is also possible. In the above-described embodiment, the number of turns of the lacquer paper for obtaining a more stable effect is suitably about 5 turns.

[Effects of the Invention] As described above, in the present invention, by applying cellophane or cellulosic lacquer as an exterior sheet and using lacquer paper, adhesion prevention and removal of metallikon particles, which were conventionally difficult, can be easily and effectively performed. This can eliminate the problem of insulation due to the remaining metallikon particles, and provide a selected SH capacitor having stable characteristics.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an SH capacitor according to the present invention, FIG. 2 is a plan view showing a capacitor element of the embodiment, FIG. 3 is a perspective view showing a metallikon state in the manufacture of the embodiment, FIG. 4 is an exploded perspective view showing another embodiment of the present invention. 1 ... SH capacitor element, 2 ... metallicon part, 3 ...
Case, 4 ... Lead wire, 5 ... External lead-out terminal, 6 ...
... core, 7 ... element dielectric material, 8 ... cellophane, 9 ...
... cover, 10 ... metallicone gun, 11 ... metallicon particles, 12 ... condenser paper, 13 ... lacquer coating layer, 14 ... lacquer paper.

Claims (3)

(57) [Claims] 1. An outer sheet is attached to the outer periphery of an SH capacitor element, metallikons are connected to both end faces of the element in this state, leads are connected to the metallikon surface, and then housed in a case.
The SH capacitor, wherein the exterior sheet is made of cellophane.
Capacitors. 2. The SH capacitor according to claim 1, wherein the cellophane has an adhesive applied to one surface thereof and a material having no affinity for the adhesive applied to the back surface. 3. An outer sheet is attached to the outer periphery of the SH capacitor element, metallikon is applied to both end faces of the element in this state, leads are connected to the metallikon surface, and then housed in a case.
The SH capacitor according to claim 1, wherein the exterior sheet is lacquer paper obtained by applying cellulosic lacquer to capacitor paper, and the lacquer surface is mounted outside.