JP2525104B2 - Resin-impregnated paper capacitor core and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-impregnated paper capacitor core used for capacitor bushings and the like, and a method for manufacturing the same.

[0002]

2. Description of the Related Art As one type of resin-impregnated paper capacitor core, a plurality of cylindrical capacitor foils are concentrically embedded in a cylinder made of resin-impregnated paper having a predetermined thickness, and each end of the capacitor in the axial direction is There is a resin impregnated paper capacitor core to which the end fittings are attached. In this type of capacitor core,
It is necessary to electrically connect the embedded one capacitor foil to the charging side or the ground side, and the electrical lead must be taken out from the above-mentioned capacitor foil by some means.

FIG. 6 shows the internal structure of one end of a conventional resin-impregnated capacitor core. In the capacitor core, a plurality of tubular shapes are provided in a tubular body 2 made of resin-impregnated paper 1 having a predetermined thickness. Capacitor foil 3a, 3b, 3c, 3d
.. is embedded, and a metal foil tape 4 such as an aluminum foil having one end soldered to the capacitor foil 3a located on the innermost peripheral side is integrally wound in the resin-impregnated paper 1, The inner end of a lead wire 7a made of a braided wire or the like inserted from the outside of the end fitting 6 is soldered to the outer end of the lead tape 5 soldered to the outer peripheral surface of the metal foil tape 4. There is. On the other hand, in the end fitting 6, a screw hole 6a extending from the outer periphery to the axial center side and a through hole 6b extending from the inner end to the axial center side are formed, and the outer end portion of the lead wire 7a is soldered. The terminal 7b faces the through hole 6b, and the terminal 7b
Is connected via a spring washer 7d with a plug 7c screwed into the screw hole 6a, so that the lead wire 7a and the end fitting 6 are electrically connected.

The capacitor core having such a structure is manufactured by the steps shown in FIGS. (1) In a cylinder forming step of winding a core paper to form a cylinder, a blade 9 or the like is provided at an end of a cylinder 8 formed by integrally winding the capacitor foil 3a and the metal foil tape 4 with the core paper. An insertion hole 8a reaching the metal foil tape 4 from the outer periphery is opened to expose the outer peripheral surface of the metal foil tape 4 at the inner end of the insertion hole 8a (see FIG. 7). (2) The inner end of the lead tape 5 is soldered to the portion exposed in the insertion hole 8a of the metal foil tape 4 (see FIG. 8A). (3) The lead tape 5 is pushed into the insertion hole 8a without bending, the strip of insulating paper is packed in the space of the insertion hole 8a, and the silicone rubber 8b is placed on the outer end portion of the lead tape 5, The whole body 8 is impregnated with an epoxy resin and is cured (see FIG. 8B). (4) Remove the silicon rubber 8b from the cylinder to form the recess 8c.
And the outer end of the lead tape 5 is exposed in the recess 8c. (See FIG. 8 (c)). (5) Solder the inner end of the lead wire 7a to the lead tape 5 exposed at the bottom of the recess 8c (see FIG. 8D).

[0005]

By the way, in the capacitor core, since the lead wire 7a electrically connected to the capacitor foil 3a is taken out in the radial direction, the diameter of the end fitting 6 becomes large and the Due to the relationship with the separation distance between and, the surrounding pipe line must be made large, and other influences are large.

Further, as problems in the method of manufacturing the capacitor core, there are the following problems. (1) Many manufacturing processes take time and trouble. (2) Since the position of the metal foil tape cannot be visually recognized in the work of forming the insertion hole to expose the metal foil tape by making a hole from the outer periphery of the cylindrical body, it is difficult to form the insertion hole accurately and defective products are generated. Frequently. (3) The soldering work in the small insertion hole and the recess is very difficult, and the surrounding core paper and resin-impregnated paper may be locally burned out. (4) In the soldering before the step of impregnating the resin, the paste cannot be used because it penetrates the core paper and impairs the electric performance when the paste is used, which makes the soldering more difficult. Therefore, an object of the present invention is to solve the above problems.

[0007]

A first aspect of the present invention relates to a resin-impregnated paper capacitor core, in which a plurality of cylindrical capacitor foils are concentrically embedded in a cylinder made of resin-impregnated paper having a predetermined thickness. In a resin-impregnated paper capacitor core with end fittings attached to each end in the axial direction,
A connection terminal electrically connected to one of the capacitor foils is exposed on the end surface of one end of the cylindrical body.
And the connection terminal is supported by the end surface of the cylindrical body.
And is electrically connected to the end fitting in the axial direction .

A second aspect of the present invention relates to a method of manufacturing a resin-impregnated paper capacitor core according to the first aspect of the present invention, wherein the core paper is wound in a tubular body forming step to form a tubular body. One or a plurality of plate-shaped electrodes having solder welded to one spiraled capacitor foil are electrically connected to embed the plate-shaped electrodes in the vicinity of one end of the cylindrical body, and a predetermined resin is applied to the cylindrical body. The resin is impregnated and cured to form a cylinder made of resin-impregnated paper, and then one end of the cylinder made of resin-impregnated paper is cut to a predetermined length and the solder welded to the plate-like electrode is welded to the cylinder. Exposed to the end face of one end of the, and then the connection terminal is electrically connected to the capacitor foil via the exposed solder to expose the connection terminal to the end face of the one end of the tubular body. To do.

[0009]

In the capacitor core according to the first aspect of the present invention, the connecting terminal is exposed at the end face of the one end in the axial direction. Therefore, if the end fitting is attached to the one end, the connecting terminal is attached. Is supported by the end face of the cylinder,
It is electrically connected to the end surface of the metal fitting in the axial direction. For this reason,
According to the capacitor core, it is not necessary to employ a large end metal fitting in the radial direction as the end metal fitting as in the conventional capacitor core, and the size can be made compact.

In the method of manufacturing the capacitor core according to the second aspect of the present invention, the following operational effects are exhibited. (1) The number of manufacturing steps is smaller than that of the conventional method for manufacturing a capacitor core, and the time and labor are not required. (2) The solder that is welded to the plate electrode electrically connected to the capacitor foil is exposed to the end face of the same end by cutting one end of the cylindrical body to a predetermined length, and thus exposing the solder. There is no difficulty in exposing work such that work is done accurately and the product is misplaced and becomes a defective product. (3) Since the soldering work is a work of connecting the connection terminal to the solder exposed on the end face of the cylindrical body, the periphery of the soldering portion is wide and the soldering work is easy. (4) Since the soldering work is performed after the core paper is impregnated with the resin, the paste can be used for the soldering work, and the soldering work is easier.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a capacitor core 10 according to the present invention and end fittings 20a and 20b are attached to both ends of the capacitor core 10 to form the core. A resin paper impregnated paper capacitor bushing is shown. In the bushing, the center conductor 21 inserted into the inner hole of the capacitor core 10 is supported by the metal fittings 20a and 20b at both ends, and the center of the outer periphery of the capacitor core 10 is supported by the support wall while penetrating the support wall. It is attached via a mounting flange 20c fixed to the section.

The capacitor core 10 is provided with a cylindrical body 11 made of resin-impregnated paper having a predetermined thickness, capacitor foils 12a, 12b, 12c and 12d concentrically embedded in the cylindrical body 11, and an electrical lead takeout mechanism 13. The tubular body 11 is formed by impregnating an epoxy resin into a tubular body formed by concentrically winding a plurality of layers of insulating paper 11b and curing the epoxy resin. Each of the capacitor foils 12a to 12d is made of aluminum foil, and is integrally wound with the insulating paper 11b at a predetermined portion in the winding process of the insulating paper 11b.

The take-out mechanism 13 is provided at one end of the cylindrical body 11, and is composed of a metal foil tape 13a made of aluminum foil,
It is composed of a plurality of plate electrodes 13b, a plurality of solder pastes 13c, and a plurality of connection terminals 13d made of metal pieces. As shown in FIG. 2, the inner end of the metal foil tape 13a is
It is soldered to the innermost capacitor foil 12a and wound integrally with the insulating paper, and each plate electrode 13b is soldered to the outer peripheral surface thereof. Further, the solder paste 13c is welded to the outer periphery of each plate electrode 13b,
Each connection terminal 13d is connected to each plate-shaped electrode 13b via each solder 13c. The connection terminal 13d has a substantially L-shape, its legs are soldered, and its end face is exposed in contact with the end face of the tubular body 11 along the end face.

A central conductor 21 which is a metal rod is inserted into the inner hole of the capacitor core 10, and the central conductor 2
1 is supported by each end fitting 20a, 20b at each end. The first end fitting 20a has a connecting projection 22b at the center of the outer surface of a circular receiving plate 22a, and one end of the center conductor 21 is screwed into a screw hole 22c on the inner surface. On the other hand, the second end fitting 20b is the spring retainer 2
3, a spring 24, a spring retainer 25, and a lock nut 26. In the second end fitting 20b, the spring retainer 23 is located on the end face of the tubular body 11 by fitting the central tubular portion 23a to the end of the inner hole of the tubular body 11, and is located in the annular recess 23b of the spring retainer 23. The spring 24 is fitted and positioned, and the spring retainer 25 holds the spring 24. Lock nut 26
Is screwed to the other end of the center conductor 21 so as to be able to advance and retreat, and abuts on the bottom of the annular recess 25a of the spring retainer 25 to press the spring retainer 25 against the spring 24. As a result, the spring retainer 23 is elastically urged toward the end surface of the cylindrical body 11 and comes into close contact with the end surface of the connection terminal 13d exposed on the end surface of the cylindrical body 11, and the capacitor foil 12a is connected to the second end fitting. It is electrically connected to 20b.

The capacitor core 10 is manufactured in the order shown in FIGS. FIG. 2 shows a state in which the insulating paper is being wound.
Metal foil tape 1 with the inner end soldered to the outer periphery of the end of 2a
3a is wound together with the insulating paper. In this case, the metal foil tape 13a has a plurality of plate-shaped electrodes 13b on its outer periphery.
What is soldered and which has the solder paste 13c welded to the outer periphery of each plate electrode 13b is used. FIG. 3 shows a partial cross section of the cylindrical body after winding the insulating paper. The metal foil tape 13a, the plate-shaped electrode 13b, and the solder paste 13c are embedded in the end portion of the tubular body, and the entire tubular body is impregnated with epoxy resin and cured to form the tubular body shown in FIG. Form.

Next, the end portion of the cylindrical body shown in FIG. 4 is cut along the portion indicated by the chain double-dashed line, and the end portion of a predetermined length and the plate electrode 13b and part of the solder paste 13c are cut. The cylindrical body shown in 5 is formed. The tubular body is the tubular body 11 shown in FIG. 1, and the cut end faces of the plate electrode 13b and the solder paste 13c are exposed on the end face 11a of the tubular body. Finally, the exposed solder 13c is melted as shown in FIG. 5 and the leg portion of the connection terminal 13d is inserted into the solder 13c, and the end face of the connection terminal 13d is pressed against the end face 11a of the cylindrical body 11 to make a close contact. Let As a result, the capacitor core 10 is formed.

In the capacitor core 10 having such a structure, the connecting terminal 13d is exposed on the end face 11a at one end of the cylindrical body 11 in the axial direction, so that the second end fitting 20b can be attached to that one end. For example, the connection terminal 13d
The second end fitting 20b is supported by the end surface 11a.
Is electrically connected to the end face of the. Therefore, according to the capacitor core 10, it is not necessary to use a large end metal fitting in the radial direction as the second end metal fitting 20b unlike the conventional capacitor core, and the size can be made compact. In the capacitor core 10, the capacitor foil 12a and the second end fitting 20b are electrically connected to each other by the end fittings 20a and 20b and the center conductor 2.
It is possible to carry out by a center clamp method utilizing the elastic center clamp axial force of No. 1, thereby obtaining a connection structure that is strong and does not loosen over time.

Further, according to the method for manufacturing the capacitor core 10, (1) the number of soldering operations and the number of manufacturing steps are smaller than those in the conventional method for manufacturing a capacitor core, and the manufacturing process does not take time and labor. (2) Solder paste 13 welded onto the plate-like electrode 13b connected to the capacitor foil 12a via the metal foil tape 13a
As a means for exposing c, one end portion of the cylindrical body 11 is cut to a predetermined length and exposed on the end face of the same end portion. Therefore, the work for exposing the solder paste 13c is performed accurately and the position is incorrect. There is no difficulty in exposing work such as defective products. (3) The only soldering work in the process of forming the take-out mechanism 13 for the capacitor core 10 is the connection terminal 13d.
Is a work for connecting to the solder 13c exposed on the end surface 11a of the cylindrical body 11, so that the periphery of the soldering portion is wide and the soldering work is easy. (4) Since the soldering work is performed after the core paper is impregnated with the resin, the paste can be used for the soldering work, and the soldering work is easier.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a bushing using a capacitor core according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the winding state of the metal foil tape in the process of manufacturing the same capacitor core during the winding of the insulating paper.

FIG. 3 is a partially enlarged vertical sectional view of a cylindrical body made of the same insulating paper.

FIG. 4 is a partially enlarged vertical cross-sectional side view of a tubular body made of the same insulating paper impregnated with resin and cured.

FIG. 5 is a partially enlarged vertical cross-sectional view showing a state in which the connection terminal is soldered to the exposed solder by cutting and exposing the end portion of the cylindrical body.

FIG. 6 is a partially enlarged vertical perspective view of a bushing using a conventional capacitor core.

FIG. 7 is an explanatory diagram showing a part of the conventional manufacturing process of the capacitor core.

FIG. 8 is an explanatory view showing another part of the conventional manufacturing process of the capacitor core.

[Explanation of symbols]

10 ... Capacitor core, 11 ... Cylindrical body, 11a ... End face, 1
2a to 12d ... Capacitor foil, 13 ... Take-out mechanism, 13
a ... Metal foil tape, 13b ... Plate-shaped electrode, 13c ... Solder solder, 13d ... Connection terminal, 20a ... First end fitting, 20b
... second end fitting, 20c ... mounting flange, 21 ... center conductor, 23 ... spring retainer, 24 ... spring, 2
5 ... Spring retainer, 26 ... Lock nut.

Claims (2)

(57) [Claims] 1. A resin-impregnated paper capacitor in which a plurality of cylindrical capacitor foils are concentrically embedded in a cylinder made of resin-impregnated paper having a predetermined thickness, and end fittings are attached to each axial end. In the core, a connection terminal electrically connected to one of the capacitor foils is exposed on an end surface of one end of the cylinder , and the connection terminal is the cylinder.
When supported by the end surface of the body, the end fitting and the axial direction
A resin-impregnated paper capacitor core characterized in that it is electrically connected to . 2. A method of forming a cylindrical body by winding a core paper, wherein a solder is welded to one capacitor foil wound in a cylindrical body forming step.
Alternatively, a plurality of plate-shaped electrodes are electrically connected to embed the plate-shaped electrodes in the vicinity of one end of the tubular body, and the tubular body is impregnated with a predetermined resin and the resin is cured to form resin-impregnated paper. A cylindrical body made of resin-impregnated paper, and then one end of the cylindrical body made of resin-impregnated paper is cut to a predetermined length to expose the solder welded to the plate-shaped electrode to the end face of the one end of the cylindrical body, and then exposed. A method of manufacturing a resin-impregnated paper capacitor core, wherein the connection terminal is electrically connected to the capacitor foil via solder to expose the connection terminal to an end face of one end of the tubular body.