JPS6255683B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a current transformer in which a primary winding is molded to prevent destruction due to the impact of electromagnetic mechanical force applied to the primary conductor of the current transformer, and in particular to reduce the consumption of expensive resin. The purpose of this is to reduce costs, simplify molding work, and stabilize quality.

FIG. 1 is a cross-sectional view showing the structure of a conventional current transformer of this type, in which an annular iron core 1, a secondary winding 2 and an insulating 3
The annular part 5 with the primary winding 4 wound thereon is housed in the head container 6, the lead wire of the primary winding is connected to the primary switching terminal 7 and the primary terminals 8a and 8b, and The container 6 is filled with resin 9 and hardened.

However, in such a structure, a large amount of expensive resin is required to fill the entire inside of the head container 6 with resin, and since the entire annular portion 5 is molded, drying treatment of the insulation 3 and a Insulating oil 10
There were disadvantages such as the time required for the impregnation treatment and the cooling effect of the insulating oil was significantly reduced.

The present invention eliminates these drawbacks, and will be described below with reference to Examples.

FIG. 2 shows a cross-sectional view of an embodiment of the invention. However, in this figure, the cut plane is perpendicular to that in Figure 1,
In FIG. 2, a cross section taken along a cut plane parallel to the annular iron core 1 is shown. Note that FIG. 3 shows a front view of the current transformer main body in the middle of manufacturing.

In FIGS. 2 and 3, the secondary winding 2 wound around the annular core 1 is drawn out in a straight line by a leader wire 11, and is integrally insulated with an annular portion 12 by insulation 13 such as insulating paper. It constitutes the main body of the basin.

As shown in FIG. 3, the annular portion 12 has a spacer 14 made of a thin piece of insulating material such as pressboard interposed on the insulation 13, and the outer periphery is made of polyester or the like which is oil-resistant and can be heated to a considerable temperature. A duct 16 is wrapped between the insulation 13 and the spacer 14 and wrapped with a thin insulation material 15 that can withstand the rise and has low absorption of insulation oil.
form. It should be noted that the damping material 15 does not perform an electrical damping action, but rather prevents resin from penetrating as will be described later. Also, the second
In the figure, the spacer 14 and the shrink material 15 are omitted. Then, an insulated primary conductor 17 is wound thereon to provide a plurality of primary windings.

The annular portion 12 constructed in this manner is fitted into a head upper container 19 provided with a partition plate 18 having a shape matching the outer shape of the annular portion 12 and the primary winding, as shown in FIG. At the same time, the primary winding lead wire 22 of the annular portion 12, that is, the primary terminal and the primary switching terminal After pulling out the resin 9, the resin 9 is injected into the head upper container 19 and hardened.

Here, the temporary lid 21 has an appropriate thickness at the pull-out hole 21a, and the lead wire of the primary winding maintains an appropriate shape by being pulled out from the pull-out hole 21a, and is fixed with resin. In addition, the temporary lid 21
In addition to this, there is a through hole 2 for the conduit for insulating oil distribution.
1b, and when the primary lead wire is drawn out from the lead-out hole, a conduit, which will be described later, is placed through the through-hole 21b and embedded in the resin.

FIG. 6 shows the state of the annular portion fitted and molded into the head upper container in this manner, and 23 is a conduit for circulating the above-mentioned insulating oil. As is clear from the figure, the inside of the head upper container 19 is divided by a partition plate 18 as shown in FIG. 4, and the resin is prevented from flowing into areas where resin does not need to be injected. Therefore, resin consumption is significantly reduced.

As shown in FIG. 2, the lower head container 24, insulator tube 25, base 26, etc. are attached to the current transformer body manufactured in this way, and the secondary lead wire 11 is connected to the secondary terminal 27. Temporary lid 21 of upper container 19
is removed, a lid 28 is applied, and insulating oil 10 is sealed inside.

In this way, in the current transformer according to the present invention, the part to be filled with resin is the head upper container 19 and the hard material 1
5 and the primary conductor lead-out portion of the head upper container 19, the amount of expensive resin used can be significantly reduced.

That is, in the present invention, the container itself is kept in a simple shape, and a partition plate is provided inside so that the inside of the container is adapted to the complicated shape of the current transformer annular portion and the primary winding wound around it. Therefore, it can be manufactured more easily than if the container itself had a complicated shape.

In addition, the resin 15 can prevent the resin from penetrating into the insulation 13 of the annular part during injection or curing, and the duct 16 between the insulation 13 of the annular part and the insulation 15 can prevent the resin from drying. Processing and impregnation with insulating oil are facilitated, and since the insulating oil is present on the surface of the mold or on the surface of the partition plate 18 in contact with the mold, cooling by the insulating oil is effectively performed. Furthermore, in the present invention, the head upper container 19 itself, which has a molded annular portion, serves as an outer box for the current transformer head, so it has many advantages such as a simple structure, and its effects are significant.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the conventional structure of this type of current transformer, Fig. 2 is a sectional view showing an embodiment of the present invention, and Fig. 3 is a current transformer in which the primary winding is wound around the annular part. A front view showing the main body, Fig. 4 is a perspective view showing the structure of the container above the head provided with a partition plate, Fig. 5 is a perspective view showing an example of a temporary lid, and Fig. 6 is a perspective view showing the structure of the case where the primary winding is wound. FIG. 3 is a perspective view showing a state in which the annular portion is fitted into the upper head container and resin is injected and hardened. 1... Iron core, 2... Secondary winding, 9... Resin, 1
3... Insulation, 14... Spacer, 15... Shrinkage material, 16... Duct, 17... Primary conductor, 18
... Partition plate, 19 ... Head upper container, 24 ...
Lower head container.

Claims (1)

[Claims] 1. A secondary winding is wound around an annular core, and insulation is applied to the secondary winding, and a shielding material is wrapped around the outside of the core through a spacer to prevent resin from penetrating, and the above-mentioned insulation is A duct is formed between the shield and the shield, and a primary winding interlinked with the annular iron core is wound around the outer periphery of the shield, so that the shield and the primary coil winding are formed. The upper head container is fitted into a head upper container provided with a partition plate to fit the outer shape of the head upper container, and a resin is injected and hardened between the above-mentioned thin material, the head upper container and the partition plate, and the above head upper container is fitted. A method for manufacturing a current transformer, comprising: combining a head lower container with a current transformer head to form a current transformer head. 2. In the method for manufacturing a current transformer according to claim 1, the upper head container and the lower head container are manufactured in advance as an integrated head container, and the inside of the head container is separated by a partition plate. A method for manufacturing a current transformer, characterized by dividing it into a predetermined shape.