JPS642429Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to improvements in molded coils used in static induction electrical equipment such as transformers.

[Prior art]

Conventionally, for example, in order to reduce the interlayer voltage, the fifth
As shown in the figure, a coil conductor 1 made of a strip-shaped conductor (strip or foil conductor) and an interlayer insulator 2 made of a semi-solid resin film wider than the coil conductor 1, such as an epoxy glass prepreg sheet, etc. A coil body 3 is provided by overlapping windings, and a thermosetting synthetic resin is applied to the gaps between the interlayer insulators 2 that protrude from the winding end faces of the coil conductor 1 on both axial end faces of the coil body 3. The resin is filled by dripping or other suitable means, and the resin is heated and cured together with the resin impregnated into the interlayer insulator 2 to form the coil body 3.
The molded coil A was manufactured by forming a resin insulating layer 4 on both ends in the axial direction. However, the ends of the interlayer insulating material 2 may shrink due to the thermal expansion difference between the interlayer insulating material 2 and the resin insulating layer 4 due to curing shrinkage of the resin or thermal shrinkage due to cooling after curing, and furthermore, thermal phenomena during operation of a transformer. There was a risk that cracks would occur in the portion of the resin insulating layer 4 having a thickness of a between the molded coil A and the end surface of the molded coil A. If a crack occurs in the portion a, this crack may propagate along the interlayer insulator 2 to the inside of the molded coil A, causing dielectric breakdown.

To overcome this drawback, for example, a resin-impregnated glass roving material is inserted into the gap between the interlayer insulators 2 during winding, and the mechanical strength of the resin insulation layer 4 is increased by this glass roving material. In addition, the thickness of the synthetic resin layer 4 itself has been increased. However, in the former case, it takes time and effort to wind the coil body 3, and the winding work is troublesome. In addition, the fuzz of the glass rovin material protrudes from the end face of the coil, spoiling the beauty of the molded coil A, and There was a risk that voids would be more likely to occur in the resin insulating layer 4 due to the insertion of the roving material. Moreover, in the latter case, in order to increase the thickness of the resin insulating layer 4, the amount of synthetic resin used increases, which is uneconomical, and the molded coil becomes large.

[Effect of idea]

The present invention eliminates the above-mentioned drawbacks and provides a molded coil in which the insulation and mechanical strength of the resin insulation layers on both end faces of the molded coil are strengthened.

[Summary of the idea]

In the molded coil of the present invention, when a coil conductor is wound, an end portion of an interlayer insulator interposed between the coil conductors that protrudes outward from the winding end surface of the coil conductor is attached in the width direction of the interlayer insulator. The interlayer insulator is tilted at a predetermined angle, and cuts are made at a required interval in the winding direction of the interlayer insulator within a range that does not reach the winding end surface of the coil conductor, and the interlayer insulator is used to form a coil conductor. When winding the molded coil, the notches formed by the notches are expanded outward in the winding direction of the coil, and the expanded portion is also filled with synthetic resin, so that the resin on both axial end surfaces of the molded coil is expanded. The feature is that the insulating layer is reinforced.

[Example of idea]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4. In FIGS. 1 to 4, the same parts as in FIG. 5 are designated by the same reference numerals and will be described. The difference between the molded coil B of the present invention and the conventional molded coil A lies in the interlayer insulator used. That is, as shown in FIGS. 2 and 3, the interlayer insulating material 2 made of a prepreg sheet or the like used in the molded coil B of the present invention has this interlayer insulating material at both ends in the width direction of the interlayer insulating material 2. Cuts 5 are provided at an angle θ (for example, 45°) at required intervals in the winding direction of the insulator 2. Said cut 5
The depth of the cut is such that it does not reach the winding end surface of the coil conductor 1.

Next, the coil conductor 1 is formed using the interlayer insulator 2.
When winding, an insulating tube 11 is placed on the outside of the winding form 10.
A coil body 3 is formed by winding a coil conductor 1 made of a strip-shaped conductor and an interlayer insulating material 2 in an overlapping manner in the same manner as in the conventional method. During the winding of the coil body 3, the notches 5a provided by the notches 5 at both ends of the interlayer insulator 2 prevent the interlayer insulator 2 from being wound as shown in FIGS. 3 and 4. It is expanded outward in the direction to form an open portion 5b. In this state, the end face of the coil body 3 is filled with synthetic resin by dropping or other suitable means. After filling the synthetic resin, the synthetic resin is heated and cured, and at the same time, the resin impregnated into the interlayer insulator 2 is melted and cured, and the coil conductors 1 are firmly and integrally bonded to each other with the interlayer insulator 2 in between. A molded coil B is manufactured by providing a resin insulating layer 4 on the end face of the coil body 3. This resin insulating layer 4 has notches 5 provided at both ends of the interlayer insulator 2, and the notches 5a are pushed outward to form an open portion 5b, so that the end face of the coil body 3 is A portion of the filled resin also permeates into the open portion 5b and is cured.
That is, the open portion 5b at the end of the interlayer insulator 2 serves as a communication path, and the coil conductor 1 of the interlayer insulator 2
Since a part of the gap defined by the end protruding from the winding end face of the molded coil B is firmly connected by the synthetic resin, the thickness b of the resin insulating layer 4 is equal to the axis of the molded coil B. It is possible to increase the thickness even if the dimension in the direction is the same as the conventional one. Therefore, the resin insulating layer 4
It becomes possible to strengthen the insulation and mechanical strength of

Although the present invention has been described with reference to an example in which a strip conductor is used as the coil conductor 1, the present invention is not limited to this, and a linear conductor may be used as the coil conductor.

[Effect of idea]

Since the present invention is configured as described above, it has the following effects.

(1) In the present invention, an inclined notch is provided at the end of the interlayer insulator which is wound overlappingly with the coil conductor, protruding from the winding end surface of the coil conductor, without reaching the end surface of the coil conductor. When the coil is wound, the cut piece formed by this cut is pushed outward to provide an interlayer communication part on the upper part of the winding end surface of the coil conductor, and when the coil is molded, it is also combined with the interlayer communication part. Since the resin can be filled with resin to form a resin insulation layer, the thickness of the resin insulation layer on both end faces of the molded coil can be increased without increasing the axial dimension of the molded coil. A molded coil with excellent mechanical strength can be obtained.

(2) In addition, when winding the coil, the present invention allows cuts of a predetermined length and angle to be made at both ends of the interlayer insulator in the width direction. Compared to the case of winding bottle material, the coil winding work can be performed more easily and smoothly. Furthermore, even if the thickness of the resin insulating layer on both end faces of the molded coil is thicker than before, the amount of resin used does not increase, so the molded coil can be manufactured economically.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the molded coil of the present invention, FIG. 2 is a perspective view showing the winding state of the coil body used in the molded coil of the present invention, and FIG. 3 is a perspective view showing the main parts of the coil body. FIG. 4 is an enlarged plan view of portion P in FIG. 1, and FIG. 5 is a longitudinal sectional view showing a conventional molded coil. A, B...Mold coil, 1...Coil conductor, 2...Interlayer insulator, 3...Coil element, 4...
...Resin insulation layer, 5...notch.

Claims (1)

[Scope of utility model registration request] In a coil formed by overlapping a coil conductor and an interlayer insulator having a width wider than the winding width of the coil conductor and winding the same a predetermined number of times, a coil is placed at both ends of the interlayer insulator in the width direction as required in the winding direction of the interlayer insulator. 1. A molded coil characterized in that inclined notches are provided at intervals of , within a range that does not reach both ends of a coil conductor.