JPH03177007A - Manufacture of molded coil - Google Patents

Abstract

PURPOSE:To decrease manhours by winding wires on inner drums, successively forming unit coils, disposing an outer drum around the inner drums and the unit coils and molding the inner drums and the unit coils with a resin. CONSTITUTION:A movable frame 34 is moved in the axial direction to an inner drum 21, the detaching of a split frame 32 is repeated and wire winding sections 35 are formed successively in the axial direction of the inner drum 21 by using the inner drum 21 installed on the shaft 23 of a winding machine 22, the split frame 32 held detachable from the side to the outer circumference of the inner drum 21 and the movable frame 34 fitted so as to be able to be shifted in the axial direction onto the outer circumference of the inner drum 21 and held so as to shape the wire winding sections 35. Wires are wound on the wire winding sections 35 every time at the same time, unit coils 36 are formed in succession, the inner drum 21 is removed from the shaft 23 together with the unit coils 36, and an outer drum 40 is arranged around the inner drum 21 and the unit coils 36 and the inner drums 21 and the unit coils 36 are molded with a resin.

Description

[Detailed Description of the Invention] [Purpose clearly stated in parentheses] (Industrial Application Field) The present invention is directed to winding a wire around an inner shell attached to a rotating shaft of a winding machine to form a plurality of unit coils in the axial direction. The present invention relates to a method of manufacturing a molded coil in which the coils are formed one after another and then resin molded.

(Conventional technology) As a molded coil used in a conventional dry type transformer,
There is a coil body made up of a plurality of unit coils that is molded in resin. A method of manufacturing this type of molded coil will be explained with reference to FIGS. 7 to 9. That is, flanges 3.
4 is attached to form a winding frame 5, and the wire 6 is wound around this winding frame 5 a predetermined number of times and in a predetermined number of stages to form a unit coil 7.
Notches 3a of flanges 3 and 4 are provided on the outer periphery of this unit coil 7.
, 4a to wrap and fix the adhesive tape 8, and then the winding frame 5 is disassembled. After producing a plurality of unit coils 7, for example, four unit coils 7, in the same manner, the four unit coils 7 are sequentially fitted into an inner shell 9 constituting a part of a resin mold through spacers 10.

Note that the spacer 10 is made of the same material as the molding resin and is formed in a semi-cured state. After that, the end plates 11, 11 and the outer body 12 constituting the resin mold are assembled around the inner phase 9 and the unit coil 7, and after preliminary drying,
Molding is performed using resin 13.

(Problems to be Solved by the Invention) However, the above manufacturing method has the following problems.

First, even if a semi-cured spacer 10 is used, curing will inevitably proceed during pre-drying. When the resin is in a hardened state, the adhesion with the molding resin is worse than in a semi-cured state, so peeling is likely to occur at the boundary between the spacer 10 and the resin 13. For this reason, cracks may occur in the resin 13 when subjected to cold shock, resulting in a decrease in dielectric strength.

Second, when defoaming the air contained in the unit coil 7 and the resin 13, this spacer 10 becomes an obstacle, preventing the bubbles from coming out smoothly, and air remains inside the unit coil 7, reducing dielectric strength. do.

Third, four middle coils 7 are placed between them with a spacer 1
unit coil 7.
It takes a lot of man-hours because connection work has to be done between the two.

The present invention has been made in view of the above circumstances, and its purpose is to provide a method of manufacturing a molded coil that can prevent the dielectric strength of the molded coil from decreasing and reduce the number of assembly steps.

[Structure of the Invention] (Means for Solving the Problems) The method for manufacturing a molded coil of the present invention includes a split frame that is detachable from an inner shell attached to a rotating shaft of a wire line machine, and a movable frame that is movable in the axial direction. By providing a frame, attaching and detaching the split frame and moving the movable frame, wire winding portions are sequentially formed in the axial direction of the inner body, and the wire is wound around the wire winding portion each time to form a unit coil. are formed one after another, and then the inner shell along with the unit coils is removed from the rotating shaft, and an outer shell is disposed around the inner shell and the unit coils, followed by resin molding.

(Function) The method for manufacturing a molded coil of the present invention involves sequentially forming unit coils by winding a wire around an inner shell, and then disposing an outer shell around the inner shell and unit coils and performing resin molding. This eliminates the conventional work of individually manufacturing and assembling multiple unit coils, resulting in a significant reduction in man-hours.Moreover, there is no need for spacers between unit coils, resulting in uniform curing of the resin and improved defoaming effect. Therefore, a decrease in dielectric strength can be prevented.

(Major Example) Hereinafter, an example in which the present invention is applied to a molded coil of a dry type transformer will be described with reference to FIGS. 1 to 6.

First, in FIGS. 1 and 2, the inner shell 21, which constitutes a part of the resin mold, has a rectangular tube shape consisting of two movable U-shaped members, and is attached to the rotating shaft 23 of the winding machine 22. installed. An insulating layer 24 is formed around the outer periphery of the inner shell 21 by wrapping a net made of high-strength fibers such as glass fibers. A flange 25 located on the root side of the rotating shaft 23 and a 7 flange 26 located on the tip side are fixed to both ends of the inner body 21 by bolts 27, respectively, and the four corners of these flanges 25 and 26 has 4 axially extending
Book guide bars 28, 29 are slidably inserted therethrough and secured in the desired position by respective bolts 30, 31. As shown in FIG. 4, the divided frame 32 includes first and second frames 32a and 32b each having a vertically long U-shape.
It is configured such that it can be attached and detached from the side to the outer circumference of the inner shell 21, and when it is attached, its inner surfaces 32c and 32d are fitted to the insulating layer 24 that is the outer circumference of the inner shell 21, respectively. It is attached to the tips of the upper and lower guide bars 28 on the left and right sides by bolts 33. Movable frame 3
4 has a rectangular shape, and the inner peripheral part 34a fits into the insulating layer 24 on the outer periphery of the inner body 21, and the four corner parts are attached to the tips of the four guide bars 29 so that It is made movable in the axial direction, and a wire winding portion 35 is formed between it and the dividing frame 32 as described later.

In forming the unit coil 36 for the first time, first, as shown in FIGS. 1 and 2, the divided frame 32 is moved so as to be in contact with the flange 25 and fitted into the insulating layer 24. This state is maintained by fixing the guide bar 28 to the flange 25 with bolts 30. On the other hand, the movable frame 34 is moved in the axial direction of arrow A together with the guide bar 29, and the distance between the movable frame 34 and the split frame 32, that is, the wire winding portion 3
A is adjusted so that the width dimension of 5 is equal to the stack dimension of the unit coil 36. This state is maintained by fixing the guide bar 29 to the flange 26 with bolts 31. This stack size is determined by the diameter of the wire 37.
If the number of meshes in one stage of the unit coil 36 is n, then L - n
It is set to X D + D/2. Therefore, the wire 37 is introduced from between the frames 32a and 32b, and the wire 37 is inserted into the inner shell 21.
The first stage coil is aligned and tightly wound in the direction of arrow B on the insulating layer 24 which is the outer periphery of the coil.

Next, the second stage coil row is wound in the opposite direction to the first stage coil row, and after this is repeated in multiple stages, the insulating tape 38 is wrapped around the outer periphery and side portions of the unit coil 36. Wrap and secure. Next, the bolt 31 is loosened, the guide bar 29 is moved in the direction of arrow A, and the movable frame 34 is moved backward. At this time, the unit coil 36 does not lose its shape because the insulating tape 38 is wrapped around it.

Next, the bolts 30 and 33 are loosened to release the split frame 32 from the guide bar 28, and the first and second frames 32a and 3
2b to the side and remove it from the left side of the intermediate coil 36. Thereafter, as shown in FIG. 3, the first and second frames 32a and 32b are fitted from the outside to the insulating layer 24, which is the outer periphery of the west body 21, so as to come into contact with the right side of the unit coil 36, and the guide Attach it to the bar 28 and tighten the bolt 33.
The guide bar 28 is fixed to the flange 25 by tightening the bolt 30. Therefore, the movable frame 34 is moved in the direction of arrow A or the direction opposite to arrow A, and the gap between the two is adjusted to match the stack size of the unit coil 36, and the guide bar 29 is fixed to the flange 26 with bolts 31. The wire winding portion 35 is formed again. Then, the wire 37 at the end of the winding of the first unit coil 36 is introduced from between n32a and 32b, and the second unit coil 36 is formed in the same manner as described above.After that, the divided frame 32 and the movable frame 34 are connected in the same manner. The wire encircling portions 35 are sequentially formed by winding the wire 37 each time, and a plurality of unit coils 36, for example, four unit coils 36, are continuously wound without interposing a spacer between them.

Next, the inner shell 21 is removed together with the flanges 25 and 26 from the rotating shaft 23 of the winding machine 22 with the four unit coils 36 still wound thereon, and the flanges 25 and 26 are removed from the inner shell 21. Then, as shown in FIG. 5, on the inner shell 21,
An end plate 39.3 forming a part of the resin mold at the lower end
9 through gaskets 38 and 38, and an outer shell 40 constituting a part of the resin mold is attached to the outer periphery of the four unit coils 36. After preliminary drying, molding resin 41 is injected from an injection port (not shown). This resin 41 permeates into the insulating layer 24, fills the outer circumferential portion of the unit coil 36, and is cured. Thereafter, the two-part inner shell 21 is moved in the radial direction so as to overlap with each other and removed from the inside of the insulating layer 24, and the packing 38. A molded coil 42 (see FIG. 6) is manufactured by removing the end plate 39 and outer shell 40.

According to the above embodiment, the following effects are achieved. That is, the wire winding parts 35 are sequentially formed in the axial direction of the wire winding part 121 attached to the rotating shaft 23 of the winding machine 22, and the wire 37 is wound around the wire winding part 35 each time to form a unit coil. Since the coils 36 are formed continuously, the number of assembly steps can be significantly reduced, unlike the conventional method in which a plurality of separately manufactured intermediate coils 7 are fitted into the inner shell 9. Further, since the plurality of unit coils 36 do not lose their shape and are wound directly on the insulating layer 24 and do not move in the axial direction, the spacer 10 is not required in the conventional case. do not. Therefore, when the resin 41 is molded in the post-process, the curing speed of the resin 41 is uniform, so that no cracks occur in the resin 41, and the defoaming effect is also improved, so that the dielectric strength can be improved.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings; for example, the outer body of the resin mold may be made of resin and may be a part of the molded coil. In this case, the insulating layer 24 may not be provided.

[Effects of the Invention] In the molded coil manufacturing method of the present invention, wire winding portions are sequentially formed in the axial direction of an inner shell attached to a rotating shaft of a winding machine, and wire is added to each wire winding portion each time. The unit coils are sequentially formed by winding the unit coils, and then the inner shell and the unit coils are removed from the rotating shaft, and the outer shell is placed around the inner shell and the unit coils, and then resin molded. This has the effect of preventing the dielectric strength of the molded coil from decreasing and reducing the number of assembly steps.

[Brief explanation of drawings]

Figures 1 to 6 show one embodiment of the present invention, with Figure 1 being an overall perspective view, Figures 2 and 3 being sectional views of essential parts showing the manufacturing process, and Figure 4 being a cross-sectional view of the main parts showing the manufacturing process. A perspective view of a split frame and a movable frame,
Fig. 5 is a cross-sectional side view of the right half in the casting process, Fig. 6 is a perspective view of the molded coil, Fig. 7 is a sectional view of the winding frame in the conventional example, and Fig. 8 is the same side view. , FIG. 9 is a diagram corresponding to FIG. 5. In the figure, 21 is an inner shell, 22 is a winding machine, 23 is a rotating shaft, and 35
is the wire winding part, 36 is! 11th coil, 37 wire, 40 outer shell, 41 resin, and 42 molded coil.

Claims (1)

[Claims] 1. an inner shell attached to the rotating shaft of the winding machine; a split frame held so as to be removable from the side with respect to the outer periphery of the inner shell; a movable frame that is fitted into the split frame and held so as to form a wire winding portion between the split frame, the movable frame is moved in the axial direction with respect to the inner shell, and the split frame is attached and detached. This process is repeated to sequentially form wire winding parts in the axial direction of the inner shell, and the wire is wound around the wire winding parts each time to form unit coils one after another. is removed from the rotating shaft, an outer shell is arranged around the inner shell and the unit coil, and these inner and outer shells are used as a resin mold mold to perform resin molding. Method.