JPS6329809B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rectangular bobbin, and is useful when applied to a wound core having a rectangular cross section.

In a columnar transformer, a bobbin is interposed between an iron core and a low voltage winding wound around the core. This bobbin is usually formed from pressboard to match the cross-sectional shape of the iron core. If the iron core has a rectangular cross section, the bobbin will also be rectangular, and in the case of pressboard, it is difficult to give a square radius, so the square of the low-voltage winding wound around this bobbin will also become rounded.

Therefore, in the pole transformer according to the prior art, the first
As shown in the drawings and FIG. 2, the cross section of the wound core 1 is nearly rectangular (stepped), and the bobbin 2 is also approximately rectangular with its square corners cut off to match the cross-sectional shape of the wound core 1. This bobbin 2 is made into a cylinder by bending a press board, and a low voltage winding 3 and a high voltage winding 4 are wound around it.

On the other hand, when winding the low voltage winding 3, as shown in FIG. The end insulator 5 is fastened with an insulating tape 6 which is wound around the low voltage winding 3 for 2 to 3 turns. At this time, this tightening is performed at several locations, and moreover, at the beginning and end of each layer. In the figure, 7 is the main insulating layer, 8 is the duct, 9,
9a is a corrugated duct.

The above prior art structure has the following drawbacks.

a The winding of the winding can be completed in a short time, but the work of fixing (tightening) the end insulating portion 5 takes time and the manufacturing efficiency of the winding is poor.

b When manufacturing the wound core 1, two types of silicon steel strips with different widths must be prepared and wound.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide a rectangular bobbin that improves the manufacturing efficiency of the winding and requires only one type of silicon steel strip constituting the winding core.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Note that parts that are the same as those in the prior art are given the same numbers and redundant explanations will be omitted.

4a, b, and c are a plan view, a front view, and a side view of this embodiment, and FIG. 5 is a perspective view.

As shown in these figures, the rectangular bobbin 11 has two
It is a rectangular cylindrical body formed by combining a single long side portion 12 and two short side portions. The long side portion 12 is a flat plate made of pressboard. Further, the short side portion 13 is a resin molded plate made of reinforced plastic (FRP) formed into a substantially rectangular wave shape (uneven wave shape) along the winding direction of the low voltage winding 3 (see Fig. 6) wound around the short side portion 13. It is. In the figure, 13a is a convex portion, and 13b is a concave portion. Further, the short side portion 13 has a protrusion formed by further protruding the upper and lower portions of the convex portion 13a outward, and this protrusion has the same function as the end insulator 5 of the prior art. An end insulator 13c is formed. That is, the end insulator 13c is formed integrally with other parts along the periphery of both the upper and lower ends of the short side part 13. The square outer peripheral surface of the short side portion 13 is a chamfered portion 13d, and the square inner peripheral surface is provided with a cut groove 14 into which the end of the long side portion 12 is inserted. That is, this short side portion 13 having a substantially rectangular wave shape has an end insulator 13c integrally attached thereto. At this time, the edge portion 13c is not provided at the lead-out line rising point 15. This is so that it does not interfere with the rise of the lead line.

FIG. 6 shows a state in which the low voltage winding 3 and the high voltage winding 4 are wound around the rectangular bobbin 11 according to this embodiment. As shown in the figure, the inner circumferential surface of the low voltage winding 3 is in contact with the convex portion 13a, and the upper and lower end surfaces are in contact with the lower and upper surfaces of the end insulator 13c, respectively. That is, the positions of both the upper and lower ends of the low voltage winding are regulated by the end insulators 13c. Furthermore, since the inner circumferential surface of the low voltage winding 3 is in contact with the convex portion 13a, a duct is formed between this inner circumferential surface and the concave portion 13b, and this portion becomes the oil flow passage 16. Further, since the wound core 1 may have a rectangular cross-sectional shape, it is sufficient to prepare only one type of silicon steel strip.

As specifically explained above with the examples,
Since the rectangular bobbin according to the present invention has the end insulator and the oil flow passage integrally attached, the winding efficiency of the winding is improved and the cooling performance of the low-voltage winding is improved. In other words, the positions of the upper and lower ends of the low-voltage winding can be regulated by the end insulators that protrude further from the convex part, and since the inner circumferential surface of the low-voltage winding abuts the convex part, the inner circumference of the low-voltage winding A space is created between the surface and the recess, and this space can be used as a passage for cooling oil.

In addition, since the squares on the short sides are chamfered, it is possible to easily wind the low-voltage winding around the rectangular bobbin of the present invention without making the squares of the low-voltage winding angular. It can be easily formed by simply preparing a silicon steel strip.

Further, in the present invention, since only the short side portions are made of FRP, the mold can be easily manufactured. Incidentally, if a rectangular bobbin with such a structure were to be integrally molded using all FRP, the mold would be complicated, and if multiple units were molded at the same time to increase bobbin production, the cost of the mold would further increase, making it more expensive than pressboard.
Since it uses FRP, it is even more expensive. Further, since the rectangular bobbin according to the present invention is a combination of long side portions and short side portions, this assembly can be performed at the site where the bobbin is used, which is the winding work site. This results in significant savings in storage space compared to conventional pressboard bobbins, which provides significant benefits to manufacturers.

[Brief explanation of the drawing]

Figures 1 to 3 show a pole-mounted transformer according to the prior art, with Figure 1 being a plan view, Figure 2 being a perspective view of its bobbin, and Figure 3 having one layer of low-voltage winding wound around the bobbin. 4a, b, c to 6 show embodiments of the present invention; FIGS. 4a, b, and c are plan views, front views, and side views thereof; The figure is a perspective view thereof, and FIG. 6 is a schematic plan view showing a winding wire wound around the bobbin of FIG. 5. In the drawing, 11 is a rectangular bobbin, 12 is a long side, 1
3 is a short side portion, 13a is a convex portion, 13b is a concave portion, 13
c is an end insulator, and 14 is a kerf.

Claims (1)

[Claims] 1. The long side of the rectangle is made of an insulating flat plate such as a press board, and the short side has a convex part and a concave part shaped into a substantially rectangular wave shape, and further outward from the convex part along the upper and lower edges of the short side. It has an integral end insulator formed to protrude, and furthermore, the rectangular outer peripheral surface of the short side is a chamfered part, and the inner peripheral surface has a cut groove into which the end of the long side is inserted. A rectangular bobbin characterized in that it is made of reinforced plastic.