JP2602126B2 - Iron core fastening structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fastening an iron core for electromagnetic induction equipment, which is formed by laminating thin steel plates.

[0002]

2. Description of the Related Art FIGS. 8 and 9 are structural views showing conventional iron core fastening in a transformer . FIG. 8 is a front view and FIG. 9 is a side view. 8 and 9, reference numeral 1 denotes a laminated iron core made of a thin steel plate;
Is a patch attached to both end faces of the iron core 1, and 3 is an iron core 1.
An insulating plate provided between the armature and the backing plate 2, 4 is a bolt for tightening the iron core 1, 5 is a nut screwed to the bolt 4, 11
Reference numerals a and 11b denote iron core tightening frames for tightening the upper and lower yoke portions, respectively, and are made of a steel material having a channel structure having a large strength. Numeral 12 is a foot for preventing overturning, which is attached to the lower core fastening frame 11b.

FIG. 10 is a sectional view taken along the line AA of FIG. 8, and FIG. 11 is a sectional view taken along the line BB of FIG. In FIGS. 10 and 11,
Reference numeral 6 denotes a metal washer, and 7 denotes an insulating washer provided between the backing plate 2 and the metal washer 6. Reference numeral 8 denotes an insulating sleeve, which is disposed on the outer periphery of the bolt 4 and extends from the iron core 1 to the bolt 4.
Is insulated. Reference numeral 10 denotes a through hole for fastening the iron core 1, and reference numeral 9 denotes a gap inside the through hole 10 of the iron core 1. Reference numeral 13 denotes an iron core circle on which primary and secondary coils are assembled.
Since the iron core 1 is of a type in which the coil horizontal section is combined with a circular coil, a plurality of types of iron cores are formed so that the outer shape is substantially circular in order to improve the space factor of the iron core 1 with respect to the inner diameter of the coil as much as possible. It is made by stacking things of width. Since the cusps of the end face of the outermost layer of the iron core 1 and the end face of the through hole of the backing plate 2 are opposed to each other, the insulating plate 3 has a thickness of 3 to 4 mm in order to secure the dielectric strength therebetween. Was used.

[0004] FIG.
Is an iron core device disclosed in Japanese Patent Publication No. 8 to 11 indicate the same or corresponding parts. Reference numeral 14 denotes an insulating washer inserted between the backing plate 2 and the insulating plate 3 and having a flange at one end. Reference numeral 15 denotes a predetermined depth formed on the backing plate 2 corresponding to the brim of the insulating washer 14. It is an insertion hole. According to this, the flange of the insulating washer 14 acts to increase the creepage distance and prevent creepage breakdown,
The insulating plate 3 could be reduced to a thickness of 0.5 to 0.8 mm.

[0005]

However, the use of an insulating plate having a thickness of 3 to 4 mm is a factor that hinders the improvement of the space factor of the iron core in the iron core circle. In such a case, the unit price of the material of the insulating plate is high, which also increases the price of the transformer. on the other hand,
In the example of Japanese Utility Model Application Laid-Open No. 56-134706, the thickness of the insulating plate can be reduced to 0.5 to 0.8 mm to improve the space factor. However, a special-shaped insulating washer is required. In addition, it is possible to assemble the iron core itself without inserting an insulating washer, and it is not possible to judge the presence or absence of an insulating washer just by looking at the finished product, which may have caused a work error during assembly. .

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and does not use any additional parts. Therefore, the present invention is excellent in economy and workability, and improves the space factor of the iron core with respect to the iron core circle. It is intended to provide an iron core fastening structure.

[0007]

According to a first aspect of the present invention, there is provided an iron core tightening structure in which a through hole for tightening is provided in each of a laminated core, an insulating plate and a backing plate, and one side of the through hole of the backing plate is expanded. Hole and
An insulating plate is brought into contact with the outermost layer of the laminated core in correspondence with these through-holes, the surface of the expanded plate of the backing plate is brought into contact with the insulating plate, and a bolt is passed through the through-hole and tightened together with a washer and a nut. It is.

[0008] A core fastening structure according to a second aspect of the present invention is obtained by expanding the through hole of the backing plate of the first aspect on both sides of the plate.

[0009]

According to the first aspect of the present invention, the hole enlarging process performed on the insulating plate side of the through hole of the backing plate is performed by:
The distance between the ends of the through holes in the iron core is increased, and the electric field strength between the ends is reduced.

[0010] In the second invention, in addition to the operation of the first invention, an enlarging process performed on the other side of the through hole of the backing plate is performed by an electric field between the backing plate and a metal washer, a bolt, and a nut. Decrease strength.

[0011]

FIG. 1 is a cross-sectional view of a core tightening portion showing one embodiment of the present invention. In the figure, reference numerals 1, 4 to 10 are the same as those described in FIG. 21
Is an insulating plate that electrically insulates between the iron core 1 and the backing plate 22, and both the insulating plate 21 and the backing plate 22 are provided with through holes for tightening. Backing plate 2 on the side facing insulating plate 21
The second through-hole 23 is provided with a countersunk processing 24 having a diameter 5 to 6 mm larger than the hole diameter. FIG. 2 is a sectional view showing the through hole 23 of the backing plate 22.

In the iron core fastening structure shown in FIG.
Although the end face of the through hole 10 of the core 1 in contact with the edge is an edge, the through plate 23 of the through hole 23 of the backing plate 22 is dished 24 so that the through hole 10 of the
The creep distance from the end surface to the end surface of the through hole 23 of the backing plate 22 is equal to or greater than that of the conventional case. Also,
Due to the dishing process 24, the electric field intensity generated on the end face of the through hole 23 of the backing plate 22 is reduced, and the dielectric strength is increased. Therefore, the thickness of the insulating plate 21 can be reduced to about 0.5 mm.

In the above-described embodiment, the counterbore 24 is shown as a method of expanding the hole, but a round finish 25 as shown in FIG. 3 or a counterbore 26 as shown in FIG.

In the above embodiment, only the side of the through-hole 23 of the backing plate 22 facing the insulating plate 21 is subjected to the widening process. . 5 to 7 are partial cross-sectional views of the backing plate 22 showing the example, FIG. 5 shows a dishing process on both sides, FIG. 6 shows a combination of a dishing process and a round finishing process, and FIG. Processing is combined, and these may be combined in any manner. By doing so, the dielectric strength between the backing plate 22 and the metal washer 6, the bolt 4, and the nut 5 in FIG. 1 can be improved, so that the insulating washer 7 can be made thinner. There is an advantage that the space factor can be further improved.

Up to now, the through holes 23 of the backing plate 22 have been used.
Although the description has been given of expanding the ends, similar effects can be expected even if similar processing is performed on the tightening holes of the iron core tightening frames 11a and 11b.

[0016]

According to the first aspect of the present invention, the hole between the end of the through hole of the backing plate and the end of the through hole of the iron core is formed by expanding the hole on the insulating plate side of the through hole of the backing plate. Therefore, the insulating plate can be made thinner, the space factor of the iron core can be improved, and the device can be reduced in size and weight, and the cost can be reduced, without performing operations such as inserting specially shaped parts.

According to the second aspect of the present invention, since the through holes are formed on both sides of the backing plate, the dielectric strength between the backing plate and the metal washers, bolts and nuts is increased, and the insulating washer is also made thinner. Further, it is possible to further improve the space factor of the iron core, thereby contributing to a reduction in size and weight of the device and a reduction in cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a core fastening portion showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of hole enlargement processing in a through hole of a backing plate.

FIG. 3 is a cross-sectional view showing another example of a hole-enlarging process in a through hole of a backing plate.

FIG. 4 is a cross-sectional view showing another example of a hole-enlarging process in a through hole of a backing plate.

FIG. 5 is a cross-sectional view showing another example of the processing for expanding the through hole of the backing plate.

FIG. 6 is a cross-sectional view showing another example of the processing for expanding a hole in a through hole of a backing plate.

FIG. 7 is a cross-sectional view showing another example of the processing for expanding the through hole of the backing plate.

FIG. 8 is a front view of a conventional iron core fastening structure.

FIG. 9 is a side view of FIG.

FIG. 10 is a sectional view taken along the line AA of FIG. 8;

11 is a sectional view taken along the line BB of FIG. 10;

FIG. 12 is a cross-sectional view of another conventional iron core fastening structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laminated iron core 4 Bolt 5 Nut 6 Metal washer 7 Insulated washer 8 Insulation sleeve 10 Laminated core through hole 21 Insulating plate 22 Backing plate 23 Backing plate through hole 24

Claims (2)

(57) [Claims] 1. A laminated core, an insulating plate, and a backing plate each having a through hole for tightening, and one side of the through hole of the backing plate is expanded, and the through holes are made to correspond to each other so as to correspond to the uppermost of the laminated core. An iron plate tightening structure, wherein an insulating plate is brought into contact with an outer layer, the surface of the expanded side of the backing plate is brought into contact with the insulating plate, and a bolt is passed through the through-hole and tightened together with a washer and a nut. 2. The iron core tightening structure according to claim 1, wherein a through hole of the backing plate is expanded on both sides of the plate.