JPH019139Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transformer core tightening device that has an improved core tightening structure.

To explain a conventional transformer core tightening device with reference to FIGS. 1A and 1B, 1 is a transformer core;
It is formed by a core leg _1a and a yoke _1b , and the core leg _1a has an insulating plate 2 in contact with the surface of the core,
The yoke 1 b is tightened by a tightening band 4 via a tightening plate 3 arranged on the outside of the insulating plate 2, and the yoke 1 _b is attached to a wedge plate 5 made of an insulating material and Fastening fitting 7 via welded connecting plate 6
is screwed onto the connecting plate 6 with the bolt 8 that prevents the tightening fitting 7 from moving from the core leg _1a , and then the tightening fitting 7 is tightened with the yoke tightening bolt 9 and the side part. By tightening using the bolt 10,
Yoke _1b is being tightened. However, in the core tightening device having the above structure, since the core leg _1a is tightened by the tightening band 4 via the tightening plate 3 connected to the connecting plate 6 and the insulating plate 2, the outside of the core leg _1a is tightened. As shown in Figure 1C, the diameter size inevitably becomes larger, and as a result, the inner diameter of the winding (not shown) also becomes larger, so the transformer becomes inevitably larger, and in addition, the winding material, etc. However, since a large amount of transformer materials such as insulating oil must be used, the transformer becomes larger and its production cost increases.

The present invention eliminates the above-mentioned drawbacks and makes it possible to sufficiently increase the mechanical strength of the transformer core against external forces without using a core leg clamping plate or a connecting plate connected to the clamping plate. The purpose of the present invention is to provide a transformer core tightening device that allows the core itself to be made small and lightweight, and also allows the core tightening work to be performed easily. 2A to 2C and 3, the explanation will be given using an example of a transformer core in which strip-shaped steel plates are laminated. Reference numeral 11 is formed by laminating and joining a yoke 13 to the joint end of the core leg 12. In the iron core of a transformer, one block of iron core steel plates 12 _a placed on both sides of the core legs 12 of this iron core 11 in the stacking direction, and one block of yoke to be laminated and joined to this iron core steel plate 12 _a have the following components: As shown in FIGS. 2A and 2B, engagement holes 14 are bored at corner positions of the iron core 12. As shown in FIGS. The engagement hole 14 may be punched out at the same time when the core steel plates of the core leg 12 and the yoke 13 are punched out, or
Alternatively, after punching out each core steel plate,
Extract only the iron core steel plate that requires 4 and insert the engagement hole 1
4 by separately punching out. The core leg 12 is tightened by a tightening band _15a via an insulating plate 15 on its outer surface in the stacking direction.
Reference numeral 16 denotes a tightening fitting for tightening the yoke 13, and an engagement hole provided at a corner of the iron core 11 is provided on the outside of the vertical plane part of the tightening fitting 16, which has a U-shaped longitudinal section. 1
At a position corresponding to 4, a locking pin 17 is made with a dimension slightly shorter than the depth of the engagement hole 14, is welded to the locking pin 17, and protrudes horizontally.
Moreover, an engaging hole 1 is provided on the outside of the locking pin 17.
4 is fitted onto the locking pin 17 while being bonded with, for example, room-temperature curing resin, and a locking protrusion 16A is formed on the fastening fitting 16 as shown in FIG. 3. do. In the figure, reference numerals 19 and 20 are bolt holes through which bolts 19 _a and 20 _a for yoke tightening and side tightening are inserted, which are drilled in the tightening fitting 16 .

Next, to explain the case of tightening the fastening fitting 16 to the yoke 13, first, the vertical plane part of the fastening fitting 16 is made to correspond to the end surface of the yoke 13 in the stacking direction, and the fastening fitting 16 is protruded from the yoke 13. The insulating tube 18 fitted onto the locking pin 17 with resin interposed therein is fitted into the engagement hole 14 provided at the corner of the iron core 11 to bring the fastening fitting 16 into contact with the yoke 13, and then A yoke tightening bolt 19 a is passed through the yoke 13 through a bolt hole ₁₉ for tightening the yoke drilled in the tightening fitting 16 , and the bolt 19 _a is tightened.
Pass the side tightening bolt 20a through the side tightening bolt hole ₂₀ provided at the end of the bolt 2.
By tightening _0a , the clamping fitting 16 is tightly fixed to the yoke 13.

Next, when the tightening device of the present invention is applied to the core _11a of a transformer in which frame _- shaped steel core plates _are laminated, as shown in FIG. Due to the fact that the iron core leg 12 _b is installed obliquely at an angle, a plurality of small-diameter _engagement holes (main In the embodiment, two fastening fittings 16 _a are provided.
The same number of locking pins _17a as the engagement holes of the iron core leg _12a are welded to the same structure as above, and,
By fitting the insulating cylinder _18a to these locking pins _17a , the tightening fitting _16a
A locking protrusion 16B is provided on the vertical plane part. Yoke 13 _a of the clamping fitting 16 _a equipped with this locking protrusion 16B
Since the installation is the same as that for the tightening fitting 16, the description thereof will be omitted.

In addition, in the iron core tightening device of the present invention, the locking protrusions _16A , 16B protruding from the tightening fittings 16, 16a
5 has explained the structure of fitting into the engaging holes 14 drilled in each of the core steel plates of one block located at the outermost side of the core legs ₁₂ , 12a. In this way, the core steel plates corresponding to one block located at the outermost side of the core leg _12c are molded with adhesive, or each steel plate is bonded one by one, so that excellent insulation and , iron core layer plate 12 _c1 with increased mechanical strength
is formed as a part of the core leg 12, and locking protrusions _16A or 16B drilled in the fastening fittings 16, _16a fit into the upper and lower parts of the core laminate _12c1 , corresponding to the yoke 13a. An engagement hole _14a is formed in the hole 14a, and the tightening fitting 16 or 16 is inserted using this engagement hole _14a .
Attach A to the yoke _13a of the iron core 11 in the same manner as above.
At this time, the mechanical strength of a part of the iron core steel plate of the iron core leg 12 _c is strengthened with adhesive, and the iron core layer plate 12
_c1 , since this core laminate 12 _c1 cannot be used for laminated bonding of the yoke, the magnetic flux flowing through the core laminate 12 _c1 is concentrated on the yoke adjacent to the core laminate 12 _c1 . Since there is a risk that the yoke may be locally overheated, the magnetic flux is reduced by using a yoke adjacent to the core layer plate _12c1 that has approximately the same width as the yoke in the adjacent previous layer. Concentration can be eased.

As explained above, in this invention, a core steel plate of the same type as the core leg corresponding to one block of the core leg is integrally solidified with adhesive at the outermost position of the core leg to which the yoke is joined, thereby providing insulation. An iron core laminate formed with excellent mechanical strength and high mechanical strength is brought into contact with the iron core laminate, and an engaging hole is bored in the yoke joint part of the iron core laminate, and on the other hand,
The tightening fitting for tightening the yoke has a locking protrusion protruding from the outer periphery fitted with an insulating tube in correspondence with the engagement hole,
This locking protrusion is fitted into the engagement hole of the core laminate, and the clamping bracket is brought into contact with the yoke of the transformer core, and the end of the clamping bracket that protrudes laterally in the length direction of the yoke. Since the parts are tightened using side tightening bolts, the present invention has the following effects.

Although the mechanical strength of each of the core steel plates is not so strong, the present invention uses adhesive to harden the core steel plates in a number equivalent to one block of the core legs to form the core laminates. Since the core laminate is arranged on the outermost side of the core leg and the fastening fitting is fastened, the mechanical strength of the core leg can be strengthened.

In addition, the yoke's fastening fittings are provided with locking protrusions covered with an insulating material, and the core laminates are provided with locking protrusions located at corners that are not affected by the magnetic properties of the core. An engagement hole is drilled in the hole, and by fitting the locking protrusion into the engagement hole,
The clamping fittings can be easily brought into contact with the yoke, and by using core laminates made of the same material as the core steel plate, the transformer core can be easily brought into contact with the yoke. Assembly work can be done quickly and easily. Furthermore, the locking protrusion is provided with the minimum necessary length to fit into the engagement hole of the core laminate through the insulator and bring the fastening fitting into contact with the yoke. It goes without saying that the layered plates can be used in the same way as the core legs, and have the advantage of not having any adverse effect on the core characteristics of the transformer.

Furthermore, since the present invention uses core laminates made of the same core material as the core legs, the effective cross-sectional area of the core is substantially increased, making it possible to manufacture a transformer core with excellent core characteristics with less loss. In addition, if this method is used to obtain the same effective cross-sectional area as a conventional core, the outer diameter of the core leg itself can be reduced by not using a clamping plate, etc., and the transformer core The entire structure can be downsized, allowing for economical production.

In addition, the iron core laminates that are integrally bonded and solidified with adhesive have a strong mechanical strength, and the locking protrusions that fit into the engagement holes of the iron core laminates are connected through an insulator. Even though it is fitted only to the core laminate, even if a large external force is applied in the axial direction of the winding during lifting of the core or in the event of a short circuit, the tightening fittings will still hold the core through the locking protrusions. The windings are firmly tightened and held so that they do not shift, and as a result, there is no possibility that the tightening strength of the windings will be weakened or that the windings will be damaged.

As described above, the present invention uses core steel plates of the same type as the core legs to form core laminates that are solidified with adhesive, and makes it possible to form engaging holes in the core laminates when punching the core steel plates. Moreover, the locking protrusion that fits into this engagement hole can be created by simply covering the locking pin welded to the fastening metal fitting with an insulating material. The production of the transformer core does not require any special effort or effort, and can be produced easily and inexpensively.Also, since the core laminates are molded with adhesive, it is easy to make the core leg machine. By using the fastening fitting of the present invention, the core can be quickly and easily assembled without damaging the core properties.

[Brief explanation of the drawing]

Figure 1A is a front view showing the main parts of a transformer core using a conventional core tightening device, Figure 1B is a longitudinal sectional view thereof, and Figure 1C is a sectional view taken along line A-A in Figure 1B. , FIG. 2A is a front view showing the main parts of a transformer core equipped with the core tightening device of the present invention, FIG. 2B is a longitudinal cross-sectional view thereof, and FIG. 3 is a perspective view showing the main parts of the fastening fitting used in the device of the present invention, and Figs. 4 and 5 are front views and longitudinal sections of the main parts of the transformer core showing other embodiments of the present invention. The top view and FIG. 6 are perspective views of essential parts showing another embodiment of the fastening fitting. 11: Iron core, 12: Iron core leg, 13: Yoke, 1
4: Engagement hole, 16: Tightening metal fitting, 16A: Locking protrusion.

Claims (1)

[Scope of utility model registration request] At the outermost position of the core leg connected to the yoke, a core steel plate of the same type as the core leg, equivalent to one block of this core leg, is integrally solidified with adhesive to provide excellent insulation and mechanical strength. A strong iron core laminate is brought into contact with the iron core leg, and the above-mentioned iron core leg is tightened with a tightening band, and one engaging hole is made in the position corresponding to the yoke of this iron core laminate.
Or a locking pin with a length that does not penetrate through the engagement hole should be installed at the position corresponding to the engagement hole on the tightening fitting that is drilled in multiple pieces and tightens the yoke through the core layer plate. , and a locking protrusion is provided by fitting an insulating cylinder on the outside of the locking pin, and the locking protrusion is fitted into the engagement hole of the iron core layer plate to bring the tightening fitting into contact with the yoke, A transformer core tightening device, characterized in that the ends of the tightening fittings protruding from both longitudinal ends of the yoke are tightened with side tightening bolts.