JPS59172957A - Manufacture of wound core - Google Patents

Abstract

PURPOSE:To form a wound core made of amorphous magnetic thin strip without slackness by forming a wound core material by winding a magnetic thin strip around a reinforcing frame, forming it in a rectangular shape, then annealing it, followed by removing the frame. CONSTITUTION:A reinforcing frame 16 is formed by winding a thin metal plate in the prescribed number of turns in a circular shape. An amorphous magnetic thin strip 12 is wound on the outer periphery of the frame 16 to form a wound core material 17. Then, this material 17 is formed in a rectangular shape by using a core metal 2 of approximately rectangular shape, and magnetically annealed in an annealing furnace. Subsequently, the frame 16 is removed from the material 17, thereby manufacturing a wound core 18 made of an amorphous magnetic thin strip.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a wound core.

In recent years, iron core materials used in transformers and the like have made remarkable progress, and various low-loss iron core materials have been developed. Among these, amorphous magnetic ribbons are attracting attention as a new core material. Various studies have been conducted to utilize this core material for distribution transformers and instrument transformers.
The above-mentioned amorphous magnetic ribbon exhibits excellent magnetic properties with significantly lower iron loss and excitation current than silicon steel sheets conventionally used as iron core materials for electrical equipment such as transformers.

However, due to the manufacturing process, it is extremely difficult to make this amorphous magnetic ribbon as thick as the conventional silicon medium plate, and the maximum thickness is thought to be around 150 pm. At present, only magnetic ribbons of about 20 to 30 μm are manufactured. When the above amorphous magnetic ribbon is used to manufacture a wound core for a power distribution transformer, for example, the wound core is manufactured by winding the amorphous magnetic ribbon around a rectangular winding frame a required number of times. In this case, as mentioned above, since the amorphous magnetic thin material is very thin, it is impossible to apply a large amount of tension when winding it, and as a result, the winding frame has a rectangular shape. The wound core can be wound with a uniform force by adapting to the corners of the winding frame at some corners, but large tension is applied to the so-called straight parts of the legs and yoke of the core. In order to prevent the amorphous magnetic ribbon from being
It becomes difficult to wind the crucible straight and linearly, and the legs and yoke of the wound core become sagging in places, and this sagging causes an increase in the exciting current, iron loss, and noise due to the characteristics of the wound core. It became. In order to eliminate this drawback, after winding the amorphous magnetic ribbon in a circle the required number of times, the legs of the wound core are pressed from both sides toward the center using a press, as shown in Figure 1. At the very least, a substantially rectangular core bar 2 with beveled corners cut is inserted into the elliptical core 1 while the circular core is pressed and maintained in an elliptical shape, and then, as shown in FIG. , by pressing the outer periphery of the iron core 1 from four directions with a press via the pressing plate 3, the circular iron core is pressed against the core metal 2.
There is also a method of manufacturing a wound core 4 made of an amorphous magnetic ribbon by forming it into a rectangular shape using For this reason, the four corners of the core metal 2 are beveled, so when the core is formed from an oval shape to a rectangular shape,
Since the above amorphous magnetic ribbon is very thin and has low rigidity per piece, iron cores are placed at the four corners of the inner peripheral surface of the wound core 4 between the diagonal cut portion 2a of the core bar 2. As shown in FIG. 2, the slack is caused by the force of forming into a rectangular shape, and as shown in FIG. 1a and will be projected. Therefore, the presence of the protrusion 1a at the inner corner of the wound core 4 not only deteriorates the core properties, but also has the drawback that the winding operation cannot be carried out smoothly due to the presence of the protrusion 1a.

In view of the above-mentioned points, the present invention uses an amorphous magnetic ribbon, which has very excellent magnetic properties but is difficult to handle as a core material, and uses an uncut wound core without impairing its properties. Embodiments of the present invention will be described below with reference to FIGS. 3 to 8. FIG. 3 shows an apparatus for winding a wound core, and in the same figure,
An amorphous magnetic ribbon 12 is wound around a freely rotatable drum 11, and a drum 14 around which a silicon steel band 13 is wound is installed behind the drum 11 (on the right side in FIG. 3). When winding a wound core using the above device,
First, the silicon steel strip 13 is circularly wound one to three times around the winding frame 15 to form a reinforcing frame 16 of the silicon steel strip. Next, an amorphous magnetic ribbon is placed on the outside of the reinforcing frame 16. 12 is wound a required number of times to form a circular wound core body 17. In addition, silicon steel strip 1
3 and the amorphous ribbon 12 are each wound while applying the required tension.

The wound core element 17 wound in a circular manner as described above is wound into the sixth
As shown in the figure, the core bar 2 is pressed into an elliptical shape using a press and inserted into the inside of the reinforcing frame 16 of the wound core element 17 with a beveled cut portion 2a formed by cutting the corners in the same manner as in the past. . after this,
Furthermore, the wound core element 17 is pressed from the top, bottom, left and right directions through the core bar 2 toward the center of the wound core element 17, thereby forming an elliptical wound core element 17 as shown in FIG. As shown in FIG. 2, it is formed integrally with the reinforcing frame 16 into a rectangular shape. At this time, the reinforcing frame 16 forming the innermost layer (5) of the wound core element 17 is provided by winding a silicon steel strip 13 having a thickness approximately 10 times that of the amorphous magnetic ribbon 12 a required number of times. Since the core body 17 is formed into a rectangular shape, the reinforcing frame 16 has a very strong rigidity.
The four inner corners of the reinforcing frame 16 are bent with a required curvature without protruding toward the diagonal cut portion 2a of the core bar 2 so that the overall shape of the reinforcing frame 16 is rectangular as shown in FIG. Therefore, the 12-layer portion of the amorphous magnetic ribbon forming the majority of the wound core body 17 is also formed into a rectangular shape integrally with the reinforcing frame 16, similarly to the reinforcing frame 16 described above. That will happen.

Moreover, when the 12 layers of amorphous magnetic ribbon are formed into a rectangular shape, the four inner corners of the 12 layers of the amorphous magnetic ribbon of the wound core element 17 sag as in the conventional case, and this sagging causes the core metal 2
However, as mentioned above, a protrusion is generated toward the diagonal cut portion 2a of the core bar 2 and the inner four corners of the 12 layers of amorphous magnetic ribbon of the wound core element 17. Since a part of the corner of the reinforcing frame 16 exists between and in contact with the four corners, the occurrence of a protrusion due to the above-mentioned sagging is completely prevented by the reinforcing frame 16 (6). Therefore, the wound core body 17 can be smoothly formed into a rectangular shape as shown in FIG. After forming the wound core body 17 into a rectangular shape as described above, this wound core body 17 is subjected to magnetic field annealing in an annealing furnace, and then the reinforcing frame 1 is formed from the wound core body 17.
By removing 6, the production of the wound core 18 made of the amorphous magnetic ribbon is completed.

Note that the number of turns of the silicon steel plate forming the reinforcing frame 16 is not limited to 1 to 3 times, and the four corners inside the 12 layers of amorphous magnetic ribbons constituting the wound core element 17 are At the time of forming the rectangle in step 17, it is sufficient to wind it to the extent that it has mechanical strength that can prevent the generation of protrusions due to slack. Further, instead of winding a silicon steel plate, the reinforcing frame 16 may be provided by winding a thin metal plate such as a steel plate or an aluminum plate.

Furthermore, the reinforcing frame 16 may be provided with a silicon steel plate that has been annealed in advance, and in this case, the wound core 18 may be formed without removing the reinforcing frame if necessary. .

As described above, the present invention forms a wound core element by winding an amorphous magnetic ribbon around the outer periphery of a reinforcing frame provided by winding a metal thin plate in a circular manner a required number of times. After forming into a rectangular shape using a nearly rectangular core metal, annealing is performed, and then
The reinforcing frame is removed to create a wound core.
In the present invention, during the production of the wound core, that is, when the wound core element is formed into a rectangular shape, the inner four corners of the amorphous magnetic ribbon layer of the wound core element become sagging, and this sagging part partially However, the reinforcing frame provided on the innermost side of the wound core body in contact with the amorphous magnetic ribbon layer completely prevents the occurrence of sagging. Therefore, a wound core made of amorphous magnetic ribbon can be manufactured without reducing the core properties to the same extent. Furthermore, since there are no protrusions due to slack at the inner corner of the window of the winding core, the winding work can be carried out smoothly. In addition, there is no need to specially manufacture the reinforcing frame, just wrap it around the take-up frame the necessary number of times before winding the core, so the core can be manufactured smoothly, and the reinforcing frame can be easily manufactured after the core is manufactured. It has a number of excellent features, such as the fact that it does not impair the properties of the wound core in any way.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams for explaining the process of manufacturing a conventional wound core, Figure 3 is a schematic diagram of an apparatus for manufacturing a wound core of the present invention, and Figure 4 is shown in Figure 3. A front view of the wound core body wound by the device, FIG. 5 is an enlarged view of part A in FIG. 4, and FIGS. 6 and 7 are explanations for explaining the manufacturing process of the wound core of the present invention. FIG. 8 is a front view of a wound core manufactured by the method of the present invention. 12. Amorphous magnetic ribbon 16. Reinforcement frame 17. Wound core element 18. Wound core Patent applicant Chubu Electric Power Co., Ltd. Aichi Electric Works Co., Ltd. (9)

Claims (1)

[Claims] A reinforcing frame is provided by winding a metal thin plate such as a silicon steel plate in a circle a required number of times, and an amorphous magnetic ribbon is wound around the outer periphery of this reinforcing frame a required number of times to form a circular wound core element. The wound core element is deformed into an elliptical shape together with the reinforcing frame, a substantially rectangular core is inserted inside the reinforcing frame of the wound core element, and the wound core element is further formed into a rectangular shape integrally with the reinforcing frame. A wound iron core characterized in that the wound iron core body formed into the rectangular shape is annealed and bound, and then a reinforcing frame is removed from the wound iron core body to form a wound core. Production method.