JPH0358165B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a wound core using an amorphous magnetic ribbon.

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, an amorphous magnetic ribbon called amorphous is attracting attention as a new core material. Various studies have been conducted to utilize this core material for wound cores of power distribution transformers and instrument transformers. However, the above-mentioned amorphous magnetic ribbon exhibits excellent magnetic properties with significantly lower core loss and excitation current than silicon steel sheets conventionally used as 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 conventional silicon steel sheets, and the maximum thickness is thought to be around 150 μm. In Japan, 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 extremely thin, it is impossible to apply a large tension when winding it, and as a result, the winding frame has a rectangular shape. The corners of the wound core fit into the corners of the winding frame and can be wound with a uniform force, but on the other hand, a large tension is applied to the so-called straight parts of the legs and yoke of the core. This makes it difficult to wind the amorphous magnetic ribbon in a straight line along the flat surface of the winding frame, causing slack in the legs and yoke of the winding core. This caused an increase in excitation current, iron loss, and noise due to the characteristics of the iron. 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. , pressing plates 3 press the outer periphery of the iron core 1 from four directions.
There is also a method of manufacturing a wound core 4 made of an amorphous magnetic ribbon by forming a circular core into a rectangular shape with a core metal 2 by pressing it with a press through a
In this manufacturing method, the four corners of the core metal 2 are beveled to make it easier to insert the core metal 2 into the iron core 1 which is pressed and maintained in an oval shape. When formed into a rectangular shape, the amorphous magnetic ribbon is very thin and has low rigidity per piece. 2a, due to the force when forming the core into a rectangular shape, and as shown in FIG. The protrusion 1a protrudes into the space 4a created between the two parts. Therefore, the formation of the protrusion 1a at the inner corner of the wound core 4 not only deteriorates the core properties, but also has the disadvantage that the winding operation cannot be carried out smoothly due to the presence of the protrusion 1a. Ta.

In view of the above-mentioned points, the present invention uses an amorphous magnetic ribbon which has very excellent magnetic properties but is very difficult to handle as a core material, thereby impairing the properties of the uncut wound core. Embodiments of the present invention will be described below with reference to FIGS. 3 to 8. FIG. 3 shows a device for winding a wound core; In,
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 core using the above-mentioned device, first, the silicon steel strip 13 is circularly wound one to three times around the winding frame 15, and the reinforcing frame 16 of the silicon steel strip is wrapped around the winding frame 15. Then, the amorphous magnetic ribbon 12 is wound a required number of times around the outside of the reinforcing frame 16 to form a circular wound core body 17. It goes without saying that the silicon steel strip 13 and the amorphous ribbon 12 are each wound while applying the required tension. As shown in FIG. 6, the wound core element 17 wound in a circular manner as described above is pressed into an elliptical shape using a press to form the reinforcing frame 1 of the wound iron core element 17.
6 Diagonally cut the corner part 2a on the inside as before.
Insert the core bar 2 provided with. After that, the wound core element 17 is further pressed from all sides of its outer periphery via the press plate 3 toward the center of the wound core element 17 along the core bar 2 to form an elliptical wound core. As shown in FIG. 7, the element body 17 is formed integrally with the reinforcing frame 16 into a rectangular shape. At this time, the reinforcing frame 16 forming the innermost layer of the wound core body 17 is provided by winding the silicon steel strip 13, which is about 10 times thicker than the amorphous magnetic ribbon 12, the required number of times. , its rigidity is very strong, and therefore, when the wound core body 17 is formed into a rectangular shape, the reinforcing frame 16 has four inner corners that do not protrude toward the diagonal cut portion 2a of the core bar 2. Even with a required curvature, the reinforcing frame 16 is curved so that the overall shape is rectangular, as shown in FIG. For this reason, the 12-layer portion of the amorphous magnetic ribbon forming the majority of the wound core element 17 is also molded into a rectangular shape integrally with the reinforcing frame 16, similar to the reinforcing frame 16 described above. The Rukoto. Moreover, when the 12 layers of amorphous magnetic ribbon are formed into a rectangular shape, the inner four 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 A protrusion tends to appear toward the diagonal cut portion 2a of the core bar 2, but as described above, the diagonal cut portion 2a of the core bar 2 and the 12 layers of amorphous magnetic ribbon of the wound core element 17 Since the corner portions of the reinforcing frame 16 exist between and in contact with the four inner corners, the reinforcing frame 16 completely prevents the formation of protrusions due to the above-mentioned sagging. 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, while maintaining the wound core body 17 in a rectangular state, magnetic field annealing is performed in an annealing furnace to remove distortion and shape it into a rectangular state. After annealing, the holding of the rectangular state of the wound core body 17 is released, and the core bar 2 and reinforcing frame 16 are removed, thereby forming a winding made of amorphous magnetic ribbon shaped into a rectangular state. This completes the production of the iron core 18. As a result, since the wound core 18 is shaped into a rectangular shape by annealing, the rectangular state is maintained even if the core bar 2 and reinforcing frame 16 are removed, so that the four corners inside the wound core have protrusions due to slack. Coupled with this, the winding operation using the wound core 18 can be carried out smoothly and favorably.

Note that the number of turns of the silicon steel plate forming the reinforcing frame 16 is not limited to 1 to 3 times;
When forming the wound core body 17 into a rectangular shape, it is sufficient to wind the core body 17 to the extent that it has a 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.

In the present invention, when manufacturing a wound core using an amorphous magnetic ribbon, during the manufacturing process, when winding the amorphous magnetic ribbon in a circular shape and forming it into a rectangular wave,
To prevent protrusions caused by sagging at the inner corner portions, a silicone sheet having a thickness greater than that of the amorphous magnetic ribbon formed by winding the wound core body in advance inside the wound core body is used. The presence of a reinforcing frame made of thin metal plates such as steel plates makes it possible to completely prevent this, and it is possible to form a wound core made of amorphous magnetic ribbon into a rectangular shape smoothly and well without impairing its core properties. It can be manufactured.

Further, in the present invention, after the amorphous magnetic ribbon is wound in a circle, it is formed into a rectangular shape to maintain the wound core body in a predetermined shape until the magnetic field annealing is completed. In addition, a reinforcing frame made of a thin metal plate made of a material different from that of the amorphous magnetic ribbon, such as a silicon steel plate, is formed integrally with the wound core body, so that, as described above, When forming the wound core element, it is necessary to completely prevent protrusions from forming at the four inner corners due to sagging, and to prevent straight parts such as legs and yokes from forming due to sagging. It can reliably prevent it from getting bent and losing its shape. Furthermore, in the present invention, the reinforcing frame is removed after annealing, and the wound core is composed only of amorphous magnetic ribbons, so that the core properties may deteriorate due to the mixture of different materials. There is nothing wrong with that,
It is possible to provide a wound core with excellent core characteristics that fully utilizes the characteristics of the amorphous magnetic ribbon.

Furthermore, in the present invention, during the forming process of the wound core element, the four corners of the core metal are beveled, so that it can be easily inserted into and taken out of the wound iron core element, and the presence of a reinforcing frame is also avoided. In addition, during the forming process, the forming process can be performed smoothly without applying special pressure to the four corners of the wound core element, so the wound core manufactured by the method of the present invention is free from internal distortion. The core properties can be significantly improved without any problems.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams for explaining the process of manufacturing a conventional wound core, FIG. 3 is a schematic diagram of an apparatus for manufacturing a wound core of the present invention, and FIG. 4 is an apparatus shown in FIG. 3. A front view of a wound core element wound by
Fig. 5 is an enlarged view of part A in Fig. 4, Figs. 6 and 7 are explanatory views for explaining the process of manufacturing the wound core of the present invention, and Fig. 8 is an enlarged view of part A in Fig. 4. It is a front view of a wound iron core. 12...Amorphous magnetic ribbon, 16...Reinforcement frame, 1
7...Wound iron core body, 18...Wound iron core.

Claims (1)

[Claims] 1. A process of forming a reinforcing frame by winding a metal thin plate such as a silicon steel plate in a circular manner multiple times around a winding frame, and winding an amorphous magnetic ribbon around the outer periphery of the reinforcing frame a necessary number of times to form a circular wound core element. a step of press-deforming the wound core body together with a reinforcing frame into an elliptical shape and inserting a core metal with diagonally cut corners at four corners into the reinforcing frame of the wound core body; The inserted wound core element is
Furthermore, a process of pressing along the core metal to form a rectangular shape integrally with the reinforcing frame, and magnetic field annealing to remove distortion and shape the wound core element into a rectangular shape while maintaining the rectangular state described above are performed. and a step of removing the core bar and reinforcing frame from the wound core body after annealing, thereby forming a wound core made of amorphous magnetic ribbon into a rectangular shape. A method for manufacturing a wound iron core characterized by: