JPS6144413A - Manufacture of iron core in electric apparatus - Google Patents

Abstract

PURPOSE:To avoid degradation of magnetic characteristics during heat treatment by previously making a bundling tape which will become a bundling reinforcement layer during the operation of an electric apparatus adhered closely to the external surface of an iron core which is wound or laminated to a required shape wound iron core or laminated iron core with a thin plate amorphous magnetic alloy while heat-treated in magnetic field. CONSTITUTION:A notch 17 and a hole 2 for inserting a coil 4 for generating magnetic field are provided in the outer circumference of a bobbin 11 and a thin plate amorphous magnetic alloy iron core 3 is wound outside of the bobbin 11. The iron core 3 is heat-treated in the magnetic field generated by making a current flow in the coil 4 and in this case, before the heat treatment, a bundling tape layer 20 which will become a bundling reinforcement layer during operation is made adhere closely to the outside of the iron core 3. Among the tape layer 20, such as a glass tape is used at the corner and a bundling tape is used for a linear part tape layer. These tapes are wound through the notch 17. This enables recovery of magnetic characteristics due to heat treatment without degradation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to a method for manufacturing an iron core for electrical equipment using a thin ribbon of an amorphous magnetic alloy, and in particular to a method for manufacturing an iron core for anti-rusting conductors.

[Prior art and its problems]

Conventionally, silicon steel sheets (AL-F) have been used as iron core materials for electrical equipment.
In recent years, low-loss amorphous magnetic alloys such as silicon and boron thread (Sl-B series) alloys have been used. Obi was developed,
i! Applied research on electrical equipment cores is actively underway.

Since amorphous magnetic alloys are manufactured by ultra-quenching a molten metal, the reality is that only thin strip-shaped materials (hereinafter referred to as amorphous strips) with a thickness of 20 to 40 mm can be obtained. Furthermore, although an amorphous band has the advantage of low loss, it is known that when mechanical strain such as bending or compression is applied, magnetic properties such as core loss and magnetizing force are significantly reduced. However, it is known that once an amorphous band whose magnetic properties have deteriorated is heat treated in a DC magnetic field to remove distortion, it will regain its excellent magnetic properties. It is common practice to incorporate a heat treatment process in a magnetic field into the manufacturing process.

Figures 8 and 9 are characteristic diagrams of small test pieces showing changes in magnetic properties before and after heat treatment. In the case of Figure 0, which shows the experimental results of the present inventors in terms of current characteristics, an amorphous band with a thickness of 25 m and Ifj of 425 m is wound into a cylindrical shape with an average radius of 6 to 26 wm to a thickness of about 2 m and K. A small test piece was prepared, the magnetic properties before heat treatment (shown by the dotted line in the figure) were determined, and then the prescribed heat treatment was performed and the magnetic properties after heat treatment (shown by the solid line in the figure) were determined. Pay close attention to the handling of the test piece after heat treatment as an experiment.In Figure 0, better recovery characteristics were obtained than for K and e.The core loss and excitation effective current before heat treatment are each inversely proportional to the radius of curvature. The bending strain applied to the amorphous band shows a tendency to increase, indicating that the magnetic properties are significantly degraded.The iron loss and excitation effective current after heat treatment each have flat characteristics that are independent of the radius of curvature. This shows that the magnetic properties are excellently recovered by heat treatment. Incidentally, the iron loss after heat treatment at a magnetic flux density of 12 tesla is approximately 0.08 W/9.

10 to 13 are structural diagrams for explaining the manufacturing method of a rectangular ring-shaped wound core by a conventional method. FIG. 10 is a plan view of the core in a heat treatment process in a magnetic field, and FIG. 12 is a side sectional view of the iron core showing the binding step after the heat treatment step in a magnetic field, and FIG. 16 is a side sectional view of FIG. 12. In Figures 10 and 11, 1 is also a winding frame made of a non-magnetic metal plate such as aluminum, 2 is a hole formed in the winding frame 1 for inserting the coil, and 3 is an amorphous band tightly wound around the winding frame. The wound iron core 4 is a coil for generating a DC magnetic field, and is made by winding a conductor having a heat-resistant insulation coating a plurality of times using the hole 2 of the winding frame 1. The workpiece thus formed is carried into a high-temperature furnace for heat treatment, and heat treatment is performed in a magnetic field in a state where a magnetic field of a predetermined magnetic flux density is generated in the direction of the magnetic path of the iron core. After completing the magnetic field heat treatment process, the cooled core is taken out of the furnace, and the coil 4 and winding frame 1 are removed.

In this state, although the amorphous body becomes hard and brittle, its shape stability increases, so that even if the winding frame 1 is removed, the rectangular ring shape can be maintained.

Therefore, as shown in FIGS. 12 and 13, a heat-resistant binding tape 6 such as glass tape is wound around the iron core 6, taking great care not to damage or deform it, thereby forming the binding tape layer 5. By binding the iron core 3 to the binding tape layer 5 in this way, the amorphous bands are in close contact with each other and frictional stress acts on each other, so that the iron core 6
can hold its shape more stably.

Figure 14 shows the magnetic flux density vs. iron loss and excitation effective current characteristics of a wound core manufactured by the conventional method.
A rectangular ring-shaped iron core as shown in Figs. DC 8
Heat treatment was performed in a magnetic field at 400°C for 2 hours while applying a magnetic field of 00 A/m, and after removing the coil 4 and the winding frame 1, a bonding tape layer 5t was formed using glass tape.
In Figure 0, which shows the AC magnetic characteristics of QHg, the iron loss at 12(T)K is 0. IW/#, and the iron loss increased by approximately 25% compared to the value of 0.08W/# for the small test piece in Figure 8. It became clear that the problem was that it was difficult to obtain this for iron cores.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and is intended to manufacture electrical equipment iron cores that have good recovery properties in their magnetic properties through heat treatment in a magnetic field and that have little risk of the magnetic properties decreasing again after the heat treatment is completed. The purpose is to provide a method.

[Key points of the invention]

The reason why the method of the present invention is not able to obtain sufficient recovery properties in the magnetic properties of the iron core after heat treatment is that the amorphous material is removed during the removal of the coil and winding frame and the application of the bonding tape layer after the heat treatment. It was discovered that stress was applied to the band, causing cracks, chips, and deformation in the weakened amorphous band due to heat treatment. By configuring the manufacturing method to perform processing, the strain applied to the core during the process of applying the bonding tape layer can be removed by heat treatment, and the bonding tape layer can be removed during the removal work of the winding frame and coil. K is used as a mechanical reinforcing layer or a slipping layer to prevent deterioration of magnetic properties.

[Embodiments of the invention]

The present invention will be explained below based on examples.

1 to 4 are explanatory diagrams of a method for manufacturing a rectangular ring-shaped wound core according to an embodiment of the present invention. FIG. 1 is a plan view of a workpiece at the time of heat treatment in a magnetic field, The figure is a side sectional view of Fig. 1, Fig. 6 is a plan view of nine iron cores after machining, and Fig. 4 is a side sectional view of Fig. 6.
2 is a winding frame made of a non-magnetic metal plate, etc.; 2 is an insertion hole for the coil 4 formed in the winding frame 11; 17 is a notch formed in the flat part of the outer periphery of the winding frame 11; and 18 is a corner of the iron core 3. A corner binding tape layer 19 binds the straight portion of the iron core B, a straight portion binding tape layer 20 binds the straight portion of the iron core B, and a numeral 20 represents a binding tape layer of the iron core consisting of the corner portion and straight portion binding tape layers 18 and 19.

Next, as a method for manufacturing the iron core, at the beginning of winding the amorphous band, a glass tape of a predetermined length, for example, which will become the corner binding tape layer 18, is sandwiched in the corner of the winding frame 11, and then the amorphous band is A wound core 6 is formed by winding the band a predetermined number of times. When the winding work of the amorphous band is completed, the corners of the iron core 6 are bound by the binding tape interposed at the corners of the winding frame to form the corner binding tape layer 18. Next, the binding tape is passed through the notch 17 of the winding frame 11 and wound around the straight portion of the iron core 3 to form the straight portion binding tape layer 19.

Further, the coil 4 is wound through the hole 2 of the winding frame 11. The workpiece formed by K in this way is carried into a heat treatment furnace, where it is heat-treated in a magnetic field, and various processing strains are removed. As the amorphous bands harden and the rigidity of the iron core 6 increases, the binding force by the binding tape layer acts to increase the frictional resistance between adjacent amorphous bands, and the shape stability of the iron core 6 can be significantly strengthened. Therefore, even if the coil 4 and the winding frame 11 are sequentially removed in this state, the iron core 3 can maintain the shape regulated by the winding frame 11. Also, as shown in FIGS. Since the n-tape layer 20 has already been applied, the coil 4 and the winding frame 11 can be removed without mechanically damaging the amorphous band, and it is possible to remove the coil 4 and the winding frame 11 without mechanically damaging the amorphous band. Since there is no step of forming the tape layer 20, the iron core 3 provided with the binding tape layer 20 can be obtained without impairing the magnetic properties recovered by heat treatment.

In the above embodiment, an amorphous band is used and an iron core is used as an example. However, the amorphous band may be U-shaped or E-shaped.

It goes without saying that this method can also be applied as a manufacturing method for stacked iron cores, in which iron cores processed into short pieces are laminated.

FIG. 5 is a magnetic characteristic diagram of a rectangular ring-shaped wound core manufactured by the manufacturing method of the above-described embodiment.

The shape and dimensions of the manufactured wound core and the processing conditions for heat treatment in a magnetic field are the same as those already explained in Fig. 14.The characteristic curve shown by the dotted line in Fig. 0 is the same as the characteristic curve in Fig. 14 obtained by the conventional manufacturing method. The characteristic curve shown by the solid line in Figure 1 shows the magnetic characteristics of the iron core according to the manufacturing method of the present invention. In Figure 0, the solid line iron loss curve 21 is the iron loss curve shown by the dotted line (conventional method). 22, and the solid excitation effective current curve 23 also shows a lower value than the dotted (conventional method) curve 24. With this result,
It can be demonstrated that the manufacturing method of the present invention can provide an iron core that retains much of the recovery effect of magnetic properties caused by heat treatment in a magnetic field. By the way, when we focus on iron loss, which is the most important factor in electrical equipment cores, and compare the basic experiment results in Figure 8 with curves 21 and 22 in Figure 5, we find that the magnetic flux density is 1.2 (the iron loss in the iron core is 0.08W
/AI'.

0 with the conventional method. IW/Misaki, 0.09 W/A in the method of invention
f, which can be brought closer to the 9 iron loss obtained in basic experiments by the manufacturing method of the present invention, and can also reduce the iron loss by approximately 10% compared to the conventional manufacturing method.

In addition, in Fig. 5, the magnetic properties were compared with the conventional method for a rectangular ring-shaped wound core with a weight of about 2.7 mm.
If the weight of the core increases further, the stress and strain applied to the core during the manufacturing process will increase, so it is expected that the effect of improving magnetic properties by the manufacturing method of the present invention will be even greater.

FIGS. 6 and 7 are explanatory diagrams of a manufacturing method showing different embodiments of the present invention, and show the state of heat treatment in a magnetic field of a circular ring-shaped wound core.

When the iron core is in the shape of a circular ring, unlike the rectangular ring-shaped iron core, the core does not deform and maintains its circular ring shape even if the frame is removed. 6o and the coil 4 are applied, heat treatment is performed in a magnetic field, and then the coil 4 is removed, thereby obtaining a circular ring-shaped wound core on which the binding tape layer 60 is applied. In this case, the method for manufacturing the rectangular ring-shaped coil differs in that there is a step of removing the coil 4 without the winding frame after heat treatment, but since the binding tape layer functions as a mechanical reinforcing layer, the coil 4 is removed. Much better recovery of the magnetic properties can be maintained than in the conventional manufacturing method, which requires a subsequent step of applying a binding tape layer.

〔Effect of the invention〕

As mentioned above, the present invention provides a method for manufacturing an iron core using an amorphous magnetic band whose magnetic properties tend to deteriorate due to mechanical stress, and a bonding tape layer to be a mechanical reinforcing layer or an insulating layer for an electric equipment iron core. After formation, it was configured to undergo heat treatment in a magnetic field. As a result, when the bonding tape layer is applied after heat treatment in the conventional manufacturing method, the mechanical stress applied to the core by K is eliminated, and the core retains the magnetic properties recovered by heat treatment. can do. In addition, when removing the winding frame and magnetic field generating coil after heat treatment, the shape stability of the core is strengthened because the binding tape layer has already been applied, and cracks in the amorphous band can be avoided. It has the advantage of preventing deterioration of magnetic properties by acting as a μ-retaining layer that prevents damage such as chipping and falling. Furthermore, by combining the above-mentioned effects, it is possible to provide an iron core with approximately 10% less iron loss than the iron loss of iron cores obtained by conventional manufacturing methods, thus contributing to lower loss in electrical equipment. .

[Brief explanation of drawings]

FIG. 1 is a plan view of the workpiece in the magnetic field heat treatment step in the manufacturing method of the embodiment of the present invention, FIG. 2 is a side sectional view of FIG. 1, and FIG. 3 is the completed processing in the manufacturing method of the embodiment. 4 is a side sectional view of FIG. 6, FIG. 5 is a magnetic characteristic diagram of the iron core according to the manufacturing method of the embodiment, and FIG. 6 is a diagram of the core according to the manufacturing method of the embodiment. Figure 7 is a side cross-sectional view of Figure 6 showing the state of the workpiece during heat treatment in a magnetic field in the manufacturing method, and Figures 8 and 9 are iron loss versus radius of curvature showing heat treatment effects in basic experiments. The characteristic diagram, excitation effective current vs. curvature radius characteristic diagram, FIGS. 10 and 11 are a plan view and side sectional view showing the shape of the workpiece during heat treatment by the conventional method, and FIGS. 12 and 13. The figures are a plan view and a side sectional view showing the process of applying a binding tape layer in a conventional method, and FIG. 14 is a characteristic diagram showing the magnetic properties of an iron core manufactured by a conventional method. 1.11... Winding frame, 2... Hole, 5... Rectangular ring-shaped iron core, 4... Coil for magnetic field generation, 5.20.30
... Bondage tape layer, 6... Bondage tape, 17...
Notch portion, 18... Corner bonding tape layer, 19... Straight portion bonding tape layer, 36... Circular ring-shaped iron core.

Claims (1)

[Claims] 1) In a manufacturing method in which a thin ribbon-shaped amorphous magnetic alloy is wound or laminated to form a wound core or stacked core of a predetermined shape, and then heat treatment is performed in a magnetic field, the electrical equipment is operated. 1. A method of manufacturing an electrical equipment iron core, comprising: closely adhering a binding tape layer to be a binding reinforcing layer of the iron core to the outer circumferential surface of the iron core, and then subjecting the iron core to heat treatment in a magnetic field. 2) In the product described in claim 1, the iron core is a rectangular ring-shaped wound core, and a notch is provided in a flat part of the outer periphery of a winding frame inscribed in this wound core to form the wound core. After that, the binding tape is wound around the straight part of the iron core through the notch, and the corner of the iron core is bound by the binding tape that has been inserted in advance at the corner of the winding frame, thereby creating a binding tape. A method for manufacturing an electrical equipment core, characterized in that layers are formed.