JPH01135011A - Magnetic field device for heat treatment of winding core - Google Patents

Abstract

PURPOSE:To give a magnetic force in an axial direction when performing heat treatment of a roll core for improving magnetic properties of the roll core by providing a core which forms a magnetic field and has a leg for connecting yokes, and a winding for excitation which is so arranged that it crosses a magnetic circuit consisting of the core and a wound core. CONSTITUTION:Cores 14, 14, a winding 15, and a wound core 1 to be heat- treated are assembled and placed within a heat-treatment furnace. Then, the winding 15 is connected to the power supply. When performing heat treatment by heating the winding core 1, magnetic field is formed to give a magnetizing force to the winding core 1. At this time, since a magnetic flux along the axial direction flows through the winding core 1 from the upper edge surface to the lower edge surface or vice versa, abnormal eddy currents can be greatly reduced. In this case, by increasing the sectional area of yokes 11, 11, 12, 12 of cores 14, 14, most of magnetic flux which is generated by the winding 15 is allowed to pass through the winding core 1 to reduce abnormal eddy current loss and to achieve superb magnetic properties.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a magnetic field device used when heat treating a wound core made of an amorphous magnetic alloy ribbon.

(Prior Art) Recently, the use of amorphous magnetic alloy ribbons with excellent magnetic properties in place of silicon steel plates in wound cores for transformers and the like has been considered.

The amorphous magnetic alloy ribbon is manufactured using an ultra-quenching method.
Although it shows excellent iron loss characteristics, it has internal distortion, and if left as is, the iron loss characteristics will deteriorate. . For this reason,
When using a wound core made of an amorphous magnetic alloy ribbon, it is necessary to heat-treat (anneal) the wound core to remove distortion of the amorphous magnetic alloy ribbon.

In this case, attempts have been made to improve the magnetic properties of the wound core by forming a magnetic field during heat treatment to apply magnetizing force to the wound core. Normally, this magnetizing force is generated in the direction of the magnetic flux generated in the core when the core is used, that is, in the circumferential direction of the core to reduce the hysteresis loss of the core. A method has also been proposed in which magnetic permeability is improved by applying magnetizing force in the radial direction of the amorphous magnetic alloy ribbon, that is, in the thickness direction of the amorphous magnetic alloy ribbon.
-38808, JP-A-56-98456). Also,
Recently, by applying magnetizing force in the axial direction of the wound core,
A method has also been proposed for reducing the abnormal thin current loss of the wound core and improving the iron loss characteristics at high frequencies accordingly.

This can be seen, for example, in R. P. Krause et al.: IEE
E Trans, Magn, 17(6), (198
1) It is listed here.

(Problems to be Solved by the Invention) However, the method of applying axial magnetizing force to the wound core during heat treatment of the wound core does not improve the magnetic properties of the wound core made of amorphous magnetic alloy ribbon. Although this is an excellent method, it has not been possible to realize this method because no suitable method for applying magnetizing force in the axial direction of the wound core has been found.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a magnetic field device that can improve the magnetic properties of the wound core by applying an axial magnetizing force to the magnetic core during heat treatment of the wound core. .

[Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, a magnetic field device for heat treatment of a wound core of the present invention is provided with a magnetic field device for heat treatment of a wound core formed by winding an amorphous magnetic alloy ribbon. A magnetic field forming iron core having yokes and legs connecting these yokes arranged at both ends in the direction, and a magnetic circuit composed of the magnetic field forming iron core and a wound iron core, arranged so as to be interlinked with the magnetic circuit. The present invention is characterized in that it includes an excitation winding.

(Function) When current is passed through the excitation winding, magnetic flux is generated in the magnetic circuit composed of the magnetic field forming iron core and the wound iron core, and as a result, magnetic flux flows in the axial direction through the wound iron core.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

A first embodiment of the magnetic field device of the present invention will be described with reference to FIG. This embodiment is directed to a magnetic field device that uses a wound core 1 on the inside. The wound core 1 is formed by winding an amorphous magnetic alloy ribbon 2 a predetermined number of times.

In the figure, 11.11 is an upper yoke arranged on both radial sides of the axial lower end surface of the wound core 1, and 12.12 is a lower yoke arranged on both radial sides of the axial lower end surface of the wound core 1. One end of the yokes 11, 11, 12° 12 is in contact with the upper and lower end surfaces of the wound core. The other ends of one upper yoke 11 and lower yoke 12 that face each other vertically, and the other ends of the other upper yoke 11 and lower yoke 12 are arranged along the height direction of the wound core 11, that is, the axial direction. The connection is fixed by legs 13, 13. Each of these yokes 11.11.12゜12 and legs, $1
3.13 is made of a ferromagnetic material, such as a mild steel plate,
Two sets of magnetic field forming iron cores 14 and 14 are formed. In a space located between these iron cores 14.degree. 14 and the wound iron core 1, an excitation winding 15 is arranged concentrically with the wound iron core 1.

That is, the winding 15 is arranged so as to be interlinked with the magnetic circuit formed by each core 14, 14 and the core 1, especially the core 1.

When the magnetic field device configured in this way is used, the iron core 14
．． 14 and the winding 15 are combined with the wound core 1 to be heat treated and put into an assembly heat treatment furnace, and the winding 15 is connected to a power source. Then, when heating the wound core 1 and performing heat treatment,
A magnetic field is formed to apply magnetizing force to the wound core 1. That is, when a current is passed through the winding 15 from the power source, the upper yoke 1
1. Each iron core 14 consisting of a lower yoke 12 and a leg 13
and the wound iron core 1.41. Magnetic flux flows through each magnetic circuit formed by S. At this time, since the magnetic flux along the axial direction of the wound core 1 flows from the upper end surface to the lower end surface or in the opposite direction, abnormal eddy current can be significantly reduced. In this case, the yoke 1 of each core 14.14
By increasing the cross-sectional area of 1, 11, 12, and 12, most of the magnetic flux generated in the winding 15 can pass through the wound core 1, and the reduction of abnormal eddy current loss can be greatly improved.

Next, the results of an experiment using the magnetic field apparatus shown in the above embodiment will be explained. A wound core was manufactured using Fe-3i-B-based amorphous magnetic alloy ribbon 2605S2 manufactured by Allied Co., Ltd.
This wound core was assembled into the magnetic field apparatus of the first embodiment, and heat-treated at 400° C. for 60 minutes in an annealing furnace in a N2 gas atmosphere. At this time, a magnetizing force of 40 A/cm was applied to the wound cores Nos. 1 to 4 in the axial direction of the wound iron cores using a magnetic field device.

However, it is assumed that all ampere turns are applied to the wound core.

After heat treatment, the core loss characteristics of the wound core were measured. The results are shown in Table 1. In addition, the iron loss is B-0.5T.

It is a value per IKg at f-5KHz.

Table 1 As seen in this table, the iron loss of the wound cores (No. 1 to 4) to which an axial magnetizing force was applied by a magnetic field device is the same as that of the wound iron core (No. 5) to which no magnetizing force was applied. It has decreased to 1/3 compared to the previous year.

FIG. 2 shows a second embodiment. This embodiment is a magnetic field device in which a wound core 1 is used in combination on the outside. That is, the upper yoke 21 and the lower yoke 22 are arranged so as to straddle and contact the upper end surface and the lower end surface of the wound core 1, respectively, and the leg 23 that connects both yokes 21 and 22 is arranged inside the wound iron core 1. An iron core 24 for forming a magnetic field is formed, and an excitation winding 25 is further arranged around the leg 23. Since this type effectively utilizes the space inside the wound core 1, it is suitable when the wound core 1 is large.

In addition, FIG. 2 shows the case where two wound cores 1 are overlapped and heat treated.

FIG. 3 shows a third embodiment. The magnetic field device of this embodiment is of a type in which a wound core 1 is assembled inside a magnetic field forming core, and the drawing is a plan view of this magnetic field device. That is, 31.31 is an upper yoke, 32.32 is a lower yoke, and 33.33 is a leg, and these parts form the magnetic field forming iron core 34. Note that the excitation winding is located at the same position as in the magnetic field device shown in FIG. 1, but is not shown in the drawing. Here, the upper yoke 31 and the lower yoke 3
2 do not contact the entire upper end surface and lower end surface of the wound core 1, and are arranged at positions different from each other by about 90 degrees in the circumferential direction of the wound iron core 1. This will be further explained with reference to FIG. This figure shows the state in which the amorphous magnetic alloy ribbon 2 of the wound core 1 is developed. Since the positions of the upper yoke 31 and the lower yoke 32 that contact the amorphous magnetic alloy ribbon 2 of the wound core 1 are shifted, the direction of the magnetic flux flowing through the wound core 1 is inclined as shown. Therefore, the magnetic flux has not only an axial component of the wound core 1 but also a circumferential component, and thereby not only the abnormal eddy current loss but also the hysteresis loss of the wound core 1 can be reduced.

FIG. 5 shows a fourth embodiment. This example is the second
The upper yoke 21 and the lower yoke 22 in the third embodiment are arranged at different positions by 90 degrees in the circumferential direction, and the same effect as in the third embodiment can be obtained.

FIG. 6 shows a fifth embodiment. This example is the first
In the embodiment, the second excitation winding 16 is wound around the wound core 1.
Since magnetic flux is generated in the circumferential direction in addition to the axial direction, the same effect as in the third embodiment can be obtained.

Note that the excitation winding may be provided at any location in the magnetic circuit comprising the winding core and the magnetic field forming core.

[Effects of the Invention] As explained above, according to the magnetic field device for heat treatment of a wound core of the present invention, when heat treating a wound core, an axial magnetic field is applied to the wound core to reduce abnormal eddy current loss, It is possible to obtain a wound core that can exhibit the excellent magnetic properties of an amorphous magnetic alloy ribbon.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a first embodiment of the magnetic field device of the present invention, FIG. 2 is a sectional view showing the second embodiment, FIG. 3 is a plan view showing the third embodiment, and FIG. The figures are explanatory diagrams showing the state of contact between the yoke and the wound core in the same embodiment, FIG. 5 is a perspective view showing the fourth embodiment, and FIG. 6 is a perspective view showing the fifth embodiment. 1... Winding core, 11, 21. 31... Upper yoke,
12,22.32...lower yoke, 13,23°33
... Leg, 14, 24. 34 ... Iron core for magnetic field formation,
15.25.35... Excitation winding. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A device for forming a magnetic field when heat-treating a wound core formed by winding an amorphous magnetic alloy ribbon, the magnetic field having yokes disposed on both ends of the wound core in the axial direction, and legs connecting these yokes. Heat treatment for a wound core, comprising: a forming core; a magnetic circuit constituted by the magnetic field forming core and the wound core; and an excitation winding arranged to interlink with the magnetic circuit. magnetic field device.