JPH0684655A - High frequency wound core and high frequency induction electric appliance employing wound core - Google Patents

Abstract

PURPOSE:To shorten annealing time for achieving low loss high rectangularity hysteresis charactrictics remarkably while allowing setting of high operational flux density B and to realize downsizing of machine. CONSTITUTION:The wound core 13 made of an amorphous magnetic thin band 11 is annealed while sandwiching an insulator 12 narrower than the thin band 11. It is placed into an insulating oil at the time of use and the insulating oil is permeated between the layers. The wound core 13 is produced by winding the amorphous magnetic thin band 11 and a heat resistant insulating film narrower than the thin band 11 while superposing and then annealing at a specific temperature or by bonding a heat resistant insulator 12 narrower than the amorphous magnetic thin band 11 thereto and winding and then annealing at a specific temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding core made of an amorphous magnetic ribbon used in a high frequency range and a high frequency induction electric device using the winding core.

[0002]

2. Description of the Related Art In recent years, an amorphous magnetic ribbon having excellent magnetic characteristics has been used as an iron core material used in an induction electric device such as a transformer, instead of a conventional silicon steel plate, permalloy, ferrite or the like. Is being considered. Particularly in induction electric devices operated at high frequencies, the tape-shaped ribbon, which is a characteristic of amorphous magnetic ribbon, can be easily manufactured, and the high frequency iron loss is reduced due to the large specific resistance. Applications are increasing.

However, since the amorphous magnetic ribbon is generally not coated with an insulating coating, it has a frequency of 1
In the case of a transformer core having a frequency of 0 kHz or more, the insulation resistance between the core layers may affect the increase of eddy current loss at high frequencies. In particular, in the case of a high-output, high-voltage pulsed saturable reactor that operates at higher frequency and voltage, the voltage of one turn of the winding becomes high, and the insulation breakdown between the core layers is low. Local heating may occur in the wound core due to such factors.

In order to obtain a large operating magnetic flux density ΔB, it is desired to have an iron core structure capable of reducing the temperature rise of the iron core together with a low loss and a high angle hysteresis characteristic. As a method for preventing an increase in eddy current loss of a saturable reactor iron core used in this high frequency pulse power supply device, Japanese Patent Laid-Open No. 63-6 is available.
As disclosed in Japanese Patent No. 822, it is possible to use a wound iron core in which an amorphous magnetic ribbon and a heat-resistant insulating film having a tape width equal to or larger than the strip width of the ribbon are superposed and annealed. Is being considered.

[0005]

However, in such a wound iron core, which is obtained by stacking and winding such an amorphous magnetic ribbon and a heat-resistant insulating film having a width wider than the strip width of the ribbon and then annealing the core, a vortex due to a poor interlayer insulation is caused. Although it is possible to prevent an increase in current loss, there is a drawback that heat conduction during annealing is poor because the heat-resistant insulating film protrudes from the end surface portion of the wound iron core, resulting in a significant increase in heating time. Further, even when the device is used, there is a drawback that the efficiency of cooling on the surface of the wound core becomes poor and the temperature rise of the wound core becomes extremely high. Therefore, in use, it is necessary to reduce the operating magnetic flux density to reduce the generated loss, which causes a problem that the winding iron core becomes large and the pulse power supply device itself also becomes large.

The present invention has been made to solve the above problems, and can significantly reduce the annealing time for obtaining low loss and high square hysteresis characteristics, and the operating magnetic flux density ΔB can be reduced. An object of the present invention is to obtain a high-frequency wound iron core that can be set high and can be made small and lightweight, and a high-frequency induction electric device using the wound iron core.

[0007]

The high frequency winding iron core of the present invention is a high frequency winding iron core formed by winding and annealing an amorphous magnetic thin ribbon. It is characterized in that an insulating material narrower than the strip width is interposed.

In this case, the wound core is obtained by stacking an amorphous magnetic ribbon and a heat-resistant insulating film having a tape width narrower than the plate width of the ribbon, winding the same, and then heating it to a predetermined temperature to anneal it.
Alternatively, it is possible to use a material obtained by attaching a heat-resistant insulating material narrower than the plate width of the amorphous magnetic ribbon to the amorphous magnetic ribbon and winding the amorphous magnetic ribbon, followed by heating to a predetermined temperature and annealing. Further, as a high frequency induction electric device, the above wound iron core is arranged in insulating oil and used.

[0009]

With this structure, the width of the amorphous magnetic ribbon is narrower than that of the heat-resistant insulator, so that the heat conduction from the end surface of the wound iron core to the width direction is good and the temperature rise time during annealing is greatly increased. Can be shortened to Further, when the device is used, the heat radiation from the surface of the wound core is improved, so that the temperature rise of the wound core can be reduced and a large operating magnetic flux density ΔB can be obtained.

Since the width of the heat-resistant insulating material at both ends of the amorphous magnetic ribbon is narrower than that of the amorphous magnetic ribbon, there is a concern that the interlayer insulation resistance may decrease due to contact. Even if both ends of the amorphous magnetic ribbon are contacted by using it in insulating oil, the insulating oil permeates into the contact parts and the insulation resistance is improved. Absent.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 and 2, the winding iron core 13 is an amorphous magnetic ribbon 11 (METGLAS2605S).
2: Allied Co., Ltd. product name) and a heat-resistant insulating film 12 having a tape width narrower than this thin strip width (for example, Upilex 7.5S: Ube Industries product name) are wound and laminated. After that, this wound iron core 13 is formed into a rectangular one-turn cut shape, and thereafter, residual quenching strain during manufacturing of the amorphous magnetic ribbon 11 and strain due to winding are removed to obtain a high-square hysteresis characteristic with low loss. And annealing temperature 3
Annealing is performed in a nitrogen atmosphere under the conditions of 80 ° C., holding time of 2 hours, and applied magnetic field of 800 A / m. And the rolled iron core 13 after annealing
Attach the winding 14 and clamp 15 as shown in FIG.
Tank 1 together with insulating oil 16 by tightening with a, 15b, etc.
Stored in 7 to form a high frequency transformer. As a result, the wound iron core 13 is used while being arranged in the insulating oil 15.

[0012] In this example, the winding iron core was annealed while applying a DC magnetic field during annealing, but in a winding iron core used at a high frequency of about 5 kHz or more, iron loss can be reduced by not applying a magnetic field. It may be annealed in the state of no magnetic field.

FIG. 6 shows a comparison with an embodiment of the present invention.
The winding iron core 3 of a prior art example is shown. A wound iron core 3 shown in FIG. 6 is obtained by stacking an amorphous magnetic thin ribbon 1 and a heat-resistant insulating film 2 having a tape width larger than the thin ribbon width, and wound the wound iron core 3 similarly to the present embodiment. It is annealed.

As for the temperature rise of the wound core during annealing, the heat conduction in the stacking direction is very poor because the heat resistant insulating film is inserted between the layers of the amorphous magnetic ribbons. I have no choice. Here, the conventional wound iron core 3 shown in FIG.
Since the heat-resistant film 2 is wider than the width of the amorphous magnetic ribbon 1, the entire end surface of the wound iron core 3 is covered with the heat-resistant film 2, so that the amorphous magnetic ribbon 1 is annealed during annealing.
The heat conduction to the core becomes extremely poor, and it takes a long time to raise the wound core 3 to a predetermined annealing temperature of 380 ° C. On the other hand, the wound iron core 13 of this embodiment shown in FIG.
Since the plate width of the amorphous magnetic ribbon 11 is wider than that of the heat-resistant insulating film 12, the amorphous magnetic ribbon 11 on the end face of the wound iron core 13 is in contact with the atmosphere of the annealing furnace. By heat conduction from the width direction of the winding core, the temperature can be raised to the central portion of the winding core in a short time.

FIG. 4 shows the results of temperature rising experiments during annealing of the wound cores of the conventional example and the present example. In the wound core according to the present example shown by the solid line, since the heat conduction in the width direction from the end of the wound core is good, an annealing temperature of 380 ° C. is reached as compared with the wound core of the conventional example shown by the broken line. It can be seen that the time required for annealing and the time required for cooling are reduced, and the time required for annealing is greatly reduced.

Similarly, FIG. 5 shows an experimental result of measuring the temperature rise of the iron core in the insulating oil when the wound iron cores of the conventional example and the present example are used as the iron core of the saturable reactor of the high voltage pulse generator. The operating conditions include a frequency of 200 kHz,
The operating magnetic flux density ΔB = 2.60 T, and the core loss in this case is about 250 W / both in the wound cores of the present example and the conventional example.
cm ³ And the repetition frequency is 1 Kpps (1000 pulses /
The total calorific value W in (sec) was 1.03 kW.

Even if both the generated losses of the wound core are the same, the temperature rise of the wound core is different due to the difference in the cooling condition of the end portion of the wound core. That is, in this embodiment shown by the solid line, since the amorphous magnetic ribbon is projected at the end of the winding core and is in contact with the insulating oil, a heat-resistant insulating film like the conventional example covers the end face of the winding core. As a result, the cooling efficiency is greatly improved and the temperature rise can be reduced. Therefore, in this embodiment, the operating magnetic flux density ΔB can be set high, and the size and weight of the device can be reduced.

In the wound iron core 13 of this embodiment, since both ends of the amorphous magnetic ribbon 11 are wider than the tape width of the heat-resistant film to be wound in layers, the layers may come into contact with each other. Therefore, even if the amorphous magnetic ribbon 11 comes into contact, the insulating oil permeates into the contact portion, so that the insulating characteristics are maintained and the characteristics of the device are not deteriorated. I'm confirming.

In the above embodiment, the case where the heat-resistant insulating film is used as the insulating material between the winding core layers is explained. However, on one surface of the amorphous magnetic ribbon, for example, SiO ₂ such as Nerita Laboratory product name Ceramica It is also possible to apply a heat-resistant coating material containing as a main component so that it is narrower than the plate width of the amorphous magnetic ribbon, and dry it to form an insulator between the wound core layers. For this wound core as well, in order to remove the residual strain and the strain due to winding that occur during the production of the amorphous magnetic ribbon, and to obtain a high-square hysteresis characteristic with a low loss, an annealing temperature of 380 ° C.
Annealing is performed in a nitrogen atmosphere under the conditions of a holding time of 2 Hr and an applied magnetic field of 800 A / m. In this case as well, since the end face portion of the wound core is not covered with the insulator, the same effect as in the above embodiment can be obtained.

[0020]

As described above, the high frequency winding core according to the present invention and the high frequency induction electric equipment using the winding core can significantly reduce the annealing time for obtaining low loss and high square hysteresis characteristics. Moreover, since the temperature rise of the winding core can be reduced, the operating magnetic flux density ΔB can be set high, and the size and weight of the device can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a wound core used in an embodiment of a high frequency transformer of the present invention.

FIG. 2 is an explanatory view showing a winding state of the wound iron core of FIG.

FIG. 3 is a partially cutaway front view showing a high frequency transformer according to an embodiment of the present invention.

FIG. 4 is a curve diagram showing the results of a temperature rising experiment during annealing of a wound iron core according to an example of the present invention and a conventional example.

FIG. 5 is a curve diagram showing the results of an iron core temperature rise experiment during use of the wound iron cores of one example of the present invention and a conventional example in insulating oil.

FIG. 6 is a schematic sectional view of a conventional wound core.

[Explanation of symbols] 11 is an amorphous magnetic ribbon, 12 is a heat-resistant insulating film, 13
Is a winding core for high frequency, 14 is a winding, 15 is insulating oil, and 17 is a tank.

Claims (4)

[Claims] 1. A high-frequency wound iron core obtained by winding and annealing an amorphous magnetic ribbon, wherein the wound iron core has a heat-resistant insulating material between the layers of the amorphous magnetic ribbon which is narrower than the strip width. A high-frequency wound iron core, characterized in that 2. The wound core comprises an amorphous magnetic ribbon and a heat-resistant insulating film having a tape width narrower than the plate width of the ribbon, which is wound and then annealed by heating to a predetermined temperature. The high frequency winding iron core according to claim 1. 3. The wound iron core is formed by attaching a heat-resistant insulating material narrower than the plate width of the amorphous magnetic ribbon to the amorphous magnetic ribbon, winding the amorphous iron ribbon, and then heating it to a predetermined temperature and annealing it. 1. A high-frequency wound iron core according to 1. 4. A high frequency induction electric device comprising the wound iron core according to claim 1 in insulating oil.