JPS63114205A - Method for working iron core of amorphous alloy thin belt - Google Patents

Abstract

PURPOSE:To prevent a surface pressure from being applied to an amorphous alloy thin belt, by using an inner frame wherein a corner part is made high and a linear part is made low, and applying a tension in the longitudinal direction to the amorphous alloy thin belt facing the linear part with the corner part as a retaining point. CONSTITUTION:A corner part 3b is made higher by h than a linear part 3a. When an amorphous alloy thin belt 1 is made up in a specified D-form by using an inner frame whose corner part 3b is made high in such a manner, both ends of the amorphous alloy thin belt 1 facing the linear part 3a are retained by the corner part 3b, and the amorphous alloy thin belt 1 is prevented from directly contacting the linear part 3a. Therefore, when a coil form shown in (a) is re-formed to a D-form shown in (b), the applied force is a tension in the longitudinal direction of the amorphous alloy thin belt 1, and the contact pressure against the linear part 3a is not applied to the amorphous alloy thin belt 1. Thereby, the surface pressure is not applied to the amorphous alloy thin belt 1, and the orientation of magnetic domain is smoothly progressed, so that the iron loss is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a core processing method for forming an amorphous alloy ribbon into a D-shaped core.

[Conventional technology]

Iron core materials used in electrical equipment such as three-rotation transformers are required to have good excitation characteristics and low iron loss. In order to reduce this iron loss, we must reduce hysteresis by reducing material defects and internal stress, and reduce eddy current loss by increasing electrical resistance and reducing plate thickness. It is necessary. Silicon steel plates or silicon steel strips have been used so far as materials that meet these requirements.

This silicon steel plate or silicon steel strip is manufactured by a conventional method that involves a number of steps such as casting, hot rolling, cold rolling, and annealing. In response, a technology has recently been developed to produce thin strips of amorphous alloys with a structure similar to that of liquids by ultra-quenching the alloys from a high-temperature molten state.

When using this method for producing an amorphous alloy, a ribbon can be produced directly without going through a process such as rolling. In addition, the electrical resistance of the obtained amorphous alloy ribbon is high, iron loss is significantly reduced due to the amorphous structure, and there is no anisotropy.Furthermore, this amorphous alloy ribbon has excellent excitation characteristics. Because of its excellent properties, it is a material that is highly anticipated as an iron core material.

When this amorphous alloy ribbon is used as an iron core for electrical equipment, the amorphous alloy ribbon is cast to a width of several to several + 1 and wound into a coil shape in a predetermined direction. A method of forming into a D shape and then annealing in a magnetic field is adopted. This annealing releases distortion during casting, aligns the magnetic domains in a predetermined direction, and improves the magnetic properties of the core. At the same time, structural relaxation of the amorphous alloy ribbon occurs, allowing the amorphous alloy ribbon to maintain its core shape without requiring external force.

However, when this winding and forming is performed, distortions such as wrinkles are likely to occur in the amorphous alloy ribbon wound around the winding frame and the forming frame.
This becomes more noticeable as the width of the amorphous alloy ribbon increases. This is due to the fact that the amorphous alloy ribbon is used in the as-cast form. In other words, when manufacturing amorphous alloy ribbons by ultra-quenching, there are several issues: rapid solidification of high-temperature molten metal, nozzle processing accuracy, and deformation at high temperatures.

Due to fluctuation factors such as expansion of the cooling roll, the shape of the amorphous alloy ribbon becomes unstable. As a result, ear waves, mid-stretching, etc. are likely to occur, and the thickness change in the width direction is also large. This distortion is fixed in the annealing process that follows the forming, and deteriorates the magnetic properties of the core.

Therefore, in order to prevent the occurrence of this distortion, the present inventors
We developed a method of winding an amorphous alloy ribbon by changing the circumference in the width direction of the winding frame depending on the flatness of the ribbon, and filed this as Japanese Patent Application No. 67216/1983.

By changing the circumference in the width direction of the reel in this way,
This prevents the occurrence of winding distortion and improves magnetic properties.

[Problem that the invention seeks to solve]

However, when the iron core of the amorphous alloy ribbon is wound into a coil,
When molding this into a predetermined D shape, there are various problems in addition to this winding distortion. In other words, the amorphous alloy ribbon is
Since it has low anisotropy and high strain sensitivity, if an unexpected force is applied during winding or molding, the magnetic domain structure will easily change in response to the force, resulting in deterioration of magnetic properties. For example, when winding an amorphous alloy ribbon around a reel in a multilayered state, the winding becomes tight. This tightening applies a force in a direction perpendicular to the surface of the amorphous alloy ribbon, that is, a surface pressure, and the magnetic domains inside the amorphous alloy ribbon are aligned along this surface pressure even after annealing. Become. Furthermore, when forming the amorphous alloy ribbon wound tightly into a coil into a D shape, the influence of the surface pressure becomes more pronounced.

In this way, the magnetic domains arranged perpendicular to the surface of the amorphous alloy ribbon act as resistance to magnetic flux when the amorphous alloy ribbon is used as an iron core, causing a significant increase in core loss. becomes.

Furthermore, when annealing the wound iron core, it is necessary to control the annealing conditions very strictly because the crystallization temperature of the amorphous alloy is close to the annealing temperature. For example, the crystallization temperature of an Fe-based amorphous alloy ribbon with a normal composition is 45
It is in the range of 0 to 600℃, and annealing is slightly lower than 3
It is carried out at 50-420'C.

For this reason, the annealed amorphous alloy ribbon will crystallize after some time, and the excellent properties unique to amorphous will be lost.Therefore, the present invention aims to form the amorphous alloy ribbon into a D-shaped core. The purpose is to prevent such unexpected forces from being applied during processing, relax annealing conditions, and easily obtain an iron core with low iron loss and excellent magnetic properties.

[Means for solving problems]

In order to achieve the purpose, the core processing method of the present invention uses an inner frame with high corner parts and low straight parts when forming a D-shaped core from an amorphous alloy ribbon wound into a coil shape. and applying tension along the longitudinal direction of the amorphous alloy ribbon facing the straight section using the corner section as a support point.

The present invention will be specifically explained below.

FIG. 1 is a diagram showing the process of the present invention following the condyle, and FIG. 2 shows an example of the inner frame used in the process.

First, the amorphous alloy ribbon 1 produced by ultra-quenching is
As shown in Figure (al), the drum 2 is wound into a coil shape. This drum 2 consists of a plurality of divided pieces, and after winding the amorphous alloy ribbon 1, the drum 2 is wound into a coil for each divided piece. By disassembling it, the coiled amorphous alloy ribbon 1 can be taken out.

Next, the amorphous alloy ribbon 1 wound into a coil shape
Insert the inner frame 3 into the inner periphery of the frame. This inner frame 3 has a straight portion 3
a and its corner portion 3b which is higher than the straight portion 3a.
It has an outer peripheral surface consisting of Note that, like the drum 2, the inner frame 3 is constructed in a split type, and can be expanded outwardly by hydraulic pressure, air pressure, or the like.

The amorphous alloy ribbon l formed into a D shape in this way is
As shown in the same figure (C1), it is charged into the annealing furnace 4, and the
Annealed at around 0°C.

FIG. 2 is an enlarged view of the inner frame 3 used in the molding process, centering on the corner portion 3b.

Conventional inner frames have rounded corners to prevent sharp bends in the magnetic material such as silicon steel plate wound around the reel, but in the inner frame 3 of the present invention, This corner portion 3b is made to protrude from the straight portion 3a.

That is, the corner portion 3b has a height h compared to the straight portion 3a.
only.

It is preferable that the height h of the corner portion 3b is greater than the thickness t of the amorphous alloy ribbon l.
It is effective to set it in the range of 2 times or more to 20 times.

If the ratio of the height h to the plate thickness t is small, the surface shape of the amorphous alloy ribbon 1 and the flatness of the straight portion 3a of the inner frame 3 will cause localized damage to the amorphous alloy ribbon 1. Surface pressure is applied. vice versa,
If the ratio of the height h to the plate thickness t is too large, deflection may occur at the edge portion during winding depending on the shape of the amorphous alloy ribbon 1. Therefore, when h-2 to 20×t, the required tension in the longitudinal direction can be applied to the amorphous alloy ribbon 1 without causing these drawbacks.

When forming the amorphous alloy ribbon 1 into a predetermined D shape using the inner frame 3 with the corner portions 3b raised in this way, the straight portions 3
Both ends of the amorphous alloy ribbon 1 facing the direction a are supported by the corner portions 3b, and the amorphous alloy ribbon 1 is prevented from directly contacting the straight portion 3a. Therefore, the force applied when forming the amorphous alloy ribbon 1 into the D shape shown in FIG. 1 (from the coiled shape shown in FIG. The tension of .--, which prevents contact pressure with the straight portion 3a from being applied to the amorphous alloy ribbon 1, is preferably 0.1 to 0.1.
It is better to set it in the range of 0.2 to 2 kg/Tsurutomi more preferably than 5 kg/2 degrees.

Further, in the amorphous alloy ribbon 1 after the 2N, the contact pressure against the preceding layer is absorbed in the space between the first layer and the straight portion 3a. Therefore, a force in a direction perpendicular to the plane of the formed amorphous alloy ribbon 1, that is, no surface pressure is applied to the formed amorphous alloy ribbon 1.

Note that when the curvature forming this height h is provided around the corner of the inner frame 3, the curvature is larger than that of the conventional inner frame corner, so the amorphous material formed at the corner 3b is The bending angle of the alloy ribbon 1 becomes gentle. Therefore, the bending stress generated in the amorphous alloy ribbon 1 can be kept small, which is more preferable.

[Effect]

FIG. 3 is a graph showing the influence of tension on iron loss. As is clear from this figure, when tension is applied to the amorphous alloy ribbon 1 in the straight portion 3a of the inner frame 3, it is effective in reducing iron loss.

This is because by applying tension to the amorphous alloy ribbon, the magnetic domains are aligned along the length direction of the amorphous alloy ribbon, that is, along the direction of the magnetic field when used as an iron core. In this way, since the magnetic domains are aligned by applying tension, it is also possible to anneal a D-shaped amorphous alloy ribbon without a magnetic field.

When this tension is less than 0.1 kg/m", the effect of aligning the magnetic domains is small, and iron loss cannot be improved. On the other hand, when the tension exceeds 5 kg/m", the corner portion of the core may seize during annealing. This is not desirable because it causes
The applied tension is 0.1 to 5 kg/m", preferably 0.2
It is preferable to maintain it in the range of ~2 kg/mu''.

Further, this tension application is also effective in relaxing the annealing conditions. FIG. 4 is a graph showing the effect of this tension on the required annealing temperature.

In the case of FIG. 4, annealing was performed by applying a magnetic field of 15 oersteds. That is, compared to magnetic field annealing with a tension of O, the larger the tension applied to the amorphous alloy ribbon, the wider the temperature range in which reduction in iron loss is observed. For example, when annealing is performed with 0 tension, the annealing temperature is 3
1, 5 that needed to be set at 80±5℃
By applying a tension of "kg/fl", the annealing temperature range can be widened to 380±30°C.

Accordingly, management of the annealing work becomes easier.

The reason why the core loss decreases over a wider temperature range as the tension increases is as follows. That is, annealing removes the stress within the amorphous alloy ribbon,
This is done to eliminate the disturbance in the magnetic domains caused by the stress, but if no tension is applied, the magnetic domains are aligned only by the strength of the magnetic field. On the other hand, when tension is applied, the magnetic domains are arranged along the direction of the tension. This tension also acts to cancel out internal stress. Since annealing is performed in this state, alignment of magnetic domains is promoted over a relatively wide temperature range.

In particular, since annealing can be performed at a lower temperature than in the past, the difference between the annealing temperature and the crystallization temperature (450 to 600°C) can be increased. Therefore, without causing crystallization of the amorphous alloy ribbon, internal stress can be removed and iron loss can be improved while maintaining the excellent properties unique to amorphous.

Furthermore, FIG. 5 is a graph showing that the strength of the magnetic field required during annealing can be reduced by applying this tension. In other words, when annealing is performed with a tension of 1.5 kg/m'', the iron loss of the amorphous alloy ribbon is low from the beginning because it is not affected much by the strength of the magnetic field. When annealing an amorphous alloy ribbon without tension in a magnetic field, the reduction in iron loss gradually decreases depending on the strength of the magnetic field, and tension is only applied when the strength of the magnetic field is increased to 10 oersteds. As can be seen from this graph, when annealing is performed under tension according to the present invention, there is no need to apply a separate magnetic field.

Furthermore, in the present invention, by using the inner frame 3 having the corner portions 3b and straight portions 3a described above, surface pressure is not applied to the amorphous alloy ribbon, and the coiled amorphous alloy ribbon is The thin ribbon 1 is formed into a D-shaped core. This surface pressure acts as compressive stress on the amorphous alloy ribbon, promotes the development of magnetic domains along that direction, and is a cause of worsening iron loss. Since such surface pressure is not applied to the amorphous alloy ribbon 1, the magnetic domains are aligned with high orientation along the direction of tension. Therefore, when used as an iron core, there are no magnetic domains that create resistance to magnetic flux, and iron loss can be improved.

〔Example〕

EXAMPLES Hereinafter, the effects of the present invention will be specifically explained with reference to Examples.

A Fe-5i-B amorphous alloy ribbon 1 with a thickness t=25P and a width of 100fl was wound into a coil shape, and then
An inner frame 3 having a corner portion 3b having a height h-0 and a height of 25Xt (h#12Xt) as shown in FIG. 1 was inserted into the coiled amorphous alloy ribbon 1. Then, the inner frame 3 was expanded by hydraulic pressure, and the amorphous alloy ribbon 1 was formed into a D shape. At this time, the tension applied to the amorphous alloy ribbon 1 was set to 1.0 kg/u'', and the amorphous alloy ribbon 1 thus formed into a D shape was heated to The cores were annealed in a magnetic field and without a magnetic field for 1 hour.The core loss of the obtained core is shown in the following table.The table also shows the case where no tension is applied as a comparative example.

As is clear from this table, it can be seen that according to this example, the application of tension is extremely effective in reducing iron loss.

〔Effect of the invention〕

As explained above, in the core processing method of the present invention, by using an inner frame with raised corner portions, 2.
The amorphous alloy ribbon is wound into a coil while applying tension along the longitudinal direction, and is formed into a D shape, and no surface pressure is applied to the amorphous alloy ribbon. When a high quality alloy ribbon is annealed, the magnetic domains are aligned extremely smoothly, and iron loss is significantly improved. In addition, by applying this tension, the range of required annealing temperatures can be expanded, so
It becomes easier to manage annealing conditions. Furthermore, even when annealing is performed without applying a magnetic field, magnetic properties superior to those of conventional products can be obtained, so that manufacturing costs can be reduced. In this manner, the present invention provides excellent productivity when manufacturing an iron core from an amorphous alloy ribbon and excellent magnetic properties of the manufactured iron core.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining the core processing method of the present invention in the order of steps, and Fig. 2 shows an inner frame used when forming a coiled amorphous alloy ribbon into a D shape, with its corner portions shown. Figure 3 shows the relationship between tension application and iron loss, Figure 4 shows the effect of tension on the range of annealing temperature, and Figure 5 shows the effect of tension on the strength of the magnetic field. This shows the effect of the applied tension.

Claims (1)

[Claims] 1. When forming the amorphous alloy ribbon wound into a coil into a D-shaped core, an inner frame with high corner portions and low straight portions is used, and the straight portions are held at the corner portions as supporting points. A method for processing an iron core of an amorphous alloy ribbon, characterized in that a tension is applied along the longitudinal direction of the amorphous alloy ribbon facing the amorphous alloy ribbon.