JPS61179518A - Manufacture of stationary induction electric apparatus - Google Patents

Abstract

PURPOSE:To reduce the generation loss at the corners of a core during the annealing process for uniformizing the temperature distribution in the whole wound core, by providing magnetic pieces at the corners of the wound core. CONSTITUTION:A magnetic piece 15 is provided between layered blocks 14A and 14B, and 14B and 14C in the portions thereof which will be the corners of a core where the lower yoke of the core intersects the legs on the sides. The layered blocks 14A-14C and reinforcing plates 16A and 16B are shaped into a U shape by bending them. The magnetic pieces 15 are held between the layered blocks and the reinforcing plates 16A and 16B are located on the lower yoke of the core and on the outer and inner peripheries of the legs. Windings 17 are fitted over the legs of the U-shaped layered blocks 14A-14C. The ends of the layered blocks 14A-14C projecting upwards from the windings 17 are bent so that the end faces of the layered blocks are butt bonded to each other. The wound core is annealed by means of high frequency excitation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a stationary iron 4 using a one-turn cut-shaped wound core made of an amorphous magnetic alloy ribbon.

[Technical background of the invention and its problems]

Recently, it has been considered to manufacture wound cores used in stationary induction appliances, such as transformers, from amorphous magnetic alloy ribbons. This material is made by ultra-quenching a magnetic alloy melt and has excellent magnetic properties with low iron loss. When manufacturing a transformer using a wound core made of this amorphous magnetic alloy ribbon, the assembly of the windings to be installed on the core becomes easier, so a method for manufacturing a transformer using a one-turn cut-shaped wound core is used. is proposed.

This is a method of forming a wound core by inserting one turn of amorphous magnetic alloy ribbon into the transformer winding. However, amorphous magnetic alloy ribbon is highly sensitive to stress, which occurs during manufacturing. Since the magnetic properties deteriorate, strain relief annealing is performed when manufacturing the wound core to fully recover the magnetic properties. The annealing temperature of the amorphous magnetic alloy material is, for example, 400°C in METG LAS 260582 manufactured by Allied.
During strain relief annealing, it is necessary to raise the temperature of the entire single-turn core to the appropriate annealing temperature range with uniform temperature distribution in order to restore the magnetic properties of the amorphous magnetic alloy ribbon well. be.

Conventionally, as a method for annealing a one-turn cut wound core made of an amorphous magnetic alloy ribbon, an external heating method has been used in which the wound core is placed in a constant temperature bath and annealed by heating and raising the temperature.

However, with this annealing method, it is not possible to uniformly heat the entire wound core, and the C1 winding suffers significant thermal damage, so in order to avoid this, it is necessary to assemble all the windings onto the core after annealing. There is.

However, since the amorphous magnetic alloy ribbon has the property of becoming brittle after annealing, when assembling the winding wire onto the wound core after annealing, external force is applied to the amorphous magnetic alloy ribbon, causing damage to the amorphous magnetic alloy ribbon. A problem arises in that the ribbon is damaged and the magnetic properties of the ribbon deteriorate, impairing the quality of the wound core.

Therefore, a method has recently been considered in which a wound core made of amorphous JR magnetic alloy ribbon is self-heated by high-frequency excitation to perform annealing. This annealing method involves exciting the wound core by passing a high-frequency alternating current vjL flow with a frequency of about 2 to 10 KHz through an excitation coil wound around the wound core, and causing the wound core to self-heat due to the loss generated in the wound core due to this excitation. This method involves annealing. According to this method, since there is little thermal influence on the winding wire, an amorphous magnetic alloy ribbon can be inserted into the winding wire to form a wound core, and annealing can be performed in a >'C state. Therefore, there is no need to assemble the windings to the wound core after annealing, which avoids processing that applies external force to the amorphous magnetic alloy ribbon, thereby preventing damage to the amorphous magnetic alloy ribbon and deterioration of magnetic properties. There is an advantage in that it can be prevented.

However, even with this high-frequency excitation annealing method, it is still insufficient to uniformly heat the entire wound core. 10th
The figure is a diagram showing the relationship between the temperature rise in each part of the core and the excitation time when the rectangular wound core shown in FIG. 9 is annealed by high-frequency excitation. The wound core shown in FIG. 9 is a one-turn cut-shaped wound core 3 formed into a rectangular shape by combining multiple sets of laminated blocks 2 formed by shifting the layers of a large number of amorphous magnetic alloy ribbons 1. This winding core 3 has a winding 4
is assembled.

According to the diagram in FIG. 10, the leg section (straight section) of the wound core 3 has a point E, the silicate section (straight section) point F, and the corner section (the section where the leg section and the silicate section intersect at right angles). ) It can be seen that the magnitude of the loss generated by high-frequency excitation is different from point D, so there is a difference in temperature rise. That is, when the corner point of the wound core 3 reaches a temperature of 410°C, the temperature of the leg point E is 320°C, and the temperature of the two silicate iron parts is 360°C.

Note that the reason why the temperature rise at two points on the silicate iron part is higher than that at point E on the leg is because the iron core window width dimension is smaller than the window height dimension. This is because the distance is small and it is affected by heat conduction.

Here, a description will be given of the phenomenon in which the temperature rise in the wound core is non-uniform. The loss that occurs in the wound core due to high frequency excitation consists of the eddy current product and hysteresis loss. The eddy current product We is expressed as follows.

However, t: equivalent plate thickness of the magnetic material, Bm: magnetic velocity density, f: current frequency, and ρ: specific resistance. As can be seen from this equation, the generation of eddy current product is proportional to the square of the thickness of the magnetic material, ie, the amorphous magnetic alloy ribbon. By the way, since there are many small protrusions on the surface of the amorphous magnetic alloy ribbon and the ribbon surface does not have an insulating coating, when the ribbons are stacked one on top of the other, the protrusions on the surface of each ribbon are Contact, amorphous magnetic alloy ribbon equivalent plate thickness tFit-αt'(α)1. t': Thickness of the amorphous magnetic alloy ribbon).

However, since the corner portions of the wound core are formed by bending the laminated blocks at right angles, the laminated amorphous magnetic alloy thin strips are pressed harder than the straight portions of the silicate iron portion and leg portions. The surface pressure applied to the belt is large. Therefore, in the corner portion, the partial contact area where the protrusions of each ribbon come into contact with each other increases depending on the surface pressure, and the equivalent plate thickness t of the amorphous magnetic alloy ribbon expressed by the above-mentioned formula increases. Therefore, the eddy current product at the corner portion is larger than that at the silicate iron portion and the leg portion. Moreover, since the eddy current product is proportional to the square of the excitation frequency of the current, high-frequency excitation of the wound iron core has a large effect on the increase in eddy current. Furthermore, hysteresis loss increases when external force is applied to the amorphous magnetic alloy ribbon.

However, no bending stress is applied to the amorphous magnetic alloy ribbon at the leg portions and silicate iron portions of the wound core, but at the corner portions, the amorphous magnetic alloy ribbon is bent at right angles and a large bending stress is applied. For this reason, hysteresis loss occurs more in the corners than in other parts. As described above, the eddy current product and hysteresis loss, that is, generated loss, occurring at the corner portions of the wound core are larger than those at the leg portions and silicate portions, and the temperature rise at the corner portions is higher than at other portions.

Therefore, it is difficult to uniformly raise and anneal each part of the wound core at an appropriate annealing temperature, and it is difficult to obtain a one-turn cut type wound core that can exhibit the excellent magnetic properties inherent to the amorphous magnetic alloy ribbon. There was a problem.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and is a method for producing a stationary induction electric appliance using a one-turn cut-shaped wound core that is well annealed and made of an amorphous magnetic alloy ribbon and has excellent magnetic properties. The purpose is to provide

[Summary of the invention]

The method for manufacturing a stationary induction electric appliance of the present invention includes forming a stacked block group t-U shape in which a plurality of stacked blocks each made by stacking a large number of amorphous magnetic alloy ribbons for each turn of a wound core are stacked. After assembling the winding wires to the laminated block group having this opening shape, when forming the wound core by bending both ends of the laminated block group inward and joining them, there is a gap between the laminated blocks at least at the corner of the wound core This method is characterized by inserting magnetic pieces to form a wound core, and then annealing the wound core by high-frequency excitation.

By providing the magnetic pieces at the corner portions of the wound core in this manner, the loss generated at the corner portions during annealing is reduced and the temperature distribution of the entire wound core is made uniform.

[Embodiments of the invention]

Embodiments of the present invention illustrated in the drawings will be described below.

1 to 6 show an embodiment of the manufacturing method of the present invention.

First, as shown in FIG. 2, an amorphous magnetic alloy ribbon 11 is continuously wound around a winding frame 12 to form a wound body 13, and a part of this wound body 13 is cut and expanded. A laminate is obtained by laminating a large number of amorphous magnetic alloy ribbons II. A plurality of /ilK divided in the radial direction of the wound core to be formed into this laminate.
A plurality of laminated amorphous magnetic alloy ribbons 11 are divided correspondingly into a plurality of layers and have a section for each turn corresponding to each turn of the wound core as shown in FIG. For example 3
Crystal blocks 141 to 14C are formed. Each of the laminated blocks 14A to 14C has an end face that is inclined by displacing the amorphous magnetic alloy ribbon II in the longitudinal direction. Although the wound body 13d is circular, it may have the same shape as the wound core.

Next, as shown in FIG.
Layer 4C. In this case, the laminated block J4A with a large length located on the outer circumferential side of the wound core is stacked on the lower side, and the laminated block J4A with a small length located on the inner circumferential side of the core is stacked on the upper side. 14C are arranged with their positions shifted in the length direction. Then, a magnetic piece 1 is placed between each of the laminated blocks 141 to 14C in the laminated blocks J (in the groups A to 14C, each of the laminated blocks 141 to 14C corresponds to the corner portion where the lower sintered iron part of the wound core intersects with the leg parts on both sides).
5 each. This magnetic piece 15 has a crescent-shaped cross section depending on the shape of the corner part, and the amorphous magnetic alloy ribbon 11
It has the same length as the width dimension. The magnetic piece 15 may be formed by stacking and bonding a plurality of amorphous magnetic alloy thin plates having different widths, as shown in FIG. 6(a), or as shown in FIG. 6(b). Amorphous magnetic alloy powder is pressed or molded using a binder.

In addition, on the lower and upper sides of the 14C group in the laminated block 14, reinforcements 16A and 16A are provided on the lower side and the upper side of the laminated block 14, with a length corresponding to the outer and inner circumferential lengths of the wound core, excluding the upper silicate portion.

Place z6B.

Next, as shown in FIG. 4, the laminated block 1411. ~z4c group and reinforcing plate 16A,
16B is formed into a mouth shape. The central part of the laminated block group formed in the shape of a mouth forms the lower silicate part of the wound core, and the raised parts on both sides form the legs and half of the upper silicate part, respectively.

In this case, a magnetic piece 15 is interposed and held between each of the laminated blocks 14A to 14C in each corner portion where the lower sintered iron part and both legs of the wound core intersect in the laminated blocks z4A 5z40 group. Ru. In addition, on the reinforcing plate 16, 16
B is located at the outer periphery and inner periphery of the lower core and leg portions of the wound core.

Next, as shown in FIG. 4, the windings 17 are respectively fitted into the leg portions of the upright portions on both sides of the mouth-shaped laminated block 14.

Next, as shown in FIG.
Both end portions of the windings 17 of the standing portions on both sides of group C are bent toward the P′3 side by press bending, and both end surfaces of each laminated block 14A to 14C are butted and joined.
Forms the upper silicate part of the wound core. In this case, in the pre-press bending process, one 14C is applied to each of the laminated blocks 14 at the corner portions where the upper silicate iron part and both side legs of the wound core intersect at both ends of the laminated blocks 148 to 14C. A magnetic piece 15 similar to that described above is placed between them, and in this state, both ends of the at layer blocks J4A to J14C are bent.

As a result, a magnetic piece 1 is placed between each laminated block 141 to 14C at each corner portion where the upper silicate iron portion and the leg portion of the wound core intersect.
5 is interposed. Note that a reinforcing plate I6c is arranged on the inner peripheral side of the upper silicate portion of the wound core.

In this way, the wound core 18 is formed.

Next, the wound core is annealed by high frequency excitation.

Figure 5 shows the electrical circuit for performing this annealing, and Figure C
F) Excitation winding temporarily wound on the silicate iron part of the 19/d winding iron core 18, 20 is a high frequency AC power supply, 2 NoiSt DC power supply, 22i
lt changeover switch 23 is a voltage regulator. First, the excitation winding 19 is connected to the alternating current power supply 20 through the switching coil 22, and a high frequency alternating current is applied to the coil core 18 to excite the wound core 18. This excitation generates an eddy current in the 9-turn iron core 18, and the loss associated with the generation of this eddy current causes self-heating and increases the temperature. When the temperature of the wound core 18 rises to the annealing temperature (400"C), the voltage of the high-frequency alternating current is adjusted by the voltage regulator 23 to maintain the annealing temperature for a certain period of time. After that, the switching switch 22Vc switches the excitation winding. H19 is disconnected from the AC power supply 20 and connected to the DC power supply 21 to flow a DC current.
The wound core is first cooled while forming a strong magnetic field. Through this annealing, the strain in the amorphous magnetic alloy ribbon 18 constituting the hem-wound core 18 is removed.

Note that it is preferable that the magnetic piece 15 be provided on the wound core 8.

However, according to the manufacturing method of the lever, the magnetic pieces 15f:
Since it is inserted, the winding iron core ZS'51 due to high frequency excitation
When annealing, the loss generated at the corner portions of the wound core 18 can be reduced. That is, the laminated block 141
By interposing the magnetic piece 15t between K and 14C, the cross-sectional area of the corner portion of the K-wound iron core I8 increases, and as the cross-sectional area increases, the magnetic flux density Bm of the coach portion decreases. The eddy current product generated in the amorphous magnetic alloy ribbon 11 is proportional to the square of the magnetic flux density Bm, and the hysteresis loss changes in proportion to the magnetic flux density Bm. In addition, the hysteresis loss, that is, the generated loss is small, and the degree of temperature rise at the corner is reduced. Therefore,
The temperature difference in each part of the wound iron core 18 becomes uniform, and the wound iron core 18
The excellent magnetic properties of the amorphous magnetic base metal ribbon 1 forming the wound core 18 can be restored by annealing the entire amorphous magnetic alloy ribbon within the appropriate annealing temperature range with uniform temperature distribution. .

FIG. 7 is a diagram showing the relationship between core temperature rise and excitation time when the wound core shown in FIG. 1 manufactured according to the present invention is annealed by high-frequency excitation. According to this diagram, the difference in the temperature rise values between point E at the corner of the core and point E at the leg is very small, indicating that the temperature of the entire core increases uniformly within the appropriate annealing temperature range. I understand.

In addition, the silicate part of the laminated block located on the innermost side of the wound core has a smaller radius of curvature than the silicate part of other laminated blocks due to its position.
The bending stress and surface pressure applied to No. 1 are large, and during annealing, hysteresis loss due to bending stress and eddy current loss due to surface pressure increase, resulting in a locally high temperature rise. Therefore, the first
If the silicate part of the laminated block 14C located on the inner peripheral side of the wound core is bent into an arc shape to increase the radius of curvature as in the embodiment shown in the figure, the above problem can be solved and the laminated block J (
It is possible to prevent a local temperature rise of C.

FIG. 8 shows a wound core in another embodiment. In this embodiment, magnetic pieces 15 are arranged at each corner of the wound core x8 and between the stacked layers of the laminated blocks 14A to Z4C in the upper silicate iron portion and the lower silicate iron portion. The magnetic piece 15Fi used in this embodiment is provided over the silicate iron part and the corner part of the wound core 18, so that it has a cross-sectional shape in which the image part is integrated.

In addition, in the embodiment described above, the laminated block 14 has 14B.
Although the magnetic piece 15 is arranged both between the stacked blocks 14B and 14C, the magnetic piece I5 may be arranged only on either one of them.

Furthermore, the magnetic piece is not limited to being formed from an amorphous magnetic alloy material, but may also be formed from other magnetic materials.

〔Effect of the invention〕

As explained above, according to the method for manufacturing a stationary induction electric appliance of the present invention, a wound core made of an amorphous magnetic alloy ribbon can be well annealed with a uniform temperature distribution, and a one-turn cut type wound core with excellent magnetic properties can be obtained. It is possible to obtain a stationary induction electric device using .

[Brief explanation of drawings]

1 to 6 show an embodiment of the manufacturing method of the present invention, FIG. 1 is an explanatory diagram showing the process of forming a wound core by bending both ends of a laminated block, and FIGS. Figure 5 is an explanatory diagram showing other steps, Figures 6 (a) and (b) are explanatory diagrams showing magnetic pieces, and Figure 7 is high-frequency excitation annealing f:
FIG. 8 is a diagram showing the relationship between the core temperature rise and the excitation time in the case where the core temperature is increased, and FIG. Figure 9 is an explanatory diagram showing a stationary induction electric appliance manufactured by the conventional manufacturing method, and Figure 10 shows the core annealing temperature and excitation time when high-frequency excitation annealing is applied to the wound core manufactured by the conventional manufacturing method. It is a line diagram showing a relationship. II...Amorphous magnetic alloy M band, 13...Wound body, 1
4AA-I4C... Laminated block, 15... Magnetic piece, 17... Winding wire, 18... Winding core. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 113 Figure 6 (a) (b) Figure 7 Ichigo #L time - htJ soot time

Claims (1)

[Claims] A step of forming a plurality of laminated blocks formed by laminating a large number of amorphous magnetic alloy ribbons each having a length equivalent to one turn of the wound core, and laminating these plurality of laminated blocks, and at least one side of the wound core. arranging a magnetic piece between the laminated blocks in a portion corresponding to a corner where the silicate iron part and the leg intersect, forming a group of laminated blocks in a shape;
(1) incorporating a winding wire into a portion corresponding to the leg of the wound core of the laminated block group forming the shape; a step of forming a butt-wound core by arranging a magnetic piece between the laminated blocks at a portion corresponding to a corner portion where the laminated blocks intersect and bending both ends of the laminated block group inward; A method for manufacturing a stationary induction electric appliance, comprising the step of annealing the wound iron core.