JPS6021511A - Core device - Google Patents

Abstract

PURPOSE:To provide a core device which has a sufficient space factor and exhibits sufficiently excellent low loss characterstics which is a feature of an amorphous magnetic material. CONSTITUTION:Core legs and yokes of a laminated core 1 are composed of a large number of laminated amorphous magnetic alloy thin strips 2 which are cut into rectangles or trapezoids. Both sides 4a, 4a of core binders 4 which are pressed against both ends of the yokes of the laminated core 1 have larger thickness than center parts 4b which are pressed against the center parts of the yokes and forms stepped protruding parts. Therefore, when the laminated core 1 is bound by the core binders 4, 4, the alloy thin strips 2 are not bound with excessive binding force at the center parts so that the deterioration of magnetic characterisitcs such as low loss characteristics of the laminated core 1 caused by an excessive compression stress is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an iron core device comprising a laminated iron core using amorphous magnetic alloy ribbons.

[Technical background of the invention and its problems]

In recent years, in response to the demand for the development of energy-saving electrical equipment, amorphous magnetic alloy materials with excellent low-loss characteristics have been developed, and are being put to practical use as laminated core materials for induction equipment such as transformers and reactors. It is progressing.

However, as is well known, this amorphous magnetic material is produced by ultra-quenching and ultra-high speed, and due to manufacturing limitations, currently only thin strips with a thickness of about 10 μm are produced. Also, unlike silicon steel sheets, the ribbon does not have an insulating coating on its surface. This is because when an insulating film is formed, the ratio occupied by the insulating film increases, and the space factor of the ribbon deteriorates. When such laminated amorphous magnetic alloy ribbons without an insulating film are laminated to form a laminated iron core for induction equipment, the interlayer eddy current product increases, and the superior properties originally possessed by amorphous magnetic materials are increased. Low loss characteristics may be impaired. The inventor constructed a laminated core by laminating amorphous magnetic alloy ribbons, and used this to fabricate a prototype three-phase 10 kVA transformer.This is thought to be due to an increase in the product of current across all layers of the laminated core. Iron loss increased. The laminated iron core used in this transformer uses 50-thick amorphous magnetic alloy ribbons without an insulating coating.
The iron core was constructed by laminating these thin strips and inserting insulating paper between the laminated layers every 20 mm in thickness. In this laminated core, in the iron loss value test after core stacking, the frequency was 50Hz.
The iron loss was 0.30 W/ at a magnetic flux density of 1.3 Tesla. However, in order to increase the core rigidity, the laminated core was tightened using a core clamping body with uniform clamping surface pressure, and a complete iron loss test was conducted in this state. As a result, the iron loss was 0 under the same conditions as the preliminary test. It had increased to 53 W/Kf. When they disassembled the laminated core to investigate the cause of this phenomenon, they discovered traces that appeared to be due to interlayer short circuits at the ends of the amorphous magnetic alloy ribbons. On the other hand, in a retest of the core from which the interlayer short-circuited portion of this ribbon was removed, an iron loss value of 0.30 W/'Kg, which was the same as the initial value, was obtained.

As is clear from these results, in a laminated core made of laminated amorphous magnetic alloy ribbons without an insulating coating, if the clamping surface pressure is not adequately controlled when the core is clamped by the core clamping body, it is possible to cause eddy current between the layers. The disadvantage is that the excellent low-loss properties of amorphous magnetic alloy materials are compromised by the increase in product.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and is a laminated core made of amorphous magnetic alloy ribbons, which has a good core space factor and the excellent low loss characteristics characteristic of amorphous magnetic materials. The purpose is to provide an iron core device that can be fully utilized.

[Summary of the invention]

The iron core device of the present invention provides a method for tightening a laminated iron core formed by laminating amorphous magnetic alloy ribbons by a fastener via core fasteners arranged on both sides of the laminated iron core. The tightening surface pressure at the corners of the core is made greater than the tightening surface pressure at other core portions excluding the corners. In other words, the reduction in magnetic properties due to excessive compressive stress in the laminated core due to the tightening of the core clamping body is reduced.

[Embodiments of the invention]

Embodiment F of the present invention will be described below with reference to the drawings.

Fig. 1 is a perspective view showing a laminated core for a single-phase transformer which is an embodiment of the present invention, Fig. 2 is a sectional view taken along line ■-■ in Fig. 1, and Fig. 3 shows a core clamping body. FIG.

In the figure, reference numeral 1 denotes a laminated iron core, and this laminated iron core 1 is constructed by laminating a large number of amorphous magnetic alloy ribbons 2 cut into rectangular or trapezoidal shapes to form core legs and yoke. The ends of each amorphous magnetic alloy ribbon 2 are abutted at the corner of the core where the core leg and yoke of each layer intersect, and the abutted portions are arranged differently for each layer to create a stacked or picture frame shape. Constitutes a laminated core. Note that the amorphous magnetic alloy ribbon 2 is not coated with an insulating coating.

As shown in Figure 2, each layer is made by laminating amorphous magnetic alloy ribbons l to a predetermined lamination thickness of, for example, 20mm, and is made of an amorphous magnetic alloy ribbon or insulating paper coated with an insulating film between each layer. Interlayer insulators 3 are inserted respectively. In the figure, reference numerals 4 and 4 designate core clamping bodies made of metal plates arranged along the longitudinal direction of the laminated core 1, for example, on both sides of the upper and lower yokes to clamp the core. Core clamping body 4゜4 is laminated core 1
It has a cross-sectional shape that is longer than that of the yoke, and one side of the yoke serves as a core tightening surface that comes into contact with the side of the laminated iron core. As shown in FIG. 3, on the core clamping surface of the core clamping body 4, both ends 4a, 4 abut against both ends of the yoke of the laminated core 1 (core corners where the yoke and core legs intersect).
The protrusion a has a larger wall thickness and is one step higher than the central portion 4b that abuts the central portion of the yoke. The core clamping bodies 4, 4 are arranged along the length direction on both sides of the yoke of the laminated core 1, and both ends 4h, 4m and the central part 4b of the core clamping surface of the core clamping body 4.4 are arranged along the length direction. It comes into contact with both ends (core corners) and the center of both sides of the yoke. Core clamping bodies 4, 40 both ends 4a' protrude from both ends of the yoke.

By passing ports 5 and 5 between 4a and tightening,
The core clamping bodies 41, 4 are fixed at both ends 4a+4a. This gel)5. By tightening ``5'', the core clamping bodies 4, 4 suppress the yoke of the laminated core 1 from both sides of the yoke ``5'', and tighten the laminated core 1, that is, the laminated amorphous magnetic alloy ribbon 2. The attachment is fixed.

In the core device configured in this way, the core clamping body 4
, 4, which form the protrusions on the core clamping surfaces of the core clamping surfaces 4m and 4m, clamp both ends (core corners) of the yoke of the laminated core 1. smaller than the gap for tightening.

For this reason,? When the core clamping bodies 4, 4 are tightened with a constant clamping force by the bolts 5, 5, both ends 4a+4 of the core clamping bodies 4, 4
m is the clamping surface pressure for clamping the amorphous magnetic alloy ribbon 2 at both ends (core corner parts) of the yoke of the laminated core 1, when the center part 4b of the core clamping bodies 4, 4 is This is greater than the tightening surface pressure for tightening the crystalline magnetic alloy ribbon 2. That is, the clamping surface pressure at the corners of the laminated core 1 is large, and the clamping surface pressure at the other core portions is small.

However, amorphous magnetic alloy ribbons are generally sensitive to compressive stress, and when excessive clamping force is applied to the laminated core 1, magnetic properties such as core loss and excitation VA deteriorate. In the core device of the present invention, the clamping surface pressure of the laminated core 1 by the core clamping body 4 is managed by maximizing the clamping surface pressure at the core corners, that is, the ribbon joints. The tightening surface pressure of the iron core can be set to a smaller value without increasing it more than necessary. Therefore, when the core clamping body 44 tightens the laminated iron core 1, excessive tightening force is not applied, and deterioration of magnetic properties such as low loss characteristics of the laminated iron core 1 due to excessive compressive stress can be suppressed.

The reason for increasing the tightening surface pressure at the corners of the laminated core 1 is that, as described above, the ends of the amorphous magnetic alloy ribbons 2 are butted together at the core corners, so This is to improve the flow of magnetic flux in this part, and if the clamping surface pressure in this part is small, the magnetic resistance of the entire core will increase and the magnetic properties will deteriorate.

FIG. 4 shows the relationship between the clamping surface pressure and iron loss of the laminated core in the case of the present invention and in the conventional case. In the case of the present invention, the relationship between the clamping surface pressure and iron loss at the corners of a laminated core clamped by a core clamping body having a protrusion on the core clamping surface is expressed by line A (actual 11
It is shown as i1j. In the conventional case, line B (broken line) shows the relationship between the clamping surface pressure and core loss of a laminated core clamped by a core clamping body with a flat core clamping surface. According to FIG. 4, in the conventional case, the iron loss tends to increase simply as the clamping surface pressure on the laminated core increases, but in the case of the present invention, the clamping surface pressure on the laminated core is 0.7 kg/ No increase in iron loss is observed up to about crn2. Also, the tightening surface pressure is o, qh/
Even if it exceeds cm2, the iron loss value up to 1.0Kg/cm2 is practically acceptable.

For this reason, it is preferable that the clamping surface pressure of the corner portion of the laminated core, which the protrusion of the core clamping body comes into contact with, be 0.5 to 1.0 K17 cm2. If the clamping surface pressure at the corners of the laminated core is managed in this way, the clamping surface pressure at other parts will be small, so as shown in Figure 4, the iron loss due to core tightening will increase. can be significantly reduced compared to the conventional case.

Furthermore, although the excitation VA of the laminated core is more sensitive to the influence of tightening stress than iron loss, we were able to significantly reduce the excitation VA by 9-.

Note that if the height h of the protrusion 4a of the core clamping body 4 is too large, the yoke surface may be bent and the characteristics may be deteriorated, so it is preferable to set it to 2III or less. In addition, the size W of the protrusion 4& is larger than the width of the ribbon and is 5 times larger than the width of the ribbon.
It is preferable to make the size smaller than the size of the throat.

On the other hand, as shown in FIG. 5, an iron core clamping body 14 may be used in which a steel plate having a constant thickness is bent and protrusions 14a are formed at both ends. Also, as shown in Figure 6, is it pressed onto a steel plate 24h such as L-beam steel? - You may use the iron core clamping body 24 with the press board 24c part as a protrusion by pasting the boards 24b and 24a.

〔Effect of the invention〕

As explained above, the core device of the present invention increases the tightening surface pressure at the corners (thin ribbon joints) of the laminated core when tightening the laminated core with the core clamping body, and increases the clamping surface pressure of the other core parts. Since the tightening surface pressure is reduced, the tightening surface pressure when tightening the core can be managed based on the tightening surface pressure at the -10- angle section of the core, and excessive tightening of the core can be prevented. Therefore, even if the laminated core is constructed using amorphous magnetic alloy ribbons without insulation coating treatment, the increase in interlayer eddy current product due to core tightening can be reduced, and the amorphous magnetic alloy material has It can fully demonstrate its excellent low loss characteristics.

Furthermore, since the laminated core is mostly made of amorphous magnetic alloy ribbons without an insulating coating, it has a good core space factor and can be miniaturized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the core device of the present invention, FIG. 2 is a sectional view of the laminated core taken along the line ■-■ in FIG. 1, and FIG. 3 is a perspective view showing the core clamping body. FIG. 4 is a diagram showing the relationship between the clamping surface pressure and iron loss of the laminated core according to the present invention and the conventional method, and FIGS. 5 and 6 are perspective views showing other embodiments of the core clamping body. . 1... Laminated iron core, 2... Amorphous magnetic alloy ribbon, 3...
...Interlayer insulator, 4,14.1!4...Iron core clamping body,
4 a * 14 a, 24 c...protrusion, 5...
・Delt. 11- Figure 1 number ￥l

Claims (2)

[Claims] (1) Core clamping bodies are placed on both sides of a laminated core made of laminated amorphous magnetic alloy ribbons, and through these core clamping bodies,
In a laminated core that is tightened by a fastener, the clamping surface pressure of a corner of the laminated core by the core clamping body is made larger than the clamping surface pressure of other core parts other than this corner. An iron core device characterized by: (2) The core clamping surface pressure of the core corner by the core clamping body is 0.
5 to 1.0 Ky/an2. The iron core device according to claim 1.