JPS5928308A - Wound-core transformer - Google Patents

Abstract

PURPOSE:To miniaturize and lighten an apparatus while preventing the degradation of magnetic characteristics by using a wound core formed by winding a thin steel band as a core and winding a primary coil and a secondary coil on the core through a spool and a duct piece. CONSTITUTION:A wound core 1 is formed by winding a thin steel band. A core protective layer 5 is formed to the outer circumferential section of the wound core 1. A plurality of split spools 2 are arranged on the layer 5. Corrugated ducts 6 are pasted and fixed to the spools 2, and a primary coil 3 is wound on the ducts. Corrugated ducts 6 are further set up on the primary coil 3, and a secondary coil 4 is wound on the ducts. According to the constitution, the apparatus can be miniaturized and lightened because the wound core using the thin steel band is employed as the core. Magnetic property does not degrade because of structure in which pressing force applied to the wound core is protected and absorbed when winding a coil.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a transformer having a wound core formed by winding a thin copper strip made of an amorphous magnetic alloy or other material for use in electrical contacting equipment.

[Technical background of the invention and its problems]

Amorphous magnetic alloys used in electrical induction equipment have excellent soft magnetic properties and low iron loss, making them suitable as core materials for transformers and the like.

However, if this amorphous magnetic alloy is not annealed after manufacturing the wound core, it is highly sensitive to strain, resulting in extremely poor excitation characteristics and increased iron loss, which may reduce its effectiveness as a magnetic core by half. be. For this reason, generally after forming the wound core, it is annealed by a magnetic field annealing method or the like to improve its magnetic properties before use. As is well known, this amorphous magnetic alloy is obtained as a continuous thin steel strip with a thickness of usually about 10 to 100 μm by an ultra-quenching method, and when annealed, it is extremely hard to bend, cracked, or cracked. Therefore, care must be taken when handling the iron core during transformer manufacturing.

Conventionally, wound cores have been known to be made by forming an electric iron plate with a thickness of about -7 from 0.2 to 0.35 m into a rectangular or shell-shaped tripod, but this shape can be made using a thin material such as an amorphous magnetic alloy. If you try to apply it to a wound core made of steel strip, because the curvature of a part of the core corner is small, the thin steel strip may crack, crack, or peel. There is a risk that it will float in the insulating oil that has fallen onto the top of the coil and cause dielectric breakdown.

Further, in the core manufacturing process using thin copper strips, it takes a long time to manufacture the wound core, so it is desirable to increase the winding speed. However, with a rectangular core, if the winding speed is increased, the thin steel strip may break, or the stacking thickness changes (due to changes in surface pressure between a part of the core corner and the legs), and the core space factor changes. Since the ratio is small at around 70%, the iron core must be large to obtain the specified core cross-sectional area, and the amount of coils wound around the core also increases, making the equipment larger. arise.

In order to improve this core space factor, there is a method of toroidally winding a coil around a circularly wound core, but this requires winding the coil in many layers and it is difficult to form oil channels.
Currently, it is rarely used in transformers due to its poor cooling effect and temperature rise problems.

[Purpose of the invention]

The present invention provides high reliability with excellent mechanical strength, magnetic properties, and cooling properties by adopting a transformer structure that fully takes into account the characteristics of N copper strips such as amorphous magnetic alloys.

[Summary of the Invention] The purpose of the present invention is to provide a high-performance wound core transformer. Therefore, the present invention provides a method for circularly winding a thin steel strip such as an amorphous magnetic alloy or a 6.5% silicon steel strip. The wound core is wound to form a wound core, a core protective layer is provided by toroidally wrapping insulating tape, etc. on this wound core, a plurality of split spools are arranged at equal intervals on top of this, and insulating paper, etc. is pressed onto this spool. The primary and secondary coils are wound through a duct piece such as a molded corrugated duct, and a slot is provided in the spool collar that communicates with the oil passage formed by the duct piece to transform the wound core. It is characterized by being configured as a container.

[Embodiments of the invention]

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

Fig. 1 shows a perspective view of the contents of a wound core transformer according to an embodiment of the present invention. It is made of a wound iron core formed by winding it around a winding form. Split spools 2 formed from this wound core IK insulated condenser/round are arranged in traps at equal intervals, and a primary coil 3 and a secondary coil 4 are wound around the spool 2 to form a wound core transformer. . In this case, although not shown, insulating tape or the like is wrapped around the entire circumference of the wound core IK or around the spool 20 to prevent deformation of the wound core 1 and to protect the core from the pressurizing force generated during coil winding work. It is configured. The wound core 1 may be formed by stacking wound cores formed by winding small copper strips to form a wound core having a predetermined cross-sectional area.

Figure 2 shows a cross-sectional view taken along line XX in Figure 1, and shows that the wound core 1, which is formed by winding an amorphous magnetic alloy or the like, has a core protective layer around its outer periphery with an insulating tape or the like wound around it. 5 is formed. This core protective layer 5 may be formed by coating or impregnating a resin or the like and curing it. A plurality of divided spools 2 formed of an insulating compound or the like are arranged on the core protective layer 5 at equal intervals so as to surround the cross section of the wound core 1.

A corrugated duct 6 made of insulating paper or the like is affixed and fixed to the spool, and the primary coil 3 is wound on top of the corrugated duct 6. At this time, an oil passage 7 is often formed by a corrugated duct 6 between the wound core 1 and the primary coil 3. - A corrugated duct 6 is further attached above the secondary coil 3, and the secondary coil 4 is wound on this.

Figure 3 is a detailed perspective view of the spool 2 divided into two parts.
The flanges 2B on both sides of the spool have two slot holes 2b at the positions where they contact the ends of the corrugated duct 6.

2c is provided so as to penetrate through the oil passage formed by the corrugated duct 6 so that a cooling medium such as insulating oil can easily pass therethrough. In addition, when forming an oil channel, a duct piece such as an insulator may be used instead of the corrugated duct 6.

According to the above transformer configuration, the wound core 1 is formed by winding a thin steel strip such as an amorphous magnetic alloy into a circular former, and as a result, the core surface is wavy and the entire core is uneven like a rectangular wound core. The shift in stack thickness is small, and the core space factor is about 10% larger.
It was observed that the amount of As a result, when obtaining a predetermined core cross-sectional area, the core cross-sectional dimension and core outer diameter υ can be reduced, and the equipment can be made smaller and lighter. Further, the winding speed of the circularly wound core can be increased compared to that of the rectangularly wound core, and the core manufacturing time is also shortened.

As described above, the wound core 1 with the thin copper strip wound thereon does not have good magnetic properties such as excitation vA and iron loss as it is, but these magnetic properties can be improved by annealing in a magnetic field. At this time, the annealed wound core 1 should not be bent very much; external pressure or tightening may cause cracks or peeling, but the core surface should be toroidally wrapped with insulating tape, Since the iron core protection material 5 is provided which is impregnated or coated with resin and hardened, it is protected from external forces and the above-mentioned problems are eliminated.

Still, since the circularly wound core 1 is adopted in this embodiment,
As a result of increasing the inner diameter of the core, the rectangularly wound core is not affected by bending curvature and cracks are prevented. Further, even if a crack occurs and the core is peeled off, the wound core is surrounded by the core protective layer 5, so the fragments will not float in the insulating oil and cause dielectric breakdown.

Further, a pressurizing force is applied to the wound core 1 during this coil winding, and the wound core 1 has a core protective layer 5. Since the spool 2 and the corrugated duct 1 provide a stiffening effect, there is almost no deterioration in magnetic properties even if an amorphous magnetic alloy with high strain sensitivity is used.

Furthermore, the primary coil 3 wound around the wound core 1 has many layers, which causes a temperature rise during transformer operation. By being subdivided, the secondary coil 3 can have a large surface area in contact with the insulating oil, and an oil pipe 7 is formed between the coiled core 1 and the primary coil 3 in the corrugated duct 6. 7 and the slot 2b formed in the collar 2a of the spool 2 shown in FIG.

Similarly, a corrugated duct 6 is installed between the primary coil 3 and the secondary coil 40, an oil passage 7 is formed, and the spool 2
Because it penetrates through the slot 2C formed in the flange 2a,
The insulating oil easily flows through the secondary coil 4 along with the secondary coil 3.
temperature rise is also suppressed. Furthermore, the secondary coil 3 and the secondary coil 4 are wound on the same spool 2, and as a result of this spool 2 being arranged at equal intervals on the circumference of the wound core 1, the leakage magnetic flux of the wound core 1 is reduced. rarely occurs. Therefore, stray loss due to leakage magnetic flux is greatly reduced, and effects such as a reduction in temperature rise and a reduction in total loss of the device can be obtained.

In the above embodiment, an example was explained in which the secondary coil 3 was arranged on the side of the wound core 1, but even if the secondary coil 4 was placed on the side of the inner wound iron core 1 of the primary coil 3, the effect is still the same. Almost no change.

Further, in the above embodiment, the case where the core cross section of the wound core 1 is rectangular has been explained as an example, but as shown in FIG. It is also possible to configure a transformer using a wound core 1 having a nearly circular cross section. In such a case, the spool 2 also has a circular ring shape, and the coil can be automatically wound by rotating the spool 2, thereby further shortening the coil winding operation time.

〔Effect of the invention〕

As described above, according to the present invention, since the iron core is a circularly wound iron core using a thin copper strip, the winding speed of the thin steel strip can be increased.
The manufacturing time of the wound core can be shortened, and the core space factor can be increased, so the equipment can be made smaller and lighter. In addition, because it has a structure that protects and absorbs the pressure applied to the wound core during fill winding in a double or triple manner using the core protective layer, spool, duct, etc., there is no deterioration of magnetic properties and υ embrittlement due to annealing. Even with polished copper strips, no cracks, splits, or peeling occur. Even if this peeling occurs, since the core protective layer is formed over the entire surface of the core, there is no risk of it falling off, floating in the insulating oil, and inducing dielectric breakdown.

Additionally, ducts are inserted between the iron core and the primary coil, and between the primary and secondary coils to form roadways that allow for easy circulation of insulating oil, improving the cooling effect and reducing the temperature rise of the transformer. can do.

In addition, since the primary coil and the secondary coil are wound on the same spool, and this spool is arranged at equal intervals on the circumference of the winding core, almost no leakage magnetic flux is generated, and the leakage magnetic flux is Stray loss is greatly reduced, temperature rise can be reduced, and total loss of the transformer can be reduced, resulting in high reliability.
High performance rolled iron

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a wound core transformer in which thin copper strips such as amorphous magnetic alloy are wound, showing one embodiment of the present invention, and FIG.
3 is a perspective view of the spool used in the wound core transformer shown in FIG. 1, and FIG. 4 is a sectional view of a wound core transformer showing another embodiment of the present invention. be. 1... Winding core, 2... Spool, 2a... Flange,
2b. 2c...Slot hole, 3...-Secondary coil, 4...Secondary coil, 5...Iron core protective layer, 6...Corrugated duct, 7
...road. 11th! l Figure 2 Figure 3

Claims (5)

[Claims] (1) A core holding layer is provided on the wound core made by winding a thin steel strip, and multiple spools are placed on top of the core holding layer, and a primary coil and a secondary coil are connected to the spools via duct pieces. A wound core transformer characterized by a wound core transformer. (2) In claim 1, a duct piece is interposed between the wound core and the coil and between the primary coil and the secondary coil to form a cavity, and the flange of one spool is provided with a duct piece in the cavity. A wound core transformer characterized by having a communicating slot. (3) In claim 1 or 2,
A wound core transformer characterized by using a corrugated duct as a duct piece. (4) In claim 1 or 2,
A wound core transformer characterized by a wound core made by winding a thin copper strip of an amorphous magnetic alloy into a circle. (5) In claim 1 or 2,
A wound core transformer characterized by having a wound core made by winding a thin copper strip of 6.5% silicon steel in a circle.