JP2000150269A - Three-phase coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-phase coil which can suppress magnetic saturation caused by a leakage magnetic flux or an inductance variation between each phase without lowing the productivity. SOLUTION: Windings 8, 9 and 10 of a three-phase coil is equipped beforehand with each leg part 3, 4 and 5 of a magnetic core 1 having an EE type. As a result, the three-phase coil can effectively be manufactured, and the three- phase coil even having the thick windings 8, 9 and 10 which can cope with a large electric current can be manufactured without hinderance. Additionally the three leg parts 3, 4 and 5 having cylinder types are provided in standing at each vertex of a regular triangle, therefore the lengths of mutual magnetic circuits between the leg parts 3, 4 and 5 become equal. Therefore magnetic saturation due to leakage magnetic flux is suppressed, and inductance variation of each phase corresponding to the windings 8, 9 and 10 can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase coil such as a three-phase common mode choke coil incorporated in a three-phase AC noise filter.

[0002]

2. Description of the Related Art Generally, a three-phase coil applied to a three-phase common mode choke coil of this type is known as shown in FIG. In the figure, reference numeral 21 denotes a ring-shaped magnetic core (toroidal core), which has a structure in which windings 22, 23, and 24 corresponding to three phases are wound around the magnetic core 21 at equal intervals. I have. However, in such a structure, since the magnetic core 21 is integrally formed in a continuous ring shape in advance, when winding the windings 22, 23, and 24, the hole of the magnetic core 21 is formed. The windings 22, 23,
It is necessary to pass 24. Such operations are difficult to mechanize, and the winding operation has to be performed manually, which is extremely laborious in production and inefficient. Furthermore, in the above-mentioned ring-shaped magnetic core 21, all the windings 22, 23, 24 are wound through the holes 25.
24 cannot be passed through the hole 25 and cannot be wound a desired number of times, which hinders the production of a three-phase coil that handles a large current.

In order to solve such a manufacturing problem, it is conceivable to divide the magnetic core into an EI type or an EE type without using a ring shape. For example, as shown in FIG.
Using an I-shaped magnetic core 31, windings 32 of each phase which have been wound in advance,
After attaching the 33, 34 to the three legs 37, 38, 39 of the E-shaped core 36, the legs 37, 38, 39 are also bonded to the upper ends of the I-shaped core 35 by abutting the three-phase coils. To manufacture. Then, the most troublesome windings 32, 33, 34 can be connected to the legs 37,
The work of winding on 38 and 39 can be mechanized, and three-phase coils can be manufactured efficiently, and even with relatively thick windings 32, 33 and 34,
It can be wrapped around the legs 37, 38, 39 without hindrance,
Three-phase coils that handle large currents can be easily manufactured.

However, in the three-phase coil shown in FIG. 4, due to its structure, the magnetic path returns from the leg 37 of the magnetic core 31 to the leg 37 via the leg 38.
40 and a magnetic path 40 returning from the leg 38 to the leg 38 via the leg 39,
A difference occurs in the length of the magnetic path 41 from the leg 37 to the leg 37 via the leg 39. In this case, the magnetic path 41 is the other magnetic path 40
The length of the winding 3 is equivalent to that between the legs 37 and 39.
The magnetic coupling between 2 and 34 is reduced, and magnetic saturation due to leakage magnetic flux is likely to occur. Further, the inductance of each phase corresponding to the windings 32, 33, 34 varies.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a three-phase coil capable of suppressing magnetic saturation due to magnetic flux leakage and variations in inductance between phases without impairing manufacturability. I do.

[0006]

The three-phase coil according to the first aspect of the present invention is obtained by mounting windings of each phase on three legs forming an EE type or EI type magnetic core. In the three-phase coil, the legs are erected at substantially the same distance from each other.

[0007] According to the above configuration, the winding can be mounted on each leg in advance by using the EE type or EI type magnetic core, so that the conventional three-phase coil having a ring-shaped magnetic core can be manufactured. Can mechanize the most troublesome winding work, and can efficiently manufacture a three-phase coil. In addition, even if the winding is thick, it can be wound without any trouble, so that a three-phase coil handling a large current can be manufactured without any trouble.

Further, since the legs are erected at substantially the same distance from each other, the magnetic path returning from one leg to the other leg via the other leg can be set regardless of which leg is used as a reference. All have almost the same length. Therefore, since the lengths of the magnetic paths between the legs are substantially equal, the magnetic coupling between the windings can be made dense, and the magnetic saturation due to the leakage magnetic flux can be suppressed. Further, variation in inductance of each phase corresponding to the winding can be suppressed.

A three-phase coil according to a second aspect of the present invention, in addition to the configuration according to the first aspect, has the leg portions erected on the vertices of an equilateral triangle.

According to the above construction, the winding can be mounted on each leg in advance by using the EE type or EI type magnetic core, so that the conventional three-phase coil having a ring-shaped magnetic core can be manufactured. Can mechanize the most troublesome winding work, and can efficiently manufacture a three-phase coil. In addition, even if the winding is thick, it can be wound without any trouble, so that a three-phase coil handling a large current can be manufactured without any trouble.

Further, since the legs are erected on the vertices of an equilateral triangle, the magnetic path returning from one leg to the other leg via the other leg can be determined based on which leg is used as a reference. But they all have the same length. Therefore, since the length of the magnetic path between the legs is equal, the magnetic coupling between the windings can be made dense, and the magnetic saturation due to the leakage magnetic flux can be suppressed. Further, variation in inductance of each phase corresponding to the winding can be suppressed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a three-phase coil according to the present invention will be described below with reference to FIGS. In addition,
The three-phase coil in the present embodiment is a three-phase common mode choke coil incorporated in a noise filter.

In FIG. 1, reference numeral 1 denotes a magnetic core, which is made of a magnetic material such as iron or ferrite. An EI type magnetic core 1 is composed of a lower member 6 in which a bottom 2 and three legs 3, 4, 5 are integrally formed.
And the upper member 7. The plate-shaped bottom portion 2 has a substantially equilateral triangular bottom surface, and three columnar legs 3, 4, and 5 are erected near the apex of the substantially equilateral triangle on the bottom portion 2, respectively. The distance between 4 and 5 is equal. That is, the legs 3, 4, and 5 are respectively set up on the vertices of the equilateral triangle. The leg portions 3, 4, 5 are provided with windings 8, 9, 10 of each phase in a predetermined number of turns, respectively.
A plate-like upper member 7 having a substantially equilateral triangular shape similar to the bottom 2 is adhered to the upper ends of the legs 3, 4, and 5. In addition,
In this embodiment, the magnetic core 1 is constituted by the E-shaped lower member 6 and the I-shaped upper member 7 when viewed from the front. It may be. Further, the shape of the bottom plate 2 in this embodiment is a substantially regular triangle, but is not limited thereto, and may be another triangle, trapezoid, or the like. However, even when the shape of the bottom plate 2 is other than a substantially equilateral triangle, the distance between the legs 3, 4, and 5 is made substantially equal, and preferably, the legs 3, 4, and 5 are each set to the vertex of the equilateral triangle. It must be erected on top.

In the above embodiment, at the time of assembly, the windings 8, 9, 10 are mounted in a predetermined number of turns corresponding to the legs 3, 4, 5 of the lower member 6. In this winding operation, since the upper member 7 is not attached, there is no need to make each of the windings 8, 9, 10 pass through a hole as in a conventional toroidal core, and the winding can be performed mechanically. it can. In this way, the upper member 7 is abutted and bonded to the upper ends of the legs 3, 4, 5 to form the magnetic core 1 having three equidistant closed magnetic paths, and the assembling work as a three-phase coil can be performed. Complete all.

As described above, in the present embodiment, the three legs 3, 4, 5 forming one EE-type or EI-type magnetic core are provided.
In a three-phase coil to which the windings 8, 9, and 10 of each phase are mounted, the legs 3, 4, and 5 are erected at substantially the same distance from each other.

According to the above configuration, the windings 8, 9, and 10 are previously attached to the legs 3, 3 by the EE or EI type magnetic core 1.
Since it can be mounted on the four or five coils, the winding work, which was the most troublesome in the production of the conventional three-phase coil having the ring-shaped magnetic core, can be mechanized, and the three-phase coil can be efficiently produced. In addition, even if the windings 8, 9, and 10 are thick, the winding can be performed without any trouble. Therefore, even a three-phase coil having large windings 8, 9, and 10 that can handle a large current can be manufactured without any trouble. .

Further, since the legs 3, 4, 5 are erected substantially equidistant from each other, the magnetic path returning from one leg 3 to the other leg 3 via the other leg 4 is as follows. Regardless of which leg 3, 4 or 5 is used as a reference, they all have substantially the same length. Therefore, since the lengths of the magnetic paths of the legs 3, 4, and 5 are substantially equal, the magnetic coupling of the windings 8, 9, and 10 can be made dense, and the magnetic saturation due to the leakage magnetic flux is suppressed. be able to. In addition, it is possible to suppress variations in inductance of each phase corresponding to the windings 8, 9, and 10.

In addition, in this embodiment, in addition to the above, the legs 3, 4, 5 are respectively set up on the vertices of an equilateral triangle.

According to the above construction, the windings 8, 9, 10 are previously connected to the legs 3, 3 by the EE type or EI type magnetic core 1.
Since it can be mounted on the four or five coils, the winding work, which was the most troublesome in the production of the conventional three-phase coil having the ring-shaped magnetic core, can be mechanized, and the three-phase coil can be efficiently produced. In addition, even if the windings 8, 9, and 10 are thick, the winding can be performed without any trouble. Therefore, even a three-phase coil having large windings 8, 9, and 10 that can handle a large current can be manufactured without any trouble. .

Since the legs 3, 4 and 5 are respectively set up on the vertices of an equilateral triangle, the magnetic path returning from one leg 3 to the other leg 3 via the other leg 4 is as follows. , Which leg 3,
All lengths are the same even when reference is made to 4,5. Therefore, since the lengths of the magnetic paths of the legs 3, 4, and 5 are equal, the magnetic coupling between the windings 8, 9, and 10 can be made dense, and the magnetic saturation due to the leakage magnetic flux can be suppressed. Can be. In addition, it is possible to suppress variations in inductance of each phase corresponding to the windings 8, 9, and 10.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the above embodiment, the legs 3,
Although the columns 4 and 5 are columnar, they may be polygonal columns such as a triangular column or a quadrangular column. However, in consideration of the ease of winding of the windings 8, 9, and 10, it is preferable to make the winding into a cylindrical shape. Also,
In the above embodiment, the magnetic core 1 has a bottom 2 and three legs 3,
Although the lower member 6 and the upper member 7 are integrally formed with the lower member 4 and the upper member 7, the position of division of the lower member 6 and the upper member 7 is not limited to the above. The lower member 6 and the upper member 7 may be formed in the same shape by dividing the upper part of the legs 3, 4, and 5 integrally with the upper member 7. Further, the central portions of the bottom 2 and the upper member 7 may be hollowed to reduce the weight.

[0022]

The three-phase coil according to the first aspect of the present invention is a three-phase coil having three phase windings mounted on three legs forming an EE type or EI type magnetic core. The legs are erected at substantially the same distance from each other, so that magnetic saturation due to magnetic flux leakage and variations in inductance between phases can be suppressed without impairing manufacturability.

In the three-phase coil according to the second aspect of the present invention, in addition to the configuration of the first aspect, each of the legs is erected on a vertex of an equilateral triangle, which impairs manufacturability. In addition, it is possible to suppress the magnetic saturation due to the leakage magnetic flux and the variation in inductance between the phases.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view when assembling the same.

FIG. 3 is a top view showing a conventional example.

FIG. 4 is a front view showing another conventional example.

[Explanation of symbols]

 1 Magnetic core 3,4,5 Leg of magnetic core 8,9,10 winding

Claims (2)

[Claims] 1. An EE-type or EI-type magnetic core 3
A three-phase coil in which windings of each phase are mounted on one leg, wherein the legs are erected substantially equidistant from each other. 2. The three-phase coil according to claim 1, wherein the legs are respectively set up on vertices of an equilateral triangle.