JPH0257686B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a three-phase planar butted core.

(Prior art) A conventional three-phase planar butted core consists of three sets of annular stratified core legs that are butted between a triangular yoke consisting of a triangularly deformed and heat-treated annular stratified core or a triangular wound core. Alternatively, a steel strip wound into a roll is straightened into a straight line, that is, flat, and annealed to remove distortion, and the steel strip is divided into two in the axial direction, and the iron core legs, each having a horseshoe-shaped cross section, are abutted against each other. According to such a configuration, the average magnetic path length of each phase becomes uniform and shortened, but the configuration of the core legs is complicated,
The windings on the core legs have the disadvantage that they are not necessarily balanced. In other words, as shown in FIG. 7, in the conventional triangular yoke, at the abutting part with the leg core, the area from a to b faces the leg near the center in the stacking direction, but the area from c to d faces the leg at both ends. Assuming that the magnetic flux is evenly distributed in the legs because the opposing parts become shorter, the magnetic flux density at points A and B in the yoke part is small, and the magnetic flux density at point C becomes high, causing leakage. This results in an increase in magnetic flux. Another problem is that only non-oriented silicon steel strips can be used for the legs.

(Problems to be Solved by the Invention) It is an object of the present invention to provide a three-phase plane-matching iron core that eliminates these drawbacks and is further miniaturized.

(Means for solving the problem) In order to solve this problem, the inventor of the present application, as a result of intensive research, adopted iron core legs made of grain-oriented silicon steel with different widths and a hexagonal three-phase yoke. By doing so, by aligning the lamination direction of the leg part and the lamination direction of the yoke part at the abutment part, it is possible to equalize the magnetic flux distribution in the leg and yoke and suppress the increase in loss due to leakage magnetic flux. I came up with this idea,
Based on this knowledge, we came up with the invention of the three-phase plane butting type iron core of the present invention.

That is, in the three-phase planar butt type core of the present invention, three core legs formed by laminating rectangular steel pieces have an angle of 120° toward each other's two centers, and equidistant from the center,
It consists of an iron core leg structure arranged and configured, a three-phase winding wound around the outer periphery of the iron core leg, and two three-phase yokes made of an annular stratified iron core heat-treated to deform into a hexagonal shape, Each of the phase yokes is a three-phase planar abutment type core connected to both ends of the core leg group so as to abut each other.

(Example) One specific example of the three-phase plane butted core of the present invention will be described in more detail.

As shown in FIG. 3, the core leg is made of laminated rectangular grain-oriented silicon steel pieces, and on its outer periphery are three-phase windings 3, 3' as shown in FIGS. 3 and 4. ，
3" is wrapped.

In other words, the three core legs around which three-phase windings are wound are arranged so that the angles they form toward each two centers are equal to 120°, and they are equidistant from the center. Then, they are arranged in such a manner that they are arranged at each vertex of the equilateral triangle toward the center of the triangle to form the core leg structure. In addition,
The steel slabs to be laminated on the core legs are curled because the raw steel strips arrive wound in rolls, so before lamination, they are straightened into straight, or flat, shapes and heat treated for strain relief annealing. I do.

On the other hand, an annular stratified iron core in which grain-oriented silicon steel strips having a required width were concentrically configured in a spiral manner was heat-treated to transform it into an annular hexagonal shape by applying pressure from six outer directions toward the center. Three-phase yokes 2 and 2' as shown in FIG. 6 are formed. The three-phase yokes 2 and 2' thus formed are connected to both ends of the core legs 1, 1' and 1'' so as to abut each other, as shown in FIGS. 1 and 2. FIGS. 8 and 9 are explanatory diagrams of the abutment surfaces between the three-phase yoke and the core legs. The length a of the inner side of the side must be the same as the width of the core leg.Therefore, the shape of the annular hexagon changes depending on the width of the core leg, and this length a must be the same as the width of the core leg. The lengths b of the inner sides between the parts that abut against the legs are not necessarily equal, and the hexagonal shape is not necessarily a regular hexagonal shape.

Next, as shown in FIGS. 1 to 4, predetermined three-phase windings 3, 3', and 3'' are wound around the core legs 1, 1', and 1'', respectively, to form a rectangular shape. These windings constitute three phases, as shown in FIG.

(Effects of the Invention) In the three-phase planar butting type core of the present invention, the core legs 1, 1', and 1'' are formed by concentrically configuring silicon steel strips and steel slabs having several different widths, and Since the three phases are arranged so that the interval between them is 120°,
The magnetic path lengths of each phase are equal, and the winding configuration is balanced.

The three-phase yokes 2 and 2' are heat-treated to transform into a hexagonal shape, and abut against the three-phase core legs 1, 1' and 1'' at six locations, resulting in good magnetic properties. The path length is significantly shortened and the size is reduced.

[Brief explanation of the drawing]

FIG. 1 is a side view of a specific example of a three-phase flat butt core of the present invention. FIG. 2 is a plan view of one specific example of FIG. 1. FIG. 3 is a plan view of the core legs and windings in one specific example of FIG. 1. FIG. 4 is a side view of the core leg and winding of FIG. 3. FIG. 5 is a plan view of the yoke in one specific example of FIG. 1. 6 is a side view of the yoke of FIG. 5. FIG. FIG. 7 is an explanatory diagram of a conventional three-phase plane butting type iron core. FIGS. 8 and 9 are explanatory diagrams of abutment surfaces between a three-phase yoke and a core leg in a specific example of the present invention, respectively.

Claims (1)

[Scope of Claims] 1. Three iron core legs made of stacked rectangular steel pieces are arranged so that the angles formed by the two legs toward each other's centers are equal to each other at 120°, and the legs are equidistant from the center. A core leg structure arranged and configured so that A three-phase planar abutment type core, in which the three-phase yokes are connected to both ends of the core legs so as to abut each other. 2. The three-phase plane-butted core according to item 1, wherein the steel billet is a grain-oriented silicon steel billet.