JPH0534090Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to the structure of an air-core reactor, particularly a magnetically shielded air-core reactor that uses rectangular conductive wire and is suitable for large currents and relatively small reactance capacity.

[Prior Art] Since all of the magnetic flux generated in the coil becomes leakage flux in an air-core reactor, a magnetically shielded reactor surrounded by an iron core is used as necessary.

For example, as shown in FIGS. 3 and 4, a coil 11 is provided in which conducting wires are wound in an overlapping manner in the axial and radial directions, and both end surfaces 11a, 11b and outer surface 11c of the coil are surrounded to prevent leakage of magnetic flux. An iron core 12 is provided. In order to facilitate winding of the coil, the coil 11 is made by arranging a large number of conductors (four conductors are shown for convenience in the figure) in the axial direction of the bobbin, not only when using round conductors but also when using rectangular conductors. Increase the winding width b of the coil and increase the winding thickness a
is made smaller than the winding width b, and is wound a required number of times to form a cylindrical shape with a large axial dimension.

[Problems to be solved by the present invention] For this reason, the workability of coil winding is good, and the coil is formed into a small size with a small ratio of diameter to height, but on the other hand, the surface area is small, and the magnetic shielding Since the coil is surrounded by the iron core 12 for use, the exposed surface of the coil is small, and when used for large currents, it is necessary to increase the current capacity by increasing the size of the coil conducting wire. In addition, since the winding width b of the coil is large and the wide surface contacts the iron core 12, a large amount of magnetic flux crosses the conductor in the radial direction and enters the iron core 12 from the coil side surface 11c, and the distribution characteristics of the magnetic flux density B are as shown in Fig. 5B. As shown, the magnetic flux density in the coil portion was small, so the required reactance was obtained by the magnetic flux φ ₁ passing through the air gap, and the magnetic flux φ ₂ passing through the coil was ignored.

[Means for solving the problem] In view of these points, this proposal uses rectangular conductive wires with a required width according to the magnetic gap, and overlaps them in the thickness direction so that the winding width in the axial direction is thin and the winding width in the radial direction is thin. A flat, large-diameter coil with increased winding thickness is constructed, and a magnetic shielding core with a laminated thickness smaller than the inner diameter of the coil is provided in the radial direction, tightly attached to both sides and the outer circumferential surface of this coil. .

[Function] Therefore, the surface area of the coil is large, the effect of heat shielding by the iron core is reduced, the coil is in direct contact with the ventilated outside air on a wide surface, improving the cooling effect, and the winding thickness of the coil is large. Reactance due to magnetic flux passing through the coil can be effectively used.

[Example] To explain this in an example shown in the drawings, in Figs. 1 and 2, 1 is a coil, insulated rectangular conducting wires 2 are wound in layers in the thickness direction, and the number of turns is adjusted to the number of turns. Accordingly, it is formed into a flat shape with a thin winding width in the axial direction and a large winding thickness in the radial direction. For this reason, the width of the rectangular conducting wire 2 is selected in accordance with the required magnetic gap size. 3 is a magnetic shielding iron core having a stacking thickness smaller than the inner diameter of the coil 1, which is brought into close contact with both side surfaces 1a, 1b and the outer circumferential surface 1c of the coil 1;
The coil is surrounded in the diametrical direction. 4 is a leader line.

In the coil 1 configured in this way, the winding thickness a of the coil is significantly larger than the winding width b, which is more than 30 times, so the radial dimension of the coil is large and it does not come into contact with the magnetic shielding core 3. The exposed surface area is increased, and all the coil conducting wires come into direct contact with the cooling outside air, improving the cooling effect and increasing the current value flowing through the rectangular conducting wire 2.

In addition, since the winding width b of the coil is small, almost no magnetic flux enters the iron core from the outer circumferential surface 1c of the coil, and the distribution characteristics of the magnetic flux density B are improved as shown in _FIG. The reactance increases in proportion to the number of turns, and a large value can be obtained by the sum of the reactance due to the main magnetic flux φ ₁ passing through the air gap in the coil inner hole, and the reactance due to the magnetic flux φ ₂ accounts for 30 to 40% of the total. You can also do it like this.

In addition, in the example, the width of the rectangular conducting wire 2 is the width of the coil 1.
However, the rectangular conducting wire may be wound in two rows in the same winding direction in the axial direction and connected to each other at the inner end of the coil.

[Effects of the present invention] As described above, the present invention is a magnetically shielded air-core reactor in which rectangular conductive wires of a required width are wound in layers in the thickness direction, so that the winding width in the axial direction is thin and the winding thickness in the radial direction is large. The coil has a flat coil and a magnetic shielding core that surrounds the coil in the diametrical direction and is in close contact with both end faces of the coil and has a thickness in the stacking direction that is smaller than the inner diameter of the coil, making the coil flat and large in diameter, reducing the cooling area of the coil. In addition to increasing the current capacity flowing through the conductor, the magnetic flux passing through the coil can be effectively used to obtain a large reactance, and this reactance can be calculated easily and accurately, making settings easier. effective.

Furthermore, when multiple units are placed side by side for multiphase AC use, the installation space can be reduced by arranging them in the axial direction.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an embodiment of the present invention, Fig. 2 is a front view thereof, Fig. 3 is a side sectional view showing a conventional embodiment, Fig. 4 is a front view thereof, and Figs. 5
FIG. B is an explanatory diagram showing the state of magnetic flux distribution. 1 is a coil, 1a and 1b are side surfaces, 1c is an outer peripheral surface, 2 is a rectangular conducting wire, 3 is a magnetic shielding core, 11 is a conventional coil, and 12 is a magnetic shielding core.

Claims (1)

[Claims for Utility Model Registration] 1. A flat coil in which insulated rectangular conducting wires are wound in a layered manner in the thickness direction, and the winding width in the axial direction is small and the winding thickness in the radial direction is large; A magnetically shielded air-core reactor comprising a magnetically shielded iron core having a thickness smaller than the inner diameter of the coil and surrounded in the diametrical direction of the coil in close contact with both side surfaces and the outer peripheral surface of the coil. 2. The magnetically shielded air-core reactor according to claim 1, wherein the coil is a rectangular conducting wire wound in one or two rows in the axial direction.