JP2013106386A - Coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further reduce an AC loss that occurs at a conductor wire due to a leakage magnetic flux.SOLUTION: A coil wire 20 used as a three-phase coil of an AC motor is constructed from a copper wire 22, a first enamel film 24 coated on an external surface of the copper wire 22, and a second enamel film 26 that is an insulation layer coated on an external surface of the first enamel film 24. The first enamel film 24 that is an intermediate layer is formed using enamel loaded with a high magnetic permeable material. With this construction, it becomes possible to divert a leakage magnetic flux, which results from electric conduction to the three-phase coil and is directed toward the copper wire 22, to a side of the first enamel film having high magnetic permeability. As a result, it becomes possible to further reduce an AC loss that occurs at the conductor wire due to the leakage magnetic flux.

Description

  The present invention relates to a coil in which an outer peripheral side of a conductor is covered with an insulating layer.

  Conventionally, as this type of coil, a coil in which an insulating film of polyimide resin is formed on the outer surface of a conductive wire and an amorphous film is deposited on the outer surface of the insulating film has been proposed (for example, see Patent Document 1). Amorphous coating has high magnetic permeability in the high frequency range, so when an AC motor is configured with a coil using this conductive wire, it prevents the influence of the harmonic magnetic flux (leakage magnetic flux) generated inside the AC motor on the inside of the conductive wire. It is said that the shielding effect is exhibited and the loss of the conductor can be reduced.

Japanese Patent Laid-Open No. 5-146105

  Thus, it can be considered as an extremely important issue to reduce the AC loss of the conductor by exerting a shielding effect on the conductor to prevent the influence of the leakage magnetic flux on the inside of the conductor.

  The coil of this invention makes it the main objective to further reduce the loss which generate | occur | produces in a conducting wire by leakage magnetic flux.

  The coil of the present invention employs the following means in order to achieve the main object described above.

The coil of the present invention
Conductors,
Formed of a highly permeable material having a higher permeability than the conductor, a highly permeable layer coated on the outer periphery of the conductor and an insulating material, and an insulating layer coated on the outer periphery of the highly permeable layer;
It is a summary to provide.

  In the coil of the present invention, the outer periphery of the conductor is covered with a highly permeable layer formed of a highly permeable material, and the outer periphery of the highly permeable layer is covered with an insulating layer. Since the intermediate layer between the conductor and the insulating layer is a highly permeable layer and the generated leakage magnetic flux can be diverted to the intermediate layer, the AC loss generated in the coil wire can be further reduced.

  The highly permeable layer may be an enamel layer filled with the highly permeable material in a filler shape or a particle shape.

It is sectional drawing of the direction orthogonal to the wire axis in the coil (coil wire 20) as one Example of this invention. FIG. 3 is a cross-sectional view in a direction perpendicular to the line axis of the coil wire 20 and a cross-sectional view in a direction along the line axis. It is explanatory drawing which shows an example of a structure of a high magnetic permeability material. It is explanatory drawing which shows a mode that a leakage magnetic flux passes with respect to the coil wire 20 of an Example, and the coil wire 20B of a comparative example. It is sectional drawing of the coil wire 120 of a modification. It is sectional drawing of the coil wire 220 of a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a cross-sectional view of a coil (coil wire 20) according to an embodiment of the present invention in a direction orthogonal to the line axis, and FIG. 2 is a cross-sectional view of the coil wire 20 in a direction orthogonal to the line axis and along the line axis. It is sectional drawing of a direction.

  As shown in FIG. 1 and FIG. 2, the coil wire 20 of the embodiment includes a copper wire 22 formed by a round wire, and a first enamel film 24 that is an intermediate layer coated on the outer surface of the copper wire 22. The second enamel film 26 is an insulating layer coated on the outer surface of the second enamel film 24. For example, a rotor to which a permanent magnet is attached and a three-phase coil are wound. It is used as a three-phase coil of an AC motor including a stator.

  The first enamel film 24 is made of enamel having high magnetic permeability and functions as a high magnetic permeability layer. Here, the formation of the highly permeable enamel is performed by, for example, filling an insulating paint (enamel) containing a solvent with a highly permeable material, and applying the insulating paint to the outer surface of the copper wire 22 by an applicator (not shown), This is performed by heating the insulating paint with a heating device (not shown) to vaporize the solvent. As the highly permeable material, a highly permeable material such as a ferrite-based material (ceramics mainly composed of iron oxide) can be used. For example, Ni—Zn ferrite or Mn—Zn ferrite that can also function as an insulator. Is mentioned. As the structure of the highly magnetically permeable material, as shown in FIG. 3, it is possible to employ a material filled in a filler shape (see FIG. 3A) or a material filled in a particle shape (see FIG. 3B). it can. The filling rate of the high magnetic permeability material can be determined as appropriate within a range of greater than 0% and not greater than 100% according to the specifications of the coil wire 20.

  The second enamel film 26 is formed of enamel that does not have high magnetic permeability, and functions as an insulating layer. The formation of the second enamel film 26 is performed by applying an insulating paint (enamel) containing a solvent to the outer surface of the first enamel film 24 and heating the insulating paint to vaporize the solvent.

  Consider a case where the coil wire 20 is applied to a winding (three-phase coil) of an AC motor. In this case, a part of the magnetic flux generated along with the energization of the coil wire 20 passes through the other coil wire 20 as a leakage magnetic flux without passing through the stator core. When the magnetic flux passes through the copper wire 22, an induced electromotive force is generated. Therefore, an eddy current is generated on the copper wire 22, and Joule loss corresponding to the product of the eddy current and the copper wire resistance is generated to generate heat. To do. FIG. 4 is an explanatory diagram illustrating a state in which leakage magnetic flux passes through the coil wire 20 of the example and the coil wire 20B of the comparative example. Note that the coil wire 20B of the comparative example includes a copper wire 22B and an enamel film 26B that covers the outer surface of the copper wire 22B and functions as an insulating layer. As shown in the figure, in the coil wire 20 of the embodiment, the leakage magnetic flux directed toward the copper wire 22 can be diverted to the first enamel film 24 side (see FIG. 4A), whereas the coil 20B of the comparative example. Then, it can be seen that the leakage magnetic flux cannot be deflected and the copper wire 22B is passed (see FIG. 4B).

  According to the coil of the embodiment described above, the copper wire 22, the first enamel film 24 coated on the outer surface of the copper wire 22, and the insulating layer coated on the outer surface of the second enamel film 24. The coil wire 20 is constituted by a certain second enamel film 26, and the first enamel film 24, which is an intermediate layer, is formed by an enamel layer filled with a high magnetic permeability material. When applied to the coil, the leakage magnetic flux toward the copper wire 22 can be diverted to the highly permeable first enamel film side. As a result, it is possible to further reduce the AC loss that occurs in the conducting wire due to the leakage magnetic flux.

  In the coil of the embodiment, the copper wire 22 is formed by a round wire, but the copper wire 122 may be formed by a flat wire as shown in the coil wire 120 of the modification of FIG. In this case, similarly to the round wire, the outer surface of the rectangular copper wire 122 is coated with the highly magnetic first enamel film 124, and then the outer surface of the first enamel film 124 is insulated with the second insulating material. The enamel film 126 may be covered.

  In the coil of the embodiment, the copper wire 22 is covered with two layers of the first enamel film 24 and the second enamel film 26, but it may be covered with three or more layers. FIG. 6 shows a modified coil wire 220. As shown in the drawing, the coil wire 220 of the modified example includes a three-layer enamel film with respect to the copper wire 222 from the inner peripheral side, a highly permeable first enamel film 224a, an insulating second enamel layer 226, The high magnetic permeability third enamel film 224b is coated in this order.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the copper wire 22 corresponds to a “conductor”, the first enamel film 24 corresponds to a “highly permeable layer”, and the second enamel film 26 corresponds to an “insulating layer”. The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention is applicable to the coil wire manufacturing industry.

  20, 20B, 120, 220 Coil wire, 22, 22B, 122, 222 Copper wire, 24, 124, 226a First enamel film, 26, 126, 224 Second enamel film, 26B Enamel film, 226b Third Enamel film.

Claims (1)

Conductors,
Formed of a highly permeable material having a higher permeability than the conductor, a highly permeable layer coated on the outer periphery of the conductor and an insulating material, and an insulating layer coated on the outer periphery of the highly permeable layer;
A coil comprising: