JP2006158024A - Coil and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil which can prevent an eddy current generated in the line material of a coil, and its manufacturing method. <P>SOLUTION: The line material 23 constituting the coil 21 heteromorphic in cross section is constituted by stacking a plurality of thin band-shaped conductor parts 27 consisting of metal such as copper or the like with its periphery covered each with an insulating layer 25 and covering the whole of the stacked conductor part 27 with an outermost insulating layer 29. The insulating layer 25 is one for preventing the eddy current Ir generated in the line material 23, and an object, which is coated with a chemical cover or low-conductive resin such as, for example, an oxide film for copper, or the like is used. The outermost insulating layer 29 is one for contriving the insulation between the turns of the line material 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coil suitable for a motor of a hybrid vehicle or an electric vehicle, and a manufacturing method thereof.

  In order to increase the efficiency and output of drive motors for hybrid vehicles and electric vehicles, it is effective to improve the space factor of the motor coils. As a method of improving the space factor, a method of changing the cross-sectional shape of the wire according to the position on the winding path of the coil has been proposed, whereas the conventional wire having a constant cross-sectional shape is wound.

  As shown in FIG. 5, such a coil 1 has a substantially truncated cone-shaped appearance, and the cross-sectional shape (substantially rectangular) of the wire 3 is on the small diameter side (lower side in FIG. 5). It gradually changes from an end toward the end on the large diameter side (upper side in FIG. 5). At both ends of the coil 1, lead portions 5 and 7 for electrical connection are provided. More specifically, the coil 1 shown in FIG. 5 has an external appearance (substantially truncated quadrangular pyramid shape) obtained by cutting off the head of a substantially quadrangular pyramid. For example, as shown in FIG. The stator core 8 is extrapolated. At this time, the coil 1 is disposed in a state where the small diameter side is directed to the rotor side.

  As a manufacturing method of such a coil 1, as shown in FIG. 7, a wire 3 is wound around a core 9 in a substantially spiral shape to form a substantially columnar intermediate coil body 11, and as shown in FIG. A method has been proposed in which the intermediate coil body 11 is set in a molding die 13 and press-molded in the axial direction.

  However, as shown in FIG. 5 and FIG. 6, when the coil 1 is formed by simply winding the wire 3 having a substantially rectangular cross section around the core material 9 and press-molding it as in the technique according to the above-mentioned proposal example, Since the portion 1a on the small diameter side of the coil 1 is easily affected by the change of the magnetic field due to the rotation of the rotor 15, the following problem occurs. That is, as shown in FIG. 9, a magnetic field B is generated around the rotor 15 by a magnetic field generation source (permanent magnet or the like) provided in the rotor 15, and depending on the rotation position of the rotor 15, a wire rod is generated as the rotor 15 rotates. The amount of magnetic flux passing through 3 changes, and an eddy current Ir is generated in the wire 3. The portion 1a on the small diameter side of the coil 1 is closer to the rotor 15 than the other portions, and the change in the magnetic field B generated in the portion 1a is large, and the thickness (the thickness in the axial direction of the coil 1) is large. Therefore, the amount of eddy current Ir becomes larger than other portions, and the efficiency of the motor decreases.

  Therefore, the problem to be solved by the present invention is to provide a coil that can prevent eddy currents generated in the coil wire and a method for manufacturing the coil.

  In order to solve the above-described problem, in the invention of claim 1, a coil is formed by winding a wire having a substantially rectangular cross section, and the wire is formed by a plurality of insulating layers provided along the longitudinal direction thereof. It is divided into conductor parts.

  According to a second aspect of the present invention, in the coil according to the first aspect of the invention, the wire is configured by laminating a plurality of thin strip-shaped conductor portions with an insulating layer interposed between the conductor portions.

  According to a third aspect of the present invention, in the coil according to the first aspect of the present invention, the wire comprises a plurality of elongated, substantially wire-like conductor portions coupled with an insulating layer interposed between the conductor portions. The

  According to a fourth aspect of the present invention, the coil according to any one of the first to third aspects of the present invention is a modified cross-section coil having a substantially truncated cone-shaped appearance.

  According to a fifth aspect of the present invention, there is provided a step of producing an intermediate coil body by winding a wire divided into a plurality of conductor portions by an insulating layer provided along a longitudinal direction thereof in a substantially spiral shape, and the intermediate coil Pressing the body in its axial direction.

  According to the first aspect of the present invention, since the wire constituting the coil is divided into the plurality of conductor portions by the insulating layer provided along the longitudinal direction, the eddy current generated in the wire by the insulating layer is reduced. This can be prevented and the efficiency can be improved.

  According to the invention described in claim 2, since the wire is formed by laminating a plurality of thin strip-like conductor portions with an insulating layer interposed between the conductor portions, eddy current generated in the wire can be prevented. .

  According to the invention described in claim 3, since the wire is configured by connecting a plurality of elongated and substantially wire-like conductor portions with an insulating layer interposed between the conductor portions, the eddy current generated in the wire is reduced. It can be prevented more reliably.

  According to the fourth aspect of the present invention, the space factor of the coil can be improved by making the coil into a deformed section coil.

  According to invention of Claim 5, the intermediate coil body is produced by winding the wire divided into the plurality of conductors by the insulating layer provided along the longitudinal direction substantially spirally, and the intermediate coil body Since the deformed section coil is manufactured by pressing in the axial direction, the deformed section coil that can prevent the eddy current generated in the wire can be easily manufactured.

<First Embodiment>
FIG. 1 is a cross-sectional view showing an installed state of a coil having a modified cross section according to the first embodiment of the present invention. The coil 21 having a modified cross section according to the present embodiment is substantially the same as the coil 1 having a modified cross section shown in FIGS. 5 and 6 described above, and the wire 23 shown in FIG. It is wound around the material 9 and finished into a substantially truncated square shape by press molding with the mold 13 of FIG.

  In the present embodiment, as shown in an enlarged view of the main part in FIG. 1, the wire 23 having a substantially rectangular cross section constituting the coil 21 is formed on the plurality of conductor parts 27 by the insulating layer 25 provided along the longitudinal direction. It is divided. More specifically, as shown in FIG. 2 which is a state before press molding, the wire 23 is formed by laminating a plurality of thin strip-shaped conductor portions 27 made of a metal such as copper, the periphery of which is covered with an insulating layer 25. The entire laminated conductor portion 27 is covered with an outermost insulating layer 29. If the insulating layer 25 covering the conductor portion 27 is provided only in a portion where the conductor portion 27 faces the adjacent conductor portion 27 (upper and lower surface portions in FIG. 1), the inner and outer peripheral sides of the coil 21 are provided. Side portions (left and right side portions in FIG. 1) may be omitted. The conductor portions 27 are bonded and fixed to each other in a stacked state, but may be fixed using a dedicated adhesive, and the insulating layer 25 may be bonded using an adhesive layer. Also good.

  The insulating layer 25 is for preventing the eddy current Ir generated in the wire 23. For example, a chemical coating such as a copper oxide film or a coating with a resin having low conductivity is used. The thickness of the insulating layer 25 is preferably set to be thin (for example, about 1 to 10 μm) from the viewpoint of securing the space factor.

  The outermost insulating layer 29 is for securing insulation between the turns of the wire 23, and an appropriate material (for example, enamel) and thickness are set in consideration of heat resistance due to heat generation.

  The coil 21 is manufactured as follows. First, the conductor portions 27 covered with the insulating layer 25 are assembled and fixed in a laminated state to form the wire 23. Subsequently, the wire material 23 is spirally wound around the core material 9 as shown in FIG. 7 to form the intermediate coil body 11, and the intermediate coil body 11 is placed in the mold 13 as shown in FIG. The coil 21 having an irregular cross section is formed by installing and press forming.

  As described above, in the coil 21 having an irregular cross section according to the present embodiment, the wire 23 constituting the coil 21 is configured by laminating a plurality of thin strip-shaped conductor portions 27 with the insulating layer 25 interposed therebetween. Therefore, the eddy current generated in the wire 23 in the portion 21a on the small diameter side of the coil 21 that is arranged close to the rotor 15 and has a large thickness can be effectively prevented, and the efficiency of the motor can be improved.

  Moreover, since the coil 21 which concerns on this embodiment is a coil of the irregular cross section which has a substantially truncated cone-shaped external appearance form, the space factor of the coil 21 can be improved.

  In addition, although it is a problem whether the insulation layer 25 in the wire 23 is destroyed by the deformation of the wire 23 when the intermediate coil body 11 is press-molded, the portion on the small diameter side of the coil 21 in which the eddy current Ir is the most problematic. Since 21a has a small degree of deformation by press molding, the insulating layer 25 is not broken. As for the large diameter portion 21b of the coil 21, the insulating layer 25 may be destroyed due to deformation during press molding, but this portion 21b is farther from the rotor 15 than the small diameter portion 21a. Since the change of the magnetic field due to the rotation of the rotor 15 is small and the thickness is small, the eddy current Ir is not a problem.

Second Embodiment
FIG. 3 is a cross-sectional view of a main part of a coil having a modified cross section according to the second embodiment of the present invention. The coil 21 having a modified cross-section according to the present embodiment is substantially different from the coil 21 having a modified cross-section according to the first embodiment described above only in the configuration of the wire 23, and the portions corresponding to each other are the same. Reference numerals are assigned and description is omitted.

  In the present embodiment, as shown in an enlarged view of the main part of the coil 21 in FIG. 3, the wire 23 constituting the coil 21 includes a plurality of elongated, substantially wire-like conductor portions 27 whose outer periphery is covered with an insulating layer 25. They are coupled to each other, and the outer periphery of the engaged conductor portion 27 is covered with an outermost insulating layer 29. Each conductor portion 27 may be bonded using a dedicated adhesive, or may be bonded to the insulating layer 25 using an adhesive layer. The configurations of the insulating layer 25 and the outermost insulating layer 29 are substantially the same as those in the first embodiment.

  As described above, in this embodiment, since the configuration of the cross section of the wire 23 constituting the coil 21 can be divided into the vertical and horizontal directions by the insulating layer 25, the eddy current Ir generated in the wire 23 can be more reliably prevented. it can. For this reason, in the present embodiment, as shown in FIG. 9 described above, not only the eddy current Ir generated along the surface perpendicular to the extending surface of each loop of the wire 23 extending in a substantially spiral shape in the wire 23. As shown in FIG. 4, the eddy current Ir ′ generated along the extending surface of each loop of the wire 23 in the wire 23 can be effectively prevented.

  When only the eddy current Ir ′ component needs to be suppressed, instead of laminating the conductor portion 27 covered with the insulating layer 25 in the axial direction of the coil 21 as shown in FIG. The wire 23 may be configured by laminating the conductor portion 27 covered with the insulating layer 25 in the radial direction of the coil 21.

It is sectional drawing which shows the installation state of the coil of the irregular cross section which concerns on 1st Embodiment of this invention. It is principal part sectional drawing which shows the state before press molding in the coil of the irregular cross section of FIG. It is principal part sectional drawing of the coil of the irregular cross section which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the eddy current suppression effect by the coil of FIG. It is a perspective view of the coil of the irregular cross section concerning a proposal example. It is sectional drawing which shows the installation state of the coil of FIG. It is explanatory drawing which shows the manufacturing process of the coil of FIG. It is explanatory drawing which shows the manufacturing process of the coil of FIG. It is explanatory drawing which shows the condition where an eddy current arises in the coil of FIG.

Explanation of symbols

8 Stator Core 9 Core Material 11 Intermediate Coil Body 13 Mold 15 Die Rotor 21 Coil 23 Wire Material 25 Insulating Layer 27 Conductor 29 Outermost Insulating Layer

Claims (5)

A coil formed by winding a wire having a substantially rectangular cross section,
The coil, wherein the wire is divided into a plurality of conductor portions by an insulating layer provided along a longitudinal direction thereof. The coil according to claim 1, wherein
The coil, wherein the wire is formed by laminating a plurality of thin strip-shaped conductor portions with an insulating layer interposed between the conductor portions. The coil according to claim 1, wherein
The coil, wherein the wire is configured by connecting a plurality of elongated, substantially wire-like conductor portions with an insulating layer interposed between the conductor portions.   The coil according to any one of claims 1 to 3, wherein the coil is a modified cross-section coil having a substantially truncated cone-shaped appearance. A step of producing an intermediate coil body by winding a wire divided into a plurality of conductor portions by an insulating layer provided along the longitudinal direction in a substantially spiral shape;
Pressing the intermediate coil body in its axial direction;
The manufacturing method of the irregular cross-section coil characterized by the above-mentioned.

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