JP4537342B2 - Coil wire - Google Patents

Description

The present invention relates to a coil wire, in particular, to coil wire for forming a coil by winding a flat wire to the core.

  2. Description of the Related Art Conventionally, a winding coil is used as an inductor in a power supply circuit and a computer circuit of an automobile, a motor of a generator, a computer circuit and a power supply circuit of a digital household electric appliance and an industrial electric appliance.

  In this winding type coil, a round wire is wound around an iron core as a core. As shown in FIG. 4, a core 50 in which a round wire 52 is wound around an iron core 51 as a core is used for a motor. As shown in FIG. 5, a core 60 in which a round wire 62 is wound around an iron core 61, which is a core, is used for a transformer and a power inductance used for an inverter power supply.

  Further, as shown in FIG. 6, this coil has a so-called vertical coil 70 in which a flat wire 71 is wound around an iron core 72. For example, a power that functions as a smoothing filter and a noise filter of a CPU circuit of a notebook personal computer. It is used for inductance (see, for example, Patent Document 1 and Patent Document 2). This vertical winding is a so-called edgewise winding method in which a rectangular short side formed in a cross section of a rectangular wire is wound around the iron core 72 with the short side inside the winding. Thus, by winding the rectangular wire 71 vertically around the iron core 72, the space factor of the winding is improved and the coil is downsized.

  In recent years, electronic devices such as these have been mainly operated at high frequency by inverter control. In particular, in the automotive field, inverter power supplies have become mainstream along with the hybridization of drive sources.

JP-A-9-306757 JP 2005-327834 A

  However, in the coil 50 shown in the background art, since the round wire 52 is used as the winding, the space factor is poor and the power-up is hindered. Also, in the coil 60 shown in the background art, since the round wire 62 is used as the winding, the space factor is bad and the coil cannot be reduced in size. Moreover, although litz wires are used for the windings in order to make these coils compatible with high frequency operation, the space factor has deteriorated because the strands are also round wires.

  In contrast to these coils, the coil 70 shown in the background art uses a rectangular wire 71 as a winding, so that the space factor of the winding can be improved, but the vortex generated in the magnetic flux generated in the core axis direction. There was a difficulty in increasing the current loss. The use of the flat wire 71 increases the eddy current loss generated in the magnetic flux generated in the core axis direction, as shown in FIG. 7, because the rectangular short side formed in the cross section of the flat wire 71 is a, long When the side is b, the eddy current loss is small when the magnetic flux F10 is orthogonal to the short side a, but the eddy current loss is large when the magnetic flux F10 is orthogonal to the long side b. Because. That is, in the coil 70 shown in FIG. 6, since the flat wire 71 is wound vertically with respect to the iron core 72 and the magnetic flux is generated in the core axis direction, the eddy current loss increases. Further, the eddy current loss increases as the current becomes higher in frequency. Therefore, there is a demand for a coil that can reduce the eddy current loss even when the inverter is controlled to operate at a high frequency and the space factor of the winding is improved.

The present invention has been made in order to solve such a conventional problem, and it is possible to provide a coil electric wire that can reduce eddy current loss even when a high-frequency operation is performed by inverter control and the space factor of the winding is improved. The purpose is to provide.

  The principle of the present invention is to reduce the eddy current loss generated in both the axial magnetic flux and the dispersed magnetic flux of a coil formed by winding a rectangular wire around a core. The distribution direction magnetic flux of a coil is a magnetic flux generated at both sides of the coil in the axial direction of the coil. In addition, a rectangular wire covered with a rectangular conductor with a long side and a short side in the cross section has a low eddy current loss when the magnetic flux is orthogonal to the short side of the rectangle, but the rectangular long When the magnetic flux is orthogonal to the side, the eddy current loss increases. Therefore, for the eddy current loss caused by the axial magnetic flux of the coil, the axial magnetic flux of the coil is orthogonal to the short side of the rectangular wire, and for the eddy current loss caused by the dispersed magnetic flux of the coil. It is preferable to cross, preferably orthogonally cross, the magnetic flux in the dispersion direction of the coil with respect to the short side of the rectangular line.

Therefore, in the first aspect of the present invention, the first rectangular wire whose resin is coated with a rectangular conductor whose transverse section has long sides and short sides, and the rectangular conductor whose transverse section has long sides and short sides are provided. is composed of a second flat wire which is resin-coated with body, a second flat wire are arranged three to face the short side to the long side of the first flat wire, the first flat wire The short side of the second rectangular wire is the same as the short side of the second rectangular wire, and the short side of the second rectangular wire is set to one third of the long side of the first rectangular wire, The long side of the rectangular wire is set to a size that is two-thirds of the long side of the first rectangular wire to provide a coil wire formed in one wire.

In such a first aspect , the coil wire includes a first rectangular wire that is resin-coated with a rectangular conductor having a long side and a short side in cross section, and a long side and a short side in cross section. A second rectangular wire coated with a resin with a rectangular conductor, and three second rectangular wires are arranged such that the short sides thereof are opposed to the long sides of the first rectangular wire; The short side of the flat wire and the short side of the second flat wire have the same size, and the short side of the second flat wire is set to one third of the long side of the first flat wire. Since the long side of the second flat wire is set to two-thirds of the long side of the first flat wire and formed into one electric wire, the coil electric wire is simply arranged in the axial direction of the core. When, for example, the long side of the second rectangular wire is arranged along the core, the axial magnetic flux of the coil is orthogonal to the short side of the second rectangular wire, It can intersect or orthogonally distributed magnetic flux of the coil with respect to the short side of the first flat wire. Therefore, this coil wire can reduce both the eddy current loss caused by the axial magnetic flux of the coil and the eddy current loss caused by the magnetic flux in the dispersed direction of the coil even when the current is high frequency.

  According to the present invention, the eddy current loss can be reduced even when the inverter is controlled to operate at a high frequency and the space factor of the winding is improved.

Hereinafter, preferred embodiments of the coil wire according to the present invention will be described with reference to the drawings. Note that the same reference numerals denote the same elements throughout the best mode for carrying out the invention. 1A and 1B are diagrams showing a configuration of a coil, where FIG. 1A is a cross-sectional view of a coil in which a coil wire is wound around a core, and FIG. 1B is a cross-sectional view of the coil wire according to the present invention that is wound around a core in FIG. FIG. 3C is a cross-sectional view of a conventional coil wire wound up on the core of FIG.

  As shown in FIG. 1 (A), a coil 1 as a preferred embodiment of the present invention has a coil wire 3 wound around an iron core 2 as a core in the core axial direction. In FIG. 1A, the coil wire 3 is separated by two turns and away from the iron core 2. However, for convenience of explanation, the coil wire 3 is actually separated and is wound up in close contact. The iron core 2 is formed in a columnar shape having flanges formed at both ends.

  As shown in FIG. 1B, the coil wire 3 has a first rectangular wire 30A resin-coated with a rectangular conductor having a long side 31 and a short side 32, and a long side 33. And a second rectangular wire 30B resin-coated with a rectangular conductor composed of a short side 34, and the second rectangular wire 30B has a short side 34 with respect to the long side 31 of the first rectangular wire 30A. For example, three wires are arranged so as to face each other, and are formed in one electric wire 3 ′. The length of the short side 34 of the second flat wire 30B is set to one third of the length of the long side 31 of the first flat wire 30A. When one first rectangular wire 30A and three second rectangular wires 30B, 30B, and 30B are combined in this way, the eddy current loss generated by the axial magnetic flux of the coil and the magnetic flux in the dispersed direction of the coil are generated. Any eddy current loss can be reduced. Further, the long side 33 of the second flat wire 30B may be formed shorter than the long side 31 of the first flat wire 30A. By configuring in this way, the eddy current loss in the axial direction of the second rectangular wires 30B, 30B, 30B can be reduced, and the eddy current loss for the corresponding number can be reduced by a plurality of parallel configurations.

  The divided coating layer 35, which is the resin coating layer of the first rectangular wire 30A, and the divided coating layer 36, which is the resin coating layer of the second rectangular wire 30B, which form the coil wire 3, are both polyurethane and polyvinyl formal. , Polyester, polyesterimide, polyamideimide, polyimide, and any one element selected from the group consisting of polyimide. These elements are all insulators, and by insulating the four rectangular wires 30A, 30B, 30B, and 30B, a minute current flows between the four rectangular wires 30A, 30B, 30B, and 30B. 30A, 30B, 30B, 30B can be prevented from flowing eddy current as a single rectangular wire. Moreover, it becomes easy to integrate the four rectangular wires 30A, 30B, 30B, and 30B by applying an adhesive to the divided coating layers 35 and 36.

  One electric wire 3 'may be further coated with a resin. The reason why the single electric wire 3 ′ is coated with the resin is to protect the single electric wire 3 ′ and increase the mechanical strength of the coil electric wire 3. The common coating layer 37 (see FIG. 1A), which is this resin coating layer, is formed by any one element selected from the group consisting of polyurethane, polyvinyl formal, polyester, polyesterimide, polyamideimide, and polyimide. Yes. Since the common covering layer 37 is also used for insulation, elements of the same type as the divided covering layers 35 and 36 of the rectangular wires 30A, 30B, 30B, and 30B of one electric wire 3 'are selected. The layer thickness of the common coating layer 37 is preferably larger than the layer thickness of the divided coating layers 35 and 36. The divided coating layers 35 and 36 have the same layer thickness. In this way, the layer thickness of the common coating layer 37 is made thicker than the layer thicknesses of the divided coating layers 35 and 36 because the conductor 38 of the first rectangular wire 30A and the conductor 39 of the second rectangular wire 30B are occupied. This is because the cross-sectional area of the cross section of the coil wire 3 is reduced and the flexibility is increased while increasing the volume factor. Further, the layer thickness of the common coating layer 37 and the layer thickness of the divided coating layers 35 and 36 may be equal. This is because when the common coating layer 37 is mechanically strong, the layer thickness of the common coating layer 37 can be reduced to the layer thickness of the divided coating layers 35 and 36.

Moreover, you may use an insulating varnish as the division | segmentation coating layers 35 and 36. FIG. For example, the divided coating layers 35 and 36 can be formed by electrodepositing an insulating varnish on the conductors 38 and 39.
As this insulating varnish, polyvinyl formal is suitable. Polyvinyl formal is generally used as a varnish for enameled wire, and has excellent mechanical strength, easy reproducibility of a cured film, and chemical resistance such as water resistance. As described above, even when the insulating varnish is used as the divided covering layers 35 and 36, a minute current flows between the four rectangular wires 30A, 30B, 30B, and 30B, and the four rectangular wires 30A, 30B, 30B, and 30B are 1 It is possible to prevent the eddy current from flowing as a flat rectangular wire, and it becomes easy to make the thickness of the divided covering layers 35 and 36 thinner than the thickness of the common covering layer 37. The insulating varnish is an adhesive varnish, so that the four rectangular wires 30A, 30B, 30B, 30B can be easily integrated. Moreover, when the insulating varnish is a solvent-free varnish, when the material for the common coating layer 37 is applied to the divided coating layers 35 and 36, the generation of solvent gas from the divided coating layers 35 and 36 can be minimized. . The common covering layer 37 is formed of any one element selected from the group consisting of polyurethane, polyester, polyesterimide, polyamideimide, and polyimide, thereby protecting one electric wire 3 ′ and the coil electric wire 3. Mechanical strength can be increased. Such an insulating varnish can also be used for the common coating layer 37.

Further, the divided coating layers 35 and 36 may be semiconductive layers, and the common coating layer 37 may be an insulating layer.
Thus, by making the division | segmentation coating layers 35 and 36 into a semiconducting layer, a micro electric current flows between the four rectangular wires 30A, 30B, 30B, and 30B, and this four rectangular wires 30A, 30B, 30B, and 30B are one. As a rectangular wire, it is possible to prevent eddy current from flowing, and the potential between the four rectangular wires 30A, 30B, 30B, 30B is resistance-divided to improve insulation and prevent corona discharge. It becomes possible. In order to make the divided coating layers 35 and 36 semiconductive layers, any one element selected from the group consisting of carbon and silver may be added. For example, any one element selected from the group consisting of carbon and silver is added to any one element selected from the group consisting of polyurethane, polyester, polyesterimide, polyamideimide, and polyimide. Further, any one element selected from the group consisting of carbon and silver is added to a solventless varnish such as an adhesive varnish or a solventless varnish. In addition, carbon and silver are made into powder, This carbon and silver can be mixed with resin uniformly and uniformly.

  Further, as shown in FIG. 2, the coil wire 3 may have the divided coating layers 35 and 36 as insulating layers and the common coating layer 37 as a semiconducting layer. Thus, by making the division | segmentation coating layers 35 and 36 into an insulating layer, generation | occurrence | production of the corona discharge between coil turns can be prevented. At this time, it is preferable that the semiconductive layer of the coil wire 3 is peeled off at least at the terminal on the high voltage side. The peeling length on the high voltage side and the low voltage side can be determined by the degree of partial resistance of the coil resistance of the semiconducting layer. By processing in this way, it becomes possible to withstand creeping discharge breakdown.

  The conductors 38 and 39 of the first rectangular wire 30A and the second rectangular wire 30B of the coil wire 3 have a long side of 0.07 to 14,000 mm and a short side of 0.02 respectively. In the case of ˜3.00 mm, the layer thickness of the divided coating layers 35 and 36 is set to 1 to 5 μm, and the layer thickness of the common coating layer 37 is set to 20 to 50 μm. For example, the long side of the conductor 38 of the first rectangular wire 30A is 0.09 mm and the short side is 0.05 mm, the long side of the conductor 39 of the second flat wire 30B is 0.07 mm, and the short side is 0. When the thickness is 0.03 mm, the layer thickness of the divided coating layers 35 and 36 is 1 μm, and the layer thickness of the common coating layer 37 is 20 μm. That is, a rectangular wire is used to form a rectangular cross section of the coil wire 3 to reduce the size and increase the mechanical strength and reduce the eddy current loss.

  The magnetic flux and eddy current in the coil 1 obtained by winding the coil wire 3 thus configured around the iron core 2 will be described below. As shown in FIG. 1A, the coil wire 3 is wound with the long side 31 of the first flat wire 30 </ b> A disposed along the iron core 2. For convenience of explanation, the coil wire 3 is wound 6 times around the iron core 2, and is wound 2 times on each of the M sections on both sides and 2 times on the central N section.

  When a current is passed through the coil wire 3 of the coil 1 shown in FIG. 1 (A), the magnetic flux F1 is applied to the winding portion 2A of the coil wire of the iron core 2, and the magnetic flux F2 is applied to the right flange portion 2B of the iron core 2 in the drawing. 2, a magnetic flux F3 is generated in the left flange portion 2C and flows in the iron core in a certain direction. Further, an axial magnetic flux AF1 parallel to the magnetic flux F1 passing through the N section of the iron core 2 flows through the coil electric wire 3 serving as the N section of the coil 1. Further, in the M section on the flange portion 2B side of the coil 1, the dispersion direction magnetic flux DF1 parallel to the magnetic flux F2 flowing in the flange portion 2B, and in the M section on the flange portion 2C side, parallel to the magnetic flux F3 flowing in the flange portion 2C. Dispersion direction magnetic flux DF2 is generated.

  Such an axial magnetic flux AF1 and distributed magnetic fluxes DF1, DF2 are the second because the coil wire 3 is divided into a first rectangular wire 30A and three second rectangular wires 30B, 30B, 30B. The axial direction magnetic flux AF1 of the coil 1 is orthogonal to the long side 33 of the rectangular wire 30B, and the dispersion direction magnetic fluxes DF1 and DF2 of the coil 1 are crossed or orthogonal to the long side 31 of the first rectangular wire 30A. Can do. Therefore, the coil wire 3 can reduce both the eddy current loss caused by the axial magnetic flux of the coil 1 and the eddy current loss caused by the distributed magnetic fluxes DF1 and DF2 of the coil even when the current is high frequency.

  Further, since the coil wire 3 is a flat wire since the first flat wire 30A and the three second flat wires 30B, 30B, 30B are all flat wires, the cross section can be formed in a square shape. Therefore, it is possible to prevent the coil from being collapsed during coil winding and to improve the space factor of the winding.

  Next, the coil electric wire 3 of the present invention shown in FIG. 1 (B) and the conventional coil electric wire 300 shown in FIG. 1 (C) are wound in the same axial state on the core 2 shown in FIG. 1 (A). The eddy current loss generated in each coil when it was wound up was compared and calculated. FIG. 1A shows a view in which the coil wire 3 of the present invention is wound up in the core axis direction of the core 2. Further, the conventional coil wire 300 has a transverse section having the same size as the transverse section of the coil wire 3 of the present invention. Further, the coil wire 3 of the present invention is provided with three second rectangular wires 30B.

  As shown in FIG. 1C, the conventional coil wire 300 has a vertical and horizontal dimension of W, a thickness of the coating layer 301 is t, and a vertical and horizontal dimension of the conductor 302 is W-2t.

  As shown in FIG. 1B, the coil wire 3 of the present invention has the same vertical and horizontal dimensions W as the vertical and horizontal dimensions of the conventional coil wire 300. The first rectangular wire 30A of the coil wire 3 has a vertical dimension of W / 3, a horizontal dimension of W, a thickness of the divided covering layer 35, a vertical dimension of the conductor 38 of (W / 3). ) -2t, the horizontal dimension is W-2t. The second rectangular wire 30B of the coil wire 3 has a vertical dimension of 2W / 3, a horizontal dimension of W / 3, a thickness of the divided coating layer 36, and a vertical dimension of the conductor 39. 2W / 3-2t, and the horizontal dimension is (W / 3) -2t.

  Further, the length of the wire wound around the core 2 in the M section is L1, and the length of the wire wound around the core 2 in the N section is L2. Further, in the conventional coil wire 300, the eddy current loss resistance r1 in the M section and the eddy current loss resistance r2 in the N section are used, and the eddy current loss resistance R1 in the M section and the eddy current in the N section in the coil wire 3 of the present invention. The loss resistance is R2.

  First, the eddy current loss Q is defined as a frequency f, a permeability μ of a wire conductor, and a resistivity σ, and when a current I flows, as shown in Equation (1),

となる。なお、Ａは導体厚さ、Ｂは導体幅、Ｋは係数とする。

It becomes. A is a conductor thickness, B is a conductor width, and K is a coefficient.

  Therefore, the eddy current loss resistance r per unit length is

となる。

It becomes.

  Further, as shown in FIG. 1A, the eddy current loss total resistance R of the coil wire in the M section, the N section, and the M section is

となる。

It becomes.

  Since the conventional coil wire 300 is W in both vertical and horizontal dimensions, the eddy current loss resistance r1 in the M section and the eddy current loss resistance r2 in the N section are:

となる。即ち、Ｍ区間における渦電流損抵抗ｒ１と、Ｎ区間における渦電流損抵抗ｒ２とは等しくなる。

It becomes. That is, the eddy current loss resistance r1 in the M section is equal to the eddy current loss resistance r2 in the N section.

  On the other hand, in the coil wire 3 of the present invention, the eddy current loss resistance per unit length of the first rectangular wire 30A is set to r21 in the N section, and the eddy current per unit length of the second rectangular wire 30B. Assuming that the loss resistance is r22, as shown in Equation (5),

となる。したがって、

It becomes. Therefore,

となる。数式（５）に数式（６）と数式（７）を代入すると、第２の平角線３０Ｂの本数ｎが３本なので、数式（８）に示すように、

It becomes. When the formula (6) and the formula (7) are substituted into the formula (5), since the number n of the second rectangular wires 30B is 3, as shown in the formula (8),

となる。

It becomes.

  That is, it was found that the coil wire 3 of the present invention in the N section of the core 2 has an eddy current loss resistance of about 1/15 compared with the conventional coil wire 300.

  In the M section, when the eddy current loss resistance per unit length of the first flat wire 30A is r11 and the eddy current loss resistance per unit length of the second flat wire 30B is r12, the equation (9 )

となる。したがって、

It becomes. Therefore,

となる。数式（９）に数式（１０）と数式（１１）を代入すると、第２の平角線３０Ｂの本数ｎが３本なので、数式（１２）に示すように、

It becomes. When the formula (10) and the formula (11) are substituted into the formula (9), since the number n of the second rectangular wires 30B is 3, as shown in the formula (12),

となる。

It becomes.

  That is, it was found that the coil wire 3 of the present invention in the M section of the core 2 has an eddy current loss resistance of about 120 times that of the conventional coil wire 300.

  Thus, it was found that an optimal value of the eddy current loss resistance with good balance can be obtained by appropriately changing the thickness, width and number to make the parallel resistance.

  In the above-described embodiment, the coil wire has the long side of the first flat wire arranged along the core. However, the present invention is not limited to this, and as shown in FIG. Since the coil wire 3 is divided into the first rectangular wire 30A and the three second rectangular wires 30B, 30B, and 30B even if the short side 32 is arranged along the core 2, the axial magnetic flux of the coil Both of the eddy current loss generated by the coil and the eddy current loss generated by the magnetic flux in the dispersion direction of the coil can be reduced.

  Moreover, in the Example mentioned above, although the electric wire for coils has arrange | positioned the number of the 2nd flat wire by three, it should just be arrange | positioned by not only this but 2-8. When the number of the second flat wires is 8 or more, the width becomes wide, so that the manufacturability such as the bonding process is lowered.

  The coil wire of the present invention configured as described above and the coil using the same are suitable for electronic control transformers that perform inverter control, motors that require higher frequencies, and the like.

  Although the present invention has been described with the specific embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and is known so far as long as the effects of the present invention are achieved. It goes without saying that any configuration can be adopted.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the preferable embodiment example in the coil using the electric wire for coils of this invention, (A) is sectional drawing of the coil by which the electric wire for coils was wound up on the core, (B) is the electric wire for coils of this invention Sectional drawing and (C) are sectional drawings of the conventional electric wire for coils. It is a perspective view which shows the state which peeled the terminal of the coil electric wire of this invention. It is sectional drawing which shows the other preferable embodiment of the coil by which the electric wire for coils of this invention was wound up by the core. It is sectional drawing which shows the conventional coil applied to the motor. It is sectional drawing which shows the conventional coil applied to the transformer. It is sectional drawing which shows the conventional coil applied to the transformer. It is explanatory drawing which shows the magnetic flux which arises in a flat wire.

DESCRIPTION OF SYMBOLS 1 ... Coil 2 ... Core 3 ... Electric wire for coils 3 '... One electric wire 30A ... 1st flat wire 31 ... Long side 32 ... Short side 35 ... Divided coating layer (resin coating layer)
30B …… Second flat wire 33 …… Long side 34 …… Short side 36 …… Division coating layer (resin coating layer)
37 …… Common coating layer (resin coating layer)

Claims (11)

A first rectangular wire whose resin is coated with a rectangular conductor whose cross section is a long side and a short side, and a second rectangular wire whose resin is coated with a rectangular conductor whose cross section is a long side and a short side is composed of a, the second flat wire are 3 disposed to face the short side to the long side of the first flat wire, the short sides and the said first flat wire The dimension of the short side of the second flat wire is the same, and the short side of the second flat wire is set to one third of the long side of the first flat wire, and The coil wire according to claim 1, wherein the long side of the second rectangular wire is formed into one electric wire having a size that is two-thirds of the length of the long side of the first rectangular wire. The coil wire according to claim 1, wherein the one wire is further coated with a resin. 3. The coil according to claim 2, wherein the resin coating layer further coated with resin on the one electric wire is thicker than the resin coating layers of the first flat wire and the second flat wire. 4. Electric wire. Each resin coating layer of the first rectangular wire and the second rectangular wire is any one element selected from the group consisting of polyurethane, polyvinyl formal, polyester, polyesterimide, polyamideimide, polyimide, and insulating varnish. The coil wire according to any one of claims 1 to 3, wherein the coil wire is a coil wire. Each resin coating layer of the first flat wire and the second flat wire is coated with an insulating varnish, and the resin coating layer further coated with resin on the one electric wire is polyurethane, polyvinyl formal, polyester, polyester The coil wire according to claim 2 or 3 , wherein the coil wire is any one element selected from the group consisting of imide, polyamideimide, polyimide, and insulating varnish. The insulating varnish according to claim 4 or claim 5 coil wire according to, characterized in that an adhesive varnish. The insulating varnish according to claim 4 or claim 5 coil wire according characterized in that it is a solvent-free varnish. Each resin coating layer of the first flat wire and the second flat wire is an insulating layer, a resin coating layer coated on said one electrical wire according to claim 2 or claims, characterized in that the semiconducting layer coil wire according to any one of claim 7. Each resin coating layer of the first flat wire and the second flat wire is a semi-conducting layer, a resin coating layer coated on said one electrical wire according to claim 2 or claims, characterized in that the insulating layer coil wire according to any one of claim 7. Claims, characterized in that the said first flat wire and the second the resin coating layer of the rectangular wire is carbon, at least any one element selected from the group consisting of silver is added the semiconducting layer The coil electric wire according to any one of Items 4 to 9 . 11. The coil wire according to claim 10 , wherein the carbon and silver are powder.

Images