EP1655740A1

EP1655740A1 - Stranded wire, coil using this wire, noise filter device having this coil, and production method for stranded wire

Info

Publication number: EP1655740A1
Application number: EP04771263A
Authority: EP
Inventors: R. c/o SOSHIN ELECTRIC CO. LTD. YAMAURA; K. c/o SOSHIN ELECTRIC CO. LTD. MACHIDA; T. c/o SOSHIN ELECTRIC CO. LTD. KOBAYASHI; Y. c/o SOSHIN ELECTRIC CO. LTD ISHIYAMA; J. c/o SOSHIN ELECTRIC CO. LTD. MAEDA; M. c/o SOSHIN ELECTRIC CO. LTD. ICHIKAWA; T. c/o SOSHIN ELECTRIC CO. LTD. YODA
Original assignee: Soshin Electric Co Ltd
Current assignee: Soshin Electric Co Ltd
Priority date: 2003-08-13
Filing date: 2004-08-05
Publication date: 2006-05-10
Also published as: CN1864234A; KR20060032217A; CN1864234B; WO2005017924A1; EP1655740A4; JP4098685B2; JP2005063830A; KR100753000B1

Abstract

To produce a large-current-adaptable common-mode coil simply and at low costs. When the drive pulley (76) of a motor (74) is rotated in an arrow B direction after the distance between pins (68, 68) is adjusted to a desired one, a rotary shaft (70) is rotated. This rotation allows a rod-like takeup bobbin (64) to take up a copper wire (60) such as UEW to produce an annular conductor (66) consisting of a specified number of wires. The conductor (66) is removed from the bobbin (64), and one end is rotated with the opposite ends kept pulled from each other to produce a strand. This strand is wound into a troidal coil or the like to produce a large-current-adaptable common-mode coil.

Description

TECHNICAL FIELD

The present invention relates to a stranded electric wire, a coil having a stranded wire wound around a core, a noise filter device, and a method of manufacturing a stranded wire of desired length. The present invention is suitably applicable to a noise filter device for use between a power supply (AC power supply or DC power supply) and a load unit which is supplied with electricity from the power supply through a power supply cord, for preventing noise from being propagated from the load unit to the power supply through the power supply cord and also preventing noise from being radiated out of the power supply cord, and a coil (normal-mode coil or common-mode coil) for use in such a noise filter device.

BACKGROUND ART

Heretofore, a noise filter device is inserted between a load unit such as an inverter unit for energizing a motor or the like and a power supply, for blocking noise from the load unit which serves as a noise generating source of conduction noise or radiation noise (see Patent Document 1).
The noise filter device employs a coil (normal-mode coil or common-mode coil) inserted in series in a connector line between the load unit and the power supply.
Patent Document 1: Japanese laid-open patent publication No. 10-107571

DISCLOSURE OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

If the load unit comprises a high-power apparatus such as a semiconductor fabrication apparatus, a machine tool, an elevator, a plant facility, or the like, then an electric current in excess of 100 [A] may flow through the coil.
Heretofore, as shown in FIG. 24, a coil 2 for use in a noise filter device for large electric current applications has electric wires 8 each comprising a cotton-covered copper wire (DCC wire) 4 having a cross-sectional area of 60 [mm²] and covered with a silicone-based insulating tube 6, the electric wire 8 having a plurality of turns wound around a toroidal core 10. The toroidal core 10 is sized such that it has an outside diameter of 130, an inside diameter of 100, and a thickness of 70. The conventional coil 2 employing the cotton-covered copper wire 4 has an allowable electric current of about 100 [A]. If a coil having an allowable electric current of about 300 [A] is to be produced, it is necessary to wind three electric wires 8 parallel to each other (providing a total cross-sectional area of 180 [mm²]) into the coil. The coil 2 is of a three-phase, three-wire 500 Vac class.
However, since the coil 2 employing the cotton-covered copper wire 4 has a hard electric wire and cannot be wound voluminously around the toroidal core 10, coils for use in high-power apparatus in excess of about 300 [A] are not presently available in the market.
Actually, the cotton-covered copper wire 4 shown in FIG. 24 is formed as a stranded wire by three stranded wire manufacturing steps of bundling and stranding 40 bare copper wires each having a diameter of 0.12, stranding 7 such bundles, and then stranding 19 such bundles.
It is thus necessary to manufacture a bundled stranded wire. As shown in FIG. 25, such a bundled stranded wire is manufactured by withdrawing bare copper wires 32 from 40 bobbins 30 (as many as the number of copper wires making up the bundled stranded wire), and winding, around a takeup bobbin 38, a bundled stranded wire 36 that is produced by stranding the 40 copper wires in a stranding process unit 34.
For manufacturing the bundled stranded wire 36, as many bobbins 30 as the number of wires making up the bundled stranded wire 36 are required in inventory. Therefore, a storage space for the bobbins 30 is large and the manufacturing facility is large in scale. Furthermore, a space for storing as many takeup bobbins 38 as the number of required bundled stranded wires 36 is necessary. The process of placing the insulating tube 6 on the long stranded wire is highly complex and costly.
As a result, the conventional coil 2 that employs the cotton-covered copper wire 4 as shown in FIG. 24 is disadvantageous in that it is limited to being used in apparatus having an allowable electric current of about 300 [A] or less, and is highly costly to manufacture.
FIG. 26 schematically shows a coil 12 for high-power apparatus in excess of about 300 [A]. The coil 12 has such a structure that three bus bars 20, 22, 24 in the form of copper plates extend through openings in three toroidal cores 14, 16, 18 that are juxtaposed for an increased inductance value. The coil 12 employing the bus bars 20, 22, 24 can be used in high-power apparatus in excess of about 400 [A].
However, the coil 12 employing the bus bars 20, 22, 24 and the coil 2 employing the cotton-covered copper wire 4 suffer various problems described below because their conductors are thick and hard.
First, since it is difficult to wind the coil around the core, the inductance value is low and the coil has a low high-frequency shield capability.
Secondly, a coil having a necessary inductance value has an increased size.
Thirdly, the cost of manufacturing a coil having a necessary inductance value is increased.
The present invention has been made in view of these various problems. It is an object of the present invention to provide a relatively thin electric wire which can be used with a large electric current.
Another object of the present invention is to provide a coil which can be used with a large electric current and has an inductance value that can easily be increased.
Still another object of the present invention is to provide a noise filter device which can be used with a large electric current.
Yet another object of the present invention is to provide a method of easily manufacturing a stranded electric wire (stranded wire) which can be used with a large electric current.
Yet still another object of the present invention is to provide a method of easily manufacturing a stranded wire for use in a coil which can be used with a large electric current.

MEANS FOR SOLVING THE PROBLEMS

An electric wire according to the present invention comprises a stranded wire having a bundle of 10 through 20,000 copper wires each having a diameter ranging from 0.4 to 1.6, and having a total cross-sectional area ranging from 10 to 10,000 [mm²], the stranded wire being produced by a single stranded wire manufacturing process. The electric wire has not been available heretofore, and has an allowable rated electric current even in excess of 400 [A], not to mention the conventional range of 50 [A] to about 300 [A].
For example, an electric wire for 50 [A] has 11 copper wires each having a diameter of 1.2 and a total cross-sectional area of 12.4 [mm²], or 105 copper wires each having a diameter of 0.4 and a total cross-sectional area of 13.2 [mm²]. An electric wire for 400 [A] has 500 copper wires each having a diameter of 1.0 and a total cross-sectional area of 392.8 [mm²], or 3200 copper wires each having a diameter of 0.4 and a total cross-sectional area of 402.2 [mm²]. These electric wires can be used with large electric currents, and are relatively thin electric wires.
Each of the copper wires comprises at least one type of a bare copper wire, a plated bare copper wire, and a copper wire coated with an insulating coating, or a mixture of at least two types of the bare copper wire, the plated bare copper wire, and the copper wire coated with the insulating coating, or a self-fused wire comprising the at least one type of the copper wires or a mixture of the at least two types of the copper wires which are coated with a self-fusing coating.
A coil comprising the above electric wire which is wound around a core for passing magnetic fluxes is relatively soft. Therefore, the electric wire can easily be wound around the core, making it possible to fabricate a coil having a high inductance value which can be used with a large electric current. The shape of the core may be a toroidal core, a rectangular core, a division rectangular core, etc.
The core of the coil may be either one of a core for use in a transformer, a core for use in a normal-mode coil (a single-phase one-wire coil), and a core for use in a common-mode coil (a single-phase two-wire coil, a single-phase three-wire coil, a three-phase three-wire coil, or a three-phase four-wire coil). The coil may preferably be used in a power supply transformer or a noise filter device. That is, it is possible to manufacture a power supply transformer (including a switching power supply transformer) having good high-frequency characteristics and a small size, or a noise filter device having good high-frequency blocking characteristics.
A method of manufacturing a stranded wire having a desired length according to the present invention comprises the winding step of winding a copper wire having a diameter in the range from 0.4 to 1.6 from a bobbin, around takeup means to produce ring-like conductors, the bundle production step of pulling the ring-like conductors to both sides from within an opening therein to produce a bundle of a number of wires having a length corresponding to the stranded wire having the desired length, and the stranded wire production step of pulling opposite ends of the bundle and rotating at least one of the ends to produce a stranded wire.
According to the present invention, it is possible to easily manufacture an electric wire (stranded wire) which can be used with a large electric current, and to easily manufacture an electric wire (stranded wire) for use in a coil which can be used with a large electric current.
The takeup means in the winding step may comprise a takeup bobbin. If the takeup bobbin comprises either one of a bar-shaped bobbin having a variable length for obtaining the desired length, a disk-shaped bobbin having a variable diameter for obtaining the desired length, and a belt-conveyor-shaped bobbin having a variable intershaft distance for obtaining the desired length, then an electric wire (stranded wire) having a desired length can easily be manufactured.
The takeup means in the winding step may comprise means for repeating a motion to draw a ring (an elongate rectangular ring, a circular ring, an elliptical ring, or the like) on one plane to unwind the copper wire from the bobbin for thereby manufacturing the ring-shaped conductors. Preferably, an NC XY two-axis robot may be used as the takeup means.
In the bundle production step and the stranded wire production step, at least one end of the ring-shaped conductors is engaged by hooks and pulled, and the hook is rotated to manufacture the stranded wire, or at least one end of the ring-shaped conductors is sandwiched by a retainer, and the retainer is rotated to manufacture the stranded wire. The stranded wire can thus be manufactured with ease.
In the manufacturing method according to the present invention, each of the copper wires preferably comprises at least one type of a bare copper wire, a plated bare copper wire, and a copper wire coated with an insulating coating, or a mixture of at least two types of the bare copper wire, the plated bare copper wire, and the copper wire coated with the insulating coating, or a self-fused wire comprising the at least one type of the copper wires or a mixture of the at least two types of the copper wires which are coated with a self-fusing coating.
The method may further comprise after the stranded wire production step, the unraveling prevention step of preventing the manufactured stranded wire from being unraveled. The unraveling prevention step comprises the steps of, if each of the copper wires comprises either one of the bare copper wire, the plated bare copper wire, and the copper wire coated with an insulating coating, securing the stranded wire with a tape or a string, if each of the copper wires comprises the self-fusing wire that can be bonded by heat, securing the stranded wire by heating, and if each of the copper wires comprises the self-fusing wire that can be bonded by a solvent, securing the stranded wire by applying a solvent thereto. In either case, the stranded wire is easily prevented from being unraveled.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of an electric wire according to an embodiment of the present invention;
FIG. 2 is a front elevational view of a takeup device having a bar-shaped takeup bobbin for manufacturing ring-like conductors;
FIG. 3 is a perspective view of the takeup device shown in FIG. 2 (before a wire is wound);
FIG. 4 is a perspective view of the takeup device shown in FIG. 2 (after a wire is wound);
FIG. 5 is a conceptual view of a bar-shaped takeup bobbin;
FIG. 6 is a view illustrative of a process of stranding a bundled wire using hooks;
FIG. 7 is a view illustrative of a process of stranding a bundled wire using retainers in the form of flat plates;
FIG. 8 is a diagram showing a method of manufacturing an electric wire (stranded wire);
FIG. 9 is a view of an arrangement for winding copper wires from two bobbins;
FIG. 10 is a front elevational view of a takeup device having a disk-shaped takeup bobbin for manufacturing ring-like conductors;
FIG. 11 is a perspective view of the takeup device shown in FIG. 10 (before a wire is wound);
FIG. 12 is a perspective view of the takeup device shown in FIG. 10 (after a wire is wound);
FIG. 13 is a conceptual view of a disk-shaped takeup bobbin;
FIG. 14 is a front elevational view of a takeup device having a belt-conveyor-shaped takeup bobbin for manufacturing ring-like conductors;
FIG. 15 is a perspective view of the takeup device shown in FIG. 14 (before a wire is wound);
FIG. 16 is a perspective view of the takeup device shown in FIG. 14 (after a wire is wound);
FIG. 17A is a view showing a stranded wire manufacturing apparatus at the time it starts winding a wire;
FIG. 17B is a view showing the stranded wire manufacturing apparatus at the time it is winding a wire;
FIG. 17C is a view showing the stranded wire manufacturing apparatus at the time it is manufacturing a stranded wire;
FIG. 17D is a view showing the stranded wire manufacturing apparatus from which a stranded wire is removed;
FIG. 18 is an enlarged view of a distal end portion of a movable shaft;
FIG. 19 is a view illustrative of a motion for drawing a ring;
FIG. 20 is a view of a common-mode coil manufactured from the electric wire according to the embodiment;
FIG. 21 is a view of a noise filter device employing the common-mode coil according to the embodiment;
FIG. 22 is a view of a normal-mode coil manufactured from the electric wire according to the embodiment;
FIG. 23 is a view of a transformer manufactured from the electric wire according to the embodiment;
FIG. 24 is a view of a conventional common-mode coil employing a cotton-covered copper wire;
FIG. 25 is a schematic view of a conventional apparatus for manufacturing a bundled stranded wire; and
FIG. 26 is a view of a conventional common-mode coil employing bus bars.

BEST MODE FOR CARRYING OUT THE INVENTION

A. an electric wire (stranded wire), B. a method of manufacturing an electric wire (stranded wire), C. a coil employing an electric wire (stranded wire), etc. according to an embodiment of the present invention will be described below with reference to the drawings. The electric wire described under A. is actually manufactured by the method of manufacturing an electric wire described under B. For an easier understanding, however, the electric wire under A. will first be described below.

A. The explanation of an electric wire (stranded wire):

FIG. 1 shows an arrangement of an electric wire (stranded wire) 50 according to an embodiment of the present invention. The electric wire 50 comprises a bundle of 10 through 20,000 copper wires 60 each having a diameter ranging from 0.4 to 1.6, and is in the form of a stranded wire having a total cross-sectional area ranging from 10 to 10,000 [mm²] (the stranded wire is produced by a single stranded wire manufacturing process as described below).
The electric wire has not been available heretofore, and has an allowable rated electric current even in excess of 400 [A], not to mention the conventional range of 50 [A] to about 300 [A].
For example, an electric wire for 50 [A] has 11 copper wires each having a diameter of 1.2 and a total cross-sectional area of 12.4 [mm²], or 105 copper wires each having a diameter of 0.4 and a total cross-sectional area of 13.2 [mm²].
An electric wire for 400 [A] has 500 copper wires each having a diameter of 1.0 and a total cross-sectional area of 392.8 [mm²], or 3200 copper wires each having a diameter of 0.4 and a total cross-sectional area of 402.2 [mm²].
Furthermore, an electric wire for 150 [A] has 100 copper wires each having a diameter of 1.2 and a total cross-sectional area of 113.2 [mm²] .
The electric wire (stranded wire) 50 has its opposite ends and necessary locations secured by resin-made string-like fasteners 52 so that it will not be unraveled. The electric wire (stranded wire) 50 may be secured by adhesive tapes as an alternative to the fasteners 52. Solder 54 is applied to the distal end of the electric wire (stranded wire) 50.
The copper wires 60 used in the electric wire (stranded wire) 50 should preferably be bare copper wires, copper wires plated with tin or the like, or copper wires (UEW wires, PEW wires, etc.) coated with an insulating coating of urethane, polyester, or the like. The electric wire (stranded wire) 50 which comprises bare copper wires or plated copper wires can be manufactured in a shorter process because no insulating coating needs to be peeled off.
Depending on the application, the copper wires 60 may be self-fused wires which comprise either bare copper wires, plated bare copper wires, or insulation-coated copper wires, which are coated with a self-fusing coating. The self-fused wires may be wires that are bonded together by heat or wires that are bonded together by a solvent. The electric wire (stranded wire) 50 made up of self-fused wires will not be unraveled.
Furthermore, the copper wires 60 may comprise a mixture of at least two types of bare copper wires, plated bare copper wires, and insulation-coated copper wires, or may comprise self-fused wires comprising at least one type of the copper wires or a mixture of at least two types of the copper wires which are coated with a self-fusing coating.
A method of manufacturing the electric wire (stranded wire) 50 will be described below.

B. The explanation of a method of manufacturing an electric wire (stranded wire):

Embodiment 1: A method of manufacturing a stranded wire using a variable-length bar-shaped bobbin as a takeup bobbin (takeup means).

FIG. 2 shows in front elevation a takeup device 58 for manufacturing ring-like conductors 66 by winding a copper wire 60, which may be either one of the copper wires 60 described above, from a single bobbin (also referred to as a copper-wire-wound drum) 62 around a bar-shaped takeup bobbin 64. The bobbin 62 is rotatably mounted on a fixed shaft, not shown.
FIG. 3 shows in perspective the takeup device 58 immediately before it produces the ring-like conductors 66.
As shown in FIGS. 2 and 3, the bar-shaped bobbin 64 comprises a rotatable shaft 70 mounted on one end of a support post 69 that is fixedly mounted on the floor, a plate 71 integrally mounted on the rotatable shaft 70, and two pins 68 mounted on the plate 71 and movable in the longitudinal direction of the plate 71. When the pins 68 are positionally varied in the longitudinal direction of the plate 71, the length of the ring-like conductors 66 is adjusted to a desired length. The lengths from the center of the rotatable shaft 70 to the respective pins 68 should preferably be the same as each other to prevent the rotatable shaft 70 from wobbling while in rotation.
The rotatable shaft 70 is integrally secured coaxially to a driven pulley 72. A power-transmitting belt 80 is trained around the driven pulley 72 and a drive pulley 76 of an electric motor 74 as a rotary actuator fixed to the floor.
As shown in FIG. 4, after the distance between the pins 68 is fixed to a desired distance, the drive pulley 76 of the electric motor 74 is rotated in the direction indicated by the arrow B to rotate the rotatable shaft 70 in the direction indicated by the arrow A. The rotation is stopped when a predetermined number of revolutions (1/2 of a predetermined number) are reached. A predetermined number of ring-like conductors 66 are thus manufactured.
In FIGS. 2 through 4, the rotatable shaft 70 is rotated by the belt 80. However, the rotatable shaft 70 may be rotated directly by the rotary actuator or may be rotated through gears. The ring-like conductors 66 are manufactured in the manner described above.
As conceptually shown in FIG. 5, the bar-shaped bobbin 64 may be of any desired structure insofar as it comprises a bar-shaped takeup bobbin 64A having a rotatable shaft 70A and a variable-length bar 64B extending perpendicularly to and on opposite sides of the rotatable shaft 70A.
The ring-like conductors 66 manufactured by the takeup device 58 are removed from the pins 68 of the bar-shaped bobbin 64, and are pulled to both sides from within an opening 82 (see FIGS. 2 and 4), thereby producing a bundle of as many wires as desired which has a length corresponding to a stranded wire having a desired length.
FIG. 6 shows a stranded wire manufacturing device 90 for pulling the ring-like conductors 66 toward outside at both sides with hooks 88, 89 from within the opening 82 and twisting them into a bundle 66B of as many wires as desired.
The bundle 66B has an end engaged by a fixed hook 89 mounted on a fixed block 81 and the other end engaged by a rotatable hook 88 fixed to a rotatable shaft 86 of an electric motor 84 which is rotatable in the direction indicated by the arrow. The distance between the fixed hook 89 and the rotatable hook 88 is variable so as to correspond to the length of the bundle 66B.
In FIG. 6, the rotatable shaft 86 of the electric motor 84 is rotated to rotate the rotatable hook 88, twisting the bundle 66B. When the rotatable shaft 86 has been rotated predetermined times, the rotation of the electric motor 84 is stopped, thereby producing a stranded wire having as many twists as desired. If the fixed hook 89 is replaced with a rotatable hook and is rotated in the direction opposite to the direction indicated by the arrow, then the time required to produced the stranded wire is reduced.
The stranded wire is removed from the hooks 88, 89. Then, as shown in FIG. 1, the stranded wire is secured at its opposite ends and necessary locations by resin-made string-like fasteners 52 or adhesive tapes so that it will not be unraveled. Thereafter, solder 54 is applied to the distal end of the stranded wire, thus producing a desired electric wire (stranded wire) 50.
If the copper wire 60 is a self-fusing wire that can be bonded with heat, then after stranded wire is removed from the hooks 88, 89, the stranded wire is left to stand at a certain temperature for a predetermined period of time in a constant-temperature container such as an oven or the like, preventing the electric wire (stranded wire) 50 from being unraveled by bonding the copper wires 60 together. Alternatively, after stranded wire is removed from the hooks 88, 89, a solvent may be sprayed onto the copper wire 60 or the copper wire 60 may be immersed in a solvent and then pulled out of the solvent, preventing the electric wire (stranded wire) 50 from being unraveled by bonding the copper wires 60 together with the solvent.
FIG. 7 shows another stranded wire manufacturing device 92. The stranded wire manufacturing device 92 differs from the stranded wire manufacturing device 90 shown in FIG. 6 in that the rotatable hook 88 of the stranded wire manufacturing device 90 is replaced with a rotatable flat presser plate 98 as a retainer and the fixed hook 89 and the fixed block 81 are replaced with a fixed flat presser plate 99 as a retainer and a fixed block 81A. The ring-like conductors 66 have their opposite ends fixed to the flat presser plates 98, 99 by screws 102, 104, and the rotatable flat presser plate 98 is rotated by the electric motor 84 for thereby manufacturing a stranded wire.
FIG. 8 is a diagram showing the steps of the B. method of manufacturing an electric wire (stranded wire) as described above. The method of manufacturing an electric wire (stranded wire) has, as its basic steps, the winding step (S1) of winding a copper wire 60 having a diameter in the range from 0.4 to 1.6 from a bobbin 62, around a takeup bobbin 64 to produce ring-like conductors 66, the bundle production step (S2) of pulling the ring-like conductors 66 to both sides from within an opening 82 or the like to produce a bundle 66B of many wires having a length corresponding to a stranded wire having a desired length, and the stranded wire production step (S3) of pulling opposite ends of the bundle 66B and rotating at least one of the ends to produce a stranded wire having a desired length.
The above basic steps are carried out to produce a stranded wire. In this manner, an electric wire (stranded wire) which can be used with a large electric current can easily be manufactured in the single stranded wire production step (S3).
The takeup device 58 may be of an arrangement for winding the copper wire 60 from the single bobbin 62. Therefore, it is not necessary to employ as many bobbins 30 as the number of wires that make up a stranded wire, as described above with reference to FIG. 25 as the prior art. The takeup device itself is simple in structure, and the space required to produce an electric wire (stranded wire) and the costs (the costs of the takeup device and the stranded wire) are greatly reduced.
In the present invention, the bobbin 62 used in the winding step (S1) does not need to be limited to a single bobbin. If two (or more) bobbins 62 are provided for winding copper wires parallel to each other, as shown in FIG. 9, then the winding time is reduced to one-half. According to the present invention, therefore, the ring-like conductors 66 can be manufactured with fewer bobbins 62 than the number of wires that make up a stranded wire, or at least one bobbin 62.
If the copper wire 60 is any one of a bare copper wire, a plated bare copper wire, or an insulation-coated copper wire, then the stranded wire is secured by tapes or string-like fasteners 52. If the copper wire 60 is a self-fusing wire that can be bonded by heat, then the stranded wire is secured by heating. If the copper wire 60 is a self-fusing wire that can be bonded by a solvent, then the stranded wire is secured by applying a solvent thereto. Therefore, it is preferable for the stranded wire production step (S3) to be followed by an unraveling prevention step (S4). As a result, a stranded wire which is prevented from being unraveled can be produced.
Another embodiment of the bundle production step (S2) will be described below. Those parts shown in the drawings to be referred to below which are identical or correspond to those shown in FIGS. 1 through 9 are denoted by identical reference characters, and will not be described in detail below.

Embodiment 2: A method of manufacturing a stranded wire using a variable-diameter disk-shaped bobbin as a takeup bobbin.

FIG. 10 shows in front elevation a takeup device 158 for manufacturing ring-like conductors 166 by winding a copper wire 60 from a single bobbin 62 around a disk-shaped bobbin (winding means) 164.
FIG. 11 shows in perspective the takeup (winding) device 158 before it produces the ring-like conductors 166.
As shown in FIGS. 10 and 11, the disk-shaped bobbin 164 comprises a rotatable shaft 70 mounted on one end of a support post 69 a disk-shaped plate 171 is integrally mounted on the rotatable shaft 70, and four pins 168 mounted on the plate 171 and movable in the radial direction of the plate 171. When the pins 168 are positionally varied in the radial direction of the plate 171, the length of the ring-like conductors 166 is adjusted to a desired length. The lengths from the center of the rotatable shaft 70 to the respective pins 168 should preferably be the same as each other to prevent the rotatable shaft 70 from wobbling while in rotation.
The rotatable shaft 70 is integrally secured coaxially to a driven pulley 72. A power-transmitting belt 80 is trained around the driven pulley 72 and a drive pulley 76 of an electric motor 74.
As shown in FIG. 12, after the pins 168 are fixed in respective given positions, the drive pulley 76 of the electric motor 74 is rotated in the direction indicated by the arrow B to rotate the rotatable shaft 70 in the direction indicated by the arrow A. The rotation is stopped when the number of revolutions of the shaft reaches a predetermined number (1/2 of a predetermined number of the wires). A ring-like conductor 166 having predetermined wire turns is thus manufactured.
As conceptually shown in FIG. 13, the disk-shaped bobbin 164 may be of any desired structure insofar as it comprises a disk-shaped bobbin 164A having a rotatable shaft 70A and a variable-diameter disk 171A.
The ring-like conductor 166 manufactured by the takeup device 158 is removed from the disk-shaped bobbin 164, and is pulled to both sides from within an opening 182 (see FIGS. 10 and 12), thereby producing a bundle of as many wires as desired which has a length corresponding to a stranded wire having a desired length.
Then, the stranded wire production step (S3) and the unraveling prevention step (S4) described above are carried out to produce an electric wire (stranded wire) having a desired length.
Still another embodiment of the bundle production step (S2) will be described below.

Embodiment 3: A method of manufacturing a stranded wire using a belt-conveyor-shaped bobbin having a variable intershaft distance, as a takeup bobbin (takeup means).

FIG. 14 shows in front elevational a takeup device 258 for manufacturing ring-like conductors 266 by winding a copper wire 60 from a single bobbin 62 around a belt-conveyor-shaped bobbin 264.
FIG. 15 shows in perspective the takeup (winding) device 258 before it produces the ring-like conductors 266.
As shown in FIGS. 14 and 15, the belt-conveyor-shaped bobbin 264 has two pulleys 281, 282. To change the distance between the pulleys 281, 282, one or both of the pulleys 281, 282 are moved toward or away from the other or each other to adjust the length of the ring-like conductors 266 to a desired length.
As shown in FIG. 16, after the distance between the pulleys 281, 282 is fixed to a desired distance, the drive pulley 281 of the electric motor 74 is rotated in the direction indicated by the arrow B to rotate the driven pulley 282 in the direction indicated by the arrow A. The rotation is stopped when the number of revolutions of the shaft reaches a predetermined number (1/2 of a predetermined number of the wires). A ring-like conductor 266 having predetermined wire turns is thus manufactured. In the belt-conveyor-shaped bobbin 264, the ring-like conductor 266 doubles as a transmission belt.
The ring-like conductor 266 is manufactured in the manner described above. After the ring-like conductor 266 is manufactured by the takeup device 258, the ring-like conductor 266 is removed from the pulleys 281, 282, and is pulled to both sides from within an opening 283 (see FIGS. 14 and 16), thereby producing a bundle of as many wires as desired which has a length corresponding to a stranded wire having a desired length.
Then, the stranded wire production step (S3) and the unraveling prevention step (S4) described above are carried out to produce an electric wire (stranded wire) having a desired length.
FIGS. 17A through 17D show an arrangement of and a manufacturing method performed by a stranded wire manufacturing apparatus 402 for manufacturing an electric wire (stranded wire) using an XY two-axis robot 400 as a takeup means in place of the takeup bobbin 64, etc.
The stranded wire manufacturing apparatus 402 has an XY two-axis robot 400 that is controlled for its operation by an NC program incorporated in a control console, not shown, a fixed shaft 404 extending in an X-axis direction, and a movable shaft 406 mounted on the fixed shaft 404 for movement in the X-axis direction and a Y-axis direction perpendicular thereto. Pulleys 408 for guiding a copper wire 60 are mounted on a side of the movable shaft 406. A nozzle-like tube 410 is mounted on the distal end of the side of the movable shaft 406.
FIG. 18 shows at an enlarged scale the distal end of the movable shaft 406 on which the tube 410 is mounted.
The stranded wire manufacturing apparatus 402 is arranged such that a copper wire 60 unreeled from a bobbin 62 and guided by the two pulleys 408 passes through a narrow hole in the tube 410 and is wound between hooks 412, 414.
The hook 412 has an opening end (hook slot) 413 directed vertically upwardly. The hook 412 is moved in the X-axis direction by the control console and fixed to a positionable base 416. With the base 416 moved in the X-axis direction and fixed in a predetermined position, the stranded wire manufacturing apparatus 402 is capable of manufacturing ring-shaped conductors 466 having a desired length.
The hook 414 is rotatable by a motor 422 fixed to a base 420. When the hook 414 starts to wind, is winding, and ends to wind the copper wire 60, the hook 414 has an opening end (hook slot) 415 directed vertically upwardly. The motor 422 is also controlled by the control console.
With the hooks 412, 414 being positionally fixed and their opening ends 413, 415 being directed vertically upwardly as shown in FIG. 17A, the copper wire 60 is trained around the hooks 412, 414. Thereafter, as shown in FIG. 19, for producing ring-like conductors 466 in the form of a predetermined number of turns, the copper wire outlet end (vertically lower end) of the tube 410 moves to repeatedly draw a ring 450 on one plane to unwind the copper wire 60 from the bobbin 62 for thereby manufacturing ring-like conductors 466. The ring 450 is not limited to an elongate rectangular shape, but may be of a shape selected from a circular shape, an elliptical shape, a lozenge shape, etc.
FIG. 17B shows the stranded wire manufacturing apparatus 402 while it is manufacturing ring-like conductors 466. FIG. 17C shows the stranded wire manufacturing apparatus 402 when the production of ring-like conductors 466 is finished.
Subsequently, as shown in FIG. 17C, when the hook 414 is rotated predetermined times by the electric motor 422, the rotation of the electric motor 422 is stopped, thereby producing a stranded wire having a predetermined number of twists.
As shown in FIG. 17D, a stranded wire 467 is removed from the hooks 412, 414. Then, as shown in FIG. 1, the stranded wire is secured at its opposite ends and necessary locations by resin-made string-like fasteners 52 or adhesive tapes so that it will not be unraveled. Thereafter, solder 54 is applied to the distal end of the stranded wire, thus producing a desired electric wire (stranded wire) 50 as shown in FIG. 1.

C. The explanation of a coil, etc. employing an electric wire (stranded wire):

FIG. 20 shows a common-mode coil 300 for use in a noise filter device, comprising a toroidal core 10 for passing magnetic fluxes which has an outside diameter of 130, an inside diameter of 100, and a thickness of 70, as shown in FIG. 24, and three electric wires 50 (see FIG. 1) each comprising 500 UEW wires manufactured by the manufacturing method according to the embodiment, each having a diameter of 1.0, and a total cross-sectional area of 392.8 [mm²], each of the electric wires 50 being wound a plurality of turns around the toroidal core 10.
The common-mode coil 300 has an allowable electric current of about 400 [A] and is of a three-phase, three-wire 500 Vac class.
The common-mode coil 300 has conductors softer than the coil 2 using the electric wires 8 each comprising a cotton-covered copper wire shown in FIG. 24, and has thin stranded wires, i.e., thin clustered conductors. It is thus possible to increase the number of turns of the common-mode coil 300 around the magnetic core 10. Therefore, it is easy to increase the inductance value for increasing an attenuated amount of high-frequency noise.
As the number of turns is increased, the inductance value is increased. It is not necessary to stack the toroidal cores 14, 16, 18 as with the noise filter device having the coil 12 using the bus bars 20, 22, 24 shown in FIG. 26.
As a result, as shown in FIG. 21, a noise filter device 320 comprising a case 311, input terminals 305, 306, 307, output terminals 308, 309, 310, the common-mode coil 300, an X capacitor block 302, and a Y capacitor block 304 is of a smaller size, a reduced weight, a lower cost, and a higher high-frequency blocking capability which can simultaneously be achieved.
The electric wire 50 according to the embodiment of the present invention is also applicable to a normal-mode coil 322 comprising a single electric wire 50 wound as a plurality of turns around a core 10, as shown in FIG. 22, in addition to the common-mode coil 300. The electric wire 50 is further applicable to a transformer 324 having a primary winding 50A and a secondary winding 50B which are wound around a core 298, as shown in FIG. 23.

INDUSTRIAL APPLICABILITY

According to the present invention, there are provided an electric wire (stranded wire) which can be used with a large electric current, a coil having a high inductance value which can be used with a large electric current, and a noise filter device which can be used with a large electric current.
According to the present invention, there is also provided a method of easily manufacturing a stranded wire which can be used with a large electric current.
According to the present invention, there is further provided a method of easily manufacturing a stranded wire for use in a coil which can be used with a large electric current.

Claims

An electric wire comprising a stranded wire (50) having a bundle of 10 through 20,000 copper wires (60) each having a diameter ranging from 0.4 to 1.6, and having a total cross-sectional area ranging from 10 to 10,000 [mm²], said stranded wire being produced by a single stranded wire manufacturing process.
An electric wire according to claim 1, wherein each of said copper wires comprises:
at least one type of a bare copper wire, a plated bare copper wire, and a copper wire coated with an insulating coating; or

a mixture of at least two types of said bare copper wire, said plated bare copper wire, and said copper wire coated with the insulating coating; or

a self-fused wire comprising said at least one type of the copper wires or a mixture of said at least two types of the copper wires which are coated with a self-fusing coating.
A coil comprising an electric wire according to claim 1 or 2, which is wound around a core (10) for passing magnetic fluxes.
A coil according to claim 3, wherein said core comprises either one of a core for use in a transformer, a core for use in a normal-mode coil, and a core for use in a common-mode coil.
A noise filter device comprising a common-mode coil (300) having an electric wire according to claim 1 or 2, which is wound around a core (10) for passing magnetic fluxes.
A method of manufacturing a stranded wire having a desired length, comprising:
the winding step (S1) of winding a copper wire (60) having a diameter in the range from 0.4 to 1.6 from a bobbin (62), around takeup means to produce ring-like conductors (66);

the bundle production step (S2) of pulling said ring-like conductors to both sides from within an opening (82) therein to produce a bundle (66B) of a number of wires having a length corresponding to the stranded wire having the desired length; and

the stranded wire production step (S3) of pulling opposite ends of said bundle and rotating at least one of the ends to produce a stranded wire.
A method according to claim 6, wherein said takeup means in said winding step comprises a takeup bobbin, said takeup bobbin comprising either one of a bar-shaped bobbin (64) having a variable length for obtaining said desired length, a disk-shaped bobbin (164) having a variable diameter for obtaining said desired length, and a belt-conveyor-shaped bobbin (264) having a variable intershaft distance for obtaining said desired length.
A method according to claim 6, wherein said takeup means in said winding step comprises means for repeating a motion to draw a ring (450) on one plane to unwind said copper wire from said bobbin for thereby manufacturing said ring-shaped conductors.
A method according to claim 6, wherein in said bundle production step and said stranded wire production step, at least one end of said ring-shaped conductors is engaged by hooks (88), (89) and pulled, and said hook (88) is rotated to manufacture said stranded wire, or at least one end of said ring-shaped conductors is sandwiched by a retainer, and said retainer is rotated to manufacture said stranded wire.
A method according to any one of claims 6 through 9, wherein each of said copper wires comprises:
at least one type of a bare copper wire, a plated bare copper wire, and a copper wire coated with an insulating coating; or

a mixture of at least two types of said bare copper wire, said plated bare copper wire, and said copper wire coated with the insulating coating; or

a self-fused wire comprising said at least one type of the copper wires or a mixture of said at least two types of the copper wires which are coated with a self-fusing coating.
A method according to claim 10, further comprising:
after said stranded wire production step, the unraveling prevention step (S4) of preventing the manufactured stranded wire from being unraveled;

wherein the unraveling prevention step (S4) comprises the steps of:

if each of said copper wires comprises either one of said bare copper wire, said plated bare copper wire, and said copper wire coated with the insulating coating, securing said stranded wire with a tape or a string;

if each of said copper wires comprises said self-fusing wire that can be bonded by heat, securing said stranded wire by heating; and

if each of said copper wires comprises said self-fusing wire that can be bonded by a solvent, securing said stranded wire by applying a solvent thereto.