BACKGROUND OF THE INVENTION 0001 1. Field of the Invention 0002 This invention relates to a square wire manufacturing machine for forming a thin square wire, which is used for a thin motor, a thin transformer, an electrical apparatus such as a voice coil for a high performance speaker or an electronic equipment, with a round conductive wire. 0003 2. Description of the Related Art 0004 When a usual round conductive wire (circular section) is wound for a coil used in a thin motor or a speaker voice coil, gaps between conductive wires and swelling on a crossing area of conductive wires result to be problems for miniaturization or dimensional accuracy of electronic components. In all electronic components which gives mechanical vibration or rotation by an interaction of a magnetic field and a generated magnetic field by electric current of an inductive wire in the magnetic field, improvement of performance and miniaturization of an inductive wire wound for a coil are required. 0005 Manufacturing a long thin square wire is required to solve the above problems. The square wire herein includes a regular square wire. 0006 Regarding usual methods of manufacturing a square wire, rolling a round wire to a rectangular-section wire by a pressure roll or drawing a round conductive wire through a draw die having a square hole are known. 0007 Objects to be Solved 0008 However, usual method of manufacturing a square wire mentioned above result always round portions (curved surface) on corners of the square wire. Therefore, when a coil is wound with a square wire manufactured by a usual method, gaps (smaller than gaps with a round conductive wire) between conductive wires still result. 0009 According to a method of rolling a round conductive wire by a pressure roll, round portions on corners always arise and shapes of the round portions are not uniform. Furthermore, deformation of the wire or dispersion of a wire diameter may be occurred easily. 0010 When a square wire is made of a thin conductive sheet metal, length of the thin sheet metal as a base material is limited to compete against a round conductive wire. More complex manufacturing machine or cost-up may be concerned. The length of a base material is short so that supplying a thin sheet metal is required at frequent intervals and then continuous automatic operation of a winding machine may be hindered. 0011 To overcome the above drawback of prior art, one object of this invention is to provide a square wire manufacturing machine which can manufacture a conductive wire, having a square section and being used for a coil, continuously and precisely in low-cost with a relatively simple structure.

SUMMARY OF THE INVENTION 0012 How to Attain the Object 0013 In order to attain the objects, a square wire manufacturing machine, according to the invention, includes four rollers being disposed in a shape of swastika to be crossed mutually for forming a square hole and a position adjusting unit for adjusting disposed positions of the four rollers. 0014 Furthermore, the position adjusting unit mentioned above includes a fixed wedge portion and a movable wedge portion contacting with the fixed wedge portion continuously with pressure and being disposed asymmetrically against the fixed wedge portion. And the movable wedge portion is mounted on a bearing unit of the roller. 0015 Furthermore, the position adjusting unit mentioned above includes a first position adjusting device for adjusting a disposed position of the roller to move the roller in a direction of an axis of rotation of the roller and a second position adjusting device for adjusting a disposed position of the roller to move the roller in a direction perpendicular to the axis of rotation. And both the first and the second position adjusting devices are mounted on the bearing units of respective four rollers. 0016 Furthermore, the position adjusting unit mentioned above including a first position adjusting means for adjusting and fixing a disposed position of a first roller of the four rollers, a second position adjusting means for adjusting a gap against the first roller to move a disposed position of a second roller in a direction of an axis of rotation of the second roller and adjusting a forming size of the square wire to move a disposed position of the second roller in a direction perpendicular to the axis of rotation of the second roller and fixing the second roller, a third position adjusting means for adjusting a gap against the second roller to move a disposed position of a third roller in a direction of an axis of rotation of the third roller and adjusting the forming size of the square wire to move a disposed position of the third roller in a direction perpendicular to the axis of rotation of the third roller and fixing the third roller, and a fourth position adjusting means for adjusting the forming size of the square wire to move a disposed position of a fourth roller in a direction of an axis of rotation of the fourth roller and adjusting a gap against the first roller to move a disposed position of the fourth roller in a direction perpendicular to the axis of rotation of the fourth roller and fixing the fourth roller is effective. 0017 Preferably, the four rollers being disposed in a shape of swastika to be crossed mutually for forming a square hole and four rotation transmitting devices including motors for driving respectively the four rollers are placed in the shape of swastika around the hole. 0018 According to this invention, a long square wire can be manufactured by forwarding a round wire through a square hole being formed with four rollers so that an accurate square wire can be formed in high speed. The disposed positions of the four rollers can be adjusted freely and then a thin square wire can be manufactured easily and precisely. 0019 Furthermore, according to this invention, a long square wire can be formed by a relatively simple machine having four rollers so that cost of a manufacturing machine can be reduced and number of interruption in process is remarkably reduced. Therefore, manufacturability for a square wire is improved and manufacturing cost of a square wire is reduced. When the four rollers are worn away, the four rollers can be reused to be re-polished so that manufacturing cost can be reduced. 0020 According to this invention, disposed positions of the four rollers can be moved freely in a very small quantity so that forming accuracy of a square wire can be improved and also a thin square wire can be formed easily and precisely. 0021 According to this invention, disposed positions of the four rollers can be adjusted both in a direction of an axis and in a direction perpendicular to an axis so that the shape of the square hole being formed by the four rollers can be fine-adjusted easily. Therefore, accuracy of the square hole for press-forming a round wire can be much improved and a thin accurate square wire can be formed continuously. 0022 According to this invention, operation for disposing the four rollers in position can be easily, quickly and effectively done. And a square hole can be easily structured to form various size of square wires, for example from a 1.5 mm square wire to a 0.02 mm extra-thin square wire. 0023 According to this invention, a whole physical size of a square wire manufacturing machine can be miniaturized so that the foot-print size can be reduced and manufacturing cost can be reduced. The machine can be miniaturized so that multiple-step can be constituted by a plurality of square wire manufacturing machines which have respective gradually decreased square holes being formed by the four rollers and forwarding a round wire through the multiple-step holes, a extra-thin and very accurate square wire can be manufactured. 0024 The above and other objects and features of this invention will become more apparent from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS 0025 FIG. 1 is a plan view, showing a layout with main components of an embodiment of a square wire manufacturing machine according to this invention; 0026 FIG. 2 is a side view, showing main area of a position adjusting unit of the embodiment of the square wire manufacturing machine according to this invention; 0027 FIG. 3 is a plan view of main area of a position adjusting unit shown in FIG. 2; and 0028 FIG. 4 is an explanation drawing of operation, showing a relationship between four rollers and position adjusting units being used in the embodiment of the square wire manufacturing machine according to this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 0029 An embodiment according to this invention will now be described with reference to figures. FIGS. 1-4 show a square wire manufacturing machine according to an embodiment of this invention. The square wire manufacturing machine is structured to have a square wire (including a regular square wire) by press-forming a circular section round conductive wire (metal wire) into square. 0030 FIG. 1 shows main components constituting the square wire manufacturing machine. The square wire manufacturing machine includes four rollers which are a first roller 1, a second roller 2, a third roller 3 and a fourth roller 4. The first roller 1, the second roller 2, the third roller 3 and the fourth roller 4 are disposed in a shape of swastika to be crossed mutually for forming a square hole 5. To pass a round conductive wire through the hole 5, being structured above, in high speed, a press-formed square wire is manufactured. 0031 Total four rotation transmitting units are provided on respective rollers 1-4 to rotate respective rollers 1-4 in high speed. Each of the four rotation transmitting units includes a motor 6 and a synchronous belt 8 for transmitting rotation of the motor 6 to a bearing unit 7. Each of the bearing units 7 is provided correspondingly with the first roller 1, the second roller 2, the third roller 3 or the fourth roller 4. 0032 The four rotation transmitting units mentioned above are disposed in a shape of swastika around the hole 5 being formed by the first roller 1-the fourth roller 4, as shown in FIG. 1. To place the four rotation transmitting units in the shape of swastika, an area for installing the machine can be decreased and operatability of the machine can be enhanced. 0033 Furthermore, the square wire manufacturing machine according to this invention has a position adjusting unit for fine-adjusting respective disposed positions of the first roller 1, the second roller 2, the third roller 3 and the fourth roller 4. The position adjusting unit being mounted on the third roller 3, shown in FIGS. 2 and 3, will be described as a example. 0034 The position adjusting unit being mounted on the third roller 3 is provided with a set of two position adjusting devices. The set of two position adjusting devices is constituted by a first position adjusting device 9 for fine-adjusting the disposed position of the third roller 3 to move the third roller 3 in a direction of an axis of the third roller 3 and a second position adjusting device 10 for fine-adjusting the disposed position of the third roller 3 to move the third roller 3 in a direction perpendicular to an axis of the third roller 3. 0035 The first position adjusting device 9 is a wedge-slide-type position adjusting mechanism and includes a fixed wedge portion 11 and a movable wedge portion 12 being placed asymmetrically (in the opposite direction) against the fixed wedge portion 11. The movable wedge portion 12 is mounted on the bearing unit 7 and is energized always in a direction of an arrow A by a restoring force of a spring 13 to contact with the fixed wedge portion 11 with pressure. The movable wedge portion 12 is slid against the restoring force of the spring 13 by rotating a micrometer head 14. The third roller 3 is moved in a direction of the axis thereof by sliding the movable wedge portion 12 so that the disposed position of the third roller 3 is fine-adjusted. 0036 The second position adjusting device 10 is a wedge-slide-type position adjusting mechanism, being constituted similarly as the first position adjusting device 9 and includes a fixed wedge portion 15 and a movable wedge portion 16 being placed asymmetrically against the fixed wedge portion 15. The movable wedge portion 16 is mounted on the bearing unit 7 and is energized always in a direction of an arrow B by a restoring force of a spring 17 to contact with the fixed wedge portion 15 with pressure. The movable wedge portion 16 is slid against the restoring force of the spring 17 by rotating a micrometer head 18. The third roller 3 is moved in a direction perpendicularly to the axis thereof by sliding the movable wedge portion 12 so that the disposed position of the third roller 3 is fine-adjusted. A wedge holding plate 19 is provided. 0037 Adjusting respective disposed positions of the first roller 1, the second roller 2, the third roller 3 and the fourth roller 4, which have respectively the position adjusting device 9 and the position adjusting device 10 mentioned above, will be described with reference to FIG. 4. In FIG. 4, four rollers of the first roller 1-the fourth roller 4 rotate respectively in a direction of an arrow C in high speed and a press-formed square wire is forwarded through the hole 5. 0038 Firstly, the first roller 1 of the four rollers 1-4 is adjusted and fixed in a predetermined position. Thereafter, the second roller 2 is fine-adjusted to have a gap (approximately 5 micron) against the first roller 1 by moving a disposed position thereof in a direction of an axis thereof shown by an arrow D. Then, the second roller 2 is adjusted to have a forming size of a square wire to be manufactured by moving the disposed position thereof in a direction perpendicular to an axis thereof shown by an arrow F and fixed. 0039 The third roller 3 is adjusted to have a forming size of a square wire by moving a disposed position thereof both in a direction of an axis thereof shown by an arrow G and in a direction perpendicular to an axis thereof shown by an arrow H. The fourth roller 4 is fine-adjusted to have a gap (approximately 5 micron) against the first roller 1 by moving a disposed position thereof in a direction perpendicular to an axis thereof shown by an arrow J. Then, the fourth roller 4 is adjusted to have a forming size of a square wire by moving the disposed position thereof in a direction of an axis thereof shown by an arrow K and fixed. 0040 Thus, the disposed positions of the first roller 1, the second roller 2, the third roller 3 and the fourth roller 4 can be adjusted freely and minutely so that a thin square wire can be formed easily and precisely. Changing a forming size can be done easily by a simple operation and then various sizes of square wires can be manufactured. 0041 Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein.