Patent Publication Number: US-9899135-B2

Title: Reactor device

Description:
TECHNICAL FIELD 
     The present invention relates to reactor devices for eliminating high-frequency components arising in a power controller system used in solar power generation when DC power is converted to AC power by means of an inverter. More particularly, the invention relates to a reactor device employing an amorphous material. 
     BACKGROUND ART 
     There is known a reactor device using an amorphous material for iron cores of a large-capacity three-phase reactor device in order to reduce loss (iron loss) during operation. Such a reactor device is disclosed in Patent Literature 1 (Japanese Patent Application Laid-Open No. 2008-218660). 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: Japanese Patent Application Laid-Open No. 2008-218660 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     Patent Literature 1 discloses the reactor device which includes: a toroidal core having a leg portion formed by stacking a plurality of ring-like core units in a magnetization direction; and a coil and in which the whole or a part of the core unit is formed of an amorphous metal. However, Patent Literature 1 teaches the structures of the core and the coil, and does not teach the structure of the whole body of the reactor device. 
     The invention has an object to provide a reactor device that employs an amorphous core for reducing the loss. 
     Solution to Problem 
     As a solution to the above problem, a structure defined by the claims of the invention, for example, is adopted. While the present application includes a plurality of means for solving the above problem, one example thereof is a reactor device which includes: a yoke core formed by toroidally winding an amorphous ribbon; a magnetic leg core formed of the amorphous ribbon; and a coil wound around the magnetic leg core, wherein the yoke core is disposed in a bottom fastening fixture, the magnetic leg cores are stacked and arranged at three places on a circumference of the yoke core with equal spacing, the coil is slidingly fitted around the magnetic leg core, the yoke core is disposed atop the magnetic leg cores, the yoke core is capped with a top fastening fixture, three studs are arranged around the circular bottom fastening fixture and top fastening fixture with equal spacing and another stud is disposed at the center of the bottom fastening fixture and top fastening fixture, and the bottom fastening fixture and top fastening fixture are fastened and fixed by means of the studs. 
     Advantageous Effects of Invention 
     According to the invention, the reactor device employs the amorphous material for the iron cores and thence, can achieve decrease in loss and size reduction. In a manufacturing method, the magnetic leg cores can be positioned and fixed with the studs and the like while the coils can be highly precisely positioned and fixed with coil metal fixtures. Thus, the three legs can be balanced with one another. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a structure of a reactor device for illustrating the principle of the reactor device employing an amorphous core according to the invention. 
         FIG. 2A  is a perspective view showing the overall structure of the reactor device employing the amorphous core according to the invention. 
         FIG. 2B  is a perspective view of the overall structure of the reactor device as seen from a bottom side of the structure of  FIG. 2A . 
         FIG. 2C  is a perspective view of the device mounted with zero-phase cores, magnetic leg cores and coils according to the invention. 
         FIG. 2D  is a vertical sectional view showing the interior of the reactor device of  FIG. 2A . 
         FIG. 2E  is a perspective view showing a reactor device mounted with the zero-phase cores, magnetic leg cores and coils according to the invention. 
         FIG. 2F  is a horizontal sectional view showing the interior of the reactor device of  FIG. 2A . 
         FIG. 3  is a group of external perspective views of a yoke core, the magnetic leg core and the zero-phase core. 
         FIG. 4  is a group of perspective views showing a step of mounting a laminate and the yoke core to a bottom fastening fixture. 
         FIG. 5  is a perspective view showing a step of mounting zero-phase core holders for mounting the zero-phase cores to studs arranged on the bottom fastening fixture. 
         FIG. 6  is a group of perspective views showing a step of stacking and mounting the magnetic leg cores. 
         FIG. 7  is a group of perspective views showing a step of slidingly fitting the coil around the magnetic leg core. 
         FIG. 8  is a group of perspective views showing the step of mounting the coils on the three magnetic leg cores, respectively. 
         FIG. 9  is a group of perspective views showing a step of mounting the zero-phase cores. 
         FIG. 10  is a group of perspective views showing a step of fixing the three coils. 
         FIG. 11  is a perspective view showing a step of mounting the laminate and the yoke core and capping them with a top fastening fixture. 
         FIG. 12  is a group of perspective views showing a step of mounting an eyenut for hanging the reactor device. 
         FIG. 13  is a group of external perspective views showing a yoke core, a magnetic leg core and a zero-phase core according to Example 3, respectively. 
         FIG. 14  is a group of perspective views showing a step of mounting the laminate and the yoke core to the bottom fastening fixture. 
         FIG. 15  is a perspective view showing a step of mounting the zero-phase cores to the bottom fastening fixture. 
         FIG. 16  is a group of perspective views showing a step of arranging coil support fixtures around a central stud. 
         FIG. 17  is a group of perspective views showing a step of stacking and mounting circular magnetic leg cores. 
         FIG. 18  is a perspective view showing a step of slidingly fitting the coil around the magnetic leg cores. 
         FIG. 19  is a perspective view showing a state where the coils are fitted around the three magnetic leg cores, respectively. 
         FIG. 20  is a group of perspective views showing a step of mounting the coil support fixture for fixing respective upper parts of the three coils. 
         FIG. 21  is a perspective view showing a step of capping the laminate and the yoke core with the top fastening fixture. 
         FIG. 22  is a group of perspective views showing a step of mounting the eyenut for hanging the reactor device. 
         FIG. 23  is a perspective view showing a completed state where casters are attached to a base of the reactor device. 
         FIG. 24  is a perspective view showing a structure where coil terminals according to Example 4 are drawn from the inside of the reactor device. 
         FIG. 25  is a perspective view showing a structure where a sound absorbing material is disposed between the top/bottom fastening fixture and the laminate. 
         FIG. 26A  is a group of perspective views showing a structure where a lower yoke core is mounted on the bottom fastening fixture. 
         FIG. 26B  is a perspective view showing a structure where the coil support fixtures and insulating materials are disposed at the center of the bottom fastening fixture. 
         FIG. 26C (a) is a perspective view showing how cylindrical magnetic leg cores are assembled, and  FIG. 26C (b) is a diagram illustrating a layout relation of the cylindrical magnetic leg cores and the yoke core. 
         FIG. 26D  is a perspective view showing a coil fitting step of slidingly fitting the coil around the stacked cylindrical magnetic leg cores. 
         FIG. 26E  is a group of perspective views showing a structure where a coil  101  is slidingly fitted around each of the three magnetic leg cores and a structure where the coils are fixed with the coil support fixture. 
         FIG. 26F  is a group of perspective views showing a step of mounting an upper yoke core atop the coils. 
         FIG. 26G  is a top view showing the reactor device having all the components assembled thereto and equipped with the magnetic leg cores having a circular cross section. 
         FIG. 26H  is a front view showing the reactor device having all the components assembled thereto and equipped with the magnetic leg cores having the circular cross section. 
         FIG. 26I  is an external perspective view showing the reactor device having all the components assembled thereto and equipped with the magnetic leg cores having the circular cross section. 
         FIG. 27  is a group of perspective views showing a structure of the magnetic leg core where a stack of four magnetic leg cores having the circular cross section is assembled with an insulating tube body. 
         FIG. 28  is a perspective view showing a yoke core according to Example 8 of the invention. 
         FIG. 29A  is a group of perspective views showing a step of mounting the lower yoke core to the bottom fastening fixture according to Example 9 of the invention. 
         FIG. 29B (a) is an external perspective view showing a step of mounting the magnetic leg core and  FIG. 29B (b) is a top view of the structure of  FIG. 29B (a). 
         FIG. 29C (a) is an external perspective view of the coil being mounted and  FIG. 29C (b) is a cross sectional view of the coil. 
         FIG. 29D  is a group of external perspective views showing a process where three magnetic leg cores and coils are mounted by repeating the step of mounting one magnetic leg core and one coil shown in  FIG. 29C (a). 
         FIG. 29E  is a group of external perspective views showing a step of mounting the yoke core atop the three coils and fixing these with the top fastening fixture. 
         FIG. 29F  is an external perspective view showing the reactor device having all the components assembled thereto and equipped with the magnetic leg cores having a fan-like cross section. 
         FIG. 29G  is a top view of the device of  FIG. 29F . 
         FIG. 29H  is a front view of the device of  FIG. 29F . 
         FIG. 30( a )  is a plan view showing a case where the coil metal fixture is mounted and  FIG. 30( b )  is an external view of the coil metal fixture. 
         FIG. 31  is a perspective view showing a coil fixing method according to Example 11 of the invention. 
         FIG. 32A  is a perspective view showing a structure where a vent hole is disposed at the center of a top fastening fixture according to Example 12 of the invention. 
         FIG. 32B  is a vertical sectional view of the reactor device for illustrating an air flow. 
         FIG. 32C  is a horizontal sectional view of a coil part of the reactor device for illustrating the air flow. 
         FIG. 33  is a perspective view of the reactor device where a fan is disposed at the center of the top fastening fixture of the reactor device. 
         FIG. 34A  is a plan view showing a layout of the magnetic leg cores, the coils and the yoke core. 
         FIG. 34B  is a diagram showing a positional relation of the fan-like magnetic leg cores and the yoke core. 
         FIG. 34C  is a diagram showing how the magnetic leg cores and the yoke core overlap with each other. 
         FIG. 34D  is a diagram showing a layout relation of the magnetic leg cores, the coils and the bottom fastening fixture or the top fastening fixture, and the location of a core positioning laminate having an equilateral triangular shape. 
         FIG. 35A  is a flow chart showing the steps of setting dimensions of the magnetic leg core, coil and yoke core. 
         FIG. 35B  is a group of partial views of the reactor device associated with the flow chart of  FIG. 35A . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The embodiments of the invention will hereinbelow be described with reference to the accompanying drawings. 
     Example 1 
     A basic structure of a reactor device of the invention is described with reference to  FIG. 1 .  FIG. 1  is a perspective view showing the basic structure of the reactor device. In  FIG. 1 , numerals  160  and  161  denote a yoke core; a numeral  140  denotes a magnetic leg core; a numeral  100  denotes a coil; and a numeral  60  denotes a zero-phase core. The yoke core  160  or  161  is formed by winding an amorphous ribbon into a toroidal shape (annular shape), having a thick hollow circular configuration. 
     The magnetic leg core  140  has a fan-like configuration. It is noted here that the term “fan-like configuration” as used herein includes: a structure formed by axially cutting a toroidally wound amorphous ribbon into blocks having the fan-like configuration and stacking the plural fan-like blocks on top of each other; and polygonal structures such as described in conjunction with Example 13 (see  FIG. 34B ,  FIG. 34C ). The characteristic of this fan-like configuration will be described in detail in conjunction with Examples 9 and 13. This embodiment is described as below in conjunction with the above-described structure formed by axially cutting the toroidally wound amorphous ribbon into the fan-like blocks and stacking the plural fan-like blocks on top of each other. In the case of such a fan-like magnetic leg core, inside and outside circumferences thereof are aligned on circles similarly to those of the yoke core. When the yoke core laps over the magnetic leg cores, therefore, the magnetic leg cores have the minimum area that is not overlapped with the yoke core so that the loss and a useless increase of the mass can be obviated. 
     The periphery of the magnetic leg core  140  is formed by winding the coil  100  therearound. The yoke cores  160  and  161  are disposed at upper and lower ends of the reactor device in opposed relation. Three pairs of magnetic leg cores  140  and coils  100  are disposed between the yoke cores  160  and  161 , magnetically interconnecting the upper and lower yoke cores. 
     The reason for the reactor device to include the three coils  100  wound around the magnetic leg cores  140  is to arrange the reactor device to function as a three-phase AC reactor device. The magnetic leg cores  140  and the coils  100  are arranged on a circumference of the yoke cores with an angular spacing of about 120° with respect to the co-axis of the yoke cores  160  and  161  having the hollow circular configuration. This is for the purpose of ensuring electrical symmetry. 
     The reactor device further includes the zero-phase cores  60  which are each formed by stacking a plurality of rectangular amorphous ribbons into a rectangular parallelepiped configuration. The zero-phase cores are arranged on the circumference about the co-axis of the yoke cores  160  and  161  having the hollow circular configuration, as shifted through about 60° from the respective positions of the magnetic leg cores  140  (or with an angular spacing of about 120° between the three zero-phase cores  60 ). Similarly to the magnetic leg cores  140 , the zero-phase cores magnetically interconnect the yoke cores  160  and  161 . These zero-phase cores  60  are disposed to provide a flow path for magnetic flux due to zero-phase impedance induced when the phases of the three-phase AC current through the coils  100  wound around the three magnetic leg cores  140  are shifted from an idealistic condition. That is the description of the basic structure of the reactor device of the invention. 
     In  FIG. 1 , the toroidally wound yoke cores  160  and  161  are configured to satisfy a relation L1&gt;2*L2, where L1 ( 300 ) denotes the inside diameter of the yoke core, and L2 ( 310 ) denotes the thickness of the coil  100  wound around the magnetic leg core  141 . Such a configuration satisfying the above relation is preferred because if the yoke core is decreased in the inside diameter of the York core L1 ( 300 ), an effect to radiate heat from the coils is reduced although the reactor device can be reduced in size. 
     Next, the structure of the reactor device of the invention is described with reference to  FIG. 2A  to  FIG. 2F . In  FIG. 2A  to  FIG. 2F , a numeral  10  denotes the reactor device; a numeral  20  denotes a top fastening fixture; a numeral  30  denotes a bottom fastening fixture; a numeral  40  denotes an inner coil terminal; a numeral  41  denotes an outer coil terminal; a numeral  50  denotes an eyenut for hanging a reactor body; a numeral  60  denotes the zero-phase core; a numeral  70  denotes a stud metal fixture; a numeral  80  denotes a zero-phase core support; a numeral  81  denotes a zero-phase core holder; a numeral  90  denotes a stud attached to an outside periphery of the reactor body; a numeral  91  denotes a stud disposed centrally of the reactor body; a numeral  100  denotes the coil; a numeral  120  denotes a coil support fixture; a numeral  130  denotes a base; a numeral  140  denotes the magnetic leg core; a numeral  150  denotes a coil support fixture; a numeral  152  denotes a coil nut for fixing the coil support fixture; and numerals  160  and  161  denote the yoke core. 
     First, an internal structure of the reactor device of the invention is described with reference to  FIG. 2C  and  FIG. 2D . The magnetic leg core  140  has the fan-like configuration narrowed toward the central axis. The coil  100  is wound around this fan-like magnetic leg core  140 . A laminate  171  is placed on the bottom fastening fixture  30  and the magnetic leg cores  140  and coils  100  are arranged on the laminate  171  with an angular spacing of 120°. As shown in  FIG. 2D , the magnetic leg cores  140  of a predetermined height are stacked on top of each other with a laminate interposed between a respective pair of magnetic leg cores. The coil  100  is wound around the whole of the magnetic leg cores  140 . 
     The magnetic leg cores  140  and coils  100  are sandwiched between the lower toroidally wound yoke core  160  and the upper toroidally wound yoke core  161 . The lower yoke core  160  is accommodated and fixed in a case of the bottom fastening fixture  30  while the upper yoke core  161  is fixed in position as capped with a case of the top fastening fixture  20 . The zero-phase cores  60  are arranged on the circumference with an equal angular spacing of 120° and disposed in between the coils. The zero-phase cores are each formed by stacking a plurality of rectangular amorphous ribbons into a rectangular parallelepiped configuration and insertably fixed in the rectangular zero-phase core holder  81  connected to the zero-phase core support  80  mounted to the stud  90 . Similarly to the magnetic leg cores  140 , the zero-phase cores  60  are sandwiched between the lower yoke core  160  and the upper yoke core  161 . 
     Respective magnetic paths are formed by arranging the three magnetic leg cores  140  and the zero-phase cores  60  to have the same height and to be sandwiched between the yoke cores  160  and  161  in this manner. Assembly work requires adjustment of gap between the magnetic leg cores  140  and the yoke cores  160  and  161  with accuracy of a millimeter order. 
     The studs  90  each supporting the zero-phase core  60  are arranged around the outside circumference of the reactor body  10  where the zero-phase cores are arranged. A shaft portion of the stud is threaded in the whole length thereof. A shaft portion of the central stud  91  is also threaded in the whole length thereof in a similar manner. An upper side of the stud  90  is fixed by tightening a locknut down on the stud metal fixture  70  which is fixedly connected to the top fastening fixture  20  by welding or the like and which is formed of a rectangular metal plate formed with a stud hole. A lower side of the stud  90  is fixed by tightening a locknut down on the stud metal fixture  71  which is fixedly connected to the bottom fastening fixture  30  by welding or the like and which is formed of a rectangular metal plate formed with a stud hole. 
     The stud  90  is provided with two zero-phase core supports  80  each formed of the rectangular metal plate formed with the stud hole and fixedly connected with the zero-phase core holder  81  formed of a rectangular frame body of metal plate for holding the zero-phase core  60 . The stud  90  is inserted through the stud holes in the zero-phase core supports  80 , which are fixed to predetermined positions on the stud by fastening the locknuts. The central stud  91  assists in fastening the top fastening fixture  20  and the bottom fastening fixture  30  while the three studs  90  arranged on the outside circumference of the reactor body  10  also assist in fastening and fixing the top fastening fixture  20  and the bottom fastening fixture  30 . Attached to a distal end of the central stud  91  is the eyenut  50  used for hanging the reactor body  10 . 
     The coil  100  is fixed in position as pressed against the triangular coil support fixture  120  disposed centrally of the reactor body  10  and fastened by the coil support fixture  150  from outside. The coil support fixture  150  is formed of an elongate metal plate and consists of two pieces. Bolts are fixedly welded to a lateral side of the bottom fastening fixture  30  while bolts are also fixedly welded to a lateral side of the top fastening fixture  20  disposed upward of the above-described bolts. The lower piece is formed of an elongate, rectangular metal plate, one end of which is folded stepwise and formed with a hole for insertion of a bolt therethrough and the other end of which has a bolt welded thereto. The coil support fixture  150  is mounted to the bottom fastening fixture  30  by inserting the bolt of the bottom fastening fixture through the hole of the coil support fixture. The metal plate as the upper piece is substantially centrally folded stepwise and formed with a bolt insertion hole in each of the step faces thereof. The upper piece is fixed in position by inserting the bolt of the top fastening fixture  20  and the bolt of the lower piece through the holes and tightening down respective nuts. While the figure illustrates the bottom fastening fixture  30  having the two-piece structure, the bottom fastening fixture may also be formed in one-piece structure using one plate member. 
     In  FIG. 2E , the coil terminals  40  and  41  are drawn up from the winding start and the winding end of the coil  100  so as to be connected to a power circuit of a power controller system. Further, an electric insulating paper is wound around the coil  100  to protect the surface thereof. 
       FIG. 2F  is a top cross-sectional view taken at the height of the center of the reactor shown in  FIG. 2E . Referring to  FIG. 2F , the fan-like magnetic leg cores  140  with the coils  100  wound therearound are arranged in a manner that outside peripheries of the fan-like magnetic leg cores  140  coincides with outside peripheries of the top fastening fixture  20  and the bottom fastening fixture  30 . That is, the fan-like coils are arranged so that outside peripheral portions thereof protrude from the top fastening fixture and the bottom fastening fixture. The fan-like coils are arranged with an angular spacing of 120°. The coil terminals are arranged at the outside peripheral portions of the coil  100 . The inner coil terminal  40  and the outer coil terminal  41  are spaced a predetermined distance from each other. The central sides of the magnetic leg core  140  and coil  100  are linearly formed but not in an arcuate shape so as to be precisely positioned and fixed as pressed against the triangular coil support fixture  120 . While  FIG. 2F  illustrates the coil  100  having the linear central side, the central side of the coil may also be in the arcuate shape and the coil support fixture  120  may also be formed in the arcuate shape. The magnetic leg core  140  and coil  100  are arranged such that the coil  100  has opposite ends laterally of the outer terminal fixed with coil support fixtures. The zero-phase cores  60  are interposed between the coils  100 . The zero-phase cores are arranged with equal angular spacing of 120°. The zero-phase core  60  is formed by stacking elongate, rectangular amorphous metal plates and arranged in parallel to the center axis of the circular reactor. The zero-phase core support  80  is arranged on an outside periphery of the zero-phase core  60  to support the zero-phase core  60 . 
     Next, an outside appearance of the reactor device of the invention is described with reference to  FIG. 2A  and  FIG. 2B .  FIG. 2A  is an external view of the reactor device as seen from diagonally above.  FIG. 2B  is an external view of the reactor device as seen from diagonally below. Referring to  FIG. 2A  and  FIG. 2B , the coil  100  is fixed in position by fastening the upper and lower pieces of the coil support fixture  150  and by fastening the top fastening fixture  20  and the bottom fastening fixture  30 . The zero-phase core  60  is supported and fixed in position by the zero-phase core supports  80  mounted to the stud  90  at two positions. This stud  90  is fixed in position by assembling the stud with the stud metal fixture  70  fixed to the top fastening fixture  20  and with the stud metal fixture  71  fixed to the bottom fastening fixture  30  and by fastening the top fastening fixture  20  and the bottom fastening fixture  30 . On a bottom of the reactor  10 , the three U-shaped bases  130  are arranged on an outside circumference with equal spacing and fixed in position. 
     Example 2 
     Next, description is made on a manufacturing method of the reactor device of the invention. The manufacturing method of the reactor device employing the fan-like magnetic leg core  140  is described with reference to  FIG. 3  to  FIG. 12 . In  FIG. 3 ,  FIG. 3( a )  is a perspective view showing the yoke cores  160  and  161  disposed at the upper and lower parts of the reactor  10  and arranged to sandwich the magnetic leg cores  140  and the zero-phase cores  60  therebetween. While the yoke core of  FIG. 3( a )  is depicted as concentric circles, the yoke core actually has a cylindrical configuration formed by toroidally winding an amorphous ribbon and including a central hole.  FIG. 3( b )  is an external perspective view of the magnetic leg core  140 . The magnetic leg core is formed in the fan-like configuration by axially cutting the iron core formed by toroidally winding the amorphous ribbon.  FIG. 3( c )  is an external perspective view of the zero-phase core  60  which is formed by stacking the elongate rectangular amorphous ribbons into the rectangular parallelepiped configuration. 
     Next, the manufacturing method of the reactor of the invention is described referring to the figures in the order of assembly steps.  FIG. 4  diagrammatically shows the assembly of the lower yoke core. Referring to  FIG. 4 , the stud metal fixtures  71  are first fixed to a bottom of the bottom fastening fixture  30  by welding or the like. The studs  90  are assembled to the stud metal fixtures while the stud  91  is also disposed at the center of the device. The studs  90  are fixed in position by tightening locknuts. Subsequently, in this state, the laminate  171  shaped like a hollow disk is placed in the bottom fastening fixture  30 . Further, the yoke core  160  is placed on the laminate and then, a laminate  172  is placed on the yoke core  160 . The right-hand diagram of  FIG. 4  shows the state where the yoke core  160  is placed. 
     Next, a step of mounting a coil metal fixture is described with reference to  FIG. 5 . In a structure shown in  FIG. 5 , the coil support fixture  120  against which the coil  100  is pressed for positioning is mounted about the central stud  91 . Subsequently, the two zero-phase core supports  80  each connected to the zero-phase core holder  81  formed of the metal frame for holding the zero-phase core  60  are mounted to each of the three studs  90  arranged on the outside periphery of the reactor body  10 . The zero-phase core supports  80  are fixed to places on the stud by tightening down the locknuts. Subsequently, the six coil fasteners  150  for fixing the coils  100  are tack welded to places on the outside circumference of the bottom fastening fixture  30  and mounted thereto. 
     Next, the assembly of the magnetic leg core  140  is described with reference to  FIG. 6 . In  FIG. 6 ,  FIG. 6( a )  is an external perspective view of the reactor device while  FIG. 6( b )  is a side view thereof. Referring to  FIG. 6( a ) , the fan-like magnetic leg cores  140  are placed on the yoke core  160 . Subsequently, the laminate  170  is placed on the magnetic leg cores  140  and then, the magnetic leg cores  140  are placed on the laminate  170 . This step is repeated to stack five magnetic leg cores  140  with the laminate  170  inserted between respective pairs of magnetic leg cores  140 . In this process, the inductance value (L value) can be adjusted because the inductance value (L value) of the reactor can be varied by changing the thickness of the laminate  140 , that is, the gap between the magnetic leg core  140  and the magnetic leg core  140 . 
     The assembling of the coil is described with reference to  FIG. 7 . In  FIG. 7 ,  FIG. 7( a )  is an external perspective view of the reactor device, while  FIG. 7( b )  is a side view thereof. Referring to  FIG. 7( a )  and  FIG. 7( b ) , the coil  100  has a fan-like configuration conforming to the fan-like configuration of the magnetic leg core  140 . The coil  100  covered with the insulating material (electric insulating paper) is slidingly fitted from above around the stack of magnetic leg cores  140  alternating with the laminates  170 . The coil support fixtures  150  are adjusted in position before fixed to places. Further, adjustment is made to eliminate backlash by inserting the electric insulating paper in a gap between the coil  100  and the coil support fixture  120  and a gap between the coil  100  and the magnetic leg core  140 . 
     Next, a step of assembling the coils  100  with the magnetic leg cores  140  for forming three legs by repeating the step of stacking the magnetic leg cores  140  shown in  FIG. 6  and the step of slidingly fitting the coil  100  around the magnetic leg core  140  shown in  FIG. 7  is shown in  FIG. 8 .  FIG. 8  shows the step of slidingly fitting the coils  100  around the three magnetic leg cores  140  respectively. After fitting, the electric insulating paper is filled in the gaps to eliminate the backlash. 
     Next, a step of mounting the zero-phase core  60  is described with reference to  FIG. 9 . In  FIG. 9 ,  FIG. 9( a )  is an external perspective view showing how to mount the zero-phase core  60 , while  FIG. 9( b )  is a front view thereof. The zero-phase core  60  is covered with the insulating material (electric insulating paper), inserted from above in the zero-phase core holder  81  formed of the metal frame and fixedly mounted on the yoke core  160 . As shown in  FIG. 9( a ) , the zero-phase core holder  81  is formed with a vertical cutout in the opposite side from the zero-phase core support  80 . There is no problem if the zero-phase core holder has a frame structure without this cutout. 
     The zero-phase cores  60  need be mounted in a manner to produce no backlash. If the backlash occurs, the electric insulating paper or the like is used to make a backlash free structure. It is also necessary to equalize the heights of the zero-phase core  60  and the magnetic leg core  140 . Therefore, height adjustment is made using the electric insulating paper is used for making when the zero-phase core and the magnetic leg core have different heights. A SUS type metal may be used as the metal plate. The zero-phase core  60  is formed by stacking the amorphous ribbon and cutting the stack into a rectangular shape or into the rectangular parallelepiped configuration. Instead of the amorphous ribbon, other metal materials such as silicon steel are also usable. 
     Next, a step of fixing an upper side of the coil  100  is described with reference to  FIG. 10 . Referring to  FIG. 10 , in a state where the coils  100  are fixed with the coil support fixtures  150 , a triangular insulating material  124  is inserted from above into the center part of the reactor device  10 . Then, a coil support fixture  123  is inserted from above. The insulating material  124  is intended to secure an insulation distance between the coils  100  constituting three legs, serving to prevent insulation breakdown and the like. A structure of the insulating material has a triangular prism tube configuration. Each of the ridge parts of the triangular prism is formed with a wing part for covering the coil end. A top of the triangular prism tube body is closed with a metal plate centrally formed with a hole for the stud  91  to penetrate. After the assembly step of inserting the insulating material  124  and coil support fixture  123 , the stud  91  is fixed in position by tightening down the locknut. 
     Next, a step of mounting the upper yoke core is described.  FIG. 11  is an external perspective view showing how the upper yoke core is mounted. In  FIG. 11 , the numeral  161  denotes the upper yoke core; numerals  173  and  174  denote laminates; the numeral  20  denotes the top fastening fixture; and the numeral  70  denotes an upper stud metal fixture. Referring to  FIG. 11 , the laminate  173  is disposed between the magnetic leg core  140  and the yoke core  161  and the yoke core  161  is mounted on the laminate  173 . The laminate  174  is mounted atop the yoke core  161 . The top fastening fixture  20  is placed on the laminate and assembled together as positioned in a manner to allow the studs  90  to penetrate the holes formed in the stud metal fixtures  70  and to allow the stud  91  to penetrate the center hole of the top fastening fixture  20 . After assembling the laminate  173 , the yoke core  161 , the laminate  174  and the top fastening fixture  20  in this order, a fastening fixture  51  is mounted on the stud  91 . In this process, the lateral side of the yoke core  161  is covered with the electric insulating paper so as to eliminate the backlash in the assembly. 
     Next, the mounting of the eyenut for hanging the reactor body  10  is described.  FIG. 12  is a group of external perspective views of the rector  10  showing how the eyenut is mounted to the reactor and a state where the assembly work is completed. Referring to  FIG. 12 , the magnetic leg cores  140 , the zero-phase cores  60  and the yoke core  161  sandwiched between the bottom fastening fixture  30  and the top fastening fixture  20  are fastened and fixed in position by mounting the fastening fixture  51  to the stud  91  penetrating the center hole of the top fastening fixture  20  and tightening down the fastening fixture. The coil support fixtures  150  are mounted to the bolts fixed to the lateral side of the top fastening fixture  20  and fixed thereto by tightening the locknuts. Subsequently, the eyenut  50  is threaded in a tip end of the stud  91 . Lines of the coil terminals  40  and  41  drawn from the coil  100  are inserted in insulation tubes to mutually separate the lines by a predetermined length or more. The above-described structure is checked using an LCR meter to determine whether U-, V-, W-phase inductance values (L values) of the reactor body are predetermined values or not. If the inductance value differs from the predetermined value, the assembly work returns to the step of assembling the magnetic leg core shown in  FIG. 6  to adjust the gap between the magnetic leg cores. That is the description on the manufacturing method of the reactor employing the fan-like magnetic leg core. 
     Example 3 
     Next, description is made on a manufacturing method of a reactor device according to a third embodiment of the invention.  FIG. 13  is a group of perspective views showing iron cores employed by the reactor of the invention.  FIG. 13( a )  shows the yoke core  160  or  161 ;  FIG. 13( b )  shows a circular magnetic leg core  141 ; and  FIG. 13( c )  shows the zero-phase core. Referring to  FIG. 13 , this embodiment differs from Example 2 in that the magnetic leg core has a circular configuration and is centrally formed with a slit. Specifically, the amorphous ribbon is wound into a cylinder which is cut along a line passing through the center. With the electric insulating paper inserted between the half cylinder bodies, the half cylinder bodies are bonded together to form the slit  143 . The yoke core shown in  FIG. 13( a )  and the zero-phase core shown in  FIG. 13( c )  are the same as those of Example 2 and hence, the description thereof is dispensed with. 
     Next, the mounting of the lower yoke core is described with reference to  FIG. 14 . Referring to  FIG. 14 , three studs  90  are arranged on the outside circumference of the stud metal fixture  71  fixed to the bottom of the bottom fastening fixture  30 . Further, the stud  91  is disposed at the center of the bottom fastening fixture  30 . The studs are fixed in position by tightening down the locknuts. Subsequently, the laminate  171  having a hollow disk configuration is placed in the case of the bottom fastening fixture  30 . Placed on the laminate  171  is the yoke core  160 , on which the insulating material (insulating sheet)  172  is placed. The laminate  171  is a sheet formed of an epoxy resin material or the like. The case of the bottom fastening fixture  30  has a height equal to the height of the stack of the laminate  171 , yoke core  160  and insulating material  172 . 
     Next, the mounting of the zero-phase core  60  is described with reference to  FIG. 15 . Referring to  FIG. 15 , the three studs  90  arranged on the outside circumference of the bottom fastening fixture  30  are each mounted with two zero-phase core supports  80 . The zero-phase core support  80  is connected to and integrated with the zero-phase core holder  81  formed of the rectangular metal frame body for receiving the zero-phase core  60  having the rectangular parallelepiped configuration. The zero-phase core  60  is inserted from above into this zero-phase core holder  81  of the metal frame and placed on the insulating sheet of the laminate  172 . The rectangular metal frame of the zero-phase core holder  81  is formed with a cutout in a center-side face so as to facilitate the insertion of the zero-phase core  60 . 
     Next, the mounting of the magnetic leg core and the coil is described with reference to  FIG. 16 .  FIG. 16  is diagrams showing a structure where coil support fixtures and the insulating material are disposed at the center of the reactor device  10 . In  FIG. 16 , a numeral  125  denotes a coil support fixture, a numeral  126  denoting the insulating material. The coil support fixture  125  has an arcuate configuration conforming to a circular configuration of a coil  101 . Three coil support fixtures  125  are arranged about the central stud  91  with an equal angular spacing of 120° and between the zero-phase cores  60 . The coil support fixtures  125  are fixed to the stud  91 . The insulating material  126  is formed of an insulating sheet in an arcuate configuration conforming to the circular configuration of the coil  101 . The insulating sheets are disposed on the outer side of the three coil support fixtures  125  for increasing insulation effect between adjoining coils  101 . An insulating material such as silicone rubber is inserted in a gap between the coil support fixture  125  and the coil  101 . 
     Next, a method of assembling the circular magnetic leg cores  141  is described with reference to  FIG. 17 . In  FIG. 17 ,  FIG. 17( a )  is a perspective view showing how the magnetic leg cores are assembled, while  FIG. 17( b )  is a diagram showing a layout relation of the yoke core  160  and the magnetic leg cores  141 . Referring to  FIG. 17( a ) , the magnetic leg cores  141  are disposed between respective pairs of zero-phase cores  60  and placed on the insulating material (insulating sheet)  172  on the yoke core  160 . Subsequently, a laminate  175  is placed on the magnetic leg cores  141  and then, place on the laminate are the magnetic leg cores  141 . This step is repeated to stack and assemble the magnetic leg cores  141 . In the figure, five magnetic leg cores  141  are stacked. 
     As shown in  FIG. 17( b ) , the layout relation of the magnetic leg cores  141  and the yoke core  160  is defined such that the sum of the diametrical length of the magnetic leg core  141  and the radius of the inner hole of the yoke core  160  is equal to the radius of the yoke core  160  and that the circular magnetic leg core  141  is circumscribed with the inner hole of the yoke core  160  and is inscribed in the outer circle of the yoke core  160 . The line of the slit  143  formed in the magnetic leg core  141  is directed parallel to a winding direction of the yoke core  160  toroidally wound. That is, the line of the slit  143  of the magnetic leg core  141  is oriented in the direction of a tangent to the winding of the toroidally wound yoke core  160 . Such a structure has an effect to reduce eddy-current loss. The inductance values (L value) of this reactor device  10  are adjusted by changing the thickness of the laminate  175  sandwiched between the magnetic leg cores  141 , that is, the gap between the magnetic leg cores  141 . 
     Next, a method of slidingly fitting the coil  101  around the stacked magnetic leg cores  141  is described with reference to  FIG. 18 . Referring to  FIG. 18 , the coil  101  is vertically slidingly fitted from above around the circular magnetic leg cores  141  stacked on the yoke core  160 . A gap between the inside diameter of the coil  101  and the outside diameter of the magnetic leg core is adjusted to eliminate the backlash by inserting the insulating material in the gap. Of the terminals  40  and  41  of the coil  101 , the inner coil terminal  40  is drawn from an inside periphery of the coil, while the outer coil terminal  41  is drawn from an outside periphery of the coil  101 . The outer coil terminal  41  is formed with a step-like fold (one step) to increase a distance from the inner coil terminal  40 . 
     Next,  FIG. 19  is a perspective view showing the three coils  101  fitted around the magnetic leg cores  141 .  FIG. 19  shows the magnetic leg cores  141  and coils  101  fixed in position by repeating the step of stacking the magnetic leg cores  141  shown in  FIG. 17  and the step of slidingly fitting the coil  101  around the magnetic leg core  141  shown in  FIG. 18 . Referring to  FIG. 19 , the three zero-phase cores  60  and the magnetic leg cores  141  interposed therebetween are substantially equalized in height. 
     Next, a method of fixing the coils  101  from above in the state where the magnetic leg cores  141  and the coils  101  are mounted is described with reference to  FIG. 20 . In  FIG. 20 , a numeral  158  denotes an insulating material while a numeral  127  denotes a coil support fixture. The insulating material  158  has an arcuate configuration conforming to the circular configuration of the coil  101  and is so formed as to cover the coil  101  thus offering an effect to gain the insulation distance between adjoining coils. The coil support fixture  127  is a substantially triangular metal plate, respective sides of which are vertically connected with a metal plate having an arcuate configuration conforming to the circular configuration of the coil  101 . After the insulating material  158  is mounted, the coil support fixture  127  is inserted from above and mounted in position. Subsequently, the stud  91  is allowed to penetrate a hole formed at the center of the coil support fixture  127  and fixed in position by tightening down a locknut. 
     Next, the mounting of the upper yoke core  161  is described with reference to  FIG. 21 . Referring to  FIG. 21 , the laminate  173  is placed on the assembled structure of the zero-phase cores  60 , magnetic leg cores  141  and coils  101 . Placed on the laminate  173  is the yoke core  161  and the laminate  174  is placed on the yoke core. Subsequently, these laminate  173 , yoke core  161  and laminate  174  are capped with the case of the top fastening fixture  20 . The stud metal fixtures  70  are fixedly welded to the outside circumference of a top side of the top fastening fixture  20 . 
     Next, a method of fastening and fixing the individual iron cores and coils of the reactor device  10  is described with reference to  FIG. 22 . Referring to  FIG. 22 , the stud metal fixtures  70  arranged on the outside circumference of the top fastening fixture  20  are formed of a rectangular metal plate formed with a hole at a portion projected from the top fastening fixture  20 . The stud metal fixtures  70  allow the three studs  90  to penetrate the holes thereof and to be fixed in position by tightening down the locknuts. The top fastening fixture  20  is centrally formed with the hole which is penetrated by the stud  91  to which the fastening fixture  51  is mounted. The top fastening fixture and the bottom fastening fixture  30  are fastened by tightening down the locknut on the fastening fixture  51  so as to fix the whole body of the reactor in position. The eyenut  50  for hanging the reactor body is mounted to the tip end of the stud  91 . Each of the coils  101  is provided with two coil retainers  200  attached to the lateral side of the top fastening fixture  20  such that the coil is retained on the both sides of the coil terminals  40  and  41 . A numeral  210  denotes a name plate showing a trade name, model code, product serial number, date of manufacture, manufacturer&#39;s name and the like of the device. 
     Next, a structure where a caster  201  is attached to a base  130  at the bottom of the reactor device  10  is shown in  FIG. 23 . Referring to  FIG. 23 , the caster  201  is attached to each of the U-shaped bases  130  disposed at three places on the circumference of the bottom of the bottom fastening fixture  30  with equal spacing so as to allow the reactor device  10  to move smoothly. Thus, the assembly work of the reactor device incorporating the circular magnetic leg cores  141  is completed. 
     Example 4 
     Next, a structure where three pairs of coil terminals are drawn from the center of the reactor device according to the invention is described with reference to  FIG. 24 .  FIG. 24  shows the structure where the coils  100  are arranged as slidingly fitted around the fan-like magnetic leg cores  140  while the zero-phase cores  60  are interposed between the coils  100 . The figure is a perspective view showing coil terminals  220  and  221  drawn upward from the center of the reactor device. Referring to  FIG. 24 , the plate-like coil terminals  220  and  221  including holes are arranged on an inner side of each of the coils  100  fitted around each of the three magnetic leg cores  140  and connected to the winding start and the winding end of the coil. The central hole of the yoke core  161 , which is not shown, is insulated so as not to make contact with the coil terminals  221 . Further, the top fastening fixture  20  is centrally formed with a hole to allow the coil terminals  220  and  221  to project therethrough. 
     Example 5 
     Next, a structure where a sound absorbing material  400  is interposed between the top/bottom fastening fixture and the laminate is described with reference to  FIG. 25 .  FIG. 25  is a perspective view showing the sound absorbing material  400  interposed between the bottom fastening fixture  30  and the laminate  171 . Referring to  FIG. 25 , the sound is absorbed by sandwiching the yoke core  160  between the laminate  170  and the laminate  172  and interposing the sound absorbing material  400  between the lower laminate  170  and the bottom fastening fixture  30 . The cause of the noises from the reactor device is an inverter incorporated in the power controller system. The inverter produces various frequency components in the electric power which oscillate the magnetic leg cores, yoke cores and the like, producing sounds. The sound absorbing material is used for absorbing these sounds. Examples of usable sound absorbing material include porous materials, namely fibrous glass wool including numerous micropores and sponge-like urethane. 
     While  FIG. 25  shows the sound absorbing material  400  interposed between the laminate  170  and the bottom fastening fixture  30 , an alternative arrangement may also be made such that the upper and lower laminates, the upper and lower yoke cores, the three magnetic leg cores and coils and the three zero-phase cores are wholly covered with the sound absorbing material. 
     Example 6 
     Next, a method of assembling a device using the circular magnetic leg core is described. A significant difference from the circular magnetic leg core described in Example 3 is that the zero-phase core is not mounted. First, the mounting of the lower yoke core is described with reference to  FIG. 26A . Referring to  FIG. 26A , the studs  90  and  91  are vertically arranged on the bottom of the bottom fastening fixture  30  at one center position and at three outside peripheral positions of the circular case of the bottom fastening fixture  30 . The three studs  90  on the outside circumference are arranged at an angular interval of 120° and positioned at the stud metal fixtures  71  fixed to the outside circumference. The central stud  91  is disposed at the center of the bottom fastening fixture  30  and fixed in position by tightening the locknut. In this state, the laminate  171  formed of a hollow disk-like silicone rubber or the like is placed in the case of the bottom fastening fixture  30 . Placed on the laminate  171  is the toroidal yoke core  160 , on which the hollow insulating material (insulating sheet)  172  is placed for insulating the magnetic leg core placed on the yoke core  160 . The laminate  170  may employ a sheet formed from silicone rubber or epoxy resin. The case of the bottom fastening fixture  30  has a height substantially equal to a height of the stack of the laminate  171 , the yoke core  160  and the insulating material  172 . 
     Next, the mounting of the magnetic leg core and the coil is described.  FIG. 26B  shows a structure where the coil support fixture  125  and the insulating material are arranged at the center of the bottom fastening fixture  30 . In  FIG. 26B , the numeral  125  denotes the coil support fixture having a surface covered with the insulating material for insulating the coils from one another. The coil support fixture  125  has the arcuate configuration conforming to the configuration of the coil  101 . The three coil support fixtures  125  are arranged about the central stud  91  with an equal angular spacing of 120° and fixed to the stud  91  or the laminate  172 . The insulating material covering the coil support fixture  125  has the arcuate configuration conforming to that of the coil support fixture  125  such as to increase the insulation effect between adjoining coils  101 . Silicone rubber or the like is used as the insulating material. 
     Next, a method of assembling the magnetic leg cores having the circular cross section is described with reference to  FIG. 26C . In  FIG. 26C ,  FIG. 26C (a) is a perspective view showing how the cylindrical magnetic leg cores  141  are assembled and  FIG. 26C (b) is a diagram showing a layout relation of the cylindrical magnetic leg cores and the yoke core. Referring to  FIG. 26C (a), the cylindrical magnetic leg cores  141  are stacked on the insulating sheet  172  on the yoke core  160 . The cylindrical magnetic leg cores  141  are stacked in four layers with the laminate  175  inserted between the individual magnetic leg cores  141 . This structure is arranged at three positions with the angular spacing of 120° in correspondence to the coil support fixtures  125 . 
     Referring to  FIG. 26C (b), the layout relation of the cylindrical magnetic leg cores  141  and the yoke core  160  is defined such that the sum of the diametrical length of the magnetic leg core  141  and the radius of the inner hole  162  of the yoke core  160  is equal to the radius of the yoke core. The magnetic leg core  141  having the circular cross section is circumscribed with the inner hole  162  of the yoke core  160  and is inscribed in the outer circle of the yoke core  160 . The line of the slit  143  formed in the magnetic leg core  141  is directed parallel to the winding direction of the yoke core  160  toroidally wound. That is, the line of the slit  143  of the magnetic leg core  141  is oriented in the direction of the tangent to the winding of the toroidally wound yoke core  160 . Such a structure has the effect to reduce eddy-current loss. The inductance values (L value) of the reactor device are dependent on the thickness of the laminate  175  interposed between the magnetic leg cores  141 , or the gap between the magnetic leg cores  141 . The L values can be adjusted by changing this gap. 
     Next, a method of slidingly fitting the coil around the stacked cylindrical magnetic leg cores  141  is described with reference to  FIG. 26D . Referring to  FIG. 26D , the coil  101  vertically approaches from above and is slidingly fitted around the magnetic leg cores  141  stacked on the yoke core  160  to reach the insulating plate  172  so as to be fixed in position. The insulating material is inserted in the gap between the inside periphery of the coil and the outside periphery of the magnetic leg core so as to adjust the gap to eliminate the backlash. Of terminals  42  and  43  of the coil  101 , the inner coil terminal  42  is drawn from the inside periphery of the coil  101 , while the outer coil terminal  43  is drawn from the outside periphery of the coil  101 . Terminal portions projected from the coil are formed with a step to increase spacing therebetween. When the coil is slidingly fitted around the magnetic leg cores  141 , the coil  101  is positioned as contacted against the coil support fixture  125 . By doing so, the coils  101  can be precisely arranged with an equal angular spacing of 120°. 
     Next, a method of mounting three coils  101  on the respective circular magnetic leg cores  141  and fixing the coils with the coil support fixtures is described.  FIG. 26E  shows a structure where the coils  101  are slidingly fitted around the three magnetic leg cores  141  respectively and placed on coil support fixtures  92 . The right-hand diagram shows a structure where the coils are fixed with the coil support fixture  127 . With the coils  101  mounted on the three circular magnetic leg cores  141 , the coil fixture  127  is disposed at the center. The coil fixture  127  is formed of a triangular metal plate and is centrally formed with a hole to allow the central stud  91  to penetrate therethrough. On a back side of the coil support fixture  127 , arcuate members conforming to the outside configuration of the coil  101  similarly to the coil support fixture  127  are arranged with an equal angular spacing of 120°. The arcuate member is covered with the insulating sheet to enhance inter-coil insulation. 
     Next, a method of mounting the upper yoke core atop the coils is described with reference to  FIG. 26F . Referring to  FIG. 26F , the laminate  173  is placed on the structure assembling the three magnetic leg cores  141  and the coils  101 . Placed on the laminate is the yoke core  161 , on which the laminate  174  is placed. Then, the laminate  173 , the yoke core  161  thereon and the laminate  174  thereon are capped with the case of the top fastening fixture  20 . Three stud metal fixtures  70  of the rectangular metal plate are arranged and fixed on the outside circumference of the top side of the top fastening fixture  20  at positions corresponding to the stud metal fixtures  71  arranged around the bottom fastening fixture  30  on the bottom side. Coil retainer holders  132  for receiving rod portions of coil retainers  134  for pressing and fixing the coils are arranged on the outside circumference of the top side of the top fastening fixture  20 . The coil retainer holders are located on the both sides of the location of each terminal pair. The coil retainer holders are disposed at six locations in total. The stud metal fixture  70  of the rectangular metal plate is formed with the hole at the portion projected from the outside circumference of the top fastening fixture  20  and allows the stud  90  to penetrate this hole so as to be fastened and fixed in position by tightening a locknut  93  applied to the stud  90 . 
     Similarly, the coil retainer holder  132  is also formed of a rectangular metal plate and formed with a hole at a portion projected from the outside circumference of the top fastening fixture  20  so as to allow a rod portion of the coil retainer  134  to penetrate therethrough. The coil retainer holder is fastened and fixed in position by tightening a locknut  133 . The fastening fixture  51  formed of a rectangular metal plate is disposed at the center of the top fastening fixture  20 . The fastening fixture  51  is centrally formed with a hole to allow the stud  91  to penetrate therethrough. After penetrated by the stud  91 , the fastener  51  is fixed in position by tightening down a locknut  95 . In this manner, the bottom fastening fixture  30  and the top fastening fixture  20  are fastened and fixed by means of the three studs  90  and the central stud  91 . Therefore, the yoke cores, magnetic leg cores and coils sandwiched between the top and bottom fastening fixtures are rigidly fixed in position. Further, the coils are strongly fixed in position by means of the coil retainers  134 . 
     Next, the eyenut  50  is mounted to the top of the central stud  91  through the top fastening fixture  20  so as to hang the reactor body. The coil retainer  134  is configured such that a tip end of a round rod thereof is shaped like a circle having a larger diameter than that of the rod portion, having an area large enough to press down a part of the coil. The coil retainer penetrates the coil retainer holder  132  and is driven by tightening the locknut  133  to press down the coil  101  against the bottom fastening fixture  30  and fix the same in position. The terminals  42  and  43  are each formed with a plurality of holes  45  to permit connection of power line. 
     Next,  FIG. 26I  is an external perspective view showing the reactor device having all the components assembled thereto and incorporating the magnetic leg cores having the circular cross section.  FIG. 26H  is a front view of the device and  FIG. 26G  is a top view thereof. Referring to  FIG. 26G ,  FIG. 26H ,  FIG. 26I , the coils  101  are placed on the coil support fixtures  92  arranged on the periphery of the bottom fastening fixture  30  and pressed down by the coil retainers  134  formed of a metal rod with the disk connected to the tip thereof. The opposite end of the metal rod is received by each of the coil retainer holders  132  arranged on the periphery of the top fastening fixture  20  and fixed in position by tightening the locknut  133 . One coil  101  is fixed at two positions on the opposite sides of the terminal plates  42  and  43 . 
     Example 7 
     Next, description is made on a fixing method for magnetic leg core according to Example 7, which is different from the fixing method of Example 3.  FIG. 27  is perspective views showing a structure of a magnetic leg core where an insulating tube body  180  is assembled from above by slidingly fitting the tube body around a stack of four magnetic leg cores  141  with the insulating laminate  175  interposed between the individual magnetic leg cores. The magnetic leg core is formed with the slit  143  and has the circular cross section. The three magnetic leg cores covered with the insulating tube body  180  shown in  FIG. 27  are arranged on the yoke core  160  with an equal angular spacing of 120° and then the coils  101  are inserted therebetween as shown in  FIG. 26E . An effect to prevent the deviation of individual magnetic leg cores  141  from a stacking direction is obtained by stacking the magnetic leg cores  141  having the circular cross section and covering the stack with the tube body  180 . In the event of a deviation of the magnetic leg cores  141 , increase in leakage flux and core loss results but can be obviated by the above structure. 
     Example 8 
     A yoke core according to Example 8 is described with reference to  FIG. 28 .  FIG. 28  is a perspective view showing the toroidal yoke core  160 ,  161  centrally formed with a circular hole. Referring to  FIG. 28 , the yoke core has an annular reinforcement metal plate  181  attached to a peripheral surface of the inner hole. This reinforcement metal plate  181  has a thickness of 2 mm or more. There is fear that the hole may be deformed in the circular configuration and subjected to core stress unless the central hole of the yoke core is reinforced on the inner side thereof. Under the core stress, the yoke core is increased in loss and deteriorated. The yoke core can be prevented from the deformation due to stress by reinforcing the inside periphery of the inner hole thereof. 
     In the yoke core of  FIG. 28 , an insulating material  163  is wound around the outermost peripheral surface of the yoke core  160  or  161 . The insulating sheet is used as the insulating material  163  and wound around the outer periphery of the yoke core. Abnormal current between the yoke core and the top fastening fixture or the bottom fastening fixture is obviated by winding the insulating sheet  163  around the outer periphery or the lateral side of the yoke core  160  or  161  in this manner. The use of the insulating sheet is useful for gaining creepage distance between the yoke core and the top fastening fixture or bottom fastening fixture and reducing stray loss, thus preventing characteristic degradation. The insulating sheet also serves to eliminate the backlash between the yoke core and the top fastening fixture or bottom fastening fixture. 
     Example 9 
     Next, a structure and assembly method of a reactor according to Example 9 of the invention is described with reference to related drawings. First,  FIG. 29A  is a group of assembly diagrams showing how to mount the lower yoke core. In  FIG. 29A , a numeral  31  denotes the bottom fastening fixture; a numeral  131  denotes the base; the numerals  90  and  91  denote the stud; the numeral  173  denotes the laminate; the numeral  161  denotes the lower yoke core; the numeral  174  denotes the laminate; a numeral  55  denotes a magnetic-leg-core positioning laminate; and the numeral  163  denotes the insulating sheet wound around the yoke core  161 . 
     The bottom fastening fixture  31  has a substantially hexagonal case configuration alternately formed with folding portions on sides thereof. The fixture has the stud  91  vertically erected from the center thereof and three studs  90  vertically erected not from the folding portions but from the center of each of the areas outside a location of the yoke core at an angular interval of 120°. The base  131  has an L-shape configuration for increasing strength. Two bases are arranged in juxtaposition with respective one sides of the L-shape welded to the bottom of the bottom fastening fixture  31 , stabilizing the reactor device. 
     The bottom fastening fixture  31  and the two bases  131  have a positional relation, as shown in  FIG. 29B (b). The bases  131  are arranged parallel to each other and perpendicular to two sides of the bottom fastening fixture  31 . Placed on the bottom fastening fixture  31  is the laminate  173  of insulating sheet, on which the hollow, toroidal yoke core  161  is placed. Further, the laminate  174  is placed on the yoke core  161 . Then, the core positioning laminate having an equilateral triangular shape is placed on the laminate  174 . The core positioning laminate  55  includes a hole at the center (middle point) of the equilateral triangle to allow the central stud  91  to penetrate therethrough. As shown in  FIG. 29B (b), the core positioning laminate is oriented in a manner that a perpendicular line drawn from one apex of the equilateral triangle is parallel to the longitudinal lines of the two bases fixed to the bottom fastening fixture  31 . Further, the insulating sheet  163  is wound around the periphery of the yoke core  161  to eliminate the backlash. 
     Next, the mounting of the magnetic leg core is described with reference to  FIG. 29B . In  FIG. 29B ,  FIG. 29B (a) is an external perspective view showing a step of mounting the magnetic leg cores and  FIG. 29B (b) is a top view of the structure of  FIG. 29B (a). It is noted here that a magnetic leg core  142  has a substantially fan-like configuration as described in Example 1. Unlike Example 1, this magnetic leg core  142  is manufactured by stacking a core material cut into a strip shape having predetermined thickness and length. This magnetic leg core  142  is placed on the laminate  174  laid on the yoke core  161 . A center part of the fan-like magnetic leg core  142  is cut off to define a flat part. As shown in  FIG. 29B (b), the magnetic leg core is positioned with this flat part contacted against one side of the core positioning laminate having the equilateral triangular shape. The magnetic leg core can be positioned with high precision by placing the magnetic leg core in this manner. The opposite wing parts of the magnetic leg core  142  are cut off, while the arc of an arcuate portion is roughly trisected and the trisected arc parts are cut. Thus is formed the deformed magnetic leg core  142  having a substantially octagonal configuration. 
     Referring to  FIG. 29B , the magnetic leg cores  142  are stacked in four layers with the laminate  175  interposed between the magnetic leg cores  142 . While a step of mounting the coil is described hereinlater, a configuration of the magnetic leg core including the coil is dependent on the configuration of the core because the coil layer is so formed as to enclose the peripheries of the magnetic leg core. In the case where the magnetic leg core has the deformed fan shape substantially of octagon, therefore, the outermost shape of the magnetic leg core can be reduced and hence, the outermost shape of the coil can also be reduced. Accordingly, the reactor as a whole can be reduced in the final radial dimension. Such a reactor is advantageous in a case where restrictions are posed on installation location of the board or the like and on dimensions. 
     Referring to  FIG. 29B , coil fasteners  151  are mounted to three studs  90  arranged on the outside circumference of the circular laminate  174 . 
     The coil fastener  151  is an elongate metal plate centrally formed with a threaded hole so as to be threadably mounted to the stud  90 . The coil fastener is fixed at a predetermined height or at a predetermined height position to support the coil by tightening a locknut applied to the back side of the coil fastener  151 . The three coil fasteners  151  are substantially at the same height. 
     Next, a step of mounting the coil is described with reference to  FIG. 29C .  FIG. 29C (a) is an external perspective view showing how the coil is mounted, while  FIG. 29C (b) is a sectional view of the coil. Referring to  FIG. 29C (a), a coil  102  is vertically slidingly fitted from above around the magnetic leg cores  142  stacked in four layers. The coil  102  is provided with the terminals  42  and  43  at the top thereof for connection to the power line. As shown in  FIG. 29C (b), an inner hole of the coil  102  has a configuration conforming to an outside configuration of the magnetic leg core  142  and is slightly larger than the core so as to permit insertion of the magnetic leg core. The coil  102  is provided with three insulating boards  176  at places on an inside periphery thereof so as to define a gap between the magnetic leg core  142  and the coil  102 . In the case of backlash, the gap is adjusted by way of the insulating board  176  to eliminate the backlash. 
     Next, a step of mounting three magnetic leg cores and coils is described with reference to  FIG. 29D . In  FIG. 29D , an external perspective view shows the three magnetic leg cores and coils mounted by repeating the step of mounting one magnetic leg core and coil as shown in  FIG. 29C (a). The right-hand diagram of  FIG. 29D  is a perspective view showing how the core positioning laminate  55  is mounted from above onto the mounted coils  102 . A step of forming one magnetic leg core  142  by stacking iron cores in four layers with the laminates  175  interposed between the individual iron cores is performed for the other two legs. As shown in  FIG. 29D , the step is performed for all the three legs to complete the mounting of the magnetic leg cores and coils. 
     In the state shown in  FIG. 29D , the core positioning laminate  55  of the equilateral triangular shape is positioned by assembling the threaded hole at the center thereof with the stud  91  and adjusts the positions of the iron cores. It is noted here that the magnetic leg cores  142  have a slightly greater height than the coils  102 . Referring to  FIG. 29D , when the coil  102  is positioned with high precision, the coil fasteners  151  are threadably mounted on the studs  90  on the outside periphery and the coil  102  is fastened with the coil fasteners  151  on the bottom side and the coil fasteners  151  on the top side and fixed in position by tightening the locknuts on the fasteners. Each of the three coils  102  is fixed in this manner. 
     Next, a step of mounting the yoke core on the coils  102  is described with reference to  FIG. 29E .  FIG. 29E  is an external perspective view showing how the yoke core is placed on the three coils  102  and fixed in position with the top fastening fixture. Referring to  FIG. 29E , a laminate  177  of a hollow disk shape is placed on the three coils  102  and a yoke core  162  is placed on this laminate. The yoke core  162  has the same circular configuration as that of the lower yoke core  161 , or has the toroidal shape. A laminate  178  having a hollow disk shape is placed on the circular yoke core  162 . The yoke core  162  is insulated from peripheral parts by winding the insulating sheet therearound. These laminates  177  and  178  and the yoke core  162  are capped with the case of the top fastening fixture  21 . The stud  91  is penetrated through a hole  57  for the central stud  91 , as located centrally of the top fastening fixture  21 , while the studs  90  are penetrated through three stud holes  56  arranged on the circumference of the top fastening fixture  21 . The magnetic leg cores, coils and yoke cores are fixed in position by tightening down the individual locknuts. The eyenut  50  is mounted to the tip end of the central stud  91  so as to hang the reactor device. The numeral  210  denotes the name plate showing the trade name, model code, product serial number, date of manufacture, manufacturer&#39;s name and the like of the device. 
     Next,  FIG. 29F  is an external perspective view sowing the reactor device having all the components assembled thereto and incorporating the magnetic leg cores having the fan-like cross section.  FIG. 29H  is a front view of the reactor device and  FIG. 29G  is a top view thereof. Referring to  FIG. 29F , the two L-shaped bases  131  are fixed to the bottom fastening fixture  31  by welding or the like. The yoke core  161  and the laminate  174  are accommodated in the case of the bottom fastening fixture  31 . The bottom fastening fixture  31  defines a deformed hexagon obtained by cutting an equilateral triangle on lines a predetermined length from the respective apexes, as shown in  FIG. 29G . Specifically,  FIG. 29G  shows an outside configuration of the fixture having the deformed hexagonal shape obtained by cutting an equilateral triangle, one side of which is assumed to be 1, on respective lines about 0.26 away from each of the apexes. The stud  90  is disposed inside of each of the cut sides while the uncut sides are folded to accommodate the yoke core and the laminate. The bottom fastening fixture is so formed as to have the minimum area, achieving size reduction. The top fastening fixture also has the same configuration. 
     The coil  102  is disposed inwardly of the folded side and is so arranged as to position the magnetic leg core in the coil  102  in an overlapping relation with the yoke core. The terminals  42  and  43  are vertically drawn from the inner side and the outer side of the coil  102  to be connected to external terminals. The coil  102  is fixed in position by means of two coil fasteners  151  mounted on the stud  90  and clamping a part of the coil  102  therebetween, the fasteners clamped down by tightening upper and lower locknuts. The bottom fastening fixture  31  and the top fastening fixture  21  are driven to fasten and fix the yoke cores  161  and  162 , the coils  102  and the magnetic leg cores  142  therebetween by tightening locknuts  96  mounted to the three studs  90  on the outside circumference and the one central stud  91 . 
     Example 10 
     Next, a method of fixing the magnetic leg cores according to Example 10 of the invention is described with reference to  FIG. 30 . In  FIG. 30 ,  FIG. 30( a )  is a plan view showing how a coil metal fixture  190  is mounted, while  FIG. 30( b )  is an external view of the coil metal fixture. As shown in  FIG. 30( b ) , the coil metal fixture  190  is formed of a metal plate having a predetermined width which is radially extended from the center in three directions and folded on respective lines at a distance from the reactor center to a gap defined between the point at which the magnetic leg core  142  is closest to the reactor center and the point at which the inner hole of the coil  102  is closest to the reactor center. The extensions of the metal plate are each bent into an L-shape so as to form a claw  192  which is inserted in the gap between the magnetic leg core  142  and the coil  102  for fixing the components. The three directions define an equal angular spacing of 120° therebetween. The coil metal fixture  190  is centrally formed with a hole  191  to allow the fixture to be mounted on the stud  91  disposed at the center of the reactor. 
       FIG. 30( a )  is the plan view showing how the coil metal fixture  190  shown in  FIG. 30( b )  and the coils  102  with the magnetic leg cores  142  mounted therein are arranged. The magnetic leg cores and coils are fixed in position by inserting the stud  91  in the central hole  191  of the coil metal fixture  190 , inserting the projecting claws  192  of the coil metal fixture  190  in the respective gaps between the magnetic leg cores  142  and the coils  102 , and fastening and fixing the magnetic leg cores and coils by tightening down the locknut on the stud  91 . By providing the above structures employing the coil metal fixtures on the upper and lower sides of the coils  102  in this manner, the coils  102  can be prevented from radially deviating from the center. Because of contact with the coils  102  and the magnetic leg cores  142 , the coil metal fixture  190  also has an effect to radiate heat from the coils  102  and the magnetic leg cores  142 , contributing to the increase in the heat radiation effect of the reactor device as a whole. 
     Example 11 
     Next, a coil fixing method according to Example 11 of the invention is described with reference to  FIG. 31 . Referring to  FIG. 31 , a band  205  is wound around the three coils  102  and the three studs  90  so that the coils  102  are fastened and fixed with the band  205 . By fastening and fixing the coil part of the reactor device with the band  205  in this manner, the radial deviation of the three coils  102  from the center can be prevented. The winding mode of the band  205  is not limited to the single winding but the band can also be wound in double or more windings. The band  205  may employ a stainless sheet material, wire formed by twisting metal lines, and the like. 
     Example 12 
     Next, a cooling structure of the reactor device according to Example 12 of the invention is described with reference to  FIG. 32A  to  FIG. 32C  and  FIG. 33 .  FIG. 32A  shows the same structure of the reactor device as that shown in the external view of  FIG. 29F , except that a vent hole  211  is disposed at the center of the top fastening fixture  21 . In  FIG. 32A , the description of the components common to those of  FIG. 29F  is dispensed with and the vent hole  211  as the different point is described. 
     Referring to  FIG. 32A , the vent hole  211  is disposed near the center of the top fastening fixture  21  disposed atop the reactor device. The vent hole  211  is formed by a mesh or a punched hole and present in the area of the inner hole of the yoke core  162 . If the vent hole  211  is similarly disposed near the center of the bottom fastening fixture  31  and in the area of the inner hole of the yoke core  161 , the air flows through a central part of the reactor device from the bottom side toward the top side of the reactor device as shown in  FIG. 32B , cooling the device by drawing heat from the magnetic leg cores  142  and the coils  102  and discharging the heat to the outside. 
       FIG. 32B  is a vertical sectional view of the central part of the reactor device  10 . Referring to the figure, the numeral  91  denotes the central stud; the numeral  161  denotes the lower yoke core; the numeral  142  denotes the magnetic leg core; the numeral  102  denotes the coil; the numeral  162  denotes the upper yoke core; and a numeral  214  denotes an air flow. A structure of the reactor device of the invention includes space around the central stud  91 . Therefore, if the vent hole  211  is arranged in a direction of the center axis of the bottom fastening fixture  31  at bottom and the top fastening fixture  21  at the top, the air  214  flows through the space at the center of the reactor device from the bottom side to the top side, cooling the magnetic leg cores  142  and the coils  102 . Hence, heat is not accumulated within the device. The heat is radiated into the atmosphere because the coil part of the reactor device is exposed to the atmosphere at the outside periphery thereof. 
       FIG. 32C  is a horizontal sectional view showing the coil part of the reactor device. Referring to  FIG. 32C , a gap  213  is defined between adjoining coils  102 . The reactor device is arranged to allow the air from the outside of the reactor device to flow to the center of the device through the gap  213  between the coils  102  (arrow  212 ) or to flow from the bottom side or the center of the reactor device to the top side and out of the device. Some air may flow out through the gap  213  between the coils  102 . Such a structure shown in  FIG. 32A  to  FIG. 32C  is adapted to cool the coils  102  and the magnetic leg cores  142 , increasing cooling efficiency. The magnetic leg core and yoke core employing the amorphous ribbon have small calorific values while the coil has a large calorific value. Hence, the cooling structure of the invention adapted to cool the peripheral area of the coil is effective. 
     Next, a cooling structure of the reactor device of the invention according to another system is shown in  FIG. 33  and described.  FIG. 33  is a perspective view of the reactor device where a fan  215  is disposed at the center of the top fastening fixture  21  at the top of the reactor device. Referring to  FIG. 33 , the cooling fan  215  is disposed above the vent hole  211  shown in  FIG. 32A . This structure is arranged to install the fan  215  at the vent hole  211  near the center of the top fastening fixture  21  of the structure shown in  FIG. 32A  to  FIG. 32C . Hence, the air is forcibly drawn in through the vent hole  211  at the center of the bottom fastening fixture  31  and the gaps  213  between the adjoining coils  102  and discharged from the center of the top fastening fixture  21 , thus cooling the device. While  FIG. 33  illustrates the fan  215  disposed at the center of the top fastening fixture  21  on the top side, the vent hole  211  at the center of the bottom fastening fixture  31  on the bottom side may also be provided with the fan for forcibly drawing in the outside air. The fan is exemplified by a propeller fan, turbofan and the like for forcing the air in one direction. 
     Example 13 
     Next, description is made on configurations of the magnetic leg core and coil and relation therebetween according to Example 13 of the invention. The reactor device is commonly installed in products such as distribution board and is often subjected to restrictions on overall dimensions and weight. In the iron cores produced at the same flux density, as the iron core is increase in mass, the iron core is also increased in core loss value. In the reactor device to which high frequencies are applied, the proportion of the core loss to the overall loss is significant and even a several percent loss is not negligible. For this reason, the increase in the total weight and volume of the reactor device must be reduced. What is most responsible for the weight and volume of the reactor device is the iron core and coil. In particular, the configuration of the three magnetic leg cores around which the coil is wound, or the cross-sectional area of the magnetic leg core is crucial. 
       FIG. 34A  is a plan view showing a layout of the magnetic leg cores, coils and yoke core. Referring to  FIG. 34A , in the case where the yoke cores  161  and  162  have the toroidal shape with the middle hole, the magnetic leg cores  142  of the same configuration are arranged with an equal angular spacing of 120° in order to equalize the three-phase inductance values. For size reduction of the cores maintaining equivalent core characteristics, the magnetic leg cores need to have a fixed cross-sectional area so as to equalize the density of magnetic flux flowing through the cores. It is noted here that the term “cross-sectional area” means the area of the overlap of the cross-sectional area of the magnetic leg core and the cross-sectional area of the end face of the yoke core in consideration of the fact that the magnetic flux flows in the yoke core. 
       FIG. 34A  shows the configuration of the magnetic leg cores arranged at an angular interval of 120°±10° in order to prevent the increase in the cross-sectional area of the core. The magnetic leg core has an apex angle of 120°±10° on an inside peripheral side. Here, a portion of the magnetic leg core that is present inside of an inner circle  164  of the yoke core  161  or  162  is an unnecessary portion where the magnetic flux does not flow. Therefore, the unnecessary portion is chamfered along an arcuate line or linear line.  FIG. 34B  shows a positional relation between the magnetic leg core  142  and the yoke core  161  or  162 . As for the upper-left fan-like magnetic leg core as seen in the figure, a fan-like outside periphery is chamfered along an arcuate line  302  while a fan-like apex (center) portion is chamfered along an arcuate line  302  conforming to the inner circle  164  of the yoke core because this portion is not overlapped with the yoke core  161  or  162  and thence is unnecessary. This arcuate portion may also be linearly chamfered. As for the upper-right magnetic leg core  142  in  FIG. 34B , the outside periphery of the magnetic leg core  142  may be chamfered along chordal lines  301  conforming to an outer circle  165  of the yoke core  161  or  162 . In this example, the arcuate line is chamfered along three chordal lines  301 . Further, the opposite ends of the fan-like shape are cut off to eliminate acute-angled corners. 
     Next, the cross-sectional area of the magnetic leg core  142  is described. The minimum cross-sectional area as defined by the upper-right magnetic leg core  142  in  FIG. 34C  illustrates a case where an arcuate outside periphery of the fan shape defines one chord  301 . Therefore, the magnetic leg core  142  need to have a cross-sectional area equal to or more than the above cross-sectional area. As for the upper-left magnetic leg core  142  in  FIG. 34C , the following equation is obtained: 
                       S   2     -     S   1       =           1   2     ⁢     R   2   2     ⁢   sin   ⁢           ⁢   110   ⁢   °     ⁢     
     -       R   1   2     ⁢   π   ×     110   360         ≈       0.47   ⁢     R   2   2       -     0.96   ⁢     R   1   2                   (     ⁢   1     )               
where the apex angle at the center of the fan shape is 120°±10°; R1 denotes the distance from the apex at the center of the fan shape to the inner circle  164  of the yoke core  161  or  162 ; R2 denotes the distance from the apex at the center of the fan shape to the outer circle  165  (outermost circle) of the yoke core  161  or  162 ; S1 denotes the cross-sectional area of a portion of the magnetic leg core  142  that is present inside of the inner circle  164  of the yoke core; and S2 denotes the cross-sectional area of the magnetic leg core  142  overlapped with the yoke core. The magnetic leg core may have a configuration represented by the area expressed as S 2 −S 1 . While the reactor device may sometimes be required of change in outside configuration depending upon the environment of installation site, the reactor device may adopt the above outside configuration so long as this configuration satisfies the required conditions of such a configuration having the minimum cross-sectional area. If the configuration of the magnetic leg core includes an acute angle, partial discharge occurs when powered up. Hence, a distance between the magnetic leg core  142  and the coil  102  is unduly increased, resulting in the increase of the weight and volume of the whole body of reactor. The increase of the weight and volume of the whole body of reactor can be controlled if all the apex angles are made 90° or more by chamfering the two outside peripheral apexes of the configuration represented by the area of S 2 −S 1 .
 
     The three magnetic leg cores  142  arranged at an angular interval of 120°±10° need be fastened with equal stress, as shown in  FIG. 34D . For this reason, the studs  90  for fastening the magnetic leg cores are arranged about the yoke core at an angular interval of 120°±10° such that the magnetic leg cores, coils and yoke cores between the top fastening fixture  21  and the bottom fastening fixture  31  are fastened and fixed by means of the studs  90  and the stud  91 . 
     Referring to  FIG. 34D , the magnetic-leg-core positioning laminate  55  has an equilateral triangular shape and is formed with a hole for the stud  91  at the middle point of the equilateral triangle. The positioning laminate is so formed as to allow the arcuate portion or linear portion on the inner side of each of the three magnetic leg cores to be contacted against each side of the equilateral triangle, whereby the positioning laminate positions the magnetic leg cores with high precision. 
     Example 14 
     Next, settings of the magnetic leg core, coil and yoke core are described with reference to a flow chart shown in  FIG. 35A  and  FIG. 35B . Referring to the flow chart of  FIG. 35A , a thickness of a coil material and the number of coil turns are first decided so as to decide the thickness of the coil (S 10 ). The thickness of the coil material is decided in consideration of the loss. The number of coil turns is decided in consideration of the inductance value. Next, the cross-sectional profile of the magnetic leg core is decided (S 20 ). Specifically, the cross-sectional area is decided by back-calculation from the number of coil turns and the design magnetic flux density. The configuration of the magnetic leg core that is within the resultant cross-sectional area is decided. The configuration of the magnetic leg core may include fan shape, circle and the like and is decided based on the mass, the overall configuration and characteristics ( FIG. 35B (a)). Next, the magnetic leg cores and coils for three phases are arranged on a circle with an equal angular spacing of 120° (S 30 ) ( FIG. 35B (b)). Next, the inside diameter of the inner hole of the yoke core and the outside diameter of the yoke core are decided (S 40 ). The positional relation between the magnetic leg core and the coil is confirmed and the inside diameter of the hole in the yoke core and the outside diameter of the outermost circle thereof are so decided as to allow the magnetic leg cores overlap with the yoke core ( FIG. 35B (c)). Next, the width of the yoke core is decided (S 50 ). Specifically, the width of the yoke core (difference between the outside diameter and the inside diameter) is decided by back-calculation from the design magnetic flux density of the coil and the laminate thickness (height) of the yoke core ( FIG. 35B (d)). Next, the coil thickness (height) and the GAP dimension between the magnetic leg cores are decided (S 60 ) ( FIG. 35B (e)). As described above, the necessary dimensions of the magnetic leg core and yoke core are decided and these values are judged in conjunction with the dimensions of individual parts of the reactor device, the connection with the stud, temperature and the characteristic of the reactor device and the like (S 70 ) ( FIG. 35B (f)). If the judgment result is ‘YES’, the design procedure is terminated. If the judgment result is ‘NO’, the design procedure returns to Step S 10  to repeat this flow. 
     LIST OF REFERENCE SIGNS 
     
         
           10 : Reactor device, 
           20 , 21 : Top fastening fixture, 
           30 , 31 : Bottom fastening fixture, 
           40 , 41 , 42 , 43 : Coil terminal, 
           50 : Eyenut, 
           51 : Central fastening fixture on top fastening fixture, 
           55 : Magnetic-leg-core positioning laminate, 
           56 : Stud hole, 
           60 : Zero-phase core, 
           70 , 71 : Stud metal fixture, 
           80 : Zero-phase core support, 
           81 : Zero-phase core holder, 
           90 , 91 : Stud, 
           92 : Coil support fixture, 
           96 : Locknut, 
           100 , 101 , 102 : Coil, 
           120 , 123 , 125 , 127 : Coil support fixture, 
           124 , 126 , 158 : Insulating material, 
           130 , 131 : Base, 
           132 : Coil retainer holder, 
           133 : Locknut, 
           134 : Coil retainer, 
           140 , 141 , 142 : Magnetic leg core, 
           143 : Slit, 
           150 : Coil support fixture 
           151 : Coil Fastener, 
           152 : Coil nut, 
           160 , 161 , 162 : Yoke core, 
           163 : Insulating material, 
           170 , 171 , 172 , 173 , 174 : Laminate, 
           180 : Insulating tube body, 
           181 : Reinforcement metal plate, 
           190 : Coil metal fixture, 
           191 : Hole of coil metal fixture, 
           192 : Claw of coil metal fixture, 
           201 : Caster, 
           205 : Band, 
           211 : Vent hole, 
           212 , 214 : Air Flow, 
           213 : Gap, 
           215 : Fan, 
           220 , 221 : Coil terminal, 
           300 : Inside diameter of yoke core, 
           301 : Chordal chamfer, 
           302 : Arcuate chamfer, 
           310 : Coil thickness, 
           400 : Sound absorbing material.