Patent Publication Number: US-2023141937-A1

Title: Coil forming apparatus and coil forming method

Description:
This application is based on and claims the benefit of priority from Japanese Patent Application No. 2021-184408, filed on 11 Nov. 2021, the content of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a coil forming apparatus and a coil forming method. 
     Related Art 
     The stator of a rotary electric machine has a band-shaped coil in a wound state. The band-shaped coil is formed in advance in a substantially cylindrical wound state having a smaller diameter than the inside diameter of the stator core, and is inserted inside of the stator core. The band-shaped coil in the wound state is expanded in diameter inside of the stator coil, and is mounted by inserting the straight portion of the band-shaped coil into a slot of the stator core. 
     Conventionally, it has been known to mold the band-shaped coil into a wound state of substantially cylindrical shape by winding on a coil winding jig, while feeding by one pitch at a time on the columnar coil winding jig (for example, refer to Patent Document 1).
     Patent Document 1: Japanese Patent No. 4953032   

     SUMMARY OF THE INVENTION 
     When forming the coil into the wound state by winding the coil, it is important that a plurality of straight portions are wound accurately without displacing. In the above prior art, by inserting a preliminary alignment member between adjacent straight portions in a position immediately preceding the coil winding jig on the conveying path of the band-shaped coil, the superposition of the immediately preceding straight portion to be wound in the coil winding jig is aligned. 
     However, in the above prior art, there is no specific disclosure about how the band-shape coil is made and conveyed and wound to the coil winding jig, and in particular, upon winding in the coil winding jig, no special viewpoint is shown for the way of reforming the band-shaped coil into an arc shape so as to follow the outer circumference of the coil winding jig. If this reforming is not favorably carried out, the band-shaped coil will not reach the wound state in accordance with the specification, and there is concern over producing poor quality. The occurrence of poor quality leads to an increase in material consumption, leading to wasteful consumption of resources. In addition, the operating time of manufacturing equipment required to achieve the scheduled production volume is extended, and the electrical consumption increases. For this reason, it consequently has an adverse impact on the global environment. 
     The present invention has been made taking account of the above-mentioned situation, and has an object of providing a coil forming apparatus and coil forming method which can easily form a band-shaped coil into a predetermined wound state, by precisely reforming into an arc shape so as to follow the outer circumference of a coil winding jig. So long as it is possible to process the band-shaped coil into a predetermined wound state with high yield without introducing a defective product, since it is possible to suppress wasteful consumption of resources, curb the operating time of manufacturing equipment, and save on electrical energy, it will contribute to preservation of the global environment. 
     A coil forming apparatus (for example, the coil forming apparatus  1  described later) according to a first aspect of the present invention forms a band-shaped coil (for example, the band-shaped coil  100  described later) in a wound state, the band-shaped coil including a plurality of straight portions (for example, the straight portion  102  described later) and side ends (for example, the side end  103  described later) provided on both ends of the plurality of straight portions, the coil forming apparatus including: a coil winding jig (for example, the coil winding jig  2  described later) having a plurality of comb-shaped grooves (for example, the comb-shaped groove  23  described later), and configured to be capable of winding the band-shaped coil by inserting the plurality of straight portions of the band-shaped coil into a respective on the plurality of comb-shaped grooves; a coiling conveying mechanism unit (for example, the coil conveying mechanism unit  3  described later) configured to be capable of pivotal conveying the band-shaped coil; and guide members (for example, the guide member  4  described later) that are provided in a vicinity of both ends of the coil winding jig in an axial direction, and guide the band-shaped coil in an arc shape while being in contact with the side end of the band-shaped coil, and insert the plurality of straight portions in a respective one of the plurality of comb-shaped grooves in a second half portion of pivotal conveying of the band-shaped coil, in which the coil conveying mechanism unit includes a conveying rail (for example, the conveying rail  31  described later) that provides a conveying path pivotally conveying the band-shaped coil along the coil winding jig, and a conveyor (for example, the conveyor  32  described later) that moves along the conveying rail in a state gripping each of the plurality of straight portions of the band-shaped coil, the conveyor has a plurality of gripping grooves (for example, the gripping groove  321  described later) which grip a respective one of the plurality of straight portions of the band-shaped coil, and the plurality of gripping grooves have a coil abutting bottom surface (for example, the coil abutting bottom surface CCB described later) of a depth according to an overlapping number of the plurality of straight portions which differ according to position in a conveying direction of the band-shaped coil. 
     According to a second aspect of the present invention, in the coil forming apparatus as described in the first aspect, the coil abutting bottom surface may be a bottom part (for example, the upper end surface  331   a  of the piece member main body  331  which is the bottom part described later) of each of the plurality of gripping grooves provided at a site at which the plurality of piece members (for example, the piece member  33  described later) adjoin of the conveyor configured by a plurality of the piece members which are rotatable accompanying pivotal conveying of the band-shaped coil while gripping the plurality of straight portions being coupled to overlap along the conveying direction of the band-shaped coil. 
     According to a third aspect of the present invention, in the coil forming apparatus as described in the first or second aspect, the guide members may include a reforming portion (for example, the reforming portion  42  described later) in a first half portion of the band-shaped coil upon pivotal conveying, and the reforming portion deforms and reforms the band-shaped coil in an arc shape in a state sandwiching the side ends of the band-shaped coil in a state gripping the plurality of straight portions in the plurality of gripping grooves. 
     A coil forming method according to a fourth aspect of the present invention forms a band-shaped coil (for example, the band-shaped coil  100  described later) in a wound state, the band-shaped coil including a plurality of straight portions (for example, the straight portion  102  described later) and side ends (for example, the side end  103  described later) provided on both ends of the plurality of straight portions, the method including: a coil conveying step of pivotally conveying the band-shaped coil in a state gripping each of the plurality of straight portions, along a coil winding jig (for example, the coil winding jig  2  described later), the coil winding jig including a plurality of comb-shaped grooves (for example, the comb-shaped groove  23  described later) on an outer periphery thereof, each of which can hold a respective one of the plurality of straight portions therein, and being configured to wind the band-shaped coil, and a guiding step of providing guide members (for example, the guide member  4  described later) in a vicinity of both ends of the coil winding jig in an axial direction, guiding the band-shaped coil so as to be in an arc shape while the side ends of the band-shaped coil being pivotally conveyed are in contact with the guide members, and inserting the plurality of straight portions into a respective one of the plurality of comb-shaped grooves of the coil winding jig, in which the coil conveying step uses a conveyor (for example, the conveyor  32  described later) having gripping grooves (for example, the gripping groove  321  described later) having a coil abutting bottom surface (for example, the coil abutting bottom surface CCB described later) of a depth according to an overlapping number of the plurality of straight portions which differs according to position in a conveying direction of the band-shaped coil to grip the plurality of straight portions by the gripping grooves. 
     According to a fifth aspect of the present invention, in the coil forming method as described in the fourth aspect, the coil conveying step may be configured to use the conveyor in which a plurality of piece members (for example, the piece member  33  described later) which are rotatable accompanying pivotal conveying of the band-shaped coil while gripping the plurality of straight portions are coupled to overlap along the conveying direction of the band-shaped coil, and grip the plurality of straight portions by the gripping groove in which the coil abutting bottom surface is provided as a bottom of each of the plurality of gripping grooves provided at a site where the plurality of piece members adjoin. 
     According to a sixth aspect of the present invention, in the coil forming method as described in the fourth or fifth aspect, the coil conveying step may further include a reforming step (for example, step performing reforming by the reforming portion  42  described later) of deforming and reforming the band-shaped coil in an arc shape, by sandwiching the side ends of the band-shaped coil in a state gripping the plurality of straight portions in the plurality of gripping grooves, in a first half portion of the band-shaped coil upon pivotal conveying. 
     In the coil forming apparatus according to the first aspect of the present invention, the plurality of gripping grooves gripping a respective one of the straight portions includes the coil abutting bottom surface of a depth according to an overlapping number of the plurality of straight portions which differs according to the position in the conveying direction of the band-shaped coil. For this reason, upon deforming and reforming on the band-shaped coil into an arc shape, force acts appropriately on the coil abutting bottom surface functioning as the force point and working point giving force for this reforming, and from the corresponding site of the guide member as the fulcrum relative to this. Therefore, it is possible to perform predetermined reforming on the band-shaped coil. 
     According to the coil forming apparatus as described in the second aspect, the conveyor is configured by the plurality of piece members which are rotatable accompanying pivotal conveying of the band-shaped coil being coupled to overlap along the conveying direction of the band-shaped coil, the gripping grooves are formed at every site at which the plurality of piece members adjoin, and the bottom part of this gripping groove makes the coil abutting bottom surface. For this reason, the convey can pivotally convey the coil conductors of the band-shape coil smoothly in an arc shape while gripping by the gripping grooves. 
     According to the coil forming apparatus as described in the third aspect, in the reforming portion, the band-shaped coil is deformed and reformed in an arc shape in a state sandwiching the side ends of the band-shaped coil in a state in which the coil conductors of the straight portions are gripped in the plurality of gripping grooves. For this reason, the force for making the bending habit in the band-shaped coil acts appropriately, and thus it is possible to make a predetermined bending habit in the band-shaped coil. 
     According to the coil forming method as described in the fourth aspect, the plurality of gripping grooves gripping a respective one of the coil conductors of the straight portions exactly support the coil conductors at the deepest part of the gripping groove by the coil abutting bottom surface of a depth according to the overlapping number of the plurality of straight portions which differs according to the position in the conveying direction of the band-shaped coil. For this reason, upon deforming and reforming on the band-shaped coil into an arc shape, force acts appropriately on the coil abutting bottom surface functioning as the force point and working point giving force for this reforming, and from the corresponding site of the guide member as the fulcrum relative to this. Therefore, it is possible to perform predetermined reforming on the band-shaped coil. 
     According to the coil forming method as described in the fifth aspect, the conveyor is configured by the plurality of piece members which are rotatable accompanying pivotal conveying of the band-shaped coil being coupled to overlap along the conveying direction of the band-shaped coil, the gripping grooves are formed at every site at which the plurality of piece members adjoin, and the bottom part of this gripping groove makes the coil abutting bottom surface. For this reason, the band-shaped coil can be pivotally conveyed by the conveyor smoothly in an arc shape by gripping the coil conductors by the gripping grooves. 
     According to the coil forming method as described in the sixth aspect, in the reforming portion, the band-shaped coil is deformed and reformed in an arc shape in a state sandwiching the side ends of the band-shaped coil in a state in which the coil conductors of the straight portions are gripped in the plurality of gripping grooves. For this reason, the force for making the bending habit in the band-shaped coil acts appropriately, and thus it is possible to make a predetermined bending habit in the band-shaped coil. 
     In addition, the coil forming apparatus as described in the first to third aspects, and the coil forming method as described in the fourth to sixth aspects are collectively premised on using material made into a series of band-shaped coils in advance, as the coils set in the stator. Upon setting the coil into the slot of the stator, the current mainstream technique is a technique which divides and forms the coil into a plurality of segments, and after inserting into the slots, welds the coil ends. In this general technique, it is necessary to use high purity copper in the coil so as to be able to withstand the thermal processing at the weld location. In contrast, since coping with the thermal processing is unnecessary with the present invention, it is possible to use recycled copper wire containing impurities, which can contribute to the realization of the recycling of resources. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side view showing an embodiment of a coil forming apparatus of the present invention; 
         FIG.  2    is a drawing viewing the coil forming apparatus shown in  FIG.  1    from the A direction in  FIG.  1   ; 
         FIG.  3    is a drawing viewing the coil forming apparatus shown in  FIG.  1    from the B direction in  FIG.  1   ; 
         FIG.  4    is a perspective view showing an embodiment of a coil winding jig; 
         FIG.  5    is a perspective view showing a piece member of a grip portion of a coil conveying mechanism unit; 
         FIG.  6    is a perspective view showing an aspect viewing the piece member of the grip portion of the coil conveying mechanism unit from the opposite side of  FIG.  5   ; 
         FIG.  7    is a perspective view showing a state connecting two piece members; 
         FIG.  8    is an enlarged view of a portion E in  FIG.  1   ; 
         FIG.  9    is an enlarged view of a portion C in  FIG.  1   ; 
         FIG.  10    is a cross-sectional view showing an aspect of the band-shaped coil being guided into an arc shape in the coil winding jig by a guide member; 
         FIG.  11    is an enlarged cross-sectional view of a portion D in  FIG.  1   ; 
         FIG.  12    is a partial enlarged view showing an aspect of the band-shaped coil being wound multiply on the coil winding jig; 
         FIG.  13    is a perspective view showing a state in which the band-shaped coil is molded in a wound state on the coil winding jig; 
         FIG.  14 A  is a conceptual diagram showing the band-shaped coil in a side view by expanding in the direction of the conveying path of linear shape of the coil forming apparatus shown in  FIG.  1   . 
         FIG.  14 B  is a conceptual diagram showing the coil conveying mechanism unit in a side view by expanding in the direction of conveying path of linear shape of the coil forming apparatus shown in  FIG.  1   . 
         FIG.  14 C  is a conceptual diagram showing in a side view the shape in a case of gripping the band-shaped coil of  FIG.  14 A  by the coil conveying mechanism unit of  FIG.  14 B . 
         FIG.  15 A  is a view for explaining an aspect of deforming and reforming the band-shaped coil gripped in the coil conveying mechanism unit into an arc shape by a reforming portion of a guide member. 
         FIG.  15 B  is a view for explaining the operation of reforming in  FIG.  15 A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, an embodiment of the present invention will be explained. As shown in  FIG.  1   , a coil forming apparatus  1  of the present embodiment includes: a coil winding jig  2 ; a coil conveying mechanism unit  3  which causes a band-shaped coil  100  to convey along the outer circumference of the coil winding jig  2 ; and a pair of guide members  4  which guide the band-shaped coil  100  conveyed by the coil conveying mechanism unit  3  so as to be wound on the coil winding jig  2 . 
     (Band-Shaped Coil) 
     As shown in  FIG.  3   , the band-shaped coil  100  is molded into an elongated corrugated band-shape by rectangular conductor wires  101  having a substantially rectangular cross-sectional shape. The rectangular conductor wires  101  are formed from a metal having high conductivity such as copper or aluminum, for example. 
     The band-shaped coil  100  has a plurality of straight portions  102  and a plurality of side ends  103 . The straight portions  102  are parts to be inserted in a slot provided in the inner circumference of a stator core which is not illustrated, and are arranged in parallel at a predetermined interval to extend substantially linearly in the same direction, respectively. The side ends  103  are respectively arranged at a position closer to the side end of the band-shaped coil  100  than the straight portion  102 , i.e. at both ends in the extending direction of the straight portion  102 . The side ends  103  couple adjacent straight portions  102  at one end portion and the other end portion alternately in a mountain shape, and constitute coil end parts, each projecting in an axial direction of the stator core from the stator, upon the band-shaped coil  100  being mounted to the stator of the stator core. 
     The band-shaped coil  100  of the present embodiment is provided in an elongated band shape by arranging six rectangular conductor wires  101  in a manner in which the plurality of straight portions  102  are provided in parallel to each other at a constant interval, and the plurality of side ends  103  are shifted by the pitch of the straight portions  102  to be stacked. The six rectangular conductor wires  101  are provided by folding the plurality of straight portions  102  and the plurality of side ends  103  respectively in a corrugated shape. The straight portions  102  of the band-shaped coil  100  are stacked in the thickness direction (the vertical direction relative to the paper plane of  FIG.  3   ) of the band-shaped coil  100  by folding back the rectangular conductor wire  101  in the middle. The band-shaped coil  100  of the present embodiment has a length that is wound four times around the coil winding jig  2  to be described later. 
     (Coil Winding Jig) 
     As shown in  FIG.  4   , the coil winding jig  2  includes: a substantially cylindrical jig main body  21 ; a plurality of comb teeth  22  protruding radially to the outer circumference of the jig main body  21 , a plurality of comb-shaped grooves  23  provided between the adjacent comb teeth  22 ,  22  in the circumferential direction, and an axial hole  24  opened at the center of the jig main body  21 . The comb teeth  22  and comb-shaped groove  23  are respectively provided at both ends in the axial direction of the jig main body  21 . The phases of the comb teeth  22  and comb-shaped groove  23  at one end of the jig main body  21  and the comb teeth  22  and comb-shaped groove  23  at the other end are aligned. The coil winding jig  2  of the present embodiment has 72 comb-shaped grooves  23  respectively at both ends in the axial direction of the jig main body  21 . The number of these comb-shaped grooves  23  matches the number of slots in the stator core in which the band-shaped coils  100  are mounted. 
     The interval distance between the comb teeth  22  and comb-shaped groove  23  at one end of the jig main body  21  and the comb teeth  22  and comb-shaped groove  23  at the other end is substantially equal to the length in the extending direction of the straight portion  102  of the band-shaped coil  100 . Therefore, the straight portion  102  of the band-shaped coil  100  can be accommodated over the comb-shaped groove  23  at one end and the comb-shaped groove  23  at the other end of the jig main body  21 . 
     The coil winding jig  2  is formed so that the outside diameter of the coil winding jig  2  defined by the position of the leading end of the comb teeth  22  is no more than the inside diameter of the stator core, so that it becomes possible to insert inside of the stator core. The coil winding jig  2  is arranged at a predetermined site of the coil forming apparatus  1 , and is provided to be rotatable in the d 1  direction shown by the arrow in  FIG.  1   , centered around the axial hole  24  by driving of a motor which is not illustrated. 
     (Coil Conveying Mechanism Unit) 
     The coil conveying mechanism unit  3  pivotally conveys the band-shaped coil  100  along at least part of the outer circumference of the coil winding jig  2 . More specifically, the coil conveying mechanism unit  3  has a pair of conveying rails  31  constituting a conveying path of the band-shaped coil  100 , and a conveyor  32  which grips the band-shaped coil  100  and conveys along the conveying rails  31 , as shown in  FIGS.  1  and  2   . 
     The conveying rails  31  are formed in a band-shaped plate made of metal, and arranged in parallel to each other with substantially equal intervals to the length of the straight portion  102  of the band-shaped coil  100 , in the width direction of the coil forming apparatus  1 . The interval of the pair of conveying rails  31  is substantially equal to the interval distance in the axial direction of the comb teeth  22  and comb-shaped groove  23  of the coil winding jig  2 , as shown in  FIG.  2   . 
     The conveying rails  31  includes a pair of upper and lower parallel linear conveying parts  311 ,  312  forming a linear conveying path, and a pivot conveying unit  313  which connects the ends of the linear conveying parts  311 ,  312  in an arc shape, thereby forming a lateral U-shaped conveying path. The conveying rails  31  are provided so as to surround the coil winding jig  2  by arranging on the inner side of the U-shaped portion, so that the pivot conveying unit  313  follows the outer circumference of the coil winding jig  2 . As shown in  FIG.  2   , pairs of guide grooves  314  spanning the entire length of the conveying rail  31  are respectively provided to the faces on which the pair of conveying rails  31  are opposing each other. The guide groove  314  forms a travel path of a conveyor  32  described later. 
     In the present embodiment, the pivot conveying unit  313  of the coil conveying mechanism unit  3  is formed along a range approximately ½ of the outer circumference of the coil winding jig  2 . The pivot conveying unit  313  includes a first half portion  313   a  on the introducing side of the band-shaped coil  100  and a second half portion  313   b  on the discharging side of the band-shaped coil  100 . The first half portion  313   a  is formed over a range of approximately ½ the first half of the pivot conveying unit  313 . The second half portion  313   b  is provided over a range of approximately ½ the second half of the pivot conveying unit  313 . However, the pivot conveying unit  313  may be configured to be able to pivotally convey the band-shaped coil  100  along at least a portion of the outer periphery of the coil winding jig  2 . 
     The conveyor  32  extends long along the conveying rail  31  and can move along the conveying rail  31  between the pair of conveying rails  31 . The conveyor  32  has a length corresponding to at least the total length of the band-shaped coil  100 , and moves along the conveying rail  31  in a state of holding the straight portions  102  of the band-shaped coil  100  on the upper surface, thereby pivotally conveying the band-shaped coil  100  along the outer periphery of the coil winding jig  2 . 
     As shown in  FIGS.  1  and  3   , the conveyor  32  includes a plurality of piece members  33  of the same structure arranged in a multilayer shape to be coupled overlapping along the conveying direction of the band-shaped coil  100 . As shown in  FIGS.  5 ,  6  and  7   , the piece members  33  each include a piece member body  331  having a substantially rectangular plate-like shape made of metal, and a pair of guide projections  332 , each projecting laterally from both ends in the width direction at the lower end of the piece member body  331 . The guide projections  332  of the present embodiment each include a rotatable roller; however, they may be simple projections. In addition, regarding the directions of the piece member  33 , in  FIGS.  5 ,  6 , and  7   , the X direction is defined as the width direction, the Y direction is defined as the thickness direction, and the Z direction is defined as the height direction. In the height direction, the upper direction in the drawings is defined as “up”, and the lower direction is defined as “down”. 
     The piece member body  331  has a thickness substantially equal to the gap between adjacent straight portions  102  and  102  in the length direction of the band-shaped coil  100 . The piece member body  331  has an upper end surface  331   a , and the upper end surface  331   a  includes a pair of first gripping claws  333 , each projecting in the height direction. The first gripping claw  333  has a thickness of approximately ½ the thickness of the piece member body  331 . The thickness of the first gripping claw  333  is substantially equal to the gap between the adjacent straight portions  102  and  102  of the band-shaped coil  100 . The first gripping claw  333  is provided at a position in the vicinity of one end in the thickness direction of the piece member body  331  on the upper end surface  331   a . The pair of first gripping claws  333  are disposed apart from each other on both end sides in the width direction of the piece member body  331  with a predetermined interval therebetween. 
     The first gripping claws  333  each have an upper end surface, and the upper end surface includes a meshing groove  333   a  that meshes with a tip of the comb tooth  22  of the coil winding jig  2 . More specifically, as shown in  FIG.  4   , the tip of the comb tooth  22  of the coil winding jig  2  has an engaging portion  22   a . The meshing groove  333   a  has a position and a shape capable of meshing with the engaging portion  22   a  of the coil winding jig  2 . 
     The first gripping claws  333  each have a tapered surface  333   b  on the side opposite to the side on which the upper end surface  331   a  is provided. The tapered surface  333   b  allows the first gripping claw  333  to be formed in a slightly tapered shape as it moves away from the piece member body  331 . 
     The pair of first gripping claws  333  has a rectangular recess  334  along the height direction of the piece member body  331  provided therebetween. The recess  334  is provided to span from the upper end surface  331   a  to the portion approximately ½ the height of the piece member body  331 . The depth of the recess  334  along the thickness direction of the piece member body  331  has a depth of approximately ½ the thickness of the piece member body  331 , similarly to the first gripping claw  333 . 
     The piece member body  331  includes a rectangular protrusion  335  provided on one side surface  331   b . The protrusion  335  is provided to protrude, in the thickness direction of the piece member body  331 , in a block shape toward a direction perpendicular to the side surface  331   b  from the side surface  331   b  which is opposite to the side where the first gripping claw  333  is provided. The protrusion  335  is provided above a site which is approximately ½ the height of the piece member body  331  in the height direction. The height of the protrusion  335  along the height direction of the piece member body  331  is substantially equal to the height of the recess  334 . The thickness of the protrusion  335  along the thickness direction of the piece member body  331  is substantially equal to the depth of the recess  334 . 
     The protrusion  335  includes a second gripping claw  336  provided at an upper end portion thereof. Similarly to the first gripping claws  333 , the second gripping claw  336  projects upward from the upper end surface  331   a  of the piece member body  331 . Similarly to the first gripping claws  333 , the thickness of the second gripping claw  336  is substantially equal to the gap between the adjacent straight portions  102  and  102  of the band-shaped coil  100 . Since the second gripping claw  336  has the same width as the protrusion  335 , as shown in  FIG.  7   , when the two piece members  33  and  33  are stacked with their directions aligned with each other, the second gripping claw  336  of the one piece member  33  is disposed between the pair of first gripping claws  333  and  333  of the other piece member  33 . 
     The second gripping claw  336  has tapered surfaces  336   a  on both the side on which the upper end surface  331   a  is provided and the opposite side thereto. These tapered surfaces  336   a  allow the second gripping claw  336  to be formed in a slightly tapered shape as it moves away from the piece member body  331 . 
     As shown in  FIG.  7   , the plurality of piece members  33  are aligned such that the first gripping claws  333  and the second gripping claws  336  are oriented in the same direction, and the protrusions  335  of the piece member  33  are stacked so as to be accommodated in the recess  334  of the adjacent piece member  33 . As a result, the adjacent piece members  33  and  33  are in close contact with each other and stacked. 
     The piece member  33  includes a through hole  337   a  extending in the width direction of the piece member  33  at a portion in the vicinity of the root of the first gripping claw  333  and substantially at the same height as the upper end surface  331   a  of the piece member body  331 . In addition, the protrusion  335  includes a through hole  337   b  extending in the width direction of the protrusion  335  at a portion in the vicinity of the root of the second gripping claw  336  and substantially at the same height as the upper end surface  331   a  of the piece member body  331 . As shown in  FIG.  7   , after the two piece members  33  and  33  are stacked, a shaft member  338  is inserted to span the through hole  337   a  and the through hole  337   b  which are in communication with each other. Thus, with the shaft member  338  as a rotation axis, the lower end sides of the plurality of pieces members  33  where the guide projections  332  are provided are coupled with each other in a rotatable (swingable) manner in the length direction of the conveyor  32 , thereby forming an elongated conveyor  32 . 
     As shown in  FIGS.  3 ,  7 ,  8 , and  9   , in the conveyor  32 , gripping grooves  321  each gripping the straight portion  102  of the band-shaped coil  100  is provided between the first gripping claws  333  and  333 , and between the second gripping claws  336  and  336  of the adjacent piece members  33 ,  33 . The gripping groove  321 , as shown in  FIG.  7   , is formed as a depression of depth d from the introduction opening  331   e , which is at the height position of the shoulder at which the first gripping claw  333  rises up from the upper end surface  331   a  of the piece member main body  331 . The bottom part of the gripping groove  321  is an upper end surface  331   a  of the piece member main body  331 . 
     The depth d of each of the plurality of gripping grooves  321  is set to a dimension according to the overlapping coil conductor number of different straight portions  102  according to the position in the conveying direction of the band-shaped coil  100 . The bottom of the depth d of the gripping groove  321  makes a coil abutting bottom surface CCB serving as the abutting surface relative to the coil conductor positioned at the deepest part of the coil conductors gripped by the gripping groove  321 . In other words, the coil abutting bottom surface CCB is the bottom of each of the plurality of gripping grooves  321 ,  321  formed at a site where the plurality of piece members  33 ,  33  are adjoining of the conveyor  32  configured by the plurality of piece members  33 ,  33  which are rotatable accompanying pivotal conveying of the band-shaped coil  100  while gripping the plurality of straight portions  102 ,  102  being coupled to overlap along the conveying direction of the band-shaped coil  100 . 
     The gripping grooves  321  each have a groove width capable of accommodating the straight portion  102  of the band-shaped coil  100 . The groove width of the gripping groove  321  is substantially equal to the groove width along the circumferential direction of the comb-shaped groove  23  of the coil winding jig  2 . The arrangement pitch of the gripping grooves  321  along the length direction of the conveyor  32  is substantially equal to the arrangement pitch of the comb-shaped groove  23  along the circumferential direction of the coil winding jig  2 . Therefore, when the meshing groove  333   a  and the engaging portion  22   a  are engaged with each other, as shown in  FIG.  8   , the gripping groove  321  of the conveyor  32  and the comb-shaped groove  23  of the coil winding jig  2  are in communication with each other in the radial direction of the coil winding jig  2 . 
     In the conveyor  32 , each guide projection  332  of the piece member  33  is slidably accommodated in the guide groove  314  of the conveying rail  31 , and protrudes toward the inside of the U-shaped conveying rail  31 . Furthermore, as shown in  FIG.  8   , the meshing groove  333   a  of the piece member  33  meshes with the engaging portion  22   a  of the coil winding jig  2  at the location immediately below the coil winding jig  2 , such that the conveyor  32  is in synchronization with the rotation of the coil winding jig  2  by the rotation of the coil winding jig  2  in the direction d 1  so as to be movable in the direction d 2 . When the conveyor  32  moves in an arc shape along the pivot conveying unit  313  of the conveying rail  31 , the guide projections  332  of the piece members  33  and  33  adjacent to each other rotate by means of the shaft member  338  so as to be isolated with the portions of the first gripping claw  333  and the second gripping claw  336  which are sites for gripping the straight portions  102  as references, such that the conveyor  32  is smoothly movable. 
     As shown in  FIGS.  3 ,  8 , and  9   , in the conveyor  32  which is slidably disposed on the conveying rail  31 , the first gripping claw  333  and the second gripping claw  336  are inserted into the gap between the straight portions  102  and  102  adjacent to each other in the length direction of the band-shaped coil  100 , and the straight portions  102  are accommodated in the respective gripping grooves  321 , whereby the band-shaped coil  100  is gripped. Therefore, it is possible for the conveyor  32  to convey the band-shaped coil  100  in a state of holding the straight portions  102  at regular intervals without displacing the straight portions. As shown in  FIGS.  2  and  3   , the side ends  103  of the band-shaped coil  100  protrude laterally on both sides in the moving direction of the conveyor  32 . It should be noted that, in  FIG.  1   , the band-shaped coil  100  to be gripped by the conveyor  32  is not shown. 
     (Guide Member) 
     As shown in  FIG.  1   , the guide members  4  are made from a metal band-shaped plate material, and provided in a substantially U-shape laterally along the pivot conveying unit  313  of the conveying rail  31 . In the guide members  4 , the inside of the U-shaped portion is provided so as to face the direction of the coil winding jig  2  in the vicinity of the both ends of the coil winding jig  2  in the axial direction (the vertical direction relative to the paper plane of  FIG.  1   , and the left-right direction in  FIG.  2   ) so as to sandwich the coil winding jig  2 , and is fixed to the conveying rail  31 . 
     The guide member  4  includes an introduction end  4   a  which introduces the side end  103  of the band-shaped coil  100  conveyed by the conveyor  32 , a discharge end  4   b  which discharges the side end  103  of the band-shaped coil  100 , and an inner wall surface  41  which guides the side end  103  from the introduction end  4   a  to the discharge end  4   b . The inner wall surface  41  is formed by a curved surface which smoothly curves continuously from the introduction end  4   a  to the discharge end  4   b  so as to follow approximately ½ of the outer periphery of the coil winding jig  2 . The guide member  4  smoothly guides the entirety of the band-shaped coil  100  into an arc shape so as to follow the outer circumference of the coil winding jig  2 , by causing the side end  103  introduced from the introduction end  4   a  to contact the inner wall surface  41 , while being pivotally conveyed by the pivot conveying unit  313 . 
     The curvature of the inner wall surface  41  of arc shape of the guide member  4  is formed so as to gradually change greatly as approaching the discharge end  4   b  from the introduction end  4   a . In more detail, as shown in  FIG.  10   , the inner wall surface  41  of the introduction end  4   a  is arranged somewhat more to the outer side in the radial direction than the outer circumference of the coil winding jig  2 . However, the inner wall surface  41  gradually reduces in diameter smoothly as approaching the discharge end  4   b  from the introduction end  4   a . The inner wall surface  41  at the discharge end  4   b  is arranged more to the inner side in the radial direction than the outer circumference of the coil winding jig  2 . For this reason, the inner wall surface  41  of the guide member  4  guides the band-shaped coil  100  so as to gradually round into an arc of a smaller diameter than the outside diameter of the coil winding jig  2 , while contacting the side end  103  of the band-shaped coil  100 , as the band-shaped coil  100  approaches the second half portion  313   b  from the first half portion  313   a  of the pivot conveying unit  313 . 
     The band-shaped coil  100  is gradually pressed toward the coil winding jig  2 , by being guided to the inner wall surface  41  of the guide member  4 , as approaching the second half portion  313   b  from the first half portion  313   a  of the pivot conveying unit  313 . The straight portion  102  gripped by the conveyor  32  thereby forcibly separates from the gripping groove  321  so as to lift up, and gradually moves towards the inside of the comb-shaped groove  23  of the coil winding jig  2 . The discharge end  4   b  of the guide member  4  is arranged more to the inner side in the radial direction than the outer circumference of the coil winding jig  2 ; therefore, the straight portion  102  is completely inserted into the comb-shaped groove  23  of the coil winding jig  2 . Subsequently, the band-shaped coil  100  is wound in the coil winding jig  2  by rotation of the coil winding jig  2 . It should be noted that, in  FIGS.  10  and  12   , the conveyor  32  is omitted from illustration, and the band-shaped coil  100  is shown to be simplified. 
     It should be noted the guide member  4  is not limited to a structure having the inner wall surface  41  which is continuous over the entirety of the pivot conveying unit  313  as in the present embodiment. The guide member  4 , although not illustrated, may be a structure arranging a plurality of guide rollers so as to follow the pivot conveying unit  313 , for example. However, in the viewpoint of configuring so as to be able to continuously guide the band-shaped coil  100  to the comb-shaped groove  23  of the coil winding jig  2 , and be able to smoothly insert the straight portion  102  into the comb-shaped groove  23 , the guide member  4  preferably has the inner wall surface  41  contacting at the wall surface with the side end  103  at the second half portion  313   b  of the pivot conveying unit  313 . In the viewpoint of configuring so as to be able to smoothly guide the band-shaped coil  100  into an arc shape over the entirety of the pivot conveying unit  313 , and be able to smoothly insert the straight portion  102  into the comb-shaped groove  23  of the coil winding jig  2 , the guide member  4  preferably has the inner wall surface  41  contacting at the wall surface with the side end  103  in the entirety of the pivot conveying unit  313  as in the present embodiment. 
     As shown in  FIGS.  1  and  2   , the guide member  4  has, at the side of the introduction end  4   a  thereof, the pair of reforming portions  42  for causing the band-shaped coil  100  introduced to the pivot conveying unit  313  to forcibly deform and reform so as to curve into an arc shape along the outer circumference of the coil winding jig  2 . In the guide member  4 , the range in which the reforming portion  42  is provided is within the range of the first half portion  313   a  of the pivot conveying unit  313 . More specifically, the reforming portion  42 , for example, can be provided from the introduction end  4   a  of the guide member  4  over a range of approximately ½ to approximately ¾ of the first half portion  313   a  of the pivot conveying unit  313 . 
     In other words, the guide members  4  include the reforming portion  42  in the first half portion  313   a  of the pivotal conveying of the band-shaped coil  100 , and the reforming portion  42  deforms and reforms the band-shaped coil  100  in an arc shape in a state sandwiching the side ends  103  of the band-shaped coil  100  in a state in which the plurality of straight portions  102 ,  102  are gripped in the plurality of gripping grooves  321 ,  321 . 
     The reforming portion  42  is configured by the inner wall surface  41  of the guide member  4  and guide plates  421 . The guide plates  421  are formed so as to smoothly curve in an arc shape along the curvature of the inner wall surface  41  of the guide member  4 . The guide plates  421 , similarly to the guide member  4 , are respectively arranged so as to sandwich the coil winding jig  2  from both end sides in the axial direction, and are fixed to the guide member  4 . In the reforming portion  42 , a reforming groove  422  pinching the side end  103  is formed between the inner wall surface  41  and guide plate  421 . The inner wall surface  41  of the reforming portion  42  contacts and supports the surface on the outer side in the radial direction of the side end  103  of the band-shaped coil  100 , and the guide plates  421  contact and support the surface on the inner side in the radial direction of the side end  103  of the band-shaped coil  100 . 
     The reforming portion  42  causes the side end  103  of the band-shaped coil  100  introduced to the introduction end  4   a  of the guide member  4  to forcibly deform so as to curve into an arc shape, by conveying while being accepted and clamped in the reforming groove  422 . The band-shaped coil  100  is reformed into an arc shape, at an early stage of introduction of the pivot conveying unit  313  before winding on the coil winding jig  2 , and the force trying to elastically recover to a flat shape while guided to an arc shape by the inner wall surface  41  of the guide member  4  subsequently is suppressed. Therefore, the band-shaped coil  100  is smoothly and precisely molded into the substantially cylindrical wound shape, in combination with being guided into the arc shape by the guide member  4 . 
     (Coil Forming Method) 
     Next, a method of forming the band-shaped coil  100  into a substantially cylindrical wound state by the coil forming apparatus  1  will be described. 
     First, the coil winding jig  2  is provided to be rotatable by the driving of a motor (not shown) inside the U-shaped portion of the conveying rail  31  of the coil forming apparatus  1  (coil winding jig arranging step). 
     After the coil winding jig  2  is provided in the coil forming apparatus  1 , the band-shaped coil  100  which is formed in advance in a long corrugated band shape is supplied to the conveyor  32  which is provided in the straight conveying unit  311  on the lower side of the conveying rail  31  by a coil feeding device or an operator (not shown). The band-shaped coil  100  is gripped by the conveyor  32  by inserting the first gripping claws  333  and the second gripping claws  336  of the respective piece members  33  of the conveyor  32  into adjacent gaps of the band-shaped coil  100 , and by accommodating the straight portions  102  in the gripping grooves  321 , respectively. 
     In detail, it uses the conveyor  32  with the gripping grooves  321  having the coil abutting bottom surface CCB of depth d according to the number of the coil conductors overlapping of the plurality of straight portions  102 ,  102  which differ according to the position in the conveying direction of the band-shaped coil  100 , and grips the plurality of straight portions  102 ,  102  by these gripping grooves  321 . 
     Thereafter, the conveyor  32  gripping the base-shaped coil  100  is pressed by a conveyer pressing device (not shown) or an operator, and the straight conveying unit  311  is moved toward the coil winding jig  2  so that the meshing groove  333   a  of the piece member  33  and the engaging portion  22   a  of the coil winding jig  2  are engaged with each other. When the coil winding jig  2  is rotationally driven in the direction d 1  after the meshing groove  333   a  and the engaging portion  22   a  are meshed with each other immediately below the coil winding jig  2 , the conveyor  32  moves the conveying rail  31  along the direction d 2  in synchronization with the rotation of the coil winding jig  2 , and pivotally conveys the band-shaped coil  100  along the outer periphery of the coil winding jig  2  (coil conveying step). 
     The conveyor  32  applied to conveyance of this band-shaped coil  100  has the gripping grooves  321  having the coil abutting bottom surface CCB of a depth according to the overlapping number of coil conductors in the plurality of straight portions  102  which differ according to the position in the conveying direction of the band-shaped coil  100 . The straight portion  102  is held by the gripping groove  321 , and the band-shaped coil  100  is conveyed (coil conveying step). 
     In the coil conveying step, when the conveyor  32  reaches the pivot conveying unit  313 , the side end  103  of the band-shaped coil  100  is first introduced into the reforming groove  422  of the reforming portion  42  from the introduction end  4   a  of the guide member.  4 , and is pivotally conveyed while being sandwiched between the inner wall surface  41  and the guide plate  421 . Thus, the band-shaped coil  100  is forcibly deformed and reformed so as to be curved in an arc shape along the reforming groove  422  (reforming step). 
     In other words, in the first half portion  313   a  of pivotal conveying of the band-shaped coil  100 , the side ends  103  of the band-shaped coil  100  are sandwiched in a state gripping the plurality of straight portions  102 , 102  in the plurality of gripping grooves  321 ,  321 , and the band-shaped coil is deformed and reformed into an arc shape (reforming step). 
     The band-shaped coil  100  passing through the reforming portion  42  is guided so as to be gradually rounded in an arc shape while being pivotally conveyed along at least a portion of the outer periphery of the coil winding jig  2  along the inner wall surface  41  of the guide member  4 , i.e., a range of approximately ½ the outer periphery of the coil winding jig  2 , accompanying the rotation of the coil winding jig  2  (guiding step). 
     Since the curvature of the inner wall surface  41  of the guide member  4  gradually increases from the first half portion  313   a  to the second half portion  313   b  of the pivot conveying unit  313 , the side end  103  of the band-shaped coil  100  is pressed by the inner wall surface  41  so as to gradually decrease the diameter inwardly in the radial direction. Thus, the band-shaped coil  100  is rounded to have a smaller diameter than the outer diameter of the coil winding jig  2 . The side end  103  which is pressed against the inner wall surface  41  gradually separates the straight portions  102  from the gripping grooves  321  toward the comb-shaped groove  23  of the coil winding jig  2  as the band-shaped coil  100  approaches the discharge end  4   bb  of the guide member  4 . As shown in  FIG.  10   , the straight portions  102  completely detached from the gripping grooves  321  are inserted into the respective comb-shaped grooves  23  of the coil winding jig  2  in communication with the gripping grooves  321 , while being pressed against the inner wall surface  41  of the guide member  4  (inserting step). Subsequently, the band-shaped coil  100  is discharged from the discharge end  4   bb  of the guide member  4 , while being wound in the coil winding jig  2 , accompanying rotation of the coil winding jig  2 . 
     If the entirety of the conveyor  32  finishes moving along the conveying rails  31 , the band-shaped coil  100  is wound four times around the coil winding jig  2  to be multiply wound, as shown in  FIG.  12   , by the coil conductors of the straight portions  102  being introduced into the comb-shaped grooves  23  in a layered manner. The band-shaped coil  100  is thereby easily molded into a substantially cylindrical wound state, as shown in  FIG.  13   . Since the straight portions  102  of the band-shaped coil  100  in the wound state is accommodated within the comb-shaped grooves  23 , there is no concern of displacing. Therefore, the band-shaped coil  100  can stably hold the substantially cylindrical wound state. It should be noted that the band-shaped coil is not limited to being multiply wound on the coil winding jig  2 . 
     Next, the characteristics of the embodiment of the present invention will be further explained by referencing  FIGS.  14 A,  14 B and  14 C , along with  FIGS.  15 A and  15 B .  FIG.  14 A  is a conceptual diagram showing in a side view the band-shaped coil  100  from the first turn to fourth turn to be expanded in the direction of the conveying path of linear shape of the coil forming apparatus  1  in every orbit, in the case of multiplex winding the band-shaped coil  100  by winding around the coil winding jig  2  so as to make  4  turns, as mentioned above. In  FIG.  14 A , the coil conductor of each orbit of the first turn, second turn, third turn and fourth turn from left to right is shown. It should be noted that the way of counting of each orbit herein calls the coil conductor on the outermost circumference side of the 4-turn multiplex winding as first turn coil conductor, calls the coil conductor of a turn immediately after this coil conductor as a second turn coil conductor, and calls the following sequence as third and fourth turn coil conductors. 
     Therefore, the fourth turn coil conductor is the inner most coil conductor in multiplex winding. The coil conductor of each orbit is two layers; however, in the specific region S corresponding to the switching site of each orbit, a step arises in the lamination direction of coil conductors due to reversing and folding back the coil conductors. For this reason, an elevation difference of height h arises from the lower end position of the band-shaped coil  100  in  FIG.  14 A , which is a surface on the inner circumferential side of the fourth turn coil conductor, until the upper end position of the band-shaped coil  100  in  FIG.  14 A , which is a surface on the outer circumferential side of the first turn coil conductor. 
     Herein, the reforming operations on the band-shaped coil  100  positioned in the reforming portion  42  will be considered in mechanical terms. In  FIG.  15 A , the force acting on the band-shaped coil  100  is conceptually shown in the case of deforming and reforming the band-shaped coil  100  gripped by the gripping grooves  321  formed in the piece member main bodies  331  of the coil conveying mechanism unit  3 , by the guide plate  421  of the reforming portion  42 .  FIG.  15 B  shows abstractly the force in  FIG.  15 A  to be enlarged. The coil conductors of the band-shaped coil  100  positioned in the reforming portion  42  is gripped by the gripping grooves  321 , and supported by the coil abutting bottom surface CCB. The coil abutting bottom surface CCB acts as force point Pf and working point Pa on the coil conductors of the band-shaped coil  100 , and the site of the guide plate  421  making sliding contact with the intermediate position of the force point Pf and working point Pa acts as a fulcrum Ps. By the force acting on this force point Pf and working point Pa, as well as the working point Pa, the band-shaped coil  100  is curved by the curvature amount b between the force point Pf and working point Pa to be reformed into an arc shape. 
     However, when evenly setting the depth d of the gripping grooves  321  explained referencing  FIG.  7    in accordance with the elevation difference h in  FIG.  14 A , a portion at which the guide plate  421  functioning as the fulcrum Ps does not come into contact with the coil conductor of the band-shaped coil  100  appears in the coil abutting bottom surface CCB functioning as the force point Pf and working point Pa. At such a portion, it is not possible to make the required bending habit in the band-shaped coil  100 . 
     Therefore, in the embodiment of the present invention, as shown in  FIG.  14 B , the depth d of the gripping grooves  321  is established as a depth which can just accommodate the step appearing in the lamination direction of the coil conductors by reversing and folding back the coil conductors only for the specific region S, and regions other than the specific region S are made evenly in accordance with the lamination number (two layers in present example) of the coil conductors. The gripping grooves  321  in the specific region S and in the vicinity thereof and the coil conductors gripped therein assume forms such as those of  FIGS.  8  and  9   . In other words, the depth d of any gripping groove  321  is a depth according to the overlapping number of the coil conductors of the straight portion  102 , and a void such that contact with the aforementioned fulcrum Ps is inhibited does not arise. It should be noted that the upper end surface  331   a  of the piece member main body  331  in  FIG.  9    is the aforementioned coil abutting bottom surface CCB. 
     By setting the depth d of the gripping groove  321  as in  FIG.  14 B , the band-shaped coil  100  becomes substantially flat over the entire range in the conveying direction as shown in  FIG.  14 C , and there is no longer an elevation difference h relative to lamination of the coil conductors in the conveying direction of the band-shaped coil  100  such as that in  FIG.  14 A . The guide plate  421  thereby comes to be able to effectively function as the fulcrum Ps, relative to the coil abutting bottom surface CCB functioning as the force point Pf and working point Pa explained by referencing  FIG.  15 A  and  FIG.  15 B , over the entire region in the conveying direction of the band-shaped coil  100 . Therefore, it is possible to perform predetermined reforming on the band-shaped coil  100 . 
     According to the above explained coil forming apparatus  1 , the following effects are exerted. In other words, a coil forming apparatus  1  of the present invention forms a band-shaped coil  100  in a wound state, the band-shaped coil  100  including a plurality of straight portions  102  and side ends  103  provided on both ends of the plurality of straight portions  102 , the coil forming apparatus  1  including: a coil winding jig  2  having a plurality of comb-shaped grooves  23 , and configured to be capable of winding the band-shaped coil  100  by inserting the plurality of straight portions  102  of the band-shaped coil  100  into a respective on the plurality of comb-shaped grooves  23 ; a coiling conveying mechanism unit  3  configured to be capable of pivotal conveying the band-shaped coil  100 ; and guide members  4  that are provided in a vicinity of both ends of the coil winding jig  2  in an axial direction, and guide the band-shaped coil  100  in an arc shape while being in contact with the side end  103  of the band-shaped coil  100 , and insert the plurality of straight portions  102  in a respective one of the plurality of comb-shaped grooves  23  in a second half portion of pivotal conveying of the band-shaped coil  100 , in which the coil conveying mechanism unit  3  includes a conveying rail  31  that provides a conveying path pivotally conveying the band-shaped coil  100  along the coil winding jig  2 , and a conveyor  32  that moves along the conveying rail  31  in a state gripping each of the plurality of straight portions  102  of the band-shaped coil  100 , the conveyor  32  has a plurality of gripping grooves  321  which grip a respective one of the plurality of straight portions  102  of the band-shaped coil  100 , and the plurality of gripping grooves  321  have a coil abutting bottom surface CCB of a depth according to an overlapping number of the plurality of straight portions  102  which differs according to position in a conveying direction of the band-shaped coil  100 . For this reason, upon deforming and reforming on the band-shaped coil  100  into an arc shape, force acts appropriately on the coil abutting bottom surface CCB functioning as the force point Pf and working point Pa giving force for this reforming, and from the corresponding site of the guide member  4  as the fulcrum Ps relative to this, and thus can make predetermined bending habit in the band-shaped coil. 
     In the coil forming apparatus  1 , the coil abutting bottom surface CCB is the bottom of each of the plurality of gripping grooves  321  formed at a site at which the plurality of piece members  33  adjoin of the conveyor  32  configured by the plurality of piece members  33  which are rotatable accompanying pivotal conveying of the band-shaped coil  100  while gripping the plurality of straight portions  102  being coupled to overlap along the conveying direction of the band-shaped coil  100 . For this reason, the conveyor  32  can smoothly pivotally convey the coil conductors of the band-shaped coil  100  into an arc shape while gripping with the gripping grooves  321 . 
     In the coil forming apparatus  1 , the guide members  4  include the reforming portion  42  in the first half portion of the pivotal conveying of the band-shaped coil  100 , and the reforming portion  42  deforms and reforms the band-shaped coil  100  in an arc shape in a state sandwiching the side ends  103  of the band-shaped coil  100  in a state in which the plurality of straight portions  102  are gripped in the plurality of gripping grooves  321 . For this reason, the force for making the bending habit in the band-shaped coil  100  appropriately acts on the coil abutting bottom surface CCB functioning as the force point Pf and working point Pa, and from the corresponding site of the guide member  4  as the fulcrum Ps relative to this, and thus can make the predetermined bending habit in the band-shaped coil. 
     The coil forming method of the present embodiment has the following advantageous effects. In other words, the coil forming method of the present embodiment is for forming the band-shaped coil  100  in a wound state, the band-shaped coil  100  including a plurality of straight portions  102  and side ends  103  provided on both ends of the plurality of straight portions  102 , the method including: a coil conveying step of pivotally conveying the band-shaped coil  100  in a state gripping each of the plurality of straight portions  102 , along a coil winding jig  2 , the coil winding jig  2  including a plurality of comb-shaped grooves  23  on an outer periphery thereof, each of which can hold a respective one of the plurality of straight portions  102  therein, and being configured to wind the band-shaped coil  100 , and a guiding step of providing guide members  4  in a vicinity of both ends of the coil winding jig  2  in an axial direction, guiding the band-shaped coil  100  so as to be in an arc shape while the side ends  103  of the band-shaped coil  100  being pivotally conveyed are in contact with the guide members  4 , and inserting the plurality of straight portions  102  into a respective one of the plurality of comb-shaped grooves  23  of the coil winding jig, in which the coil conveying step uses a conveyor  32  having gripping grooves  321  having a coil abutting bottom surface CCB of a depth according to an overlapping number of the plurality of straight portions  102  which differs according to position in a conveying direction of the band-shaped coil  100  to grip the plurality of straight portions  102  by the gripping grooves  321 . For this reason, upon deforming and reforming on the band-shaped coil  100  into an arc shape, force acts appropriately on the coil abutting bottom surface CCB functioning as the force point Pf and working point Pa giving force for this reforming, and from the corresponding site of the guide member  4  as the fulcrum Ps relative to this, and thus can make predetermined bending habit in the band-shaped coil. 
     In the coil forming method of the present embodiment, the coil conveying step uses the conveyor  32  in which the plurality of piece members  33  which are rotatable accompanying pivotal conveying of the band-shaped coil  100  while gripping the plurality of straight portions  102  are coupled to overlap along the conveying direction of the band-shaped coil  100 , and grips the plurality of straight portions  102  with the gripping grooves  321  in which the coil abutting bottom surface CCB is configured as the bottom of each of the plurality of gripping grooves  321  formed at the site where the plurality of piece members  33  adjoin. For this reason, the band-shaped coil  100  can be gripped by the gripping grooves  321  and smoothly pivotally conveyed into an arc shape the coil conductors by the conveyor  32 . 
     In the coil forming method of the present embodiment, the coil conveying step includes a reforming step of sandwiching the side ends  103  of the band-shaped coil  100  in a state gripping the plurality of straight portions  102  in the plurality of gripping grooves  321  in a first half portion of pivotal conveying of the band-shaped coil  100 , and deforming and reforming of the band-shaped coil  100  into an arc shape. For this reason, the force for making a bending habit in the band-shaped coil appropriately acts, and it is possible to make a predetermined bending habit in the band-shaped coil. 
     Although embodiments of the present invention have been explained above, the present invention is not to be limited thereto. The configurations of detailed parts may be modified where appropriate within the scope of the gist of the present invention. For example, in the aforementioned embodiment, in order to establish the depth d of the gripping groove  321  as different depths than other regions for the region corresponding to region S in  FIG.  14 B , although the piece members  33  having different dimensions of the corresponding parts, an alternate configuration can be adopted. In other words, the piece members  33  may be prepared as having entirely the same shape and same dimension, and may be configured so as to laminate a dummy member in the gripping grooves  321  for adjusting the depth d. 
     EXPLANATION OF REFERENCE NUMERALS 
     
         
         
           
               1  coil forming apparatus 
               2  coil winding jig 
               23  comb-shaped groove 
               3  coil conveying mechanism unit 
               31  conveying rail 
               313  pivot conveying unit 
               313   a  first half portion 
               313   b  second half portion 
               314  guide groove 
               32  conveyor 
               321  groove entrance 
               33  piece member 
               333  first gripping claw 
               336  second gripping claw 
               4  guide member 
               41  inner wall surface 
               42  reforming portion 
               100  band-shaped coil 
               102  straight portion 
               103  side end 
             CCB coil abutting bottom surface 
             d depth 
             Pa working point 
             Pf force point 
             Ps fulcrum