Patent Publication Number: US-2023163667-A1

Title: Stator assembly apparatus and stator assembly method

Description:
This application is based on and claims the benefit of priority from Japanese Patent Application No. 2021-138911, filed on 19 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 stator assembly apparatus and a stator assembly method. 
     Related Art 
     Conventionally, the technology described in Patent Document 1 has been known as a technology for inserting a coil into slots of a stator core in which insulating members are mounted, from inside the stator core while preventing the insulating members from being caught. 
     In the technology described in Patent Document 1, two guide jigs are inserted into each slot of the stator core in which the insulating members are mounted before insertion of the coil, from outside in the central axis direction of the stator core to open each of the insulating members, and, in that state, the coil is moved in each slot while being applied to one guide jig. After guide members mutually come into contact, the two guide jigs are retreated from inside the slot. 
     Patent Document 1: Japanese Patent No. 6733823 
     SUMMARY OF THE INVENTION 
     However, in the technology described in Patent Document 1, the shape of the guide jigs on the tip side is such that a pair of side faces with a substantially quadrilateral-shaped section are merely tapered along the radial direction of the stator core. Therefore, if the opening between the opening ends of the insulating member in the slot is almost as narrow as being closed, there is a possibility that it is difficult to insert the guide jigs into the slot. 
     An object of the present invention is to provide a stator assembly apparatus and a stator assembly method with a good stator assembly workability capable of, even if the opening between opening ends of an insulating member in a slot is almost as narrow as being closed, causing the insulating member to return to an opened state prior to insertion of a coil. 
     (1) A stator assembly apparatus according to the present invention is a stator assembly apparatus (for example, a stator assembly apparatus  1  described later) for assembling a stator (for example, a stator  200  described later) by inserting a coil (for. example, a belt-shaped coil  100  described later) into each of slots (for example, slots  22  described later) of a stator core (for example, a stator core  2  described later) from inside the stator core, insulating members (for example, pieces of insulating paper  24  described later) being mounted in the slots, the stator assembly apparatus including leading guide members (leading guide members  61  described later) provided movably along a central axis direction of the stator core, each of the leading guide members being, by moving toward the stator core, inserted into an inside of the respective insulating member before the coil is inserted, and arranged ahead in a movement direction of the coil moving toward the respective slot, in a state of at least a part of the leading guide member being in contact with opening ends (for example, opening ends  24   a  described later) of the insulating member; the leading guide member having a quadrilateral shape when viewed in a longitudinal direction; a tip portion (for example, a tip portion  61   a  described later) of the leading guide member being inclined along a radial direction of the stator core with one end portion (for example one end portion  61   b  described later) side in the radial direction of the stator core as an apex (for example, an apex P described later), and having a shape tapered toward a center line (for example, a center line O described later) of the leading guide member along the radial direction of the stator core; and the apex being arranged on an outer side in the radial direction of the stator core. 
     (2) In the stator assembly apparatus according to (1) above, a lateral width (for example, a lateral width W 12  described later) of the leading guide member along a circumferential direction of the stator core is equal to or more than a width (for example, a width W 0  described later) of the coil along the circumferential direction of the stator core. 
     (3) A stator assembly method according to the present invention is a stator assembly method for assembling a stator (for example, the stator  200  described later) by inserting a coil (for example, the belt-shaped coil  100  described later) into each of slots (for example, the slots  22  described later) of a stator core (for example, the stator core  2  described later) from inside the stator core, insulating members (for example, the pieces of insulating paper  24  described later) being mounted in the slots, the stator assembly apparatus including a process of, before inserting the coil into each of the slots, inserting each of leading guide members (for example, leading guide members  61  described later) into an inside of the respective insulating member from an outer side in a central axis direction of the stator core such that the leading guide member is arranged ahead in a movement direction of the coil moving toward the respective slot, in a state of at least a part of the leading guide member being in contact with opening ends (for example, the opening ends  24   a  described later) of the insulating member; the leading guide member having a quadrilateral shape when viewed in a longitudinal direction; a tip portion (for example, a tip portion  61   a  described later) of the leading guide member being inclined along a radial direction of the stator core with one end portion (for example one end portion  61   b  described later) side in the radial direction of the stator core as an apex (for example, an apex P described later), and having a shape tapered toward a center line (for example, a center line O described later) of the leading guide member along the radial direction of the stator core; and the apex being arranged on an outer side in the radial direction of the stator core. 
     (4) In the stator assembly method according to (3) above, a lateral width (for example, a lateral width W 12  described later) of the leading guide member along a circumferential direction of the stator core is equal to or more than a width (for example, a width W 0  described later) of the coil along the circumferential direction of the stator core. 
     According to (1) above, even if the opening between the opening ends of the insulating member is almost as narrow as being closed, it is possible to smoothly insert the leading guide member into the inside of the insulating member. The leading guide member has a quadrilateral shape when viewed in the longitudinal direction, has a shape of being inclined along the radial direction of the stator core with one end portion side in the radial direction of the stator core as the apex and being tapered toward a center line along the radial direction of the stator core, and has a configuration in which the apex is arranged on the outer side in the radial direction of the stator core. The leading guide member is inserted into the slot in the state of at least a part thereof being in contact with the opening ends of the insulating member. Therefore, it is possible to, only by inserting the leading guide member into the inside of the insulating member, cause the opening ends of the insulating member to return to the opened state prior to insertion of the coil. Therefore, it is possible to provide a stator assembly apparatus with a good stator assembly workability. 
     According to (2) above, since it is possible to cause the opening between the opening ends of the insulating member to open wider than the width of the coil, the insertability of the coil is further improved. 
     According to (3) above, even if the opening between the opening ends of the insulating member is almost as narrow as being closed, it is possible to smoothly insert the leading guide member into the inside of the insulating member along the central axis direction of the stator core. The leading guide member has a quadrilateral shape when viewed in the longitudinal direction, has a shape of being inclined along the radial direction of the stator core with one end portion side in the radial direction of the stator core as the apex and being tapered toward a center line along the radial direction of the stator core, and has a configuration in which the apex is arranged on the outer side in the radial direction of the stator core. The leading guide member is inserted into the slot in the state of at least a part thereof being in contact with the opening ends of the insulating member. Therefore, it is possible to, only by inserting the leading guide member into the inside of the insulating member, cause the opening ends of the insulating member to return to the opened state prior to insertion of the coil. Therefore, it is possible to provide a stator assembly method with a good stator assembly workability. 
     According to (4) above, since it is possible to cause the opening between the opening ends of the insulating member to open wider than the width of the coil, the insertability of the coil is further improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side view showing the appearance of a stator assembly apparatus; 
         FIG.  2    is a perspective view showing a positioning jig and a coil winding jig in the stator assembly apparatus, the positioning jig and the coil winding jig being disassembled; 
         FIG.  3    is a perspective view showing insulating members mounted in slots of a stator core; 
         FIG.  4    is a development view showing an example of a coil; 
         FIG.  5    is a perspective view showing that a coil expansion device is mounted in the coil winding jig mounted inside the stator core; 
         FIG.  6    is a diagram of a guide mechanism in the stator assembly apparatus viewed in the central axis direction; 
         FIG.  7    is a sectional view showing leading guide members in the guide mechanism; 
         FIG.  8    is a sectional view showing reinforcing guide members in the guide mechanism; 
         FIG.  9 A  is a diagram of a tip portion of each leading guide member when viewed along the radial direction of the stator core; 
         FIG.  9 B  is a diagram of the tip portion of the leading guide member when viewed along the circumferential direction of the stator core; 
         FIG.  9 C  is a diagram of the tip portion of the leading guide member when viewed along the central axis direction of the stator core; 
         FIG.  10    is a perspective view showing that the guide members are inserted into the slots of the stator core; 
         FIG.  11 A  is a diagram showing the shape of the section of each leading guide member in the slot when the leading guide member is inserted into the slot up to a position A in  FIGS.  9 A  and  9 B; 
         FIG.  11 B  is a diagram showing the shape of the section of the leading guide member in the slot when the leading guide member is inserted into the slot up to a position B in  FIGS.  9 A and  9 B ; 
         FIG.  11 C  is a diagram showing the shape of the section of the leading guide member In the slot when the leading guide member is inserted into the slot up to a position C in  FIGS.  9 A and  9 B ; 
         FIG.  12 A  is a diagram illustrating an operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 B  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 C  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 D  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 E  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 F  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 G  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 H  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 I  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  12 J  is a diagram illustrating the operation process of inserting the coil into the slots from inside the stator core; 
         FIG.  13 A  is a diagram showing that the coil is inserted into each slot; 
         FIG.  13 B  is a diagram showing that the coil is inserted into the slot; 
         FIG.  13 C  is a diagram showing that the coil is inserted into the slot; 
         FIG.  13 D  is a diagram showing that the coil is inserted into the slot; 
         FIG.  13 E  is a diagram showing that the coil is inserted into the slot; 
         FIG.  13 F  is a diagram showing that the coil is inserted into the slot; 
         FIG.  13 G  is a diagram showing that the coil is inserted into the slot; 
         FIG.  13 H  is a diagram showing that the coil is inserted into the slot; 
         FIG.  13 I  is a diagram showing that the coil is inserted into the slot; 
         FIG.  13 J  is a diagram showing that the coil is inserted into the slot; and 
         FIG.  14    is a perspective view showing the appearance of a stator. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of the present invention will be described below in detail with reference to drawings. As shown in  FIGS.  1  and  2   , a stator assembly apparatus  1  is provided with a stator core  2 , a positioning jig  3  that positions and fixes the stator core  2 , a coil winding jig  4  around which a belt-shaped coil  100  is annularly wound, coil expansion mechanism units  5  that expand the belt-shaped coil  100  wound around the coil winding jig  4 , and guide mechanism units  6  that guide insertion of the belt-shaped coil  100  into slots  22  of the stator core  2 . 
     As shown in  FIGS.  2  and  3   , the stator core  2  has an annular portion  21  configured, for example, with a laminate in which a plurality of thin core plates are laminated. In the center of the annular portion  21 , there is a through-hole  20  penetrating the annular portion  21  in the axial direction. The stator core  2  has a plurality of slots  22  penetrating the stator core  2  in the axial direction. The slots  22  are radially arranged at regular intervals along the circumferential direction of the annular portion  21 , and have opening portions  22   a  that are open to the through-hole  20  inside the annular portion  21  in the radial direction. The stator core  2  of the present embodiment has seventy-two slots  22 . On the outer periphery of the annular portion  21  of the stator core  2 , there are six tab portions  23  protruding at regular intervals. 
     In the stator core  2  and the positioning jig  3 , an X direction in which the slots  22  are arranged is the circumferential direction as shown in  FIG.  2   . A Y direction along a radial direction from the center of the through-hole  20  is the radial direction. A Z direction orthogonal to the X and Y directions and along the central axis of the through-hole  20  of the stator core  2  is the central axis direction. 
     As shown in  FIGS.  1  and  2   , the positioning jig  3  is formed in a hexagonal cylinder shape having a dimension in the central axis direction substantially equal to the dimension of the stator core  2  in the central axis direction, and has, at the center thereof, a stator core insertion hole  31  in which the stator core  2  can be inserted and arranged. The positioning jig  3  fixes the stator core  2  at a predetermined position and in a predetermined posture in the stator core insertion hole  31  by supporting each of the six tab portions  23  of the stator core  2 . In the stator assembly apparatus  1  of the present embodiment, the positioning jig  3  is fixed to a center portion of a base  11  of the stator assembly apparatus  1  such that the central axis direction of the stator core  2  fixed in the stator core insertion hole  31  is a horizontal direction. 
     As shown in  FIG.  3   , pieces of insulating paper  24 , which are insulating members, are mounted in the slots  22  of the stator core  2 , respectively, in advance. Each piece of insulating paper  24  is formed by being folded in a substantially U-shape so as to follow the substantially U-shaped inner surface of each slot  22  when the stator core  2  is viewed in the axial direction. The pieces of insulating paper  24  are open to the through-hole  20  inside the stator core  2  in the radial direction. Opening ends  24   a  of the pieces of insulating paper  24  are arranged at opening portions  22   a  of the slots  22  and open the insides of the pieces of insulating paper  24  to the through-hole  20 . 
     As shown in  FIG.  2   , a plurality of cuff guides  32  formed in elongated thin plate shapes are radially arranged on both end faces  3   a  of the positioning jig  3  in the central axis direction, at regular intervals along the circumferential direction. At the time of inserting the belt-shaped coil  100  described later into the slots  22  of the stator core  2 , the cuff guides  32  support the pieces of insulating paper  24  protruding from both end faces of the stator core  2  in the central axis direction and guide movement of the belt-shaped coil  100  into the slots  22 . The cuff guides  32  are provided so as to be movable back and forth along the radial direction of the stator core  2  by driving of an actuator such as a cylinder not shown. 
     The coil winding jig  4  has a jig main body  41  in a substantially cylindrical shape and a plurality of comb tooth portions  42  radially protruding from the outer periphery of the jig main body  41 . The comb tooth portions  42  are provided on both end portions of the jig main body  42  in the axial direction. The number of comb tooth portions  42  arranged in the circumferential direction of the jig main body  41  matches the number of slots  22  provided in the stator core  2 . In order that the coil winding jig  4  can be inserted in the through-hole  20  of the stator core  2 , the coil winding jig  4  is formed such that the outer diameter of the coil winding jig  4  defined by the positions of the tips of the comb tooth portions  42  is equal to or smaller than the hole diameter of the through-hole  20  of the stator core  2 . 
     The belt-shaped coil  100  to be mounted in the stator core  2  is annularly wound over the plurality of comb tooth portions  42 . As shown in  Fig.  4   , the belt-shaped coil  100  is configured with an elongated belt-shaped continuous wave-wound coil formed by flat type conducting wires  101  each of which has a substantially rectangular section. In the case of the continuous wave-wound coil, at the time of setting the coil into the stator core  2 , the technology of molding a coil divided in a plurality of segments and welding coil ends after insertion into the slots, which is a technology mainly adopted in the world, is not required. Therefore, it is not necessary to use, for example, high-purity copper material for the coil in order to cope with thermal processing of welding points is eliminated. Therefore, it becomes possible to use recycled copper material that includes impurities, and it is possible to contribute to realization of reuse of resources. Moreover, since the wave-wound coil does not require welding, it is possible to reduce the weight of the coil and reduce the weight of a rotary electric machine using the coil. When the rotary electric machine is mounted on a hybrid car, it is possible to, by the vehicle weight being reduced, reduce carbon dioxide and reduce the harmful effect on the global environment. 
     The belt-shaped coil  100  has a plurality of straight portions  102  and a plurality of coil end portions  103 . The straight portions  102  are parts to be inserted into the slots  22  of the stator core  2 , and the straight portions  102  extend substantially linearly and are arranged in parallel at regular intervals. The coil end portions  103  are arranged at positions nearer to the side ends of the belt-shaped coil  100  than the straight portions  102 , and alternately connect end portions on one side of adjacent straight portions  102  and end portions on the other side of adjacent straight portions  102  in substantially triangular chevron shapes along the length direction of the belt-shaped coil  100 . The coil end portions  103  are parts that protrude from the slots  22  in the axial direction of the stator core  2  when the belt-shaped coil  100  is mounted in the slots  22  of the stator core  2 , and are pressed by the coil expansion mechanism units  5  described later when the belt-shaped coil  100  is inserted into the slots  22 . The belt-shaped coil  100  of the present embodiment is formed in an elongated belt shape by bundling six flat type conducting wires  101  with the plurality of straight portions  102  and the plurality of coil end portions  103  foldedly formed, such that the straight portions  102  are arranged side by side in parallel at regular intervals. 
     The coil winding jig  4  winds the belt-shaped coil  100  in many layers by sequentially inserting each of the straight portions  102  of the belt-shaped coil  100  between comb tooth portions  42  from outward before being inserted into the through-hole  20 . As a result, as shown in  FIG.  2   , the coil winding jig  4  around which the belt-shaped coil  100  is wound in an annular shape is configured. 
     The coil winding jig  4  inserted in the through-hole  20  inside the stator core  2  is held at a predetermined position and in a predetermined posture by being supported by the paired coil expansion mechanism units  5  arranged to face both sides of the stator core  2  in the central axis direction with the positioning jig  3  therebetween. Each of the coil expansion mechanism units  5  of the present embodiment has a substantially cylindrical appearance shape as shown in  FIG.  5   , and is arranged to face the coil winding jig  4  inserted inside the stator core  2 , in the central axis direction of the coil winding jig  4  as shown in  FIG.  1   . Each of the coil expansion mechanism units  5  is provided so as to be linearly movable on the base  11  and movable in directions of coming into contact with and being separated from the coil winding jig  4  by driving of an actuator not shown. 
     Each of the coil expansion mechanism units  5  is formed in a substantially cylindrical shape and has a plurality of coil pressers  51  on the outer periphery on the tip side. The plurality of coil pressers  51  are arranged along the outer periphery of the coil expansion mechanism unit  5  on the tip side and provided so as to be expanded and reduced in diameter along the radial direction by driving of an actuator not shown. The outer diameter of the coil pressers  51  in a diameter-reduced state is equal to or smaller than the inner diameter of the annular belt-shaped coil  100  wound around the coil winding jig  4 . The outer diameter of the coil pressers  51  in a diameter-expanded state is larger than the outer diameter of the coil winding jig  4 . The coil expansion mechanism unit  5  holds the coil winding jig  4  by inserting the coil pressers  51  in the diameter-reduced state inside the annular belt-shaped coil  100  wound around the coil winding jig  4 . When the coil pressers  51  inserted in the belt-shaped coil  100  are expanded in diameter, the belt-shaped coil  100  is pressed outward and expanded in diameter. As a result, the straight portions  102  of the belt-shaped coil  100  move toward the insides of the pieces of insulating paper  24  in the slots  22  arranged outside in the radial direction and inserted into the slots  22 . The coil pressers  51  of the coil expansion mechanism unit  5  constitute pressers that press the belt-shaped coil  100  outward in the radial direction and cause the straight portions  102  of the belt-shaped coil  100  to move into the insides of the pieces of insulating paper  24  in the slots  22 . 
     As shown in  FIG.  1   , the paired guide mechanism units  6  are arranged to face both sides of the stator core  2  in the central axis direction with the positioning jig  3  therebetween, similarly to the coil expansion mechanism units  5 . The paired guide mechanism units  6  are arranged outside the coil expansion mechanism units  5  in the central axis direction, respectively, the guide mechanism units  6  and the coil expansion mechanism unit  5  being concentric with one another. 
     Since the paired guide mechanism units  6  are in the same configuration, the configuration of one guide mechanism unit  6  will be described with reference to  FIGS.  6  to  9   .  FIG.  6    is a diagram of one guide mechanism unit  6  viewed in a direction along the central axis direction of the stator core  2 . The guide mechanism unit  6  has a plurality of leading guide members  61  that are annually arranged, and a plurality of reinforcing guide members  62  that are annually arranged on the outer side of the leading guide members  61 . 
     Each of the leading guide members  61  is configured with a rod-shaped body with a length enough for the leading guide member  61  to be inserted inside the piece of insulating paper  24  mounted inside the slot  22 . The section orthogonal to the longitudinal direction of the leading guide member  61  is a quadrilateral shape with rounded corners except for a tapered tip portion. Therefore, the leading guide member  61  has a quadrilateral shape when viewed in the longitudinal direction. The longitudinal direction of the leading guide member  61  is arranged along the central axis direction of the stator core  2 . 
     A longitudinal width W 11  (see  FIG.  13 A ) of the leading guide member  61  along the radial direction of the stator core  2  is sufficiently smaller than the depth of the slot  22  along the radial direction of the stator core  2 . The longitudinal width W 11  of the leading guide members  61  of the present embodiment is set to approximately ⅕ of the depth of the slots  22 . A lateral width W 12  (see  FIG.  13 A ) of each leading guide member  61  along the circumferential direction of the stator core  2  is equal to or smaller than the width inside the piece of insulating paper  24  in the slot  22  along the circumferential direction of the stator core  2 . The lateral width W 12  of the leading guide members  61  is larger than a width W 0  (see  FIG.  13 A ) of the straight portions  102  of the belt-shaped coil  100  inserted into the slots  22  along the circumferential direction of the stator core  2 . 
     At least one leading guide member  61  is provided for one slot  22 , and the leading guide members  61  are annularly arranged with the same arrangement pitch as the arrangement pitch of the slots  22 . Though one leading guide member  61  is provided for one slot  22  in the present embodiment, a plurality of leading guide members  61  may be provided for one slot  22 . 
     As shown in  FIG.  7   , the tip of each leading guide member  61  is formed in a tapered shape. The shape of the tip of each leading guide member  6   i  will be described later. Operation portions  611  are annularly formed on the base end sides of the leading guide members  61 , respectively, the operation portions  611  protruding outward in the radial direction. In each of the operation portion  611 , a guide hole  612  elongatedly extending outward in the radial direction is provided. In the guide hole  612 , a support plate portion  601  provided in the guide mechanism unit  6  is fitted slidably in the radial direction (in the vertical direction in  FIG.  7   ). Each leading guide member  61  is thereby supported by the guide mechanism unit  6  movably in the radial direction. 
     On the tip end side of the operation portion  611 , one end of a connecting plate  613  is rotatably attached by a rotating shaft  613   a.  The other end of the connecting plate  613  extends in a direction opposite to the direction of extension of the leading guide member  61  relative to the operation portion  611  (the right direction in  FIG.  7   ) and rotatably attached to a leading guide supporting portion  602  of the guide mechanism unit  6  by a rotating shaft  613   b.  On the other end side of the connecting plate  613  on the opposite side of the operation portion  611  relative to the rotating shaft  613   b,  an elastic member  614  configured with a coil spring or the like is provided, the elastic member  614  energizing the other end side of the connecting plate  613  outward in the radial direction. 
     By the elastic member  614  energizing the other end side of the connecting plate  613  outward in the radial direction, the leading guide member  61  is pushed by the connecting plate  613  and is always pushed inward in the radial direction. However, when a pressing force exceeding the energizing force of the elastic member  614  acts on the leading guide member  61  outward from inside in the radial direction, the leading guide member  61  can move outward in the radial direction to expand in diameter, along a white arrow in  FIG.  7   . When the pressing force is released, the leading guide member  61  is reduced in diameter inward in the radial direction by the energizing force of the elastic member  614  acting thereon, and returns to a steady state. 
     The plurality of leading guide members  61  are provided so as to be movable in the central axis direction of the stator core  2  by driving of an actuator  610  for driving leading guide members, which is provided in the guide mechanism unit  6 . The actuator  610  is controlled by a controller  10  of the stator assembly apparatus  1  shown in  FIG.  1   . When being driven, the actuator  610  causes the leading guide supporting portion  602  to move in a direction toward the stator core  2  and in a direction away from the stator core  2 , along the central axis direction of the stator core  2 . By the leading guide supporting portion  602  moving in the direction toward the stator core  2 , the plurality of leading guide members  61  are inserted inside the pieces of insulating paper  24  in their corresponding slots  22 , respectively, in the central axis direction of the stator core  2 . By the leading guide supporting portion  602  moving in the direction away from the stator core  2 , the plurality of leading guide members  61  are withdrawn outside in the central axis direction of the stator core  2  from inside the pieces of insulating paper  24  in the slots  22 . 
     Each reinforcing guide member  62  is configured with a rod-shaped body with such a length that the reinforcing guide member  62  can be inserted inside the piece of insulating paper  24  mounted inside the slot  22 , the length being shorter than the length of the leading guide member  61 . The section orthogonal to the longitudinal direction of the reinforcing guide member  62  has a quadrilateral shape with rounded corners except for a tapered tip portion. A longitudinal width W 21  (see  FIG.  13 A ) of the reinforcing guide member  62  along the radial direction of the stator core  2  is substantially the same as the longitudinal width W 11  of the leading guide members  61 . A lateral width W 22  (see  FIG.  13 A ) of the reinforcing guide member  62  along the circumferential direction of the stator core  2  is substantially the same as the lateral width W 12  of the leading guide members  61 . 
     Three reinforcing guide members  62  are provided for one slot  22 . That is, as shown in  FIG.  8   , the three reinforcing guide members  62  include a first reinforcing guide member  62   a  on the radially innermost side, a second reinforcing guide member  62   b  arranged on the outer side of the first reinforcing guide member  62   a  in the radial direction, and a third reinforcing guide member  62   c  arranged on the outer side of the second reinforcing guide member  62   b  in the radial direction. The first reinforcing guide members  62   a,  the second reinforcing guide member  62   b,  and the third reinforcing guide members  62   c  are annularly arranged, with the same arrangement pitch as the arrangement pitch of the slots  22  and stacked in the radial direction. However, the first reinforcing guide member  62   a  on the radially innermost side, among the three reinforcing guide members  62 , and the leading guide member  61  are separated from each other by a distance L corresponding to each of the longitudinal width W 11  of one leading guide member  61  and the longitudinal width W 21  of each of one first reinforcing guide member  62   a,  one second reinforcing guide member  62   b,  and one third reinforcing guide member  62   c  (see  FIGS.  10  and  13 A ). The specific distance L is to be appropriately set according to the specifications of the slots  22 , the type of the insulating paper  24 , and the like and is not especially limited. In the present embodiment, the distance L is set to 4.2 mm. 
     As shown in  FIG.  8   , the tips of the first reinforcing guide member  62   a,  the second reinforcing guide member  62   b,  and the third reinforcing guide member  62   c  are formed being tapered. On the base end sides of the first reinforcing guide members  62   a,  the second reinforcing guide members  62   b,  and the third reinforcing guide members  62   c,  operation portions  621   a,    621   b  and  621   c  protruding outward in the radial direction are annularly formed, respectively. The operation portions  621   a,    621   b,  and  621   c  are individually coupled with actuators  620  of the guide mechanism unit  6 , respectively. 
     The first reinforcing guide members  62   a,  the second reinforcing guide members  62   b,  and the third reinforcing guide members  62   c  are provided so as to be individually movable in the central axis direction of the stator core  2  by driving of the actuators  620  for driving reinforcing guide members, which are provided in the guide mechanism unit  6 . As shown in  FIG.  6   , the actuators  620  include a first reinforcing guide actuator  620   a,  a second reinforcing guide actuator  620   b,  and a third reinforcing guide actuator  620   c,  which are individually controlled by the controller  10  of the stator assembly apparatus  1  shown in  FIG.  1   . 
     When being driven, the actuators  620  cause the first reinforcing guide members  62   a,  the second reinforcing guide members  62   b,  and the third reinforcing guide members  62   c  to individually move in the direction toward the stator core  2  and in the direction away from the stator core  2 , along the central axis direction of the stator core  2 . By moving in the direction toward the stator core  2 , the first reinforcing guide members  62   a,  the second reinforcing guide members  62   b,  and the third reinforcing guide members  62   c  are inserted inside the pieces of insulating paper  24  in their corresponding slots  22 , respectively, in the central axis direction of the stator core  2 . By moving in the direction away from the stator core  2 , the first reinforcing guide members  62   a,  the second reinforcing guide members  62   b,  and the third reinforcing guide members  62   c  can be individually withdrawn outside in the central axis direction of the stator core  2  from inside the pieces of insulating paper  24  in the slots  22 , respectively. 
     Here, the shape of the tip of each leading guide member  61  will be described with reference to  FIGS.  9 A to  9 C . A tip portion  61   a  of each leading guide member  61  has an apex P on one end portion  61   b  side of the leading guide member  61 . The tip portion  61   a  of the leading guide member  61  is inclined along the radial direction of the stator core  2 , from the apex P toward the other end portion  61   c  side of the leading guide member  61  along the radial direction of the stator core  2 . Though the tip portion  61   a  of each leading guide member  61  of the present embodiment is linearly inclined as shown in  FIG.  9 B , it may be inclined like drawing a curve. 
     Furthermore, as shown in  FIGS.  9 A and  9 C , the tip portion  61   a  of the leading guide member  61  has a shape tapered toward a center line O of the leading guide member  61  along the radial direction of the stator core  2 . Both side faces  61   d  of the leading guide member  61  facing the circumferential direction of the stator core  2  are gradually thinner as being closer to the tip, and abut each other almost on the center line O. Thereby, a ridgeline Fa inclined from the apex P on the one end portion  61   b  side toward the other end portion  61   c  side is formed on the tip portion  61   a  of the leading guide member  61 . The ridgeline Pa substantially corresponds to the center line O of the leading guide member  61 . On the leading guide member  61  of the present embodiment, inclined faces  61   d   1  formed by both side faces  61   d  being tapered are formed by linearly inclined planes as shown in  9 A, but may be formed by curved surfaces. 
     The leading guide member  61  having such a tip shape is attached to the guide mechanism unit  6  so as to be arranged on the outer side in the radial direction of the stator core  2  (the y 1  side) as shown in  FIGS.  9 B and  9 C . 
     Next, description will be made on a process of inserting the straight portions  102  of the belt-shaped coil  100  inside the pieces of insulating paper  24  in the slots  22  of the stator core  2  in the stator assembly apparatus  1 .  FIG.  10   ,  FIGS.  10 A to  11 C , and  FIGS.  12 A to  12 J  schematically show an operation process of inserting the belt-shaped coil  100  wound around the coil winding jig  4  inside the pieces of insulating paper  24  in the slots  22  of the stator core  2  from inside the stator core  2 . Since the operation processes on both sides of the stator core  2  in the central axis direction progress in synchronization with each other,  FIGS.  12 A to  12 J  show only the operation process on one side of the stator core  2  in the central axis direction.  FIGS.  13 A to  13 J  schematically show the leading guide member  61  and the reinforcing guide members  62  in one slot  22  of the stator core  2 .  FIGS.  13 A to  13 J  temporally correspond to  FIGS.  12 A to  12 J . In  FIG.  10   ,  FIGS.  12 A to  12 J , and  FIGS.  13 A to  13 J , the positioning jig  3  is not shown. 
     First, as shown in  FIG.  10   , after the coil winding jig  4  around which the belt-shaped coil  100  is wound is supported in the through-hole  20  of the stator core  2  by the coil expansion mechanism units  5 , the actuators  610  and  620  of the guide mechanism unit  6  are drive-controlled by the controller  10  to insert all the leading guide members  61  and the reinforcing guide members  62  inside the pieces of insulating paper  24  in the slots  22 , respectively, from both outer sides of the stator core  2  in the central axis direction. The tips of the leading guide members  61 , and the tips of the reinforcing guide members  62  inserted inside the piece of insulating paper  24  in each slot  22  are arranged to face each other in the slot  22 . 
     Each leading guide member  61  is arranged on the radially innermost side in the guide mechanism unit  6 , and arranged near the opening portion  22   a  of the slot  22  when moving toward the stator core  2  and being inserted into the slot  22 . Therefore, by moving toward the stator core  2 , the leading guide member  61  is inserted into the inside of the piece of insulating paper  24  in a state of being in contact with the opening ends  24   a  of the piece of insulating paper  24  ( FIG.  11 C ). 
     At this time, the leading guide member  61  enters the inside of the piece of insulating paper  24  from the apex P side. Since the apex P is arranged on the outer side in the radial direction of the stator core  2  (the Y 1  side) on the leading guide member  61 , the leading guide member  61  enters the inside of the piece of insulating paper  24  from a position on the depth side (the Y 1  side) relative to the opening ends  24   a  or the piece of insulating paper  24  in the slot  22  ( FIG.  11 A ). 
     After that, as the leading guide member  61  is inserted more, the two inclined faces  61   d   1  advance toward the opening ends  24   a  of the piece of insulating paper  24  from inside, along the inclination of the tip portion  61   a  of the leading guide member  61 . Thereby, even if the opening between the opening ends  24   a  of the piece of insulating paper  24  is almost as narrow as being closed, the opening ends  24   a  can be guided to open, from inside the piece of insulating paper  24 . At the same time, both side faces  61   d  of the leading guide member  61  also guide the vicinities of the opening ends  24   a  of the piece of insulating paper  24  to gradually open outward from inside ( FIG.  11 B ). 
     When insertion of the leading guide member  61  is completed, the leading guide member  61  is arranged in the slot  22  in a state of at least a part thereof being in contact with the opening ends  24   a  of the piece of insulating paper  24  in the slot  22 . A side face on the other end portion  61   c  side of the leading guide member  61  is arranged at the same position as the opening ends  24   a  of the piece of insulating paper  24 , or on the outer side of the slot  22  than the opening ends  24   a,  that is, on the inner side in the radial direction of the stator core  2  (the Y 2  side) ( FIG.  11 C ). Thereby, the opening between the opening ends  24   a  of the piece of insulating paper  24  increases by the width W 0  of the belt-shaped coil  100  or more, and it is possible to, by the straight portions  102  of the belt-shaped coil  100  coming into contact with the leading guide member  61 , smoothly introduce the straight portions  102  into the inside of the piece of insulating paper  24 . 
     The tips of the reinforcing guide members  62  (the first reinforcing guide members  62   a,  the second reinforcing guide members  62   b,  and the third reinforcing guide members  62   c ) may be also formed in a shape similar to the shape of the tips of the leading guide members  61 . 
     In a state immediately after all the leading guide members  61  and the reinforcing guide members  62  are inserted inside the pieces of insulating paper  24  in the slots  22 , each leading guide member  61  is arranged in the slot  22  in the state of at least a part thereof being in contact with the opening ends  24   a  of the piece of insulating paper  24  as described above. The first reinforcing guide member  62   a,  the second reinforcing guide member  62   b,  and the third reinforcing guide member  62   c,  which are the reinforcing guide members  62 , are arranged in a state of being stacked on the outer side in the slot  22  (on the depth side of the slot  22 ) in the radial direction. The leading guide member  61  and the first reinforcing guide member  62   a  on the radially innermost side are separated from each other by the distance L. 
     The state in which the leading guide member  61  and the reinforcing guide members  62  are inserted inside the piece of insulating paper  24  in the slot  22  is close to a state in which the straight portions  102  of the belt-shaped coil  100  are inserted inside the piece of insulating paper  24 . Therefore, the piece of insulating paper  24  before the straight portions  102  of the belt-shaped coil  100  are inserted therein is in a state of the piece of insulating paper  24  after the straight portions  102  or the belt-shaped coil  100  are inserted, and the shape of the piece of insulating paper  24  is held in a proper shape prior to insertion of the belt-shaped coil  100 . Moreover, since at least a part of the leading guide member  61  is arranged in each slot  22  in the state of being in contact with the opening ends  24   a  of the piece of insulating paper  24 , it is possible to hold the opening ends  24   a  of the piece of insulating paper  24  in an opened state prior to insertion of the belt-shaped coil  100 . As a result, the piece of insulating paper  24  is prevented from coming into contact with the belt-shaped coil  100  that is moving. Therefore, it is possible to smoothly introduce the belt-shaped coil  100  inside the piece of insulating paper  24 . 
     After insertion of the leading guide members  61  and the reinforcing guide members  62  is completed, the controller  10  causes the coil expansion mechanism unit  5  to operate to expand the coil presser  51  in diameter in the direction of a white arrow shown in  FIG.  12 A . The coil end portions  103  of the belt-shaped coil  100  wound around the coil winding jig  4  is thereby pressed by the coil presser  51  expanding in diameter and move outward in the radial direction of the stator core  2 . The belt-shaped coil  100  gradually expands in diameter, accompanying the movement, and the straight portions  102  gradually move toward the inside of the piece of insulating paper  24  in each slot  22  ( FIGS.  12 A and  13 A ). 
     The belt-shaped coil  100  expanded in diameter comes into contact with the leading guide member  61  arranged ahead in the movement direction of the belt-shaped coil  100 , and presses the leading guide member  61  outward in the radial direction of the stator core  2  by being further pressed by the coil presser  51 . By being pressed by the belt-shaped coil  100 , the leading guide member  61  moves outward in the radial direction to reduce the distance L against the energizing force of the elastic member  614 . As a result, the leading guide member  61  pressed by the belt-shaped coil  100  comes into contact with or close to the first reinforcing guide member  62   a  arranged on the radially innermost side among the reinforcing guide members  62  ( FIGS.  12 B and  13 B ). 
     When the leading guide member  61  is pressed by the belt-shaped coil  100 , a pushing force inward in the radial direction occurs on the leading guide member  61  due to the energizing force of the elastic member  614 . Therefore, while moving, being pushed by the belt-shaped coil  100 , the leading guide member  61  moves inside the piece of insulating paper  24  while pushing the belt-shaped coil  100  against the coil presser  51  inward in the radial direction. The belt-shaped coil  100  is thereby always constricted between the leading guide member  61  and the coil presser  51  while moving. Therefore, loosening of the belt-shaped coil  100  on the front side in the movement direction is prevented. In the present embodiment, the connecting plate  613  and the elastic member  614  constitute pushers that push the belt-shaped coil  100  inward in the radial direction of the stator core  2 . 
     When the leading guide member  61  moves so as to reduce the distance L and comes into contact with or close to the first reinforcing guide member  62   a  on the radially innermost side, the controller  10  causes the first reinforcing guide actuator  620   a  to be driven to cause the first reinforcing guide member  62   a  to move outward in the central axis direction of the stator core  2 . The first reinforcing guide member  62   a  thereby retreats from inside the piece of insulating paper  24  in the slot  22 . The leading guide member  61  and the second reinforcing guide member  62   b  after the retreat of the first reinforcing guide member  62   a  are separated from each other by the distance L ( FIGS.  12 C and  13 C ). 
     As the belt-shaped coil  100  further expands in diameter, the leading guide member  61  is pushed by the belt-shaped coil  100  and moves outward in the radial direction to reduce the distance L from the second reinforcing guide member  62   b.  As a result, the leading guide member  61  pressed by the belt-shaped coil  100  comes into contact with or close to the second reinforcing guide member  62   b  arranged on the radially innermost side, between the second reinforcing guide member  62   b  and the third reinforcing guide member  62   c  that remain in the slot  22  ( FIGS.  12 D and  13 D ). 
     When the leading guide member  61  moves so as to reduce the distance L and comes into contact with or close to the second reinforcing guide member  62   b,  the controller  10  causes the second reinforcing guide actuator  620   b  to be driven to cause the second reinforcing guide member  62   b  to move outward in the central axis direction of the stator core  2 . The second reinforcing guide member  62   b  thereby retreats from inside the piece of insulating paper  24  in the slot  22 . The leading guide member  61  and the third reinforcing guide member  62   c  after the retreat of the second reinforcing guide member  62   b  are separated from each other by the distance L ( FIGS.  12 E and  13 E ). 
     As the belt-shaped coil  100  further expands in diameter, the leading guide member  61  is pushed by the belt-shaped coil  100  and moves outward in the radial direction to reduce the distance L from the third reinforcing guide member  62   c.  As a result, the leading guide member  61  pressed by the belt-shaped coil  100  comes into contact with or close to the third reinforcing guide member  62   c  arranged on the radially innermost side, which remains in the slot  22  ( FIGS.  12 F and  13 F ). 
     When the leading guide member  61  moves so as to reduce the distance L and comes into contact with or close to the third reinforcing guide member  62   c,  the controller  10  causes the third reinforcing guide actuator  620   c  to be driven to cause the third reinforcing guide member  62   c  to move outward in the central axis direction of the stator core  2 . The third reinforcing guide member  62   c  thereby retreats from inside the piece of insulating paper  24  in the slot  22 . Inside the piece of insulating paper  24  after the retreat of the third reinforcing guide member  62   c,  a gap corresponding to the distance L is formed on the outer side of the leading guide member  61  in the radial direction ( FIGS.  12 G and  13 G ). 
     As the belt-shaped coil  100  further expands in diameter, the leading guide member  61  is pushed by the belt-shaped coil  100  and moves outward in the radial direction so as to reduce the distance L that remains in the slot  22 . As a result, the leading guide member  61  pressed by the belt-shaped coil  100  comes into contact with or close to a wall surface  22   b  on the deepest side in the radial direction in the slot  22  ( FIGS.  12 H and  13 H ). 
     When the leading guide member  61  moves so as to reduce the distance L and comes into contact with or close to the wall surface  22   b  on the deepest side in the slot  22 , the controller  10  causes the actuator  610  to be driven to cause the leading guide member  61  to move outward in the central axis direction of the stator core  2 . The leading guide member  61  thereby retreats from inside the piece of insulating paper  24  in the slot  22 . Inside the piece of insulating paper  24  after the retreat of the leading guide member  61 , a gap corresponding to the distance L is formed between the straight portions  102  of the belt-shaped coil  100  and the wall surface  22   b  ( FIGS.  12 I and  13 I ). 
     When the belt-shaped coil  100  further expands in diameter, the belt-shaped coil  100  moves outward in the radial direction so as to reduce the distance L that remains in the slot  22 . As a result, the straight portions  102  of the belt-shaped coil  100  are accommodated inside the piece of insulating paper  24  in the slot  22  ( FIGS.  12 J and  13 J ). The belt-shaped coil  100  is thereby mounted in the slots  22  of the stator core  2 , and a stator  200  is completed ( FIG.  14   ). 
     According to the stator assembly apparatus  1  and the stator assembly method according to the above embodiment, the following effects can be obtained. That is, the stator assembly apparatus  1  according to the present embodiment is a stator assembly apparatus for assembling the stator  200  by inserting the belt-shaped coil  100  into the slots  22  of the stator core  2  in which the pieces of insulating paper  24  are mounted, from inside the stator core  2 . The stator assembly apparatus  1  includes leading guide members  61  provided movably along a central axis direction of the stator core  2 , each of the leading guide members  61  being, by moving toward the stator core  2 , inserted into the inside of the piece of insulating paper  2 A before the belt-shaped coil  100  being inserted, and arranged ahead in the movement direction of the belt-shaped coil  100  moving toward the slot  22 , in the state of at least a part of the leading guide member  61  being in contact with the opening ends  24   a  of the piece of insulating paper  24 . The leading guide member  61  has a quadrilateral shape when viewed in the longitudinal direction; the tip portion  61   a  of the leading guide member  61  is inclined along the radial direction of the stator core  2  with one end portion side (the Y 1  side) in the radial direction of the stator core  2  as the apex P, and has a shape tapered toward the center line O of the leading guide member  61  along the radial direction of the stator core  2 ; and the apex P is arranged on the outer side in the radial direction of the stator core  2 . According to the above, even if the opening between the opening ends  24   a  of the piece of insulating paper  24  is almost as narrow as being closed, it is possible to smoothly insert the leading guide member  61  into the inside of the piece of insulating paper  24 . The leading guide member  61  has a quadrilateral shape when viewed in the longitudinal direction, has a shape of being inclined along the radial direction of the stator core  2  with one end portion side (the Y 1  side) in the radial direction of the stator core  2  as the apex P and being tapered toward the center line O along the radial direction of the stator core  2 , and has a configuration in which the apex is arranged on the outer side in the radial direction of the stator core  2 . The leading guide member  61  is inserted into the slot  22  in the state of at least a part thereof being in contact with the opening ends  24   a  of the piece of insulating paper  24 . Therefore, it is possible to, only by inserting the leading guide member  61  into the inside of the piece of insulating paper  24 , cause the opening ends  24   a  of the piece of insulating paper  24  to return to the opened state prior to insertion of the coil. Therefore, it is possible to provide the stator assembly apparatus  1  with a good workability of the stator  200 . 
     In the present embodiment, the lateral width W 12  of each leading guide member  61  along the circumferential direction of the stator core  2  is equal to or more than the width W 0  of the straight portions  102  of the belt-shaped coil  100  along the circumferential direction of the stator core  2 . According to the above, since it is possible to cause the opening between the opening ends  24   a  of the piece of insulating paper  24  to open wider than the width W 0  of the straight portions  102  of the belt-shaped coil  100 , the insertability of the belt-shaped coil  100  is further improved. 
     The stator assembly method according to the present embodiment is a stator assembly method for assembling the stator  200  by inserting the belt-shaped coil  100  into each of the slots  22  of the stator core  2  from inside the stator core  2 , the pieces of insulating paper  24  being mounted in the slots  22 . The stator assembly method includes the process of, before inserting the belt-shaped coil  100  into each of the slots  22 , inserting each of the leading guide members  61  into the inside of the piece of insulating paper  24  from the outer side in the central axis direction of the stator core  2  such that the leading guide member  61  is arranged ahead in the movement direction of the belt-shaped coil  100  moving toward the slot  22 , in the state of at least a part of the leading guide member  61  being in contact with the opening ends  24   a  of the piece of insulating paper  24 . The leading guide member  61  has a quadrilateral shape when viewed in the longitudinal direction; the tip portion  61   a  of the leading guide member  61  is inclined along the radial direction of the stator core  2  with one end portion side (the Y 1  side) in the radial direction of the stator core  2  as the apex P, and has a shape tapered toward the center line O of the leading guide member  61  along the radial direction of the stator core  2 ; and the apex P is arranged on the outer side in the radial direction of the stator core  2 . According to the above, even if the opening between the opening ends  24   a  of the piece of insulating paper  24  is almost as narrow as being closed, it is possible to smoothly insert the leading guide member  61  into the inside of the piece of insulating paper  24 . The leading guide member  61  has a quadrilateral shape when viewed in the longitudinal direction, has a shape of being inclined along the radial direction of the stator core  2  with one end portion side (the Y 1  side) in the radial direction of the stator core  2  as the apex P and being tapered toward the center line O along the radial direction of the stator core  2 , and has a configuration in which the apex P is arranged on the outer side in the radial direction of the stator core  2 . The leading guide member  61  is inserted into the slot  22  in the state of at least a part thereof being in contact with the opening ends  24   a  of the piece of insulating paper  24 . Therefore, it is possible to, only by Inserting the leading guide member  61  into the inside of the piece of insulating paper  24 , cause the opening ends  24   a  of the piece of insulating paper  24  to return to the opened state prior to insertion of the belt-shaped coil  100 . Therefore, it is possible to provide a stator assembly method with a good workability of assembly of the stator  200 . 
     In the present embodiment, the lateral width W 12  of each leading guide member  61  along the circumferential direction of the stator core  2  is equal to or more than the width W 0  of the straight portions  102  of the belt-shaped coil  100  along the circumferential direction of the stator core  2 . According to the above, since it is possible to cause the opening between the opening ends  24   a  of the piece of insulating paper  24  to open wider than the width W 0  of the straight portions  102  of the belt-shaped coil  100 , the insertability of the belt-shaped coil  100  is further improved. 
     The stator assembly apparatus  1  in the embodiment described above is configured such that the central axis direction of the stator core  2  and the coil winding jig  4  is arranged in the horizontal direction. However, the stator assembly apparatus  1  may be configured such that the central axis direction of the stator core  2  and the coil winding jig  4  is arranged in a direction other than the horizontal direction, such as the vertical direction. 
     EXPLANATION OF REFERENCE NUMERALS 
       1  stator assembly apparatus 
       2  stator core 
       22  slot 
       24  insulating paper (insulating member) 
       24   a  opening end 
       61  leading guide member 
       61   a  tip portion 
       100  belt-shaped coil 
       200  stator 
     P apex 
     W 0  width of belt-shaped coil 
     W 12 , W 22  lateral width