Patent Publication Number: US-2023155464-A1

Title: Coil insertion guide device

Description:
This application is based on and claims the benefit of priority from Japanese Patent Application No. 2021-186271, filed on 16 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 insertion guide device. 
     Related Art 
     Conventionally, there is known a technique for guiding a strip-shaped coil wound in a substantially cylindrical shape using a spacer extending in a radial direction, in order to suppress deformation of a bent portion of a coil end portion when the coil is inserted into slots from inside of a stator core (see, for example, Japanese Unexamined Patent Application, Publication No. 2017-112749).
     Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2017-112749   

     SUMMARY OF THE INVENTION 
     According to the above technique of Japanese Unexamined Patent. Application, Publication No. 2017-112749, the spacer for guiding the insertion of the strip-shaped coil is a component of the stator and hence cannot be reused. Therefore, it is necessary to provide the spacer for each stator. 
     In addition, guiding the strip-shaped coil with the spacer has the following disadvantages. As shown in  FIG.  17   , a strip-shaped coil C is generally shaped by way of sequential bending to form a plurality of straight portions C 1  that are parallel to each other and coil end portions C 2  that alternately connect end portions of the adjacent straight portions C 1  and C 1  to each other and have a chevron-like shape. As the strip-shaped coil C moves radially outward in the slots, the circumference of the strip-shaped coil C increases, whereby the coil is deformed so that a pitch Pt of the straight portions C 1  increases and the coil end portions C 2  expands. Therefore, as shown with white arrows in  FIG.  17   , a reaction force F to close the coil end portion C 2  acts on the strip-shaped coil C in the vicinity of each connecting portion between the straight portion C 1  and the coil end portion C 2 . 
       FIG.  18    schematically shows a behavior of the straight portion C 1  in a slot ST when the reaction force F acts on the coil end portion C 2  of the strip-shaped coil C. The coil end portion C 2  is pulled to be inclined in a circumferential direction as a diameter increases. Consequently, a contact region with the spacer indicated by a triangle in  FIG.  18    serves as a fulcrum P 1 , and a point at which the reaction force F acts serves as a point of effort, whereby the principle of leverage works. As a result, the straight portion C 1  in the slot ST is inclined and comes into contact with an inner wall surface of the slot ST on a side opposite to the contact region, and the straight portion C 1  is deformed while the contact region serving as a point of load P 2 . Since the reaction force F acts in opposite directions at both end portions of the straight portion C 1 , the straight portion C 1  in the slot ST comes into contact with opposed inner wall surfaces of the slot ST on each of opposite sides of a stator core in an axial direction. A load continues to be applied locally to the point of load P 2  until the insertion of the strip-shaped coil C into the slots ST is completed, and hence the straight portion C 1  in the slot ST is deformed into a substantially S shape. The deformed straight portion C 1  bites or breaks insulating paper in the slot ST, and reduces workability in mounting the strip-shaped coil C in the slots ST. However, Japanese Unexamined Patent Application, Publication No. 2017-112749 does not disclose any specific measures for suppressing the deformation of the straight portion in the slot. 
     An object of the present invention is to provide a coil insertion guide device capable of suppressing deformation of a straight portion of a strip-shaped coil to be inserted into slots of a stator core and capable of improving workability in mounting the coil in the slot. 
     A first aspect of the present invention is directed to a coil insertion guide device (for example, a coil insertion guide device  1  described later) including a plurality of guide portions (for example, guide portions  331  described later) arranged over each of end faces (for example, end faces  2   a  described later) of a stator core (for example, a stator core  2  described later) that are opposite in an axial direction (for example, a Z-direction described later), the stator core including insulating members (for example, insulating paper  24  described later) in slots (for example, slots  22  described later), the guide portions being configured to guide movement of a strip-shaped coil (for example, a strip-shaped coil  100  described later) that is insertable into the slots along a radial direction (for example, a Y-direction described later) of the stator core. The strip-shaped coil includes a plurality of straight portions (for example, straight portions  102  described later) insertable into the slots and a plurality of coil end portions (for example, coil end portions  103  described later) each connecting adjacent straight portions to each other among the plurality of straight portions. In each of the guide portions, a shoulder portion (for example, a shoulder portion  331   b  described later) that comes into contact with the coil end portion of the strip-shaped coil has a convex curved surface that is continuous from a top (for example, a top  331   c  described later) to a maximum width portion (for example, a maximum width portion  331   d  described later). 
     A second aspect is an embodiment of the first aspect. In the coil insertion guide device according to the second aspect, it is preferable that each of the guide portions has, in a portion facing the end face of the stator core, a regulating groove portion that accommodates and regulates the insulating member protruding from the end, and a height of the regulating groove portion is defined as “insulating member regulating height”, a radius of a curved surface of a corner portion formed between the regulating groove portion and the maximum width portion of the guide portion adjacent to the regulating groove portion is defined as “coil contact surface escape R”, a height, from the end face of the stator core, of a region in which the guide portion first comes into contact with the strip-shaped coil is defined as “coil initial contact position”, and a height, from the end face of the stator core, of a boundary between the straight portion and the coil end portion of the strip-shaped coil is defined as “coil R start point”, 
     the guide portion satisfies:
 
condition A: “insulating member regulating height”+“coil contact surface escape R”≤“coil initial contact position”≤“coil R start point”.
 
     A third aspect is an embodiment of the second aspect. In the coil insertion guide device according to the third aspect, it is preferable that in the condition A, a bend radius of a root portion of the coil end portion is defined as “coil end shoulder R”, and “coil R start point”  5  “coil end shoulder R”. 
     A fourth aspect is an embodiment of any one of the first to third aspects. In the coil insertion guide device according to the fourth aspect, it is preferable that a width of the strip-shaped coil is defined as “coil width”, a clearance between adjacent ones of the guide portions is defined as “guide CL”, and 
     the guide portion satisfies:
 
condition B: “coil width”≤“guide CL”.
 
     A fifth aspect is an embodiment of any one of the first to fourth aspects. In the coil insertion guide device according to the fifth aspect, it is preferable that a radius of a curved surface of the shoulder portion of the guide portion is defined as “guide shoulder R”, a bend radius of a root portion of the coil end portion is defined as “coil end shoulder R”, and 
     the guide portion satisfies:
 
condition C: “guide shoulder R”≤“coil end shoulder R”.
 
     A sixth aspect is an embodiment of any one of the first to fifth aspects. It is preferable that the coil insertion guide device according to the sixth aspect further includes a coil winding jig (for example, a coil winding jig  4  described later) including comb teeth (for example, comb teeth  42  described later) around which the strip-shaped coil is wound and held before insertion into the slot. Preferably, a radius of a curved surface of a shoulder portion of the comb tooth that comes into contact with the strip-shaped coil is defined as “comb tooth shoulder R”, and 
     the guide portion satisfies:
 
condition D: “guide shoulder R”≤“comb tooth shoulder R”.
 
     According to the first aspect, each coil end portion is gradually deformed to be inclined along the curved surface of the shoulder portion of the guide portion as the strip-shaped coil moves in the slots, whereby a position of a contact portion between the strip-shaped coil and the shoulder portion of the guide portion shifts. Therefore, when a point at which a reaction force acts on the coil end portion serves as a point of effort and the contact portion serves as a fulcrum, a position of a point of load at which the straight portion of the strip-shaped coil abuts on an inner wall surface of the slot also shifts. Consequently, local application of a load to the straight portion is avoided, and substantially S-shaped deformation of the straight portion is suppressed. As a result, workability in mounting the strip-shaped coil in the slots improves. 
     According to the second aspect, setting “coil initial contact position” to be equal to or more than “insulating member regulating height.”+“coil contact surface escape R” results in a decrease in a distance between the fulcrum and the point of effort, and makes it unlikely for the straight portion is to be inclined. Setting “coil R start point” to be equal to or more than “coil initial contact position” further reduces the inclination of the straight portion with a contact portion as the fulcrum. Thus, the guide portion can more effectively suppress the substantially S-shaped deformation of the straight portion. 
     According to the third aspect, the contact height of the guide portion with the strip-shaped coil can be kept low, and an effect of an excessive length of the straight portion on a motor performance can be reduced. 
     According to the fourth aspect, damage to a coating of the strip-shaped coil can be reduced while reducing the inclination of the straight portion. 
     According to the fifth aspect, when the strip-shaped coil comes into contact with the guide portion and the strip-shaped coil starts to be plastically deformed, the position of the contact portion serving as the fulcrum is likely to gradually move in a direction away from the end face of the stator core. Thus, a situation is more effectively prevented or reduced in which the straight portion is deformed into the substantially S-shape due to a local increase in load in the slot that can be caused by shifting of the position of the point of load. 
     According to the sixth aspect, it is possible to reduce the inclination of the straight portions of the strip-shaped coil after the strip-shaped coil comes into contact with the shoulder portions of the guide portions from the comb teeth and transfers from the comb teeth to the guide portions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view showing a coil insertion guide device to which a stator core is mounted; 
         FIG.  2    is a perspective view showing an insulating member mounted in a slot of the stator core; 
         FIG.  3    is a plan view showing a part of the coil insertion guide device to which a coil winding jig and the stator core are mounted; 
         FIG.  4    is a side view of a guide member; 
         FIG.  5    is a cross-sectional view along the A-A line in  FIG.  4   ; 
         FIG.  6    is a perspective view showing the coil winding jig; 
         FIG.  7    is a front view showing a strip-shaped coil; 
         FIG.  8    is a perspective view showing a behavior in inserting a coil expander inside the strip-shaped coil; 
         FIG.  9    is a plan view showing a part of the coil insertion guide device before the strip-shaped coil is inserted with a guide portion being disposed at the guide position; 
         FIG.  10    is a plan view showing a part of the coil insertion guide device after the strip-shaped coil is inserted with the guide portion being disposed at the guide position; 
         FIG.  11    is an explanatory view of a relation between the guide portion and the strip-shaped coil; 
         FIG.  12    is an explanatory view of a force acting on the strip-shaped coil during insertion into the slot; 
         FIG.  13    is an explanatory view of respective regions of the guide portion and strip-shaped coil; 
         FIG.  14    is an explanatory view of a coil end portion shoulder R; 
         FIG.  15    is an explanatory view of a comb tooth shoulder R; 
         FIG.  16    is a perspective view showing appearance of a stator; 
         FIG.  17    is an explanatory view of a force acting on the coil during the insertion into the slot; and 
         FIG.  18    is an explanatory view of a force acting on the strip-shaped coil during the coil insertion. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention will be described in detail with reference to the drawings. A coil insertion guide device  1  shown in  FIG.  1    includes a stator: core  2 , a positioning jig  3  that positions and fixes the stator core  2  in an inside thereof, and a coil winding jig  4  insertable inside the stator core  2  and having a strip-shaped coil  100  wound in an annular shape therearound. 
     The stator core  2  includes an annular portion  21  including a laminate of a plurality of thin core plates. The stator core  2  has a through hole  20  that penetrates a center of the annular portion  21  in an axial direction. As shown in  FIG.  2   , the stator core  2  has a plurality of slots  22  that penetrate the stator core  2  in the axial direction. The slots  22  are arranged radially at regular intervals along a circumferential direction of the annular portion  21  and have openings  22   a  that open toward the through hole  20  provided radially inside the annular portion  21 . The stator core  2  of the present embodiment has seventy-two slots  22 . The annular portion  21  of the stator core  2  has, on its outer periphery, six ear portions  23  that protrude at regular intervals. For the stator core  2  and the positioning jig  3 , as shown in  FIG.  1   , an X-direction in which the slots  22  are arranged corresponds to the circumferential direction, a Y-direction along the radial direction from a center of the through hole  20  corresponds to the radial direction, and a Z-direction corresponds to the axial direction. 
     The positioning jig  3  has a hexagonal prism shape with an axial dimension substantially equal to an axial dimension of the stator core  2  and has, at a center, a stator core insertion hole  31  into which the stator core  2  can be inserted and disposed. The positioning jig  3  has core pressing blocks  32  that respectively hold the six ear portions  23  arranged on an outer periphery of the stator core  2 , thereby fixing the stator core  2  in the stator core insertion hole  31  at a predetermined position and in a predetermined posture. 
     As shown in  FIG.  2   , in each slot  22  of the stator core  2 , an insulating paper  24  that is an insulating member is mounted in advance. The insulating paper  24  is folded into a substantially U-shape to follow an inner surface of the slot  22  having a substantially U-shape when the stator core  2  is viewed in the axial direction. Specifically, the insulating paper  24  includes a pair of radial portions  241  and  241  along an inner wall surface of the slot  22  extending in the radial direction of the stator core  2 , and a circumferential portion  242  that is a back portion connecting radially outer ends of the radial portions  241  and  241  to each other along the circumferential direction of the stator core  2 . 
     The insulating paper  24  mounted in the slot  22  has a cuff portion  24   a . The cuff portion  24   a  is a portion in which the radial portions  241  and  241  and the circumferential portion  242  of the insulating paper  24  are extended in the axial direction beyond the stator core  2  to protrude from the slot  22  and protrude outward from the end face  2   a  of the stator core  2  in the axial direction. While  FIG.  2    shows only one cuff portion  24   a  of the insulating paper  24  that protrudes from one end face  2   a  of the stator core  2 , the cuff portion  24   a  protrudes from each of opposite end faces  2   a  and  2   a  of the stator core  2  in the axial direction. 
     As shown in  FIGS.  1  and  3   , a plurality of cuff guides  33  are attached to each of axially opposite end faces  3   a  and  3   a  of the positioning jig  3 , to which the stator core  2  is fixed in advance, so that the cuff guides are arranged radially at regular intervals along the circumferential direction. Each of the cuff guides  33  includes guide portions  331  that guide movement of the strip-shaped coil  100  to be described later when it is in inserted into the slot  22  of the stator core  2 . The cuff guide  33  is capable of advancing and retracting along the radial direction of the stator core  2  when driven by an actuator such as an unshown cylinder. The cuff guide  33  is positioned at a guide position to guide the strip-shaped coil  100  by being moved when moving inward in the radial direction of the stator core  2  (see  FIG.  9   ). 
     The cuff guide  33  has a thin plate shape that is long in the radial direction of the stator core  2 . As shown in  FIGS.  3 ,  4  and  5   , each cuff guide  33  has a pair of guide portions  331  and  331  that are provided adjacent to an inner end  33   a , protrude inward in the radial direction, and guide the movement of the strip-shaped coil  100  to be described later. The pair of guide portions  331  and  331  are formed by cutting out a portion near the inner end  33   a  of the cuff guide  33  in a U-shape along a length direction of the cuff guide  33 . Between the pair of guide portions  331  and  331 , a groove portion  332  is formed that opens inward and that receives the strip-shaped coil  100 . A clearance between the pair of guide portions  331  and  331  (i.e., a width of the groove portion  332 ) is substantially equal to a width of the slot  22  along the circumferential direction of the stator core  2 . A length D of each of the guide portions  331  (i.e., a groove depth of the groove portion  332 ) is equal to or greater than a depth of the slot  22  along the radial direction of the stator core  2 . The cuff guide  33  has a long hole  333  that regulates a radial movement range of the cuff guide  33 , and that is formed toward an outer end  33   b  in comparison with the guide portions  331  and  331 . 
     The coil insertion guide device  1  of the present embodiment includes thirty-six cuff guides  33  corresponding to every other slot  22  of the stator core  2 , per end face  3   a  of the positioning jig  3 . In a state where each cuff guide  33  is positioned at the guide position, the clearance between the guide portions  331  and  331  of the adjacent cuff guides  33  and  33  is also set to be substantially equal to the width of the slot  22  and the width of the groove portion  332  along the circumferential direction of the stator core  2 . Therefore, the clearance between the guide portions  331  and  331  of the adjacent cuff guides  33  and  33  is configured to receive the strip-shaped coil  100  and to guide insertion into the slot  22  in the same manner as the groove portion  332 . 
     As shown in  FIGS.  4  and  5   , the guide portion  331  has a cuff portion-regulating groove portion  331   a  that accommodates and regulates the cuff portion  24   a  of the insulating paper  24  disposed on opposite sides of the guide portion  331  at the guide position. The cuff portion-regulating groove portion  331   a  is formed at each of both side edges of the guide portion  331  by narrowing a width of a portion of the cuff guide  33  adjacent to a bottom surface  33   c  (surface facing the end face  2   a  of the stator core  2 ). The cuff portion-regulating groove portion  331   a  has a height with which the cuff portion  24   a  of the insulating paper  24  protruding from the end face  2   a  of the stator core  2  can be accommodated. The cuff portion-regulating groove portions  331   a  and  331   a  extend over at least the entire length of the guide portion  331  of the cuff guide  33 . 
     As shown in  FIG.  5   , a portion of the guide portion  331  above the cuff portion-regulating groove portions  331   a  and  331   a  (portion away from the bottom surface  33   c  of the cuff guide  33 ) is wide and has a substantially hemispherical cross-sectional shape. The surface of the guide portion  331  above the cuff portion-regulating groove portions  331   a  and  331   a  forms shoulder portions  331   b  and  331   b  that come into contact with a coil end portion  103  of the strip-shaped coil  100  to be described later and that guide movement of the strip-shaped coil  100 . 
     As shown in  FIG.  5   , the shoulder portions  331   b  and  331   b  each have a cross-sectional shape symmetrical with respect to a centerline O that passes through a center of the guide portion  331  along the axial direction of the stator core  2 . Specifically, the shoulder portion  331   b ,  331   b  is formed by a convex curved surface that is continuous from the top  331   c  on the centerline O to the maximum width portion  331   d ,  331   d  immediately above the cuff portion-regulating groove portion  331   a ,  331   a . Corner portion  331   e ,  331   e  each located between an associated one of the cuff portion-regulating groove portions  331   a ,  331   a  and an associated one of the maximum width portions  331   d ,  331   d  forms a rounded curved surface. The guide portions  331  have the same thickness along the length direction (the radial direction of the stator core  2 ) and have the same cross-sectional shape. A relationship between the guide portion  331  and the strip-shaped coil  100  will be described later in more detail. 
     As shown in  FIG.  3   , on each of the opposite end faces  3   a  and  3   a  of the positioning jig  3 , an inner diameter-side regulation pin  34   a  and an outer diameter-side regulation pin  34   b  are provided in a pair in correspondence with each of the cuff guides  33 . The inner diameter-side regulation pin  34   a  abuts on an inner end portion  333   a  of the long hole  333  when the cuff guide  33  moves outward in the radial direction of the positioning jig  3 , thereby positioning the cuff guide  33  at a non-guided position that is outermost in the radial direction, as shown in  FIG.  3   . In the non-guided position, the inner end  33   a  of the cuff guide  33  is positioned outside the stator core insertion hole  31  in the radial direction. The outer diameter-side regulation pin  34   b  abuts on an outer end portion  333   b  of the long hole  333  when the cuff guide  33  moves inward in the radial direction of the positioning jig  3 , thereby positioning the cuff guide  33  at a guide position that is innermost in the radial direction. At this time, the inner end  33   a  of the cuff guides  33  is positioned outside the coil winding jig  4  in the radial direction (see  FIG.  9   ). 
     Since the stator core  2  is inserted into the stator core insertion hole  31  of the positioning jig  3  from either one side in the axial direction, the cuff guides  33  disposed on the side opposite to the side from which the stator core  2  is inserted may be disposed so that the inner ends  33   a  interfere with the annular portion  21  of the stator core  2  in a state where the outer diameter-side regulation pins  34   b  abut on the inner end portions  333   a  of the long holes  333  as shown in  FIG.  3   . However, the inner diameter-side regulation pin  34   a  and the outer diameter-side regulation pin  34   b  may be configured to selectively protrude and retreat with respect to the surface of the positioning jig  3 , by an advancing/retracting mechanism (not shown) including an actuator such as a cylinder provided inside the positioning jig  3 . Thereby, in the case where the cuff guides  33  are arranged as shown in  FIG.  3   , the inner diameter-side regulation pins  34   a  and the outer diameter-side regulation pins  34   b  are retracted below the surface of the positioning jig  3  as needed, thereby allowing the cuff guide  33  to move further outward in the radial direction, so that the cuff guide  33  can be retracted completely from the annular portion  21  of the stator core  2 , as shown in  FIG.  1   . 
     As shown in  FIG.  6   , the coil winding jig  4  includes a substantially cylindrical jig body  41 , a plurality of comb teeth  42  that radially protrude from an outer periphery of the jig body  41 , a plurality of coil mounting grooves  43  formed between the comb teeth  42  adjacent to each other in the circumferential direction, and a shaft hole  44  that opens at a center of the jig body  41 . The comb teeth  42  and the coil mounting grooves  43  are provided on each of axially opposite end portions of the jig body  41 . A distance between the comb teeth  42  and the comb teeth  42  on each of the axially opposite end portions of the jig body  41  is substantially equal to a distance between the guide portions  331  and  331  arranged over each of the opposite end faces  2   a  and  2   a  of the stator core  2 . Phases of the comb teeth  42  and the coil mounting grooves  43  on one of the opposite end portions of the jig body  41  are aligned in the axial direction with those on the other of the opposite end portions. The number of the coil mounting grooves  43  arranged in the circumferential direction of the jig body  41  matches the number of the slots  22  provided in the stator core  2 . The coil winding jig  4  is formed so that its outer diameter defined by the position of tips of the comb teeth  42  is smaller than the diameter of the through hole  20  of the stator core  2 , whereby the jig can be inserted into the annular portion  21  of the stator core  2 . 
     The strip-shaped coil  100  is wound in an annular shape around the coil winding jig  4 . As shown in  FIG.  7   , the strip-shaped coil  100  is a continuous wave winding coil having a shape of a long strip and made of a flat wire  101  of copper, aluminum or the like with a substantially rectangular cross-sectional shape. Setting the continuous wave winding coil to the stator core  2  does not require a common dominant technique for forming a plurality of coil segments and welding ends of the coil segments after insertion in slots, thereby eliminating, for example, the need to use a high-purity copper material for the coil in order to cope with thermal processing of welded portions. Therefore, it is also possible to use a recycled copper material containing impurities, and to contribute to achieving of recycling of resources. In addition, the wave winding coil does not have to be welded, so that a weight of the coil can be reduced, and a weight of a rotary electric machine including this coil can be reduced. When the rotary electric machine is mounted in a hybrid car, the vehicle weight is reduced, enabling reduction in carbon dioxide emissions can be reduced, and reduction of adverse effects on global environment. 
     The strip-shaped coil  100  includes a plurality of straight portions  102  and a plurality of coil end portions  103 . Each of the straight portions  102  is to be inserted into the slot  22  of the stator core  2 , and the straight portions extend substantially linearly and are arranged in parallel at regular intervals. The coil end portions  103  are each arranged at a position closer to a side end of the strip-shaped coil  100  than the straight portions  102 , and alternately connect end portions of adjacent straight portions  102  to each other and the opposite end portions of the adjacent straight portions  102  to each other in a substantially triangular chevron-like shape. Each of the coil end portions  103  is a portion disposed to protrude from the slot  22  in the axial direction of the stator core  2  when the strip-shaped coil  100  is mounted in the slots  22  of the stator core  2 . The strip-shaped coil  100  of the present embodiment has the shape of a long strip and is formed by bundling six flat wires  101  that have been bent to have the plurality of straight portions  102  and the plurality of coil end portions  103  so that the straight portions  102  are arranged in parallel at regular intervals. 
     The coil winding jig  4  winds up the strip-shaped coil  100  multiple turns by sequentially inserting the straight portions  102  of the strip-shaped coil  100  into the coil mounting grooves  43  before the jig  4  is inserted inside the stator core  2 . Thereby, as shown in  FIG.  1   , the coil winding jig  4  is prepared, which has the strip-shaped coil  100  wound therearound in an annular shape. 
     The strip-shaped coil  100  wound around the coil winding jig  4  is disposed inside the stator core  2 , and then pushed and expanded from inside by a coil expander  5  shown in  FIG.  8    to increase in diameter. While  FIG.  8    shows only one coil expander  5 , coil expanders  5  are arranged on axially opposite sides of the coil insertion guide device  1  and push and expand the coil end portions  103  of the strip-shaped coil  100  from the axially opposite sides. 
     As shown in  FIGS.  8  to  10   , the coil expander  5  includes a spindle portion  51  and a plurality of coil pressing portions  52  provided on an outer periphery of an end portion of spindle portion  51 . The plurality of coil pressing portions  52  are arranged in an annular shape along the outer periphery of the end portion of the coil expander  5  and are capable of increasing and reducing in diameter by moving in the radial direction by being driven by an actuator (not shown). As shown in  FIGS.  8  and  9   , an outer diameter defined by the coil pressing portions  52  with the reduced diameter is equal to or less than an inner diameter of the annular strip-shaped coil  100  wound around the coil winding jig  4 . As shown in  FIG.  10   , an outer diameter defined by the coil pressing portions  52  with the increased diameter is larger than an outer diameter of the coil winding jig  4 . 
     The coil expander  5  inserts the coil pressing portions  52  with the reduced diameter inside the coil end portions  103  of the annular strip-shaped coil  100  wound around the coil winding jig  4 , and fits a tip portion  51   a  of the spindle portion  51  into the shaft hole  44  of the coil winding jig  4  so as to hold the coil winding jig  4 . As shown in  FIG.  10   , when the coil pressing portion  52  inserted inside the strip-shaped coil  100  expands in diameter, the coil end portions  103  of the strip-shaped coil  100  are pressed outward, and the strip-shaped coil  100  expands in diameter. As a result, the straight portions  102  of the strip-shaped coil  100  move toward the inside of the insulating papers  24  in the slots  22  located radially outside, and then are inserted into the slots  22 . 
     As shown in  FIG.  11   , when each of the straight portions  102  is inserted into the slot  22 , a contact portion CP of the strip-shaped coil  100  first comes into contact with the shoulder portion  331   b  of the guide portion  331 . The contact portion CP has about the same height as a coil end R-start point BP that is a boundary between the straight portion  102  and the coil end portion  103  and at which the coil end portion  103  starts to bend. Thereafter, the strip-shaped coil  100  is pushed by the coil pressing portions  52 , and each coil end portion  103  moves toward the interior of the slot  22  inside the insulating paper  24  while being guided by the shoulder portion  331   b  of the guide portion  331 . As the diameter of the strip-shaped coil  100  expands, a pitch of the straight portions  102  gradually increases, and the coil end portions  103  are expanded to open in the circumferential direction. 
     Here, the shoulder portion  331   b  of the guide portion  331  is constituted by the convex curved surface that is continuous from the top  331   c  on the centerline O to the maximum width portion  331   d  immediately above the cuff portion-regulating groove portion  331   a ,  331   a , as shown in  FIG.  5   . Therefore, as shown in  FIG.  12   , following the strip-shaped coil  100  first coming into contact with the guide portion  331  at a contact portion CP 1 , as the strip-shaped coil  100  moves in the slot  22 , the coil end portion  103  is gradually deformed to be inclined along the curved surface of the shoulder portion  331   b  of the guide portion  331 . Accordingly, a contact region between the strip-shaped coil  100  and the guide portion  331  shifts from the first contact portion CP 1  to a contact portion CP 2  that is closer to the top  331   c  of the guide portion  331 . Therefore, the principle of leverage works while a point at which a reaction force F acting on the coil end portion  103  serves as the point of effort and the contact portion CP serves as the fulcrum. The point of load at which the straight portion  102  abuts on the inner wall surface of the slot  22  also shifts from a point of load P 21  at the time when the fulcrum corresponds to the first contact portion CP 1 , to a point of load P 22 , due to the fulcrum moving to the contact portion CP 2 . Consequently, a situation in which a load is locally applied to the straight portion  102  is avoided, making it unlikely for the straight portion  102  to be deformed into a substantially S shape. As a result, workability in mounting the strip-shaped coil  100  in the slots  22  is improved. 
     Here, it is desirable that the guide portions  331  of the coil insertion guide device  1  satisfy at least one selected from the following conditions A to D. 
     Condition A: “insulating member regulating height”+“coil contact surface escape R”≤“coil initial contact position”≤“coil R start point” 
     Condition B: “coil width”≤“guide CL”. Condition C: “guide shoulder R”≤“coil end shoulder R”
 
Condition D: “guide shoulder R”≤“comb tooth shoulder R”
 
     The above condition A will be described with reference to  FIG.  13   . The term “insulating member regulating height” indicates a height of the cuff portion-regulating groove portion  331   a  of the guide portion  331 . The term “coil contact surface escape R” indicates a radius of a curved surface of the corner portion  331   e  immediately above the cuff portion-regulating groove portion  331   a  of the guide portion  331 . The term “coil initial contact position” indicates a height, from the end face  2   a  of the stator core  2 , of the contact portion CP in which the strip-shaped coil  100  first comes into contact with the guide portion  331 . The term “coil R start point” indicates a height of the R start point BP of the coil end portion  103  from the end face  2   a  of the stator core  2 . In the present embodiment, the coil initial contact position is set to the same height as the coil R start point. Setting “coil initial contact position” to be equal to or more than “insulating member regulating height”+“coil contact surface escape R” results in a decrease in a distance between the fulcrum and the point of effort, and makes it less likely for the straight portion  102  to be inclined. Setting “coil R start point” to be equal to or more than “coil initial contact position” further reduces the inclination of the straight portion  102  from the contact portion CP as the fulcrum. Therefore, by satisfying the above condition A, the guide portions  331  can further effectively suppress the substantially S-shaped deformation of the straight portion  102 . 
     It is further desirable that “coil R start point” S “coil end shoulder R” in the above condition A. As shown in  FIG.  13   , “coil end shoulder R” indicates a bend radius of a root portion of the coil end portion  103 . Specifically, as shown in  FIG.  14   , “coil end shoulder R” indicates a radius r centered at a position P 0  at which a center of a pitch Pa of the adjacent straight portions  102  and  102  inserted into the adjacent slots  22  and  22  intersects with the height, from the end face  2   a  of the stator core  2 , of the R start point BP at which the coil end portion  103  starts to bend. The radius r indicates a radius of a curved surface disposed inside in a bending direction of the coil end portion  103 . Thereby, a contact height of the guide portion  331  with the strip-shaped coil  100  can be kept low, and an effect of an excessive length of the straight portion  102  on a motor performance can be reduced. 
     The above condition B will be described with reference to  FIG.  11   . The term “coil width” indicates a maximum width dimension W of the straight portion  102  of the strip-shaped coil  100 . The term “guide CL” indicates a clearance CL between the adjacent guide portions  331  and  331 . The clearance CL indicates a dimension between the maximum width portions  331   d  and  331   d  of the adjacent guide portions  331  and  331 . It is advantageous that “guide CL” is narrow from the viewpoint of reducing the inclination of the straight portion  102 , but there is concern that, when the strip-shaped coil  100  moves, a coating formed on the surface of the strip-shaped coil  100  is damaged. Setting “guide CL” to be equal to or greater than “coil width” makes it possible to reduce damage to the coating of the strip-shaped coil  100  while reducing the inclination of the straight portion  102 . 
     The above condition C will be described with reference to  FIG.  13   . The term “guide shoulder R” indicates a radius of a curved surface of the shoulder portion  331   b  of the guide portion  331 . As “guide shoulder R” increases, the position of the contact portion CP between the strip-shaped coil  100  and the guide portion  331  increases in height, and the inclination of the straight portion  102  decreases. When “guide shoulder R” is large, the contact surface with the strip-shaped coil  100  becomes larger, a contact surface pressure between the strip-shaped coil  100  and the guide portion  331  accordingly decreases, and damage to the strip-shaped coil  100  can be reduced. Setting “guide shoulder R” to be equal to or less than “coil end shoulder R” makes it likely for the position of the contact portion CP serving as the fulcrum to gradually move in a direction away from the end face  2   a  of the stator core  2  when the strip-shaped coil  100  comes into contact with the guide portion  331  and starts to be plastically deformed. Therefore, a situation is more effectively prevented or reduced in which the straight portion  102  is deformed into the substantially S-shape due to a local increase in load in the slot  22  that can be caused by shifting of the position of the point of load. 
     The above condition D will be described with reference to  FIG.  15   . The term “comb tooth shoulder R” indicates a radius of a curved surface of a shoulder portion of the comb tooth  42  of the coil winding jig  4  around which the strip-shaped coil  100  is wound and held before the insertion into the slot  22 . The shoulder portion of the comb tooth  42  is a shoulder portion located inside in a bending direction of the coil end portion  103 . The coil end portions  103  expands in diameter also when the strip-shaped coil  100  moves toward the slots  22  while being guided by the comb teeth  42 . Setting “guide shoulder R” to be equal to or less than “comb tooth shoulder R” makes it possible to reduce the inclination of the straight portion  102  of the strip-shaped coil  100  after the strip-shaped coil  100  comes into contact with the shoulder portions  331   b  of the guide portions  331  from the comb teeth  42  and transfers from the comb teeth  42  to the guide portions  331 . 
     As described above, the coil insertion guide device  1  guides the strip-shaped coil  100  by means of the guide portions  331  so as to insert the coil  100  into the slots  22 , whereby a stator  200  in which the strip-shaped coil  100  is mounted in the slots  22  is produced, as shown in  FIG.  16   . 
     The coil insertion guide device  1  according to the present embodiment provides the following effects. The coil insertion guide device  1  according to the present embodiment includes the plurality of guide portions  331  arranged over each of the axially opposite end faces  2   a  and  2   a  of the stator core  2  including the insulating papers  24  in the slots  22 , and the guide portions  331  guide movement of the strip-shaped coil  100  that is insertable into the slots  22  along the radial direction of the stator core  2 . The strip-shaped coil  100  includes the plurality of straight portions  102  insertable into the slot.  22  and the plurality of coil end portions  103  each connecting the adjacent straight portions  102  and  102  to each other among the plurality of straight portions  102 . In each of the guide portions  331 , the shoulder portion  3331   b  that comes into contact with the coil end portion  103  of the strip-shaped coil  100  has the convex curved surface that is continuous from the top  331   c  to the maximum width portion  331   d . Due to this feature, each coil end portion  103  is gradually deformed to be inclined along the curved surface of the shoulder portion  331   b  of the guide portion  331  as the strip-shaped coil  100  moves in the slots  22 , whereby the position of the contact portion CP between the strip-shaped coil  100  and the shoulder portion  331   b  of the guide portion  331  shifts. Therefore, when a point at which the reaction force F acts on the coil end portion  103  serves as the point of effort and the contact portion CP serves as the fulcrum, the position of the point of load at which the straight portion  102  of the strip-shaped coil  100  abuts on the inner wall surface of the slot  22  also shifts. Consequently, local application of the load to the straight portion  102  is avoided, and the substantially S-shaped deformation of the straight portion  102  is suppressed. As a result, the workability in mounting the strip-shaped coil  100  in the slots  22  improves. 
     In the present embodiment, each of the guide portions  331  has, in its portion facing the end face  2   a  of the stator core  2 , the cuff portion-regulating groove portion  331   a  that accommodates and regulates the insulating paper  24  protruding from the end face  2   a . The height of the cuff portion-regulating groove portion  331   a  is defined as “insulating member regulating height”, the radius of the curved surface of the corner portion formed between the cuff portion regulating groove portion  331   a  and the maximum width portion  331   d  of the guide portion  331  adjacent to the cuff portion regulating groove portion  331   a  is defined as “coil contact surface escape R”, the height, from the end face  2   a  of the stator core  2 , of the region in which the guide portion  331  first comes into contact with the strip-shaped coil  100  is defined as “coil initial contact position”, the height, from the end face  2   a  of the stator core  2 , of the boundary between the straight portion  102  and the coil end portion  103  of the strip-shaped coil  100  is defined as “coil R start point”, and it is preferable that the guide portion  331  satisfies condition A: “insulating member regulating height”+“coil contact surface escape R”≤“coil initial contact position”≤“coil R start point”. Setting “coil initial contact position” to be equal to or more than “insulating member regulating height”+“coil contact surface escape R” results in a decrease in the distance between the fulcrum and the point of effort, and makes it less likely for the straight portion  102  to be inclined. Setting “coil R start point” to be equal to or more than “coil initial contact position” further reduces the inclination of the straight portion  102  with the contact portion CP as the fulcrum. Thus, the guide portion  331  can more effectively suppress the substantially S-shaped deformation of the straight portion  102 . 
     In the present embodiment, it is preferable that in the condition A, “coil R start point”≤“coil end shoulder R”. Due to this feature, the contact height of the guide portion  331  with the strip-shaped coil  100  can be kept low, and the effect of an excessive length of the straight portion  102  on the motor performance can be reduced. 
     In the present embodiment, it is preferable that the width of the strip-shaped coil  100  is defined as “coil width”, and the clearance between the adjacent guide portions  331  and  331  is defined as “guide CL”, and the guide portion  331  satisfies the condition B: “coil width”≤“guide CL”. Due to this feature, the damage to the coating of the strip-shaped coil  100  can be reduced while reducing the inclination of the straight portion  102 . 
     In the present embodiment, it is preferable that the radius of the curved surface of the shoulder portion  331   b  of the guide portion  331  is defined as “the guide shoulder R”, and the bend radius of the root portion of the coil end portion  103  is defined as “coil end shoulder R”, and the guide portion  331  satisfies the condition C: “guide shoulder R” “coil end shoulder R”. Due to this feature, when the strip-shaped coil  100  comes into contact with the guide portion  331  and the strip-shaped coil  100  starts to be plastically deformed, the position of the contact portion CP serving as the fulcrum is likely to gradually move in the direction away from the end face  2   a  of the stator core  2 . Thus, a situation is more effectively prevented or reduced in which the straight portion  102  is deformed into the substantially S-shape due to a local increase in load in the slot  22  that can be caused by shifting of the position of the point of load. 
     In the present embodiment, the coil insertion guide device  1  further includes the coil winding jig  4  including the comb teeth  42  around which the strip-shaped coil  100  is wound and held before insertion into the slot  22 . It is preferable that the radius of the curved surface of the shoulder portion of the comb tooth  42  that comes into contact with the strip-shaped coil  100  is defined as “comb tooth shoulder R”, and the guide portion  331  satisfies the condition D: “guide shoulder R”≤“comb tooth shoulder R”. This feature makes it possible to reduce the inclination of the straight portions  102  of the strip-shaped coil  100  after the strip-shaped coil  100  comes into contact with the shoulder portions  331   b  of the guide portions  331  from the comb teeth  42  and transfers from the comb teeth  42  to the guide portions  331 . 
     EXPLANATION OF REFERENCE NUMERALS 
     
         
           1 : Coil insertion guide device 
           2 : Stator core 
           2   a : End face 
           22 : Slot 
           24 : Insulating paper (Insulating member) 
           331 : Guide portion 
           331   a : Cuff portion-regulating groove portion (Regulating groove portion) 
           4 : Coil winding jig 
           42 : Comb tooth 
           100 : Strip-shaped coil 
           102 : Straight portion 
           103 : Coil end portion