Patent Publication Number: US-2023151915-A1

Title: Connector

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present international application claims priority based on Japanese Patent Application No. 2020-070254 filed to Japanese Patent Office on Apr. 9, 2020, and the content of Japanese Patent Application No. 2020-070254 is incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a connector. 
     BACKGROUND ART 
     Patent Document 1 discloses a pipe joint. The pipe joint includes a male member, a female member, and a locking member. The locking member brings the male member and the female member into a locked state in a state where the male member is inserted into the female member. The locking member includes a pair of engaging shaft portions and a coupling shaft portion connecting them. The locking member is attached to the female member. When the male member is inserted into the female member, the locking member is pressed and deformed by a large-diameter portion of the male member. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     Patent Document 1: Japanese Unexamined Patent Application Publication No. H05-33891 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     A mode of deformation of the locking member is a mode in which each of the pair of engaging shaft portions rotates outward about an end portion on a coupling shaft portion side. Therefore, when the locking member is deformed, an end portion of the engaging shaft portion on a side opposite to the coupling shaft portion largely protrudes outward. As a result, it is necessary to provide a large gap around the pipe joint in order to allow deformation of the locking member. 
     In one aspect of the present disclosure, it is preferable to provide a connector capable of reducing a gap around a retainer. 
     Means for Solving the Problems 
     One aspect of the present disclosure is a connector including a connector body and a retainer, and configured to couple a first pipe having a bulge portion and a second pipe. 
     The connector body includes an insertion hole into which the first pipe is inserted, a first opening portion communicating with the insertion hole from an outer peripheral surface of the connector body, and a second opening portion communicating with the insertion hole from an outer peripheral surface of the connector body and opposing the first opening portion. 
     The retainer includes a first leg portion that is inserted into the first opening portion and configured to abut on a portion on a front side relative to the bulge portion in an outer peripheral surface of the coupled first pipe to regulate disengagement of the first pipe, a second leg portion that is inserted into the second opening portion and configured to abut on a portion on a front side relative to the bulge portion in an outer peripheral surface of the coupled first pipe to regulate disengagement of the first pipe, and an intermediate portion that connects a first connection portion in the first leg portion and a second connection portion in the second leg portion and is elastically deformable in an open manner so that a distance between the first connection portion and the second connection portion is widened. 
     An end surface of the first opening portion includes a first guide surface that guides the first leg portion in a direction where the distance is widened when a force in an insertion direction of the first pipe is applied to the first leg portion. 
     An end surface of the second opening portion includes a second guide surface that guides the second leg portion in a direction where the distance is widened when a force in the insertion direction is applied to the second leg portion. 
     When the first pipe is inserted into the insertion hole, the first leg portion to which the force in the insertion direction is applied by the bulge portion is guided by the first guide surface, and the second leg portion to which the force in the insertion direction is applied by the bulge portion is guided by the second guide surface, so that a distance between the first leg portion and the second leg portion becomes a distance that permits passage of the bulge portion. 
     When the first pipe is inserted into the insertion hole included in the connector that is one aspect of the present disclosure, the retainer is elastically deformed in an open manner such that a distance between the first connection portion and the second connection portion is widened. Therefore, in the connector that is one aspect of the present disclosure, the first leg portion can be suppressed from rotating outward about the first connection portion. In the connector that is one aspect of the present disclosure, the second leg portion can be suppressed from rotating outward about the second connection portion. Therefore, the connector that is one aspect of the present disclosure can suppress the retainer from largely protruding outward when the first pipe is inserted into the insertion hole. As a result, the connector that is one aspect of the present disclosure can reduce a gap around the retainer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an explanatory view illustrating a configuration of the coupled connector and first pipe viewed from a viewpoint on a side of an upward direction U. 
         FIG.  2    is an explanatory view illustrating the configuration of the coupled connector and first pipe viewed from a viewpoint on a side of a leftward direction L. 
         FIG.  3    is an explanatory view illustrating the configuration of the coupled connector and first pipe viewed from a viewpoint on a side of a downward direction D. 
         FIG.  4    is an explanatory view illustrating the configuration of the coupled connector and first pipe viewed from a viewpoint on a side of a rightward direction R. 
         FIG.  5    is an explanatory view illustrating the configuration of the coupled connector and first pipe viewed from a viewpoint on a side of an axial forward direction F. 
         FIG.  6    is an explanatory view illustrating the configuration of the coupled connector and first pipe viewed from a viewpoint on a side of an axial backward direction B. 
         FIG.  7    is a cross-sectional view at a VII-VII cross section in  FIG.  1   . 
         FIG.  8    is a cross-sectional view at a VIII-VIII cross section in  FIG.  2   . 
         FIG.  9 A  is an explanatory view illustrating a configuration of the retainer viewed from a viewpoint on the side of the upward direction U, and  FIG.  9 B  is an explanatory view illustrating a configuration of the retainer viewed from a viewpoint on the side of the axial forward direction F. 
         FIG.  10    is an explanatory view illustrating a configuration of the first pipe. 
         FIGS.  11 A and  11 B  are explanatory views illustrating the connector and the first pipe when the first pipe is inserted into the insertion hole and the bulge portion is not yet in contact with the first leg portion and the second leg portion. 
         FIGS.  12 A and  12 B  are explanatory views illustrating the connector and the first pipe when the bulge portion applies a force to the retainer to increase the distance. 
         FIGS.  13 A and  13 B  are explanatory views illustrating the coupled connector and first pipe. 
         FIGS.  14 A and  14 B  are explanatory views illustrating the retainer when no force is applied from the bulge portion.  FIGS.  14 C and  14 D  are explanatory views illustrating the retainer when the distance is increased by receiving the force from the bulge portion. 
         FIGS.  15 A and  15 B  are explanatory views illustrating a configuration of the checker. 
         FIGS.  16 A and  16 B  are explanatory views illustrating the connector when the first pipe is inserted into the insertion hole and the bulge portion is not yet in contact with the first leg portion and the second leg portion. 
         FIGS.  17 A and  17 B  are explanatory views illustrating the connector when the bulge portion applies a force to the retainer to increase the distance. 
         FIGS.  18 A and  18 B  are explanatory views illustrating the connector coupled to the first pipe. 
         FIGS.  19 A and  19 B  are explanatory views illustrating a state of the connector when the checker is rotated. 
         FIGS.  20 A and  20 B  are explanatory views illustrating the checker when the bulge portion does not apply a force to the retainer.  FIGS.  20 C and  20 D  are explanatory views illustrating the checker when the bulge portion applies a force to the retainer to increase the width. 
     
    
    
     EXPLANATION OF REFERENCE NUMERALS 
       1  . . . connector,  3  . . . connector body,  5  . . . retainer,  6  . . . checker,  7  . . . first pipe,  9  . . . tip end,  11  . . . bulge portion,  13  . . . tip end portion,  15  . . . large-diameter portion,  17  . . . medium-diameter portion,  19  . . . small-diameter portion,  21  . . . projection,  23  . . . through hole,  25 ,  27  . . . step portion,  29  . . . insertion hole,  31  . . . first opening portion,  33  . . . second opening portion,  35 ,  39 ,  43 ,  47  . . . end portion,  37 ,  41 ,  45 ,  49  . . . oblique portion,  50  . . . O-ring,  51 ,  53  . . . projection portion,  52  . . . bush,  55  . . . first leg portion,  55 A . . . first connection portion,  57  . . . second leg portion,  57 A . . . second connection portion,  59  . . . intermediate portion,  61  . . . elastic deformation portion,  71  . . . ring split portion,  73  . . . body portion,  75  . . . cover portion,  77 ,  79  . . . groove,  81 ,  83  . . . side surface,  82 ,  84  . . . end surface,  91 ,  93  . . . first guide surface,  95 ,  97  . . . second guide surface,  101 ,  103  . . . first regulation surface,  105 ,  107  . . . second regulation surface 
     MODE FOR CARRYING OUT THE INVENTION 
     Illustrative embodiments of the present disclosure will be described with reference to the drawings. 
     1. Configuration of Connector  1   
     (1-1) Overall Configuration of Connector  1   
     As illustrated in  FIGS.  1  to  8   , a connector  1  includes a connector body  3  and a retainer  5 . The connector  1  further includes a checker  6  illustrated in  FIG.  15   . The connector  1  is coupled to a first pipe  7  illustrated in  FIG.  10   . The connector  1  is coupled to a second pipe not illustrated. The second pipe is, for example, a resin tube. 
     Hereinafter, the leftward direction in  FIG.  1    is the axial backward direction B, and the rightward direction in  FIG.  1    is the axial forward direction F. The direction toward the viewer in  FIG.  1    is the upward direction U, and the direction opposite to the direction toward the viewer in  FIG.  1    is the downward direction D. The downward direction in.  FIG.  1    is the leftward direction L, and the upward direction in  FIG.  1    is the rightward direction R. 
     (1-2) Configuration of First Pipe  7   
     The configuration of the first pipe  7  will be described with reference to  FIG.  10   . The first pipe  7  has a hollow cylindrical basic form. The first pipe  7  is open at a tip end  9 . The first pipe  7  is also open at an end portion on an opposite side to the tip end  9 . 
     The first pipe  7  includes a bulge portion  11  at a position distanced in the axial forward direction F from the tip end  9 . The description of the direction of the first pipe  7  indicates a direction when the first pipe  7  is coupled to the connector  1 . 
     An outer diameter of the bulge portion  11  is d1. The outer diameter of the first pipe  7  is constant at a place other than the bulge portion  11 . An outer diameter at a place other than the bulge portion  11  is d2. d1 is larger than d2. A portion of the first pipe  7  on the side of the tip end  9  relative to the bulge portion  11  is a tip end portion  13 . An outer diameter of the tip end portion  13  is d2. 
     (1-3) Configuration of Connector Body  3   
     The configuration of the connector body  3  will be described with reference to  FIGS.  1  to  8   . The connector body  3  has a hollow cylindrical basic form. The connector body  3  includes a large-diameter portion  15 , a medium-diameter portion  17 , and a small-diameter portion  19 . The large-diameter portion  15  is positioned in the connector body  3  on the side of the axial forward direction F. The large-diameter portion  15  has an outer diameter larger than those of the medium-diameter portion  17  and the small-diameter portion  19 . 
     The small-diameter portion  19  is positioned in the connector body  3  on the side of the axial backward direction B. The small-diameter portion  19  has an outer diameter smaller than those of the large-diameter portion  15  and the medium-diameter portion  17 . A plurality of annular projections  21  are formed on the outer peripheral surface of the small-diameter portion  19 . When the small-diameter portion  19  is inserted inside the second pipe, the second pipe is coupled to the connector  1 . Since the projection  21  bites into an inner peripheral surface of the second pipe, the second pipe hardly disengages from the small-diameter portion  19 . The medium-diameter portion  17  is at a position interposed between the large-diameter portion  15  and the small-diameter portion  19 . 
     As illustrated in  FIGS.  5  to  8   , the, connector body  3  includes a through hole  23  inside thereof. The through hole  23  extends parallel to the axial backward direction B and the axial forward direction F and penetrates the connector body  3 . 
     As illustrated in  FIG.  8   , step portions  25  and  27  are formed on the inner peripheral surface of the connector body  3 . The step portion  25  is formed in the medium-diameter portion  17 . The step portion  27  is formed in the large-diameter portion  15  on the side of the axial backward direction B. The diameter of the through hole  23  is the largest on the side of the axial forward direction F relative to the step portion  27 . A portion of the through hole  23  on the side of the axial forward direction F relative to the step portion  27  is an insertion hole  29 . The diameter of the insertion hole  29  is slightly larger than d1. 
     The diameter of the through hole  23  is the smallest on the side of the axial backward direction B relative to the step portion  25  and is smaller than d2. The diameter of the through hole  23  is slightly larger than d2 and smaller than d1 in a portion between the step portion  25  and the step portion  27 . 
     As illustrated in  FIGS.  1  to  4  and  8   , the connector body  3  includes a first opening portion  31  and a second opening portion  33 . The first opening portion  31  is a groove formed on the large-diameter portion  15  on the side of the axial forward direction F and on the side of the rightward direction R. The width of the groove is slightly larger than the diameter of a first leg portion  55  described later. The first opening portion  31  communicates from the outer peripheral surface of the large-diameter portion  15  to the insertion hole  29 . 
     The first opening portion  31  basically extends along the circumferential direction of the large-diameter portion  15 . However, as illustrated in  FIGS.  1  and  4   , the first opening portion  31  includes an oblique portion  37  near an end portion  35  on the side of the upward direction U. The direction away from the end portion  35  along the oblique portion  37  is a direction having a component of the axial backward direction B, a component of the rightward direction R, and a component of the downward direction D. 
     As illustrated in  FIGS.  3  and  4   , the first opening portion  31  includes an oblique portion  41  near an end portion  39  on the side of the downward direction D. The direction away from the end portion  39  along the oblique portion  41  is a direction having a component of the axial backward direction B, a component of the rightward direction R, and a component of the upward direction U. 
     The second opening portion  33  is a groove formed on the large-diameter portion  15  on the side of the axial forward direction F and on the side of the leftward direction L. The width of the groove is slightly larger than the diameter of a second leg portion  57  described later. The second opening portion  33  communicates from the outer peripheral surface of the large-diameter portion  15  to the insertion hole  29 . The second opening portion  33  opposes the first opening portion  31  across the center of the insertion hole  29 . 
     The second opening portion  33  basically extends along the circumferential direction of the large-diameter portion  15 . However, as illustrated in  FIGS.  1  and  2   , the second opening portion  33  includes an oblique portion  45  near an end portion  43  on the side of the upward direction U. The direction away from the end portion  43  along the oblique portion  45  is a direction having a component of the axial backward direction B, a component of the leftward direction L, and a component of the downward direction D. 
     As illustrated in  FIGS.  2  and  3   , the second opening portion  33  includes an oblique portion  49  near an end portion  47  on the side of the downward direction D. The direction away from the end portion  47  along the oblique portion  49  is a direction having a component of the axial backward direction B, a component of the leftward direction L, and a component of the upward direction U. 
     As illustrated in  FIGS.  1 ,  2 , and  4   , the connector body  3  includes projection portions  51  and  53 . The projection portions  51  and  53  are formed on a portion of the outer peripheral surface of the large-diameter portion  15  on the side of the upward direction U. The projection portions  51  and  53  protrude radially outward of the large-diameter portion  15  from the periphery thereof. The projection portions  51  and  53  are arranged at distances along the circumferential direction of the large-diameter portion  15 . 
     As illustrated in  FIG.  8   , an O-ring  50  and a bush  52  are internally inserted into the insertion hole  29 . The O-ring  50  is positioned on the insertion hole  29  on the side of the axial backward direction B. The bush  52  is positioned on the side of the axial forward direction F relative to the O-ring  50 . 
     The first pipe  7  is inserted into the insertion hole  29  with the tip end  9  as a head, and is coupled to the connector  1 . As illustrated in  FIG.  8   , when the first pipe  7  is coupled to the connector  1 , the tip end  9  reaches near the step portion  25 . The bulge portion  11  abuts on the side surface of the bush  52  from the side of the axial forward direction F. The tip end portion  13  is internally inserted into the O-ring  50  and the bush  52 . The bulge portion  11  is positioned slightly on the side of the axial backward direction B relative to the first opening portion  31  and the second opening portion  33 . 
     (1-4) Configuration of Retainer  5   
     The configuration of the retainer  5  will be described with reference to  FIG.  9   . The retainer  5  is comprised of, for example, a wire material such as metal. The retainer  5  is made of an elastically deformable material. The retainer  5  includes the first leg portion  55 , the second leg portion  57 , and an intermediate portion  59 . 
     Each of the first leg portion  55  and the second leg portion  57  extends in the downward direction D and has a shape bent inward near the lower end. 
     The intermediate portion  59  is a portion that connects a first connection portion  55 A of the first leg portion  55  and a second connection portion  57 A of the second leg portion  57 . The first connection portion  55 A is an upper end of the first leg portion  55 . The second connection portion  57 A is an upper end of the second leg portion  57 . 
     The intermediate portion  59  includes an elastic deformation portion  61  bent in a U shape. The elastic deformation portion  61  can be elastically deformed such that a width W thereof changes. More specifically, the elastic deformation portion  61  can be elastically deformed (hereinafter referred to as elastic deformation in an open manner) such that an opening in the U shape widens, for example. When the elastic deformation in the open manner occurs, a distance D between the first connection portion  55 A and the second connection portion  57 A in the rightward direction R and the leftward direction L is enlarged. When the elastic deformation in the open manner occurs, the width W becomes larger than that before the elastic deformation in the open manner occurs. When the elastic deformation in the open manner occurs, the width W becomes relatively narrower in the elastic deformation portion  61  as the measurement position of the width W goes in the axial backward direction B. 
     A state where the retainer  5  is attached to the connector body  3  and the first pipe  7  is coupled to the connector  1  is as illustrated in  FIGS.  1  to  8   . The state of the retainer  5  at this time is assumed to be a basic state hereinafter. In addition to the basic state, the state of the retainer  5  includes an expanded state described later. 
     The first leg portion  55  is inserted into the first opening portion  31 . As illustrated in  FIGS.  1 ,  3 , and  4   , the first leg portion  55  deeply enters the first opening portion  31  to come into contact with the end portion  35  and the end portion  39 . As illustrated in  FIGS.  5  and  8   , the first leg portion  55  has advanced in the center direction of the insertion hole  29 . The first leg portion  55  is at a position overlapping the bulge portion  11  when viewed from the side of the axial forward direction F. The first leg portion  55  is present on the side of the axial forward direction F relative to the bulge portion  11 . The first leg portion  55  abuts against a portion of the outer peripheral surface of the first pipe  7  on the side of the axial forward direction F relative to the bulge portion  11 . The side of the axial forward direction F relative to the bulge portion  11  corresponds to the front side relative to the bulge portion  11 . The first leg portion  55  regulates disengagement of the first pipe  7  coupled to the connector  1 . 
     The second leg portion  57  is inserted into the second opening portion  33 . As illustrated in  FIGS.  1 ,  2 , and  3   , the second leg portion  57  deeply enters the second opening portion  33  to come into contact with the end portion  43  and the end portion  47 . As illustrated in  FIGS.  5  and  8   , the second leg portion  57  has advanced in the center direction of the insertion hole  29 . The second leg portion  57  is at a position overlapping the bulge portion  11  when viewed from the side of the axial forward direction F. The second leg portion  57  is present on the side of the axial forward direction F relative to the bulge portion  11 . The second leg portion  57  abuts against a portion of the outer peripheral surface of the first pipe  7  on the side of the axial forward direction F relative to the bulge portion  11 . The second leg portion  57  regulates disengagement of the first pipe  7  coupled to the connector  1 . 
     As illustrated in  FIGS.  1 ,  6 , and  7   , the intermediate portion  59  is in contact with a portion of the outer peripheral surface of the large-diameter portion  15  on the side of the upward direction U. The elastic deformation portion  61  is positioned between the projection portions  51  and  53 . The orientation of the elastic deformation portion  61  is an orientation where the apex of the U shape is on the side of the axial backward direction B. When the retainer  5  is in the basic state, the width W and the distance D are smaller than those when the retainer  5  is in the expanded state. 
     (1-5) Configuration of Checker  6   
     The configuration of the checker  6  will be described with reference to  FIG.  15   . The checker  6  has an annular basic form. More specifically, the checker  6  has a C shape form having a ring split portion  71  when viewed in an axial direction of the ring. The checker  6  is externally inserted to the large-diameter portion  15 . The large-diameter portion  15  is inserted into the checker  6 . The checker  6  can be elastically deformed to enlarge the ring split portion  71 . 
     The checker  6  includes a body portion  73  and a cover portion  75 . The body portion  73  is a portion that abuts on the outer peripheral surface of the large-diameter portion  15 . The cover portion  75  is a portion extending in the axial forward direction F from the outer peripheral side of the body portion  73 . There is a gap between the outer peripheral surface of the large-diameter portion  15  and the cover portion  75 . 
     Grooves  77  and  79  are formed on the inner peripheral surface of the body portion  73 . The grooves  77  and  79  are formed in the body portion  73  from an end portion on the side of the axial backward direction B to an end portion on the side of the axial forward direction F. The grooves  77  and  79  are disposed so as to sandwich the ring split portion  71 . 
     Of the side surfaces of the groove  77 , a side surface  81  farther from the ring split portion  71  is inclined such that a point on the side surface  81  approaches an end surface  82  as the point is directed in the axial backward direction B. The end surface  82  is an end surface of the body portion  73  facing the ring split portion  71 . Of the side surfaces of the groove  79 , a side surface  83  farther from the ring split portion  71  is inclined such that a point on the side surface  83  approaches an end surface  84  as the point is directed in the axial backward direction B. The end surface  84  is an end surface of the body portion  73  facing the ring split portion  71 . 
     2. Operation of Retainer  5   
     The operation of the retainer  5  when the first pipe  7  is coupled to the connector  1  will be described with reference to  FIGS.  11  to  14   . In  FIGS.  11  to  13   , description of the checker  6  will be omitted for convenience of description. 
     The state illustrated in  FIGS.  11 A and  11 B  is a state where the first pipe  7  is inserted into the insertion hole  29 , and the bulge portion  11  is not yet in contact with the first leg portion  55  and the second leg portion  57 . At this time, the state of the retainer  5  is the basic state. In the state illustrated in  FIGS.  11 A and  11 B , as illustrated in  FIG.  14 A , no elastic deformation in the open manner occurs in the elastic deformation portion  61 , and the width W is small. As illustrated in  FIG.  14 B , the distance D is small. 
     When the first pipe  7  is inserted deeper from the state illustrated in  FIGS.  11 A and  11 B , the bulge portion  11  applies a force in the axial backward direction B to the first leg portion  55  and the second leg portion  57 . The axial backward direction B corresponds to the insertion direction. 
     The first leg portion  55  is pressed against a first guide surface  91  illustrated in  FIG.  1   . The first guide surface  91  is an end surface of the large-diameter portion  15  facing the oblique portion  37  and is an end surface on the side of the axial backward direction B. The first leg portion  55  is pressed against a first guide surface  93  illustrated in  FIG.  3   . The first guide surface  93  is an end surface of the large-diameter portion  15  facing the oblique portion  41  and is an end surface on the side of the axial backward direction B. The first guide surfaces  91  and  93  are inclined such that points on the first guide surfaces  91  and  93  are directed in the rightward direction R as the points are directed in the axial backward direction B. Therefore, as illustrated in  FIG.  12 A , the first leg portion  55  is guided by the first guide surfaces  91  and  93  and moves in the rightward direction R. 
     The second leg portion  57  is pressed against a second guide surface  95  illustrated in  FIG.  1   . The second guide surface  95  is an end surface of the large-diameter portion  15  facing the oblique portion  45  and is an end surface on the side of the axial backward direction B. The second leg portion  57  is pressed against a second guide surface  97  illustrated in  FIG.  3   . The second guide surface  97  is an end surface of the large-diameter portion  15  facing the oblique portion  49  and is an end surface on the side of the axial backward direction B. The second guide surfaces  95  and  97  are inclined such that the points on the second guide surfaces  95  and  97  are directed in the leftward direction L as the points are directed in the axial backward direction B. Therefore, as illustrated in  FIG.  12 A , the second leg portion  57  is guided by the second guide surfaces  95  and  97  and moves in the leftward direction L. 
     When the first leg portion  55  moves in the rightward direction R and the second leg portion  57  moves in the leftward direction L, as illustrated in  FIGS.  12 A and  14 C , elastic deformation in the open manner occurs in the elastic deformation portion  61 , and the width W increases. As a result, as illustrated in  FIGS.  12 B and  14 D , the distance D is widened. 
     Since the distance D is widened, the distance between the first leg portion  55  and the second leg portion  57  becomes a distance that permits passage of the bulge portion  11 . The state of the retainer  5  at this time is the expanded state. The bulge portion  11  passes through between the first leg portion  55  and the second leg portion  57  and advances in the axial backward direction B relative to the first leg portion  55  and the second leg portion  57 . 
     When the bulge portion  11  advances in the axial backward direction B relative to the first leg portion  55  and the second leg portion  57 , the bulge portion  11  no longer applies a force to the first leg portion  55  and the second leg portion  57 , and therefore, the first leg portion  55  and the second leg portion  57  return to the state illustrated in  FIGS.  14 A and  14 B  by a restoring force generated by elastic deformation. That is, the state of the retainer  5  returns to the basic state. The states of the connector  1  and the first pipe  7  at this time are illustrated in  FIGS.  13 A and  13 B . 
     As illustrated in  FIG.  13 A , the first leg portion  55  and the second leg portion  57  are on the side of the axial forward direction F relative to the bulge portion  11 . As illustrated in  FIG.  13 B , the first leg portion  55  and the second leg portion  57  are at positions overlapping the bulge portion  11  when viewed from the side of the axial forward direction F. Therefore, the first leg portion  55  and the second leg portion  57  regulate disengagement of the first pipe  7 . As a result of the above process, the first pipe  7  is coupled to the connector  1 . 
     When a force in the axial forward direction F is applied to the coupled first pipe  7 , the bulge portion  11  presses the first leg portion  55  against a first regulation surface  101  illustrated in  FIG.  1    and a first regulation surface  103  illustrated in  FIG.  3   . The axial forward direction F corresponds to a disengagement direction. The first regulation surface  101  is an end surface of the large-diameter portion  15  facing the oblique portion  37  and is an end surface on the side of the axial forward direction F. The first regulation surface  103  is an end surface of the large-diameter portion  15  facing the oblique portion  41  and is an end surface on the side of the axial forward direction F. 
     The first regulation surfaces  101  and  103  are inclined such that points on the first regulation surfaces  101  and  103  are directed in the rightward direction R as the points are directed in the axial backward direction B. Therefore, even if a force in the axial forward direction F is applied to the first leg portion  55  and the first leg portion  55  is pressed against the first regulation surfaces  101  and  103 , the first leg portion  55  is not guided in the rightward direction R. That is, even if a force in the axial forward direction F is applied to the first pipe  7 , the first leg portion  55  is not guided in a direction where the distance D is widened. 
     When a force in the axial forward direction F is applied to the coupled first pipe  7 , the bulge portion  11  presses the second leg portion  57  against a second regulation surface  105  illustrated in  FIG.  1    and a second regulation surface  107  illustrated in  FIG.  3   . The second regulation surface  105  is an end surface of the large-diameter portion  15  facing the oblique portion  45  and is an end surface on the side of the axial forward direction F. The second regulation surface  107  is an end surface of the large-diameter portion  15  facing the oblique portion  49  and is an end surface on the side of the axial forward direction F. 
     The second regulation surfaces  105  and  107  are inclined such that points on the second regulation surfaces  105  and  107  are directed in the leftward direction L as the points are directed in the axial backward direction B. Therefore, even if a force in the axial forward direction F is applied to the second leg portion  57  and the second leg portion  57  is pressed against the second regulation surfaces  105  and  107 , the second leg portion  57  is not guided in the leftward direction L. That is, even if a force in the axial forward direction F is applied to the first pipe  7 , the second leg portion  57  is not guided in a direction where the distance D is widened. 
     Therefore, even if a force in the axial forward direction F is applied to the coupled first pipe  7 , the distance D is not widened, and the bulge portion  11  cannot pass through between the first leg portion  55  and the second leg portion  57 , so that the first pipe  7  does not disengage from the connector  1 . 
     3. Operation of Checker  6   
     The operation of the checker  6  when the first pipe  7  is coupled and when the first pipe  7  is to be removed will be described with reference to  FIGS.  16  to  20   . 
     The state illustrated in  FIGS.  16 A and  16 B  is a state where the first pipe  7  is inserted into the insertion hole  29 , and the bulge portion  11  is not yet in contact with the first leg portion  55  and the second leg portion  57 . At this time, the state of the retainer  5  is the basic state. 
     The checker  6  is externally inserted to the large-diameter portion  15  in a portion on the side of the axial forward direction F. The cover portion  75  is on the side of the axial forward direction F relative to the body portion  73 . The elastic deformation portion  61  is inserted into the ring split portion  71 . Since no elastic deformation in the open manner occurs in the elastic deformation portion  61 , the ring split portion  71  is not expanded as illustrated in  FIGS.  16 A,  16 B,  20 A, and  20 B . 
     The positions of the projection portions  51  and  53  in the circumferential direction of the large-diameter portion  15  are shifted from the positions of the grooves  77  and  79 . Even if a force in the axial backward direction B is applied to the checker  6 , the projection portions  51  and  53  are brought into contact with the body portion  73 , so that the checker  6  cannot move in the axial backward direction B. The projection portions  51  and  53  and the grooves  77  and  79  correspond to movement regulation portions. 
     When the first pipe  7  is further deeply inserted from the state illustrated in  FIGS.  16 A and  16 B , the state becomes the state illustrated in  FIGS.  17 A and  17 B . The elastic deformation portion  61  has an expansion deformation and the width W increases. As a result, as illustrated in  FIGS.  17 A,  17 B,  20 C, and  20 D , the checker  6  is elastically deformed such that the ring split portion  71  is enlarged. 
     The end surfaces  82  and  84  facing the ring split portion  71  are pressed against the elastic deformation portion  61  by the restoring force generated by elastic deformation, and receive a reaction force from the elastic deformation portion  61 . As illustrated in  FIG.  17 A , since the elastic deformation portion  61  has a shape in which the width W is narrower as the measurement position of the width W is directed to the axial backward direction B, the reaction force includes a component of the axial backward direction B. As a result, the checker  6  is biased in the axial backward direction B. The axial backward direction B corresponds to the axial direction of the insertion hole  29 . 
     In the state illustrated in  FIGS.  17 A and  17 B , the positions of the projection portions  51  and  53  in the circumferential direction of the large-diameter portion  15  coincide with the positions of the grooves  77  and  79 . Therefore, the checker  6  biased in the axial backward direction B can move in the axial backward direction B. When the checker  6  moves, the projection portions  51  and  53  pass through in the grooves  77  and  79 . 
     When the projection portions  51  and  53  pass through in the grooves  77  and  79 , the side surfaces  81  and  83  are pressed against the projection portions  51  and  53 , and receive the reaction force from the projection portions  51  and  53 . Since the side surfaces  81  and  83  are inclined as described above, the reaction force includes a component of the axial backward direction B. As a result, the checker  6  is more strongly biased in the axial backward direction B. 
       FIGS.  18 A and  18 B  illustrate a state where coupling of the first pipe  7  is completed. The checker  6  is moved in the axial backward direction B compared to that before the first pipe  7  is coupled. The retainer  5  returns to the basic state, and the width W has become small. Therefore, the ring split portion  71  has been reduced. Since the ring split portion  71  is reduced, the positions of the projection portions  51  and  53  in the circumferential direction of the large-diameter portion  15  are shifted from the positions of the grooves  77  and  79 . As a result, even if a force in the axial forward direction F is applied to the checker  6 , the checker  6  does not move. 
       FIGS.  19 A and  19 B  illustrate a state where the checker  6  is rotated in the circumferential direction of the large-diameter portion  15  in a state where the first pipe  7  is coupled to the connector  1 . Since the elastic deformation portion  61  is inserted into the ring split portion  71 , the retainer  5  rotates together with the checker  6 . At this time, as illustrated in  FIG.  19 B , the distance between the first leg portion  55  and the second leg portion  57  becomes wider than the bulge portion  11 . As a result, it becomes possible to remove the first pipe  7  from the connector  1 . 
     4. Effects Achieved by Connector  1   
     (1A) When the first pipe  7  is inserted into the insertion hole  29 , the retainer  5  is elastically deformed in the open manner so that the distance D is widened. Therefore, the connector  1  can suppress the first leg portion  55  from rotating outward about the first connection portion  55 A. The connector  1  can suppress the second leg portion  57  from rotating outward about the second connection portion  57 A. Therefore, the connector  1  can suppress the retainer  5  from largely protruding outward when the first pipe  7  is inserted into the insertion hole  29 . As a result, the connector  1  can reduce the gap around the retainer  5 . 
     (1B) When a force in the axial forward direction F is applied to the first pipe  7  coupled to the connector  1 , the first regulation surfaces  101  and  103  and the second regulation surfaces  105  and  107  do not guide the first leg portion  55  and the second leg portion  57  in a direction where the distance D is widened. Therefore, even if a force in the axial forward direction F is applied to the first pipe  7  coupled to the connector  1 , the first pipe  7  hardly disengages from the connector  1 . 
     (1C) The connector  1  includes the checker  6 . The position of the checker  6  is different between before and after the first pipe  7  is coupled to the connector  1 . Therefore, the user can see whether or not the first pipe  7  is coupled to the connector  1  by looking at the position of the checker  6 . The user can easily remove the first pipe  7  from the connector  1  by rotating the checker  6 . 
     Other Embodiments 
     Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and can be carried out in various modifications. 
     (1) A function of one component in each of the above embodiments may be shared by a plurality of components, or a function of a plurality of components may be exerted by one component. A part of the configuration of each of the above embodiments may be omitted. At least a part of the configuration of each of the above embodiments may be added to, replaced with, or the like with respect to the configuration of another of the above embodiments. 
     (2) In addition to the connector  1  described above, the present disclosure can be achieved in various forms such as a system with the connector  1  as a component and a manufacturing method of the connector  1 .