Patent Publication Number: US-2022231462-A1

Title: Connector

Description:
TECHNICAL FIELD 
     The present disclosure relates to a connector. 
     BACKGROUND ART 
     For example, a connector for sending high frequency signals that is used in a vehicle is disclosed in Japanese Unexamined Patent Application Publication No. 2005-317267. The connector includes a female connector and a male connector. The female connector includes an outer conductor that receives an inner conductor via a derivative. The inner conductor is connected to a coaxial cable. The male connector includes an electrical grounding member that receives a core wire terminal via a male-side derivative. The core wire terminal is to be connected to a board. 
     According to the coupling of the female connector and the male connector of the connector, the derivative of the female connector and the derivative of the male connector are opposite each other in the coupling direction and the core wire terminal that protrudes frontward from the derivative of the male connector is inserted in the derivative of the female connector. Thus, the core wire terminal and the inner conductor are connected. 
     RELATED ART DOCUMENT 
     Patent Document 
     [Patent Document 1]
     Japanese Unexamined Patent Application Publication No. 2005-317267   

     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     Generally, the characteristic impedance is set to a predefined value to perform impedance matching in a transmission line for transmitting high frequency signals. Therefore, the impedance matching is performed between the coaxial cable, the inner conductor, and the core wire terminal of the connector. However, in the above connector, a gap may be created between the derivative of the female connector and the derivative of the male connector when the female connector and the male connector are coupled together. If so, no derivative is between the core wire terminal and the electrically grounding member in the gap between the derivatives, and the relative permittivity in the gap is changed and the impedance in the gap becomes high. This may cause impedance mismatching in the gap and reflection of transmission signals are caused and this may lower transmission efficiency. 
     The technology of suppressing impedance change is disclosed herein. 
     Means for Solving the Problem 
     A connector described herein includes a female terminal module and a male terminal module that is to be coupled to the female terminal module. The female terminal module includes a female-side inner conductor that is electrically conductive, a female-side derivative that has insulating properties, and a female-side outer conductor that is electrically conductive. The female-side outer conductor receives therein the female-side inner conductor via the female-side derivative. The male terminal module includes a male-side inner conductor that is electrically conductive, a male-side derivative that has insulating properties, and a male-side outer conductor that is electrically conductive. The male-side outer conductor receives therein the male-side inner conductor via the male-side derivative and is connected to the female-side outer conductor when the female terminal module and the male terminal module are coupled together. The female-side derivative includes a female-side fitting portion. The male-side derivative includes a male-side fitting portion. When the female terminal module and the male terminal module are coupled together in a coupling direction, the female-side fitting portion and the male-side fitting portion are fitted to each other in the coupling direction with recess-protrusion fitting. The male-side inner conductor includes a male connection portion. The male connection portion extends further than the male-side fitting portion toward the female terminal module. When the female terminal module and the male terminal module are coupled together, the male connection portion is inserted in the female-side fitting portion and connected to the female-side inner conductor. 
     Advantageous Effects of Invention 
     According to the present disclosure, impedance change is suppressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a connector according to one embodiment. 
         FIG. 2  is a cross-sectional view of the connector taken along line A-A in  FIG. 1 . 
         FIG. 3  is an enlarged cross-sectional view of a portion of  FIG. 2 . 
         FIG. 4  is a perspective view of a male terminal module. 
         FIG. 5  is a perspective view of a male-side front derivative. 
         FIG. 6  is a front view of the male-side front derivative. 
         FIG. 7  is a side view of the male-side front derivative. 
         FIG. 8  is a perspective view illustrating a male-side inner conductor that is connected to a cable core wire. 
         FIG. 9  is a perspective view of a female terminal module. 
         FIG. 10  is a perspective view of a female-side front derivative. 
         FIG. 11  is a front view of the female-side front derivative. 
         FIG. 12  is a side view of the female-side front derivative. 
         FIG. 13  is a perspective view illustrating a female-side inner conductor that is connected to a cable core wire. 
         FIG. 14  is an enlarged cross-sectional view of a portion of a connector according to another embodiment corresponding to  FIG. 3 . 
         FIG. 15  is an enlarged cross-sectional view of a portion of a connector according to a prior art corresponding to  FIG. 3 . 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     Description of Embodiments According to the Present Disclosure 
     First, embodiments according to the present disclosure will be listed and described. 
     (1) A connector includes a female terminal module and a male terminal module that is to be coupled to the female terminal module. The female terminal module includes a female-side inner conductor that is electrically conductive, a female-side derivative that has insulating properties, and a female-side outer conductor that is electrically conductive. The female-side outer conductor receives therein the female-side inner conductor via the female-side derivative. The male terminal module includes a male-side inner conductor that is electrically conductive, a male-side derivative that has insulating properties, and a male-side outer conductor that is electrically conductive. The male-side outer conductor receives therein the male-side inner conductor via the male-side derivative and is connected to the female-side outer conductor when the female terminal module and the male terminal module are coupled together. The female-side derivative includes a female-side fitting portion. The male-side derivative includes a male-side fitting portion. When the female terminal module and the male terminal module are coupled together in a coupling direction, the female-side fitting portion and the male-side fitting portion are fitted to each other in the coupling direction with recess-protrusion fitting. The male-side inner conductor includes a male connection portion. The male connection portion extends further than the male-side fitting portion toward the female terminal module. When the female terminal module and the male terminal module are coupled together, the male connection portion is inserted in the female-side fitting portion and connected to the female-side inner conductor. 
     When the male connection portion protruding from the male-side fitting portion is inserted in the female-side fitting portion and connected to the female-side inner conductor after the coupling of the female terminal module and the male terminal module, the female-side fitting portion and the male-side fitting portion are fitted to each other in the coupling direction with the recess-protrusion fitting. Therefore, at least the male-side fitting portion or the female-side fitting portion is disposed around the male connection portion. 
     Accordingly, the relative permittivity is less likely to be changed in the male connection portion and this keeps the impedance change to be small. Therefore, the reflection loss of high frequency signals can be made small and the transmission efficiency is less likely to be lowered. 
     (2) One fitting portion out of the female-side fitting portion and the male-side fitting portion is a protrusion member and includes a first tapered surface and other fitting portion out of the female-side fitting portion and the male-side fitting portion is a recessed member and includes a second tapered surface. The first tapered surface is sloped to be closer to an axis of the male connection portion as it extends closer to the other fitting portion. The second tapered surface is sloped to be closer to the axis of the male connection portion as it extends farther away from the one fitting portion and the second tapered surface extends along the first tapered surface. 
     Generally, a space is provided between a distal end of the male-side fitting portion and a distal end of the female-side fitting portion in a portion where the male connection portion is inserted into the female-side fitting portion. This prevents the male-side fitting portion from abutting on the female-side fitting portion in the coupling direction and the fitting of the fitting portions is not failed. 
     For example, if one fitting portion out of the male-side fitting portion and the female-side fitting portion has a circular columnar shape and other fitting portion out of the fitting portions includes a circular columnar recess, a space that is created around the outer periphery of the male connection near a recessed bottom of the recess has a diameter that is same as an inner diameter of the recess. Therefore, the impedance change tends to be great in the male connection. 
     However, according to the above configuration, the one fitting portion is the protrusion member including the first tapered surface and the other fitting portion is the recessed member including the second tapered surface. 
     Namely, the other fitting portion, which is the recessed member, has an inner space that becomes smaller as it is closer to the recessed bottom. This reduces the space around the outer periphery of the male connection portion near the recessed bottom of the other fitting portion. Accordingly, the impedance change in the male connection portion can be made much smaller and the reflection loss of high frequency signals in the male connection portion can be further decreased. Even if a first tapered surface and a second tapered surface are not completely contacted with each other, a space between the first tapered surface and the second tapered surface can be uniform and a local change of the impedance is less likely to be caused. 
     (3) The first tapered surface is formed in a conical shape that is tapered toward a distal end and the second tapered surface is formed in a conical shape whose diameter is reduced as it extends closer to a recessed bottom of the recessed member. 
     The other fitting portion, which is the recessed member, has a smaller space around the male connection portion and near the recessed bottom due to the second tapered surface. Therefore, the space between the male-side fitting portion and the female-side fitting portion can be made smaller compared to a configuration including a second tapered surface in a portion of the other fitting portion. Accordingly, the impedance change can be made much smaller and the reflection loss of high frequency signals can be further decreased. 
     (4) The first tapered surface and the second tapered surface are closely contacted with each other when the female terminal module and the male terminal module are coupled together. 
     The close contact between the first tapered surface and the second tapered surface further makes the space between the female-side fitting portion and the male-side fitting portion smaller. Accordingly, the impedance change can be made much smaller and the reflection loss of high frequency signals can be further reduced. 
     (5) The connector further includes a female housing in which the female terminal module is arranged, and a male housing in which the male terminal module is arranged and that can be coupled to the female housing. 
     Detail of Embodiment According to the Present Disclosure 
     Embodiments of the connector according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments. All modifications within and equivalent to the technical scope of the claimed invention may be included in the technical scope of the present disclosure. 
     First Embodiment 
     A first embodiment according to the present disclosure will be described with reference to  FIGS. 1 to 13 . 
     A connector  10  according to this embodiment is for connecting electric devices installed in a vehicle and transmitting high frequency electric signals. 
     [Connector  10 ] 
     As illustrated in  FIGS. 1 and 2 , the connector  10  includes a male connector  20  and a female connector  60 . The male connector  20  is to be connected to an end of a shielded electric wire W. The female connector  60  is to be connected to an end of a shielded electric wire W and coupled to the male connector  20 . In the following description, as to a front-rear direction, a front side is defined with reference to a coupling direction in which corresponding one of the male connector  20  and the female connector  60  is coupled to other one. 
     [Shielded Electric Wire W] 
     As illustrated in  FIG. 2 , the shielded electric wire W is a coaxial cable that includes a cable core wire W 1 , a braided member W 2 , and an outer cover W 3 . The outer periphery of the cable core wire W 1  is covered with the braided member W 2  and the outer periphery of the braided member W 2  is covered with the outer cover W 3 . The braided member W 2  and the outer cover W 3  are removed from the shielded electric wire W in the front end portion thereof and the insulation member is also removed and the cable core wire W 1  is exposed. Only the outer cover W 3  is removed from the shielded electric wire W in the portion behind the exposed cable core wire W 1  and the braided member W 2  is exposed. 
     [Male Connector  20 ] 
     As illustrated in  FIGS. 1 and 2 , the male connector  20  includes a male housing  21  and a male terminal module  30 . 
     [Male Housing  21 ] 
     The male housing  21  is a tubular member that is made of insulating synthetic resin. The male housing  21  can receive the male terminal module  30  from a rear side. The male housing  21  includes a stopper, which is not illustrated, therein. When the male terminal module  30  reaches a correct position within the male housing  21 , the male terminal module stops at the stopper. Accordingly, the male terminal module  30  is held in the male housing  21  so as not to come out therefrom. 
     [Male Terminal Module  30 ] 
     As illustrated in  FIG. 2 , the male terminal module  30  includes a male-side inner conductor  31 , a male-side derivative  40 , and a male-side outer conductor  50 . 
     [Male-Side Inner Conductor  31 ] 
     The male-side inner conductor  31  is formed by processing an electric conductive metal plate. As illustrated in  FIGS. 2, 3, and 8 , the male-side inner conductor  31  includes a male connection portion  32  and an electric wire connection portion  33  that is behind the male connection portion  32 . 
     The male connection portion  32  has a pin shape that extends in the front-rear direction. The male connection portion  32  is connected to a female-side inner conductor  71  that is arranged in a female-side derivative  80  of the female connector  60 , which will be described later, when the male connector  20  and the female connector  60  are coupled together. 
     As illustrated in  FIG. 8 , the electric wire connection portion  33  is crimped on and fixed to the cable core wire W 1  that is exposed at a distal end of the shielded electric wire W. Thus, the male-side inner conductor  31  is electrically connected to the cable core wire W 1  of the shielded electric wire W. 
     [Male-Side Derivative  40 ] 
     As illustrated in  FIGS. 2 and 3 , the male-side derivative  40  is a tubular member that is made of insulating synthetic resin having predefined relative permittivity. 
     The male-side derivative  40  receives the exposed cable core wire W 1  and the male-side inner conductor  31  therein. The exposed cable core wire W 1  extends frontward from the insulator and the braided member W 2 . The male-side inner conductor  31  is connected to the exposed cable core wire W 1 . The male-side derivative  40  includes a male-side front derivative  41  and a male-side rear derivative  48  that is behind the male-side front derivative  41 . 
     As illustrated in  FIGS. 3 and 5 to 7 , the male-side front derivative  41  has a tubular shape that is elongated in the front-rear direction. The male-side front derivative  41  includes a male-side body portion  42  and a male-side fitting portion  44  that is continuous frontward from the male-side body portion  42 . 
     The male-side body portion  42  has a circular tube shape that extends in the front-rear direction. The male-side body portion  42  can receive the electric wire connection portion  33  of the male-side inner conductor  31  therein. 
     The male-side fitting portion  44  protrude frontward from a front end of the male-side body portion  42 . 
     The male connection portion  32  is inserted frontward through the male-side fitting portion  44  in the front-rear direction so as to protrude from the male-side fitting portion  44 . The male-side fitting portion  44  has a first tapered surface  45  and a distal end surface  46 . 
     The first tapered surface  45  is sloped to have a conical shape and sloped closer to an axis of the male-side fitting portion  44  as it extends frontward from the front end of the male-side body portion  42 . The first tapered surface  45  extends around an entire periphery of the male connection portion  32  to surround the male connection portion  32  when the male connection portion  32  is inserted through the male-side fitting portion  44 . 
     The distal end surface  46  is at the front end portion of the first tapered surface  45  and has a circular ring shape seen from the front such that the distal end surface  46  extends perpendicular to the axis of the male-side fitting portion  44 . When the male connection portion  32  is inserted through the male-side fitting portion  44 , the male connection portion  32  protrudes frontward from the distal end surface  46 . 
     As illustrated in  FIG. 2 , the male-side rear derivative  48  is fitted to the outer periphery of the cable core wire W 1  that is exposed and extends from the braided member W 2  in the shielded electric wire W. A male-side outer conductor  50 , which will be described later, is fitted to the outer periphery of the male-side rear derivative  48  and pressed such that the male-side rear derivative  48  is disposed around the outer periphery of the cable core wire W 1  and surrounds the entire periphery of the cable core wire W 1 . A space is provided between the cable core wire W 1  and the male-side rear derivative  48  for adjusting the impedance. 
     [Male-Side Outer Conductor  50 ] 
     The male-side outer conductor  50  is formed by processing an electric conductive metal plate. As illustrated in  FIGS. 2 and 4 , the male-side outer conductor  50  includes a male-side front outer conductor  51  and a male-side rear outer conductor  58  to which the male-side front outer conductor  51  is fitted from outside. 
     The male-side rear outer conductor  58  has a tubular shape and extends in the outer peripheral area ranging from the exposed braised member W 2  to the front end portion of the outer cover W 3  of the shielded electric wire W. The front portion of the male-side rear outer conductor  58  is crimped on and fixed to the braided member W 2  to be electrically connected to the braided member W 2 . The rear portion of the male-side rear outer conductor  58  is crimped and fixed to the outer cover W 3  and is fixed to the shielded electric wire W. 
     As illustrated in  FIG. 2 , the male-side front outer conductor  51  is a tubular member that has a diameter almost same as that of the male-side rear outer conductor  58 . The male-side front outer conductor  51  extends in the outer peripheral area ranging from the front end portion of the male-side rear outer conductor  58  to the middle section of the male-side inner conductor  31  in the front-rear direction. The rear end portion of the male-side front outer conductor  51  is a conductor crimp portion  54  of a barrel shape and the conductor crimp portion  54  is crimped on the front end portion of the male-side rear outer conductor  58 . The conductor crimp portion  54  is crimped on the male-side rear outer conductor  58  such that the male-side front outer conductor  51  and the male-side rear outer conductor  58  are integrally configured as the male-side outer conductor  50 . 
     The male-side front outer conductor  51  includes a middle crimp portion  55  in a middle section thereof with respect to the front-rear direction. The middle crimp portion is crimped on the outer periphery of the male-side rear derivative  48 . The middle crimp portion  55  has a small inner diameter so as not to overpressure the male-side rear derivative  48  (such that the space between the cable core wire W 1  and the male-side rear derivative  48  is not decreased) in the crimping on the male-side rear derivative  48 . 
     As illustrated in  FIGS. 2 and 3 , the front end portion of the male-side front outer conductor  51  is a connection tubular portion  56  that is a circular tube. The connection tubular portion  56  is disposed to surround the outer peripheries of the male-side front derivative  41  and the male connection portion  32  and receive therein the portion ranging from the rear end portion of the male-side front derivative  41  to the middle portion of the male connection portion  32  in the front-rear direction. 
     Therefore, as illustrated in  FIG. 2 , the male-side outer conductor  50  covers the portion ranging from the middle portion of the male connection portion  32  in the front-rear direction to the front end portion of the outer cover W 3  while being connected to the braided member W 2  of the shielded electric wire W. 
     [Female Connector  60 ] 
     As illustrated in  FIGS. 1 and 2 , the female connector  60  includes a female housing  61  and a female terminal module  70 . 
     [Female Housing  61 ] 
     The female housing  61  is a tubular member that is made of insulating synthetic resin. The female housing  61  can receive the female terminal module  70  from a rear side. The female housing  61  includes a stopper, which is not illustrated, therein. When the female terminal module  70  reaches a correct position within the female housing  61 , the female terminal module  70  stops at the stopper. Accordingly, the female terminal module  70  is held in the female housing  61  so as not to come out therefrom. 
     [Female Terminal Module  70 ] 
     As illustrated in  FIGS. 1 and 2 , the female terminal module  70  is coupled to the male terminal module  30  when the male connector  20  and the female connector  60  are coupled together. Therefore, the female terminal module  70  and the male terminal module  30  are configured as a portion of the connector  10 . As illustrated in  FIG. 2 , the female terminal module  70  includes a female-side inner conductor  71 , a female-side derivative  80 , and a female-side outer conductor  90 . 
     [Female-Side Inner Conductor  71 ] 
     The female-side inner conductor  71  is formed by processing an electric conductive metal plate. As illustrated in  FIGS. 2, 3, and 12 , the female-side inner conductor  71  includes an elastic connection portion  72  and an electric wire connection portion  73  that is behind the elastic connection portion  72 . 
     As illustrated in  FIGS. 9 and 13 , the elastic connection portion  72  includes two elastic pieces  72 A that are opposite each other. The elastic pieces  72 A are elastically movable to be away from each other. The male connection portion  32  is inserted from a front side to a space between the elastic pieces  72 A during the coupling process of the male connector  20  and the female connector  60 . After the coupling of the male connector  20  and the female connector  60 , as illustrated in  FIG. 3 , the elastic pieces  72 A are elastically contacted with the male connection portion  32 , and the female-side inner conductor  71  and the male-side inner conductor  31  are electrically connected. 
     As illustrated in  FIG. 13 , the electric wire connection portion  73  is crimped on and fixed to the cable core wire W 1  that is exposed at a distal end of the shielded electric wire W. Thus, the female-side inner conductor  71  is electrically connected to the cable core wire W 1  of the shielded electric wire W. 
     [Female-Side Derivative  80 ] 
     As illustrated in  FIGS. 2 and 3 , the female-side derivative  80  is a tubular member that extends in the front-rear direction and is made of insulating synthetic resin having predefined relative permittivity. The female-side derivative  80  receives the exposed cable core wire W 1  and the female-side inner conductor  71  therein. The exposed cable core wire W 1  extends frontward from the braided member W 2 . The female-side inner conductor  71  is connected to the exposed cable core wire W 1 . The female-side derivative  80  includes a female-side front derivative  81  and a female-side rear derivative  87  that is behind the female-side front derivative  81 . 
     As illustrated in  FIGS. 3 and 10 to 12 , the female-side front derivative  81  has a tubular shape that is elongated in the front-rear direction. The female-side front derivative  81  includes a female-side body portion  82  and a female-side fitting portion  84 . 
     The female-side body portion  82  has a smaller diameter in the front and rear end portions than in the middle portion with respect to the front-rear direction. The female-side body portion  82  receives the elastic connection portion  72  of the female-side inner conductor  71  in the area ranging from the front end portion to the middle portion with respect to the front-rear direction. The female-side body portion  82  receives the electric wire connection portion  73  of the female-side inner conductor  71  in the rear end portion thereof. As illustrated in  FIG. 2 , the rear end portion of the female-side body portion  82  is compressed in an upper-lower direction and fixed to the electric wire connection portion  73  by crimping of a female-side front outer conductor  91  of the female-side outer conductor  90 . 
     As illustrated in  FIGS. 3, and 10 to 12 , the female-side fitting portion  84  has a circular tube shape that protrudes frontward from the front end portion of the female-side body portion  82 . The female-side fitting portion  84  includes a recess having an inner surface of a conical shape such that an inner diameter of the recess is decreased as the inner surface extends toward a recessed bottom (rearward). Therefore, the inner space of the female-side fitting portion  84  becomes smaller as it is closer to the rear portion. The inner surface of the female-side fitting portion  84  is a second tapered surface  85  that is sloped closer to an axis of the female-side fitting portion  84  as it extends to the rear side from the front side. 
     An inclination angle of the second tapered surface is same as an inclination angle of the first tapered surface  45  of the male-side fitting portion  44  of the male-side derivative  40 . In this description, the configuration in which the inclination angle of the second tapered surface  85  is same as the inclination angle of the first tapered surface  45  includes a configuration in which the inclination angle of the second tapered surface  85  is same as the inclination angle of the first tapered surface  45  and a configuration in which the inclination angle of the second tapered surface  85  is not same as the inclination angle of the first tapered surface  45  but is considered to be substantially same as the inclination angle of the first tapered surface  45 . 
     The male-side fitting portion  44  of the male-side derivative  40  is inserted into the female-side fitting portion  84  from a front side during the coupling process of the male connector  20  and the female connector  60 . After the coupling of the male connector  20  and the female connector  60 , as illustrated in  FIGS. 2 and 3 , the first tapered surface  45  of the male-side fitting portion  44  is closely contacted with the second tapered surface  85  of the female-side fitting portion  84  over the entire peripheries thereof. Namely, since the first tapered surface  45  and the second tapered surface are closely contacted with each other over the entire peripheries thereof, no gap is between the first tapered surface  45  and the second tapered surface  85 . 
     Since the female-side fitting portion  84  has a smaller space as it extends in the rear portion, a space S that is created in the rear portion of the female-side fitting portion  84  is small when the male connector  20  and the female connector  60  are coupled together. 
     As illustrated in  FIG. 2 , the female-side rear derivative  87  is fitted to the outer periphery of the cable core wire W 1  that is exposed and extends from the braided member W 2  in the shielded electric wire W. A female-side outer conductor  90 , which will be described later, is fitted to the outer periphery of the female-side rear derivative  48  and pressed such that the female-side rear derivative  87  is disposed around the outer periphery of the cable core wire W 1  and surrounds the entire periphery of the cable core wire W 1 . A space is provided between the cable core wire W 1  and the female-side rear derivative  87  for adjusting the impedance. 
     [Female-Side Outer Conductor  90 ] 
     The female-side outer conductor  90  is formed by processing an electric conductive metal plate. As illustrated in  FIGS. 1, 2 and 9 , the female-side outer conductor  90  includes a female-side front outer conductor  91 , a female-side middle outer conductor  95 , and a female-side rear outer conductor  97 . 
     The female-side rear outer conductor  97  has a tubular shape and extends in the outer peripheral area ranging from the exposed braised member W 2  to the front end portion of the outer cover W 3  of the shielded electric wire W. The front portion of the female-side rear outer conductor  97  is crimped on and fixed to the braided member W 2  to be electrically connected to the braided member W 2 . The rear portion of the female-side rear outer conductor  97  is crimped on the outer cover W 3  and is fixed to the shielded electric wire W. 
     As illustrated in  FIGS. 2 and 9 , the female-side middle outer conductor  95  is a tubular member that has a diameter almost same as that of the female-side rear outer conductor  97 . The female-side middle outer conductor  95  extends in the outer peripheral area ranging from the front end portion of the female-side rear derivative  87  to the front end portion of the female-side rear outer conductor  97 . The front portion of the female-side middle outer conductor  95  is crimped on the female-side rear derivative  87  so as not to overpressure the female-side rear derivative  87 . The rear portion of the female-side middle outer conductor  95  is crimped on the front portion of the female-side rear outer conductor  97  to be electrically connected to the female-side rear outer conductor  97 . 
     As illustrated in  FIGS. 2 and 9 , the female-side front outer conductor  91  is a tubular member that has a diameter almost same as that of the female-side middle outer conductor  95 . The female-side front outer conductor  91  extends in the outer peripheral area ranging from the front end portion of the female-side middle outer conductor  95  to the front end portion of the female-side derivative  80 . The rear end portion of the female-side front outer conductor  91  is a tubular crimp portion  92  that is crimped on the front end portion of the female-side middle outer conductor  95  and the rear end portion of the female-side front derivative  81 . The tubular crimp portion  92  is crimped on the female-side front derivative  81  such that the female-side front derivative  81  is fixed to the female-side inner conductor  71 . The tubular crimp portion  92  is crimped on the female-side middle outer conductor  95  such that the female-side front outer conductor  91  and the female-side middle outer conductor  95  are electrically connected to each other. Accordingly, the female-side front outer conductor  91 , the female-side middle outer conductor  95 , and the female-side rear outer conductor are integrally configured as the female-side outer conductor  90 . 
     As illustrated in  FIGS. 2 and 3 , the front portion of the female-side front outer conductor  91  that is on a front side with respect to the middle portion in the front-rear direction is a connection large-diameter portion  93 . The connection large-diameter portion  93  has a tubular shape and is continuous from the front end of the tubular crimp portion  92 . The connection large-diameter portion  93  receives the front portion of the female-side front derivative  81  that is on a front side with respect to the middle portion in the front-rear direction. 
     Therefore, the female-side outer conductor  90  that is connected to the braided member W 2  of the shielded electric wire W covers the area ranging from the elastic connection portion  72  of the female-side inner conductor  71  to the front end portion of the outer cover W 3 . 
     Namely, as illustrated in  FIG. 2 , the male connector  20  and the female connector  60  that are coupled together are covered with the male-side outer conductor  50 , which has a substantially uniform diameter in the front-rear direction, and the female-side outer conductor  90 , which has a substantially uniform diameter in the front-rear direction. 
     As illustrated in  FIGS. 1 and 9 , the connection large-diameter portion  93  includes slits  93 A that extend in the front-rear direction and elastic connection portions  94  that are between the slits  93 A. The elastic connection portions  94  are elastically deformable outward in a radial direction. 
     As illustrated in  FIGS. 2 and 3 , the connection tubular portion  56  of the male-side outer conductor  50  can be inserted in a space between the connection large diameter portion  93  and the female-side front derivative  81 . The connection tubular portion  56  is inserted in the space between the connection large-diameter portion  93  and the female-side front derivative  81  when the male connector  20  and the female connector  60  are coupled together. When the connection tubular portion  56  that is inserted in the connection large-diameter portion  93  is elastically contacted with the elastic connection portions  94 , the female-side outer conductor  90  and the male-side outer conductor  50  are electrically connected to each other. 
     [Operations and Advantageous Effects of Connector  10 ] 
     This embodiment includes the above-described configuration and operations and advantageous effects of the connector  10  will be described next. 
     Generally, the characteristic impedance is set to a predefined value to perform impedance matching in a transmission line for transmitting high frequency signals. 
     As illustrated in  FIG. 15 , for example, in a connector  1  that includes a female connector  2  and a male connector  6 , the female connector  2  and the male connector  6  are coupled. The female connector  2  includes a female-side outer conductor  3  that receives therein a female-side inner conductor  5  via a female-side derivative  4 . The male connector  6  includes a male-side outer conductor  7  that receives therein a male-side inner conductor  9  via a male-side derivative  8 . After the coupling, the female-side derivative  4  and the male-side derivative  8  are opposite each other in the coupling direction and a male-side inner conductor  9  that protrudes frontward from the male-side derivative  8  is inserted in the female-side derivative  4  and the male-side inner conductor  9  is connected to the female-side inner conductor  5 . 
     However, a space S may be provided between the female-side derivative  4  and the male-side derivative  8  to prevent direct contact between the female-side derivative  4  and the male-side derivative  8  or due to a production tolerance and mounting tolerance. If the space S is created between the female-side derivative  4  and the male-side derivative  8 , the male-side inner conductor  9  includes an outer peripheral portion where no derivative  4 ,  8  is disposed. This changes the relative permittivity of the portion of the male-side inner conductor  9  that is in the space S and the impedance in the male-side inner conductor becomes high. As a result, impedance mismatching is caused in the space S and transmission signals are reflected and this may lower transmission efficiency. 
     As a result of earnest examination of the present inventors to solve the above problems, they found the configuration of this embodiment. This embodiment relates to the connector  10  that includes the female terminal module  70  and the male terminal module  30  that is to be coupled to the female terminal module  70 . The female terminal module  70  includes the electrically conductive female-side inner conductor  71 , the insulating female-side derivative  80 , and the electrically conductive female-side outer conductor  90 . The female-side outer conductor  90  receives therein the female-side inner conductor  71  via the female-side derivative  80 . The male terminal module  30  includes the electrically conductive male-side inner conductor  31 , the insulating male-side derivative  40 , and the electrically conductive male-side outer conductor  50 . As illustrated in  FIGS. 2 and 3 , the male-side outer conductor  50  receives therein the male-side inner conductor  31  via the male-side derivative  40 . The male-side outer conductor  50  is connected to the female-side outer conductor  90  when the female terminal module  70  and he male terminal module  30  are coupled together. The female-side derivative  80  includes the female-side fitting portion  84  and the male-side derivative  40  includes the male-side fitting portion  44 . 
     When the female terminal module  70  and the male terminal module  30  are coupled together, as illustrated in  FIGS. 2 and 3 , the female-side fitting portion  84  and the male-side fitting portion  44  are fitted to each other with recess-protrusion fitting in the coupling direction in which the female terminal module  70  and the male terminal module  30  are coupled together. The male-side inner conductor  31  includes the male connection portion  32  and the male connection portion  32  extends frontward than the male-side fitting portion  44  and toward the female terminal module  70 . When the female terminal module  70  and the male terminal module  30  are coupled together, as illustrated in  FIG. 2 , the male connection portion  32  is inserted in the female-side fitting portion  84  and connected to the female-side inner conductor  71 . 
     According to this embodiment, when the male connection portion  32  protruding from the male-side fitting portion  44  is inserted in the female-side fitting portion  84  and connected to the female-side inner conductor  71  after the coupling of the female terminal module  70  and the male terminal module  30 , the female-side fitting portion  84  and the male-side fitting portion  44  are fitted to each other in the coupling direction with the recess-protrusion fitting. 
     Therefore, at least the male-side fitting portion  44  or the female-side fitting portion  84  is disposed around the male connection portion  32 . Accordingly, the relative permittivity is less likely to be changed in the male connection portion  32  and this keeps the impedance change to be small. Therefore, the reflection loss of high frequency signals can be made small and the transmission efficiency is less likely to be lowered in the connector  10 . 
     The male-side fitting portion  44 , which is one of the female-side fitting portion  84  and the male-side fitting portion  44 , is a protrusion member including the first tapered surface  45 . The female-side fitting portion  84 , which is another one of the fitting portions, is a recessed member including the second tapered surface  85 . The first tapered surface  45  is sloped closer to the axis of the male connection portion  32  as it extends frontward (toward the other fitting portion) and the second tapered surface  85  is sloped closer to the axis of the male connection portion  32  as it extends away from the male-side fitting portion  44  and the second tapered surface  85  extends along the first tapered surface  45 . 
     Generally, a space is provided between a distal end of the male-side fitting portion and a distal end of the female-side fitting portion in a portion where the male connection portion is inserted into the female-side fitting portion. This prevents the distal end of the male-side fitting portion from abutting on the distal end of the female-side fitting portion in the coupling direction and the fitting of the fitting portions is not failed. 
     For example, if one fitting portion out of the male-side fitting portion and the female-side fitting portion has a circular columnar shape and other fitting portion out of the fitting portions includes a circular columnar recess, a space that is created around the outer periphery of the male connection near a recessed bottom of the recess has a diameter that is same as an inner diameter of the recess. Therefore, the impedance change tends to be great in the male connection. 
     However, according to this embodiment, the male-side fitting portion  44 , which is the one fitting portion, is the protrusion member including the first tapered surface  45  and the female-side fitting portion  84 , which is the other fitting portion, is the recessed member including the second tapered surface  85 . 
     Namely, as illustrated in  FIG. 3 , the female-side fitting portion  84 , which is the recessed member, has an inner space that becomes smaller as it is closer to the recessed bottom. This reduces the space S around the outer periphery of the male connection portion  32  near the recessed bottom of the female-side fitting portion  84 . Accordingly, the impedance change in the male connection portion  32  can be made much smaller and the reflection loss of high frequency signals in the male connection portion  32  can be further decreased. 
     As illustrated in  FIGS. 5 to 7 , the first tapered surface  45  is sloped and formed in a conical shape that is tapered toward a distal end. As illustrated in  FIGS. 10 to 12 , the second tapered surface  85  extends to form a conical shape whose diameter is decreased as it extends toward the recessed bottom of the recess. 
     Namely, the female-side fitting portion  84 , which is the recessed member, has a smaller space around the male connection portion  32  and near the recessed bottom due to the second tapered surface  85 . Therefore, as illustrated in  FIG. 3 , the space between the male-side fitting portion  44  and the female-side fitting portion  84  can be made smaller compared to a configuration including a second tapered surface in a portion of the female-side fitting portion. Accordingly, the impedance change can be made much smaller and the reflection loss of high frequency signals can be further decreased. 
     As illustrated in  FIG. 3 , the first tapered surface  45  and the second tapered surface  85  are closely contacted with each other when the female terminal module  70  and the male terminal module  30  are coupled together. Namely, the close contact between the first tapered surface  45  and the second tapered surface  85  further makes the space between the female-side fitting portion  84  and the male-side fitting portion  44  smaller. Accordingly, the impedance change can be made much smaller and the reflection loss of high frequency signals can be further reduced. 
     As described above, according to this embodiment, at least the female-side derivative  80  or the male-side derivative  40  is arranged around the outer periphery of the male connection portion  32  and a small space is provided between the male-side fitting portion  44  and the female-side fitting portion  84 . Namely, in the connector  10  of this embodiment, the impedance change in the male connection portion  32  can be suppressed to be small and the reflection loss of high frequency signals can be reduced and the transmission efficiency is less likely to be lowered. 
     Other Embodiments 
     The present disclosure is not limited to the embodiment described above and illustrated in the drawings. The following embodiments may be included in the technical scope of the technology described herein. 
     (1) In the above embodiment, the shielded electric wire W is a coaxial cable. However, a shielded electric wire may include multiple cable core wires, and a male-side derivative may include multiple male-side fitting portions and a female-side derivative may include multiple female-side fitting portions. 
     (2) In the above embodiment, the female-side derivative  80  includes two derivatives and the male-side derivative  40  includes two derivatives. However, each of the female-side derivative and the male-side derivative may include a single derivative. 
     (3) In the above embodiment, the female-side outer conductor  90  includes three outer conductors and the male-side outer conductor  50  includes two outer conductors. However, each of the female-side outer conductor and the male-side outer conductor may include a single outer conductor. 
     (4) In the above embodiment, the male-side fitting portion  44 , which protrudes in a conical shape and includes the first tapered surface, and the female-side fitting portion  84 , which includes a conical recess and the second tapered surface  85 , are fitted to each other with recess-protrusion fitting in the front-rear direction. However, a female-side fitting portion may protrude in a conical shape and a male-side fitting portion may include a conical recess. The female-side fitting portion may include a recess having a polygonal pyramid shape and the male-side fitting portion may include a protrusion having a polygonal pyramid shape. 
     As illustrated in  FIG. 14 , a male-side derivative  140  may include a male-side fitting portion  144  having a protrusion of a circular columnar shape and a female-side derivative  180  may include a female-side fitting portion  184  having a recess of a circular columnar shape. The male-side fitting portion  144  and the female-side fitting portion  184  may be fitted to each other with recess-protrusion fitting in the front-rear direction. In such a configuration, even if a first tapered surface and a second tapered surface are not completely contacted with each other, a space between the first tapered surface and the second tapered surface can be uniform and a local change of the impedance is less likely to be caused. 
     EXPLANATION OF SYMBOLS 
     
         
         
           
               10 : Connector 
               20 : Male connector 
               23 : Male housing 
               30 : Male terminal module 
               31 : Male-side inner conductor 
               32 : Male connection portion 
               33 : Electric wire connection portion 
               40 : Male-side derivative 
               41 : Male-side front derivative 
               42 : Male-side body portion 
               45 : First tapered surface 
               46 : Distal end surface 
               48 : Male-side rear derivative 
               50 : Male-side outer conductor 
               51 : Male-side front outer conductor 
               54 : Conductor crimp portion 
               55 : Middle crimp portion 
               56 : Connection tubular portion 
               58 : Male-side rear outer conductor 
               60 : Female connector 
               61 : Female housing 
               70 : Female terminal module 
               71 : Female-side inner conductor 
               72 : Elastic connection portion 
               72 A: Elastic piece 
               73 : Electric wire connection portion 
               80 : Female-side derivative 
               81 : Female-side front derivative 
               82 : Female-side body portion 
               84 : Female-side fitting portion 
               85 : Second tapered surface 
               87 : Female-side rear derivative 
               90 : Female-side outer conductor 
               91 : Female-side front outer conductor 
               92 : Tubular crimp portion 
               93 : Large-diameter portion 
               93 A: Slit 
               94 : Elastic connection portion 
               95 : Female-side middle outer conductor 
               97 : Female-side rear outer conductor 
             W 1 : Cable core wire 
             W 2 : Braided member 
             W 3 : Outer cover 
             W: Shielded electric wire