Patent Publication Number: US-10790617-B2

Title: Shield connector and shield cable with terminal

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2018-116166 filed on Jun. 19, 2018, the contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a shield connector and a shield cable with a terminal in which the shield connector is mounted on the terminal of the shield cable. 
     BACKGROUND ART 
     In a related art, there is known a shield connector including an inner terminal which is connected to a counterpart terminal and conductively connected to a conductor core wire of a shield cable, a housing which accommodates and holds the inner terminal, and an outer terminal which accommodates the housing inside and is conductively connected to a shield body of the shield cable (for example, see Patent Document 1). 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: JP-A-2003-086308 
     SUMMARY OF INVENTION 
     Generally, in view of a viewpoint of reducing a reflection loss caused by impedance mismatching at a connection place with a shield cable, a shield connector is designed so that characteristic impedance of the shield connector (specifically, characteristic impedance of a cylindrical structure formed by an inner terminal and an outer terminal) becomes a predetermined target value corresponding to the shield cable. Meanwhile, when a positional relationship (for example, an inter-terminal distance) between the inner terminal of the shield connector and the outer terminal thereof is changed during the transport and use of the shield connector, a shape of the above-described cylindrical structure is changed, thereby the characteristic impedance of the shield connector is also changed. 
     Further, from a viewpoint of improving communication quality via the shield cable on which the shield connector is mounted, it is desirable that the characteristic impedance of the shield connector (specifically, a cylindrical structure) is maintained at a designed target value as much as possible. 
     The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a shield connector and a shield cable with a terminal capable of maintaining desirable communication quality. 
     In order to achieve the above-described object, a shield connector according to the present invention is characterized by the following configurations (1) to (4): 
     (1) 
     A shield connector which is mounted on a terminal of a shield cable including a conductor core wire and a shield body surrounding the conductor core wire, the shield connector including: 
     a conductive inner terminal which is connected to the conductor core wire; 
     a conductive cylindrical outer terminal which is connected to the shield body; and 
     an inner housing holding the inner terminal in a hollow part of the outer terminal, 
     wherein a projection part is provided on an outer surface of the inner housing to maintain a distance between an outer surface of the inner terminal and an inner surface of the outer terminal at a predetermined inter-terminal distance from a tip side of the shield connector to a base end side thereof. 
     (2) 
     The shield connector according to the configuration (1), wherein 
     the projection part is a rib having an elongated protruding shape extending in a fitting direction of the shield connector. 
     (3) 
     The shield connector according to the configuration (1) or (2), wherein 
     the projection part is formed to maintain the inter-terminal distance in which characteristic impedance of a cylindrical structure formed by the inner terminal and the outer terminal becomes a predetermined target value. 
     (4) 
     The shield connector according to any one of the configurations (1) to (3), further including: 
     an outer housing which includes a terminal accommodating chamber capable of accommodating a terminal body formed by the inner terminal, the outer terminal, and the inner housing. 
     According to the shield connector of the configuration (1), the inter-terminal distance between the inner terminal and the outer terminal can be maintained at the predetermined design value from the tip side of the shield connector to the base end side thereof by the projection part provided on the inner housing holding the inner terminal in the hollow part of the outer terminal. As a result, for example, the inclination of the inner terminal with respect to the outer terminal can be suppressed, thereby making it possible to suppress a variation of the characteristic impedance of the cylindrical structure formed by the inner terminal and the outer terminal. Further, a shape of the projection part is not particularly limited as long as the aforementioned inter-terminal distance can be maintained. For example, the shape thereof may be an elongated projection (a rib extending in a predetermined direction), a dot shaped projection, or a combination thereof. 
     Further, according to the shield connector of the above-described configuration, in comparison with a case in which the projection part is not provided on the inner housing (for example, a case in which an outer wall surface of the inner housing is in contact with the outer terminal, thereby maintaining the inter-terminal distance), since a volume of the inner housing existing in the hollow part of the outer terminal becomes small, it is possible to reduce a change in the inter-terminal distance caused by influences of thermal expansion, thermal contraction, and the like of the inner housing. 
     According to the shield connector of the configuration (2), the inclination, and the like of the inner terminal can be appropriately suppressed by the rib having the protruding shape extending in the fitting direction. Further, since a contact area between the inner housing and the outer terminal becomes larger than a case in which the dot shaped projection is used, a positional deviation in the fitting direction of the inner housing in the hollow part of the outer terminal can be suppressed. 
     According to the shield connector of the configuration (3), a shape of the projection part is designed so that the characteristic impedance of the cylindrical structure formed by the inner terminal and the outer terminal becomes the predetermined target value (for example, a design value corresponding to the shield connector). In other words, the characteristic impedance of the cylindrical structure can be arbitrarily controlled by adjusting the shape, and the like of the projection part. 
     According to the shield connector of the configuration (4), it is possible to improve a function as a connector by allowing the outer housing to include an engagement assurance function with a counterpart connector. 
     In order to achieve the above-described object, a shield cable with a terminal according to the present invention is characterized by the following configuration (5): 
     (5) 
     A shield cable with a terminal, including: 
     a shield cable which includes a conductor core wire and a shield body surrounding the conductor core wire; and 
     a shield connector according to any one of the configurations (1) to (4) which is mounted on a terminal of the shield cable. 
     According to the shield cable with the terminal of the configuration (5), the inter-terminal distance between the inner terminal and the outer terminal can be maintained at the predetermined design value from the tip side of the shield connector to the base end side thereof by the projection part provided on the inner housing holding the inner terminal in the hollow part of the outer terminal. As a result, for example, the inclination of the inner terminal with respect to the outer terminal can be suppressed, thereby making it possible to suppress a variation of the characteristic impedance of the cylindrical structure formed by the inner terminal and the outer terminal. Further, in comparison with a case in which the projection part is not provided on the inner housing (for example, a case in which the outer wall surface of the inner housing is in contact with the outer terminal, thereby maintaining the inter-terminal distance), since the volume of the inner housing existing in the hollow part of the outer terminal becomes small, it is possible to reduce the change in the inter-terminal distance caused by the influences of the thermal expansion, the thermal contraction, and the like of the inner housing. 
     According to the present invention, it is possible to provide a shield connector and a shield cable with a terminal capable of maintaining desirable communication quality. 
     As described above, the present invention is briefly described. Further, details of the present invention will be further clarified by reading through a form (hereinafter referred to as “an embodiment”) for performing the invention described hereinbelow with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a shield cable with a terminal in which a shield connector is mounted on the terminal of the shield cable; 
         FIG. 2  is an exploded perspective view of the shield connector illustrated in  FIG. 1 ; 
         FIG. 3A  is a first diagram illustrating an assembly process of the shield connector illustrated in  FIG. 1 , and  FIG. 3B  is a second diagram illustrating the assembly process thereof; 
         FIG. 4  is a cross sectional view taken along the A-A line of  FIG. 3B ; and 
         FIG. 5A  is a cross sectional view taken along the B-B line of  FIG. 4 , and  FIG. 5B  is a cross sectional view taken along the C-C line of  FIG. 4 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 
     Hereinafter, a shield cable with a terminal  2  in which a shield connector  1  is mounted on a terminal of a shield cable  70  according to an embodiment of the present invention will be described with reference to the accompanying drawings. Hereinafter, for convenience of description, in an axial direction of the shield connector  1  (a fitting direction), a side (a left side in  FIGS. 1 to 3B ) to which a counterpart terminal (not illustrated) is fitted is referred to as a tip side (a front side) and an opposite side thereof (a right side in  FIGS. 1 to 3B ) is referred as a base end side (a rear side). 
     As illustrated in  FIGS. 1 and 2 , the shield connector  1  which is mounted on the terminal of the shield cable  70  is provided with an inner terminal  10 , an inner housing  20 , an outer terminal  30 , and an outer housing  60  (particularly, refer to  FIG. 2 ). 
     As illustrated in  FIGS. 2, 3A, 3B, and 5B , the shield cable  70  is formed with a plurality of electric wires  73  (two electric wires in the embodiment) which are respectively formed by a linear conductor core wire  71  and a cylindrical resin insulator  72  covering an outer periphery of the conductor core wire (particularly, refer to  FIG. 5B ); a cylindrical resin outer cover  74  collectively covering the plurality of electric wires  73 ; and a cylindrical shield body (a braid material)  75  provided on an inner peripheral surface of the outer cover  74 . When the shield cable  70  is connected to the shield connector  1 , a tip part of the conductor core wire  71  is exposed to the outside in advance by performing a predetermined terminal process, and a tip part of the shield body  75  is folded back to a base end side so as to cover an outer periphery of the outer cover  74  (refer to  FIG. 2 ). Hereinafter, respective components forming the shield connector  1  will be described in order. 
     First, the inner terminal  10  will be explained. The inner terminal  10  has a function of being connected to a counterpart terminal (not illustrated) and being conductively connected to the conductor core wire  71  of the shield cable  70 . As illustrated in  FIGS. 2 and 5B , the inner terminal  10  which is made of metal integrally includes a rectangular cylindrical connecting part  11  which is positioned at a tip part thereof and is connected to the counterpart terminal and a pressing part  12  which is positioned at a base end part thereof and is formed by a pair of crimping pieces for pressing the conductor core wire  71  of the shield cable  70 . The counterpart terminal is (a male terminal) is inserted into a hollow part (a through hole) of the connecting part  11 . 
     Next, the inner housing  20  will be explained. The inner housing  20  accommodates and holds the connecting part  11  of the inner terminal  10 , and is accommodated and held in the outer terminal  30 , thereby having a function of maintaining the inner terminal  10  and the outer terminal  30  in an insulated state. As illustrated in  FIGS. 2, 3A, and 3B , the inner housing  20  is made of an insulating synthetic resin having a predetermined dielectric constant and has an approximately rectangular cylindrical shape. A plurality of terminal accommodating chambers  21  (two in the embodiment) for accommodating and holding the inner terminal  10  are formed so as to be penetrated in the axial direction in the inner housing  20  (particularly, refer to  FIG. 5B ). 
     As illustrated in  FIGS. 2 to 5B , on an upper surface of the inner housing  20 , a pair of ribs  22  extending in the axial direction (the fitting direction) from a tip part of the inner housing  20  to a base end part thereof are formed side by side in a width direction. As illustrated in  FIGS. 4, 5A, and 5B , on a lower surface of the inner housing  20 , a pair of ribs  23  extending in the axial direction over a tip side portion in the axial direction of the inner housing  20  are formed side by side in the width direction, and a pair of ribs  24  extending in the axial direction over a base end side portion in the axial direction of the inner housing  20  are formed side by side in the width direction. 
     The pair of ribs  23  are provided at the same width direction positions as those of the pair of ribs  22 , and the pair of ribs  24  are provided at positions outside the pair of ribs  23  in the width direction. Lower end positions of the pair of ribs  23  and ribs  24  (a tip position in a protruding direction) coincide with each other. Functions of the ribs  22 ,  23 , and  24  will be described later. 
     As illustrated in  FIGS. 2, 3A, and 3B , a pair of projections  25  protruding in the width direction are provided at a predetermined position near the tip part on a pair of side surfaces of the inner housing  20 . A pair of elongated projections  26  (in total, two pairs (four) of elongated projections  26 ) protruding in the width direction and extending in the axial direction are provided at respective predetermined positions of an approximately central position in the axial direction and near the base end part on the pair of side surfaces of the inner housing  20 . As illustrated in  FIG. 5B , a protruding part  27  protruding downward is provided at a predetermined position between the two pairs of elongated projections  26  in the axial direction on a bottom surface of the inner housing  20 . Functions of the projection  25 , the elongated projection  26 , and the protruding part  27  will be described later. 
     Next, the outer terminal  30  will be described. The outer terminal  30  accommodates and holds the inner housing  20  and has a function of being conductively connected to the shield body  75  of the shield cable  70 . As illustrated in  FIGS. 2, 3A , and  3 B, the outer terminal  30  is provided with a lower side part  40  which is made of metal and an upper side part  50  which is made of metal, and the lower side part  40  and the upper side part  50  are assembled with each other, thereby having a rectangular cylindrical shape. 
     The lower side part  40  is provided with a bottom plate part  41  having a flat plate shape and extending in the axial direction; a pair of first side wall parts  42  rising upward from opposite end parts in the width direction of the bottom plate part  41  over a tip side portion in the axial direction of the bottom plate part  41 ; a pair of second side wall parts  43  rising upward from opposite end parts in the width direction of the bottom plate part  41  over a base end side portion in the axial direction of the bottom plate part  41 . The pair of second side wall parts  43  are positioned outside the pair of first side wall parts  42  in the width direction. 
     A pair of through holes  44  having a rectangular shape and extending in the axial direction are formed in the pair of first side wall parts  42 . A pair of projections  45  (in total, two pairs (four) of projections  45 ) protruding inwardly in the width direction are provided on respective inner side surfaces in the width direction of opposite end parts in the axial direction of the pair of second side wall parts  43 . A rectangular opening  46  is formed by providing a rectangular cut and raised part extending in a cantilever shape obliquely downward from the tip side toward the base end side at a predetermined position between the two pairs of projections  45  in the axial direction on the bottom plate part  41 . When assembling the shield connector  1 , the through hole  44  of the lower side part  40  and the projection  45  thereof are respectively engaged with the projection  25  of the inner housing  20  and the elongated projection  26  thereof (refer to  FIG. 3A ), and the protruding part  27  of the inner housing  20  is inserted into the opening  46  of the lower side part  40  (refer to  FIG. 5B ). A pair of crimping pieces  48  extending upward are provided to be connected on base end side end surfaces of the bottom plate part  41  and the pair of second side wall parts  43  via a connecting part  47 . 
     The upper side part  50  is provided with a top plate part  51  having a flat plate shape extending in the axial direction; a pair of first side wall parts  52  extending downward from opposite end parts in the width direction of the top plate part  51  over a tip side portion in the axial direction of the top plate part  51 ; and a pair of second side wall parts  53  extending downward from opposite end parts in the width direction of the top plate part  51  over a base end side portion in the axial direction of the top plate part  51 . The pair of second side wall parts  53  are positioned outside the pair of first side wall parts  52  in the width direction. When assembling the shield connector  1 , the pair of first side wall parts  52  of the upper side part  50  and the pair of second side wall parts  53  thereof are brought into face-to-face contact with the pair of first side wall parts  42  of the lower side part  40  and the pair of second side wall parts  43  thereof outside in the width direction (refer to  FIG. 4 ). 
     A pair of cut and raised parts  54  having a rectangular shape and extending in a cantilever shape inwardly in an oblique width direction from the lower side to the upper side are formed at a predetermined position on a base end side in the axial direction of the pair of first side wall parts  52 . When assembling the shield connector  1 , the cut and raised part  54  of the upper side part  50  is engaged with the through hole  44  of the lower side part  40  (refer to  FIG. 4 ). A tongue-shaped piece  56  protruding toward the base end side is provided to be connected on a base end side end surface of the top plate part  51  via a connecting part  55 . 
     Next, an assembly procedure of the inner terminal  10 , the inner housing  20 , and the outer terminal  30  (=the lower side part  40 +the upper side part  50 ) will be described with reference to  FIGS. 3A and 3B . First, as illustrated in  FIG. 2 , the tip parts of the plurality of conductor core wires  71  of the shield cable  70  on which the terminal process is performed are respectively pressed by the pair of crimping pieces of the pressing part  12  of the corresponding inner terminal  10 . 
     Next, as illustrated in  FIG. 3A , the plurality of inner terminals  10  to which the shield cable  70  is connected are respectively inserted into the corresponding terminal accommodating chambers  21  of the inner housing  20  from the base end side, thereby being accommodated therein. 
     Next, as illustrated in  FIG. 3A , the inner housing  20  is assembled to the lower side part  40  so as to sandwich the inner housing  20  between the pair of first side wall parts  42  of the lower side part  40  and the pair of second side wall parts  43  thereof. 
     Accordingly, the pair of projections  25  of the inner housing  20  are locked to upper edges of the pair of through holes  44  of the lower side part  40 , and four elongated projections  26  of the inner housing  20  are respectively locked to the four projections  45  of the lower side part  40 . In addition, the protruding part  27  of the inner housing  20  is inserted into the opening  46  of the lower side part  40 . As a result, as illustrated in  FIGS. 4 and 5B , the pair of ribs  23  and the pair of ribs  24  positioned on the bottom surface of the inner housing  20  are maintained in a state of being in contact with the bottom plate part  41  of the lower side part  40  over the whole region in the respective axial directions, and the inner housing  20  is held so as not to be relatively moved to the lower side part  40  from the tip side to the base end side. 
     Next, as illustrated in  FIG. 3B , the upper side part  50  is assembled to the lower side part  40  so as to respectively sandwich the pair of first side wall parts  42  of the lower side part  40  and the pair of second side wall parts  43  thereof by the pair of first side wall parts  52  of the upper side part  50  and the pair of second side wall parts  53  thereof. Accordingly, as illustrated in  FIG. 4 , the tip parts (upper end parts) of the pair of cut and raised parts  54  of the upper side part  50  are locked to the upper edges of the pair of through holes  44  of the lower side part  40  (refer to  FIG. 4 ). In this state, the pair of crimping pieces  48  of the lower side part  40  are positioned on a lower side of the folded-back part of the shield body  75  of the shield cable  70 , and the tongue-shaped piece  56  of the upper side part  50  is positioned on an upper side of the folded-back part of the shield body  75 . 
     Next, as illustrated in  FIG. 3B , the pair of crimping pieces  48  of the lower side part  40  are pressed and fixed so as to collectively cover the folded-back part of the shield body  75  of the shield cable  70  and the tongue-shaped piece  56  of the upper side part  50 . As a result, as illustrated in  FIGS. 4 and 5A , the pair of ribs  22  positioned on the upper surface of the inner housing  20  are maintained in a state of being in contact with the top plate part  51  of the upper side part  50  over the whole region in the respective axial directions, and the lower side part  40  and the upper side part  50  are held so as not to be relatively moved to each other. 
     As described above, the assembly of the inner terminal  10 , the inner housing  20 , and the outer terminal  30  (=the lower side part  40 +the upper side part  50 ) is completed (refer to  FIG. 3B ). In this state, as described above, the pair of ribs  23  and the pair of ribs  24  positioned on the bottom surface of the inner housing  20  are maintained in the state of being in contact with the bottom plate part  41  of the lower side part  40  over the whole region in the respective axial directions, and the pair of ribs  22  positioned on the upper surface of the inner housing  20  are maintained in the state of being in contact with the top plate part  51  of the upper side part  50  over the whole region in the respective axial directions, whereby a distance between an outer surface of the inner terminal  10  and an inner surface of the outer terminal  30  (=the lower side part  40 +the upper side part  50 ) is maintained at a predetermined inter-terminal distance from the tip side to the base end side. 
     Accordingly, the outer terminal  30  (refer to  FIG. 3B ) in which the inner terminal  10  and the inner housing  20  are held is accommodated and fixed in the terminal housing chamber  61  of the outer housing  60  as illustrated in  FIG. 1 . As described above, the assembly of the shield connector  1  is completed. As a result, the shield cable with the terminal  2  in which the shield connector  1  is mounted on the terminal of the shield cable  70  is obtained (refer to  FIG. 1 ). 
     As described above, according to the shield connector  1  and the shield cable with the terminal  2  according to the embodiment of the present invention, the inter-terminal distance between the inner terminal  10  and the outer terminal  30  can be maintained at a predetermined design value from the tip side of the shield connector  1  to the base end side thereof by the ribs  22 ,  23 , and  24  provided on the inner housing  20  for holding the inner terminal  10  in a hollow part of the outer terminal  30 . As a result, inclination of the inner terminal  10  with respect to the outer terminal  30  can be suppressed, thereby making it possible to suppress a variation of characteristic impedance of a cylindrical structure formed by the inner terminal  10  and the outer terminal  30 . Further, in comparison with a case in which the projection is not provided on the inner housing  20 , and the outer wall surface of the inner housing  20  is in contact with the outer terminal  30 , thereby maintaining the inter-terminal distance, a degree of the inclination of the inner terminal  10  with respect to the outer terminal  30  caused by influences of thermal expansion, thermal contraction, and the like of the inner housing  20  during the use of the shield connector  1  is considered to become small. 
     Further, since the ribs  22 ,  23 , and  24  have elongated protruding shapes extending in the fitting direction, the inclination of the inner terminal  10  in the fitting direction can be appropriately suppressed. 
     Further, the shapes of the ribs  22 ,  23 , and  24  are designed so that the characteristic impedance of the cylindrical structure formed by the inner terminal  10  and the outer terminal  30  becomes a predetermined target value. In other words, it is possible to arbitrarily control the characteristic impedance of the cylindrical structure. 
     Other Embodiments 
     Further, the present invention is not limited to each embodiment described above, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiment, but can be appropriately modified, improved, and the like. In addition, the material, shape, dimension, number, arrangement place, and the like of each component in the above-described embodiment are arbitrary and not limited thereto as long as the present invention can be achieved. 
     In the embodiment, as the “projection part”, the ribs  22 ,  23 , and  24  having the elongated protruding shapes and extending in the fitting direction are adopted, however, alternatively, for example, a number of projections protruding in a dot shape may be adopted as the “projection part”. 
     Here, the characteristics of the embodiments of the shield connector  1  and the shield cable with the terminal  2  according to the present invention described above are briefly summarized in the respective following (1) to (5): 
     (1) 
     A shield connector ( 1 ) which is mounted on a terminal of a shield cable ( 70 ) including a conductor core wire ( 71 ) and a shield body ( 75 ) surrounding the conductor core wire ( 71 ), the shield connector ( 1 ) including: 
     a conductive inner terminal ( 10 ) which is connected to the conductor core wire ( 71 ); 
     a conductive cylindrical outer terminal ( 30 ,  40 ,  50 ) which is connected to the shield body ( 75 ); and 
     an inner housing ( 20 ) holding the inner terminal ( 10 ) in a hollow part of the outer terminal ( 30 ,  40 ,  50 ), 
     wherein a projection part ( 22 ,  23 ,  24 ) is provided on an outer surface of the inner housing ( 20 ) to maintain a distance between an outer surface of the inner terminal ( 10 ) and an inner surface of the outer terminal ( 30 ) at a predetermined inter-terminal distance from a tip side of the shield connector ( 1 ) to a base end side thereof. 
     (2) 
     The shield connector ( 1 ) according to the configuration (1), wherein 
     the projection parts are ribs ( 22 ,  23 , and  24 ) having elongated protruding shapes extending in a fitting direction of the shield connector ( 1 ). 
     (3) 
     The shield connector ( 1 ) according to the configuration (1) or (2), wherein 
     the projection parts ( 22 ,  23 , and  24 ) are formed to maintain the inter-terminal distance in which characteristic impedance of a cylindrical structure formed by the inner terminal ( 10 ) and the outer terminal ( 30 ) becomes a predetermined target value. 
     (4) 
     The shield connector ( 1 ) according to any one of the configurations (1) to (3), further including: 
     an outer housing ( 60 ) which includes a terminal accommodating chamber ( 61 ) capable of accommodating a terminal body formed by the inner terminal ( 10 ), the outer terminal ( 30 ), and the inner housing ( 20 ). 
     (5) 
     A shield cable with a terminal ( 2 ), including: 
     a shield cable ( 70 ) which includes a conductor core wire ( 71 ) and a shield body ( 75 ) surrounding the conductor core wire ( 71 ); and 
     a shield connector ( 1 ) according to any one of the configurations (1) to (4) which is mounted on a terminal of the shield cable ( 70 ).