Abstract:
A terminal-connection structure is characterized in that a terminal member includes the following: a main terminal-member body that has an attachment section to which terminals on long members are attached and an insertion section that is inserted into the aforementioned insertion opening; and a fitting element that fits together with said insertion section. This terminal-connection structure is also characterized in that: the fitting element is provided with a plurality of elastic prongs and a plurality of restricting parts that restrict axial movement of the fitting element; the insertion section of the main terminal-member body has a shaft section that has a narrowed section that is narrowed in one axial direction; each restricting part has a displaced part that is displaced in the axially inward direction of the fitting element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a national phase application based on the PCT International Patent Application No. PCT/JP2015/065339 filed May 28, 2015, claiming priority to Japanese Patent Application No. 2014-111438 filed May 29, 2014, the entire contents of both of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a terminal connection structure. 
       BACKGROUND ART 
       [0003]    Patent Document 1 discloses a relay mechanism for connecting control cables as one of the structures for connecting a long member, such as a control cable, to a mating member. As illustrated in  FIG. 9 , a relay mechanism  100  according to Patent Document 1 is in relay-connection with a control cable  101   a  extending in one direction from the relay mechanism  100  and a control cable  101   b  extending in the other direction from the relay mechanism  100 . Specifically, a cable end  103  of an inner cable  102   a  of the control cable  101   a  on one side is locked to one end (left side in  FIG. 9 ) of a joint member  104 . An inner cable  102   b  of the control cable  101   b  on the other side is locked to an attachment member  105 , and the attachment member  105  is inserted into an insertion hole  106  formed in the joint member  104  and is attached to the joint member  104 . 
         [0004]    The attachment member  105  inserted into the insertion hole  106  of the joint member  104  is provided with a spring member  107 , and the spring member  107  includes plate springs  108  partially expanding in the circumferential direction. The spring member  107  elastically deforms when the spring member  107  is inserted into the insertion hole  106  of the joint member  104 . After the spring member  107  enters inside the joint member  104 , the plate springs  108  of the spring member  107  expand outward, and the attachment member  105  is joined to the joint member  104 . As illustrated in  FIG. 10 , the spring member  107  is press-fitted from the front end of the attachment member  105 , and is fitted to and attached to an attachment portion  109 , which is a narrowed portion of a shaft-like portion of the attachment member  105 . The spring member  107  includes a restricting part  110  provided between the plate springs  108  and placed by steps  109   a  and  109   b  formed on both sides in the axial direction of the attachment portion  109 , in addition to the plate springs  108  partially expanding in the circumferential direction. When the attachment member  105  is inserted into the insertion hole  106  of the joint member  104 , the restricting part  110  restricts axial movement of the spring member  107  with respect to the attachment member  105 . 
       CITATION LIST 
     Patent Literature 
       [0005]    PTL1: JP-A 2013-177936 Gazette 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    However, when the spring member  107 , which is a fitting piece fitted to a terminal member, is press-fitted from the front end of the attachment member  105 , which is a terminal member, the restricting part  110  is plastically deformed depending on the manner in which the spring member  107  is press-fitted, such as a case where the spring member  107  is press-fitted in a state where the axis of the attachment member  105  and the axis of the spring member  107  are inclined with each other. Therefore, the restricting part  110 , which is not originally expand outward, may be expanded outward and may not be engaged well with the steps  109   a  and  109   b  (especially the step  109   b ) of the attachment portion  109 . In such a case, when the attachment member  105  is inserted into the insertion hole  106  of the joint member  104 , the spring member  107  may deviate in the axial direction (right side in  FIG. 9 ) with respect to the attachment portion  109  of the attachment member  105 , an end part of the restricting part  110  may get on the step  109   b  such that the end part covers the step  109   b , and thus the attachment member  105  and the joint member  104  may not be well-connected. Consequently, additional post-process and/or correction-process to the spring member  107  may be needed. Therefore, it is necessary to check the engagement state when the spring member  107  is press-fitted to the attachment member  105 . In addition, in a case where the engagement state is not appropriate, a process step such as correction is necessary. That is, a structure where the spring member  107  and the attachment member  105  are easily attached together is desired. 
         [0007]    In view of the above problems, the object of the present invention is to provide a terminal connection structure capable of easily realizing appropriate fitting between a terminal member main body and a fitting piece fitted to the terminal member main body. 
       Solution to Problem 
       [0008]    A terminal connection structure according to the present invention includes a terminal member to which a terminal of a long member is attached and which is connected to a mating member, and the terminal member is inserted into an insertion opening part of the mating member and is connected to the mating member. The terminal member includes: a terminal-member main body including an attachment part to which the terminal of the long member is attached, and an insertion part which extends from the attachment part and is inserted into the insertion opening part; and a fitting piece which is fitted to the insertion part of the terminal-member main body. The fitting piece includes: elastic parts which deform elastically when the elastic parts are inserted into the insertion opening part and are engaged with an inside engagement part of the mating member by expanding after the elastic parts are inserted into the insertion opening part, and restricting parts which extend in an axial direction of the insertion part between the elastic parts and restrict movement of the fitting piece in the axial direction of the insertion part with respect to the insertion part by engaging the terminal-member main body to end of the restricting parts in both side. The insertion part includes a shaft part which extends in the axial direction and is provided with a reduced-diameter part that is reduced in diameter toward one side in the axial direction. The restricting part includes a displacement part which is displaced inwardly in an axial direction of the fitting piece, and the fitting piece is attached to the terminal-member main body with the displacement part positioned along the reduced-diameter part. 
         [0009]    In addition, it is preferable that engagement parts which are engaged with the restricting parts are provided on the front end side and the rear end side of the shaft part, a front end part and a rear end part of each of the restricting parts are engaged with the engagement parts, and the reduced-diameter part is provided adjacent to at least one engagement part. 
         [0010]    In addition, it is preferable that the reduced-diameter part is a tapered part reduced in diameter toward a rear end, and the displacement part is displaced toward the inside of the fitting piece correspondingly to the tapered part. 
         [0011]    In addition, it is preferable that each of the restricting parts has spring elasticity, and the displacement part is displaced so as to be brought into contact with the reduced-diameter part by an elastic force due to the spring elasticity in a state where the fitting piece is mounted to the terminal-member main body. 
       Advantageous Effects of Invention 
       [0012]    With the terminal connection structure according to the present invention, it is possible to restrict axial movement of the fitting piece, which includes the elastic parts and the restricting parts and is fitted to the terminal-member main body, with respect to the terminal-member main body. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0013]      FIG. 1  shows a terminal connection structure according an embodiment of the present invention. 
           [0014]      FIG. 2  is an exploded view of the terminal connection structure in  FIG. 1 . 
           [0015]      FIG. 3(A)  is a perspective view of a terminal-member main body used in the terminal connection structure in  FIG. 1 , and  FIG. 3(B)  is a side view of the terminal-member main body in  FIG. 3(A) . 
           [0016]      FIG. 4(A)  is a side view of a fitting piece used in the terminal connection structure in  FIG. 1 ,  FIG. 4(B)  is a view of the fitting piece in  FIG. 4(A)  seen from a base end side, and  FIG. 4(C)  is a bottom view of the fitting piece in  FIG. 4(A) . 
           [0017]      FIGS. 5(A) to 5(C)  show states of connecting the terminal member used in the terminal connection structure in  FIG. 1  to a mating member. 
           [0018]      FIG. 6(A)  is a side view of the terminal member in which the fitting piece shown in  FIGS. 4(A) to 4(C)  are attached to the terminal-member main body shown in  FIGS. 3(A) and 3(B) , and  FIG. 6(B)  is a side view of the terminal member in which the fitting piece in  FIG. 6(A)  is attached in a state where a restricting part of the fitting piece is deformed. 
           [0019]      FIG. 7(A)  shows a state before a fitting piece is fitted to an insertion part in a conventional terminal connection structure,  FIG. 7(B)  shows a state where the fitting piece in  FIG. 7(A)  is fitted in a state where the fitting piece is inclined with respect to a front end part of the insertion part,  FIG. 7(C)  shows a state where the fitting piece in  FIG. 7(A)  is pushed in in a state where the fitting piece is inclined with respect to the front end part of the insertion part and a restricting part is deformed, and  FIG. 7(D)  shows a state where the fitting piece in  FIG. 7(A)  is fitted to the insertion part in a state where the restricting part is plastically deformed. 
           [0020]      FIG. 8(A)  shows a state of the fitting piece in  FIG. 7(A)  when an elastic part of the fitting piece is brought into contact with an opening edge of an insertion opening part of the mating member, and  FIG. 8(B)  shows a state where the fitting piece in  FIG. 8(A)  deviates in the axial direction with respect to the insertion part and comes off from a fitting portion. 
           [0021]      FIG. 9  shows a conventional relay mechanism of control cables. 
           [0022]      FIG. 10  is an exploded view of the relay mechanism in  FIG. 9 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0023]    Hereinafter, a terminal connection structure according to the present invention will be described in detail with reference to the accompanying drawings. 
         [0024]    As illustrated in  FIGS. 1 and 2 , the terminal connection structure  1  according to the present invention includes a terminal member  4  to which terminals  21   a  and  21   b  of long members  2  are attached and which is connected to a mating member  3 . The terminal member  4  is inserted into an insertion opening part  3   a  of the mating member  3  and is connected to the mating member  3 . The terminal connection structure  1  is used for connecting the mating member  3  and the long member  2  via the terminal member  4 , and can be applied, for example, to a vehicular seat operation device, a vehicular fuel lid opening and closing mechanism, and a vehicular trunk opening and closing mechanism which interconnect control cables mutually. In addition, the terminal connection structure  1  can be applied to usage other than vehicles. 
         [0025]    The long member  2  has a predetermined length, and is used for connecting distant spots via the terminal member  4 . In addition, the long member  2  is not particularly limited as long as the long member  2  connects spots separated from each other; however, the long member  2  may be a control cable including an inner cable  22   a  or  22   b  and an outer casing  23   a  or  23   b  as illustrated in  FIGS. 1 and 2 , or may be a rod-like member transmitting an operation force. Note that the terminals  21   a  and  21   b  on one end side of the inner cables  22   a  and  22   b  of the control cables are attached to the terminal member  4  in the present embodiment; however, terminals of the outer casings  23   a  and  23   b  may be attached to the terminal member  4 . In addition, in  FIG. 1 , two long members  2  are attached to the terminal member  4 ; however, the number of long members  2  attached to the terminal member  4  is not particularly limited, and the number may be one or may be three or more. 
         [0026]    The terminal member  4  is connected to the mating member  3  and functions as a connecting part that connects the long member  2  to the mating member  3 . The terminal member  4  will be described later in detail. The manner of attaching the terminals  21   a  and  21   b  of the long members  2  to the terminal member  4  is not particularly limited. The terminals  21   a  and  21   b  of the long members  2  may be attached by engagement as illustrated in the present embodiment, or may be attached by another known fixation means such as casting, welding, or screwing. As described above, the terminal member  4  to which the long member  2  is attached is inserted into the insertion opening part  3   a  of the mating member  3  and is connected to the mating member  3 . 
         [0027]    The mating member  3  is a connection target to which the terminal member  4  is connected, and includes the insertion opening part  3   a  into which the terminal member  4  can be inserted as illustrated in  FIG. 1 . The shape and the structure of the mating member  3  is not limited as long as the terminal member  4  can be connected to the mating member  3  according to usage of the terminal connection structure  1 . In addition, the shape of the insertion opening part  3   a  can be appropriately changed according to the shape of the terminal member  4  to be inserted; however, as will be described later, the size of the insertion opening part  3   a  is set such that elastic parts  61  of a fitting piece  6  of the terminal member  4  are brought into contact with an opening edge of the insertion opening part  3   a  and are displaced inward in the radial direction when the terminal member  4  is inserted into the insertion opening part  3   a , the elastic parts  61  are engaged with an inside engagement part  3   b  provided on the periphery of the insertion opening part  3   a  when the elastic parts  61  expand after insertion of the terminal member  4  has been completed, and thus the terminal member  4  is prevented from coming off from the mating member  3 . 
         [0028]    Note that in the present embodiment, as illustrated in  FIG. 1 , the mating member  3  is illustrated as an substantially cylindrical joint member having an internal space S into which the terminal member  4  can be inserted. In the embodiment illustrated in  FIG. 1 , the terminal member  4  is connected to one side of the mating member  3  (joint member), and another inner cable  22   c  is connected to the other side of the mating member  3 . Thus, the other inner cable  22   c  and the long members  2  are interconnected by means of the mating member  3  (joint member). Although the connection structure between the mating member  3  and the terminal member  4  will be described later, in the case of the present embodiment, the mating member  3  is configured such that when the other inner cable  22   c  is pulled, the two long members  2  can be pulled via the mating member  3  (joint member). More specifically, as illustrated in  FIG. 1 , the terminal member  4  is connected to one end side of the mating member  3 , a terminal  21   c  of the other inner cable  22   c  is locked to the other end side of the mating member  3 , and the mating member  3  is slidably accommodated in a cylindrical joint case C. 
         [0029]    The joint case C accommodates the mating member  3  engaged with the terminal member  4 . Terminals of the two outer casings  23   a  and  23   b  are fixed to a member on one side (right side in  FIG. 1 ) of the joint case C, a terminal of an outer casing  23   c  through which the other inner cable  22   c  is inserted is fixed to a member on the other side (left side in  FIG. 1 ) of the joint case C, and thus a relay mechanism is constituted. As described above, such a relay mechanism can be applied to, for example, a vehicular seat operation device. Note that the relay mechanism described in the present embodiment is the one which interconnects one long member (the outer casing  23   c  or the inner cable  22   c ) and each of the two long members  2  (the outer casing  23   a  and the inner cable  22   a ; or the outer casing  23   b  and the inner cable  22   b ). However, the relay mechanism is not limited to the above structure. The relay mechanism may be applied to a relay mechanism that interconnects one long member and one long member such as a fuel lid opening and closing mechanism, or may be a mechanism that connects two long members and two long members. In addition, in the present embodiment, the terminal member  4  is connected to only one end side of the mating member  3 . However, the terminal members  4  may be connected to the both ends of the mating member  3 . Alternatively, the terminal member  4  may be attached to a bracket or the like in order to connect a terminal of the long member  2 . 
         [0030]    Next, the structure of the terminal member  4  and the connection structure between the terminal member  4  and the mating member  3  will be described. As described in  FIGS. 1 and 2 , the terminal member  4  includes a terminal-member main body  5  and a fitting piece  6  attached to the terminal-member main body  5 . The terminal-member main body  5  is a member for connecting the long members  2  to the mating member  3 . The terminal-member main body  5  includes an attachment part  51  to which the terminals  21   a  and  21   b  of the long members  2  are attached, and an insertion part  52  extending from the attachment part  51  and inserted into the insertion opening part  3   a.    
         [0031]    The attachment part  51  of the terminal-member main body  5  is a portion to which the terminals  21   a  and  21   b  of the long members  2  are attached. The shape of the attachment part  51  may be any shape as long as the terminals  21   a  and  21   b  of the long members  2  can be attached to the attachment part  51 . The outer shape of the attachment part  51  may be substantially columnar as illustrated in  FIGS. 2, 3 (A), and  3 (B), or may be prismatic or another shape. As described above, the manner of attaching the terminals  21   a  and  21   b  of the long members  2  to the attachment part  51  is not particularly limited, and the terminals  21   a  and  21   b  of the long members  2  are attached by a known fixation means such as engagement. In the case of attaching the terminals  21   a  and  21   b  of the long members  2  to the attachment part  51  by engagement, the engagement and fixing method is not particularly limited. The terminals  21   a  and  21   b  may be engaged with the attachment part  51  from the outer circumference side of the attachment part  51 . In a case where there is only one long member  2 , a cavity may be provided inside the insertion part  52  of the terminal-member main body  5 , and the terminal  21   a  or  21   b  may pass through the insertion part  52  and may be engaged with the attachment part  51 . Note that in the present embodiment, as illustrated in  FIGS. 3(A) and 3(B) , the attachment part  51  of the terminal-member main body  5  is formed to be a columnar shape larger than the insertion part  52 , and locking recess parts  51   a , to which cable ends (terminals  21   a  and  21   b ) of the inner cables  22   a  and  22   b  of the control cables are locked, are formed on the attachment part  51 . The locking recess part  51   a  is opened on an end surface  51   b  (see  FIG. 3(B) ) on the side from which the insertion part  52  extends, the end surface  51   b  being one of the both end surfaces of the attachment part  51 . Since the locking recess parts  51   a  are provided, the axial length of the attachment part  51  can be made shorter and the terminal-member main body  5  can be smaller and more lightweight. As described in  FIGS. 3(A) and 3(B) , the locking recess part  51   a  is opened to the outer circumference side and the end surface  51   b  of the attachment part  51 . The terminals  21   a  and  21   b  of the inner cables  22   a  and  22   b  are inserted from the outer peripheral side of the attachment part  51  and locked to the locking recess parts  51   a , and the inner cables  22   a  and  22   b  are attached along guide grooves  51   c  (see  FIG. 3(A) ) guiding the inner cables  22   a  and  22   b  when the inner cables  22   a  and  22   b  are attached. 
         [0032]    In addition, the shape of the terminal-member main body  5  illustrated in  FIGS. 3(A) and 3(B)  is only an example, and the sizes (sizes in the axial direction and around the axis) of the attachment part  51  and the insertion part  52  are not particularly limited. In addition, the shape of the locking recess part  51   a  is not limited to the illustrated shape, and may be appropriately changed according to the shape or the like of the terminals  21   a  and  21   b  of the long members  2 . In addition, in the present embodiment, as illustrated in  FIG. 3(A) , the guide groove  51   c  extends from the locking recess part  51   a  along the circumferential direction of the attachment part  51 , and then extends in the axial direction of the attachment part  51 . However, the shape of the guide groove  51   c  is not particularly limited to the illustrated shape. Furthermore, the engagement structure of the terminals  21   a  and  21   b  of the long members  2  to the attachment part  51  can be appropriately changed according the number of long members  2  to be used, the shapes or the sizes of the terminals  21   a  and  21   b , or the shape or the size of the terminal-member main body  5 , and a known engagement structure can be used. 
         [0033]    As illustrated in  FIGS. 2, 3 (A), and  3 (B), the insertion part  52  of the terminal-member main body  5  extends from the attachment part  51  coaxially with the attachment part  51 . As illustrated in  FIG. 1 , the insertion part  52  is a portion where the fitting piece  6  is fitted to and inserted into the insertion opening part  3   a  of the mating member  3 . The insertion part  52  includes a shaft part  52   b  extending in the axial direction. The shaft part  52   b  is a shaft-shaped portion of the insertion part  52 , and the fitting piece  6  is attached to the shaft part  52   b . In the present embodiment, as illustrated in  FIGS. 3(A) and 3(B) , the insertion part  52  includes a rear end portion  52   c  provided on the rear end side of the insertion part  52  and having a size capable of being inserted into the insertion opening part  3   a , the shaft part  52   b  extending from the rear end portion  52   c  to the front end side, and a front end portion  52   a  provided on the front end side of the shaft part  52   b . In the present embodiment, as illustrated in  FIGS. 3(A) and 3(B) , the front end portion  52   a  includes an substantially columnar part, and a truncated cone-shaped part formed on the substantially columnar part on the side of the front end of the insertion part. The rear end portion  52   c  is formed into an substantially columnar shape coaxially with the attachment part  51  on the front end side of the attachment part  51 . The rear end portion  52   c  is formed to have substantially the same diameter as the diameter of the substantially columnar part of the front end portion  52   a . In the present embodiment, the shaft part  52   b  is formed to have the diameter smaller than the diameter of the substantially columnar part of the front end portion  52   a  and the diameter of the rear end portion  52   c . Note that, as used herein, “front end” refers to a free end of the insertion part  52 , and “rear end” refers to the end part on the side opposite to the front end of the insertion part  52 . Similarly, the front end side and the rear end side of the shaft part  52   b  mean the same sides as the front end side (left side in  FIGS. 3(A) and 3(B) ) of the insertion part  52  and the rear end side (right side in  FIGS. 3(A) and 3(B) ) of the insertion part  52 , respectively. In addition, as will be described later, a front end part and a rear end part of a restricting part  62  mean an end part of the restricting part  62  on the front end side of the insertion part  52  and an end part of the restricting part  62  on the rear end side of the insertion part  52 , respectively, when the fitting piece  6  is attached to the shaft part  52   b.    
         [0034]    As will be described later, the shaft part  52   b  is a portion to which the fitting piece  6  is fitted, and includes engagement parts E 1  and E 2  on the front end side and the rear end side of the shaft part  52   b , respectively, in order to prevent the fitting piece  6  fitted to the shaft part  52   b  from moving in the axial direction. The engagement parts E 1  and E 2  are portions with which the both ends of each of the restricting parts  62  to be described later are brought into contact in the axial direction, and which are engaged with the restricting parts  62 . The engagement parts E 1  and E 2  restrict axial movement of the fitting piece  6 . In the present embodiment, the engagement part E 1  on the front end side is illustrated as a step between the front end portion  52   a  and the shaft part  52   b , and the engagement part E 2  on the rear end side is illustrated as a step between the shaft part  52   b  and the rear end portion  52   c . However, the engagement parts E 1  and E 2  are not limited to the step between the front end portion  52   a  of the insertion part  52  and the shaft part  52   b  and the step between the rear end portion  52   c  of the insertion part  52  and the shaft part  52   b , respectively. The structures of the engagement parts E 1  and E 2  are not particularly limited as long as the engagement parts E 1  and E 2  can be engaged with the fitting piece  6  so as to restrict axial movement of the fitting piece  6 , as will be described later. 
         [0035]    Next, the fitting piece  6  attached to the insertion part  52  will be described. The fitting piece  6  has a function of preventing the terminal member  4  from coming out of the insertion opening part  3   a  during operation or the like, after the fitting piece  6  is fitted to and attached to the insertion part  52  and the insertion part  52  is inserted into the insertion opening part  3   a . As illustrated in  FIGS. 4(A) to 4(C) , the fitting piece  6  includes elastic parts  61  and restricting parts  62  provided between the elastic parts  61  and extending in the axial direction of the insertion part  52 . As illustrated in  FIG. 1 , elastic parts  61  and the restricting parts  62  are alternately arranged in the direction around the axis so that the fitting piece  6  is coaxial with the shaft part  52   b  when the fitting piece  6  is fitted to the shaft part  52   b  of the insertion part  52  of the terminal-member main body  5 . The fitting piece  6  is configured to be elastically deformable when the fitting piece  6  is fitted to the shaft part  52   b  and/or when the fitting piece  6  is inserted into the insertion opening part  3   a . More specifically, the fitting piece  6  according to the present embodiment is configured such that, on the front end side (the front end side (left side in  FIGS. 4(A) and 4(C) ) of the shaft part  52   b  when the fitting piece  6  is attached to the shaft part  52   b ) of the fitting piece  6 , the elastic parts  61  and the restricting parts  62  are connected in the circumferential direction at a substantially ring-shaped base part  63 . Slit SL is provided along the axial direction on the substantially ring-shaped base part  63  so that the base part  63  can be expanded in diameter when the fitting piece  6  is fitted from the front end portion  52   a  of the insertion part  52 . The fitting piece  6  may be fitted to the insertion part  52  in any manner as long as the fitting piece  6  is fitted so as not to come off from the insertion part  52 . For example, as illustrated in  FIG. 2 , the rear end side (right side in  FIG. 2 ) of the fitting piece  6  is press-fitted and put in from the side of the front end portion  52   a  of the insertion part  52  while the restricting parts  62  and the base part  63  are expanded outward by using a tool or the like, and the restricting parts  62  and the base part  63  are returned to the original state after the fitting piece  6  is put in. Thereby, the fitting piece  6  is fitted. 
         [0036]    As illustrated in  FIGS. 5(A) to 5(C) , elastic parts  61  elastically deforms upon insertion into the insertion opening part  3   a , expands after the elastic parts  61  are inserted into the insertion opening part  3   a , and are engaged with the inside engagement part  3   b  of the mating member  3 . Since the elastic parts  61  are engaged with the inside engagement part  3   b  of the mating member  3 , the terminal-member main body  5  to which the fitting piece  6  is fitted is prevented from being come out of the insertion opening part  3   a  of the mating member  3 , for example, when the long member  2  is operated. In the present embodiment, as illustrated in  FIGS. 4(A) , and  5 (A) to  5 (C), the elastic part  61  is formed into a plate-spring shape expanding outward from the base part  63  to the rear end side of the shaft part  52   b , and (two) elastic parts  61  is provided such that the elastic parts  61  are separated from each other at nearly equal intervals in the circumferential direction. As illustrated in  FIG. 5(A) , the elastic parts  61  expand outward so as to be brought into contact with the opening edge of the insertion opening part  3   a  upon insertion into the insertion opening part  3   a . As illustrated in  FIG. 5(B) , after the elastic parts  61  are brought into contact with the opening edge of the insertion opening part  3   a , the insertion part  52  is further pushed into the insertion opening part  3   a  and, thereby, the elastic parts  61  which has been expanded outward elastically deform toward the axis of the insertion part  52  so that the elastic parts  61  are inserted into the insertion opening part  3   a . After the elastic parts  61  are inserted into the insertion opening part  3   a , the elastically deformed elastic parts  61  return to the original state and expand outward as illustrated in  FIG. 5(C) . As illustrated in  FIG. 5(C) , the elastic parts  61  which have returned to the original state can be engaged with the inside engagement part  3   b  of the mating member  3 . Even when the long member  2  attached to the terminal member  4  is pulled, the terminal-member main body  5  will not come out of the insertion opening part  3   a . For example, the inner cable  22   c  on the left side in  FIG. 1  is pulled to the left, the mating member  3  also moves to the left in the joint case C. When the mating member  3  moves to the left, the terminal member  4  also moves to the left together with the mating member  3  as the elastic parts  61  are engaged with the inside engagement part  3   b . Thus, the two long members  2  (inner cables  22   a  and  22   b ) on the right side in  FIG. 1  are operated. 
         [0037]    In the fitting piece  6  illustrated in  FIGS. 4(A) to 4(C) , the elastic part  61  linearly extends from the substantially ring-shaped base part  63 ; however, the shape of the elastic part  61  is not particularly limited as long as the elastic part  61  elastically deforms when the insertion part  52  is inserted into the insertion opening part  3   a , is engaged with the inside engagement part  3   b  of the mating member  3  after the insertion part  52  is inserted, and thus can prevent the terminal-member main body  5  from coming out of the insertion opening part  3   a . In addition, the number of elastic parts  61  provided at the fitting piece  6  is not particularly limited as long as the elastic parts  61  are engaged with the inside engagement part  3   b  of the mating member  3  so as to prevent the terminal-member main body  5  from coming out of the insertion opening part  3   a  of the mating member  3 . The number of elastic parts  61  may be two as illustrated in  FIGS. 4(A) to 4(C) , or may be three or more. 
         [0038]    As illustrated in  FIG. 5(B) , since the elastic part  61  is inserted while being in contact with the opening edge of the insertion opening part  3   a  when the insertion part  52  is inserted into the insertion opening part  3   a , the elastic part  61  receives a reaction force from the opening edge of the insertion opening part  3   a  in the direction (toward the right side in  FIG. 5(B) ) opposite to the insertion direction (toward the left side in  FIG. 5(B) ). Therefore, restricting parts  62 , where the both ends in the axial direction of the fitting piece  6  are engaged with the terminal-member main body  5 , is provided in order to prevent the fitting piece  6  from deviating in the axial direction with respect to the insertion part  52  due to the reaction force received by the elastic part  61  and in the direction opposite to the insertion direction. 
         [0039]    The restricting part  62  restricts axial movement of the fitting piece  6  with respect to the insertion part  52 . Here, “restrict axial movement” in the description of the restricting part  62  means to restrict axial movement of the fitting piece  6  which causes the fitting piece  6  to come off from the insertion part  52  (shaft part  52   b ) as described above. Note that “axial movement” herein does not include a case where the fitting piece  6  axially moves on the shaft part  52   b  without coming off from the shaft part  52   b  since the axial length of the restricting part  62  is shorter than that of the shaft part  52   b , for example, in a case where the fitting piece  6  axially moves a little on the shaft part  52   b  due to a small clearance between the end of the fitting piece  6  and the end of the shaft part  52   b  of the insertion part  52 . 
         [0040]    In the present embodiment, as illustrated in  FIGS. 5(A) to 5(C) , a front end part  62   a  of the restricting part  62  is engaged with the engagement part E 1  on the front end side of the shaft part  52   b , and a rear end part  62   b  of the restricting part  62  is engaged with the engagement part E 2  on the rear end side of the shaft part  52   b . Therefore, when the insertion part  52  is inserted into the insertion opening part  3   a , the rear end part  62   b  of the restricting part  62  is engaged with the engagement part E 2  on the rear end side of the shaft part  52   b , and thus the fitting piece  6  is restricted, by the restricting part  62 , from moving to the rear end side with respect to the insertion part  52 . When the elastic part  61  is engaged with the inside engagement part  3   b  of the mating member  3  through operation of the long member  2  or the like after the insertion part  52  is inserted into the insertion opening part  3   a , a force in the direction of moving the fitting piece  6  to the front end side of the insertion part  52  with respect to the insertion part  52  is applied to the fitting piece  6  due to a reaction force from the inside engagement part  3   b . However, since the front end part  62   a  of the restricting part  62  is engaged with the engagement part E 1  on the front end side of the shaft part  52   b , the fitting piece  6  is restricted from moving to the front end side with respect to the insertion part  52 . 
         [0041]    The restricting part  62  is provided between the elastic parts  61  provided at the fitting piece  6 . That is, the restricting part  62  is provided between the elastic parts  61  such that the restricting part  62  is separated from or adjacent to the elastic part  61  in the circumferential direction. Similarly to the elastic part  61 , the restricting part  62  is a plate-shaped member extending from the ring-shaped base part  63 . In the present embodiment, the restricting part  62  has an substantially rectangular shape. In the present embodiment, as illustrated in  FIGS. 4(A) to 4(C) , two restricting parts  62  are provided in spaces between the two elastic parts  61 . However, the number of restricting parts  62  is not particularly limited. For example, in a case where four elastic parts  61  are provided, it is not necessary to provide a restricting part  62  in each of the four spaces between the elastic parts  61  as long as at least two restricting parts  62  are provided. 
         [0042]    Next, the shaft part  52   b  and the restricting part  62  will be described in more detail. 
         [0043]    As illustrated in  FIGS. 2, 3 (A), and  3 (B), the shaft part  52   b  includes a reduced-diameter part  52   d  reduced in diameter and provided on one side in the axial direction. The reduced-diameter part  52   d  is a portion of the shaft part  52   b , where its diameter is reduced in order to allow a displacement part  62   c  which is displaced inward in the radial direction of the fitting piece  6  to be positioned along the reduced-diameter part  52   d  when the fitting piece  6  is attached to the shaft part  52   b . The shape or the structure of the reduced-diameter part  52   d  can be changed according to the shape or the structure of the displacement part  62   c  as long as the reduced-diameter part  52   d  is reduced in diameter at least on a part of the outer circumference of the shaft part  52   b  so that the displacement part  62   c  is positioned along the reduced-diameter part  52   d . The reduced-diameter part  52   d  may be formed at an axial position corresponding to the position where the displacement part  62   c  of the restricting part  62  is formed, and may be provided on one side in the axial direction, that is, at least one of the front end side and the rear end side of the shaft part  52   b . In the present embodiment, as illustrated in  FIGS. 2, 3 (A), and  3 (B), the shaft part  52   b  includes a columnar part  52   e , and the reduced-diameter part  52   d  smaller in diameter than the columnar part  52   e . In addition, the reduced-diameter part  52   d  is illustrated as a tapered part reduced in diameter toward the rear end of the shaft part  52   b , and the reduced-diameter part  52   d  is provided adjacent to the engagement part E 2  on the rear end side. Furthermore, in the present embodiment, as illustrated in  FIGS. 3(A) and 3(B) , the engagement part E 1  on the front end side illustrated as a step is formed between the front end portion  52   a  and the columnar part  52   e  of the insertion part  52 , and the engagement part E 2  on the rear end side is formed as a step between the rear end portion  52   c  and the end part of the reduced-diameter part  52   d  illustrated as a tapered part of the insertion part  52 . In the present embodiment, the engagement part E 1  on the front end side is formed as a step with the height, with respect to the end part of the columnar part  52   e  of the shaft part  52   b , nearly equal to the thickness of the plate member of the fitting piece  6 , and the engagement part E 2  on the rear end side is formed as a step with the height, with respect to the rear end of the reduced-diameter part  52   d  of the shaft part  52   b , higher than the height of the step on the engagement part E 1  side. Note that the reduced-diameter part  52   d  may have a shape other than a tapered shape. For example, the reduced-diameter part  52   d  may be reduced in diameter stepwise, or may be reduced in diameter in a groove shape. In addition, in the present embodiment, as illustrated in  FIG. 3(A) , the reduced-diameter part  52   d  is reduced in diameter continuously in the circumferential direction of the shaft part  52   b ; however, the reduced-diameter part  52   d  may be reduced in diameter only on part in the circumferential direction. 
         [0044]    The restricting part  62  includes the displacement part  62   c  correspondingly to the above-described reduced-diameter part  52   d . As illustrated in  FIG. 6(A) , the fitting piece  6  is attached to the terminal-member main body  5  such that the displacement part  62   c  is positioned along the reduced-diameter part  52   d . The displacement part  62   c  is disposed along the reduced-diameter part  52   d  when the fitting piece  6  is attached to the terminal-member main body  5 . Since the displacement part  62   c  is displaced in advance inward in the radial direction, even if the restricting part  62  is displaced outward in the radial direction and its diameter is increased when the fitting piece  6  is attached to the terminal-member main body  5 , the restricting part  62  returns to the original state before the diameter is increased due to elasticity of the restricting part  62 . Therefore, the restricting part  62  can be engaged with the engagement part E 2 . By more securely engaging the restricting part  62  with the terminal-member main body  5 , the terminal member  4  and the mating member  3  can be connected without causing the restricting part  62  to get on the engagement part. Here, “along the reduced-diameter part  52   d ” means, as will be described later, that the displacement part  62   c  is disposed to allow the restricting part  62  to be securely engaged with the terminal-member main body  5  according to the shape and the position of the reduced-diameter part  52   d  when, for example, the fitting piece  6  is fitted from the side of the front end portion  52   a  of the insertion part  52  while being expanded and is attached to the shaft part  52   b . The displacement part  62   c  may be in contact with the reduced-diameter part  52   d  or may be in a state not contacting with the reduced-diameter part  52   d  (state where the displacement part  62   c  is slightly separated from the surface of the reduced-diameter part  52   d ) as long as the displacement part  62   c  is configured so as to be positioned along the reduced-diameter part  52   d . In the present embodiment, the displacement part  62   c  is disposed along (so as to be fitted into) the reduced-diameter part  52   d , the restricting part  62  is engaged with the engagement parts E 1  and E 2 , and the like, and thus axial movement of the fitting piece  6  is restricted. However, for example, movement of the fitting piece  6  may be restricted by fitting the displacement part  62   c  into a groove-like reduced-diameter part  52   d  and engaging the displacement part  62   c  with the groove-like reduced-diameter part  52   d , or movement of the fitting piece  6  may be restricted by a friction force due to contact between the surface of the displacement part  62   c  and the surface of the reduced-diameter part  52   d.    
         [0045]    As illustrated in  FIGS. 4(C) and 6(A) , the displacement part  62   c  is displaced toward the axis of the fitting piece  6 . That is, the displacement part  62   c  is relatively displaced toward the axis of the fitting piece  6  (closer to the axis of the fitting piece  6 ). Note that the displacement part  62   c  may be displaced, for example, by bending the fitting piece  6  upon manufacture of the fitting piece  6 , or may be displaced before the fitting piece  6  is assembled to the terminal-member main body  5 . In the present embodiment, as illustrated in  FIGS. 4(C) and 6(A) , the reduced-diameter part  52   d  is a tapered part reduced in diameter toward the rear end, and the displacement part  62   c  is displaced toward the inside of the fitting piece  6  correspondingly to the tapered part. More specifically, the restricting part  62  is bent inward at the central part in the axial direction, and includes a flat part  62   d  extending in the axial direction nearly in parallel to the axis of the fitting piece  6  and the tapered displacement part  62   c  inclined with respect to the flat part  62   d . The tapered displacement part  62   c  is displaced to the side of the reduced-diameter part  52   d  illustrated as a tapered part. Here, the displacement part  62   c  may be displaced “correspondingly to the tapered part” in any manner as long as the displacement part  62   c  is displaced at a position and within a range where the displacement part  62   c  does not interfere with the reduced-diameter part  52   d  illustrated as the tapered part, does not deform the shape of the tapered part, and does not inhibit the connection between the terminal member  4  and the mating member  3 . The displacement part  62   c  is not necessarily formed into a tapered shape. For example, the displacement part  62   c  may be curved or may be configured to project stepwise to the inside of the fitting piece  6 . In addition, in a case where the displacement part  62   c  is formed into a tapered shape, the taper angle of the displacement part  62   c  may be substantially identical to or different from the taper angle of the tapered part of the reduced-diameter part  52   d.    
         [0046]    As described above, as illustrated in  FIG. 2 , the fitting piece  6  is fitted to from the front end side (front end portion  52   a ) of the insertion part  52  with a tool or the like. At that time, the restricting parts  62  of the fitting piece  6  expand outward in the radial direction while being elastically deformed. If the fitting piece  6  is further fitted toward the rear end side of the insertion part  52  in that state, the substantially ring-shaped base part  63  is elastically deformed and expanded by the front end portion  52   a  of the insertion part  52 . When the substantially ring-shaped base part  63  goes beyond the front end portion  52   a , the fitting piece  6  returns to the original shape and is fitted to the shaft part  52   b . In this state, the end part  62   a  on the front end side of the restricting part  62  and the end part  62   b  on the rear end side of the restricting part  62  are engaged with the engagement parts E 1  and E 2 , respectively, the fitting piece  6  is sandwiched between the engagement parts E 1  and E 2  and is fitted to the shaft part  52   b  of the insertion part  52 , and thus the fitting piece  6  is attached to the terminal-member main body  5 . 
         [0047]    As illustrated in the above-described Patent Document 1, also in the case of a conventional structure, a structure including an substantially ring-shaped base part and a restricting part exists, and a fitting piece is attached to an insertion part in a similar attachment manner. A case of attaching the fitting piece to the insertion part in this conventional structure will be described with reference to  FIGS. 7(A) to 7(D), 8(A) , and  8 (B). 
         [0048]    In the conventional structure, as illustrated in  FIG. 7(A) , a shaft part  520   b  does not include a reduced-diameter part, and a restricting part  620  is provided in parallel to the axis of the fitting piece  600 . From the state illustrated in  FIG. 7(A) , front end parts of the restricting parts  620  of the fitting piece  600  are inserted and attached to a front end portion  520   a  of an insertion part  520 . However, when the fitting piece  600  is strongly inserted to the insertion part  520 , unless the fitting piece  600  is pushed in a state where the fitting piece  600  and the insertion part  520  are coaxial with each other and, additionally, a force is evenly applied to the fitting piece  600 , the axis of the fitting piece  600  may be inclined with respect to the axis of the insertion part  520  as illustrated in  FIG. 7(B) . If the fitting piece  600  is strongly pushed to the insertion part  520  in this state, at least one restricting part  620  (restricting part  620  on the lower side in  FIG. 7(C) ) may be plastically deformed as illustrated in  FIG. 7(C) . In such a case, if the fitting piece  600  is further inserted to the insertion part  520  in this state, even though the fitting piece  600  is attached to a shaft part  520   b  of the insertion part  520 , the plastically deformed restricting part  620  is not engaged with a step part St 2  on the rear end side of the shaft part  520   b  of the insertion part  520 , as illustrated in  FIG. 7(D) , and axial movement of the fitting piece  600  with respect to the insertion part  520  cannot be restricted. That is, as illustrated in  FIG. 8(A) , if the insertion part  520  is inserted into an insertion opening part  300   a  of a mating member  300  in a state where an end part on the rear end side of the restricting part  620  cannot be engaged with the step part St 2  on the rear end side of the shaft part  520   b , an opening edge of the insertion opening part  300   a  and an elastic part  610  which expands outward are brought into contact with each other. If the insertion part  520  is further inserted in that state after the opening edge of the insertion opening part  300   a  and the elastic part  610  are brought into contact with each other, the elastic part  610  receives a reaction force toward the right side in the figure from the opening edge of the insertion opening part  300   a , and the fitting piece  600  receives a force toward the right side from the opening edge. One of the restricting parts  620  of the fitting piece  600  is plastically deformed and is not engaged with the step part St 2 , resulting in the fitting piece  600  being unstably fitted to the shaft part  520   b . Therefore, if the insertion part  520  is further inserted into the insertion opening part  300   a  in that state, the fitting piece  600  which is unstably fitted goes beyond the step St 2  of the shaft part  520   b  and gets on a portion away from the axis of the shaft part  520   b  as illustrated in  FIG. 8(B) . In such a case, a terminal member may not be able to be attached well to a mating member. It may be necessary to attach the fitting piece  600  after applying post-processing or processing for correction to the fitting piece  600 , or to replace the fitting piece  600  before attaching the fitting piece  600  again. 
         [0049]    In contrast, in the terminal connection structure  1  according to the present invention, as illustrated in  FIG. 6(A) , the shaft part  52   b  includes the reduced-diameter part  52   d , the restricting part  62  includes the displacement part  62   c , and the fitting piece  6  is attached to the terminal-member main body  5  such that the displacement part  62   c  is positioned along the reduced-diameter part  52   d . Therefore, the displacement part  62   c  displaced toward the axis of the fitting piece  6  enters inside, in the radial direction, of the terminal member  4  toward the reduced-diameter part  52   d , and the both ends in the axial direction of the restricting part  62  of the fitting piece  6  are engaged with the terminal-member main body  5 . Then, even if the restricting part  62  expands outward to some extent when the fitting piece  6  is attached from the front end portion  52   a  side of the insertion part  52 , since the displacement part  62   c  is displaced toward the axis of the fitting piece  6 , the displacement part  62   c  is disposed along the reduced-diameter part  52   d , that is, disposed such that the displacement part  62   c  is not separated from the reduced-diameter part  52   d  to the extent that the displacement part  62   c  gets on the engagement part E 2  on the rear end side. Therefore, even in a case where the restricting part  62  (displacement part  62   c ) expands outward to some extent and is plastically deformed to some extent upon insertion, the restricting part  62  can still be engaged with the shaft part  52   b.    
         [0050]    In addition, as illustrated in  FIG. 6(B) , even in a case where the restricting part  62  is plastically deformed to a relatively large extent, the restricting part  62  of the fitting piece  6  is displaced to the inside due to the existence of the displacement part  62   c  before the fitting piece  6  is attached to the terminal-member main body  5 . Accordingly, even if the restricting part  62  is plastically deformed to some extent, the restricting part  62  is more securely engaged with the shaft part  52   b  than in the conventional structure. In a state where the fitting piece  6  is fitted to the shaft part  52   b  (see  FIG. 5(A) ), if the insertion part  52  of the terminal-member main body  5  is inserted into the insertion opening part  3   a  of the mating member  3  (see  FIG. 5(B) ), the elastic part  61  is brought into contact with the opening edge of the insertion opening part  3   a , and the elastic part  61  receives a reaction force toward the right side in  FIG. 5(B)  from the opening edge of the insertion opening part  3   a . At that time, as illustrated in  FIG. 6(A) , the displacement part  62   c  enters inside, in the radial direction of the terminal member, toward the reduced-diameter part  52   d , and the both ends in the axial direction of the restricting part  62  are engaged with the terminal-member main body  5 . Alternatively, as illustrated in  FIG. 6(B) , even if the restricting part  62  is deformed, the both ends in the axial direction of the restricting part  62  are engaged with the terminal-member main body  5 . Therefore, with the displacement part  62   c  and the reduced-diameter part  52   d , the rear end part  62   b  of the restricting part  62  does not go beyond the engagement part E 2  even if the fitting piece  6  receives a reaction force from the opening edge of the insertion opening part  3   a  when the insertion part  52  is inserted into the insertion opening part  3   a , and axial movement of the fitting piece  6  with respect to the terminal-member main body  5  is restricted. 
         [0051]    In addition, in  FIGS. 5(A) to 5(C) , a description has been given regarding restriction of axial movement of the fitting piece  6  when the terminal member  4 , to which the fitting piece  6  has already been attached, is attached to the mating member  3 . The same effect is achieved when the fitting piece  6  is attached to the insertion part  52  with a tool. For example, when the fitting piece  6  is attached to the insertion part  52 , only the fitting piece  6  is attached to the tool and the insertion part  52  is pushed and inserted into the fitting piece  6  from the rear end side of the fitting piece  6  attached to the tool, and thus the fitting piece  6  is attached to the insertion part  52 . In the conventional structure, if the insertion part  520  is further pushed to the tool in a state where the fitting piece  600  has already been fitted to the insertion part  520 , the rear end part of the restricting part  620  may get on the step part St 2 . In contrast, in the terminal member  4  including the reduced-diameter part  52   d  and the displacement part  62   c , as described above, even in a case where the restricting part  62  is plastically deformed upon insertion, engagement between the restricting part  62  and the shaft part  52   b  can be maintained. Therefore, also when the fitting piece  6  is attached to the insertion part  52 , the rear end part  62   b  of the restricting part  62  does not go beyond the engagement part E 2 , and axial movement of the fitting piece  6  with respect to the terminal-member main body  5  can be restricted. 
         [0052]    In addition, in a case where the engagement parts E 1  and E 2  engaged with the restricting part  62  are provided at the front end side and the rear end side of the shaft part  52   b , respectively, the front end part  62   a  and the rear end part  62   b  of the restricting part  62  are engaged with the engagement parts E 1  and E 2 , respectively, and the reduced-diameter parts  52   d  are provided adjacent to the engagement parts E 1  and E 2 , engagement between the front end part  62   a  of the restricting part  62  and the engagement part E 1 , and engagement between the rear end part  62   b  of the restricting part  62  and the engagement part E 2  have been completed when the fitting piece  6  is attached to the terminal-member main body  5 , and the front end part and the rear end part of the restricting part  62  are prevented from getting on the engagement parts E 1  and E 2 , respectively. Therefore, axial movement of the fitting piece  6  with respect to the terminal-member main body  5  is restricted. 
         [0053]    In addition, in the present embodiment, the reduced-diameter part  52   d  is provided adjacent to the engagement part E 2  on the rear end side, and the displacement part  62   c  is provided on the rear end side of the restricting part  62 . The engagement part E 2  on the rear end side is a portion with which the rear end part  62   b  of the restricting part  62  is engaged when the insertion part  52  is inserted into the insertion opening part  3   a  or when the fitting piece  6  is attached to the insertion part  52  with a tool. Therefore, in a case where the reduced-diameter part  52   d  is provided adjacent to the engagement part E 2  on the rear end side and the displacement part  62   c  is provided on the rear end side of the restricting part  62 , the rear end part  62   b  of the restricting part  62  and the engagement part E 2  of the rear end side are more securely engaged with each other. That is, engagement of the restricting part  62  can be secured in various states between the state of the displacement part  62   c  illustrated in  FIG. 6(A)  (a case where the restricting part  62  is hardly plastically deformed) and the state of the displacement part  62   c  illustrated in  FIG. 6(B)  (a case where the restricting part  62  expands outward and is plastically deformed). Therefore, the allowable deformation range of the restricting part  62  upon insertion to the insertion part  52  can be made greater than in the conventional structure. Furthermore, since the reduced-diameter part  52   d  is provided, it is not necessary to increase the diameter of the rear end portion  52   c  of the insertion part  52  in order to form the engagement part E 2  on the rear end side, the size of the insertion opening part  3   a  of the mating member  3  into which the rear end portion  52   c  of the insertion part  52  is inserted can be made small, and the mating member  3  can be made compact. 
         [0054]    In addition, in the present embodiment, the reduced-diameter part  52   d  is a tapered part reduced in diameter toward the rear end, and the displacement part  62   c  is displaced toward the inside of the fitting piece correspondingly to the tapered part. In a case where the reduced-diameter part  52   d  is formed into a groove without the length in the axial direction, dimensional accuracy is required in order to align the axial positions of the reduced-diameter part  52   d  and the displacement part  62   c . However, in a case where the reduced-diameter part  52   d  is formed into a tapered part reduced in diameter toward the rear end, even if there is a dimensional error in the axial direction of the displacement part  62   c , the dimensional error is absorbed and the displacement part  62   c  can be easily positioned along the tapered surface of the tapered part. The fitting piece  6  can also be easily attached, and the rear end part  62   b  of the restricting part  62  is more securely engaged with the engagement part E 2  on the rear end side. 
         [0055]    In addition, in the present embodiment, the restricting part  62  has spring elasticity, and the displacement part  62   c  is configured to be displaced so as to be brought into contact with the reduced-diameter part  52   d  by an elastic force due to the spring elasticity in a state where the fitting piece  6  is mounted to the terminal-member main body  5 . Due to the spring elasticity of the restricting part  62 , at least part of the displacement part  62   c  of the restricting part  62  is brought into contact with the reduced-diameter part  52   d . More specifically, when the fitting piece  6  is mounted to the terminal-member main body  5 , the displacement part  62   c  displaced toward the axis of the fitting piece  6  once expands outward, and then returns to be displaced inward due to the spring elasticity. The end part (rear end part  62   b  of the restricting part) on the rear end side of the displacement part  62   c  returned to be displaced inward due to the spring elasticity of the restricting part  62  (or the entire inside surface of the displacement part  62   c ) is brought into contact with the tapered part of the reduced-diameter part  52   d . As described above, in a case where the restricting part  62  has spring elasticity and the displacement part  62   c  is brought into contact with the surface of the reduced-diameter part  52   d  due to the elastic force of the spring elasticity, the restricting part  62  is more securely engaged with the terminal-member main body  5 . Therefore, axial movement of the fitting piece  6  can be more reliably restricted. 
       REFERENCE SIGNS LIST 
       [0000]    
       
         
           
               1 : Terminal connection structure 
               2 : Long member 
               21   a ,  21   b ,  21   c : Terminal 
               22   a ,  22   b ,  22   c : Inner cable 
               23   a ,  23   b ,  23   c : Outer casing 
               3 : Mating member 
               3   a : Insertion opening part 
               3   b : Inside engagement part 
               4 : Terminal member 
               5 : Terminal-member main body 
               51 : Attachment part 
               51   a : Locking recess 
               51   b : End surface of attachment part 
               51   c : Guide groove 
               52 : Insertion part 
               52   a : Front end portion of insertion part 
               52   b : Shaft part of insertion part 
               52   c : Rear end portion of insertion part 
               52   d : Reduced-diameter part 
               52   e : Columnar part 
               6 : Fitting piece 
               61 : Elastic part 
               62 : Restricting part 
               62   a : Front end part of restricting part 
               62   b : Rear end part of restricting part 
               62   c : Displacement part 
               62   d : Flat part 
               63 : Base part 
             C: Joint case 
             E 1 , E 2 : Engagement part 
             S: Internal space 
             SL: Slit