Patent Publication Number: US-10784625-B2

Title: Connector including fitting assuring component

Description:
CROSS-REFERENCES TO RELATED APPLICATION(S) 
     This application is based on and claims priority from Japanese Patent Application No. 2018-205579 filed on Oct. 31, 2018, and the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     Field of the Invention 
     The present invention relates to a connector which is equipped with a housing and a fitting assuring component. 
     Description of Related Art 
     A technique of detecting whether a housing and a counterpart housing are in a properly fitted state (hereinafter referred to as a “complete fitting state”) using a fitting assuring component (what is called CPA (connector position assurance) is known. 
     In general, fitting assuring components (CPAs) are used in housings having a lock arm capable of switching between keeping and cancellation of a complete fitting state (mentioned above). More specifically, the lock arm and the fitting assuring component are configured so that interference between them is avoided and the fitting assuring component is attached at a prescribed attachment position only in the complete fitting state. In other words, when the housing and the counterpart housing are not in the complete fitting state, the fitting assuring component interferes with the lock arm and is not attached at the prescribed attachment position. Thus, whether the housing and the counterpart housing are in the complete fitting state can be detected on the basis of whether the fitting assuring component can be attached at the prescribed attachment position. 
     As for details of the above terminal-attached electric wire, refer to JP 4,664,436 B and JP 2017-098222 A. 
     SUMMARY 
     Incidentally, from the viewpoint of improving the functions of a connector, to prevent occurrence of an event that the complete fitting state is cancelled unintentionally, it is conceivable to add, to the connector, a member for restricting an unintentional movement of a lock arm. However, the size of the connector may be increased if such a component is added carelessly. Thus, it is desirable to construct a connector so as to restrict movement of a lock arm in such a manner that size increase of the connector is minimized. 
     An object of the invention is to provide a connector capable of preventing occurrence of an event that fitting in or with a counterpart connector is canceled unintentionally, in such a manner that size increase of the connector is minimized. 
     Embodiments of the present invention provide the following items (1) to (3): 
     (1) A connector comprising: 
     
         
         
           
             a housing having a lock portion capable of switching between keeping and cancellation of a state of the housing and a counterpart housing being fitted with each other; and 
             a fitting assuring component attached to the housing and detecting whether the housing and the counterpart housing being fitted with each other by being prevented from interfering with the lock portion and attached at a preset attachment position upon the housing and the counterpart housing being fitted with each other, 
             the fitting assuring component having a hollow portion to house at least part of the lock portion to surround the at least part of the lock portion upon the fitting assuring component being located at the preset attachment position, and the fitting assuring component preventing the lock portion from switching to cancellation of the state of the housing and the counterpart housing being fitted with each other by interfering with an inside wall of the hollow portion.
 
(2) The connector according to the item (1), wherein
 
             the lock portion is a cantilever-shaped lock arm switching between keeping and cancellation of the state of the housing and the counterpart housing being fitted with each other by deforming in a preset bending direction; and 
             the inside wall of the hollow portion having: one portion facing the lock portion on one side in the bending direction upon the fitting assuring component being in the preset attachment position; the other portion facing the lock portion on the other side in the bending direction; and an interference portion between the one portion and the other portion and preventing the lock portion from deforming to cancel the state of the housing and the counterpart housing being fitted with each other.
 
(3) The connector according to the item (1) or the item (2), wherein
 
             the housing having: a cantilever-shaped lock piece capable of deforming elastically in a direction to separate from the fitting assuring component; and a lock projection provided in the lock piece and preventing the fitting assuring component from separating from the housing by engaging with the fitting assuring component. 
           
         
       
    
     According to first aspect of the invention, relating to the item (1), when the fitting assuring component (what is called CPA) is located at the prescribed attachment position, at least part of the lock portion of the housing is housed in the hallow portion of the fitting assuring component and surrounded by the fitting assuring component. As a result, the lock portion is prevented from receiving an unintentional external force or the like from the outside. Furthermore, should an unintentional external force acts on the lock portion from the outside, the lock portion interferes with the inside wall of the hollow portion and is prevented from switching so as to cancel the fitting state. In this manner, unintentional cancellation of the fitting between the connector and the counterpart connector can be prevented. 
     Furthermore, the size of the connector can be made smaller than in a case that a member for protecting the above-described lock portion or a member that interferes with the lock portion is provided separately from the fitting assuring component because part (i.e., hollow portion) of the fitting assuring component serves as such a member. 
     As such, the connector having the above configuration can prevent unintentional cancellation of fitting in or with the counterpart connector while minimizing size increase of the connector. 
     According to second aspect of the invention, relating to the item (2), the interference portion for restricting movement of the lock portion by interfering with the lock portion (i.e., lock arm) is provided in the hollow portion at a middle position in the bending direction of the lock portion. The middle position is located between the one portion (e.g., a top wall of the hollow portion) and the other portion (e.g., a bottom wall of the hollow portion) of the inside wall in the bending direction. Thus, when, for example, an unintentional external force acts on the lock portion, the lock portion comes into contact with the interference portion of the inside wall before reaching the one portion or the other portion of the inside wall and is prevented from being bent further. Thus, the movable range of the lock portion is made narrower than in a case that the lock portion is prevented from being bent further by coming into contact with the one portion or the other portion. As such, the connector having the above configuration can prevent unintentional cancellation of fitting between the connector and the counterpart connector more reliably. 
     According to third aspect of the invention, relating to the item (3), the cantilever-shaped lock piece is provided with the lock projection to engage with the fitting assuring component. Thus, when the fitting assuring component comes into contact with the lock projection in attaching the fitting assuring component to the housing, the lock piece is bent elastically in such a direction as to go away from the fitting assuring component. As a result, attachment of the fitting assuring component to the housing is made easier than in a case that the lock projection is provided in a portion that is hard to bend. As such, the connector having the above configuration can increase the efficiency of work of attaching the fitting assuring component to the housing. 
     The invention can provide a connector capable of preventing occurrence of an event that fitting in or with a counterpart connector is canceled unintentionally, in such a manner that size increase of the connector is minimized. 
     The invention has been described above concisely. The details of the invention will become more apparent when the description of the embodiments described below are read through with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a connector according to an embodiment of the present invention. 
         FIG. 2A  is a perspective view of a fitting assuring component shown in  FIG. 1  and  FIG. 2B  is a rear view of the fitting assuring component. 
         FIG. 3A  is a rear perspective view of a housing shown in  FIG. 1  and FIG.  3 B is a top view of the housing. 
         FIG. 4A  is a sectional view taken along line A-A in  FIG. 1  and showing a halfway stage of attachment of the fitting assuring component to the housing, and  FIG. 4B  is an enlarged view of part B of  FIG. 4A . 
         FIG. 5  is a sectional view corresponding to  FIG. 4A  and shows a stage that a counterpart housing and the housing have been rendered in a complete fitting state in a state that the fitting assuring component is located at a tentative lock state. 
         FIG. 6  is a sectional view corresponding to  FIG. 4A  and shows a stage that the fitting assuring component has moved from the tentative lock state to a real lock state in a state that the counterpart housing and the housing are in the complete fitting state. 
         FIG. 7  is an enlarged view of part C of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     Embodiment 
     A connector  1  according to an embodiment of the present invention will be hereinafter described with reference to the drawings. In the following, for convenience of description, the “front-rear direction,” “width direction,” “top-bottom direction,” “front,” “rear,” “top,” and “bottom” are defined as shown in  FIG. 1 . The “front-rear direction” and the “width direction” are perpendicular to each other. The “front-rear direction” coincides with a direction in which the connector  1  and a counterpart connector  5  (see  FIGS. 5 and 6 ) are fitted with each other. The front side is defined as the fore side (left side in  FIG. 1 ) of a fitting direction in which the connector  1  is fitted in the counterpart connector  5 , and the rear side is defined as the back side (right side in  FIG. 1 ), opposite to the fore side, in the fitting direction. 
     As shown in  FIG. 1 , the connector  1  includes a housing  2 , a fitting assuring component  3  (what is called CPA) which is attached to a top portion of the housing  2 , and a front holder  4  which is attached to the housing  2  from the front side. The structures of the individual components of the connector  1  will be hereinafter described in order. 
     First, the housing  2  will be described with reference to  FIG. 1 ,  FIGS. 3A and 3B , and  FIGS. 4A and 4B . The housing  2  which is made of a resin is equipped with a housing main body  11  which is approximately shaped like a rectangular prism. A top wall of the housing main body  11  projects rearward by a prescribed distance from its rear end surface. The thus-projected portion will be hereinafter referred to as a “projected portion.” The housing main body  11  is fitted into a hood portion of a counterpart housing  61  of a counter connector  5  (see  FIGS. 5 and 6 ), whereby the housing  2  and the counterpart housing  61  are fitted with each other. 
     As shown in  FIGS. 3A and 3B  and  FIGS. 4A and 4B , plural terminal housing rooms  12  for housing respective female terminals (not shown) are formed inside the housing main body  11  so as to extend in the front-rear direction. In this example, the plural terminal housing rooms  12  are formed so as to be arranged in the horizontal direction in each of two (i.e., top and bottom) stages. In each terminal housing room  12 , a small-diameter insertion hole  13  is formed through a front end portion and a rear end portion is opened. The female terminals are inserted into the respective terminal housing rooms  12  from the rear end side. When the housing  2  and the counterpart housing  61  are fitted with each other, male terminals  62  housed in the counterpart housing  61  are inserted into the respective insertion holes  13  (see  FIGS. 5 and 6 ). 
     In fitting the housing  2  into the counterpart housing  61 , a state that the housing  2  and the counterpart housing  61  are fitted with each other completely (i.e., the state shown in  FIG. 5 ) past a halfway fitting state. In the following, for convenience of description, the former state will be referred to as a “complete fitting sate” and the latter state will be referred to as an “incomplete fitting state.” 
     As shown in  FIG. 4A , a cantilever-shaped lance  14  which can deform elastically in the top-bottom direction is provided in each terminal housing room  12  so as to enter the terminal housing room  12  from below and extend forward from a position on the rear end side of the terminal housing room  12 . A lance projection  15  which projects upward in the terminal housing room  12  is formed at the tip of the lance  14  so as to be unitized with the other portion of the lance  14 . The lance  14  exercises a function of preventing the associated female terminal from coming off rearward when a prescribed edge portion of the female terminal that is inserted into the terminal housing room  12  from the rear side is locked on the lance projection  15 . 
     In a state that the female terminal is located at a regular insertion position (in other words, a state that the lance  14  is exercising its coming-off preventing function) in the terminal housing room  12 , the lance projection  15  is put in the edge portion of the female terminal, whereby the lance  14  keeps a regular posture (see  FIG. 4A ) that it is not deformed elastically. On the other hand, in a state that the female terminal is located at a halfway insertion state (i.e., a state that the lance  14  is not exercising its coming-off preventing function), the lance  14  keeps a posture that it is deformed downward (i.e., away from the female terminal) elastically because the lance projection  15  cannot put in the edge portion of the female terminal. 
     As shown in  FIGS. 3A and 3B , a rear portion of the top wall of the housing main body  11  is formed (unitized) with a pair of protective walls  16  which are erected upward, extend in the front-rear direction, and are opposed to each other in the width direction. The space formed between the pair of protective walls  16  functions as a space for attachment of the fitting assuring component  3 . The fitting assuring component  3  is inserted into this space from the rear side and attached to the top wall of the housing main body  11 . 
     The inner surface, in the width direction, of each protective wall  16  is formed with a guide groove  17  which is recessed outward in the width direction, is opened inside in the width direction, and extends in the front-rear direction. The top surface of each protective wall  16  is formed with a guide rib  18  which is erected upward and extend in the front-rear direction. The guide grooves  17  and the guide ribs  18  are used for guiding the fitting assuring component  3 . 
     The projected portion of the top wall of the housing main body  11  is formed with, at the center in the width direction, a pair of slits  19  which extend in the front-rear direction and are spaced from each other in the width direction. A portion, located between the pair of slits  19 , of the projected portion is a cantilever-shaped lock piece  20  which can deform elastically in the top-bottom direction. A lock projection  21  projects upward from the top surface of the lock piece  20 . The lock projection  21  has a function of holding the fitting assuring component  3  at a tentative lock position (see  FIG. 5 ). 
     As shown in  FIGS. 3A and 3B , a front portion of the top wall of the housing main body  11  is formed (unitized) with a pair of protective walls  22  which are erected upward, extend in the front-rear direction, and are opposed to each other in the width direction. A lock portion  23  is provided in the space formed between the pair of protective walls  22 . The lock portion  23  has a function of enabling switching between keeping and cancellation of the complete fitting state of the housing  2  and the counterpart housing  61  through engagement/disengagement between the lock portion  23  and a counterpart lock portion  63  (see  FIGS. 5 and 6 ) of the counterpart housing  61 . 
     As shown in  FIGS. 3A and 3B  and  FIGS. 4A and 4B , the lock portion  23  has a pair of lock arms  24  which extend rearward like a cantilever from a front end portion, between the pair of protective walls  22 , of the front portion of the top wall of the housing main body  11  so as to be spaced from each other in the width direction. The pair of lock arms  24  can deform elastically in the top-bottom direction. 
     The pair of lock arms  24  are unitized with a manipulation portion  25  which connects tip portions of the pair of lock arms  24  in the width direction and an engagement portion  26  which connects intermediate portions, in the front-rear direction, of the pair of lock arms  24  in the width direction. The complete fitting state of the housing  2  and the counterpart housing  61  is maintained as a result of engagement of the counterpart lock portion  63  (see  FIGS. 5 and 6 ) with the engagement portion  26 . When the manipulation portion  25  is pushed down in the complete fitting state, the engagement portion  26  is disengaged from the counterpart lock portion  63 , whereby the housing  2  and the counterpart housing  61  can be separated from each other in the front-rear direction. 
     A link portion  27  which connects (is unitized with), in the width direction, so as to bridge, from above, the pair of lock arms  24  with a space formed in between, a pair of boundary portions between the pair of protective walls  22  and the pair of protective walls  16  which are formed on the front portion and the rear portion of the top wall of the housing main body  11 , respectively. The link portion  27  has a function of suppressing excessive upward deformation of the pair of lock arms  24  by interfering with them when they are deformed upward elastically. 
     Next, the fitting assuring component  3  will be described with reference to  FIGS. 2A and 2B . The fitting assuring component  3  which is made of a resin has a base portion  31  which is approximately shaped like rectangular frame and has a hollow portion  32  inside. The base portion  31  is composed of a top wall  33  which extends in the width direction, a bottom wall  34  which extends in the width direction, and a pair of side walls  35  which extend in the top-bottom direction so as to connect two end portions, in the width direction, of the top wall  33  and two end portions, in the width direction, of the bottom wall  34 , respectively. The hollow portion  32  is a space surrounded by the top wall  33 , the bottom wall  34 , and the pair of side walls  35 . In this example, the hollow portion  32  is a through-hole that penetrates through the fitting assuring component  3  in the front-rear direction. 
     The bottom wall  34  is formed (unitized) with a pair of seat portions  36  which project upward from two respective end portions, in the width direction, of the top surface of the bottom wall  34 . On the hollow portion  32 , a rectangular space, surrounded by the top wall  33 , the pair of seat portions  36 , and the pair of side walls  35 , is designed so as to have a width and a height that allow the manipulation portion  25  of the lock portion  23  to be inserted into the rectangular space. 
     Top portions of the two outer side surfaces, in the width direction, of the base portion  31  are formed with a pair of guide grooves  37 , respectively, which are recessed upward, are opened at the bottom, and extend in the front-rear direction. Bottom portions of the two outer side surfaces, in the width direction, of the base portion  31  are formed with a pair of guide ribs  38 , respectively, which project outward in the width direction and extend in the front-rear direction. These guide grooves  37  and guide ribs  38  are used for guiding the fitting assuring component  3  itself. 
     A lock projection  39  projects downward from the bottom surface of the bottom wall  34  of the base portion  31  (also refer to  FIGS. 4A, 5 , etc.). The fitting assuring component  3  is held at the tentative lock position when the lock projection  21  (see  FIGS. 3A and 3B ) of the housing  2  and the lock projection  39  of the fitting assuring component  3  engage with each other (see  FIG. 5 ). 
     The bottom wall  34  of the base portion  31  is formed (unitized) with a detection arm  40  which extends forward from the front surface of the bottom wall  34 . A tip portion (front end portion) of the detection arm  40  is formed with an engagement portion  41  (see  FIGS. 4A and 5 ) which projects upward and is to be engaged with the engagement portion  26  of the lock portion  23 . 
     Next, the front holder  4  will be described with reference to  FIG. 1 . The front holder  4  which is made of a resin is equipped with a base portion  51  which is approximately shaped like a rectangular frame and plural detection arms  52  which project rearward from (are unitized with) the base portion  51 . 
     The front holder  4  is inserted into the housing main body  11  from the front side of the housing  2 . When inserted in the housing main body  11 , the front holder  4  is locked at a tentative lock position or a real lock position which is located in the rear of the tentative lock position by a lock mechanism (not shown).  FIGS. 4A and 4B ,  FIG. 5 , and  FIG. 6  show a state that the front holder  4  is located at the real lock position. 
     When the female terminals are inserted into the terminal housing rooms  12  to regular insertion positions in a state that the front holder  4  is located at the tentative lock position, as described above the lances  14  keep their regular postures (i.e., postures shown in  FIG. 4A ). Thus, tip portions of the detection arms  52  of the front holder  4  can be inserted into gaps formed under the lances  14 . As a result, in a state that the female terminals are located at the regular insertion positions, when the front holder  4  located at the tentative lock position is pushed rearward, as shown in  FIGS. 4A and 5  the tip portions of the detection arms  52  enter the gaps formed under the lances  14  to thereby allow the front holder  4  to move to the real lock position. 
     On the other hand, in a state that the female terminals are located at the halfway insertion positions, as described above the lances  14  keep postures that they are deformed downward (i.e., away from the female terminals) elastically. Thus, the gaps formed under the lances  14  are narrowed to establish a state that the tip portions of the detection arms  52  interfere with tip portions of the lances  14  and cannot enter the gaps formed under the lances  14 . As a result, the front holder  4  cannot move from the tentative lock position to the real lock position. In this manner, the front holder  4 &#39;s being incapable of moving from the tentative lock position to the real lock position makes it possible to detect half insertion of the female terminals easily. 
     Next, an operation that is performed when the fitting assuring component  3  is attached to the housing  2  will be described with reference to  FIGS. 4A and 4B ,  FIG. 5 , and  FIG. 6 . To attach the fitting assuring component  3  to the housing  2 , as shown in  FIG. 4A  the fitting assuring component  3  is brought closer to the space formed between the pair of protective walls  16  (see  FIGS. 3A and 3B ) of the housing  2  from the rear side. The guide ribs  18  (see  FIGS. 3A and 3B ) of the protective walls  16  are inserted into the respective guide grooves  37  (see  FIGS. 2A and 2B ) of the fitting assuring component  3  and the guide ribs  38  (see  FIGS. 2A and 2B ) of the fitting assuring component  3  are inserted into the guide grooves  17  (see  FIG. 3A ) of the protective walls  16 , respectively. Then the fitting assuring component  3  is moved forward while being guided by the pair of protective walls  16 . 
     The above forward movement of the fitting assuring component  3  is continued until the lock projection  39  of the fitting assuring component  3  goes over the lock projection  21  of the housing main body  11  and reaches the front side of the lock projection  21 . The fitting assuring component  3  is held at the tentative lock position as a result of the lock projection  39 &#39;s being located in front of the lock projection  21  as shown in  FIG. 5 . 
     When the lock projection  39  goes over the lock projection  21 , the lock projection  39  pushes down the lock projection  21 , whereby as shown in  FIG. 4B  the cantilever-shaped lock piece  20  which is formed with the lock projection  21  is bent downward elastically. In this manner, the lock projection  21  is moved downward easily. As a result, attachment of the fitting assuring component  3  to the housing  2  is easier than in a case that the lock projection  21  is not formed on the cantilever-shaped lock piece  20  (i.e., the lock projection  21  is not moved downward easily). Furthermore, crushing of portions, to come into contact with each other, of the lock projection  39  and the lock projection  21  can be prevented effectively when the former goes over the latter. 
     When the fitting assuring component  3  is located at the tentative lock position, the engagement portion  41  which is located at the tip portion of the detection arm  40  of the fitting assuring component  3  engages with the rear surface of the engagement portion  26  of the lock portion  23  of the housing  2 . However, in the state shown in  FIG. 5  shows a state that the engagement portion  41  of the detection arm  40  is pushed down by the counterpart lock portion  63  of the counterpart housing  61 . Thus, in the state of  FIG. 5 , the engagement portion  41  is not engaged with the rear surface of the engagement portion  26  of the lock portion  23 . The engagement portion  41  engages with the rear surface of the engagement portion  26  of the lock portion  23  in a state that the fitting assuring component  3  is located at the tentative lock position and the counterpart housing  61  and the housing  2  have not been in the complete fitting state yet. As a result, the fitting assuring component  3  cannot move from the tentative lock position to the real lock position (see  FIG. 6 ) which is in front of the tentative lock position. 
     If as shown in  FIG. 5  the counterpart housing  61  of the counterpart connector  5  is fitted with the housing  2  and the complete fitting state is thereby established in a state that the fitting assuring component  3  is located at the tentative lock position, the counterpart lock portion  63  engages with the rear surface of the engagement portion  26 . As a result, the complete fitting state of the housing  2  and the counterpart housing  61  is maintained. Furthermore, at this time, the counterpart lock portion  63  pushes down the engagement portion  41 , whereby the detection arm  40  is deformed downward elastically and the engagement portion  41  and the engagement portion  26  are disengaged from each other. That is, the fitting assuring component  3  can be moved from the tentative lock position to the real lock position. 
     Thus, in the complete fitting state (the state shown in  FIG. 5 ), the fitting assuring component  3  is moved from the tentative lock position to the real lock position (see  FIG. 6 ) while the detection arm  40  is kept deformed downward elastically by pushing the fitting assuring component  3  forward. As soon as the fitting assuring component  3  reaches the real lock position, the engagement portion  41  completes going over the engagement portion  26  and the detection arm  40  recovers elastically, whereby the engagement portion  41  comes to be located in front of the engagement portion  26 . As a result, the fitting assuring component  3  is held at the real lock position. 
     In a state that the fitting assuring component  3  is located at the real lock position, as shown in  FIGS. 6 and 7  the manipulation portion  25  of the lock portion  23  is located in the hollow portion  32  of the fitting assuring component  3  and surrounded by the base portion  31  of the fitting assuring component  3 . Thus, the manipulation portion  25  of the lock portion  23  is prevented from receiving external force or the like from the outside. Furthermore, should external force act on the manipulation portion  25  from the outside so as to push it down, the manipulation portion  25  interferes with the pair of seat portions  36  (see  FIG. 2B ) of the base portion  31 . That is, the manipulation portion  25  comes into contact with the seat portions  36  before reaching the bottom wall  34  of the base portion  31 ; the downward bend (i.e., movable range) of the lock arms  24  is restricted. As a result, the engagement between the engagement portion  26  and the counterpart lock portion  63  is not canceled and hence the complete fitting state of the housing  2  and the counterpart housing  61  is maintained. That is, unintentional cancellation of the complete fitting state is prevented. 
     To cancel the complete fitting state shown in  FIG. 6 , first, the engagement portion  41  is disengaged from the engagement portion  26  by pushing the engagement portion  41  downward and, in this state, the fitting assuring component  3  is moved from the real lock position to the tentative lock position, that is, the manipulation portion  25  is moved to outside the hollow portion  32 . What should be done in this state (i.e., the state of  FIG. 5 ) is to push the manipulation portion  25  downward. As a result, the engagement between the engagement portion  26  and the counterpart lock portion  63  is canceled to establish a state that the housing  2  and the counterpart housing  61  can be detached from each other in the front-rear direction. 
     On the other hand, when the counterpart housing  61  and the housing  2  are in the incomplete fitting state, the counterpart lock portion  63  does not push the engagement portion  41  downward and hence the engagement between the engagement portion  41  and the engagement portion  26  is not canceled. Thus, the fitting assuring component  3  cannot move from the tentative lock position to the real lock position. The fact that the housing  2  and the counterpart housing  61  are in the incomplete fitting state can be detected easily through detection of the state that the fitting assuring component  3  cannot move from the tentative lock position to the real lock position. 
     As described above, in the connector  1  according to the embodiment of the invention, when the fitting assuring component  3  (what is called CPA) is located at the real lock position, the manipulation portion  25  of the lock portion  23  of the housing  2  is housed in the hallow portion  32  of the fitting assuring component  3  and surrounded by the frame-shaped base portion  31  of the fitting assuring component  3 . As a result, the lock portion  23  is prevented from receiving external force or the like from the outside. Furthermore, should external force acts on the lock portion  23  from the outside, the manipulation portion  25  of the lock portion  23  interferes with the seat portions  36  of the base portion  31 . In this manner, unintentional cancellation of the complete fitting state can be prevented. 
     Furthermore, since the manipulation portion  25  of the lock portion  23  is housed in the hollow portion  32  of the fitting assuring component  3 , the size of the entire connector  1  including the housing  2  and the fitting assuring component  3  can be made smaller than in a case that a member for protecting the lock portion  23  or a member that interferes with the lock portion  23  is provided separately from the fitting assuring component  3 . 
     As such, the connector  1  having the above configuration can prevent unintentional cancellation of fitting in the counterpart connector  5  while minimizing size increase of the connector  1 . 
     The seat portions  36  for restricting movement of the lock portion  23  by interfering with (the manipulation portion  25  of) the lock portion  23  is provided in the hollow portion  32  at a middle position (between the top wall  33  and the bottom wall  34 ) in the bending direction of the lock portion  23 . Thus, when, for example, an unintentional external force acts on the lock portion  23 , the lock portion  23  comes into contact with the seat portions  36  before reaching the bottom wall  34  and is prevented from being bent further. Thus, the movable range of the lock portion  23  is made narrower than in a case that there are no interference portions such as the seat portions  36  and the lock portion  23  reaches the bottom wall  34 . As such, the connector  1  having the above configuration can prevent unintentional cancellation of fitting in the counterpart connector  5  more reliably. 
     Since the bottom wall  34  is offset downward from the seat portions  36 , a die for forming the hollow portion  32  (more specifically, a block of the die) can be made larger than in a case that the seat portions  36  are not provided and instead only the bottom wall  34  occupies the regions of the missing seat portions  36 . As such, the connector  1  having the above configuration is easier in handling of a die for manufacture of the connector  1  and higher in strength. 
     Furthermore, the cantilever-shaped lock piece  20  is provided with the lock projection  21  which is to engage with the lock projection  39  of the fitting assuring component  3 . Thus, when the lock projection  39  of the fitting assuring component  3  comes into contact with the lock projection  21  in attaching the fitting assuring component  3  to the housing  2 , the lock piece  20  is bent elastically in such a direction as to go away from the fitting assuring component  3 . As a result, attachment of the fitting assuring component  3  to the housing  2  is made easier than in a case that the cantilever-shaped lock piece  20  is not provided with the lock projection  21 . In is therefore understood that in the connector  1  having the above configuration the fitting assuring component  3  can restrict movement of the lock portion  23  easily and reliably and unintended cancellation of fitting in the counterpart connector  5  can be prevented more reliably. 
     Other Embodiments 
     The invention is not limited to the above embodiment and various modifications, improvements, etc. can be made as appropriate within the scope of the invention. The materials, shapes, sets of dimensions, numbers, locations, etc. of the respective constituent elements of the above embodiment are not limited to those disclosed but can be determined in desired manners as long as the invention can be implemented. 
     In the above embodiment, the pair of seat portions  36  which project upward from the two respective end portions of the top surface of the bottom wall  34  are provided as an interference portions” which is a term employed in the claims. In contrast, a pair of projection portions which project inward in the width direction from middle positions, in the top-bottom direction, of the inner surfaces, in the width direction, of the pair of side walls  35  may be provided as the “interference portion.” Also with this measure, when an unintentional external force, for example, acts on the lock portion  23 , the lock portion  23  comes into contact with the pair of projection portions before reaching the bottom wall  34 , whereby the lock portion  23  can be prevented from bending further. 
     Furthermore, in the embodiment, the through-hole which penetrates through the fitting assuring component  3  in the front-rear direction is provided as a “hollow portion” which is a term employed in the claims. However, the “hollow portion” need not always penetrate through the fitting assuring component  3  as long as it houses end portions of the lock arms  24  and can thereby prevent unintentional deformation of the lock arms  24 . For example, the fitting assuring component  3  may be formed with, as the “hollow portion,” a housing hole (e.g., recess or groove) which is recessed so as to be open on the front side where it is opposed to the lock arms  24  and to be closed on the rear side. 
     Features of the above-described connector  1  according to the embodiment of the invention will be summarized below concisely in the forms of items [1] to [3]; 
     [1] A connector ( 1 ) comprising: 
     
         
         
           
             a housing ( 2 ) having a lock portion ( 23 ) capable of switching between keeping and cancellation of a state of the housing ( 2 ) and a counterpart housing ( 61 ) being fitted with each other; and 
             a fitting assuring component ( 3 ) attached to the housing ( 2 ) and detecting whether the housing ( 2 ) and the counterpart housing ( 61 ) being fitted with each other by being prevented from interfering with the lock portion ( 23 ) and attached at a preset attachment position upon the housing ( 2 ) and the counterpart housing ( 61 ) being fitted with each other, 
             the fitting assuring component ( 3 ) having a hollow portion ( 32 ) to house at least part of the lock portion ( 23 ) to surround the at least part of the lock portion ( 23 ) upon the fitting assuring component ( 3 ) being located at the preset attachment position, and the fitting assuring component ( 3 ) preventing the lock portion ( 23 ) from switching to cancellation of the state of the housing ( 2 ) and the counterpart housing ( 61 ) being fitted with each other by interfering with an inside wall ( 36 ) of the hollow portion ( 32 ).
 
[2] The connector ( 1 ) according to the item [1], wherein
 
             the lock portion ( 23 ) is a cantilever-shaped lock arm ( 24 ) switching between keeping and cancellation of the state of the housing ( 2 ) and the counterpart housing ( 61 ) being fitted with each other by deforming in a preset bending direction; and 
             the inside wall ( 36 ) of the hollow portion ( 32 ) having: one portion ( 33 ) facing the lock portion ( 23 ) on one side in the bending direction upon the fitting assuring component ( 3 ) being in the preset attachment position; the other portion ( 34 ) facing the lock portion ( 23 ) on the other side in the bending direction; and an interference portion ( 36 ) between the one portion ( 33 ) and the other portion ( 34 ) and preventing the lock portion ( 23 ) from deforming to cancel the state of the housing ( 2 ) and the counterpart housing ( 61 ) being fitted with each other.
 
[3] The connector ( 1 ) according to the item [1] or the item [2], wherein
 
             the housing ( 2 ) having: a cantilever-shaped lock piece ( 20 ) capable of deforming elastically in a direction to separate from the fitting assuring component ( 3 ); and a lock projection ( 21 ) provided in the lock piece ( 20 ) and preventing the fitting assuring component ( 3 ) from separating from the housing ( 2 ) by engaging with the fitting assuring component ( 3 ). 
           
         
       
    
     REFERENCE SIGNS LIST 
     
         
           1 : Connector 
           2 : Housing 
           3 : Fitting assuring component 
           20 : Lock piece 
           21 : Lock projection 
           23 : Lock portion 
           24 : Lock arm 
           25  (At least part of) manipulation portion 
           32 : Hollow portion 
           33 : Top wall (one portion) 
           34 : Bottom wall (the other portion) 
           36 : Seat portion (inside wall, interference portion) 
           61 : Counterpart housing