Patent Publication Number: US-2023163519-A1

Title: Connector unit, wire harness, and connector fitting structure

Description:
BACKGROUND 
     Field of the Disclosure 
     The present disclosure relates to a connector unit, a wire harness, and a connector fitting structure. 
     Related Art 
     Connectors are used to electrically connect in-vehicle devices. One type of such a known connector is a connector unit including a connector cover that encloses a connector and is formed from an elastic material. Japanese Laid-Open Patent Publication No. 2011-44303 (JP&#39;303) discloses a structure in which a rubber boot, serving as a connector cover, covers a housing and the electric wires extending out of the housing. Such a connector cover is structured to cover the housing of the connector and the electric wires. This effectively protects the housing and electric wires accommodated in the connector cover from water, heat, and the like. 
     SUMMARY 
     In the connector unit described in JP&#39;303, the connector cover merely covers the housing. Thus, it is required that the water resistance be improved in the portion of the connector that is fitted to a mating connector so that the connector can be used at a location that is likely to be exposed to water. 
     Accordingly, the present disclosure discloses a connector unit, a wire harness, and a connector fitting structure that are novel and improve water resistance at an area including a portion fitted to a mating connector. 
     A connector unit in accordance with the present disclosure includes a connector and a tubular connector cover. The connector includes a terminal fitting that is connected to a terminating end portion of an electric wire and a housing that holds the terminal fitting. The connector cover covers the housing and is formed from an elastic material. The connector cover includes a looped seal portion, and the looped seal portion is arranged at a position allowing for contact with a surface of a mating connector in a state fitted to the mating connector. 
     A wire harness according to the present disclosure includes a connector unit and an electric wire connected to the terminal fitting of the connector unit. 
     A connector fitting structure in accordance with the present disclosure includes a connector unit and a mating connector fitted to the connector unit. The looped seal portion of the connector unit contacts a surface of the mating connector in a state in which the connector unit is fitted to the mating connector. 
     The present disclosure provides a connector unit, a wire harness, and a connector fitting structure that improve water resistance at an area including a portion fitted to a mating connector. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view showing a state in which a mating connector is coupled to a connector unit according to a first embodiment of the present disclosure. 
         FIG.  2    is an exploded perspective view of the connector unit and the mating connector shown in  FIG.  1   . 
         FIG.  3    is an exploded perspective view of the connector unit shown in  FIG.  2   . 
         FIG.  4    is a rear exploded perspective view of the connector unit shown in  FIG.  3   . 
         FIG.  5    is a rear perspective view of the mating connector shown in  FIG.  2   . 
         FIG.  6    is a perspective view showing a window in the connector unit of  FIG.  2    in a closed state. 
         FIG.  7    is a plan view of the connector unit shown in  FIG.  2    in which an upper portion of the connector unit in the Z-axis direction is cut and removed in a transverse direction, with a connector position assurance component located at a tentative engagement position. 
         FIG.  8    is a plan view of the connector unit shown in  FIG.  1    in which the upper portion of the connector unit in the Z-axis direction is cut and removed in a transverse direction, with the connector position assurance component located at a final engagement position. 
         FIG.  9    is an enlarged transverse cross-sectional view of the connector unit shown in  FIG.  2    in which a middle portion of the connector unit in the Z-axis direction is cut in a transverse direction. 
         FIG.  10    is an enlarged view of a portion where the mating connector and the connector unit shown in  FIG.  9    are fitted together. 
         FIG.  11    is an enlarged cross-sectional view taken along line XI-XI in  FIG.  6   . 
         FIG.  12    is a perspective view showing a window in a second embodiment of the connector unit and corresponding to  FIG.  6   . 
     
    
    
     DETAILED DESCRIPTION 
     Description of Embodiments of Present Disclosure 
     First, embodiments of the present disclosure will be listed and described. 
     Connector unit in accordance with present disclosure 
     (1) A connector unit includes a connector and a tubular connector cover. The connector includes a terminal fitting that is connected to a terminating end portion of an electric wire and a housing that holds the terminal fitting. The connector cover covers the housing and is formed from an elastic material. The connector cover includes a looped seal portion, and the looped seal portion is arranged at a position allowing for contact with a surface of a mating connector in a state fitted to the mating connector. 
     With the connector unit in accordance with the present disclosure, the looped seal portion is arranged at a position allowing for contact with a surface of a mating connector in a state fitted to the mating connector. More specifically, the looped seal portion arranged on the connector cover is located at an outermost part of the edge of the connector unit. The looped seal cover contacts a surface of a mating connector to seal the gap between the connector cover and the surface of the mating connector. This improves water resistance at the side of the connector unit fitted to the mating connector. Further, when in use, the looped seal portion of the connector cover will stop foreign matter such as mud collected around the connector cover from entering the connector cover. Thus, during maintenance or the like, when fitting or removing the connector unit to or from the mating connector, foreign matter will not enter the housing. Accordingly, defects that may be caused by such foreign matter will not occur when refitting the connector unit to the mating connector. 
     (2) Preferably, the looped seal portion has a tapered shape so as to be enlarged in diameter toward the mating connector. The looped seal portion has a tapered shape. Thus, the distal end of the looped seal portion is enlarged in a direction extending away from the center axis of the looped seal portion when contacting the surface of the mating connector. This increases the area of contact with the surface of the mating connector and improves the seal of the looped seal portion. 
     (3) Preferably, the connector cover includes a positioning portion that positions the connector cover on the housing, and the positioning portion contacts the housing to position the connector cover. The housing and the cover are easily coupled to each other at the proper position by having the positioning portion of the connector contact the housing. When fitted to the mating connector, the looped seal portion can easily contact the surface of the mating connector. 
     (4) Preferably, the connector includes a connector position assurance component assuring proper fitting to the mating connector, and the connector cover includes a window that exposes the connector position assurance component to the outside of the connector cover and a lid that freely opens and closes the window. The connector cover, which covers the housing, includes a window that exposes the connector position assurance component to the outside of the connector cover. Thus, the connector position assurance component arranged on the housing is visible and can be checked through the window of the connector cover even when the connector cover is attached to the connector. In addition, the connector cover includes the lid that closes the window. This improves the water resistance and the like of the connector cover while obtaining a protective functionality. 
     (5) Preferably, the window has an inner edge surface that includes a ridge, the lid has an outer edge surface that contacts the inner edge surface and includes a valley, the ridge projects toward the outer edge surface, and the valley accommodates the ridge in a state contacting the ridge. Contact of the ridge and valley improves the seal between the contacting surfaces of the lid and the window and improves the water resistance of the connector cover. This also limits unexpected separation of the lid from the window. 
     (6) Preferably, the connector cover includes a first end, including the looped seal portion, and a second end, at a side opposite the first end. The second end of the connector cover includes an electric wire passage tube through which the electric wire connected to the terminal fitting extends, and the electric wire passage tube includes an inner surface that is in tight contact with an outer surface of the electric wire. The looped seal portion provides the connector cover with water resistance at the side of the first end. Contact of the inner surface of the electric wire passage tube with the outer surface of the electric wire provides the connector cover with water resistance at the side of the first end. This further improves the water resistance of the connector cover. 
     (7) Preferably, the terminal fitting held by the housing includes a plurality of terminal fittings, the electric wire includes a plurality of electric wires, the electric wires are connected to the terminal fittings and extend through the electric wire passage tube of the connector cover, the electric wire passage tube includes a partition wall located between the electric wires and arranged on the inner surface, the partition wall includes a projecting end that is separable from the inner surface, and the partition wall defines a passage region that contacts outer surfaces of each of the electric wires passing therethrough. The electric wire passage tube includes the partition wall located between the electric wires and arranged on the inner surface. The partition wall defines a passage region that contacts outer surfaces of each of the electric wires passing therethrough. This avoids interference between the electric wires. Interference refers to a state in which the electric wires contact each other. Further, each electric wire is stably held in the electric wire passage tube. In addition, the partition wall located between the electric wire closes gaps between the electric wires. This provides water resistance between the electric wires which would be an issue when passing the electric wires through the electric wire passage tube. Further, the projecting end of the partition wall is separable from the inner surface. Thus, the arrangement and passage of the electric wires through the electric wire passage tube can be performed using the electric wire passage tube as an electric wire passage tube that includes a single electric wire passage conduit. This facilitates the passage of each electric wire through the electric wire passage region. 
     (8) Preferably, a tying member is fixed to the electric wire passage tube. The tying member has the inner surface of the electric wire passage tube contact the outer surface of the electric wire. Contact of the inner surface of the electric wire passage tube with the outer surfaces of the electric wires further improves the water resistance of the electric wire passage tube. 
     Wire Harness in Accordance with Present Disclosure 
     (9) A wire harness according includes a connector unit and an electric wire. The connector unit includes a connector and a tubular connector cover. The connector includes a terminal fitting that is connected to a terminating end portion of the electric wire and a housing that holds the terminal fitting. The connector cover covers the housing and is formed from an elastic material. The connector cover includes a looped seal portion, and the looped seal portion is arranged at a position allowing for contact with a surface of a mating connector in a state fitted to the mating connector. The electric wire is connected to the terminal fitting of the connector unit. 
     The wire harness according to the present disclosure includes the connector unit described above in paragraph (1) and thus has the same advantages as the connector unit described in paragraph (1). 
     Connector Fitting Structure in Accordance with Present Disclosure 
     (10) A connector fitting structure includes the connector unit according to any one of paragraphs (1) to (8) and a mating connector fitted to the connector unit. The looped seal portion of the connector unit contacts a surface of the mating connector in a state in which the connector unit is fitted to the mating connector. 
     The connector fitting structure according to the present disclosure includes the connector unit according to any one of paragraphs (1) to (8) and a mating connector fitted to the connector unit. The looped seal portion of the connector unit contacts a surface of the mating connector in a state in which the connector unit is fitted to the mating connector. This improves water resistance at the portion where the connector unit is fitted to the mating connector. Further, when in use, the looped seal portion of the connector cover in the connector unit will stop foreign matter such as mud collected around the connector cover from entering the connector cover. Thus, during maintenance or the like, when fitting or removing the connector unit to or from the mating connector, since foreign matter will not enter the housing of the connector unit, defects caused by such foreign matter will not occur when refitting the connector unit to the mating connector. 
     An embodiment of a connector unit, a wire harness, and a connector fitting structure will now be described with reference to the drawings. The present disclosure is not limited to these examples and is intended to include all modifications described by the scope of claims and corresponding to equivalents of the scope of claims. 
     A first embodiment of the present disclosure will now be described with reference to  FIGS.  1  to  11   .  FIG.  1    is a perspective view showing a state in which a mating connector  12  is coupled to a connector unit  10  according to a first embodiment of the present disclosure. The mating connector  12 , to which the connector unit  10  is coupled, is fixed to a case or the like of an electric device such as an inverter (not shown). With regard to the X, Y, and Z axes indicated in the drawings, the X-axis direction is the lengthwise direction of the connector unit  10 , the Y-axis direction is the widthwise direction of the connector unit  10 , and the Z-axis direction is the vertical direction. Identical components in the drawings will not all be denoted with a reference character, that is, only representative ones of identical components will be denoted with reference characters. 
     Mating Connector  12   
     As shown in  FIG.  2   , the mating connector  12  includes a mating connector housing  14 . The mating connector housing  14  is formed from a synthetic resin. As shown in  FIG.  2   , the mating connector housing  14  has the form of a polygonal tube and is arranged so as to be open toward the front in the lengthwise direction (one side in X-axis direction) and toward the rear in the lengthwise direction (toward other side in X-axis direction). The lengthwise direction (X-axis direction in drawing) is the direction in which the connector unit  10  is attached to and detached from the mating connector  12 . More specifically, the phrase toward the front in the lengthwise direction means the direction in which the connector unit  10  is moved when fitting the connector unit  10  to the mating connector  12 . A fixed portion  18  is formed on the front side of the mating connector housing  14 . The fixed portion  18  is a flange projecting outward in a direction orthogonal to the center axis of the mating connector housing  14  from the rim of a front open portion  16 . The fixed portion  18  has the form of a rectangular plate in a front view taken from the front side with respect to the lengthwise direction. A through hole  20  having a circular cross-section extends through each of the four corners of the fixed portion  18  in a thickness-wise direction. Bolts are inserted through the through holes  20  of the fixed portion  18  to fix the mating connector housing  14  to a case of the electric device (not shown). A ring-shaped rubber seal  24  is attached to a front surface  22  of the fixed portion  18  in tight contact with the case and shield of the electric device (not shown). This limits the entry of water and dust into the electric device (not shown). 
     Further, as shown in  FIG.  2   , mating connector electric wire insertion portion  26  is arranged inside the front open portion  16  of the mating connector housing  14 . The mating connector electric wire insertion portion  26  is coupled to the edge of the front open portion  16  and projected frontward. The mating connector electric wire insertion portion  26  has the form of a polygonal tube. The projecting end of the mating connector electric wire insertion portion  26  includes two mating connector electric wire passage conduits  28  that are separated from each other in the widthwise direction. The two mating connector electric wire passage conduits  28  are open toward the front and rear. The two mating connector electric wire passage conduits  28  each have a rectangular cross section. As shown in  FIGS.  1  and  2   , mating connector terminal fittings crimped to terminating end portions of terminal fitting-added electric wires  30  are inserted through the two mating connector electric wire passage conduits  28 , respectively. 
     In addition, as shown in  FIG.  2   , two rails  32  are arranged on the outer upper surface of the mating connector housing  14  at a central portion in the widthwise direction (Y-axis direction as viewed in the drawing). The two rails  32  extend over substantially the entire length in the lengthwise direction and are separated from each other in the widthwise direction. The widthwise direction (Y-axis direction as viewed in the drawing) is the left-right direction in a view of the connector unit  10  taken from the front or rear in a state in which the Z-axis direction in the drawing corresponds to the vertical direction. An engagement projection  34  is formed on the rear side of each rail  32  with respect to the lengthwise direction. The engagement projections  34  have trapezoidal cross sections and extend in the widthwise direction from the sides of the rails  32  facing away from each other. An engagement protrusion  36  is formed between the rear sides of the rails  32  with respect to the lengthwise direction. The engagement protrusion  36  has a substantially triangular cross section in the widthwise direction. The front surfaces of the engagement projections  34  and the engagement protrusion  36  with respect to the lengthwise direction are vertical surfaces extending upward in the vertical direction. The rear surfaces of the engagement projections  34  and the engagement protrusion  36  are sloped surfaces extending diagonally downward. Further, as shown in  FIG.  5   , a rail  38  is arranged on the lower outer surface of the mating connector housing  14  toward one side (farther side) with respect to the widthwise direction. The rail  38  projects diagonally downward over the entire length in the lengthwise direction. The two rails  32  and the rail  38  are formed at different positions or with different dimensions for each type of the mating connector  12 . 
     Connector Unit  10   
     As shown in  FIG.  3   , the connector unit  10  includes a connector  11  including terminal fittings  42 , each of which is a female terminal fitting connected to a terminating end portion of an electric wire  40 , a housing  44 , which holds the terminal fittings  42 , and a connector position assurance component  46 , which assures proper fitting to the mating connector  12 . The connector unit  10  includes a connector cover  48  having the form of a polygonal tube and covering the housing  44  of the connector  11 . 
     Housing  44   
     The housing  44  is formed from a synthetic resin. As shown in  FIG.  3   , the housing  44  has the form of a polygonal tube that extends in the lengthwise direction and opens toward the front and rear. Terminal fitting holders  52  are formed in the housing  44  at two locations separated in the widthwise direction. The terminal fitting holders  52  include mating connector terminal fitting passage conduits  50  that receive mating connector terminal fittings (not shown) connected to terminating end portions of the terminal fitting-added electric wires  30 , respectively. The terminal fittings  42  connected to the terminating end portions of the electric wires  40  are also held and accommodated in the terminal fitting holders  52 . A terminal fitting passage conduit  54  that receives the terminal fittings  42  is formed in the rear side of the housing  44 . 
     As shown in  FIGS.  3  and  4   , the housing  44  includes a front portion  44   a  with respect to the lengthwise direction that is larger in diameter than a rear portion  44   b . The front portion  44   a  with respect to the lengthwise direction includes a connector position assurance component accommodation portion  58 . The connector position assurance component accommodation portion  58  projects upward from a middle section with respect to the widthwise direction of an upper part of a peripheral wall  56  forming the housing  44  over the entire length in the lengthwise direction. The rear side of the connector position assurance component accommodation portion  58  with respect to the lengthwise direction extends further rearward. The rear side of the connector position assurance component accommodation portion  58  with respect to the lengthwise direction is open rearward and upward. An engagement portion  60  is formed on the upper part of the peripheral wall  56  of the rear portion  44   b  of the housing  44  at the rear side of the connector position assurance component accommodation portion  58  with respect to the lengthwise direction. The engagement portion  60  projects upward and then extends toward opposite sides with respect to the lengthwise direction. As shown in  FIGS.  7  and  8   , the front side of the engagement portion  60  is frame-shaped and extends toward the front. The front central part of the engagement portion  60  includes an engagement hole  62  extending in the vertical direction. The rear side of the engagement portion  60  is cantilevered and has the form of a rectangular plate. The rear side of the engagement portion  60  when pushed, as will be described later, allows the engagement hole  62  and the engagement protrusion  36  to be easily disengaged from each other. 
     Further, as shown in  FIGS.  3  and  4   , in the front portion  44   a  of the housing  44  with respect to the lengthwise direction, non-slip recesses  68  are formed in the peripheral wall  56  at the rear end in parts opposed in the widthwise direction. The non-slip recesses  68  are each formed by joining three rectangular recessed parts in a side view taken in the widthwise direction. The three recessed parts of each non-slip recess  68  become deeper and longer in the vertical direction toward the rear. The non-slip recesses  68  allow the housing  44  to be held stably with the fingers when inserting the connector position assurance component  46  into the connector position assurance component accommodation portion  58 . In addition, the rear portion  44   b  of the housing  44  includes engagement protrusions  70  arranged at the rear side of the peripheral wall  56  on parts opposed in the widthwise direction. The engagement protrusions  70  are used to attach a back retainer  80 , which will be described later, to the rear portion  44   b  of the housing  44 . Further, as shown in  FIGS.  2  and  3   , an accommodation recess  72  that receives the rail  38  is arranged in the peripheral wall  56  of the front portion  44   a  of the housing  44 . The accommodation recess  72  is open inward and frontward at a position corresponding to the rail  38  of the mating connector housing  14  shown in  FIG.  5   . 
     Connector Position Assurance Component  46   
     The connector position assurance (CPA) component  46  is formed from a synthetic resin. As shown in  FIG.  3   , the connector position assurance component  46  has the form of a U-shaped frame and is open toward the front and in the vertical direction. A bar-shaped coupling portion  74  connects the upper surface of the connector position assurance component  46  at the central part with respect to the lengthwise direction. The front end of the connector position assurance component  46  is bent downward in an L-shaped manner to form two engagement portions  76 ,  76 . The rear end of the connector position assurance component  46  defines an operating portion  78 . 
     Electric Wire  40 , Back Retainer  80 , and Seal Member  82   
     The housing  44  further includes the electric wires  40 , which are connected to the terminal fittings  42  and extend out of the rear end of the housing  44 , the back retainer  80 , which is attached to the rear end of the housing  44  and which holds the electric wires  40 , and a seal member  82 . 
     Connector Cover  48   
     The connector cover  48  is formed from an elastic material, for example, an elastomer such as an elastic synthetic rubber, a thermoplastic elastomeric, or the like. As shown in  FIGS.  3  and  4   , the connector cover  48  has the form of a polygonal tube that extends in the lengthwise direction and opens toward the front and rear. The connector cover  48  has a front side that is larger in diameter than a rear side. The front side of the connector cover  48  defines a housing holder  84  that accommodates and holds the housing  44  of the connector unit  10 . The rear side of the connector cover  48  defines an electric wire passage tube  86 . The electric wires  40  connected to the terminal fittings  42  and extended toward the rear are held and accommodated in the electric wire passage tube  86 . 
     As shown in  FIG.  3   , the housing holder  84  at the front side of the connector cover  48  includes a recess accommodation portion  88 . The recess accommodation portion  88  is open frontward and inward at a part corresponding to the accommodation recess  72  of the housing  44 . Further, an accommodation portion  89  is arranged on the front side of the upper surface of the housing holder  84  to accommodate the connector position assurance component accommodation portion  58  of the housing  44 . The accommodation portion  89  is open frontward and inward and has the form of a rectangular block projecting upward. Further, a projection  90  that has the form of a rectangular block projects upward from the rear side of the housing holder  84 . A window  92  that opens upward and into the housing holder  84  extends through the central portion of the projection  90 . The window  92  has a substantially rectangular cross section. As shown in  FIGS.  1  and  2   , the window  92  is formed to expose the connector position assurance component  46  to the outside of the connector cover  48 . Thus, the connector position assurance component  46  arranged on the housing  44  is visible and can be checked through the window  92  even when the connector cover  48  is attached to the housing  44  of the connector  11 . As shown in  FIG.  11   , the window  92  has an inner edge surface that includes a looped ridge  94  having a substantially triangular cross section projecting inward and extending in the looping direction. There is more than one ridge  94  (three in the present embodiment) spaced apart in the vertical direction (Z-axis direction as viewed in the drawing). The inner edge surface of the window  92  refers to the surface defining the opening of the window  92  and extending in the open direction (Z-axis direction as viewed in the drawing) of the window  92 . In the direction that orthogonally intersects the X-axis direction, the vertical direction (Z-axis direction as viewed in the drawing) refers to the open direction of the window  92  of the connector unit  10  and the opposite direction. 
     Additionally, a lid  98  is coupled by a coupling portion  96  to the projection  90  at a side surface in the widthwise direction. The lid  98  has a bottom surface (surface located at upper side in vertical direction and extending in X-axis direction and Y-axis direction as viewed in  FIG.  4   ) where a detection rib  100 , which has the form of a rectangular plate, is arranged at the rear side over the entire length in the widthwise direction. The lid  98  has a top surface (surface located at lower side in vertical direction and extending in X-axis direction and Y-axis direction as viewed in  FIG.  4   ) where a holding protrusion  102  having the form of a circular tube is arranged at the central portion. This facilitates the attachment and detachment of the lid  98 , and improves operability for attaching and detaching the lid  98  to and from the window  92 . Further, the outer edge surface of the lid  98  includes a looped valley  104  having a substantially triangular cross section projecting outward and extending in the looping direction. There is more than one valley  104  (three in the present embodiment) spaced apart in the vertical direction (Z-axis direction). The coupling portion  96  of the lid  98  has the form of a thin rectangular plate and is bendable in a thickness-wise direction or the like. The lid  98  can easily be fitted into the window  92  from the side of the detection rib  100 . That is, the lid  98  can freely open and close the window  92 . As shown in  FIG.  11   , when the window  92  is closed by the lid  98 , the ridges  94  in the inner edge surface of the window  92  project toward the outer edge surface of the lid  98 . The valleys  104  in the outer edge surface of the lid  98  accommodate the ridges  94  in a state contacting the ridges  94 . This improves the seal between the contacting surfaces of the lid  98  and the window  92  and improves the water resistance of the connector cover  48 . This also limits unexpected separation of the lid  98  from the window  92 . 
     As shown in  FIG.  4   , a pushing portion  106  having an arcuate shape bulged upwardly is arranged at the rear side of the projection  90  including the window  92  of the connector cover  48 . The pushing portion  106  is formed so that it can easily be deformed when pushed in the lengthwise direction. For example, as shown in  FIG.  2   , the pushing portion  106  is located at a position opposing the operating portion  78 , which is defined by the rear end of the connector position assurance component  46 . The pushing portion  106  is pushed forward with respect to the lengthwise direction from outside the connector cover  48  to push the operating portion  78 . This allows the operating portion  78  to be pushed from outside the connector cover  48  even if the operating portion  78  is covered by the connector cover  48  and not visible. Accordingly, the assembling efficiency of the connector unit  10  is improved. 
     As shown in  FIGS.  4  and  6   , a support  108  is arranged on each of the two side surfaces of the housing holder  84  of the connector cover  48  at the rear end. More specifically, the supports  108  are arranged on the side surfaces of the connector cover  48  in a direction (in present embodiment, widthwise direction) intersecting the direction in which the connector unit  10  is fitted to the mating connector  12  (in present embodiment, frontward in lengthwise direction). This allows the pushing force in the direction in which the connector unit  10  is fitted to the mating connector  12  to be stably transmitted to the connector unit  10  when fitting the connector unit  10  to the mating connector  12 . Thus, the assembling efficiency of the connector unit  10  is improved. In addition, the supports  108  are each formed so that its projected height increases in a stepped manner from the outer surface of the connector cover  48  toward the side fitted to the mating connector  12  (i.e., frontward in lengthwise direction). In this manner, the supports  108  are shaped so that one can place his or her fingers along the supports  108  to stably push the supports  108 . The projecting height of each support  108  gradually increases toward the side fitted to the mating connector  12 . 
     As shown in  FIGS.  7  to  10   , the edge around the front opening in a first end  109 , or the front end, of the housing holder  84  of the connector cover  48  includes a positioning portion  110  and a looped seal portion  112 . More specifically, the flange-shaped positioning portion  110  that projects inwardly extends along the entire edge of the front opening in the connector cover  48 . As shown in  FIG.  9   , contact of the positioning portion  110  with the entire edge of the front opening in the front portion  44   a  of the housing  44  allows for easy positioning of the housing  44  and the connector cover  48 . Accordingly, the assembling efficiency of the connector unit  10  is improved. The looped seal portion  112  can easily contact the rear surface  113  of the mating connector  12 . Further, the looped seal portion  112  is arranged along the entire outer edge of the positioning portion  110 . The looped seal portion  112  has a tapered shape so as to be enlarged in diameter toward the mating connector  12  (frontward in lengthwise direction). The looped seal portion  112  of the connector unit  10  contacts the rear surface  113  of the mating connector  12  when the connector unit  10  is fitted to the mating connector  12 . The distal end of the looped seal portion  112  is enlarged in a direction extending away from the center axis of the looped seal portion  112  when the mating connector  12  comes into contact with the rear surface  113 . This increases the area of contact with the rear surface  113  of the mating connector  12  and improves the seal of the looped seal portion  112 . 
     As shown in  FIGS.  4  and  9   , the electric wire passage tube  86  of the connector cover  48  includes two electric wire passage conduits  114  that open toward the front and rear. The two electric wire passage conduits  114  have circular cross sections, extend in the lengthwise direction, and are separated from each other in the widthwise direction. Thus, the electric wires  40  respectively connected to the two terminal fittings  42  extend through the electric wire passage tube  86  of the connector cover  48 . A first partition wall  115   a  and a second partition wall  115   b , which are partition walls that contact the outer surface of each electric wire  40 , are arranged between the two electric wire passage conduits  114  in the electric wire passage tube  86 . The first partition wall  115   a  and the second partition wall  115   b  arranged on the inner surface are located between the two electric wires  40  and define a passage region through which each of the electric wires  40  passes. This avoids interference between the two electric wires  40  while stably holding each of the electric wires  40  in the electric wire passage tube  86 . Further, gaps that may be formed between the electric wires  40  when passing the two electric wires  40  through the electric wire passage tube  86  are eliminated by the first partition wall  115   a  and the second partition wall  115   b  located between the electric wires  40 . This provides water resistance between the electric wires  40  which would be an issue when passing the electric wires  40  through the electric wire passage tube  86 . Further, the inner surface of the electric wire passage tube  86  includes a first surface  116   a  and a second surface  116   b  opposing each other in the vertical direction and sandwiching the two electric wires  40 , which are arranged next to each other. The first surface  116   a  projects toward the second surface  116   b  and includes the first partition wall  115   a , which is located between the two electric wires  40  and contact the outer surface of each electric wire  40 . The second surface  116   b  projects toward the first surface  116   a  and includes the second partition wall  115   b , which is located between the two electric wires  40  and contact the outer surface of each electric wire  40 . 
     As shown in  FIG.  9   , the electric wires  40 , subsequent to passage, are tied and fixed by a tying member  118  or the like at the rear side of the electric wire passage tube  86 . This results in the projecting end of the first partition wall  115   a  contacting and joining the projecting end of the second partition wall  115   b  so as to define the electric wire passage conduits  114  through which the electric wire  40  pass. In this manner, the projecting end of the first partition wall  115   a  and the projecting end of the second partition wall  115   b  are not coupled at the inner surface of the electric wire passage tube  86  and are separable from the inner surface. Thus, the arrangement and passage of the two electric wires  40  through the electric wire passage tube  86  can be performed with the single electric wire passage tube  86 . More specifically, the projecting end of the first partition wall  115   a  is separated from the projection end of the second partition wall  115   b  so that the two electric wire passage conduits  114  can be connected to each other. This facilitates the task for passing the electric wire  40  through the electric wire passage conduits  114 . Further, as described above, the electric wire  40 , subsequent to passage, are tied and fixed at the rear side of the electric wire passage tube  86  by the tying member  118 . This improves the water resistance and dust resistance of the electric wire passage tube  86 . More specifically, the tying member  118  is fixed to the outer surface of the electric wire passage tube  86  so that the inner surface of the electric wire passage tube  86  contacts the outer surfaces of the electric wires  40 . Further, the electric wire passage tube  86 , through which the electric wires  40  pass, includes a first end  109 , which is the front end (left end in  FIG.  9   ) of the connector cover  48 , and a second end  119 , which is located at the opposite side (right side in  FIG.  9   ) in the lengthwise direction. The inner surface of the electric wire passage tube  86  is in tight contact with the outer surfaces of the electric wires  40 . The inner surface of the electric wire passage tube  86  includes the surfaces forming the partition walls, namely, the first partition wall  115   a  and the second partition wall  115   b . Thus, the looped seal portion  112  provides the connector cover  48  with water resistance at the side of the first end  109 . Contact of the inner surface of the electric wire passage tube  86  with the outer surfaces of the electric wires  40  provides the connector cover  48  with water resistance at the side of the second end  119 . This further improves the water resistance of the connector cover  48 . 
     An assembling method of the present embodiment will now be described. First, the rear end of each electric wire  40  is passed in advance through the connector cover  48 , the back retainer  80 , and the seal member  82  in this order. Then, the terminal fittings  42  are prepared to conductively connect the terminal fittings  42  to the terminating end portions of the electric wires  40 . The terminal fittings  42  connected to the two electric wires  40  in this manner are inserted from the terminal fitting passage conduit  54  deep into the terminal fitting holders  52 . Consequently, the rear ends of the terminal fittings  42  are engaged with retainers arranged in the terminal fitting holders  52 . This stably accommodates and holds the terminal fittings  42  in the terminal fitting holders  52 . Then, the back retainer  80  and the seal member  82  are moved toward the housing  44  so that the back retainer  80  engages the engagement protrusions  70  of the housing  44 . This fixes the back retainer  80  to the rear portion  44   b  of the housing  44 . Then, after inserting the connector position assurance component  46  into the connector position assurance component accommodation portion  58  of the housing  44 , the connector cover  48  is moved toward the housing  44  to cover the housing  44 . Here, the connector position assurance component accommodation portion  58  is in tight contact with and accommodated in the accommodation portion  89 , which is defined by the inner surface of the connector cover  48  to accommodate the connector position assurance component accommodation portion  58 . The accommodation portion  89  is arranged on the outer surface of the housing  44  that contacts the inner surface of the connector cover  48 . The connector position assurance component accommodation portion  58  projects from the upper part of the outer surface of the housing  44  toward the inner surface of the connector cover  48 . Thus, the connector cover  48  will not be erroneously coupled in a manner upside down or the like to the housing  44 . 
     As shown in  FIG.  9   , the positioning portion  110 , which is arranged on the front end of the housing holder  84  of the connector cover  48  is engaged with the front end of the front portion  44   a  of the housing  44 . The rear end of the housing holder  84  of the connector cover  48  is engaged with the rear surface of the back retainer  80 . This positions and fixes the connector cover  48  to the housing  44 . As shown in  FIG.  9   , the inner surface of the connector cover  48  is reduced in diameter at the rear end of the front portion  44   a  of the housing  44  and the front side of the rear portion  44   b  of the housing  44 . This allows the inner surface of the connector cover  48  to contact the outer surface of the housing  44 . As a result, the pushing portion  106  contacts the operating portion  78  of the connector position assurance component  46  as shown in  FIG.  7   . This positions the connector position assurance component  46  at a tentative engagement position, which is an initial position. As shown in  FIG.  7   , in this state, two accommodation recesses  120  that are open frontward and upward to accommodate the two rails  32 ,  32 , which are arranged on the upper surface of the mating connector housing  14 , extend between the connector position assurance component  46  and the front side of the engagement portion  60 . As shown in  FIG.  2   , this completes a wire harness  122  in accordance with the first embodiment of the present disclosure that includes the connector unit  10  and the electric wires  40 , which are connected to the connector  11  of the connector unit  10 . 
     Finally, the connector unit  10  is coupled to the mating connector  12 . More specifically, the two rails  32 ,  32  and the rail  38 , which are arranged on the outer surface of the mating connector housing  14 , are accommodated in the two accommodation recesses  120  and the accommodation recess  72 , which are arranged in the front portion  44   a  of the housing  44  of the connector unit  10 . Thus, the connector unit  10  will not be erroneously coupled in a manner upside down or the like to the mating connector housing  14 . As shown in  FIG.  7   , in this state, the two rails  32  are inserted in the two accommodation recesses  120 , and the engagement portions  76 , which are arranged on the front end of the connector position assurance component  46 , are disposed on the sloped surfaces of the engagement projections  34 . Further, the engagement protrusion  36 , which is arranged on the mating connector housing  14 , is fitted to the engagement hole  62  of the engagement portion  60  to fix the connector unit  10  to the mating connector  12 . The fixed state can be easily cancelled by pushing the rear side of the engagement portion  60 . Then, the pushing portion  106  of the connector cover  48  is pushed toward the front to engage and securely fix the engagement portions  76  with the engagement projection  34 . 
     The operating portion  78  of the connector position assurance component  46  is inserted into the rear lower side of the engagement portion  60  so that the fixed state cannot be cancelled (refer to  FIGS.  7  and  8  and  1  and  2   ). As shown in  FIGS.  1  and  8   , in this state, a detection rib accommodation recess  124  is formed between the pushing portion  106  and the operating portion  78  of the connector position assurance component  46 . This accommodates the detection rib  100  in the detection rib accommodation recess  124  and allows the lid  98  to close the window  92 . In this manner, the detection rib  100  of the lid  98  projects toward the housing  44 . Thus, when the connector position assurance component  46  is located at the final engagement position assuring proper fitting, the detection rib  100  does not interfere with the connector position assurance component  46 , which is located at the final engagement position, and allows the lid  98  to be fitted to the window  92 . When the connector position assurance component  46  is not located at the final engagement position assuring proper fitting, the detection rib  100  interferes with the connector position assurance component  46  so that the lid  98  cannot be fitted to the window  92 . In this manner, the detection rib  100  is arranged at a position satisfying a predetermined condition. More specifically, the predetermined condition is in that the detection rib  100  interferes with the connector position assurance component  46  when the connector position assurance component  46  is located at a first position that differs from a second position that is the final engagement position. When the connector position assurance component  46  is located at the second position, the detection rib  100  does not interfere with the connector position assurance component  46 . The connector position assurance component  46  is movable from the predetermined first position to the second position. 
     This avoids errors such as the connector position assurance component  46  not being checked or the lid  98  being inadvertently closed. Additionally, when the window  92  is closed by the lid  98 , this allows for easy recognition that the connector position assurance component  46  is located at the final engagement position assuring proper fitting. This improves the assembling efficiency and assembling reliability of the connector unit  10 . This completes the coupling of the connector unit  10  to the mating connector  12 . When fitted to the mating connector  12 , the looped seal portion  112  of the connector cover  48  is in tight contact with the rear surface  113  of the mating connector housing  14 . That is, when fitted to the mating connector  12 , the looped seal portion  112  is arranged at a position where it can contact the rear surface  113  at the rear side of the mating connector  12 . 
     With the connector unit  10  of the present disclosure having such a structure, when fitted to the mating connector  12  of the connector unit  10 , the looped seal portion  112  of the connector unit  10  contacts the rear surface  113  of the mating connector  12 . In this state, the gap between the connector cover  48  and the rear surface  113  of the mating connector  12  is sealed. This improves water resistance at the side of the connector unit  10  fitted to the mating connector  12 . Further, when in use, foreign matter such as mud collected around the connector cover  48  will not enter the connector cover  48 . Moreover, during maintenance or the like, when fitting or removing the connector unit  10  to or from the mating connector  12 , since foreign matter will not enter the housing  44 , defects caused by such foreign matter will not occur when refitting the connector unit  10  to the mating connector  12 . 
     The wire harness  122  includes the connector unit  10  and the electric wires  40 , which are connected to the connector  11  of the connector unit  10 . Thus, the same advantages as the connector unit  10  described above are obtained with the wire harness  122  that includes the connector unit  10 . 
     With the connector unit  10  and the connector fitting structure fitting the connector unit  10  to the mating connector  12 , the looped seal portion  112  of the connector unit  10  contacts the rear surface  113  of the mating connector  12  when the connector unit  10  is fitted to the mating connector  12 . Thus, the connector fitting structure has the same advantages as the connector unit  10 . 
     There is no limitation to the technology described in this specification and the embodiment illustrated with the drawings. For example, the embodiments described below are included in the technical scope described in this specification. 
     (1) In the first embodiment, the holding protrusion  102  is arranged on the top surface of the lid  98  and sized for easy holding with the fingers but not limited in such a manner.  FIG.  12    shows a connector unit  126  according to a second embodiment of the present disclosure including a holding protrusion  128  that is sized such that it would be difficult to be held with the fingers. For example, the holding protrusion  128  may include a slit-shaped recess  130  that allows for engagement with a tool (not shown). In this manner, one cannot hold the holding protrusion  128  with his or her fingers because of its size, and a tool is inserted in the recess  130  to hold the holding protrusion  128 . As a result, the projecting height of the holding protrusion  128  can be reduced to limit interference of the holding protrusion  128  with other members. Further, unintentional separation of the lid  98  from the window  92  can be avoided. This improves the water resistance and the reliability of the protective functionalities such as shielding of the connector cover  48 . 
     (2) In the first embodiment, the partition walls contacting the outer surfaces of the electric wires  40  include the first partition wall  115   a , which projects from the first surface  116   a , and the second partition wall  115   b , which projects from the second surface  116   b , but are not limited in such a manner. The partition wall may project from only one of the first surface  116   a  and the second surface  116   b . Further, there may be any number of partition walls with any projecting height. 
     (3) In the first embodiment, the inner edge surface of the window  92  includes the ridges  94 , and the outer edge surface of the lid  98  includes the valleys  104 . Instead, valleys may be arranged in the inner edge surface of the window  92 , and ridges may be arranged on the outer edge surface of the lid  98 . 
     (4) In the first embodiment, the inner surface of the connector cover  48  includes the recess accommodation portion  88 , and the outer surface of the housing  44  includes the accommodation recess  72 . Instead, the inner surface of the connector cover  48  may include the accommodation recess  72 , and the outer surface of the housing  44  may include the recess accommodation portion  88 . 
     DESCRIPTION OF THE REFERENCE CHARACTERS 
     
         
           10  connector unit (first embodiment) 
           11  connector 
           12  mating connector 
           14  mating connector housing 
           16  front open portion 
           18  fixed portion 
           20  through hole 
           22  front surface 
           24  rubber seal 
           26  mating connector electric wire insertion portion 
           28  mating connector electric wire passage conduit 
           30  terminal fitting-added electric wire 
           32  rail 
           34  engagement projection 
           36  engagement protrusion 
           38  rail 
           40  electric wire 
           42  terminal fitting 
           44  housing 
           44   a  front portion 
           44   b  rear portion 
           46  connector position assurance component 
           48  connector cover 
           50  mating connector terminal fitting passage conduit 
           52  terminal fitting holder 
           54  terminal fitting passage conduit 
           56  peripheral wall 
           58  connector position assurance component accommodation portion 
           60  engagement portion 
           62  engagement hole 
           68  non-slip recess 
           70  engagement protrusion 
           72  accommodation recess 
           74  coupling portion 
           76  engagement portion 
           78  operating portion 
           80  back retainer 
           82  seal member 
           84  housing holder 
           86  electric wire passage tube 
           88  recess accommodation portion 
           89  accommodation portion 
           90  projection 
           92  window 
           94  ridge 
           96  coupling portion 
           98  lid 
           100  detection rib 
           102  holding protrusion 
           104  valley 
           106  pushing portion 
           108  support 
           109  first end 
           110  positioning portion 
           112  looped seal position 
           113  rear surface 
           114  electric wire passage conduit 
           115   a  first partition wall (partition wall) 
           115   b  second partition wall (partition wall) 
           116   a  first surface 
           116   b  second surface 
           118  tying member 
           119  second end 
           120  accommodation recess 
           122  wire harness 
           124  detection rib accommodation recess 
           126  connector unit (second embodiment) 
           128  holding protrusion 
           130  recess