Abstract:
A waterproof rubber plug has a through hole through which an electric wire is inserted to be connected to a terminal. A connector housing includes a terminal chamber for accommodating the terminal and a wall portion having a through hole formed so as to oppose to the terminal chamber, through which the electric wire is inserted. A recess for accommodating the rubber plug to thereby seal the electric wire and the terminal chamber. The recess is formed on an inner side face of the wall portion of the connector housing so as to communicate with the through hole of the wall portion. A window hole is formed on a part of the wall portion surrounding the recess so as to expose an anti-sealing part of the rubber plug accommodated in the recess.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a small-size multi-way waterproof connector in which waterproofing property between a connector housing and a plurality of electric wires connected with terminals is improved. 
     A related waterproof connector, which is disclosed in Japanese Patent Publication No. 11-329571 will be explained with reference to FIGS. 7 to  9 E. A connector housing  11  of the waterproof connector  10 ″ consists of an inner housing  12  formed of a synthetic resin and including a plurality of terminal chambers  13  integrally formed therewith, an outer. housing  17  formed of a synthetic resin into which the inner housing  12  is adapted to be inserted, and a spacer  28  interposed between the inner housing  12  and the outer housing  13  in order to hold female terminals  14  contained in the above described terminal chambers  13  respectively. 
     As shown in FIGS. 7 and 8, the inner housing  12  has a box-like portion  12   a  of which an upper and a lower faces are open at their rearward ends. The above described terminal chambers  13  are formed in a space defined by a central horizontal wall  12   b  and vertical side walls  12   c  which also serve as partition walls. The female terminals  14  are adapted to be contained in the terminal chambers  13  respectively. The box-like portion  12   a  is integrally formed with projecting engagement claws  15  at opposite sides and a center of its upper and lower faces. Flange portions  16  are integrally formed so as to project from both sides of the box-like portion  12   a  at a center of its front face. Moreover, the front wall of the box-like portion  12   a  is provided with rectangular through holes  12   d  at positions corresponding to the terminal chambers  13 , into which male terminals of a mating connector (not shown) are adapted to be inserted. Further, each of the female terminals  14  has a pair of press-connection blades  14   b  which are bent from plate portions at both sides in the rear of a box-like portion  14   a.    
     As shown in FIGS. 7 and 8, the outer housing  17  is in a form of double boxes which are open at the front face, consisting of an inner wall portion  17   a  in a shape of substantially rectangular column, an outer wall portion  17   b  in a shape of substantially rectangular column enclosing the inner wall portion  17   a,  and a bottom wall portion (one wall portion)  17   c  connecting the inner and the outer wall portions  17   a,    17   b  at their rear parts. A central part of the bottom wall portion  17   c  is formed as a thick wall portion. In front of the thick wall portion are provided rubber plug chambers  19  each having a larger diameter and a circular cross section and in which waterproof rubber plugs  18  are contained by press-fitting or the like, at positions facing with the terminal chambers  13 . In the back of the thick wall portion are formed electric wire through holes  21  each having a smaller diameter and a circular cross section and through which electric wires  20  are adapted to pass so as to communicate with the corresponding rubber plug chambers  19 . Each of the waterproof rubber plugs  18  is substantially in a form of a cylinder having undulations at both inner and outer peripheral faces, so that the electric wire  20  is adapted to pass therethrough without clearance. 
     At front opposite sides of the upper and lower walls of the inner wall portion  17   a  of the outer housing  17 , are respectively provided rectangular slits  22  for engaging and disengaging with the engagement claws  15  which are formed at the opposite sides of the upper and lower faces of the box-like portion  12   a  of the inner housing  12 . At the front center of the upper and lower walls of the inner wall portion  17   a  is provided rectangular longer locking slits  23  for engaging and disengaging with the engagement claws  15  formed at the center of the upper and lower faces of the box-like portion  12   a  of the inner housing  12 . Moreover, in a depth of the outer face of the inner wall portion  17   a  of the outer housing  17 , is integrally formed a V-shaped packing receiving portion  25  in a projecting manner which is adapted to receive an annular waterproof packing  24  formed of rubber. Tapered faces  26  are respectively provided at front edges of the inner faces of the inner wall portion  17   a  at positions facing with the locking slits  22  and  23 . Further, the upper and lower walls of the outer wall portion  17   b  of the outer housing  17  are respectively provided in their forward parts with locking holes  27  for engaging and disengaging with flexible locking arms of the mating connector (not shown). 
     As shown in FIGS. 7 and 8, the spacer  28  is in a form of a box which opens at the front face, consisting of a body portion  28   a  in a shape of substantially rectangular column adapted to be fitted to the inner face of the inner wall portion  17   a  of the outer housing  17 , a flange portion  28   b  in a shape of substantially rectangular column which is integrally formed with the body portion  28   a  so as to be bent backwardly from the front end thereof and adapted to be fitted to the outer face of the inner wall portion  17   a  of the outer housing  17 , and a bottom wall portion  28   c  of the body portion  28   a.    
     The box-like portion  12   a  of the inner housing  12  is adapted to be inserted into the body portion  28   a  of the spacer  28 . At inner faces of the upper and lower walls of the body portion  28   a  of the spacer  28 , are integrally provided rib-like projections  29  for preventing detachment of the terminals which are adapted to engage with a rear end edge of the box-like portion  12   a  of the inner housing  12  and rear end edges of the box-like portions  14   a  of the female terminals  14  which are contained in the respective terminal chambers  13 . 
     In the front of the connected portion between the body portion  28   a  and the flange portion  28   b  of the spacer  28  are provided notches  30 ,  31  respectively at positions corresponding to the engagement claws  15  and the flange portions  16  of the inner housing  12 . At outer faces of the upper and lower walls of the body portion  28   a  of the spacer  28  between the vertically arranged notches  30  are integrally formed engagement claws  32  for engaging and disengaging with the locking slits  23  in the outer housing  17 . Moreover, a distal end of the flange portion  28   b  of the spacer  28  is in such a form that it holds the packing  24  engaged in the packing receiving portion  25  in the inner wall portion  17   a  of the outer housing  17  when the spacer has been inserted in the outer housing  17 . 
     The bottom wall portion  28   c  of the spacer  28  is formed with electric wire through holes  33  at positions corresponding to the respective electric wire through holes  21  in the outer housing  17 . The bottom wall portion  28   c  of the spacer  28  serves to hold the rubber plugs  18  which are inserted into the respective rubber plug chambers  19  in the bottom wall portion  17   c  of the outer housing  17 , when the spacer has been fitted into the outer housing  17 . The electric wires  20  passed through the electric wire through hole  21  in the outer housing  17 , the rubber plugs  18 , and the electric wire through holes  33  in the spacer  28  are press-connected between a pair of the press-connection blades  14   b  of the female terminals  14  contained in the terminal chambers  13  in the inner housing  12 . The terminal chambers  13  and the electric wires  20  are sealed with the rubber plugs  18  and the packing  24  respectively. 
     In order to assemble the above structured waterproof connector  10 ″, the rubber plugs  18  are first inserted in a fitting direction of the connector housing into the respective rubber plug chambers  19  inside the bottom wall portion  17   c  of the outer housing  17  which constitutes the exterior of the connector housing  11 , and set as shown in FIG.  9 A. Then, the packing  24  is inserted and set in the packing receiving portion  25  in the inner wall  17   a  of the outer housing  17 . 
     After that, the body portion  28   a  of the spacer  28  is inserted into the inner wall portion  17   a  of the outer housing  17  as shown in FIG. 9B, and the engagement claws  32  in the body portion  28   a  of the spacer  28  are locked in the respective locking slits  23  formed in the inner wall portion  17   a  of the outer housing  17 . This locking action of the engagement claws  32  of the body portion  28   a  of the spacer  28  with the respective locking slits  23  in the inner wall portion  17   a  of the outer housing  17  will prevent withdrawal of the rubber plugs  18  in cooperation with the bottom wall portion  17 c of the outer housing  17 , and at the same time, withdrawal of the packing  24  in cooperation with the slanted distal end of the flange portion  28   b  of the spacer  28 . Thus, the waterproofing property of the whole connector housing can be remarkably enhanced. 
     Next, as shown in FIG. 9C, the electric wires  20  are inserted from the electric wire through holes  21  in the bottom wall portion  17   c  of the outer housing  17  to pass through the rubber plugs  18  and the electric wire through holes  33  in the bottom wall portion  28   c  of the spacer  28  from the exterior. Then, as shown in FIG. 9D, the electric wires  20  are press-connected to a pair of the press-connection blades  14   b  of the female terminals  14  contained in the terminal chambers  13  in the inner housing  12  which constitutes the interior of the connector housing  11 . 
     Next, as shown in FIG. 9E, the inner housing  12  is inserted into the body portion  28   a  of the spacer  28 , and the engagement claws  15  of the box-like portion  12   a  of the inner housing  12  are locked in the locking slits  23  in the inner wall portion  17   a  of the outer housing  17 , thereby completing the assembly of the waterproof connector  10 ″. On this occasion, because the rear end edge of the box-like portion  12   a  of the inner housing  12  and the rear end edges of the  1 box-like portions  14   a  of the female terminals  14  are respectively locked by the projections  29  which project from the inner faces of the upper and lower walls of the body portion  28   a  of the spacer  28 , and the projections  29  will not be deformed outwardly, the female terminals  14  can be surely prevented from withdrawing from the respective terminal chambers  13 . Moreover, as the female terminals  14  and the rubber plugs  18  can be held by the spacer  28  at the same time, those components exclusively for preventing the withdrawal of the rubber plugs are not necessary, and accordingly, the components can be reduced in number thereby enabling a low cost production to be attained. In addition, the spacer  28  can be double locked by both the engagement of its own engagement claws  32  with the locking slits  23  in the outer housing  17  and the engagement of the engagement claws  15  in the inner housing  12  with the locking slits  23  in the outer housing  17 . Therefore, the withdrawal of the rubber plugs  18  and the packing  24  can be surely prevented, and reliability in the waterproofness can be remarkably improved. 
     However, in the related waterproof connector  10 ″, the rubber plugs  18  are covered with the bottom wall portion  17   c  of the outer housing  17  and the peripheral wall portion  17   d  around the rubber plug chambers  19  in a completely enclosed state, and therefore, it has been difficult to confirm from the exterior whether or not the rubber plugs  18  are provided in the rubber plug chambers  19  (lack of components) in assembling the waterproof connector  100 ″. Moreover, as shown in FIG. 10, water intruded from the electric wire insertion inlets outside the electric wire through holes  21  in the outer housing  17  has been liable to stay in spaces S respectively formed between the rubber plug chambers  19  in the outer housing  17  and one ends  18   a  of the rubber plugs.  18 . There has been a fear that in case where this water thus staying is frozen, the bottom wall portion  17   c  and the peripheral wall portion  17   d  of the outer housing  17  formed of a hard synthetic resin may be broken because they cannot absorb a volume expansion when the water thus staying is frozen into ice. 
     SUMMARY OF THE INVENTION 
     Therefore, the invention has been made to solve the above described problems, and it is an object of the invention to provide a multi-way connector in which the presence of the rubber plugs can be easily confirmed to improve assembling grade, and water which has intruded into the rubber plug chambers from the electric wire insertion inlets outside the electric wire through holes in the connector housing can be easily drained, thereby to reliably prevent the peripheral wall portion, etc. from being broken due to freezing of the water. 
     In order to achieve the above object, according to the present invention, there is provided a waterproof connector comprising: 
     a waterproof rubber plug having a through hole through which an electric wire is inserted to be connected to a terminal; 
     a connector housing including a terminal chamber for accommodating the terminal and a wall portion having a through hole formed so as to oppose to the terminal chamber, through which the electric wire is inserted; 
     a recess for accommodating the rubber plug to thereby seal the electric wire and the terminal chamber, the recess formed on an inner side face of the wall portion of the connector housing so as to communicate with the through hole of the wall portion; and 
     a window hole formed on a part of the wall portion surrounding the recess so as to expose an anti-sealing part of the rubber plug accommodated in the recess. 
     According to the above configuration, the presence of the rubber plug can be confirmed from the exterior of the connector housing through the window hole, and the assembling grade can be enhanced. Moreover, the water intruded into the recess through the through holes in the connector housing will be drained through the window hole to the exterior and will not stay in the recess, and therefore, the wall portion, etc. will not be broken on occasion of freezing. 
     Preferably, a diameter of one end portion of the rubber plug which faces inside of the connector housing is reduced to extend outside of the recess, and a diameter of one end portion of the rubber plug which faces outside of the connector housing is reduced as the anti-sealing part. 
     According to the above configuration, the one end of the rubber plug can be easily observed from the exterior of the connector housing through the window hole. With this structure, the presence of the rubber plug can be easily confirmed, and the assembling grade can be remarkably enhanced. 
     Preferably, the window hole is formed so as to bore through the portion of the wall portion surrounding the recess in the vertical direction, and so as to extend up to a position adjacent to a portion where the through hole of the wall portion is provided. 
     According to the above configuration, the presence of the rubber plug can be more certainly confirmed from the exterior of the connector housing through the window hole, and the assembling grade can be enhanced. Moreover, the water intruded into the recess through the through holes in the connector housing will be more certainly drained through the window hole to the exterior and will not stay in the recess, and therefore, the wall portion, etc. will not be broken on occasion of freezing. 
     Preferably, the connector housing includes an inner housing having the terminal chamber and an outer housing having sidewalls for defining a chamber together with the wall portion, into which the inner housing is fitted. 
     According to the above configuration, the presence of the rubber plug can be very easily confirmed through the window hole from the exterior of the outer housing, even in case where the recess are provided in the wall portion of the outer housing in a plurality of rows both in a vertical and lateral directions. Further, the water which has intruded into the recess through the through hole in the outer housing can be smoothly and reliably drained through the lower portion of the window holes, and the damages of the wall portion, etc. on occasion of freezing can be surely avoided. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a sectional view showing a waterproof connector according to a first embodiment of the invention in a completely assembled state; 
     FIG. 2 is a sectional view showing the above waterproof connector in a state before assembled; 
     FIG. 3 is a sectional view of the essential part of the above waterproof connector; 
     FIG. 4 is a fragmentary rear view partly shown in section of the essential part of the above waterproof connector; 
     FIG. 5 is a fragmentary perspective view of the essential part of the above waterproof connector; 
     FIG. 6 is a fragmentary rear view partly shown in section of the essential part of a waterproof connector according to a second embodiment of the invention; 
     FIG. 7 is a sectional view showing a related waterproof connector in a state before assembled. 
     FIG. 8 is a perspective view of the related waterproof connector in a state before assembled partly shown in section; 
     FIG. 9A is a sectional view showing the related waterproof connector in a state before assembled; 
     FIG. 9B is a sectional view showing the related waterproof connector in a state wherein a spacer has been fitted in an outer housing; 
     FIG. 9C is a sectional view of the related waterproof connector in a state wherein electric wires are passed through the outer housing and the spacer,; 
     FIG. 9D is a sectional view of the related waterproof connector in a state wherein the electric wires are connected to terminals which are contained in the terminal chambers in an inner housing; 
     FIG. 9E is a sectional view showing the related waterproof connector in a completely assembled state; and 
     FIG. 10 is a sectional view showing the related waterproof connector in a state before the inner housing is fitted to the spacer which has been fitted into the outer housing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now, embodiments according to the invention will be described by way of examples referring to the accompanying drawings. 
     FIG. 1 is a sectional view showing a waterproof connector according to a first embodiment of the invention in a completely assembled state, FIG. 2 is a sectional view showing the waterproof connector in a state before assembled, FIG. 3 is a sectional view of the essential part of the waterproof connector, FIG. 4 is a fragmentary rear view of the essential part partly shown in section, and FIG. 5 is a fragmentary perspective view of the essential part. 
     As shown in FIG. 1, as well as the related waterproof connector, a connector housing  11  of the waterproof connector  10  consists of an inner housing  12  formed of a synthetic resin and including a plurality of terminal chambers  13  integrally formed therewith and arranged both in vertical and lateral directions, an outer housing  17  formed of a synthetic resin into which the inner housing  12  is adapted to be inserted, and a spacer  28  interposed between the inner housing  12  and the outer housing  17  in order to hold female terminals  14  contained in the above described terminal chambers  13  respectively. 
     As shown in FIGS. 1 to  3 , the electric wire through holes  21  are formed in the bottom wall portion  17   c  of the outer housing  17  at the positions facing with the terminal chambers  13  respectively, and the rubber plug chambers  19  are formed inside the bottom wall portion  17   c  at the positions facing with the electric wire through holes  21  respectively. The rubber plug chambers  19  are arranged in two rows in a vertical direction and in a plurality of rows in a lateral direction. In the peripheral wall portion  17   d  of the outer housing  17  surrounding the rubber plug chambers  19 , are formed rubber plug exposing holes  17   e,    17   f  and  17   g  at areas except the areas sealed with respect to the respective rubber plugs  18  (in a corner zone between the peripheral wall portion  17   d  and the bottom wall portion  17   c ). As shown in FIGS. 1 to  5 , the rubber plug exposing holes  17   e,    17   f,    17   g  are formed so as to linearly pass through the peripheral wall portion  17   d  in a vertical direction, and the rubber plug exposing holes  17   e,    17   f,    17   g  thus vertically passing are so provided as to extend up to positions adjacent to the electric wire through holes  21  in the bottom wall portion  17   c.    
     The rubber plugs  18  are adapted to be inserted into the rubber plug chambers  19  in a direction of A which is a direction wherein the inner housing  12  is fitted into the inner wall portion  17   a  of the outer housing  17  (in a fitting direction of the connector) by way of the spacer  28 . Each of the rubber plugs  18  is integrally formed at its both ends  18   a  with extended portions  18   b  having a smaller diameter and extending up to an inner face of the bottom wall portion  17   c  of the outer housing  17  and an outer face of the bottom wall portion  28   c  of the spacer  28 . An electric wire through hole  18   c  through which the electric wire  20  passes is formed at the center of the rubber plug  18  between the both ends  18   a.  The middle part of the rubber plug  18  is in a form of undulated cylinder so that the electric wire can be passed therethrough leaving no clearance. This waterproof connector  10  is substantially the same as the related waterproof connector  10 ″ with respect to other structures, the same components will be denoted with the same reference numerals to omit a further explanation. 
     The waterproof connector  10  according to the embodiment is manufactured in a similar assembling manner to the related waterproof connector  10 ″. However, as shown in FIGS. 1 and 3, there are respectively formed the rubber plug exposing holes  17   e,    17   f  and  17   g  in the peripheral wall portion  17   d  of the outer housing  17  surrounding the rubber plug chambers  19  at the areas except the areas sealed with respect to the rubber plugs  18  in such a manner that the rubber plug exposing holes  17   e,    17   f  and  17   g  linearly pass through the peripheral wall portion  17   d  in a vertical direction, and the rubber plug exposing holes  17   e,    17   f,    17   g  thus vertically passing are so provided as to extend up to the positions adjacent to the electric wire through holes  21  in the bottom wall portion  17   c.  Therefore, the presence of the rubber plugs  18  (lack of components) can be very easily confirmed from the exterior of the outer housing  17  through the vertically passing rubber plug exposing holes  17   e,    17   f,    17   g,  even in case where the rubber plug chambers  19  are arranged in two rows in a vertical direction and in a plurality of rows in a lateral direction in the bottom wall portion  17   c  of the outer housing  17 . The assembling grade of the waterproof connector  10  can be thus improved. 
     Further, as shown in FIGS. 3 to  5 , because water (water drops) B which has intruded into the rubber plug chambers  19  from the electric wire insertion inlets outside the electric wire through holes  21  in the outer housing  17  can be smoothly and reliably drained through the lowermost rubber plug exposing holes  17   g,  the water B will not stay in the rubber plug chambers  19 . With this structure, the peripheral wall portion  17   d  and the bottom wall portion  17   c  of the outer housing  17  can be surely prevented from being broken when the water is frozen, and the reliability in the waterproofness by means of the rubber plugs  18  can be enhanced. 
     Further, as shown in FIG. 3, because the extended portion  18   b  is integrally formed at the one end  18   a  of the rubber plug  18  so as to extend up to the inner face of the bottom wall portion  17   c  of the outer housing  17 , the extended portions  18   b  at the both ends  18   a  of the rubber plug  18  can be easily observed from the exterior of the outer housing  17  through the rubber plug exposing holes  17   e,    17   f,    17   g.  With this structure, the presence of the rubber plugs  18  (lack of components) can be easily confirmed, and the assembling grade of the waterproof connector  10  can be remarkably improved. 
     FIG. 6 is a fragmentary rear view of a waterproof connector  10 ′ according to a second embodiment of the invention partly shown in section. There are respectively formed the rubber plug exposing holes  17   e,    17   f,    17   g  and  17   h  in the peripheral wall portion  17   d  of the outer housing  17  surrounding the rubber plug chambers  19  at the areas except the areas sealed with respect to the rubber plugs  18 . These rubber plug exposing holes  17   e,    17 ,  17   g,    17   h  are formed so as to linearly pass through the peripheral wall portion  17   d  in a vertical direction, and the rubber plug exposing holes  17   e,    17   f,    17   g,    17   h  thus vertically passing are so provided as to extend up to the positions adjacent to the electric wire through holes  21  in the bottom wall portion  17   c.  This waterproof connector  10 ′ is substantially the same as the waterproof connector  10  in the first embodiment with respect to other structures, the same components will be denoted with the same reference numerals to omit a further explanation. 
     This waterproof connector  10 ′ attains similar effects to the above described waterproof connector  10 . In short, the presence of the rubber plugs  18  (lack of components) can be very easily confirmed from the exterior of the outer housing  17  through the vertically passing rubber plug exposing holes  17   e,    17   f,    17   g,    17   h  even in case where the rubber plug chambers  19  are arranged in three rows in a vertical direction and in a plurality of rows in a lateral direction in the bottom wall portion  17   c  of the outer housing  17 . The assembling grade of the waterproof connector  10 ′ can be thus improved. 
     In addition, because water (water drops) B which has intruded into the rubber plug chambers  19  from the electric wire insertion inlets outside the electric wire through holes  21  in the outer housing  17  can be smoothly and reliably drained through the lowermost rubber plug exposing holes  17   h,  the water B will not stay in the rubber plug chambers  19 . With this structure, the peripheral wall portion  17   d  and the bottom wall portion  17   c  of the outer housing  17  can be surely prevented from being broken when the water is frozen, and the reliability in the waterproofness by means of the rubber plugs  18  can be enhanced. 
     In the above described embodiments, a pair of the rubber plug exposing holes are formed at upper and lower positions of the peripheral wall portion surrounding the rubber plug chambers, and an air is introduced through the upper rubber plug exposing holes in order to drain the water through the lower rubber plug exposing holes. However, the rubber plug exposing holes may be provided only at the upper side of the peripheral wall portion in case of confirming the presence of the rubber plugs (lack of components) only, and the rubber plug exposing holes may be provided only at the lower side of the peripheral wall portion in case of draining the water only. Moreover, the description has been made referring to the case where the electric wire is press-connected to the press-connected terminal, but the terminal is not limited to the press-connected type. It is apparent that the above described embodiments can be applied to the case where the electric wire is crimped to the crimp terminal.