Abstract:
A waterproof rubber plug has a through hole through which an electric wire is inserted. The electric wire is connected to a terminal. An inner housing has a terminal chamber for accommodating the terminal. An outer housing has sidewalls for defining a chamber provided with a bottom wall, into which the inner housing is fitted. A through hole, through which the electric wire is inserted, is formed on the bottom wall so as to face the terminal chamber when the inner housing is inserted into the chamber of the outer housing. A recess is formed on the bottom wall so as to communicate with the through hole and opened to the outside of the outer housing, into which the rubber plug is fitted after the inner housing is completely fitted into the chamber of the outer housing, thereby sealing the electric wire and the terminal chamber.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a small size multi-way water proof connector with an improved water proof property between a connector housing and a plurality of electric wires connected with terminals, and a method of assembling the same. 
     A related waterproof connector, which is disclosed in Japanese Patent Publication No. 11-329571, will be explained specifically with reference to FIGS. 8 to  10 E. A connector housing  11  of a water proof connector  10 ″ comprises a synthetic resin inner housing  12  having a plurality of terminal chambers  13  formed integrally therewith, a synthetic resin outer housing  17  for fitting the inner housing  12  to the inside thereof, and a synthetic resin spacer  28  disposed between the inner housing  12  and the outer housing  17  for holding female terminals  14  accommodated in each terminal chamber  13  of the inner housing  12 . 
     As shown in FIGS. 8 and 9, the inner housing  12  has a box part  12   a  with the rear side of the upper and lower faces opened, for forming the terminal chambers  13  in a space formed with the center horizontal wall  12   b  and vertical side walls  12   c , serving also as partition walls in the vertical direction. The female terminals  14  can be accommodated in each terminal chamber  13 . Moreover, engagement claws  15  are formed integrally, projecting from both sides and the center of the upper and lower faces of the box part  12   a  as well as flange parts  16  are formed integrally projecting from the front end of the both side center parts. Rectangular insertion holes  12   d  through which female terminals of a mating connector (not illustrated) are inserted are formed in the front wall of the box part  12   a  at a position corresponding to each terminal chamber  13 . Furthermore, a pair of press-connecting blades  14   b  are formed by bending each in both side plate parts in the rear part of a box part  14   a  of the female terminals. 
     As shown in FIGS. 8 and 9, the outer housing  17  has a double box-like shape with the front side opened, with a substantially quadrilateral pipe-like inner wall part  17   a , a substantially quadrilateral pipe-like outer wall part  17   b  for containing the inner wall part  17   a , and a bottom wall part  17   c , connecting the rear parts of the inner and outer wall parts  17   a ,  17   b . A thick portion is provided in the center of the bottom wall part  17   c . Rubber plug chambers  19  having a large diameter round cross-section for storing the water proof rubber plugs  18  by press-in are formed at a position corresponding to each terminal chamber  13  at the front side with respect to the thick portion as well as insertion holes  21  having a small diameter round cross-section for inserting electric wires  20  therethrough are formed, communicating with each corresponding rubber plug chamber  19  at the rear side with respect to the thick portion. The water proof rubber plugs  18  have a substantially cylindrical shape with the rugged inner and outer circumferential faces so that the electric wires  20  can be inserted through the inside thereof without having a gap. 
     Moreover, rectangular engagement holes  22  to be engaged with each engagement claw  15  at both sides of the upper and lower faces of the box part  12   a  of the inner housing  12  are formed at both front sides of the upper and lower walls of the inner wall part  17   a  of the outer housing  17  as well as rectangular longitudinal engagement holes  23  to be engaged with each engagement claw  15  at the center of the upper and lower faces of the box part  12   a  of the inner housing  12  are formed at the front center portion of the upper and lower walls of the inner wall part  17   a . Furthermore, a V-shaped packing receiving part  25  for receiving an annular rubber water proof packing  24  is formed integrally, projecting from the deep part of the outer face side of the inner wall part  17   a  of the outer housing  17 . Tapered faces  26  are formed in the front rim of the inner face side of the inner wall part  17   a  of the outer housing at a position corresponding to each engagement hole  22 ,  23 . Moreover, engagement holes  27  to be engaged with flexible engagement arms of a mating connector (not illustrated) are formed at the front side of the upper and lower walls of the outer wall part  17   b  of the outer housing  17 . 
     As shown in FIGS. 8 and 9, the spacer  28  forms a box-like shape with the front side opened, with a substantially quadrilateral pipe-like body  28  to be fitted with the inner face side of the inner wall part  17   a  of the outer housing  17 , a substantially quadrilateral pipe-like brim part  28   b  formed integrally with the front end of the body  28   a , bent rearward therefrom, to be fitted with the outer face side of the inner wall part  17   a  of the outer housing, and a bottom wall part  28   c  of the body  28   a.    
     Accordingly, the box part  12   a  of the inner housing  12  can be fitted into the body  28   a  of the spacer  28 . Rib-like projections  29  for preventing fall-off of the terminals are formed integrally, projecting from the inner face of the upper and lower walls of the body  28   a  of the spacer  28 , to be engaged with the rear end rim of the box part  14   a  of the female terminals  14  accommodated in each terminal chamber  13 . 
     Moreover, notch portions  30 ,  31  are formed in the front side of the portion connecting the body  28   a  and the brim part  28   b  of the spacer  28  at a position corresponding to each of the engagement claw  15  and the flange part  16  of the inner housing  12 . Engagement claws  32  to be engaged with each engagement hole  23  of the outer housing  17  are formed integrally, projecting form the outer face side of the upper and lower walls of the body  28   a  of the spacer  28  between the upper and lower side notch portions  30 . Furthermore, the tip portion of the brim part  28   b  can hold the packing  24  engaged with the packing receiving part  25  of the inner wall part  17   a  of the outer housing  17  when the fitting operation with respect to the outer housing  17  is completed. 
     Moreover, insertion holes  33  are formed in the bottom wall part  28   c  of the spacer  28  at a position corresponding to each insertion hole  21  of the outer housing  17 . Furthermore, the bottom wall part  28   c  of the spacer  28  can hold the rubber plugs  18  inserted in each rubber plug chamber  19  of the bottom wall part  17   c  of the outer housing when the fitting operation with respect to the outer housing  17  is completed. As shown in FIG. 8, each electric wire  20  inserted through each insertion hole  21  of the outer housing  17 , each rubber plug  18  and each insertion hole  33  of the spacer  28  is press-connected between the pair of the press-connecting blades  14   b ,  14   b  of each female terminal accommodated in each terminal chamber  13  of the inner housing  12  so that each terminal chamber  13  and each electric wire  20  are sealed with the rubber plug  18  and the packing  24 , respectively. 
     In assembling the water proof connector  10 ″ with the above-mentioned configuration, as shown in FIG. 10A, the rubber plugs  18  are inserted and set in each rubber plug chamber  19  inside the bottom wall part  17   c  of the outer housing  17  comprising the outside of the connector housing  11  from the connector housing fitting direction as well as the packing  24  is inserted and set in the packing receiving part  25  of the inner wall part  17   a  of the outer housing  17 . 
     Then, as shown in FIG. 10B, the body  28   a  of the spacer  28  is fitted into the inner wall part  17   a  of the outer housing  17  so that each engagement claw  32  of the body  28   a  of the spacer  28  is engaged with each engagement hole  23  of the inner wall part  17   a  of the outer housing  17 . According to the engagement of each engagement hole  23  of the inner wall part  17   a  of the outer housing  17  and each engagement claw  32  of the body  28   a  of the spacer  28 , fall-off of each rubber plug  18  is prevented by the bottom wall part  17   c  of the outer housing  17  as well as fall-off of the packing  24  is prevented by the oblique tip end of the brim part  28   b  of the spacer  28  so that the water proof property of the connector housing as a whole can further be improved. 
     As shown in FIG. 10C, the electric wires  20  are inserted through each insertion hole  21  of the bottom wall part  17   c  of the outer housing  17 , each rubber plug  18 , and each insertion hole  33  of the bottom wall part  28   c  of the spacer  28  from the outside. Then, as shown in FIG. 10D, each electric wire  20  is press-connected with the pair of the press-connecting blades  14   b  of the female terminals  14  accommodated in each terminal chamber  13  of the inner housing  12  comprising the inner side of the connector housing  11 . 
     As shown in FIG. 10E, the inner housing  12  is fitted into the body  28   a  of the spacer  28  so that each engagement claw  15  of the box part  12   a  of this inner housing  12  is engaged with each engagement hole  23  of the inner wall part  17   a  of the outer housing  17  so as to complete the assembly of the water proof connector  10 ″. At the time, since the rear end rim of the box part  12   a  of the inner housing  12  and the rear end rim of the box part  14   a  of the female terminals  14  accommodated in each terminal chamber  13  are locked according to each projection  29  projecting to the inner face of the upper and lower walls of the body  28   a  of the spacer  28  as well as each projection  29  cannot deform outward, fall-off of the female terminals  14  from each terminal chamber can be prevented certainly. Besides, since the spacer  28  can hold each female terminal  14  and each rubber plug  18  at the same time, a component dedicated to prevention of fall-off of the rubber plug can be eliminated, and thus a low cost can be achieved by cutback of the number of the components. Furthermore, since the spacer  28  can be locked doubly according to the engagement of each engagement claw  32  of the spacer  28  itself with each engagement hole  23  of the outer housing  17  and the engagement of each engagement claw  15  o the inner housing  12  with each engagement hole  23  of the outer housing  17 , fall-off of each rubber plug  18  and the packing  24  can be prevented certainly so that the water proof reliability can further be improved. 
     However, according to the related water proof connector  10 ″, since the rubber plugs  18  are accommodated preliminarily in the rubber plug chambers  19  of the outer housing  17  as shown in FIG. 10B, the electric wires  20  can easily be bent due to the sliding friction between the rubber plugs  18  and the electric wires as shown in FIG. 11 at the time of the electric wire insertion by inserting the electric wires  20  through the insertion holes  21  of the outer housing  17  and the insertion holes  33  of the spacer  28  shown in FIGS. 10B to  10 C, and at the time of fitting the housing by sliding the electric wires  20  with respect to the insertion holes  33  of the spacer  28  and the insertion holes  21  of the outer housing  17  so as to fit the inner housing  12  into the spacer  28  fitted inside the outer housing  17  shown in FIGS. 10D to  10 E so that there is a risk of causing a trouble in the wire harness production. That is, there is a risk of deteriorating the assembly operativity of the water proof connector  10 ″ due to the increased operation load by the sliding friction between the rubber plugs  18  and the electric wires  20  at the time of the electric wire inserting operation of the electric wires  20  and the housing fitting operation of fitting the inner housing  12  into the outer housing  17  side. 
     SUMMARY OF THE INVENTION 
     Accordingly, in order to solve the above-mentioned problems, an object of the invention is to provide a small size multi-way water proof connector with an improved assembly operativity, and a method of assembling the same. 
     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; 
     a terminal to which the electric wire is connected; 
     an inner housing having a terminal chamber for accommodating the terminal; 
     an outer housing having sidewalls for defining a chamber provided with a bottom wall, into which the inner housing is fitted; 
     a through hole, through which the electric wire is inserted, formed on the bottom wall so as to face the terminal chamber when the inner housing is inserted into the chamber of the outer housing; and 
     a recess formed on the bottom wall so as to communicate with the through hole and opened to the outside of the outer housing, into which the rubber plug is fitted after the inner housing is completely fitted into the chamber of the outer housing, thereby sealing the electric wire and the terminal chamber. 
     According to the above configuration, since the rubber plug can be accommodated in the recess of the outer housing from the outside thereof after connecting the electric wire placed through the through holes of the outer housing with the terminal accommodated in the terminal chamber of the inner housing and fitting the inner housing into the outer housing, the friction between the electric wire and the rubber plug can be eliminated at the time of fitting the inner housing into the inside of the outer housing so as to prevent generation of bend of the electric wire, and thus the assembly operativity of the water proof connector can be improved. That is, production of the wire harness can be facilitated. 
     Preferably, a hook member is formed an inner wall of the recess for retaining the rubber plug inside of the recess. 
     According to the above configuration, fall-off of the rubber plug accommodated in the recess of the outer housing from the outside thereof can be prevented certainly. 
     Preferably, the waterproof connector further comprises a leverage member pivotably provided on the outside of the outer housing for press-fitting the rubber plug into the recess by the leverage action thereof. 
     According to the above configuration, the press-fitting operation of the rubber plug can be executed easily with a small operation force of the leverage member in a short time so that the assembly operativity of the water proof connector can be improved. Accordingly, production of the wire harness can be facilitated. 
     According to the present invention, the above waterproof connector is assembled by the steps of: 
     passing the electric wire through the through hole of the rubber plug; 
     passing the electric wire through the through hole on the bottom wall of the outer housing while staying the rubber plug outside of the outer housing; 
     connecting the electric wire to the terminal; 
     fitting the terminal into the terminal chamber of the inner housing; 
     fitting the inner housing into the chamber of the outer housing; and 
     fitting the rubber plug into the recess of the outer housing. 
     According to the above configuration, the electric wire is in a free state without being slid with the rubber plug at the time of inserting the electric wire through the through hole of the outer housing and at the time of fitting the inner housing into the chamber of the outer housing, and thus the assembly can be executed smoothly without generation of bend of the electric wire so as to drastically alleviate the operation load of the electric wire insertion force and the housing fitting force. Accordingly, a waterproof connector having the excellent water proof property can be assembled easily in a short time, and thus the assembly operativity as a whole can further be improved. 
     Preferably, the rubber plug is press-fitted into the recess by leverage action of a leverage member pivotably provided on the outside of the outer housing. 
     According to the above configuration, the press-fitting operation of the rubber plug can be executed easily with a small operation force of the leverage member in a short time so that the assembly operativity of the water proof connector can be improved. Accordingly, production of the wire harness can be facilitated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a cross-sectional view showing a water proof connector according to a first embodiment of the invention in a state before assembling rubber plugs; 
     FIG. 2 is a partial cross-sectional view showing a state before fitting the rubber plugs into rubber plug chambers of an outer housing of the waterproof connector shown in FIG. 1; 
     FIG. 3 is a partial cross-sectional view showing a state that the rubber plugs are fitted into the rubber plug chambers; 
     FIG. 4 is an enlarged cross-sectional view of the X portion of FIG. 3; 
     FIG. 5A is a cross-sectional view showing a state that electric wires are preliminarily placed through the rubber plugs inserted through the outer housing and a spacer; 
     FIG. 5B is a cross-sectional view showing a state before fitting the rubber plugs into the rubber plug chambers from the outside; 
     FIG. 5C is a cross-sectional view showing a state after completing the assembly of the water proof connector; 
     FIG. 6 is a lateral cross-sectional view showing a state before fitting rubber plugs into rubber plug chambers from the outside of a water proof connector according to a second embodiment of the invention; 
     FIG. 7 is an explanatory diagram of the water proof connector of FIG. 6, viewed from a rubber plug insertion member side; 
     FIG. 8 is a cross-sectional view of a related water proof connector in a state before assembled; 
     FIG. 9 is a perspective view with a partial cross-section of FIG. 2; 
     FIG. 10A is a cross-sectional view of the related water proof connector in the state before assembled; 
     FIG. 10B is a cross-sectional view of the related water proof connector showing a state with a spacer fitted in an outer housing; 
     FIG. 10C is a cross-sectional view showing a state with electric wires inserted through and outer housing and the spacer; 
     FIG. 10D is a cross-sectional view showing a state with the electric wires connected with terminals accommodated in terminal chambers of an inner housing; 
     FIG. 10E is a cross-sectional view showing a state after completing the assembly of the related water proof connector; and 
     FIG. 11 is a cross-sectional view showing a state before fitting the inner housing into the spacer fitted in the inside of the outer housing of the related water proof connector. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter a first embodiment of the invention will be explained with reference to the drawing. 
     As shown in FIGS. 1 and 5, similar to the case of the related waterproof connector, a connector housing  11  of a water proof connector  10  comprises a synthetic resin inner housing  12  having a plurality of terminal chambers  13  formed integrally therewith, a synthetic resin outer housing  17  for fitting the inner housing  12  to the inside thereof, and a synthetic resin spacer  28  to be fitted into the outer housing  17  for holding a water proof packing  24  for sealing a mating connector (not illustrated). The same components as in the related water proof connector  10 ″ are applied with the same numerals. 
     As shown in FIGS. 1 and 2, the rubber plugs  18  are accommodated with pressure in each rubber plug chamber  19  inside the bottom wall part  17   c  of the outer housing  17  along the electric wires  20  from the direction A outside the outer housing  17  so as to complete the assembly of the water proof connector  10 . When the rubber plugs  18  are press-fitted into each of the rubber plug chambers  19  of the outer housing  17  from the outside, as shown in FIG. 2, since the sliding distance L of the rubber plugs  18  with respect to the electric wires  20  is short, bend of the electric wires  20  can hardly be generated, and thus the assembly of the water proof connector  10  can be improved. Moreover, as show on in FIGS. 3 and 4, since the rubber plugs  18  accommodated in each of the rubber plug chambers  19  of the outer housing  17  are engaged by the hood portion  21   a  around each through hole  21  of the outer housing, the rubber plugs  18  will not fall out of each rubber plug chamber of the outer housing  17  to the outside. 
     As shown in FIGS. 2 and 3, reverse conical faces  18   b  are formed on both end sides of the through holes  18   a  of the rubber plugs  18  with the electric wires  20  inserted therethrough. The face (inner peripheral face) of the through holes  18   a  and the outer peripheral face of the rubber plugs have a rugged shape so that the electric wires can be inserted through the inside of the through holes  18   a  without having a gap. Moreover, a conical face  18   d  is formed on the outer periphery of the front side of the rubber plugs  18  for facilitating the insertion into the rubber plug chambers  19 . Furthermore, an annular engagement recess  18   f  is formed on the rear end of a body  18   e  at the outer periphery of the rear side of the rubber plugs  18 . As shown in FIGS. 3 and  4 , when the rubber plugs  18  are accommodated in the rubber plug chambers  19  of the outer housing  17 , the rubber plugs  18  are engaged such that the hook portion  21   a  around each through hole  21  of the outer housing  17  cuts into the engagement recess  18   f  of the body  18   e  of the rubber plugs  18 . Since the other parts of the configuration are the same as those of the related water proof connector  10 ″, the same components are applied with the same numerals and further explanation is not provided herein. 
     In assembling the water proof connector  10  of this embodiment, the packing  24  is inserted and set preliminarily into the packing receiving part  25  of the inner wall part  17   a  of the outer housing  17  comprising the outside of the connector housing  11  as well as each electric wire  20  is inserted through the rubber plug  18  preliminarily at the outside of the bottom wall part  17   c  of the outer housing. Then, as shown in FIG. 5A, the electric wires  20  are inserted through the plurality of the through hole  21  of the bottom wall part  17   c  of the outer housing  17  from the outside thereof as well as they are inserted through each through hole  33  of the bottom wall part  28   c  of the spacer  28 . 
     The electric wires  20  are pressure welded with a pair of the pressure blades  14   b  of each terminal  14  accommodated in the plurality of the terminal chambers  13  of the inner housing  12  comprising the inside of the connector housing  11 . By pulling the electric wires  20  to the outside direction with respect to the outer housing so as to slide with each through hole  33  of the bottom wall part  28   c  of the spacer  28  and each through hole  21  of the bottom wall part  17   c  of the outer housing  17 , the inner housing  12  is fitted into the inside of the body  28   a  of the spacer  28  as shown in FIG. 5B for fitting the inner housing  12  and the outer housing  17  via the spacer  28 . 
     As shown in FIGS. 1 and 2, the rubber plugs  18  are accommodated with pressure in each rubber plug chamber  19  inside the bottom wall part  17   c  of the outer housing  17  along with the electric wires  20  from the direction A outside the outer housing  17  so as to complete the assembly of the water proof connector  10 . When the rubber plugs  18  are press-fitted into each rubber plug chamber  19  of the outer housing  17  from the outside, as shown in FIG. 2, (the sliding distance L of the rubber plugs  18  with respect to the electric wires  20  is short) a bend of the electric wires  20  can hardly be generated, and thus the assembly of the water proof connector  10  can be improved. Moreover, as shown in FIGS. 3 and 4, since the rubber plugs  18  accommodated in each rubber plug chamber  19  of the outer housing  17  are engaged certainly by the hook portion  21   a  around each through hole  21  of the outer housing, the rubber plugs  18  cannot fall off from each rubber plug chamber of the outer housing  17  to the outside. 
     Accordingly, since the rubber plugs  18  are accommodated in each rubber plug chamber  19  of the outer housing  17  after fitting the inner housing  12  and the outer housing  17  via the spacer  28 , since the electric wires  20  are in the free state without being slid with the rubber plugs  18  at the time of inserting the electric wires  20  through each through hole  21  of the outer housing  17  and at the time of fitting the inner housing  12  with the outer housing  17  via the spacer  28 , the assembly can be executed smoothly without generation of bend of the electric wires  20  so as to drastically alleviate the operation load of the electric wire insertion force and the housing fitting force. Accordingly, the multi-way water proof connector  10  having the excellent water proof property can be assembled easily in a short time. That is, production of a wire harness comprising a bundle of the electric wires  20  can be facilitated, and thus the assembly operativity as a whole can further be improved. 
     FIG. 6 is a lateral cross-sectional view showing a state before fitting rubber plugs into rubber plug chambers of an outer housing from the outside of a water proof connector according to a second embodiment of the invention. FIG. 7 is an explanatory diagram of the water proof connector, viewed from a rubber plug insertion member side. 
     A water proof connector  10 ′ of this embodiment is for successively storing the rubber plugs  18  by pressure into each rubber plug chamber  19  of the outer housing from the outside direction A, using a lever  40  rotatable around the spindle  17   e  of the outer housing  17 . That is, a rectangular horizontal brim part  17   d  is formed integrally, projecting from one side face of the outer wall part  17   b  of the outer housing  17 . A pair of columnar spindles  17   e  are formed integrally, projecting in the upper and lower direction on the upper and lower faces of the brim part  17   d.    
     The lever  40  is made from a synthetic resin with a U-shaped front view, with the pair of the tip parts  41  formed with a curved shape having a substantially S-shaped side view. The pair of the tip parts  41  of the lever  40  are supported detachably by the pair of the spindles  17   e  of the outer housing  17  such that the lever  40  can rotate around each spindle  17   e  in the clockwise direction in FIG.  6 . At the time, the electric wires  20  are inserted in a space  42  at the center of the lever  40 . Since the configuration is same as that of the water proof connector  10  of the first embodiment except that the inner housing  12  to be fitted into the outer housing  17  via the spacer  28  comprises a plurality of the terminal chambers  13  adjacent with each other only in the right and left direction (horizontal direction), the same components are applied with the same numerals and further explanation is not given herein. 
     The water proof connector  10 ′ of this embodiment can be assembled in the same manner as the assembling method for the water proof connector  10  of the first embodiment, but in storing the rubber plugs  18  into each rubber plug chamber  19  of the outer housing  17  from the outside direction A, the operation is executed by the leverage of the lever  40 . That is, as shown in FIG. 6, since the rear faces  18   g  of the plurality of the rubber plugs  18  disposed in the horizontal direction are pushed successively by the pressing face  44  of the lever  40  with a small operation force of the operation part  43  of the lever  40  rotatable around the pair of the spindles  17   e  of the outer housing  11 , the rubber plugs  18  can be accommodated in the plurality of the rubber plug chamber  19  of the outer housing  17  easily in a short time, and thus the assembling operativity of the water proof connector  10 ′ can be improved. Accordingly, production of a wire harness comprising a bundle of the electric wires  20  can be facilitated, and thus the assembly operativity as a whole can further be improved. 
     Moreover, the lever  40  can be detached from the outer housing  17  after the assembly of the water proof connector  10 ′ so as to be used repeatedly. 
     Although the case of pressure welding of the electric wires to the pressure terminals has been explained in the above-mentioned embodiments, the terminals are not limited to the pressure terminals, but the embodiments can also be adopted to the case of the pressure connection of the electric wires to crimp-style terminals. 
     Although the present invention has been shown and described with reference to specific preferred embodiments, various changes and modifications will be apparent to those skilled in the art from the teachings herein. Such changes and modifications as are obvious are deemed to come within the spirit, scope and contemplation of the invention as defined in the appended claims.