Patent Document

BACKGROUND OF THE INVENTION 
     This invention relates to a connector, such as a waterproof connector, in which a wire, connected to a terminal received in a chamber in a connector housing, is sealed by a rubber plug. 
     A connector of the type described is disclosed in Japanese Patent Publication No. 9-106847A, this connector being shown in FIGS. 7 to  10 . As shown in FIGS. 7 and 8, this connector  1  comprises a housing  2 , having a pair of right and left tubular chambers  3  for respectively receiving terminals  9  each press-clamping a wire  7  and a rubber plug  8 , a box-shaped fixture  5  fitted on outer faces of peripheral walls of the two tubular chambers  3  at front end portions thereof, and an annular waterproof packing  6  fitted on the outer faces of the peripheral walls of the two tubular chambers  3  at rear end portions thereof. A notch  3   a  is formed in a central portion of the upper front portion of the peripheral wall of each tubular chamber  3 , and a cantilevered flexible arm  4  for retaining the terminal  9  is formed so as to extend in this notch portion  3   a.    
     For assembling the connector  1 , a pair of small projections  5   b , formed respectively on inner faces of right and left side walls of the fixture  5 , are fitted respectively in front ends of slots  3   b  formed respectively in the side walls of the two tubular chambers  3  as shown in FIGS. 8 and 9, so that the fixture  5  is provisionally fitted (provisionally retained) on the front end portions of the two tubular chambers  3  each of which is disposed forwardly of a region where the flexible arm  4  can be elastically deformed. Then, the terminals  9 , each press-clamping the wire  7  and the rubber plug  8 , are inserted respectively into the tubular chambers  3  from the rear side of the housing  2  as shown in FIG. 8, so that each terminal  9  is primarily retained in the tubular chamber  3  by the flexible arm  4 . Then, when the fixture  5  is further pushed as shown in FIG. 10, projections  5   a , formed on an inner face of an upper wall of the fixture  5 , are fitted respectively into front ends of the notches  3   a , and are disposed respectively at the regions of elastic deformation of the flexible arms  4 , so that the fixture  5  is completely fitted (completely retained) on the pair of tubular chambers  3 . As a result, the elastic deformation of each flexible arm  4  is prevented, so that each terminal  9  is retained in a double manner. 
     In the conventional connector  1 , each terminal  9  is received in the corresponding tubular chamber  3  in the housing  2 , and is retained by the elastic arm  4 . When vibrations, applied to the housing  2 , are transmitted to each terminal  9 , the vibrations are absorbed only by the rubber plug  8  press-clamped to a rear portion of the terminal  9 . Therefore vibrations, acting on a terminal body of the terminal  9 , could not be absorbed only by the rubber plug  8 , and when the connector  1  is mounted, for example, on a vehicle, a portion of contact of the terminal  9  with a mating terminal is worn by the vibrations, so that the reliability (contact reliability) of the terminal  9  becomes low. 
     SUMMARY OF THE INVENTION 
     Therefore, this invention has been made in order to solve the above problem, and an object of the invention is to provide a connector in which vibrations, transmitted to a terminal, are positively absorbed by an elastic member, interposed between and held in intimate contact with an outer housing and an inner housing, thereby enhancing a contact reliability of the terminal. 
     In order to achieve the above object, according to the present invention, there is provided a connector, comprising: 
     a terminal; 
     a first elastic member, provided at a rear end portion of the terminal; 
     an inner housing, including an inner peripheral wall which defines a first chamber for retaining at least a front end portion of the terminal, and an outer peripheral wall extending parallel with the inner peripheral wall while defining a gap therebetween; 
     an outer housing, including a peripheral wall which defines a second chamber for retaining at least first elastic member; and 
     a second elastic member, fitted around the peripheral wall of the outer housing, 
     wherein the inner housing and the outer housing are engaged with each other such that a front end portion of the peripheral wall of the outer housing is inserted into the gap formed between the inner peripheral wall and the outer peripheral wall of the inner housing, and such that a rear end face of the outer peripheral wall of the inner housing is brought into an intimate contact with the second elastic member. 
     In this configuration, in addition to the first elastic member fitted in the outer housing, vibrations, applied to the outer housing, are absorbed by the second elastic member, interposed between and held in intimate contact with the inner housing and the outer housing, and therefore will not be transmitted to the terminal. Therefore, when the connector is mounted, for example, on a vehicle, that portion of contact of the terminal with a mating terminal will not be subjected to wear, so that the contact reliability of the terminal is enhanced. 
     Preferably, the inner housing and the outer housing are engaged with each other such that a clearance is formed between an outer face of the inner peripheral wall of the inner housing and an inner face of the peripheral wall of the outer housing. 
     In this configuration, since the vibrations applied to the outer housing can be further prevented from being transmitted to the terminal, the contact reliability of the terminal is further enhanced. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, and wherein. 
     FIG. 1 is a vertical cross-sectional view of one preferred embodiment of a connector of the invention, showing a condition before this connector is assembled, 
     FIG. 2 is a vertical cross-sectional view of the connector, showing a condition in which an inner housing is provisionally fitted in an outer housing, with terminals not yet inserted; 
     FIG. 3 is a vertical cross-sectional view of the connector in the above provisionally-fitted condition, showing a condition during the insertion of the terminals; 
     FIG. 4 is a vertical cross-sectional view of the connector in the provisionally-fitted condition, showing a condition in which the terminals are primarily retained; 
     FIG. 5 is a vertical cross-sectional view of the connector in a completely-assembled condition in which the inner housing is completely fitted in the outer housing; 
     FIG. 6 is a front-elevational view of the connector in its completely-assembled condition; 
     FIG. 7 is a vertical cross-sectional view of a related connector, showing a condition before this connector is assembled; 
     FIG. 8 is a horizontal cross-sectional view of the related connector, showing a condition in which a fixture is provisionally fitted on a housing; 
     FIG. 9 is a vertical cross-sectional view of the related connector, showing a condition in which the fixture is provisionally fitted on the housing; and 
     FIG. 10 is a vertical cross-sectional view of the related connector in its completely-assembled condition in which the fixture is completely fitted on the housing 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     One preferred embodiment of the present invention will now be described with reference to the drawings. 
     As shown in FIGS. 1 to  6 , a connector housing  11  of the connector  10  comprises the inner housing  12 , made of a synthetic resin, and the outer housing  21  of a synthetic resin to be fitted with the inner housing  12 . The inner housing  12  has a pair of right and left chambers  13  formed integrally therewith for respectively receiving terminals  32  each press-clamping a wire  30  and a rubber plug  31 . The outer housing  21  has a pair of right and left insertion paths  23  of a substantially cylindrical shape each formed integrally therewith for receiving the wire  30 , the rubber plug  21  and the terminal  32 . A waterproof packing  20  is provided between the inner housing  12  and the outer housing  21 . 
     The inner housing  12  includes an inner peripheral wall portion  14  of a substantially square shape (having an open rear end) for fitting in an inner peripheral wall portion  24  of the outer housing  21 , an outer peripheral wall portion  15  of a substantially square shape, which extends rearwardly in surrounding relation to the inner peripheral wall portion  14 , and can be fitted on the inner peripheral wall portion  24  of the outer housing  21 , and a front wall portion  16  from which the inner and outer peripheral wall portions  14  and  15  extend rearwardly. Within the inner peripheral wall portion  14 , the pair of right and left chambers  13  are formed respectively on opposite sides of a partition wall  14   a  serving also as a central side wall of the inner peripheral wall portion  14 . 
     Cantilevered flexible retainers  17  each for retaining the terminal  32  received in the chamber  13  are formed integrally on an inner face of an upper portion of the inner peripheral wall portion  14  of the inner housing  12 , and are opposed to the chambers  13 , respectively, the flexible retainers  17  extending from the front portion to the rear end. A retaining projection  17   a  for retaining engagement with a retained portion  33   a  of the terminal  32  is formed integrally on a lower face of a free end of each flexible retainer  17 , and a cancellation projection  17   b  is formed integrally on a rear portion of the flexible retainer  17  near to the free end thereof. A flexure-allowing space  18  is formed between each flexible retainer  17  and an upper wall of the inner peripheral wall portion  14 . A recessed groove  14   c  serving as a positioning guide portion, is formed in each of opposed side walls  14   a  and  14   b  of each chamber  13  in the inner peripheral wall portion  14 , and extends horizontally, the groove  14   c  being disposed substantially centrally of the height of the wall  14   a ,  14   b.    
     A provisional fitting claw (provisional fitting member)  19   a  is formed integrally on a lower outer face of the inner peripheral wall portion  14  of the inner housing  12  at a rear portion thereof, and this claw  19   a  can be engaged in an engagement hole  27 , formed in the inner peripheral wall portion  24  of the outer housing  21 , to hold the two housings  12  and  21  in a provisionally-fitted condition A complete fitting claw (complete fitting member)  19   b  is formed integrally on the lower outer face of the inner peripheral wall portion  14  at a front portion thereof, and this claw  19   b  can be engaged in the engagement hole  27  in the outer housing  21  to hold the two housings  12  and  21  in a completely-fitted condition. 
     In the above provisionally-fitted condition, when each terminal  32  is inserted into the corresponding insertion path  23  of a substantially cylindrical shape from the rear side thereof, and is received in the corresponding chamber  13 , the terminal  32  is retained by the flexible retainer  17 . In the provisionally-fitted condition, the front wall portion  16  of the inner housing  12  forwardly projects a predetermined distance from the front side of the outer housing  21  (This projection distance is indicated by reference character Y in FIG.  2 ). The rubber plug  31 , press-clamped by a plug clamper  35  formed at a rear end portion of the terminal  32 , serves also as a visual confirmation member. When the connector is shifted from the provisionally-fitted condition to the completely-fitted condition, each rubber plug (visual confirmation member)  31  moves into the corresponding insertion path  23 , and this movement of the rubber plug  31  can be visually confirmed from the rear side of the outer housing  21  (The amount of movement of each rubber plug  31  is indicated by reference character Z in FIG.  4 ). 
     A distal end  15   a  of the outer peripheral wall portion  15  of the inner housing  12  is formed into a tapering shape, so that when the inner housing  12  and the outer housing  21  are completely fitted together, the distal end  15   a  of the outer peripheral wall portion  15  of the inner housing  12  and a packing support portion  28 , formed on the inner peripheral wall portion  24  of the outer housing  21 , hold the waterproof packing  20  therebetween in closely-contacted relation thereto. 
     Through holes  16   a  each for passing a mating terminal of a mating connector (not shown) therethrough are formed respectively through those portions of the front wall portion  16  of the inner housing  12  substantially aligned respectively with the chambers  13 . A tapering guide face  16   b  is formed at a front peripheral edge portion of each through hole  16   a . Jig insertion holes  16   c  each for inserting a bar-like terminal-withdrawing jig (not shown) therethrough are formed through the front wall portion  16  of the inner housing  12 , and are disposed above the through holes  16   a , respectively. 
     When a distal end portion of the terminal-withdrawing jig is inserted into the jig insertion hole  16   c  in the same direction as a mating connector-inserting direction, the distal end portion of this terminal-withdrawing jig is brought into abutting engagement with a slanting face of the cancellation projection  17   b  of the flexible retainer  17  to move the retaining projection  17   a  upward. More specifically, in the provisionally-fitted condition of the inner and outer housings  12  and  21 , the cancellation projection  17   b  of the flexible retainer  17  is pressed by the distal end portion of the terminal-withdrawing jig, inserted through the jig insertion hole  16   c , so that the retaining projection  17   a  of the flexible retainer  17  is displaced out of engagement with the retained portion  33   a  of the terminal  32  in the flexure-allowing space  18 . 
     The waterproof packing  20  is made of rubber, and has an annular shape. Front and rear convex portions  20   a  of a substantially triangular cross-section are formed integrally on the outer peripheral face of the waterproof packing  20 . The front and rear convex portions  20   a  are held between the distal end  15   a  of the outer peripheral wall portion  15  of the inner housing  12  and the packing support portion  28 , formed on the inner peripheral wall portion  24  of the outer housing  21 , in closely-contacted relation thereto. 
     The outer housing  21  includes the pair of insertion paths  23  of a substantially cylindrical shape, integrally formed on and extending rearwardly from a central partition wall  22 , the inner peripheral wall portion  24  of a substantially square shape, which is integrally formed on and extends forwardly from the partition wall  22 , and serves as a insertion path communicating with the insertion paths  23 , and the outer peripheral wall portion  25  of a substantially square shape surrounding the inner peripheral wall portion  24 . Thus, the outer housing  21  has a double-wall construction having open front and rear ends. The rubber plug (waterproof plug)  31 , which is press-clamped to the terminal  32 , and is closely fitted on the wire  30 , is inserted into the insertion path  23  by press-fitting or other means. Namely, in the completely-fitted condition of the connector, the rubber plug  31 , which is fitted on the wire  30 , and is secured to the terminal  32 , is held between the wire  30  and the insertion path  23  of a substantially cylindrical shape in closely-contacted relation thereto. 
     Plate-shaped flexure-preventing members  26  are formed integrally on the partition wall  22  of the outer housing  21 , and extend therefrom into the interior of the inner peripheral wall portion  24 , and these flexure-preventing members  26  are opposed respectively to the flexure-allowing spaces  18  for the flexible retainers  17  of the inner housing  12 . In the completely-fitted condition of the inner and outer housings  12  and  21 , each of the flexure-preventing members  26  is inserted in the flexure-allowing space  18  to prevent the flexing (or elastic deformation) of the flexible retainer  17 . 
     The engagement hole  27  is formed through the lower wall of the inner peripheral wall portion  24  of the outer housing  21 , and the provisional fitting claw  19   a  and the complete fitting claw  19   b , formed on the inner peripheral wall portion  14  of the inner housing  12 , can be releasably engaged with this engagement hole  27 . A tapered packing support portion  28  is formed integrally at the proximal end of the inner peripheral wall portion  24  of the outer housing  21  at which the partition wall  22  is provided. The tapered face is so formed as to be along with a surface of the convex portion  20   a  of the annular waterproof packing  20  of rubber. 
     Recesses  25   d  for respectively guiding convex portions, formed respectively on opposite sides of the mating connector (not shown), are formed respectively in inner faces of the opposite side walls of the outer peripheral wall portion  25  of the outer housing  21 , each of the recesses  25   d  being disposed substantially centrally of the height of the side wall. A retaining hole  29  is formed through a front portion of the upper wall of the outer peripheral wall portion  25  of the outer housing  21 , and an elastic retaining arm on the mating connector (not shown) is releasably engageable in this retaining hole  29 . In an assembled condition of the inner and outer housings  12  and  21 , a clearance t is formed between the inner peripheral wall portion  14  of the inner housing  12  and the inner peripheral wall portion  24  of the outer housing  21 , as shown in FIG.  5 . 
     As shown in FIGS. 1 and 2, the terminal  32  has a female terminal body  33  of a square tubular shape, and convex portions  33   c , each serving as a positioning member, are integrally formed respectively on opposite side faces of the terminal body  33 , and extend horizontally, each of the convex portions  33   c  being disposed substantially centrally of the height of the side face. The convex portions  33   c  are engaged respectively in the grooves  14   c , formed respectively in the opposed side walls of the chamber  13 , thereby properly positioning the terminal  32  received in the chamber  13 . When the terminal is thus received in the chamber, the upper edge (retained portion)  33   a  of the rear end of the terminal body  33 , which serves as the retaining portion, is retained by the retaining projection  17   a  of the flexible retainer  17 . A conductor  30   a  of the wire  30  is press-clamped by a conductor clamper  34  of the terminal  32 , and the front end portion of the rubber plug  31  is press-clamped by the plug clamper  35  of the terminal  32 . 
     For assembling the connector  10  of this embodiment, the waterproof packing  20  is fitted in the packing support portion  28  of the inner peripheral wall portion  24  of the outer housing  21  forming the outer portion of the connector housing  11 , as shown in FIG.  2 . Then, the inner peripheral wall portion  14  of the inner housing  12 , forming the inner portion of the connector housing  11 , is fitted into the inner peripheral wall portion  24  of the outer housing  21 , and the provisional fitting claw  19   a , formed on the inner peripheral wall portion  14  of the inner housing  12 , is engaged with the engagement hole  27  in the inner peripheral wall portion  24  of the outer housing  21 , thereby provisionally fitting the inner housing  12  in the outer housing  21 . In this provisionally-fitted condition, the front wall portion  16  of the inner housing  12  forwardly projects a distance Y from the outer housing  21 . 
     Then, in the provisionally-fitted condition, when each terminal  32 , press-clamping the wire  30  and the rubber plug  31 , is inserted into the insertion path  23  in the outer housing  21 , and is received in the chamber  13  in the inner housing  12  as shown in FIG. 3, the rear upper edge  33   a  of the terminal body  33  of the terminal  32  is retained by the retaining projection  17   a  of the flexible retainer  17  as shown in FIG. 4, so that the terminal  32  is primarily retained by the flexible retainer  17 . 
     Then, when the inner peripheral wall portion  14  of the inner housing  12  is further fitted into the inner peripheral wall portion  24  of the outer housing  21  as shown in FIG. 5, the complete fitting claw  19   b , formed on the inner peripheral wall portion  14  of the inner housing  12 , is retainingly engaged in the engagement hole  27  in the inner peripheral wall portion  24  of the outer housing  21 , and the inner housing  12  is completely fitted in the outer housing  21 , thus completing the assembling of the connector  10 . 
     When the inner housing  12  is completely fitted into the outer housing  21 , each flexure-preventing member  26  of the outer housing  21  is inserted into the flexure-allowing space  18  for the flexible retainer  17  of the inner housing  12 . As a result, the flexure-preventing member  26  positively prevents the flexible retainer  17 , primarily retaining the terminal  32 , from being elastically deformed away from the terminal  32 . Therefore, the terminal  32  is retained by the retaining projection  17   a  of the flexible retainer  17 , and also is indirectly retained by the flexure-preventing member  26  which prevents the elastic deformation of the flexible retainer  17 . Thus, each terminal is easily and positively retained in a double manner. 
     The completion of the double-retaining of each terminal  32  by the flexible retainer  17  of the inner housing  12  and the flexure-preventing member  26  of the outer housing  21  can be easily confirmed from the rearward movement (i.e., the movement over the distance Y in FIG. 2) of the inner housing  12  at the front side of the outer housing  21  at the time of shifting of the inner housing  12  from the provisionally-fitted condition to the completely-fitted condition, and also from the rearward movement (i.e., the movement over a distance Z in FIG. 4) of the rubber plug  31  in the substantially-cylindrical insertion path  23  at the rear portion of the outer housing  21 . 
     Namely, the rearward movement of the inner housing  12  at the front side of the outer housing  21  at the time of shifting of the inner housing  12  from the provisionally-fitted condition to the completely-fitted condition and the rearward movement of the rubber plug  31  (occurring simultaneously with the above rearward movement of the inner housing  12 ) in the substantially-cylindrical insertion path  23  at the rear portion of the outer housing  21  can be confirmed at the front and rear sides of the connector housing  11 , respectively. Therefore, in a wire harness-producing process, the movement of the operator for inspection and confirmation purposes is much less as compared with the related construction, and the efficiency of the operation is much enhanced. 
     When the inner housing  12  and the outer housing  21  are completely fitted together, the slanting face of the distal end  15   a  of the outer peripheral wall portion  15  of the inner housing  12  and the packing support portion  28  hold the waterproof packing  20  therebetween in closely-contacted relation thereto. In this completely-fitted condition, the rubber plug  31 , which is fitted on the wire  30 , and is secured to the terminal  32 , is received in the insertion path  23  in the outer housing  21  in closely-contacted relation thereto. With these effects, the waterproof performance of the assembled connector  10  is much enhanced. 
     Thus, in the completely-fitted condition of the inner housing  12  and the outer housing  21 , the convex portions  20   a  of the waterproof packing  20 , made of rubber, are disposed between and held in intimate contact respectively with the slanting face of the distal end  15   a  of the outer peripheral wall portion  15  of the inner housing  12  which retains the front end portion of the terminal  32 , and the packing support portion  28  of a V-shaped cross-section formed at the proximal end of the inner peripheral wall portion  24  of the outer housing  21  which retains the rear end portion of the terminal  32 . Therefore, vibrations, applied to the outer housing  21 , can be absorbed by the waterproof rubber packing  20 . Therefore, vibrations, applied to the outer housing  21 , will not be transmitted directly to the terminals  32 , and when the connector  10  is mounted, for example, on a vehicle (not shown), that portion of contact of each terminal  32  with the mating terminal, fitted in the terminal body  33 , will not be worn by the vibrations applied to the outer housing  21 , so that the contact reliability of the terminal  32  is enhanced. 
     Particularly, as shown in FIG. 5, the predetermined clearance t is formed between the inner peripheral wall portion  14  of the inner housing  12  and the inner peripheral wall portion  24  of the outer housing  21 , and the rubber plug  31  is mounted on that portion of each wire  30  connected to the terminal  32 , and in the completely-fitted condition of the inner housing  12  and the outer housing  21 , the rubber plug  31  is held between the wire  30  and the substantially cylindrical insertion path  23  of the outer housing  21  in closely-contacted relation thereto. Therefore, vibrations, applied to the outer housing  21 , can be positively absorbed by the waterproof rubber packing  20  and the rubber plugs  31 , and will not be transmitted directly to the terminal body  33  of each terminal  32 , and wear of the contact portion of each terminal  32  due to such vibrations can be positively prevented, so that the contact reliability of the terminal  32  is further enhanced. 
     In the above embodiment, although the terminals, each press-clamping the rubber plug at its rear end portion, are used, there may be used the type of terminals to which a rubber plug is not press-clamped, in which case the rubber plug is fitted on the wire. 
     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.

Technology Category: h