Patent Publication Number: US-7722396-B2

Title: Seal body and connector including the same

Description:
BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   The present invention relates to a connector for use in connection of electric wires and so on, in particular, a connector including: a housing for receiving a terminal fitting attached to an end of an electric wire; and a seal body to maintain a watertight characteristic between an inner surface of the housing and the electric wire. 
   (2) Description of the Related Art 
   Various electronic instruments are mounted on a motor vehicle as a mobile unit. The motor vehicle mounts a wiring harness for transmitting electric power and control signals to the electronic instruments. The wiring harness includes a plurality of electric wires and connectors. 
   As shown in  FIG. 9 , a connector  100  including: a connector housing  103  for receiving terminal fittings  102 , attached to ends of electric wires  101 ; and a seal member  104  to maintain a watertight characteristic between an inner surface of the connector housing  103  and outer surfaces of the electric wires  101  is known (see Japanese Patent Application Laid-Open No. 2000-323229). 
   The seal member  104  is made of resilient material such as rubber and constructed with a pair of seal bodies  105  and  106 , which puts the electric wire  101  therebetween. One end of the seal body  105  and one end of the seal body  106  are connected by a hinge  107 . As shown in  FIGS. 9 and 10 , each seal body  105 ,  106  has a plurality of grooves  108  each formed in a semi-circle-shape in cross section. The grooves  108  are lined up in parallel to each other. The electric wire  101  is positioned within the grooves  108 . 
   Each seal body  105 ,  106  is provided with a lip part  110  which projects from an inner surface of the groove  108  toward the inside of the groove  108  in a diameter direction thereof. Because the lip part  110  resiliently comes in contact with an outer periphery of the electric wire  101 , therefore the watertight characteristic between the electric wires  101  and inner surfaces of the pair of the seal bodies  105 ,  106  is maintained. The seal member  104  is press-fit into the connector housing  103  on a condition that the electric wires  101  are placed between the pair of the seal bodies  105  and  106 . 
   As for the seal member  104  of the connector  100 , the thickness of the lip part  110  is formed identical throughout the entire region of the lip part  110 . That is, the thickness S 1  of the lip part  110  in the proximity of an abutting surface  111  between the seal bodies  105  and  106  is formed identical to the thickness  32  of the lip part  110  at a bottom part  112  of the groove  108  being farthest away from the abutting surface  111 . In such a construction, because a portion of the lip part  110  near the abutting surface  111  is less resilient than a portion of the lip part  110  at the bottom part  112  of the groove  108 , there is a problem in that contact pressure, that is, a sealing characteristic of the lip part  110  against the electric wire  101  in the proximity of the abutting surface  111  becomes small and ineffective. 
   Moreover, as for the seal member  104 , depending on its attaching condition to the connector  100  and size dispersion of the seal member  104 , as shown in  FIG. 11 , there is a problem that a working pitch of the grooves  108  between the seal bodies  105  and  106  might be undesirably displaced. In this case, because the abutting surface  111  positioned in between the grooves  108  adjacent to each other has a small width and low mechanical strength, the abutting surface  111  of the seal body  105 ,  106  does not abut against an abutting surface  111  of the mating seal body  105 ,  106  and as shown in  FIG. 12 , the abutting surface  111  might be undesirably turned up, causing a problem that the sealing characteristic between the abutting surfaces  111  becomes inferior. 
   SUMMARY OF THE INVENTION 
   It is therefore an objective of the present invention to solve the above problems and to provide a seal body having an excellent sealing characteristic and a connector including such a seal body. 
   In order to attain the above objective, the present invention is to provide a seal body which puts an electric wire between the seal body and the other seal body so as to maintain a watertight characteristic between the electric wire and the seal bodies, the seal body including: 
   an abutting surface of the seal body, which abuts against a mating abutting surface of the other seal body when the seal bodies overlap each other; 
   a groove which positions the electric wire inside the seal bodies; and 
   a lip part which projects from an inner surface of the groove and from the abutting surface. 
   With the construction described above, the abutting surfaces can be securely adhere closely to each other, so that the sealing characteristic (sealing strength) between the abutting surfaces can be prevented from deteriorating. Accordingly, the seal body having an excellent sealing characteristic can be provided. 
   A thickness of the lip part on the abutting surface and a thickness of the lip part on the inner surface of the groove in the proximity of the abutting surface are larger than a thickness of the lip part on the inner surface of a bottom part of the groove. 
   With the construction described above, the resilient force of the lip part on the abutting surface and in the proximity of the abutting surface can be prevented from becoming smaller than the resilient force of the lip part on the bottom part of the groove. Further, an area of contact between the seal bodies can be large due to the thickness of the lip part in the proximity of the abutting surface. Accordingly, the sealing characteristic between the seal bodies, that is, between the abutting surfaces and the sealing characteristic of the groove in the proximity of the abutting surface can be prevented from deteriorating. Accordingly, the seal body having an excellent sealing characteristic can be provided. 
   The seal body includes a plurality of the grooves arranged in parallel with each other. 
   With the construction described above, even when a width of the abutting surface, which is located between the grooves arranged in parallel with each other, is small, the mechanical strength and resilient force of the abutting surface can be increased since the lip part is formed on the abutting surface. Therefore, the abutting surfaces can be securely adhere to each other and the sealing characteristic between the abutting surfaces can be prevented from deteriorating. Accordingly, the seal body having an excellent sealing characteristic can be provided. 
   In order to attain the above objective, the present invention is also to provide a connector including: 
   a housing which receives a terminal fitting attached to an end of an electric wire; and 
   a seal member which is attached to the proximity of an aperture of the housing and maintains a watertight characteristic between an inner surface of the housing and the electric wire, 
   wherein the seal member includes a plurality of the seal bodies as described above. 
   With the construction described above, since the seal member includes the seal bodies having an excellent sealing characteristic, therefore a connector which can securely maintain a watertight characteristic between the inner surface of the housing and the electric wire can be provided. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view illustrating a connector according to the first preferred embodiment of the present invention; 
       FIG. 2  is an exploded perspective view illustrating a seal member of the connector shown in  FIG. 1 ; 
       FIG. 3  is a perspective view illustrating a seal body of the seal member shown in  FIG. 2 ; 
       FIG. 4  is an illustration of the seal body of the seal member shown in  FIG. 2 ; 
       FIG. 5  is an illustration of the seal body of the seal member shown in  FIG. 2 , illustrating a state when the seal bodies shown in  FIG. 4  overlap one another; 
       FIG. 6  is an illustration of the seal body of the seal member shown in  FIG. 2 , illustrating a state when the pitches of the grooves of the seal bodies are different from each other; 
       FIG. 7  is an illustration of the seal body of the seal member shown in  FIG. 2 , illustrating a state when the seal bodies shown in  FIG. 5  overlap one another; 
       FIG. 8  is a perspective view illustrating a seal member constituting a connector according to the second preferred embodiment of the present invention; 
       FIG. 9  is a perspective view illustrating a connector having conventional seal bodies; 
       FIG. 10  is a view explaining a problem of the conventional seal bodies shown in  FIG. 9 ; 
       FIG. 11  is a view explaining a problem of the conventional seal bodies shown in  FIG. 9 , illustrating a state when the pitches of the grooves of the conventional seal bodies are different from each other; and 
       FIG. 12  is a view explaining a problem of the conventional seal bodies shown in  FIG. 9 , illustrating a state when the conventional seal bodies shown in  FIG. 11  overlap one another. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   First Preferred Embodiment 
   In the following, a connector according to the first preferred embodiment of the present invention will be explained with reference to  FIGS. 1-7 . As shown in  FIG. 1 , the connector  1  includes an outer housing  2  (i.e. the housing), a plurality of plate-laminated bodies  3 , and a plurality of seal members  4 . 
   The outer housing  2  is made of electrically insulating synthetic resin and formed in a tube-shape including a facing wall  6  having a plurality of holes  5  for allowing male terminals of a mating connector, to which the connector  1  fits, to pass, and a plurality of peripheral walls  7  rising up from an outer edges of the facing wall  6 . A space within the outer housing  2  is partitioned into plural parts (three parts in an example shown in  FIG. 1 ). 
   Three plate-laminated bodies  3  are provided in an example shown in  FIG. 1  (only one plate-laminated body  3  being shown in  FIG. 1  since the three plate-laminated bodies  3  have the same construction). As shown in  FIGS. 1 and 2 , the plate-laminated body  3  includes a plurality of plate-shaped housings  10  and a cover member  11 . In an example shown in the figure, the plate-laminated body  3  includes four plate-shaped housings  10 . 
   The plate-shaped housing  10  is made of electrically insulating synthetic resin and formed in a flat plate-shape. The plate-shaped housing  10  is provided with a plurality of terminal-receiving chambers  14  for receiving terminal fittings  13  (shown in  FIG. 3 ). A plurality of the terminal-receiving chambers  14  are formed concave from an outer surface of the plate-shaped housing  10  and arranged in parallel with each other. A plurality of the plate-shaped housings  10  are piled up in parallel with one another. 
   The cover member  11  is made of electrically insulating synthetic resin and formed in a U-shape including a flat ceiling wall  11   a  and rising-up walls  11   b  rising up from outer edges of the ceiling wall  11   a . The cover member  11  is fixed to the plate-shaped housings  10  in such a manner that the ceiling wall  11   a  is placed on one plate-shaped housing  10  so as to close the terminal-receiving chambers  14  of the one plate-shaped housing  10  that is situated uppermost among a plurality of the plate-shaped housings  10  and the cover member  11  positions a plurality of the plate-shaped housings  10  between the pair of the rising-up walls  11   b.    
   Thus, the plate-laminated body  3  is assembled in such a way that the plate-shaped housings  10 , into the terminal-receiving chambers of which the terminal fittings  13  attaching the electric wires  12  are received, are piled up one another and the cover member  11  covers the plate-shaped housings  10  so that the plate-shaped housings  10  and the cover member  11  are fixed to one another. 
   Three seal members  4  are provided in an example shown in  FIG. 1  (only one seal member  4  being shown in  FIG. 1  since the three seal members  4  have the same construction). As shown in  FIG. 2 , the seal member  4  is made of hard synthetic resin including: five holders  18   d ,  18   e ,  18   f  (i.e. including two holders  18   d  having the same construction and two holders  18   f  having the same construction) which are piled up one another; and five seal bodies  27   a ,  27   b ,  27   c  (i.e. including three seal bodies  27   c  having the same construction) attached to the five holders  18   d ,  18   e ,  18   f.    
   When a plurality of the holders  18   d ,  18   e ,  18   f  are piled up one another, two holders  18   d  situated at both ends of a plurality of the holders  18   d ,  18   e ,  18   f  are formed in the same shape and as shown in  FIG. 2 , each include a bar-shaped body part  42 , a pair of side plate parts  43  rising up in the same direction from both ends in the longitudinal direction of the body part  42 , and a plurality of partition parts  44 . The partition part  44  rises up from the body part  42  in the same direction as the pair of the side plate parts  43 . The partition parts  44  are arranged at regular intervals between the side plate parts  43  and position the electric wire  12  therebetween. The partition part  44  includes a pair of rising-up bars  45  spaced from each other in the longitudinal direction of the electric wire  12 . 
   When a plurality of the holders  18   d ,  18   e ,  18   f  are piled up one another, as shown in  FIG. 2 , one holder  18   e  situated at the center of a plurality of the holders  18   d ,  18   e ,  18   f  includes, a bar-shaped body part  42 , two pairs of side plate parts  43  rising up in both directions from both ends in the longitudinal direction of the body part  42 , and a plurality of partition parts  44 . The partition parts  44  rise up from the body part  42  in the same direction as the two pairs of the side plate parts  43 . The partition parts  44  are arranged at regular intervals between the side plate parts  43  and position the electric wire  12  therebetween. The partition part  44  includes a pair of rising-up bars  45  spaced from each other in the longitudinal direction of the electric wire  12 . 
   As shown in  FIG. 2 , two holders  18   f  arranged between the holders  18   d  and  18   e  each include a bar-shaped body part  42  and a plurality of partition parts  44 . The partition parts  44  rise up from the body part  42  in both directions, are arranged at regular intervals along the longitudinal direction of the body part  42 , and position the electric wire  12  therebetween. 
   Further, the holder  18   f  is provided with positioning bars  46  which project from both ends in the longitudinal direction of the holder  18   f  toward the holders  18   d ,  18   e . The side plate part  43  of the holder  18   d ,  18   e  is provided with a positioning hole  47 . When the positioning bar  46  enters the positioning hole  47 , the holders  18   d ,  18   e ,  18   f  piled up one another are positioned with respect to one another. 
   Each seal body  27   a ,  27   b ,  27   c  is made of resilient material such as rubber. Each seal body  27   a ,  27   b ,  27   c  is formed in a bar-shape and piled up in parallel with one another along the laminating direction of the plate-shaped housings  10 . Each seal body  27   a ,  27   b ,  27   c  includes: flat abutting surfaces  29  on which the seal body  27   a ,  27   b ,  27   c  overlaps with another seal body  27   a ,  27   b ,  27   c ; grooves  28  for positioning the electric wires  12  inside; and lip parts  26 . 
   The seal body  27   a  situated lowest in  FIG. 2  among a plurality of the seal bodies  27   a ,  27   b ,  27   c  includes the abutting surfaces  29 , grooves  28 , and lip parts  26  on its surface which faces the other seal body  27   c . The seal body  27   a  is attached to the holder  18   d  by an adhesive. 
   The seal body  27   b  situated highest in  FIG. 2  among a plurality of the seal bodies  27   a ,  27   b ,  27   c  includes the abutting surfaces  29 , grooves  28 , and lip parts  26  on its surface which faces the other seal body  27   c . The seal body  27   b  is attached to the holder  18   d  by an adhesive. 
   The three seal bodies  27   c  each include the abutting surfaces  29 , grooves  28 , and lip parts  26  on both its surface which faces the other seal body  27   c  and its surface which faces the seal body  27   a  or  27   b . The seal body  27   c  is attached to the holder  18   e  or  18   f  by an adhesive. 
   The groove  28  is formed in an arc-shape in cross section concave from the abutting surface  29 . The groove  28  extends straight along the longitudinal direction of the electric wire  12 . A plurality of the grooves  28  are arranged spaced from each other in parallel with each other along a direction crossing at right angles the longitudinal direction of the electric wire  12 . The grooves  28  and abutting surfaces  29  are arranged alternately. 
   The lip part  26  is formed projecting from an inner surface of the abutting surface  28  and from the abutting surface  29  throughout the inner surface of the abutting surface  28  and the abutting surface  29 . The lip part  26  extends along a direction in which a plurality of the grooves  28  are arranged. The lip part  26  extends thoroughly along a longitudinal direction of the seal body  27   a ,  27   b ,  27   c . In an example shown in the figure, two lip parts  26  are provided on the abutting surface  29  and the groove  28 . A portion of the lip part  26  formed on the abutting surface  29  comes in resilient contact with (or closely adheres to) the lip part  26  of the facing seal body  27   a ,  27   b ,  27   c . A portion of the lip part  26  formed on the inner surface of the groove  28  comes in resilient contact with (or closely adheres to) an outer periphery of the electric wire  12  which is to be positioned within the grooves  28 . 
   As shown in  FIG. 4 , a thickness T 1  of the lip part  26  on the abutting surface  29  and a thickness T 2  of the lip part  26  on the inner surface of the groove  28  in the proximity of the abutting surface  29  are larger than a thickness T 3  of the lip part  26  on the inner surface of a bottom part  25  of the groove  28 . Here, the bottom part  25  means a portion of the groove  28 , said portion being located farthest away from the butting surface  29 . 
   When seal bodies  27   a ,  27   b  and  27   c  are piled up one another, as shown in  FIG. 5 , the seal bodies  27   a ,  27   b  and  27   c  closely adhere to one another in such a manner that the lip parts  26  formed on the respective abutting surfaces  29  are crushed with each other. Since the thickness of a portion  24  of the lip part  26  in the proximity of the abutting surface  29  is larger than the thickness of the lip part  26  on the inner surface of the bottom part  25  of the groove  28 , therefore the portion  24  of the lip part  26  closely adhere to the electric wire  12 , which is to be positioned within the groove  28 , with a high contact pressure. 
   That is, in the present invention, the lip part  26  is formed on the abutting surface  29  so that a sealing characteristic among the seal bodies  27   a ,  27   b  and  27   c , i.e. between the abutting surfaces  29  is improved. Moreover, the portion  24  of the lip part  26  in the proximity of the abutting surface  29  is formed thick so that the contact pressure of the lip part  26  on the inner surface of the groove  28  against the electric wire  12  becomes uniform throughout the entire periphery of the electric wire  12 . 
   Even if the pitches of the seal bodies  27   a ,  27   b  and  27   c  facing each other do not match with each other due to the size dispersion as shown in  FIG. 6 , since the portion  24  of the lip part  26  in the proximity of the abutting surface  29  is formed thick, the contact area among the seal bodies  27   a ,  27   b  and  27   c  facing each other is set large, therefore as shown in  FIG. 7 , the seal bodies  27   a ,  27   b  and  27   c  closely adhere to each other, that is, the abutting surfaces  29  facing each other closely adhere to each other, so that the sealing characteristic among the seal bodies  27   a ,  27   b  and  27   c , i.e. between the abutting surfaces  29  can be prevented from deteriorating. That is, a mismatch between the pitches of the grooves  28  can be absorbed. 
   The connector  1  described above is assembled as follows. First, the terminal fitting  13  attaching the electric wire  12  is press-fit into the terminal-receiving chamber  14  of the plate-shaped housing  10 . Then, as shown in  FIG. 2 , the electric wire  12  of one plate-shaped housing  10  is positioned within the groove  28  of the seal body  27   a  and between the partition parts  44  of the holder  18   d . Then, the seal body  27   c  and the holder  18   f  are placed on the electric wire  12 . Then, the electric wire  12  of another plate-shaped housing  10  is placed on the seal body  27   c  and the holder  18   f . In such a manner, the other seal bodies  27   c  and  27   b  and the holders  18   e ,  18   f  and  18   d  are placed on (i.e. piled on) the electric wire  12 , thereby assembling the seal member  4 . 
   Thereafter, the cover member  11  is attached on a plurality of the plate-shaped housings  10  piled up one another so as to fix a plurality of is the plate-shaped housings  10  to one another, so that the plate-laminated body  3  is assembled. Then, after the assembled plate-laminated body  3  is inserted in the outer housing  2 , the assembled seal member  4  is press-fit into the proximity of the aperture of the outer housing  2 . Thus, each seal body  27   a ,  27   b ,  27   c  of the seal member  4  maintains the watertight characteristic between the inner surface of the outer housing  2  and the electric wire  12 , so that the connector  1  is assembled. 
   Further, the connector  1  assembled as described above is coupled with a mating connector so as to construct a wiring harness to be mounted on a motor vehicle and so on. 
   According to the preferred embodiment described above, the lip part  26  is formed on the abutting surface  29 , so that the sealing characteristic between the abutting surfaces  29  can be prevented from deteriorating. Moreover, the thickness of the portion  24  of the lip part  26  in the proximity of the abutting surface  29  is larger than the thickness of the lip part  26  on the inner surface of the bottom part  25  of the groove  28 , so that the sealing characteristic of the portion  24  of the lip part  26  in the proximity of the abutting surface  29  can be prevented from deteriorating and the contact area among the seal bodies  27   a ,  27   b  and  27   c  facing each other can be large, therefore the sealing characteristic among the seal bodies  27   a ,  27   b  and  27   c , i.e. between the abutting surfaces  29  can be prevented from deteriorating. 
   Since the seal bodies  27   a ,  27   b  and  27   c  are in advance attached to the respective holders  18   e ,  18   f  and  18   d  by an adhesive, therefore even if the resilient restoring force occurs when the holders  18   e ,  18   f  and  18   d  are attached to each other, the seal bodies  27   a ,  27   b  and  27   c  can be prevented from coming off from the holders  18   e ,  18   f  and  18   d . Therefore, the seal member  4  can be easily assembled. 
   Further, as for the seal member  4 , since a positional relation among the holders  18   e ,  18   f  and  18   d , that is, a positional relation among the seal bodies  27   a ,  27   b  and  27   c  can be always maintained constant by the positioning bar  46  and the positioning hole  47 , therefore the watertight characteristic between the seal bodies  27   a ,  27   b ,  27   c  and the electric wire  12  can be securely attained, that is, liquid such as water can be securely prevented from entering the connector  1 . 
   Second Preferred Embodiment 
   In the following, a seal member constituting a connector according to the second preferred embodiment of the present invention will be explained with reference to  FIG. 8 . 
   As shown in  FIG. 8 , each of seal bodies  27   a ,  27   b  and  27   c  according to the second preferred embodiment includes a lip part  26 ′ instead of the lip part  26  of the seal body  27   a ,  27   b ,  27   c  according to the first preferred embodiment (only the seal body  27   a  being shown in  FIG. 8 ). A width of the lip part  26 ′ along the longitudinal direction of the wire  12  is formed larger than that of the lip part  26 . Therefore, the resilient force of the lip part  26 ′ is larger than that of the lip part  26 . Similarly to the lip part  26 , a thickness of the lip part  26 ′ on the abutting surface  29  and a thickness of the lip part  26 ′ on the inner surface of the groove  28  in the proximity of the abutting surface  23  are formed larger than a thickness of the lip part  26 ′ on the inner surface of a bottom part  25  of the groove  28 . 
   The sealing characteristic between the sealing body  27   a ,  27   b ,  27   c  according to the second preferred embodiment including such a lip part  26 ′ and the other sealing body  27   a ,  27   b ,  27   c  including such a lip part  26 ′, that is, the sealing characteristic between the abutting surfaces  29  is higher than that in the first preferred embodiment. 
   Thus, in the present invention, the degree of the sealing characteristic can be adjusted by changing the width of the lip part  26 ,  26 ′. Moreover, in the present invention, the degree of the sealing characteristic can also be adjusted by changing the number of the lip parts  26 ,  26 ′. 
   Further, for example, when the width of the lip part  26 ,  26 ′ is small, there is a possibility that the lip parts  26 ,  26 ′ might buckle with each other when the sealing bodies  27   a ,  27   b ,  27   c  are placed one upon another. However, by making the width of the lip part  26 ′ large as shown in the second preferred embodiment, the lip parts  26 ,  26 ′ can be securely prevented from buckling with each other when the sealing bodies  27   a ,  27   b ,  27   c  are placed one upon another. 
   The aforementioned preferred embodiments are described to aid in understanding the present invention and variations may be made by one skilled in the art without departing from the spirit and scope of the present invention.