Patent Publication Number: US-8118614-B2

Title: Molded connector

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a molded connector. 
     2. Description of the Related Art 
     U.S. Pat. No. 6,932,657 discloses a molded connector with a terminal metallic member and a coated electrical cable. An insulation sheath is stripped from the coated electrical cable to expose a core wire, and the terminal metallic member is secured to the core wire. A synthetic resin then is molded on the portion of the terminal metallic member secured on the distal end of the coated electrical cable. The insulation sheath of the coated electrical cable generally is made from a different from a material than the molded resin layer of the prior art molded connector. As a result, adhesion bond between the insulation sheath and the molded resin layer is not always sufficient. A clearance will be created between the electrical cable and the molded resin layer, particularly in an extended portion of the electrical cable, if the electrical cable repeatedly is bent significantly. Consequently, there is a possibility that a waterproofing function will be lowered. 
     Accordingly, JP 2008-258103 attempts to address the problems of U.S. Pat. No. 6,932,657 by applying a seal agent to an extended portion of the electrical cable in a connector housing. The seal agent seals a clearance between the extended portion of the electrical cable and the molded resin layer to improve a waterproofing function. However, the seal agent requires a long drying time, and hence lengthens the producing process. Further, temperature and humidity must be controlled for optimal drying of the seal agent, thereby adding to the production cost. 
     In view of the above problems, an object of the invention is to provide a molded connector that can lower a producing cost and can perform waterproofing. 
     SUMMARY OF THE INVENTION 
     A molded connector in accordance with the invention has a molded connector main body that includes a metallic terminal secured to a core wire that has been exposed by stripping an insulation sheath from a coated electrical cable. A molded resin layer is formed by molding synthetic resin on a section that contains a secured portion of the terminal and a distal end of the coated electrical cable. A barrel-like cap is attached to the molded connector main body and covers an outer periphery of a support of the molded connector main body. The cap has an electrical cable insertion hole for passing the electrical cable. An annular seal is provided on an inner surface of the cap for closely contacting and sealing an outer periphery of the coated electrical cable. The seal waterproofs the extended portion of the coated electrical cable in the molded connector main body without using adhesive, thereby restraining production cost. 
     Forming a seal in the molded connector is difficult. However, the seal can be provided relatively easily on the inner surface of the separate cap. 
     The seal member may include a cable seal portion for sealing an outer periphery of the coated electrical cable and a molded seal portion for sealing an outer periphery of the support. The molded seal portion for sealing the outer periphery of the support waterproofs the extended portion of the coated electrical cable more surely. 
     A boundary between the cable seal portion and the molded seal portion may define a step. The support is provided at an extended end of the cable and may have a small diameter portion. The molded seal portion closely contacts an outer periphery of the small diameter portion and the step at the boundary between the cable seal portion and the molded seal portion contacts an end of the small diameter portion when the cap is attached to the support to seal the molded connector more positively. 
     An inner periphery of the seal may have annular projections extending in a peripheral direction. The cap closely contacts the seal and collapses the annular projections to seal the molded connector more positively. 
     The support preferably has latching projections that engage in latching apertures in the cap to define a simple structure for ensuring that the cap does not disengage from the molded connector main body. 
     The invention provides a molded connector with a low production cost and a good waterproofing function. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially broken-away plan view of a molded connector in accordance with the invention coupled with an instrument side connector. 
         FIG. 2  is a longitudinal section view of the molded connector, illustrating the coupled state of the molded connector with the instrument side connector. 
         FIG. 3  is a side elevation view of the molded connector. 
         FIG. 4  is a longitudinal section view of the molded connector. 
         FIG. 5  is an exploded longitudinal section view of the molded connector, illustrating a molded connector main body and a cap section. 
         FIG. 6  is a side elevation view of the molded connector main body. 
         FIG. 7  is a top plan view of the molded connector main body. 
         FIG. 8  is a side elevation view of the cap section. 
         FIG. 9  is a top plan view of the cap section. 
         FIG. 10  is a longitudinal section view of the cap section. 
         FIG. 11  is a front side elevation view of the cap section. 
         FIG. 12  is a rear side elevation view of the cap section. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A molded connector in accordance with the invention is identified generally by the numeral  20  in  FIGS. 1 to 12 . The molded connector  20  is disposed on a path for supplying an electrical power to a motor (not shown) to be mounted on a hybrid car or the like and is attached to an equipment side connector  10  provided on a metallic motor casing (not shown). A vertical direction designates upper and lower sides in  FIG. 2  and a horizontal direction designates right and left sides in  FIG. 2 . 
     The equipment side connector  10  includes an equipment side terminal  11  provided with a screw hole  10 A, and a synthetic resin housing  12  that contains the equipment side terminal  11 , as shown in  FIG. 2 . The equipment side connector  10  is inserted into and secured in a through-hole (not shown) provided in the motor casing. The housing  12  has a fitting recess  13  that opens upward. The equipment side terminal  11  is contained in a central part of the fitting recess  13 . 
     As shown in  FIG. 1 , the equipment side connector  10  is configured to receive three molded connectors  20  and a coated electrical cable  40  extends from each molded connector  20 . The cables  40  are bundled and shielded by a braided wire  43 . 
     As shown in  FIG. 4 , each molded connector  20  includes a molded connector main body  21  and a cap  50  adapted to be attached to an end of the main body  21  at an extending side of the coated electrical cable  40 . 
     The molded connector main body  21  includes a metallic terminal  22  attached to an end of the coated electrical cable  40  and a molded resin section  26  molded around the terminal  22  and the end of the cable  40  including part of an insulation sheath  42 . 
     The terminal  22  is formed by bending a conductive metallic sheet and has opposite front and rear ends. A connecting portion  23  is formed at the front end of the terminal  22  and is configured to be coupled to the equipment side terminal  11 . A bolt insertion aperture  24  is provided in the connecting portion  23  and can receive a bolt. A barrel-shaped press-contact portion is formed at the rear end of the terminal  22  and is configured to be crimped on an exposed core wire  41  ( FIGS. 2 ,  4 ,  5 ) of the cable  40  from which the insulation sheath  42  has been stripped. Three terminals  22  have the same shapes and size so that they can be connected to three-phase windings of a motor. 
     The molded resin section  26  is made of synthetic resin and includes a head  27  to be coupled to a mating terminal and an extension  36  that projects back from the head  27 . The head  27  is substantially barrel-shaped and has a through-hole  28  ( FIGS. 4 ,  5 ) extending in a vertical direction. The through-hole  28  has an upper receiving part  28 A into which an inner lid  29  is fit. 
     As shown in  FIG. 2 , a lower end of the inner lid  29  has a bolt recess for receiving a head of a bolt (not shown) that secures the connecting portion  23  of the terminal  22  to the equipment side terminal  11 . A sealing groove is formed in the outer periphery of the inner lid  29  and a seal ring  32  is mounted in the seal groove. 
     A connector fitting part  33  is defined at a lower end of the head  27  and can be coupled to the fitting recess  13  in the equipment side connector  10 . A seal groove is provided in an outer periphery of the connector fitting part  33  and a seal ring  35  ( FIG. 2 ) is mounted in the seal groove. 
     As shown in  FIG. 5 , the extension  36  extends back from an upper part of the head  27  and is slightly slanted up from an intermediate part to a rear end in an axial direction. 
     The press-contact portion of the terminal  22  is crimped onto the end of the cable  40  and is molded in the extension  36 . 
     A rear end of the extension  36  is connected to a support section  37  on which the cap  50  is mounted. 
     The support section  37  includes a circular portion  38  continued from an outer periphery of the extension  36 , and a smaller diameter portion  45  that decreases a diameter at a rear end of the circular portion  38  in a stepped manner. 
     Latches  39  project from upper and lower sides of the circular portion  38  ( FIG. 5 ). Each latch  39  increases in height from a front end to an outer periphery of the extension  36  in a stepped manner and decreases in height from there back in a slanted manner. 
     The smaller diameter portion  45  has a barrel shape configured to cover an outer periphery of the insulation sheath  42  of the cable  40 . Additionally, the smaller diameter portion  45  is thin and has a low stiffness so that the small diameter portion  45  can be deformed in association with movement of the cable  40  without causing a significant clearance between the cable  40  and the smaller diameter portion  45 . 
     The molded connector main body  21  is formed by first crimping the terminal  22  onto the end of the cable  40 . The terminal  22  then is set in a mold (not shown) and molten resin is injected into the mold at a high pressure to form the molded connector main body  21 . 
     As shown in  FIG. 5 , the cap section  50  is formed into a cylindrical shape with an insertion hole (electrical cable passing hole)  50 A. The cap section  50  includes a synthetic resin barrel  51  and a rubber seal  55  that closely contacts an inner periphery of the barrel  51 . 
     The barrel  51  has a substantially constant thickness. A large diameter portion  52  is at the front end of the barrel  51  and is to be fit closely on the circular portion  38  of the support section  37 . A first small diameter portion  53  is stepped inward at the rear end of the large diameter portion  52  and projects toward the rear. A second small diameter portion  54  is stepped inward at the rear end of the first small diameter portion  53  and projects toward the rear end of the barrel  51 . 
     Slits  58  extend axially on each of the upper and lower sides of the barrel  51  to form latches  59 , as shown in  FIG. 10 . A square latching aperture  60  is provided in an intermediate part of each latch  59 . 
     As shown in  FIG. 8 , the barrel  51  is provided on one (a right side in  FIG. 11 ) out of right and left sides with a single slit  51 A extending in the axial direction. 
     Annular projections  61  protrude slightly back from the rear end of the second small diameter portion  54  to the rear end of the barrel  51 , as shown in  FIGS. 9 and 12 , to define a rear entry to the insertion aperture  50 A. The annular projection  61  has a shape in which only intermediate portions in the vertical direction do not protrude. A circular aperture gate  62  is provided on one side of the annular projection  61 . The gate  62  enables injection of a rubber material to form the seal  55  after forming the barrel  51 . 
     As shown in  FIG. 5 , the seal  55  has a substantially constant thickness and includes a molded seal portion  56  for sealing an outer periphery of the small diameter portion  45  of the support section  37 , and a cable seal portion  57  that is stepped to a smaller diameter at a rear end of the molded seal portion  56  for sealing an outer periphery of the cable  40 . 
     The outer periphery of the molded seal portion  56  closely contacts an inner periphery of the large diameter portion  52  of the barrel  51  while the outer periphery of the cable seal portion  57  closely contacts an inner periphery of the first small diameter portion  53  of the barrel  51 . 
     A diameter of the insertion aperture  50 A in the molded seal portion  56  is determined so that the inner periphery of the molded seal  56  closely contacts the outer periphery of the small diameter portion  45  of the support section  37 , when the cap  50  is attached to the support section  37  of the molded connector main body  21 . On the other hand, a diameter of the insertion aperture  50 A in the cable seal portion  57  is determined so that the inner periphery of the cable seal  57  closely contacts the insulation sheath  42  of the cable  40 . 
     A rear end of the cable seal portion  57  engages the second small diameter portion  54  convexed in at the rear end of the barrel  51 . 
     Annular projections  55 B protrude in at axially spaced positions along the whole inner periphery of the seal  55 . Thus, the inner periphery of the seal  55  has projections and depressions in the axial direction. When the cap  50  is attached to the support  37 , the annular projections  55 B are compressed between the barrel  51  and either the small diameter portion  45  or the cable  40 , depending on the axial position. 
     A leading end of the barrel  51  contacts the latching projections  39  as the cap  50  is approached to and fit into the support section  37 . Thus, the latches  59  of the barrel  51  deflect out. The latching pieces  59  return to the original states when the latching projections  39  reach the latching apertures  60  and the latching projections  39  engage edges around the latching apertures  60 , as shown in  FIG. 4 . At this time, the step  55 A ( FIG. 5 ) at a boundary between the cable seal portion  57  and the molded seal portion  56  contacts an end  45 A of the small diameter portion  45 . 
     The cap  50  may be produced by forming the seal  55 , disposing the seal  55  in a mold, and then injecting resin into the mold to form the barrel  51  around the seal  55 . 
     As shown in  FIG. 1 , the three molded connectors  20  are shielded by a metallic shield shell  70  and the three coated electrical cables  40  led out from the three molded connectors  20  are bundled together and shielded by the braided wire  43 . 
     As shown in  FIG. 2 , the shield shell  70  includes a shield barrel  71  to which an end of the braided wire  43  is connected. A shell connecting portion  76  is connected to the shield barrel  71  for covering a rear end of the molded connector  20 . A shell main body  79  covers a leading end of the molded connector  20  and a rear end of the shell main body  79  is superimposed on the shell connecting portion  76 . 
     The shield barrel  71  includes a barrel main body  72  with an electrical cable insertion aperture for receiving the coated electrical cable  40 . A flange  73  protrudes out from the entire periphery of the barrel main body  72 . A front surface of the flange  73  contacts a rear surface of the shell connecting portion  76  and is secured to the shell connecting portion  76  by a screw that passes through a screw hole in the flange  73 . A buffer made of an insulation material is provided in an inner periphery the shield barrel  71  to prevent the insulation sheath  43  from being damaged even if the cable  40  contacts with the shield barrel  71 . 
     The shell connecting portion  76  has a cap shield  77  and a lapping portion  78 . The cap shield  77  covers from an upper side a portion to which the cap  50  is attached. The lapping portion  78  is superimposed on the shell main body  79  and decreases a height from the cap shield  77  to the front. 
     The shell main body  79  covers a front end of the shell connecting portion  76  on the molded resin section  26  from an upper side. 
     An end of the braided wire  43  is covered on the outer periphery of the barrel main body  72  of the shield barrel  71  and a calking ring  75  is crimped onto the outer periphery of the braided wire  43  that covers the barrel main body  72 . Thus, the braided wire  43  and shield barrel  71  are electrically continuous with each other. 
     The terminal  22  is superimposed on the equipment side terminal  11 . A bolt then is inserted into the bolt insertion hole  24  in the terminal  22  and is fastened onto the equipment side terminal  11  to couple the connector fitting portion  33  at the head  27  of the molded connector  20  to the fitting recess  13  in the equipment side connector  10 . The inner lid  29  then is put onto the bolt, the shield shell  70  is put onto the molded connector  20 , and the shield shell  70  is secured to the outer surface of the motor casing. 
     The seal  55  on the inner surface of the cap  50  seals the outer periphery of the cable  40  when the cap  50  is attached to the support section  37  of the molded connector main body  21  to waterproof the portion of the cable  40  in the molded connector main body  21 . This waterproofing of the portion of the cable  40  in the molded connector main body  21  is achieved without adhesive, thereby restraining production cost. 
     It would be difficult to form a seal in the molded connector  20 . However, it is relatively easy to provide the seal  55  on the inner surface of the cap  50 , which is separate from the molded connector main body  21 . Therefore, it is easy to provide the seal  55  in the molded connector  20 . 
     The seal  55  includes the cable seal portion  57  for sealing the outer periphery of the cable  40 , and the molded seal portion  56  for sealing the outer periphery of the support section  37 . Thus, the outer periphery of the support section  37  also is sealed and to waterproof the extended portion of the cable  40  more surely. 
     The step  55 A at the boundary between the cable seal portion  57  and the molded seal portion  56  contacts with the end  45 A of the small diameter portion  45  when attaching the cap  50  to the molded connector main body  21 . Thus, it is possible to seal the molded connector  20  more positively. 
     Annular projections  55 B extend circumferentially around the inner periphery of the seal  55 . Thus, it is possible to seal the molded connector  20  more positively by closely contacting the seal  55  with the annular projection  55 B while collapsing the annular projections  55 B. 
     The support section  37  has the latching projections  39  and the cap  50  has the latching apertures  60  that engage the latching projections  39 . Thus, a simple structure prevents the cap  50  from disengaging from the molded connector main body  21 . 
     The invention is not limited to the embodiment described above and shown in the drawings. For example, the following embodiments fall within the technical scope of the invention. 
     The molded connector  20  functions to supply electrical power to a motor (not shown) in the above embodiment. However, the molded connector of the invention can supply electrical power to various kinds of equipment. 
     The molded connector  20  is shielded by the shield shell  70  in the above embodiment. However, the shield shell may not be required.