Patent Publication Number: US-10770804-B2

Title: Wire with terminal and method for producing wire with terminal

Description:
BACKGROUND 
     Field of the Invention 
     A wire with terminal is disclosed in this specification. 
     Related Art 
     Japanese Unexamined Patent Publication No. 2011-18489 discloses a terminal with a first crimping portion to be crimped to an insulation coating of a wire and a second crimping portion to be crimped to a conductor of the wire. The first and second crimping portions are crimped simultaneously after a resin material is applied to the conductor of the terminal or the wire. The resin material applied to the conductor or the terminal is pressed at the time of crimping, and the conductor and an exposed part of the second crimping portion are covered by the resin material. 
     The first crimping portion is crimped to an exposed surface of an insulation coating in the configuration of Japanese Unexamined Patent Publication No. 2011-18489. Thus, the first crimping portion and the insulation coating are in contact. A clearance may be formed between the first crimping portion and the insulation coating due to vibration of a vehicle, aged deterioration or the like, and water attached to the wire from outside may move toward an end of the wire through this clearance to cause electrolytic corrosion in a part where the conductor of the wire and the terminal are in contact. 
     The invention was completed on the basis of the above situation and aims to prevent the intrusion of water into a part where a conductor of a wire and a terminal are connected. 
     SUMMARY 
     A wire with terminal disclosed in this specification includes a wire and a terminal. The wire has a conductor and an insulation coating surrounding the conductor. A water stop is to be held in close contact with an outer surface of the insulation coating. The terminal has a conductor crimping portion to be crimped to the conductor and a water stop holding portion configured to hold the water stop by being held in close contact with an outer surface of the water stop. 
     A method for producing the above-described wire with terminal includes a conductor part crimping step of crimping the conductor crimping portion to the conductor, a water stop forming step of forming the water stop by holding a resin in close contact with the insulation coating after the conductor crimping step, and a water stop holding step of holding the water stop from an outer surface by the water stop holding portion after the water stop forming step. 
     According to these configurations, the water stop prevents formation of a clearance between the insulation coating of the wire and the water stop holding portion, thereby preventing intrusion of water into a part where the conductor of the wire and the terminal are connected. 
     The water stop holding portion may include a bottom plate on which the wire is placed, and two barrel pieces may rise from the bottom plate. The water stop may be disposed between the bottom plate and the insulation coating. According to this configuration, the water stop prevents intrusion of water passing between the bottom plate and the insulation coating. 
     The water stop may be held in close contact with an entire outer periphery of the insulation coating, and the water stop holding portion may be held in close contact with an entire outer periphery of the water stop. 
     The water stop may be made of resin, and a viscosity of the resin before curing may be 1000 to 10000 mPa·s. According to this configuration, balance between the permeability of a water stopping agent into a clearance between conductors and stable retention of the resin at a desired position during application is excellent and waterproof performance and workability can be combined. 
     The resin may be a photocurable resin. According to this configuration, if the barrel pieces are set in an open state when the resin is cured, irradiated light is not blocked by the barrel pieces. Therefore the curing of the water stop between the bottom plate and the insulation coating can be promoted. 
     The water stop holding portion may include a bottom plate on which the wire is placed, and two barrel pieces rising from the bottom plate. The resin may be a photocurable resin, and the resin may be cured by having light irradiated thereto in the water stop forming step. 
     According to this specification, it is possible to suppress the intrusion of water into a part where a conductor of a wire and a terminal are connected. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view showing a state where a conductor of a wire is placed on a terminal in an embodiment. 
         FIG. 2  is a side view showing a state where a conductor crimping portion of the terminal is crimped to a conductor part. 
         FIG. 3  is a section along A-A of  FIG. 2 . 
         FIG. 4  is a plan view showing a state where an anticorrosive agent is applied from the state of  FIG. 2 . 
         FIG. 5  is a side view showing the state where the anticorrosive agent is applied from the state of  FIG. 2 . 
         FIG. 6  is a section along B-B of  FIG. 5 . 
         FIG. 7  is a plan view showing a wire with terminal. 
         FIG. 8  is a side view showing the wire with terminal. 
         FIG. 9  is a section along C-C of  FIG. 8 . 
         FIG. 10  is a side view showing a wire with terminal as a comparative example. 
     
    
    
     DETAILED DESCRIPTION 
     An embodiment is described with reference to  FIGS. 1 to 10 . A wire with terminal  10  of this embodiment can constitute a power supply path, for example, by being mounted in a vehicle such as an automotive vehicle. 
     (Wire with Terminal  10 ) 
     As shown in  FIG. 8 , the wire with terminal  10  includes a wire  11 , a terminal  20  mounted on an end of the wire  11 , and a water stop  40  for restricting intrusion of water into a part where the wire  11  and the terminal  20  are connected. 
     (Wire  11 ) 
     As shown in  FIG. 1 , the wire  11  is a coated wire including a conductor  12  and an insulation coating  13  (insulation layer) made of synthetic resin and surrounding the outer periphery of the conductor  12 . A material constituting the conductor  12  is aluminum or aluminum alloy in this embodiment. Note that the material constituting the conductor  12  is not limited to this, and copper, copper alloy, or other material can be selected according to need. The insulation coating  13  is removed on an end part of the wire  11 , and the conductor  12  is exposed in front of (left side in  FIG. 1 ) a tip  13 A of the insulation coating  13 . Note that although the conductor part  12  is a twisted wire formed by twisting a plurality of metal strands in this embodiment, there is no limitation to this and a single-core wire made of one conductor may be used. 
     (Terminal  20 ) 
     The terminal  20  is, for example, a female terminal and includes a terminal connecting portion  21  to be connected to a mating terminal, a bottom plate  22  on which the conductor  12  of the wire  11  is placed, a conductor crimping portion  24  to be crimped to the conductor  12 , and a water stop holding portion  27  to be crimped to hold the water stop  40  covering the insulation coating  13  from the outside of the water stop  40 . The terminal connecting portion  21  is box-shaped and a resilient contact piece (not shown) configured to resiliently contact a mating male terminal (not shown) is resiliently deformably provided inside. 
     The conductor crimping portion  24  includes two wire barrel pieces  25  rising from left and right sides of the bottom plate  22 . The wire barrel pieces  25  are crimped by a mold including an anvil  50  (lower mold) and a crimper  52  (upper mold), arcuately deformed inwardly by being contacted by the lowered crimper  52 , and connected to the conductor  12  to bite into the conductor  12 . The water stop holding portion  27  is provided behind and at a distance from the conductor crimping portion  24  and includes two barrel pieces  28  rising from the left and right sides of the bottom plate  22 . The barrel pieces  28  are crimped by a mold including the anvil  50  and a crimper  54  (upper mold) after the wire barrel pieces  25  are crimped, and arcuately deformed inwardly by being contacted by the lowered crimper  54 . Thus, an upper surface  22 A of the bottom plate  22  and the inner surfaces of the wire barrel pieces  25  are held in close contact with the entire outer periphery of the water stop  40 . Cutouts  29 ,  30  are formed before and behind the conductor crimping portion  24  above the bottom plate  22 . One cutout  29  divides between the terminal connecting portion  21  and the conductor crimping portion  24  and the other cutout  30  divides between the conductor crimping portion  24  and the water stop holding portion  27 . 
     The bottom plate  22  is connected behind a bottom plate of the terminal connecting portion  21  and has a cross-sectional shape arcuately curved along the outer periphery of the wire  11 , as shown in  FIG. 3 . The upper surface  22 A of the bottom plate  22  has an arcuate shape in conformity with the outer shape of the wire  11 , is arranged to face the insulation coating  13  while being spaced apart by a clearance G (interval), and is in contact with the conductor  12  in front of the insulation coating  13 . 
     A metal material constituting the terminal  20  is copper or copper alloy in this embodiment. Note that the metal material constituting the terminal  20  is not limited to this and may be aluminum, aluminum alloy or the like. A metal material can be selected according to need, but the use of a material that easily is corroded electrolytically with the conductor part  12  is an option since electrolytic corrosion can be suppressed by the water stop  40  of this embodiment. This terminal  20  is formed by stamping a metal plate material into a development shape of the terminal  20  and applying bending. Note that plating layers (not shown) may be formed on surfaces of this embodiment. Examples of a metal constituting the plating layers include tin, nickel and the like and an appropriate metal material is selected according to need. 
     (Water Stop  40 ) 
     As shown in  FIG. 6 , the water stop  40  can be formed by curing an anticorrosive agent  40 A made of synthetic resin and attached to the wire  11  and the terminal  20 . A material of the anticorrosive agent  40 A can be selected, for example, from a urethane UV acrylate resin, an olefin resin, a polyamide resin, a polyester resin, an acrylic resin, an epoxy resin, a silicone resin, a urethane resin, a phenol resin and the like, but the urethane UV acrylate resin (an example of a “photocurable resin”) that is cured by the irradiation of ultraviolet rays (an example of “light”) is more preferable. Further, a resin that is cured by heat may be used. One or more types of photoinitiators that start a reaction by the irradiation of ultraviolet rays and peroxides that start a reaction by heat may be added. The anticorrosive agent  40 A may have one of various viscosities. For example, the viscosity of the anticorrosive agent  40 A can be set at 1000 to 10000 mPa·s. The water stop  40  after curing is preferably resiliently deformable to such an extent that the water stop  40  is not damaged when the barrel pieces  28  are crimped to the water stop  40 . 
     A method for producing the wire with terminal  10  is described. 
     (Conductor Part Crimping Step) 
     As shown in  FIG. 1 , the insulation coating  13  on the end part of the wire  11  is removed to expose the conductor  12 , and the conductor  12  is placed at a predetermined position on the bottom plate  22  of the terminal  20  placed on the anvil  50 . At this time, the clearance G is formed between the upper surface  22 A of the bottom plate  22  and the insulation coating  13  of the wire  11  (see  FIG. 3 ), and the bottom plate  22  and the insulation coating  13  are not in contact. Subsequently, when the crimper  52  (upper mold) is lowered, the wire barrel pieces  25  are deformed by being contacted by the crimper  52 , and crimped to the conductor  12  ( FIG. 2 ). Note that although the clearance G is formed between the bottom plate  22  and the insulation coating  13  when the conductor part  12  is crimped, there is no limitation to this. For example, the upper surface  22 A of the bottom plate  22  and the insulation coating  13  may be held in contact when the conductor part  12  is crimped, and the upper surface  22 A of the bottom plate  22  and the insulation coating  13  may be separated to form the clearance G after the conductor  12  is crimped. 
     (Water Stop Portion Forming Step) 
     Subsequently, an ultraviolet curable urethane UV acrylate resin is, for example, applied as the anticorrosive agent  40 A to an area of the insulation coating  13  at a position corresponding to the exposed conductor part  12  of the wire  11 , the conductor crimping portion  24  of the terminal  20 , the upper surface  22 A of the bottom plate  22  and the barrel pieces  28 , as shown in  FIG. 5 , and ultraviolet rays are irradiated from above, as shown in  FIG. 6 . At this time, the barrel pieces  28  are not crimped and are in an open state. Thus, the ultraviolet rays are irradiated to an upper surface side of the anticorrosive agent  40 A without being blocked by the barrel pieces  28 . As the upper surface side of the anticorrosive agent  40 A is cured by the ultraviolet rays, the anticorrosive agent  40  on a lower side is cured by a chain reaction (radical reaction). When the anticorrosive agent  40 A between the bottom plate  22  and the insulation coating  13  is cured, the entire anticorrosive agent  40 A is cured to form the water stop  40 . 
     (Water Stop Portion Holding Step) 
     Subsequently, when the crimper  54  is lowered with the bottom plate  22  of the terminal  20  placed on the anvil  50 , the barrel pieces  28  are deformed by being contacted by the crimper  54 . When the tips of the barrel pieces  28  come into contact with each other, the barrel pieces  28  are crimped to the water stop  40  (and the wire  11  including the insulation coating  13 ) from outside to form the annular water stop holding portion  27  ( FIG. 9 ). At this time, the water stop holding portion  27  is held in close contact with the outer surface of the water stop  40  and holds the water stop  40  (and the wire  11  including the insulation coating  13 ) from the outer surface side of the water stop  40 . 
     According to this embodiment, the following functions and effects are achieved. 
     The wire with terminal  10  includes the wire  11  having the conductor part  12  and the insulation coating  13  surrounding the conductor part  12 , the water stop  40  to be held in close contact with the outer surface of the insulation coating  13 , and the terminal  20  having the conductor crimping portion  24  to be crimped to the conductor part  12  and the water stop holding portion  27  configured to hold the water stop  40  by being held in close contact with the outer surface side of the water stop  40 . 
     For example, if a water stop portion AC is formed by applying an anticorrosive agent after a conductor crimping portion  24  is crimped to the conductor part  12  and an insulation barrel IB of a terminal TE is crimped to the insulation coating  13 , for example, as shown in  FIG. 10  as a comparative example, the insulation barrel IB is directly in contact with the insulation coating  13  (without the water stop portion). Thus, clearances are easily formed between the insulation barrel IB and the insulation coating  13  and between a bottom plate  22  and the insulation coating  13  due to the vibration of a vehicle, aged deterioration or the like. If water adhering to the wire  11  intrudes into connecting parts of the wire  11  and the terminal TE through this clearance, electrolytic corrosion may take place. According to this embodiment, since the clearance G through which water passes is not easily formed between the insulation coating  13  of the wire  11  and the water stop holding portion  27  due to the water stop  40 , the intrusion of water into a part where the conductor part  12  of the wire  11  and the terminal  20  are connected is suppressed. 
     Further, a cross-sectional area of the wire with terminal can be reduced as compared to a configuration in which the water stop  40  is disposed, for example, on the outer surface side of the water stop holding portion  27  by being between the insulation coating  13  of the wire  11  and the water stop holding portion  27 , the wire with terminal  10  can be, for example, easily inserted into a cavity of a connector. 
     Further, the water stop holding portion  27  includes the bottom plate  22  on which the wire  11  is placed and the two barrel pieces  28  rising from the bottom plate  22 , and the water stop  40  is between the bottom plate  22  and the insulation coating  13 . According to this configuration, the intrusion of water passing between the bottom plate  22  and the insulation coating  13  can be suppressed by the water stop  40 . 
     Further, the water stop  40  is made of resin and the viscosity of the resin before curing is 1000 to 10000 mPa·s. According to this configuration, balance between the permeability of a water stopping agent into a clearance or the like between conductors and stable retention of the resin at a desired position during application is excellent and waterproof performance and workability can be combined. 
     Further, the water stop  40  is made of the photocurable resin that is cured by the ultraviolet rays L (light). According to this configuration, if the barrel pieces  28  are set in the open state when the resin is cured, the irradiated light is not blocked by the barrel pieces  28 . Therefore the curing of the water stop  40  between the bottom plate  22  and the insulation coating  13  can be promoted. 
     The invention is not limited to the above described and illustrated embodiment. For example, the following embodiments also are included in the scope of the invention disclosed in this specification. 
     Although the water stop  40  is held in close contact with the entire outer periphery of the insulation coating  13  and the water stop holding portion  27  is held in close contact with the entire outer periphery of the water stop  40 , there is no limitation to this. For example, the water stop  40  may be formed only between the bottom plate  22  and the insulation coating  13 . 
     Although the tips of the barrel pieces  28  come into contact with each other, there is no limitation to this and the barrel pieces may partially overlap. Further, although the conductor crimping portion  24  and the water stop holding portion  27  are of an open barrel type including the two wire barrel pieces  25  or the barrel pieces  28 , the conductor crimping portion  24  and the water stop holding portion  27  may be of an annular closed barrel type and barrel portions may be crimped with the conductor part  12  and the insulation coating  13  inserted in the annular barrel portions. 
     LIST OF REFERENCE SIGNS 
       10 : wire with terminal 
       11 : wire 
       12 : conductor 
       13 : insulation coating 
       20 : terminal 
       22 : bottom plate 
       24 : conductor crimping portion 
       27 : water stop holding portion 
       28 : barrel piece 
       40 : water stop 
       40 A: anticorrosive agent 
     G: clearance