JP2014164959A - Electric wire connection structure and terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric wire connection structure in which corrosion of a core wire can be suppressed with a configuration capable of being easily manufactured without passing through a complicated process, and also to provide a terminal.SOLUTION: Disclosed is an electric wire connection structure 10 in which an electric wire 13 having a core wire 14 and a conductor insulation layer 15 formed in the outer periphery of the core wire 14 and a tube-shaped terminal 11 composed of a conductor are crimped and joined together. A water-absorbing member 52 is arranged in at least a part of the outer surface of the conductor insulation layer 15, and the water-absorbing member 52 is prevented from coming into contact with the core wire 14.

Description

  The present invention relates to a component responsible for electrical continuity, and more particularly to a wire connection structure in which an electric wire and a terminal are connected, and a terminal connected to the electric wire.

  Conventionally, in wire harnesses used for automobiles, etc., an electric wire formed by coating a core wire (conductive wire) with an insulator is used, and this type of electric wire has a metal at the end of the core wire exposed by peeling off the coating. The terminal is crimped. In the conventional wire-terminal connection structure, the surface of the end of the core wire from which the insulator has been peeled is exposed. Therefore, when applied to applications such as vehicles, the wire is exposed to rainwater, etc. Corrosion of the core wire has been a concern when running for a long time in a humid environment.

In particular, in recent years, in order to reduce the weight of a wire harness for the purpose of improving the fuel efficiency of an automobile, the core wire material has been replaced with an aluminum-based material such as aluminum or aluminum alloy from a conventional copper-based material. When the core wire of aluminum material is used for the electric wire and the copper material is used for the metal terminal of the crimping part, there is a potential difference between the metal constituting the electric wire (aluminum material) and the metal constituting the metal terminal (copper material). Arise. At this time, when moisture or the like adheres to the connecting portion between the electric wire and the terminal, the conductor (core wire) of the electric wire is exposed, so that corrosion between different metals occurs and corrosion of any metal proceeds. In the corrosion between dissimilar metals of an aluminum-based material and a copper-based material, the aluminum-based material is thinned by the corrosion. For this reason, there is a risk that poor contact may occur in the wire connection portion.
In order to solve these problems, conventionally, a technique has been proposed in which the entire outer periphery of the end exposed region of the crimped portion and the vicinity thereof is molded with a resin (see, for example, Patent Document 1).
Further, a technique has been proposed in which a metal intermediate cap is attached to a core wire exposed portion of an electric wire and then a terminal is crimped to protect the crimp portion of the electric wire and the terminal (for example, see Patent Document 2).

JP 2011-222243 A JP 2004-207172 A

However, since the molding which is the technique described in Patent Document 1 requires an operation of molding a resin on each crimped portion after crimping, the task becomes complicated and the number of steps of manufacturing the wire harness greatly increases. There was a problem. Furthermore, the crimping part is enlarged by molding, and it is necessary to increase the size of the connector housing to which each terminal is attached. Thereby, a connector will be enlarged and the whole wire harness could not be shape | molded in high-density small.
Moreover, in the technique described in Patent Document 2, the process of attaching the intermediate cap to each core wire exposed portion before pressure bonding is complicated. Furthermore, when the intermediate cap is broken by the wire barrel at the time of crimping, there is a problem that a water immersion path to the core wire is generated and the waterproof property is impaired.
Then, an object of this invention is to provide the electric wire connection structure and terminal which can suppress corrosion of a core wire by the structure which can be manufactured easily without passing through a complicated process.

  In order to solve the above-mentioned problems, an electric wire connection structure of the present invention is an electric wire connection structure in which an electric wire having a core wire and a conductor insulating layer formed on the outer periphery of the core wire and a tubular terminal made of a conductor are bonded by pressure bonding. And a water absorbing member is arrange | positioned in at least one part of the outer surface of the said conductor insulating layer, The said water absorbing member does not touch the said core wire, It is characterized by the above-mentioned.

  In this configuration, the water absorbing member may be disposed between the conductor insulating layer and the tubular terminal. The tubular terminal may have a wire insertion port, and the water absorbing member may be disposed so as to be in close contact with the wire insertion port and the conductor insulating layer.

Moreover, it is good also as a structure by which the water stop member is further arrange | positioned between the said conductor insulating layer and the said tubular terminal, and the said water stop member and the said water absorption member are arrange | positioned adjacently. Moreover, it is good also as a structure arrange | positioned so that the said water absorption member may be pinched | interposed into the said water stop member in an axial direction.
Furthermore, it is good also as a structure by which the end of the said tubular terminal is obstruct | occluded and the said water stop member is arrange | positioned between the said tubular terminal and the said electric wire in the other end of the said tubular terminal.
The water absorbing member may be made of a water absorbing material that adsorbs and holds water.
Further, the water stop member may be made of a material having elasticity or plasticity.

  Moreover, the said structure WHEREIN: The sheet-like water absorbing member containing a water absorbing resin or a water absorbing resin may be sufficient as the said water absorbing member. The tubular terminal may be made of copper or a copper alloy, and the core wire may be made of aluminum or an aluminum alloy.

  Moreover, the terminal of this invention has the tubular crimping | compression-bonding part crimped | bonded and joined with an electric wire, The water absorbing material was arrange | positioned at the said crimping | compression-bonding part, It is characterized by the above-mentioned.

  This structure WHEREIN: The said water absorbing member is good also as a structure arrange | positioned cyclically | annularly along the internal peripheral surface of the said crimping | compression-bonding part in at least one part in the axial direction of the said crimping | compression-bonding part.

  According to the present invention, by arranging the water-absorbing material in the tubular crimping portion that is crimp-bonded to the electric wire, the moisture entering the crimping portion is collected and the adhesion of moisture to the electric wire conductor is suppressed. Corrosion can be suppressed.

It is a perspective view showing an electric wire connection structure concerning an embodiment. It is principal part sectional drawing of the longitudinal direction of an electric wire connection structure. It is sectional drawing of the radial direction in the tubular crimping part of an electric wire connection structure. It is sectional drawing which shows another structural example of an electric wire connection structure. It is sectional drawing which shows another structural example of an electric wire connection structure. It is sectional drawing which shows another structural example of an electric wire connection structure. It is explanatory drawing which shows the manufacturing method of an electric wire connection structure. It is explanatory drawing which shows the manufacturing method of an electric wire connection structure, (A) is sectional drawing in the longitudinal direction of a tubular terminal, (B) is sectional drawing in radial direction. It is explanatory drawing of the crimping | compression-bonding process of an electric wire connection structure. It is explanatory drawing which shows the manufacturing method of a tubular terminal. It is explanatory drawing which shows another example of the manufacturing method of a tubular terminal. It is explanatory drawing which shows another example of the manufacturing method of a tubular terminal. It is explanatory drawing which shows another example of the manufacturing method of a tubular terminal. It is explanatory drawing which shows another example of the manufacturing method of an electric wire connection structure. It is sectional drawing which shows the structure of the electric wire connection structure of a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Drawing 1 is a perspective view showing electric wire connection structure 10 of one embodiment.
The electric wire connection structure 10 includes a tubular terminal 11 (terminal) and an electric wire 13 that is pressure-bonded to the tubular terminal 11. The tubular terminal 11 has a box portion 20 of a female terminal and a tubular caulking portion 30 (crimping portion), and has a transition portion 40 as a bridge between them.
The tubular terminal 11 is basically made of a base material made of a metal material (copper or copper alloy in this embodiment) in order to ensure conductivity and strength. In addition, the base material of the tubular terminal 11 is not limited to copper or a copper alloy, and aluminum, steel, an alloy containing these as a main component, or the like can also be used.
Moreover, in order to ensure various characteristics as a terminal, the tubular terminal 11 may be subjected to, for example, a plating process such as tin, nickel, silver plating, or gold on part or all of the tubular terminal 11. Further, not only plating but also reflow treatment of tin or the like may be performed.

  The box portion 20 of the tubular terminal 11 is a female terminal box portion that allows insertion of an insertion tab such as a male terminal. In the present invention, the shape of the details of the box portion 20 is not particularly limited. That is, the tubular terminal 11 only needs to have the tubular caulking portion 30 via at least the transition portion 40. For example, the tubular terminal 11 does not have to have a box portion. For example, the box portion is an insertion tab of a male terminal. Also good. Moreover, the shape by which the terminal edge part which concerns on another form to the tubular crimping part 30 was connected may be sufficient. In this specification, in order to explain the tubular terminal of the present invention, an example in which a female box is provided for convenience is shown.

FIG. 2 is a cross-sectional view of the main part of the wire connection structure 10 in the longitudinal direction. 3 is a radial cross-sectional view of the tubular caulking portion 30 of the wire connection structure 10. FIG.
The electric wire 13 is configured, for example, by covering a core wire 14 in which strands 14a made of metal or alloy are bundled with a conductor insulating layer 15 made of an insulating resin (for example, polyvinyl chloride). The core wire 14 is formed by twisting the strands 14a so as to have a predetermined cross-sectional area. However, the core wire 14 is not limited to this form and may be formed by a single wire. In addition, the metal material which comprises a core wire should just be a metal which has high electroconductivity, and you may use copper or a copper alloy other than aluminum or an aluminum alloy.

  The resin material constituting the conductor insulating layer 15 is polyvinyl chloride. Besides this polyvinyl chloride, for example, halogen resins mainly composed of cross-linked polyvinyl chloride, chloroprene rubber, polyethylene, cross-linked polyethylene, etc. Further, halogen-free resins mainly composed of ethylene propylene rubber, silicon rubber, polyester, etc. are used, and these may contain additives such as plasticizers and flame retardants.

The tubular caulking portion 30 is a portion that crimps and joins the tubular terminal 11 and the electric wire 13, and includes a conductor crimping reduced diameter portion 35 and a coated crimping reduced diameter portion 36.
Usually, when crimped and joined, the conductor crimped reduced diameter portion 35 and the coated crimped reduced diameter portion 36 are each plastically deformed to be reduced in diameter from the original diameter, thereby allowing the core wire tip 14b and the sheath tip of the electric wire 13 to be reduced. (Crimped part) 15a is crimped and coupled. A serration 33 is formed in the conductor crimping reduced diameter portion 35. The serration 33 is an annular groove that is formed in advance along the inner peripheral surface of the tubular terminal 11 before the crimp bonding. When the compression bonding is performed, the core wire 14 is locked by the serration 33, and there is an effect of increasing the contact pressure between the core wire 14 and the tubular terminal 11. When aluminum or an aluminum alloy is used for the core wire 14, it has been pointed out that the contact resistance is lower than when copper or a copper alloy is used. However, by providing the serration 33 on the inner peripheral surface of the tubular terminal 11, reliable conduction is achieved. Can be secured.

One end of the tubular caulking portion 30 has an electric wire insertion port 31 into which the electric wire 13 can be inserted, and the other end is connected to the transition portion 40. The transition portion 40 side of the tubular caulking portion 30 is closed by means such as welding, and is formed so that moisture or the like does not enter from the transition portion 40 side.
When moisture adheres to the joint between the metal substrate (copper or copper alloy) of the tubular terminal 11 and the core wire 14 (aluminum or aluminum alloy), the core wire 14 corrodes due to the difference in electromotive force (ionization tendency) between the two metals. Further, even if the tubular terminal 11 and the core wire 14 are made of aluminum, their joints are easily corroded due to a subtle difference in alloy composition.

  In this configuration, the tubular caulking portion 30 is formed in a bottomed tubular shape, so that intrusion of moisture and the like is suppressed from the outside, and corrosion of the joint portion between the tubular terminal 11 and the electric wire 13 can be suppressed. If the tubular caulking portion 30 is tubular, a certain effect against corrosion can be obtained. Therefore, the tubular caulking portion 30 is not necessarily cylindrical with respect to the longitudinal direction, and may be an elliptical or rectangular tube depending on circumstances. . Further, the diameter does not need to be constant, and the radius may change in the longitudinal direction.

As will be described later, the tubular caulking portion 30 is formed by punching a strip made of a metal such as copper or a copper alloy into a shape that is flattened and bending. In this case, the box unit 20 may be provided integrally.
Since the portion corresponding to the caulking portion has a C-shaped cross section when bent from a flat state, the tubular caulking portion 30 is formed by joining both open ends and joining them by welding or the like. The Laser welding is preferable for joining the tubular caulking portion 30, but welding methods such as electron beam welding, ultrasonic welding, and resistance welding may be used. Also, joining using a connection medium such as solder or solder may be used. The tubular caulking portion 30 is not limited to the method of joining both end portions of the C-shaped cross section, and may be formed by a deep drawing method. Furthermore, the tubular crimping portion 30 may be formed by cutting the continuous tube and closing one end side.

In the tubular caulking portion 30, the metal base material constituting the tubular caulking portion 30 and the electric wire 13 are mechanically pressure-bonded to ensure electrical connection at the same time. The caulking is performed by plastic deformation of a base material or an electric wire (core wire). Accordingly, the tubular caulking portion 30 needs to be designed to have a thickness so that it can be caulked and joined, but since it can be joined freely by manual machining or machining, it is particularly limited. is not.
The tubular caulking portion 30 is required to have a function of maintaining the electrical conduction by strongly compressing the core wire 14 and a function of maintaining the sealing performance by compressing the conductor insulating layer 15. In the coated crimped reduced diameter portion 36, the cross section thereof is caulked into a substantially circular shape, and by applying substantially the same pressure over the entire circumference of the conductor insulating layer 15, a uniform elastic repulsive force is generated over the entire circumference. It is preferable to obtain a sealing property.

  Since aluminum or aluminum alloy used for the core wire has higher contact resistance than copper and copper alloy, there is anxiety in connection. For this reason, the inner wall surface of the tubular caulking portion 30 is provided with a wire locking groove (not shown) extending in the circumferential direction of the electric wire 13 at a position in contact with the core wire 14 inserted from the electric wire insertion port 31. The contact pressure may be maintained.

And in the crimping | compression-bonding reduced diameter part 36, the water stop member 51 and the water absorption member 52 are arrange | positioned between the tubular terminal 11 and the conductor insulating layer 15. FIG.
The water blocking member 51 is made of a material having elasticity or plasticity, and preferably made of a water-impermeable material. The water absorbing member 52 absorbs or removes moisture.
The water stopping member 51 and the water absorbing member 52 have a shape in which a sheet having a predetermined thickness is formed in an annular shape surrounding the conductor insulating layer 15. Although it is preferably formed in an endless ring, the end may be joined by winding a long sheet in an annular shape, or may be formed in a superposed shape.
The water-stop member 51 and the water-absorbing member 52 are provided so as to be interposed between the conductor insulating layer 15 and the tubular terminal 11 before the electric wire 13 is crimped and joined, and are crimped by the coated crimping reduced diameter portion 36. For this reason, in the cover crimping reduced diameter portion 36, the water stop member 51 and the water absorbing member 52 are in close contact with the inner surface of the tubular caulking portion 30 and the surface of the conductor insulating layer 15, and between the tubular caulking portion 30 and the conductor insulating layer 15. Fill.

  The water stop member 51 may be any member that can be deformed at room temperature. More specifically, any material having at least one of plasticity and elasticity may be used. For example, synthetic resin, synthetic rubber, natural rubber, and various elastomers are used. Specific examples of synthetic resins include polyolefin resins (polyethylene, crosslinked polyethylene, polypropylene, polyisobutylene, etc.), halogen-containing resins (polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, etc.), polyester resins (polyethylene terephthalate). (PET) etc.), polyurethane resin, polyvinyl acetate resin, silicone resin, acrylic resin, copolymer resin (ABS resin (acrylonitrile-butadiene-styrene copolymer resin), AS resin (acrylonitrile-styrene copolymer resin), EVA resin (Ethylene vinyl acetate copolymer resin) and the like), mixtures of these resins, and those obtained by adding additives such as stabilizers and plasticizers to these resins. In addition, as a so-called synthetic rubber, which is a kind of synthetic resin, silicone rubber, fluorine rubber, butyl rubber, butadiene rubber, styrene-butadiene rubber, ethylene propylene rubber, epichlorohydrin rubber, chloroprene rubber, nitrile rubber, and the like can be used. . These synthetic rubbers may contain additives such as fats and oils and stabilizers.

Furthermore, the material of the water stop member 51 is more preferably a material having heat resistance that does not cause a change in physical properties in the usage environment of the wire connection structure 10. For example, in the electric wire connection structure 10 used as a harness of an automobile, sufficient heat resistance is provided when it is disposed in the vicinity of an engine, an exhaust system component, a driving component such as a motor or a transmission, a battery, a peripheral circuit, or a lamp. In order to exhibit, it is more preferable that the heat resistant temperature is 120 degrees Celsius, 160 degrees Celsius, or 180 degrees Celsius. Silicone rubber, fluorine rubber, butyl rubber, butadiene rubber, ethylene propylene rubber, and nitrile rubber are preferable materials from the viewpoints of heat resistance and alkali resistance and plasticity and elasticity as a water-stopping member.
Further, a polyvinyl chloride resin or a cross-linked polyvinyl chloride resin can be used for the conductor insulating layer 15 of the electric wire 13. Further, as the conductor insulating layer 15, a halogen-free resin (non-halogen resin) whose main component is polyolefin resin, ethylene-propylene rubber, silicon rubber, polyester, silicon resin, or the like can be used. These halogen-free resins may be a mixture of a flame retardant such as a metal hydrate.

  In selecting the material of the water blocking member 51, the conductor insulating layer 15 may be combined so as not to cause a change in physical properties due to the transfer of additives, oils and fats, or the solvent between the conductor insulating layer 15 and the water blocking member 51. It is preferable to select according to the material. Specifically, when a halogen-free resin other than silicon resin is used as the conductor insulating layer 15, the water-stopping member 51 avoids a synthetic rubber or synthetic resin containing a halogen-containing resin, oil or a solvent as a mixture, and other materials. It is preferable to use a synthetic resin. On the other hand, when a halogen-containing resin is used as the conductor insulating layer 15, it is preferable to use a silicon resin or a halogen-containing resin as the water stop member 51.

  The water absorbing member 52 is obtained by processing a water absorbing material having a function of absorbing moisture into the above shape, or holding the water absorbing material on a carrier having the above shape. Examples of the water-absorbing material include a reactive type that removes moisture by reacting with water, and a non-reactive type (adsorptive type) that adsorbs and holds water. In consideration of the influence on the core wire 14 and the conductor insulating layer 15 inside the tubular caulking portion 30 and the influence on the installation environment of the wire connection structure 10, a non-reactive type is preferable. Specific examples of non-reactive types include minerals such as zeolite, water adsorbents using inorganic materials such as ceramics, silica gel, activated carbon, water-absorbing polymers such as polyacrylates, water-absorbing sponges made of synthetic resins, etc. Is mentioned. Moreover, as a support | carrier, what formed said synthetic resin in the sheet form is mentioned, For example, the nonwoven fabric made from a polypropylene resin or a polyethylene resin is mentioned, for example. In consideration of the moldability and water absorption ability to form a thin sheet that can be accommodated in the tubular caulking portion 30, a preferred example is a polyacrylic acid salt held on a nonwoven fabric sheet.

In this embodiment, the structure which has arrange | positioned the two water-stop members 51 and 51 and the one water absorption member 52 as shown in FIG. 2 as an example. That is, in the axial direction of the tubular caulking portion 30, the water stopping member 51, the water absorbing member 52, and the water stopping member 51 are arranged in this order from the transition portion 40 side. The water stop member 51 close to the electric wire insertion port 31 may reach the electric wire insertion port 31 or may be inside the electric wire insertion port 31. In the example of FIG. 2, the end of the water stop member 51 located on the transition portion 40 side is substantially at the same position as the tip of the conductor insulating layer 15, but the tip of the conductor insulating layer 15 protrudes from the water stop member 51. May be.
Since the water stop member 51 is caulked in the covering crimping reduced diameter portion 36 as described above, the wire insertion port 31 side is closed without any gap by the water stop member 51 and the conductor insulating layer 15. For this reason, the water is surely stopped so that moisture does not enter from the wire insertion port 31. The water absorbing member 52 is disposed in a space (region) where water is stopped by the water stopping member 51. As the action of the water absorbing member 52, the moisture is tubular beyond the action of removing the moisture inside the tubular caulking portion 30 which is a space stopped by the water stopping member 51 and the water stopping member 51 on the electric wire insertion port 31 side. The action of removing this water when entering the caulking portion 30 is mentioned. For example, when the electric wire connection structure 10 is bent by the external force at or near the covering crimping reduced diameter portion 36, the water stop member 51 on the electric wire insertion port 31 side and the conductor insulating layer 15 are displaced or deformed. There is a possibility that the water stop will be released. In such a case, when moisture enters the inside of the tubular caulking portion 30, it is absorbed by the water absorbing member 52. If the material of the water absorbing member 52 is a material that retains absorbed moisture, it is possible to more reliably prevent moisture from entering the conductor crimping reduced diameter portion 35. Further, another water-stop member 51 is disposed on the transition portion 40 side, and this water-stop member 51 is also caulked at the cover crimping reduced diameter portion 36. The water stop member 51 has an effect of preventing moisture from entering the conductor crimping reduced diameter portion 35 even when the water stop by the water stop member 51 on the wire insertion port 31 side is released.
As described above, the tubular caulking portion 30 can surely prevent moisture from entering the conductor crimping reduced diameter portion 35 by the water stop members 51, 51 and the water absorbing member 52, so that the corrosion of the core wire 14 can be suppressed.

The arrangement method of the water absorbing member in the tubular caulking portion 30 is not limited to the example of FIG.
FIGS. 4, 5, and 6 are longitudinal cross-sectional views showing configurations of the wire connection structures 10 </ b> A to 10 </ b> E as configuration examples different from the wire connection structure 10. The wire connection structures 10 </ b> A to 10 </ b> E shown in FIGS. 4 to 6 include a position where the water absorbing member is disposed in the cover crimping reduced diameter portion 36 when the tubular terminal 11 and the electric wire 13 are joined, and the water stopping member and the water absorbing member. It is the example which was set as the structure of those other than the electric wire connection structure 10 of FIG.
The wire connection structure 10A shown in FIG. 4A is the same as the wire connection structure 10 (FIG. 2) in that the tubular terminal 11 and the wire 13 are joined by pressure bonding. In the electric wire connection structure 10 </ b> A, one water-stop member 51 and one water-absorbing member 52 are arranged in the coated crimping reduced diameter portion 36. The water-stop member 51 and the water-absorbing member 52 are formed in an annular shape as described above, are disposed so as to surround the outer periphery of the conductor insulating layer 15, and are pressure-bonded at the cover crimping reduced diameter portion 36. The water stop member 51 is disposed on the electric wire insertion port 31 side, and prevents moisture from entering the tubular caulking portion 30. The water absorbing member 52 is located inside the space stopped by the transition portion 40 and the water stopping member 51 and absorbs moisture. Also in this configuration, it is possible to prevent moisture from entering the conductor crimping reduced diameter portion 35 from the wire insertion port 31 side and to suppress corrosion of the core wire 14. Further, in the electric wire connection structure 10A, since the water absorbing member 52 is in contact with the space connected to the conductor crimping reduced diameter portion 35 inside the tubular caulking portion 30, an effect that this space can be kept dry can be expected.

The wire connection structure 10B shown in FIG. 4B is the same as the wire connection structure 10 in that the tubular terminal 11 and the wire 13 are joined by pressure bonding. In the wire connection structure 10 </ b> B, one water absorbing member 52 is disposed in the coated crimping reduced diameter portion 36. The water absorbing member 52 is formed in an annular shape as described above, is disposed so as to surround the outer periphery of the conductor insulating layer 15, and is crimped by the coated crimping reduced diameter portion 36.
The water absorbing member 52 is disposed at the approximate center of the coated crimping reduced diameter portion 36 in the longitudinal direction (axial direction) of the tubular caulking portion 30. Further, the water absorbing member 52 is not exposed to the electric wire insertion port 31 side. In this configuration, water is not stopped by the water stop member 51, but water is stopped by caulking the conductor insulating layer 15 in the coated crimping reduced diameter portion 36. Therefore, it can be said that the water absorbing member 52 is located inside the water-stopped space, and absorbs moisture in this space. When moisture enters the tubular caulking portion 30 from the wire insertion port 31 side, the moisture absorbing member 52 absorbs this moisture, thereby preventing moisture from entering the conductor crimping reduced diameter portion 35 and the core wire 14. Corrosion can be suppressed.

  The wire connection structure 10C shown in FIG. 5A is the same as the wire connection structure 10 in that the tubular terminal 11 and the wire 13 are joined by pressure bonding. In the wire connection structure 10 </ b> C, the water absorption member 52 </ b> A is disposed in the wire insertion port 31 and the vicinity thereof. The water absorbing member 52 </ b> A is formed by annularly forming a sheet-shaped water absorbing member like the water absorbing member 52 described above, and is disposed so as to surround the outer periphery of the electric wire 13. The water absorbing member 52A is larger in size in the axial direction of the tubular caulking portion 30 than the water absorbing member 52, and is disposed so as to straddle from the inside of the coated crimping reduced diameter portion 36. The distal end portion of the water absorbing member 52A is caulked together with the electric wire 13 inside the coated crimping reduced diameter portion 36, and the proximal end portion of the water absorbing member 52A is exposed outside the tubular caulking portion 30. The water absorbing member 52 </ b> A included in the electric wire connection structure 10 </ b> C prevents moisture from entering the tubular caulking portion 30 by absorbing moisture that enters the tubular caulking portion 30 at the electric wire insertion port 31. In addition, if the material of the water absorbing member 52A includes a non-reactive water absorbing agent, water is released when the periphery of the wire connection structure 10C is in a dry state. Can be prevented. The electric wire connection structure 10C is suitable as a material for a harness that is installed in a place that is often dry, for example.

The wire connection structure 10D shown in FIG. 5B is the same as the wire connection structure 10 in that the tubular terminal 11 and the wire 13 are joined by pressure bonding. In the electric wire connection structure 10 </ b> D, the water absorbing member 52 </ b> B is disposed outside the electric wire insertion port 31. The water absorbing member 52 </ b> B is formed by annularly forming a sheet-shaped water absorbing member in the same manner as the above-described water absorbing members 52 and 52 </ b> A, and is disposed so as to surround the outer periphery of the electric wire 13. The water absorbing member 52 </ b> B is larger in size in the axial direction of the tubular caulking portion 30 than the water absorbing member 52, and is disposed outside the covering crimping reduced diameter portion 36, that is, at a position in contact with the end of the tubular caulking portion 30. The tip of the water absorbing member 52B is not inside the coated crimping reduced diameter portion 36 and is not crimped. The electric wire connection structure 10D can be manufactured, for example, by winding the water absorbing member 52B after the tubular terminal 11 and the electric wire 13 are joined by pressure bonding.
The water absorbing member 52 </ b> B absorbs moisture to enter the tubular caulking portion 30 from the wire insertion port 31 outside the tubular caulking portion 30, and prevents moisture from entering the tubular caulking portion 30. Further, if the material of the water absorbing member 52B includes a non-reactive water absorbing agent, when the surroundings of the wire connection structure 10D are in a dry state, water is quickly released and the water absorbing ability is restored. For this reason, electric wire connection structure 10D is suitable as a material of the harness installed in the place where it is often dry, for example.

  The wire connection structure 10E shown in FIG. 6 is the same as the wire connection structure 10 in that the tubular terminal 11 and the wire 13 are joined by pressure bonding. In the electric wire connection structure 10 </ b> E, one water-stop member 51 and one water-absorbing member 52 are arranged in the coated crimping reduced diameter portion 36. The water-stop member 51 and the water-absorbing member 52 are formed in an annular shape as described above, are disposed so as to surround the outer periphery of the conductor insulating layer 15, and are pressure-bonded at the cover crimping reduced diameter portion 36. The water stop member 51 is disposed on the transition portion 40 side, and the water absorption member 52 is disposed on the wire insertion port 31 side. For this reason, the water | moisture content which is going to enter in the tubular crimping part 30 from the electric wire insertion port 31 is absorbed by the water absorption member 52, and the penetration | invasion of the water | moisture content in the tubular crimping part 30 is prevented. Further, even when water that cannot be absorbed by the water absorbing member 52 enters, the water is stopped by the water stopping member 51, so that the water does not enter the tubular caulking portion 30. For this reason, it is possible to more reliably prevent moisture from entering the conductor crimping reduced diameter portion 35.

Then, the manufacturing method of an electric wire connection structure is demonstrated.
7-13 is explanatory drawing which shows the 1st manufacturing method of the electric wire connection structure 10. FIG. This 1st manufacturing method is suitable when manufacturing the electric wire connection structure 10 and electric wire connection structure 10A, 10B, 10E.
FIG. 7 is a perspective view illustrating the configuration of the tubular terminal 11 and the electric wire 13 to be joined, and FIG. 8 is a cross-sectional view illustrating the configuration of the tubular terminal 11. 8A is a sectional view in the longitudinal direction of the tubular terminal 11, and FIG. 8B is a sectional view in the radial direction.
As shown in FIG. 7, the tubular terminal 11 before being crimp-bonded has a tubular portion 25 connected to the box portion 20 via the transition portion 40. The tubular part 25 has an enlarged diameter part 26 connected to the transition part 40 and a tubular part 27 having substantially the same diameter, and the tubular part 27 becomes the tubular caulking part 30 (FIG. 1).
The electric wire 13 is inserted into the cylindrical portion 27 with the conductor insulating layer 15 at the tip end peeled off by a wire stripper or the like and the core wire 14 is exposed.

  As shown in FIGS. 8A and 8B, a water stop member 51 and a water absorption member 52 are arranged in advance on the inner peripheral surface of the cylindrical portion 27. The water-stop member 51 and the water-absorbing member 52 are attached to the inner peripheral surface of the cylindrical portion 27 by a method such as application or sticking, and are annular as shown in FIG. For this reason, if the electric wire 13 is inserted in the cylinder part 27, the electric wire 13 will be arrange | positioned inside the water stop member 51 and the water absorption member 52. FIG.

FIG. 9 is an explanatory diagram of a process of crimping and joining the electric wire 13 to the tubular terminal 11, and is a cross-sectional view corresponding to a transverse cross section of the cylindrical portion 27. In FIG. 9, the width of the anvil 103 is indicated by symbol A, and the lateral width (diameter) of the tubular terminal 11 when installed on the anvil 103 is indicated by symbol B.
As shown in FIG. 9, the tubular terminal 11 and the electric wire 13 are crimped and joined (crimped) using a crimper 101 and an anvil 103. The crimper 101 has a crimp wall 102 in which the tubular terminal 11 is formed of a curved surface, and the anvil 103 has a receiving portion 104 on which the tubular terminal 11 is placed. The receiving portion 104 of the anvil 103 is a curved surface corresponding to the outer shape of the tubular portion 25. With the wire 13 inserted in the tubular terminal 11, the tubular terminal 11 is placed on the receiving portion 104, and the crimper 101 is lowered as indicated by an arrow in the drawing, whereby the tubular portion is formed by the crimping wall 102 and the receiving portion 104. 25 is compressed and pressure bonded.

9 shows a cross section of the cylindrical portion 27, the conductor insulating layer 15, the water absorbing member 52, and the cylindrical portion 27 outside the core wire 14 are illustrated, but the crimper 101 and the anvil 103 are In addition to the cylindrical portion 27, other portions can be compressed. That is, the crimper 101 and the anvil 103 have a depth capable of compressing almost the entire portion excluding the enlarged diameter portion 26 of the tubular portion 25. For this reason, both the portion where the core wire 14 and the tubular portion 25 are pressure-bonded and the portion where the electric wire 13 including the conductor insulating layer 15 and the tubular portion 25 are pressure-bonded are connected to the pair of crimpers 101 and the anvil 103. Can be compressed at once. Moreover, you may compress these parts separately.
9 shows an example in which the inner diameter of the cylindrical portion 27 (the diameter of the space inside the water absorbing member 52) and the outer diameter of the electric wire 13 are substantially equal, and there is almost no space around the electric wire 13. The scope of the invention is not limited to this. In the state where the outer diameter of the electric wire 13 is smaller than the inner diameter of the cylindrical portion 27 (the diameter of the space inside the water absorbing member 52) and there is a gap around the electric wire 13, it can be crimped as shown in FIG. . Also in this case, the diameter of the cylindrical portion 27 is reduced by the compression, and the cylindrical portion 27, the water blocking member 51 or the water absorbing member 52, and the conductor insulating layer 15 are brought into close contact with each other.
And the tubular terminal 11 after crimping | combination comprises the electric wire connection structure 10 with the electric wire 13. FIG.

  In the wire connection structure 10 manufactured in this way, the tubular portion 25 undergoes plastic deformation and is reduced in diameter by the crimping process shown in FIG. 9, so that the core wire tip portion 14 b of the core wire 14 becomes the tubular terminal 11. Be joined. As shown in FIG. 2, serrations 33 are fitted to the core wire tip end portion 14 b and are more firmly joined. The conductor crimping reduced diameter portion 35 is a portion having the highest diameter reduction ratio in the tubular caulking portion 30. As shown in FIGS. 1 and 2, in the tubular caulking portion 30, the diameter reduction ratios of the conductor crimping reduced diameter portion 35 and the coated crimping reduced diameter portion 36 are different, but the crimping wall 102 and the receiving portion 104 in the depth direction are different. By adjusting the shape and depth according to the conductor crimping reduced diameter portion 35 and the coated crimping reduced diameter portion 36, the tubular caulking portion 30 can be configured with a necessary diameter reduction ratio by a single crimping process.

  The tubular caulking portion 30 is required to have a function of maintaining the electrical conductivity by strongly compressing the core wire 14 and a function of maintaining the sealing performance by compressing the conductor insulating layer 15. In the coated crimped reduced diameter portion 36, the cross section thereof is caulked into a substantially circular shape, and by applying substantially the same pressure over the entire circumference of the conductor insulating layer 15, a uniform elastic repulsive force is generated over the entire circumference. It is preferable to obtain a sealing property. However, in the actual crimping process, as shown in FIG. 3, since the anvil 103 and the crimper 101 are clamped from above and below, the metal material of the tubular terminal 11 protrudes into the gap between the two tools. Occur. More specifically, the behavior in which the tubular terminal 11 protrudes from the contact portion between the edge portion 105 of the anvil 103 and the crimping wall 102 occurs. This behavior occurs because the compression space formed between the anvil 103 and the crimper 101 does not become a perfect circle, and can occur regardless of the size of the anvil 103. That is, FIG. 9 shows the case where the width A of the anvil 103 is larger than the lateral width B of the tubular terminal 11, but even if the size of the width A of the anvil 103 is smaller than the lateral width B of the tubular terminal 11, This behavior can occur.

For this reason, as shown in FIG. 3, the shape of the inner surface of the coated crimping reduced diameter portion 36 in the cross-section is not a substantially circular shape, and the portions 37 and 37 corresponding to the gaps between the tools protrude to the outside. End up. Since the protrusions of the portions 37 and 37 occur at the contact positions of the crimper 101 and the anvil 103, they occur along the depth direction of the crimper 101 and the anvil 103. Therefore, in the tubular caulking portion 30, a similar bulge occurs in the conductor crimping reduced diameter portion 35, and this bulge extends in the axial direction of the tubular caulking portion 30.
At positions corresponding to the portions 37, 37, the pressure from the coated crimping reduced diameter portion 36 to the conductor insulating layer 15 is insufficient, and a gap is generated between the inner surface of the coated crimped reduced diameter portion 36 and the surface of the conductor insulating layer 15. There is a concern that moisture may enter the tubular caulking portion 30 from the side of the electric wire insertion port 31 as this gap becomes a leak path.
When moisture adheres to the joint between the metal base (copper or copper alloy) of the tubular terminal 11 and the core wire 14, the core wire 14 corrodes due to the difference in electromotive force (ionization tendency) between the two metals. Further, even if the tubular terminal 11 and the core wire 14 are made of aluminum, their joints are easily corroded due to a subtle difference in alloy composition. For this reason, in the configuration in which moisture enters the inside of the tubular caulking portion 30 in the wire connection structure 10, the progress of corrosion is a concern.

In the present embodiment, the tubular caulking portion 30 has a weld bead 43 welded when the tubular portion 25 is formed. Depending on the welding conditions, sink marks may occur in the weld bead 43, the thickness of the weld bead 43 is reduced, and the bead of the weld bead 43 forms an irregular concavo-convex structure instead of a smooth inner surface. There is also concern that the inner surface near 43 becomes a leak path.
Further, since the strength of a portion adjacent to the weld bead 43 and affected by heat due to welding is reduced, the weld bead 43 and the vicinity thereof are subjected to inhomogeneous deformation at the time of the crimping process. There is a possibility of becoming.
Further, in the crimping process of the anvil 103 and the crimper 101 from above and below, the pressure on the lower side (anvil 103 side) of the tubular caulking portion 30 tends to be stronger than the upper side (the crimper 101 side). The elastic repulsion force of the conductor insulating layer 15 sometimes became stronger on the lower side (anvil 103 side) than on the upper side (crimper 101 side). For this reason, the elastic repulsive force on the upper side (crimper 101 side) of the tubular caulking portion 30 is insufficient, and the entire interface area between the conductor insulating layer 15 and the tubular caulking portion 30 on the upper side may become a leakage path.

  In the electric wire connection structure 10 and the electric wire connection structures 10A to 10E according to the present embodiment, the weld bead 43 and the parts are arranged by disposing a water absorbing member in the tubular caulking portion 30 to which the tubular terminal 11 and the electric wire 13 are crimped. Even if moisture enters from the gap generated due to 37, 37, the moisture can be prevented from entering the conductor crimping reduced diameter portion 35 and corrosion of the core wire 14 can be suppressed.

10 and 11 are explanatory views showing a method for manufacturing the tubular terminal 11.
FIG. 10A is a cross-sectional view in the longitudinal direction of the tubular terminal 11, and FIG. 10B shows the chain terminal 151 before the tubular terminal 11 is formed by bending, and each part of the tubular terminal 11 and the chain terminal 151. Is shown by a broken line. For convenience of understanding, the surfaces of the water stopping member 51 and the water absorbing member 52 are indicated by hatching.
In manufacturing the tubular terminal 11, first, the chain terminal 151 is formed by punching the strip 150 which is a long metal plate. The strip 150 is formed into a tape shape by applying a treatment such as plating or surface coating to a metal material (copper or copper alloy in this embodiment) in advance. As shown in FIG. 10 (B), the chain terminal 151 has a shape in which a plurality of terminal molded pieces 160 each forming one tubular terminal 11 are arranged, and each terminal molded piece 160 is connected by a tape-like connecting tape 164. It has become. Since the chain terminal 151 is formed by punching the strip 150, it has a flat plate shape. When the chain terminal 151 is punched from the strip 150, a positioning hole 165 indicating the position of each terminal molding piece 160 is punched into the connecting tape 164 at the same time.
The terminal molding piece 160 includes a box molding portion 161 that is molded into the box portion 20 by bending, and a spring molding portion 162 that is connected to the box molding portion 161 and is molded into a spring inside the box portion 20 by bending. . Further, the box forming portion 161 is connected to a tubular forming portion 163 that is formed into a tubular portion 25 by bending.
After punching the chain terminal 151 from the strip 150, each of the chain terminal 151 is bent or bent to obtain a plurality of tubular terminals 11 connected by the connecting tape 164. By disconnecting each tubular terminal 11 from the connecting tape 164, the tubular terminal 11 is completed.

The serrations 33 provided inside the tubular portion 25 can be formed by press processing or the like on the chain terminal 151 or the strip 150 before punching.
The water blocking member 51 and the water absorbing member 52 can be arranged in the state of the chain terminal 151. That is, when the tubular forming portion 163 is formed into the tubular portion 25, the water-stop member 51 and the water-absorbing member 52 are attached in advance to a portion corresponding to the tubular portion 27 by a method such as application or sticking. If the tubular molded portion 163 is bent to form the tubular portion 25, the annular water stop member 51 and the water absorbing member 52 are already formed on the inner peripheral surface of the tubular portion 27 when the tubular portion 25 is formed. The

The water stopping member 51 and the water absorbing member 52 may be attached to the strip 150 before the chain terminal 151 is punched out.
For example, as shown in FIG. 11 (A), the water stop member 51 and the water absorbing member 52 can be attached to the positions where the tubular molded portion 163 is to be formed after punching in the strip 150. If this method is used, the water-stopping member 51 and the water-absorbing member 52 can be used without waste, and the water-stopping member 51 and the water-absorbing member 52 are less likely to adhere to the mold during punching.
Further, as shown in FIG. 11B, the water stop member 51 and the water absorbing member 52 may be attached to the entire region extending in the longitudinal direction of the strip 150 regardless of the position of the terminal molding piece 160. Since the water stop member 51 and the water absorption member 52 may be disposed along the peripheral surface of the cylindrical portion 27, the water stop member 51 and the water absorption member 52 can be disposed in the entire longitudinal direction of the strip 150 as shown in FIG. In this case, the position where the water blocking member 51 and the water absorbing member 52 are attached in the width direction of the strip 150 may be controlled, and positioning in the longitudinal direction of the strip 150 is not necessary.

  In addition, as a method of forming the tubular portion 25 by bending the tubular molded portion 163, as described above, there is a method in which both ends of the tubular molded portion 163 are abutted and joined by laser welding. It is not limited to. Hereinafter, another example of the joining method of the tubular molded portion 163 will be described.

FIG. 12 is a diagram showing a configuration of a tubular terminal 11A as another configuration example of the tubular terminal. 12A is a perspective view, and FIG. 12B is a cross-sectional view of a main part.
The tubular terminal 11 </ b> A has a box portion 20 similar to the tubular terminal 11. For convenience of understanding, the box unit 20 is indicated by a virtual line.
11 A of tubular terminals have the tubular part 25A connected with the box part 20 via the transition part 40A. The tubular portion 25A includes an enlarged diameter portion 26A that gradually increases in diameter from the transition portion 40A, and a cylindrical portion 27A that extends in a cylindrical shape from the edge of the enlarged diameter portion 26A. The tubular portion 25A is a hollow tube, and an electric wire insertion port 31 into which the electric wire 13 can be inserted is opened at one end of the tubular portion 25A. The other end of the tubular portion 25A is connected to the transition portion 40A. The electric wire 13 is inserted into the tubular portion 25A from the electric wire insertion port 31 and the tubular portion 27A is compressed by a crimping tool, whereby the tubular terminal 11 and the electric wire 13 are crimped and joined to form an electric wire connection structure.

  For example, the tubular portion 25A is formed by bending the tubular molded portion 163 into a C-shaped cross section. Here, the end portion of the tubular molded portion 163 is further bent at a substantially right angle, and the rising portions 45 and 45 are formed at the joint portion. Therefore, when the tubular portion 25A is a closed tube, the side surfaces of the rising portion 45 are abutted and joined. When joining the rising portions 45, 45 by laser welding, since there is a depth of the joining portion (rising portion) in the laser irradiation direction, as shown in FIG. 12B, the weld bead 43A is formed of the tubular portion 25A. It stays outside and does not reach the inner surface of the tubular portion 25A.

As described with reference to FIGS. 10 to 11, when the water stop member 51 and the water absorbing member 52 are arranged before the tubular portion 25 </ b> A is formed into a tubular shape, the inner peripheral surface of the tubular portion 25 </ b> A is exposed to a high temperature by laser welding. Then, there is a possibility that the water stopping member 51 and / or the water absorbing member 52 is deteriorated. Therefore, as shown in FIG. 12, when the tubular molded portion 163 is provided with a rising portion 45 and welding is performed by irradiating a laser from the rising portion 45 (outer surface of the tubular portion 25A) side, the temperature becomes high due to welding. Thus, the portion that dissolves does not reach the inner surface of the tubular portion 25A. For this reason, there exists an advantage that 25 A of tubular parts can be shape | molded, without affecting the water stop member 51 and the water absorption member 52 which have already adhered.
Further, in order to reliably close the distal end portion of the tubular portion 25A in the transition portion 40A, the distal end welded portion 44 may be formed by applying laser welding to the transition portion 40A.

FIG. 13 is a diagram showing a configuration of a tubular terminal 11B as another configuration example of the tubular terminal. FIG. 13A is a perspective view, and FIG.
This tubular terminal 11 </ b> B has a box portion 20 similar to the tubular terminal 11. For convenience of understanding, the box unit 20 is indicated by a virtual line.
The tubular terminal 11B has a tubular part 25B connected to the box part 20 via the transition part 40B. The tubular portion 25B includes an enlarged diameter portion 26B that gradually increases in diameter from the transition portion 40B, and a cylindrical portion 27B that extends in a cylindrical shape from the edge of the enlarged diameter portion 26B. The tubular portion 25B is a hollow tube, and an electric wire insertion port 31 into which the electric wire 13 can be inserted is opened at one end of the tubular portion 25B. The other end of the tubular portion 25B is connected to the transition portion 40B. The electric wire 13 is inserted into the tubular portion 25B from the electric wire insertion port 31, and the tubular portion 27B is compressed by a crimping tool so that the tubular terminal 11 and the electric wire 13 are crimped and joined to form an electric wire connection structure.

The tubular portion 25B is configured, for example, by bending the tubular molded portion 163 into a C-shaped cross section. At this time, the end portions of the tubular molded portion 163 are overlapped with each other to form the overlapping portion 46. By irradiating the overlapping portion 46 with laser from the overlapping direction, the tubular portion 25B is closed. When the overlapping portion 46 is joined by laser welding, since the two plate materials are overlapped in the laser irradiation direction, the weld bead 43B remains outside the tubular portion 25B as shown in FIG. It does not reach the inner surface of the portion 25B.
For this reason, since the laser welding does not expose the inner peripheral surface of the tubular portion 25B to a high temperature, welding can be performed without causing alteration of the water-stopping member 51 and the water-absorbing member 52. And the tubular portion 25B can be formed without affecting the water absorbing member 52. Further, since the overlapping portion 46 can be realized without increasing the number of bending steps, the influence on the productivity of the tubular terminal 11B is negligible.
Also in this case, since the distal end portion of the tubular portion 25B is reliably closed in the transition portion 40B, the distal end weld portion 44 may be formed by performing laser welding on the transition portion 40B.

Next, the 2nd manufacturing method of an electric wire connection structure is demonstrated.
FIG. 14 is an explanatory view showing a second manufacturing method of the wire connection structure 10. This second manufacturing method is suitable for manufacturing the wire connection structure 10 and the wire connection structures 10A, 10B, 10C, 10D, and 10E.
FIG. 14 is a perspective view showing configurations of the tubular terminal 11 and the electric wire 13 to be joined. As shown in FIG. 14, in the second manufacturing method, a water stop member 51 and a water absorption member 52 are provided on the conductor insulating layer 15 at the tip end portion of the electric wire 13. The water-stop member 51 and the water-absorbing member 52 are arranged by winding the electric wire 13 through the water-stop member 51 and the water-absorbing member 52 that are formed around the conductor insulating layer 15 or formed in an annular shape. Further, the step of arranging the water blocking member 51 and the water absorbing member 52 may be performed after the step of peeling the conductor insulating layer 15 in order to expose the core wire 14 or may be performed before this step. 14 shows a configuration in which the water stop member 51 and the water absorption member 52 are in close contact with the outer peripheral surface of the conductor insulation layer 15, but the inner diameters of the water stop member 51 and the water absorption member 52 are outside the conductor insulation layer 15. It may be larger than the diameter. That is, in the state shown in FIG. 14, there may be a gap between the water stopping member 51 and the water absorbing member 52 and the conductor insulating layer 15. Whether or not to stop the water-stopping member 51 and the water-absorbing member 52 on the conductor insulating layer 15 is arbitrary, and the water-stopping member 51 and the water-absorbing member 52 are disposed at desired positions when the electric wire 13 is inserted into the electric wire insertion port 31. I can do it.

  Thus, the electric wire connection structures 10, 10 </ b> A to 10 </ b> E to which the present invention is applied are obtained by pressure-bonding the electric wire 13 having the core wire 14 and the conductor insulating layer 15 formed on the outer periphery of the core wire and the tubular terminal 11. The water absorbing members 52, 52 A, 52 B, 52 C are arranged on at least a part of the outer surface of the conductor insulating layer 15, and the water absorbing members 52, 52 A, 52 B, 52 C are not in contact with the core wire 14. Thereby, the penetration | invasion of the water | moisture content to the inside of the tubular crimping part 30, especially the conductor crimping | compression-reducing diameter part 35 which the core wire 14 exposed can be prevented more reliably. Therefore, corrosion of the core wire 14 in the conductor crimping reduced diameter portion 35 can be suppressed.

Next, examples will be described.
Example 1
The wire connection structure of Example 1 uses the form (a) of the wire connection structure 10 shown in FIG. 2, and the copper alloy FAS-680 (thickness 0. 25 mm, H material). The alloy composition of FAS-680 is nickel (Ni) 2.0-2.8 mass%, silicon (Si) 0.45-0.6 mass%, zinc (Zn) 0.4-0.55. It contains 0.1% to 0.25% by mass of tin (Sn) and 0.05 to 0.2% by mass of magnesium (Mg), with the balance being copper (Cu) and inevitable impurities.
The tubular portion 25 was subjected to laser welding so that both end portions of the bent C-shaped cross section were butted to have an inner diameter of 3.2 mm.

  The core wire 14 of the electric wire 13 has an alloy composition of about 0.2% by mass of iron (Fe), about 0.2% by mass of copper (Cu), about 0.1% by mass of magnesium (Mg), and silicon (Si). Is about 0.04 mass%, the balance is aluminum (Al) and an aluminum alloy wire (wire diameter 0.42 mm) which is an unavoidable impurity. 19 strands 14a were used to form a core wire 14 of 2.5 sq, 19 strands. Moreover, the conductor insulating layer 15 of the electric wire 13 used the ethylene vinyl acetate copolymer as halogen-free resin. The conductor insulating layer 15 was formed by an extrusion method around the core wire 14 so that the outer diameter was 2.8 mm.

  The electric wire 13 peeled off the conductor insulating layer 15 at the end of the electric wire using a wire stripper to expose the core wire 14. In this state, the electric wire 13 was inserted into the tubular portion 25 of the tubular terminal 11, and the tubular portion 27 of the tubular portion 25 was partly strongly compressed by using the crimper 101 and the anvil 103 to be bonded by pressure bonding.

  The water absorbing member and the water stopping member are configured as the water stopping member 51 and the water absorbing member 52 shown in FIG. As the water absorbing member 52, an aqua pearl (registered trademark) E-200 (0.1 mm thickness) manufactured by Sanyo Chemical Industries, Ltd., which is a non-woven fabric coated with a highly water-absorbing resin, which is a crosslinked polyacrylate, is circular. What was made into was used. Moreover, as the water stop member 51, a silicon rubber sheet (0.1 mm thickness) was used.

In the environmental test, two types of tests 1 and 2 were performed in the following procedure.
(Test 1)
The tubular terminal 11 of the electric wire connection structure 10 was inserted into the cavity, the electric wire side was set to the ceiling, and the terminal side was directed to the ground.
In the salt spray test, 5% by weight salt water was adjusted to 35 ° C. and sprayed continuously for 1000 hours.
Thereafter, the electrical resistance between the conductor crimping reduced diameter portion 35 and the end portion of the core wire 14 on the side where the tubular terminal 11 is not attached was measured using a four-terminal method. Furthermore, after measuring the electrical resistance, the tubular terminal 11 was disassembled, and the corrosion (deterioration) state of the core wire 14 in the tubular caulking portion 30 was visually confirmed and evaluated. The measurement of the electrical resistance by the above four-terminal method was performed before the environmental test, and the change in the electrical resistance before and after the environmental test was evaluated.

(Test 2)
One end of the electric wire 13 and the tubular terminal 11 were respectively gripped, and the operation of bending the electric wire 13 at the end of the tubular terminal 11 was repeated to give a bending load 100 times.
Next, the tubular terminal 11 was inserted into the cavity, and the electric wire side was set to the ceiling and the terminal side was directed to the ground. In the salt spray test, 5% by weight salt water was adjusted to 35 ° C. and sprayed continuously for 1000 hours.
Thereafter, the electrical resistance between the conductor crimping reduced diameter portion 35 and the end portion of the core wire 14 on the side where the tubular terminal 11 is not attached was measured using a four-terminal method. Furthermore, after measuring the electrical resistance, the tubular terminal 11 was disassembled, and the corrosion (deterioration) state of the core wire 14 in the tubular caulking portion 30 was visually confirmed and evaluated. The measurement of the electrical resistance by the above four-terminal method was performed before the environmental test, and the change in the electrical resistance before and after the environmental test was evaluated.

(Example 2)
The form (b) of the wire connection structure 10A shown in FIG. 4 (A) was used. That is, the water stop member 51 and the water absorption member 52 are arranged one by one. Other conditions and environmental tests were the same as in Example 1.

(Example 3)
The form (c) of the wire connection structure 10B shown in FIG. 4 (B) was used. That is, one water absorbing member 52 is arranged without arranging the water stopping member 51. Other conditions and environmental tests were the same as in Example 1.

Example 4
The form (d) of the wire connection structure 10C shown in FIG. 5 (A) was used. That is, the water absorbing member 52 </ b> A that is disposed across the inside and outside of the tubular caulking portion 30 without using the water stopping member 51 is used. Other conditions and environmental tests were the same as in Example 1.

(Example 5)
The form (e) of the wire connection structure 10D shown in FIG. 5 (B) was used. That is, the water absorbing member 52 </ b> B that contacts the outside of the tubular caulking portion 30 without using the water stopping member 51 is used. Other conditions and environmental tests were the same as in Example 1.

(Example 6)
The form of the wire connection structure 10E (f) shown in FIG. 6 was used. That is, the water-stop member 51 is disposed on the transition portion 40 side and the water-absorbing member 52 is disposed on the wire insertion port 31 side in the inside of the coated crimping reduced diameter portion 36. Other conditions and environmental tests were the same as in Example 1.

(Comparative Example 1)
As shown in FIG. 15 (A), the wire connection structure of Comparative Example 1 used the form (g) of the wire connection structure 12A in which the water absorbing member is not disposed. The wire connection structure 12 </ b> A is obtained by eliminating the water absorbing member 52 in the wire connection structure 10 shown in FIG. 2 and arranging a water stop member 51 </ b> A inside the coated crimping reduced diameter portion 36. The water stop member 51 </ b> A was formed in an annular shape covering the outer periphery of the conductor insulating layer 15 from the tip position of the conductor insulating layer 15 to the wire insertion port 31. The material of the water stop member 51A was the same as that of the water stop member 51 of Example 1. Other conditions were the same as in Example 1. Tests 1 and 2 were performed in the same manner as in Example 1 by using this wire connection structure 12A.

(Comparative Example 2)
As shown in FIG. 15 (B), the electric wire connection structure of Comparative Example 2 has a configuration (h) of the electric wire connection structure 12B in which the water absorbing member 52C is arranged inside the coated crimping reduced diameter portion 36 and the water stop member is not arranged. ) Was used. The wire connection structure 12B eliminates the water-stopping member in the wire connection structure 10 shown in FIG. 2, and the water-absorbing member so as to straddle the conductor insulating layer 15 and the core wire 14 inside the coated crimping reduced diameter portion 36. 52C is arranged. That is, the water absorbing member 52 </ b> C has a configuration that surrounds the outer periphery of the core wire 14 that is exposed when the conductor insulating layer 15 is peeled off and the tip of the conductor insulating layer 15. The material of the water absorbing member 52C was the same as that of the water absorbing member 52 of Example 1. Other conditions were the same as in Example 1. Tests 1 and 2 were performed in the same manner as in Example 1 by using this wire connection structure 12B.

(Comparative Example 3)
As shown in FIG. 15C, the wire connection structure of Comparative Example 3 is a form (i) of the wire connection structure 12C in which the water stop member 51 and the water absorption member 52 of the wire connection structure 10 (FIG. 2) are not arranged. ) Was used. Other conditions were the same as in Example 1. Tests 1 and 2 were performed in the same manner as in Example 1 using the wire connection structure 12C.

Table 1 shows the test results of Examples 1 to 12 and Comparative Examples 1 and 2 described above.
In Table 1, the corrosion test observation evaluation was divided into four stages and evaluated.
<Corrosion test observation evaluation>
The corrosion state of the core wire 14 in the tubular caulking portion 30 was visually evaluated in four stages A to D.
◎… No corrosion.
○: Discoloration of the surface is seen on part of the core wire
Δ: Corrosion is observed on a part of the core wire.
X: Most of the core wire is corroded.
In this evaluation, 80% or more of the exposed conductor (core wire) surface is discolored (corroded), and most of the surface is less than 10%.

  As shown in Table 1, in Examples 1 to 6 in which the water absorbing members are arranged, only the core wire 14 was discolored in the corrosion tests of Test 1 and Test 2, and excellent corrosion that attention should be paid was not observed. Results were obtained. Further, in Comparative Example 1, a favorable result was obtained in Test 1 by arranging the water-stop member 51A, but in the more severe Test 2, corrosion of the core wire 14 was observed. In Comparative Example 2, a water absorbing member was disposed, but in Test 2, corrosion of the core wire 14 occurred. From these results, it has been clarified that the corrosion of the core wire 14 can be effectively suppressed by arranging the water absorbing member in the tubular caulking portion 30 which is a crimping portion for crimping and joining the tubular terminal 11 and the electric wire 13. Further, from the comparison of the results of Examples 1 to 6 and Comparative Example 2, when the water absorbing member is arranged in the tubular caulking portion 30 so as not to contact the core wire 14 from which the conductor insulating layer 15 has been peeled off, the core wire 14 It can be said that it is possible to significantly suppress corrosion of the steel.

10 Wire connection structure 11, 11A, 11B Tubular terminal (terminal)
13 Electric wire 14 Core wire 15 Conductor insulation layer 20 Box part 25, 25A, 25B Tubular part (part to be crimped)
27, 27A, 27B Cylinder part 30 Tubular caulking part (crimp part)
33 Serration 35 Conductor crimping reduced diameter part 36 Covering crimping reduced diameter part 40, 40A, 40B Transition part 51, 51A, 51B Water stop member 52, 52A, 52B, 52C Water absorption member

Claims (12)

An electric wire connection structure in which an electric wire having a core wire and a conductor insulating layer formed on the outer periphery of the core wire, and a tubular terminal made of a conductor are pressure-bonded,
A wire connection structure, wherein a water absorbing member is disposed on at least a part of an outer surface of the conductor insulating layer, and the water absorbing member does not contact the core wire.   The wire connection structure according to claim 1, wherein the water absorbing member is disposed between the conductor insulating layer and the tubular terminal.   The wire connection structure according to claim 1 or 2, wherein the tubular terminal has an electric wire insertion opening, and the water absorbing member is disposed so as to be in close contact with the electric wire insertion opening and the conductor insulating layer.   4. The water stop member is further disposed between the conductor insulating layer and the tubular terminal, and the water stop member and the water absorption member are disposed adjacent to each other. The electric wire connection structure of crab.   The electric wire connection structure according to claim 4, wherein the water absorbing member is disposed so as to be sandwiched between the water stopping members in the axial direction.   The wire connection according to claim 4 or 5, wherein one end of the tubular terminal is closed, and the water stop member is disposed between the tubular terminal and the wire at the other end of the tubular terminal. Structure.   The wire connection structure according to any one of claims 1 to 6, wherein the water absorbing member is made of a water absorbing material that adsorbs and holds water.   The wire connection structure according to any one of claims 4 to 6, wherein the water stop member is made of a material having elasticity or plasticity.   The wire connection structure according to any one of claims 1 to 8, wherein the water absorbing member is a water absorbing resin or a sheet-like water absorbing member containing a water absorbing resin.   The wire connection structure according to any one of claims 1 to 12, wherein the tubular terminal is made of copper or a copper alloy, and the core wire is made of aluminum or an aluminum alloy.   A terminal having a tubular crimping portion to be bonded together by being crimped together with an electric wire, and a water absorbing member disposed in the crimping portion.   The terminal according to claim 11, wherein the water absorbing member is arranged in an annular shape along an inner peripheral surface of the to-be-crimped portion at least at a part in the axial direction of the to-be-crimped portion.

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