JP2014164956A - Electric wire connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric wire connection structure capable of inhibiting water from infiltrating into a tube-shaped terminal while achieving down-sizing of a connector.SOLUTION: An insulation layer of a crimp part of an electric wire 13 crimped together with a tube-shaped terminal is formed as a coating layer of two layers or more including a water repellent layer 44 in the outermost layer, and the electric wire 13 having the coating layer and the tube-shaped terminal are crimped together. At this time, since only the water repellent layer 44 is provided, the crimp part of the tube-shaped terminal becomes compact.

Description

  The present invention relates to a component responsible for electrical continuity, and more particularly to an electric wire connection structure including an electric wire and a tubular terminal connected to an end portion of the electric wire.

  Conventionally, in an electric wire formed by covering a core wire with an insulator, a metal terminal is crimped and connected to the end portion of the core wire that is exposed by peeling off the insulator. In the conventional connection structure between an electric wire and a terminal, the surface of the end portion of the core wire from which the insulator is peeled is exposed, so that there is a problem that the core wire is easily corroded when the electric wire is exposed to rainwater or the like.

  For example, in the case of wire harnesses used in automobiles, in recent years, the core wire material has been replaced with aluminum-based materials such as aluminum or aluminum alloys in order to reduce the weight for the purpose of improving the fuel efficiency of automobiles. It has been. For this reason, when a core wire made of an aluminum-based material is crimped to a terminal, aluminum, which is a base metal, is brought into contact with a noble metal such as tin plating, gold plating, or copper alloy of the terminal material through water. There is a problem that a product life is shortened due to a phenomenon that a system material is corroded (that is, electric corrosion).

  As an electric wire connection structure with such countermeasures against water, (1) an outer peripheral surface of a conductor of an electric wire and an inner peripheral surface of a covering material are covered with a water-repellent coating (for example, see Patent Document 1) (2) One in which a water-swelling water-stopping material is provided at the attachment portion of the tubular body to the piping box (for example, see Patent Document 2), (3) One in which a urethane foam material is used as a waterproof seal (for example, Patent Document 3) References) and (4) are known in which a sealing body made of a water-absorbing elastomer is fitted into an electric wire inserted into a connector housing (see, for example, Patent Document 4).

JP 2007-52991 A JP 2007-262841 A Japanese Patent Laid-Open No. 2005-150009 JP 2001-313113 A

In each said patent document, the water stop countermeasure is not taken between the crimped | bonded terminal and the insulation part of an electric wire.
For example, when a tubular terminal is used as a terminal to be crimped to an electric wire, one end of the tubular terminal on the distal end side of the core wire from which the insulating portion of the electric wire is peeled is closed, so that water is Although it does not enter the inside, there is a wire insertion port on the other end portion side of the tubular terminal, and there is a possibility that water may enter from between the crimped tubular terminal and the insulating portion of the wire.
Therefore, if the water stop material is interposed between the crimped tubular terminal and the insulating portion of the electric wire, the crimped portion becomes large, and when the tubular terminal is assembled to the connector, the connector is enlarged.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide an electric wire connection structure capable of suppressing water intrusion into a tubular terminal while reducing the size of a connector. .

In order to solve the above-described problems, the present invention provides an electric wire connection structure in which a tubular terminal and an electric wire are crimped, and an insulating layer of the electric wire in a crimping portion between the tubular terminal and the electric wire, and a water repellent layer as an outermost layer. It is characterized by using two or more coating layers containing
According to this configuration, water can be repelled by the water repellent layer of the insulating layer, so that water can be prevented from entering the crimping portion between the tubular terminal and the electric wire, and core wire corrosion can be prevented. At this time, since only the water repellent layer is provided on the insulating layer, the crimping portion of the tubular terminal can be reduced in size, and the connector can be reduced in size. In addition, a water-repellent layer can be easily formed on the surface of an electric wire on which an inner layer is formed as an insulating layer before the tubular terminal is crimped to the electric wire.

The said structure WHEREIN: It is good also considering the said insulating layer of the said crimping | compression-bonding part as a coating layer which contains an oil-fat layer or a silicon resin layer in an outermost layer, and a halogen-free resin layer in an inner layer. According to this structure, it can be made water-repellent by an oil-fat layer or a silicon resin layer.
In the above configuration, the insulating layer of the pressure-bonding portion may be a coating layer including an oil and fat layer, a silicon resin layer or a fluororesin layer as an outermost layer, and a polyvinyl chloride layer as an inner layer. According to this structure, it can be made water-repellent with an oil-and-fat layer, a silicon resin layer, or a fluororesin layer.

Moreover, the said structure WHEREIN: As the said tubular terminal, you may use the terminal which shape | molded the strip in the cylinder shape and made the seam the sealing structure by welding. According to this configuration, even if a gap is formed between the welded portion of the tubular terminal and the insulating layer, the water-repellent layer repels water and blocks the movement of water from the gap, so that water enters the tubular terminal. Can be suppressed.
In the above-described configuration, the tubular terminal may be made of copper or a copper alloy, and the wire conductor of the electric wire conducting to the tubular terminal may be made of aluminum or an aluminum alloy. According to this structure, it can prevent that water intervenes between a tubular terminal and an electric wire conductor, and can prevent corrosion of an electric wire conductor.

  In the present invention, the insulating layer of the electric wire in the crimping portion between the tubular terminal and the electric wire is made of two or more coating layers including a water-repellent layer as the outermost layer. Infiltration of water at the crimping portion between the tubular terminal and the electric wire can be suppressed, and core wire corrosion can be prevented. At this time, since only the water repellent layer is provided on the insulating layer, the crimping portion of the tubular terminal can be reduced in size, and the connector can be reduced in size. Moreover, a water-repellent layer can be easily formed on the surface of the electric wire on which the inner layer is formed as an insulating layer before the tubular terminal is crimped to the electric wire.

It is a perspective view which shows the electric wire connection structure of one Embodiment. It is principal part sectional drawing of the longitudinal direction of an electric wire connection structure. It is a perspective view which shows the tubular terminal and electric wire before crimping. It is explanatory drawing explaining extrusion molding of the insulation part of an electric wire, and formation of the water repellent layer of an insulation part. It is an operation | movement figure which shows the effect | action which inserts an electric wire in a tubular terminal.

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 and an electric wire 13 crimped to the tubular terminal 11. The tubular terminal 11 includes a female terminal box portion 20 and a tubular caulking portion 30, and includes 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.
The electric wire 13 is configured, for example, by covering a core wire 14 in which metal or alloy wires 14a are bundled with an insulating portion 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 tubular caulking part 30 is a part for crimping the tubular terminal 11 and the electric wire 13 and includes a conductor crimping reduced diameter part 35 and a coated crimping reduced diameter part 36.
Normally, when crimped, the conductor crimping reduced diameter portion 35 and the coated crimping reduced diameter portion 36 are each plastically deformed and are reduced in diameter from the original diameter, thereby causing the core wire tip portion 14b and the sheath tip portion ( Crimped to the crimping portion 15a.
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.

The tubular caulking portion 30 is formed, for example, by punching a strip made of copper or a copper alloy into a flattened shape and bending it. In this case, the box portion 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 The tubular caulking portion 30 is preferably joined by laser welding, but welding methods such as electron beam welding, ultrasonic welding, and resistance welding may also 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, thereby simultaneously ensuring electrical joining. 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 conductivity by strongly compressing the core wire 14 and a function of maintaining the sealing performance by compressing the insulating portion 15. In the coated crimping 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 insulating portion 15, a uniform elastic repulsive force is generated over the entire circumference, It is preferable to obtain a sealing property.

  When aluminum or an aluminum alloy is used for the core wire, the contact resistance is higher than when copper or a copper alloy is used, so 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.

A water repellent layer 44 is formed on the outer peripheral surface of the insulating portion 15 including the covering tip portion 15 a of the electric wire 13. The insulating portion 15 and the water repellent layer 44 constitute a covering layer (insulating layer) 47, and the electric wire 13 is composed of a core wire 14 and a covering layer 47 covering the core wire 14.
The water repellent layer 44 is a portion that suppresses the intrusion of water into the tubular terminal 11 from between the coated crimped reduced diameter portion 36 of the tubular caulking portion 30 and the coated distal end portion 15 a of the electric wire 13. For example, even if there is a slight gap between the coated crimping reduced diameter portion 36 and the coated distal end portion 15a in the vicinity of the wire insertion port 31 of the tubular terminal 11, water can be supplied to the gap by repelling water with the water repellent layer 44. Can be prevented from entering.

FIG. 3 is a perspective view showing the tubular terminal 11A and the electric wire 13 before being crimped.
11 A of tubular terminals before crimping have the box part 20 and the tubular part 25 of a female terminal, and have the transition part 40 as a bridge | bridging of these. The tubular portion 25 includes an enlarged diameter portion 26 that gradually increases in diameter from the transition portion 40, and a cylindrical portion 27 that extends in a cylindrical shape from an edge of the enlarged diameter portion 26.
The enlarged diameter portion 26 is formed with a conductor crimping reduced diameter portion 35 (see FIG. 1), and the cylindrical portion 27 is formed with a coated crimping reduced diameter portion 36 (see FIG. 1). The tubular terminal 11A is partially or entirely subjected to a treatment such as tin plating.

  The resin material constituting the insulating portion 15 of the electric wire 13 is polyvinyl chloride. Besides this polyvinyl chloride, for example, halogen-based resins mainly composed of crosslinked polyvinyl chloride, chloroprene rubber, polyethylene, Halogen-free resins mainly composed of crosslinked polyethylene, ethylene propylene rubber, silicon rubber, polyester, etc. are used, and these may contain additives such as plasticizers and flame retardants.

FIG. 4 is an explanatory view for explaining the extrusion molding of the insulating portion 15 of the electric wire 13 and the formation of the water repellent layer 44 of the insulating portion 15. 4A is an explanatory view showing the procedure for extrusion molding of the insulating portion 15 and the formation of the water repellent layer 44, FIG. 4B is an operation diagram showing the procedure for peeling off the end portion of the insulating portion 15, and FIG. ) Is a cross-sectional view showing a state after the water-repellent layer 44 is formed.
As shown in FIG. 4A, the electric wire 13 is manufactured by extruding resin melted by the resin extrusion device 50 continuously around the core wire 14.
The resin extrusion apparatus 50 includes a hollow portion 50a that penetrates and a resin supply path 50b that communicates with the hollow portion 50a, and the core wire 14 passed through the hollow portion 50a is indicated by a hollow arrow in its longitudinal direction. The molten resin serving as the insulating portion is supplied into the hollow portion 50a from the resin supply passage 50b while being moved at a constant speed. Thereby, molten resin is extruded one after another so that the core wire 14 may be surrounded, and the electric wire 13 is completed when a molten resin hardens | cures. If the oil and fat that becomes the water repellent layer 44 is supplied to the surface of the resin during the resin extrusion step, the electric wire 13 with the water repellent layer 44 formed immediately becomes.

  As shown in FIG. 4B, the finished electric wire 13 is subjected to a process of peeling off the end portion of the insulating portion 15 from the core wire 14 so as to be crimped to the tubular terminal 11A (see FIG. 3). Specifically, the pair of cutter blades 52, 52 arranged on both sides of the end portion of the electric wire 13 are brought close to each other as indicated by an arrow A, and dig into the insulating portion 15, and further in the state of being bitten. As shown by B, the wire 13 is moved in the longitudinal direction.

As a result, as shown in FIG. 4C, the end portion of the insulating portion 15 is peeled off from the core wire 14. The symbol LA in the figure is the length of the insulating portion 15 that is crimped to the tubular terminal 11A (the length from the end surface 15b of the insulating portion 15), and the length of the water repellent layer 44 (from the end surface 15b of the insulating portion 15). The length (L) is larger than the length LA of the insulating portion 15 to be crimped.
Thus, by satisfying L> LA, even if there is a production variation in the length LA of the crimped portion between the tubular terminal 11 (see FIG. 2) and the insulating portion 15, the water-repellent layer is reliably provided on the crimped portion. 44 can be formed. Moreover, it is possible to prevent water from collecting in the electric wire insertion port 31 (see FIG. 2) of the tubular terminal 11, and to further suppress the intrusion of water into the tubular terminal 11.

FIG. 5 is an operation diagram showing an operation of inserting the electric wire 13 into the tubular terminal 11A.
In the electric wire 13, the end portion of the insulating portion 15 is peeled off by a predetermined length, and a water repellent layer 44 is formed by applying grease to the entire outer peripheral surface of the end portion of the insulating portion 15. Is inserted into the tubular portion 25 of the tubular terminal 11A as indicated by an arrow. At this time, due to the lubricating action of the outer peripheral surface of the insulating portion 15 by the oil and fat, insertion can be performed smoothly even if the gap between the tubular portion 25 side and the electric wire 13 side is small, and assemblability can be improved.

As fats and oils that are components of the water repellent layer 44, the following are suitable.
(A) Water-insoluble cutting oil “Searching Cut AL-100” mainly composed of medium-chain chlorinated paraffin (sales: Kyowa Oil Lubricants Co., Ltd.)
(B) Water-insoluble oil “Kubitrak AL50” mainly composed of synthetic ester (sales: Toho International Co., Ltd.)
(C) “Metal Thin AS35” mainly composed of mineral oil
In addition to the above fats and oils, a fluororesin and a silicon resin are suitable as the water repellent layer.

For example, when a halogen-free resin is used for the insulating portion 15, an oil or a silicone resin layer is combined with the water repellent layer 44.
When polyvinyl chloride is used for the insulating portion 15, the water repellent layer 44 is combined with fats and oils, a silicon resin, or a fluororesin.

  As shown in FIGS. 2, 3, and 4 (B) above, the insulating layer of the crimping portion of the electric wire 13 as the electric wire to be crimped to the tubular terminal 11 </ b> A is composed of two or more layers including the water repellent layer 44 in the outermost layer. The electric wire 13 having the coating layer and the tubular terminal 11A were pressure-bonded.

According to this configuration, water can be repelled by the water repellent layer 44 of the insulating layer, so that water can be prevented from entering at the crimping portion between the tubular terminal 11 and the electric wire 13, and core wire corrosion can be prevented. At this time, since the water repellent layer 44 is only provided between the tubular terminal 11 and the electric wire 13, the crimping part of the tubular terminal 11 can be reduced in size, and the connector can be reduced in size.
Further, the water repellent layer 44 can be easily formed on the inner layer of the electric wire 13, that is, on the surface of the insulating portion 15, before the tubular terminal 11 </ b> A is crimped to the electric wire 13.

Moreover, since the insulating layer of the crimping portion is a coating layer containing an oil or fat layer or a silicon resin layer as the outermost layer and a halogen-free resin layer as the insulating portion 15 of the inner layer, it can be made water-repellent with the oil or fat layer or the silicon resin layer. .
Moreover, since the insulating layer of the crimping part is a coating layer containing an oil / fat layer, a silicon resin layer or a fluororesin layer as the outermost layer and a polyvinyl chloride layer as the insulating part 15 of the inner layer, the oil / fat layer, the silicon resin layer or the fluororesin Can be made water repellent in the layer.

In addition, since the tubular terminal 11A is a terminal in which a strip is formed into a cylindrical shape and a seam is formed by welding, a gap is formed between the welded portion of the tubular terminal 11A and the insulating portion 15. The water repellent layer 44 repels water and blocks the movement of water in the gap, thereby suppressing the ingress of water into the tubular terminal 11.
Further, since the tubular terminal 11A is made of copper or copper alloy and the core wire as the electric wire conductor is made of aluminum or aluminum alloy, it is possible to prevent water from intervening between the tubular terminal 11 and the core wire. Corrosion can be prevented.

The above-described embodiment is merely an aspect of the present invention, and can be arbitrarily modified and applied without departing from the gist of the present invention.
The present invention can be applied to a wire harness of an automobile, but is not limited to this, and may be applied to wiring of other vehicles or wiring of devices other than vehicles.

DESCRIPTION OF SYMBOLS 10 Electric wire connection structure 11, 11A Tubular terminal 13 Electric wire 14 Core wire (electric wire conductor)
15 Insulation part (inner layer)
44 Water repellent layer

Claims (5)

In the electric wire connection structure in which the tubular terminal and the electric wire are crimped,
An electric wire connection structure characterized in that an insulating layer of the electric wire in a crimping portion between the tubular terminal and the electric wire is a two or more coating layers including a water repellent layer as an outermost layer.   The electric wire connection structure according to claim 1, wherein the insulating layer of the crimping portion is a coating layer including an oil or fat layer or a silicon resin layer as an outermost layer and a halogen-free resin layer as an inner layer.   The wire connection structure according to claim 1, wherein the insulating layer of the crimping portion is a coating layer including an oil and fat layer, a silicon resin layer or a fluororesin layer as an outermost layer, and a polyvinyl chloride layer as an inner layer. .   The wire connection structure according to any one of claims 1 to 3, wherein the tubular terminal is a terminal in which a strip is formed into a cylindrical shape and a seam is formed into a sealed structure by welding.   The electric wire connection according to any one of claims 1 to 4, wherein the tubular terminal is made of copper or a copper alloy, and the electric wire conductor of the electric wire conducting to the tubular terminal is made of aluminum or an aluminum alloy. Structure.

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