JP2011204440A - Electric wire with terminal fitting and method of manufacturing the same - Google Patents

Abstract

An object of the present invention is to reliably prevent electrolytic corrosion at a connecting portion between an electric wire and a terminal fitting without using an anticorrosive agent.
An electric wire 10 in which a metal core wire 11 is covered with an insulation coating 13, a terminal fitting 20 made of a metal different from the core wire 11 and provided with an electric wire connecting portion 25 connected to the core wire 11, It is made of a metal that is close in ionization tendency to the terminal fitting 20, and is a thin wall that can be applied over the end of the insulation coating 13 left from the end of the core wire 11 exposed by peeling off the insulation coating 13 of the electric wire 10. An adherend 30 is provided. The adherend 30 is formed by winding a copper foil around a plurality of layers. The adherend 30 is joined to the core wire 11 of the electric wire 10 by ultrasonic welding, and the electric wire connection portion 25 of the terminal fitting 20 is crimped to the adherend 30.
[Selection] Figure 1

Description

  The present invention relates to an electric wire with a terminal fitting and a manufacturing method thereof.

  In recent years, aluminum electric wires have been used in the field of automobile wire harnesses and the like for the purpose of weight reduction and the like. An aluminum electric wire has, for example, a structure in which a core wire made of a twisted wire obtained by twisting a plurality of aluminum strands is covered with an insulating coating, and when a harness is formed, a terminal fitting is generally connected to the end of the electric wire. Specifically, the terminal end of the aluminum wire is peeled off to expose the end of the core wire, and the wire barrel (electric wire connecting portion) provided on the terminal fitting is crimped to the exposed end of the core wire. In addition, an insulation barrel provided behind the wire barrel is crimped and connected to the terminal of the insulation coating remaining together (for example, see Patent Document 1).

By the way, when conducting the electrical connection of the electric wire to the terminal fitting, when the core wire of the electric wire and the terminal fitting are formed of different kinds of metals, especially when moisture is present at the contact portion between the two, the two metals dissolve as ions in the water. It is known that galvanic corrosion occurs due to electrochemical reaction. Since terminal fittings are generally made of a copper alloy due to problems in strength and the like, if aluminum wires are used for the wires as described above, electrolytic corrosion is a problem. Specifically, at the portion where the wire barrel is crimped to the core wire, when dust or sand enters and the mixed salt adheres and moisture further adheres, the contact portion becomes immersed in the electrolyte solution, and ionization occurs. There is a possibility that aluminum which is a metal having a large tendency (base metal) is dissolved, that is, electrolytic corrosion proceeds.
Conventionally, therefore, electrolytic corrosion has been prevented by applying an anticorrosive agent made of silicone rubber, a chelating agent or the like to the crimped portion of the wire barrel.

JP-A-2005-50736

However, in the above-described method of applying the anticorrosive agent, it is necessary to change the application conditions depending on the pressure-bonding shape of the barrel, the thickness of the application layer varies, the quality is not stable, the care of peeling of the application layer is necessary, and There were a number of problems, such as inability to easily repair during maintenance, and the emergence of new countermeasures was anxious.
The present invention has been completed based on the above situation, and an object of the present invention is to reliably prevent electrolytic corrosion at the connection portion between the electric wire and the terminal fitting without using an anticorrosive agent.

  The electric wire with a terminal fitting of the present invention is an electric wire in which a metal core wire is covered with an insulation coating, a terminal fitting provided with an electric wire connecting portion that is made of a metal different from the core wire and is connected to the core wire, A thin adherend that is made of a metal that has a similar ionization tendency to that of the terminal fitting, and that can be applied to the end of the insulation coating remaining from the end of the core wire exposed by peeling off the insulation coating of the wire. And the adherend is joined to the core wire of the electric wire by ultrasonic welding, and the wire connection portion of the terminal fitting is crimped to the adherend.

The adherend is attached to the end of the insulation coating remaining from the end of the exposed core wire in the electric wire, and the adherend is joined to the core wire by ultrasonic welding, and the adherend generates heat at that time. As a result, it is welded to the insulation coating. The electrical connection between the core wire and the terminal fitting is taken by crimping the wire connecting portion of the terminal fitting to the adherend.
In the crimped portion of the wire connecting portion, the metals that are close to ionization tend to be in contact with each other. Therefore, even if moisture adheres, electrolytic corrosion is unlikely to occur. On the other hand, the dissimilar metals are in contact with each other between the inner surface of the adherend and the core wire. The adherend is welded to the insulating coating and sealed inside the contact portion, that is, the inner side of the adherend. As a result, inundation is prevented, so that electrolytic corrosion does not occur at the contact portion. As a result, it is possible to reliably prevent electrolytic corrosion at the connection portion between the electric wire and the terminal fitting without using an anticorrosive agent.

In addition, it is good also as following structures.
(1) While the electric wire is an aluminum electric wire having a core wire made of aluminum or aluminum alloy, the terminal fitting is made of copper alloy. Even when an aluminum electric wire that has a high possibility of electrolytic corrosion is used, the occurrence of electrolytic corrosion can be effectively prevented.
(2) The adherend is formed by winding a copper foil around a plurality of layers.

(3) The electric wire connecting portion is composed of two front and rear barrels, and the front barrel is crimped and crimped to an area of the adherend attached to the end of the electric wire and attached to the end of the core wire. The rear barrel is caulked and crimped to a region of the adherend that is attached to the end of the insulating coating.
The existing terminal fitting provided with the wire barrel and the insulation barrel can be applied as it is. Further, the seal between the adherend and the insulating coating is more reliably taken.

  (4) Moreover, as a manufacturing method of the electric wire with a terminal metal fitting, the electric wire connection part provided in the terminal of the said core wire in the electric wire which covered the metal core wire with the insulation coating, and the terminal metal fitting different from the said core wire Is a method of manufacturing an electric wire with a terminal fitting to which the terminal of the insulation coating of the electric wire is peeled to expose the end of the core wire, and the exposed end of the core wire of the electric wire is left. A step of attaching a thin adherend made of a metal having an ionization tendency close to that of the terminal fitting, a step of joining the adherend to the core wire by ultrasonic welding, The step of crimping the wire connection portion of the terminal fitting to the body is sequentially performed. The electric wire with a terminal metal fitting of the present invention can be manufactured reliably.

  ADVANTAGE OF THE INVENTION According to this invention, the electric corrosion of the connection part of an electric wire and a terminal metal fitting can be prevented reliably, without using a corrosion inhibitor.

Schematic which shows the ultrasonic welding process which concerns on one Embodiment of this invention. Perspective view of female terminal fitting Side view of a state where a female terminal fitting is crimped to the end of an aluminum wire Side sectional view showing the operation of inserting an aluminum wire with a female terminal fitting into the female housing Side sectional view when insertion is complete

<Embodiment>
An embodiment of the present invention will be described with reference to FIGS. In this embodiment, the case where it applies to the aluminum electric wire 10 is illustrated, and as shown in FIG. 3, the terminal metal fitting 20 (henceforth, female terminal metal fitting 20) is connected to the terminal of the aluminum electric wire 10. ing.
As shown in FIG. 1, the aluminum electric wire 10 has a core wire 11 formed of a twisted wire obtained by twisting a plurality of strands 12 made of aluminum or aluminum alloy, and an insulating coating 13 made of synthetic resin is formed around the core wire 11. The structure is covered with.

The female terminal fitting 20 is formed by pressing a copper alloy plate, and as shown in FIG. 2, has a substantially rectangular tube shape that is electrically connected to a mating male terminal fitting (not shown). A wire barrel 25 and an insulation barrel 26 are provided behind the terminal connection portion 21. The front wire barrel 25 corresponds to the wire connecting portion of the present invention.
An elastic contact piece 23 is provided inside the terminal connection portion 21 so as to be folded back from the front edge of the bottom plate 22, and the tab of the mating male terminal fitting described above is connected to the terminal connection portion 21 from the front. By inserting and elastically contacting the elastic contact piece 23, the male terminal fitting and the female terminal fitting 20 are electrically connected.

  The wire barrel 25 is of an open barrel type, and a pair of left and right wide barrel pieces 25 </ b> A are formed to rise from the left and right side edges of the bottom plate 22 so as to face each other. The wire barrel 25 is caulked and crimped to the end of the core wire 11 of the aluminum electric wire 10, and the so-called overlap type is formed by embedding the outer periphery of the core wire 11 from both the left and right sides while overlapping the protruding ends of both barrel pieces 25A. It can be squeezed.

  The insulation barrel 26 is also of an open barrel type, and a pair of left and right barrel pieces 26A which are narrower and taller than the barrel piece 25A on the wire barrel 25 side are also opposed to each other from the left and right side edges of the bottom plate 22. In this way, it is formed to rise. The insulation barrel 26 is caulked and crimped to the remaining end of the insulating coating 13 of the aluminum electric wire 10 and is caulked in an overlapping manner in the same manner.

Then, the manufacturing process of the electric wire with a terminal metal fitting which concerns on this embodiment is demonstrated.
As shown in FIG. 1, the terminal of the insulation coating 13 of the aluminum electric wire 10 is peeled off, and the terminal of the core wire 11 is exposed over a predetermined length. A thin adherend 30 is attached from the exposed end of the core wire 11 to the end of the insulation coating 13 in the aluminum electric wire 10. Specifically, the adherend 30 is formed by winding a copper foil around a plurality of layers, and the front side is formed in a closed state.

Next, the first half of the adherend 30 is joined to the core wire 11 by ultrasonic welding. Specifically, the front region 30A attached to the core wire 11 in the adherend 30 is received on the anvil X constituting the ultrasonic welding machine, while the upper surface side of the front region 30A is received by the horn Y. Apply pressure while applying lateral vibration. As a result, impurities on the bonding surface of the adherend 30 and the core wire 11 are removed by friction due to ultrasonic vibration, while atomic diffusion is induced by heating due to frictional heat, and a solid-phase welding state is generated on the bonding surface. Is done. That is, the outer peripheral surface of the core wire 11 and the inner peripheral surface of the adherend 30 are joined to establish an electrical connection.
Further, since the rear region 30 </ b> B of the adherend 30 is also heated with the ultrasonic welding described above, the outer peripheral surface of the insulating coating 13 is welded to the inner peripheral surface of the adherend 30 by receiving the heat. Thereby, the space between the opening edge of the rear end of the adherend 30 and the outer peripheral surface of the insulating coating 13 is sealed so as not to be submerged.

When the adherend 30 is attached to the end of the aluminum electric wire 10, the female terminal fitting 20 is crimped and connected to the adherend 30 by a crimping device. Specifically, the crimping device is provided with an anvil and a crimper, and the front region 30A attached to the core wire 11 of the adherend 30 with respect to the wire barrel 25 of the female terminal fitting 20 is also attached to the insulation barrel 26. On the other hand, the rear region 30B attached to the insulating coating 13 in the adherend 30 is set in a state where it is arranged, and as shown in FIGS. 3 and 4, both barrels 25 and 26 are connected to the anvil and crimper. And are crimped together in an overlap type.
The insulation coating 13 and the adherend 30 are welded to each other due to the residual heat of ultrasonic welding. However, even if the mutual welding is weak, there is an overlap pressure bonding of the insulation barrel 26 at the end. Insufficient adhesion (welding force) can be covered. The reason why the overlap pressure bonding is adopted is to prevent breakage of the adherend 30.

Thereby, in particular, the inner peripheral surface of the wire barrel 25 and the outer peripheral surface of the adherend 30 are brought into close contact with each other, and electrical connection is established. Further, the insulation barrel 26 is wound around the outer periphery of the adherend 30 at the position close to the opening edge and crimped and crimped, so that the gap between the opening edge of the adherend 30 and the outer peripheral surface of the insulating coating 13 is more reliable. Closed.
Thus, the operation for connecting the female terminal fitting 20 to the terminal of the aluminum electric wire 10 according to the present embodiment is completed.

  A plurality of aluminum wires 10 with female terminal fittings 20 formed as described above are gathered to form a harness. For example, as shown in FIG. 4, the female terminal fitting 20 at the end of the aluminum wire 10 is a female housing. 5 is inserted from the rear into the corresponding cavity 51 formed in 50, and is received and retained by the lance 52 as shown in FIG. 5, and is wired at a predetermined location of the vehicle. By fitting with the male housing, the corresponding female terminal fitting 20 and the male terminal fitting are electrically connected to each other.

  As described above, according to this embodiment, the crimped portion between the wire barrel 25 and the adherend 30 of the female terminal fitting 20 is in contact with the copper alloy and copper. Eating is difficult. On the other hand, the dissimilar metals are in contact with each other between the inner surface of the adherend 30 and the core wire 11 of the aluminum electric wire 10, but the outer surface of the insulating coating 13 is welded and sealed to the adherend 30, thereby making contact. Since water intrusion into the portion, that is, the adherend 30 is prevented, electrolytic corrosion does not occur at the contact portion. As a result, it is possible to reliably prevent electrolytic corrosion at the connecting portion between the aluminum electric wire 10 and the female terminal fitting 20 without using an anticorrosive.

In this embodiment, in order to connect the female terminal fitting 20 to the adherend 30, both the wire barrel 25 and the insulation barrel 26 are caulked and crimped to the adherend 30. Thus, the existing female terminal fitting 20 provided with the wire barrel 25 and the insulation barrel 26 can be applied as it is without preparing a new structure.
Further, the insulation barrel 26 is caulked and crimped to the outer periphery at a position close to the opening edge of the adherend 30, so that the seal between the opening edge of the adherend 30 and the outer peripheral surface of the insulating coating 13 is more reliably achieved. Can be taken to.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) The adherend is not limited to one formed by wrapping the copper foil exemplified in the above embodiment around a plurality of layers. If ultrasonic welding is possible, for example, a thin cap shape made of copper or copper alloy It may be.

(2) The metal foil constituting the adherend when the electric wire is an aluminum electric wire and the terminal fitting is made of a copper alloy, in addition to the copper foil exemplified in the above embodiment, is as follows. Also good. That is, the foil material needs to be a noble metal rather than aluminum, and preferably has a similar ionization tendency to the terminal fitting material (copper alloy), such as zinc, iron, nickel and tin.
(3) Similarly, as the material of the thin cap constituting the adherend when the electric wire is an aluminum electric wire and the terminal fitting is made of a copper alloy, in addition to the copper or copper alloy shown above, it is nobler than aluminum. Zinc, iron, nickel, tin and lead, which are similar metals and have a tendency to ionize with the material of the terminal fitting (copper alloy).

(4) In the above embodiment, both the wire barrel and the insulation are used for pressure bonding to the cap. However, the insulation barrel may be removed to include only the wire barrel.
(5) The form of the wire barrel is not limited to the overlap form exemplified in the above embodiment, and the pair of left and right barrel pieces may be arranged so as to be shifted in the axial direction of the core wire. There may be only one piece. Furthermore, it may be a closed barrel type formed in a cylindrical shape in advance before caulking. In short, it is preferable that when the barrel is caulked, it does not break by piercing the adherend.

(6) In the above embodiment, the female terminal fitting is exemplified as the terminal fitting to be connected to the terminal of the aluminum electric wire, but other terminals such as a male terminal fitting having a male tab or an LA terminal having an eyeball-shaped connecting portion. It may be a metal fitting.
(7) The present invention is not limited to the case where a copper alloy terminal fitting is connected to the aluminum electric wire exemplified in the above embodiment, and the core wire of the electric wire and the terminal fitting connected thereto are formed of different metals. In general, it can be widely applied.

10 ... Aluminum wire (wire)
DESCRIPTION OF SYMBOLS 11 ... Core wire 13 ... Insulation coating 20 ... Female terminal metal fitting (terminal metal fitting)
22 ... Bottom plate 25 ... Wire barrel (wire connection part)
25A ... barrel piece 26 ... insulation barrel 26A ... barrel piece 30 ... adherend 30A ... front region 30B ... rear region X ... anvil Y ... horn

Claims (5)

An electric wire having a metal core wire covered with an insulation coating;
A terminal fitting provided with an electric wire connecting portion made of a metal different from the core wire and connected to the core wire,
A thin-walled deposit that is made of a metal that is close to ionization to the terminal fitting and that can be deposited over the end of the insulation coating left from the end of the core wire exposed by peeling off the insulation coating of the electric wire. A body,
An electric wire with terminal fitting, wherein the adherend is joined to the core wire of the electric wire by ultrasonic welding, and the wire connecting portion of the terminal fitting is crimped to the adherend. The electric wire with terminal fitting according to claim 1, wherein the electric wire is an aluminum electric wire having a core wire made of aluminum or aluminum alloy, and the terminal fitting is made of copper alloy. The electric wire with a terminal fitting according to claim 2, wherein the adherend is formed by winding a copper foil around a plurality of layers. The electric wire connecting portion is composed of two front and rear barrels, and the front barrel is caulked and crimped to a region of the adherend attached to the end of the electric wire and attached to the end of the core wire. The terminal according to any one of claims 1 to 3, wherein the barrel on the side is crimped and crimped to a region of the adherend that is attached to the end of the insulating coating. Wire with bracket. This is a method of manufacturing an electric wire with a terminal fitting in which an electric wire connecting portion provided on a metal terminal fitting different from the core wire is connected to an end of the core wire in an electric wire in which a metallic core wire is covered with an insulating coating. And
Peeling the end of the insulation coating of the electric wire to expose the end of the core wire; and
A step of attaching a thin adherend made of a metal having a close ionization tendency to the terminal fitting, over the end of the insulation coating left from the exposed end of the core wire in the electric wire;
Joining the adherend to the core wire by ultrasonic welding;
Crimping the wire connecting portion of the terminal fitting to the adherend;
Are sequentially performed. The manufacturing method of the electric wire with a terminal metal fitting characterized by the above-mentioned.

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