JPH0982447A - Electric wire connecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish an electric wire connecting method which can give a stable, small contacting resistance and a sufficient bonding strength to the connecting part between a terminal and an electric wire. SOLUTION: The core (soft copper wire) of a wire harness is exposed by stripping the insulative covering at the foremost part of an insulated electric wire to constitute the harness. A band-shaped brazing material 20 is inserted between the core 11 and the connection part 31 of a terminal (copper alloy) 30, and these parts 11 and 31 are pinched by pressure in the electrode 41 of a resistance welding machine 40 followed by current feeding, and now the band- shaped brazing material 20 will quickly be melted by the resistance heating to establish strong connection of the core 11 with the terminal 30 through the brazing material 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting terminals to wires in a large current circuit among electric wires used in automobiles, industrial equipment, etc., and in particular, connecting them by environmental temperature or self-heating when energized with a large current. The present invention relates to an electric wire connection method effective when a part is exposed to high temperature.

[0002]

2. Description of the Related Art Up to now, a crimping method of crimping and fixing a terminal to an electric wire has been widely used for connecting the electric wire and the terminal, but recently, a contact resistance at a connecting portion between the terminal and the electric wire is reduced. For this reason, welding methods such as resistance welding and ultrasonic welding have come to be used.

[0003]

In the crimping method, the contact resistance is not stable unless the electric wire is sufficiently compressed by the terminal fitting, and conversely, if the electric wire is excessively compressed, the strength of the electric wire itself decreases. Severe control was required to satisfy the severe connection conditions regarding crimp height and the like.
Further, when the connecting portion between the electric wire and the terminal is exposed to a high temperature, there is concern that the contact resistance may increase due to surface oxidation or stress relaxation of the connecting portion.

On the other hand, when the welding method is adopted, if excessive energy is applied to the connection portion during welding, the electric wire itself is greatly damaged and the connection strength is reduced as in the case of the crimping method. When used in a high temperature environment, terminals formed of stainless steel, nickel, nickel-plated copper alloy, etc., and nickel-plated annealed copper wire are often used. There was a problem that it became difficult.

Therefore, an object of the present invention is to provide an electric wire connecting method capable of giving a stable small contact resistance and sufficient joint strength to a connecting portion between a terminal and an electric wire.

[0006]

In order to solve the above-mentioned problems, the present invention is a method for connecting an electric wire to a terminal in a large current circuit, wherein a strip-shaped electric wire is provided between the electric wire and the terminal. It is intended to provide an electric wire connecting method in which a brazing material is inserted and the terminal and the electric wire are mutually connected by a welding method.

Further, a band-shaped brazing material is adhered to the electric wire connecting portion of the terminal, and the terminal and the electric wire are mutually connected by a welding method, or the band-shaped brazing material is wound around the electric wire.
The terminal and the electric wire can be connected to each other by a welding method while the brazing material portion of the electric wire is in contact with the terminal.

The brazing material has a melting temperature of 60.
It is preferable to use silver brazing filler metal or phosphor copper brazing filler metal having a temperature of 0 ° C. or higher and 800 ° C. or lower, and when the terminal or the electric wire is stainless steel, nickel or nickel plated material, use silver brazing material containing zinc or nickel as the brazing material. Is desirable.

[0009]

Embodiments will be described below with reference to the drawings. This wire connection method is, among wire harnesses used in automobiles, a method that is particularly effective when connecting wires and terminals in a large current circuit,
The following steps are performed.

First, the core wire portion (soft copper wire) is exposed by stripping off the coating on the tip end portion of the insulation-coated electric wire constituting the wire harness. Then, as shown in FIG. 1, welding of the resistance welding machine 40 is performed with the strip-shaped metal brazing 20 inserted between the core wire portion 11 of this insulation-coated electric wire and the electric wire connecting portion 31 of the terminal (copper alloy) 30. When the core wire portion 11 and the wire connection portion 31 of the terminal 30 are sandwiched between the electrodes 41 in a pressurized state and electricity is applied, as shown in FIG. 2, the strip-shaped metal brazing 20 is rapidly melted by resistance heating and the terminal 30 The core portion 11 of the insulation-coated electric wire is firmly connected via the metal brazing 20. At this time, the metal brazing material 20 to be used is preferably a silver brazing material or a phosphorous copper brazing material having a melting temperature of about 600 to 800 ° C., and the thickness and width of the metal brazing material 20 are appropriately determined according to the wire diameter and the terminal size. do it.

FIG. 3 shows another embodiment. In this electric wire connecting method, first, as shown in FIG. 3A, a strip-shaped metal brazing 20 is attached to the inner surface of the electric wire connecting portion 31 of the terminal 30, and then the electric wire connecting portion is bent into a predetermined shape.

Then, as shown in FIG. 1B, the core wire portion 11 of the insulation-coated electric wire 10 is inserted into the metal braze 20 portion bonded to the connection portion of the terminal (copper alloy) 30, and the resistance welding machine 40 is used. When the welding electrode 41 is sandwiched in a pressurized state and energized, as shown in FIG. 2, the metal brazing 20 is quickly melted by resistance heating, and the terminal 30 and the core wire portion 11 of the insulation-coated electric wire 10 cause the metal brazing 20 to move. Is firmly connected via.

In this way, the strip-shaped metal braze 20 is connected to the terminal 30.
Adhering to the electric wire connecting portion 31 has the advantage that the supply mechanism of the metal brazing 20 in the welding process can be omitted.

FIG. 4 shows another embodiment. In this electric wire connecting method, first, as shown in FIG. 1A, the coating of the tip end portion of the insulation-coated electric wire 10 constituting the wire harness is stripped to expose the core wire portion 11 (soft copper wire), and the core wire A band-shaped metal brazing wire 20 is wound around the connection portion with the terminal, which is the tip of the portion 11.

Then, as shown in FIG. 1B, the portion of the core wire portion 11 around which the strip-shaped metal brazing wire 20 is wound is inserted into the wire connecting portion 31 of the terminal (copper alloy) 30, and the resistance welding machine 40 is used. When the welding electrode 41 is sandwiched in a pressurized state and energized, as shown in FIG. 2, the metal brazing 20 is quickly melted by resistance heating, and the terminal 30 and the core wire portion 11 of the insulation-coated electric wire 10 cause the metal brazing 20 to move. Is firmly connected via.

The above-described work of winding the metal brazing wire 20 around the core wire portion 11 may be performed continuously with the work of stripping the insulation-coated electric wire 10. Further, if the metal brazing member 20 is wound around the core wire portion 11 in a crimped state, it is effective in preventing the core wire portion 11 from coming loose.

As described above, in each of the embodiments, the terminal 30 and the core wire portion 11 of the insulation-coated electric wire 10 are connected through the metal braze 20 that melts at a low temperature to some extent, so that the core wire portion 11 and the terminal 30 are connected. In addition, it is not necessary to apply an unnecessarily large current, and it is possible to prevent the insulation-coated electric wire 10 from being damaged due to resistance welding. Further, as shown in FIG. 2, the metal brazing 20 is filled in the void portion formed between the core wire portion 11 and the terminal 30 and the void portion formed between the strands 11 a of the core wire portion 11. , The contact resistance is extremely low, and
Since the metal brazing 20 firmly joins the terminal 30 and the core wire portion 11, both strength and contact resistance are stable.

In each of the above-described embodiments, the terminal 30 made of a copper alloy and the core wire portion 1 made of annealed copper wire.
Although the case where one of the core wire portion 11 and the terminal 30 is formed of stainless steel, nickel, or a nickel plating material has been described, the diffusion at the bonding interface is less likely to occur, and the welding is not performed. Therefore, as shown in Table 1, as the metal braze 20,
Good joining can be obtained by using silver brazing containing zinc or nickel.

[0019]

[Table 1]

[0020]

As described above, according to the electric wire connecting method of the present invention, a strip-shaped brazing material is inserted between the electric wire and the terminal, or a strip-shaped brazing material is attached to the electric wire connecting portion of the terminal. Since the brazing material is interposed between the electric wire and the terminal by winding a band-shaped brazing material around the wire, the electric wire and the brazing material,
Good diffusion bonding can be obtained between the brazing material and the electric wire, and low, stable contact resistance and sufficient bonding strength can be obtained.

Further, the terminal or the electric wire is stainless steel,
Even in the case of nickel or nickel-plated material, by selecting a silver braze containing zinc or nickel that is suitable for joining stainless steel or nickel as the brazing material, it is possible to avoid welding difficulties and obtain good joining. it can.

[Brief description of drawings]

FIG. 1 is a process drawing showing an embodiment according to the present invention.

FIG. 2 is a view showing a connecting portion obtained by the above electric wire connecting method.

FIG. 3 is a process drawing showing another embodiment.

FIG. 4 is a process drawing showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Insulation coated electric wire 11 Core wire part 11a Element wire 20 Metal brazing 30 Terminal 31 Electric wire connection part 40 Resistance welding machine 41 Welding electrode

Claims (5)

[Claims] 1. A wire connecting method for connecting a terminal and an electric wire in a large current circuit, wherein a band-shaped brazing material is inserted between the electric wire and the terminal, and the terminal and the electric wire are welded by a welding method. How to connect electric wires to each other. 2. A wire connecting method for connecting a terminal and an electric wire in a large current circuit, wherein a band-shaped brazing material is attached to an electric wire connecting portion of the terminal, and the terminal and the electric wire are mutually connected by a welding method. How to connect the electric wire. 3. A wire connecting method for connecting a terminal and an electric wire in a large current circuit, comprising: winding a band-shaped brazing material around the electric wire, wherein the brazing material portion of the electric wire is in contact with the terminal. An electric wire connecting method for connecting a terminal and the electric wire to each other by a welding method. 4. A silver braze or a phosphor copper braze having a melting temperature of 600 ° C. or higher and 800 ° C. or lower is used as the brazing filler metal.
The electric wire connection method according to 2 or 3. 5. The electric wire connecting method according to claim 1, 2 or 3, wherein when the terminal or the electric wire is made of stainless steel, nickel or a nickel plated material, silver brazing containing zinc or nickel is used as the brazing material.