JPH08132245A - Method for connecting electric conductive wire to connection terminal - Google Patents

Abstract

PURPOSE: To provide a connecting method to prevent the deterioration of the connection strength in connecting the electric conductor to a connection terminal having a mating part. CONSTITUTION: An end part of an electric conductor 8 is inserted into a hook part 9a of a connection terminal 9 having a mating part (s), and the mating part (s) of this hook part 9a is received by a recessed groove (o) of a recessed electrode 4 with this mating part on the lower side. A projecting part (t) of a projecting electrode 3 is abutted on the upper surface of the hook part 9a and pressed thereagainst to form a caved-in recessed part (u). The insulation, covering of a part of the electric conductor 8 in the hook part 9a is melted and removed by heating it by electrode tips 3b, 4b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a connecting method for connecting an electrically conductive wire coated with an insulating coating and a connecting terminal having a mating portion.

[0002]

2. Description of the Related Art Conventionally, a twisted coated electric wire is inserted into a hook portion of a connection terminal, and the hook portion is sandwiched between a pair of electrodes and heated by applying electric current while deforming under pressure to dissolve and remove an insulating coating to electrically remove it. As a method of connecting to the above, a technique such as Japanese Patent Laid-Open No. 5-38583 is known.
-48194 is proposed. This technology is by pressing the hook part sandwiched by a pair of electrodes,
A recessed recess is formed in the hook to improve the mechanical coupling strength, and at the same time, the heat is concentrated in the recess so that the insulating coating is melted only at the minimum necessary portion.

[0003]

However, in the above technique, when the hook portion of the connection terminal is formed into a tubular shape having a mating portion by bending a metal plate, the electrodes are sandwiched. It is necessary to consider the pressure direction. In other words, a depressed recess is formed in the hook by pressing the electrodes together, but at this time, it is necessary to prevent the formation of the recess from affecting the mating part and to prevent the gap in the mating part from expanding. There is a need to.

[0004]

In order to solve such a problem, the present invention inserts a conductive wire into a hook portion having a mating portion, and sandwiches the hook portion with a concave electrode and a convex electrode to apply pressure and heat. By forming a recessed concave portion in a part of the hook portion and simultaneously dissolving and removing a part of the insulating coating of the conductive wire in the hook portion, the mating portion is received by the concave portion of the concave electrode. Pressurized and heated.
In addition, the mating portion of the hook portions is kept in a joined state by, for example, brazing before inserting the conductive wire. Further, the hook receiving area of the concave electrode is made larger than the hook contact area of the convex electrode.

[0005]

The hook portion is sandwiched between the concave electrode and the convex electrode and pressed, and the concave electrode is formed in the hook portion by the convex electrode, and the electrode is heated to dissolve the insulating coating. At this time, if the mating portion of the hook portion is received by the concave portion of the concave electrode,
A recessed concave portion formed by the convex electrode is formed on the back side of the mating portion, so that the influence of the deformation on the mating portion is reduced and the problem of widening the gap is reduced. In addition, it is possible to prevent the gap from expanding and to increase the mechanical joining strength by joining the mating portion by brazing or the like, but the joining work is easy if the joining is performed before inserting the conductive wire. .
Further, if the hook receiving area of the concave electrode is made larger than the hook contact area of the convex electrode, the surface pressure of the hook portion received from the concave electrode is lower than that of the convex electrode side, and the heat dissipation effect of the concave electrode is the side of the convex electrode. As a result, the mechanical deformation and thermal deformation of the mating portion are suppressed.

[0006]

Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is a process diagram showing a connection method of the present invention, and FIG. 2 shows a connection state of a conductive wire and a connection terminal.
Is a side for forming a recessed portion, (B) is a side for a mating portion, (C) is a longitudinal sectional view, and FIG. 3 is an overall view of a connecting device embodying the present invention. The connection method of the present invention is performed, for example, by a connection device 1 as shown in FIG. 3, and this connection device 1 is provided with an upper convex electrode 3 and a lower concave electrode 4 projecting on the front surface of a main body 2. The mold electrode 3 is vertically movable by a driving source 5.

On the other hand, in front of the main body 2, a work cradle 6 is provided.
The work table 6 is provided with a stator 7 of an electric motor, which is supported so as to be movable up and down, movable back and forth, and rotatable about a central axis. The stator 7 is wound with three windings whose outer side is covered with an insulating coating, and the connecting terminals 9 as shown in FIG. 2 are sequentially connected to the conducting wires 8 at the winding start end and the winding end end. Go on. This connection terminal 9 is shown in FIG.
As shown in (B), it is provided with a hook portion 9a and a terminal portion 9b, and the hook portion 9a is formed by curling a flat metal plate into a tubular shape. A mating portion s facing each other is formed.
It is desirable that the predetermined interval be equal to or smaller than the outer diameter of the conductive wire 8.

On the other hand, the convex electrode 3 and the concave electrode 4 are configured as shown in the perspective view of FIG. 4, and the convex electrode 3 is composed of an electrode body 3a made of, for example, chrome copper and a tip of the electrode body 3a. An electrode tip 3b made of pure tungsten that can be inserted into the hole is provided, and a hemispherical convex portion t is formed at the tip of the electrode tip 3b. The concave electrode 4 includes, for example, an electrode body 4a made of chrome copper and an electrode tip 4b made of pure tungsten that can be freely inserted into the insertion hole at the tip of the electrode body 4a. A circular groove o is formed. The electrode chips 3b and 4b are made of pure tungsten having a high electric resistance value in order to enhance heat generation efficiency, but molybdenum or the like may be used.

The radius of curvature of the groove o of the concave electrode 4 is made larger than the radius of the hook portion 9a of FIG. 2B so that the lower surface of the hook portion 9a can be received with a margin. At the same time, the surface area (hook receiving area) of the concave groove o is larger than the surface area (hook contacting area) of the convex portion t of the convex electrode 3. Incidentally, the radius of curvature of the convex portion t is about 5 mm, and the radius of curvature of the concave groove o is about 6 mm.

Next, a connecting method using the connecting device 1 as described above will be described with reference to FIG. First, the connection terminal 9 made of a metal plate is bent in advance to form the tubular hook portion 9a, and then the mating portion s is joined by brazing or the like. Then, at this time, the joining operation is easily performed by joining the mating portion s. Then, the conducting wire 8 is inserted into the hook portion 9a, and the hook portion 9a is positioned in the groove groove o of the concave electrode 4 in the state where the convex electrode 3 is raised as shown in FIG. 1 (A). Set to state. At this time, the alignment portion s is oriented downward and aligned with the substantially central portion of the groove groove o.

Next, the convex electrode 3 is lowered from above,
As shown in (C), the electrode tip 3 is provided on the upper surface of the hook portion 9a.
Pressing is started by abutting the convex portion t of b, and at the same time, the upper and lower electrode chips 3b and 4b are energized to generate heat and the conductive wire 8 is heated through the hook portion 9a. Therefore, as shown in (D), a recessed concave portion u (see FIG. 2) is formed and crimped on the hook portion 9a pressed by the convex portion t of the convex electrode 3 and, at the same time, the lower surface of the hook portion 9a. In the grooved groove o spreads over the entire width of the groove so as to follow the groove shape, and a force is applied in a direction in which the gap of the mating portion s is narrowed. Further, at the same time as the pressurization, the convex portion t and the concave groove o are heated, and the insulating coating of the electric conducting wire 8 inside is melted in a spotwise manner from the periphery of the concave portion u to the lower surface, so that the electric conducting wire 8 and the hook portion 9a are electrically connected. Be combined.

At this time, the mating portion s of the hook portion 9a is received by the lower groove groove o, and is located on the opposite side of the convex portion t of the electrode tip 3b descending from above, so that the convex portion t is depressed. The influence of the pressurizing deformation when the concave portion u is molded is smaller.
Moreover, since the work receiving area of the concave groove o is larger than the work contact area of the convex portion t, the surface pressure applied to the lower surface side of the hook portion 9a becomes lower than the surface pressure received from the convex portion t, and mechanical deformation is suppressed. To be done.

Further, the heat radiation effect is higher on the side of the concave groove o than on the side of the convex portion t, and the influence of thermal deformation on the mating portion s is small.
That is, the bonding such as brazing of the mating portion s is not easily broken, and the connection strength between the conductive wire 8 and the connection terminal 9 can be increased.

[0014]

As described above, according to the method of connecting a conductive wire and a connection terminal of the present invention, a cylindrical hook portion having a mating portion is formed on the connection terminal, and the mating portion is received by the concave portion of the concave electrode and applied. Since the pressure is applied, the influence of pressure deformation on the mating portion is reduced, and the connection strength between the conductive wire and the connection terminal can be increased. Further, by joining the mating portions of the hooks before inserting the conductive wire, the joining work can be facilitated, and the connection strength can be increased when the conductive wire and the connection terminal are connected. Further, by making the hook receiving area of the concave electrode larger than the hook contact area of the convex electrode, it is possible to further reduce the influence of pressure deformation and thermal deformation on the mating portion.

[Brief description of drawings]

FIG. 1 is a process diagram showing a connection method of the present invention.

2A and 2B show a connection state of a conductive wire and a connection terminal, in which FIG. 2A is a recessed recess molding side, FIG. 2B is a mating portion side, and FIG.

FIG. 3 is an overall view of a connecting device embodying the present invention.

FIG. 4 is a perspective view of a convex electrode and a concave electrode.

[Explanation of symbols]

3 ... Convex electrode, 4 ... Recessed electrode, 8 ... Conductive wire, 9 ... Connection terminal, 9a ... Hook part, s ... Alignment part, o ... Recessed groove.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area // B23K 101: 38

Claims (3)

[Claims] 1. A plurality of conductive wires covered with an insulating coating are bundled and inserted into a hook portion of a connection terminal, and the hook portion is sandwiched between a concave electrode and a convex electrode to pressurize and heat the hook portion. A hook-shaped concave portion is formed in a part of the hook, and at the same time, the insulating coating of a part of the conductive wire in the hook portion is dissolved and removed to electrically connect the conductive wire and the hook portion. Is a plate-shaped member formed by bending into a tubular shape to form a mating portion, and the mating portion is received by the concave portion of the concave electrode to apply pressure and heat to the connection between the conductive wire and the connection terminal. Method. 2. The method for connecting a conductive wire and a connection terminal according to claim 1, wherein the mating portion of the hook portion is already in a joined state before the conductive wire is inserted. Connection method. 3. The method for connecting a conductive wire and a connection terminal according to claim 1 or 2, wherein the hook receiving area of the concave electrode is larger than the hook contact area of the convex electrode. And how to connect the connection terminal.