JP3438809B2 - Laser welding method for welding electric wires to terminal members - Google Patents

Description

Detailed Description of the Invention

[0010]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser welding method for welding an electric wire to a terminal member and a structure of the terminal member suitable for this type of welding.

[0020]

2. Description of the Related Art Recently, laser welding has been widely used for joining electric wires and terminal members. Laser welding is a welding method that melts and joins the welded part of the work piece with the energy of the laser beam, and there is no harmfulness (environmental problem) such as solder, and deterioration over time (electrical corrosion) such as caulking. There is no fear.

As shown in FIG. 5, according to the conventional laser welding method of this kind, one end of the conductor portion 102a of the electric wire 102 is placed on the surface of the welded portion of the terminal member 100, and the laser beam LB is irradiated from directly above it. The energy of the laser beam LB is used to melt and join the electric wire conductor portion 102a and the welded portion of the terminal member 100 in an instant.

[0040]

However, in the conventional laser welding method as described above, the electric wire conductor portion 102a is formed.
The laser energy of the laser beam LB incident on the irradiated portion of No. 2 stays in the vicinity without any other place and does not spread widely to the welded portion. Therefore, as shown in FIG. 6, only the irradiated portion of the wire conductor portion 102a is melted intensively or locally and largely dented (thinned), and the dented portion g easily breaks. .

The present invention has been made in view of the above problems, and is intended to ensure the safety of the laser optical system and to prevent the welding of electric wire.
Heat input efficiency of laser energy
The energy is quickly released to the inner side of the wire weld,
An object of the present invention is to provide a laser welding method capable of obtaining good welding quality .

[0060]

[0070]

In order to achieve the above object, a laser welding method of the present invention is a laser welding method for welding an electric wire to a terminal member.
The tip of the electric wire is received in the welding site by multidirectional contact.
To form a recess, and the end of the wire in the recess of the terminal member.
With the ends in contact, see from the wire side
Also from the direction tilted a certain angle from the front and vertically above
The laser beam is irradiated on the tip portion of the wire, welding the distal end of the wire to the recess of the terminal member by a laser energy of the laser beam.

In the laser welding method of the present invention,
The position of the laser beam irradiation at the tip of the wire.
The point of the laser beam irradiation direction
May be set at about 15 °.

In the laser welding method of the present invention, from the wire side
A certain angle (preferred
Irradiate laser light from a tilted direction, preferably about 15 °,
Laser-insert the tip of the wire (preferably near the tip).
The shooting position. Wire from diagonally above in this direction
With laser irradiation on the tip, the
The safety of the optical system is reduced by reducing the light reflected in the direction of the exit
Not only can you plan, but the amount of reflected light is small
Increased heat input efficiency of laser energy to (irradiated part)
At the same time, the excess laser energy is applied to the wire tip.
To quickly escape to the inner side of the wire to obtain good welding quality.
You can

[0100]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a structural example of an electric wire and a terminal member to which the laser welding method of the embodiment is applied.

The electric wire 10 may be any insulated electric wire formed by covering the conductor portion (core portion) 10a with the insulating material 10b. Even if the conductor portion 10a is a single wire (A), a stranded wire or a multi-core wire (B) is used. ) May be sufficient. Usually, as shown in the figure, one end of the conductor portion 10a exposed by peeling off the insulating material 10b is used as a welded portion (a portion to be welded).

The terminal member 12 may be a conductive metal piece having an arbitrary basic form, and the welding portion thereof has a recess for receiving the conductor end portion (welding portion) 10a of the electric wire 10 in multidirectional contact according to the present invention. A (dent) 12a is formed. Further, the terminal member 12 is also formed with an opening 12b for passing a screw (not shown) for fixing the terminal.

The recess 12 at the welded portion of the terminal member 12
a is a press work by a machine tool, a forming work by a mold, a bending work by a tool, a cutting work, etc.
It may be formed in a shape and size corresponding to the conductor end portion 10a.

Here, the shape and size of the recess 12a corresponding to the conductor end 10a of the electric wire 10 means that the conductor end 10a of the electric wire is received in a multidirectional contact in a plane perpendicular to the axial direction of the electric wire. Preferably, as shown in FIG. 3, the upper surface of the electric wire 10 and the upper surface of the conductor end 10a are substantially flush with each other so that the welded portion of the electric wire 10 contacts the inner surface of the recess 12a. Due to such multi-directional contact, a large contact area can be obtained at the weld. In that respect, conventionally, as shown in FIG. 6, the wire conductor portion 104 only contacts the flat welded portion of the terminal member 100 in one direction (vertical direction), and the contact area of the welded portion is small.

Further, the length of the recess 12a may be selected as an appropriate length in consideration of the ease of processing the recess 12a, the positioning of the electric wire conductor end portion 10a, the ease of holding, and the like.

FIG. 2 shows the implementation status of the laser welding method in this embodiment. As shown in the figure, the conductor end 10a of the electric wire 10 is placed in the recess 12a of the terminal member 12 in the multidirectional contact as described above, and welding laser light, for example, YAG laser light LB is applied from above when viewed from the terminal member 12 side. The conductor end 10a is irradiated with a beam diameter larger than the diameter of 10. The laser energy of this laser beam LB is the electric wire conductor portion 10.
The value is selected according to the material and diameter of a. For example, in the case of a copper-based stranded wire, 13 to 14 J (joule) is selected for a wire diameter of 0.3 and 32 J is selected for a wire diameter of 1.0.

In this embodiment, the YAG laser beam LB oscillated and output from a YAG laser oscillator (not shown) is transmitted to the emitting unit 16 at the welding work position via the optical fiber 14, and the optical lens inside the emitting unit 16 transmits it. The YAG laser light LB is condensed and irradiated. The optical fiber 14 is
It has been confirmed that the graded index (GI) type gives better welding results than the step index (SI) type.

In order to prevent oxidation of the welded portion during laser welding, an inert gas (shield gas) such as argon gas or nitrogen gas may be sprayed onto the welded portions of the materials 10 and 12 to be welded. Further, with respect to the irradiation range of the laser light LB, usually, one point (one place) irradiation is sufficient, but multi-point irradiation or scanning irradiation can be performed as necessary.

As shown in the sectional view of FIG. 3, in this embodiment, the conductor end portion 1 of the electric wire 10 is inserted into the recess 12a of the terminal member 12.
0a is in contact with the vertical direction (vertical direction) to the horizontal direction (horizontal direction) over a half circumference in multiple directions, so that the energy of the laser beam LB is the irradiated portion G of the wire conductor end portion 10a as indicated by an arrow A. It spreads widely and quickly to the welded part without being concentrated and concentrated in the radial direction. As a result, the welded portion is instantly melted over a large contact area in multiple directions, and the conductor end portion 10a of the electric wire 10 is welded to the recess 12a of the terminal member 12 with a sufficiently large joint area. Therefore, the deformation (dent) of the irradiated portion G of the wire conductor end portion 10a is small, and good welding quality and strength can be obtained.

Further, as clearly shown in the side view of FIG. 4, in the present embodiment, the direction which is tilted by a predetermined angle θ (preferably about 15 °) from the front side of the tip as viewed from the electric wire 10 side and from the vertical upper side. Irradiate YAG laser light LB from the wire conductor 1
The tip portion of 02a (more accurately, the portion near the tip) is the laser incident position G.

By irradiating the conductor tip portion obliquely from above, the light reflected from the wire conductor 10a in the direction of the laser emission unit 16 can be reduced and the safety of the optical system can be improved. It is possible to increase the heat input efficiency of the laser energy to the irradiated portion (tip portion) G of the electric wire conductor portion 10a by a small amount, and at the same time, to release the excess laser energy to the inner back side of the electric wire conductor portion 10a promptly. Therefore, better welding quality can be obtained.

Further, after welding, the wire conductor end portion 10a is held in the recess 12a of the terminal member 12, and the protrusion from the main surface of the terminal member 12 is small, so that there is an advantage that it is protected from external force such as rubbing. is there.

The preferred embodiments of the present invention have been described above, but various modifications are possible within the scope of the technical idea of the present invention.

For example, the electric wire 1 in the above embodiment.
Although 0 is an insulated wire, it may be a bare wire. Also,
The position, shape, and size of the recess of the welded portion of the terminal member can be variously selected, and for example, the cross-sectional shape of the recess 12a can be changed to an elliptical shape, a V shape, a rectangular shape, etc. instead of the above-mentioned circular shape. Is also possible. As the welding laser, a laser other than the above YAG laser, such as a CO2 laser or a semiconductor laser, can be used.

[0260]

As described above, the laser welding of the present invention is performed.
According to the connection method, the safety of the laser optical system is ensured and
Improves the heat input efficiency of laser energy to the welded part
The excess laser energy to the inside of the tip of the wire.
Can be quickly released and good welding quality can be obtained.
It

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration example of an electric wire and a terminal member to which a laser welding method according to an embodiment is applied.

FIG. 2 is a perspective view showing an implementation status of a laser welding method in an embodiment.

FIG. 3 is a cross-sectional view for explaining the operation of the laser welding method in the example.

FIG. 4 is a partial cross-sectional side view showing a laser irradiation method in an example.

FIG. 5 is a diagram showing a conventional laser welding method.

FIG. 6 is a diagram showing a problem in the conventional laser welding method.

[Explanation of symbols]

10 electric wires 10a Electric wire conductor 12 terminal members 12a dent 14 optical fiber 16 Output unit

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) H01R 43/02 B23K 26/00 310 H01R 4/02

Claims (3)

(57) [Claims] 1. A laser welding method for welding an electric wire to a terminal member, wherein a recess for receiving a tip end portion of the electric wire by multidirectional contact is formed at a welding portion of the terminal member, and the recess of the terminal member is formed. the distal end portion of the wire being in contact on either the wire side
Seen from the front, tilted a prescribed angle from the front and vertically above the tip
A laser welding method comprising irradiating the tip of the electric wire with a laser beam from a vertical direction, and welding the tip of the electric wire to the recess of the terminal member by the laser energy of the laser light. 2. The laser beam is attached to the tip of the electric wire.
The laser welding method according to claim 1 , wherein irradiation is performed on a nearby portion . 3. The predetermined angle is set to about 15 °.
Item 3. A laser welding method according to Item 1 or 2 .