JP3370799B2 - Laser welding method of electric wire - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser welding method for electric wires in which electric wires or electric wires and other members are joined by laser welding.

[0002]

2. Description of the Related Art Conventionally, as a method of connecting electric wires,
The method described in JP-A-56-1267 is known. In this method, as shown in FIG. 7, when connecting two thin wires (electric wires) 1 and 2, the tip portion 1 of one thin wire 1 is connected.
a is bent into an L shape, the tip portion 2a of the other thin wire 2 is superposed on the bent portion 3, and the electrode 4 is provided outside the tip portions 1a and 2a in the superposed portion of the two thin wires 1 and 2. The target positions 5 and 5 are set and plasma spot welding is performed.

Further, Japanese Utility Model Laid-Open No. 6-31072 discloses that
As shown in FIG. 8, a method is described in which a thermocompression-bonding terminal 8 is pressure-bonded to the end portion of the electric wire 7 by using a pressure electrode 9, and the thermocompression-bonding terminal 8 is used to connect to a mating member.

[0004]

The conventional method for connecting electric wires described in FIG. 7 is a method for connecting the ends of the electric wires, and the target position of the welding electrode 4 is set to that of each thin wire 1, 2. By setting the positions 5 and 5 outside the tips 1a and 2a, the problem of constriction (also called "thinning" or "thin") that occurs during welding (effect of surface tension of the conductor melted during welding, melting Due to scattering or evaporation of conductors,
I am trying to solve the problem that the metal on both sides of the weld is attracted and constriction occurs, but the setting of the target positions 5 and 5 of the electrode is delicate, and even a little inside position (for example, the position shown by 10 in the figure) There was a problem that when you move to, you may have a neck.

Further, the method of connecting by using the thermocompression bonding terminal described in FIG. 8 requires a dedicated terminal, so that there is a problem that the weight is increased, the connecting portion is enlarged, and the cost is increased. .

In consideration of the above circumstances, the present invention is capable of connecting electric wires to each other or an electric wire to a terminal fitting without using a dedicated terminal fitting, and prevents a constriction from being generated at the connection point. An object of the present invention is to provide a laser welding method for an electric wire that can be performed.

[0007]

According to a first aspect of the present invention, a conductor exposed portion is formed by removing an insulating coating from an electric wire, the conductor exposed portion is superposed on another member, and the superposed portion is a laser. At the time of welding, at the time of laser welding, at least one side of the conductor exposed portion of the electric wire in the longitudinal direction is pushed and moved to the welded portion side.

According to a second aspect of the present invention, a conductor exposed portion from which an insulating coating is peeled off is formed on an electric wire, the conductor exposed portion is superposed on another member, and the superposed portion is laser-welded. Sometimes, the auxiliary conductor is made into a rod shape for the welded part.
Constituting and bending the tip part diagonally,
A lever-shaped auxiliary conductor was sent out and bent diagonally
Align the tip with the exposed conductor and run it
Characterized by laser welding with

According to a third aspect of the present invention, there is provided a laser welding method for an electric wire according to the second aspect, wherein the outer periphery of the rod-shaped auxiliary conductor is provided.
With a gap in the longitudinal direction,
It is characterized in that a notch for cutting is provided .

According to a fourth aspect of the present invention, there is provided a laser welding method for an electric wire according to the third aspect, wherein the rod-shaped auxiliary conductor is used as the auxiliary conductor.
It is characterized in that it moves when the tip of the conductor is melted .

The invention of claim 5 is any one of claims 2 to 4.
The method of laser welding an electric wire according to claim 1,
The body is sandwiched between the conductor exposed portion of the electric wire and another member .

The invention of claim 6 is any of claims 1 to 5.
A laser welding method for an electric wire according to claim 1, wherein the other
The member is also an electric wire, and the above-mentioned
Form exposed conductors and intersect the exposed conductors of both wires.
It is characterized in that they are superposed in a state and the superposed portion is laser-welded .

According to a seventh aspect of the present invention, there is provided an electric wire according to the sixth aspect.
A laser welding method, the electric wire as the other member
At least one side of the conductor exposed part in the longitudinal direction
It is characterized by pushing and moving to the welded part side .

The invention of claim 8 is any of claims 1 to 5.
A laser welding method for an electric wire according to claim 1, wherein the other
The member is a terminal fitting, and
It is characterized in that the protruding portions are overlapped and the overlapped portions are laser-welded .

The invention of claim 9 is any of claims 1 to 8.
A laser welding method for an electric wire according to
If the conductor inside is a bundle of multiple thin wires,
It is characterized in that the protruding portion is crushed by a press and then laser-welded .

According to a tenth aspect of the invention, the electric wire is provided with an insulating coating.
A conductor exposed portion that has been peeled off is formed, and the conductor exposed portion is attached to another member.
When laser welding the overlapped part
Supply an auxiliary conductor to the weld during laser welding
However, if the conductor in the wire is a bundle of thin wires,
If the auxiliary conductor is composed of independent conductor pieces,
The exposed conductor part is pressed together with the conductor piece as the auxiliary conductor.
Crush it with a press and attach the conductor piece to the exposed conductor.
It is characterized in that it is laser-welded from .

The invention of claim 11 is that of claim 1 or 7.
The method of laser welding the electric wire of
The electric wire placed on the cradle or roll,
Is a motor that drives the drive roll that sandwiches the wire facing the roll.
It is characterized in that it is performed by rotating with.

[0018]

[0019]

According to the invention of claim 1, when the conductor exposed portion of the electric wire is laser-welded with another member, the molten conductor is scattered or evaporated, or is attracted to the center of the welded portion due to surface tension or the like. There is a constriction on both sides of the welded part of the conductor, but when the conductor is melted, the electric wire is pushed and moved to the welded part so that the constricted part is replenished, resulting in no constriction and connection strength. Increase.

According to the second aspect of the invention, when the conductor exposed portion of the electric wire is laser-welded to another member, a constriction occurs on both sides of the welded portion. However, by supplying the auxiliary conductor to the welded portion during welding. Since a sufficient amount of molten metal is secured, constriction does not occur and the connection strength increases. Also, rod-shaped
Of the tip of the auxiliary conductor of
Adjust the amount of auxiliary conductor to be supplied at the time of welding once
In addition to being able to
You can also intermittently feed. In addition, the auxiliary conductor
Bend the tip at an angle and expose the conductor at the tip of the angle
Since it is arranged so as to run substantially parallel to the part,
Auxiliary conductor is sent out diagonally above
In the case of
Can supply the body.

According to the third aspect of the invention, the notch is formed for each welding.
At the position of the part, the auxiliary conductor is melted and separated .

According to the invention of claim 4, the tip portion of the auxiliary conductor is
Move the rod-shaped auxiliary conductor when it is difficult to separate.
As a result, the melted tip is naturally separated .

According to the invention of claim 5, the auxiliary conductor is connected to the wire.
Since it is sandwiched between the exposed body and other members, it can be used as an auxiliary conductor during welding.
Stable welding is possible without the body being displaced .

According to the invention of claim 6, both electric powers to be connected are connected.
The exposed conductors in the middle of the wire in the longitudinal direction are mutually lasered.
When welding, there are usually constrictions on both sides of the weld.
Occurs, but the wire is pushed and moved during welding, and the auxiliary conductor
, So that the constriction can be suppressed.
Can .

In the invention of claim 7, as the other member
Since the electric wire also pushes and moves during welding, it becomes more constricted.
Occurrence of is suppressed .

According to the invention of claim 8, it is provided at the end of the electric wire.
Strip the intermediate skin on the exposed conductor or at a position near the end.
Place the exposed conductor section on the terminal metal
Even when welding, the welding should be performed while suppressing the occurrence of necking.
You can

In the invention of claim 9, the conductor is not a single wire but a double conductor.
In the case of a bundle of fine wires, it is possible to include an air layer.
The conductor scattering during welding becomes more noticeable,
There is concern about the occurrence of fins, but the conductor is exposed when welding
Since the part is crushed by a press in advance and laser welding is performed,
It is possible to minimize the scattering of the molten conductor. Yo
And push one wire to the welded part in that state,
Since the auxiliary conductor is supplied to the welded part, necking may occur.
Disappears .

In the invention of claim 10, the auxiliary conductor is a conductor piece.
Since it is supplied in the form of,
Can be paid. Also, put the conductor pieces together when pressing.
Since it is attached to the exposed conductor, an auxiliary conductor will be provided later.
No need to supply, conductor piece automatically constricts with welding
Add minutes .

According to the invention of claim 11, the motor is rotated.
Then, the electric wire is sent out in the longitudinal direction by the rotation of the drive roll.
And is pushed and moved toward the weld .

[0030]

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] A first embodiment will be described with reference to FIGS. 1 and 2. In this embodiment, the two electric wires 20, 30
Conductor exposed portions 22 and 32 from which the insulating coatings 21 and 31 have been peeled off are formed at intermediate portions in the longitudinal direction of the conductor exposed portions 22 and 32.
A case where the overlapping portions 40 are crossed and overlapped and the overlapping portion 40 is joined by laser welding is shown.

The joining procedure will be described with reference to FIG.

First, as shown in FIGS. 1 (a) and 1 (b),
By removing the insulating coating 21 on the intermediate portion of the first electric wire 20 using the cutter 51, the conductor exposed portion 22 having a required size is obtained.
To form. Then, as shown in FIG. 1C, one end 2 of the electric wire 20 in which a conductor exposed portion 22 is formed in the longitudinal middle portion.
0a is fixed by the pressing jig 52, the other end 20b is placed on the receiving plate 61 of the pushing mechanism 60, and is pressed by the drive roll 63 provided on the rotating shaft of the motor (step motor or servo motor) 62.

Then, as shown in FIG. 1D, a second electric wire (another member) 30 is arranged on the first electric wire 20 so as to intersect with the second electric wire 30. To the conductor exposed portion 22 of the first electric wire 20.
Then, both ends 30a and 30b of the second electric wire 30 are pressed by the pressing jig 52 in this state.

Next, from the laser welding machine 55 arranged directly above the overlapping portion 40 of the two conductor exposed portions 22 and 32,
The welding is performed by irradiating the laser beam 57 toward the overlapping portion 40, and at the same time as irradiating the laser beam 57, the motor 62 of the pushing mechanism 60 is operated to move the other end 20a side of the first electric wire 20. It pushes and moves in the direction of arrow A, that is, in the direction of the welded portion 58.

When laser welding is performed in this manner, as shown in FIG. 2 (a), the molten conductor is usually scattered or evaporated, or attracted to the center of the welded portion due to surface tension or the like, so that the wire 20 Constrictions 59 are formed on both sides of the welded portion 58 of the conductor exposed portion 2 in the present embodiment.
Since the other end 20b side of the first electric wire 20 is pushed in the direction of the arrow A when the central portions of the second and the second wires 32 are in a molten state, the conductor exposed portion 22 is replenished with the conductor material corresponding to the constricted portion. As a result, as shown in FIG. 2B, the molten conductor is solidified with the constriction eliminated.

Therefore, the connection strength is increased by eliminating the constriction. At this time, the molten conductor replenished by pushing also turns to the conductor exposed portion 32 side of the second electric wire 30, so that the constriction on the conductor exposed portion 32 side does not occur.

As described above, the two electric wires 20, 30 can be directly connected by laser welding without any constriction without using a dedicated terminal fitting or the like, so that a reliable and strong electric wire connecting portion can be obtained. be able to. Also, the electric wire 2
When pushing and moving 0, it is only necessary to rotate the motor 62, so the work is simple.

In the above embodiment, the case where only the other end 20a side of the first electric wire 20 is pushed and moved toward the welding portion 58 has been shown, but the one end 20a side is also pushed and moved toward the welding portion 58 at the same time. You may do it.

Further, in the above embodiment, the case where only the first electric wire 20 side is pushed and moved is shown, but as shown in FIG.
On the second electric wire 30 side as well, if the pushing mechanism 60 newly provided pushes and moves toward the welded portion 58 as indicated by the arrow B during welding, the effect of eliminating the constriction can be further improved, and the connection can be made. Strength increases more. In that case also, the ends 30a and 30b of the second electric wire 30 are welded to the welded portion 5
Of course, it may be configured so as to push and move toward 8.

Further, the end portion of the second electric wire 30 is not limited to the intermediate connection between the electric wires 20 and 30 but the end portion of the second electric wire 30 is T-shaped or Y-shaped in the conductor exposed portion 22 formed in the longitudinal middle portion of the first electric wire 20. The present invention can also be applied to the case of joining to. In that case, the first electric wire 20 side may be pushed and moved during welding.

Further, as shown in FIG. 4, the present invention can be applied even when the mating partner is the terminal fitting 45. That is, if the other party is the terminal fitting 45, the electric wire 2
The end of 0 or a position near the end is peeled off to form the exposed conductor portion 22, which is placed on the terminal fitting 45,
The caulking portion 46 caulks. Then, in this state, the conductor exposed portion 22 is superposed on the welding plate portion 47 to form the superposed portion 4
Laser weld No. 9. Also in this case, the electric wire 20 during welding
By pushing and moving to the welded portion 58 side, it is possible to perform welding while suppressing the occurrence of constriction on the conductor exposed portion 22 side.

When the conductors in the electric wires 20 and 30 are single wires, the constriction is relatively small, but when the conductor is composed of a bundle of fine wires such as twisted wires, the air layer is in the conductor. Therefore, the scattering at the time of laser welding tends to be large. Therefore, in such a case, as shown in FIG. 5, the conductor exposed portion 22 is crushed by a press in advance (25 in FIG. 5 is a portion crushed by the press) to make a dense state, and then laser welding is performed. To do. Thereby, the squeezing can be reduced, and the squeezing elimination action by the push movement can be made more reliable.

Further, in the above embodiment, the pushing mechanism 60 is used.
Although the portion facing the drive roll 63 is used as the cradle 61, a roll may be provided instead of the cradle 61. In that case, the lower roll may be the drive roll.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG.
An example will be described. Also in this embodiment, similarly to the first embodiment,
Insulating coating 2 is provided on the middle portion of the two electric wires 20 and 30 in the longitudinal direction.
A case is shown in which the exposed conductor portions 22 and 32 from which the conductors 1 and 31 are peeled off are formed, the exposed conductor portions 22 and 32 are crossed and overlapped, and the overlapped portion 40 is joined by laser welding.

The procedure of joining will be described with reference to FIG.

First, as shown in FIGS. 6 (a) and 6 (b),
By removing the insulating coating 21 on the intermediate portion of the first electric wire 20 using the cutter 51, the conductor exposed portion 22 having a required size is obtained.
To form. Then, as shown in FIG. 3C, one end 20 of the electric wire 20 having a conductor exposed portion 22 formed in the middle portion in the longitudinal direction.
A is fixed by a pressing jig 52. Here both ends 20
It does not matter if a and 20b are fixed.

Next, as shown in FIG. 6 (d), as a supplementary conductor, a copper plate (which may be a copper strip) 71 formed in the shape of a thin rod is drawn from the reel 72 while the tip portion 71a of the copper plate 71 is being fed. Is supplied to the upper surface position of the conductor exposed portion 22 by a delivery roll 82 driven by a motor 81.
In this case, the copper plate 71 is provided with notches 71b at its side edges at a predetermined pitch as shown in FIG. 6 (d-1), which facilitates fusing at that position. Further, since the feeding position of the copper plate 71 is diagonally above the conductor exposed portion 22 (this position does not interfere with the laser welding machine 55), the tip portion 71a of the copper plate 71 has the bending tool 7
It is bent at an angle by 5 and is positioned in parallel with the conductor exposed portion 22 arranged just horizontally. The width of the copper plate 71 is preferably equal to or less than the beam diameter of laser welding (for example, about 1 mm).

Then, the tip portion 71a of the copper plate 71 is positioned on the exposed conductor portion 22, and then the first electric wire 2 is placed thereon.
The second electric wire 30 is arranged so as to intersect with 0, and the conductor exposed portion 32 similarly provided at the intermediate portion of the second electric wire 30 is provided on the conductor exposed portion 22 of the first electric wire 20. The copper plate 71 is superposed with the tip portion 71a sandwiched therebetween. Fig. 6 (d-
2) shows the overlapping portion 40 in an enlarged manner. And
In this state, the one end 30a of the second electric wire 30 is held by the holding jig 52. Also in this case, both ends may be fixed. Next, welding is performed by irradiating a laser beam 57 toward the overlapping portion 40 from a laser welding machine 55 arranged directly above the overlapping portion 40 of the two conductor exposed portions 22 and 32.

Then, normally, when laser welding is performed, constrictions occur on both sides of the welded portion, but since the copper plate 71 is supplemented to the welded portion as an auxiliary conductor during welding, a sufficient amount of molten metal is secured, The constriction will not occur and the connection strength will increase. Further, since the conductor is directly joined by the laser, it is possible to reduce the size, weight and cost of the connecting portion, as in the first embodiment.

Further, in this embodiment, the continuous copper plate 71 is used.
Since the tip portion 71a of the copper plate 71 is sent out and supplied to the welded portion 58, the amount of the copper plate 71 to be supplied at the time of one welding can be appropriately adjusted, and the copper plate 71 can be welded one after another.
Can be sent intermittently. Therefore, it is possible to flexibly deal with the case where a large number of welds of the same type or a large number of different types are performed, and the copper plate 71 can be easily supplied.

Further, since the tip end portion 71a of the copper plate 71 is bent obliquely and the tip end portion 71a which is bent obliquely is made to extend substantially parallel to the conductor exposed portion 22, the position of the feeding mechanism of the copper plate 71 is set as follows. It can be arranged with a margin at a position that does not interfere with the laser welding machine, and the tip portion 71a of the copper plate 71 can be supplied to the welded portion 58 at an appropriate position and in an appropriate posture. There is no risk of supply failure. Furthermore, since the tip end portion 71a of the copper plate 71 is sandwiched between the conductor exposed portions 22 and 32 of both electric wires 20 and 30, the copper plate 71 is not displaced during welding, and stable welding is possible. Further, the copper melt is spread over both conductor exposed portions 22 and 32 in good balance.

Further, the copper plate 71 is provided with a notch portion 71b so that it can be separated by a necessary amount each time welding is performed.
When the tip portion 71a of the copper plate 71 is melted in accordance with the laser welding, the tip portion 71a is automatically cut off at the position of the cutout portion 71b. Therefore, since a proper amount of copper is always supplied to the welded portion 58, it is possible to create a connection portion having a constant quality. If the separation cannot be reliably performed, the molten tip portion 71a can be reliably separated by moving the copper plate 71, for example, as shown by the arrow C.

In the above embodiment, the case where the copper plate 71 is formed into a rod shape and continuously fed is shown. However, a small piece of copper (conductor piece) is prepared and welded each time. Alternatively, copper (auxiliary conductor) may be supplied to the welded portion 58 in the form of a small piece. In that case, a small piece of copper may be attached to the exposed conductor portion 22 in advance by some means. In such cases, it is easier to supply the proper amount of copper.

When the conductors in the electric wires 20, 30 are composed of a bundle of fine wires such as twisted wires, the conductor exposed portions 22, 32 are crushed by pressing as in the first embodiment. If laser welding is performed, the same effect as that of the first embodiment can be obtained. The subsequent work will be easier if the small pieces of copper are pressed together, especially when pressing.

Further, the present embodiment can be applied to other than the intermediate connection of the electric wires as in the first embodiment.

[0058]

As described above, according to the first aspect of the invention, since the electric wire is directly joined to the other member by laser welding, unlike the case where the dedicated terminal fitting is used for the connection, It is possible to reduce the size, weight and cost. Further, since it is possible to suppress the generation of the constriction of the conductor due to the laser welding, it is possible to enhance the connection strength.

According to the invention of claim 2, since the electric wire is directly joined to the other member by laser welding, the size, weight and cost of the connecting portion can be reduced as in the invention of claim 1. You can Further, since it is possible to suppress the generation of the constriction of the conductor due to the laser welding, it is possible to enhance the connection strength. Also, feed the tip of the rod-shaped auxiliary conductor.
Since it protrudes and is supplied to the welded part, the auxiliary conductor can be securely and
It can be easily supplied to the welded part and the supply of auxiliary conductor
You can freely adjust the amount and the delivery timing.
be able to. Therefore, many of the same kind or many of different kinds
It is possible to flexibly deal with welding of
The conductor can be easily supplied. Also, auxiliary guidance
The body is configured to be delivered to the weld from an obliquely upper position, for example.
The auxiliary conductor feeding device layer
It's easier to do things. In addition, the auxiliary conductor from the diagonal direction
The proper position and posture for the welded part
Since auxiliary conductor can be supplied with
Always create good quality connections without risk
be able to.

According to the third aspect of the invention, every welding is performed once.
Since a proper amount of auxiliary conductor is supplied, the quality is constant.
Can make connections .

According to the invention of claim 4, the separation is surely performed.
Can be carried out by supplying an appropriate amount of auxiliary conductor to the weld.
Therefore, it is possible to create a connection part having a constant quality .

According to the invention of claim 5, the auxiliary conductor is welded.
Since it is sandwiched between the parts to be tried, there is no auxiliary conductor during welding.
Don't worry about it coming off, it will surely melt and contribute to the connection.
Can be made .

According to the invention of claim 6, two or more electric wires
The problem of constriction when connecting the
The continuous strength can be increased .

According to the invention of claim 7, the occurrence of the constriction is confirmed.
It can be pressed down really and the connection strength is increased stably.
You can

According to the invention of claim 8 , the terminal is connected to the electric wire.
Even if you continue to connect with high strength by suppressing the occurrence of constriction
You can

According to the invention of claim 9, the conductor has a plurality of thin wires.
Even when it is composed of a bundle of lines, it effectively prevents the occurrence of necking.
The connection strength can be increased .

According to the invention of claim 10, the auxiliary conductor is guided.
Since it is supplied in the form of a body piece, an appropriate amount of auxiliary conductor is always welded.
Can be supplied to the
Moreover, a complicated mechanism such as a feeding mechanism is unnecessary. Well
Also, when pressing the exposed conductor part, the conductor piece is welded at the same time.
Since it is attached to the place, it takes time to supply the auxiliary conductor.
The auxiliary conductor can be reliably and easily supplied to the proper position.
You can

According to the invention of claim 11, the motor is operated.
You can push and move the wire easily and securely just by
It is possible to eliminate the constriction during welding .

[0069]

[Brief description of drawings]

FIG. 1 is an explanatory view showing a procedure for carrying out a laser welding method according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an effect of the first embodiment of the present invention,
(A) is a side view of the welded part shown as a comparative example, (b) is a side view showing the welded part according to the present embodiment.

FIG. 3 is an explanatory diagram of a modified example of the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of another modification of the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of still another modification of the first embodiment of the present invention.

FIG. 6 is an explanatory view showing a procedure for carrying out the laser welding method according to the second embodiment of the present invention.

FIG. 7 is an explanatory view of a conventional example, (a) is a plan view,
(B) is a side view.

FIG. 8 is a perspective view showing another conventional example.

[Explanation of symbols]

20 first electric wire 20b The other end (one side) 21 Insulation coating 22 Conductor exposed part 30 Second electric wire (other member) 32 Conductor exposed part 40 Overlap part 45 Terminal fittings (other members) 49 Overlap part 58 Weld 61 pedestal 62 motor 63 drive roll 71 Copper plate (auxiliary conductor) 71a tip 71b Notch

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Claims (11)

(57) [Claims] 1. A conductor-exposed portion from which an insulating coating is peeled off is formed on an electric wire, the conductor-exposed portion is overlapped with another member, and the superposed portion is laser-welded. A laser welding method for an electric wire, characterized in that at least one side of the conductor exposed portion in the longitudinal direction is moved to the welding portion side. 2. An electric wire is provided with a conductor exposed portion from which an insulating coating is peeled off, the conductor exposed portion is superposed on another member, and the superposed portion is laser-welded. On the other hand, the auxiliary conductor is formed in a rod shape, and the tip end portion thereof is bent obliquely, and the rod-shaped auxiliary conductor is sent out to the welding portion, and the tip end portion bent obliquely is made substantially parallel to the conductor exposed portion. A laser welding method for electric wires, characterized in that the laser welding is carried out along with it. 3. The laser welding method for an electric wire according to claim 2, wherein a notch portion for separating a melted tip portion is formed at each outer circumference of the rod-shaped auxiliary conductor at intervals in the longitudinal direction. A laser welding method for an electric wire, which is characterized by being provided. 4. The laser welding method for an electric wire according to claim 3, wherein the rod-shaped auxiliary conductor is moved when a tip portion of the auxiliary conductor is melted. 5. The method for laser welding an electric wire according to claim 2, wherein the auxiliary conductor is sandwiched between a conductor exposed portion of the electric wire and another member. Laser welding method for electric wires. 6. The laser welding method for an electric wire according to claim 1, wherein the other member is also an electric wire, and the conductor exposed portion is formed at a longitudinal intermediate portion of both electric wires. A laser welding method for electric wires, characterized in that the conductor exposed portions of both electric wires are superposed in a crossing state, and the superposed portions are laser-welded. 7. The laser welding method for an electric wire according to claim 6, wherein at least one side of the conductor exposed portion of the electric wire as the other member in the longitudinal direction is pushed and moved to the welding portion side. Laser welding method for electric wires. 8. The method of laser welding an electric wire according to claim 1, wherein the other member is a terminal fitting, and the conductor exposed portion of the electric wire is superposed on the terminal fitting. A laser welding method for an electric wire, characterized in that the overlapping portion is laser-welded. 9. The method for laser welding an electric wire according to claim 1, wherein when the conductor in the electric wire is a bundle of a plurality of thin wires, the conductor exposed portion is crushed by a press. A laser welding method for electric wires, characterized in that the laser welding is performed first. 10. An electric wire is formed with a conductor exposed portion from which an insulating coating is peeled off, and the conductor exposed portion is superposed on another member,
When laser welding the overlapping portion, an auxiliary conductor is supplied to the welding portion during laser welding, and when the conductor in the electric wire is a bundle of a plurality of thin wires, the auxiliary conductor is an independent conductor piece. And crushing the conductor exposed portion together with the conductor piece as the auxiliary conductor by pressing,
A laser welding method for an electric wire, comprising: attaching the conductor piece to an exposed conductor portion and then performing laser welding. 11. The method for laser welding an electric wire according to claim 1, wherein the electric wire placed on a pedestal or a roll is pushed and moved so as to face the pedestal or the roll. A laser welding method for electric wires, which is performed by rotating a drive roll that holds the electric wires with a motor.