JPH11192567A - Metal sheet welding method - Google Patents

Abstract

(57) [Problem] Welding of a metal sheet that can perform stable welding without tilting the metal sheet at the center axis by welding using a laser beam and that can perform high-quality welding. Provide a way. SOLUTION: A metal thin plate 10 having a shaft fitting portion 11 formed at a center portion has a protruding shaft portion 21 fitted into the shaft fitting portion 11 and a shoulder portion 22 formed at the base of the protruding shaft portion 21. This is a method of welding a thin metal plate to be welded to the center shaft 20, and the periphery of the shaft fitting portion 11 of the thin metal plate 10 is fitted in a state where the projecting shaft portion 21 of the center shaft 20 is fitted to the shaft fitting portion 11 of the thin metal plate 10. With a plurality of pulsed laser beams 30 having the same energy while relatively rotating on the same circumference.
Are welded to the shoulder 22 at a plurality of locations.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of welding a metal sheet to a central axis, and more particularly to a method of welding a metal sheet by laser light.

[0002]

2. Description of the Related Art Conventionally, as a method of welding a thin metal plate to a central axis, for example, there is a method shown in FIG.

In this conventional welding method, a shaft fitting portion 111 formed of a circular hole provided at the center of a thin metal plate 110 is inserted into a protruding shaft portion 121 of a center shaft 120, and is positioned above the thin metal plate 110. 13 that presses down while pressing
0 and the central axis 120, the electrode 130 and the central axis 12
An electric current is passed from the electrode 150 connected to the wire 0 and the wires 141 and 142, and the thin metal plate 110 is welded to the central shaft 120 by heat generated by contact resistance.

[0004]

However, in the above-mentioned conventional welding method, the electrode 150 has a life, and it is necessary to replace the electrode 150 every several hundred shots, which is troublesome. was there.

In addition, there is a problem that there is a limit in performing high-quality welding because the flow of current greatly changes depending on the contact state due to the roughness and shape of the surface of the metal sheet 110.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and makes it possible to perform stable welding without tilting a thin metal plate on a central axis by welding using a laser beam, and to perform high-quality welding. It is an object of the present invention to provide a method of welding a metal sheet that can be performed.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a thin metal plate having a shaft fitting portion formed at a center portion, and a projecting shaft portion fitted into the shaft fitting portion and a projecting shaft portion. In a method of welding a thin metal plate to be welded to a center shaft having a shoulder formed at the base of a shaft portion, in a state where the projecting shaft portion of the center shaft is fitted to a shaft fitting portion of the thin metal plate,
Around the shaft fitting portion of the thin metal plate, a plurality of pulsed laser beams having equal energy are welded to a plurality of portions on the shoulder portion of the central axis while relatively rotating on the same circumference. .

In order to solve the above-mentioned problems, the method for welding a thin metal plate according to the present invention includes pressing a periphery of a shaft fitting portion of the thin metal plate with a pressing means, and excluding a plurality of points except for the pressing position by the pressing means. Is fixed with a pulsed laser beam having equal energy, and after removing the pressing means, around the shaft fitting portion of the thin metal plate, a plurality of pulsed laser beams are rotated relative to the shoulder of the central axis while rotating relatively. It is preferable to weld at a plurality of locations.

Further, in order to solve the above-mentioned problems, the method for welding a thin metal plate of the present invention presses the periphery of a shaft fitting portion of the thin metal plate with a pressing means, and applies a plurality of pulsed laser beams to the pressing means. Preferably, the plurality of pulsed laser beams are used to weld the periphery of the shaft fitting portion of the thin metal plate to the shoulder of the central shaft at a plurality of positions while rotating the periphery of the shaft fitting portion.

In order to solve the above-mentioned problems, a method for welding a thin metal plate according to the present invention includes: a fixed optical system fixed together with a laser device for irradiating a laser beam around the thin metal plate; A rotating optical system that irradiates laser light while rotating relative to the same circumference on the circumference of the shaft fitting portion, and from the fixed optical system, laser light having the same axis as the shaft fitting portion of the metal thin plate from the fixed optical system. When irradiating the laser light toward the periphery of the shaft fitting portion of the metal thin plate and condensing the laser light with a beam split mirror attached to the rotating optical system, light larger than the condensed spot diameter is emitted. A laser attached to the tip of the optical fiber while condensing on an optical fiber having an incident area and eliminating a change in a laser irradiation spot position due to a center fluctuation of laser light irradiation from the fixed optical system. The laser beam from the morphism barrel was irradiated toward the periphery of the shaft fitting portion of the metal sheet, it is preferable to multiple locations welded to the shoulder portion of the central axis around the shaft fitting portion of the sheet metal.

Furthermore, in order to solve the above-mentioned problems, the method for welding a metal sheet according to the present invention measures the height of the metal sheet on the same plane by a measuring means, and there is a fluctuation exceeding a certain height. In such a case, it is desirable to determine that there is a gap between the metal thin plate and a central axis supporting the metal thin plate to determine poor welding.

In order to solve the above-mentioned problems, in the method for welding a thin metal plate according to the present invention, the shaft fitting portion of the thin metal plate is formed by a circular hole into which the protruding shaft portion of the central shaft is fitted. Is preferred.

According to the present invention, the projecting shaft portion of the central shaft is fitted into the shaft fitting portion of the thin metal plate, and in this state, a plurality of the same thin plates having the same energy while rotating relative to each other on the same circumference. Since the laser beam is welded to the shoulder of the central axis at a plurality of points with pulsed laser light, the laser irradiation is performed in a well-balanced manner at the same energy and under the same conditions. Welding can be performed, and high-quality welding can be reliably performed.

The pressing means presses the periphery of the shaft-fitting portion of the thin metal plate and fixes it with a pulsed laser beam having equal energy. Then, the holding means is removed, and thereafter, the periphery of the shaft-fitting portion of the thin metal plate. Is welded to the shoulder of the central axis with a plurality of pulsed laser beams while rotating relative to each other,
Even if there is a gap in the thickness of the thin metal plate, good welding can be performed.

Further, the pressing means presses the periphery of the shaft fitting portion of the thin metal plate, and the pressing means and the plurality of pulsed laser beams rotate around the shaft fitting portion together with the plurality of pulsed laser beams while rotating around the shaft fitting portion. By welding a plurality of portions around the shaft fitting portion of the thin plate to the shoulder of the central shaft, good welding can be performed even if the gap amount of the thickness of the thin metal plate is large.

Further, if the periphery of the shaft fitting portion of the thin metal plate is welded with the laser light from the fixed optical system and the rotary optical system, the rotational optical By irradiating the laser beam from the system, it is possible to weld the periphery of the shaft fitting part of the thin metal plate to the shoulder of the central axis at multiple locations while eliminating the fluctuation of the laser irradiation spot position, and perform stable laser beam welding be able to.

Further, by measuring the height of the metal sheet on the same plane by the measuring means, it is possible to determine that there is a gap between the metal sheet and the central axis when there is a fluctuation exceeding a certain height. It is possible to judge defective welding by this measurement, so that the quality of welding can be easily and reliably detected.

Further, by forming the shaft fitting portion of the thin metal plate with a circular hole, the protruding shaft portion of the central shaft can be easily and reliably fitted into the shaft fitting portion formed of the circular hole, and welding work can be performed. It can be done easily and reliably.

Further, the shaft fitting portion of the thin metal plate is formed by a raised portion provided with a concave portion on the rear surface side into which the protruding shaft portion of the central shaft is fitted, and the concave portion on the rear surface side of the raised portion is formed by the central shaft. By fitting into the protruding shaft portion, it is possible to weld the protruded shaft portion of the central shaft portion in a sealed state from above without forming a gap between the metal sheet and the central shaft portion. It can be held in a stable state on the central axis, and stable welding can be performed.

[0020]

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

FIG. 1 shows a method for welding a thin metal sheet according to the first embodiment. The method for welding a thin metal sheet according to the first embodiment employs a shaft fitting comprising a circular hole at the center of a circular thin metal sheet 10. The part 11 is fitted into the projecting shaft part 21 of the center shaft 20,
The metal thin plate 10 is placed on the shoulder 22 of the central axis 20, and a pulsed laser beam 30 of equal energy and the same focused spot diameter is applied to a contact portion between the metal thin plate 10 and the shoulder 22 of the central axis 20.
Is irradiated while rotating around the shaft fitting portion 11 of the thin metal plate 10 to weld the same circumference of the thin metal plate 10 to the shoulder 22 of the central shaft 20.

The thickness of the thin metal plate 10 is preferably not more than 0.3 mm, the spot diameter of the pulsed laser beam 30 is preferably 0.1 mm, and the energy is preferably several joules.

It is preferable that the surface finish quality of the thin metal plate 10 be such that the irradiation waveform of the pulsed laser beam 30 is increased stepwise.

In the method for welding a metal sheet according to the first embodiment, the pulsed laser beam 30 is irradiated onto the metal sheet 10 in a well-balanced manner under the same energy and the same conditions. The reaction force is canceled, and the metal sheet 10 can be stably welded to the central axis 20 without inclination, and high-quality welding can be reliably performed.

FIG. 2 shows a method for welding a thin metal plate according to the second embodiment. The method for welding a thin metal plate according to the second embodiment employs a shaft fitting comprising a circular hole at the center of a circular thin metal plate 10. In a state where the portion 11 is fitted into the protruding shaft portion 21 of the central shaft 20, the protruding shaft portion 21 on the surface of the circular thin metal plate 10 is formed.
Holding means 4 consisting of holding pins
In a state where pressure is applied with equal force at 0, 40, the projecting shaft 2 is at a position rotated by 90 degrees from the holding means 40, 40.
Positions symmetrical from 1 are fixed by irradiating pulsed laser beams 30, 30 with equal energy and the same focused spot diameter.

Thereafter, after the holding means 40, 40 are removed, the entire periphery of the thin metal plate 10 is welded to the shoulder 22 of the central shaft 20 while irradiating the surface of the thin metal plate 10 with pulsed laser beams 30, 30. I do.

In the method of welding a thin metal plate according to the second embodiment, the surface of the thin metal plate 10 is pressed by the holding means 40, 40, and the periphery of the shaft fitting portion of the thin metal plate 10 is centered by the pulsed laser beams 30, 30. After fixing to the shoulder 22 of the shaft 20,
Since the entire circumference of the metal sheet is welded at a plurality of locations, good welding can be performed even if there is a gap in the sheet thickness of the metal sheet.

FIG. 3 shows a method of welding a thin metal plate according to the third embodiment. The method of welding a thin metal plate according to the third embodiment employs a shaft fitting comprising a circular hole at the center of a circular thin metal plate 10. In a state where the portion 11 is fitted into the projecting shaft portion 21 of the center shaft 20, the center shaft 20 is
The plurality of laser emission barrels 35 for generating the pulsed laser light 30 are rotated together with the holding means 41 while being pressed against the thin metal plate 10 so as to mesh with the protruding shaft portions 21 of the plurality of laser emission barrels 21. A plurality of portions around the shaft fitting portion 11 of the thin metal plate 10 are welded to the shoulder portion 22 of the center shaft 20 with the pulsed laser beam 30.

The holding means 41 formed by a holding rod is
In order to provide abrasion resistance, it is preferable to use a metal coated with a ceramic. Further, it is preferable that the point at which the metal thin plate 10 is pressed by the pressing means 41 be removed from the same circumference of the metal thin plate 10 where the pulsed laser light is irradiated so as not to damage the laser emission lens barrel 35.

In the method of welding a thin metal plate according to the third embodiment, the pressing means 41 presses the periphery of the shaft fitting portion 11 of the thin metal plate 10, and the pressing means 41 and the plurality of pulsed laser beams 30 are axially fitted together. While rotating around the part 11,
Since a plurality of pulsed laser beams 30 are used to weld the periphery of the shaft fitting portion 11 of the thin metal plate 10 to the shoulder 22 of the central shaft 20 at a plurality of locations, good welding can be performed even if there is some gap in the thickness of the thin metal plate 10. It can be performed.

FIG. 4 schematically shows a method for welding a thin metal plate according to the fourth embodiment. The method for welding a thin metal plate according to the fourth embodiment is based on the optical fiber 5 from the YAG laser device 51.
YAG laser light generated via the optical system 2
The light is collimated by the 0 convex lens 53, is reflected by the first half mirror 54 that reflects the YAG laser light at a high wavelength, and becomes a parallel beam 56 having a diameter of 2 cm centered on the laser beam center axis 55. Furthermore, this parallel beam 56
Is a second half mirror 61 attached to the same rotary optical system 60 as the exit lens barrel 35 and reflecting 50% of the YAG laser light.
And a third half mirror 62 that reflects 100% of the YAG laser light, is converged by two convex lenses 63, 63, and is incident on two optical fibers 64, 64.
At this time, the two condensing spots 65, 65 are condensed to be smaller than the incident cross-sectional area of the optical fibers 64, 64, so that the center of the laser beam of the fixed optical system 50 to which the convex lens 53 and the first half mirror 54 are attached. Shaft 55
Even if the center axis 66 of the rotary optical system 60 has a mechanical runout, the incident cross-sectional area of the optical fibers 64, 64 is always collected by the convex lenses 63, 63 which fluctuate due to the runout. Since it is larger than the light spots 65, 65, the optical fiber 6
4, 64 power fluctuations hardly occur. The laser light incident on the optical fibers 64 is irradiated on the thin metal plate 10 from the laser emission lens barrels 35 provided at the tips.

The conditions are as follows: optical fibers 52 and 6
For 4, 64, it is preferable to use the GI type rather than the SI type because the beam is concentrated at the center.

The focusing distance of the convex lenses 63, 63 is
In order to reduce the beam size, it is preferable that the length is shorter than the convex lens 53.

In the method for welding a thin metal plate according to the fourth embodiment, if the periphery of the shaft fitting portion 11 of the thin metal plate 10 is welded by laser light from the fixed optical system 50 and the rotary optical system 60, the fixed optical system 50 is welded. Irradiation of the laser beam from the rotating optical system 60 eliminates fluctuations in the laser irradiation spot position even when the laser beam irradiation from the
The periphery of the 0 shaft fitting portion 11 can be welded to the shoulder 22 of the central shaft 20 at a plurality of locations, and stable laser beam welding can be performed.

FIG. 5 shows a method of welding a metal sheet according to a fifth embodiment.

As shown in FIG. 6, the maximum point of the quality of the laser welding is the gap G of the contact surface at the welding point.
It is known as a well-known fact that the size of the steel has a great influence on the welding quality. The gap G is preferably 1/10 or less of the plate thickness, and if it is 1/4 or less, it is difficult to perform welding by ordinary YAG laser welding, and high-brightness laser characteristics that allow high penetration into the center are required. In any case, if the beam quality of the spot of the welding irradiation part is secured, FIG.
As shown in FIG. 5, the reference height H of the metal sheet 10 during or before and after laser welding is measured by the distance sensor 70, and if the change is within a certain amount, it can be considered that the sheet is almost good.

FIG. 7 shows a method of welding a thin metal plate according to the sixth embodiment, in which not only the height but also the inclination of the thin metal plate 10 can be detected by a laser beam instead of a distance sensor. is there.

The parallel laser light R1 emitted from the laser light source 75 is reflected on the surface of the thin metal plate 10 and strikes the linear sensor 76. If the metal sheet 10 is tilted as shown by a broken line, the linear sensor 76 is tilted by the linear sensor 76 to follow another path like a laser beam R2, compared to the case where the metal sheet 10 is horizontal as shown by a solid line. Can be detected.

FIG. 8 shows a method of welding a thin metal plate according to a modification of the above-described third embodiment, in which a pressing means 42 comprising a concave pressing rod is used instead of a pressing rod, and Of the center shaft 2 on the back side
In the case where the protruding portion 21a of the central shaft 20 is fitted into the protruding portion 21a of the center shaft 20, when the protruding portion 21a of the center shaft 20 is formed by the protruding portion 11A provided with the recess 11a into which the zero protruding portion 21 is fitted. The protruding portion 11A is pressed by pressing means 42 comprising a concave pressing rod, and the shaft fitting portion 11 of the thin metal plate 10 is pressed.
Is welded with the laser light 30 emitted from the emission lens barrel 35.

FIG. 9 shows a method of welding a thin metal plate according to a modification of the above-described fourth embodiment.
The YAG laser light from the A branch mirrors 66, 66 may be directly guided to the convex lenses 63, 63 by using the return mirrors 67, 67, and may be focused on the surface of the thin metal plate 10.

Further, as shown in FIG.
The optical fiber 52A from 1 may be directly guided to the emission barrels 35, 35, while the rotation direction of the rotating optical system 60B may be changed every half rotation.

In each of the above embodiments, a circular metal sheet has been described. However, the present invention is not limited to this. For example, a quadrilateral metal sheet can be applied.

[0043]

According to the present invention, a thin metal plate is irradiated with a laser beam in a well-balanced manner at equal energy and under the same conditions using a laser beam. , A stable welding can be performed without inclination around the central axis, and a high-quality welding can be performed.

[Brief description of the drawings]

FIGS. 1A and 1B show a welding method of a metal sheet according to a first embodiment of the present invention, wherein FIG. 1A is a partially sectional front view at the time of welding, and FIG. 1B is a plan view at the time of welding.

FIG. 2 shows a method for welding a metal sheet according to a second embodiment,
(A) is a plan view showing a state in which the metal thin plate is held down by the holding means and fixed to the central axis, (b) is a front view in the state of (a), and (c) is a state in which the holding means is removed and welding is performed. (D) is a front view in a state where the pressing means is removed.

FIG. 3 shows a method for welding a metal sheet according to a third embodiment;
(A) is a plan view at the time of welding, and (b) is a partially sectional front view at the time of welding.

FIG. 4 is a schematic front view showing a method for welding a metal sheet according to a fourth embodiment.

FIG. 5 is a partially sectional schematic front view showing a method of welding a metal sheet according to a fifth embodiment.

FIG. 6 is an explanatory diagram for explaining a gap of a metal sheet with respect to a central axis in the method for welding a metal sheet of the present invention.

FIG. 7 is an explanatory view showing a method for welding a metal sheet according to a sixth embodiment.

FIG. 8 is a partially sectional front view showing a method for welding a thin metal plate according to a modification of the third embodiment.

FIG. 9 is a schematic front view showing a method of welding a thin metal plate according to a modification of the fourth embodiment.

FIG. 10 is a schematic front view showing a method of welding a thin metal plate according to another modification of the fourth embodiment.

FIG. 11 is an explanatory view showing a conventional method for welding a thin metal plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Metal thin plate 11 Shaft insertion part 20 Center axis 21 Protruding shaft part 22 Shoulder part 30 Pulse laser beam 35 Emission lens barrel 40 Pressing means 41 Pressing means 42 Pressing means 50 Fixed optical system 51 Laser device 52 Optical fiber 52 First half mirror 60 Rotating optical system 61 Second half mirror 62 Third half mirror 64 Optical fiber 65 Focused spot 76 Linear sensor (measuring means)

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI G01B 11/30 101 G01B 11/30 101A (72) Inventor Fujio Kaneko 4-3-1 Tsunashimahigashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Matsushita Communication Industrial Inside (72) Inventor Shogo Asano 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama City, Kanagawa Prefecture Inside Matsushita Communication Industrial Co., Ltd. (72) Inventor Koji Funami 1006 Kadoma, Kazuma, Kadoma, Osaka Matsushita Electric Industrial Inside

Claims (7)

[Claims] 1. A metal thin plate having a shaft fitting portion formed at a central portion thereof is welded to a central shaft having a projecting shaft portion fitted into the shaft fitting portion and a shoulder formed at the base of the projecting shaft portion. In the method for welding a thin metal plate, the protruding shaft portion of the central shaft is fitted in the shaft fitting portion of the thin metal plate, and the periphery of the shaft fitting portion of the thin metal plate is relatively rotated on the same circumference. A method of welding a thin metal plate, wherein a plurality of pulsed laser beams having equal energy are welded at a plurality of positions to a shoulder of the central axis. 2. The pressing means presses down the periphery of the shaft fitting portion of the thin metal plate, and a plurality of positions except for the pressing position by the pressing means are fixed with pulsed laser light having equal energy, and the pressing means is removed. 2. The welding of the metal sheet according to claim 1, wherein a plurality of pulsed laser beams are welded to the shoulder of the central axis at a plurality of positions while rotating relatively around the shaft fitting portion of the metal sheet. 3. Method. 3. A plurality of pulsed laser beams are pressed by the pressing means around the shaft fitting portion of the thin metal plate, and the plurality of pulsed laser lights are rotated by the plurality of pulsed laser beams while rotating around the shaft fitting portion together with the pressing device. The method according to claim 1, wherein the periphery of the shaft fitting portion of the metal sheet is welded to the shoulder of the central axis at a plurality of locations. 4. A fixed optical system fixed together with a laser device for irradiating a laser beam around the thin metal plate and a laser beam while relatively rotating around the shaft fitting portion of the thin metal plate on the same circumference. Using a rotating optical system to irradiate, and irradiating a laser beam having the same axis as the shaft fitting portion of the thin metal plate from the fixed optical system toward the periphery of the shaft fitting portion of the thin metal plate, Is focused by a beam split mirror attached to the rotating optical system, and is focused on an optical fiber having a light incident area larger than the focused spot diameter, and the laser light from the fixed optical system is focused on. Irradiating a laser beam from the laser emission barrel attached to the tip of the optical fiber toward the periphery of the shaft fitting portion of the thin metal plate while eliminating the change in the laser irradiation spot position due to the core deflection of the irradiation. The method according to any one of claims 1 to 3, wherein the periphery of the shaft fitting portion of the thin metal plate is welded to a shoulder of the central shaft at a plurality of positions. 5. The height of the metal sheet on the same plane is measured by a measuring means, and when there is a variation of a certain height or more,
5. The thin metal sheet according to claim 1, wherein a gap between the thin metal sheet and a central axis supporting the thin metal sheet is measured to determine a poor welding. Welding method. 6. The thin metal plate according to claim 1, wherein the shaft fitting portion of the thin metal plate is formed by a circular hole into which the protruding shaft portion of the central shaft is fitted. Welding method. 7. The shaft fitting portion of the thin metal plate is formed by a raised portion provided with a concave portion on the back surface side into which the protruding shaft portion of the central shaft is fitted. The method for welding a metal sheet according to any one of the above.