US-20260124701-A1 - LASER WELDING DEVICE AND LASER WELDING METHOD

US20260124701A1US 20260124701 A1US20260124701 A1US 20260124701A1US-20260124701-A1

Abstract

A laser welding device includes a first laser oscillator configured to generate a first laser beam, a second laser oscillator configured to generate a second laser beam, and a processing head configured to irradiate a workpiece with the first laser beam and the second laser beam. The first laser beam and the second laser beam are radiated substantially in parallel at a prescribed interval in a direction along a welding direction. The second laser beam is radiated toward a keyhole formed by the first laser beam.

Inventors

Jingbo Wang
MASATOSHI NISHIO
Toshihiro OSUMI
KENZO SHIBATA
Atsuki Yamamoto

Assignees

PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20260107
Priority Date: 20230714

Claims (14)

1 . A laser welding device comprising: a first laser oscillator that generates a first laser beam; a second laser oscillator that generates a second laser beam; and a processing head that irradiates a workpiece with the first laser beam and the second laser beam, wherein the first laser beam and the second laser beam are radiated in parallel at a prescribed interval in a direction along a welding direction, and the second laser beam is radiated toward a keyhole formed by the first laser beam.
2 . The laser welding device according to claim 1 , wherein the second laser beam is radiated to a rear side of the keyhole in a direction opposite to the welding direction.
3 . The laser welding device according to claim 1 , wherein the processing head controls an irradiation position of the second laser beam such that the second laser beam draws a prescribed trajectory.
4 . The laser welding device according to claim 3 , wherein the prescribed trajectory is an arc connecting two intersection points of two parallel straight lines parallel to a weld line of the workpiece and a circumference of a circle centered on an irradiation position of the first laser beam, and a distance between each of the intersection points and the weld line is a prescribed distance.
5 . The laser welding device according to claim 3 , wherein the prescribed trajectory is a trajectory along an orthogonal direction orthogonal to a weld line of the workpiece, and is a line segment connecting two points at a prescribed distance from the weld line.
6 . The laser welding device according to claim 3 , wherein the prescribed trajectory is a trajectory along a direction connecting an irradiation position of the first laser beam and the irradiation position of the second laser beam, and is a line segment connecting two points each located at a prescribed distance around a position separated from the first laser beam by the prescribed interval.
7 . The laser welding device according to claim 3 , wherein the prescribed trajectory is a circumference centered on a position separated from an irradiation position of the first laser beam by the prescribed interval.
8 . The laser welding device according to claim 7 , wherein a radius of the circumference is equal to or less than a beam radius of the first laser beam.
9 . The laser welding device according to claim 4 , wherein the prescribed distance is equal to or less than a first beam radius of the first laser beam.
10 . The laser welding device according to claim 1 , wherein the first laser beam and the second laser beam are radiated in an order of the first laser beam and the second laser beam in the welding direction.
11 . The laser welding device according to claim 1 , wherein a beam radius of the first laser beam is equal to or larger than a beam radius of the second laser beam.
12 . The laser welding device according to claim 1 , wherein the processing head includes a Galvano unit capable of controlling an irradiation position of the second laser beam.
13 . The laser welding device according to claim 1 , wherein the processing head includes a mirror that controls an irradiation position of the second laser beam on a two-dimensional coordinate.
14 . A laser welding method performed by a laser welding device, the laser welding device including a first laser oscillator that generates a first laser beam, a second laser oscillator that generates a second laser beam, and a processing head that irradiates a workpiece with the first laser beam and the second laser beam, the laser welding method comprising: radiating the first laser beam and the second laser beam substantially in parallel at a prescribed interval in a direction along a welding direction; and radiating the second laser beam toward a keyhole formed by the first laser beam.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation of International Application No. PCT/JP2024/022975 filed on Jun. 25, 2024, and claims priority from Japanese Patent Application No. 2023-116130 filed on Jul. 14, 2023, the entire content of which is incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to a laser welding device and a laser welding method. BACKGROUND ART Patent Literature 1 discloses a laser beam generation method in which laser beams are combined at a fiber end of a multi-clad fiber, particularly a double-clad fiber, and emitted from the other fiber end of the multi-clad fiber to generate output laser beams having different beam profile characteristics. In the laser beam generation method, input laser beams are optically coupled to at least a fiber core of the multi-clad fiber or at least one ring core of the multi-clad fiber, or the laser beams are at least coupled to the fiber core of the multi-clad fiber and at least coupled to at least one ring core. CITATION LIST Patent Literature Patent Literature 1: US2013/0223792A Non-Patent Literature Non Patent Literature 1: Nakamura, Improvement of Welding Quality by Beam Profile Control BrightLine Weld, Proceedings of 91st Laser Processing Society Conference, (2019), p. 87-91. SUMMARY OF INVENTION The present disclosure is made in view of circumstances in the related art, and provides a laser welding device and a laser welding method that more effectively prevent welding defects such as porosity or spatter. The present disclosure provides a laser welding device including a first laser oscillator configured to generate a first laser beam, a second laser oscillator configured to generate a second laser beam, and a processing head configured to irradiate a workpiece with the first laser beam and the second laser beam. The first laser beam and the second laser beam are radiated substantially in parallel at a prescribed interval in a direction along a welding direction. The second laser beam is radiated toward a keyhole formed by the first laser beam. Further, the present disclosure provides a laser welding method performed by a laser welding device including a first laser oscillator configured to generate a first laser beam, a second laser oscillator configured to generate a second laser beam, and a processing head configured to irradiate a workpiece with the first laser beam and the second laser beam. The laser welding method includes radiating the first laser beam and the second laser beam substantially in parallel at a prescribed interval in a direction along a welding direction, and radiating the second laser beam toward a keyhole formed by the first laser beam. According to the present disclosure, welding defects such as porosity or spatter can be more effectively prevented. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a schematic configuration example of a laser welding device according to Embodiments 1 and 2; FIG. 2 schematically shows a configuration example of a processing head in Embodiment 1; FIG. 3 shows an example of a positional relationship between a first laser beam and a second laser beam relative to a weld line; FIG. 4 is a top view showing an arrangement example of the first laser beam and the second laser beam; FIG. 5 is an AA-AA cross-sectional view showing an example of a melt pool and a keyhole in Embodiments 1 and 2; FIG. 6 shows a first scanning trajectory example of the second laser beam; FIG. 7 shows a second scanning trajectory example of the second laser beam; FIG. 8 shows a third scanning trajectory example of the second laser beam; FIG. 9 shows a fourth scanning trajectory example of the second laser beam; FIG. 10 shows a first scanning speed example of the second laser beam; FIG. 11 shows a second scanning speed example of the second laser beam; FIG. 12 schematically shows a configuration example of a processing head in Embodiment 2; and FIG. 13 shows an example of a melt pool and a keyhole in the related art. DESCRIPTION OF EMBODIMENTS Background of Present Disclosure Laser light has a high power density, can perform high-speed and high-quality welding, and is applied to welding of various workpieces. Various types of processing heads are used for laser welding. A highly functional device such as a Galvano head that can scan a welding point of a workpiece with laser light (in other words, a laser beam) at high speed is used instead of a simple device that includes a collimator lens and a focus lens and has a fixed optical axis. Here, a keyhole KH formed by a laser processing method in the related art will be described. FIG. 13 shows an example of a melt pool WP and the keyhole KH in the related art. The keyhole KH shown in FIG. 13 shows an instantaneous shape for easy understanding of description, and the present disclosure is not limited thereto. When the laser power density is sufficiently high, the keyhole KH having a depth L is formed in the melt pool WP by a laser beam LB. Al