EP-4737048-A1 - LASER WELDING APPARATUS

EP4737048A1EP 4737048 A1EP4737048 A1EP 4737048A1EP-4737048-A1

Abstract

A laser head (10) changes the emission position of a laser beam (LB) relative to the tip of a filler wire (WA) during laser filler welding, and performs a scanning operation along an emission path (SD) that has a convex section (30) extending in a direction intersecting a welding direction (WD) and protruding in the opposite direction to the welding direction. The filler wire can thus be smoothly melted in the laser filler welding.

Inventors

WANG, JINGBO
NISHIO, MASATOSHI
OSUMI, Toshihiro
ISHII, Yuya
TAKAHASHI, WATARU
YOSHIMURA, Shukoh
SHIBATA, Kenzo
YAMAMOTO, ATSUKI

Assignees

Panasonic Intellectual Property Management Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20251009

Claims (4)

A laser welding apparatus including a wire feeding unit that feeds a filler wire toward a workpiece, a laser head that emits a laser beam toward a tip of the filler wire to perform laser filler welding on the workpiece, and a manipulator that moves the laser head in a predetermined welding direction, the laser welding apparatus comprising: an emission position changing unit that performs a scanning operation that changes an emission position of the laser beam relative to the tip of the filler wire; and a control unit that controls an operation of the emission position changing unit such that, during the laser filler welding, the scanning operation is performed along an emission path that includes a convex section extending in a direction intersecting the welding direction and protruding in an opposite direction to the welding direction.
The laser welding apparatus of claim 1, wherein the emission path includes a plurality of the convex sections.
The laser welding apparatus of claim 1 or 2, wherein the workpiece is made of a 2000-series, 6000-series, or 7000-series aluminum alloy, and the filler wire is made of a 4000-series aluminum alloy.
The laser welding apparatus of claim 1 or 2, wherein the control unit controls the operation of the emission position changing unit such that a scanning speed during the scanning operation is constant.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Japanese Patent Application No. 2024-186134 filed on October 22, 2024, the entire disclosure of which is incorporated herein by reference. BACKGROUND The present disclosure relates to laser welding apparatuses. Japanese Unexamined Patent Application Publication No. 2022-077544 discloses a welding method in which metal plates are butt-welded together by laser welding while feeding a filler wire into the gap between the metal plates. In Japanese Unexamined Patent Application Publication No. 2022-077544, a laser beam moves along the gap while oscillating across it. As the laser beam moves, a wire feeding unit operates to start feeding the filler wire into the gap from the front side toward the rear side in the welding direction. However, during the wire feeding operation, the tip of the filler wire may wobble, causing the position of the tip of the filler wire relative to the workpiece to vary. In such a case, the filler wire may not be sufficiently irradiated with the laser beam, and smooth melting of the filler wire may be hindered. The present disclosure has been made in view of the above circumstances, and an object thereof is to enable the filler wire to be smoothly melted in laser filler welding. SUMMARY According to a first aspect, a laser welding apparatus including a wire feeding unit that feeds a filler wire toward a workpiece, a laser head that emits a laser beam toward a tip of the filler wire to perform laser filler welding on the workpiece, and a manipulator that moves the laser head in a predetermined welding direction includes: an emission position changing unit that performs a scanning operation that changes an emission position of the laser beam relative to the tip of the filler wire; and a control unit that controls an operation of the emission position changing unit such that, during the laser filler welding, the scanning operation is performed along an emission path that includes a convex section extending in a direction intersecting the welding direction and protruding in an opposite direction to the welding direction. In the first aspect, even when the tip of the filler wire vibrates and wobbles during feeding of the filler wire, causing the position of the tip of the filler wire to vary relative to the workpiece, the filler wire can still be smoothly melted by the laser beam emitted along the emission path that includes the convex section extending in a direction intersecting the welding direction and protruding in the opposite direction to the welding direction. As a result, a wide, high-quality weld bead can be obtained. According to a second aspect, in the laser welding apparatus of the first aspect, the emission path includes a plurality of the convex sections. In the second aspect, the filler wire can be smoothly melted by the laser beam emitted along the emission path including the convex sections. According to a third aspect, in the laser welding apparatus of the first or second aspect, the workpiece is made of a 2000-series, 6000-series, or 7000-series aluminum alloy, and the filler wire is made of a 4000-series aluminum alloy. In the third aspect, by appropriately determining the material of the workpiece and the material of the filler wire, the likelihood of defects such as weld cracks can be reduced. According to a fourth aspect, in the laser welding apparatus of the first or second aspect, the control unit controls the operation of the emission position changing unit such that a scanning speed during the scanning operation is constant. In the fourth aspect, the energy of the laser beam can be uniformly applied to the tip of the filler wire. As a result, even when the feeding speed of the filler wire is increased, the filler wire can be smoothly melted. The present disclosure enables smooth melting of the filler wire in laser filler welding. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic configuration of a laser welding apparatus according to a first embodiment.FIG. 2 is a side view illustrating the arrangement of a laser beam and a filler wire.FIG. 3 is a plan view illustrating the emission path of the laser beam.FIG. 4 is an enlarged plan view of the emission path of the laser beam.FIG. 5 shows coordinates on the emission path.FIG. 6 is a graph illustrating the relationship among the angle, coordinates, and scanning speed when drawing a Lissajous waveform.FIG. 7 is a graph illustrating the relationship among the angle, coordinates, and scanning speed when drawing a Lissajous waveform in a second embodiment.FIG. 8 is an enlarged plan view of the emission path of the laser beam in a third embodiment.FIG. 9 shows coordinates on the emission path.FIG. 10 is a graph illustrating the relationship among the angle, coordinates, and scanning speed when drawing a Lissajous waveform.FIG. 11 is a graph illustrating the relationship among the angle, coordinates, and scanning speed when drawing a Lissa