Laser welding method and laser welding system
AssigneeNissan Motor Co., Ltd.
InventorNobuhiro Yoshikawa
Life of this patent
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Abstract
A focal point controlling section is configured and arranged to control a focal point of the laser beam outputted from a laser oscillator to selectively focus the laser beam on a surface of a workpiece. A laser irradiation position moving section is configured to move a laser irradiation position at which the laser beam strikes on the surface of the workpiece. A control unit is configured to change a heat amount imparted on the surface of the workpiece to switch between a welding state and a non-welding state by controlling at least one of the focal point controlling section and the laser irradiation position moving section while controlling the laser oscillator to continuously output the laser beam before and after switching between the welding state and the non-welding state.
Claims14
A laser welding method comprising:
- controlling a focal point of a laser beam outputted from a laser oscillator to selectively focus the laser beam on a surface of a workpiece;
- moving a laser irradiation position at which the laser beam strikes on the surface of the workpiece;
- and
- selectively switching between a welding state and a non-welding state by changing a distance between the focal point and where the laser beam strikes the surface of the workpiece such that in the welding state the focal point is aligned with respect to the surface of the workpiece and such that in the non-welding state the focal point is positioned away from the surface of the workpiece while continuously outputting the laser beam from the laser oscillator before and after the switching between the welding state and the non-welding state,
- the selectively switching between the welding state and the non-welding state further including switching to the welding state by starting to increase a laser output power of the laser oscillator from a low power level toward a power level required for welding at a prescribed amount of time before the laser irradiation position reaches a welding start point, and starting to align the focal point with respect to the surface of the workpiece at the welding start point.
A laser welding system comprising:
- a laser oscillator configured and arranged to output a laser beam to selectively weld a surface of a workpiece;
- a focal point controlling section including a lens set configured and arranged to control a focal point of the laser beam outputted from the laser oscillator to selectively focus the laser beam on the-surface of the workpiece;
- a laser irradiation position moving section configured and arranged to move a laser irradiation position at which the laser beam strikes on the surface of the workpiece;
- and
- a control unit configured to selectively switch between a welding state and a non-welding state by changing a distance between the focal point and where the laser beam strikes the surface of the workpiece such that in the welding state the focal point is aligned with respect to the surface of the workpiece and such that in the non-welding state the focal point is positioned away from the surface of the workpiece while controlling the laser oscillator to continuously output the laser beam before and after switching between the welding state and the non-welding state,
- the control unit being further configured to
- start increasing a laser output power of the laser oscillator from a low power level toward a power level required for welding at a prescribed amount of time before the laser irradiation position reaches a welding start point, and
- start aligning the focal point with respect to the surface of the workpiece at the welding start point to switch from the non-welding state to the welding state.
Dependencies are inferred from the claim text.