JP-7854619-B2 - Laser processing apparatus and laser processing method

JP7854619B2JP 7854619 B2JP7854619 B2JP 7854619B2JP-7854619-B2

Inventors

中川龍幸
吉田裕也
龍堂誠
山口秀明

Assignees

パナソニックＩＰマネジメント株式会社

Dates

Publication Date: 20260507
Application Date: 20210915

Claims (6)

A laser processing apparatus comprising a laser oscillator that outputs multiple laser beams of different wavelengths by wavelength synthesis, and a laser processing head that emits the laser beams output from the laser oscillator onto a workpiece, A manipulator for changing the position of the laser processing head relative to the workpiece, A distance measuring unit for measuring the distance between the laser processing head and the workpiece, A laser processing apparatus comprising a control unit that, based on the measurement results of the distance measuring unit, calculates the amount of movement of the laser processing head by the manipulator and the amount of focal length adjustment by changing the wavelength of the laser light, and changes the wavelength of the laser light while adjusting the distance between the laser processing head and the workpiece based on the amount of movement and the amount of focal length adjustment, thereby changing the focal position of the laser light emitted from the laser processing head.
In claim 1, The control unit lengthens the wavelength of the laser light when the focal position of the wavelength-combined laser light is shorter than the distance to the workpiece, and shortens the wavelength of the laser light when it is longer than the distance to the workpiece.
In claim 1 or 2, The laser oscillator comprises a plurality of laser diodes that emit a plurality of laser beams, and a diffraction grating that causes the laser beams to resonate externally. The plurality of laser diodes include a long-wavelength laser diode that emits laser light with a wavelength longer than the central wavelength of the wavelength-combined laser light, and a short-wavelength laser diode that emits laser light with a wavelength shorter than the central wavelength. The control unit selectively operates the long-wavelength laser diode or the short-wavelength laser diode to change the incident angle of the laser light on the diffraction grating, thereby changing the wavelength of the laser light.
In claim 1 or 2, The laser oscillator comprises a plurality of laser diodes that emit a plurality of laser beams, a diffraction grating that causes the laser beams to resonate externally, and an angle adjustment mechanism that adjusts the tilt angle of the diffraction grating relative to the laser diodes. The control unit operates the angle adjustment mechanism to change the incident angle of the laser light on the diffraction grating, thereby changing the wavelength of the laser light in the laser processing apparatus.
A laser processing method comprising combining multiple laser beams of different wavelengths and emitting the combined laser beam from a laser processing head toward a workpiece, A first step is to measure the distance between the laser processing head and the workpiece, A laser processing method comprising : a second step of calculating the amount of movement of the laser processing head and the amount of focal length adjustment by changing the wavelength of the laser light based on the measurement results in the first step, and changing the focal position of the laser light emitted from the laser processing head by changing the wavelength of the laser light while adjusting the distance between the laser processing head and the workpiece based on the amount of movement and the amount of focal length adjustment.
In claim 5, In the second step, a laser processing method is provided in which the wavelength of the combined laser light is lengthened when the focal position of the combined laser light is shorter than the distance to the workpiece, and the wavelength of the laser light is shortened when the focal position is longer than the distance to the workpiece.

Description

This invention relates to a laser processing apparatus and a laser processing method. Patent Document 1 discloses a configuration that increases the machining depth for thick workpieces by focusing the beam at different focal points on the optical axis and repeatedly illuminating the laser light in order of increasing wavelength, thereby moving the center of machining from the surface of the workpiece in order of increasing depth. Japanese Patent Publication No. 2008-44000 This is a schematic diagram showing the configuration of the laser processing apparatus according to this embodiment 1.This is a schematic diagram showing the configuration of a laser oscillator.This is a diagram to explain the principle of wavelength synthesis.This graph shows the relationship between the measurement location and the power density ratio.This is a schematic diagram showing the configuration of a laser oscillator when a long-wavelength laser diode is in operation.This graph shows the relationship between the wavelength and light intensity of a laser light with a longer wavelength.This is a schematic diagram showing the configuration of a laser oscillator when a short-wavelength laser diode is in operation.This graph shows the relationship between the wavelength and light intensity of a shortened laser light.This figure shows the state in which the focal position of the laser beam is changed according to the distance to the workpiece.This figure shows the state in which the focal position of the laser beam is changed according to the distance to the workpiece.This figure shows the state in which the focal position of the laser beam is changed according to the distance to the workpiece.This figure shows the controllable amount of the focal position and the power density.This graph shows the relationship between the laser light emission time and output power.This graph shows the relationship between the processing speed of the laser beam and the amount of travel required to reach the rise time.This is a schematic diagram showing the configuration of the laser oscillator according to this second embodiment.This diagram illustrates the principle by which laser light becomes longer in wavelength based on the tilt angle of the diffraction grating.This graph shows the relationship between the wavelength and light intensity of a laser light with a longer wavelength.This is a schematic diagram showing the configuration of a laser oscillator with the diffraction grating tilted inward.This diagram illustrates the principle by which laser light is shortened in wavelength based on the tilt angle of the diffraction grating.This graph shows the relationship between the wavelength and light intensity of a shortened laser light.This is a schematic diagram showing the configuration of the laser oscillator according to this third embodiment.This diagram illustrates the principle by which laser light becomes longer in wavelength based on the tilt angle of the diffraction grating.This is a schematic diagram showing the configuration of a laser oscillator with the diffraction grating tilted inward.This diagram illustrates the principle by which laser light is shortened in wavelength based on the tilt angle of the diffraction grating.This is a schematic diagram showing the configuration of the laser oscillator according to this fourth embodiment.This is a schematic diagram showing the configuration of a laser oscillator with the diffraction grating tilted inward. The embodiments of the present invention will be described below with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended to limit the present invention, its applications, or its uses. Embodiment 1 As shown in Figure 1, the laser processing apparatus 1 comprises a laser oscillator 10, an optical fiber 2, a laser processing head 3, an assist gas supply device 4, a manipulator 5, and a control unit 6. The laser oscillator 10 outputs laser light having multiple wavelength components (hereinafter referred to as multi-wavelength laser light) and directs it into the optical fiber 2. The optical fiber 2 transmits the multi-wavelength laser light output by the laser oscillator 10 to the laser processing head 3. The laser processing head 3 emits multi-wavelength laser light transmitted through the optical fiber 2 onto the workpiece 30. The workpiece 30 can be made of materials such as mild steel, stainless steel, or aluminum alloy. The laser processing head 3 is equipped with a distance measuring unit 15. The distance measuring unit 15 is composed of, for example, a capacitive sensor. The distance measuring unit 15 measures the distance between the laser processing head 3 and the workpiece 30. The measured value obtained by the distance measuring unit 15 is transmitted to the control unit 6. The assist gas supply device 4 is connected to the laser processing head 3. The assist gas supply device 4 supplies assist gas to the