Device and method for laser cutting a workpiece and producing workpiece parts

Patent metadata

Field	Value
Publication number	US-12042880-B2
Application number	US-202218263785-A
Country	US
Kind code	B2
Filing date	Mar 9, 2022
Priority date	Mar 9, 2021
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

Cutting a workpiece and producing workpiece parts are disclosed. The device has a cutting head with laser beam optics with a dynamic laser beam movement unit. A cutting head movement unit moves the laser beam over the workpiece. A control unit has a determination module to determine a movement trajectory of the laser beam, a memory unit from which at least one predetermined parameter selected from a movement parameter of the cutting head movement unit, a movement parameter of the laser beam movement unit and a parameter of a deviation of a cut contour from a predetermined contour is retrievable, and an optimization module for adjusting the movement trajectory by overlaying the movement of the laser beam via the cutting head with a high frequency beam-shaping movement of the laser beam via the laser beam movement unit based on the at least one predetermined parameter.

First claim

The invention claimed is:

1. A device for laser cutting a workpiece and producing workpiece parts, the device comprising:
a cutting head, the cutting head having an interface for a laser source for generating a machining laser beam with a power of at least 200 W or at least 1 kW,
an exit aperture for the machining laser beam, and
laser beam optics between the interface and the exit aperture,
the laser beam optics having at least one dynamic laser beam movement unit for producing a high frequency beam-shaping movement of the machining laser beam at least perpendicular to its direction of propagation;
a cutting head movement unit for performing a movement of the machining laser beam over the workpiece via the cutting head; and
a control unit for controlling the cutting head movement unit and the laser beam movement unit, the control unit comprising:
a determination module for determining at least one movement trajectory (X, Y) of the machining laser beam in at least one workpiece plane according to at least one predetermined contour (X, Y) of the workpiece parts to be produced; and
a memory unit from which at least one predetermined parameter selected from a movement parameter of the cutting head movement unit, a movement parameter of the laser beam movement unit and a parameter of a deviation of a cut contour from the predetermined contour is retrievable;
wherein the control unit comprises:
an optimisation module for adjusting the movement trajectory (X, Y) by overlaying the movement of the machining laser beam via the cutting head with the high frequency beam-shaping movement of the machining laser beam via the laser beam movement unit based on the at least one predetermined parameter retrievable from the memory unit;
wherein the optimisation module is configured for optimising the movement trajectory (X; Y) by redundantly partitioning the movement trajectory of the machining laser beam between the cutting head movement unit and the laser beam movement unit.

2. The device according to claim 1 , wherein the optimisation module is configured for adjusting and/or optimising at least one parameter selected from the movement parameter of the cutting head movement unit, the movement parameter of the laser beam movement unit and the parameter of a deviation of a cut contour from the predetermined contour, and for predetermining the at least one predetermined parameter.

3. The device according to claim 1 , wherein the movement parameter of the cutting head movement unit is at least one parameter selected from a dynamic limit (DG) of the cutting head movement unit, a rounding tolerance (VT) of the cutting head movement unit at an angle of the predetermined contour, and a rounding tolerance (VT) of the cutting head movement unit at a radius of the predetermined contour.

4. The device according to claim 1 , wherein the movement parameter of the laser beam movement unit is at least one parameter selected from a dynamic limit (DG) of the laser beam movement unit and a maximum movement amplitude of the machining laser beam that can be generated with the laser beam movement unit.

5. The device according to claim 1 , wherein the parameter of a deviation of a cut contour from the predetermined contour (X, Y) is at least one parameter selected from an estimated deviation, a parameter resulting from a measured deviation, a rounding of the cut contour at an angle of the predetermined contour, a rounding of the cut contour at a radius of the predetermined contour, an estimated surface defect (OD) of a cut edge, and a parameter resulting from a measured surface defect of a cut edge.

6. The device according to claim 1 , wherein the optimisation module for adjusting the movement trajectory is designed based on at least one increased rounding tolerance (VT) of the cutting head movement unit and is for compensating for the resulting deviation of the cut contour from the predetermined contour.

7. The device according to claim 1 , wherein a machine model (MM) representing the kinematic behaviour of the moving cutting head is stored in the memory unit and estimates, as a movement parameter of the cutting head movement unit, state data of the cutting head movement and, as a further parameter, a resulting deviation of the cut contour from the predetermined contour, and wherein the optimisation module is in data communication with the memory unit for reading the machine model.

8. The device according to claim 1 , wherein the optimisation module is configured to adjust the movement trajectory based on at least one increased dynamic limit (DG) of the cutting head movement unit.

9. The device according to claim 1 , wherein a process model representing the laser cutting process and estimating as parameters state data of the laser cutting process and a resulting deviation of the cut contour from the predetermined contour is stored in the memory unit, and wherein the optimisation module is in data communication with the memory unit for reading the process model.

10. The device according to claim 1 , wherein the control unit comprises a database of predetermined 2- and/or 3-dimensional Lissajous figures and the laser beam movement unit is configured to induce a high frequency oscillation of the focal point of the machining laser beam on a focal point oscillation path in the form of a Lissajous figure or a combination of more than one Lissajous figure based on the database.

11. The device according to claim 1 , wherein a detector device connected in a data-transmitting manner to the memory unit is provided on or in the cutting head for measuring a surface defect of a cut edge, including a scoring, as the parameter of a deviation of the cut contour from the predetermined contour (X, Y); and/or
wherein a model (MOD) for estimating a surface defect of a cut edge, in particular of scoring, is stored in the memory unit, which estimates as a parameter a surface defect (OD) and a resulting deviation of the cut contour from the predetermined contour, and wherein the optimisation module is in data communication with the memory unit in order to read the model for estimating a surface defect.

12. A method for laser cutting a workpiece and producing workpiece parts with a device for laser cutting a workpiece and producing workplace parts, wherein, the device comprises:
a cutting head, the cutting head having an interface for a laser source for generating a machining laser beam with a power of at least 200 W or at least 1 kW,
an exit aperture for the machining laser beam, and
laser beam optics between the interface and the exit aperture,
the laser beam optics having at least one dynamic laser beam movement unit for producing a high frequency beam-shaping movement of the machining laser beam at least perpendicular to its direction of propagation;
a cutting head movement unit for performing a movement of the machining laser beam over the workpiece via the cutting head; and
a control unit for controlling the cutting head movement unit and the laser beam movement unit, the control unit comprising:
a determination module for determining at least one movement trajectory (X, Y) of the machining laser beam in at least one workpiece plane according to at least one predetermined contour (X, Y) of the workpiece parts to be produced; and
a memory unit from which at least one predetermined parameter selected from a movement parameter of the cutting head movement unit, a movement parameter of the laser beam movement unit and a parameter of a deviation of a cut contour from the predetermined contour is retrievable;
wherein the control unit comprises:
an optimisation module for adjusting the movement trajectory (X, Y) by overlaying

Assignees

• Bystronic Laser Ag

Inventors

• Haas Titus
• Scheidiger Simon
• Steinlin Markus
• Berger Michael

Classifications

• B23K31/12

  relating to investigating the properties, e.g. the weldability, of materials · CPC title

• B23K26/0876

  in at least two axial directions · CPC title

• B23K26/0648

  comprising lenses · CPC title

• B23K26/0643

  comprising mirrors · CPC title

• B23K26/082

  Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head · CPC title