Machining apparatus for laser machining a workpiece, set of parts for a machining apparatus for laser machining a workpiece and method for laser machining a workpiece using such machining apparatus

Patent metadata

Field	Value
Publication number	US-11471979-B2
Application number	US-202017310982-A
Country	US
Kind code	B2
Filing date	Aug 14, 2020
Priority date	Aug 16, 2019
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

A machining apparatus for laser machining a workpiece (12) in a machining zone (13) is provided, having a first interface (14) for a machining laser source for generating a machining laser beam (15), an outlet opening (18) for the machining laser beam (15), In an optical system between the first interface (14) and the outlet opening (18), which has at least one laser beam guiding device (22) having at least one movable surface (24) and at least one actuator (26), with which the movable surface (24) is dynamically adjustable, and a cooling device (28) for cooling the at least one actuator (26), wherein the cooling device (28) has at least one primary circuit (30) through which a first cooling fluid can flow without contact with the actuator (26). Furthermore, a set of parts for a machining apparatus for laser machining a workpiece (12) and a method of laser machining a workpiece (12) using such machining apparatus are also provided.

First claim

The invention claimed is:

1. A machining apparatus for laser machining a workpiece in a machining zone, the machining apparatus comprising:
a laser machining head, having a first interface for a machining laser source for generating a machining laser beam;
an outlet opening for the machining laser beam;
an optical system between the first interface and the outlet opening, which has at least one laser beam guiding device having at least one movable surface and at least one actuator, with which the movable surface is dynamically adjustable; and
a cooling device for cooling the at least one actuator, wherein the cooling device has at least one primary circuit through which a first cooling fluid can flow without contact with the actuator;
characterized in that the cooling device has a closed secondary circuit, through which a second cooling fluid can flow in contact with the actuator and which can be cooled by a first of the primary circuits.

2. The machining apparatus according to claim 1 ,
wherein the cooling device has at least one element selected from a cooling structure and an interior of the cooling device in which the at least one actuator and/or the laser beam guiding device is at least partially arranged.

3. The machining apparatus according to claim 2 ,
wherein the interior is part of the secondary circuit; and/or
wherein the cooling structure is part of the first or a second of the primary circuits.

4. The machining apparatus according to claim 2 ,
wherein the cooling structure has a wall of the cooling device, which wall can be flowed through and at least partially surround the interior of the cooling device and/or the laser beam guiding device; and/or
wherein the cooling structure has at least one cooling fin, which can be flowed through and is arranged in the interior of the cooling device.

5. The machining apparatus according to claim 1 ,
wherein the machining apparatus has a second interface, at which the cooling device and/or the laser beam guiding device are interchangeably provided; and/or
wherein the first cooling fluid is liquid and/or the second cooling fluid is gaseous; and/or
wherein the cooling device is provided in a gas-tight manner on the machining apparatus.

6. The machining apparatus according to claim 1 ,
wherein the at least one actuator is selected from a piezo actuator, an actuator of a galvanometer scanner, a plurality thereof and a combination thereof; and/or
wherein the at least one movable surface is at least partially reflective for the machining laser beam, and/or
wherein the at least one movable surface is dynamically orientable; and/or
wherein the at least one movable surface is a continuous surface that is dynamically deformable; and/or
wherein the movable surface is dynamically adjustable such that it modifies the beam parameter product of the temporally integrated machining laser beam; and/or
wherein the at least one movable surface is adjustable such that it modifies the focal length of the optical system; and/or
wherein the at least one movable surface is adjustable such that it modifies the axial focus position of the machining laser beam.

7. The machining apparatus according to claim 1 ,
wherein the laser beam guiding device has, as the at least one movable surface, at least one segmented mirror with a plurality of mirror segments, each of which are dynamically orientable; and/or
wherein the laser beam guiding device has, as the at least one movable surface, at least one dynamically deformable mirror.

8. The machining apparatus according to claim 1 ,
wherein the at least one movable surface is adjustable such that it dynamically moves the machining laser beam at least perpendicular to the direction of propagation; and/or
wherein the at least one movable surface is adjustable such that it dynamically moves the machining laser beam and generates at least one focal point oscillation with at least one oscillation amplitude and at least one oscillation frequency and with a focal point oscillation path that corresponds to a two- or three-dimensional Lissajous figure or a combination of two- or three-dimensional Lissajous figures.

9. The machining apparatus according to claim 1 ,
wherein the at least one actuator is configured to dynamically adjust the movable surface at a high frequency; and/or
wherein the at least one movable surface is adjustable with a frequency between 10 Hz and 15 kHz.

10. The machining apparatus according to claim 9 , wherein the at least one movable surface is adjustable with a frequency between 100 Hz and 10 kHz.

11. The machining apparatus according to claim 9 , wherein the at least one movable surface is adjustable with a frequency between 400 Hz and 10 kHz.

12. The machining apparatus according to claim 1 ,
wherein the at least one movable surface of the laser beam guiding device is arranged and configured such that the machining laser beam is deflected at an angle of less than, equal to, or greater than 90°; and/or
wherein the first interface is connected or provided with a machining laser source for generating the machining laser beam; and/or
wherein a control unit for controlling the laser beam guiding device is provided; and/or
wherein the machining laser source provides a laser power of at least 1 kW.

13. The machining apparatus according to claim 12 , wherein the machining laser source provides a laser power of at least 4 kW.

14. The machining apparatus according to claim 12 , wherein the machining laser source provides a laser power of between 1 kW to 30 kW.

15. The machining apparatus according to claim 12 , wherein the machining laser source provides a laser power of between 1 kW to 25 kW.

16. A method for laser machining a workpiece with a machining apparatus according to claim 1 , comprising:
irradiation of a machining zone of a workpiece with a machining laser beam from a machining laser source, which is provided at the first interface of the machining apparatus, through the outlet opening of the machining apparatus;
cooling of the at least one actuator of the laser beam guiding device by means of the first cooling fluid flowing through the at least one primary circuit without contact with the actuator; and
dynamic adjustment of the movable surface with the at least one cooled actuator.

17. The method according to claim 16 , wherein cooling the actuator comprises at least one step selected from:
the second cooling fluid in contact with the actuator flowing through the closed secondary circuit, wherein the closed secondary circuit is cooled by the first cooling fluid flowing through the first of the primary circuits; and
the first cooling fluid flowing through the first and/or the second of the primary circuits.

18. The method according to claim 16 ,
wherein the movable surface is dynamically adjusted such that it modifies the beam parameter product of the temporally integrated machining laser beam; and/or
wherein the laser beam guiding device dynamically moves the machining laser beam at least perpendicular to the direction of propagation; and/or
wherein the laser beam guiding device dynamically moves the machining laser beam and generates at least one focal point oscillation with at least one oscillation amplitude and at least one oscillation frequency and with a focal point oscillation path that corresponds to a two- or three-dimensional Lissajous figure or a combination of two- or three-dimensional Lissajous figures.

Assignees

• Bystronic Laser Ag

Inventors

• Scheidiger Simon
• Luedi Andreas
• Zollinger Roland
• Mumenthaler Martin

Classifications

• B23K26/703

  Cooling arrangements (by using a fluid stream B23K26/14) · CPC title

• B23K26/14

  using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor (B23K26/12 takes precedence) · CPC title

• G02B26/0825

  the reflecting element being a flexible sheet or membrane, e.g. for varying the focus (flexible mirrors for cosmetic use A45D42/24) · CPC title

• B23K26/38 Primary

  by boring or cutting · CPC title

• B23K26/0643

  comprising mirrors · CPC title