Irradiating a machining field

Patent metadata

Field	Value
Publication number	US-11007576-B2
Application number	US-201916419249-A
Country	US
Kind code	B2
Filing date	May 22, 2019
Priority date	Nov 23, 2016
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

An irradiating device for irradiating a machining field with a machining beam, in particular with a laser beam, for carrying out a welding process, is provided. The irradiating device includes a beam scanner for aligning the machining beam to a machining position in the machining field. The irradiating device has an imaging device for imaging a part-region of the machining field on a pyrometer which has at least two pyrometer segments. The imaging device images thermal radiation which emanates from the machining position in the machining field on a first pyrometer segment, and images thermal radiation which emanates from a position in the machining field being situated ahead of or behind the machining position along an advancing direction of the machining beam in the machining field on at least one second pyrometer segment. A machine tool having such an irradiating device is also provided.

First claim

What is claimed is:

1. An irradiating device for irradiating a machining field with a machining beam for carrying out a welding process, the irradiation device comprising:
a beam scanner configured to align the machining beam along a machining beam path to a machining position in the machining field; and
an imaging device configured to image a part-region of the machining field on a pyrometer having at least two pyrometer segments,
wherein the imaging device is configured to
image thermal radiation emanating from the machining position in the machining field and being aligned by the beam scanner along an observation beam path on a first pyrometer segment of the pyrometer, and
image thermal radiation emanating from at least one position in the machining field situated ahead of or behind the machining position along an advancing direction of the machining beam in the machining field and being aligned by the beam scanner along the observation beam path on at least one second pyrometer segment of the pyrometer,
wherein the observation beam path is at least partially coaxial with the machining beam path in an opposing direction, and
wherein the first pyrometer segment and the at least one second pyrometer segment are associated with different responsive characteristics in relation to the thermal radiation emanating from the machining field.

2. The irradiating device of claim 1 , wherein the first pyrometer segment and the at least one second pyrometer segment are formed on a surface of a structured diode.

3. The irradiating device of claim 2 , wherein at least two of the pyrometer segments on the surface of the structured diode have different wavelength-dependent sensitivities in relation to the thermal radiation emanating from the machining field.

4. The irradiating device of claim 3 , wherein the first pyrometer segment of the structured diode has a maximum sensitivity at a first maximum wavelength that is less than a second maximum wavelength of the at least one second pyrometer segment of the structured diode.

5. The irradiating device of claim 1 , wherein each of the first pyrometer segment and the at least one second pyrometer segment is connected to a respective detector by a respective radiation transporter.

6. The irradiating device of claim 5 , wherein at least two of the detectors have different wavelength-dependent sensitivities in relation to the thermal radiation emanating from the machining field.

7. The irradiating device of claim 6 , wherein a first detector connected to the first pyrometer segment has a maximum sensitivity at a first maximum wavelength that is less than a second maximum wavelength of at least one second detector connected to the at least second pyrometer segment.

8. The irradiating device of claim 1 , further comprising a filter disposed between the machining field and at least one of the first pyrometer segment or the at least one second pyrometer segment,
wherein the filter is configured for wavelength-dependent attenuation of the thermal radiation emanating from the machining field.

9. The irradiating device of claim 1 , wherein at least one of the first pyrometer segment or the at least one second pyrometer segment has at least one curved external edge.

10. The irradiating device of claim 1 , wherein the first pyrometer segment is circular.

11. The irradiating device of claim 1 , which the pyrometer has at least two second pyrometer segments configured as annular segments.

12. The irradiating device of claim 11 , wherein the at least two second pyrometer segments are disposed to be rotationally symmetrical about the first pyrometer segment.

13. The irradiating device of claim 11 , wherein the at least two second pyrometer segments are disposed in a plurality of concentric rings.

14. The irradiating device of claim 1 , wherein the pyrometer is disposed in an observation beam path running coaxially with the machining beam.

15. The irradiating device of claim 1 , further comprising:
a loop controller configured to predefine the advancing direction in a movement of the machining beam across the machining field.

16. The irradiating device of claim 15 , further comprising:
an evaluator configured to identify at least one of second pyrometer segments disposed ahead of the machining position in the advancing direction or second pyrometer segments disposed behind the machining position in the advancing direction.

17. The irradiating device of claim 16 , wherein the evaluator is configured to:
determine a temperature at the machining position and at least one of a temperature at a position in the machining field ahead of the machining position or a temperature at a position in the machining field behind the machining position; and
determine at least one temperature gradient by at least two of the temperatures.

18. The irradiating device of claim 17 , wherein the loop controller is configured to regulate, based on at least one of the determined temperature gradient or at least one of the determined temperatures, at least one of an output of the machining beam in the machining field or an advancing speed.

19. A machine tool for producing three-dimensional components by irradiating powder layers by a machining beam, comprising:
a machining chamber having a support for applying the powder layers; and
an irradiating device configured to irradiate the powder layers in the machining chamber with the machining beam, the irradiating device comprising:
a beam scanner configured to align the machining beam to a machining position in a machining field in the machining chamber;
an imaging device configured to image a part-region of the machining field on a pyrometer having at least two pyrometer segments,
wherein the imaging device is configured to
image thermal radiation emanating from the machining position in the machining field on a first pyrometer segment of the pyrometer, and
image thermal radiation emanating from at least one position in the machining field situated ahead of or behind the machining position along an advancing direction of the machining beam in the machining field on at least one second pyrometer segment of the pyrometer;

a loop controller configured to predefine the advancing direction in a movement of the machining beam across the machining field; and
an evaluator configured to identify at least one of second pyrometer segments disposed ahead of the machining position in the advancing direction or second pyrometer segments disposed behind the machining position in the advancing direction.

20. The machine tool of claim 19 , wherein the irradiating device is disposed in relation to the machining chamber such that the machining field of the beam scanner in which the machining beam is focused is congruent with a position of one of the powder layers to be irradiated by the machining beam.

21. An irradiating device for irradiating a machining field with a machining beam for carrying out a welding process, the irradiation device comprising:
a beam scanner configured to align the machining beam to a machining position in the machining field;
an imaging device configured to image a part-region of the machining field on a pyrometer having at least two pyrometer segments,
wherein the imaging device is configured to
image thermal radiation emanating from the machining position in the machining field on a first pyrometer segment of the pyrometer, and
image thermal radiation emanating from at least one position in the machining field situated ahe

Assignees

• Trumpf Laser & Systemtechnik Gmbh

Inventors

• Wuest Frank Peter
• Schaal Frederik
• Allenberg-Rabe Matthias

Classifications

• B23K26/034 Primary

  Observing the temperature of the workpiece · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F12/49

  Scanners · CPC title

• B22F12/44

  characterised by the configuration of the radiation means · CPC title

• B22F10/368

  Temperature or temperature gradient, e.g. temperature of the melt pool · CPC title