Laser machining head

• US 6,614,002 B2
• Filed: 12/04/2001
• Issued: 09/02/2003
• Est. Priority Date: 12/04/2000
• Status: Active Grant

• Current Assignee: Precitec GmbH & Co. KG
• Original Assignee: Precitec GmbH & Co. KG
• Inventors: Weber, Ludwig
• Primary Examiner(s): ELVE, MARIA ALEXANDRA
• Application Number:
  US10/000,401
• Publication Number:
  US 20020088783A1
• Time in Patent Office: 637 Days
• Field of Search: 219/121.78, 219/121.81, 219/121.82, 219/121.83, 219/121.86
• US Class Current: 219/121.78
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/034 Observing the temperature of the workpiece
• CPC Class Codes: B23K 26/1462 Nozzles; Features related to nozzles
• CPC Class Codes: B23K 26/707 for monitoring laser beam transmission optics

Abstract

A laser machining head for machining a workpiece by a laser beam having a housing which has an inlet opening and an outlet opening between which a passage is constructed for the laser beam through which is led a working beam pathway; focusing optics for focusing the laser beam into a working focus which is located outside the housing at a distance from the outlet opening; a sensor arrangement, and a beam deflecting device. In order to provide a laser beam machining head which, whilst having fixed and compact external dimensions, enables a simple adaptation of the sensors to the respective machining tasks, the sensor arrangement comprises a sensor module arranged in a side wall of the housing next to the laser beam through passage; and the radiation diverting device directs the radiation, coming from a zone of interaction determined by the working focus, onto sensors of the sensor arrangement so that at least one portion of the radiation can be detected for monitoring the machining of a workpiece.

Claims

1. A laser machining head for machining a workpiece by means of a laser beam comprising:

a housing having an inlet opening and an outlet opening between which a passage for the laser beam is constructed through which a pathway for the working beam is led;

focusing optics for focusing the laser beam into a working focus which is located outside the housing at a distance from the outlet opening;

a sensor arrangement having a sensor module arranged in a side wall of the housing beside the laser beam passage; and

a beam deflecting device which directs radiation coming from a zone of interaction determined by the working focus onto sensors of the sensor arrangement so that at least a portion of the radiation can be detected for monitoring the machining of a workpiece.

2. The laser machining head according to claim 1, wherein the beam deflection device comprises an imaging optics which is arranged behind the focusing optics with respect to the radiation coming from the zone of interaction in order to image the zone of interaction onto the sensor module.

3. The laser machining head according to claim 1, wherein the beam deflection device possesses a first beam splitter, which separates a portion of the radiation coming from the zone of interaction out of the working beam path, and a second beam splitter which directs a portion of the incident radiation to the sensor module while it allows a further portion through.

4. The laser machining head according to claim 2, wherein the beam deflection device possesses a first beam splitter, which separates a portion of the radiation coming from the zone of interaction out of the working beam path, and a second beam splitter which directs a portion of the incident radiation to the sensor module while it allows a further portion through.

5. The laser machining head according to claim 3, wherein the second beam splitter is arranged in another side wall of the housing ahead of a connecting aperture to which an observation device can be connected.

6. The laser machining head according to claim 4, wherein the second beam splitter is arranged in another side wall of the housing ahead of a connecting aperture to which an observation device can be connected.

7. The laser machining head according to claim 3, wherein the second beam splitter is arranged in another side wall of the housing which is arranged opposite the sensor module, and that the beam deflection device has first and second deflection mirrors in order to redirect the portion of the radiation coming from the zone of interaction separated out by the beam splitters transversely across the passage to the side of the sensor module or parallel to the side wall accommodating the sensor module.

8. The laser machining head according to claim 5, wherein the second beam splitter is arranged in the another side wall of the housing which is arranged opposite the sensor module, and that the beam deflection device has first and second deflection mirrors in order to redirect the portion of the radiation coming from the zone of interaction separated out by the beam splitters transversely across the passage to the side of the sensor module or parallel to the side wall accommodating the sensor module.

9. The laser machining head according to claim 1, wherein the sensor module is constructed as a side wall module.

10. The laser machining head according to claim 1, wherein the sensor module has at least two sensors to which the incident radiation can be supplied via a third beam splitter.

11. The laser machining head according to claim 10, wherein the third beam splitter, on which the zone of interaction is imaged by the imaging optics, is constructed as a reflecting position filter aperture so that the sensors measure different regions of the zone of interaction.

12. The laser machining head according to claim 10, wherein individual sensors of the sensor arrangement comprise a filter device, so that they detect a selected spectral region of radiation coming from the zone of interaction.

13. The laser machining head according to claim 1, wherein individual sensors of the sensor arrangement comprise a filter device, so that they detect a selected spectral region of radiation coming from the zone of interaction.

14. The laser machining head according to claim 1, wherein the sensor module is provided with a reference sensor which detects a portion of the working laser beam which is separated out by the first beam splitter.

15. The laser machining head according to claim 1, wherein the sensor arrangement encompasses at least one sensor arranged in the region of the inlet opening in one or different side walls of the housing constructed for the detection of radiation coming from the zone of interaction.

16. The laser machining head according to claim 15, wherein the at least one sensor includes a plurality of sensors and wherein the radiation detected is plasma radiation.

17. The laser machining head according to claim 1, wherein the sensor arrangement further comprises at least one further sensor for monitoring a protective glass, which is arranged in the working beam path between the outlet opening and the focusing optics, the at least one further sensor is arranged in a lateral section of the housing in the area of the protective glass in order to pick up scattered light coming from the protective glass.