Laser Processing Machines and Methods of Processing Workpieces

• US 20090057283A1
• Filed: 07/28/2008
• Published: 03/05/2009
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: Trumpf Werkzeugmaschinen GmbH + Company KG (Trumpf GmbH + Company KG)
• Original Assignee: Trumpf Werkzeugmaschinen GmbH + Company KG (Trumpf GmbH + Company KG)
• Inventors: Bunz, Andreas, Schmauder, Frank
• Granted Patent: US 8,217,301 B2
• Time in Patent Office: Days
• US Class Current: 219/121.720
• CPC Class Codes: B23K 26/0093 combined with mechanical machining or metal-working covered by other subclasses than B23K combined welding or cutting procedures or apparatus B23K28/02
• CPC Class Codes: B23K 26/38 by boring or cutting
• CPC Class Codes: B23K 28/02 Combined welding or cutting procedures or apparatus
• CPC Class Codes: B23P 23/04 for both machining and other metal-working operations

Abstract

A laser processing machine for processing workpieces, in particular metal sheets, includes a workpiece support and a beam receiver for the laser beam used as a processing tool. The distance between a workpiece lying on the workpiece support and the beam receiver is variable, owing to the fact that the workpiece support and the beam receiver are positionable relative to one another along the beam axis of the laser beam by means of an adjusting drive of an adjusting device with a positioning movement of a variably definable magnitude. A method for processing workpieces, in particular metal sheets, is also provided.

Claims

1. A laser processing machine for processing workpieces, the machine comprising:

a workpiece support configured to support a workpiece;

a laser processing head configured to deliver a laser beam;

a beam receiver with a receiving opening for the laser beam, which the laser beam enters after piercing through the workpiece, the laser processing head being arranged on the one side of the workpiece and the workpiece support and the beam receiver being arranged on the opposite side of the workpiece; and

an adjusting device configured to vary the distance between the workpiece and the beam receiver existing along a beam axis of the laser beam,

the adjusting device comprising an adjusting drive configured to position the workpiece support and the beam receiver relative to one another with a positioning movement of variably definable magnitude along the beam axis.

2. A laser processing machine according to claim 1, wherein the distance between the workpiece and the beam receiver is adjustable, by a positioning movement of corresponding magnitude, to different distance values, each associated with a processing phase of the workpiece processing.

3. A laser processing machine according to claim 1, wherein, with the laser beam switched off, the workpiece and the beam receiver are movable with a positioning movement relative to one another parallel to a support plane formed at the workpiece support, and the distance between the workpiece and the beam receiver is adjustable to a distance value for the positioning movement.

4. A laser processing machine according to claim 1, wherein, with the laser beam switched on, the workpiece and the beam receiver are movable with a processing movement relative to one another parallel to a support plane formed at the workpiece support, and the distance between the workpiece and the beam receiver is adjustable to a distance value for the processing movement.

5. A laser processing machine according to claim 4, wherein for a positioning movement the distance between the workpiece and the beam receiver is adjustable to a larger distance value than for a processing movement.

6. A laser processing machine according to claim 1, characterised in that during a mutual state of movement of workpiece and beam receiver, the workpiece is processable by means of the laser beam, and the distance between the workpiece and the beam receiver is adjustable to a distance value correlated to the mutual state of movement of workpiece and beam receiver.

7. A laser processing machine according to claim 1, wherein the distance between the workpiece and the beam receiver is adjustable to a distance value correlated to the material of the workpiece.

8. A laser processing machine according to claim 1, wherein the distance between the workpiece and the beam receiver is adjustable to a distance value correlated to the thickness of the workpiece.

9. A laser processing machine according to claim 1, further comprising a drive control for the adjusting drive, the drive control being configured to control the adjusting drive so that, for the duration of at least one processing phase of the workpiece processing, the distance between the workpiece and the beam receiver is maintainable at a constant distance value by corresponding mutual positioning of the workpiece support and the beam receiver along the beam axis of the laser beam.

10. A laser processing machine according to claim 9, wherein the drive control is formed at least partially by a drive control of a second adjusting drive configured to adjust the mutual distance between the laser processing head and the workpiece.

11. A laser processing machine according to claim 1, wherein the adjusting drive comprises a numerical drive control, and the distance between the workpiece and the beam receiver is adjustable by the adjusting drive to at least an empirically determined distance value that is stored in a memory of the numerical drive control.

12. A laser processing machine according to claim 1, further comprising a device configured to determine a distance value to be set for the distance between the workpiece and the beam receiver, and the distance between the workpiece and the beam receiver is adjustable to this distance value by the adjusting drive.

13. A laser processing machine according to claim 12, wherein the device configured to determine a distance value to be set for the distance between the workpiece and the beam receiver is at least partially formed by a device configured to determine the distance between the laser processing head and the workpiece existing along the beam axis of the laser beam.

14. A laser processing machine according to claim 1, wherein the adjusting drive comprises an adjusting drive motor configured to adjust the relative positioning of the workpiece support and the beam receiver when either the beam receiver or the workpiece support is in a fixed position along the beam axis of the laser beam.

15. A laser processing machine according to claim 1, wherein the adjusting drive is formed by a discharging and adjusting drive configured to move the workpiece support and/or the beam receiver along the beam axis to discharge products of the workpiece processing.

16. A laser processing machine according to claim 15, wherein the workpiece support and the beam receiver are jointly movable, to discharge products of the workpiece processing, and, for mutual positioning of the workpiece support and the beam receiver when movement of the beam receiver is impeded in the direction of movement of the workpiece support, the workpiece support is positionable along the beam axis relative to the beam receiver, or when movement of the workpiece support is impeded in the direction of movement of the beam receiver, the beam receiver is positionable along the beam axis relative to the workpiece support.

17. A laser processing machine according to claim 1, further comprising a stop configured to block the beam receiver or the workpiece support during mutual positioning of the workpiece support and the beam receiver, the stop being active in the direction of the positioning movement.

18. A laser processing machine according to claim 17 wherein the stop is adjustable in the direction of the mutual positioning movement of the workpiece support and the beam receiver.

19. A method for processing workpieces using a laser beam, the method comprising:

supporting the workpiece on a workpiece support,

piercing the workpiece with a laser beam from a laser processing head that is arranged on the one side of the workpiece, the laser beam entering a receiving opening of a beam receiver arranged on the opposite side of the workpiece, and

varying the distance between the workpiece and the beam receiver along a beam axis of the laser beam, using of an adjusting device, by positioning the workpiece support and the beam receiver relative to one another, with a positioning movement of variably defined magnitude along the beam axis, using an adjusting drive of the adjusting device.

20. A method according to claim 19, wherein the varying step comprises adjusting the distance between the workpiece and the beam receiver to two or more distance values, each distance value being correlated to a processing phase of the workpiece processing, by positioning the workpiece support and the beam receiver relative to one another along the beam axis with a positioning movement having a corresponding magnitude.

21. A method according to claim 19, wherein the varying step comprises adjusting the distance between the workpiece and the beam receiver to a distance value correlated to the material of the workpiece.

22. A method according to claim 19, wherein the varying step comprises adjusting the distance between the workpiece and the beam receiver to a distance value correlated to the thickness of the workpiece.

23. A method according to claim 19, wherein the varying step comprises, for the duration of at least one processing phase of the workpiece processing, maintaining constant the distance between the workpiece and the beam receiver at a set distance value.

24. A method according to claim 19, further comprising empirically determining a distance value for the distance between the workpiece and the beam receiver, storing the distance value in a memory of a numerical drive control of the adjusting drive, and setting position of the beam receiver to this distance value.

25. A method according to claim 19, further comprising determining a distance value to be set for the distance between the workpiece and the beam receiver at the workpiece to be processed, and setting the distance between the workpiece and the beam receiver to this distance value.

26. A method according to claim 19, further comprising determining a distance value to be set for the distance between the workpiece and the beam receiver at the workpiece to be processed according to a determination method having the following steps:

positioning the workpiece support and the beam receiver relative to one another in the direction of the beam axis to a mutual distance with the distance value zero,

with the workpiece on the workpiece support and on the beam receiver, starting from the mutual distance with the distance value zero, positioning the workpiece support and the beam receiver relative to one another in the direction of the beam axis so that the beam receiver is removed from the workpiece,

during the mutual positioning of workpiece support and beam receiver with removal of the beam receiver from the workpiece, determining the moment at which the workpiece above the beam receiver reaches its maximum sag,

at the moment at which the workpiece reaches its maximum sag, determining the actual value of the mutual distance between the workpiece support and the beam receiver,

on the basis of the actual value determined, determining the distance value to be set for the distance between the workpiece and the beam receiver.

27. A method according to claim 26, wherein the maximum sag of the workpiece above the beam receiver is determined on the basis of the distance existing along the beam axis of the laser beam between a reference level and the workpiece above the beam receiver.

28. A computer-readable medium having encoded thereon software for operating a laser processing machine for processing workpieces, the machine comprising:

a workpiece support configured to support a workpiece;

a laser processing head configured to deliver a laser beam;

a beam receiver with a receiving opening for the laser beam, which the laser beam enters after piercing through the workpiece, the laser processing head being arranged on the one side of the workpiece and the workpiece support and the beam receiver being arranged on the opposite side of the workpiece; and

an adjusting device configured to vary the distance between the workpiece and the beam receiver existing along a beam axis of the laser beam,

the adjusting device comprising an adjusting drive configured to position the workpiece support and the beam receiver relative to one another with a positioning movement of variably definable magnitude along the beam axis, the software comprising;

instructions for causing the adjusting drive of the adjusting device to determine a distance value to be set for the distance between the workpiece and the beam receiver.

29. The computer-readable medium of claim 28 wherein the instructions are configured to be run on a numerical machine control system.