Laser Processing Heads with a Cross-Jet Nozzle

Patent metadata

Field	Value
Publication number	US-2016354866-A1
Application number	US-201615244098-A
Country	US
Kind code	A1
Filing date	Aug 23, 2016
Priority date	Feb 27, 2014
Publication date	Dec 8, 2016
Grant date	—

Abstract

A laser machining head includes a focusing optical unit for focusing a laser beam in a direction of a machining zone of a workpiece and includes a cross-jet nozzle for producing a cross flow that passes through the focused laser beam transversely (e.g., at a right angle to) a beam axis of the focused laser beam. The distance of the cross-jet nozzle from the workpiece is less than 20 mm (e.g., between 8 mm and 12 mm). A nozzle body having a bottom opening that faces downward toward the workpiece is provided laterally adjacent to the focused laser beam. A protective gas flows out of the bottom opening, which is arranged below the cross-jet nozzle in order to entrain the protective gas flowing between the nozzle body and the workpiece due to the cross flow of the cross-jet nozzle so that the protective gas flows over the machining zone.

First claim

What is claimed is:

1 . A laser processing head, comprising:
focusing optics for focusing a laser beam in a direction of a processing zone of a workpiece; and a cross-jet nozzle for generating a transverse flow that passes through the focused laser beam transversely to a beam axis the focused laser beam, wherein a distance (D) from the cross-jet nozzle to the workpiece is less than 20 mm.

2 . The laser processing head of claim 1 , further comprising a nozzle body out of which a protective gas flows, wherein the nozzle body includes a bottom opening that faces downward toward the workpiece, and that is arranged below the cross-jet nozzle such that the protective gas flowing out of the nozzle body and between the nozzle body and the workpiece adjacent the transverse flow of the cross-jet nozzle in a transverse direction is entrained at least to such an extent that the protective gas flows over the processing zone.

3 . The laser processing head of claim 2 , wherein a distance (d) from the bottom opening to the cross-jet nozzle is less than 10 mm.

4 . The laser processing head of claim 2 , further comprising a device for generating a laminar flow of the protective gas upstream of the bottom opening.

5 . The laser processing head of claim 2 , wherein the bottom opening is formed by a first tube end of a tube section that is connected at a second tube end to a protective gas feed via a throttle.

6 . The laser processing head of claim 5 , wherein an axis of the first tube end of the tube section is oriented obliquely and pointed in a downward direction toward the focused laser beam.

7 . The laser processing head of claim 2 , wherein the bottom opening is a first bottom opening, wherein the nozzle body further includes a second bottom opening that faces downward toward the workpiece and that is located adjacent the first bottom opening along a side that faces away from the focused laser beam, and wherein the protective gas also flows out of the second bottom opening.

8 . The laser processing head of claim 7 , further comprising a device for generating a laminar flow of the protective gas upstream of the second bottom opening.

9 . The laser processing head of claim 7 , wherein the second bottom opening is formed by an outlet end of a line section that is connected at another line end to a protective gas feed via a throttle.

10 . The laser processing head of claim 9 , wherein an axis of the outlet end of the line section is oriented parallel to the beam axis.

11 . The laser processing head of claim 7 , wherein, in the transverse direction, a length (L 2 ) of the second bottom opening is at least as great as a length (L 1 ) of the first bottom opening.

12 . The laser processing head of claim 2 , wherein at least a lower side of the nozzle body that faces toward the workpiece is made of copper.

13 . The laser processing head of claim 2 , wherein the nozzle body is mounted adjustably in height on a portion of the laser processing head.

14 . The laser processing head of claim 13 , wherein the nozzle body is fastened magnetically to the portion of the laser processing head.

15 . The laser processing head of claim 2 , wherein the cross-jet nozzle is arranged on the nozzle body.

16 . A method for laser processing a workpiece, comprising:
focusing a laser beam in a direction of a processing zone of a workpiece; and passing a transverse flow emerging from a cross-jet nozzle) through the focused laser beam transversely to a beam axis of the focused laser beam, wherein during processing of the workpiece, the distance (D) from the cross-jet nozzle to the workpiece is less than 20 mm.

17 . The method of claim 16 , further comprising flowing a protective gas out of a bottom opening of a nozzle body located laterally next to the focused laser beam, the bottom opening facing downward toward the workpiece such that the protective gas flowing between the nozzle body and the workpiece is entrained by the transverse flow of the cross-jet nozzle in the transverse direction at least to such an extent that the protective gas flows over the processing zone.

18 . The method of claim 17 , wherein the protective gas flows laminarly out of the bottom opening of the nozzle body.

19 . The method of claim 17 , wherein the protective gas flows out of the bottom opening obliquely in a downward direction with a flow component in a direction of the transverse flow.

20 . The method of claim 17 , wherein the bottom opening is a first bottom opening, and wherein the protective gas flows out of a second bottom opening of the nozzle body, wherein the second bottom opening faces downward toward the workpiece, and is located adjacent to the first bottom opening along a side facing away from the focused laser beam.

21 . The method of claim 20 , wherein the protective gas flows out laminarly from the second bottom opening of the nozzle body.

22 . The method of claim 20 , wherein the protective gas flows out of the second bottom opening downwardly and parallel to the beam axis.

Assignees

• Trumpf Laser & Systemtechnik Gmbh

Inventors

• Broghammer Gerhard
• Meyer Jeremy
• Rominger Volker

Classifications

• B23K26/1476

  Features inside the nozzle for feeding the fluid stream through the nozzle · CPC title

• B23K26/142 Primary

  for the removal of by-products · CPC title

• B23K26/064

  by means of optical elements, e.g. lenses, mirrors or prisms · CPC title

• B23K26/1435 Primary

  involving specially adapted flow-control means · CPC title