LASER PROCESSING HEAD FOR LASER-WIRE BUILD-UP WELDING

Abstract

A laser beam is directed onto a pyramid-shaped element, wherein the beam is directed onto at least three reflecting surfaces and the respective reflected partial beams are incident on reflecting surfaces arranged on an optics carrier element. The partial beams are aligned such that they intersect in a common plane. An internal wire feed is arranged in a housing, having an outlet nozzle for a fusible wire-shaped material, which material is using the energy of the partial beams. The outlet nozzle is arranged in front of the plane in which the reflected partial beams intersect. The pyramid-shaped element and the reflecting surfaces are formed on a carrier element, which is arranged in such a way that it is displaceable following the outlet nozzle in two perpendicular directions to the optical axis of the laser beam or perpendicular to the central longitudinal axis of the wire-shaped material.

Claims

1. A laser processing head which is formed for laser wire build-up welding, wherein a laser beam is directed through a housing onto a pyramid-shaped element and in doing so onto at least three reflecting surfaces of the pyramid-shaped element which are aligned at equal angular distances from each other and the respective partial beams reflected by the reflecting surfaces are incident on reflecting surfaces arranged radially on the outside of an optics carrier element, wherein the reflecting surfaces are aligned such that the partial beams reflected at them are aligned such that they intersect in a common plane and an internal wire feed is arranged in the housing, said feed having an outlet nozzle, arranged in the direction of a workpiece to be processed, a wire-shaped material, which material is fusible using the energy of the partial beams incident on the wire-shaped material, the outlet nozzle and is arranged in the feed movement of the wire-shaped material in front of the common plane in which the reflected partial beams intersect; the improvement being that the pyramid-shaped element and the reflecting surfaces are formed on a single optics carrier element and the optics carrier element is arranged and fixable in an optical adjustment means in such a way that it is displaceable following the outlet nozzle in two axis which are perpendicular to the optical axis of the laser beam or perpendicular to the central longitudinal axis of the wire-shaped material for the optical adjustment means.

2. The laser processing head as claimed in claim 1, wherein the optics carrier element is a monolith which is made of a single material and no individual part present at the optics carrier element is attached to the optics carrier element as a result of assembly and this monolith is simultaneously a central displacement element perpendicular to the optical axis of the laser beam or perpendicular to the central longitudinal axis of the wire-shaped material for the optical adjustment means.

3. The laser processing head as claimed in claim 1, wherein at least one cooling channel and cooling grooves are formed at or in the optics carrier element, which are connectable to a feed and discharge for a cooling medium.

4. The laser processing head as claimed in claim 1, wherein the optics carrier element is adjustable in the two axes which are aligned perpendicularly to one another by means of two adjusting elements provided with threads which are perpendicular to one another.

5. The laser processing head as claimed in claim 1, wherein a plurality of external wire feeds for feeding different wire materials are present and the wire-shaped material is feedable from each of the external wire feeds to the internal wire feed, wherein a funnel-shaped inlet opening for the introduction of-a the wire-shaped material from one of the external wire feeds into the internal wire feed is formed at the end side opposite the outlet nozzle.

6. The laser processing head as claimed in claim 1, wherein a smoke extractor is present at the housing and at an assembly unit at the end side facing a workpiece.

7. The laser processing head as claimed in claim 6, wherein the smoke extractor is formed having a plurality of perforations arranged around ts outer circumference, which perforations open in a common extraction channel.

8. The laser processing head as claimed in claim 7, wherein the sum of free cross-sectional areas of the perforations through which smoke is extracted from a processing area of the respective workpiece corresponds to the free cross-sectional area of the common extraction channel or the sum of the free cross-sectional areas of the perforations is at most 10% larger or smaller than the free cross-sectional area of the common extraction channel and thus flow inlet and flow outlet have the same, at least almost the same, cross sections.

9. The laser processing head as claimed in claim 7, wherein the smoke from the perforations is guided in the common extraction channel and then in a circular tube element which is fastenable to the assembly unit to a device for welding smoke extraction.

10. The laser processing head as claimed in claim 9, wherein the smoke extractor is nozzele-shaped, which is fastenable to the housing and to the assembly unit and a wire adjustment means, is formed with at least one cooling channel which is connectable to a feed and a discharge for a cooling medium.

11. The laser processing head as claimed in claim 10, wherein the feed and discharge are guided through the common extraction channel through the circular tube element of the assembly unit and the cross-sectional area required for this discharge is almost the same.

12. The laser processing head as claimed in claim 1, wherein the internal wire feed and the outlet nozzle is displaceable and lockable perpendicular to the plane in which the optics carrier element is displaceable and adjustable in two dimensions, for a defined positioning in relation to the plane in which the reflected partial beams intersect.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The invention will be explained in greater detail by way of example below. In the figures:

[0030] FIG. 1 consists of FIGS. 1A and 1B which show a perspective and an exploded illustration of an example of a laser processing head according to the invention;

[0031] FIG. 2 consists of FIGS. 2A and 2B which show two illustrations of an optics carrier element that can be used in the invention;

[0032] FIG. 3 consists of FIGS. 3A, 3B, and 3C which show three illustrations of a smoke extractor at a laser processing head;

[0033] FIG. 4 consists of FIGS. 4A and 4B which show two illustrations with which the beam guiding of the laser beam, the three partial beams formed with said beam and the feeding of wire-shaped material should be rendered recognizable in exemplary fashion, and

[0034] FIG. 5 consists of FIGS. 5A and 5B which show two views of an embodiment option in which wire-shaped material is feedable to an internal wire feed by a plurality of external wire feeds.

DETAILED DESCRIPTION OF THE INVENTION

[0035] In FIGS. 1A and 1B, an example of a laser processing head according to the invention is shown. Here, an internal wire feed 2 for feeding wire-shaped material 3, optical components 4 for shaping a laser beam 6, and an optics carrier element 5.1 for deflecting the laser beam 6 and splitting the laser beam into three partial beams 6.1-6.3 are arranged in a housing 1.

[0036] An optical unit 4 for an optical fiber 4.1 is fastened to the housing 1, through which unit the laser beam 6 is directed onto reflecting surfaces 8.1 of a pyramid-shaped element 8 and reflecting surfaces 8.2 that are formed at an optics carrier element 5.1.

[0037] At the opposite end side of the laser processing head, a smoke extractor 9 is present, having a screw-on cone 9.7 with an opening through which the wire-shaped material 3 can be fed into the area of influence of the partial beams 6.1-6.3 intersecting in a plane, in the direction of a workpiece, not shown. A extraction channel 9.1 is present at the cone 9.7, which is connected on the suction side to a unit that achieves negative pressure, not shown. The smoke extracted through the extraction channel 9.1 can be guided to a filter unit, also not shown.

[0038] In the housing 1, between the optics carrier element 5.1 and the smoke extractor 9, there is a protective glass module 16 with at least one, in this example three, protective glasses, through which the three partial beams 6.1-6.3 propagate in the direction of the plane in which they intersect 6.4 and the other components contained in the housing 1, in particular the optical components 4 and the optics carrier element 5.1, can be protected from contamination by said protective glasses. The protective glass module 16 and/or the protective glasses should be replaceable.

[0039] Furthermore, an XYZ wire adjustment means 15 for adjusting the wire-shaped material 3 to the intersection of the three partial beams 6.4 and an assembly unit 14 are present at the laser processing head. Various external wire drives 10, 11, 12, 13, other optical units from other laser manufacturers 7 and a collision and safety shutdown 17 can also be installed.

[0040] FIG. 2A shows a perspective illustration of an optics carrier element 5.1. The optics carrier element 5.1 is formed in such a way that the apex of a pyramid-shaped element 8 is arranged in the center. The laser beam 6 focused by the optical components is incident on the apex and the three reflecting surfaces 8.1 which adjoin and are inclined at an angle. The three reflecting surfaces 8.1 of the pyramid-shaped element 8 are aligned and arranged with respect to one another in such a way that the incident laser beam 6 is split into three partial beams 6.1-6.3 and each partial beam 6.1-6.3 is incident on one reflecting surface 8.2 formed at the optics carrier element 5.1. The reflecting surfaces 8.2 are aligned in such a way that the partial beams 6.1-6.3 are each reflected through an opening 8.3 in the optics carrier element 5.1 at an angle directed obliquely toward one other in the direction of a workpiece to be processed. In doing so, the reflections take place in such a way that the partial beams 6.1-6.3 intersect in a plane that is arranged above the surface to be processed on a workpiece, and there wire-shaped material 3 is also fed from the outlet nozzle 2.1. Furthermore, it can be seen in FIG. 2B that a cooling channel 8.4 and cooling grooves 8.5 are formed in the optics carrier element 5.1, through which a cooling medium, in particular cooling water, for cooling can be passed.

[0041] In doing so, the opening in the smoke extractor 9 is selected to be so large that, in addition to the outlet nozzle 2.1 of the internal wire feed 2, the partial beams 6.1-6.3 can also pass through this opening without any problems.

[0042] The optics carrier element 5.1 is made of copper or a copper alloy and has been produced as one piece by machining.

[0043] The optics carrier element 5.1 is guided in a guide carriage (optical adjustment means) 5, which is likewise fastened in the housing 1. In doing so, the optics carrier element 5.1 and guide carriage 5 are aligned perpendicular to the optical axis of the laser beam 6. The optics carrier element 5.1 can be displaced in two dimensions in this plane oriented perpendicular to the optical axis of the laser beam 6 and thus be adjusted in relation to the optical axis, in particular with its reflecting surfaces 8.1 formed at the pyramid-shaped element 8, and therefore also necessarily with the reflecting surfaces 8.2. For this purpose, two adjusting elements 5.2 can be used, which are aligned at a right angle to each other and provided with a thread, and with which the optical adjustment means 5 can respectively be displaced in one axial direction, preferably in the X or Y axis direction, for adjustment and can be locked against one another.

[0044] FIGS. 3A to 3C show a smoke extractor 9. Here, a nozzle-shaped cone 9.7 is fastenable to the housing 1 by a screw connection. An opening that tapers conically in the direction of a workpiece is formed in the cone 9.7, through which opening the outlet nozzle 2.1 with the wire-shaped material (3) and the three partial beams 6.1-6.3 can pass without them abutting the wall of the smoke extractor 9 and continuing to be exposed to protective gas.

[0045] Furthermore, perforations 9.2 are formed in the smoke extractor 9, in this example in the form of bores into which smoke formed during processing can be extracted and discharged by way of the extraction channel 9.1. The free cross-sectional areas of the perforations 9.2 and of the extraction channel 9.1 are dimensioned as explained in the general part of the description. The perforations 9.2 have the same free cross-sectional areas through which the smoke formed during processing can be extracted. Said perforations are arranged in a manner distributed at equal angular distances over the circumference of the smoke extractor 9.

[0046] A cooling channel 9.3 is also formed in the smoke extractor 9 and connected to a coolant feed 9.4 and to a coolant discharge 9.5. In this example, the coolant feed 9.4 and the coolant discharge 9.5 are guided through the extraction channel 9.1 such that they do not disturb and cannot be damaged from the outside. Here, too, the dimensioning information given in the general part of the description, which relates to the free cross-sectional areas, should be observed. The smoke extractor 9 is likewise made of copper or a copper alloy and can also be additively manufactured.

[0047] FIGS. 4Aand 4B illustrate the advantageous guidance of the laser beam 6 with its partial beams 6.1-6.3 and the feeding of the wire-shaped material 3 by the internal wire feed 2.

[0048] In doing so, the focused laser beam 6 is incident on the three reflecting surfaces 8.1 of the pyramid-shaped element 8 and the three partial beams 6.1-6.3 obtained in the process are each reflected at a reflecting surface 8.2 formed at the optics carrier element 5.1. By means of the reflecting surfaces 8.2, the three partial beams 6.1-6.3 are aligned toward each other at an obliquely inclined angle such that they intersect 6.4 in a common plane. This plane 6.4 is arranged in the direction of a workpiece to be processed in front of the outlet opening of the outlet nozzle 2.1 from which the wire-shaped material 3 and protective gas for shielding the melt pool 2.4 exit, such that the wire-shaped material 3 is irradiated and heated uniformly from three sides by the three partial beams 6.1-6.3, such that uniform heating of the wire-shaped material 3 can be achieved on all sides, which leads to its complete melting in the irradiated area.

[0049] In the process, the wire-shaped material 3 is fed in the center of the three intersecting partial beams 6.1-6.3.

[0050] FIGS. 5A and 5B are intended to show the possibility of feeding different wire-shaped materials 3 or the possibility of using a plurality of external wire feeds 10, 11, 12 for an almost uninterrupted processing option when the same wire-shaped material 3 can be supplied by a plurality of external wire feeds 10, 11, 12.

[0051] The external wire feeds 10, 11, 12 are each formed with a dedicated drive for feeding the respective wire-shaped material 3. Said feeds can be activated one after the other in order to achieve a change in the fed wire-shaped material 3 or, when reaching the end of a wire-shaped material 3 of an external wire feed 10, 11, 12, to be able to switch to another external wire feed 10, 11, 12.

[0052] If there is a change from one external wire feed 10, 11, 12 to another, the wire-shaped material 3 conveyed by the subsequently activated external wire feed 10, 11, 12 is formed in the funnel-shaped area 2.2, which is arranged at the end side of the internal wire feed 2, which is located opposite the outlet nozzle 2.1. The newly fed wire-shaped material 3 can then be threaded into the bore, which is formed to reach as far as the outlet nozzle 2.1 for the wire-shaped material 3, with the aid of the funnel-shaped area 2.2, without any further measures or mechanism being required.