LASER CUTTING HEAD COMPRISING A BODY MADE OF TWO PARTS, BEING LINKED TOGETHER BY A FLEXIBLE MEMBER

Abstract

A laser cutting head includes a body, a laser light source located at a first end of the body, a nozzle located at another end of the body, an optical system located inside the body between the laser light source and the nozzle. The body includes at least two parts, which are slidable relative to each other in such a way that, due to their reciprocal displacement, the mutual position of the laser light source and/or the nozzle and/or the optical system can be changed, so that the geometry of the laser beam inside the body can be changed during use to achieve the desired parameters of the focus of the laser beam on the surface of the workpiece.

Claims

1. A Laser cutting head, comprising a body; a laser light source located at a first end of the body; a nozzle located at the other end of the body; and an optical system located inside the body between the laser light source and the nozzle in such a way that during operation a laser beam passes from the laser light source through the optical system and then the nozzle, wherein the body comprises at least two body parts of the body which are slidable relative to each other, wherein with a mutual displacement of the two body parts, a position of the laser light source and/or the nozzle and/or the optical system is changed, and wherein, during use, a geometry of the laser beam inside the body is changed to achieve a desired focus of the laser beam on a surface of a workpiece.

2. The head according to claim 1, wherein at least the two body parts are mutually displaceable along and/or across an optical axis of the body.

3. The head according to claim 2, wherein a first part of the two body parts of the body is integrated with the laser light source and a second part of the two body parts of the body is integrated with the nozzle, wherein the first part of the body is slidable relative to the second part of the body along and/or across an optical axis of the head so as to provide a range of movement of the first part of the body required to achieve desired focusing parameters of the laser beam on the surface of the workpiece.

4. The head according to claim 3, wherein at least the first part of the body is connected to the second part of the body by means of a flexible and hollow shielding member with a tight-sealed outer jacket, and a first opening with a first rim sealed to the first part of the body opposites to a part of the first part integrated with the laser light source, and a second opening with a second rim sealed to the second part of the body integrated with the nozzle, wherein during operation the first part of the body is moved relative to the second part of the body along and/or across the optical axis of the head with ensured sealing from surroundings of an inner space of the head between the laser light source and a first element of the optical system, viewed from a laser light source side.

5. The head according to claim 4, wherein the hollow flexible shielding member is made in a form of flexible bellows.

6. The head according to claim 5, wherein at least two elements of the optical system are positioned respectively in the first part and the second part of the body.

7. The head according to claim 6, wherein the second part of the body comprises also a connector for connecting a compressed gas conduit and at least one opening in the second body part tight-sealed to the connector, wherein, during operation, a stream of a compressed gas prevents a deposition of impurities on a surface of the first element of the optical system or a protection glass, as viewed from a nozzle side, and then escapes through the nozzle outside the head towards the optical axis of the head.

8. The head according to claim 7, wherein the nozzle is made as replaceable.

9. The head according to claim 8, wherein the nozzle is detachably connected to the second part of the body with a possibility of centering or moving perpendicularly to the optical axis of the head and/or along the optical axis of the head, and when operated the nozzle is automatically replaced with nozzle with other parameters, in particular with other dimensions of an opening of the nozzle and other nozzle length along the optical axis of the head.

10. The head according to claim 9, wherein the head comprises a fixings necessary for attachment of the head to a laser cutter for moving and positioning the head along a reference system axis.

11. The head according to claim 10, wherein the nozzle is centerable relative to the optical axis of the head by immobilizing at least the nozzle with respect to the reference system axis, and moving relative to the reference system axis of at least a part of the body, to which the nozzle is slidably attached and/or moving the laser light source relative to the optical system and/or the nozzle.

12. A laser cutter, comprising the laser cutting head according to claim 1.

13. The head according to claim 10, wherein the nozzle is centerable relative to the optical axis of the head by means of immobilizing the nozzle relative to the reference system axis, and moving relative to the reference system axis of a part of the body to which the nozzle is slidably attached, or of another part of the body by means of one or more drives of the laser cutter responsible for movement of the head in one or more axes of the reference system axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The invention is explained in more detail by way of example and in the drawing, where:

[0008] FIG. 1 schematically shows a perspective view of the laser cutting head,

[0009] FIG. 2 schematically shows a longitudinal section of the laser cutting head, showing the laser beam's path through the optical system in the position with no laser beam focus on the workpiece surface,

[0010] FIG. 3 schematically shows a fragment of the longitudinal section of the laser cutting head nozzle, showing the laser beam's path through the optical system in the position with laser beam focus on the workpiece surface,

[0011] FIG. 4 schematically shows a perspective view of the exchangeable nozzle, showing its connector,

[0012] FIG. 5 schematically shows a top view of the laser cutter comprising the head according to the invention,

[0013] FIG. 6 schematically shows a front view of the laser cutter comprising the head according to the invention, and

[0014] FIG. 7 schematically shows a side view of the laser cutter comprising the head according to the invention.

LIST OF REFERENCE SIGNS

[0015] 1laser cutting head [0016] 2body [0017] 3laser light source [0018] 4the first end of body [0019] 5body [0020] 6nozzle [0021] 7the second end of body [0022] 8optical system [0023] 9laser beam [0024] 10the first part of body [0025] 11the second part of body [0026] 12optical axis of head [0027] 13shielding member, shielding sleeve, shielding bellows [0028] 14outer jacket [0029] 15the first opening [0030] 16the first rim [0031] 17the second opening [0032] 18the second rim [0033] 19inner space of head [0034] 20connector [0035] 21compressed gas conduit [0036] 22opening [0037] 23first element of optical system [0038] 24nozzle opening [0039] 25fixings [0040] 26laser cutter [0041] 27workpiece [0042] 28distance of nozzle tip from workpiece [0043] 29nozzle length along the optical axis of head [0044] 30nozzle coupler

DETAILED DESCRIPTION

[0045] FIG. 1 and FIG. 2 show, respectively, perspective and cross-sectional views of a laser cutting head 1, comprising a laser light source 3 connected to an optical fibre 2 and located at a first end 4 of a body 5, a nozzle 6 located at the other end 7 of the body 5, an optical system 8 inside the body 5 between the laser light source 3 and the nozzle 6 so that during operation the laser beam 9 passes from the laser light source 3 through the optical system 8 and then through the nozzle 6. The body 2 comprises the first part 10 of the body 5 integrated with the laser light source 3 and the second part 11 of the body 5 integrated with the optical system 8 and the nozzle 6. The first part 10 of the body 5 is slidable relative to the second part 11 of the body 5 along and across the optical axis 12 of the head 1 to provide the range of movement of the first part 10 of the body 5 relative to the second part 11 of the body 5 required to control the focus of the laser beam 9 on the workpiece surface 27. The first part 10 of the body 5 is connected to the second part 11 of the body 5 by means of a hollow flexible shielding member 13 in the form of bellows. The bellows 13 have a sealed outer jacket 14 and a first opening 15 with a first rim 16 sealed to the first part 10 of the body 5 opposite to the part integrated with the laser light source 3, and a second opening 17 with a second rim 18 sealed to the second part 11 of the body 5, integrated with the optical system 8 and the nozzle 6, in such a way that during operation the first part 10 of the body 5 can be moved relative to the second part 11 of the body 5 along and across the optical axis 12 of the head 1 with the assurance of tight sealing from the surroundings of the inner space 19 of the head 1 between the laser light source 3 and the the first optical element 8, viewed from the laser light source 3 side and with the assurance that, when operated, there are no moving parts inside inner the space 19 of the head 1. The laser light source 3 is made in the form of so called fiber end, to which the laser light is supplied from the outside of the head 1 by the optical fibre 2. All elements of the optical system 8 are stationary relative to each other and relative to the second part 11 of the body 5. In addition, the second part 11 of the body 5 comprises a connector 20 for connecting a compressed gas conduit 21 and an opening 22 in the second part 11 of the body 5 tight-tied to said connector 20. The opening 22 is positioned is such a way that during operation the stream of compressed gas is directed to the surface of the first element 23 of the optical system 8 as viewed from the nozzle 6 side, and then exits through the nozzle 6 outside the head 1 in the direction of the optical axis 12 of the head 1. Such a positioning of the opening 22 ensures cooling of the optical system 8 and prevents deposition of impurities on the surface of the first optical element 8 viewed from the side of the nozzle 6. The nozzle 6 is made removable and tightly and detachably coupled with the second body part 11, with the possibility of centering with respect to the optical axis 12 of the head 1, and during operation, to allow the proper focus of the laser beam 9 on the surface of the workpiece 27 and to allow the optimum parameters of the gas stream penetrating the workpiece 27, regarding the diameter of the opening 24 of the nozzle 6 and the distance 28 of the tip of the nozzle 6 from the workpiece 27, shown in FIG. 3, may be automatically replaced by the nozzle 6 with other parameters, in particular other dimensions of the opening 24 of the nozzle 6 and the other length 29 of the nozzle 6 along the optical axis 12 of the head 1. FIG. 4 shows a perspective view of the exchangeable nozzle 6 showing a connector 30 of the nozzle 6. The head 1 comprises a fixings 25, shown schematically in FIG. 5, necessary for its attachment to laser cutter 26 for moving and positioning of the head 1.

[0046] FIG. 5 schematically shows a perspective view of the laser cutter 26 with the head 1 shown in FIGS. 1-4 and described above. FIG. 5, FIG. 6 and FIG. 7 schematically show, respectively, top view, front view, and side view of the laser cutter (viewed from the side of the head 1), showing possible directions of movement of the head 1 (or a laser cutter guides) indicated by arrows. The head 1 can, for example, be so positioned that the laser beam is directed to the workpiece surface 27 at a certain angle.

INDUSTRIAL APPLICABILITY

[0047] With the above-described head 1, the laser cutter 26 provides a faster and more precise process of cutting the workpiece 27 with a smoother and cleaner cut surface compared to the prior art laser cutters, so that further workpiece machining is unnecessary. The advantage of the solution according to the invention is also a narrower cut gap and a smaller heat transfer zone compared to the prior art laser cutters.