DE102007024366A1 - Device for changing a laser processing nozzle on a laser processing head - Google Patents

Abstract

A device (13) for changing a laser processing nozzle (12) on a laser processing head is provided. A component (22) is pneumatically displaceable for locking and unlocking the laser processing nozzle (12).

Description

The The invention relates to a device for changing a laser processing nozzle on a laser processing head.

The Change of laser processing nozzles a laser processing head of a laser processing machine, for example on a laser welding head or on a laser cutting head, provides a repetitive action represents.

specially in a 2D laser cutting machine for sheet metal comes the laser cutting head and thus also the cutting nozzle a special meaning too. To ensure an optimal cutting result To achieve different sheet thicknesses, different nozzles must be used become. In the previous laser cutting machines can use automatic Loading equipment Sheets of different thickness on the machine be put to work. A change of the cutting nozzle is using so-called nozzle changer carried out. The preliminary stage for a fully automated nozzle change is to perform the detection of the laser processing nozzle. A safer automatic nozzle detection is a useful addition for the fully automated operation of the laser processing machine. By a wrong assembly of the nozzle magazine at Unmanned operation of the laser processing machine can lead to significant Expenses come from mishaps.

Generally common it, laser processing nozzles screw in a laser processing head. rotational movements to lead but to a higher one Effort, which makes automation difficult.

Of the Applicant has set itself the task of a simple and secure base for to provide an automatable laser machining nozzle change.

These The object is achieved by a device according to claim 1. advantageous Further developments of the invention are described in the further claims.

at a preferred embodiment the invention, the process gas for laser processing and the activity of the component for the pneumatic locking and unlocking of the laser machining used. The process gas has a dual function. It is not required to use a separate gas for pneumatic actuation. The output of the Nozzle off the pneumatically unlocked mechanism also takes place a pressure pulse of the process gas in the boiler chamber of the cutting head, resulting in a manual nozzle change outside the automated system operation, without tools possible is.

Around to adapt the mechanics to existing cutting machines is only an exchange of the "ceramic part" in the cutting head against the changer module and the installation of a pneumatic valve with the associated supply line necessary for the module. The nozzle magazine must be located either within reach of the cutting head or swing in. Except This possibly required pivoting mechanism is available at the nozzle magazine no actuators.

A damage The mechanics by lateral collision can by a sheet thickness-dependent depth limitation of the Z-measure respectively. The limitation may be in the calibration of the distance sensor respectively.

One embodiment The invention is illustrated schematically in the drawing and will be described below explained in more detail with reference to the figure of the drawing. It shows in detail:

1 a perspective view of a laser system;

2 a side view of a device for changing a laser cutting nozzle on a laser cutting head of the laser cutting machine;

3 a longitudinal section of the device according to 2 in accordance with III-III in 2 ;

4 a longitudinal section of the device according to 2 according to IV-IV in 2 ;

5a 5b the locking mechanism of the laser cutting nozzle;

6a 6b 6c the inclusion of a laser cutting nozzle from a magazine;

7a 7b 7c the inclusion of another laser cutting nozzle from a magazine;

From the 1 is the basic structure of a laser processing system 1 for laser cutting with a CO ₂ laser 2 , a control device 3 , a laser processing head 4 and a workpiece support 5 seen. A generated laser beam 6 turns into a laser processing head by means of deflecting mirrors 4 guided and onto a workpiece 8th directed.

Both piercing and laser cutting are assisted by the addition of a gas. As cutting gases 9 For example, oxygen, nitrogen, compressed air and / or application-specific gases can be used. Which gas last is finally used depends on which materials cut and what quality standards are placed on the workpiece.

When cutting is usually carried out with a gas pressure of up to 20 bar. There, where the laser beam 6 on the sheet 8th impinges, the material is melted and / or oxidized. The resulting melt is blown out together with the iron oxides. Particles and gases can be generated by means of a suction device 10 from a suction chamber 11 be sucked off.

To change a laser cutting nozzle 12 on the laser cutting head 4 includes the laser cutting head 4 An institution 13 according to 2 , The device 13 for changing the laser cutting nozzle 12 can by using a union nut 14 on the laser cutting head 4 according to 1 be attached. In the device 13 is a dielectric 15 integrated for a known distance control. The mechanism for changing the laser cutting nozzle is by an outer housing 16 covered. Furthermore, in the 2 a first gas connection 17 and a second gas connection 18 for a pneumatic actuation of the mechanism for changing the laser cutting nozzle 12 to recognize. The operation of locking and unlocking the laser cutting nozzle 12 takes place pneumatically over the already at the laser cutting head 4 available process gas or auxiliary gas.

As in 3 represented, the dielectric component can be 15 using the union nut 14 at one in the 3 detachably fasten the not shown component of the laser cutting head. The laser cutting nozzle 12 is attached to a ball cage 20 releasably secured, leaving the laser cutting nozzle 12 can be exchanged and automatically changed by machine. The locking or unlocking takes place via the interaction between one according to the double arrow 21 in the axial direction displaceable lifting cylinder 22 and radially displaceable balls 23 (please refer 5a . 5b ). A mold surface 19 on the lifting cylinder 22 pushes the balls with appropriate axial movement of the lifting cylinder 22 in a radial guide on the ball cage 20 and then into an annular groove 32 on a shaft 25 the laser cutting nozzle 12 , The actuation of the lifting cylinder 22 is carried out by pressurizing with a process gas.

The displacement of the lifting cylinder 22 in the direction of the laser cutting nozzle 12 takes place by activation of the second gas connection 18 , In the ball cage 20 is a channel 27 designed to process the process gas into a pressure chamber 28 to conduct and a top 29 the lifting cylinder 22 pressurize. The pressure in the pressure chamber 28 is connected to the gas connection by means of a valve 18 regulated so that the pressure chamber 28 can be vented to the lift cylinder 22 to move in the axial direction.

The displacement of the lifting cylinder 22 in the direction of the union nut 14 takes place by activation of the first gas connection 17 , As in 4 can also be a base 30 the lifting cylinder 22 be pressurized by using the channel 31 and the other gas connection 17 Gas is led there.

• 1. Die Lagerung der Düse 12 ist so gestaltet, dass der Schaftmittelpunkt eine definierte Lage hat. Dadurch hat die Aufnahmevorrichtung eine definierte Anfahrposition. Der Kugelkäfig 20 und die Düse 12 weisen eine konische Innenfläche C und eine Außenfläche 24 auf, wodurch die Düse 12 beim Einfahren der Aufnahmevorrichtung ggfs. etwas aufgerichtet wird (5b).
• 2. Im weiteren Aufnahmeprozess fährt der Kugelkäfig 20 über den Ballen B bis die Fase C auf der Zentrierfase D aufliegt. Ein Verkanten der Düse ist aufgrund der Geometrie und des gewählten Spiels nicht möglich.
• 3. Durch Druckbeaufschlagung der Unterseite des Hubzylinders 22 wird der Hubzylinder 22 entgegen der Strahlrichtung bewegt, wobei die im Kugelkäfig 20 gelagerten Kugeln 23 in die Ringnut 32 am Düsenschaft 25 gepresst werden. Durch Aufbringen einer radial nach innen wirkenden Kraft wird die Düse 12 zentriert und durch eine axial und radial verspannt (5a) nach oben wirkende Kraft formschlüssig über die Fasen C und D eingezogen..

From the 5a and 5b This results in the mechanism for locking and unlocking the laser cutting nozzle 12 using the device 13 , For the sake of clarity, only the components essential for the mechanism are shown: Laser cutting nozzle 12 , Lifting cylinder 22 , Bullet 23 , The recording process takes place in three phases:

• 1. The storage of the nozzle 12 is designed so that the shaft center has a defined position. As a result, the receiving device has a defined starting position. The ball cage 20 and the nozzle 12 have a conical inner surface C and an outer surface 24 on, causing the nozzle 12 something is raised when retracting the recording device if necessary ( 5b ).
• 2. In the further recording process the ball cage moves 20 over the bale B until the bevel C rests on the centering bevel D. Tilting the nozzle is not possible due to the geometry and the chosen game.
• 3. By pressurizing the underside of the lifting cylinder 22 becomes the lifting cylinder 22 moved in the direction of the beam, with the ball cage 20 stored balls 23 in the ring groove 32 at the nozzle shaft 25 be pressed. By applying a radially inward force is the nozzle 12 centered and braced by an axial and radial ( 5a ) upward-acting force positively retracted over the chamfers C and D.

In the sequence according to the 6a to 6c is the image of a laser cutting nozzle 34 with crowned nozzle tip 35 seen. Indicated is a nozzle magazine 36 with a hole 37 for storage of the laser cutting nozzle 34 , 6a shows the optimal vertical alignment of the laser cutting nozzle for recording. Due to the crowned nozzle tip 35 , whose radius center lies in the middle of the upper shaft end, the laser cutting nozzle 34 not be aligned exactly vertically when the laser cutting nozzle 34 is recorded, as in the 6b and 6c shown.

In the sequence according to the 7a to 7c is the image of a laser cutting nozzle 38 with conical nozzle tip 39 seen. Indicated is again a nozzle magazine 40 with a hole 41 for storage of the laser cutting nozzle 38 , 7a shows the optimal vertical alignment of the laser cutting nozzle 38 for receiving. 7b and 7c show a tilted laser cutting nozzle 38 , The size important for the pickup process is the positional deviation of the nozzle shaft center M. The positional deviation of the nozzle shaft center M is lowest when the center perpendicular H of the cone flank 39 the nozzle shaft center M intersects. For optimal alignment of the laser cutting nozzle 38 must be D / 2 of the hole 41 be as large as the distance from point K to the center line of the nozzle. The distance K-M must be as long as possible, at least 1.5 times D.

1

Laser processing system

2

laser

3

control device

4

Laser processing head

5

Workpiece support

6

laser beam

7

8th

workpiece

9

cutting gas

10

suction

11

suction

12

laser cutting nozzle

13

Facility for changing the laser cutting nozzle

14

Nut

15

dielectric

16

outer casing

17

gas connection

18

gas connection

19

contact plug

20

ball cage

21

double arrow

22

lifting cylinder

23

Bullet

24

sloping surface

25

shaft

26

26 '

chamfer

27

channel

28

pressure chamber

29

top

30

bottom

31

channel

32

ring groove

33

34

jet

35

nozzle tip

36

nozzle magazine

37

drilling

38

jet

39

nozzle tip

40

nozzle magazine

41

drilling

Claims (8)

Facility ( 13 ) for changing a laser processing nozzle ( 12 ) on a laser processing head, characterized in that a pneumatically displaceable component ( 22 ) for locking and unlocking the laser processing nozzle ( 12 ) is provided. Device according to claim 1, characterized in that means for using a process gas for the laser processing for the pneumatic actuation of the component ( 22 ) are provided. Device according to claim 2, characterized in that the means by a first gas connection ( 17 ) and a second gas connection ( 18 ) for pressurizing the top or bottom of the component ( 22 ) are formed. Device according to one of the preceding claims, characterized in that the component ( 22 ) is formed by a lifting cylinder. Device according to one of the preceding claims, characterized in that on the component ( 22 ) a molding surface 19 to move the balls 23 is trained. Device according to one of the preceding claims, characterized in that on a shaft 25 a laser processing nozzle ( 12 ) an annular groove 32 for receiving the balls 23 is trained. Device according to one of the preceding claims, characterized in that the shaft of the laser processing nozzle ( 12 ) an introduction phase ( 24 ), an annular groove ( 32 ), a bale (B) and a centering bevel (D). Device according to one of the preceding claims, characterized characterized in that a component of the device for a dielectric Decoupling of the nozzle changer provided by the laser processing head.