EP1890835A1

EP1890835A1 - Laser machine tool with laser machining nozzle alignment for orienting the laser beam to the laser machining nozzle hole

Info

Publication number: EP1890835A1
Application number: EP06753958A
Authority: EP
Inventors: Jürgen-Michael Weick; Michael Häcker
Original assignee: Trumpf Werkzeugmaschinen SE and Co KG
Current assignee: Trumpf Werkzeugmaschinen SE and Co KG
Priority date: 2005-05-31
Filing date: 2006-05-30
Publication date: 2008-02-27
Also published as: EP1728581B1; CN201128048Y; WO2006128663A1; EP1728581A1; ATE446159T1; DE502005008372D1; US20090001063A1

Abstract

A laser-processing machine comprises optics to guide and focus a laser beam (5) and has a device (11) to illuminate the laser processing nozzle hole (10) of the head and to use this to determine the hole center and a device to determine the distance between the nozzle center and the laser beam focus.

Description

DESCRIPTION

LASER PROCESSING MACHINE WITH LASER PROCESSING NOZZLE ADJUSTMENT FOR ALIGNING THE LASER BEAM WITH THE LASER PROCESSING NOZZLE DRILLING

The present invention relates to a laser processing machine

with an optical system for beam guidance and focusing of a

Laser processing beam.

Such laser processing machines are well known.

For optimal material processing it is necessary to use the

Laser beam within the laser processing nozzle as centric as possible

to arrange. This laser processing nozzle adjustment is so far

done manually.

The applicant has set himself the task, the most centric possible

Arrangement of the laser processing beam within the nozzle bore

Automate a laser processing nozzle of the laser cutting head

to be able to. This object is achieved by a laser processing machine according to

Claim 1 solved.

By the invention, the nozzle center by a

Reference measurement are determined, each with a picture of the

illuminated nozzle and a focused beam

and evaluated. The measuring signals can be transmitted via the

Machine control for automatic laser nozzle centering

be used.

It is a separate light source for illuminating the nozzle bore

This has the advantage of being used for laser processing

trained laser beam does not have to be adjusted. Another

significant advantage of using a separate light source

is that you can use visible light. Therefore, you can

Visible light detectors are used, which

standard and inexpensive to manufacture. The

Use of existing optics for coupling light beam of the Light source has the advantage that no additional optics for

Coupling is needed.

In technical implementation of the operation with a separate

Light source come a laser diode for beam generation, optics

for beam expansion, a deflection mirror and a mirror for

Reflection of the light beam collinear to the laser processing beam

into consideration.

When the deflecting mirror and the mirror become part of one

Process light measuring device, the invention with a per se

known process light measuring device combined and advantageous in

a laser processing machine can be integrated.

For evaluation is an image acquisition and image evaluation

advantageous.

The optics for beam guidance and focusing of a laser beam can

an adaptive mirror used to adjust the

Illumination can be used. Preferred embodiments of the invention will be described with reference to

Schematic drawing explained. It shows:

FIG. 1 shows a laser cutting machine;

Figure 2 shows a part of the laser beam guide and a reflection

another laser beam for illuminating the

Cutting nozzle bore;

Figure 3 shows a variant of the reflection in conjunction with a

Process light measurement;

FIG. 4 shows the focused laser cutting beam within the

cutting nozzle;

Figure 5 shows the illumination of the cutting nozzle bore using the

another laser beam;

FIG. 6 is a plan view of a quadrantector. FIG. 1 shows the structure of a laser processing machine 1

for laser cutting with a CXV laser 2, a

Laser processing head 3 and a workpiece support 4 can be seen.

A generated laser beam 5 is using deflecting mirrors for

Laser processing head 3 guided and with the help of mirrors on a

Workpiece 6 directed. In the beam guide of the laser beam 5 can

the device according to the invention installed at any point

become.

Before a continuous kerf arises, the laser beam must be 5

penetrate the workpiece 6. The sheet 6 must be in one place

punctiform molten or oxidized, and the melt

must be blown out.

When slow penetration with a ramp, the laser power

gradually increased, reduced and over a period of time

kept constant until the piercing hole is created. Either

the grooving as well as the laser cutting are done by adding

a gas supported. As cutting gases 7 can oxygen, Nitrogen, compressed air and / or application-specific gases used

become. Which gas is ultimately used is of it

depending on which materials are cut and which ones

Quality demands are placed on the workpiece.

Where the laser beam 5 impinges on the sheet 6, the material

melted and oxidized for the most part. The resulting

Melt is blown out together with the iron oxides.

Particles and gases can be generated by means of a

Suction device 8 are sucked out of a suction chamber 9.

According to Figure 2, the means for illuminating a

Cutting nozzle bore IO of a cutting nozzle 10 'of the cutting head 3

essentially a laser diode 11, one at an angle of

45 ° arranged deflecting mirror 12 and a mirror 13, which it

allows a visible laser beam 14 collinear to

Beam laser cutting beam 5 of the CO ₂ laser. This is the

Laser beam 14 of the laser diode 11 is widened so that it on the

Edge of the mirror 13 hits. The focal length of a Aufweitlinse 15 and

their distance from the mirror 13 are chosen so that a Focusing optics 16 (lens or mirror) using the laser beam 14

the laser diode 11 is fully illuminated.

By means of an adaptive mirror 17, the focus position of lens or

Focusing mirror 16 now adjusted so far that the nozzle bore 10th

is fully lit. The laser beam 14 touches the edge of the

Nozzle bore 10. One directly under the laser cutting nozzle 10 '

arranged screen 18 shows a red spot with a

Diameter D, whose boundary exactly the nozzle bore 10th

equivalent. By means of camera and image analysis can now in one

first method step exactly the nozzle center of the nozzle bore 10th

be determined and evaluated (see Figure 4). The focus position

is in a second step exactly in the plane of

Lower edge of nozzle placed. The spot corresponding to the focus possesses

a diameter D 'of about 0.1 mm. Its middle will be again

determined (see Figure 5). The deviation from beam center to

Nozzle center can be determined and for automatic adjustment

be used. Figure 3 shows the combination of the invention with a

Process light measuring device. The most important point is that the

Mirror 13 'has a hole through which the machining laser beam

5 passes. The additional beam source is via a

partially transparent mirror 12 'and the so-called. Scraper mirror 13' in the

Beam guide coupled. As a mirror 13 'is with the PCS Scraper

a suitable mirror in the laser cutting machine already

present, which can additionally be used for this purpose.

The laser cutting machine can work with the optical

Be provided process light measuring device, wherein the mirror 13 'part

the process light measuring device is. The process light measuring device

may be of conventional design. Such measuring devices

are for example from the company TRUMPF, Ditzingen, Germany

sold under the name "PCS". PCS is an optical one

System that measures the process light during the puncture.

According to the selected function in the DIAS-PCS-PC you can use

Help of these readings controlled by the plunge process (gentle

Grooving) and / or the piercing end are detected (gentle

and full grooving). Back-reflected process light 5 'due to

the laser power beam is created at the puncture position is directed by the scraper mirror 13 'on a photodiode 19, the

whose intensity is converted into a corresponding current. The

Electronics 20 in the measuring head measures this current and transmits it

Measurements digitally to the evaluation electronics, this data

processed accordingly.

Similarly, instead of the laser beam 14 with a

attenuated laser processing beam 5 for illuminating the

Nozzle hole 10 are worked. The sensor is then a CO ₂ -

Laser light sensitive camera or at least a CO2 laser light

sensitive quadrant detector necessary.

The quadrant detector could be used as follows:

1st variant

The laser beam 5 is defocused so far that it the nozzle bore

10 of the stationary arranged cutting head 3 fills. The laser beam

becomes so far with the help of the optical elements of the beam guide

shifted, that the signal disappears eg in the -X-quadrant. This value is saved. Then the value becomes + X direction

determined by methods with the X-axis. The nozzle center is the

Average of the two values obtained. Analogously, in the Y

Proceed in the direction. Now, the focal point by means of the mirror 17

mapped to the quadrant detector 18. The adjusting device in

Cutting head is now adjusted until all 4 quadrants the same

Display measured value (see Figure 6). The laser beam 5 is centered.

2nd variant

When stationary focusing mirror, the nozzle is moved. With

The machine axis is the small imaged beam on the

Detector proceed that all 4 quadrants of the quadrant detector

18 show the same reading. Now the laser beam is using

Defocusing by the mirror 17 is increased so that he

Nozzle hole 10 fills. Now the nozzle 10 'will be in the two

Axes adjusted until all 4 quadrants show the same reading.

Claims

PAT EN TA NSP RICK

1. Laser processing machine (1) with an optics for

Beam guidance and focusing of a laser beam (5) with

a device for illuminating the nozzle bore (10)

a laser processing nozzle (10 ') of the laser processing head

(3), with a facility for determining the center of

Nozzle hole (10) using the illumination and with a

Device for determining the distance of the

Laser beam focus to the nozzle center, characterized

a separate light source (11) for illuminating the

Nozzle bore (10) and an optical element of

Beam guide of the laser beam (5) for coupling the

Light beam (14) are provided.

2. Laser processing machine according to claim 1, characterized

characterized in that a laser diode (11) for

Beam generation, an optical system (15) for beam expansion, a

Deflection mirror (12, 12 ') and a mirror (13, 13') for Reflection of the light beam (14) collinear to

Laser processing beam (5) are provided.

3. Laser processing machine according to claim 1, characterized

characterized in that the deflecting mirror (12 ') and the mirror

(13 ') are part of a process light measuring device.

4. Laser processing machine according to one of the preceding

Claims, characterized in that a

Image acquisition and image evaluation is provided.

5. Laser processing machine according to one of the preceding

Claims, characterized in that the optics for

Beam guidance and focusing of a laser beam one

includes adaptive mirror (17).