How to adjust the focus of the laser cutting machine

How to adjust the focus of the laser cutting machine

As we all know, laser cutting machine has the unparalleled advantage of cutting sheet metal. It not only has high cutting precision, but also has a smooth cross section and no burr. It can achieve good results whether it is cutting thick plate or thin plate. However, it is impossible to get rid of the relationship, just with the focusing of the SLR camera, to achieve a better imaging effect is a principle.

So, what is focus control?

Those who are familiar with laser cutting machines know that when cutting laser cutting machines of different materials and different thicknesses. In order to achieve better cutting results, the focus of the laser beam will set in different places.
In laser cutting applications, the main way of focusing is to rely on manual to complete. Nowadays,the laser’s full range of laser cutting machines are equipped with fully automatic focusing. Then, some people will say that the light path is integrate in the cutting head. Is it possible to achieve the focusing function by changing the height of the cutting head? However, it turns out that it is not as simple as everyone imagined (shown below).

The bottom of the cutting head is a nozzle. During the cutting process, the distance between the nozzle and the workpiece (nozzle height) is about 0.5 to 1.5 mm. It may be regarded as a fixed value, that is, the nozzle height is constant, so it cannot be adjusted by lifting the cutting head. Coke (otherwise it is impossible to complete the cutting process).
The focal length of the focusing mirror is immutable. So,changing the focal length cannot achieve focus. If  it change the position of the focusing mirror, the focus position also change.   This is a way of focusing. Using a motor-driven focusing mirror for up and down motion will achieve automatic focusing.

Another method of auto-focusing is to set a variable curvature mirror (or adjustable mirror). And change the divergence angle of the reflected beam by changing the curvature of the mirror to change the focus position.

With the auto focus function, the machine can automatically adjust the focus to the most suitable position. This can significantly improve the processing efficiency of the laser cutting machine, and  it greatly reduce the slab perforation time.
Therefore, for the laser cutting machine, the auto focus function is an important and indispensable function.