Initially in the application of laser cutting, focusing mainly depends on manual. However, with the continuous development of laser technology, manual focusing will eventually be eliminated and replaced by automatic focusing.

For example, the high-power laser cutting machine has a highly efficient automatic focusing function. However, some people will say that the light path is integrated in the cutting head. Can we simply change the height of the cutting head? When the cutting head rises,

The focus position is high. When the cutting head drops, the focus position is low. However, it turns out that this is not as simple as everyone imagined.

There is a nozzle at the bottom of the cutting head. In the cutting process, the distance between the nozzle and the workpiece (nozzle height) is about 0.5 - 1.5 mm, which can be regarded as a fixed value, so it is impossible to focus by lifting the laser head.

The focal length of the focusing mirror is constant, so it is unrealistic to focus by changing the focal length.

Changing the position of the focusing mirror will change the focus position accordingly: if the focusing mirror drops, the focus will drop; When the focusing mirror rises, the focus will rise. This is indeed a focusing mode. A motor driven focusing mirror is used to move up and down, which can realize automatic focusing

Another method of automatic focusing is to place a variable curvature mirror (or adjustable mirror) before the beam enters the focusing mirror, and change the divergence angle and focus position of the reflected beam by changing the curvature of the mirror.

With automatic focusing function, when processing workpieces of different materials and thicknesses, the machine can automatically and quickly adjust the focus to the appropriate position through numerical control. Therefore, the processing efficiency of the laser cutting machine can be significantly improved, and the perforation time of thick plates can be greatly reduced.

Therefore, the auto focusing function is an indispensable and important function of laser cutting machine tools.