How to make the laser cutting machine proofing more accurate?

In the laser cutting machine, several key technologies must be mastered and solved for parts with higher cutting accuracy or larger thickness. Focus position control is one of them. One of the advantages of laser cutting is that the energy density of the beam is high, so the focal spot diameter is as small as possible in order to produce a narrow slit. Because the smaller the focal depth of the focusing lens, the smaller the focal spot diameter. For high-quality cutting, the effective focal depth is also related to the lens diameter and the material to be cut. Therefore, it is important to control the position of the focus relative to the surface of the material being cut.

Because the laser power density has a great influence on the cutting speed, the choice of lens focal length is an important issue. After the laser beam is focused, the spot size is proportional to the lens focal length. After the beam is focused by a short focal length lens, the spot size is very small, and the power density at the focal point is very high, which is very beneficial for material cutting; but its disadvantage is that the focal depth is very short, and the adjustment margin Small, generally suitable for high-speed cutting of thin materials. Since the long focal length lens has a wider focal depth, as long as it has sufficient power density, it is more suitable for cutting thick workpieces.

After determining which focal length lens to use, the relative position of the focal point and the surface of the workpiece can ensure cutting quality especially important. Due to the high power density at the focal point, in most cases, the focal point is just on the surface of the workpiece during cutting, or slightly below the surface. During the entire cutting process, ensuring a constant relative position between the focus and the workpiece is an important condition for obtaining stable cutting quality. Sometimes, the lens is heated due to poor cooling during operation, which causes the focal length to change, which requires timely adjustment of the focal position.

Laser cutting machine

When the focus is in the right position, the slit is small, the efficiency is high, and the cutting speed can be obtained. The cutting result. In most applications, the beam focus is adjusted to just under the nozzle. The distance between the nozzle and the surface of the workpiece is generally about 1.5 mm.

In the laser application process, we often encounter problems such as focusing. There are three common simple methods to determine the focus position:

(1) Printing method: The cutting head is moved from top to bottom, and laser beam printing is performed on the plastic plate, with the smaller printing diameter as the focus.

(2) Inclined plate method: Use a plastic plate placed obliquely at an angle to the vertical axis to pull it horizontally, looking for a smaller spot of the laser beam as the focus.

(3) Blue spark method: remove the nozzle, blow air, hit the pulse laser on the stainless steel plate, and make the cutting head move from top to bottom until the blue spark is the focus.