Influencing factors of high-quality cutting of laser cutting machine
Fiber laser cutting machine has many advantages, such as high cutting precision, narrow slit, smooth cutting surface and high efficiency. At the same time, the use of fiber laser cutting machines has significant advantages in terms of safety and environmental protection. In the future development trend, fiber laser cutting machine will occupy the status of mainstream equipment.
1. Cutting speed
Fast cutting speed is one of the advantages of laser cutting, but the cutting speed is not as fast as possible. In the case of a certain laser power, it is necessary to select an appropriate cutting speed according to the cutting plate, so as to make the cutting surface beautiful and obtain high quality. When cutting workpieces, the following methods can be used to judge whether the cutting speed is appropriate, and then adjust the cutting speed:
Observe the cutting sparks: when the cutting speed is appropriate, the cutting sparks spread evenly from top to bottom; when the cutting speed is too fast, the cutting sparks will tilt; when the cutting speed is too slow, the cutting sparks gather together, do not spread and do not spread. few.
Observe the cutting plate: when the cutting speed is appropriate, the cutting surface presents a relatively smooth line, and no slag is produced in the lower half. When the cutting speed is too fast, it may not be able to be cut through, and the sparks will spray randomly; some areas can be cut through, but some areas cannot be cut through; the cutting section is slanted, and the lower part produces slag. When the cutting speed is too slow, it will cause over-melting, the cutting section will be rough, and the kerf will become wider.
2. Nozzle and Nozzle Height
The nozzle is used as a beam and auxiliary gas channel, and the shape, aperture and nozzle height of the nozzle will affect the cutting effect.
The nozzle is mainly to control the gas diffusion area and size, so as to control the cutting quality; to prevent debris such as slag from rebounding upward, passing through the nozzle, and contaminating the lens. Generally speaking, when cutting thin plates, the defocus amount is small, and small-diameter nozzles are used; while when cutting thick plates, the required slits and spots are large, and large-diameter nozzles are used.
The nozzle is divided into single-layer and double-layer. The single-layer laser nozzle is used for melting and cutting, that is, using nitrogen as an auxiliary gas to cut stainless steel and aluminum plates, etc.; Cut carbon steel.
The nozzle height is the distance between the nozzle outlet and the workpiece surface. When cutting, we generally set this height at 0.3mm-0.8mm. If it is too low, the nozzle will easily collide with the surface of the workpiece. If it is too high, the concentration and pressure of the auxiliary gas will be reduced, resulting in a decrease in the cutting quality. When perforating, in order to prevent the generated slag from being reflected on the lens, the height of the nozzle can be appropriately raised.
3. Focus position
After checking the actual zero focus of cutting through the previous article, in the actual cutting process, we need to set an appropriate focus position to obtain a cutting workpiece with better cutting effect:
Zero focal length: The focus is on the surface of the workpiece, which is suitable for cutting thin sheets.
Negative focal length: the focus is under the surface of the workpiece, generally at 1/2-2/3 of the thickness of the workpiece, so the range of the smooth surface is larger, and the slit will be wider than the zero focal length.
Positive focal length: The focus is on the upper surface of the workpiece, which is generally suitable for the cutting of thick carbon steel (thick plates require a larger kerf, and a negative focus will cause the carbon steel to overburn).
