Precision cutting | how nozzle matching

2023-03-25

Laser cutting is through the laser beam irradiation of the workpiece local rapid heating and melting, and then at a very high speed instantaneous vaporization, cutting, so as to form the slit. The nozzle in laser cutting is the key component of laser cutting machine.

The main function is to control the focusing position of the laser beam on the workpiece surface, at the same time to accelerate the beam, so that the part of the irradiated area is melted and vaporized, forming a slit. Nozzle geometry and size on cutting quality

Quantity matters.

In the cutting process, the nozzle is the interaction medium between the laser beam and the workpiece, the nozzle will concentrate the laser beam to form a beam beam, the beam beam at a certain direction and speed (generally a certain size) to the work

A slit is formed on the surface of the piece. This process is called laser cutting.

The shape and size of nozzle have great influence on the cutting quality. There are three types of nozzles: parallel type, collecting type and cone type.

The influence of improper nozzle on cutting quality and the relationship between nozzle and cutting quality

Improper nozzle selection will cause the flow rate of gas to weaken, the direction of the flow becomes unstable, which affects the melting of the material in the cutting process, and the cutting of the thick plate will even cause the inability to cut.

Concentricity is not enough, cutting section is easy to dissolve stain, sharp corner local easy to melt, laser point and actual deviation, finish is not enough melt easy to adhere, cutting precision is not allowed, debugging difficult laser head easy to damage.

• Nozzle selection

When cutting thin plate (below 3mm) : the aperture range of the general nozzle is 0.8-15mm, and the flow rate of the small nozzle aperture is faster, and a good section will be formed. If a larger nozzle aperture is selected, the flow rate is slow, and slag will be formed on the back of the plate section.

When cutting the medium thickness (3mm-10mm) range: 1.5mm to 3.0mm aperture nozzle is generally selected. Although the flow rate of the smaller nozzle is faster, the insufficient flow will cause insufficient combustion, and the slow flow rate of the larger nozzle will also form slag.

When cutting thick plate (greater than 10mm) : the aperture of 2.5mm to 5.0mm is generally selected. Thick plate has a higher requirement for gas flow, so it needs a larger aperture.

• The choice of single nozzle and double nozzle

1, single layer nozzle is generally used for stainless steel plate, aluminum plate, copper plate cutting;

2. Double layer nozzle is generally used for cutting carbon steel plate;

The size of nozzle aperture has great influence on cutting quality and punching quality. Small hole nozzle cutting, small perforation, narrow slit, small gas diffusion area, corner place is not easy to hang slag, suitable for thin plate cutting; Thick plate cutting,

Because of the large amount of slag, slow speed, wide slit, so the need for a large aperture nozzle to blow the slag, aperture is large, the probability of the spark of the molten substance splashing into the nozzle is high, the protection lens is easy to bond flying slag, protect the life of the lens

The shorter it is.