CNC flame cutting machine is generally suitable for processing metal materials with a thickness of 5-200mm. Its working principle is a kind of cutting equipment that uses gas with oxygen or gasoline with oxygen to cut metal materials.

The system parameters of CNC flame cutting machine are the basis for determining the system function. If the parameters are set incorrectly, the system failure or the failure of a function may be caused. In case of failure, the system parameters shall be checked in time. The parameters are generally stored in the magnetic bubble memory or in the CMOS ram to be maintained by the battery. Once the battery power is insufficient or due to external interference and other factors, individual parameters are lost or changed, resulting in confusion, making the NC cutting machine unable to work normally. At this time, the fault can be eliminated by checking and correcting parameters.

The specific cutting parameters of CNC flame cutting machine are set as follows:

1. The cutting speed should be moderate: moderately increasing the cutting speed can improve the quality of the incision, that is, the incision is slightly narrower, the surface of the incision is smoother, and the deformation can be reduced at the same time.

When the cutting speed is too fast: the linear energy of cutting is lower than the required value. The jet in the cutting seam can not quickly blow off the molten cutting melt immediately, resulting in a large amount of drag. With the slag hanging on the notch, the quality of the notch surface decreases.

When the cutting speed is too low: because the cutting place is the Yang of the plasma arc, in order to maintain the stability of the arc itself, the positive spot or positive area must find the place of conducting current near the cutting seam close to the arc, and will

The radial direction of the jet transfers more heat, so the notch is widened. The molten materials on both sides of the notch gather and solidify at the bottom edge to form slag hanging that is not easy to clean, and the upper edge of the notch forms a fillet due to excessive heating and melting.

When the speed is low: because the notch is too wide, the arc will even go out. It can be seen that good cutting quality is inseparable from cutting speed.

The cutting speed range can be selected according to the equipment description or determined by test. Due to the thickness of materials, different materials, high and low melting point, thermal conductivity and surface tension after melting, the cutting speed also changes accordingly.

2. Arc voltage: it is generally believed that the normal output voltage of the power supply is the cutting voltage. Plasma arc cutting machine usually has high no-load voltage and working voltage. When using gases with high ionization energy such as nitrogen, hydrogen or air, the voltage required to stabilize the plasma arc will be higher. When the current is fixed, the increase of voltage means the increase of arc enthalpy and cutting ability. If we increase the enthalpy, reduce the diameter of the jet and increase the gas flow rate, we can often obtain faster cutting speed and better cutting quality.

Adjustment of parameters of CNC plasma cutting machine.

1. Cutting current: cutting current is an important cutting process parameter, which directly determines the cutting thickness and speed of CNC plasma cutting machine, that is, cutting capacity.

a. With the increase of cutting current, the arc energy increases, the cutting ability increases, and the cutting speed increases;

b. With the increase of cutting current, the diameter of arc increases, and the arc becomes thicker, which makes the notch wider;

c. If the cutting current is too high, the nozzle heat load will increase, the nozzle will be damaged prematurely, and the cutting quality will naturally decline, or even normal cutting can not be carried out. Therefore, the cutting current and corresponding nozzle should be correctly selected according to the thickness of the material before cutting.

2. Nozzle height: refers to the distance between the nozzle surface and the cutting surface, which constitutes the part of the whole arc length. Because the plasma arc cutting of CNC plasma cutting machine uses constant current or steep drop external power supply, the current change is very small after the nozzle height increases, but it will increase the arc length and lead to the increase of arc voltage, so as to improve the arc power; But at the same time, it will also increase the arc length exposed to the environment and the energy lost by the arc column.

Under the combined action of the two factors, the effect of the former is often offset by the latter, which will reduce some cutting energy and reduce the cutting capacity. It usually shows that the blowing force of the cutting jet is weakened, the residual slag at the lower part of the incision is increased, and the fillet appears due to over melting at the upper edge.

In addition, considering the shape of plasma jet, the jet diameter expands outward after leaving the muzzle, and the increase of nozzle height will inevitably lead to the increase of notch width. Therefore, choosing the nozzle height as small as possible is beneficial to improve the cutting speed and cutting quality of CNC plasma cutting machine. However, when the nozzle height is too low, it may cause double arc phenomenon. Using ceramic external nozzle, the nozzle height can be set to zero, that is, the nozzle surface directly contacts the cut surface, and good results can be obtained.