All kinds of thermal laser cutting technology, except a few cases can start the edge of the plate, generally must be in the plate through a small round hole. Previously, in the laser stamping die compound machine, punch needle was used to break a hole, then laser was used to start laser cutting the small hole. There are two basic ways to break holes in fiber laser cutting without stamping die equipment

(1) Blast drilling

After the raw material is directly irradiated by the continuous laser, a dent is produced in the management center, then the melted raw material is quickly removed by the oxygen flow coaxial with the particle beam to produce a hole. Generally, the size of the hole is related to the thickness of the plate. The average diameter of the engineering blasting hole is half of the thickness. Therefore, the hole diameter of the engineering blasting with partial thickness is very large round, which is suitable for the application on the parts with higher requirements (such as crude oil screen seam pipe), only for waste. In addition, because the common working pressure of CO2 is the same as that of laser cutting, the splash is very large.

(2) Pulse drilling

The pulse light with peak output power is selected to melt gasify a small amount of raw materials. The common gas N2 is used as auxiliary vapor to reduce the hole expansion caused by causticization. The air pressure is lower than the CO2 working pressure during laser cutting. Each pulse light only causes small particles to gush gradually deepens. Therefore, the time to break a hole in thick steel plate must be several seconds. Once the hole is broken, the auxiliary steam is replaced by CO2 to carry out laser cutting. As a result, the hole diameter is smaller, the hole quality is better than that of engineering blasting. Therefore, the laser generator used should only have high power, but also the time space characteristics of the time line. Therefore, the general astigmatic C02 laser generator can be incorporated into the provisions of fiber laser cutting. In addition, a reliable air supply automatic control system is needed to complete the conversion of vapor type, air pressure hole breaking time. In order to get high-quality wound, the pipe cutting saw machine uses the single pulse to break the hole. We should attach great importance to the connection technology the single pulse hole breaking when the workpiece is still to the constant speed continuous laser cutting. Generally speaking, the laser cutting standard of accelerating section can be changed in theory, such as lens focal length, nozzle position, air pressure, etc., but in fact, the probability of changing the above standard is large because of the short time.