The hole required to start processing at the beginning of the division is called perforation. The thicker the plate, the more unstable the perforations. It can be said that in thick plate cutting with a plate thickness greater than 12.Omm, 70% of the occurrence of processing failure is due to poor perforation. In order to perform stable perforation, the processing characteristics of perforation will be described here.

2.The principle of perforation

During the piercing process, the molten metal generated during the process before the penetration is deposited around the hole on the surface of the workpiece. Kunshan sheet metal processing technology, sheet metal has not yet had a relatively complete definition. According to a definition in a foreign professional journal, it can be defined as: sheet metal is a comprehensive cold working process for thin metal plates, including shearing, punching / cutting / compositing, folding, riveting, splicing, forming, etc. From the process of heating the surface of the workpiece after light emission, to the perforation effect of slow heating, until the final penetration is continuous. In this method, if the thickness of the plate is more than 9.0 mm, the perforation time will increase sharply, but the hole diameter is about 0.5 mm, which is narrower than the cut and the influence of heat is also small. Therefore, if the processing capacity is increased and the output energy is increased, it is difficult to completely discharge the molten metal from the upper part of the aperture, and an excessive combustion phenomenon occurs. The CW condition is a method of setting the focal position slightly above the surface of the workpiece, increasing the processing aperture, and rapidly heating it. Although a large amount of molten metal appeared and scattered on the surface of the workpiece, the processing time was greatly shortened.

Absorption of laser energy also occurs on the wall of the perforation. Suzhou sheet metal processing technology, sheet metal has not yet had a relatively complete definition. According to a definition in a foreign professional journal, it can be defined as: sheet metal is a comprehensive cold working process for thin metal plates (usually below 6mm), including shearing, punching / cutting / compositing, folding, riveting, splicing, Molding, etc. Suzhou chassis processing is the key technology that sheet metal technicians need to master, and it is also an important process for forming sheet metal products. It includes traditional cutting and blanking, punching, bending and forming methods and process parameters, as well as various cold stamping die structures and process parameters, various equipment working principles and operating methods, as well as new stamping technologies and new Craft. During the process of perforation, the irradiated laser light is reflected multiple times in the perforation and propagates downward while being absorbed. In order to shorten the perforation time, it is necessary to supplement the energy absorbed and weakened by the hole wall, that is, it is necessary to increase the output power during the perforation process. In addition, in order to minimize the thermal impact on the hole wall, it is necessary to increase the output power while shortening the perforation time as much as possible and reducing the laser irradiation on the hole wall.

3.Four principles for dealing with defects in perforation

When defects occur in the perforation process, it is necessary to analyze the causes of various phenomena and find out how to deal with them.

(1) The moment the defect occurs

For sheet metal processing, confirm whether the defect occurred during the piercing process or when the segmentation started after the piercing process. If it occurs during the punching process, the problematic output power and air pressure conditions are corrected according to the specific conditions at the beginning of the punching process or when the conditions are switched during the punching process. If the defect occurs before the end of the piercing, it is necessary to increase the piercing time because it is switched to the cutting condition before penetrating.

If a machining defect occurs at the beginning of the division, it is because it is difficult to pass the molten metal parts accumulated around the surface of the hole, so it is necessary to set a pulse condition or a low speed condition at the starting position.

Sheet metal processing