This article introduces six little-known practical functions, which can greatly improve the processing efficiency and cutting performance of the laser cutting machine.
1. Frog Jump
Frog leaping is an empty way of laser cutting machine. As shown in the figure below, after cutting hole 1, cut hole 2. The cutting head shall be moved from point A to point B. Of course, the laser must be turned off during the movement. The movement process from point A to point B, the machine“ Empty” Running is called empty distance.
The idle travel of the early laser cutting machine is shown in the figure below. The cutting head needs to complete three actions successively: rising (to a safe enough height), translation (reaching above point B), and descending.
Compressing the idle time can improve the efficiency of the machine. If you change the three actions completed one after the other to“ At the same time” When it is finished, the idle travel time can be shortened: when the cutting head moves from point A to point B, it rises at the same time; When approaching point B, descend at the same time. As shown in the figure below.
The path of the empty motion of the cutting head is like an arc drawn by a frog jumping.
In the development process of laser cutting machine, leapfrog is an outstanding technological progress. Frog jumping only takes up the translation time from point A to point B, saving the time for rising and falling. The frog jumped and caught the food; Leapfrog of laser cutting machine,“ Snap” To achieve high efficiency. If the laser cutting machine does not have the frog jumping function now, I'm afraid it will not enter the stream.
2. Auto focus
When cutting different materials, the focus of the laser beam is required to be at different positions of the workpiece section. As shown in the figure below.
Therefore, it is necessary to adjust the focus position (focusing). The early laser cutting machine generally adopts manual focusing mode; At present, many manufacturers' machines have realized automatic focusing.
It may be said that it is better to change the height of the cutting head. When the cutting head is raised, the focus position will be higher, and when the cutting head is lowered, the focus position will be lower. It's not that simple.
As shown in the figure below, the nozzle is at the bottom of the cutting head. In the cutting process, the distance between the nozzle and the workpiece (nozzle height) is about 0.5~1.5mm, which can be regarded as a fixed value, that is, the nozzle height remains unchanged, so the focus cannot be adjusted by lifting the cutting head (otherwise, the cutting process cannot be completed).
The focal length of the focusing mirror is unchangeable, so it can not be expected to focus by changing the focal length. If you change the position of the focusing mirror, you can change the focus position: if the focusing mirror drops, the focus drops, and if the focusing mirror rises, the focus rises& mdash;& mdash; This is really a way of focusing. Auto focusing can be realized by using a motor to drive the focusing mirror to move up and down.
Another automatic focusing method is to set a variable curvature mirror (or adjustable mirror) before the beam enters the focusing mirror, and change the divergence angle of the reflected beam by changing the curvature of the mirror, thus changing the focus position. As shown in the figure below.
With the auto focusing function, the processing efficiency of the laser cutting machine can be significantly improved: the thick plate perforation time is greatly reduced; When processing workpieces of different materials and thicknesses, the machine can automatically quickly adjust the focus to the most appropriate position.
3. Automatic edge searching
As shown in the figure below, when the sheet is placed on the workbench, if it is skewed, it may cause waste during cutting. If the inclination angle and origin of the sheet can be sensed, the cutting program can be adjusted to suit the angle and position of the sheet, so as to avoid waste. The automatic edge searching function came into being.
After the automatic edge searching function is started, the cutting head starts from point P, automatically measures three points on the two vertical edges of the sheet: P1, P2, P3, and automatically calculates the inclination angle A of the sheet and the origin of the sheet.
With the help of the automatic edge searching function, the time for adjusting the workpiece earlier is saved&mdash& mdash; It is not easy to adjust (move) workpieces weighing hundreds of kilograms on the cutting workbench, which improves the efficiency of the machine.
A high-power laser cutting machine with advanced technology and powerful functions is a complex system integrating light, machinery and electricity. Subtle points often hide mysteries. Let's explore the mystery.
4. Centralized perforation
Centralized piercing, also known as pre piercing, is a processing process, not a function of the machine itself. When laser cutting thick plates, the cutting process of each contour will go through two stages: 1. piercing and 2. cutting.
Conventional machining process (A point piercing→ cutting contour 1→ B point piercing→ cutting contour 2→……), The so-called centralized piercing refers to the centralized execution of all piercing processes on the whole board in advance, and then the cutting process is executed later.
Centralized piercing process (complete the piercing of all contours→ return to the starting point→ cut all contours). Compared with the conventional processing process, the total length of the machine's running track is increased during centralized piercing. Then why should we use concentrated perforation?
Centralized perforation can avoid over burning. In the process of thick plate perforation, heat accumulation is formed around the perforation point. If the cutting is followed closely, overburning will occur. The centralized piercing process is adopted. When all perforations are completed and the starting point is returned for re cutting, due to sufficient time for heat dissipation, the over burning phenomenon is avoided.
Concentrated piercing can improve processing efficiency. At present, there are still many laser cutting machines that do not have the function of automatic focusing. The process parameters (laser mode, power, nozzle height, auxiliary gas pressure, etc.) of thick plate processing, perforation and cutting are different. The nozzle height during piercing shall be higher than that during cutting. If the conventional machining process is adopted (contour 1 piercing→ contour 1 cutting→ contour 2 piercing→ contour 2 cutting→……), In order to ensure the cutting quality and efficiency, the focus of the laser beam can only be manually set to the optimal position according to the cutting needs (imagine this: at the beginning, manually set the focus to the position required for piercing, piercing; then, set the focus to the position required for cutting, cutting; and then set the focus to the piercing position, piercing;…; until the processing is completed— this is a nightmare). Therefore, the focus of perforation must not be in the optimal position, and the perforation time will be longer. However, if centralized piercing is adopted, the focus can be adjusted to the position suitable for piercing. After the completion of piercing, the machine will be paused, and then the focus position will be adjusted to the optimal position required for cutting; In this way, the perforation time can be shortened by more than half, greatly improving the efficiency. Of course, if necessary, other process parameters can also be adjusted or changed during centralized perforation and cutting (for example, air+continuous wave can be used for perforation, while oxygen can be used for cutting, and there is enough time to complete the gas switching between them). We generally call the driving focus lens auto zoom F-axis; Is it possible to use manual zoom to focus on piercing and cutting; H” (Hand) Axis“ Zoom” What about?
Concentrated piercing also carries risks. If a collision occurs during the cutting process, resulting in the change of the plate position, the part that has not been cut may be scrapped. Centralized piercing process needs the help of automatic programming system.
5. Bridge location (micro connection)
During laser cutting, the sheet metal is held by the serrated support strip. If the cut part is not small enough, it cannot fall from the gap of the support strip; If it is not big enough, it cannot be supported by the support strip; It may lose balance and tilt. The cutting head moving at high speed may collide with it, which may cause shutdown or damage to the cutting head.
This phenomenon can be avoided by using the bridge (micro connection) cutting process. When programming the laser cutting of graphics, the closed contour is intentionally disconnected in several places to make the parts stick to the surrounding materials after the cutting is completed without falling. These disconnection places are bridge positions. It is also called breakpoint, or micro connection (this is called from the hard translation of MicroJoint). The distance of disconnection, about 0.2~1mm, is inversely proportional to the thickness of the sheet. Based on different angles, we have these different names: based on the contour, broken, so called breakpoint; Based on the part, it is adhered to the base metal, so it is called bridge position or micro connection.
The bridge position connects the parts with the surrounding materials. The mature programming software can automatically add a suitable number of bridge positions according to the length of the contour. It can also distinguish the internal and external contours, and decide whether to add bridge positions, so that the internal contour (waste) without bridge positions will fall, while the external contour (parts) of bridge positions will stick to the base metal without falling, thus eliminating the sorting work.
6. Common edge cutting
If the contour of adjacent parts is a straight line with the same angle, they can be combined into a straight line and cut only once. This is called co edge cutting. Obviously, co edge cutting reduces the cutting length and can significantly improve the processing efficiency.
Common edge cutting does not require the shape of the part to be rectangular. See the figure below.
The sky blue line is a common edge, cutting at the same edge, which not only saves cutting time, but also reduces the number of perforations. Therefore, the benefits are very obvious. If 1.5 hours are saved every day due to common edge cutting, about 500 hours are saved every year, and the comprehensive cost per hour is calculated as 100 yuan, it is equivalent to creating an additional benefit of 50000 yuan per year. Common edge cutting depends on intelligent automatic programming software.