A comprehensive analysis of technology characteristic of laser cutting machine

A comprehensive analysis of technology characteristic of laser cutting machine

With the development of laser technology and mature, laser equipment has been widely application in all walks of life, such as laser marking machine, laser welding machine, laser drilling machine and laser cutting machine, and so on, especially CNC laser cutting machinery and equipment in recent years rapid development, is widely used in sheet metal, metal products, steel structure, precision machinery, auto parts, glasses, jewelry, nameplate, advertisement, arts and crafts, electronics, toys, packaging and other industries. Compared with other cutting equipment, CNC laser cutting machine is mainly reflected in the following aspects:

1, with high cutting speed, cutting quality is good, high precision;      
2, cut line is narrow, the cutting surface is smooth, does not damage the work piece;          
3, not affected by the shape of the workpiece, the material is not affected by the hardness;          
4, in addition to the processing of metal materials, but also for non metal cutting processing;          
5, saving investment, saving materials, more effective cost savings;      
6, the operation is simple, safe, stable performance, improve the speed of new product development, with a wide range of adaptability and flexibility.

Mechanical structure of metal CNC laser cutting machine is the most important part, not only most of the components are installed in the rack, and also the work gravity and acceleration and deceleration during the full impact loads.

CNC laser cutting machine design and development work including:

1, determine the CNC laser cutting equipment in a variety of conditions and the environment of fast, high precision, stable operation of the conditions.       2, according to the functional requirements of the frame structure, parameters, combined with the structural characteristics of the laser cutting machine, the establishment of the corresponding dynamic model.          
3, the structure and parameters of the frame are studied, the influence of the parameters on the static and dynamic stiffness and thermal stability of the frame are studied, and the theoretical basis for the design of the frame is provided. 4, determine the frame and other parts of the mutual coupling relationship

Therefore, CNC metal cutting machine designed in how to arrange the metals to reduce weight, increase body stiffness, reduce the effects of temperature change on accuracy, it is necessary to focus on the problems in the design process.
Therefore, in CNC metal cutting machine design how reasonable layout of metal, reduce weight, improve the body stiffness, reduce the influence of temperature change on the accuracy, is should be focus on the problem of the design process.
In the metal cutting laser circuit, there is a strong interference between analog signal and digital signal problem. Photoelectric isolation circuit is in electrical isolation to light for coal medium of transmission signal, the input and output circuit can isolate. So it can effectively suppress noise in the system, to clear the earth loop interference, responds faster, long service life, small volume, shock resistance etc. the benefits the in the strong - weak interface, especially in microcomputer system of backward and to the channel obtained widely application.

Photoelectric coupler has three characteristics:          
1, the signal is transmitted to take the form of electric light electricity, the light emitting part and the light receiving part are not in contact, which can avoid the feedback and the interference of the output end to the input end;     2, the ability to suppress noise interference;          
3, with a durable, high reliability and high speed and other advantages, the response time is generally within a few, the response time of high-speed optoelectronic coupler and some even less than 10ns.
Therefore, in the numerical control laser cutting machine system circuit design, should pay attention to the isolation of the input signal circuit and SCM connection. Here, the use of photoelectric coupling is the most commonly used method.
In the industrial manufacturing system of heavy metal processing industry, a lot of metal materials, no matter what kind of hardness it is, can be carried out without deformation cutting. Of course, for high reflectivity materials, such as gold, silver, copper and aluminum alloys, they are also good heat transfer conductor, so the laser cutting machine is difficult, and even can not be cut.
In spite of the laser cutting machine specific technology was a huge advantage, but as a high-tech equipment to use laser cutting machine to achieve the ideal cutting and processing effect, must also master the processing technical parameters and operation processes. Especially in the metal laser cutting machine cutting process, to select the appropriate cutting speed, or may cause some undesirable cutting results, mainly in the following:
1, when the laser cutting speed is too fast, it will cause the following adverse results:          
①.Method of cutting, spark spraying;          
②.The cutting surface is inclined to the lines, and the lower part of the production of molten stains;          
③.Cause the whole section is rough, but no melt stain is produced;
2, on the contrary, when the laser cutting speed is too slow, it will cause:   ①.Melting condition, the cutting surface is rough.          
②.The slit width, in sharp parts of the whole.          
③.Affect the cutting efficiency.
Therefore, in order to make the laser cutting machine equipment to better play its cutting function, you can cut the spark from the laser equipment to determine whether the feed rate is suitable:          
1, if the spark from the top down, it indicates that cutting speed is appropriate;          
2, if the spark back tilt, it indicates that the feed rate is too fast;       3, if the spark is not diffusion and less, together, it indicates that the speed is too slow.          
Most organic and inorganic materials can be used as laser cutting machine. Compared with other traditional cutting methods, laser cutting has obvious advantages compared with other traditional methods. Laser cutting machine has the characteristics of narrow slit, small deformation of the workpiece and high speed, high efficiency, low cost, safe operation, stable performance and so on.

Several major problems of laser cutting thick metal plate

Several major problems of laser cutting thick metal plate

Laser processing, as an advanced material cutting method, has been more and more accepted by the sheet metal producers. With the progress of computer control technology and optical technology, increasingly high expectations for its processing capacity, looking forward to this is not only to cut, it is to cut and sliced expectations. But can give the answer of course can not be separated from the processing machine performance, while the quality of processed materials directly affect the effect of the answer.
Laser processing started earlier in the Europe and the United States and Japan, in the eighties of the last century began by laser processing machine manufacturers of steel production put forward specific quality requirements, and the difference from the ordinary steel but the price is on the high side of laser special steel. And with the laser processing as the main cutting tool is accepted, 25mm the following common steel plate on the laser professional materials as a standard material. However, due to China's development is too fast, too late to adapt to the production of steel, there is a difference between China's steel and imported steel. The main difference is that the content of impurities in steel and the processing of steel surface and transport custody and a series of reasons, resulting in the current situation of Chinese sheet metal cutting.
Today, China's crude steel production is not only the world's first, is more than 50% of global output, developing countries, and even some like Australia, South Korea and other developed countries in order to save costs also used in a large number of board of China, so instead of expecting China steel to adapt to laser cutting as research and put forward to quality processing of inferior materials methods and proposal. Some of these ideas are presented in this paper.
Problems encountered in the processing of medium and heavy plate
1.Carbon steel plate perforation in processing thick plates perforated time accounted for a large proportion, the laser manufacturers have developed a technique for rapid perforation, more representative is high-energy perforation (hole), the advantages of this method is fast (1 second, to t16mm as an example, following the same), but the drawback is that the enormous energy not only affects the processing of small shape, perforation injection of the plate temperature elevated and the impact on the rest of the whole cutting process. With a small power pulse perforation, then a long time (12 seconds), will lead to the cutting efficiency and the unit cost of the increase.
2.Cutting surface quality problem          
Figure 1 and Figure 2 shows a section cutting processing plate often meet, such cutting not only product quality has been questioned, but also with the slag sticking of burn and severe, that reflected not expensive laser processing machine difference to other ways of cutting the value.

3.Stability of whole plate processing          
In the whole process of domestic steel, there will often be a local area of the phenomenon of poor processing. This kind of phenomenon is sometimes very random, even if the machine is in good condition, it will appear. In order to deal with the local fault products and greatly affect the whole work progress, this is not the cause of the processing failure also gives some of the author's analysis and countermeasures.

Solutions of the above problems
1.Peak perforation (HPP) scheme          
As the name suggests is the use of a small duty cycle of the peak pulse laser, combined with the material on the surface of the fuel injection is not fuel to clear the opening edge of the attachment, the reasonable frequency of the control pulse edge cooling edge. Is characterized by relatively deep hole, although a slightly longer time (3 seconds), but penetrated aperture small (about diameter 4mm) and open hole edge without attachments and into the heat is low, to facilitate the next normal cutting, compared to ordinary perforated is to improve the efficiency of 4 times. Figure 3 shows the difference between an ordinary perforation, a HPP perforation, and a high energy punch.

2.Cutting section improvement program          
For the carbon steel, the important factor to improve the cutting section is to control the heat input to the plate and to ensure the full combustion of the laser irradiation. MITSUBISHI motor development K-CUT processing conditions better to complete the mission. Fig. 4 Comparison of the effects of traditional and K-CUT conditions on the same piece of domestic plate. For stainless steel, the important factor to improve the cutting section is the improvement of the beam (improving the depth of focus) and the effective utilization of the auxiliary gas. The bright surface cutting technique is to improve the results obtained by the oscillator and the nozzle. Figure 5 is the effect after improvement. The lower part of the upper part of the section of rough 8 mu and 12 Mu as mechanical processing.

3.Scheme to ensure processing stability          
At present, in order to improve the running speed of the processing machine, the laser machine adopts the structure that is called the flight light path, that is, the material tray does not move and the processing head can move in the whole processing area. In order to compensate for the change of the relative position of the working head and the light source, the manufacturers can also ensure the consistency of the light spot in the range of processing. Although this method has simple structure, it will change the depth of focus, so that in the depth of the depth of the plate is very sensitive to cutting the thick plate will appear to be inadequate (both to keep the light spot and keep the focus depth constant). MITSUBISHI motor using the same length of light path (in the range of light source and the processing of the optical path between the processing head) can avoid the depth of focus changes, so that the spot and the depth of focus are consistent. In addition, the heat gained by the hot plate is controlled, which can solve the stability problem. Figure 6 shows the principle of long path and in the processing area at different points in the processing effect.

Take seriously the problems in the process, study the mechanism and find the solution to the problem. Through the traditional laser technique, a series of exploration and improvement, for more complex plate cutting developed new technology and its application to the ex plus, Rx, XL, etc. series of products, to meet the actual needs of customers in the domestic plate materials processing, thereby greatly improving the production efficiency. We will further efforts to explore new technologies to solve more difficult problems in the processing of the majority of users.

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