新闻资讯

　　In recent years, laser cutting technology is facing changes and opportunities. The change means that laser enterprises should not only increase the investment in cutting technology, but also conform to the trend of industrial automation to make laser cutting more personalized. At the same time, laser enterprises will also welcome greater opportunities. Laser cutting technology has irreplaceable advantages in improving the efficiency of industrial processing. The development of industrial control technology brings more possibilities to the laser industry. Cutting technology will expand into more fields in the future and play an important role in promoting the development of the industry.

　　In the future, laser cutting will develop in these directions. High-speed, high-precision cutting technology, thick plate cutting and large-size workpiece cutting, three-dimensional multi-axis numerical control laser cutting technology, unmanned and automated laser cutting technology will become the main research directions.

　　Laser cutting head plays a vital role in laser cutting.

　　Laser cutting machine is a direct device embodying laser cutting technology. It focuses the laser emitted from the laser into a laser beam with high power density through an optical path system. The laser beam irradiates the surface of the workpiece to make the workpiece reach the melting point or boiling point, and the high pressure gas coaxial with the beam blows away the molten or vaporized metal. With the movement of the relative position between the beam and the workpiece, the material finally forms a slit, thus achieving the purpose of cutting.

　　Laser cutting machine, as a new type of plate processing equipment, has been continuously updated and developed in technology. Laser cutting technology and laser cutting machine equipment are being familiar and accepted by most plate processing enterprises. It has gradually replaced traditional plate processing methods such as plasma cutting, water cutting, flame cutting, numerical control punching machine and so on with many advantages such as high processing efficiency, high processing precision, good cutting section quality and capability of three-dimensional cutting processing. According to the difference of laser generators, there are three kinds of laser cutting machines on the market: CO2 laser cutting machine, solid state (YAG) laser cutting machine and fiber laser cutting machine.

　　The quality of nozzle, focusing lens and focusing tracking system is related to cutting quality.

　　Among several key technologies of laser cutting machine, the quality of laser cutting head directly affects the cutting quality. The common cutting head of laser cutting machine consists of nozzle, focusing lens and focusing tracking system.

　　1. The function of laser head nozzle in laser cutting

　　Laser head nozzle is a consumable part commonly used in fiber laser cutting machine. With the development and wide application of fiber laser cutting technology, the demand for laser head nozzle has increased greatly in recent years. There are three types of nozzles: parallel type, convergent type and cone type. The cutting quality is closely related to the nozzle type and nozzle size.

　　The first function is to collect the capacitance signal and transmit it to the signal processor through the ceramic ring. The signal processor sends a signal to the machine tool control center. The machine tool control center makes feedback according to the signal and adjusts the position of the laser head in the vertical direction so as to keep the distance tracking of the laser head to the workpiece during cutting.

　　The second function is to use its internal shape to guide the gas to smoothly pass through the workpiece to be cut and form high pressure at the nozzle outlet attachment. The smaller the nozzle outlet aperture, the higher the air pressure formed. If it is oxidative cutting, after high-pressure oxygen passes through the nozzle, a part of the working surface provides heat through oxidation reaction with the cut piece to accelerate cutting; The other part passes through the cutting surface at a high speed to take away the slag and maintain appropriate pressure on the cutting surface to ensure smooth cutting.

　　The third function is to protect the inner lens of the laser head. In the laser cutting process, especially when drilling holes, there is often slag splashing. The high-pressure gas blown out from the nozzle of the laser head can block most of the sputtered objects outside to protect the lens from damage.

　　2. Relationship between Focus Lens and Laser Cutting

　　Focusing lens has the general characteristics of ordinary optical lens, but it also has its unique features. It can be used to make lenses with ultra-short focal length, and also form real images on the end surface, so that it is easy to obtain positive real images with the same size as objects.

　　In order to cut with the energy of laser beam, the original beam emitted by laser must be focused by lens to form light spot with high energy density. The transmission lens is very simple to use. When the laser beam passes through the lens, the lens focuses the laser beam onto the workpiece in the axial direction. In common industrial laser systems, nozzles all contain the function of gas washing, i.e. gas jet is introduced at the nozzle to help improve the interaction performance between laser beam and material, while high-speed gas flow also acts as isolation from optical system. The gas jet prevents material processing contaminants from entering the nozzle and contaminating the lens surface. The reflective focusing system uses an additional beam deflector and a rear focusing mirror. In this condition, there are two additional optical systems, i.e. zinc selenide window and beam deflector. The role of the window is to seal off the focusing system above the nozzle.

　　The transmissive focusing head has two main advantages, that is, the light beam is easy to adjust and small deviation such as eccentricity is allowed, that is, the light beam is allowed to enter the lens eccentrically or angularly. Reflective transflective lenses are suitable for high-power applications. They are ideal for high-power laser systems, produce less thermal lens effect, and are durable in harsh welding environments. In theory, a parabolic mirror should focus the laser beam to the diffraction limit of the beam. The diffraction limit is the minimum focal spot that can be achieved for a specific laser beam diameter and mode quality. Parabolic mirror is one of the most difficult mirror systems to adjust, so it is usually difficult to reach the diffraction limit focus in high power laser systems. For welding, the use of small spots is not always required, so mirrors are suitable for this application.

　　The focal length and focal position of the focusing lens have an impact on the laser cutting quality. Short focal length lens is suitable for high-speed cutting of thin materials, and long focal length lens is suitable for cutting thick workpieces.

　　3. The Role of Focus Tracking System in Laser Cutting

　　The focus tracking system of laser cutting machine is generally composed of focus cutting head and tracking sensor system. The cutting head comprises a light guide focusing part, a water cooling part, an air blowing part and a mechanical adjusting part. The sensor is composed of a sensing element and an amplification control part. The tracking system varies with different sensor elements.

　　At present, there are mainly two types of tracking systems. The first is capacitive sensor tracking system, also known as non-contact tracking system. The second is inductive sensor tracking system, also known as contact tracking system.

　　The working flow of the laser head is as follows: the laser generates laser, which is transmitted through the external light path. After being focused by the focusing mirror in the cutting head, the laser acts on the surface of the processed material to gasify the material or form a molten pool with the aid of cutting gas (mainly oxidation). After the cutting auxiliary gas is guided by the cutting head (including the nozzle), a strong airflow is generated to blow off the generated slag, meanwhile, the material is prevented from being gasified and attached to the surface of the focusing mirror to cause damage, and plasma or a mixture of plasma and gas is prevented from being generated.

　　New Requirement in Intelligent Manufacturing Era: Auto-focusing Cutting Head Is Popular

　　Intelligent manufacturing technology is a subject that industrial automation must study. At present, there is not much that can really be done in the market. Take auto-focus cutting head as an example, domestic laser cutting head manufacturers mainly based in Otellico have the ability to do so.

　　(Alus Auto Focus Cutting Head)

　　Focus control refers to the laser cutting machine when cutting different materials and plates with different thicknesses, in order to achieve better cutting effect, the focus of the laser beam will be set in different places, which is called focusing. With the breakthrough of industrial control technology, a cutting head capable of automatic focusing is indispensable in laser cutting automation.

　　In the application of laser cutting, focusing is mainly done manually. Now with the development of laser technology, this manual focusing method has gradually been phased out and the automatic focusing function has begun to be realized slowly.

　　The bottom of the laser cutting head is a nozzle. During cutting, the height of the nozzle will not change, so the focus cannot be adjusted by lifting the cutting head. The focal length of the focusing mirror cannot be changed, so you cannot expect to focus by changing the focal length. If the position of the focusing mirror is changed, the focus position can be changed: if the focusing mirror is lowered, the focus is lowered, and if the focusing mirror is raised, the focus is raised, which is a way of focusing. Using a motor to drive the focusing mirror to move up and down can realize automatic focusing.

　　Another method of automatic focusing is to install a variable curvature mirror before the light beam enters the focusing mirror, and change the divergence angle of the reflected light beam by changing the curvature of the mirror, thus changing the focus position.

　　With the automatic focusing function, when processing workpieces of different materials and thicknesses, the machine can automatically quickly adjust the focus to the most appropriate position, which can significantly improve the processing efficiency of the laser cutting machine and greatly reduce the perforation time of thick plates. Therefore, for laser cutting machine, auto-focusing function is an important and indispensable function.

　　In recent years, the use rate of automatic cutting heads in China has become higher and higher. However, due to higher prices, many domestic manufacturers were hesitant in purchasing. With the investment of domestic manufacturers in automatic cutting technology, domestic manufacturers such as Otellico have made many breakthroughs in automatic cutting head technology.

　　The combination of automatic cutting head and numerical control system makes laser cutting more "intelligent"

　　The emergence of auto-focusing cutting head makes laser cutting technology go further. It plays an indispensable role in promoting the automation of laser cutting, while having a numerical control system matched with it makes laser cutting more "intelligent".

　　The main advantage of the auto-focusing cutting head is to dynamically adjust the focus position, air pressure and follow-up height through the numerical control system, thus realizing the automatic adjustment of the cutting process. In this way, not only the technological requirements that cannot be completed by common manual cutting heads are realized, but also the complex technological process can be solidified into the numerical control system.

　　The close cooperation between laser cutting numerical control system and automatic focusing cutting head, laser and other intelligent equipment can make laser cutting become "intelligent".

　　As a domestic scientific and technological enterprise specializing in the research, development and manufacturing of laser cutting focusing system, machine tool motion control system and equipment internet of things, alus, relying on years of research and technology accumulation in mechanical design, automatic control and engineering optics, has launched a three-in-one laser cutting application solution of "laser cutting+multi-axis motion control system+equipment management cloud platform", which makes production and manufacturing truly intelligent, more efficient, lower in cost and more complete in function, and is the best choice for customers to pursue core competitiveness and maximize benefits.

　　It is reported that Alus' laser cutting application solution consists of three parts: ALS-cutter series optical fiber cutting head, laser cutting numerical control system and Au3tech numerical control cloud platform.

　　Alus Helps Laser Cutting Automation

　　2018 is a year of rapid growth for the laser industry. With the continuous expansion of laser application field and the increase of application depth, the future demand of the industry is promising, and the compound growth rate of the industry scale is expected to be above 10%. The new application scenario requires higher laser cutting technology, which requires laser cutting machine manufacturers to upgrade their own technology, conform to the new market trend, and seize new business opportunities. It is urgent to apply laser cutting automation technology.

　　It is reported that Suzhou alus photoelectric technology co., ltd is a high-tech enterprise specializing in the design, development and sales of industrial laser focusing systems and automatic control systems, which was established in 2013. The company focuses on the industrial laser focusing system and integrates the three technical fields of mechanical design, automatic control and engineering optics.

　　Opportunities and Challenges Faced by Laser Cutting

　　Summary: The popularization of any technology requires a process. As the demand for laser processing increases, the automation of laser cutting technology becomes more and more important. Laser cutting head plays a vital role in laser cutting technology, and high-quality auto-focusing cutting head technology is undoubtedly an accelerator to promote this industry. In the future, it will play a mainstay role in promoting the automation of laser cutting technology.