The laser cutting machines is to focus the laser light emitted from the laser into a high power density laser beam through the optical path system. The laser beam irradiates the surface of the workpiece to make the workpiece reach the melting point or boiling point, while the high-pressure gas coaxial with the beam blows away the molten or vaporized metal.
As the relative position of the beam and the workpiece moves, the material will finally form a slit, so as to achieve the purpose of cutting.
Laser cutting processing is to replace the traditional mechanical knife with an invisible beam. It has the characteristics of high precision, fast cutting, not limited to the cutting pattern, automatic typesetting, saving materials, smooth cutting, and low processing cost. It will gradually improve or replace it. Traditional metal cutting process equipment. The mechanical part of the laser cutter head has no contact with the workpiece, and it will not scratch the surface of the workpiece during work; the laser cutting speed is fast, the incision is smooth and flat, and generally does not need subsequent processing; the cutting heat affected zone is small, the plate deformation is small, and the slit is narrow ( 0.1mm~0.3mm); the incision has no mechanical stress, no shearing burrs; high processing accuracy, good repeatability, and no damage to the surface of the material; CNC programming, can process any plan, and can cut large-format whole plates without Opening the mold saves time and economy.
Table of Contents
1 Introduction
2 Principle
3 Main process
4 key technology
▪ Main parameters
▪ Cutting quality
▪ Cutting perforation
▪ Nozzle design
5 components
▪ Laser
▪ Industry application
6 Application comparison
▪ Material analysis
▪ Competitive advantage
▪ CNC cutting machine
▪ Five-axis machine
▪ Laser punching machine
7 Optical path compensation measures
8 Operation details
▪ Note
▪ Advantages
9 Machine maintenance
10 How to Buy
Table of Contents
Introduction
Compared with traditional oxyacetylene, plasma and other cutting processes, laser cutting machines cutting speed is fast, the slit is narrow, the heat-affected zone is small, the edge of the slit is perpendicular, and the cutting edge is smooth. At the same time, there are many types of materials that can be laser cut, including carbon steel. , Stainless steel, alloy steel, wood, plastic, rubber, cloth, quartz, ceramics, glass, composite materials, etc. With the rapid development of the market economy and the rapid development of science and technology, laser cutting technology has been widely used in automobiles, machinery, electricity, hardware, and electrical appliances. In recent years, laser cutting technology is developing at an unprecedented speed, with an annual growth rate of 15% to 20%. Since 1985, my country has grown at a rate of nearly 25% per year. At present, the overall level of laser cutting technology in my country still has a big gap compared with advanced countries. Therefore, laser cutting technology in the domestic market has broad development prospects and huge application space [1].
During the cutting process of the laser cutting machine, the beam is focused by the lens of the cutting head into a small focal point, so that the focal point reaches a high power density, and the cutting head is fixed on the z axis. At this time, the heat input by the beam far exceeds the part of the heat reflected, conducted or diffused by the material, and the material is quickly heated to the melting and vaporization temperature. At the same time, a high-speed airflow will melt from the coaxial or non-coaxial side. And the vaporized material is blown out to form holes for cutting the material. With the relative movement of the focus and the material, the hole forms a continuous slit with a very narrow width to complete the cutting of the material [1].
Currently, the outer optical path part of the laser cutting machine mainly uses the flying optical path system. The light beam emitted from the laser generator reaches the focusing lens on the cutting head through the reflecting mirrors 1, 2, and 3, and forms a light spot on the surface of the material to be processed after focusing. The reflecting lens 1 is fixed on the fuselage without moving; the reflecting mirror 2 on the beam moves in the x direction with the movement of the beam; the reflecting lens 3 on the z axis moves in the y direction with the movement of the z axis. It is not difficult to see from the figure that during the cutting process, as the beam moves in the x direction and the z-axis moves in the y direction, the length of the light path changes every moment [1].
At present, due to the manufacturing cost and other reasons, the laser beams emitted by the civilian laser generators have a certain divergence angle and are "conical". When the height of the "cone" changes (equivalent to a change in the optical path length of the laser cutting machine), the cross-sectional area of the beam on the surface of the focusing lens also changes. In addition, light also has the nature of waves. Therefore, diffraction phenomenon will inevitably occur. Diffraction will cause the beam to expand laterally during propagation. This phenomenon exists in all optical systems and can determine the performance of these systems. Limit value. Due to the "cone" of the Gaussian beam and the diffraction of light waves, when the length of the optical path changes, the diameter of the beam acting on the lens surface changes momentarily, which will cause changes in the focus size and depth, but affect the focus position Very small. If the focus size and focus depth are changed during continuous processing, it will inevitably have a great impact on the processing, for example, it will cause inconsistent cutting slit widths, incomplete cutting or ablation of the plate under the same cutting power, etc.
principle for laser cutter
Laser is a kind of light, like other natural light, it is produced by the transition of atoms (molecules or ions, etc.). However, it is different from ordinary light in that the laser only relies on spontaneous emission for a very short period of time, and the subsequent process is completely determined by the excitation radiation. Therefore, the laser has a very pure color, almost no divergence, and extremely high luminous intensity. And high coherence.
Laser cutting is achieved by applying high power density energy generated by laser focusing. Under the control of the computer, the laser is discharged through pulses, thereby outputting a controlled repetitive high-frequency pulsed laser to form a beam with a certain frequency and a certain pulse width. The pulsed laser beam is guided and reflected by the optical path and focused by the focusing lens group. On the surface of the processed object, a small, high-energy density light spot is formed. The focal spot is located near the surface to be processed, and the processed material is melted or vaporized at an instant high temperature. Each high-energy laser pulse instantly sputters a small hole on the surface of the object. Under computer control, the laser processing head and the processed material perform continuous relative movement according to the pre-drawn graphics, so that the object will be processed into The shape you want.
The process parameters (cutting speed, laser power, gas pressure, etc.) and motion trajectory during slitting are controlled by the numerical control system, and the slag at the slit is blown away by a certain pressure of auxiliary gas.
Main process for laser cutter
1. Vaporized cutting.
In the laser gasification cutting process, the speed of the material surface temperature rising to the boiling point temperature is so fast that it is enough to avoid melting caused by heat conduction, so part of the material vaporizes into steam and disappears, and part of the material is sprayed from the bottom of the slit by auxiliary gas The flow blows away. In this case, very high laser power is required.
In order to prevent material vapor from condensing on the slit wall, the thickness of the material must not greatly exceed the diameter of the laser beam. This process is therefore only suitable for applications where the removal of molten material must be avoided. This processing is actually only used in areas where iron-based alloys are very small.
This process cannot be used for materials such as wood and certain ceramics that are not in a molten state and are therefore unlikely to recondense the material vapor. In addition, these materials usually require thicker cuts. In laser gasification cutting, the optimal beam focus depends on the material thickness and beam quality. The laser power and the heat of vaporization have only a certain influence on the optimal focus position. In the case of a certain sheet thickness, the maximum cutting speed is inversely proportional to the vaporization temperature of the material. The required laser power density is greater than 108W/cm2 and depends on the material, cutting depth and beam focus position. In the case of a certain sheet thickness, assuming sufficient laser power, the maximum cutting speed is limited by the gas jet speed.
2. Melting and cutting.
In laser melting and cutting, the workpiece is partially melted and the melted material is ejected by airflow. Because the transfer of the material only occurs in its liquid state, the process is called laser melting and cutting.
The laser beam is matched with high-purity inert cutting gas to drive the melted material to leave the kerf, and the gas itself does not participate in the cutting. Laser melting cutting can get a higher cutting speed than gasification cutting. The energy required for gasification is usually higher than the energy required to melt the material. In laser melting and cutting, the laser beam is only partially absorbed. The maximum cutting speed increases with the increase of laser power, and decreases almost inversely with the increase of sheet thickness and material melting temperature. In the case of a certain laser power, the limiting factor is the air pressure at the slit and the thermal conductivity of the material. Laser melting and cutting can obtain oxidation-free incisions for iron materials and titanium metals. The laser power density that produces melting but not gasification is between 104 W/cm2 and 105 W/cm2 for steel materials.
3. Oxidation melting cutting (laser flame cutting).
Melting cutting generally uses inert gas. If it is replaced by oxygen or other active gases, the material is ignited under the irradiation of the laser beam, and a fierce chemical reaction with oxygen generates another heat source to further heat the material, which is called oxidative melting cutting .
Due to this effect, for structural steel of the same thickness, the cutting rate that can be obtained by this method is higher than that of melting cutting. On the other hand, this method may have worse cut quality compared to fusion cutting. In fact, it will produce wider kerf, obvious roughness, increased heat-affected zone and worse edge quality. Laser flame cutting is not good when processing precision models and sharp corners (there is a danger of burning the sharp corners). A pulsed laser can be used to limit the thermal influence, and the power of the laser determines the cutting speed. In the case of a certain laser power, the limiting factor is the supply of oxygen and the thermal conductivity of the material.
4. Control fracture cutting.
For brittle materials that are easily damaged by heat, high-speed and controllable cutting is performed by laser beam heating, which is called controlled fracture cutting. The main content of this cutting process is: the laser beam heats a small area of brittle material, causing a large thermal gradient and severe mechanical deformation in this area, causing the material to form cracks. As long as a uniform heating gradient is maintained, the laser beam can guide cracks in any desired direction.
Key technology
There are two types of laser cutting technology: One is pulsed laser which is suitable for metal materials. The second is that continuous laser is suitable for non-metallic materials, and the latter is an important application field of laser cutting technology.
Several key technologies of laser cutting machine are integrated technology of light, machine and electricity. In the laser cutting machine, the parameters of the laser beam, the performance and accuracy of the machine and the CNC system all directly affect the efficiency and quality of the laser cutting. Especially for parts with higher cutting accuracy or larger thickness, the following key technologies must be mastered and solved:
Focus position control technology
One of the advantages of laser cutting is the high energy density of the beam, generally 10W/cm2. Since the energy density is inversely proportional to the area, the focal spot diameter is as small as possible to produce a narrow slit; at the same time, the focal spot diameter is also proportional to the focal depth of the lens. The smaller the focal depth of the focusing lens, the smaller the focal spot diameter. However, there are spatters in cutting, and the lens is too close to the workpiece to damage the lens. Therefore, the focal length of 5"~7.5" (127~190mm) is widely used in general high-power CO2 laser cutting machine industrial applications. The actual focal spot diameter is 0.1~0.4 mm. For high-quality cutting, the effective focal depth is also related to the lens diameter and the material to be cut. For example, cutting carbon steel with a 5" lens, the focal depth is within +2% of the focal length, that is, about 5mm. So control The position of the focus relative to the surface of the material to be cut is very important. Considering factors such as cutting quality, cutting speed, etc., in principle, 6mm metal materials, the focus is on the surface; 6mm carbon steel, the focus is on the surface; 6mm stainless steel, the focus Below the surface. The specific size is determined by experiment.
There are three easy ways to determine the focal position in industrial production:
(1) Printing method: The cutting head is moved from top to bottom, and laser beam printing is performed on the plastic plate, with the smallest printing diameter as the focus.
(2) Inclined plate method: Use a plastic plate placed obliquely at an angle to the vertical axis to pull it horizontally to find the smallest point of the laser beam as the focus.
(3) Blue spark method: remove the nozzle, blow air, hit the pulse laser on the stainless steel plate, and make the cutting head move from top to bottom until the largest blue spark is the focus.
For the cutting machine of the flying light path, due to the beam divergence angle, the length of the optical path is different between the near end and the far end, and the beam size before focusing is different. The larger the diameter of the incident beam, the smaller the diameter of the focal spot. In order to reduce the change of the focal spot size caused by the change of the beam size before focusing, the manufacturers of laser cutting systems at home and abroad provide some special devices for users to choose:
(1) Collimator. This is a commonly used method, that is, add a collimator to the output end of the CO2 laser for beam expansion. The beam diameter after beam expansion becomes larger and the divergence angle becomes smaller, so that the proximal and distal ends of the cutting work range The beam size before focusing is nearly the same.
(2) Add an independent lower axis of the moving lens to the cutting head. It and the Z axis that control the distance from the nozzle to the material surface (stand off) are two independent parts. When the machine tool table moves or the optical axis moves, the beam moves from the proximal end to the distal F axis at the same time, so that the beam spot diameter remains the same in the entire processing area after the beam is focused. As shown in Figure 2.
(3) Control the water pressure of the focusing lens (usually a metal reflective focusing system). If the beam size before focusing becomes smaller and the focal spot diameter becomes larger, the water pressure is automatically controlled to change the focus curvature to make the focal spot diameter smaller.
(4) Add x and y direction compensation optical path system on the flying optical path cutting machine. That is, when the optical path at the distal end of the cutting is increased, the compensation optical path is shortened; on the contrary, when the optical path at the proximal end of the cutting is decreased, the compensation optical path is increased to keep the optical path length consistent.
The main parameters
X, Y working range: 1300mm*2500mm
Cutting focus lens: F=80mm
Maximum laser output power: 500W
Adjust the follow-up frequency: $300Hz
Power pulse width: 0.5ms-2ms
Laser: dual-lamp gold-plated condenser cavity
Cutting interface card: CNC 3000 control card
Cutting software: adapt to PLT, DXF and other formats
Cooling power: 4W
Repeat positioning accuracy: ±0.03/300mm
Idle speed: 0-20000mm/min
Cutting speed: 0-15000mm/min
Cutting quality
Cutting accuracy is the first element to judge the quality of a CNC laser cutting machine. Four factors affecting the cutting accuracy of CNC laser cutting machines:
1. The size of the laser agglomeration of the laser generator. If the light spot is very small after gathering, the cutting accuracy is very high, and the gap after cutting is also very small. It shows that the precision of the laser cutting machine is very high, and the quality is very high. But the beam emitted by the laser is cone-shaped, so the slit cut out is also cone-shaped. Under this condition, the greater the thickness of the workpiece, the lower the accuracy, so the larger the slit.
2. The accuracy of the workbench. If the accuracy of the table is very high, the accuracy of cutting will also be improved. Therefore, the accuracy of the workbench is also a very important factor to measure the accuracy of the laser generator.
3. The laser beam is condensed into a cone. When cutting, the laser beam is tapered downwards. At this time, if the thickness of the cut workpiece is very large, the cutting accuracy will be reduced, and the cut gap will be very large.
4. Different materials to cut will also affect the accuracy of the laser cutting machine. Under the same circumstances, the accuracy of cutting stainless steel and aluminum will be very different, the cutting accuracy of stainless steel will be higher, and the cut surface will be smoother.
Generally speaking, the quality of laser cutting can be measured by the following 6 standards.
1. Cutting surface roughness
2. Cutting slag size
3. Cutting edge perpendicularity and slope
4. Cutting edge round corner size
5. Drag after stripes
6. Flatness
Cutting perforation
Cutting perforation technology: Any kind of thermal cutting technology, except for a few cases, which can start from the edge of the board, generally a small hole must be drilled in the board. Earlier on the laser stamping compound machine, a punch was used to punch out a hole, and then a laser was used to start cutting from the small hole. There are two basic methods of perforating for laser cutting machine price without punching devices:
(1) Blast drilling: (Blast drilling), the material is irradiated by continuous laser to form a pit in the center, and then the molten material is quickly removed by the oxygen stream coaxial with the laser beam to form a hole. Generally, the size of the hole is related to the plate thickness. The average diameter of the blasting hole is half of the plate thickness. Therefore, the blasting hole of the thicker plate is larger and not round, and it is not suitable for use on parts with higher requirements (such as oil screen pipe ), can only be used on scrap. In addition, since the oxygen pressure used for perforation is the same as that used for cutting, the splash is larger.
(2) Pulse drilling: (Pulse drilling) uses high peak power pulse laser to melt or vaporize a small amount of material. Air or nitrogen is often used as auxiliary gas to reduce the expansion of the hole due to exothermic oxidation. The gas pressure is higher than the oxygen pressure during cutting. small. Each pulse laser only produces small particle jets, which gradually penetrate deeper, so it takes a few seconds to perforate thick plates. Once the perforation is completed, immediately change the auxiliary gas to oxygen for cutting. In this way, the perforation diameter is smaller and the perforation quality is better than blast perforation. For this reason, the laser used should not only have a higher output power; more importantly, the time and space characteristics of the time beam, so the general cross-flow CO2 laser cannot meet the requirements of laser cutting.
In addition, pulse perforation requires a more reliable gas path control system to realize the switching of gas types, gas pressure and perforation time control. In the case of pulse perforation, in order to obtain a high-quality cut, the transition technology from pulse perforation when the workpiece is stationary to continuous cutting of the workpiece at constant velocity should be paid attention to. Theoretically speaking, the cutting conditions of the acceleration section can usually be changed: such as focal length, nozzle position, gas pressure, etc., but in fact, it is unlikely to change the above conditions due to too short time. In industrial production, the main method of changing the average power of the laser is more realistic.
There are three specific methods:
(1) changing the pulse width;
(2) changing the pulse frequency;
(3) simultaneously changing the pulse width and frequency. The actual results show that
(4) has the best effect.
Nozzle design
Nozzle design and air flow control technology: When laser cutting steel, oxygen and the focused laser beam are shot through the nozzle to the material to be cut to form an air flow. The basic requirement of the air flow is that the air flow into the incision should be large and the speed should be high, so that enough oxidation can make the incision material fully carry out the exothermic reaction; at the same time, there is enough momentum to spray the molten material out. Therefore, in addition to the quality of the beam and its control directly affecting the cutting quality, the design of the nozzle and the control of the airflow (such as the nozzle pressure, the position of the workpiece in the airflow, etc.) are also very important factors.
The nozzle used for laser cutting adopts a simple structure, namely a tapered hole with a small round hole at the end (Figure 4). Usually design with experiment and error method. Since the nozzle is generally made of red copper, the volume is small, it is a vulnerable part and needs to be replaced frequently, so fluid mechanics calculation and analysis are not performed. When in use, a certain pressure Pn (gauge pressure is Pg) gas is introduced from the side of the nozzle, which is called the nozzle pressure, which is sprayed from the nozzle outlet and reaches the surface of the workpiece after a certain distance. The pressure is called the cutting pressure Pc, and finally the gas expands to atmospheric pressure. Pa. Research work shows that with the increase of Pn, the air flow rate increases, and Pc also increases.
The following formula can be used to calculate: V=8.2d2(Pg+1)
V-gas flow rate L/min
d- nozzle diameter mm
Pg- nozzle pressure (gauge pressure) bar
There are different pressure thresholds for different gases. When the nozzle pressure exceeds this value, the gas flow is a normal oblique shock wave, and the gas flow velocity transitions from subsonic to supersonic. This threshold is related to two factors: Pn, Pa ratio and the degree of freedom of gas molecules (n): For example, oxygen and air have n=5, so the threshold Pn=1bar×(1.2)3.5=1.89bar. When the nozzle pressure is higher Pn/Pa=(1+1/n)1+n/2 (Pn; 4bar), the normal airflow oblique shock wave seal becomes a positive shock wave, the cutting pressure Pc drops, the airflow speed decreases, and The formation of vortex on the surface of the workpiece weakens the effect of the air flow to remove the molten material and affects the cutting speed. Therefore, the nozzle with a tapered hole and a small round hole at the end is used, and the oxygen nozzle pressure is often below 3bar.
In order to further increase the speed of laser cutting, according to the principle of aerodynamics, without generating a positive shock wave under the premise of increasing the nozzle pressure, a zoom nozzle, namely Laval nozzle, can be designed and manufactured. To facilitate manufacturing, the structure shown in Figure 4 can be used. The Laser Center of the University of Hannover in Germany used a 500W CO2 laser with a lens focal length of 2.5〃, and a small hole nozzle and a Laval nozzle were used for experiments, as shown in Figure 4. The test results are shown in Fig. 5: It respectively represents the function relationship between the surface roughness Rz and the cutting speed Vc of the NO2, NO4, and NO5 nozzles under different oxygen pressures. It can be seen from the figure that the cutting speed of the NO2 small hole nozzle can only reach 2.75m/min (the thickness of the carbon steel plate is 2mm) when the Pn is 400Kpa (or 4bar). The cutting speed of NO4 and NO5 Laval nozzles can reach 3.5m/min and 5.5m/min when Pn is 500Kpa to 600Kpa. It should be pointed out that the cutting pressure Pc is also a function of the distance between the workpiece and the nozzle. Because the oblique shock wave is reflected multiple times at the boundary of the airflow, the cutting pressure changes periodically.
The first high cutting pressure zone is next to the nozzle outlet, and the distance between the workpiece surface and the nozzle outlet is about 0.5~1.5mm. The cutting pressure Pc is large and stable, which is a commonly used process parameter for cutting handles in industrial production. The second high cutting pressure zone is about 3~3.5mm of the nozzle outlet, and the cutting pressure Pc is also relatively large, which can also achieve good results, and is beneficial to protect the lens and increase its service life. Other high cutting pressure areas on the curve cannot be used because they are too far away from the nozzle outlet and difficult to match the focused beam.
Component
The laser cutting machine system generally consists of a laser generator, an (external) beam transmission component, a workbench (machine tool), a microcomputer numerical control cabinet, a cooler, and a computer (hardware and software).
1) The main machine part of the machine tool: the machine part of the laser cutting machine, the mechanical part that realizes the movement of the X, Y, and Z axes, including the cutting work platform. It is used to place the workpiece to be cut and can move it correctly and accurately according to the control program, usually driven by a servo motor.
2) Laser generator: a device that generates a laser light source. For the purpose of laser cutting, except for a few occasions using YAG solid-state lasers, most of them use CO2 gas lasers with higher electrical-optical conversion efficiency and higher output power. Because laser cutting requires high beam quality, not all lasers can be used for cutting. The Gaussian mode is suitable for less than 1500W, low-order mode carbon dioxide lasers 100W-3000W, and multimode above 3000W.
3) External optical path: Refractive mirror, used to guide the laser in the required direction. In order to prevent the beam path from malfunctioning, all mirrors must be protected by a protective cover, and a clean positive pressure protective gas is passed to protect the lens from contamination. A set of lenses with good performance will focus a beam with no divergence angle into an infinitely small spot. Generally, a lens with a focal length of 5.0 inches is used. The 7.5 inch lens is only used for >12mm thick materials.
4) Numerical control system: control the machine tool to realize the movement of X, Y, Z axis, and also control the output power of the laser.
5) Regulated power supply: connected between the laser, CNC machine tool and the power supply system. Mainly play a role in preventing external grid interference.
6) Cutting head: It mainly includes parts such as cavity, focusing lens holder, focusing lens, capacitive sensor and auxiliary gas nozzle. The cutting head drive device is used to drive the cutting head to move along the Z axis according to the program, and is composed of a servo motor and a screw or gear.
7) Operating table: used to control the working process of the entire cutting device.
8) Water chiller: used to cool the laser generator. A laser is a device that converts electrical energy into light energy. For example, the conversion rate of a CO2 gas laser is generally 20%, and the remaining energy is converted into heat. The cooling water takes away the excess heat to keep the laser generator working normally. The chiller also cools the light path mirror and focusing mirror outside the machine tool to ensure stable beam transmission quality and effectively prevent the lens from being deformed or broken due to excessive temperature.
9) Gas cylinders: Including the working medium gas cylinders and auxiliary gas cylinders of the laser cutting machine, which are used to supplement the industrial gas for laser oscillation and supply auxiliary gas for the cutting head.
10) Air compressor, air storage tank: provide and store compressed air.
11) Air cooling dryer, filter: used to supply clean and dry air to the laser generator and beam path to keep the path and reflector working normally.
12) Ventilation dust collector: extract the smoke and dust produced during processing, and carry out filtering treatment, so that the exhaust gas discharge meets the environmental protection standards.
13) Slag discharge machine: remove the leftover material and waste generated during processing.
Laser Source
CO2 gas laser
Since laser technology was introduced to cut thin metal sheets, CO2 lasers have dominated the market. The CO2 laser light source requires a lot of energy to excite nitrogen molecules to collide with CO2 molecules (laser gas), prompting them to emit photons, and finally forming a laser beam that can cut through the metal. The molecular activity in the cavity releases light while also releasing heat, which requires a cooling system to cool the laser gas. This means that more energy is consumed during the cooling process, which further reduces energy efficiency.
Fiber-optic laser
The machine using fiber laser occupies a small area, the laser light source and cooling system are also smaller; there is no laser gas pipeline, and no need to adjust the lens. The 2kw or 3kw fiber laser light source only needs 50% of the energy consumption of the 4kw or 6kw CO2 laser light source to achieve the same performance, and is faster, lower energy consumption, and has less impact on the environment.
The fiber laser uses solid-state diodes to pump the molecules in the double-clad ytterbium-doped fiber. The stimulated emission of light passes through the fiber core many times, and then the laser is output through the transmission fiber to the focusing head for cutting. Since all intermolecular collisions occur in the fiber, no laser gas is needed, so the energy required is greatly reduced-about one-third of the CO2 laser. As the less heat is generated, the volume of the cooler can be reduced accordingly. In short, while achieving the same performance, the overall energy consumption of fiber lasers is 70% lower than that of CO2 lasers.
MicroVector equipment uses vectors to describe the path of the laser, making it smoother. The contour edges of the cover film cut by such a laser system are neat and round, smooth, without burrs, and without glue overflow. It is inevitable to open the window with molds and other machining methods. There will be burrs and glue overflow after punching. Such burrs and glue overflow are difficult to remove after bonding and pressing on the pad, which will directly affect the subsequent The quality of the coating. With the MicroVector system, this problem can be solved, because you only need to import the modified CAD data into the MicroVector software system to easily and quickly process the cover film you want to open the window, which will reduce the time and cost. For you to win market competition opportunities. MicroVector equipment integrates CNC technology, laser technology, software technology and other high-tech optoelectronics. It has the characteristics of advanced manufacturing technology such as high flexibility, high precision, and high speed. It can enable circuit board manufacturers to be technically, economically, and time-sensitive. Change the traditional processing and delivery method of flexible board in terms of upper and autonomy.
Industry Application
The application of metal laser cutting machine is very extensive, covering many industries, and it is one of the necessary equipment for many companies, including advertising sign production (these are mainly stainless steel LOGO and logo cutting), sheet metal processing (sheet Metal processing basically includes all metal materials. These generally include bending, polishing, etc., and cutting is the most important process), chassis and cabinet production (in this regard, carbon steel or stainless steel is generally useful, but also mainly folding Bending and cutting 2 cutting processes), springs (belonging to the finishing process), subway parts, and the production of elevator casings, mechanical equipment casings, and kitchen utensils (mostly stainless steel), which surpass lasers The laser cutting machine setting of the company also participated in the production of the Seven Gods Eight Spacecraft, which actually involves various aspects. Widely used in sheet metal processing, advertising sign production, high and low voltage electrical cabinet production, mechanical parts, kitchenware, automobiles, machinery, metal crafts, saw blades, electrical parts, glasses industry, springs, circuit boards, electric kettles, medical micro Electronics, hardware, knife measuring tools and other industries.
The application of laser processing technology in the advertising industry mainly includes two working methods: laser cutting and laser engraving.
Laser engraving: It is mainly carried out on the surface of the object, divided into two types: bitmap engraving and vector engraving:
Bitmap engraving: We first carry out the screen processing of the graphics we need to engrave in PHOTOSHOP and convert them into monochrome BMP format, and then open the graphics file in the dedicated laser engraving and cutting software. According to the material we are processing, we can set the appropriate parameters, and then click Run, the laser engraving machine will engrave according to the dot matrix effect produced by the graphic file.
Vector engraving: Use vector software such as Coreldraw, AutoCad, Illustrator and other typesetting design, and export the graphics to PLT, DXF, AI format, marking machine, and then use the special laser cutting and engraving software to open the graphic file and transfer it to laser engraving Processing in the machine.
In the advertising industry, it is mainly suitable for the processing of wood, two-color boards, plexiglass, colored paper and other materials.
Laser cutting: We can understand it as the separation of edges. For such processing purposes, we should first make the graphics in the form of vector lines in CORELDRAW, AUTOCAD, pneumatic marking machine, and then save the corresponding PLT, DXF format, use the laser cutting machine operating software to open the file, according to our The processed material can be operated after setting the parameters such as energy and speed. The laser cutting machine will automatically cut according to the flight path generated by the software after receiving instructions from the computer. For example, the existing laser cutting machine can draw a template according to the computer, and then directly input the computer to automatically cut the graphics. Existing laser cutting machines generally have their own hard disk, which can input massive data sources.
Application comparison
In the 1950s and 1960s, it was used as the main method of sheet blanking cutting: oxyacetylene flame cutting was used for medium and thick plates; shearing was used for thin plates, and large quantities of complex parts were formed by stamping, and single pieces were used for vibration shear. After the 1970s, in order to improve and improve the cutting quality of flame cutting, oxyethane precision flame cutting and plasma cutting were promoted. In order to reduce the manufacturing cycle of large stamping dies, CNC nibbling and electrical machining technologies have been developed. Various cutting methods have their shortcomings and have a certain scope of application in industrial production. The development and application of laser cutting machines are undoubtedly a major improvement and innovation breakthrough in modern industrial production.
Competitive Advantage
Laser cutting machine is a technological revolution in sheet metal processing, and it is the "processing center" in sheet metal processing. The laser cutting machine has high flexibility, fast cutting speed, high production efficiency, and short product production cycle. It has won a wide range of customers In the market, this technology has a long effective lifespan. Most foreign plates with a thickness of more than 2 mm use laser cutting machines. Many foreign experts agree that the next 30-40 years will be the golden period for the development of laser processing technology.
Generally speaking, it is recommended to use a laser cutting machine to cut metal materials such as carbon steel plates within 12mm and stainless steel plates within 10mm. The laser cutting machine has no cutting force, no deformation in processing: no tool wear, good material adaptability: no matter it is simple or complex parts, it can be cut with precision and rapid prototyping at one time: its slit is narrow, the cutting quality is good, and the degree of automation is high. Easy to operate, low labor intensity, no pollution: It can realize automatic cutting and nesting, improve the utilization rate of materials, low production costs, and good economic benefits.
There are many factors to consider when choosing a laser cutting machine. In addition to considering the maximum size of the workpiece, the material, the maximum thickness that needs to be cut, and the size of the raw material, more needs to consider the future development direction, such as the product The size of the largest workpiece to be processed after the technical transformation, the breadth of the material provided by the steel market, which is the most economical for its products, and the loading and unloading time.
CNC cutting machine
It consists of three parts, namely the worktable (usually a precision machine tool), the beam transmission system (sometimes called the external optical path, that is, the optical and mechanical components that transmit the beam in the entire optical path before the laser beam reaches the workpiece) and the microcomputer numerical control system. According to the relative movement of the cutting cabinet and the worktable, it can be divided into the following three types:
(1) During the cutting process, both the beam (ejected by the cutting torch) and the worktable move. Generally, the beam moves in the Y direction and the worktable moves in the X direction.
(2) During the cutting process, only the beam (cutting torch) moves, and the worktable does not move.
(3) During the cutting process, only the worktable moves, and the beam (cutting torch) is fixed.
Operation details
When the laser cutting machine is working, it is very dangerous if it fails. Novices must be trained by professionals to operate independently. Based on experience, 13 details of the safe work of the laser cutting machine are summarized:
1. Observe the general safety operation regulations of cutting machines. Start the laser strictly in accordance with the laser start procedure.
2. Operators must be trained, familiar with the structure and performance of the equipment, and master the knowledge of the operating system.
3. Wear labor protection equipment according to regulations, and must wear protective glasses that meet the regulations near the laser beam.
4. Do not process a material before it is clear whether it can be irradiated or heated by laser to avoid the potential hazards of smoke and steam.
5. When the equipment is started, the operator shall not leave the post or be taken care of without authorization. If it is necessary to leave, the operator should stop the machine or cut off the power switch.
6. Keep the fire extinguisher within easy reach; turn off the laser or shutter when not working; do not place paper, cloth or other flammable materials near the unprotected laser beam.
7. When an abnormality is found during processing, the machine should be shut down immediately, and the fault should be eliminated or reported to the supervisor.
8. Keep the laser, the bed and the surrounding area clean, orderly, and free of oil pollution, and stack the workpieces, plates, and waste materials as required.
9. When using gas cylinders, avoid crushing the welding wires to avoid leakage accidents. The use and transportation of gas cylinders shall comply with gas cylinder supervision regulations. It is forbidden to explode gas cylinders in the sun or close to heat sources. When opening the bottle valve, the operator must stand on the side of the bottle mouth.
10. Observe high-voltage safety regulations when repairing. Every 40 hours of operation or weekly maintenance, every 1,000 hours of operation or every six months of maintenance shall be carried out in accordance with regulations and procedures.
11. After turning on the machine, manually start the machine in the X and Y directions at low speed, and check whether there is any abnormality.
12. After inputting the new part program, test run it first and check its operation.
13. When working, pay attention to observe the operation of the machine tool to avoid accidents caused by the cutting machine going out of the effective stroke range or two collisions.
The polarization properties of the laser beam. Laser, like any other electromagnetic wave transmission, also has two mutually perpendicular electric and magnetic vectors, and both are orthogonal to the laser transmission direction. It is generally believed that the direction of the electric vector is the polarization direction of the beam. The polarization properties of the beam affect the absorption of the beam energy by the material. Cutting parallel to the polarization direction of the beam will result in a narrow cut with smooth and straight edges. If there is an angle between the cutting direction and the polarization plane, the energy absorption will decrease and the cutting speed will slow down. The cut will widen and the edges will be rough and not at right angles to the material surface. Once the cutting direction is perpendicular to the polarization direction, the edge will not be rough, but the cutting speed will be slower and the mouth will be wider? The cutting quality will be significantly reduced. Although this is required in principle, it is difficult to keep the cutting direction parallel to the polarization direction during multi-axis motion. To overcome this instability, a phase delayer is provided. Studies have shown that circularly polarized light is best for cutting metals. Most lasers produce polarized light at 45 degrees from the vertical. The phase retarder converts this linearly polarized light into circularly polarized light. This method is effective for cutting metal? But it does not work for other materials such as plastic and wood.
Selection of auxiliary gas and air pressure setting. The typical pressure value when cutting sheet materials at high speed is 150-300kpa? Cutting 12-thick iron plates usually only requires 40-60kpa.
Cutting speed. When the speed is too slow, the plume-shaped Martian particle beam flows directly downward. When the speed is too fast, the plume-shaped Martian particle beam forms an acute angle with the vertical and is unstable. The appropriate speed is when the plume-shaped Martian particle beam forms an obtuse angle with the vertical.
Set the air pressure. The auxiliary gas pressure is controlled by a CNC machine. The correct way is to select automatic mode when calibrating the air pressure controller. Activate the program. After activating the program, press the cycle button and follow the prompts on the screen. The program will automatically calibrate the air pressure system.
Five tips for using fiber laser cutting machine
1) The dual-focus laser cutting head is a fragile item on the laser cutting machine. Long-term use will damage the laser cutting head.
2) Check the straightness of the fiber laser cutting machine track and the verticality of the machine every six months, and if it is found to be abnormal, it will be maintained and adjusted in time. If this is not done, the cutting effect may not be so good, the error will increase, and the cutting quality will be affected. This is the top priority and must be done.
3) Use a vacuum cleaner to suck up dust and dirt from the machine once a week, and all electrical cabinets should be closed and dustproof.
4) Check the steel belt of the fiber laser cutting machine frequently to ensure that it is tight. Otherwise, if something goes wrong during the operation, people may be injured, or even death may be serious. The steel belt looks like a small thing, but the problem is still a bit serious.
5) The guide rails of the fiber laser cutting machine should be cleaned frequently to remove dust and other debris to ensure that the equipment is normal. The rack should be wiped frequently and lubricated to ensure lubrication without debris. The guide rails should be cleaned and lubricated frequently, and the motor should also be cleaned and lubricated frequently. The machine can move better and cut more accurately, and the quality of the cut products will be improved. .
Precautions
The matters needing attention in operating the laser cutting machine are as follows:
1. Comply with the general safety operation regulations of cutting machines. Strictly follow the laser start procedure to start the laser, adjust the light, and test the machine.
2. The operator must be trained to be familiar with cutting software, equipment structure, performance, and knowledge of the operating system.
3. Wear labor protection equipment according to regulations, and must wear protective glasses that meet the regulations near the laser beam.
4. Do not process a certain material before it can be irradiated or cut by laser to avoid the potential danger of smoke and steam.
5. Operators are not allowed to leave their posts or be entrusted to take care of them when the equipment is started. If they really need to leave, they should stop the machine or cut off the power switch.
6. When an abnormality is found during processing, the machine should be shut down immediately, and the fault should be eliminated or reported to the supervisor in time.
7. Keep the fire extinguisher within easy reach; turn off the laser or shutter when not working; do not place paper, cloth or other flammable materials near the unprotected laser beam.
Machine maintenance
The price of laser cutting machine is not low, ranging from hundreds of thousands to millions. Therefore, as long as possible to extend the service life of the laser cutting machine in order to better save production costs and win greater benefits. This shows that the daily maintenance and maintenance of the laser cutting machine is very important. The following mainly explains from six aspects:
1. Circulating water replacement and water tank cleaning: Before the machine works, make sure that the laser tube is filled with circulating water. The water quality and temperature of the circulating water directly affect the service life of the laser tube. Therefore, it is necessary to regularly replace the circulating water and clean the water tank. This is best done once a week.
2. Fan cleaning: Long-term use of the fan in the machine will accumulate a lot of solid dust in the fan, make the fan a lot of noise, and it is not conducive to exhaust and deodorization. When the fan suction is insufficient and the smoke is not smoothly discharged, the fan must be cleaned.
3. Lens cleaning: there will be some reflectors and focusing lenses on the machine. The laser light is emitted from the laser head after being reflected and focused by these lenses. The lens is easy to be stained with dust or other contaminants, causing laser loss or lens damage. So clean the lenses every day. At the same time of cleaning, pay attention to: 1. The lens should be wiped gently, and the surface coating should not be damaged; 2. The wiping process should be handled gently to prevent falling; 3. When installing the focusing lens, be sure to keep the concave surface down.
4. Guide rail cleaning: guide rails and linear shafts are one of the core components of the equipment, and their function is to play a guiding and supporting role. In order to ensure the high processing accuracy of the machine, the guide rails and straight lines are required to have high guiding accuracy and good motion stability. During the operation of the equipment, due to the large amount of corrosive dust and smoke generated during the processing of the processed parts, these smoke and dust will be deposited on the surface of the guide rail and linear shaft for a long time, which has a great impact on the processing accuracy of the equipment, and will Corrosion points are formed on the surface of the linear axis of the guide rail, which shortens the service life of the equipment. So clean the machine guide every half a month. Turn off the machine before cleaning.
5. Fastening of screws and couplings: After the motion system has been working for a period of time, the screws and couplings at the motion connection will loosen, which will affect the stability of mechanical motion. Therefore, observe the transmission components during the operation of the machine. There is no abnormal noise or abnormal phenomenon, and the problem should be confirmed and maintained in time. At the same time, the machine should use tools to tighten the screws one by one after a period of time. The first firming should be about one month after the equipment is used.
6. Inspection of the optical path: The optical path system of the machine is completed by the reflection of the mirror and the focusing of the focusing mirror. There is no offset problem of the focusing mirror in the optical path, but the three mirrors are fixed by the mechanical part and offset There is a high possibility that, although there will be no offset under normal circumstances, it is recommended that the user check whether the optical path is normal before each work.
Every other week, you must check the X-axis guideway and lead screw, Y-axis guideway and lead screw, Z-axis guideway and lead screw lubricating oil filling, to maintain the lubrication of all moving parts, and extend the X, Y, Z axis guide and lead screw. Service life. b. According to the environment of the workshop, check the contamination of the reflector and focusing lens from time to time (at least once within a month), and clean the optical lenses in time to ensure their service life (see the maintenance of optical lenses for details)
Regularly clean up the debris passing the ventilation vent to ensure the ventilation effect.
Check the filter in the air circuit regularly to remove the water and debris in the filter in time.
Regularly check whether the travel switch bracket and the striker bracket screws are loose.
Clean the dust on the ventilation fan filter of the electric control cabinet in time to ensure good ventilation to facilitate the heat dissipation of internal electrical components.
The bed is cleaned of debris in the protective skin cavity of the guide rail in time to avoid damage to the guide rail, thereby prolonging the service life of the guide rail.
After the machine is installed and used for a period of time, the level of the machine should be re-adjusted to ensure the cutting accuracy of the machine
Lens cleaning
During the replacement process, the placement, inspection, and installation of optical lenses must be done to prevent damage and contamination of the lenses. After a new lens is installed, it should be cleaned regularly.
When the laser cuts the material, the working surface will release a large amount of gas and splashes, which will cause damage to the lens. When contaminants fall on the surface of the lens, it will absorb energy from the laser beam, causing a thermal lens effect. If the lens has not yet formed thermal stress, the operator can remove it and clean it.
During the installation and cleaning of the lens, any sticky matter, or even oil droplets printed on the nails, will increase the absorption rate of the lens and reduce the service life. Therefore, the following precautions must be taken:
1. Never install the lens with bare fingers. Wear finger cots or rubber gloves.
2. Do not use sharp instruments to avoid scratches on the lens surface.
3. Do not touch the film when taking the lens, but hold the edge of the lens.
4. The lens should be placed in a dry and tidy place for testing and cleaning. A good workbench should have several layers of cleaning paper towels and several sheets of lens cleaning tissue on the surface.
5. The user should avoid talking above the lens and keep food, beverages and other potential pollutants away from the work environment.
In the process of cleaning the lens, a method with relatively low risk should be adopted. The following steps are set up for this purpose, and users should use them. First use a blowing balloon to blow off the float on the surface of the original, especially the lens with tiny particles and floc on the surface. This step is necessary. But do not use compressed air on the production line, because the air will contain oil mist and water droplets, which will deepen the pollution of the lens.
In the second step, analytical pure acetone is used to clean the lens slightly. This grade of acetone is almost anhydrous, which reduces the possibility of lens contamination.
The cotton ball must be dipped in acetone and the lens must be cleaned under light and moved in a circular motion. Once the cotton swab is dirty, it must be replaced. The cleaning should be done at one time to avoid the formation of crevices. If the lens has two coated surfaces, such as a lens, each surface needs to be cleaned in this way. The first side needs to be placed on a layer of clean lens paper for protection.
If acetone cannot remove all the dirt, use acid vinegar to clean it next. Acid vinegar cleaning uses the dissolution of dirt to remove dirt, but it will not cause damage to the optical lens. This acid vinegar can be experimental grade (diluted to 50% strength), or white vinegar containing 6% acetic acid for household use. The cleaning procedure is the same as that of acetone, and then use acetone to remove the acid vinegar and dry the lens. At this time, the cotton balls should be changed frequently to completely absorb the acid and hydrate. Until it is cleaned.
When contaminants and lens damage cannot be removed by cleaning, especially the film burned due to metal splash and dirt, the only way to restore good performance is to replace the lens.
How to Buy
1. First of all, you must figure out the scope of your company's production, processing materials and cutting thickness, etc., so as to determine the model, format and quantity of the equipment to be purchased, and make a simple pavement for the later procurement work. The application fields of laser cutting machines involve mobile phones, computers, sheet metal processing, metal processing, electronics, printing, packaging, leather, clothing, industrial fabrics, advertising, crafts, furniture, decoration, medical equipment and many other industries. The mainstream on the market is 3015 and 2513, that is, 3 meters times 1.5 meters and 2.5 meters times 1.3, but the format is not a problem. Generally, companies will have many formats for customers to choose from, which can be customized. [3]
2. Professionals conduct on-site simulation solutions or provide solutions, and at the same time, they can also take their own materials to the manufacturer for proofing.
1) The cutting seam is fine: the cutting seam of laser cutting is generally 0.10mm-0.20mm;
2) The cutting surface is smooth: whether the laser cutting surface has burrs or not; in general, YAG laser cutting machines have some burrs, which are mainly determined by the cutting thickness and the gas used. Generally, there are no burrs below 3mm. Nitrogen has the best effect, oxygen has the second best effect, and air has the worst effect. The fiber laser cutting machine has minimal or no burrs, the cutting surface is very smooth, and the speed is very fast.
3) Look at the deformation of the material: the deformation of the material is very small
4) Power size: For example, most factories cut metal sheets below 6mm. There is no need to buy a high-power laser cutting machine. A 500W fiber laser cutting machine can meet production needs. If the production volume is large, worry about 500W efficiency Inferior to high-power laser cutting machines, the best choice is to buy two or more small and medium-power laser cutting machines, which will help manufacturers in controlling costs and improving efficiency.
5) The core parts of laser cutting: Are lasers and laser heads imported or domestically produced. Imported lasers generally use more IPG, and domestic ones generally use Raycus. At the same time, other accessories for laser cutting are also required. Pay attention to whether the motor is imported servo motor, guide rail, bed, etc., because they affect the cutting accuracy of the machine to a certain extent. One thing that needs special attention is the cooling system of the laser cutting machine-the cooling cabinet. Many companies directly use household air conditioners for cooling. In fact, everyone knows that the effect is very bad. The best way is to use industrial air conditioners, which are dedicated for special machines. , In order to achieve the best results.
3. Any piece of equipment will experience varying degrees of damage during use, so in terms of repairing after damage, whether the repair is timely and the level of charges have become issues that need to be considered. Therefore, when purchasing, we need to understand the after-sales service of the company through multiple channels, such as whether the maintenance fee is reasonable, etc.
Actually , if you want buy a good fiber laser cutting machine , you can visit China BossorLaser Company to choose , this is the Branch Company of China Durmapress Brand .
