technology is an important part of the laser processing applications, and ’s one of the most advanced cutting technologies. technology has high speed, high precision, high adaptability and other characteristics. Laser cutting technology is widely used in automotive, aviation, oil, metallurgical industries and many other industrial sectors. In order to meet the needs of the automotive and aviation industries on three-dimensional parts cutting, three-dimensional laser cutting machine and its supporting automatic programming system software and other related researches are fast developing.The purpose of the study is to develop the CAM software of 5-axis laser cutting for three-dimensional punched pieces. In this paper, is used as the object of study, the redundant date was processed and the topology information was established for the read STL file, and the STL file was read and visualized; Algorithm of of cutting shape on sheet metal was studied; Radius compensation of laser beam for cutline was conducted used the vertex offset method; The method of cutting knife-point CL of 5-axis CNC was studied; The posture of laser head was fixed through getting the surface direction of incidence point on cutting surface, and the angleαandβof laser beam was calculated, as a result, the path of laser cutting for sheet metal was received.In the Windows XP environment, the above algorithms were realized used the VC++ and OpenGL, while the 5-axis laser cutting simulation was realized and the relevant NC file was generated automatically. The cutting path of 5-axis laser cutting generated by this CAM software and the path generated by UG software were compared used by the path comparing software Tool manager. The applied examples show that the above algorithms are accurate and feasible, the system is reliable, stable and practical.
Post about "Laser cutting"
Heat-affected zone exists in the outer skins laser cutting and certainly affects material properties.has great significance to research the influence of heat-affected zone for ensuring the quality of the cutting products. experiment is carried out on TC1 thin sheet (1.5mm) through using OPTIMO 2535 five-axis laser cutter in the papers. The metallographic test, the tensile test, the fatigue test and the incidence angle cutting test were carried out to research on influence of laser cutting parameters on cutting precision and quality. provides technical guidance for laser cutting titanium and the alloy thin sheet of our country. The main contents and conclusions have been shown as following:First, laser cutting experiment was finished by using orthogonal test method. The size precision was measured and the most superior laser cutting parameter was attained.The results show that cutting speed and the auxiliary gas pressure are the primary factors influencing on cutting precision and laser power remarkably influence on the quality.Second, heat-affected zone of cutting test sample was studied. The metallographic test indicated that heat-affected zone near the laser source is narrower than that of the side far from the laser source,the organization crystal grain gradually increases from inside to outside,and Beta of the organization has had the marten-site transformation. The tensile test indicated that the laser cutting test specimen does not have the obvious necking in the stretch process,and breaks immediately after necking. The biggest loads, the yield strength, the longitudinal strength, the elongation ratio of machine-finishing test specimen are higher than the laser cutting test specimen. The fatigue test indicated that the safety life of the laser cutting test specimen is as 8.76% of the machine-finishing test specimen.Finally, the influence of the laser incident angle on cutting quality was studied. The results show that laser incidence angle has a little affection on cutting quality in the change of certain angular region.
The Effect Analysis of Assistant Gas Flow by Nozzle Structure and Cutting Parameter in Laser Cutting
is one of the most important application technologies in laser machining industry. Compared with the traditional flame cutting and plasma cutting, laser cutting has plenty of remarkable advantages, such as excellent cutting quality, rapid cutting velocity, high automation, large range of cutting materials and so on. The implementation of laser cutting is the result of the interaction of high power laser bean and assist gas. On the one hand, the machining materials is melted down by high power laser bean, on the other hand, melten metal and part of heat are expelled from the kerf. Reasonable nozzle structure and cutting parameter can limit the heat effect area to a very small scope, and can also ensure machining quality and efficiency.Under the support of the two important science and technology projects, the paper discusses the research present status and development, analyses the influence law of gas about jet flow effected by nozzle structure, constructs three-dimensional symmetry model of laser cutting impinging flow and studies the influence to gas by cutting parameter in kerf. The concrete research content is as follows: First for two assemble of taper and convergence, based on the axial symmetric N-S equation of compressible liquid, the paper establishes the onflow model to simulate convergent ’free jet of different internal parameters by using structural grid and finite volume of quadratic precision. The law is revealed that how contractive angle of taper and curvature radius of convergence nozzles’convergent section effect jet structure parameters, and evidence is provided for optimization selection and design about laser cutting nozzles.The paper describes simply the cutting parameter and kerf structure of laser cutting, analyses the dynamics effect of assist gas in kerf, constructs three-dimensional symmetry model of laser cutting impinging flow, and has a simple description of adopted control equation and onflow model.The plane symmetry impinging jet process is analysed, the interaction mechanism between gas and workpiece is studied and the relationship between gas assistant machining ability and stand off distance, workpiece thickness, kerf width respectively. According to the evaluation criterion of velocity and mass flow rate, the gas dynamics performance of taper nozzle in kerf excels obviously than that of convergence nozzle. And with the increasing of stand off distance, at least two reasonable cutting scopes exist. With the increasing of workpiece thickness, the position of expansion wave will be bigger relatived to the nether surface and will result in worse gas dynamics performance close to the nether surface and bad cutting quality and efficiency. Under the same inlet pressure, with the increasing of the cutting kerf, the change grads of pressure and velocity on the axes of convergence nozzles are smaller and smaller.On the base of theory research, a kind of taper nozzles and convergence nozzles with optimized structure are developed. By contrast experiment with the German PRECITEC NOZZLEφ1.25HD nozzles, the developed nozzles have corresponding cutting effect. At the same time, the theory analysis result of the relationship between cutting quality and stand off distance, workpiece thickness, kerf width are validated by experiment respectively, and can provide theory guidance and experiment data with optimization cutting in future.Finally, the paper summarizes all the done work and views the study direction in future.
, as one of the most important technology in the field of laser-processing, is widely used in the modern industry. Much work about the effects of the cutting parameters on the quality of laser cutting has been done by researchers. Unfortunately, few studies about the systematic summary in laser cutting quality have been reported. In this study, laser cutting was carried out on low-carbon steel plate with a thickness of 2mm. The effects of the experimental parameters on the quality of laser cutting, such as laser power, cutting speed, distance between the nozzle and the sample surface as well as pressure/type of the assistant gas, were systematicly analyzed. Kerf width, kerf roughness, slag thickness and striation spacing were selected as criteria of cutting quality. The influences regulation of cutting parameters on the laser cutting quality were synthetically analyzed. At the same time, a proper cutting parameter window in laser cutting of low-carbon steel was obtained when nitrogen and oxygen were used as assistant gas.Based on experimental data, mathematics models of laser-cutting quality including kerf width, kerf roughness, slag thickness and striation spacing were established by using . Furthermore, the models were verified by cutting experiments.The experimental data were trained and analyzed by using artificial neural network, which can forecast the cutting quality and feedback neural network to in turn optimize the models.The experimental errors of cutting quality models established by using and artificial neural network were compared. In addition, the synthetical influences of laser output power, cutting speed, nozzle distance from the surface, assistant gas pressure on the cutting quality were studied by using these models.The experimental data of laser cutting low-carbon steel were summarized and analyzed, which provides conditions for the database establishment of technology parameters in laser cutting low-carbon steel and provides experimental basis for establishing a physical model of laser cutting.
is an important application technology and the most widely used processing method in laser processing industry. Currently laser cutting has been widely used in all kinds of machinery manufacturing and processing industries. The open CNC system is the development trend of CNC system. The total software CNC system which is the latest open CNC system provides a high degree of open . And becomes one of the hottest research subjects.The total software CNC system of laser-cutting machine has been developed in this paper, which can implement two-axis control of laser-cutting machine and laser monitoring. The following are the main contents of this paper:The first chapter discusses the development of laser-cutting machine and CNC techonology at home and abroad, explains research objectives and research significance, proposes research contents and research methods.The second chapter describes the hardware designing of total software CNC system based on ARM and CPLD structure, disscusses the characteristics and advantages of this structure, establishes a hardware system according to the hardware designing.The third chapter describes the development tools language of the control software of CNC system and .NET runtime platform of language, analysises the control software, and sets up its modules.The forth chapter describes the implementation of programming module of control software, designs a special NC code for laser-cutting, and studies file convertion algorithms of CAD files and path optimal algorithms of laser-cutting.The fifth chapter describes the implementation of motion control module of control software, discusses the theory of sampled data , proposes optimal sampled data , discusses the interrupt control algorithm, makes experiment about motion control to verify the accuracy of the motion control.The last chapter summarizes this paper and prospectes the following research.
Three-dimensional laser cutting technology and equipment represents the highest level of laser cutting technology research and application. As a highly flexible and intelligent manufacturing technology , three-dimensional laser cutting technology has been widely used in automobile manufacturing, aerospace and other areas to realize complex surface three-dimensional sheet metal parts and efficient cutting in the United States, Germany, Japan and other developed industrial countries in recent years. Three-dimensional laser cutting technology research now mainly focused on some key technologies, such as high-precision five-axis machine tool design, flying optics design, five-axis numerical control system development, three-dimensional laser cutting technology research and development and othersystem. The mature three-dimensional laser cutting systems currently used in domestic are from abroad, which greatly restrict the application of three-dimensional laser cutting technology.Aiming at the key technologies of the development of the three-dimensional laser cutting automatic programming system, such as discrete tracks、paths planning、interference checking and simulation process, this paper gives the solutions and develop the relative programming system. The concrete research content is as follows:For the problem of discrete the points of the space trajectory curve, an improved discrete algorithm based on the dichotomy has been presented in this paper. Discrete point error can be dynamically adjusted based on the actual processing requirements, and the test result proved that the machining accuracy and smoothness requirements can be meet in the complex curve in CNC.The quadratic programming method of the nonlinear optimization theory has been introduced to the interference detection algorithm, and the corresponding methods of avoiding interference have been presented which has great theoretical and practical significance. In the meanwhile, the rules of the three-dimensional laser processing movement have been studied. In order to improve processing efficiency, the motion paths of the laser head and the processing orders have been rational planned.Based on the study of the above-mentioned key technologies, combined with simulation process, the main function modules and sub-function modules of the three-dimensional laser cutting automatic programming system have been developed. In order to achieve the best simulation results, the optimization of the simulation process have been discussed which has great theoretical and practical value.Introducing the workflow of the three-dimensional laser cutting automatic programming system by giving a typical automobile panel parts which involving three-dimensional processing path. The cutting codes generated by the programming system are proved that the software developed is functional and feasible in three-dimensional laser cutting machine .
Ceramic is widely used in the aerospace, MEMS, and daily life. The traditional methods of slicing ceramics are based the diamond saw. These methods are difficult and expensive to process ceramics due to hardness and brittleness et al, The research about controlled fracture method based on laser cutting technology is widely focused in recent years. The thermal crack technology has many advantages, Such as high efficiency, high cutting quality and cleaning machining environment. Ceramic thermal crack cutting technology based on continuous YAG laser has small heat affected zone, smooth crack surface and no loss of materials, and so on.This dissertation carried out the thermal analysis and cutting experiment, according related researcher’s researching progress, and the rationale between laser and ceramic.Firstly, symmetrical cutting of ceramic was simulated by using Finite Element Methods. Mechanism of YAG laser cutting glasses was studied, according to the simulation temperature and stress fields. Comparison between simulation temperature and testing temperature is carried. Give analysis to the cleaving deviation at the start crack path.White ZrO2 ceramic has low absorption rate to the continuous YAG laser. Graphite coated ceramic surface can effectively improve the absorption rate to laser. Experimental research on white and blackceramic, Alumina ceramic and a kind of machinable ceramic were cutting. A series of single factor experiment have carried to black zirconia ceramic. Nano-indentor, Surface Profiler and SEM are used to test the result.Finally, the optimum parameters of YAG laser cutting black zirconia ceramic in straight lines were obtained. The width of color change area and Roughness of crack surface are tested, and gives the curve to laser power, laser spot size and laser scanning velocity, respectively.
Laser processing technology is the combination of light,, electrical, material processing, and detection of complex multi-disciplinary and advanced manufacturing technology. Laser known as the “universal processing tool,” a common future manufacturing system processing means, laser application project is expanding.Development of large stroke and high-power laser cutting machine high- , high precision, multi-functional and high adaptability of C laser cutting machine to meet the major domestic industry demand for high-end laser processing equipment, on the one hand can promote the development of our laser cutting technology, The equipment also can promote the development of manufacturing and related industries, to improve international competitiveness.Firstly, by analyzing the status of domestic and international comparison of laser technology, laser applications in laser technology research and development of future scenarios.Second, by analyzing the mechanism of laser cutting, laser cutting parameters selection, a laser cutting machine is designed to determine the necessity and design requirements.Finally, based on cutting power needs of large travel requirements from the machine tool design, selection of laser generator, optical transmission request, the host FEM, C electric control introduces the LR model to track CNC laser cutting machine. And the whole product installation notes, and other routine maintenance.R & D products have to be a debugger to use, can meet user needs, to achieve laser cutting large stroke, high power, high precision cutting.
Experiments and Mathematical Model of Laser Cutting Aluminum Alloy Sheet Based on Vaporization-melt Ratio Controlled
Aluminum alloy slot array antenna is an important part of aircraft missile guidance. One of the key restraining factors of antenna performance is machining method of micro slot array on the antenna. The problem in laser cutting this aluminum alloy sheet lies in obtaining high surface quality, as there are micro adhering slag, recast layer and stripes on the cut. At present, some achievements in studying of process and mathematical model of laser cutting sheet have been got, and quality defects have been controlled. However, these studies did not connect the internal mechanism and cut quality together. Quality factors are depended on vaporization and melt during laser cutting, which are the twoforms of material flows. The ratio of vaporization to melt is defined as vaporization-melt ratio and has great influence on laser cutting process and cut quality. To establish the relations between vaporization-melt ratio and cut quality and to improve cut quality based on vaporization-melt ratio controlled, have great applied value and theoretical meaning for high-precision laser cutting.A new method of laser precision cutting based on vaporization-melt ratio controlled is presented. Evaporation and melt phenomenon during laser cutting are researched and different forms of material flows are pointed out too. By means of the analysis of influencing factors of vaporization-melt ratio, is found that material characteristics, input laser energy and scanning speed have direct effects on vaporization-melt ratio, under the condition that the pressure of assist gas must be big enough. Applied range of this method is given too.Based on the above analysis, laser cutting of 6063 aluminum sheets,0.5 mm in thickness, is carried out on a JK701H Nd:YAG laser machining system. The effect of assist gas pressure on cut quality is firstly achieved, as must be big enough for the following experiments. The optimized assist gas pressure is used in experiments of studying the effects of laser power and scanning speed on vaporization-melt ratio and residual molten layer. Microscopic examination is carried out to observe the adhering slag, recast layer and stripes. The results show that laser power and scanning speed affect vaporization-melt ratio by instant vaporization and constant vaporization. Vaporization-melt ratio increases and residual molten layer decreases when laser power is high and scanning speed is slow Then good cut quality can be acquired. Therefore, the processing parameters can be controlled by vaporization-melt ratio and good quality can be got at high vaporization-melt ratio. According to experiments data and theoretical research, a vaporization-melt ratio mathematical model is developed. The effects of assist gas pressure on vaporization-melt ratio and residual molten layerare are simulated, as well as laser power and scanning speed. The comparison results show good agreement between the model and experiments. So it can be concluded that this mathematical model is of good foreseeability.This thesis supplies theory analysis of laser cutting sheet metal based on vaporization-melt ratio controlled. Simulation model and experimental dates are performed. The variation of vaporization-melt ratio, residual molten layer against laser power and scanning speed is presented. Cut kerfs, with no adhering slag on the bottom, recast layer 1.28μm in thickness and improved stripe situation are obtained using parameters optimized by vaporization-melt ratio experiments. So, high vaporization-melt ratio during laser cutting can contribute to improving cut quality and this method provides reference for laser precision cutting.
This paper describes theprinciple of laser cutting; laser shows Clothing automatic cutting machine system design program, and a brief description of the various subsystems of the design ideas and work. Studied in detail of how to using the cutting trajectory algorithm for the control of two-dimensional space. The cuttings of lines and arcs, respectively, principles and deviation have been discussed. Automated cutting of clothing is given the electronic control system the main structural framework. Software in the system, the application of technology to solve the queue problem of inadequate storage capacity, provides software protocol and gives the software data flow. The design system has met the needs of practical application.