CNC Dissertation Outline
Whether it is in school or in society, we always have to contact or use the dissertation, right? The dissertation is important for all educators and for the improvement of human understanding as a whole. So how is the general thesis written? The following is my collection of CNC thesis outline for you, just for reference, I hope to be able to help you.
CNC Thesis Outline Part 1
Abstract: China began to develop CNC technology in 1958, and now has established a certain scale system. So far China's CNC market is mostly occupied by foreign CNC systems, this paper mainly discusses how domestic low-priced CNC machine tools, high-speed and high-efficiency CNC machine tools and heavy-duty CNC machine tools have occupied the domestic market.
Keywords: Domestication of CNC machine tools; low-priced, high-speed and heavy-duty CNC machine tools; after-sales guarantee mechanism
Since China began to study CNC technology in 1958, it has now established an industrial system based on medium- and low-grade CNC machine tools. The ultimate success of CNC industrialization will be reflected in the national industrialization and market share of CNC machine tools. So far, most of China's CNC market is occupied by foreign CNC systems, such as Japan's FANUC system, Germany's SIEMENS system and some other well-known foreign brands in our country occupies a large market, while the domestic system due to a variety of reasons by the cold.
CNC technology and CNC equipment is an important foundation for the modernization of manufacturing industry. Whether this foundation is solid will have a direct impact on a country's economic development and comprehensive national strength, related to a country's strategic position. Therefore, it is necessary to quickly recover lost ground in the domestic market, a steady march in the international market, in order to ultimately win the domestic CNC machine tool market turnaround battle. The following is only a brief discussion on the development of low-priced CNC machine tools, high-speed and efficient CNC machine tools and heavy-duty CNC machine tools.
First, vigorously develop low-priced CNC machine tools
Low-priced CNC machine tools, that is, to meet the function of the user's small batch, multi-variety production requirements (no functional waste), moderate technical indicators, good reliability, inexpensive, small and medium-sized enterprises are able to accept the popularity of CNC machine tools. This kind of machine tool has become one of the development trends of CNC machine tools in the international market, but also many domestic users are thirsty for the product, more suitable for China's national conditions, its market prospects are quite broad. However, if the use of foreign CNC systems (including servo components) in accordance with traditional thinking to develop low-priced machine tools, it is difficult to reduce the price to the level acceptable to the majority of users. Therefore, the use of this paper proposes a new type of integrated domestic data system to develop high-performance low-priced CNC machine tools, will be one of the most promising road to success. As long as there is a certain batch, which constitutes the domestic popularity of CNC lathes can be completely controlled within 100,000 yuan, three-coordinate CNC milling machine can be controlled at l50,000 yuan or so, machining centers can be controlled at 2O million yuan or so. This price of domestic CNC machine tools will be highly competitive.
Second, accelerate the development of high-speed CNC machine tools
High-speed, high-efficiency is the development of CNC machine tools is another major trend. Development of high-speed, high-efficiency CNC machine tool technology path can be the following:
① By increasing the cutting speed and feed rate method to meet the doubled to improve productivity, effectively improve the quality of surface machining of parts and machining accuracy of the machining effect, and this method can also be resolved to solve the conventional machining difficult to solve some special materials (such as aluminum and titanium alloys, die steel, hardened steel) and special shapes of the part (such as complex thin-walled parts) of the efficient processing problems.
② through the process of composite methods to reduce the number of workpiece installation,
This can effectively reduce the handling and clamping time. For example, the five-sided five-axis machining center and vertical composite constitute a universal machining center, can be realized once the card to complete most of the parts (or all) processing tasks.
③ high-speed, high-precision circumferential milling method, can complete the helical trajectory interpolation to achieve the direct tapping without drilling the bottom hole and other new machining methods, this method can significantly reduce the number of tool changes, improve machining efficiency.
④ Develop intelligent position-finding machining functions for CNC machine tools to eliminate the dependence on precision fixtures and manual alignment, effectively reducing the preparation time for single-piece, small-lot machining.
In our country's real conditions, if the traditional thinking is difficult to realize the above path, so we must be based on national conditions, combined with the actual, innovative, bold to explore new roads. Considering the conventional CNC machine tools in the overall structure of the basic use of workpiece and tool along their respective guideway *** with the program, on the one hand, due to the lack of rigidity of the machine tool transmission link and guideway in the friction resistance, so that the moving parts are difficult to obtain a high feed rate; on the other hand, due to the total mass of the workpiece, fixtures and table is relatively large, making it difficult to obtain a high degree of acceleration. In addition, the traditional machine tool structure is a tandem open chain structure, composed of many links, complex structure, and due to the existence of cantilever part, parts and links between the joint gap, so it is not easy to obtain high overall stiffness, so it is difficult to adapt to the special requirements of high-speed and efficient machining. For this reason, the development of domestic high-speed and high-efficiency CNC machine tools, the workpiece can be fixed to form a parallel short chain of linear motors to directly drive the spindle and tool movement, high-speed and high-precision transmission and high stiffness of the support for a new structure suitable for high-speed and high-efficiency machining centers. The structure of the high-speed and efficient CNC machine tools is not only high speed, high stiffness, if properly handled in the transmission and control, but also to achieve higher machining accuracy and machining quality than conventional machine tools, but also has a simple mechanical structure, parts and components of the generalization and standardization of a high degree of manufacturing cost is low, easy to economize on mass production and other significant advantages. Therefore, the development of high-speed and efficient CNC machine tools along this line of thought will be a national conditions, easy to achieve success on the road.
Third, the breakthrough in the design and manufacture of heavy-duty CNC machine tools
Heavy-duty CNC machine tools (especially multi-coordinate heavy-duty CNC machine tools) is the national economy and national defense production of major key equipment, belonging to the strategic goods, the real advanced heavy-duty CNC machine tools abroad is not possible to sell to us. Therefore, in our country in the next century the development of CNC products must rely on their own strength to solve. The development of heavy-duty CNC machine tools must have a solid foundation, we should continue to sum up the experience in the process of localization of CNC machine tools, strengthen the basic technology and key technology research, give full play to the advantages of my country, learning, research, the combination of various sectors of the cooperation, *** with efforts to achieve breakthroughs in a short period of time.
Four, the establishment of a strong after-sales support mechanism
CNC systems and CNC machine tools as a typical high-tech products, technical support and service to users is quite important, before the loss of credibility of domestic CNC products, in addition to the reliability of the problem, the other major problem should be the lack of strong technical support and service. Users spend a lot of money to buy CNC machine tools or CNC systems, once the problem is called every day should not be, called the ground does not work, even if the manufacturer promised, maintenance personnel can not be in place in a timely manner, and the technical level of maintenance personnel are also uneven, in this era of efficiency, such after-sales service is not feasible, and in the long run, who would also dare to buy our products it. Therefore, the user's technical support and service should become our important daily work, so that we are in the market to the depth of the market at the same time, there is a strong back to do security. Therefore, in order to achieve a comprehensive victory in the market competition of CNC products, it is necessary to establish a technical support and service as the core of a strong after-sales service base.
CNC thesis outline Part 2Abstract: This paper addresses the emergence of today's CNC machining simulation software, CNC machining teaching and training requirements, as well as CNC machine tool training sessions are prone to accidents, machine tool loss is serious, the cost is high, the characteristics of the principle of the CNC machining simulation system, the role of the function of the The use of CNC machining simulation system software, students, trainees, the basic operation of CNC machine tool training, in order to achieve more, faster, better, save the purpose.
Keywords: CNC machine tools, CNC machining, virtual reality, simulation system
Introduction
With the rapid development of China's higher vocational education, as well as the `widely used' of CNC machining technology in the machinery manufacturing industry, a large number of CNC machine tools operators of professional training has become an urgent and difficult to solve. Professional training has become an urgent and difficult to solve the problem. In the traditional operation training, the effective training of CNC machine tool programming and operation must be carried out on real machine tools. However, with the increasing number of students, the limited number of machine tools is difficult to ensure that each student has enough time to operate on the machine, while the students operate on the real machine tools also have certain dangers and insecurity, misuse in training often leads to damage to equipment, tools, and so on, and even lead to accidents and injuries, which increases the cost of training. Therefore, the traditional machine tool operation training method is inefficient, the teacher's workload is large, the training cost is high, and need to be replaced by newer methods.
1, virtual reality technology
Virtual reality, the English name Virtual Reality, referred to as VR technology. This term was proposed by Jaron Lanier, the founder of VPL in the United States, in the early 80s, also known as the spiritual realm technology or artificial environment. As a cutting-edge technology, virtual reality integrates the latest development of computer graphics technology, computer simulation technology, artificial intelligence, sensing technology, display technology, network parallel processing and other technologies, and is a computer-generated high-tech simulation system, which first originated from the U.S. military's combat simulation system, and gradually became the focus of attention for all walks of life in the early nineties, and was further developed in the commercial field. This technology is characterized by the computer to generate an artificial virtual environment, this virtual environment is composed of computer graphics three-dimensional digital model, and compiled into the computer to generate a visual perception-based, but also includes auditory, tactile, integrated perceptible artificial environment, so that the visual produce a feeling of immersion in the environment, you can directly observe, operate, touch, detect Surrounding environment and the inner changes of things, and can occur with the "interactive" role, so that people and computers are very good "into one", giving people a sense of "immersive".
Virtual reality is the development of a certain level of computer technology and thinking about the combination of science products, its emergence for human knowledge of the world opened up a new way. The biggest feature of virtual reality is: users can interact with the virtual environment in a natural way, changing the past human beings, in addition to personal experience, can only indirectly understand the environment of the model, so as to effectively expand their own means of cognition and the field. In addition, virtual reality is not only a presentation media, but also a design tool, which produces a humanized multi-dimensional information space in visual form, providing us with favorable support for creating and experiencing virtual worlds. Due to the real-time three-dimensional spatial representation capability of virtual reality technology, the human-computer interactive operation environment and the immersive feeling it brings to people, it plays a pivotal role in the simulation and training in the military and aerospace fields. In recent years, with the development of computer hardware and software technology and people increasingly recognize its important role, virtual technology in all walks of life have been developed to varying degrees, and more and more show broad prospects for application.
Virtual reality technology in the transformation of traditional industries on the value embodied in: for product design and manufacturing, you can reduce costs, to avoid the risk of new product development; for product demonstration, multimedia effects can be used to attract customers, for orders; for training, can be used to increase the operation of the "virtual equipment" staff proficiency. Virtual reality technology will revolutionize many traditional industries.
2, CNC machining simulation system
With the development of virtual reality technology and computer technology, the emergence of the actual machine tool machining environment and its working state of the computer simulation machining system, which is an application of virtual reality technology in the CNC machining operation skills training simulation software. The use of computer simulation training system for learning and training, not only can quickly improve the theory of the trained personnel, the level of operation, and very safe, reliable and good, low training costs.
At present in China, there have been a number of institutions of higher learning computer simulation used in the teaching of CNC operator training, but also appeared in a variety of CNC machining simulation teaching system, such as Shanghai Yulong, Beijing Fike, Nanjing Aerospace, Guangzhou super-soft, Wuhan Honeysuckle, and so on, different CNC machining simulation software. These teaching systems can be a stand-alone system to run independently, but also to achieve online operation. Independent operation that is, the machine model approach, its training facilities only a microcomputer, CNC machine simulation operation in the display screen shows the simulation panel, and the parts cutting process by the machine model through three-dimensional animation demonstration. Practice has proved that the initial training in this way is very cost-effective. Online operation that is, the machine tool mode of operation, in this way, the teaching system will be connected to the actual machine tool, the hardware to achieve the parts cutting process, in addition to the operator is to use the simulation panel operation, the other is the same as the actual machine tool in the real situation. That is, the use of computers and other specialized hardware, software to produce a real scene of the simulation, the operator can interact with the simulation scene, to experience a close to the real scene of the feeling. Therefore, taking this approach can further improve the operator's practical skills.
The core of the CNC simulation system is the virtual CNC machine, and the virtual CNC machine is an important execution unit in virtual manufacturing technology. It is not only in the CNC machining process for product design provides a manufacturable analysis, but also in the learning and training of CNC systems, for the trained personnel to provide a perfect learning method and learning environment. The CNC simulation system completely simulates the processing of real parts, and can check whether various CNC commands are correct or not. It can provide the same operation panel as the real machine tool, and its debugging, editing, modifying, and tracking functions are also available.
3, the construction of the virtual CNC machine platform
The virtual CNC machine is generally through the following construction platform to achieve the above functions:
(1) NC interpretation platform. NC interpretation platform includes the NC interpreter and NC verifier. The task assignment database accepts CNC code from task scheduling and translates it into information about the movement of virtual machine components, tools, etc., and simulates the response of the machine through the computational module, and the NC interpreter can be freely configured to simulate the CNC controller of any kind of CNC machine tool.
(2) NC Validator. It can verify that the syntax of the NC code is correct.
(3) Tool library. Tool library should include all the tools needed for a CNC machine tool, and can freely configure the tool number in the tool library, so as to be able to simulate any kind of CNC machine tool change form and cutting processing requirements.
(4) simulation platform. Simulation platform including tool trajectory simulation, cutting force simulation, machining accuracy simulation, three-dimensional animation simulation, processing time statistical analysis, simulation platform is the core technology of virtual CNC machine tools. The operator can carry out the simulation of machine movement and cutting process in the virtual environment, from which relevant processing data can be obtained. Such as the displacement of the feed axis, tool change status, spindle speed, acceleration, feed, machining time and so on. Through the simulation of the machining process, the machinability of the designed workpiece is understood, the correctness of the NC code is verified, and the machining process is evaluated and optimized, and it is optimized by modifying the NC code online.
(5) computing platform. The calculation platform is used to complete a variety of calculations in the virtual CNC machine tool, such as calculating the new geometry of the machined part according to the NC code, calculating the amount of tool compensation and thermal compensation according to the material of the tool, the running time, the nature of the part's material and lubrication medium. The results of these calculations are necessary for the evaluation of the machining program and the manufacturability analysis of the virtual CNC machine tool applied to the virtual manufacturing process.
(6) design and development platform. Virtual CNC machine tool design platform is an object-oriented CNC software library and its development environment. Through the standardization of CNC software, standardization of research and other CAD / CAM software data exchange, and the typical parts of the package, designed to have a stable, universal interface reusable software.
(7) operation running platform and monitoring platform. In the virtual environment to fully realize the operation of real machine tools, so that users can fully feel the operating characteristics of real machine tools. On the basis of these monitoring hardware and software, used to control simple machine tools. Increase the realism of the virtual CNC machine tool. And can carry out experimental trial cutting of typical parts processing, so that the user has a sense of presence. Especially in the CNC teaching and training process, the beginning of CNC programming needs a lot of programming practice, and practical debugging. Using the test cut method to check the CNC machining program is obviously unreasonable and difficult to achieve. If the use of simulation technology, these problems can be easily solved, so as to avoid programming human error or process irrationality caused by workpiece scrap.
4, CNC simulation system functions and applications in teaching
Virtual CNC machine tool is actually a model of the CNC machine tool in the virtual environment. Compared with the real machine tool, the virtual CNC machine tool has the following functions and features:
The virtual CNC machine tool has the exact same structure as the real machine tool. Virtual CNC machine tools can mimic any function of the real machine tool without adopting some kind of approximate substitution resulting in some kind of structure and information distortion or loss, and with the real machine tool has the exact same interface style and corresponding functions, such as dynamic rotation, zoom, move and other functions of the real-time interactive operation, so as to provide a guarantee for the student's learning and training.
The whole process of machine operation simulation. Simulates the entire process of machine operation: blank definition, workpiece clamping, platen mounting, datum tool setting, tool mounting, and manual operation of the machine.
Rich and diverse tool library. The system adopts a unified database management of tool materials, characteristics and parameters of the library, containing hundreds of different materials, types and shapes of turning tools, milling cutters, while also supporting user-defined tools and related characteristics.
Comprehensive collision detection. Real-time collision detection in manual and automatic machining modes, including collision between the tool and fixture, platen, tooling, machine travel boundary crossing, tool shank and workpiece when the spindle is not rotating, and so on. There will be an alarm or prompt when the error occurs, thus preventing the occurrence of misoperation.
Powerful measurement function. It can realize the measurement of roughness of parts based on cutting parameters of the tool, and can carry out completely automatic and intelligent measurement of the workpiece after machining on the simulation software.
With perfect graphics and standard data interfaces. Users can run the virtual machine tool in the real environment, but also to observe its various operating parameters, and other CAD / CAM software, such as UG, Pro / E, Mastercam, etc. generated by the three-dimensional design post-processing of the NC program, directly into the processing.
Practical and flexible examination system. Can be used for remote network learning, homework, exams and other functions, and to achieve the answer sheet preservation, automatic scoring, results query and analysis of the function, easy to realize the paperless assessment and evaluation.
Virtual CNC machine tool powerful network functions, can realize remote education. Not only in the LAN with two-way interactive teaching functions, but also has the Internet-based two-way interactive distance learning functions, data transmission can be used satellite, broadband (ADSL, ISDN, cable CABLE, etc.) or narrow-band Internet (56K Modem) and other ways. This makes distance learning a real thing, and it represents the future direction of education.
5. Conclusion
Given that the virtual CNC machine tool has such outstanding features, for the current CNC teaching courses in various institutions and to participate in the reality of the increasing number of students in CNC internships, as well as CNC machine tools, precision, expensive features, the CNC machining simulation system software is introduced into the teaching of CNC machine tools used for programming and operation training, is undoubtedly a wise idea. and operation training, is undoubtedly a wise move. This can avoid damage to expensive CNC machine tools due to misoperation, but also allows operators to simulate the operation of CNC machine tools in the process of generating a sense of site and a sense of reality. At the same time, due to its low cost, can be configured in large numbers of terminals, completely solve the problem of insufficient number of CNC machine tools, so that each student can have enough practice opportunities, so it can allow students to more quickly familiarize themselves with and understand the work process of CNC machining, to master a variety of CNC machine tool operation methods. Its greater benefit is also that, in the case of the same training effect, the processing error rate and the incidence of accidents is reduced to a minimum.
From the effect of the use of our hospital, the introduction of CNC simulation system, so that students in the study of CNC programming theory, classroom teaching has become more vivid, more specific, to enhance students' learning interest, teaching results have been significantly improved. In learning the actual operation, because the simulation software does not exist security problems, which makes the students can boldly, independently study and practice, and can self-test the accuracy of the geometry of the machined parts, the cultivation of students' ability to operate the machine tool, has played a great role in improving and strengthening the role. At the same time the system can also reduce the teacher's work intensity, reduce the consumption of workpiece materials and energy, saving the training costs of the practice session, the effect is very significant. I believe that in the near future, it will become an important and indispensable means of teaching CNC.
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