Since 2000, our school has educated students of numerical control processing to take the lead in innovating the teaching content of professional disciplines, actively carrying out reforms in the teaching mode of numerical control processing technology and applying research on numerical control processing simulation systems in numerical control teaching and appraisal, and achieved good results. The teaching and appraisal results have been welcomed by students, parents, and the society, making the NC professional one of the fist professional of our school. The NC professional students account for one-third of the total number of students in our school to meet the needs of CNC machining professionals. The urgent need for a cultured society.
I. Proposal of the problem
With the development of science and technology, CNC machining technology is widely used. CNC talents have become urgently needed talents in the labor market. How to cultivate NC skilled talents that meet market needs and master NC machine tool programming knowledge and operation skills as soon as possible becomes a problem that CNC teaching workers must study. As a professional teacher of numerical control programming and operation, I deeply feel that how to combine the teaching of NC programming with the operation practice of CNC machine tools is worthy of our careful discussion and research.
As CNC machine tools are a new type of technology equipment, the training of CNC technicians and the teaching of CNC machine tools are still in a state of starting. How to use CNC machining simulation systems for teaching and appraisal is still in the exploratory stage, so it is necessary to The exploration of numerical control teaching mode, teaching methods and teaching methods is conducive to exploration, and the working methods of professional skills appraisal of CNC professional are innovated to establish a complete new system of numerical control teaching and appraisal.
CNC machine tools belong to high-tech products, high variety and high prices, a CNC lathe or CNC milling machine generally need two or three hundred thousand, a CNC machining center is also less than a few hundred thousand more than a few million. If the operation training of CNC machine tools depends entirely on CNC machine tools for practical training, the cost of input is high and the cost is high. Even powerful training schools and enterprises are neither necessary nor able to undertake such consumption and investment. Therefore, exploring a new teaching mode of numerical control processing technology to achieve low investment, quick results, strong student adaptability, and enterprise-welcomed teaching mode is inevitable. This teaching mode should be distinguished from the traditional mechanical processing training mode. Different from the general electromechanical profession. The use of numerical control machining simulation system teaching is an important way to solve this problem. It can not only solve the problems of the NC system operation and control panel when the students are practicing, but also can greatly improve students' learning interest, and can also improve students' programming ability and adaptability to different numerical control systems with different CNC machine tools. It is an effective method. A good attempt at the pre-teaching of numerical control practice is also an effective method for professional skills assessment of CNC machine tools.
Second, determine the teaching mode of CNC machining technology
Vocational and technical education in the CNC machining technology application professional vocational training is to enable students to obtain professional skills in the application of numerical control technology, to obtain the protection needed to use this professional skills to survive and develop, that is, to learn a kind of advanced socially needed to earn a living. Skills. For this purpose, we have actively explored and researched the teaching mode of the numerical control processing application technology, aiming to establish a set of reasonable and perfect training and authentication systems for numerical control machine tools that are suitable for teaching and appraisal. Our guiding ideology and goals are:
1. Completely reform the teaching mode of CNC machining technology and realize two transformations, that is, shifting theoretical teaching to the emphasis on theoretical teaching and skill training. Combining the pure operation and pure consumption of skills training with the application of numerical control simulation system to test the programming effects in combination with CNC machine tools Change the training;
2. Change the content and methods of the original lectures, integrate the traditional teaching content of machinists, and enrich the necessary teaching content related to CNC processing technology, supplemented by a series of computer-assisted multimedia teaching methods; Reforming the teaching content and methods of NC programming and operation courses, changing the traditional teaching methods into modern teaching methods, and emptying space-over-programming methods to cultivate the comprehensive programming ability to verify the programming effect immediately;
3. Abandon demonstrable programming, establish a programming system that includes conventional programming, comprehensive programming, designing programming, and practical programming to improve the students' hands-on brain abilities, and create middle and high-level numerical control programming that is practical and creative. It lays a solid foundation for the operation of skilled personnel.
4. To broaden students' employability, so that they can quickly adapt to the operation or programming of CNC machine tools of different companies with different CNC systems, have strong processing and on-site problem processing capabilities, and have strong computer design and manufacturing application capabilities.
Our specific approach is to correctly determine the professional location of CNC machining applications:
1) Positioning of professional positions in NC machining application technology professional fields:
CNC machining application technology professional areas generally have the following professional positions: general machine tools and CNC machine operators, CNC programming process personnel, CNC equipment maintenance personnel, CNC equipment marketing, mold design and manufacturing personnel.
According to the research on the demand of CNC talent market, combined with the characteristics and positioning of Chinese and secondary vocational schools, high-tech and higher vocational education, the major orientation of this major is: training posts with strong adaptability, large shortages, and certain processing Process knowledge and numerical control machining operations, programming skills, both common machine operation skills, CAD drawing skills, "technical skills" talent.
Training objectives: This professional field is oriented towards the manufacturing industry and fosters the full development of Germany, Chile, China, and the United States. It has the cultural level and quality that are compatible with the direction of the professional field, and has a good professional ethics and innovative spirit. Technical knowledge, with corresponding practical skills and strong practical ability, grasp the working principle and structural knowledge of CNC machine tools, grasp the characteristics of the main CNC system, have a certain knowledge of CNC machining technology, with ordinary machine tool operation, CNC machine tool operation, manual Programming, automatic programming, CAD drawing capabilities.
Career-oriented: The main jobs are: CNC machining technology and CNC machining program; operation of CNC machine tools
2) The determination of the teaching mode of numerical control processing application technology: The teaching mode of numerical control processing application technology should be the same as the traditional machining professional, and it is different from the new teaching mode. In the application of the teaching mode, we comprehensively refer to the German education model. Germany does not have the expertise of applying CNC technology. They are collectively referred to as metal cutting technology workers. CNC technology needs corresponding theoretical knowledge and practical experience and skills in metal processing as a basis. Therefore, in addition to the completion of professional courses such as drawing, professional mathematics, mechanism technology, and metallurgy, students must also complete a large number of machining practices such as locksmiths, turners, and milling cutters before learning CNC techniques.
Third, the application of numerical control processing simulation system in teaching
(a) Selection of CNC machining simulation system:
The numerical control machining simulation system has many software forms, some of which are self-contained simulation systems of the numerical control machine tools. However, the simulation system of the numerical control machine tools is limited in teaching and is not suitable for teacher teaching and student training; there are some first composition and then automatic Programming simulation software also does not meet the requirements of manual programming teaching. There are several other kinds of CNC machining simulation software in China, but they all have some unsatisfactory features. After several comparisons, we finally chose the teaching software of Shanghai Yulong CNC machining simulation system. The software is based on virtual reality simulation software from the United States and is a valuable teaching aid. It can simulate the entire process of machining parts for CNC milling machines, CNC machining centers and CNC lathes, including blank definition and fixtures. Tool definition and selection, part reference measurement and setting, NC program input, editing and debugging, FANUC CNC system, SIEMENS CNC system, Huazhong CNC system, Guangzhou CNC system and other CNC systems, with multiple systems, multi-machine tools, multi-parts The simulation simulation function of the process, the software has originality, reached the international and domestic leading level.
(II) Application methods of CNC machining simulation system:
How to use this software for teaching, we mainly explore and practice in the following aspects in teaching.
1. Flexible application of teaching methods, changing students’ passive learning into active learning in classroom teaching
Nowadays, because most of the students with good learning foundations choose to go to college, teaching in vocational and technical schools is very difficult. Traditional teaching methods have made it difficult for students to accept them. Therefore, using advanced teaching methods and teaching methods to improve students’ interest in learning Particularly important. The numerically-controlled professional teachers should have higher teaching standards and teaching abilities, and have a strong numerical control professional ability that is NC programming ability, process processing ability, practical hands-on ability, automatic programming ability, and can be more skillful in using action-oriented teaching methods. Classroom teaching truly embodies students as the main body, highlighting the activities of students' hands and brains, and changing students' passive learning as active learning. In the teaching process, teachers play a guiding role, that is, to guide and explain problems that are difficult or impossible in student activities. The knowledge of each lesson in the classroom teaching is as concentrated as possible, so it is easy to understand programming methods and techniques.
2. Properly use CNC machining simulation system to give full play to its role in classroom teaching
CNC machining simulation system is mainly applied to the theory teaching of NC programming and operation, and can also be used as an auxiliary tool for NC operation skills training. Teachers should attach great importance to the application of numerical control processing simulation system in teaching. The position of the numerical control processing simulation system in teaching can neither rely solely on the numerical control processing simulation system to abandon the guiding role of teachers in teaching, nor can it be used in teaching. The teacher sings the monologue and adopts the conventional teaching mode while ignoring the application of the numerical control processing simulation system. The role of the numerical control processing simulation system in teaching should be played scientifically and fully.
3. Arrange teaching contents scientifically and gradually master NC programming and operation skills
The arrangement of teaching content in the teaching process is divided into three modules. The first is the basic module, which mainly explains and trains the programming methods, operations and applications of CNC lathes, CNC milling machines, and CNC machining centers in the most commonly used FANUC CNC system. This module is the teaching focus and must be mastered by students and applied flexibly. : The second is to improve the module, mainly to explain and train SIEMENS CNC system programming and operation of three kinds of machine tools, to help students further enhance the understanding of the different CNC machine tools under the CNC system programming methods and application capabilities: Module 3 is to expand The module mainly explains the programming and operation methods of CNC lathes in CNC NC system and CNC lathe in CNC CNC system in China. It expands students' knowledge and improves students' ability to program and operate different operating systems and different operation panels. The teaching of these three modules can be arranged according to different levels of students. The technical level of technical secondary schools is less difficult, the level of high-tech college is slightly more difficult, and the three modules are more time-consuming. In this way, students can confidently handle the CNC machine tools they are working in and adapt to their work quickly.
4. Correct teaching evaluation to improve students' learning awareness and consciousness
The teaching evaluation conducted during the teaching includes the student's self-evaluation, student's mutual evaluation and teacher's evaluation. On the machine application of numerical control processing simulation system for numerical control programming and operation exercises to teacher evaluation, timely registration of each practice results. Evaluation methods include verbal evaluations and evaluations of test questions, and test evaluation methods include subject assessment and final assessment. Teachers should pay attention to the choice of methods and language when making verbal assessments to students, and do not use direct criticism for students who do not do well, but only indicate which areas of the students are doing well and which are not. How to improve; for comparison Poor students are called "weaker students". Classroom testing should have a strong purpose, not be difficult for students, but by testing students to improve students' learning awareness, learning enthusiasm, self-consciousness and self-confidence learning, therefore, test questions should be with classroom teaching, The application requirements of the NC machining simulation system are adapted. The review before the exam should have a strong purpose and should not go beyond the scope. The score of the general assessment of the course does not focus on the results of a final exam, but rather pays more attention to the student's learning effect throughout the entire learning process. The teacher has a clear teaching purpose in teaching, explaining and arranging exercises on a system-by-system-by-special-type machine-by-machine basis. It is just right for students to teach and teach students in accordance with their aptitude.
IV. Application of NC Machining Simulation System in Professional Skill Identification
CNC operators are divided into two major categories according to the national occupational skill appraisal standards: theoretical assessment and skill assessment. Among them, the skill assessment is divided into five modules: the operation of CNC machine tools (using manual programming to process actual parts), process planning, CAD computer graphics, analysis and explanation of NC machine tool troubleshooting, and CAM automatic programming module. The skills assessment of the third and fourth-level operators of CNC machine tools only evaluates the first module, that is, the CNC machine tool operation module for manual programming of the parts. If all the skill operation assessment modules are arranged on the CNC machine tool according to the routine assessment, it usually takes 4-6 hours to occupy the CNC machine tools. We use the NC machining simulation system software to assist in the examination. After the examinee obtains the drawings of the parts to be examined, they are manually programmed in the numerical control car (or milling) bed of the NC machining simulation system. After passing the inspection, the program is transmitted to the CNC machine tool through data transmission. Processing, which reduces manual programming, input programs, calibration procedures, and simulation processing time on the machine tool. It takes only about 2 hours to occupy the CNC machine tool, which shortens the machine time by at least 50%, greatly improves the efficiency of identification, and greatly increases the efficiency. Improve the safety at the time of identification. In order to reduce the consumption of tools and materials, and further shorten the operation time of CNC machine tools, it is also possible to divide the operation into two parts. The difficult parts can be manually programmed on the NC machining simulation system to simulate processing, but the difficulty will be smaller. , less material parts simulation and then processed on CNC machine tools.
In a word, the application of NC machining simulation software in teaching and appraisal is still in the initial stage of research and exploration. As long as we actively think about the problems arising from the application and take the initiative to take countermeasures, we must properly play its role in teaching and appraisal. Can get twice the result with half the effort.
Application of Numerical Control Processing Simulation System Software in Numerical Control Teaching and Identification
The development of the global knowledge economy has made mechanical engineering a multidisciplinary comprehensive technology application subject spanning machinery, electronics, computers, information, control, management, and economics. The application of numerical control processing technology came into being. This is a traditional mechanical Processing professional education puts forward new and higher requirements. Zhuzhou Institute of Technology seizes opportunities and is committed to reforms. It actively explores new modes of training of professional technicians in numerical control processing, and strives to cultivate intermediate-level and advanced-level broad- and multi-layered, open, and skillful NC processing and application technical talents for the country. The economic construction transports a large number of applied-type skilled personnel.