Product design of CNC milling machine and machining center

2 reasons for choosing this topic

Manufacturing technology is one of the important pillars of economic competition in various countries, and the economic success largely benefits from advanced manufacturing technology. Machine tool is an important carrier of mechanical manufacturing technology, which indicates a country's production capacity and technical level. Machine tool industry is an important leading sector of the national economy, which undertakes the task of providing modern technology and equipment for all sectors of the national economy. Taking 1994 as an example, the global basic consumption reached $266,543.8+700 million. Among them, US$ 5.6 billion and China $3.36 billion. Therefore, the machine tool industry plays an important role in China's national economic construction. In the machinery manufacturing industry, a large number of special machine tools, modular machine tools, special automatic lines and other equipment are mass-produced with corresponding tooling. These equipments have high initial investment cost and long production preparation time, which are not suitable for product upgrading. In single piece and small batch production, due to the wide variety of products, it is not suitable to use special machine tools, especially in national defense, aviation, aerospace, deep diving and other departments. Its parts have high precision, more and more complex geometric shapes, frequent modifications and short production cycle, which require rapid adaptation to the processing of different parts. The empty book machine tool is a new type of automatic machine tool which is produced and developed under this background. It solves the automatic machining problem of small batch, multi-variety, complex shape and high precision parts. With the development of computer technology, especially microcomputer technology and its application in CNC machine tools, the CNC technology of machine tools is developing from ordinary CNC to computer CNC. The number (relative value) of CNC machine tools in a country indicates the modernization of the country's machinery manufacturing industry. CNC milling machine and machining center occupy a considerable proportion in CNC machine tools because of their unique machining methods and wide machining range, so it is of great significance to study the product design of CNC milling machine and machining center.

3 Research status at home and abroad

In today's world, industrialized countries attach great importance to the machine tool industry and compete to develop advanced machine tools with high quality, high precision, high efficiency and automation to accelerate the development of industry and national economy. For a long time, Europe, America and Asia have been fiercely competing with each other in the international market, forming an invisible front. Especially with the progress of microelectronics and computer technology, the development speed of CNC machine tools has been accelerated since 1980s, and users from all sides have put forward more demands, which has already become the focus of machine tool manufacturers all over the world competing to display advanced technology, compete for users and expand the market at four international machine tool exhibitions. After China joined the WTO, it formally participated in the fierce competition in the world market. How to strengthen the strength of machine tool industry and accelerate the development of CNC machine tool industry in the future is an urgent and arduous task. In the past 50 years, CNC machine tools have developed with the progress of science and technology, especially microelectronics and computer technology. The United States, Germany and Japan are the countries with the most advanced technology and experience in the research, design, manufacture and use of CNC machine tools.

For example, 1 mm was1mm at the beginning of the 9th century, and increased to 0.0 1 mm at the beginning of the 20th century. In recent 30 years, the general machining accuracy has increased from 0.0 1 mm to 0.005 mm, the precision machining accuracy has increased from 1 um to 0.02 um, and the ultra-precision machining accuracy has increased from 0.02 um. About 0.0 1 micron to nanometer. In terms of surface roughness, in Japan, the surface roughness of less than 0.0005 um was successfully obtained by polishing with fluorescent carbon foam polishing agent and fine SiO2 _ 2 powder. In the past, scientists only paid attention to the surface characteristics such as surface roughness, waviness and texture, ignoring the internal effects within the range of 0.38 mm below the surface, that is, the influence of subsurface effects on the reliability of parts. This aspect needs further study, and corresponding measures should be taken to improve the quality, service life and reliability of products.

China developed the first CNC machine tool in 1958, and the development process can be roughly divided into two stages. The first stage is from 1958 to 1979 and the second stage is from 1979. In the first stage, there was a lack of understanding of the characteristics and development conditions of CNC machine tools. In the case of poor personnel quality, poor foundation and poor accessories, they rushed up and down, and finally stopped because of poor performance and could not be used for production. The main problems are blindness and lack of scientific spirit of seeking truth from facts. In the second stage, CNC system technology was introduced from Japan, Germany, the United States and Spain, and advanced CNC machine tools were introduced from Japan, the United States, Germany, Italy, Britain, France, Switzerland, Hungary, Austria, South Korea and Taiwan Province Province * *11countries (regions), which solved the reliability and joint venture production. In more than 20 years, the design and manufacturing technology of CNC machine tools has been greatly improved, mainly in three aspects: (1) training a group of talents for design, manufacture, use and maintenance; Through the cooperative production of advanced CNC machine tools, the level of design, manufacture and use has been greatly improved, and the gap with the world's advanced technology has been narrowed; Using foreign advanced components and numerical control systems, we can design and manufacture high-speed, high-performance five-axis or five-axis CNC machine tools to meet the needs of the domestic market, but it is poor in testing, digesting, mastering and innovating key technologies. Up to now, many important functional parts, automatic tools and numerical control systems are supported by foreign technology, and cannot be independently developed. They are basically in the stage from imitation to independent development, which is far from the level of Japanese numerical control machine tools. The main problems include: lack of guidance like Japan's Electromechanical Law and Machine Letter Law; There is a serious shortage of experts and skilled workers in various fields; Lack of in-depth and systematic scientific research work; Components are not compatible with CNC system; There is a lack of cooperation between enterprises and majors, and they are basically fighting alone. Although there are many people in the factory, they cannot form a joint force.

4 Research contents:

1. Make a real process plan according to the drawing requirements.

2. Choose a reasonable tool and cutting process parameters.

3. Write the NC machining program

5 Research methods:

First of all, read a lot of relevant documents, teaching materials and news background materials, including the principles and methods of mechanical manufacturing, the application of quality management, the existing technical level of CNC machine tools, books and newspapers on international level discussions, so as to understand the content of reliability, the general situation of quality management and the basic knowledge system in the field of CNC machine tools. Then, through investigation, we can further understand the current situation and needs of enterprises. Next, analyze and design, determine the true and accurate data source, and then design the system.

Because the existing equipment adopts the analysis and design method, the original equipment can be properly tested and debugged first, and then the processing quality can be improved by using the rapid prototyping method. After obtaining the effective feedback information from the enterprise, the statistical analysis method and the Brown method can be considered for the next reanalysis and redesign.

6 in order of progress:

1. Preparation stage (1February 15 to1February 30). Collect relevant information and prepare reference materials.

2. Complete the opening report and the outline of the paper and submit it to the teacher for review (1 month 1 day to 1 month 15).

According to the outline of the paper, complete the first draft of the paper and submit it to the teacher for review (1 month 16 ~ March 10).

4. Complete the second draft of the paper and submit it to the teacher for review (March 1 1 day ~ April 10).

5. Complete the third draft (April 1 1 day ~ April 30th)

6. Complete the introduction of relevant papers and the outline of defense, and prepare for the defense stage (May 1 day to May 10).

7 Graduation design defense stage (mid-May)

7 main reference materials:

1 Zhou Changzhi, yang,,, Chen guangling, mechanical manufacturing technology, published by Chongqing university press, the sixth printing in 20061February,

2 Zhang Lihua, Malik, NC programming and machining technology, Dalian University of Technology Press, 2nd edition, July 2006.

4. Yang Jianming, NC Machining Technology and Programming, beijing institute of technology press, the third printing in April 2007.

5. Lv Tianyu, Gong Bo, Tolerance Fit and Measurement Technology, Dalian University of Technology Press, the third printing in July 2006.

6. Gao Bo, Fundamentals of Mechanical Manufacturing, Dalian University of Technology Press, printedNo. 1 in August 2006.

7. Huang Heting, Wang Furong, Metal Cutting Machine Tool (I), Machinery Industry Press, July 2006, p. 1 edition? 6? 1 the first printing 10

8 Result form:

Completed in the form of a paper.