我国数控系统的发展史_毕业论文外文翻译.doc

外文资料　　　 Thesis 　　　 First, the development history of Chinas NC system 　　 1. China from 1958 onwards, by a group of research institutes, colleges and universities and a few machine tool plant started to conduct research and development of numerical control system. At that time due to the low level of domestic electronic components, departments, economic and other constraints, unable to obtain a larger development. 　　 2. In the reform and opening up, China was gradually numerical control technology to achieve substantial development. After 65 (81 ---- 85 years) and the introduction of foreign technology, 75 (86 ------ 90 years) is digested and absorbed and the 85 (91 ~ 1 -95 years) national organizations, scientific and technological research, that make our countrys CNC technology has been a qualitative leap, when the acceptance through national research and identification of products, including Beijings China-I Mount Everest, central Chinas central NC I-type and high-grade CNC Shenyang National Engineering Research Center of the blue sky I, and others through the National Quality Supervision and Testing Center machine test qualified domestic CNC systems such as Nanjing, four open companys products. 　 3. Chinas CNC machine tool manufacturing industry in the 80 years have had the stage of rapid development, many machine tool plant products from traditional products to achieve the transition to the CNC. However, in general, technical level is not high, poor quality, so in the early 90s to face the national economy from planned economy to a market economy and the transfer of adjustment, has experienced the most difficult Depression years, when production dropped to 50 %, stocks more than four months. From 1995, 95 after the country from the start the machine tool market to expand domestic demand to strengthen the restrictions on the approval of imports of CNC equipment, the investment and key support for key numerical control system, equipment, technology res