如何快速看懂机械图纸(国外英文资料).docVIP

如何快速看懂机械图纸(国外英文资料) Since the reform and opening to the outside world, many foreign equipment, drawings and other technical information have been imported in China. Many developed countries have different mechanical projection methods and different projection methods adopted in china. In order to better learn advanced technology in developed countries, it is necessary to quickly understand foreign mechanical drawings. 1 Overview In todays world, the ISO standard specifies that the first and third projection are equally valid. According to the national conditions are different, including Russia, Ukraine, Germany, Romania, Czech, Slovakia and Eastern Europe and other countries are mainly using the first angle projection, and the United States, Japan, France, Britain, Canada, Switzerland, Australia, Holland and Mexico and other countries are mainly used for projection. Before liberation, our country also adopted the third triangle projection. After the founding of new China, the first angle projection was used. The triangular projection is often encountered in imported mechanical drawings and scientific books and periodicals. The ISO international standard specifies the projection marks for the first and third angles (FIGS. 1 and 2). In the title column, there are markers, which can be used to identify drawings, but some drawings do not have a projection mark. Figure 1 first drawing notation Figure 2. Triangle notation 2 triangular projection The space can be divided into eight regions by the positive plane V, the horizontal plane H and the lateral plane W, which are first, second, third, fourth, fifth, sixth, seventh and eighth, respectively, as shown in figure 3. Figure 3 2.1, the object in the first part of the projection, known as the first corner projection, also known as the E - European approach. 2.2, the object in the third angle projection, known as the third triangle projection, also known as the A method - the United States approach. Our country uses the thi