飞机骨架和舱门框等镁合金大件,都具有理论外形(不规则的双曲型面)并带有空间角度,外廓尺寸为1200～1500毫米,对于这些零件需要划全线检验几何尺寸和工序线。过去划线用千斤顶把零件支承起来,甚至用铅锤吊线,或用一个大的九十度弯板(弯板不能转动)找正,工作笨重,又不准确,效率低,有时一天两个人还划不 Aircraft skeletons and door frames and other magnesium alloy bulky, have a theoretical shape (irregular hyperbolic surface) and with a spatial angle, the outline size of 1200 ~ 1500 mm, for these parts need to draw a full line test geometry and procedures line. In the past, scribing jacks used to support parts, even plumbing them with plumb bobs, or using a large ninety-degree bend (the bend could not be turned) to find a job that was bulky, inaccurate, inefficient, and sometimes two people a day No plan