我国目前的塔式起重机的塔身及臂架的结构,已有不少采用了无缝钢管。它虽然在材料性能方面具备了不少的优点,但是在加工方面却存在一定的难度。因为腹杆与主弦杆交接处的端面形状为一相贯曲面,特别是斜腹杆的端面形状更为复杂,用一般的机床设备是难以解决的。目前大部分生产厂家对腹杆的加工工艺流程一般为:样板划线→气割落料→手工磨管→装焊。采用此工艺流程加工的腹杆主要有以下缺点:1.腹杆长度、焊缝间隙均难以控制,因此导致构件焊接质量差、变形大、刚度差,保证不 China’s current tower cranes and boom structure, there have been many uses of seamless steel pipe. Although it has a lot of advantages in material properties, it has a certain degree of difficulty in processing. Because the shape of the end surface of the interface between the web and the main chord is an intersecting curved surface, especially the shape of the end surface of the web is more complicated, it is difficult to solve with the general machine tool. At present, most manufacturers of web processing process is generally as follows: a model crossed → gas cutting blanking → manual grinding tube → welding. The webs processed by the process have the following disadvantages: 1. The length of the webs and the gap of the weld are difficult to control, which leads to poor welding quality, large deformation and poor rigidity of the components, and guarantees no