制作大口径薄壁塔吊时,在没有特定工装设备的条件下,环缝的组装是在预制好的筒节内焊接支撑幅管以防变形。在环缝组对时,从筒壁内部用导链或千斤顶找圆对口,并在环缝两侧焊接工卡具进行对接。这种方法费工、费料且对口错边量和椭圆度又不好保证。在清除支撑幅管和卡具的焊疤时工作量大,打磨费工 In the production of large-diameter thin-walled crane, in the absence of specific tooling equipment, the ring seam assembly is welded in the prefabricated tube section support tube to prevent deformation. In the ring seam group right, from the inner wall of the cylinder with a chain or jack to find a round counterpart, and on both sides of the ring seam welding jig docking. This method is laborious, costly materials and the wrong side of the amount of ovality and ovality is not guaranteed. Work in the removal of the width of the braces and fixtures work, finishing time