1983年我厂铸造车间安装了一台ZS900直线振动筛。用了两年后,因外接卸料口(卸废料和砂团)的连接螺栓1松动(见图1),机器工作时噪声增大,并破坏了机器的动平衡,造成外接卸料口与机架焊缝之间疲劳断裂。断裂处焊补后,仍在原处或其它薄弱焊缝处继续被振裂,断裂次数与日俱增,有时每隔2～3天就要补焊一次。而且,在哪里焊补,哪里就被振裂。于是我们又采取刚性加固措施,即在断裂的地方应用M30螺纹拉 1983 I foundry workshop installed a ZS900 linear vibrating screen. Two years later, due to loosening of the connecting bolt 1 (see Figure 1) of the external discharging port (discharging waste and sand group), the noise of the working machine increases and the dynamic balance of the machine is destroyed, resulting in the external discharging port and Fatigue fracture between frame welds. Broken after welding, still in place or other weak welds continue to be shattered, increasing the number of cracks, and sometimes every 2 to 3 days to repair welding once. And, where the welding, where it was shattered. So we take a rigid reinforcement measures, that is, where the fracture M30 thread pull