Performance optimization design of TNX625 heavy boring bar based on multi-objective method

Due to the large size and weight of the heavy boring bar, its manufacturing is difficult, and the cross-section size of the bar is difficult to determine. When it is subjected to cutting force, the deformation and stress of the boring bar affect the machining accuracy. In this paper, the numerical control horizontal boring lathe boring bar of TNX625 heavy boring bar is taken as the research object. The finite calculation of the mechanical and torsional characteristic parameters of the boring bar under certain working conditions is carried out. The results show that the maximum stress is 176 MPa, the maximum deformation is 2.97 mm, and the maximum torsion angle is 0.11°. Based on the response surface method, the structure size is optimized. The optimized structure size is as follows: upper wing plate of 156 mm, lower wing plate position of 167 mm, middle rib plate thickness of 152 mm, and the maximum stress of 153 MPa, which is reduced by 13.07% before optimization. The maximum deformation is 2.87 mm, which is reduced by 3.42% before optimization. The torsion angle is 0.079°, which is reduced by 28.18% before optimization.