薄壁套筒类零件磨削夹具的设计及其可靠性分析

Design and feasibility analysis of grinding fixture for thin-walled parts

为提高薄壁类零件的加工精度,利用蛇形弹簧受轴向力产生径向膨胀而夹紧零件的原理设计了一套薄壁套筒类零件磨削夹具.对夹具中的螺栓拧紧力矩与蛇形弹簧的轴向力之间的关系进行研究显示,当蛇形弹簧所受轴向力为5000 N时,螺栓所需拧紧的力矩为309.46 N·m.利用Workbench软件对夹具中螺栓拧紧力矩(309.46 N·m)的工作状态进行有限元分析表明,夹具所使用的材料可满足其性能要求;蛇形弹簧应力集中处为Φ25轴径处,蛇形弹簧过盈配合处(Φ36内径)胀紧变形为0.007 mm,最大应变为0.00051,最大应力为101.79 MPa;蛇形弹簧膨胀接触处为套阀阀芯变形最大处,最大径向变形量为0.0021 mm、最大应力为25.22 MPa、最大应变为0.00013.对夹具进行可靠性分析表明,其应力可靠度为100%.

In order to improve the machining precision of thin-walled parts,a set of clamping fixture is designed by means of radial expansion of serpentine springs.A thin-walled sleeve-type grinding tool is designed by using the principle that the serpentine spring is radially expanded by the axial force to clamp the part.When the axial force of the serpentine spring is 5000 N,the tighten torque required for bolts is 309.46 N·m.The finite element analysis of the working state of the bolt tightening moment of 309.46 N·m in the fixture shows that the material used in the fixture can meet its performance requirements.At the stress concentration of the serpentine spring is at the diameterΦ25,the expansion deformation of the serpentine spring in the interference fit(the inner-diameter ofΦ36)is 0.007 mm,the maximum strain is 0.00051,and the maximum stress is 101.79 MPa;The expansion contact of the serpentine spring is the maximum deformation of the valve spool,and the maximum radial deformation of the valve spool is 0.0021 mm,the maximum stress is 25.22 MPa,and the maximum strain is 0.00013.The reliability analysis of the fixture shows that the stress reliability is 100%.