【摘要】 针对42CrMo高强度合金结构钢在传统钻削加工中出现的断屑、排屑困难及加工质量差等问题，基于纵扭超声振动钻削的运动特性和刀具与工件的切削分离条件，对42CrMo钢进行了不同工艺参数的钻削试验，探究了工艺参数对切屑形态、出入口孔径和孔壁表面粗糙度值的影响规律，为42CrMo钢的纵扭超声振动精密制孔提供了工艺参数优化依据。结果表明，纵扭超声振动改变了刀具切削运动轨迹，通过刀具与工件间歇性分离实现了良好的断屑效果；增大超声振幅能有效改善切屑形态获得C形短切屑，但振幅过大会增大孔壁粗糙度值、降低孔径精度；孔壁粗糙度值和孔径尺寸随着超声振幅和转速的增大先减小后增大，随着进给量的增大而增大，在超声振幅为10μm、转速为2 000 r/min、进给量为0.005 mm/r时，能够获得较好的加工质量。更多还原

【Abstract】 Focusing on the issues of chip breaking and evacuation difficulties and poor machining quality in the traditional drilling process of 42CrMo high strength alloy structural steel, drilling tests with different process parameters were carried out on 42CrMo steel based on the motion characteristics of longitudinal torsion ultrasonic vibration drilling and the conditions of cutting separation between the tool and the workpiece. The influence of process parameters on chip shape, inlet and outlet aperture and hole wall surface roughness were studied, which provided a basis for the optimization of process parameters for 42CrMo steel precision hole making by ultrasonic vibration. The results show that the longitudinal torsion ultrasonic vibration changes the cutting motion path of the tool, and achieves good chip breaking performance through intermittent separation of the tool and the workpiece. Increasing the ultrasonic amplitude can effectively improve the chip shape and obtain C-shaped chips, but an overly large amplitude can increase the roughness of the hole wall and reduce the aperture precision. With the increase of ultrasonic amplitude and speed, the roughness of the hole wall and the size of the aperture first decrease and then increase, and increase with the increase of the feed rate. Better machining quality can be obtained when the ultrasonic amplitude is 10 μm, the speed is 2 000 r/min and the feed rate is 0.005 mm/r.更多还原