圆环斜槽传振杆的纵扭振动转换

Longitudinal-torsional Vibration Converter of Cylinder with Multiple Diagonal Slits

工具的复合振动在切削和焊接加工中能得到优于单向振动输出模态加工的质量,并可大幅提高加工效率和延长工具寿命。利用圆环斜槽传振杆可使单向模态的纵振换能器实现超声纵扭共振模态的输出。这种方法结构简单、使用方便,并具有很高的转换效率。研究从斜槽对应力波的反射作用原理出发,推出纵波在斜槽作用后的应力波应力状态。研究这种应力波在圆环斜槽传振杆中的传播形式,指出它是沿螺旋线传播的主应力波并推出了其传播声速。在此基础上,证明圆环斜槽传振杆存在纵扭共振模态,利用传输线等效电路导出传振杆的频率方程。通过分析圆环斜槽传振杆的振动特性,得出影响纵扭振动输出参数的因素。根据加工要求的振动输出参数,在实际应用中可准确地确定圆环斜槽传振杆的几何尺寸。有限元模态分析、试验结果与理论分析一致。

Compound vibration of tool in cutting and welding makes the machining quality of work pieces finer than one-way vibration, and can greatly improve machining efficiency and extend tool life. Cylinder with multiple diagonal slits can change transducer of longitudinal resonance mode into longitudinal-torsional resonance mode outputting. This technique features simple structure, convenient use and high conversion efficiency. The state of plane principal stress in diagonal slits is derived with longitudinal stress wave reflecting principle to diagonal slit. Propagation of principal stress wave in cylinder is studied. The analysis result shows that principal stress wave propagates along helical line, and its sound propagation velocity is derived. The fact is proved that cylinder with multiple diagonal slits exists longitudinal-torsional resonance mode and the resonance frequency explicit expression is given by means of the equivalent circuit. Based on the analysis of ultrasonic vibration features of cylinder with multiple diagonal slits, factors which affect longitudinal-torsional vibration outputting parameter are established. According to the vibration outputting parameter required by the machining, the geometric size of cylinder with multiple diagonal slits can be accurately defined in application. The finite element mode analysis and experiment results agree with the theoretical analysis.