内柱孔和内锥孔圆柱形变幅杆

A uniform ultrasonic horn with an inner cylindrical holeoran inner cone hole

激光和水射流是对陶瓷等易碎材料进行辅助打孔的传统方法,其设备存在大而复杂等缺点。加工陶瓷等易碎材料时,利用超声振动的带孔变幅杆的设备比起传统的利用激光和水射流的的设备更简易和小型化,因此,超声加工受到了人们的重视。文章对中心孔分别为柱形和锥形、外形为圆柱形的超声杆件,基于解析法推导了这两种孔型变幅杆的频率方程及性能参数表达式,分析了不同参量对其性能参数的影响,并利用有限元法计算了在谐振状态下这两种变幅杆的应力及振动位移沿轴向分布的规律。结果表明,在相同谐振频率及面积系数下,带孔变幅杆的放大系数大于实心圆柱杆的放大系数;锥形孔变幅杆的放大系数小于柱形孔变幅杆的放大系数,但前者应力曲线光滑且应力极大值较小。

Lasers and water jets are traditional methods for auxiliary punching of fragile materials such as ceramics,however,the equipment used is large and complex.When processing fragile materials such as ceramics,the equipment using ultrasonic vibration with a hole amplitude converter is simpler and smaller than the traditional equipment using laser and water jet.Ultrasonic machining has been paid more attention recently.In this paper,a uniform ultrasonic horn with an inner cylindrical hole or an inner cone hole is proposed to do the punching work.Based on the analytical method,the frequency equations and performance parameters expressions of the two types of horns are derived,and the influences of different geometrical sizes on performance parameters are analyzed.The finite element method is used to calculate the distributions of stress and vibration displacement along the axial direction of the two horns at their resonant frequencies.The results show that the amplification factor of the apertured horn is greater than that of the solid uniform rods under the same area coefficient and the same resonant frequency;and the amplification factor of the horn with tapered hole is smaller than that of the horn with cylindrical hole,but the stress distribution of the former is smoother and its maximum value is less.