多孔矩形六面体超声变幅器设计与仿真分析

Design and simulation for a porous rectangular block ultrasonic horn

矩形六面体超声变幅器具有丰富的谐振频率有利于实现工件的辅助超声振动,但需要对矩形六面体结构进行优化设计,通过在矩形六面体内设置圆柱形孔使其振动特性满足工件辅助超声振动的要求。采用表观弹性法设计矩形六面体辐射面的基本尺寸,利用有限元法研究圆柱形孔高度、数量和直径对矩形六面体超声谐振特性和辐射面振幅的影响规律。结果表明,在尺寸为137.3×121.2×40 mm的矩形六面体中均匀分布9×9个直径为7 mm的竖直圆柱形通孔时,工作频率为20 kHz,在辐射面中心区域可获得均匀的Z向位移,适合负载工件实现辅助的垂直超声振动。

It is useful to use a rectangular block ultrasonic horn to realize auxiliary ultrasonic vibration of a workpiece,because the horn has abundant harmonic frequencies.But the structure of the horn should be designed and optimized with distributed cylindrical holes inside to make its coupled vibration characteristics meet the requirements of the auxiliary ultrasonic vibration of the workpiece.The apparent elasticity method was adopted to design the basic sizes of the rectangular block’s radiant surface.The FE method was used to study the influence of height,number and diameter of cylindrical holes on the ultrasonic vibration characteristics of the rectangular block horn and the vibration amplitude of the radiant surface.It was shown that the designed size of the block horn is 137.3 ×121.2 ×40mm,inside it the cylindrical holes are evenly and vertically distributed with the number of 9×9 and the diameter of 7 mm;the working frequency of the horn reaches 20 kHz and the uniform vibration amplitude in Z-direction at the central area of the radiant surface can be gained,it is suitable for the auxiliary ultrasonic vibration of the workpiece.