中文摘要：

提出了一种大尺寸长条形超声塑焊开槽焊头的设计方法，并对其进行了实验验证。首先将长条形焊头合理划分为若干单元，从而把结构复杂的开槽焊头的设计转化为结构简单的焊头单元设计；然后将焊头单元和考虑了耦合振动的等截面半波振子比较，利用等效机械阻抗的概念得出了焊头的频率方程；最后利用该方程研究了开槽数、槽宽度以及槽长度等因素对焊头振动特性的影响。按此方法设计加工了几组大尺寸长条形开槽焊头，实验结果表明焊头共振频率的实测值和理论值符合很好。

英文摘要：

A new design method for large cross-section blade-like ultrasonic plastic welding horns with slots is presented, and relative experiments have been done to validate this method. Firstly, the blade-like horns with slots are rationally divided into horn parts, and accordingly the design of horns with complex structure is transformed into the design of horn parts with simple structure. Then by comparing horn parts with half wavelength constant section resonator considering its coupled vibration, the frequency equation of large cross-section blade-like horn with slots is derived based on the idea that the mechanical impedances of horn parts are equivalent to that of half wavelength resonator. Finally, the relations between the number, width or length of slot and the vibrational characteristics of horn are derived from this frequency equation. Several large cross-section blade-like ultrasonic plastic welding horns are machined by this method, and it is shown that the measured resonance frequencies are in good agreement with the calculated results.