基于声子晶体的带隙理论以及耦合振动理论, 对大尺寸矩形超声塑料焊接系统的耦合振动性能以及横向振动抑制进行研究。通过设计不同尺寸的散射体，改变散射体空气层的尺寸，得到系统的纵向共振频率、工具头的横向振动带隙及工具头辐射面位移分布与散射体宽度及高度间的关系。结果表明：通过合理设计类声子晶体结构式工具头中散射体的尺寸，能够使不同工作频率下系统工具头的横向振动得到有效抑制，同时使焊接工具辐射面纵向振动位移增大且均匀，保证了焊接系统的高效运行。

Based on the band gap theory of phononic crystals and coupled vibration theory, the coupling vibration and lateral vibration suppression of large-size rectangular ultrasonic plastic welding systems were investigated.By designing different size scatterers, the relationship between the transverse vibration band gap of the tool, the longitudinal resonance frequency of the tool, and the displacement of the radiating surface of the tool and the width and height of the scatterer were obtained.The results show that by reasonably designing the size of the scatterers in the tool of a typical phononic crystal structure, the transverse vibration of the tool in the welding system can be effectively suppressed at different working frequencies, and at the same time, the longitudinal vibration displacement of the welding tool surface increases and tends to homogenize, ensure the welding system works efficiently.