可调频悬臂梁式动力吸振器多频减振研究

Study on Multi-frequency Vibration Reduction of Cantilever Type Dynamic Vibration Absorbers with Tunable Resonant Frequency

手持打磨工具振动大,存在多个振动峰,且不同工况振动峰对应的频率不同。动力吸振器是控制窄带振动峰的有效方法,传统的“弹簧—质量”形式动力吸振器频率不易调节,且不能同时对多个频率进行动力吸振。为适应实际工程应用,以频率可调、可多频减振为目标,首先从结构阻抗角度阐述动力吸振器减振原理,然后设计一种适用于手持打磨工具的频率可调悬臂梁式动力吸振器,推导悬臂梁等效刚度阐述频率调节方法,该结构可方便地布置多重动力吸振器。最后结合仿真分析与实验测试对悬臂梁式动力吸振器的实用性进行验证,证明频率可调并取得良好的多频减振效果。

The hand-held grinding tools have several vibration peaks with large amplitude,and the frequency of the vibration peaks are various under different working conditions.Using dynamic vibration absorbers is an effective method to attenuate narrow frequency band vibration.However,the resonant frequency of traditional“spring-mass”dynamic vibration absorber is not tunable,and it can’t absorb the vibrations with several different frequencies simultaneously.In this paper,the vibration reduction principle of dynamic vibration absorbers was described based on the impedance analysis.Then,a cantilever type dynamic vibration absorber with tunable resonant frequency was designed for hand-held grinding tools.And the frequency adjustment method was described based on the stiffness of the cantilever beam.The structure could hold multiple dynamic vibration absorbers conveniently.Finally,the practicability of cantilever type dynamic vibration absorbers was verified through simulation analysis and experiment,the frequency tunability was proved,and the effect of the multi-frequency vibration reduction was achieved.