Design And Research Of Large-size Rectangular Ultrasonic Plastic Welding Tool System With Typical Phononic Crystal Structure

Ultrasonic soldering is an important technology in the field of high-power ultrasound,which is widely used in plastic soldering engineering.The core components of the ultrasonic plastic soldering system are transducers,horns and tools.For large-sized plastic welds,they are usually soldered by large-sized tools.Rectangular tools are commonly large-size tools.In practical engineering applications,lateral vibration of the large-sized rectangular tool will seriously cause the displacement of the tool's radiation surface uneven.Phononic crystal materials are periodically arranged by two or more different materials(including matrix material and scattering material),and they can suppress vibration.In order to improve the working efficiency of the large-size rectangular ultrasonic plastic soldering system,this paper uses periodic slotted structure quasi to suppress the lateral vibration of the large-sized rectangular tool.The periodic slotted structure is called quasi phononic crystal structure in this paper.Ideal phononic crystal structure material has an infinite number of periods,but quasi phononic crystal material has a finite number of periods.In this paper,the lateral vibration band gap of large-size rectangular tool which has quasi phononic crystal structure is simulated.In addition,the influence of the scatterer's size on the lateral vibration band gap is also obtained.At the same time,the magnitude and uniformity of the tool's radiation surface displacement before and after slotting is compared.The research shows that by reasonably designing the structure and size of the quasi phononic crystal,the lateral vibration of the large-sized rectangular tool can be effectively suppressed,and the displacement of the tool's radiation surface can be more even.After research,several important conclusions have been obtained as following:(1)The lateral vibration band gap exists in the phononic crystal structure,which can effectively suppress the lateral vibration of the large-sized rectangular tool and improve the quality of the soldering system.(2)The radiation surface displacement of the large-sized tool slotted periodically is more uniform compared to the tool without the periodic structure.(3)The change of the scatterer's size has influence on the long tool ultrasonic plastic soldering system.The increase of the width will cause the start and stop frequency of the lateral vibration band gap decrease and reduce the longitudinal resonance frequency of the soldering system.The displacement of the radiation surface of the tool will be reduced with the increase of the width about the scatterer.But the change of height has little effect on the vibration performance and parameters of the soldering system.In summary,the large-sized rectangular tool slotted periodically(which is called phononic crystal structure)can optimize the soldering quality.