超声振动辅助微塑性成形系统设计与开发

Design and Development of Ultrasonic Assisted Micro Forming System

针对微塑性成形工艺过程对位移、力等参数精确控制的要求,分析了超声振动辅助成形系统的设计要点,提出了关键设计参数。超声振动辅助微塑性成形系统由机床本体系统、超声振动系统和伺服控制系统等主要单元组成。机床本体设计参考四柱液压机结构形式,采用两端固支梁和压杆的简化模型,计算得到主要结构尺寸,并用ABAQUS验证其刚度。通过选用匹配的超声发生器和换能器,满足成形过程中的超声振动要求,利用理想变截面杆纵振波动方程设计变幅杆结构,并用ABAQUS进行变幅杆模态分析,确保设计振幅满足要求。伺服控制系统采用可编程多轴控制器PMAC卡控制伺服电机,通过光栅尺和力传感器反馈实现高精度的位置及成形压力控制。通过测试证明在纯铜压缩试验中叠加超声振动,成形压力显著降低,成形精度达到4μm。

Key parameters of the ultrasonic vibration assisted forming system are analyzed according to the requirements of micro forming process. The ultrasonic vibration assisted forming system consists of the mechanical structure,ultrasonic vibration unit and the servo control subsystem, etc. The fixed end beam and the compression bar are adopted to design the mechanical structure with reference to the four-column press structure for simplification. The structural dimensions are calculated and its rigidity is verified with ABAQUS. Ultrasonic generator and ultrasonic transducer are assembled for ultrasonic vibration system to achieve the required vibration during the forming process. The booster is designed using longitudinal vibration wave function for variable cross-section bar,which are verified by FEM simulation. The programmable multi-axis controller （PMAC） is utilized as the servo motor controller,and grating scale and force transducer are enrolled in the closed loop control system to realize accurate position and pressing force control. A reduction of forming force is confirmed and the forming accuracy is proved to be below 4 μm in the pure copper compression test by using the developed ultrasonic vibration assisted forming system.