针对充液拉深新工艺对设备的控制精度和操作灵活性的要求,对充液拉深控制系统的结构、压力控制和用户编程等关键问题进行了全面地研究。充液拉深控制系统采用了"高性能PLC+大屏幕触摸屏"的结构形式,以使加工过程可视化并支持用户编程技术。设计了压力闭环控制系统并采取了分段积分的控制算法,以解决电磁比例溢流阀单独使用时压力调节存在静差的问题。以高性能PLC为控制器,采用结构化编程和人机界面技术开发了支持用户编程的柔性控制系统,以满足新工艺对设备操作灵活性的要求。采用上述技术研制的多台充液拉深设备已投入实际生产。实践结果表明:设备压力控制的稳态精度和调节时间均满足要求,且用户可根据新工艺要求,灵活地设定手动调试操作和自动加工流程。
Aiming at control precision and operation flexibility of sheet hydroforming by deep drawing, the construction of hydrodynamic deep drawing control system and its key techniques were fully investigated, such as pressure control and user programming. The control system adopted the structure of high performance PLC + big screen touch screen to make the process visualization and support user programming.The closed loop pressure control system was designed and subsection integral control algorithm was adopted to reduce the static error of pressure control system with electromagnetic proportional relief valve. A flexible control system was developed with user programmable functions to meet operation flexibility of the new technology, which used structured programming and HMI techniques based on PLC. Many sets of hydrodynamic deep drawing equipment developed by above techniques have put in actual production. Technological experiments show that steady accuracy and dynamic response time of the pressure control system can all meet the demands, and according to request of the new process manual operation and automatic process can be flexibly set by user.