基于PLC的卷板机液压同步控制

Hydraulic synchronous control on bending machine based on PLC

针对原卷板机开环控制系统的性能不稳定、卷板精度不足的缺陷,现卷板机采用了基于PLC的液压同步闭环控制改造。改造过程中,尽量采用成熟技术。改造后的硬件组成为液压同步驱动设备、SIEMENS公司的S7-300和SMART 1000IE等,液压系统主油缸的工作压力为19.5 MPa,上辊加压力10500 k N。研究结果表明,改造后的卷板机实现了弯曲过程的数字控制,弯曲过程自动补偿,同步控制精度达到或小于±0.5 mm,能够自由地设定端部预弯直边长度,连续弯曲无后角。控制系统性能稳定,安全便捷。

For the issue that the open-loop control system of the original version of bending machine is neither stable nor precise enough, the new version was improved with a hydraulic synchronous dosed-loop control system based on the technique of PLC. The mature technology was applied during the modified process. The modified hardware was composed of hydraulic synchronous driver devices, $7 - 300 and SMART 1000IE produced by SIEMENS and so on. The working pressure of the main hydraulic cylinder was 19. 5 MPa. The dynamic pres- sure of the upper roll was 10500 kN. It is found that the modified bending machine can realize digital control and automatic compensation in the bending process. The precision of the synchronization control can achieve or less than ＋ 0. 5 mm. The machine can set the length of the preflex straight flange at the end. Also, it can flex materials continuously without a relief angle. Therefore, the new controlling system is stable, safe and convenient.