圆盘机的注塑过程中的锁模、射料、熔胶、开模、圆盘快慢速等各个动作,对速度、压力的要求都不一样,它们由控制面板上的比例值设定,如:P1设定关模压、P2设定射料一次压、P3设定射料二次压、P4设定进料压。当圆盘机的流量压力需求发生变化时,由设在油泵出口的比例阀(溢流阀)来调节负载压力和流量,将多余的油高压溢流回油箱。
单色圆盘机只有一台主机,主要向系统提供压力,完成射胶熔胶动作及锁模开模动作,另外控制一个转盘系统,完成模具的移动与定位。
双色机既有主机、副机之分。它们主要由加热、射胶、熔胶系统、锁模系统组成。三色机则与双色机类似,它有一台主机,两台副机组成。主机负责圆盘的旋转及定位。
圆盘机工作时分手动运行和自动运行两部分。
手动运行时,操作人员必须提供相应的命令,圆盘机才会完成相应的动作。如射胶、熔胶、上模、下模、圆盘旋转等动作。
自动运行时,各模位选用完成,进料量压力、时间都设定完成且料管温度加热已到达后,将主机油泵启动,将手动、自动开锁切换至自动位置,按一次自动启动按键即可进行自动步骤。
1) 如果现在模位有使用,按自动启动键后,进料量为这模设定量。若进料未达设定量,而有锁模的动作。只允许快速锁模动作,等进料到达设定量后才有慢速锁模动作。锁模停止后,执行射料、开模动作。
2) 若现在模位不使用,按自动启动键,则圆盘运行往下一有使用的模位,且进料的进料量到达,也以下一有使用的模位之设定量执行进料动作,转盘定位后,快速锁模(用时间设定),计时止,且进料时到达,执行慢速锁模,锁模停止后执行射料、开模动作。
3) 主副机同时使用时,须等主、副机自动动作皆完成至开模止,圆盘才运行并旋转至下一使用模位。
4) 转盘暂停在圆盘“慢速点”前动作时,圆盘即在“慢速点”检出时,慢速至定位停止。若该模位有使用,定位后,这模动作会做锁模等动作至开模为止。转盘即不动作,但进料动作,会执行下一使用模次的进料,将转盘暂停解除(顺时针旋转)圆盘即往下一模位移动。如果这模位未使用,则圆盘即在最近一模执行定位,直到解除转盘暂停,方往下一模移动。
5) 在自动运行中,将自动状态切回手动状态,除圆盘会执行慢速定位的动作外(圆盘在运行中作此切换)其他动作及时停止。可用手动操作复位。controlled variable reverts to the sub-set value, thus, the influence of disturbance on the master controlled variable is reduced. That is, the sub-loop recovery to the disturbance coarse adjustment, the main loop to the disturbance fine adjustment. Therefore, the cascade control can quickly overcome the influence of the disturbance entering the secondary loop. Quantitative Analysis: According to the Cascade Control System Block Diagram, the sub-loop transfer function is Gy (s) GP2(s) , whereas the sub-loop transfer function in a single loop control system is Gy (s) GP2(s) ; therefore, the transfer function of the disturbance channel of the subloop is: The transfer function of the disturbance of the subloop in the single loop control system is y 2(s)/F 2(s) = GP2(s) ; The equivalent disturbance entering the secondary loop in a cascade control system is the same as the disturbance entering the secondary loop in a single loop control system, the residual error of the control system is the residual error of the single loop control system. Therefore, the cascade control system can overcome the disturbance of the secondary loop and reduce the residual error greatly. 2. Cascade Control System can cascade control, master control and sub-control, the master control mode is to cut off the sub-loop, the master controlled variable as the controlled variable single loop control, the sub-control mode is to cut off the main loop, single-loop control with auxiliary controlled variable as controlled variable. Therefore, in the running process of cascade control system, if some parts failure, it can be flexible to switch; reduce the impact on the production process. Finally, after more than two years of operation, the system meets the requirements of continuous stability and high precision of blast furnace coal injection. The PLC control system and computer network system of converter in steel-making plant are introduced. Key words: Frequency Converter PLC WINCC coaxial cable, fast Ethernet, fiber redundant ring 1 system