锻造液压机锻件变形量精准补偿控制研究

Forging Dimension Accurate-exact Control of Forging Hydraulic Press

锻造液压机锻件变形量是通过液压缸位移来间接推算,忽略了机架变形等因素的影响,造成锻件变形量描述不准确。针对这一问题,提出一种对锻件变形量的二次补偿控制算法。分析锻造液压机机架变形等因素对锻件尺寸精度的影响,利用拉格朗日函数建立锻造液压机机架变形的弹性动力学模型,通过几何分析计算得到机架变形量、实际锻件尺寸、传感器测量尺寸之间的数学函数关系,基于机架变形量提出一次补偿控制。在此基础上,结合锻造液压机工作过程中主缸压力变化的工况,分析不同升压速率对锻件变形量的影响,并将其引入,进行二次补偿控制。基于0.6MN锻造液压机试验台,通过对比采用补偿控制算法前后的试验,分析基于机架变形量和由升压速率引起变形量的补偿控制对锻件变形量精准控制的效果,验证锻件变形量补偿控制算法的有效性。试验结果表明,锻件变形量补偿控制算法有效克服了机架变形及主缸压力变化对锻件变形量影响,实现了锻件变形量直接控制,提高了锻件尺寸精度,为实现锻件变形量精准控制提供了一种新方法。

At present,the forging dimension of the hydraulic press is indirectly calculating without considering the factor of frame deformation and so on,which causes the forging dimension is not accurate-exact.A novel compensation algorithm of forging deformation precise control is proposed to address the issues.Firstly,the influence of the deformations of the forging hydraulic press frame on the accuracy of the forging dimension is analyzed,we investigate the effect between the deformations of the forging hydraulic press frame and the accuracy of the forgings dimension,and the elastic-dynamics model of the frame is established using Lagrange Function.Then,through further geometrical analysis,the functional relation of frame deformation,actual forging dimension,and sensor measurement has been derived and the once compensation control has been present.Combined with the pressure change of the forging main cylinder,we investigate the influence of the different main cylinder pressure changes on forging deformation is further obtained.Then,the twice compensation control is introduced into the accurate-exact control.For proving the proposed compensation control methods based on press frame deformation and pressure-change deformation,the comparative experiments of before and after using compensation control algorithm are conducted on 0.6 MN forging hydraulic press to analyze the effect on the forging dimension accuracy.The results of comparative experiments indicate that the proposed twice compensation controller overcome the effect of the forging deformation,and realize the directly the forging dimension control.It improves the forging dimension accuracy,which provides a novel method for forgings dimension accurate-exact control.