导　　师： 谭建平

学科专业： 080202

授予学位： 博士

作　　者： ;

机构地区： 中南大学

摘　　要： 300MN模锻水压机是我国国防建设和基础建设的关键设备,其动梁驱动及速度控制技术是它的关键技术之一。动梁驱动系统流量大,工作框架系统所受载荷巨大、变形大,锻压力不断变化,以及各参数之间耦合关系非常复杂等特点,是一个复杂的机电液耦合系统;当前该水压机无锻压自动化和等温锻压功能,其驱动系统的动态响应特性不明;动梁速度控制系统载荷瞬变、惯性巨大,控制滞后、控制精度低、鲁棒性差。因此,以动梁驱动及速度控制系统为研究对象,围绕其控制机理、动态响应特性、控制策略进行了研究,以提高速度控制精度,为实现模锻自动化、等温锻压或模拟等温锻压提供技术基础。 论文的主要研究内容和结论如下: /(1/)分析国内外巨型模锻水压机动梁速度控制技术及液压系统特性研究的现状和发展趋势,针对控制系统惯性巨大、载荷瞬变、水路长而导致控制滞后、鲁棒性差、控制精度低等特点,基于“油控水”控制方式,采用“液压缸+齿轮齿条机构+凸轮机构+转角位移检测装置”的分配阀芯开启度控制方式,提出了内环采用PID-H/_∞控制凸轮轴转角、外环采用PFC控制动梁速度的双闭环串级控制策略。 /(2/)考虑流体的可压缩性、粘性阻力、泄漏及工作框架系统变形等因素,分空程、锻压和提升三种工况,建立分配阀口、液压管道、液压缸的流量方程,建立动梁和上横梁的动力学方程,建立动梁驱动系统动态模型,进行仿真和试验研究。同时,对锻压行程的动梁速度、位移,工作缸压力,以及分配阀口压力差的动态响应特性进行仿真分析。仿真和试验研究表明,动梁速度等参数在阀芯开启瞬间瞬变载荷的作用下产生振荡,响应时间约0.7秒,控制精度受到影响。 /(3/)分析300MN模锻水压机动梁速度控制系统液压操作控制原理和结构,通过计算和仿真� The 300MN die forging hydraulic press is key equipment of national defence and foundation construction of our country.Its moving beam's drive and control technology is one of its key technology.The flow of the beam's driving system is giant.The load and deformation of working house's system are giant.The forging force is continuously varing.A complex coupling relation exists in all kinds of its parameters.The drive and control system is a complex mechanical-electrical-hydraulic coupling system.There are't automation forging system or isothermal forging system in the hydraulic presses presently.The dynamics response characteristic of the driving system is unknown.Transient load,giant inertance,hysteretic control,low control accurancy and low robustness exist in the moving beam's speed control system.Therefore,this paper studied the speed drive and control system of the hydraulic press,based on its control mechanism,dynamic response characteristic and control strategies,to improve speed control accurancy and supply technical base for realization of die forging automation,isothermal forging or simulation isothermal forging.In this paper,these main research works and conclusions as following: /(1/)Based on analysis of present state and perspectives on the speed control technology of these domestic and foreign giant die forging hydraulic press,and such characteristics as control hysteresis,low robustness and low control accuracy because of giant inertia,transient load,long waterway,'oil control water' control mode was applied.A new control mode of the distributor's spools open gap was applied based on the mode of 'hydraulic cylinder+gear and rack machnism+cam machnism+rotary displacement testing device',to control the flow and direction of the waterway distribution system.A double-closed-loops cascade control strategy was put forward that inner loop was used to control cam shaft angle by PID-H/_∞control and external loop to control moving beam speed by PFC-/(PID-H/_∞/)control. /(2/)Based on coercibility,vi

关 键 词： 模锻水压机 驱动系统 液压系统 动态响应特性 速度控制 预测函数控制

领　　域： [金属学及工艺]