【作者】 臧贻娟；

【导师】 刘延俊；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2006， 硕士

【摘要】 随着现代汽车工业、电子技术、以及国防工业的发展，国内市场对冲压设备尤其是高速冲压设备的需求越来越大。目前国内高速冲压设备所用液压系统几乎全部采用进口，其成本高，不适应我国国情，所以开发适合我国现状的高速冲床液压系统成为目前研究的一个重要课题。本论文开发研制的数控高速冲床液压系统采用比例伺服控制，结构简单、冲压频率高、安全可靠。 针对系统工作要求，本文首先提出了高速冲床液压系统三种设计方案，并进行相互比较，确定出最优方案。然后对该液压系统所用液压元件进行设计或选用，其中主要介绍了执行元件液压缸的设计。系统方案确定且基本液压元件设计完成后对该液压系统进行了动态特性研究，以了解系统动态参数变化。在此基础上本文对液压系统进行了数学建模，首先建立各个元件的子模型然后按照系统拓扑关系图合成整个液压大系统数学模型，按照系统的工作特点，将工作过程分为差动下降、冲压、快速返回三个阶段来进行建模。同样还是按照这三个不同的工作阶段对系统进行了仿真分析，得出了系统工作过程中各参数变量(位移、压力、速度)随时间的变化曲线，并对曲线进行了分析，针对系统中的问题提出了改进措施。最后本论文将PID控制算法加入到系统中，采用积分分离PID控制方法对本液压系统进行了仿真分析，结果显示加入PID控制方法后系统稳定性得到了提高，具有良好的工作性能。 系统的仿真结果表明，系统冲程12mm，冲载板厚1mm时，其冲压周期0.2s每分钟能冲压300次，此时最大冲压力为200KN，满足设计要求，且系统冲击小，工作平稳，可以转化成产品，直接投入市场，从而改变我国高速冲压设备依赖进口的局面。更多还原

【Abstract】 With the development of automobile industry, electronic technology and defence industry, more and more pressing machines especially high speed punches are demanded in domestic market. At present, the hydraulic system of high speed punch nearly adopts import completely, and it does not meet the national conditions of our country because of the high cost, so it is an important task to develop hydraulic system of the high speed punch which suits the present situation of our country. In the paper, a kind of numerical control high speed punch hydraulic system is designed. It has the characters of simple structure, high stepping frequency, and safety.In the paper, firstly, three design scheme of high speed punch hydraulic system are put forward and they are compared each other, then the optimum scheme is chosen. Secondly, the paper introduces not only the design and selection of the hydraulic elements, but also the design of the hydraulic cylinder importantly. In order to know the change of the dynamic parameters, we must study the dynamic characteristics of this hydraulic system. Based on this, the paper establishes the mathematical mode of the hi-speed punch hydraulic system. Sub-models of each element are established, then they are merged into a big system mathematical model according to the picture of topological relation. According to the work characteristic of the system, the working process is divided into three phases as falling differential motion, punching, returning fleetly, and we establish the mathematical models of these three phases. These three work phases are simulated and analyzed, and we gain several curves that the parameter variables changed with time. These curves are analyzed and put forward improved measure aiming at the problem of the system. At last, the paper joins PID control algorithm into the system, and adopts integral apart PID algorithm to control the system, then analyzes the simulation results. The stability of this system is improved after joins PID control method, and the system has good operating characteristic.The simulation results showed that the punch cycle is 0.2s and it can punch 300 times per minute and the biggest punching force is 200KN, when the thickness of punched steel plate is 1mm, and the stroke is 12mm. The system has smaller impact, working stabilization, and can satisfy design specification. This hydraulic system can make into the product and be launched into market, so the situation that the hi-speed punch in our county depended on importation will be changed.更多还原