单自由度八连杆机构运动学分析与优化研究

发布时间：2018-03-28 02:19

本文选题：八连杆机构　切入点：类型综合　出处：《扬州大学》2013年硕士论文

【摘要】：随着冲压行业的飞速发展,冲压工艺的要求越来越高,机床的更新换代也越来越快。传统机械压力机的主传动机构主要采用曲柄连杆机构。曲柄连杆机构在冲压工作时,由于滑块的加速度大而引起的噪声和振动,降低了机床和模具的使用精度。因此,需要寻找到新型的传动机构代替曲柄连杆机构。本文提出一种采用单自由度八连杆机构替代曲柄滑块机构的新型机构,并分析了其运动特性,同时对单自由度八连杆机构进行优化设计,全文的工作内容如下： 1)通过对单自由度八连杆机构的运动链进行类型综合,将得到所有的八连杆机构运动链类型进行拓扑特性的计算、比较、分析,从而选择适合构型。 2)对单自由度八连杆机构构型建立直角坐标系并进行运动学分析,运用解析法分析各个杆件的角位移、角速度、角加速度；得到压力机滑块的位移、速度、加速度；通过运动仿真软件获得滑块的运动轨迹,并与曲柄连杆机构的运动轨迹进行对比分析,得到八连杆机构的优势所在。在运动学的分析的基础上进行动力学分析,得到各个杆件质心处的位移、速度、加速度,运用动态静力分析法求得杆件的惯性力和惯性力矩,最终建立了拉格朗日的动力学模型,为下面的研究提供理论基础。 3)利用动力学仿真软件ADAMS建立与实际传动机构等比例的单自由度八连杆机构的运动学仿真模型。通过参数化设计方法,以降低杆件质心处加速度为目标对连杆机构进行优化设计,从而获得较小的惯性力和惯性力矩。 4)根据优化所得到的数据,运用三维设计软件对单自由度八连杆机构的各个杆件零件重新设计,并且将其装配模型导入到ADAMS中,再次进行运动学和动力学仿真。得到优化后滑块的运动轨迹和部分杆件质心的加速度曲线图。通过降低加速度的大小,也就降低机构杆件在工作时的惯性力以及惯性力矩的大小,从而达到优化的目的。
[Abstract]:With the rapid development of stamping industry, the requirements of stamping technology are becoming higher and higher, and the replacement of machine tools is becoming faster and faster. The main transmission mechanism of traditional mechanical press mainly adopts crank and connecting rod mechanism. The noise and vibration caused by the acceleration of the slider reduce the accuracy of the machine tool and die. It is necessary to find a new transmission mechanism to replace the crank linkage mechanism. In this paper, a new type of mechanism is proposed to replace the crank slider mechanism with a single degree of freedom eight linkage mechanism, and its motion characteristics are analyzed. At the same time, the optimization design of the single-degree-of-freedom eight-bar mechanism is carried out. The work of this paper is as follows:. 1) by synthesizing the kinematic chain of the single-degree-of-freedom eight-bar linkage mechanism, the topological characteristics of all the kinematic chain types of the eight-bar linkage mechanism are calculated, compared and analyzed, and the suitable configuration is selected. 2) establishing the right-angle coordinate system for the configuration of the single-degree-of-freedom eight-bar linkage mechanism and analyzing the kinematics, using the analytical method to analyze the angular displacement, angular velocity and angular acceleration of each member, and to obtain the displacement, velocity and acceleration of the slide block of the press. The motion trajectory of the slider is obtained by the motion simulation software, and compared with that of the crank linkage, the advantage of the eight-bar mechanism is obtained. The dynamic analysis is carried out on the basis of kinematics analysis. The displacement, velocity and acceleration of the center of mass of each member are obtained, and the inertia force and inertia moment of the member are obtained by using dynamic static analysis method. Finally, the Lagrange dynamic model is established, which provides the theoretical basis for the following research. 3) using the dynamic simulation software ADAMS to establish the kinematics simulation model of the single-degree-of-freedom eight-bar mechanism with equal proportion to the actual transmission mechanism. With the aim of reducing the acceleration at the center of mass of the rod, the linkage mechanism is optimized and the inertial force and moment of inertia are obtained. 4) according to the data obtained from the optimization, three dimensional design software is used to redesign each member part of the single-degree-of-freedom eight-bar mechanism, and the assembly model is imported into ADAMS. The kinematics and dynamics simulation is carried out again. The trajectory of the optimized slider and the acceleration curve of the center of mass of some members are obtained. By reducing the acceleration, It also reduces the inertia force and the inertia moment of the mechanism member in operation, so as to achieve the purpose of optimization.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TH112

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