压力机传动机构可靠性分析与设计

发布时间：2018-01-16 05:06

本文关键词：压力机传动机构可靠性分析与设计　出处：《西华大学》2015年硕士论文　论文类型：学位论文

【摘要】：机械式压力机是成形领域中应用较为广泛的锻压设备,其在性能上能够很好的满足锻压工艺的要求。而多杆机构作为该类压力机的主传动系统,其运动与动力学性能的好坏直接关系到产品成形质量,因此,对压力机传动机构的设计至关重要。在压力机传动机构的设计中,传统方法在确定性范围对机构的运动与动力性能进行讨论和设计。但机构系统中的不确定性是固有的,这些不确定性因素对机构的性能具有极大的影响。为此,本文以双动压力机连杆机构为对象,开展该压力机传动机构运动学分析、概率建模、可靠性分析与设计,其具体内容如下:1、传动机构的运动学分析。建立了双动压力机连杆机构的运动学解析方程,完成了机构位移、速度、加速度的解析求解,为机构的可靠性分析与稳健性设计奠定基础。2、传动机构的概率建模与可靠性分析。考虑机构构件尺寸公差,以机构滑块位移波动量在允许波动量范围内建立其极限状态方程,进而建立了双动压力机连杆机构的可靠性分析模型。采用泰勒级数线性化极限状态方程,由此导出滑块位移的均值和方差,进而采用一次二阶矩法获得机构运动的可靠度。3、传动机构的可靠性设计。以机构运动失效概率最小为目标函数建立了双动压力机连杆机构的可靠性优化设计模型。由于考虑了机构构件尺寸的随机性,则将机构的确定性优化综合中的约束函数也处理成随机函数,并采用一次二阶矩方法求解约束条件的可靠度。数值实例表明,机构的可靠性综合能够有效减小滑块位移波动量,并且能够明显提高机构运动的可靠度。4、传动机构的稳健性设计。在压力机运动学和可靠性分析的基础上,考虑设计变量的不确定对机构性能的影响,建立机构的可靠性稳健性设计模型。数值实例表明,稳健性设计能够有效的控制连杆机构输出位移波动量的均值和标准差,降低了不确定性因素对输出位移波动量的干扰,提高了机构的可靠性,也同时提高了压力机的整机性能。
[Abstract]:Mechanical press is a kind of forging equipment which is widely used in forming field. It can meet the requirements of forging process well in performance, and multi-bar mechanism is the main transmission system of this kind of press. The quality of its motion and dynamics is directly related to the forming quality of the product. Therefore, it is very important for the design of the transmission mechanism of the press, and in the design of the transmission mechanism of the press. The traditional method discusses and designs the kinematic and dynamic performance of the mechanism in the deterministic range, but the uncertainties in the mechanism system are inherent, and these uncertainties have a great impact on the performance of the mechanism. In this paper, the kinematics analysis, probabilistic modeling, reliability analysis and design of the driving mechanism of the double-acting press are carried out. The specific contents are as follows: 1. Kinematics analysis of the transmission mechanism. The kinematics analysis equation of the linkage mechanism of the double action press is established, and the analytical solution of the displacement, velocity and acceleration of the mechanism is completed. It lays a foundation for reliability analysis and robust design of mechanism. 2. Probabilistic modeling and reliability analysis of transmission mechanism. The limit state equation of the mechanism slider displacement fluctuation is established within the allowable fluctuation range, and the reliability analysis model of the linkage mechanism of the double-action press is established. The limit state equation is linearized by Taylor series. The mean and variance of the displacement of the slider are derived, and the reliability of the mechanism is obtained by using the first-order second-order moment method. Reliability design of transmission mechanism. Taking the minimum failure probability of mechanism as objective function, the reliability optimization design model of linkage mechanism of double-action press is established. The randomness of component size of mechanism is considered. Then the constraint function in the deterministic optimization synthesis of the mechanism is also treated as a random function, and the reliability of the constraint condition is solved by the first-order second-moment method. The reliability synthesis of the mechanism can effectively reduce the displacement fluctuation of the slider, and can obviously improve the reliability of the mechanism movement. 4, and the robust design of the transmission mechanism, on the basis of kinematics and reliability analysis of the press. Considering the effect of uncertainty of design variables on mechanism performance, the reliability robust design model of mechanism is established. The robust design can effectively control the mean and standard deviation of the output displacement fluctuation of the linkage mechanism, reduce the disturbance of the uncertainty factors to the output displacement fluctuation, and improve the reliability of the mechanism. At the same time, the performance of the press is improved.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG315

【相似文献】