基于统计特征的弯板链节距精度计算机仿真

Computer Simulation of the Pitch Precision of Cranked Chains Based on Statistics

利用理论计算和计算机仿真技术 ,根据链条各零件尺寸的不同分布规律建立了特征零件数据库 ;以链长精度为约束条件 ,从零件库随机抽取不同分布规律产生的数据 ,按不同方法模拟装配链条 ;通过不断改变公差 ,求出节距偏差范围 ,同时进行比较分析。结果表明 ,理论概率法偏差值偏小 ,合格品率低 ;理论极值法偏差值偏大 ,易使链长超差 ;计算机仿真方法则可求解出满足优化目标和链长约束条件的最佳节距精度 。

The pitch precision is one of the important conditions to keep the correct meshing of the cranked chains during transmission. Based on the theoretical ana lysis and the computer simulation,the database for the part characteristic dimensions is built up according to the distributions of different parts of the chain. Data are obtained from the database with different size distribution. The imitated chains are assembled in the computer taking the chain length as the constraint condition. The deviation range of the pitch precision is calculated by changing the size tolerance of parts of the chains. It is shown that the discrepancy from the probability method is smaller, and it makes the ratio of eligible chains is lower. The discrepancy from the extremism method is larger, and it makes chains length be easy to over size. The pitch precision, which matches the optimum object and the chain length constraint condition, could be achieved by the si mulation method.The simulation makes the analysis result of the discrepancy of the pitch precision is more scientific and more reasonable.