不同类型接触面机械零件装配误差的自动计算方法研究

Automatic calculation method of assembly error of mechanical parts with different contact surfaces

针对目标要素位置误差受不同类型装配方式实际表面接触情况影响的问题,研究了目标要素的装配位置与装配误差和零件几何要素误差的关系,建立了基于真实机器的目标要素位置误差自动计算方法。首先,归纳、总结了装配接触面仅限于最常见的平面和圆柱面的前提下的零件装配方式和接触几何类型的组合形式;然后,介绍了表示真实零件的控制点变动模型,给出了各种装配组合形式下的基于真实装配接触关系的目标要素位置计算算法;最后,编制了基于蒙特卡洛模拟和真实机器装配位置的计算程序,并得到了机器模型中所有公差因子的敏感度列表、贡献率列表,以及目标要素实际位置相对于理想位置的概率分布。研究结果表明:针对第一基准为平面与平面贴合、第二三基准均为平面圆柱面接触的装配类型所提出的实际位置计算方法是正确的。

Aiming at the problem that position error of the target feature was affected by the real contact surfaces in different assembly modes,the relationship between the assembly position of geometric feature with the assembly error and geometric error of the assembling part was studied,and the automatic calculation method of the position error of the geometric feature based on the real machine model was proposed.Firstly,the combination of part assembly method and contact geometry type was summarized under the premise that the assembly contact surface was limited to the most common plane and cylindrical surface.Then,the control point variation model of real parts was introduced,and the algorithms for calculating assembly position of geometric features on the machine model,based on the various combination schemes of the assembly datum and the real assembly contact relationship,were established.Finally,the software for the real assembly position calculation was programed based on the Monte Carlo simulation,the sensitivity list and contribution rate list of all tolerance factors in the machine model and the probability distribution of the real position relative to the ideal position for the target feature were obtained.The experiment results show that the real position calculation method proposed for the assembly type,where the first datum is plane-to-plane bonding and the second and third datum are plane-cylinder surface contact,is correct.