基于ADAMS的平底从动件凸轮轮廓曲线设计

Design of Cam Profile Curve of Flat Bottom Follower Based on ADAMS

使用ADAMS软件反转法设计平底从动件凸轮的轮廓曲线时,由于推杆与凸轮的接触点位置不固定,生成的凸轮轮廓线实际为推杆轮廓的包络线,误差较大。为提高设计精度,将推杆轮廓离散化,利用离散后的多个接触点生成多条曲线并取交集运算,得到了较理想的凸轮轮廓曲线,为ADAMS设计平底从动件凸轮提供新的方法。将生成的凸轮机构进行仿真模拟,与设计目标作比较,探讨离散点个数与设计的精度关系。结果表明:使用离散化方法所设计的凸轮,从动件位移最大误差约为0.207 mm,从动件的推程为20 mm,最大误差比例为1%;误差大部分在0.1 mm范围内,整体误差比例为0.5%;增加离散点个数可以提高凸轮设计的精度。

When design the contour curve of flat-bottomed follower cam through the method of ADAMS software inversion,the error range was always large which resulted from the unfixed place of contact point between the push rod and the cam,as the generated cam contour was actually the envelope of the push rod contour.To improve the accuracy of the design,the discretization method was proposed for the push rod contour.By taking intersection operation of the multiple curves generated from discrete contact points,ideal cam contour curve was obtained,which could provide a new method for designing flat-bottomed follower cam in ADAMS.Here,by doing the analogue simulation and comparing performance with the design target of the cam mechanism,this paper discussed the relationship between the number of discrete points and the accuracy of design.The results showed that the cam mechanism designed by using the discretization method,the follower had a maximum displacement error of about 0.207 mm,the follower’s thrust was 20 mm,and the maximum error ratio was 1%;the error was mostly within the range of 0.1 mm,and the overall error ratio was 0.5%;and the accuracy of cam design could be improved by increasing the number of discrete points.