| In this paper,from the dimension formula to the process dimension path diagram to the assembly dimension path diagram,the use of the path diagram to establish the relevant all relevant dimension model to obtain the dimensional tolerance information found that the relevant calculation only considered the dimensional tolerance information,and did not consider the geometric tolerance Information;nor does it consider the accumulation of tolerances.In this way,it is incomplete and incomplete to use the dimensional path diagram to analyze the tolerance.The small displacement screw theory(SDT)is introduced to parameterize the tolerance domain.Whether it is dimensional tolerance information or geometric tolerance information,the effect on the target size can also be considered.Introduce the mathematical transfer model of tolerance screw parameter—homogeneous coordinate matrix transfer model and Jacobian matrix transfer model.At the same time,the mathematical transfer model of deviation in flexible assembly under external factors such as temperature and load is also considered.In this paper,the influence of the relative path of each component path in the size path diagram on the target size FR is determined,so as to calculate the target size tolerance.The dimension path diagram is like a medium,connecting related dimensions together and providing their relationship.Finally,two examples of planar hole system parts processing and assembly are listed,and related models are established.The simulation proves the feasibility of the theory,and also provides a new direction for the study of the size path diagram. |
