Abstract: This paper puts forward a parametric design method based on sketch assembly and
sketch constraint by taking the parametric modeling of power ultrasonic honing device as an
instance. This method uses the sketch function of UG modeling to conduct geometric constraint
and size constraint on parts’ models so as to , establish the relations between the variable sizes of
multiple parts and assembly sketches in function expressions. It can realize the linkage between
assembly parts by managing the variable sizes in the assembly sketches.

Key words: UG assembly, modeling, parametric design, Ultrasonic honing