Abstract: :Focusing on the impact of each component of microwave oven on the clearance and gap in the assembly process. Assembly constraints and dimensional tolerances are applied to the components according to the drawings, the three-dimensional tolerances analysis mode is established in CETOL. In the basis of setting the target value of the clearance and gap of the model. The critical dimension impacting the clearance and gap were founded through sensitivity and contribution value analysis. The reasonable optimization of critical dimensional tolerances is putting forward according to the actual manufacturing process level, thus solve the assembly problem of excessive clearance and gap in product and improve the assembly accuracy.

Key words: Microwave oven, Tolerance analysis, Clearance, Gap, Contribution