Modelling of Dynamic Behavior of Machine Assembly with certain Machining Accuracy for Assembled Parts

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The aim of this research is to establish a modelling methodology of machine products for analyzing the effects of machining shape errors to the accuracy of functional kinematic motion of assembled machine products. Various types of machining errors are classified according to the difference of machine tools and machining modes, and the modelling methods have been developed for modifying parts shape according to the imposed machining errors. A method for simulating dynamic behavior of machine assembly under the various part shape error conditions has been investigated. Particularly an efficient method for rigid body assembly and a sophisticated method for flexible and deformable objects are considered. For the case of rigid body motion, efficient and computationally-robust algorithms are developed for detecting interferences among object, which is fundamentally important for simulating arbitrary motion under unknown shape variations. Any constraints can be imposed among rigid objects to satisfy functional mechanisms of the original products. For the analysis of flexible bodies, a general Finite Element Analysis method is introduced to allow various types of machining and deterioration errors which have critical influences on machine functionality. Models of flexible parts, such as springs, rubber bushes and rollers, are defined for easy generation of complicated products. The developed method has been applied for analyzing the behavior of paper feed and copying mechanism of a copying machine. Some of the unexpected malfunctions of the machine are detected due to the error of the composing parts by this simulation analysis. Further enhancement of the analysis method is necessary for dealing with wide variety of error types.