Control And System Calibration Of The Precision Press-fit Assembly Device For Miniature Components

In recent years, with the development of national defense, precision assembly for miniature components becomes hotspot. The component pressed in this paper plays an important role in the electro-hydraulic servo valve. The size of the component is in millimeter level, and it requires high precision assembly. At present, the miniature components are still assembled manually. The quality conformity cannot be ensured, the precision and the rate of assembly success is very low. So this paper does certain research in order to solve these problems and promote the development of automatic assembly.Firstly, the research on press-fit system was reviewed and technologies about the precision assembly of miniature components were summarized. Based on the precision press-fit assembly device along with the structure of the miniature components, analysis the overall function for the press-fit device, compiles the control software. Then the alignment of the components was completed using machine vision technology. After finishing the development of press control and displacement control strategy, the control software and a friendly human-computer interface were realized based on LabVIEW programs.Secondly, according to the requirement of the parallelism between the planes, the perpendicularity between the straight edge and the height dimension, the influence of the factors on the precision of the components were analyzed in many ways and the calibration parameters of the automatic press-fit assembly device were determined.Finally, each modular of the precision press-fit assembly device was calibrated including straightness of four guide posts, the pixels of CCDs, the relative position of the upper and lower CCD, the precision of the pressure sensor and the grating ruler, the baseline for the press-fit and the deformation of the fixture. According to the results of the press-fit experiments, the feasibility of the control system for the precision press-fit assembly device was verified and suggestions for improvement were put forward.