Reverse Engineering and NC Cutting Path Planning of an Impeller Prototype

• Main Authors: Chao-Chih Huang, 黃照智
• Other Authors: Jinn-Jong Sheu
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/88387416929236462528

碩士 === 國立高雄應用科技大學 === 模具工程系碩士班 === 96 === In this thesis, techniques of reverse engineering (RE) and cutting path planning were proposed to reproduce a prototype of centrifugal impeller. The efficiencies of different coordinate measurement and surface constructing methods were compared to find a better way of the reproduction. Machining times and precision of the reproduced part were studied to verify the accuracy and feasibility of the proposed RE and cutting path planning techniques. First, a coordinate measurement machine (CMM) with the rotational degree of freedom was adopted to obtain the geometrical coordinate points of prototype. Second, feature curves and surfaces were built to give the hub and a basic leaf of impeller. Finally, the built surfaces were trimmed and mirrored to form a closed 3D solid CAD model. The cutting path simulations and NC machining were done to validate the proposed NC path planning. In this research, advantages of the rotational symmetric characteristics of the impeller were utilized to enhance the coordinate measurement of prototype surfaces. The proposed processes of the coordinate measurement and the surface rebuilding were compared with that of the traditional way. It shows that the consuming time of the measurement and surface rebuilding processes can be shortened from 9 to 7 hours using the proposed methods. The accuracy of the reproduced part can be improved using different cutting paths planned according to the surface features of the impeller. Measurements showed the range of the surface errors was 0.028mm to 0.074m. The results of the cutting tests had validated the feasibility of the proposed techniques.