| In recent years, with the rapid development of the astronautics of China, aerospace parts are required not only to have higher precision and stability, but also to be miniature. This causes the high-precision measurement of its key parts is harder.As for one of the key parts of Aerospace vehicles ——miniature cylindrical helicaltorsion springs, Because they are small with poor rigidity, easy to deform, hard to test, the measurement of their characteristics is not easy to satisfy high-precision requirement. So this paper is aimed to develop a good measurement system, reduce the error and ensure the accuracy and liability.According to the characteristics of torsion spring's deformation and load, the dissertation first discusses theory of elastic deformation and focuses on beam's pure bending, which is the basic theory supporting stiffness measurement here.Based on the characteristics of the spring's stiffness test, traditional method can't work. So this paper designs new method and verifies its feasibility by FEA, good results come out, which are the basis of the following research work.The later chapters discuss the process of the new measurement system's development. Traditional fixing method of the spring causes measuring error and it's unallowable for this miniature spring. So the whole measuring instrument is designed systematically and the development of new fixing and positioning devices are focused on. The new fixture method is analyzed by FEA and results are good.The whole stiffness measurement instrument and spring's fixture are completed in this paper, using computer to control the machine and acquire and handle data, with angle positioning and torque loading and stiffness testing automatically. Finally, this measuring system is debugged and used practically. Its accuracy is also calibrated. All the results prove the system's accuracy and repeatability and other features. It comes up to the requirement.
|
PDF Full Text Request