Research On Model Analysis With Stiffness And Conversion Of Relevant Measuring Mode Of Spring-Tube

Precise elastic parts are widely used as sensitive parts to gain feedback signals in the control devices such as electro-hydraulic servo valve or the navigation system such as flexible gyro in the field of astronavigation, navigation and aviation. Their stiffness parameters are directly correlated with the performance of corresponding system. Therefore, not only has a rather high standard been set for their dimensional precision and geometrical precision of them, but also certain demands are made against theirs stiffness characteristics. Due to their complicated geometry, along with machining errors and changes of materials characteristic, it is impossible to gain the accurate values of the stiffness by calculation. At present, measuring is the only way to assure the stiffness requirement in production. With the improvement of manufacturing level and development of aerospace technology, higher accuracy and efficiency in measurement are demanded. Therefore, studies on the stiffness measurement of sophisticated elastic elements, is of great importance in enhancing strength of national defense.Firstly, the design and development of stiffness surveying instruments which includes mechanical part and circuit section is described in detail. Integrating with the definition and classification of stiffness, the stiffness measuring principle of spring-tube, feedback-rod is expounded in detail.Secondly, the design and development of stiffness surveying instruments which includes mechanical part and circuit section is described in detail. The mechanical part which is supporter of sensors includes workbench and all kinds of fixtures. Dependable clamping ensures high accuracy of repetition of the system. The circuit section mainly includes secondary instrument circuit amplified of sensor, choose of A/D converter circuit, which amplifies and converts signal. Aiming at this stiffness measuring system, the calibration of sensor and experimental data handling and analysis are introduced in detail.Finally, according to the actual production situation of a factory in Nanjing, the theoretical corresponding relation between angular stiffness of spring-tube and linear displacement of the bulb of craft pole is deduced and revised by means of experimental data. The relation has instructive effect to practical production. According to the experimental data, the thin-wall dimension of spring-tube is reversed, a three-dimensional model is built, and angular stiffness of specific dimension spring-tube is solved by means of finite element analysis.