Measurement and Evaluation of the Stiffness Characteristics of Precision Spring Tubes in Hydraulic Servovalves

Abstract

The spring tube is the core component of the hydraulic servo valve, and its stiffness characteristics determine the sensitivity of the servo valve. For the difficulty in measuring and ensuring the stiffness of spring tube in complex structures, based on the principle of structural characteristics and stiffness measurement, an effective method for measuring and evaluating the stiffness of spring tube was proposed. Firstly, by the force analysis of the spring tube in the valve structure, using improved stiffness measurement theory, an equivalent measurement model of single-arm is established. Secondly, the stiffness measurement system of the spring tube is constructed based on this model. Furthermore, using the deformation and the spatial position recurrence method, the accuracy of the measurement system is further improved. Thirdly, using the orthogonal test method and linear optimization method of the Neural network model, the stiffness characteristics of the spring tube under the influence of different factors are studied further. Finally, the validity of the models is verified by using the software COMSOL and the experimental platform. The stability of the effective stiffness for the spring tube is further analyzed by the measurement data. The contribution and novelty of this paper are that based on the force analysis of the spring tube in the servo valve internal structure, an effective and systematic stiffness measurement and evaluation method are proposed. On this basis, experiments and stiffness characteristics analysis are carried out. Furthermore, several structural factors affecting the stiffness characteristics of spring tube are considered, and the stiffness characteristics of spring tube are systematically studied and analyzed. Based on this research and analysis, the systematic study of measurement and characteristics of precision components is very important for practical complex systems in this field. This makes it possible to further study the measurement of precision components which are difficult to measure in the actual structure. It is instructive to study the characteristics of precision components in complex structures.