| In recent decades, with the development of aerospace engineering and modern machine building industry, there has been increasing demand for synchronous drive technology. Among them, hydraulic control system of synchronous, with the advantage of high precision, fast response, and great anti-load rigidity, has attracted widespread attention. The synchronous hydraulic control technology now has been intensively used in the load device of large-scale structural links. As a kind of hydraulic components of synchronous control, synchronous valve has simple structure, low cost, easy manufacturing, reliability and many other advantages. However, the problem of overlarge volume and inconvenient assembly of our domestic Synchronous valve has not been well addressed. Most designers rely on the experience to carry out the feasibility project, which fail to achieve the automatic decision-making and optimization. These issues, to some extent, have restricted the scope of application of domestic synchronous valve. Therefore, it is of great theoretical and engineering significance to start study on how to reduce the volume of domestic synchronous valve as well as ensuring its performance liability.This paper mainly studies the piston synchronization valve. The purpose of the research is to analysis and improve the structure and size of existing synchronous valve and try to reduce its size on the premise of performance. This paper takes the theoretical analysis as a breakthrough point. With the analysis of the structural characteristics of synchronous valve and thorough understanding of its working principle, I first established a mathematical model to analyze its static and dynamic characteristics theoretically. Then, with the help of the computer simulation software AMESim, I established models of synchronous valve and focused on its static and dynamic performance. Based on this, I further analyzed the main parameters of size and structure which affect its performance, in order to analyze the feasibility of changing one parameter to improve the structure of synchronous valve. After that I established mathematical model of optimal design for these key parameters. But according to the mathematical model, the structural improvement of synchronous valve is a multi-objective optimization problem. So after a careful analysis of the advantages and disadvantages of traditional optimization design and modern design methods, I chose the suitable Genetic algorithm. In order to reduce the errors during the data transmission among softwares, the data was optimized by Genetic algorithm integrated in AMESim. In the circumstances of AMESim I simulated the improved synchronous valve, focusing on its static and dynamic performance. The results showed that the improved synchronous valve remained a stable performance but the pressure loss was larger than the original ones. This was because the fixed orifice and variable orifice were narrowed, which would increase local pressure loss. Thus, the larger pressure loss is inevitable. The improved synchronous valve had changed largely in size and structure. In order to make sure it can meet the practical engineering requirements, strength analysis must be carried out. I simplified synchronous valve in accordance with practical situation and established a model with CATIA, and then analyzed the finite element of synchronous valve with finite element analysis software ANSYS. We can see clearly from the stress diagram that maximum stress of valve body is 380MPa, which took place on the inner hole that has screw thread; maximum stress of the spool is 282MPa ,which took place on the inner wall of variable orifice on spool; maximum stress of the end cover is 70MPa ,which took place on the center of the end cover; maximum stress of bolt is 382MPa . Therefore, the synchronous valve could meet the strength requirements.This research has achieved the major goal, i.e. a synchronous valve with stable performance and coMPact size. In research methods I combined the heoretical analysis with the computer simulation. Under the guidance of theory, I established the physical model of synchronous valve with AMESim, focusing on the relationship among the parts and abandoned the procedure process in traditional research methods. In research ideas I boldly assumed the major factor that determined the size of synchronous valve was performance rather than stress damage. In this premise this paper made large adjustments on radial structure of the synchronous valve. Latter strength analysis showed that the idea was correct.Nowadays, with the rapid scientific and technological development, hydraulic synchronous technology is becoming more and more important. However, the domestic research and development of synchronous valve started relatively late and is still in the stage of immitation. The related theories and technologies are to be further improved, and its application and development remains to be deepened. The main problem that domestic synchronous valve faced with is still over-large volume and unstable performance. It is based on current status quo of domestic synchronous valve that I chose performance analysis and structural studies as the research topic. After more than one year of research, there has been some useful results. But since the study involves wide range of theories and subjects like machinery, materials, fluid, control, advanced manufacturing, and there is a lack of design methods, limited experimental conditions and personal ability, my paper was limited to more in-depth development. However, this study indicates that internal synchronous valve still has much room for improvement. I believe that with the deepening of theoretical research, there will be more and more people who are concerned about the improvement of domestic synchronous valve. With the rapid development of the optimization technology of hydraulic components, the improvement of synchronous valve is just like a new-born baby~no matter how bumpy the road will be, it will continue to thrive.
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