The Parameterized Design Of The Valve Groove Structure And Its Morphological Researches On Stress And Deformation

Valve is one of the important parts of engine valve train, which has great effects on the performance and service life of engine. With the development of engine technology, the precision design of the valve structures was required by the dynamics characteristics of the engine valve train. The structural design of valve plate is significant because its structure has great effects on the thermal stress and cylinder compression ratio of the engine. In the thesis, the effects of the structure parameters of valve plate on its stress and deformation have been investigated based on the finite element method.In the thesis, the structure of the valve was introduced and the failure forms caused by the valve plate structure, valve materials and processing technology were reviewed. Meanwhile, the software platform of finite element, which was applied to the analysis of the stress and deformation of the valve groove were discussed.In order to facilitate analysis, the identification figure of structure characteristics of valve plate was established based on the structure feature of the valve plate, and the parameterized groove valve structure has been realized using ANSYS second development tool APDL and nested technology of VC++. On this basis, the coupling hot-stress analysis of valve was analyzed, and the influence of the valve groove structure on the stress and deformation of the valve groove and the transition arc part were discussed. The results show that:the influence of the valve groove structure on its stress and deformation was great. For example, when analyzing the influence of the valve groove to its maximum stress, it was discovered that the maximum stress was related to the radius of the valve groove R, and they present non-linear relation; the impact of the groove chord length L and arc height H on it maximum stress was interactive, which revealed that the stress level will be improved by the optimization design of the valve groove structure.The parameterized model of the valve groove was established using VC++ to encapsulate APDL, thus the design parameter can be input to the parameterized interface to establish the finite element model of the valve, which avoided the information lose in the process of constructing and analyzing of valve model and promoted the efficiency of optimization design and the reliability.Because of research about the influence of the valve groove structure on its stress and deformation was based on the engineering practice. Therefore, the results of research can be directly apply in the plate structure design of the valve, and provide theory basis for reducing the total weight of the valve and lowering its fatigue life.