| The engine is the most important part of car.With the development of modern technology,there is higher and higher requirement of engine performance.Engine sealing performance is the main influential factor of the overall performance.However,because the researchers focused on the study of engine performance in terms of power and energy consumption,few people to deeply study of its sealing performance.So,the engine sealing performance of research and development is relatively slow,which has seriously hampered the whole engine performance improvement.Taking Dongan 513 gasoline engine as an example,this paper conducts an in-depth study on its sealing performance based on relevant domestic and foreign materials,which mainly includes the following parts:(1)The model of engine cylinder head and block is obtained by combining reverse engineering with forward modeling.Firstly,the point cloud data of engine cylinder head and cylinder block were obtained through Handyscan 3D laser scanning system,and the accurate point cloud data of watercourse and airway were obtained by filling with silica gel.Then,the point cloud data is imported into Geomagic Studio,which is a professional point cloud data preprocessing software.Next,the processed point cloud data was imported into CATIA V5 for model reconstruction and error detection.In order to improve work efficiency and model quality in the reverse process,the forward/reverse method is used for reconstruct the model.That is to say,forward design with reverse engineering technique is used in combination to get high precision of the model.Last,the 3d modeling software SolidWorks is used to carry out forward modeling operation for engine cylinder gasket and bolt.And then,assemble the engine cylinder head,cylinder block,cylinder gasket and bolt,finally obtains the engine assembly model.(2)The professional finite element analysis software ANSYS Workbench was used to analyze the static field of Dongan 513 engine.The material nonlinearity was considered in the analysis process.And then,the analysis results were compared with the surface pressure test to verify the accuracy of the model and the necessity of considering nonlinearity.The analysis method of simplified cylinder gasket was put forward by observing the data of analysis results,and the feasibility of the new method was verified.(3)The embossing structure of the engine cylinder gasket was optimized to improve the sealing performance of the engine assembly structure under steady state.In the research process,in order to effectively reduce the production cost and reduce the research and development cycle.And the finite element analysis software was proposed to simulate the compression-rebound experiment process,and the feasibility of the method was verified.(4)There-physical and two-way coupling of Dongan 513 engine is studied by finite element method.Through ANSYS Workbench software,carries on the fluid field,the transient temperature field and transient structure field three two-way coupling research,according to the cooling liquid velocity vector diagram,the body temperature distribution in the cloud,the whole machine stress nephogram and so on,to study the thermal stress and mechanical load on the engine sealing performance,the influence of and adjustment according to the results of the coupling field analysis of bolt pre-tightening force size and distribution,so as to realize the purpose of increase engine sealing performance.The key technology of engine sealing performance is studied,the simulation analysis of there-physical and two-way coupling of engine is completed effectively.Found and solved the sealing defects in engine combination structure.The study not only provide guidance for engine design and development,but also provide a new method of thinking for engine coupling field research. |
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