Study on 3-D Computer Aided Design for the small bore directed-injection engine combustion system

摘要

Computer-Aided Design is used to carry out 3-D (three dimensions) design for diesel engine combustion system. The diesel engine combustion system is designed and each part is modeled in Pro/E. Pro/E is a solid modeler and this offers considerable advantage for solid model creation. Normally, the geometry is first sketched in 2-D and then extruded in the third direction to generate a 3-D model. In Pro/E, it is important to first create the base geometry. The base geometry is that captures the design intent of the part to be modeled. This base geometry can be created using either the EXTRUDE or the REVOLVE options. Once this base geometry has been created, additional features like holes, rounds, chamfers, fillets, ribs, etc can be added in the finishing stages of the part creation. The center of the bowl does not coincide with the center of the cylinder due to the presence of valve pockets. The obvious advantage of this configuration is that is gives the true geometry of the piston and the connecting rod ports can be accommodated when the piston is at the top dead center. Further, the simulation mesh is built and the final piston structure is got. The results between original combustion system and the modified combustion system is analyzed. The results indicate the modified combustion system can fulfill Euro-4 instead of original Euro-3 standard and the 3-D model can carry out optimization design for a high-pressure common rail diesel engine.