Research Of Assembly Technology And Technique Process Optimization Of Engine Cylinder Head

With the incessant progress of science and technology, modern engine is developing in the direction of high speed, high density, high power, low energy, small size and lightweight. Engine cylinder head is one of the most complex structures of all engine accessories. In addition, it also has high precision and complicated technology. Its machining quality and precision directly influence the whole performance of the engine.The deformation of the engine is much larger than allowed in the manufacturing process. It influences engine cylinder head quality or even produces waste product.The author carrys out the research on this problem. Firstly the author optimizes the assembly technology of the seat ring, then does multivariate optimization of technique process of milling and drilling. Ultimately achieve the purpose of decreasing the deformation caused by the seat ring assembly technology and technique process.Firstly, the author studies structure technique of the engine cylinder head and analyses assembly technology of the seat ring. They laid the foundation for assembly technology optimization and finite element analysis of the seat ring. Do deep analysis of engine cylinder head technique in order to lay the foundation for multivariate optimization. Summarize reasons for engine cylinder head deformation and put forward the approach to decrease the deformation of engine cylinder head.Secondly, work over on the optimization of seat ring assembly technology. Seat rings are assembled by the principle of expansion and contraction. Engine cylinder head deformation caused by the seat ring assembly process is the main factor which influences the assembly quality. Analyze engine cylinder head deformation when the seat ring is being pressed into the engine cylinder head using finite element analysis then optimizes the assembly technology of the seat ring on the basis of the engine cylinder head deformation.Gain the A-C-E-B-D-F assembly scheme which can achieve the smallest engine cylinder head deformation.This assembly scheme not only makes the whole cylinder head deformation the smallest of all but also makes the centre deformation and endpoints deformation the smallest. The conclusion achieves the purpose of decreasing the engine cylinder head deformation effectively. The scheme is feasible at the same time. It can be used in practice and establish the foundation for the further analysis of other factors which influence the engine cylinder head deformation.Thirdly, develop cutting force calculation software which can realize function of calculating milling force and drilling force according to cutting force empirical model. Analyze the largest deformation of engine cylinder head on the basis of cutting force. We draw a conclusion from the simulation results that the cylinder head deformation conforms to reality that is the largest deformation produces in the centre of engine cylinder head in actual production and the largest deformation is 0.5mm after machining process. Based on this, optimize cutting parameters in order to decrease deformation caused by cutting force. After verification optimized cutting parameters not only can make the most metal removal rate but also can decrease cutting force effectively. Therefore, reach the target of decreasing cylinder head deformation caused by cutting force.Finally, do multivariate optimization of technique process of milling top surface and bottom surface and drilling the seat ring holes. Study on the cylinder head deformation under the action of one single factor namely clamping scheme. Impose clamping force calculated on cylinder head according to the three schemes. By comparing cylinder head deformation under the three schemes, the author gains the best clamping scheme that is when we elect vertical angle position as imposing clamping force position, we can obtain the smallest cylinder head deformation. Then do comprehensive research on location mode and clamping force which influence cylinder head deformation using orthogonal test.By analyzing the largest deformation of cylinder head under nine schemes which includes three factors and three levels the author achieves the best technique scheme that is electing vertical angle position as imposing clamping force position, the clamping force is 6400 Newton and impose full restriction on the bottom surface.Through computer simulation the author gains the largest deformation under this scheme and verifies this scheme is the best scheme to make cylinder head deformation the smallest of all. Therefore attain the expected research purpose and provide technical support for the bottleneck problem that is the deformation of the engine is much larger than allowed or even produces waste cylinder head in the manufacturing process.