现生产缸盖进气道与座圈错位问题的分析与改进

Analysis and Solution for Misalignment of Cylinder Intake Port and Valve Seat

为了解决现生产汽油机缸盖座圈与进气道喉口的错位问题,提高产品的一致性,一方面加强供应商的过程控制及模具定位精度调整,另一方面利用三维模型设计软件Pro/E Wildfire 3.0对原始气道进行重新设计,在气道喉口处增加加工余量,通过机械加工把毛坯的余量去掉,从而保证座圈与气道口不再发生错位问题。更改后的气道与原始气道分别通过三维流体动力学软件AVL-fire稳态模拟计算和气道试验台试验结果对比,更改后的气道流量系数与原始方案相当,滚流比有所提升。通过台架性能对比试验验证满足发动机性能要求。

In order to solve the problem of vertical orientation between valve seat and intake port throat of the gasoline engine and also insure that the series products have a same performance. There are two ways to control this problem. One is to improve the casting process and let our suppliers to control precision of machining moulds. The other one is to redesign the intake port with the Pro/E Wildfire 3.0 soft, increasing the material allowance to the intake port inner surface. This allowance is cut off in process of machining the semifinished product to enable that the valve seat and intake port have a good location. The former intake port is compared with the redesigned intake port with the AVL -fire simulation software and tested in the bench test. The results indicate that the flow co- efficient of the new port is equivalent to the plans and that the tumble ratio of the new port increases. The performance test on test bench is verified to meet the demand for engine performance.