【作者】 宋现锋；

【导师】 邵明； 屈盛官；

【作者基本信息】 华南理工大学 ， 机械设计及理论， 2010， 硕士

【摘要】 气门—气门座圈摩擦副是发动机配气机构中的关键摩擦副之一,由于工作环境恶劣,气门座圈易发生磨损失效,对增压程度越来越高的大功率发动机来说,这种磨损失效更加严重。本文拟在选用高铬铸铁材料成分配方的基础上,设计和研制气门座圈离心铸造试验装置,制定相应的金属型离心铸造技术工艺路线,研制出具有高致密组织、高性能的气门座圈毛坯,以满足396系列柴油机的使用要求,实现高性能气门座圈国产化的目的。本文设计和研制了适合高铬铸铁气门座圈的金属型离心铸造试验装置,该装置采用悬臂式和托辊式相结合的铸型安装型式,并在铸型设计过程中考虑到排气和小口径浇铸等因素,在铸型上设计了排气孔、喇叭口形状的前挡圈等。试验结果表明,该装置转动平稳、变速范围大,铸件质量和成品率符合设计要求。本文对高铬铸铁气门座圈离心铸造工艺进行了研究。涂料配方:锆英粉(ZrO2,-320目)、钙基膨润土和水分别为2kg、0.5kg和2000ml;涂料涂敷温度120℃-150℃、涂料涂敷厚度为1mm;浇注时铸型转速1600r/min、铸型温度270℃-300℃;金属液浇铸温度:1460℃-1480℃、浇铸速率1kg/s,浇铸完成30秒后打开冷却水冷却150-180秒后停机出型。本文在对国外气门座圈分析的基础之上,确定了高铬铸铁气门座圈用材料成分范围,制订了炉料配方,对离心铸造气门座圈进行了金相组织观察和力学性能分析。检测结果表明,气门座圈离心铸造毛坯组织和力学性能达到了396柴油机的工作要求。本文在SRV-Ⅳ摩擦磨损试验机上对气门座圈材料的磨损特性进行了研究,探讨了温度和载荷对磨损特性的影响,实验结果表明,气门座圈材料的磨损特性满足了大功率发动机的装机要求。更多还原

【Abstract】 Valve-valve seat friction pair is one of the most important frictional pairs in the engine, because of the severe working condition, the valve seat is easy be worn out. The wear-out failure becomes worse as the increasing high power engine’s compression ratio. This paper designed and developed centrifugal casting experimental device of valve seat, and formulated the corresponding metal mold centrifugal casting process route based on the selection of high chromium cast iron valve seat material composition and formula, developed a high-density tissue and high-performance valve seat blank to meet the using requirements of 396 series diesel engine, achieved the purposes of high performance valve seat’s localization.This paper designed and developed a metal mold centrifugal casting valve seat experimental device. The device used a combination mold installation type of cantilevered and the roller-type. Centrifugal cast valve seat is a small caliber blank pipe, We design the gas vent and the bell-shaped front ring in the mold design process with the consideration of exhaust and small-caliber cast and so on. The results show that the machine has a smooth rotation, variable speed rang, and the casting has a good quality and yield.High-chromium cast iron valve seat centrifugal casting process was studied in this paper. The coating formulation: Zircon flour, Ca-bentonite and water were 2kg, 0.5kg and 2000ml. The speed of the mold is1600r/min, the temperature of the mold is 270℃-300℃, pouring temperature of the liquid metal is 1460℃-1480℃, casting rate: 1kg/s, we open the cooling water 30 seconds after casting completed for 150-180 seconds.This paper identified the high chromium cast iron valve seat material composition range and developed the charging formula based on the analysis of the foreign vavle seat. We also observed the microstructure and mechanical properties of the centrifugal casting valve seat, which meet the working requirements of the 396 diesel engine.We also studied the wear characteristic of the valve seat used the SRV-Ⅳwear testing machine, discussed the effects of temperature and load to the wear characteristic.The results show that, the wear resistance of the valve seat meets the requirements of high power engines.更多还原