EA211轴承壳体的生产方法

Production Methods of EA211 Bearing Housing

介绍了涡轮增压器轴承壳体的铸件结构的特殊性及技术要求，针对原工艺的工艺出品率低的问题，对铸造工艺进行改进：采用KOYO线水平浇注，一型8件；采用树脂砂与湿型砂相结合的造型方法，整个铸件在树脂砂芯壳内，浇注系统和冒口为湿型砂；对砂芯、芯头设置排气道，同时外壳也贴排气片，使型腔内的气体及时排出；加大定位芯头面积和深度，对芯头的间隙进行了调整，油路芯将定位槽改为定位芯头。工艺改进后使铸件的出品率提高了154％，铸件的成品率由50％～60％稳定在95％以上。通过采用倒包孕育方法及过程控制，使铸件的金相组织符台技术要求。

The particularity and technical requirements of turbocharger bearing housing casting structure was introduced.According to the low final products rate of original process,the casting production was improved as follows. Horizontal casting was used on KOYO production line. It's one type and eight pieces. Resin sand and wet sand were mixed to molding. The whole casting was inside the sand core-shell. Gating system and riser were wet sand. In order to discharge the cavity gas in time,exhaust tract was set on the sand core and core head. Exhaust sheets were also set on the shell. The positioning of the core head area and depth were increased. The tolerance of core head was adjusted and the positioning groove on oil core was changed to locate core head. After the casting process improvements,production rate increased by 15.4 percent. Finished castings rate increased from 50%~60% to 95%. By using ladle to ladle inoculation control methods and processes,the microstructure of the casting meet the technical requirements.