4G6系列气缸体生产工艺的改进

Improvement of the Production Technology of 4G6 Series Cylinder Block

介绍了4G6系列气缸体的铸件结构及技术要求,详细阐述了该缸体的生产工艺:采用HWS静压造型线造型,侧卧底注式浇注系统水平浇注,内浇道设在曲轴箱底部法兰边缘。为消除生产过程中产生的气孔及砂眼缺陷,采取了以下措施:增大直浇道2的截面积,缩短浇注时间;在型腔内局部存在气孔的位置增加或增大排气针,同时在铸件顶面增设排气冒口和排气针,将型腔内的气体引到型腔外;降低树脂加入量,增加型砂透气性;浇注温度提高至1 440~1 470℃;在缸筒芯冷芯盒模具上适当布置7处射嘴,增加射砂面积,改善固化质量;降低回用砂温度。通过采取上述措施,气孔缺陷稳定在5%以内,砂眼缺陷控制在4%左右。

The structure and technical requirements of 4G6 cylinder block casting were introduced. The production process of the cylinder block was described in detail. HWS static molding line was used in molding. The casting was laying aside and poured from bottom. The inner runner was located at the flange edge of the bottom of the crankcase. In order to eliminate the pores and trachoma defects in production process, the following measures were taken ：The cross-sectional area was increased on vertical sprue 2 and the pouring time was shortened. Exhaust pins were added or increased in section area at the air holes position on cavity. At the same time in the top of the castings additional exhaust riser and exhaust needle were added in order to lead the air out of cavity. The amount of resin was decreased to increase sand permeability. Pouring temperature was increased to 1 440-1 470℃. In the cold core box on cylinder die,seven nozzles were set appropriately to increase the sand shot area and improve the curing quality. The temperature of reused sand was reduced. By adopting the above measures, the porosity defects were stabilized within 5% and the trachoma defects were controlled at around 4%.