在浇铸图示的铸铁件时,由于头小、脖长、壁薄、喉头小,使芯子排气不良,因此极易产生气孔及呛火缺陷造成大量废品。尽管芯子里留有连通气孔(采用芯子两平面均挖通气槽或用蜡线等方法),但由于铸件结构的限制,通气效果很不理想。现利用铸件头部小横筋中间处要求有M6螺孔,用0.4 Casting cast iron pieces, due to the small head, neck length, wall thin, throat small, the core exhaust poor, so prone to stomatal and choke fire caused a lot of waste. Although there are vents in the core (holes are drilled in the two planes of the core or the method of using wax lines), the ventilation effect is not satisfactory due to the structure of the casting. The use of castings is now required at the middle of the small transverse bar M6 screw hole, with 0.4