运用均衡凝固理论设计液压机上横梁底雨淋式浇注系统

Design of Bottom Shower Gating System Using Proportional Solidification Technology at Top Beam of Hydraulic Machine

400 t液压机上横梁,材质HT200,铸件重4 670 kg,主要壁厚55 mm,轮廓尺寸1 818 mm×1 262 mm×730 mm,普通粘土砂手工造型,干型、干芯。运用大孔出流理论设计底雨淋式浇注系统,直浇道直径φ85 mm,位于55/65 mm×52 mm横浇道中间,两侧横浇道上均布12 mm×60 mm、长40 mm底雨淋内浇道共14只。用均衡凝固收缩模数法核算浇注系统当冒口的补缩能力。生产结果表明,铸件没有气孔、夹砂、夹渣、收缩等铸造缺陷,铸件品质稳定。实测浇注时间平均92 s,与计算值偏差1%,工艺出品率94%。生产实践证明,采用大孔出流理论设计浇注系统,用均衡凝固收缩模数法校核浇注系统的补缩功能,可以满足铸件充型和补缩要求,具有实用价值。

The top beam of 400 t hydraulic machine is made of HT200, the total weight and main thickness are 4 670 kg and 55 mm respectively. The contour dimensions are 1 818 mm in length, 1 262 mm in width and 730 in height. The dry mould with dry core is made artificially using clay bonded sand, In order to produce the casting, a bottom shower gating system is adopted according to the large orifice discharge theory. A sprue with a size of 85 mm diameter is located at the center of runner with a size of 55/65 mm ×52 mm. The runners at two sides are uniformly distributed on 12 mm × 60 mm. There are 14 bottom shower ingates whose length is 40 mm. Its feeding ability of the gating system was checked though moduli calculation method. The result shows that there are no casting defects, such as shrinkages, blowholes, and slag inclusions and the quality of casting is steady. During the casting process, the measured pouring time is 92 s; which has only 1% deviation from the calculated value.. The overall yield rate is 94 %. It is indicated by the production practice that using large orifice discharge theory and proportional solidification process though moduli calculation method to design the gating systemcan meet the requirements offilling and feeding, Thus it has practical values.