利用负压消失模工艺生产机架铸件

Produce The Rack Casts by Using Negative Pressure Lost Foam Process

介绍了机架铸件的铸件结构及技术要求,详细阐述了其工艺设计:采用底注、开放式浇注系统,浇口比为ΣF直:ΣF横:ΣF内=1:1.32:2,其中,直浇道截面尺寸为φ90 mm,横浇道截面尺寸为60 mm×70 mm,共2道,内浇道截面尺寸为25 mm×25 mm,共20道,在铸件关键部位设计一定数量尺寸为70 mm×70 mm的集渣包,浇注温度1 420±10℃,负压度0.4 MPa,保压时间15 min。为防止模样变形,采用竹木条拉筋粘接固定模样簇及消失模易变形的部位,通过设计使用一种中空芯铁填充物,有效降低该缺陷的发生几率。最终生产的铸件各项指标均符合技术要求,废品率由原来的80%降到20%以内,已达到批量生产状态。

The casting structure and technical requirements of racks castings was introduced. Its process design was elaborated as follows：bottom gating open system was used. Gating ratios is ∑Fpouring：∑Frunner：∑Fflow=1：1.32：2. The dimensions of pouring gate, runner gate and flow gate is φ90 mm,60 mm×70 mm and 25 mm×25 mm,respectively. There are 2 pouring gates and runner gates and 20 flow gates. Slag straps in a size of 70 mm×70 mm were used on key position of casting. The pouring temperature was 1 420±10 ℃. The negative pressure is 0.4 MPa and holding for 15 rain. Bamboo Wooden bar reinforcement was adhesively fixed on clusters and easily deformable parts to prevent deformation. A kind of hollow iron fillings was designed to reduce the probability of this defect. As a resuh,the indicators of casting meet the technical requirements and rejection rate drops to less than 20% from 80%. It achieved to a mass production status.