降低发动机正时齿轮室盖废品率的措施

Rejecting Rate Reducing Measures of Cover of the Engine Timing Gear Chamber

分析了正时齿轮室盖产生废品的原因,并采取了相应改进措施,结果显示:(1)改进浇注系统,提高浇注速度,降低入型铁液压力,是解决夹(冲)砂、浇不足、冷隔等缺陷的有效途径;(2)合理增设加强筋和增加局部壁厚以及改进抛丸清理、人工低温时效处理工艺,可以有效解决因铸造应力造成的变形、开裂问题。

The reason causing the timing gear chamber cover rejected was analyzed,and corresponding improving measures were adopted.The result showed：（a）improving gating system to increase filling rate and decrease the pressure of the iron melt entering the mould was the effective way to prevent the defects such as the sand inclusion,miss run,cold shut and so on;（b）properly setting enforcing ribs and increasing local wall thickness,as well as improving shot-blasting and artificial low-temperature aging treating process could effectively avoid the casting stress-caused deformation and cracking.