EA211曲轴动平衡的改善方法

Method to Improve Dynamic Balance of EA211 Crankshaft

介绍了曲轴的动平衡原理、EA211曲轴的生产及加工工艺,分析了曲轴动平衡的影响因素,并采取了相应的改进措施:(1)将钻中心孔位置参数由仅对X轴方向补偿-0.3^+0.3 mm改为同时对X轴和Y轴方向进行补偿;(2)保证每个成品箱内的曲轴为同一模具编号,上线时将同一模具编号的曲轴集中加工,避免各模具编号的曲轴频繁切换;(3)将模具结构改为整体的空心型板,在固定框上方放置一块平板,模样直接通过螺栓固定在平板表面,并用可以沿轴向活动的销子使模样定位,消除模样加热膨胀对螺栓的应力;(4)型壳涂上热熔胶后,使用专用的粘接板将其压紧,保证型壳粘接过程中保持平直状态。工艺改进后,曲轴的动平衡合格率由89.05%提高到99%以上。

The dynamic balance principle of the crankshaft,casting production process and machining process of EA211 crankshaft were introduced.The factors influencing dynamic balance of crankshaft were analyzed,and corresponding improving measures were adopted:(1)Changing the drilling center position compensating parameters from originally compensating only for X-axis direction by-0.3-+0.3 mm to simultaneously for X-axis and Y-a xis.(2)Guarantee that the crankshafts in the finish products box having the same pattern number,and machine the crankshafts together from the same pattern number by putting them together onto the machining line to prevent crankshafts from various pattern numbers to be changed frequently.(3)Change the pattern construction into integral hollow pattern plate,put a flat on the top of the fixing frame,the patterns directly fixed on the surface of the flat by bolts and locate the patterns with pins which could move along axial direction to eliminate the stress of bolts caused by heat expansion of the patterns.(4)After mold shell had been brushed with melt adhesive,compressed it tightly with special bonding plate to ensure the mold shell keeping straightness.After process improvement,the dynamic balance qualification rate of the crankshaft was elevated from 89.05%to higher than 99%.