车用曲轴弯曲镦锻成形工艺模拟及试验研究

Simulation and experiment study on upset-bending forging process of crankshaft in automobile

对一种车用曲轴的弯曲镦锻成形工艺难点和解决措施进行了研究。采用有限元模拟方法,直观地再现了曲拐镦挤成形过程中的金属流动情况和容易出现的成形缺陷,研究了飞边厚度和过渡圆角大小对曲拐成形质量的影响,优化出飞边预留厚度为8 mm、曲臂顶部过渡圆角为R5 mm、主轴颈部过渡圆角为R3 mm时,能够获得无缺陷的曲拐。以单拐曲轴为研究对象,开展了曲轴弯曲镦锻成形的工艺试验,验证了模拟结果的准确性,最终制备出的单拐曲轴充型饱满,飞边合理,没有出现塌角、折叠等缺陷,质量完全能够满足技术要求。

For the upset-bending forging process of a kind of crankshaft in automobile,the technical difficulties and solutions were discussed.The metal flowing and the forming defects occurred easily during the upsetting-extruding process of crank,which were simulated intuitively by FEM.Moreover,the influences of thickness of flash and the size of fillet on the forming quality of crank were also analyzed.The parameters were optimized by a flash thickness of 8 mm,top fillet of R5 mm and neck fillet of R3 mm,from which the crank without defects could be obtained.Taking the crankshaft with single crank as an object,the experiment of upset-bending forging process of crankshaft was carried on,which verified the accuracy of simulation results.Finally the crankshaft with single crank was qualified with full deformation and reasonable flash,while without collapsing or folding,and all of the technical requirements can be satisfied.