推式割草机机盘拉深成形规律分析与模具设计

Analysis on forming laws and die design for the machine plate of pushed mower

针对推式割草机机盘拉深成形工艺,采用数值模拟方法,分析了机盘拉深成形过程中的金属流动规律,预测了出现的问题和缺陷。对整个拉深过程缺陷产生原因的力学特征进行了分析,采用修正凹模圆角和布置分段拉延筋等措施,改进了成形工艺及模具参数,确定了零件的拉深成形工艺为：拉延筋高度1-5段取5mm、6-9段取3mm,压边力为150kN,并设计了割草机机盘拉深模具,最后通过拉深试验,生产出合格拉深件。该拉深件无裂纹,起皱区域控制在凸缘区域,且最大减薄率小于25%。

For the drawing of the machine plate,the law of metal flow in the process of drawing was analyzed by numerical simulation,and the potential problems and defects were predicted. Then,the analysis on the mechanical characteristics of the defects was carried out through the entire drawing process by amending die radius and arranging segmented drawbead. Furthermore,the processing and the die parameters were improved,and the drawing technology parameters of the parts were determined with the height of the drawbeads 5 mm from 1 to 5 segments and 3 mm from 6 to 9 segments,blank holder force 150 kN. Therefore,the drawing dies of pushed mower machine plate were designed. Finally,the qualified drawing parts were manufactured by drawing tests without crack and with wrinkling area controlled within the flange area,and the maximum thinning rate is less than 25%.