某厂用于制造汽车离合器支承环的成形机,采用的固定切断刀如图1所示,最大设计切断线径为(?)5mm,但在实际工作中切断(?)4mm制件时,刀具寿命少则几件,多则三、四千件,沿图示双点划线方向断裂,且断口均呈早期断裂状,以致该机床引进三年多来一直未能正常使用。笔者从分析刀具受力着手,找出刀具早期断裂的原因,进而提出改变刀具结构、材料的方案。 A factory for the manufacture of automobile clutch support ring forming machine, the use of fixed cutting knife shown in Figure 1, the maximum design cut off diameter (?) 5mm, but in the actual work cut (?) 4mm parts, the tool Life expectancy is as few as several, as many as three or four thousand, along the dotted line along the direction of fracture, and fracture were early rupture, so that the introduction of the machine for more than three years has been unable to normal use. I analyze the force from the tool to find out the reasons for the early rupture of the tool, then proposed to change the tool structure, materials program.