经扩隅预成形的从动曲齿锥齿轮精密成形试验研究

Experimental research on precision forming of driven spiral bevel gear preformed by enlarging die corner

提出了一种采用“外闭-内开”式模具,从环形坯料起步,先扩隅预成形再终成形的分步成形工艺。以一种齿数为25、大端模数为9(齿宽L为40 mm)的从动曲齿锥齿轮为研究对象,借助Deform-3D软件进行数值模拟研究,探索预成形模具的扩隅长度l及扩隅高度h对填充效果及终成形力的影响。结果表明,l的合理范围为13~17 mm、h的合理范围为3~4 mm,获得相同填充效果时,分步成形的终成形力降低14.3%。表明采用适当参数的扩隅预成形,可以使从动曲齿锥齿轮轮齿小端角隅较容易填充,同时能较大幅度降低终成形力;模具作用/运动方向与变形金属表面夹角较大或近似正交的情况下,扩隅空间也有分流和储备金属作用,可为其它锻件的模具设计提供借鉴。采用物理模拟试验对模拟结果进行验证,结果表明所获齿轮齿形填充饱满、轮廓清晰。

A step-by-step forming process was proposed with“outside closed-inside opened”molds,starting from a ring blank,first expanding and preforming,and then finally forming.A kind of driven spiral bevel gear with teeth of 25,modulus of 9(the tooth width L of 40 mm),was taken as the research object,the influence of corner length l and expansion height h on filling effect and final forming force was explored by numerical simulation using Deform-3D software.The results show that the reasonable range of l is 13-17 mm,the reasonable range of h is 3-4 mm,and for the same filling effect,the final forming force of the step-by-step forming is reduced by 14.3%,which indicates that the small end corner of the driven spiral bevel gear can be filled easily preformed by enlarging die corner with appropriate parameters,and the final forming force can be greatly reduced.When the angle between the action/motion direction of the die and the deformed metal surface is large or approximately orthogonal,the expanding corner space also has the function of diverting and storing metal,which can be used for reference in mold design of other forgings.The simulation results were verified by the physical simulation tests.The results show that the obtained driven spiral bevel gear is full filling with clear outline.