基于圆弧砂轮的环面蜗轮滚刀顶后角面磨削方法

Generating method of top relief surface of an toroidal worm wheel hob by an arc grinding wheel

环面蜗轮滚刀的齿顶设计出一定宽度的顶刃带可提高滚刀的使用寿命,目前生产中多采用手工加工的方式获得顶后角面,导致各刀齿的顶刃带宽和顶后角难以保证。为了实现环面蜗轮滚刀顶后角面的数控加工,文中提出由圆弧砂轮磨削顶后角面的方法。使前刀面绕滚刀轴线旋转获得前刀面的旋转映射曲面,使其与齿顶环面相交构建出顶刃带线。为保证磨削出的顶刃带线形状的正确性,采用截形圆半径与滚刀齿顶环面半径相同的圆弧砂轮磨削顶后角面。基于四轴联动环面蜗杆磨床,建立顶后角面磨削运动模型,并基于VERICUT软件实现各刀齿顶后角面的仿真加工。算例分析结果表明,磨削出的顶后角面的顶刃带宽度与设计值相符,且获得的顶后角大小在11.0°~12.1°之间。

In order to improve the service life of the toroidal worm wheel hob,top land surfaces with a certain width are designed for the tooth top of the hob.At present,manual processing is mostly used in production to obtain the top relief surface,which makes it difficult to guarantee the top land width and top relief angle of each tooth.In order to realize the NC machining of the top relief surface of the toroidal worm hob,this paper proposes a method of grinding the top relief surface by an arc grinding wheel.The rake face is rotated around the hob axis to obtain the rotation mapping surface of the rake face,which intersects with the tooth top torus to construct the top land line.In order to ensure the correctness of the shape of the top land line,the arc grinding wheel whose section circle radius is equal with the radius of the hob’s top torus is used to grind the relief surface.Based on the four-axis linkage toroidal worm grinding machine,the grinding motion model of the top relief surface is established.The simulation machining of the top relief surface of each tooth is carried out by the VERICUT software.The results of example analysis show that the top land width is consistent with the design value,and the size of the top relief angle is between 11.0°and 12.1°.