磨床参数调整对杯型挺杆母线平行度的影响

Effects of Grinder Parameter Adjustment on Bus Parallelism of the Cuppy Tapper

杯型、薄壁的气门挺杆外圆直径两端母线的平行度容易超差。这是因为,这类杯型挺杆材料采用低碳钢,渗碳淬火,而且其壁很薄,很容易由于挤压力发生弹性变形。在磨削区内被挤压变形,出来磨削区后又回弹。由于其结构为一端敞口,一端为底面,就出现一端尺寸大、另一端小的现象,造成外圆直径两端母线的平行度超差。在精磨挺杆外圆时,为保证平行度的公差要求,应当采用高精度的无心外圆磨床,而且,磨削时挺杆的中心高应比计算值略高些,导轮在垂直面内的倾斜角和导轮修整器在水平面内的回转角都要稍小些。

Bus parallelism along the external diameter may be easily beyond the limit in the cup - typed, thin wall valve tappet because the tappet is made of low carbon steel through quenching and carburizing and get distortion easily after suffering from spring force. The piston is structured of one - open end and one - closed bottom, the phenomena occurs that one side gets large but other side gets small which may cause error parallelism. To meet de demands of parallelism, the centerless grinder with high precision should be used to carry out the external financing grinding of the tappet. It is to ensure to make the center height of tappet larger than the calculated value and the tilt angle of the guiding wheel in the vertical plane and the rotation angle of the dresser in the horizontal plane should be smaller.