摘要
微细钻头的几何结构是影响刀具钻削性能和微孔加工质量的关键因素。非共轴螺旋面钻尖由连续的螺旋后刀面组成,相比平面钻尖能有效的提高刀具的刃磨效率及其钻削性能。针对非共轴螺旋面钻尖,推导后刀面形成过程中螺旋运动发生线的位置方程,建立了基于砂轮和钻头接触线的后刀面数学模型。根据六轴数控工具磨床的运动原理,提出非共轴螺旋后刀面五轴联动刃磨方法。分析砂轮与螺旋槽之间的相对运动关系,提出微细钻头螺旋槽的数控加工方法。进行非共轴螺旋后刀面微钻的刃磨试验,验证了该刃磨方法的可行性。进而采用制备出的具有相同几何结构参数的平面、锥面和非共轴螺旋面微细钻头进行不锈钢钻削试验,结果表明非共轴螺旋面和锥面微钻的钻削力、后刀面磨损明显小于平面微钻,并且非共轴螺旋后刀面微钻的横刃磨损程度小于平面和锥面微钻。研究证实了所提出的五轴联动刃磨方法可以有效地制备出较高钻削性能的非共轴螺旋后刀面微细钻头。
Drill point geometry is a most significant element for drilling performance and micro-hole quality. Non-coaxial helical drill point is characterized by a continuous helical flank surface, and its special geometry contributes to a better grinding efficiency and a superior drilling performance. The position equation of generating line of helical surface is obtained, and the mathematical model of contact line between helical drill flank and wheel is proposed. According to the motion of 6-axis CNC tool grinder, a 5-axis coordinated grinding method of helical drill flank is presented. Based on the relative motion of drill flute and wheel, a CNC grinding process of micro-drill flute is proposed. Then this grinding method is validated by fabricating the helical micro-drill. For the planar, conical and helical micro-drills with the same geometry parameters, the drilling experiments on austenitic stainless steel are conducted, and the drilling force and tool wear are measured and analyzed. The results show that the thrust force and flank wear of helical, conical drill point are smaller than that of planar drill point, and the chisel edge wear of helical drill point is smaller than that of planar, conical drill point. It is confirmed that the proposed grinding method is effective to fabricate the helical micro-drill with good drilling performance.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2018年第19期204-211,共8页
Journal of Mechanical Engineering
基金
国家自然科学基金(51575049)
国家重点基础研究发展计划(973计划,2015CB059900)资助项目
关键词
刃磨方法
微细钻头
非共轴螺旋后刀面
钻削性能
grinding method
micro drill
non-coaxial helical flank
drilling performance
