扩孔钻结构的改进与设计  

Modification and Design of Expanding Drill Structure

作　　者：贾建军[1] 陈晓东[1] 于广伟[1] 于小宁[1] 

机构地区：[1]西安工业大学

出　　处：《工具技术》2015年第8期36-40,共5页Tool Engineering

基　　金：陕西省教育厅专项科研计划资助项目(12JK0671)

摘　　要：在不同切削材料、不同切削参数条件下,为提高扩孔钻的切削性能,其结构需要随之改变。提出由三段相互相切的圆弧构成扩孔钻容屑槽型。根据扩孔钻的切削特点和排屑要求,三段圆弧分别由切削圆弧、卷屑圆弧及容屑圆弧构成;切削圆弧构成的切削刃前角可根据被加工材料与切削参数的不同任意选取,刃瓣宽度根据扩孔钻的外径和强度取值,扩孔钻的芯径依据容屑槽需要的空间大小及扭转强度的要求确定。此结构根据加工材料特性选取所需要的前角、芯径、刃宽等参数,不会改变切削圆弧、卷屑圆弧和容屑圆弧两两相切的槽型设计。与直线切削刃相比,圆弧切削刃轴向力和扭矩低,所提出的结构既可以保证扩孔钻切削刃强度,又有足够的容屑空间,切屑容易卷曲并折断,避免了切屑碰伤已加工表面,且排屑流畅。对改进的扩孔钻结构,应用计算机仿真容易设计出扩孔钻槽铣刀刃形,以方便扩孔钻的设计、检验、制造。For the cutting materials and cutting parameters have changed, the cutting tool structure must be changed with it, so that the cutting performances and cutting mechanisms of tool will be improved, for this, the three-section circu-lar arcs of tangent to each other constitute the chip flute cross section curve of expanding drill be proposed. The three-sec-tion circular arcs consist of cutting edge arc, chip breaker groove arc and chip flute arc according to the requirements of cutting parameters and chip removal. As cutting edge arc that it forms expanding drill rake angle which can be selected at random in different workpiece materials, the numerical value of cutting tool tread be selected according to the expanding drill external diameter, the internal diameter of expanding drill be ensured based on chip space and torsional strength. The improved structure of expanding drill will remain always the three-section circular arcs of tangent to each other when numer-ical number alteration of the expanding drill rake angle, internal diameter, cutting tool tread and so on. Straight cutting edge cannot compare with arc cutting edge in axial force and torsion, so the improved structure not only can ensure the ex-panding drill＆#39; s intensity, but also have adequate chip apace, and the chip can easily curling and breaking to ensure the quality of processing, moreover, fluting cutters for expanding drills are easily designed by the use of computer, the struc-ture improves the efficiency and accuracy in design, inspection, manufacturing for expanding drill.

关 键 词：刀具技术 扩孔钻 容屑槽 排屑 切削刃 

分 类 号：TG713[金属学及工艺—刀具与模具]