Общий каталог Sumitomo 2018 - 2019 - страница 568

Technical Guidance Basics of Drilling Parts of a Drill Hight of point Leading edge Margin width Back taper Margin Lead Neck Tang Flank Body clearance Taper shank Tang thickness Flute diamerer Drill Chis th La el e wid nd wid dge te th Cutting edge Heel Helix angle Flu ang Point Body clearance Cutting Outer corner Neck le edge angle Rake face Flute length length Shank length Overall length Chisel edge Straight shank Tang thickness Chisel edge corner Depth of Body clearance an ke gle Tang length Ra Chisel edge length Relief angle Diameter of Body clearance B Web thickness A Web thinning Web Cutter sweep A : B or A/B = Flute width ratio Point Angle and Force Min. Requirement Relief Angle Width of Edge Threatment and Cutting Force 8000 6000 Thrust (N) 4000 2000 Point angle (small) Point angle (large) 0 0,2 0,3 0,4 When point angle is large, thrust becomes Feed rate (mm/rev) * Large relief angle is needed at the center of the drill. large but torque becomes small. Web Thickness and Thrust Torque (N . m) 60 Point Angle and Burr Effects of thinning 40 20 Burr height (mm) Thrust Thrust 0 0,2 0,3 0,4 Feed rate (mm/rev) Drill: KDS 215 MAK Work material: C50 (230HB) Thickness Cutting conditions: Feed rate (mm/rev) vc = 50 m/min, Water soluble Work : SS41 Web thinning decreases the thrust concentrated Cutting speed : 50m/min at chisel edge, makes the drill edge sharp and When point angle is large, burr height becomes improves chip control. Tool life is also longer. low. Decrease Chisel Width by Thinning Typical types of thinning Technical Guidance S type N type X type S type : Standard type used generaly. N type : Suitable for thin web drills. X type : F  or hard-to-cut material or deep hole drilling. N13