549 Каталог SUMITOMO 2015 Режущий инструмент и инструментальная оснастка Стр.545

Каталог SUMITOMO 2015 Инструмент и оснастка Стр. 545 0549 ENG Lab2u

Technical Guidance Calculating Power Requirement Cutting Force TECHNICAL GUIDANCE Basics of Turning n Relation Between Cutting Speed and Cutting Force P vc x fx ap x kc Pc Net power requirement (KW) vc Cutting speed (m/min) f Feed rate (mm/rev) ap Depth of cut (mm) kc Specific cutting force (MPa) H Required horsepower (HP) h Machine efficiency (0.70 to 0.85) c 60 x 103 xh H = Pc H = 075 D RoughValue of Kc Aluminium 800MPa General Steel 2,500 to 3,000MPa Cast Iron 1,500MPa P, Principal force P2 Feed force P3 Back force D Calculating Cutting Force K P Cutting force (kN) P = ‘0 kc Specific cutting force (MPa) q Chip area (mm2) Calculating Cutting Speed (1) Calculating rotation speed from cutting speed 1,000 x vc p x Dm n Spindle speed (min-1) vc Cutting speed (m/min) Dm Diameter of work piece (mm) p = 3.14 (Ex.) vc=150m/min, Dm=100mm 1,000 x 150 ,, n= 3.14x 100 = 478 (min ) 2) Calculating cutting speed from rotational speed v p x Dm x n c 1000 Refer to the above table vc Cutting speed (m/min) f Feed rate (mm/rev) ap Depth of cut (mm) Dm Diameter of work piece (mm) Relation Between Rake Angle and Cutting Force Relation Between Feed Rate and Specific Cutting Force (For Carbon Steel) Theoretical Surface Finish f2 h = f x 103 8 x re h Theoretical surface roughness (mm) f Feed rate (mm/rev) re Nose radius (mm) ; ; /k = X. re Tf Actual Surface Roughness Steel Theoretical surface finish x 1.5 to 3 Cast iron Theoretical surface finish x 3 to 5 Ways to Improve Surface Finish (1) Use an insert with a larger nose radius. (2) Optimise the cutting speed and feed rate so that built-up edge does not occur. (3) Select an appropriate insert grade. (4) Use wiper insert Relation Between Nose Radius and Cutting Force 4000 3500 u - I1 1500 1000 500 0.4 0.8 1.2 1.6 Nose Radius (mm) Large nose radius increases back force. Work SCM440(38HS) Inserts TNGA2204 SS Holder PTGNR2525-43 Cutting Conditions vc=100m/min ap=4mm f=0.45mm/rev 545 Technical Guidance