铣刀技术培训.pdf

可转位铣刀培训可转位铣刀培训 2008 Kennametal Inc.l All rights reserved.l 1 Milling Cutter Styles 铣削刀具类型铣削刀具类型 Face Mills面铣刀 Slot Mills槽铣刀 Solid Carbide End Mills 硬质合金端铣刀 Helical Mills 螺旋铣刀 Copy Mills仿形铣刀 90Shoulder Mills 方肩铣 2008 Kennametal Inc.l All rights reserved.l 2 Milling Insert Designation 铣刀片标记 2008 Kennametal Inc.l All rights reserved.l 3 切削速度(Vc m/min)切削速度是指加工过程中刀具切削速度是指加工过程中刀具刃口在切削工件时，两者之间刃口在切削工件时，两者之间相对线速度相对线速度。n vc 铣削铣削-相相关关概念概念 2008 Kennametal Inc.l All rights reserved.l 4 铣削的定义铣削的定义-相相关关概念概念 每刃进给量(fz mm)每刃进给量(fz mm)2008 Kennametal Inc.l All rights reserved.l 5 铣削的定义铣削的定义-相相关关概念概念 进给速度 Vf 2008 Kennametal Inc.l All rights reserved.l 6 实际计实际计算算 面铣刀直径面铣刀直径80mm,6个刀片刃口，若刀片的切削速个刀片刃口，若刀片的切削速度为度为150m/min,问主轴的转速是多少？如果每齿进刀量问主轴的转速是多少？如果每齿进刀量为为fz=0.2mm/z,问机床的工作台进刀量是多少？问机床的工作台进刀量是多少？2008 Kennametal Inc.l All rights reserved.l 7 Face Mill Dimensioning 面铣刀几何尺寸 D 1 AR LA B K D 2 H BC RR D 1=Effective Cutter Diameter有效切削直径有效切削直径 RR=Radial Rake径向前角径向前角 K=Keyway Width键槽宽度键槽宽度 B=Bore Diameter刀柄安装直径刀柄安装直径 LA=Lead Angle 主偏角主偏角 BC=Bolt Circle Diameter螺栓孔周向直径螺栓孔周向直径 AR=Axial Rake轴向前角轴向前角 H=Cutter Body Height高度高度 D 2=Maximum Diameter最大直径最大直径 ap=Maximum Depth of cut最大切深最大切深 ap Catalog Examples:KSSISR394SE44345C5 -ANSI format 100B05RS45SE14E -ISO format 2008 Kennametal Inc.l All rights reserved.l 8 90 Lead 45 Lead 75 Lead Milling Cutter Lead Angle 铣削刀具主偏角铣削刀具主偏角 Effects:影响影响:Variation of forces into the spindle改变轴的受力 Chip thickness切屑厚度 Depth of cut切深 Cutting diameters切削直径 Forces Z-axis/Plunge Forces Forces Forces 2008 Kennametal Inc.l All rights reserved.l 9 Lead Angle Effect on Chip Thickness 主偏角对切屑厚度的影响主偏角对切屑厚度的影响 Example shown with centerline of cutter on the workpiece 例子表示了刀具中线在工件的位置 Lead Angle vs.Chip thickness Lead Angle Feed per Tooth Actual Chip Thickness 0 A A 15 A.96 x A 20 A.94 x A 30 A.86 x A 45 A.70 x A Lead Angle vs.Chip thickness:example Lead Angle Feed per Tooth Actual Chip Thickness 0.010in.(0,25mm).010in.(0,25mm)15.010in.(0,25mm).0096in.(0,25mm)20.010in.(0,25mm).0094in.(0,24mm)30.010in.(0,25mm).0086in.(0,22mm)45.010in.(0,25mm).0071in.(0,18mm)2008 Kennametal Inc.l All rights reserved.l 10 Rake Angle 前角前角 Axial Rake轴向前角 Axial View轴向视图(Front前)Lead Angle 主偏角 Radial View径向视图 (Top顶)Radial Rake径向前角(+)(-)(+)(-)2008 Kennametal Inc.l All rights reserved.l 11(-)(-)Negative Axial Rake负轴向前角负轴向前角 Negative Radial Rake 负径向前角负径向前角 Disadvantages缺点缺点 Higher cutting forces切削力较大 Directs chips back into workpiece排屑朝向工件 Can create a burr会产生毛刺 Advantages优点优点 Heavier feeds possible可进行重切削 Maximizes insert strength刀片强度最大化 Maximum number of cutting edges available 切刃利用最大化 Double Negative Milling Cutter 双负角铣刀双负角铣刀 (-)(-)Neg.Radial Rake径向前角径向前角 Neg.Axial Rake 轴向前角轴向前角 Chip Flow Characteristics排屑 2008 Kennametal Inc.l All rights reserved.l 12 Disadvantages缺点缺点 Weak Cutting Edges 切刃薄弱 Can Lift Workpiece if not fixtured properly 如定位不当,会加工时抬起工件 Double Positive Milling Cutter 双正角铣刀双正角铣刀 Advantages优点优点 Reduced Cutting Forces减小切削力 Lowest Hp Consumption机床马力消耗最小 Chips are directed up from the workpiece排屑远离工件 Positive Axial Rake 正轴向前角正轴向前角 Positive Radial Rake 正径向前角正径向前角(+)(+)(+)(+)Chip Flow Characteristics排屑 Pos.Radial Rake 径向前角径向前角 Pos.Axial Rake 轴向前角轴向前角 2008 Kennametal Inc.l All rights reserved.l 13 Advantages优点优点 Lower cutting forces than previous mentioned geometry和前述几何形状更小的切削力 Freer cutting action Increased MRR achievable增加可达到的MRR Chips are directed up and away from the workpiece 排屑向上远离工件 Shear Milling Cutters 正负前角铣刀正负前角铣刀 Positive Axial Rake正轴向前角正轴向前角(Axial Rake 10 High Shear)(Axial Rake 10 Shear)Negative Radial Rake 负径向前角负径向前角(-)(+)(+)(-)Neg.Radial Rake 径向前角径向前角 Pos.Axial Rake 轴向前角轴向前角 Chip Flow排屑 Characteristics 2008 Kennametal Inc.l All rights reserved.l 14 True Differential Pitch 不等距齿距不等距齿距 68 75 73 74 70 2008 Kennametal Inc.l All rights reserved.l 15 Coarse 粗齿 Heavier IPT较重的IPT Larger Gullets 宽的排屑槽 Larger DOCs切深较大 Least HP 小功率消耗 Fewest Teeth齿数最少 Fine 密齿 More Teeth Engaged 更多有效齿数 More IPM更多的IPM Lighter DOCs切深较小 Higher HP较高的功率消耗 Less Chip Clearance容屑空间少 Most applications will use coarse or medium pitch 大多数应用使用粗或中等齿数大多数应用使用粗或中等齿数 Milling Cutter Pitch 铣刀齿数铣刀齿数 2008 Kennametal Inc.l All rights reserved.l 16 Coarse粗齿粗齿 Fine密齿密齿 500 RPM.005 IPT 7 Teeth x.005 IPT x 500 RPM=17.5 IPM 12 Teeth x.005 IPT x 500 RPM=30 IPM Milling Cutter Pitch 铣铣刀刀齿齿数数 2008 Kennametal Inc.l All rights reserved.l 17 LH Less Common 左手刀盘左手刀盘 不常见不常见 Application Specific特殊应用特殊应用 RH More Common 右手刀盘常见右手刀盘常见 General Purpose通用通用 Cutter Rotation 铣刀旋转方向铣刀旋转方向 2008 Kennametal Inc.l All rights reserved.l 18 Varying Rake Face Angles 不同前角不同前角-5,11,15 Insert Rake Face Contours 刀片前刀面轮廓刀片前刀面轮廓 2008 Kennametal Inc.l All rights reserved.l 19 15 rake face angle Insert orientation should be with the icon location consistent in each pocket for best radial and axial TIR.刀片上须标明方向以便每个刀座上的刀片的轴向及径向跳动均保持一致刀片上须标明方向以便每个刀座上的刀片的轴向及径向跳动均保持一致 Insert Indexing 刀片转位刀片转位 2008 Kennametal Inc.l All rights reserved.l 20 Milling Cutter Basic Operation 铣刀基本操作铣刀基本操作 Direction of cut 切削方向 Position of cutter 刀具位置 Engagement of cutter 刀具切入 Angle of entry of the cutter 刀具进入角度 Average chip thickness 平均切屑厚度 Surface Finish 表面粗糙度 2008 Kennametal Inc.l All rights reserved.l 21 Milling Techniques 铣削技术铣削技术 Climb Milling 顺铣顺铣 Conventional Milling逆铣逆铣 Cutter Rotation 刀具旋转 Cutter Rotation 刀具旋转 Table Feed 工作台进给 Table Feed工作台进给(Use with Ball Screw machines)(Use with Lead Screw machines)Recommended technique 推荐使用 Avoid when drive system has backlash 驱动系统有背隙时避免使用 Could be a solution for flame cut or heavy slag material 用于淬硬材料及表面黑皮材料 ClimbCutting Parameter参数Conv.LessHeat Generation热量MoreMoreTool Life寿命LessMoreEfficiency 效率Less 2008 Kennametal Inc.l All rights reserved.l 22 Cutter Position Workpiece 6”9”Diameter Cutter Milling Cutter Positioning 铣刀位置铣刀位置 Offset Cutter Slightly from Centerline 略微偏离中心线 Less Chance of Chatter 减少振刀机率 Good Chip Thickness 进入退出时切屑厚度好 at Entry and Exit 2008 Kennametal Inc.l All rights reserved.l 23 Cutter Position Workpiece Feed Cutter Overhang Requires two passes需两刀 1/4 to 1/3 cutter overhang 铣刀悬深1/4到1/3 Climb Milling 顺铣 Negative angle of entry负角进入 Avoid full cutter engagement 避免整个刀具参与 Use lead angle geometry whenever possible 可能时应用主偏角几何形状 Select pitch that keeps 2 to 4 teeth engaged in work 挑选齿数使2到4齿参与工作 Milling Cutter Positioning 铣刀位置铣刀位置 2008 Kennametal Inc.l All rights reserved.l 24 Thin chip-6 Teeth in the cut 薄切屑-6齿切削 Undesirable不期望的 Thicker chip 4 teeth in the cut 较厚切屑-4齿切削 Desirable期望的 Work feeds in this direction 进给方向+4 6 Milling Cutter Engagement 铣刀的了解铣刀的了解 2008 Kennametal Inc.l All rights reserved.l 25+Milling Cutter Size vs.Position 铣刀尺寸和位置铣刀尺寸和位置 2008 Kennametal Inc.l All rights reserved.l 26 The Truth About Milling 铣削原理铣削原理 The importance of edge preparation刃部处理的重要性 Edge preparation and average chip thickness 刃部处理和平均切屑厚度 Cutter ratio and average chip thickness刀具比率和平均切屑厚度 Feed rate compensation进给率 Lead angles effect on average chip thickness 主偏角对平均切屑厚度的影响 2008 Kennametal Inc.l All rights reserved.l 27 Cutting forces 切削力切削力 Cutting forces 切削力切削力 Cutting forces 切削力切削力 Cutting forces 切削力切削力 Sharp Edge 锋利刃口锋利刃口 Honed Edge 倒圆刃口倒圆刃口 T-Land Edge 倒棱刃口倒棱刃口 T-Land Edge With Hone倒棱及倒圆倒棱及倒圆 Edge Preparation and Chip Thickness 刃部处理和切屑厚度刃部处理和切屑厚度 2008 Kennametal Inc.l All rights reserved.l 28 Feed rate vs.Average Chip Thickness(hm)Feed rate vs.Average Chip Thickness(hm)进给率和平均切屑厚度进给率和平均切屑厚度(hm)(hm)fz=feed per rev hm=average chip thickness n feed direction Average chip thickness(hm)must be greater that insert edge preparation.平均切屑厚度必须大于刀片刃部处理 ensures proper chip formation保证适当的切屑形成 prevents rubbing避免刮擦 2008 Kennametal Inc.l All rights reserved.l 29 n n n n n n n n n Chip thinning effect 铁铁屑厚薄影响屑厚薄影响 Percent Engagement Programmed Feed(fz)Average chip thickness(hm)100%.006in.0042in.50%.006in.0042in.40%.006in.0037in.20%.006in.0026in.10%.006in.0018in.100%50%40%20%10%hm=.0042”fz=.006”fz=.006”fz=.006”fz=.006”hm=.0026”hm=.0037”hm=.0018”hm=.0042”hm=.0042”Feed rate vs.Average Chip Thickness(hm)进给率和平均切屑厚度进给率和平均切屑厚度(hm)(hm)2008 Kennametal Inc.l All rights reserved.l 30 Average Chip Thickness(hm)Calculations 平均切屑厚度平均切屑厚度(hm)(hm)计算计算 d1 ae fz=hm()sin(k)To Calculate feed per insert:计算每刃进给 To Calculate average chip thickness:计算平均铁屑厚度 ae fz d1 hm n fz =Feed per insert 每齿进给 hm=Average chip thickness平均铁屑厚度 d1=Dia.Of cutter 刀体直径 ae=Radial engagement 切宽 k =Lead angle主偏角 ae d1 hm=fz ()sin(k)1 2008 Kennametal Inc.l All rights reserved.l 31 Compensated Feed Rate 合成进给率合成进给率 n n n n n n n n n 100%50%40%20%10%hm=.0066”fz=.0093”fz=.0132”fz=.006”fz=.006”hm=.0042”hm=.0042”hm=.0042”hm=.0042”hm=.0042”Chip thinning effect Percent Engagement Programmed Feed(fz)Average chip thickness(hm)100%.006in.0042in.50%.006in.0042in.40%.0066in.0042in.20%.0093in.0042in.10%.0132in.0042in.2008 Kennametal Inc.l All rights reserved.l 32 First choice starting feed(fz)is in bold type 加黑字体为进给的首选值 Use corresponding speed(vc).fz and vc are valid for ae 0.4 D1.当切宽大于0.4D1时使用相应的线速度和进给 For smaller ae,fz and vc should be multiplied by the factor given below:更小的切宽进给和线速度必须乘上系数 Feed Rate Compensation 90Lead 9090度偏角进给率补偿度偏角进给率补偿 2008 Kennametal Inc.l All rights reserved.l 33 Feed Rate Compensation Round Inserts 圆刀片进给率补偿圆刀片进给率补偿 Lead angles on round inserts change depending on DOC 圆刀片的主偏角随切深变化 Both radial engagement and depth of cut must be taken into consideration when calculating feed rate.计算进给率时,必须考虑径向切入和切深 2008 Kennametal Inc.l All rights reserved.l 34 Feed Rate Compensation Round Insert 圆圆刀片刀片进给进给率率补偿补偿(ex RD1204)2008 Kennametal Inc.l All rights reserved.l 35 Roughness Chip Thickness Variations 切屑厚度变化切屑厚度变化 2008 Kennametal Inc.l All rights reserved.l 36 Radius Flats Wipers 圆弧圆弧 平底平底 修光刃修光刃 Large Radius wiper radius facet radius Ex.SPCW Style 3 ipm Ex.SEHW Style 11 ipm Ex.SEHW-W 47 ipm Insert Corner Style 刀片刃口形式刀片刃口形式 Surface Finish 表面光洁度表面光洁度 Generated Surface(60AA)6 Diameter,382 rpm 在在6英寸直径刀盘，英寸直径刀盘，382rpm下产生的光洁度下产生的光洁度 2008 Kennametal Inc.l All rights reserved.l 37 Trouble Shooting Chatter 故障诊断故障诊断-振纹振纹 condition of vibration involving the milling machine and milling cutter 振动和铣床和铣刀有关 tends to be self-sustaining 倾向于自维持 results in lines or grooves appear at regular intervals in the work piece 在工件上产生等距的线和沟槽 grooves are caused by the teeth of the cutter as they vibrate 沟槽是由刀齿在它们振动时产生的 2008 Kennametal Inc.l All rights reserved.l 38 Trouble Shooting Burring 故障诊断故障诊断-毛刺毛刺 a condition whereby small slivers of alloy roll out over the edge of the work shoulders and points of the workpiece as the tool exits the cut.刀具离开工件时在加工面边缘产生的 This effect will usually occur more frequently when cutting soft,gummy materials.在加工软性,粘刀材料时较常见 2008 Kennametal Inc.l All rights reserved.l 39 Trouble Shooting Breakout 故障诊断故障诊断-崩边崩边 an uneven break of material breaking off as the cutter exits the part.This is very evident when cutting cast iron and other 刀具离开工件时产生的不规则缺口.在切削铸铁时较常见 powdered-metal materials.粉末冶金材料 2008 Kennametal Inc.l All rights reserved.l 40 Trouble Shooting Chipping 故障诊断故障诊断-崩刃崩刃 Appears like normal flankwear to the untrained eye外观和普通后刀面磨损相似 normal flank wear lands have a fine,smooth wear pattern 普通后刀面磨损面具有细小光滑的形态 a land formed by chipping has a saw-toothed,uneven surface.由崩刃产生的磨损面有锯齿壮不规则表面 If chipping is not detect edit may be perceived as depth of cut notching.如未及时发现,可导致切深处磨损 2008 Kennametal Inc.l All rights reserved.l 41 Trouble Shooting Notching 故障诊断故障诊断-切深处磨损切深处磨损 When chipping or localized wear at the depth of cut line on the rake face and flank of the insert occurs.在刀片前后刀面切深处有崩刃或定点磨损时产生 Caused by the condition of the workpiece material.由工件材料状况造成 Material conditions prone to depth of cut notch include:易于造成切深处磨损的材料 abrasive workpiece 耐磨性材料 skin of scale,表面黑皮 abrasive properties of high-temperature alloys like INCONEL,高温合金材料 a work-hardened outer layer 加工硬化材料 heat-treated material above 55 HRC.高于55HRC硬材料 2008 Kennametal Inc.l All rights reserved.l 42 Trouble Shooting Thermal Cracks 故障诊断故障诊断-热裂纹热裂纹 cracks run perpendicular to the inserts cutting edge裂纹和刀片切刃平行 caused by the extreme temperature variations involved in milling由铣削时的热冲击造成 varying chip thickness also changes the temperature throughout the cut 变化的切屑厚度也改变切削时的温度 air or coolant flow rapidly cools the insert before it reenters the cut 切削时压缩气或切削液突然喷到刀片上 temperature variations create heat stresses in the insert,which can result in thermal cracks 温度变化在刀片中产生热应力,从而产生热裂纹 advanced thermal cracking could appear as chipping.先期热裂纹外观可能和崩刃类似 2008 Kennametal Inc.l All rights reserved.l 43 Trouble Shooting Built up Edge(BUE)故障诊断故障诊断-积屑瘤积屑瘤 adhesion of layers of workpiece material to the top surface of the insert.工件材料在刀片前刀面的堆积 Hardened pieces of the adhered material periodically break free chipping the cutting edge硬化的堆积材料定期崩落造成崩刃 This causes damage to the part and insert.会造成对刀片和零件的损伤 Cutting forces will be increased due to built-up edge.积屑会使切削力增加 2008 Kennametal Inc.l All rights reserved.l 44 Trouble Shooting Flank Wear 故障诊断故障诊断-后刀面磨损后刀面磨损 Uniform flank wear is the preferred method of insert failure because it can be predicted.均匀后刀面磨损由于可以预测,是希望看到的磨损形式 flank wear increases cutting forces and contributes to poor surface finish.后刀面磨损加大切削力,并导致表面光洁度下降 when flank wear occurs an unacceptable rate or becomes unpredictable 当后刀面磨损达到不可接受的速率或变的不可预测时 key elements that must be investigated are speed,feed,grade,and insert/cutter geometry.必须研究的关键因素是速度,进给,材质,刀片/刀盘几何形状 NOTE:Inserts should be indexed when roughing(.015“.020”flank wear is reached)and finishing(.008“.012”flank wear or sooner).注意注意:当粗加工当粗加工(后刀面磨后刀面磨损损.015”-.020”)和精加工和精加工(后刀面磨后刀面磨损损.008”-.012”或更早或更早)时时,刀片刀片应转应转位位 2008 Kennametal Inc.l All rights reserved.l 45 Trouble Shooting It Broke!故障诊断故障诊断-破损破损 When wear,chipping,thermal cracking,and breakage occur at once,the machine operator must look beyond the normal feed,speed,and depth of cut adjustments to find the root cause of the problem.当磨损,崩刃,热裂纹,和破损发生时,机床操作员必须研究进给、速度、和切深，以发现问题的原因 2008 Kennametal Inc.l All rights reserved.l 46 Questions?问题？