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Tool and Die DesignTool and Die DesignPTB 31304PTB 31304PTB 31304PTB 31304
Raja Aziz Raja Ma’arofRaja Aziz Raja Ma’arof
Institute of Product Design and ManufacturingInstitute of Product Design and Manufacturing
UniKL IPROMUniKL IPROM
ReferencesReferences
§§ SuchySuchy, I., , I., Handbook of die designHandbook of die design; McGraw Hill 2; McGraw Hill 2ndnd Ed., Ed., 2006.2006.
§§ BoljanovicBoljanovic, V., , V., Sheet Metal Forming Processes and Die Sheet Metal Forming Processes and Die DesignDesign, , AlkemAlkem, 2004., 2004.
§§ Alvarez, W., Alvarez, W., Roll Form Tool Design: FundamentalsRoll Form Tool Design: Fundamentals, , §§ Alvarez, W., Alvarez, W., Roll Form Tool Design: FundamentalsRoll Form Tool Design: Fundamentals, , AlkemAlkem, 2006., 2006.
§§ SzumeraSzumera, J., , J., The Metal Stamping ProcessThe Metal Stamping Process, , AlkemAlkem, 2003., 2003.
§§ SpitlerSpitler, David (tech. reviewer), David (tech. reviewer), Fundamentals of tool , Fundamentals of tool designdesign, Society of Mechanical Engineers, 2003., Society of Mechanical Engineers, 2003.
§§ PaquinPaquin, J. R., , J. R., Die design fundamentalsDie design fundamentals, Industrial Press, , Industrial Press, 19861986
Credit hoursCredit hours
§§ Four (4) credit hours (2K, 2P)Four (4) credit hours (2K, 2P)§§ Lecture (room nr 2038)Lecture (room nr 2038)§§ Two credit hoursTwo credit hours§§ Two hours per weekTwo hours per week§§ Two hours per weekTwo hours per week§§ Every Tuesday, 0830 Every Tuesday, 0830 –– 1030 hrs1030 hrs
§§ Practical (room nr 0016)Practical (room nr 0016)§§ Two credit hoursTwo credit hours§§ Four hours per weekFour hours per week§§ Wednesday, 0830 Wednesday, 0830 –– 1230 hrs1230 hrs
Main topicsMain topics§§ Sheet metal die design principlesSheet metal die design principles
§§ Press machine specificationsPress machine specifications
§§ Die plates and insert materialsDie plates and insert materials
§§ Detail single die designDetail single die design
§§ Detail design for progressive dies, incorporating Detail design for progressive dies, incorporating piercing, blanking, bending, forming, embossing, piercing, blanking, bending, forming, embossing, piercing, blanking, bending, forming, embossing, piercing, blanking, bending, forming, embossing, etc.etc.
§§ Deep Drawing DiesDeep Drawing Dies
§§ Casting DiesCasting Dies
§§ Basic operation and design knowledge of Basic operation and design knowledge of specialized diesspecialized dies
§§ Large and Super Large Stamping DiesLarge and Super Large Stamping Dies
SheetmetalSheetmetal Die Making flowDie Making flow
Sheet metal product & Product design
Ordered volume
Volume per batch
Forming machine
Forming machine selection
Sheet metal die design…
Assessment Assessment §§ Coursework, 60%Coursework, 60%§§ At least two assignments: total 40%At least two assignments: total 40%§§ At least one on sketching (at 10%)At least one on sketching (at 10%)
§§ At least one on Die design using CAD system At least one on Die design using CAD system ((SolidWorksSolidWorks / / CatiaCatia / / Inventor) (at 30%)Inventor) (at 30%)((SolidWorksSolidWorks / / CatiaCatia / / Inventor) (at 30%)Inventor) (at 30%)
§§ At least one test (mid semester): 20%At least one test (mid semester): 20%§§ Approx 30% on theoryApprox 30% on theory
§§ Approx 70% on practical using CAD systemApprox 70% on practical using CAD system
§§ Final exam, 40%Final exam, 40%§§ Approx 30% on theoryApprox 30% on theory
§§ Approx 70% on practical using CAD systemApprox 70% on practical using CAD system
Sheetmetal Die Sheetmetal Die Design…Design…Flat Blank design
Strip layout design
Die design
Machining
Product design
Die commissioning
Assembly
Trial and debugging (trouble shooting)
Sheet metal product designSheet metal product design
§§ Dimensioning tolerancesDimensioning tolerances
§§ Positioning tolerancesPositioning tolerances
§§ Burr directionBurr direction
§§ Tensile strength (Tensile strength (δδ or or RR ) (supplier)) (supplier)§§ Tensile strength (Tensile strength (δδ or or RRmm) (supplier)) (supplier)
§§ Material content (supplier)Material content (supplier)
§§ ThicknessThickness
§§ Surface pressure...Surface pressure...
Burr:
Flat blank / blank sheet designFlat blank / blank sheet design§§ Def: Unfolded representation of Def: Unfolded representation of sheetmetalsheetmetal
product design.product design.
§§ It incorporated the forming processes, It incorporated the forming processes, egeg. . Bending, deep drawing, embossing, lancing, etc.Bending, deep drawing, embossing, lancing, etc.
§§ CuttingCutting clearanceclearance§§ Normally 2 to 5% of strip thickness per sideNormally 2 to 5% of strip thickness per side
§§ Die clearance: total clearance (both sides)Die clearance: total clearance (both sides)
§§ Less than 1% per side: to use fine blanking Less than 1% per side: to use fine blanking technologytechnology
§§ Bending factor / processesBending factor / processes
§§ Drawing factor / processesDrawing factor / processes
26 July 2011
Blank design with bending Blank design with bending
§§ Bending factor (v) parametersBending factor (v) parameters§§ Bending radius (r)Bending radius (r)
§§ SheetmetalSheetmetal thickness (t or s)thickness (t or s)
§§ L = a + b + c + …L = a + b + c + …-- n.vn.v§§ L = a + b + c + …L = a + b + c + …-- n.vn.v§§ L = flat blank lengthL = flat blank length
§§ a, b, c = flange length (outer side)a, b, c = flange length (outer side)
§§ n = number of n = number of bendingsbendings
§§ v = bending factorv = bending factor
Bending operation: minimum Bending operation: minimum allowable internal radius (r)allowable internal radius (r)
Bending operation: determining Bending operation: determining Bending Factor (v) valueBending Factor (v) value
Bending angle: other shapesBending angle: other shapes
§§ ß = 0º to 90ºß = 0º to 90º
§§ ß = >90º to 165ºß = >90º to 165º
L = a + b – vv = Equivalent Valuek = Correction FactorS = Material Thickness
Verhaeltnis r:s =
Ratio of radius:thickness
SpringbackSpringback by bendingby bending
§§ rr11 = = kkRR . (r. (r22 + 0.5.s) + 0.5.s) –– 0.5.s0.5.s§§ rr11 = bending radius on tooling= bending radius on tooling
§§ rr22 = bending radius on product= bending radius on product
§§ kk = = springbackspringback factorfactor§§ kkRR = = springbackspringback factorfactor
§§ s = sheet thicknesss = sheet thickness
§§ αα11 = = αα22 / / kkRR
§§ αα11 = bending angle on tooling= bending angle on tooling
§§ αα22 = bending angle on product / = bending angle on product / workpieceworkpiece
SpringbackSpringback by bendingby bending
Deep drawing (Deep drawing (TiefziehenTiefziehen))
§§ Deep drawing process and components:Deep drawing process and components:§§ Flat blank Flat blank sheetmetalsheetmetal
§§ Drawing punchDrawing punch
§§ Drawing insertDrawing insert§§ Drawing insertDrawing insert
§§ Drawing thrust plateDrawing thrust plate
§§ Flat blank calculationFlat blank calculation§§ Refer to die catalogue #2Refer to die catalogue #2
§§ To be discussed in laterTo be discussed in later
Piercing punch strokePiercing punch stroke
§§ Punch stroke = x + t + yPunch stroke = x + t + y
§§ x =x =
§§ t = t =
§§ y = y = §§ y = y =
y
xt
Punch & Die dimensionsPunch & Die dimensions
§§ Piercing / punchingPiercing / punching§§ DDpunchpunch = hole dimension on product= hole dimension on product
§§ BlankingBlanking
Dpunch
§§ BlankingBlanking§§ DDdiedie = blank dimension on product= blank dimension on product
Ddie
Cutting & Die clearancesCutting & Die clearances§§ Cutting clearance (Cutting clearance (ShneidspaltShneidspalt), U), U§§ Per sidePer side
§§ U = U = DDdiedie -- DDpunchpunch
§§ Die clearance, 2UDie clearance, 2UU
2U§§ Die clearance, 2UDie clearance, 2U
§§ Both sidesBoth sides
§§ Punch (Punch (SchneidstempelSchneidstempel))
§§ Die (Die (SchneidplattenSchneidplatten))
§§ Hole (Hole (LochenLochen))
§§ Blanking (Blanking (AusscheidenAusscheiden))
U U
Draft (Free) angle (Freiwinkel)
Cutting angle on DieCutting angle on Die
§§ Cutting Clearance Cutting Clearance ((SchneidspaltSchneidspalt))
§§ Material (Material (WerkstoffWerkstoff))
§§ Sheet thickness Sheet thickness
U
§§ Sheet thickness Sheet thickness ((BlechdickeBlechdicke))
§§ MitMit FreiwinkelFreiwinkel (with (with cutting angle)cutting angle)
§§ OhneOhne FreiwinkelFreiwinkel((FlateFlate cutting cutting surface)surface)
Flat cutting surface
Cutting Clearance (U)Cutting Clearance (U)Based on:1.Strip thickness2.Cutting angle on Die3.Strip Tensile Strength
14 Feb 12
Strip layout designStrip layout design
§§ Production volume (yearly, monthly)Production volume (yearly, monthly)
§§ TypeType§§ SingleSingle
§§ CompoundCompound§§ CompoundCompound
§§ TransferTransfer
§§ Progressive (normally Production Progressive (normally Production VolVol > 10k / > 10k / month)month)
§§ Burr directionBurr direction
Strip layout design (2)Strip layout design (2)§§ Strip flowStrip flow
§§ Scrap flowScrap flow
§§ Product flowProduct flow
§§ Force calculationForce calculation§§ CuttingCutting
§§ StrippingStripping
§§ SpringSpring
§§ BendingBending
§§ DrawingDrawing
§§ Force centre pointForce centre point
Cutting force (Cutting force (FFcutcut))
§§ Tensile strength (Tensile strength (δδ or or RRmm) [N/mm) [N/mm22]]
§§ Shear Stress (Shear Stress (tt) = 0.7 to 0.9 ) = 0.7 to 0.9 δδ
§§ FFcutcut = = tt [N/mm[N/mm22]] x x AAcutcut [mm[mm22]]
§§ FF = = tt [N/mm[N/mm ]] x x LL [mm] [mm] x x tt [mm][mm]§§ FFcutcut = = tt [N/mm[N/mm22]] x x LLcutcut [mm] [mm] x x ttcutcut [mm][mm]§§ Where:Where:§§ AAcutcut = Cutting cross sectional area= Cutting cross sectional area
§§ LLcutcut = Cutting length= Cutting length
§§ ttcutcut = Material thickness= Material thickness
Stripping forceStripping force§§ Function:Function:§§ To strip punches from strip layoutTo strip punches from strip layout
§§ The smaller the cutting clearance, the higher the The smaller the cutting clearance, the higher the stripping force requiredstripping force required§§ Also it depends on strip material and thicknessAlso it depends on strip material and thickness§§ Also it depends on strip material and thicknessAlso it depends on strip material and thickness§§ FFstripstrip = 0.2 to 0.5 (Stripping Factor, = 0.2 to 0.5 (Stripping Factor, SSFacFac) of cutting ) of cutting
forceforce§§ SOP for piercing or blanking processSOP for piercing or blanking process§§ Thrust plate touches and holds strip layoutThrust plate touches and holds strip layout§§ Then piercing or blanking punch cuts through the strip Then piercing or blanking punch cuts through the strip
layoutlayout
§§ Thus, at opening position, punch must be Thus, at opening position, punch must be securely positioned inside the thrust platesecurely positioned inside the thrust plate
Spring Spring
§§ TypesTypes§§ Elastomer / urethane (normally for stripper Elastomer / urethane (normally for stripper
spring)spring)
§§ Coil (round & rectangular cross sectional Coil (round & rectangular cross sectional §§ Coil (round & rectangular cross sectional Coil (round & rectangular cross sectional type)type)
§§ LeafLeaf
21 feb 2012
Strip layout design (3)Strip layout design (3)§§ Pitch puncher / Notching Pitch puncher / Notching
punchpunch§§ Function: To ensure strip layout Function: To ensure strip layout
moves forward at a fixed moves forward at a fixed distancedistance
§§ No autoNo auto--feeder machinefeeder machine§§ ‘U’ profile; material overcut to ‘U’ profile; material overcut to §§ ‘U’ profile; material overcut to ‘U’ profile; material overcut to
avoid obstruction of strip flowavoid obstruction of strip flow§§ Based on material thickness Based on material thickness
§§ Pitch / strip stopperPitch / strip stopper§§ Function: to ensure strip layout Function: to ensure strip layout
stops at the desired positionstops at the desired position§§ Fixed on guide fence or die Fixed on guide fence or die
plate (more precise)plate (more precise)§§ Web widthWeb width
Web designWeb design
§§ Minimum web width is required:Minimum web width is required:§§ To have a stable strip layoutTo have a stable strip layout§§ During forward motionDuring forward motion
§§ Avoid saggingAvoid sagging§§ Avoid saggingAvoid sagging
§§ To have sufficient thrust force to hold the stripTo have sufficient thrust force to hold the strip§§ Insufficient thrust, the strip will be pulled by the Insufficient thrust, the strip will be pulled by the
punch, hence damaging the strippunch, hence damaging the strip
Bridge / Web width (Bridge / Web width (WWwebweb))§§ Based on material thicknessBased on material thickness§§ Minimum widthMinimum width§§ To reduce scrap. Optimise material utilization, To reduce scrap. Optimise material utilization, ηηMatlUtilMatlUtil
(flat blank area / pitch area)(flat blank area / pitch area)§§ Optimum widthOptimum width§§ To have sufficient thrust force to hold the strip. To have sufficient thrust force to hold the strip.
Insufficient thrust, the strip will be pulled by the Insufficient thrust, the strip will be pulled by the Insufficient thrust, the strip will be pulled by the Insufficient thrust, the strip will be pulled by the punch, hence damaging the strippunch, hence damaging the strip
§§ To avoid incomplete blank / punch operationTo avoid incomplete blank / punch operation§§ To avoid deformation on web, hence strip pitch To avoid deformation on web, hence strip pitch
distance will be distorteddistance will be distorted§§ To minimise strip overhangTo minimise strip overhang
Web designWeb design
§§ a = Web a = Web width at width at external external profileprofile
Streifenbreite = Strip width
profileprofile
§§ b = Web b = Web width width between between profilesprofiles
Strip layout design (4)Strip layout design (4)§§ Bullet Casing, Mini StaplerBullet Casing, Mini Stapler
§§ OneOne--side carrier (bridge / web)side carrier (bridge / web)
§§ Consider also:Consider also:§§ Burr directionBurr direction
§§ Strip flow (on die or with springStrip flow (on die or with spring--activated guide lifter)activated guide lifter)
§§ Strip over hang conditionStrip over hang condition§§ Strip over hang conditionStrip over hang condition
Strip layout design (5)Strip layout design (5)§§ Hinge, Door BracketHinge, Door Bracket§§ Centre Centre carriercarrier§§ Take note on three (3) idle stationsTake note on three (3) idle stations
Strip layout design (6)Strip layout design (6)
§§ CapCap
§§ TwoTwo--side side carriercarrier
Mon 31 Jan 2011
Strip layout design (7)Strip layout design (7)§§ Opening and closed conditionsOpening and closed conditions§§ Punches and diesPunches and dies
§§ Displacement (closed to open positions)Displacement (closed to open positions)
§§ Punch and blank processesPunch and blank processes§§ From top preferredFrom top preferred
§§ Scrap downwardsScrap downwards
§§ Strip level position during forward directionStrip level position during forward direction§§ On die plate preferred. No over hang. No guide lifter. On die plate preferred. No over hang. No guide lifter.
Bend down on product parallel to flow (slot on die Bend down on product parallel to flow (slot on die plate)plate)
§§ At a distance above die At a distance above die plate (with strip lifters)plate (with strip lifters)§§ For product with bends. For product with bends. §§ For drawing processFor drawing process
Strip layout design (8)Strip layout design (8)
§§ Force calculationForce calculation§§ Cutting (pierce, blank, etc.), bending, drawingCutting (pierce, blank, etc.), bending, drawing
§§ SpringSpring§§ StrippingStripping§§ StrippingStripping
§§ DrawingDrawing
§§ Return (bending, levelling)Return (bending, levelling)
§§ Strip carrierStrip carrier
Stripper spring designStripper spring design
Gap
Stripper spring calculationStripper spring calculation
§§ FFTotalCutTotalCut=?=?§§ FFStripStrip =?=?
§§ Punch travel distance (x + t + y)Punch travel distance (x + t + y)§§§§ Spring load, Spring load, FFmaxmax and Maximum deflection and Maximum deflection
ffmaxmax per spring?per spring?
§§ Nr of spring?Nr of spring?
§§ FFstripstrip/spring/spring
Piercing punch strokePiercing punch stroke§§ Punch stroke = x + t + yPunch stroke = x + t + y
§§ x = Distance inside trust platex = Distance inside trust plate
§§ t = Strip thicknesst = Strip thickness
§§ y = Punch penetration distance from strip bottomy = Punch penetration distance from strip bottom
y
xt
Citation & ReferencesCitation & References§§ In text: Based on 90º bending formula, L = In text: Based on 90º bending formula, L =
a + b + c +… a + b + c +… --nvnv ((HeinzlerHeinzler et al., 1997), et al., 1997), the flat length is thus xx mm…. (p. 260).the flat length is thus xx mm…. (p. 260).
§§ In text: In text: HeinzlerHeinzler et al. (1997) proposes the et al. (1997) proposes the 90º bending formula, L = a + b + c +… 90º bending formula, L = a + b + c +… --nvnv90º bending formula, L = a + b + c +… 90º bending formula, L = a + b + c +… --nvnv(p. 260). (p. 260).
§§ In references: In references: HeiznlerHeiznler, M., , M., KilgusKilgus, R., , R., NäherNäher, F., , F., PaetzoldPaetzold, H., , H., RöherRöher, W., , W., Schilling, K. (1997). Schilling, K. (1997). TabellenbuchTabellenbuch MetallMetall. . LeinfeldenLeinfelden--EchterdingenEchterdingen, Germany: , Germany: EuropaEuropa--LehrmittelLehrmittel..
Die designDie design§§ Standard platesStandard plates§§ Top, pressure, punch holder, stripper, thrustTop, pressure, punch holder, stripper, thrust
§§ Bottom, die, guide fenceBottom, die, guide fence
German German design
Die designDie designJapanese Japanese
designdesign
Die design (Japanese typical Die design (Japanese typical design)design)
§§ Paper stapler, spring Paper stapler, spring puncherpuncher
§§ Note: stoppers on top & bottom dies are crucial Note: stoppers on top & bottom dies are crucial to avoid over travel of bending and drawing to avoid over travel of bending and drawing punchespunches
Die design (German typical design)Die design (German typical design)§§ Paper Puncher: BasePaper Puncher: Base
Die designDie design
§§ Datum (normally die top position)Datum (normally die top position)
§§ Closed positionClosed position§§ Piercing / blanking punchesPiercing / blanking punches
§§ Bending punchesBending punches
0
Die plate
§§ Bending punchesBending punches
§§ Drawing punchesDrawing punches
§§ Spring maximum load conditionSpring maximum load condition
Die designDie design§§ Opening positionOpening position§§ Spring preSpring pre--load condition. Better life spanload condition. Better life span§§ Spring selectionSpring selection§§ ElastomerElastomer / urethane spring/ urethane spring
§§ Higher force (approx. 20 times higher than coil spring: Higher force (approx. 20 times higher than coil spring: 150kN)150kN)150kN)150kN)
§§ Lower compressible length (approx. 20%)Lower compressible length (approx. 20%)
§§ Coil springCoil spring§§ Higher compressible length (up to 50%)Higher compressible length (up to 50%)§§ Max. load approx. 7kNMax. load approx. 7kN
§§Gas springGas spring§§ Linear load increase (300N to 180kN)Linear load increase (300N to 180kN)§§ Drawing and deep drawing processDrawing and deep drawing process
§§ Disc springDisc spring
Die design Die design –– Spring selectionSpring selection
§§ LLprepre--CompComp, Pre, Pre--load length: 2mm or 5% load length: 2mm or 5% –– 10% 10% of spring length. Higher length for higher of spring length. Higher length for higher compressioncompression
§§ LLstrokestroke, Punch stroke = X + T + Y, Punch stroke = X + T + Y
§§§§ LLDeflDeflTotalTotal compressed length (Deflection)compressed length (Deflection)§§ Consider punches (pierce, bend, draw, etc.) Consider punches (pierce, bend, draw, etc.)
movementmovement
§§ Load to strip the strip layoutLoad to strip the strip layout§§ Spring load at preSpring load at pre--load length + piercing load length + piercing
punch travel up to thrust plate bottom level = punch travel up to thrust plate bottom level = F F stripstrip
Die design Die design –– Spring selectionSpring selection§§ Assume material: St 70Assume material: St 70--2, 3mm thick, total 2, 3mm thick, total
cutting length at 300mmcutting length at 300mm
§§ Tensile strength, Tensile strength, δδ or or RRmm for St 70for St 70--2 = 690 2 = 690 -- 830 N/mm2. 830 N/mm2.
§§ assume average, assume average, δδaveave = (690 + 830)/ 2 = = (690 + 830)/ 2 = §§ assume average, assume average, δδaveave = (690 + 830)/ 2 = = (690 + 830)/ 2 = 760 N/mm2760 N/mm2
§§ Shear stress, Shear stress, tt = = 0.7 to 0.9 0.7 to 0.9 δδ. Assume . Assume average, average, ttaveave = 0.8 x = 0.8 x 760760 N/mm2 = 600 N/mm2 = 600 N/mm2N/mm2
§§ F F shear or cut shear or cut = ? N= ? N
§§ F F strip strip = ? N= ? N
Die design Die design –– Spring selectionSpring selection§§ F F shear or cutshear or cut = = tt x Area cut = x Area cut = tt x x LcutLcut x thick = 600 x thick = 600
N/mm2 x 300mm x 3mm = 540,000N = 54,000kgf N/mm2 x 300mm x 3mm = 540,000N = 54,000kgf =54T=54T§§ F F stripstrip = 20% = 20% -- 50% of 50% of F F cut . cut . Assume Assume FFstripstrip = 35% of = 35% of
54T = 19T54T = 19T§§ E.g. PreE.g. Pre--load distance = 2mm (load distance = 2mm (LptLpt), pierce punch ), pierce punch
distance to thrust bottom level distance is 3 (x) and distance to thrust bottom level distance is 3 (x) and distance to thrust bottom level distance is 3 (x) and distance to thrust bottom level distance is 3 (x) and working stroke is 9mm (t + y)working stroke is 9mm (t + y)
§§ Total spring compressed length = Total spring compressed length = Lpt+x+t+yLpt+x+t+y
Die design Die design –– Coil spring selection Coil spring selection (Stripper Spring)(Stripper Spring)
§§ Compressed length, f = Compressed length, f = LLPrePre--CompComp + + LLStrokeStroke
§§ LLPrePre--CompComp = Pre= Pre--compressed lengthcompressed length§§ fmaxfmax (Spring Tech Spec) > f(Spring Tech Spec) > f
§§ Compressed length, Compressed length, fmaxfmax = 2+3+3+6 = = 2+3+3+6 = §§ Compressed length, Compressed length, fmaxfmax = 2+3+3+6 = = 2+3+3+6 = 14mm14mm§§ Consider to use 20 springsConsider to use 20 springs§§ Thus, F strip/spring 19T/20= 0.95T = Thus, F strip/spring 19T/20= 0.95T =
9,500N9,500N§§ Select coil spring SB x dia50x70LSelect coil spring SB x dia50x70L§§ 9,807N at 14mm compressed9,807N at 14mm compressed
Die design Die design –– ElastomerElastomer spring spring selectionselection
§§ Or 4 springsOr 4 springs§§ Thus, F strip/spring 19T/4= 4.75T = Thus, F strip/spring 19T/4= 4.75T =
47,500N47,500N§§ Find spring Find spring fmaxfmax at 14mm, nearest at 14mm, nearest FmaxFmax§§ Find spring Find spring fmaxfmax at 14mm, nearest at 14mm, nearest FmaxFmax
at 30,100N for at 30,100N for elastomerelastomer spring spring 246.5.090.040246.5.090.040§§ Nr of springs is 190,000N / 30,100N = 6 Nr of springs is 190,000N / 30,100N = 6
springssprings
Die design Die design –– Strip lifter springStrip lifter spring
§§ Strip weight = Strip weight = ρρ x Volumex Volume
§§ Number of springsNumber of springs
§§ Weight per spring to hold stripWeight per spring to hold strip
§§ Spring selectionSpring selection§§ Spring selectionSpring selection
§§ Compressed Length f = Compressed Length f = LpcLpc + + LstrokeLstroke§§ LpcLpc = Pre= Pre--compressed lengthcompressed length
§§ LcLc = = LdeflLdefl = = LpcLpc + + LstrokeLstroke
§§ fmaxfmax (Spring Tech spec) > f(Spring Tech spec) > f
Die designDie design
§§ Punches safety levelPunches safety level§§Opening and closed positionsOpening and closed positions
§§ Piercing / blanking punchesPiercing / blanking punches
§§ Bending punchesBending punches
§§ Drawing punchesDrawing punches
§§ Punch strokePunch stroke
§§ Die total strokeDie total stroke
Die type determinationDie type determination§§ Die lifeDie life§§ Small life volume (<50k): Single die Small life volume (<50k): Single die §§ High life volume: Progressive dieHigh life volume: Progressive die§§ E/E: product life of 200k to 300k in two yearsE/E: product life of 200k to 300k in two years§§ Automotive: product life of 500k to 2mil in five to Automotive: product life of 500k to 2mil in five to
seven yearsseven yearsseven yearsseven years
§§ Case studyCase study§§ Die life of 500k in six yearsDie life of 500k in six years§§ Monthly volume required: 500k / 6yrs / 12mths = Monthly volume required: 500k / 6yrs / 12mths =
approx. 6,945 monthlyapprox. 6,945 monthly
§§ Production dataProduction data§§ Eight hours per shiftEight hours per shift§§ 22 days per month22 days per month
Production planning calculationProduction planning calculation§§ Production allocation (Volume per batch)Production allocation (Volume per batch)§§ Press machine 80 SPM (Press machine 80 SPM (egeg AMADA TPAMADA TP--45 45
EX)EX)
§§ Press machine cycle time = 1/80 min x 60 Press machine cycle time = 1/80 min x 60 sec/min = 0.75 secsec/min = 0.75 sec
§§ Daily time: 1day x 8hrs per day x 60 min/hr = Daily time: 1day x 8hrs per day x 60 min/hr = §§ Daily time: 1day x 8hrs per day x 60 min/hr = Daily time: 1day x 8hrs per day x 60 min/hr = 480 min / day480 min / day
§§ Volume / day = 480 min/day x 80 strokes/min Volume / day = 480 min/day x 80 strokes/min = 38,400 strokes / day.= 38,400 strokes / day.
§§ For 6,945 volume per month requirementFor 6,945 volume per month requirement§§ Time allocation to produce the part: 6,945/38,400 Time allocation to produce the part: 6,945/38,400
x 8 hours / day = approx. 1.5 hoursx 8 hours / day = approx. 1.5 hoursMon 7 Feb 2011
Production planning calculation: Production planning calculation: Alternative Alternative
§§ Machine cycle time: 0.75 secMachine cycle time: 0.75 sec
§§ For 6,945 volume, time to produce = 6,945 For 6,945 volume, time to produce = 6,945 x 0.75 sec = 5,209 secx 0.75 sec = 5,209 sec
§§ Or 5,209 sec / 3600 sec/hr = approx 1.5 Or 5,209 sec / 3600 sec/hr = approx 1.5 §§ Or 5,209 sec / 3600 sec/hr = approx 1.5 Or 5,209 sec / 3600 sec/hr = approx 1.5 hourshours
Production planning calculationProduction planning calculation§§ Production allocation (Volume per batch)Production allocation (Volume per batch)§§ Press machine cycle time: 60 to 100 spm. Take average, Press machine cycle time: 60 to 100 spm. Take average,
80 spm80 spm
§§ Take average to cater down time & maintenanceTake average to cater down time & maintenance
§§ Cycle time or time per stroke or time per pieceCycle time or time per stroke or time per piece
§§ Cycle time = 1/80 spm or 0.0125 min/stroke or 0.75sec Cycle time = 1/80 spm or 0.0125 min/stroke or 0.75sec Cycle time = 1/80 spm or 0.0125 min/stroke or 0.75sec Cycle time = 1/80 spm or 0.0125 min/stroke or 0.75sec (60sec/80spm)(60sec/80spm)
§§ Daily volume: 8hrs per day x 3,600sec per hr / 0.75sec Daily volume: 8hrs per day x 3,600sec per hr / 0.75sec per stroke = 38,400 strokes per day (press machine per stroke = 38,400 strokes per day (press machine capacity).capacity).
§§ For 6,945 volume per month requirementFor 6,945 volume per month requirement§§ Nr. of days allocation per month: 6,945 units/38,400 units per day Nr. of days allocation per month: 6,945 units/38,400 units per day
= approx. 0.2 day, namely 0.2day x 8hrs per day= 1.6hrs for one = approx. 0.2 day, namely 0.2day x 8hrs per day= 1.6hrs for one shift to produce one month requirement (6,945 units)shift to produce one month requirement (6,945 units)
Forming / Stamping machinesForming / Stamping machines
C-Frame Hydraulic press
Stamping / forming machineStamping / forming machine
§§ Machine tonnageMachine tonnage
§§ Bolster sizeBolster size
§§ Slide sizeSlide size
§§ Shut heightShut height§§ Shut heightShut height
§§ Stroke Stroke
§§ Die height (closed position)Die height (closed position)
Tue 20 Sept 2011
Stamping machine selectionStamping machine selection§§ TonnageTonnage§§ Cutting, bending, drawing, stripping forcesCutting, bending, drawing, stripping forces
§§ Opening heightOpening height
§§ StrokeStroke
§§ Tightening positionTightening position§§ Tightening positionTightening position§§ Bolster dimensionBolster dimension
§§ Slide dimensionSlide dimension
§§ Feeding methodFeeding method
§§ Die heightDie height
§§ Die weightDie weight
Bending force parameter Bending force parameter calculationscalculations
§§ VV--BendingBending Fb1 = 2 x Fb
b
S0Fb = C x Rm x b x S0
2
W
Rm = Tensile Strength
r
W
W
C = 1 + 4S0
W C = Bending factor
Fb = Open bending
Fb1 = Closed bending
Bending force parameter Bending force parameter calculationscalculations
§§ UU--BendingBending
Uniform bending
Fb = 0.4 x Rm x b x S0
S0
b1
b2
Fb
L- Bending (one side)L
Non-uniform bending
Fb = 0.2 x Rm (b1+b2) x S0
Bending without opposing spring
Ff = 2.5 x Fb
Ff
Mon 12 Oct 09
L- Bending (one side)
Fb = 0.2 x Rm x b x S0
Bending force parameter Bending force parameter calculationscalculations
§§ UU--BendingBendingFos
Bending with opposing springBending with opposing spring
Fos = 1.3 x Fb
Opposing spring
Deep drawing: flat blankDeep drawing: flat blank
§§ TiefziehenTiefziehen = Deep drawing= Deep drawing
§§ ZiehtailZiehtail = Drawn component= Drawn component
§§ ZuschnittdurchmesserZuschnittdurchmesser = Diameter of flat = Diameter of flat blankblankblankblank
§§ OhneOhne Rand = without additional flat ends Rand = without additional flat ends (lips)(lips)
§§ MitMit Rand = with additional flat endRand = with additional flat end
Deep drawing: Flat blank Deep drawing: Flat blank calculationcalculation
Deep drawing: Drawing clearance & Deep drawing: Drawing clearance & corner radiicorner radii
w Drawing Clearance
s Sheet Thickness
k Sheet Material Factor (Wekstofffaktor)
rr Corner Radius at Drawing
§ Ziehspalt und Radien am Ziehringund Ziehstempel = Drawing clearance & rr Corner Radius at Drawing
Ring
rpp or rst Corner Radius at Drawing Punch
D Cut Sheet Diameter
dr Drawing Ring Diameter
d Punch Diameter
Drawing clearance & drawing radius on drawing ring & drawing punch
Stahl = steelSonstige NE-Metalle = Special non-ferrous metal
Deep drawing: Drawing Deep drawing: Drawing clearance & corner radiiclearance & corner radii
Deep drawing parameter: Deep drawing parameter: Number of Number of drawing stages and drawing factordrawing stages and drawing factor
§§ Zug = TravelZug = Travel
D Cut Sheet Diameter
§§ Ziehstufen & Ziehstufen & Ziehverhaeltnis = Ziehverhaeltnis = Number of drawing Number of drawing stages and drawing stages and drawing
d1 First Stage Punch Diameter
d2 Second Stage Punch Diameter
b1 First Stage Drawing Factor
b2 Second Stage Drawing Factor
s Sheet Thickness
stages and drawing stages and drawing factorfactor
§§ Werkstoff = MaterialWerkstoff = Material
§§ Zwichengluehen = Zwichengluehen = heating during heating during drawingdrawing
§§ Mit = withMit = with
§§ Ohne = withoutOhne = without
Deep drawing parameter: Deep drawing parameter: Number of Number of drawing stages and drawing factordrawing stages and drawing factor
Deep drawing parameter: Deep drawing parameter: Number of drawing stagesNumber of drawing stages
Deep drawing: force calculationsDeep drawing: force calculations
§§ Force calculationForce calculation
§§ TiefziehkraftTiefziehkraft = Deep = Deep drawing forcedrawing force
§§ NiederhalterkraftNiederhalterkraft = =
FD or Fz Deep Drawing Force
d1 Punch Diameter, first stage
s Sheet Thickness
Rm Tensile Strength (or δ)
b Actual Drawing Factor§§ NiederhalterkraftNiederhalterkraft = = Thrust plate forceThrust plate force bmax Highest Allowable Drawing
Factor
FT or FN Thrust or Holding Force
D Cut Sheet Diameter / Flat blank diameter
dN Diameter on holding plate
p Thrust Plate Pressure
w Drawing Clearance (per side)
Deep drawing: force calculationsDeep drawing: force calculations
Dimensioning & machining proceduresDimensioning & machining procedures
§§ Standard: Standard: ±±0.10.1
§§ Standard : Standard : ±±0.05 (pressure and punch 0.05 (pressure and punch holder)holder)
§§ Thrust plateThrust plate§§ Vertical: 0 to +0.05Vertical: 0 to +0.05§§ Vertical: 0 to +0.05Vertical: 0 to +0.05
§§ Horizontal: Horizontal: ±±0.10.1
§§ Guide fenceGuide fence§§ Horizontal top: Horizontal top: --2 to 2 to -- 33
§§ Horizontal bottom: Horizontal bottom: --0.1 to 0.1 to --0.20.2
§§ Vertical: 0 to Vertical: 0 to --0.050.05In mm
DimensioningDimensioning
§§ Die plate assembled in ground plateDie plate assembled in ground plate§§ Vertical: 0 to +0.1Vertical: 0 to +0.1
§§ Horizontal: Horizontal: --0.1 to 00.1 to 0
§§ Die plate opening, on top of ground plateDie plate opening, on top of ground plate§§ Die plate opening, on top of ground plateDie plate opening, on top of ground plate§§ Horizontal: +0.1 to +0.2Horizontal: +0.1 to +0.2
§§ Vertical: Vertical: ±±0.050.05
Die materialsDie materials§§ Base plates: Mild steel. E.g. MS45, C45Base plates: Mild steel. E.g. MS45, C45§§ PunchesPunches§§ Materials: HSS (Euro), DF2, SKD11, SKHMaterials: HSS (Euro), DF2, SKD11, SKH§§ Hardness: HRC 60 Hardness: HRC 60 -- 6464
§§ InsertsInserts§§ Materials: HSS, DF2, SKD11, SKHMaterials: HSS, DF2, SKD11, SKH§§ Materials: HSS, DF2, SKD11, SKHMaterials: HSS, DF2, SKD11, SKH§§ Hardness: HRC 55 Hardness: HRC 55 –– 63 (normally lower than 63 (normally lower than
punches for maintenance purpose. Insert to punches for maintenance purpose. Insert to break rather than punch)break rather than punch)
§§ Standard partsStandard parts§§ Guide pillars & bushes (SUJ2,…)Guide pillars & bushes (SUJ2,…)§§ boltsbolts
Common problems in Common problems in sheetmetalsheetmetal productsproducts
§§ BurrBurr§§ Higher than specificationHigher than specification
§§ Wrong directionWrong direction
§§ Dented: Foreign materialsDented: Foreign materials
§§ Different thickness / surface thinningDifferent thickness / surface thinning
§§ Elongated hole (bend after hole punch)Elongated hole (bend after hole punch)
§§ Wrinkle surfaceWrinkle surface
§§ Torn off Torn off
§§ SpringbackSpringback
§§ Surface crackSurface crack
§§ RustyRusty
Finished product problems in Finished product problems in sheetmetalsheetmetal
WrinkleSurface thinning
Common problems on sheetmetal dieCommon problems on sheetmetal die
§§ Misalignment between top and bottom die Misalignment between top and bottom die plate setsplate sets
§§ Forming machine stops halfway throughForming machine stops halfway through§§ Insufficient loadInsufficient load
§§ Obstruction between punches and dies Obstruction between punches and dies §§ Obstruction between punches and dies Obstruction between punches and dies
Tue 18 Oct 2011
Special Special sheetmetalsheetmetal diesdies
§§ Cam design, angular cut / bendCam design, angular cut / bend
§§ Side cutSide cut
§§ SensorsSensors
§§ AirAir--assisted scrap / product removalassisted scrap / product removal§§ AirAir--assisted scrap / product removalassisted scrap / product removal
Special forming machinesSpecial forming machines
§§ FineblankingFineblanking
§§ Highspeed forming machinesHighspeed forming machines
§§ MultiMulti--actions bending machinesactions bending machines
§§ Sensors in forming machines Sensors in forming machines §§ Sensors in forming machines Sensors in forming machines
Cost calculation: Cost calculation: Main cost Main cost componentscomponents
§§ DesignDesign§§ Raw materials and standard partsRaw materials and standard parts§§ MachiningMachining§§ Heat treatmentHeat treatment§§ Heat treatmentHeat treatment§§ HandlingHandling§§ DeliveryDelivery§§ AdministrationAdministration§§ Profit marginProfit margin§§ QuotationQuotation
Design costDesign cost
§§ RM / hrRM / hr
§§ Design durationDesign duration§§ Design objective (based on problem Design objective (based on problem §§ Design objective (based on problem Design objective (based on problem
statement)statement)
§§ Design needs analysisDesign needs analysis
§§ Research ideasResearch ideas
§§ Design alternativesDesign alternatives
§§ Final designFinal design
Raw material & standard part Raw material & standard part costcost
§§ Raw material, by:Raw material, by:§§ Request for quotation from suppliersRequest for quotation from suppliers
§§ WeightWeight
§§ Size or volumeSize or volume§§ Size or volumeSize or volume
§§ Standard part catalogueStandard part catalogue§§ Price list from suppliersPrice list from suppliers
§§ Request for quotation from suppliersRequest for quotation from suppliers
Machining costMachining cost§§ Machine typeMachine type§§ MillingMilling§§ TurningTurning§§ GrindingGrinding§§ WirecutWirecut§§ WirecutWirecut§§ DiesinkDiesink§§ WeldingWelding
§§ Machining accuracyMachining accuracy§§ Machining time calculationMachining time calculation§§ RM / hr rate, by machine depreciationRM / hr rate, by machine depreciation
Machining costMachining cost§§ Normally based on depreciationNormally based on depreciation§§ Cost to purchase a machine, e.g. RM300k (plus Cost to purchase a machine, e.g. RM300k (plus
interest)interest)§§ For forming machine: E.g. 80 For forming machine: E.g. 80 spmspm. Cycle time = . Cycle time =
0.0125min/stroke or 0.75sec/stroke0.0125min/stroke or 0.75sec/stroke§§ Year to depreciate, e.g. 7 yearsYear to depreciate, e.g. 7 years§§ Year to depreciate, e.g. 7 yearsYear to depreciate, e.g. 7 years§§ RM/yr:RM/yr:§§ RM/month:RM/month:§§ RM/day:RM/day:§§ RM/hr:RM/hr:§§ RM/min:RM/min:§§ RM per 0.0125min or RM per stroke:RM per 0.0125min or RM per stroke:
Heat treatmentHeat treatment
§§ RM / kg rateRM / kg rate
§§ RM for special requirementRM for special requirement§§ MaterialMaterial
§§ Heat treatment methodHeat treatment method§§ Heat treatment methodHeat treatment method§§ Electrical furnaceElectrical furnace
§§ InductionInduction
§§ Process controlProcess control
Handling costHandling cost
§§ Machine settingMachine setting
§§ Assembly and dismantlingAssembly and dismantling
§§ Quality controlQuality control
§§ Progress controlProgress control§§ Progress controlProgress control
§§ StorageStorage
§§ RM/hrRM/hr
DeliveryDelivery§§ Transportation modeTransportation mode§§ Lorry or car or motorcycle (depreciation)Lorry or car or motorcycle (depreciation)
§§ DriverDriver
§§ PetrolPetrol
§§ Maintenance (Maintenance (tyretyre wear, engine oil, etc)wear, engine oil, etc)§§ Maintenance (Maintenance (tyretyre wear, engine oil, etc)wear, engine oil, etc)
§§ Toll Toll
§§ RM / kmRM / km§§ Weight category , e.g.Weight category , e.g.§§ Less than 150 kg at RM1/kgLess than 150 kg at RM1/kg
§§Others at RM2/kgOthers at RM2/kg
§§ Size or volume categorySize or volume category
Administration costAdministration cost§§ Apportionment: % to be budgeted on Apportionment: % to be budgeted on
capital expenditure, e.g. supporting capital expenditure, e.g. supporting machines, furniture, forklift, etcmachines, furniture, forklift, etc
§§ RM/hrRM/hr
§§ EgEg..§§ Admin staff payroll: Total RM50,000 per Admin staff payroll: Total RM50,000 per
monthmonth
§§ Power & utility: RM5,000 per monthPower & utility: RM5,000 per month
§§ Building depreciation or rentals: RM10,000 Building depreciation or rentals: RM10,000 monthmonth
§§ 2 shifts, 8 hours / shift, 22 days / month. 2 shifts, 8 hours / shift, 22 days / month. Equals to 352 hours / monthEquals to 352 hours / month
Administration costAdministration cost
§§ Admin cost / month: RM65,000Admin cost / month: RM65,000
§§ Rate: RM65,000 / 352 hoursRate: RM65,000 / 352 hours
§§ RM185 / hrRM185 / hr
§§ For e.g. 50 projects per year. For e.g. 50 projects per year. §§ For e.g. 50 projects per year. For e.g. 50 projects per year. Apportionment equals 1/50. or RM3.70 / hr Apportionment equals 1/50. or RM3.70 / hr / project/ project
Profit marginProfit margin
§§ % of total production cost% of total production cost
§§ % value depends on:% value depends on:§§ Difficulty levelDifficulty level
§§ Timeline given by customerTimeline given by customer§§ Timeline given by customerTimeline given by customer
§§ Wisdom: Wisdom: §§ Can others do it?Can others do it?
§§ Rule of thumbRule of thumb
Quotation to customerQuotation to customer
§§ Project nameProject name
§§ Project reference numberProject reference number
§§ PricePrice
§§ WarrantyWarranty§§ WarrantyWarranty
§§ Delivery dateDelivery date
AmortisationAmortisation
§§ Definitions (ref: Wikipedia)Definitions (ref: Wikipedia)§§ of capital expenditures of certain assets under of capital expenditures of certain assets under
accounting rules, particularly accounting rules, particularly intangible intangible assetsassets, in a manner analogous to , in a manner analogous to depreciationdepreciationassetsassets, in a manner analogous to , in a manner analogous to depreciationdepreciation
§§ is the distribution of a single is the distribution of a single lumplump--sumsum cash cash flowflow into many smaller cash flow installments, into many smaller cash flow installments, as determined by an as determined by an amortization scheduleamortization schedule
§§ E.g. soft tools, R&D, prototypeE.g. soft tools, R&D, prototype
Cost summaryCost summaryItemItem BasisBasis Rate (e.g.)Rate (e.g.) RMRM
DesignDesign HrsHrs RM25/hrRM25/hr
Raw materialRaw material KgKg RM7/kgRM7/kg
Std. partStd. part L/sL/s As manufacturer listAs manufacturer list
MachiningMachining HrsHrs RM5 to RM60/hrRM5 to RM60/hr
Heat treatmentHeat treatment KgKg RM5/kgRM5/kg
HandlingHandling HrsHrs RM5/hrRM5/hr
DeliveryDelivery Km, weight, volumeKm, weight, volume RM5 to RM60/kmRM5 to RM60/km
AdminAdmin HrsHrs RM4RM4
TotalTotal --
Profit marginProfit margin %% 50 to 20050 to 200
QuotationQuotation
Cost summaryCost summary
Tue 09 Mar 2010
Forming technologiesForming technologies§§ Forming Forming
automationautomation
§§ High Speed High Speed Forming MachineForming Machine
§§ FineblankingFineblanking§§ FineblankingFineblanking Yamada Omega: 3,000RPM
Fineblanking: 300 pcs/min
Forming machine with auto-feeder
Design samplesDesign samples
Special designsSpecial designsSensors in die
Ball catch
Strip utilizationStrip utilization§§ Utilization rate of strip in producing the Utilization rate of strip in producing the
workpieceworkpiece flat blankflat blank
§§ Determines a good design or otherwiseDetermines a good design or otherwise
§§ To determine the best configurationTo determine the best configuration§§ Nr of rowNr of row
§§ Straight or slanting layoutStraight or slanting layout
Strip utilizationStrip utilization§§ Calculation:Calculation:§§ Ŋ = Utilization efficiency (%)Ŋ = Utilization efficiency (%)
§§ R = Nr of rowR = Nr of row
§§ A = flat blank surface area (inclusive holes)A = flat blank surface area (inclusive holes)
§§ V = Strip pitchV = Strip pitch§§ V = Strip pitchV = Strip pitch
§§ B = Strip widthB = Strip width
V.BR.A
η =
Force centre pointForce centre point§§ U = perimeter of each punchU = perimeter of each punch
§§ a = distance of punch centre point to a reference a = distance of punch centre point to a reference pointpoint
§§ x = distance between force centre point to x = distance between force centre point to reference pointreference point
.........
321
332211
++++++
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