Tool Design Cutting Tool Design Basic tool angles (Tool Signature)
Transcript of Tool Design Cutting Tool Design Basic tool angles (Tool Signature)
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Tool DesignCutting Tool Design
Nageswara Rao Posinasetti
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Guidelines for Cutting tool Design
RigidityStrengthWeak linksForce limitationsSpeed, feed and sizeRelated force componentsChip disposalUneven motionsChatter
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Basic tool angles (Tool Signature)
Back rake angleSide rake angleEnd relief angleSide relief angleEnd cutting edge angleSide cutting edge angleNose radius
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Selecting carbide ToolsEstablish the operating conditionsSelect the
–Cemented carbide grade–Nose radius–Insert shape–Insert size–Insert thickness–Tool style–Rake angle–Shank size–Chip breaker
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Establish the operating conditions
Feed, speed and depth of cut greatly influence the machining performance.Also lead angle affects the performance
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FIGURE F-27 The difference in style A and style D holders for depth of cut and cutting edge engagement length (copyright ©General Electric Company).
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
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FIGURE F-28 Large, well-formed chips were produced by this tool with built-in chip breaker (Kennametal, Inc., Latrobe, PA).
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
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Large depth of cut
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To reduce cutting edge chipping
Increase the speedDecrease the feed and/or depth of cutChange to a tougher grade carbide insertUse a negative rake Hone the cutting edge before useCheck the rigidity and tool overhang
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Select the cemented carbide grade
Resistance to edge wear
Cast iron, nonferrous and nonmetallic materials
Straight carbides -Tungsten carbide (WC) and cobalt binder
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Select the cemented carbide grade
Coated carbides
Resistance to cratering
SteelsWC + Titanium carbide + Tantalum carbide with cobalt binder
Resistance to edge wear
Cast iron, nonferrous and nonmetallic materials
Straight carbides -Tungsten carbide (WC) and cobalt binder
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Select the nose radius
Based on surface finish
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FIGURE F-34 Surface finish versus nose radius (copyright © General Electric Company).
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Select the insert shape
Round – strong and large radius, good for higher feed ratesSquare – medium strongerTraingular – least stronger, less number of cutting edges, but more versatile in use
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FIGURE F-35 Insert shapes for various applications (Kennametal, Inc., Latrobe, PA)
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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FIGURE F-36 A 38-degree triangular insert used for a tracing operation (copyright © General Electric Company).
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Select the insert size
Smallest size based on the depth of cut usedCutting edge should be 1.5 times that of the length of cutting edge engagement.
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Select the insert thickness
Gives the strength of the tool
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FIGURE F-37 Insert thickness as determined by length of cutting edge engagement and feed rate (copyright © General Electric Company).
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Select the tool style
Based on the geometry of the operation to be performed.
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FIGURE F-38 Several of the many tool styles available (Kennametal, Inc., Latrobe, PA).
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Select the rake angle
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FIGURE F-39 Side view of back rake angles.
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Select the shank size
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FIGURE F-40 Determining shank size according to depth of cut, feed rate, and tool overhang (copyright © General Electric Company).
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
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FIGURE F-41 A boring bar with various interchangeable adjustable heads (Kennametal, Inc., Latrobe, PA).
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Select the chip breaker
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FIGURE F-42 Chip breakers used are the adjustable chip deflator (center) with a straight insert and the type with the built-in chip control groove.
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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FIGURE F-43(b, c) (a) Negative rake two-sided Kenloc inserts; *Maximum D.O.C. and feed rates (ipr) are limited by the insert thickness and cutting edge length. Application ranges are for AISI 1045 steel at 180 to 220 BHN (Kennametal, Inc., Latrobe, PA.)
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Tool Holder Identification
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FIGURE F-44 ASA tool identification system (Tool Application Handbook; data courtesy of Kennametal, Inc., Latrobe, PA, 1973.)
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Carbide Insert Identification
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FIGURE F-45 ASA carbide insert identification (Tool Application Handbook; data courtesy of Kennametal, Inc., Latrobe, PA, 1973.)
Richard R. Kibbe, John E. Neely, Roland O. Meyer, and Warren T. WhiteMachine Tool Practices, 7e
Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458
All rights reserved.
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Multiple-Point Cutting Tools
DrillingReamingMillingGear cutting
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Power requirement for Drilling
d = drill diameter, inf = feed in/rev
8.18.0200,25, dfMTorque =28.08.0 625500,57, ddfTThrust +=
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Power requirement for Reaming
⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢
⎣
⎡
⎟⎠⎞
⎜⎝⎛+
⎟⎠⎞
⎜⎝⎛−
= 2.01
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8.18.0
1
1300,23
dddd
dfkM
⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢
⎣
⎡
⎟⎠⎞
⎜⎝⎛ +
⎟⎠⎞
⎜⎝⎛−
= 2.01
1
8.08.0
1
1600,42
dddd
dfkT
d1 = reamer diameter, in.
f = feed in/rev
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Power
Power in HP
M = tool torque, in-lbN = speed, rpmPower in Watts = Hp * 746
025,63NMPc =
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Milling Cutters
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Machining Power
Depends on the material removal rateUses empirical equations developed based on experimentsSee Machinery’s Handbook– pp 1046 – 1055 (26th Edition)
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Pc = power at the cutting tool
Pm = power at the motor
Kp = power constant (see tab 24, 25 and 30)
Q = metal removal rate (tab 29)
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fm = feed rate, in/min or mm/min
f = feed rate for turning, in/rev or mm/rev
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Drilling
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T = Thrust; lb or N
M = Torque; in-lb or N.m
N = Spindle rpm
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