QUICK DIE CHANGE SECOND EDITION David Smith Society of Manufacturing Engineers Dearborn, Michigan Copyright © 2004 Society of Manufacturing Engineers 987654321 All rights reserved, including those of translation This book, or parts thereof, may not be reproduced by any means, including photocopying, recording or microfilming, or by any information storage and retrieval system, without permission in writing of the copyright owners No liability is assumed by the publisher with respect to use of information contained herein While every precaution has been taken in the preparation of this book, the publisher assumes no responsibility for errors or omissions Publication of any data in this book does not constitute a recommendation or endorsement of any patent, proprietary right, or product that may be involved Library of Congress Catalog Card Number: 2004103070 International Standard Book Number: 0-87263-715-8 Additional copies may be obtained by contacting: Society of Manufacturing Engineers Customer Service One SME Drive, P.O Box 930 Dearborn, Michigan 48121 1-800-733-4763 www.sme.org Persons who contributed to producing this book: Robert King, Manager, SME Reference Publications Rosemary Csizmadia, SME Production Editor Frances Kania, SME Administrative Coordinator Jon Newberg, Contributing Editor Printed in the United States of America To all people who bring their enthusiasm and knowledge to the pressroom for advancement of the art of die setting Preface When asked by SME to write the first edition of Quick Die Change, which was published in 1991, I had just finished editing the third edition of Die Design Handbook SME was one of many engineering societies and trade associations holding seminars on the topic of quick die change The topic was drawing interest in trade publications, most notably Automotive Industries (AI) magazine Annually in the 1980s, under the leadership of AI editor John McElroy, an open competition was held to see who within the automotive industry could change over a line the most quickly Books flooded the marketplace, including English translations of Japanese works, which claimed discovery of the quick changeover of press tools from one part to another in less than 10 minutes For the reader and historians who study technology transfer, Quick Die Change, second edition provides references to the original invention to establish the true source of claims of die changes of under 10 minutes Quick Die Change, second edition builds off the success and strong points of the first edition It covers the tooling engineering aspects of quick changeover as well as the human resources, fair play, and safety issues facing those entrusted to carry out the task In comparison to the first edition, there are many more figures depicting the methods and people who make quick die change a standard way of doing business This includes those managers who take the time to learn from the real experts on the shop floor and provide a safe workplace and all needed equipment and training Dave Smith can be contacted by e-mail: dsmith@smithassoc.com Or, visit his website: www.smithassoc.com xv Table of Contents Preface xv Acknowledgments xvii Chapter Introduction History of Quick Die Change Why We Failed How Quick Die Change Works Keep Training Simple Quick Die Change in a World Economy Chapter Relationship of QDC to Economic Order Quantity and Just-in-Time Pitfalls of Excessive Run-ahead Working Toward an Economic Order Quantity of One The Economic Order Quantity Model 10 Reducing the EOQ 14 The Impact on Just-in-Time 14 Economic Order Quantity Analysis 17 Chapter Training, Acceptance, Involvement, and Support 19 The Survival Instinct 19 Training in Proper Procedures is Essential 20 Effective Employee Involvement 23 Respected Experts can be Valuable 24 Meeting Room Requirements 24 Training Materials and Instruction 27 Strategy for Scheduling Training 28 Union Involvement 29 Production Management Acceptance 30 Killing Two Birds with One Stone 30 Have Students Develop Their Own Work Rules 31 Support is Needed 33 Support Activities and Responsibilities 33 ix x Quick Die Change Chapter Basic Good Die Setting Practices Die Setters 47 The Die Setter Helps the Operator Avoid Shortcuts 48 Good Practices 48 Improving Die Alignment 59 Die Locating Methods 61 47 48 Chapter Die Clamping Methods 65 Examples of Poor Practices 66 Mechanical Die Fastening 75 Threaded Fastener Styles 82 Die Setting Wrenches 84 Standardized Clamping Height 84 Fastening Methods 86 Power-actuated Die Clamps 106 Powered Systems versus Manual Bolting 121 Chapter Die Parallels and Die Locating Methods 125 Die Parallels 125 Die Location 142 Chapter Quick Die Change Strategy 167 Importance of Quick Die Change 167 Automotive Supplier Case Study 168 Chapter Grouping Presses and Dies for Quick Die Change 173 Evaluating Presses and Dies for Grouping 173 Dealing with a Mix of Equipment 174 Every Shop Needs a Plan 175 Common Press Factors 177 Using Existing Records 181 Critical Factors for Running Jobs in the Home Press 182 Chapter Setting Progressive Dies Quickly and Accurately 183 Work Assignments Vary from Shop to Shop 184 Providing Feedback to the Die Repair Activity 184 Table of Contents xi Setting Progressive Dies 185 Starting Strips in Progressive Dies 194 Chutes and Conveyors 195 Camber Compensation 199 Designing Dies that Tolerate Cambered Stock 200 Plan a Good Starting Sequence 204 Lubrication 205 Cam Limit Switches 206 Die Protection Systems 206 Planning Sequence of Operations 208 Inductive Proximity Sensors 210 Photoelectric Sensors 213 Chapter 10 Setup of Tandem Line Dies 217 Care in Setting Draw and Stretch Form Dies 217 Bottoming Draw Dies in a Single-action Press 217 Single-action Inverted Draw Die with a Nitrogen Manifold 218 Systematic Procedures for Setting Single-action Draw Dies 220 Making Important Setup Information Available Directly on the Die 230 Slide Adjustment Mechanism and Hydraulic Overload 235 Making the Final Adjustment to Bottom the Die 236 Setting and Adjusting Double-action Press Draw Dies 236 Chapter 11 Operating Dies at a Common Shut Height 237 Definition of Shut Height 237 Common Pass Height Adds Advantages 238 Avoiding Damage During Conventional Die Setup 238 Shut Height Readout and Auto Adjustment 239 A Dangerous Assumption 240 How a Press Develops Tonnage 241 Deflection or Compression in Solid Steel 242 Applying the Law of the Spring to Presses 244 Example of How Slide Adjustment Increases Tonnage 245 Cutting Dies are an Exception 245 Die Shut Height May Vary with Tonnage Requirements 246 Measuring Press Deflection with Load Cells 247 Why Die Shut Height May Need Compensation 249 Retrofitting Example What Can Go Wrong? 250 xii Quick Die Change Common Press Shut Height Adjustment Procedure 254 Sources of Press Error 258 Common Die Shut Height Adjustment Procedure 261 Maintaining a Common Shut Height 262 Procedure for Transfer Presses 262 Exchanging Dies Between Presses at a Common Shut Height 266 Important Points to Remember 267 Chapter 12 Decoiling, Straightening, and Feeding Coil Stock 269 Example of Coil Feeding Auxiliary Equipment 269 Decoiling Systems 271 Quick Coil Change 272 Stock Straighteners 277 Crop Shears 279 Computer Integration of Pressworking Processes is Not Always Easy 280 Roll Straighteners are Not Always Necessary 281 Cases Where Coil Set May Not be a Problem 282 Determining the Bend Radius to Produce Coil Set 283 Quick Die Change and Quality Considerations 284 When Stock Curvature is Necessary 284 Chapter 13 Transfer Press and Die Operations 285 Typical Transfer Press Features 285 Examples of Transfer Press Operations 289 Multiple Slide Straightside Presses 292 Automatic Transfer Press Die Change at Auto Alliance 295 Employee Training 301 Die Design for Transfer Presses 302 CAD Design Considerations 302 Ford Woodhaven Stamping Plant Transfer Die Change 303 Problems Installing Transfer Presses in Old Plant Layouts 305 Safety When Inching the Press 306 Chapter 14 Basic Principles of Press Force Monitors 311 Force Monitoring 311 Measuring Press Strain to Determine Force 315 Table of Contents Poor Sensor Mounting 318 Gap-frame Press Sensor Locations 325 Gaging Underdriven Presses 326 Chapter 15 An Overview of Press Safeguarding 329 Company Standards 329 Historic Pre-OSHA Overview of Edward Crane 330 The Engineer’s Historic Duty in Safe Operations 330 Working in Presses and on Automation Safety 331 Avoiding Operator Injury 339 Power Press Law, Training, and Shop Rules 355 Presence Sensing Device Initiation (PSDI) 355 Chapter 16 Press Counterbalance Adjustment and Maintenance 357 Correct Air Counterbalance Pressure 357 Spring Counterbalances 357 Air Counterbalance Safe Construction Features 358 Air Counterbalance Function 359 Counterbalance System Components 360 Setting Correct Counterbalance Pressure 364 Common Errors in Counterbalance Adjustment 365 Automatic Pressure Adjustment 365 Establishing Correct Counterbalance Settings 366 Counterbalance Maintenance 368 Chapter 17 Ergonomics in the Pressroom 371 Carpal Tunnel Syndrome 371 Back Injuries 372 Implement Ergonomic Improvements Lifestyle Off the Job 374 374 Chapter 18 Dealing with the Unthinkable 377 Training and Preparedness 378 Raising the Ram 379 Regular Emergency Drills 381 Entrapment Occurrence 381 The Goal 382 xiii xiv Quick Die Change Chapter 19 Unsticking Presses Stuck on Bottom Dead Center 383 Action Plan if the Press Sticks on Bottom 383 Dealing with Stuck C-frame Presses 385 Unsticking Straightside Presses 385 Press Tie-rod Pre-stressing Theory and Procedures 386 Assembling Straightside Presses that have Tie Rods 397 Benefits of Proper Tie-rod Pre-stressing 398 Action to Take in the Event of a Large Overload 398 Example of a Broken Tie-rod Failure 401 Conclusion 403 Chapter 20 Die Maintenance Documentation and Tracking 405 Die Maintenance Team 405 Systematic Die Maintenance System 405 The Request for Maintenance Form 412 Case Study 413 Continuous Improvement 415 Index 417 Index Terms Links forged steel clamps 87 forklift operation 36 French gut 171 202 G gage accuracy 365 gage factor 313 gaggable tooling 14 gagging 14 gaging underdriven presses 326 gain sharing 304 gap-frame press 325 gear reduction nut 93 gibbing 225 gibs 225 grouping presses and dies decision-making factors 181 evaluation 173 existing records 181 manufacturing flexibility 174 metalworking speed 180 mix of equipment 174 mix of work 174 planning 175 press condition 180 press database 176 press factors 177 ram risers 178 This page has been reformatted by Knovel to provide easier navigation Index Terms Links H Harley Davidson 38 hearing 24 history holdout or restraint devices 340 hollow-piston cylinder clamp 109 hot-finished steel plate 126 hot-rolled steel bar 126 375 human entrapment overview 377 ram raising 379 rescue goal 382 severity 381 training and preparedness 378 hydraulic ledge clamp 111 hydraulic tie-rod nuts 392 hydraulically powered clamp 108 I inching the press 306 incremental deflection factor 248 inductive proximity sensors 210 injury prevention cumulative trauma 371 holdout or restraint devices 340 human entrapment 377 light curtains 345 This page has been reformatted by Knovel to provide easier navigation Index Terms Links injury prevention (Cont.) overview 339 physical barrier guard 342 presence sensing device initiation (PSDI) pullout devices 355 340 radio frequency (RF) safeguarding devices 348 rules and law 355 safety distance 352 safety training 354 two-hand controls 350 J jackbolt actuated tie-rod nuts 394 just-in-time economic order quantity 14 purpose key locator 160 K L lifestyle 374 light curtains 345 load cells 247 loading locating methods 59 398 149 This page has been reformatted by Knovel to provide easier navigation Index Terms lubrication Links 205 M maintenance manufactured part cost 34 mechanical clamps 93 mechanical die fastening 75 mechanical readout devices 240 mechanical strain measurement 312 metalworking speed 180 metric die setting 80 microstrain 266 misalignment 224 mis-hit damage 405 59 modulus of elasticity 244 multiple slide straightside press 292 N necking 227 never-lie inventory 15 nitrogen systems pressure 227 safety 226 setting a die 234 O Occupational Safety and Health Administration (OSHA) 329 346 354 This page has been reformatted by Knovel to provide easier navigation Index Terms offsetting dies Links 57 operator injury prevention 339 oyster shell 399 P part cost photoelectric sensors 213 physical barrier guards 342 piezoelectric sensors 315 pin locator 61 pinch point 330 pitch notch stops 200 positive stops 195 142 power-actuated die clamps automatic traveling 116 case study 117 compressed-air-powered 107 electrically powered 107 hollow-piston cylinder 109 hydraulic ledge 111 hydraulically powered 108 maintenance 120 power sources 106 safety 108 sliding 112 specialized pull-in type 114 power lockout presence sensing device 23 332 355 This page has been reformatted by Knovel to provide easier navigation Index Terms Links press adjustment 254 centering the load 56 deflection 57 developing tonnage 241 factors 177 gaging underdriven presses 326 identification 230 measuring press strain 315 multiple straightside presses 292 ram 160 safety 331 shut height adjustment 254 straightside press tie rods 397 transfer press 262 unsticking 383 production scheduling 244 247 287 37 progressive dies air blow-off devices 199 cam limit switches 206 camber compensation 199 cambered stock 200 chutes 195 containers 198 conveyors 195 die protection systems 206 die repair 184 406 This page has been reformatted by Knovel to provide easier navigation Index Terms Links progressive dies (Cont.) inductive proximity sensors 210 lubrication 205 photoelectric sensors 213 positive stops 195 sequence of operations 208 setting 183 setup blocks 186 setup 31 starting sequence 204 starting stops 194 starting strips 194 work assignments 184 proportional limit 243 proximity sensor 210 prussian blue 228 pry bar 158 pull-in type clamp 114 pullout devices 340 Q quick coil change 272 quick die change strategy 167 R radio frequency (RF) safeguarding devices 348 This page has been reformatted by Knovel to provide easier navigation Index Terms ram Links 160 raising 379 radio frequency (RF) safeguarding risers 178 tipping 293 repeatability 296 retrofitting 250 reverse surface 235 roll straightener 278 281 S safety air counterbalance construction 358 blocks 332 company standards 329 Crane, Edward 330 die clamping 65 die weights 364 distance 352 fastener standards 76 fork trucks 171 holdout or restraint devices 340 inching the press 306 nitrogen systems 226 Occupational Safety and Health Administration (OSHA) operator injury prevention 329 346 354 339 This page has been reformatted by Knovel to provide easier navigation Index Terms Links safety (Cont.) physical barrier guards 342 pinch point 330 power-actuated die clamps 108 power lockout 23 presence sensing device 355 presses and automation safety 331 pullout devices 340 332 radio frequency (RF) safeguarding devices rules and law threaded fasteners 348 355 82 torch heat 386 two-hand controls 350 training 354 scrap chute 53 semiconductor strain gages and sensors 314 adjustable proximity 213 attachment of strain gages 315 die protection systems 206 gap-frame press 325 inductive proximity 210 making your own 206 mounting 318 photoelectric 213 piezoelectric 315 sensors This page has been reformatted by Knovel to provide easier navigation Index Terms Links sensors (Cont.) pitman locations 317 specialized inductive 212 straightside press 318 servo drive 288 setup blocks 51 shear collars 232 Shingo, Shigeo shock absorbers shut height 69 101 237 adjustment 254 261 avoiding damage 238 common pass height advantages 238 compensation 249 49 exchanging dies 266 importance 267 maintaining 262 press adjustment 254 readout and adjustment 239 retrofitting 250 tonnage requirements 246 transfer presses 262 single-minute exchange of dies slide adjustments slugs 186 49 definition 87 237 235 245 49 spotting blue 228 spring counterbalance 357 This page has been reformatted by Knovel to provide easier navigation Index Terms Links stacking 397 stamping die weights 364 starting strips 194 statistical process control 44 stock straighteners overview 277 roll straighteners 278 tension leveling 278 two-position transducers 278 stops storage chutes 281 202 56 straightside press 292 strain gages and sensors 314 strain links 266 315 strain measurement 312 315 stretch form die 218 229 stretch leveling 42 stretch links 232 stroke-per-minute (SPM) meter 367 stuck presses 383 subplates 154 SUPERBOLT 394 318 385 397 support teams maintenance 34 manufacturing engineering 33 material handling 36 production 36 purchasing 40 This page has been reformatted by Knovel to provide easier navigation Index Terms Links support teams (Cont.) quality control 43 sales 44 toolroom 45 surge tanks swivel clamps 362 94 T T-slot bolt T-slot key locators 82 105 160 T-slot nut 82 teams 33 tension leveling 278 tie-rod failure 401 tie-rod pre-stressing benefits 398 electrical resistance heaters 392 hydraulic nuts 392 jackbolt actuated nuts 394 marking the nut 389 overview 386 pre-stress amount 387 procedure 387 thickness gage 390 torch heat 391 tonnage development 241 monitors 384 245 This page has been reformatted by Knovel to provide easier navigation Index Terms Links tonnage (Cont.) requirements 231 toolroom 45 torch heat 386 torque capacity 384 Toyota 246 training employee involvement human entrapment 23 378 instructor qualifications 24 meeting room 24 production management 30 proper procedure 20 safety scheduling statistical process control 354 28 support teams 33 transfer press 301 union involvement transfer press 29 262 Auto Alliance case study 295 CAD design 302 die design 302 drive methods 287 dual-axis feed 287 employee training 301 eyeleting machines 286 287 This page has been reformatted by Knovel to provide easier navigation Index Terms Links transfer press (Cont.) features 285 installing in old plant layouts 305 operations 289 servo drive 288 two-hand controls 350 U unbalanced loading 59 unsticking presses action plan 383 bumping 385 C-frame presses 385 crack propagation 399 engaging the clutch 385 machine damage 398 overload overview 398 straightside presses 385 tonnage monitors 384 torch heat 386 torque capacity 384 V V-and bumper pin locators V-locator attachments vendor certification 61 142 146 43 This page has been reformatted by Knovel to provide easier navigation Index Terms Links W washers welding die components Western Electric Company 68 140 wheatstone bridge strain link 313 world class 168 world economy Y Young's Modulus 244 This page has been reformatted by Knovel to provide easier navigation ... Chapter Quick Die Change Strategy 167 Importance of Quick Die Change 167 Automotive Supplier Case Study 168 Chapter Grouping Presses and Dies for Quick Die Change 173 Evaluating Presses and Dies... Several points to decrease changeover cost should be kept in mind: • Be ready for a die change • Semi-automatic die change • Automatic die change Die change time is reduced to almost zero with:... transfer, Quick Die Change, second edition provides references to the original invention to establish the true source of claims of die changes of under 10 minutes Quick Die Change, second edition