Illustration for Creep Feed Grinding

TABLE OF CONTENTS
Development and Analysis of the Creep Feed Process, 1
Definition of the process, 1
History of its development, 2
Existing applications, 4
Workpiece materials, 8
Analysis of the creep feed process, 10
Basic grinding mechanics, 18
Application of the Creep Feed Process, 22
Introduction, 22
Depth of cut, 22
Feed rate, 23
Wheel type, 23
Wheel direction, 26
Wheel speed, 30
Coolant type, 32
Coolant application, 33
Avoiding workpiece burn, 39
Improving surface finish, 40
Avoiding chatter, 42
Main recommendations, 44
Preparation of the Wheel for Grinding, 47
Introduction, 47
Dressing of conventional wheels, 48
Preparation of semipermanent wheels, 65
Main recommendations, 73
The Limitation of Workpiece Burn in the Creep Feed Process, 76
Introduction, 76
The characteristics of burn in creep feed grinding, 76
Explanations of the thermal surge phenomenon, 80
Predicting the onset of workpiece burn, 84
Explanation of the influence of MNIR on the power flux at burn, 88
Thermal models, 89
Coolant Application, 100
Introduction, 100
Coolant application using a jet, 101
Coolant application using a shoe, 102
Warming~up of the coolant, 107
Effect of wheel structure, 109
Effect of wheel speed, 111
Effect offluid type, 113
Main conclusions, 115
Continuous Dressing, 117
The principle of continuous dressing, 117
Methods of continuous dressing, 118
The effects of continuous dressing on creep feed grinding, 124
Practical considerations in implementing continuous dressing, 134
Main conclusions, 137
Comparison of Creep Feed with Pendulum Grinding, 139
Introduction, 139
Comparison of grinding power, 139
Comparison of wheel wear and form retention, 146
Comparison of surface finish, 155
Workpiece temperatures and thermal damage, 161
Comparison of production times, 168
Comparison of workpiece accuracy, 171
Other competitors, 173
Summary of factors affecting the choice between creep feed and pendulum grinding, 174
Case Studies Group 1High Volume Applications Using
Conventional Abrasives, 176
Introduction, 176
Applications in the automotive industry, 177
Slot grinding applications in pump manufacture, 183
Applications in die and mould manufacture, 186
Creep feed grinding of Hirth serrations for precision alignment and indexing applications (heavy gas turbine and machine tool industries), 188
Applications in the manufacture of cutting instruments. 189
Applications in the manufacture of cutting tools, 194
Case Studies Group ~Continuous Dressing Applications, 196
Introduction, 196
Case studies in the aeroengine industry, 196
Case studies in general manufacturing industry, 200
Automated operations incorporating continuous dressing, 203
Case Studies Group ~Applications Using CBN and Diamond
Abrasives, 210
Introduction, 210
Form grinding operations using electroplated wheels, 212
Form grinding operations using crushable diamond and CBN wheels, 215
Case studies~CBN wheels, 216
Case studies~diamond wheels, 223
Other Applications of the Creep Feed Grinding Technique, 228
Introduction, 228
Cylindrical grinding applications~general considerations, 228
Grinding of partial cylindrical surfaces, 232
Grinding of complete cylindrical surfaces. 237
Thread grinding, 240
Cam grinding, 243
Gear grinding, 247
Flute grinding, 248
Concluding remarks, 248
Appendices
Appendix I
Appendix 2
Appendix 3
Measurement of grinding power using a dynamometer, 250
Specific energy graphs, 252
Recommended wheel specifications for creep feed grinding
operations, 255
Appendix 4 Prediction of spindle power required to accelerate the coolant when using the shoe application method, 256
Appendix 5 Calculations for assessing the economics of continuous dressing, 257
Appendix 6 Workpiece material specifications, 262
Glossary, 265
Index, 269
