 | Altintas Y. Manufacturing automation: metal cutting mechanics, machine tool vibrations, and CNC design. - 2nd ed. - Cambridge; New York: Cambridge University Press, 2012. - xii, 366 p.: ill. - Bibliogr.: p.357-362. - Ind.: p.363-366.
- ISBN 978-0-521-17247-9
Шифр: (И/К6-А44) 02
|
Preface ........................................................ ix
1 INTRODUCTION ................................................. 1
2 MECHANICS OF METAL CUTTING ................................... 4
2.1 Introduction ............................................ 4
2.2 Mechanics of Orthogonal Cutting ......................... 4
2.3 Mechanistic Modeling of Cutting Forces ................. 15
2.4 Theoretical Prediction of Shear Angle .................. 18
2.5 Mechanics of Oblique Cutting ........................... 19
2.5.1 Oblique Cutting Geometry ........................ 19
2.5.2 Solution of Oblique Cutting Parameters .......... 21
2.5.3 Prediction of Cutting Forces .................... 25
2.6 Mechanics of Turning Processes ......................... 27
2.7 Mechanics of Milling Processes ......................... 35
2.7.1 Mechanics of Helical End Mills .................. 41
2.8 Analytical Modeling of End Milling Forces .............. 43
2.8.1 Mechanistic Identification of Cutting Constants
in Milling ...................................... 46
2.9 Mechanics of Drilling .................................. 47
2.10 Tool Wear and Tool Breakage ............................ 54
2.10.1 Tool Wear ....................................... 56
2.10.2 Tool Breakage ................................... 61
2.11 Problems ............................................... 62
3 STRUCTURAL DYNAMICS OF MACHINES ............................. 66
3.1 Introduction ........................................... 66
3.2 Machine Tool Structures ................................ 66
3.3 Dimensional Form Errors in Machining ................... 68
3.3.1 Form Errors in Cylindrical Turning .............. 68
3.3.2 Boring Bar ...................................... 70
3.3.3 Form Errors in End Milling ...................... 71
3.4 Structural Vibrations in Machining ..................... 74
3.4.1 Fundamentals of Free and Forced Vibrations ...... 75
3.4.2 Oriented Frequency Response Function ............ 82
3.4.3 Design and Measurement Coordinate Systems ....... 83
3.4.3 Analytical Modal Analysis for Multi-Degree-of-
Freedom Systems ................................. 85
3.4.4 Relative Frequency Response Function between
Tool and Workpiece .............................. 90
3.5 Modal Testing of Machine Structures .................... 92
3.5.1 Theory of Frequency Response Testing ............ 92
3.5.2 Experimental Procedures in Modal Testing ........ 97
3.6 Experimental Modal Analysis for Multi-Degree-of-
Freedom Systems ........................................ 98
3.7 Identification of Modal Parameters .................... 109
3.7.1 Global Nonlinear Optimization of Modal
Parameter Identification ....................... 113
3.8 Receptance Coupling of End Mills to Spindle-Tool
Holder Assembly ....................................... 115
3.8.1 Experimental Procedure ......................... 118
3.9 Problems .............................................. 120
4 MACHINE TOOL VIBRATIONS .................................... 125
4.1 Introduction .......................................... 125
4.2 Stability of Regenerative Chatter Vibrations in
Orthogonal Cutting .................................... 126
4.2.1 Stability of Orthogonal Cutting ................ 126
4.2.2 Dimensionless Analysis of Stability Lobes in
Orthogonal Cutting ............................. 132
4.2.3 Chatter Stability of Orthogonal Cutting with
Process Damping ................................ 135
4.3 Chatter Stability of Turning Operations ............... 139
4.4 Chatter Stability of Turning Systems with Process
Damping ............................................... 142
4.4.1 Metal Cutting Forces ........................... 144
4.4.2 Process Damping Gains Contributed by Flank
Wear ........................................... 145
4.4.3 Stability Analysis ............................. 147
4.5 Experimental Validation ............................... 148
4.6 Analytical Prediction of Chatter Vibrations in
Milling ............................................... 149
4.6.1 Dynamic Milling Model .......................... 149
4.6.2 Zero-Order Solution of Chatter Stability in
Milling ........................................ 154
4.6.3 Multi-Frequency Solution of Chatter Stability
in Milling ..................................... 160
4.7 Chatter Stability of Drilling Operations .............. 172
4.7.1 Dynamic Drilling Force Model ................... 173
4.8 Frequency Domain Solution of Drilling Stability ....... 176
4.9 Semidiscrete Time Domain Solution of Chatter
Stability ............................................. 178
4.9.1 Orthogonal Cutting ............................. 178
4.9.2 Discrete Time Domain Stability Solution in
Milling ........................................ 182
4.10 Problems .............................................. 186
5 TECHNOLOGY OF MANUFACTURING AUTOMATION ..................... 191
5.1 Introduction .......................................... 191
5.2 Computer Numerically Controlled Unit .................. 191
5.2.1 Organization of a CNC Unit ..................... 191
5.2.2 CNC Executive .................................. 193
5.2.3 CNC Machine Tool Axis Conventions .............. 193
5.2.4 NC Part Program Structure ...................... 193
5.2.5 Main Preparatory Functions ..................... 196
5.3 Computer-Assisted NC Part Programming ................. 201
5.3.1 Basics of Analytical Geometry .................. 201
5.3.2 APT Part Programming Language .................. 206
5.4 Trajectory Generation for Computer-Controlled
Machines .............................................. 211
5.4.1 Interpolation with Constant Displacement ....... 212
5.4.2 Acceleration-Limited Velocity Profile
Generation with Constant Interpolation Period .. 216
5.4.3 Jerk-Limited Velocity Profile Generation ....... 220
5.5 Real-Time Interpolation Methods ....................... 229
5.5.1 Linear Interpolation Algorithm ................. 230
5.5.2 Circular Interpolation Algorithm ............... 234
5.5.3 Quintic Spline Interpolation within CNC
Systems ........................................ 239
5.6 Problems .............................................. 245
6 DESIGN AND ANALYSIS OF CNC SYSTEMS ......................... 250
6.1 Introduction .......................................... 250
6.2 Machine Tool Drives ................................... 250
6.2.1 Mechanical Components and Torque Requirements .. 251
6.2.2 Feedback Devices ............................... 256
6.2.3 Electrical Drives .............................. 257
6.2.4 Permanent Magnet Armature-Controlled dc
Motors ......................................... 258
6.2.5 Position Control Loop .......................... 263
6.3 Transfer Function of the Position Loop ................ 264
6.4 State Space Model of Feed Drive Control Systems ....... 268
6.5 Sliding Mode Controller ............................... 281
6.6 Active Damping of Feed Drives ......................... 285
6.7 Design ofanElectrohydraulic CNC Press Brake ........... 293
6.7.1 Hydraulic Press Brake System ................... 293
6.7.2 Dynamic Model of Hydraulic Actuator Module ..... 296
6.7.3 Identification of Electrohydraulic Drive
Dynamics for Computer Control .................. 299
6.7.4 Digital Position Control System Design ......... 301
6.8 Problems .............................................. 307
7 SENSOR-ASSISTED MACHINING .................................. 313
7.1 Introduction .......................................... 313
7.2 Intelligent Machining Module .......................... 313
7.2.1 Hardware Architecture .......................... 314
7.2.2 Software Architecture .......................... 315
7.2.3 Intelligent Machining Application .............. 316
7.3 Adaptive Control of Peak Forces in Milling ............ 317
7.3.1 Introduction ................................... 317
7.3.2 Discrete Transfer Function of the Milling
Process System ................................. 319
7.3.3 Pole-Placement Control Algorithm ............... 321
7.3.4 Adaptive Generalized Predictive Control of
Milling Process ................................ 325
7.3.5 In-Process Detection of Tool Breakage .......... 330
7.3.6 Chatter Detection and Suppression .............. 333
7.4 Intelligent Pocketing with the IMM System ............. 334
7.5 Problems .............................................. 336
APPENDIX A: LAPLACE AND z TRANSFORMS .......................... 341
А.1 Introduction .......................................... 341
A.2 Basic Definitions ..................................... 343
A.3 Partial Fraction Expansion Method ..................... 347
A.4 Partial Fraction Expansion Method to Determine
Inverse Laplace and z Transforms ...................... 349
APPENDIX B: OFF-LINE AND ON-LINE PARAMETER ESTIMATION WITH
LEAST SQUARES ................................................. 353
B.1 Off-Line Least-Squares Estimation ...................... 353
B.2 Recursive Parameter Estimation Algorithm .............. 355
Bibliography .................................................. 357
Index ......................................................... 363
|
|
