Small Machine Tools for Small Workpieces (eBook)

Preface 6
Acknowledgements 7
Contents 8
Abbreviations 10
1 Introduction to the Priority Programme SPP1476—Small Machine Tools for Small Workpieces 13
Abstract 13
1 Historical Development of Machine Tools and Production Engineering 13
2 Idea and Motivation of the Priority Programme SPP1476 15
3 Project Partners of the SPP1476 19
4 Organisational Structure 19
4.1 Communication 20
4.2 Harmonisation 21
4.3 Standardisation 21
5 How Modules Are Combined to a Small Machine Tool for Micro Manufacturing 24
6 Sample Machine Tool Configurations 24
7 External Visibility and Publications of SPP1476 28
8 Summary and Outlook 29
References 30
Tools 31
Compact Air Bearing Spindles for Desktop Sized Machine Tools 32
1 Introduction 32
2 Compact Air Bearing Spindles for Micro Machining 34
2.1 Numerical Simulation of the Air Bearings 35
2.2 Stability Analysis 40
2.3 Basic Performance Evaluations 41
3 Micro Machining Experiments 42
4 Conclusion 43
References 44
3 Module for Micro Electrical Discharge Machining with Gaseous Dielectrics 46
Abstract 46
1 Introduction 46
2 Investigations on Dry-EDM Milling 47
2.1 Experimental Setup and Materials 48
2.2 Technological Research 48
2.3 Machining Strategy 50
3 Module for Dry-EDM Milling 52
3.1 Motion System 52
3.2 Control Architecture 53
3.3 System Performance Limits in Operation 54
3.4 Machining Results 55
4 Summary and Outlook 57
References 57
4 Compact Module for Maskless and Simultaneous 2D Laser Chemical Machining 59
Abstract 59
1 Introduction 59
2 Digital Micromirror Device: Technology 61
3 DMD-Jet: From a Large Prototype to a Compact Machine Tool 62
4 DMD Characterisation 64
4.1 Diffraction Efficiency 64
4.2 Imaging Quality 65
5 DMD-Based Laser Chemical Machining: Quality and Limitations 66
5.1 Intensity Threshold of Laser Chemical Machining of Metals 66
5.2 Quality of Laser Chemical Removal 67
6 Optical Modelling of DMD Projection 69
6.1 Model Description 69
6.2 Verification of Imaging Quality 71
7 Conclusions and Outlook 72
References 73
GrindBall---A Novel Drive and Bearing Concept for Micro Grinding Tools 75
1 Introduction 75
2 The GrindBall Concept and Design Requirements 77
3 Simulation and Dimensioning of Module and Main Functions 78
3.1 Dimensioning and Simulation of the Electromagnetic Bearing 78
3.2 Numerical Study of the Hydraulic Propulsion Concept 83
4 Experimental Validation of the Numerical Results for the Fluidic Tool Drive 86
5 Effect of Environmental Air on the Grinding Force 88
6 Implementation of Machining Technology 88
6.1 Manufacturing of Spherical Grinding Tools 89
6.2 Force Controlled Grinding 90
6.3 System Integration 92
7 Summary and Outlook 93
References 95
Actuators 96
6 Design and Experimental Validation of a Hybrid Actuator Based on Piezoceramics and Shape-Memory-Alloys 97
Abstract 97
1 Introduction 97
2 SMA Actuator 99
2.1 SMA Actuating Principle 99
2.2 SMA Actuator Design 100
2.3 SMA Control Concept 102
3 Piezo Actuator 103
3.1 Piezo Actuator Design 103
3.2 Piezo Actuator Control Concept 103
4 Hybrid Actuator 104
4.1 Hybrid Actuator Design 104
4.2 Hybrid Actuator Control Concept 105
4.2.1 Dynamic Splitting 105
4.2.2 Cascaded Control 106
5 Experimental Results 106
6 Summary and Outlook 108
References 109
7 Highly Integrated Self-compensating Hydraulic Feed Axis for Small Machine Tools 111
Abstract 111
1 Introduction 111
2 Approach 112
3 Requirements for a Feed Axis Module in the Context of Small Machine Tools for Small Workpieces 113
4 Synthesis of a Highly Integrated Hydraulic Feed Axis 114
5 Results 115
5.1 Hydraulic Linear Actuator with High Positioning Accuracy 115
5.2 Actively Controlled Guidance System for the Compensation of Geometric Errors 116
5.3 Evaluation of the Feed Axes Characteristics 119
6 Exemplary Application of the Feed Axis Module 121
7 Summary and Outlook 122
References 123
8 Modular Desktop Machining Centre with SMA Actuation 124
Abstract 124
1 Introduction 124
2 Shape Memory Technology 124
3 Overall Machine Concept 126
4 Design of the Modular Actuators 128
5 Control Strategies 131
6 Development of the z-Axis 134
7 Summary and Outlook 136
References 136
9 Fluid Dynamic Drive Module for Planar Motion in Three Degrees of Freedom 138
Abstract 138
1 Introduction 138
2 The Fluid Dynamic Three-Phase Linear Actuator 139
2.1 Working Principle 139
2.2 Control System 141
2.3 Prototype 141
3 The Fluid Dynamic XY-Drive 142
3.1 Multi-variable Control System 143
3.2 Results 143
4 The Fluid Dynamic XY?-Drive 144
4.1 Modified Drive Principle 144
4.1.1 Optimisation of the Flow Grid 145
4.2 Design of the XY?-Drive 146
4.3 Three Layer Control System 147
4.3.1 Liquid Media 148
5 Summary and Outlook 149
References 150
Novel Electrodynamic Feed Units for Small Machine Tools and Automation 151
1 Introduction 151
2 Linear Tables 153
3 Cylindrical Linear Axes 155
3.1 Linear Actuator with Flexure Guide 155
3.2 Highly Integrated Linear Axis 157
3.3 Integrated Position and Force Control 159
4 Novel Planar Direct Drive 160
5 Summary and Outlook 163
References 164
Functional Integrated Feed-Units Based on Flexible Mechanisms in Small Machine Tools for Small Workpieces 166
1 Introduction and Methodology 167
2 Optimized Design and Efficient Modeling of Compliant Mechanisms 167
2.1 Mechanical Properties of Flexure Hinges and Compliant Mechanisms 168
2.2 Topology Generation of Compliant Mechanisms 169
2.3 Pseudo-Rigid-Body Models with 3-DOF Joints 170
2.4 Substructuring and Model Order Reduction of a Finite Element Model 172
3 Mathematical Optimisation of the Trajectory 174
3.1 The Direct Kinematic Problem 175
3.2 A Control Problem for Trajectory Optimisation 175
3.3 A Hybrid Strategy to Solve the Optimal Control Problem 176
3.4 Numerical Evaluation of the Solver 177
4 Feed Units Based on Compliant Mechanisms 179
4.1 Design Methodology of New Feed Units 179
4.2 Realisation, Validation and Qualification of Feed Units 179
5 Summary and Conclusion 181
References 182
Additional Modules 184
High Accuracy Millimetre Wave Radar for Micro Machining 185
1 Introduction 186
2 Hardware of Radar Sensor Front-Ends 186
2.1 80GHz Radar Sensor with External Lens Antenna 186
2.2 240GHz Radar Sensor with On-chip Antennas 188
3 Signal Processing and System Analysis 190
3.1 Signal Processing 190
3.2 Evaluation of the Implemented System 195
4 Integration in Compact Machine Tools 196
4.1 Highly Integrated Drive Unit Module 197
4.2 Sub-micrometer Accuracy Measurements in Free Space Measurements 197
4.3 Free Space Integration in Machine Tool Cube 198
5 Conclusion 200
References 202
13 Multifunctional and Intelligent Mechanical Interface for a Fast, Easy and Precise (Re-)Configuration of Small Modular Machine Tools 203
Abstract 203
1 Introduction 203
2 Methodology 204
3 Interface System and Development 205
4 Domain Specific Design 205
4.1 Mechanical Design—Interface as Mating Area 206
4.2 Electronic and Information Technology Draft 208
5 Integration of Components and Design Verification 210
5.1 Integration of Components 210
5.2 Design Verification 211
6 Summary and Outlook 214
References 215
14 Modularly Structured, (Re-)Configurable Machines for Micro Machining by Means of Cooperative Motion Generation 217
Abstract 217
1 Initial Questions and Objectives 217
2 Machine Variants and Drive Concepts 218
2.1 Design Possibilities for the Base Module 218
2.2 Analysis of Drive Concepts 220
2.3 Extension of the PCM for 5-Axes Machining 221
2.4 Miniaturization of the PCM by Means of Generative Processes 222
3 Machine-Oriented Process Components and Variables 223
3.1 Detection of Machine- and Plant-Related Process Variables 223
3.2 Workpiece Clamping Systems 223
3.3 Workpiece Feed and Transport 226
4 Design Process and Inspection of PCMs 229
4.1 Simulation and Virtual Development Environment for Machine Models 229
4.2 Calibration Methods for (Re)Configuration Processes 230
4.3 Design of the Demonstrator 231
5 Summary 232
References 233