Adaptive Control System for Optimizing the ECG Process under the Overcut Constraint
One of the main limitations 1n Peripheral Electro Chemical Grinding (ECG) is the overcut phenomenon. The dominant parameters which govern the dimensions of the geometrical overcut are the voltage and the feedrate. This paper deals with the development of an empirical model which describes the overcut as a function of the dominant parameters. Pased on this model an adpative control system was built and experiments in Profile Peripheral ECG were carried out. A comparison of the results obtained with and without the adaptive control system is presented as well as the relationship between the side and bottom overcuts. According to the above an adaptive strategy to control the geometrical overcut in Profile ECG is suggested.
EXPERIMENTAL DETERMINATION OF THE PARAMETERS AFFECTING THE SURFACE QUALITY OF ELECTROCHEMICAL MACHINING PROCESSES
•An experimental study was made to investigate the role of cell: :voltage, electrolysing current, tool feed rate and additives to electrolyte, in the quality of drilled specimens, with respect to hole over-size, hole conicity and surface finish. :Tests were carried with the objective of finding the operating '. conditions of electrochemical drilling (ECD) which can lead to good accuracy and dimensional control of the products. The .results are also compared with the available literature data • •Finally the effects of various parameters are discussed in some detail. INTRODUCTION 'In a previous work [1] an experimental investigation of the effect of process parameters on productivity and rate of metal. removal during electrochemical machining of low carbon steels :was reported. In the present work some factors affecting the quality of the drilled surfaces are discussed. Emphasis is made on accuracy and dimensional control. EFFECT OF TOOL FEED RATE The effect of tool feed rate on ECD process with respect to hole oversize, hole conicity,.and surface roughness is investigated. 1. Effect of Tool Feed Rate on the Hole Oversize :Fig.1, shows a falling tendency for the hole oversize as a function of the tool feed rate at different gap voltages. This: :falling tendency of the oversize with the feed rate can be explained by the reduced time of the side machinig when higher feed rates are used. *Professor,Dean,Faculty of Eng. Minia University, Egypt **Associate Professor, Prod.Eng.Dept.College of Eng. King Abdulaziz Univ.Jeddah, Saudi Arabia. ***Assistant Lecturer Prod.Eng.Dept. Minia University,Egypt L FIRST A.M.E. CONFERENCE 29-31 Hay 1984, Cairo Obviously, a higher metal removal rate is obtained with high tool feed rates. Thus, the precipitation rate of anode product on the hole inner surface is increased. This precipitate forms a protective film, which prevents excessive side machining through a progressively increasing resistance. The latter will control the flow of side currents in the side gap, resulting in smaller hole oversize. 2. Effect of Tool Feed Rate on the Hole Conicity As expected, the hole conicity decreases as the tool feed rate increases. This behaviour is shown in Fig.2. As the tool feed rate increases the side machining effect decreases due to the reduced time, during which side machining occurs. Hopenfeld and Cole [2] showed that the gap becomes covergent in the downstream direction. The conicity may be reduced greatly if side tool insulation is used. Moreover, hole conicity was found to greatly depend on the tool shape. 3. Effect of Tool Feed Rate on the Surface Roughness Fig.3, shows the variation of the centreline average(C.L.A.)of the roughness as a function of tool feed rate at different gap voltages. The curves show that at a given gap voltage theC.L.A differes with the variations in feed rate. At the low feed rates of 0.55 to 1 mm/min., better values of C.L.A. were obtained with a gap voltage of 22V. At high feed rates of 2 to 2.45 mm/ min., values of C.L.A. are almost the same at different gap voltages. Higher values of surface roughness were observed at a gap voltage of 20 V. At a tool feed rate range of 1-2 mm/min., good surface roughness was obtained at various gap voltages. At low tool feed rate, the forward gap may not be stable due to the variation in the metal removal rate and the tool feed rate. Therefore, the gap resistance varies continuously with time. In this case poor surface finish was obtained duet o periodic dissolution of metal. But, on increasing tool feed rate, the forward gap decreases and the resistance to current flow also decreases. Therefore, current increases until it is sufficient to remove material at exactly the same rate of tool advancement. Therefore,good surface finish is associated with relatively high metal removal rates as determined by voltage, feed rate, and by keeping a constant -electrodes gap for a given cathode configuration. EFFECT OF ELECTROLYSING CURRENT The effect of the electrolysing current on ECD process with respect to hole oversize, hole conicity and surface roughness was investigated.
Managerial Economics and Organizational Architecture
PART 1: Basic Concepts Chapter 1: Introduction Chapter 2: Economists' View of Behavior Chapter 3: Markets, Organizations, and the Role of Knowledge PART 2: Managerial Economics Chapter 4: Demand Chapter 5: Production and Cost Chapter 6: Market Structure Chapter 7: Pricing with Market Power Chapter 8: Economics of Strategy: Creating and Capturing Value Chapter 9: Economics of Strategy: Game Theory Chapter 10: Incentive Conflicts and Contracts PART 3: Designing Organizational Architecture Chapter 11: Organizational Architecture Chapter 12: Decision Rights: The Level of Empowerment Chapter 13: Decision Rights: Bundling Tasks into Jobs and Subunits Chapter 14: Attracting and Retaining Qualified Employees Chapter 15: Incentive Compensation Chapter 16: Individual Performance Evaluation Chapter 17: Divisional Performance Evaluation Capstone Case Study on Organizational Architecture: Arthur Andersen LLP PART 4: Applications of Organizational Architecture Chapter 18: Corporate Governance Chapter 19: Vertical Integration and Outsourcing Chapter 20: Leadership: Motivating Change within Organizations Chapter 21: Understanding the Business Environment: The Economics of Regulation Chapter 22: Ethics and Organizational Architecture Chapter 23: Organizational Architecture and the Process of Management Innovation Glossary Index