© /JS/AQH fzcJ'Q DESIGN OF GREEN TIRE PAINTING MACHINE A dissertation submitted to the Department of Electrical Engineering, University of Moratuwa in partial fulfilment of the requirement for the degree of Master of Science ^ L I B R A R Y UNIVERSITY OF MORATUWA. SRI LANK > MORATUWA by SAMINDA ASELA BANDARA Supervised by Dr. Nalin Wickramarachchi University of Moratuwa — * " ' "" '"' * *"% H 93951 Department of Electrical Engineering University of Moratuwa, Sri Lanka August 2009 93 9$/ 9 3 3 5 1 DECLARATION The work submitted in this dissertation is the result of my own investigation, except where otherwise stated. It has not already been accepted for any degree, and is also not being concurrently submitted for any other degree. Saminda'Asela Bandara I endorse the declaration by the candidate. Supervisor: Dr. Nalin Wickramarachchi i CONTENTS Declaration i Abstract iv Acknowledgement v List of Figures vi List of Tables vii 1. Introduction 1 1.1 Background 1 1.2 Tire manufacturing process 2 1.3 Present method of the green tire painting 7 1.4 Objective of the project 9 2. Design Approaches 10 2.1 Initial attempts and problems 10 2.2 final approach 12 3. Detailed Design 14 3.1 Overview of the design 14 3.2 Loading Station 16 3.2.1 Loading station operational flowchart 17 3.3 Painting Station 18 3.3.1 Painting station operational flowchart 21 3.4 Unloading Station 22 3.4.1 Unloading station operational flowchart 24 3.5 Main arm rotation circuit 25 3.5.1 Main arm rotation flowchart 25 3.6 Clamping disk circuit 26 3.6.1 Clamping disk rotational flowchart 27 4. Components Selection 29 4.1 Pneumatic cylinders selection 29 4.1.1 Loading/Unloading cylinders 29 ii 4.1.2 Clamping cylinder 29 4.1.3 Main painting cylinder 30 4.1.4 Inside/Outside painting cylinders 31 4.2 Pressure switch selection 31 4.3 Motor selection 31 4.3.1 Main drive motor 31 4.3.2 Rotary drive 33 4.4 Indexing gearbox 34 4.5 PLC selection 35 4.6 Proximity sensors / Reflective sensors 36 4.7 Nozzles 36 4.8 Encoders 37 4.9 Rotary air union 38 4.10 Display 39 5. Discussion, Conclusion and Future Developments 41 5.1 Discussion 41 5.2 Payback calculation 42 5.3 Future developments 43 References 44 Appendix-A PLC Ladder Diagram .• 46 in Abstract The tire manufacturing process is a long process that includes lots of hazard operations. Manual green tire painting method is also considered in to this category. Green tire is the tire which builds according to the tire construction and which is ready for the curing process. Before the curing process, it has to apply lubricant inside the green tire and flow property improving agent on the out side. This application is called green tire painting. The main objective of this project is to design a new machine for green tire painting and protect operators from harsh environment, and improve the productivity. This project is focused more on actual requirements and takes a practical approach. When selecting components, it is restricted to select popular brands, which is recommended by the company. All the selected components are available in the market with reasonable price. As this is an actual machine design, I focused more on durability, productivity, safety and budget. The green tire painting machine is automated by the control unit which is a commercially available programmable logic controller (PLC). The requirement of the sensor units for the PLC and the control program is also implemented as part of this design. IV Acknowledgement Thanks are due first to my supervisor, Dr. Nalin Wickramarachchi, for his great insights, perspectives, guidance and sense of humor. His guidance directed me to the success of this project. My sincere thanks go to the officers in Post Graduate Office, Faculty of Engineering, University of Moratuwa, Sri Lanka for helping in various ways to clarify the things related to my academic works in time with excellent cooperation and guidance. Sincere gratitude is also extended to the people who serve in the Department of Electrical Engineering office. I sincerely gratitude to Mr. Jonas Lundgren, General Manager, Light Industrial Tire division, for his approval and guide to perform this project. I must thank Mr. Dian Gunathilake, HR Director, who made financial support for the second year of my masters studies. Their support directed me to the success of this project. Lastly, I should thank many individuals, friends and colleagues who have not been mentioned here personally in making this educational process a success. May be I could not have made it without your supports. List of Figures Figure Page 1.1 Pneumatic tire manufacturing process 2 1.2 Cross section of a tire 4 1.3 Green tire 5 1.4 Green tire with polythin wrap around the bead 5 1.5 Tire mould in the press with curing bladder 6 1.6 Cured tire 6 1.7 Manual green tire inside painting method 7 1.8 Manual green tire outside painting method 8 2.1 Basic design of fist attempt 10 2.2 Basic design of second attempt 11 2.3 Final design 12 3.1 Main arm rotation and positions 14 3.2 Green tire loading-1 15 3.3 Green tire loading-2 15 3.4 Loading station operational flowchart 16 3.5 Clamping disk at painting position 18 3.6 Green tire at painting position-1 18 3.7 Green tire at painting position-2 19 3.8 Painting station operational flowchart 20 3.9 Unloading position -1 22 3.10 Unloading position -2 22 3.11 Unloading station operational flowchart : 23 3.12 Main arm rotation flowchart 24 3.13 Clamping disk operation 25 3.14 Clamping disk operational circuit 26 4.1 Force distribution between green tire and grabbing arm 29 4.2 Pressure switch •. 30 4.3 Indexing gearbox 34 4.4 Retro reflective sensor 35 4.5 Paint nozzle 36 4.6 Incremental encoder 37 4.7 Rotary air union 37 4.8 Rotary air union assembly 38 4.9 TD 200C display 38 VI List of Tables Table Page 3.1 Digital position indication by Arm-1 & Arm-2 switches 15 4.1 PLC specifications 36 5.1 Costing 41 Vll List of Tables Table Page 3.1 Digital position indication by Arm-1 & Arm-2 switches 15 4.1 PLC specifications 36 5.1 Costing 41 Vll