About the Book This book, Design of Jigs, Fixtures and Press Tools, is aimed at providing the introductory knowledge on the subject to the undergraduate students studying mechanical and manufacturing engineering at most universities. Many of the universities prescribe a syllabus that contains both Design of Jigs and Fixtures, and Design of Press Tools in a single semester course. Keeping the above in mind, this book is designed in two parts. Part-I deals with Jigs and Fixtures and Part-II is earmarked exclusively for the study of Press Tools.
Both these subjects are built progressively in successive chapters. A separate appendix, in each part, provides short answer questions with answers, which will help the students in clarifying doubts and strengthen their knowledge base. The explanatory notes and illustrations provided in the book will serve the purpose of awakening the interest of the students and invoking in them the passion for tooling in their study of mechanical, manufacturing, or production engineering. Contents Foreword, Preface, PART I—JIGS AND FIXTURES 1.
Introduction to Jigs and Fixtures 2. Design of Locators 3. Design of Clamps 4. Design of Milling Fixtures 6.
Other Types of Fixtures, Design Exercises for Jigs and Fixtures, Worked Examples for Jigs and Fixtures, Appendix A: Metal Cutting Tools, Appendix B: Fits and Tolerances, Appendix C: Suggested Questions and Answers, PART II—PRESS TOOLS 1. Introduction to Presses and Auxiliary Equipment 2. Sheet Metal Forming Processes 3. Introduction to Press Tools, 4.
Introduction to the Design of Blanking, Piercing, Progressive and Compound Dies, K. Bending, Drawing and Forming Dies, Design Exercises for Press Tools, Appendix A: Properties of Materials, Appendix B: Drawing Speeds and Lubricants, Appendix C: Press Tools–Suggested Questions and Answers, References , Index About the Author K. Venkataraman is a Mechanical Engineer by training. He did his graduation from College of Engineering, Guindy (presently Anna University) and post-graduation from Concordia University, Canada.
He did his graduate apprenticeship in Durgapur Steel Plant of SAIL in the year 1971–72 and later worked with renowned engineering consultancy organisation, MECON for nearly 30 years. He was associated with steel, oil, defense and general industries. He got separated from MECON in October 2000 under the voluntary retirement scheme and joined as a faculty member in Sathyabama Institute of Science and Technology, Chennai and later on moved into the Mechanical Engineering department of Anna University. From the year 2005, he was a faculty of BITS Pilani, Chennai centre and was involved in the off-campus activities until 2014.
His wide experience extends from industry to academia. He is a member of the Institution of Engineers (India) and American Society of Mechanical Engineers. Venkataraman Design of Jigs, Fixtures and Press Tools Design of Jigs, Fixtures and Press Tools K. Venkataraman External Faculty Mechanical Engineering Department Anna University, Chennai, India John Wiley & Sons Ltd.
Design of Jigs, Fixtures and Press Tools K. Venkataraman © Author 2015 This Edition Published by John Wiley & Sons Ltd The Atrium, Southern Gate Chichester, West Sussex PO19 8SQ United Kingdom Tel : +44 (0)1243 779777 Fax : +44 (0)1243 775878 e-mail : customer@wiley.com Web : www.com For distribution in rest of the world other than the Indian sub-continent and Africa. Under licence from: Athena Academic Ltd Suite LP24700, Lower Ground Floor 145-157 St. John Street, London ECIV 4PW.
United Kingdom e-mail: athenaacademic@gmail.com Web: www.com ISBN : 978-11-1915-567-6 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the U. Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Designations used by companies to distinguish their products are often claimed as trademarks.
All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. Library Congress Cataloging-in-Publication Data A catalogue record for this book is available from the British Library. To My Dear Parents Late V.
Kalyanaraman and Mrs. Rajalakshmi Kalyanaraman Preface The subject ‘Tooling’ encompasses areas such as (i) Cutting Tools (ii) Gauges, (iii) Jigs and Fixtures, and (iv) Press Tools. Each of these fields is very vast. To become a successful professional, be it a designer or a production or manufacturing engineer, the student needs to have an in-depth knowledge of all the above topics.
In addition to the expertise needed in such specific areas, knowledge of Materials Science, Costing and Economics and Computer Modeling of components and sub-systems is also essential. The present book, Design of Jigs, Fixtures and Press Tools, is aimed at providing the introductory knowledge on the subject to the undergraduate students of mechanical and manufacturing engineering of Anna University. Many of the universities in India prescribe a syllabus that contains both Design of Jigs and Fixtures, and Design of Press Tools in a single semester course. Keeping the above in mind, this book is designed in two parts.
Part I deals with Jigs and Fixtures and Part II is earmarked exclusively for the study of Press Tools. Both these subjects are built progressively in successive chapters. A separate appendix in each part, provides short answer questions with answers, which will help the students in clarifying doubts and strengthen their knowledge base. The explanatory notes and illustrations provided in the book will serve the purpose of awakening the interest of the students and invoking in them the passion for tooling in their study of mechanical, manufacturing, or production engineering.
Finally, I wish to express my gratitude to the Anna University for providing support in my endeavour to write a book on the subject. Venkataraman Foreword The book, Design of Jigs, Fixtures and Press Tools by K. Venkataraman, is intended for undergraduate students in Mechanical Engineering and Production/Manufacturing Engineering students. It is a treatise on two major topics in ‘Tooling’, viz.
(a) Jigs and Fixtures and (b) Press Tools and thus makes it comprehensive for undergraduate students of Mechanical Engineering and allied branches. The book covers all the major topics in the subject. Some of the salient features of the book are as follows: Exhaustive illustrations covering almost all variants in the subject of Jigs, Fixtures and Press Tools. An appendix at the end of Part I of the book dealing with the mechanics of cutting tool operation and the forces involved in various tools such as turning, milling, drilling and broaching.
An appendix on worked examples for the first part showing the 2-D drawings of the typical jigs/fixtures as well as a 3-D model of a jig will be very useful for the beginner. 3-D models of fixtures such as (a) a common vise used in milling operations, (b) Three-jaw chuck and in the field of press tools a model of a progressive die with associated components for making the students understand the concepts better. The final chapter in Part II showing typical worked examples of drawing dies. Separate appendices giving suggested questions and answers in both the parts to facilitate review of the subject by the students.
I am sure that this book will go a long way in filling the long-felt gap by covering both the topics of tooling under one cover. I congratulate the author for this effort and hope the students make full use of it. Srinivasan Director AU-FRG Institute for CAD/CAM Anna University Contents Preface vii Foreword ix PART I : JIGS, FIXTURES 1. Introduction to Jigs and Fixtures 1.1 Introduction to Modern Day Production 1.2 Definition of Jigs, Fixtures and Tooling 1.3 Fundamental Concepts in the Design of Jigs and Fixtures 1.
Design of Locators 2.1 General Principles of Degrees of Freedom and Constraints 2.3 Other Principles in the Design of Locators 2.4 Various Types of Locators 2. Design of Clamps 3.1 Principles of Clamping 3.2 Classification of Clamps 3.2 Types of Jigs 4.3 Components of Jig 4.11 xii Design of Jigs, Fixtures and Press Tools 5. Design of Milling Fixtures 5.1 Salient Features of Milling Fixtures 5.2 Classification of Milling Fixtures 5. Other Types of Fixtures 6.1 Turning, Grinding, Broaching, 6.1 Welding and Modular Fixtures 6.7 Advantages and Disadvantages of Modular Fixtures 6.13 Worked Examples for Jigs and Fixtures WE.
Inclined Drilling Jig with Indexing (Chapter 4) WE. Box Jig (Chapter 4) WE. Indexing Milling Fixture (Chapter 5) WE. String Milling Fixture (Chapter 5) WE.
External Broaching Fixture (Chapter 6) WE. Boring Fixture (Chapter 6) WE.7 Appendix A: Metal Cutting Tools A.2 Single-Point Cutting Tools Used in Turning and Boring Fixtures A.3 Multi-point Cutting Tools A.4 Appendix B: Fits and Tolerances B.2 Unilateral and Bilateral Tolerances B.3 Shaft and Hole Basis of Specifying Tolerances B.7 Appendix C: Suggested Questions and Answers C.8 Contents xiii PART II: Press Tools 1. Introduction to Presses and Auxiliary Equipment 1.1 Classification of Presses 1.2 Classification Based on Power Source 1.3 Classification Based on Type of Press Frame 1.4 Classification Based on Method of Actuation of Slide 1.5 Classification Based on the Number of Slides in Action 1. Sheet Metal Forming Processes 2.2 Calculation of Force Requirements in Blanking and Piercing 2.3 Die Clearances in Blanking and Piercing 2.4 Process of Bending through ‘V’ Die and ‘Wiping’ Die 2.7 Drawing of Box-like Shells 2.8 Direct and Reverse Redrawing 2.
Introduction to Press Tools 3.1 Standard Die Set 3.2 Description of Press Tools 3. Introduction to the Design of Blanking, Piercing, Progressive and Compound Dies 4.1 Design of Blanking, Piercing, Progressive and Compound Dies 4.2 Guidelines for the Design of Press Tools 4.3 Design of Progressive Dies 4.5 Calculation of Centre of Pressure in Unsymmetrically Profiled Components 4.17 xiv Design of Jigs, Fixtures and Press Tools 5. Bending, Drawing and Forming Dies 5.2 Classification of Bending and Other Forming Dies 5.21 Design Exercises for Press Tools DE.3 Appendix A: Properties of Materials A.4 Appendix B: Drawing Speeds and Lubricants B.3 Appendix C: Press Tools–Suggested Questions and Answers C.11 References 1 PART-I I n T his P art JIGS AND FIXTURES 1. Introduction to Jigs and Fixtures 2.
Design of Locators 3. Design of Clamps 4. Design of Milling Fixtures 6. Other Types of Fixtures Design Exercises Worked Examples Appendix A: Metal Cutting Tools Appendix B: Fits and Tolerances Appendix C: Suggested Questions and Answers 1 Introduction to Jigs and Fixtures 1.1 INTRODUCTION TO MODERN DAY PRODUCTION The advent of industrialisation in the early decades of the 20th century has ushered in the concept of providing goods and services to the common man, like the motorcar, electric motors, ceiling fans, etc.
This enabled the government as well as the leaders in industry to provide affordable goods to the consumers. By improving the production techniques and by providing specialized tooling equipments, such as jigs, fixtures, special tools, and gauges, the production cost have reduced considerably without sacrificing the accuracy and interchangeability of parts and components. To achieve the desired quality and quantity of production, the concept of accuracy and interchangeability go hand in hand. They play a major role in meeting the present day classes of engineering production, namely, “flow production” and “batch production”.
To necessitate the need of jigs, fixtures and special tools, the four main engineering classes of production are as follows: 1. Job Production: This involves the manufacture of specialized components or systems to meet the specific needs of the customers. Examples of job production are the manufacture of jigs, fixtures and press tools. Batch Production: Some of the examples of batch production are the manufacture of aeroplanes, aero-engines, battle tanks, etc., that use the concept of intermittent manufacture of large range of products, produced in batches.
Some brands of motorcars like “Benz” and “BMW” may be classified under “batch production” as they are required to meet specific requirements. Flow Production: In flow production, the standardised finished products are produced in plants, specifically laid out for this purpose. Examples of flow production are the modern motorcar plants.