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Introductory Concepts and BIS Conventionspress Machine Drawing Press Basudeb Bhattacharyya Associate Professor Department of Aerospace Engineering and Applied Mechanics Indian Institute of Engineering Science and Technology, Shibpur University Oxford © Oxford University Press. All rights reserved. 3 Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries. Published in India by Oxford University Press Ground Floor, 2/11, Ansari Road, Daryaganj, New Delhi 110002, India © Oxford University Press 2018 The moral rights of the author/s have been asserted. First published in 2018 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, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, by licence, or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above. Press You must not circulate this work in any other form and you must impose this same condition on any acquirer. ISBN-13: 978-0-19-948749-3 ISBN-10: 0-19-948749-9 Typeset in Times New Roman by Anvi Composers, New Delhi Printed in India by Magic International (P) Ltd., Greater Noida Cover image:University Iaroslav Neliubov / Shutterstock Third-party website addresses mentioned in this book are provided by Oxford University Press in good faith and for information only. Oxford University Press disclaims any responsibility for the material contained therein. Oxford © Oxford University Press. All rights reserved. Preface A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. William Strunk, Jr Drawing is an art and artists aim at drawing objects the way machine parts after the design is finalized. This is also why they are visible to the naked eye or to beautify objects be- gradually the study of such software has become a part of yond their original form. Engineering or machine drawing the curriculum of machine drawing. Keeping this in mind is somewhat different in the sense that it requires the engi- this book, Machine Drawing, aims at providing readers a neer to not only sketch the object almost as a photographic comprehensive understanding of the subject. image but also represent it in different views. These dif- ferent views are detailed exploded views of the object that ABOUT THE BOOKPress are required to manufacture or engineer a product. Machine This book is primarily meant for undergraduate students of drawing in particular requires not just a steady hand but mechanical engineering for the course on machine draw- also a sense of perspective. ing. It takes readers through a gradual process of master- Machine drawing is a subject of utmost importance in ing the subject by first providing a detailed discourse on the mechanical engineering curriculum because the manu- elementary generalized items covering drawing boards, facturing of a machine depends completely on the design sheets, instruments to conventional representation of vari- and drawing, including dimensional specifications, of the ous items in context with the recommendations of relevant machine down to the last minute detail. For fabricating or latest BIS codes of practice. A list of relevant codes is also manufacturing a machine or a component of a machine,University the provided in the Appendix as a ready reckoner. In modern design is first prepared through analytical computations. times, drawings prepared by hand using pencils or inking Then the designed component is converted into pictorial device are losing their importance especially in case of re- representation on paper. It may be represented through petitive and large scale use in industries as they cause num- two-dimensional or three-dimensional drawings, or both, ber of inconveniences. Computer-Aided Drafting (CAD) is depending on the requirement. For two dimensional rep- the best suited alternative in such cases. Hence, relevant resentations, orthographic views are used and for picto- Oxford chapters are supplemented with drawing methods using rial representations, conventionally isometric drawings are AutoCAD. used. For the manufacturing process, the knowledge of pre- sentation of limits, tolerances, etc., on paper is a prerequi- KEY FEATURES site. All these, including the method of dimensioning, must follow the methods laid out in the various codes of practice Comprehensive Coverage The book provides compre- published by the Bureau of Indian Standards (BIS). In fact, hensive coverage of drawing instruments, sheets, lettering, starting from the size and shape of drawing boards, draw- and dimensioning, which enable students to understand ing tools, to the representation methods of machine compo- different aspects of machine drawing. This is followed by nents, are all guided by Indian Standard codes of practice. a chapter on sectional views focusing on both obvious and Traditionally this subject depended completely on manual specified section planes. A wide variety of fastening ar- drawings that were made using drafters. However, with the rangements such as welding, riveting, cotter, and pin along passage of time, computers have taken over, and machine with the different styles of attachment for shaft and pipe are parts are drawn using software applications for 2D and 3D discussed at length. Assembly and disassembly drawings design and drafting such as AutoCAD and SOLID EDGE. are discussed in terms of different components of inter- Design engineers now use these software for modelling nal combustion engine and steam power plant. Moreover, © Oxford University Press. All rights reserved. vi Preface some machine tools and their components and some mis- Chapter 3 presents different fastening arrangements that cellaneous machines are discussed. include welded, riveted, and threaded joints along with Illustrations Figures are the soul of this book. The size of variety of threads, bolt–nut assembly, and their drawing the book has been especially chosen to ensure that there methods. is enough space to illustrate figures with clarity so that Chapter 4 discusses shaft and pipe joining arrangements students get an explicit view of the drawings. Neat labels, and shaft attachments. Different types of valves and belt– proper dimensioning, and different views make the figures pulley assembly are detailed here. This chapter also in- totally unambiguous and easy to analyse and understand. cludes of a variety of bearing, gears, and worm wheel. Full pages are dedicated to a number of complicated and Chapter 5 discusses part and assembly drawings in rela- intricate figures. As much as possible, it has been tried to tion to parts of internal combustion engine (ICE) and steam place figures as close to the relevant text so that the stu- power plant. Major components of ICE and steam power dents do not have to flip pages while reading. plant are suitably presented here either in orthographic or isometric or both systems. AutoCAD and BIS codes Each relevant chapter has an Chapter 6 provides detailed drawings of some common AutoCAD supplement which provides drawing examples machine tools and some miscellaneous equipment such as using AutoCAD. The book presents specifications of BIS crane hook, surface roughness measuring stand, screw jack, codes of practice, up to the latest available edition, wher- knife switch, centrifugal pump, relief valve, belt drive, ever required. worm reduction gear box, and bevel gear junction box. Rich Pedagogy There are a number of solved examples in each chapter with step-by-step solutions. A detailed point- ACKNOWLEDGEMENTSPress wise recapitulation at the end of each chapter revisits all the It is a great pleasure and honour for me to be associated important points discussed in the chapter making for a fine with Oxford University Press. I express my sincere grati- guide for revision before the exams. This is followed by tude and thanks to the entire editorial team and production numerous multiple-choice questions, review questions, and department of Oxford University Press for publishing my numerical problems that promise to provide students ample book in time while maintaining a high degree of precision practice to make them perfect in the subject. Answers to the and accuracy. I thank the senior teachers of my department multiple choice questions have also been provided at the for their encouragement. I also express gratitude towards end of the chapters. my family members for their unfathomable inspirations. A Universityvery special mention goes to Mr Subir Pal of M/s Books CONTENTS AND COVERAGE and Equipment Distributors, Howrah. I am thankful to Prof. D.V. Srikanth (St. Martin’s Engineering The book is divided into 6 chapters. A brief of each of the College, Secunderabad) for his valuable feedback and con- chapters is mentioned below: tribution in enhancing the content. Chapter 1 deals with different items in context with the Every effort has been made to produce an error-free text; provisions laid out in the various codes of practice pub- however, I would be grateful if readers can point out any lished by the Bureau of Indian
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