دانلود کتاب نقشه کشی هندسی و مهندسی

Engineering drawings have been used to convey clear information about an object or system for many decades. They are graphic representations of prod- ucts and depict how an object is designed, how it functions and how it is sup- posed to be manufactured and assembled. With the advent of comprehensive computer-aided design (CAD) programs, the way engineering drawings are cre- ated significantly changed. The introduction of three-dimensional (3D) CAD systems especially has revolutionised the approach for conveying the specifica- tions of a technical product. Although the tools for creating engineering draw- ings have changed dramatically with time, the underlying principles are still the same. The fundamentals of descriptive geometry are still necessary for many applications of geometric drawing, and the same conventions and best prac- tices still apply to the drafting process. Despite the rapid pace of computational improvements and the resulting possibilities of supporting and rationalising the drafting process, the basic concepts of geometric and engineering draw- ing have lost nothing of their relevance. Nowadays, geometric drawing is an essential skill for graphically solving geometric problems as part of a concept phase in a design process and for understanding the theory behind CAD sys- tems. Although the current trend is to communicate product data exclusively with means of 3D CAD models for paperless production, we are far away from sending engineering drawings into retirement. Engineering drawings, no mat- ter if resulting from manual drafting or as end products of a CAD modelling process, are still an efficient form of communication, required in all engineering disciplines. This fourth edition has been entirely revised and heavily updated. While the fundamentals of geometric drawing have been taken from earlier editions, some completely new chapters are included that emphasise each part of the engineering drawing. The new edition starts with an introduction to engineering communication and some basics of engineering drawing such as drafting equipment, interna- tionally agreed conventions and principal techniques of technical sketching. The chapter on geometric constructions is almost unchanged from earlier editions. It shows specific drawing solutions to many geometric problems. Before intro- ducing readers to the different types of views in engineering drawing, methods of spatial visualisation and basic concepts of descriptive geometry are pre- sented. New chapters thoroughly address the important topics of dimensioning and tolerancing. Further, we introduce common representations of workpiece elements and frequently occurring machine elements as well as assembly draw- ings and their properties. All chapters related to engineering drawing have been updated to the lat- est recommendations from the International Organization for Standardiza- tion (ISO), that is, best practices from the international standards developing organisation. However carefully one checks a manuscript, errors creep in. We shall be very grateful if any readers who find errors let us know through the publishers.