Prelims-H8037.qxd 8/19/06 12:33 PM Page I Light and Heavy Vehicle Technology Prelims-H8037.qxd 8/19/06 12:33 PM Page II When theory and practice do not agree, you should examine the facts to see what is wrong with the theory Charles F. Kettering, General Motors (1934) Prelims-H8037.qxd 8/19/06 12:33 PM Page III Light and Heavy Vehicle Technology Fourth edition M.J. Nunney CGIA, MSAE, MIMI Amsterdam • Boston • Heidelberg • London • New York • Oxford Paris • San Diego • San Francisco • Singapore • Sydney • Tokyo Butterworth-Heinemann is an imprint of Elsevier P r e l i m s - H 8 0 3 7 . q x d 8 / 1 9 / 0 6 1 2 : 3 3 P M P a g e I V Butterworth-Heinemann is an imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP 30 Corporate Drive, Suite 400, Burlington, MA 01803 First published 1988 Reprinted 1991 Second edition 1992 Third edition 1998 Reprinted 1998, 2000, 2001, 2002, 2003, 2004, 2005 Fourth edition 2007 Copyright © 2007, M.J. Nunney. Published by Elsevier Ltd. All rights reserved. The right of M.J. Nunney to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988. 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 without the prior written permission of the publisher. Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone (⫹44) (0) 1865 843830; fax (⫹44) (0) 1865 853333; email: Prelims-H8037.qxd 8/19/06 12:33 PM Page V Contents Preface IX 5 Engine cooling, vehicle heating and air Acknowledgements X conditioning 124 Automotive technical abbreviations XI 5.1 Heat transfer and cooling media 124 5.2 Engine air-cooling system 125 1 The reciprocating piston petrol engine 1 5.3 Engine water-cooling system 127 5.4 Engine cooling systems for passenger 1.1 Modern requirements 1 cars and heavy vehicles 139 1.2 Engine nomenclature 2 5.5 Engine coolant 141 1.3 Operating principles 4 5.6 Interior ventilation and heating 143 1.4 Basic structure and mechanism 9 5.7 Introduction to passenger car air 1.5 Cylinder and crankthrow arrangements 12 conditioning systems 147 1.6 Cylinder block, crankcase and head 16 5.8 Principles of refrigerated air conditioning 147 1.7 Pistons and connecting rods 26 5.9 Refrigerated air conditioning system 1.8 Crankshaft assembly and main bearings 35 components 148 1.9 Crankshaft torsional vibration dampers 44 5.10 Full air conditioning systems 153 1.10 Valve train 47 5.11 Commercial vehicle refrigeration units 153 1.11 Timing drive 60 1.12 The principles of valve timing 66 6 Carburation and fuel injection 156 2 The diesel engine 71 6.1 Fuel supply system 156 6.2 Fixed-choke carburettors 162 2.1 Suitability for road transport 71 6.3 Variable-choke carburettors 168 2.2 Operating principles 71 6.4 Multiple and compound carburettors 171 2.3 Cylinder block, crankcase and head 74 6.5 Electronically controlled carburettors 173 2.4 Pistons and connecting rods 77 6.6 Petrol engine fuel injection 173 2.5 Crankshaft assembly and main 6.7 Multi-point fuel injection 175 bearings 80 6.8 Single-point fuel injection 178 2.6 Valve train and timing drive 82 6.9 Direct fuel injection 180 6.10 Electronic throttle control 181 3 Combustion chambers and processes 86 7 Intake and exhaust systems 183 3.1 Basic layouts of combustion chambers 86 7.1 Air cleaner and silencer 183 3.2 Combustion in the petrol engine 87 7.2 Intake and exhaust manifolds 185 3.3 Petrol engine combustion chambers 89 7.3 Exhaust system 189 3.4 Combustion in the diesel engine 94 7.4 Vacuum gauge and exhaust gas analyser 191 3.5 Diesel engine combustion chambers 95 3.6 Cylinder charge agitation 98 8 Diesel fuel injection systems 193 4 Engine lubrication 100 8.1 Fuel injection systems 193 8.2 Fuel supply system 193 4.1 Friction and wear 100 8.3 In-line fuel injection pump 196 4.2 The lubrication process 100 8.4 Governing the in-line fuel injection pump 200 4.3 Engine lubricating oils 102 8.5 Distributor fuel injection pump 205 4.4 Engine lubrication systems 106 8.6 Governing the distributor fuel injection pump 207 4.5 Oil pumps and pressure relief valves 114 8.7 Timing in-line and distributor fuel 4.6 Oil filtration and cooling 117 injection pumps 208 4.7 Oil retention and crankcase 8.8 Fuel injectors for jerk pump systems 209 ventilation 119 8.9 Unit fuel injection 213 V P r e l i m s - H 8 0 3 7 . q x d 8 / 1 9 / 0 6 1 2 : 3 3 P M P a g e V I VI C O N T E N T S 8.10 Introduction to electronic diesel control 215 15.4 Improvements to torque converters 323 8.11 Common rail fuel injection 218 15.5 Fluid couplings and torque converters 8.12 Cold starting devices 220 in service 323 9 Forced induction 223 16 Epicyclic gearboxes 326 9.1 Natural aspiration and forced induction 223 16.1 Basic epicyclic gearing 326 9.2 Methods of pressure charging 223 16.2 Operation of epicyclic gear trains 327 16.3 Friction brakes for epicyclic gearboxes 335 10 Ignition and starter systems 232 17 Semi-automatic and automatic 10.1 Coil ignition equipment 232 transmissions 340 10.2 Ignition coil and capacitor 233 10.3 Ignition distributor and sparking plugs 236 17.1 Semi-automatic transmissions for 10.4 Introduction to electronic ignition systems 243 passenger cars 340 10.5 Types of electronic ignition system 245 17.2 Semi-automatic transmissions for heavy 10.6 Ignition timing 247 vehicles 341 10.7 Damp ignition in service 249 17.3 Automatic transmissions for 10.8 The starter system 249 passenger cars 344 17.4 Hydraulic control systems 347 11 Engine emission control 255 17.5 Electrohydraulic control systems 354 17.6 Automatic transmission fluid 356 11.1 Petrol engine pollutants 255 17.7 Checking the level and changing the fluid 358 11.2 Petrol engine emission control 256 17.8 Automatic layshaft gearboxes 359 11.3 Diesel engine pollutants 258 17.9 Dual mode transmissions with 11.4 Diesel particulate filters 259 sequential gearchange 359 17.10 Direct shift gearbox 361 17.11 Continuously and infinitely variable 12 Rotary piston engine 261 transmissions 363 12.1 Rotary piston engine 261 18 Overdrive gears 371 13 Friction clutches 265 18.1 Purpose and position of an overdrive gear 371 18.2 Epicyclic overdrive gears 372 13.1 Types of single-plate clutch 265 18.3 Layshaft overdrive gears 374 13.2 Clutch control systems 268 18.4 Automatic transmission overdrive gears 377 13.3 Clutch centre plate construction 275 13.4 Direct-release clutch 279 13.5 Centrifugally operated clutches 279 19 Drive lines 379 13.6 Multiplate clutches 280 13.7 Angle spring clutch 282 19.1 Universal joints 379 13.8 Clutch misbehaviour in service 282 19.2 Constant-velocity joints 382 13.9 Flywheel and clutch housing alignment 286 19.3 Propeller shaft construction 389 19.4 Drive line arrangements 392 14 Layshaft gearboxes 288 19.5 Rear-wheel drive and front-wheel drive layouts 396 14.1 Purpose and elements of the gearbox 288 19.6 Front-wheel drive shafts 399 14.2 Constant-mesh gearboxes 292 19.7 Tandem axle drives for heavy vehicles 400 14.3 Synchromesh gearboxes 297 19.8 Drive lines for public service vehicles 401 14.4 Gear selector mechanisms 303 14.5 Heavy-vehicle gearboxes 308 20 Final drives and rear axles 403 14.6 Gearbox lubrication and sealing 313 14.7 Gearbox misbehaviour in service 316 20.1 Final drive gears and bearings 403 20.2 Adjusting the final drive gears 408 15 Fluid couplings and torque converters 317 20.3 Differential gears 414 20.4 Rear axle construction 418 15.1 Fluid couplings 317 20.5 Final drive lubrication and sealing 423 15.2 Improvements to fluid couplings 319 20.6 Rear axle misbehaviour in service 425 15.3 Torque converters 319 20.7 Heavy-vehicle rear axles 426 Prelims-H8037.qxd 8/19/06 12:33 PM Page VII C O N T E N T S VII 21 Four-wheel-drive systems 431 26 Four-wheel-steering systems 543 21.1 Types of four-wheel drive 431 26.1 The need for four-wheel 21.2 Basic considerations of four-wheel drive 432 steering 543 21.3 Part-time four-wheel drive 433 26.2 Types of four-wheel steering 547 21.4 Full-time four-wheel drive 435 27 Hydraulic brake systems 552 22 Tyres, road wheels and hubs 442 27.1 Drum brake arrangements 552 22.1 Tyre requirements 442 27.2 Disc brake arrangements 559 22.2 Introduction to tyre characteristics 442 27.3 Brake friction materials 565 22.3 Tyre construction 444 27.4 Hydraulic brake systems and 22.4 Road wheels and hubs 452 components 566 22.5 Wheel balancing 457 27.5 Hydraulic brake fluids 577 22.6 Safety precautions in tyre servicing 459 27.6 Vacuum servo-assisted braking 579 27.7 The parking brake system 582 27.8 Hydraulic power brakes 584 23 Suspension systems 461 27.9 Maintenance of hydraulic brakes 586 27.10 Brake efficiency and testing 589 23.1 Basic ride considerations 461 23.2 Types of suspension 461 23.3 Basic handling considerations 472 28 Air and endurance brake systems 591 23.4 Types of suspension spring 472 23.5 Tandem axle suspension 486 28.1 Principles of air brakes 591 23.6 Shock dampers 489 28.2 Compression and storage 592 23.7 Adaptive suspension systems 493 28.3 System control 594 23.8 Active roll control systems 494 28.4 System actuation 600 23.9 Suspension misbehaviour in service 495 28.5 Hand-operated brake valves and other equipment 605 28.6 Air disc brakes 606 24 Manual steering 496 28.7 Endurance brake systems 610 24.1 Steering principles and layout 496 24.2 Front end geometry and wheel alignment 499 29 Anti-lock brakes and traction control 614 24.3 Steering and suspension ball joints 506 24.4 Manual steering gears 509 29.1 Background to anti-lock braking 614 24.5 Inspecting and adjusting the steering 29.2 Basic components of anti-lock brake mechanism 515 systems 614 24.6 Conventionally steered and self-steering 29.3 Types of anti-lock brake systems 615 axles for heavy vehicles 518 29.4 Output control channels for anti- 24.7 Steering wheel airbags 519 lock brakes 618 29.5 Anti-lock air brakes for heavy 25 Power-assisted steering 521 vehicles 620 29.6 Traction control systems 621 25.1 The need for power-assisted steering 521 29.7 Vehicle dynamics control 622 25.2 Principles of hydraulic power- assisted steering 521 25.3 Hydraulic power-assisted steering 30 Vehicle structure and aerodynamics 625 components 524 25.4 Speed-sensitive hydraulic power- 30.1 Integral body construction 625 assisted steering 532 30.2 Aluminium body construction 636 25.5 Hydraulic power-assisted steering 30.3 Multi-purpose vehicles 638 misbehaviour in service 536 30.4 Commercial vehicle chassis frames 638 25.6 Electro-hydraulic power-assisted steering 536 30.5 Trailer and caravan couplings 644 25.7 Introduction to electrical power-assisted 30.6 Introduction to vehicle aerodynamics 648 steering 538 30.7 Basic considerations of vehicle 25.8 Electrical power-assisted steering aerodynamics 649 components 539 30.8 Aerocoustics 650 25.9 Types of electrical power-assisted steering 540 30.9 Heavy vehicle aerodynamics 651 P r e l i m s - H 8 0 3 7 . q x d 8 / 1 9 / 0 6 1 2 : 3 3 P M P a g e V I I I VIII C O N T E N T S 31 Alternative power sources and fuels 652 32.3 Layout of battery-electric vehicles 655 32.4 Basic units of battery-electric vehicles 655 31.1 General background 652 32.5 Hybrid-electric vehicles 657 31.2 Modern requirements for alternative fuels 652 32.6 Layout of hybrid-electric vehicles 657 31.3 Classification of alternative fuels 653 32.7 Basic units of hybrid-electric vehicles 658 32.8 Fuel-cell vehicles 659 32.9 Operation and types of fuel-cell 659 32 Battery-electric, hybrid and fuel-cell vehicles 655 32.10 Layout of fuel-cell vehicles 660 32.1 General background 655 32.2 Battery-electric vehicles 655 Index 661 Prelims-H8037.qxd 8/19/06 12:33 PM Page IX Preface The purpose of this new fourth edition of Light and Heavy Two entirely new sections of the book provide a topical Vehicle Technology remains one of providing readily accessi- introduction to alternative power sources and fuels, and battery- ble information, which bridges the gap between the purely electric, hybrid and fuel-cell vehicles. Also, the number of basic and the more advanced treatments of the subject. By entries in the list of automotive technical abbreviations has understanding the reasons behind the design, construction now increased to over 200. Finally, as in previous editions of and operation of the many and varied components of modern the book, the tradition of including brief historical notes on motor vehicles, the technician should be better equipped to the development of modern automotive concepts has been deal with their servicing and overhaul. Some references to continued. past automotive practice have been retained, not only M.J. Nunney because a technician may still be required to test and repair older vehicles, but also to provide a convenient transition to later practice. IX