Advanced Vehicle Technology To my long-suffering wife, who has provided sup- port and understanding throughout the preparation of this book. Advanced Vehicle Technology Second edition Heinz Heisler MSc., BSc., F.I.M.I., M.S.O.E., M.I.R.T.E., M.C.I.T., M.I.L.T. Formerly Principal Lecturer and Head of Transport Studies, College of North West London, Willesden Centre, London, UK OXFORD AMSTERDAM BOSTON LONDON NEW YORK PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO Butterworth-Heinemann An imprint of Elsevier Science Linacre House, Jordan Hill, Oxford OX2 8DP 225 Wildwood Avenue, Woburn, MA 01801-2041 First published by Edward Arnold 1989 Reprinted by Reed Educational and Professional Publishing Ltd 2001 Second edition 2002 Copyright # 1989, 2002 Heinz Heisler. All rights reserved The right of Heinz Heisler 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 in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a license issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1T 4LP. Applications for the copyright holder's written permission to reproduce any part of this publication should be addressed to the publishers Whilst the advice and information in this book are believed to be true and accurate at the date of going to press, neither the authors nor the publisher can accept any legal responsibility or liability for any errors or omissions that may be made. Library of Congress Cataloguing in Publication Data A catalogue record for this book is available from the Library of Congress ISBN 0 7506 5131 8 For information on all Butterworth-Heinemann publications visit our website at www.bh.com Typeset by Integra Software Services Pvt. Ltd, Pondicherry, India www.integra-india.com Printed and bound in Great Britain 1 Vehicle structure 1.1 Integral body construction 1.2 Engine, transmission and body structures 1.3 Fifth wheel coupling assembly 1.4 Trailer and caravan drawbar couplings 1.5 Semi-trailer landing gear 1.6 Automatic chassis lubrication system 2 Friction clutch 2.1 Clutch fundamentals 2.2 Angular driven plate cushioning and torsional damping 2.3 Clutch friction materials 2.4 Clutch drive and driven member inspection 2.5 Clutch misalignment 2.6 Pull type diaphragm clutch 2.7 Multiplate diaphragm type clutch 2.8 Lipe rollway twin driven plate clutch 2.9 Spicer twin driven plate angle spring pull type clutch 2.10 Clutch (upshift) brake 2.11 Multiplate hydraulically operated automatic transmission clutches 2.12 Semicentrifugal clutch 2.13 Fully automatic centrifugal clutch 2.14 Clutch pedal actuating mechanisms 2.15 Composite flywheel and integral single plate diaphragm clutch 3 Manual gearboxes and overdrives 3.1 The necessity for a gearbox 3.2 Five speed and reverse synchromesh gearboxes 3.3 Gear synchronization and engagement 3.4 Remote controlled gear selection and engagement m 3.5 Splitter and range change gearboxes 3.6 Transfer box power take-off 3.7 Overdrive considerations 3.8 Setting gear ratios 4 Hydrokinetic fluid couplings and torque converters 4.1 Hydrokinetic fluid couplings 4.2 Hydrokinetic fluid coupling efficiency and torque capacity 4.3 Fluid friction coupling 4.4 Hydrokinetic three element torque converter 4.5 Torque converter performance terminology 4.6 Overrun clutches 4.7 Three stage hydrokinetic converter 4.8 Polyphase hydrokinetic torque converter 4.9 Torque converter with lock-up and gear change friction clutches 5 Semi- and fully automatic transmission 5.1 Automatic transmission consideration 5.2 Four speed and reverse longitudinally mounted automatic transmission mechanical power flow 5.3 The fundamentals of a hydraulic control system 5.4 Basic principle of a hydraulically controlled gearshift 5.5 Basic four speed hydraulic control system 5.6 Three speed and reverse transaxle automatic transmission mechanical power flow 5.7 Hydraulic gear selection control components 5.8 Hydraulic gear selection control operation 5.9 The continuously variable belt and pulley transmission 5.10 Five speed automatic transmission with electronic-hydraulic control 5.11 Semi-automatic (manual gear change two pedal control) transmission system 6 Transmission bearings and constant velocity joints 6.1 Rolling contact bearings 6.2 The need for constant velocity joints 7 Final drive transmission 7.1 Crownwheel and pinion axle adjustments 7.2 Differential locks 7.3 Skid reducing differentials 7.4 Double reduction axles 7.5 Two speed axles 7.6 The third (central) differential 7.7 Four wheel drive arrangements 7.8 Electro-hydralic limited slip differential 7.9 Tyre grip when braking and accelerating with good and poor road surfaces 7.10 Traction control system 8 Tyres 8.1 Tractive and braking properties of tyres 8.2 Tyre materials 8.3 Tyre tread design 8.4 Cornering properties of tyres 8.5 Vehicle steady state directional stability 8.6 Tyre marking identification 8.7 Wheel balancing 9 Steering 9.1 Steering gearbox fundamental design 9.2 The need for power assisted steering 9.3 Steering linkage ball and socket joints 9.4 Steering geometry and wheel alignment 9.5 Variable-ratio rack and pinion 9.6 Speed sensitive rack and pinion power assisted steering 9.7 Rack and pinion electric power assisted steering 10 Suspension 10.1 Suspension geometry 10.2 Suspension roll centres 10.3 Body roll stability analysis 10.4 Anti-roll bars and roll stiffness 10.5 rubber spring bump or limiting stops 10.6 Axle location 10.7 Rear suspension arrangements 10.8 Suspension design consideration 10.9 Hydrogen suspension 10.10 Hydropneumatic automatic height correction suspension 10.11 Commercial vehicle axle beam location 10.12 Variable rate leaf suspension springs 10.13 Tandem and tri-axle bogies 10.14 Rubber spring suspension 10.15 Air suspensions for commercial vehicles 10.16 Lift axle tandem or tri-axle suspension 10.17 Active suspension 10.18 Electronic controlled pneumatic (air) suspension for on and off road use 11 Brake system 11.1 Braking fun 11.2 Brake shoe and pad fundamentals 11.3 Brake shoe expanders and adjusters 11.4 Disc brake pad support arrangements 11.5 Dual- or split-line braking systems 11.6 Apportional braking 11.7 Antilocking brake system (ABS) 11.8 Brake servos 11.9 Pneumatic operated disk brakes (for trucks and trailers) 12 Air operated power brake equipment and vehicle retarders 12.1 Introductions to air powered brakes 12.2 Air operated power brake systems 12.3 Air operated power brake equipment 12.4 Vehicle retarders 12.5 Electronic-pneumatic brakes 13 Vehicle refrigeration 13.1 Refrigeration terms 13.2 Principles of a vapour-compression cycle refrigeration system 13.3 Refrigeration system components 13.4 Vapour-compression cycle refrigeration system with reverse cycle defrosting 14 Vehicle body aerodynamics 14.1 Viscous air flow fundamentals 14.2 Aerodynamic drag 14.3 Aerodynamic lift 14.4 Car body drag reduction 14.5 Aerodynamic lift control 14.6 Afterbody drag 14.7 Commercial vehicle aeordynamic fundamentals 14.8 Commercial vehicle drag reducing devices Index 1.1.1 Description and function of body components (Fig. 1.2) The major individual components comprising the body shell will now be described separately under the following subheadings: 1 Window and door pillars 2 Windscreen and rear window rails 3 Cantrails 4 Roof structure 5 Upper quarter panel or window 6 Floor seat and boot pans 7 Central tunnel 8 Sills 9 Bulkhead 10 Scuttle 11 Front longitudinals 12 Front valance 13 Rear valance 14 Toe board 15 Heel board Window and door pillars (Fig. 1.2(3, 5, 6, and 8)) Windowscreen and door pillars are identified by a letter coding; the front windscreen to door pillars are referred to as A post, the centre side door pillars as BC post and the rear door to quarter panel as D post. These are illustrated in Fig. 1.2. These pillars form the part of the body structure which supports the roof. The short form A pillar and rear D pillar enclose the windscreen and quarter windows and provide the glazing side channels, whilst the centre BC pillar extends the full height of the passenger compartment from roof to floor and supports the rear side door hinges. The front and rear pillars act as struts (compressive members) which transfer a proportion of the bending effect, due to underbody sag of the wheelbase, to each end of the cantrails which thereby become reactive struts, opposing horizontal bending of the pas- senger compartment at floor level. The central BC pillar however acts as ties (tensile members), trans- ferring some degree of support from the mid-span of the cantrails to the floor structure. Windscreen and rear window rails (Fig. 1.2(2)) These box-section rails span the front window pillars and rear pillars or quarter panels depending upon design, so that they contribute to the resist- ance opposing transverse sag between the wheel track by acting as compressive members. The other function is to support the front and rear ends of the roof panel. The undersides of the rails also include the glazing channels. Cantrails (Fig. 1.2(4)) Cantrails are the horizon- tal members which interconnect the top ends of the vertical A and BC or BC and D door pillars (posts). These rails form the side members which make up the rectangular roof framework and as such are subjected to compressive loads. Therefore, they are formed in various box-sections which offer the greatest compressive resistance with the minimum of weight and blend in with the roofing. A drip rail (Fig. 1.2(4)) is positioned in between the overlap- ping roof panel and the cantrails, the joins being secured by spot welds. Roof structure (Fig. 1.2) The roof is constructed basically from four channel sections which form the outer rim of the slightly dished roof panel. The rectangular outer roof frame acts as the com- pressive load bearing members. Torsional rigidity to resist twist is maximized by welding the four corners of the channel-sections together. The slight curvature of the roof panel stiffens it, thus prevent- ing winkling and the collapse of the unsupported centre region of the roof panel. With large cars, additional cross-rail members may be used to provide more roof support and to prevent the roof crushing in should the car roll over. Upper quarter panel or window (Fig. 1.2(6)) This is the vertical side panel or window which occupies the space between the rear side door and the rear window. Originally the quarter panel formed an important part of the roof support, but improved pillar design and the desire to maximize visibility has either replaced them with quarter windows or reduced their width, and in some car models they have been completely eliminated. Floor seat and boot pans (Fig. 1.3) These consti- tute the pressed rolled steel sheeting shape to enclose the bottom of both the passenger and lug- gage compartments. The horizontal spread-out pressing between the bulkhead and the heel board is called the floor pan, whilst the raised platform over the rear suspension and wheel arches is known as the seat or arch pan. This in turn joins onto a lower steel pressing which supports luggage and is referred to as the boot pan. To increase the local stiffness of these platform panels or pans and their resistance to transmitted vibrations such as drumming and droning, many narrow channels are swaged (pressed) into the steel sheet, because a sectional end-view would show a 2 [...]... would improve the quality of a ride 30 30 a) n0 ˆ p ˆ p x 0:0 02 30 ˆ 670:84 vib/min 0:044 72 n 800 ; ˆ 1: 193 ˆ n0 670:84 ˆ The ratio 1. 193 is very near to the resonance condition and should be avoided by using softer mounts n 800 b) ˆ ˆ 2: 5 n0 n0 800 ˆ 320 vib/min 2: 5 30 Now n0 ˆ p x p 30 thus x ˆ n0   2  30 30 2 ;xˆ ˆ n0 320 ; n0 ˆ 1 .2. 10 Types of rubber flexible mountings A survey of typical rubber... Ft ˆ Fd 1  2 n 1 n0 transmitted force or amplitude imposed disturbing force or amplitude This relationship between transmissibility and the ratio of disturbing frequency and natural frequency may be seen in Fig 1. 17 Fig 1. 16 Relationship of static deflection and natural frequency 16 Fig 1. 15 (a±e) Coupled and uncoupled mounting points 17 The transmissibility to frequency ratio graph (Fig 1. 17) can... centre of gravity 2 Rotational flexibility around both the horizontal lateral and the vertical axis to accommodate any horizontal and vertical shake and rock caused by unbalanced reciprocating forces and couples Inclined interleaf rectangular sandwich mounting (Fig 1. 18(c)) These rectangular blocks are 19 Fig 1. 18 (a±h) Types of rubber flexible mountings 20 Fig 1. 18 contd 21 Fig 1. 18 contd designed... such components as the exhaust pipe and silencer system 8 To restrict engine movement in the fore and aft direction of the vehicle due to the inertia of the engine acting in opposition to the accelerating and braking forces 1 .2. 3 Rubber flexible mountings (Figs 1. 10, 1. 11 and 1. 12 ) A rectangular block bonded between two metal plates may be loaded in compression by squeezing the plates together or by... beam under rough abnormal operating conditions, thus preventing over-straining the drawbar and chassis system 27 Fig 1 .23 (a±d) Fifth wheel coupling with twin jaws plunger and pawl 28 Fig 1 .24 (a±d) Fifth wheel coupling with single jaw and pawl 29 Fig 1 .26 (a±e) Automatic drawbar coupling 31 ... Fig 1 .20 (a±c) 1. 3 .1 Operation of twin jaw coupling (Fig 1 .23 (a±d)) With the trailer kingpin uncoupled, the jaws will be in their closed position with the plunger withdrawn from the lock gap between the rear of the jaws, which are maintained in this position by the pawl contacting the hold-off stop (Fig 1 .23 (a)) When coupling the tractor to the trailer, the jaws of the Hydroelastic engine mount 25 Fig... around the sides of the block, when no support is provided, whereas with the interleaf a pair of much smaller bulges are observed Fig 1. 11 Fig 1. 10 (a and b) Modes of loading rubber blocks When two rubber blocks are inclined to each other to form a `V' mounting, see Fig 1. 11, the rubber will be loaded in both compression and shear shown by the triangle of forces The magnitude of compressive force will... rubber between the flanged sleeve and lower plate (Fig 1. 19(a)) reduces the rebound, but an increase in depth of rubber increases rebound (Fig 1. 19(b)) The load deflection characteristics are given for both mounts in Fig 1. 19c These mountings are used extensively for body to subframe and cab to chassis mounting points Metacone sleeve mountings (Fig 1. 18(f and g)) These mounts are formed from male and female... frequency to that of the natural frequency of vibration of the Fig 1. 17 Relationship of transmissibility and the ratio of disturbing and natural frequencies for natural rubber, Butyl rubber and steel 18 of vibration and the new static deflection of the engine Comment of these conditions 1 .2. 9 Subframe to body mountings (Figs 1. 6 and 1. 19) One of many problems with integral body design is the prevention... gravity of both the engine and gearbox (Figs 1. 13(a, b and c)) This normally produces an axis of oscillation inclined at about 10 20  to the crankshaft axis To obtain the greatest degree of freedom, the mounts must be arranged so that they offer the least resistance to shear within the rubber mounting 1 .2. 5 Six modes of freedom of a suspended body (Fig 1. 14) If the movement of a flexible mounted engine . suspension 10 .17 Active suspension 10 .18 Electronic controlled pneumatic (air) suspension for on and off road use 11 Brake system 11 .1 Braking fun 11 .2 Brake shoe and pad fundamentals 11 .3 Brake. 12 Air operated power brake equipment and vehicle retarders 12 . 1 Introductions to air powered brakes 12 . 2 Air operated power brake systems 12 . 3 Air operated power brake equipment 12 . 4 Vehicle. OX2 8DP 22 5 Wildwood Avenue, Woburn, MA 018 01 -20 41 First published by Edward Arnold 19 89 Reprinted by Reed Educational and Professional Publishing Ltd 20 01 Second edition 20 02 Copyright # 19 89,