BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

Participant's Manual

Vehicle Chassis, Suspension and

Dynamic Driving Systems E87

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

The information contained in this Participant's Manual is intended solely for the participants ofthis seminar run by BMWAftersales Training.

Refer to the latest relevant "BMW Service" information for any changes/supplements to theTechnical Data.

Information status: April 2004

conceptinfo@bmw.de

© 2004 BMW Group

Aftersales Training, München, Germany.

Reprints of this manual or its parts require the written approval of BMW Group,München.

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

Participant's Manual

Vehicle Chassis, Suspension andDynamic Driving Systems E87

Front axleRear axle

Electric steering lockSuspension and damping

Adaptation of dynamic driving systems

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

Contents

Vehicle Chassis,Suspension andDynamic DrivingSystems E87

ObjectivesModelsIntroductionSystem componentsService information

1

3

5

7

31

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

Objectives

Vehicle Chassis, Suspension and Dynamic DrivingSystems E87

The Ultimate Driving Machine

This Participant's Manual is intended toprovide fundamental information on the

subjectsofthevehiclesuspensionandthe,inpart, known, dynamic driving systems.With its balances rear-wheel drive, the E87 isalso characterized by BMW's brand-namestandards.

By working through this Participant's Manual,you will gain fundamental knowledge of thefollowing areas:–E87 Front axle–E87 Rear axle

–Electric steering lock (ELV)–E87 Suspension and damping

–E87 Adaptation of chassis and suspensioncontrol systems

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

Models

BMW Rear axles

Development of BMW rear axles

BMW chassis and suspension systems andthe integral optimum chassis and suspensiontherefore the sportive and dynamic charactertuning.

oftheindividualmodelshavelongbeenbasedonthespecialaxledesignsand,ofcourse,on

The following table shows the developmenthistory of BMW rear axles:

HA 2Screw-link axle

E23, E24, E32, E34HA 3Central-link rear axle

Z1, E36/2, E36/3,E36/4, E36/C, E46,E83, E85Double lateral control arm axleE26HA 4Experimental study

HA 5Dispersed double control arm axleE87

Integral IExperimental studyIntegral IIExperimental study

Integral IIIE31Integral IVSteel, spring, damper tower

E38Integral IVAluminium, spring, damper tower

E39Integral IVAluminium, spring on body and damper on axleE39/2

carrier

Integral IV

Steel axle carrier, aluminium link and steel wheelE53carrier, spring and damper separated but bothsupported on body

Integral IV

Aluminium axle carrier with cast node technologyE65and cast swing arm, spring strut shock absorber

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

Introduction

Vehicle Chassis, Suspension and Dynamic DrivingSystems E87

E87 Chassis and suspension

1 -

E87

As can already be seen from the illustration,the chassis and suspension of the E87

represent a new step forward in the compactclassbothatthefrontaxleaswellasattherearaxle. The front axle is designed as a doublepivot spring strut axle (MacPherson strut) inaluminium.

Thedesignprincipleofthedoublepivotspringstrut front axle of the E87 was installed in theE23asearlyas1977.Atthattime,however,itwas installed with recirculating ball-and-nutsteeringbehindtheaxle.TheE87ontheotherhand features a front-positioned rack andpinion steering system as was used on theE39basicaxle.Thedesignofthefrontaxleinthe 1 Series is generally very similar to that ofthe E39 not least because all its componentsare made of aluminium.

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

2 -

E87

Therearaxlewascompletelyredesignedasafive-linkaxlefortheE87.ThepropertiesoftheE87 front and rear axle are described in thefollowing.

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

System components

Vehicle Chassis, Suspension and Dynamic DrivingSystems E87

E87 Front axle

Althoughatensionstrutversionofthedoubleadvantages, specifically compared to thepivotspringstrutaxlehasbeenusedinBMWsingle-joint or pivot axle, are listed in thevehicles for over 25 years, some of the

following.

1 -

E87 Front axle

Both a positive (+) as well as a negative (-)kingpinoffsetcanbeachievedbyrealizingthevirtual "pivot axle" (also known as "spreadingaxle", "steering pivot" or "steering axle").

BMW E87 Vehicle Chassis Suspension and Dynamic Driving Systems

2 -Pivot axle/steering axle

3 -

Double pivot spring axle/determining the lower pivot point

Initially, it was thought that a negative kingpinoffset should always be selected.

However, when taking into consideration theself-stabilizing effect of a negative kingpinoffset in connection with asymmetrical

breaking forces, this presumption is justifiedonlyunderuniformdecelerationconditions(inthe stationary or steady range). In the

unsteadycase,i.e.atthestartofthebreakingprocedure, an implausible steering wheelmovement occurs that could convey to thedriver a false impression of the drivingsituation.

In addition, driving tests have shown that astabilizing effect is also achieved at a smallpositive kingpin offset.

In view of the many other influencing factorssuchasthecastorangle,momentofinertiaof …… 此处隐藏：7183字，全部文档内容请下载后查看。喜欢就下载吧 ……