宝马E87 车辆底盘悬挂行驶动态驱动系统学员培训手册

1、宝马E87 车辆底盘悬挂行驶动态驱动系统学员培训手册 Participant's ManualVehicle Chassis, Suspension andDynamic Driving Systems E87BMW Service Aftersales TrainingThe information contained in this Participant's Manual is intended solely for the participants ofthis seminar run by BMW Aftersales Training.Refer to the la

2、test relevant "BMW Service" information for any changes/supplements to theTechnical Data.Information status: April 2004conceptinfobmw.de2004 BMW GroupAftersales Training, München, Germany.Reprints of this manual or its parts require the written approval of BMW Group,München.Parti

3、cipant's ManualVehicle Chassis, Suspension andDynamic Driving Systems E87Front axleRear axleElectric steering lockSuspension and dampingAdaptation of dynamic driving systemsContentsVehicle Chassis,Suspension andDynamic DrivingSystems E87Objectives 1Models 3Introduction 5System components 7Servic

4、e information 315ObjectivesVehicle Chassis, Suspension and Dynamic DrivingSystems E87The Ultimate Driving MachineThis Participant's Manual is intended toprovide fundamental information on thesubjects of the vehicle suspension and the, inpart, known, dynamic driving systems.With its balances rear

5、-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 an

6、d suspensioncontrol systems1526ModelsBMW Rear axlesDevelopment of BMW rear axlesBMW chassis and suspension systems and the integral optimum chassis and suspensiontherefore the sportive and dynamic character tuning.of the individual models have long been basedThe following table shows the development

7、on the special axle designs and, of course, onhistory of BMW rear axles:Designation Distinguishing features ModelHA 1 Semi-trailing arm axle E3, E9, E12, E21,E28, E30, E36/5,E36/7, E114HA 2 Screw-link axle E23, E24, E32, E34HA 3 Central-link rear axle Z1, E36/2, E36/3,E36/4, E36/C, E46,E83, E85Doubl

8、e lateral control arm axle E26HA 4 Experimental studyHA 5 Dispersed double control arm axle E87Integral I Experimental studyIntegral II Experimental studyIntegral III E31Integral IV Steel, spring, damper tower E38Integral IV Aluminium, spring, damper tower E39Integral IV Aluminium, spring on body an

9、d damper on axle E39/2carrierIntegral IV Steel axle carrier, aluminium link and steel wheel E53carrier, spring and damper separated but bothsupported on bodyIntegral IV Aluminium axle carrier with cast node technology E65and cast swing arm, spring strut shock absorbertowerIntegral IV Aluminium axle

10、carrier with cast node technology E6xand cast swing arm, spring strut shock absorbertower3647IntroductionVehicle Chassis, Suspension and Dynamic DrivingSystems E87E87 Chassis and suspension1 - E87As can already be seen from the illustration,the chassis and suspension of the E87represent a new step f

11、orward in the compactclass both at the front axle as well as at the rearaxle. The front axle is designed as a doublepivot spring strut axle MacPherson strut inaluminium.The design principle of the double pivot springstrut front axle of the E87 was installed in theE23 as early as 1977. At that time,

12、however, itwas installed with recirculating ball-and-nutsteering behind the axle. The E87 on the otherhand features a front-positioned rack andpinion steering system as was used on theE39 basic axle. The design of the front axle inthe 1 Series is generally very similar to that ofthe E39 not least be

13、cause all its componentsare made of aluminium.572 - E87The rear axle was completely redesigned as afive-link axle for the E87. The properties of theE87 front and rear axle are described in thefollowing.68System componentsVehicle Chassis, Suspension and Dynamic DrivingSystems E87E87 Front axleDouble

14、pivot spring strut axleAlthough a tension strut version of the double advantages, specifically compared to thepivot spring strut axle has been used in BMW single-joint or pivot axle, are listed in thevehicles for over 25 years, some of the following.1 - E87 Front axleBoth a positive + as well as a n

15、egative -kingpin offset can be achieved by realizing thevirtual "pivot axle" also known as "spreadingaxle", "steering pivot" or "steering axle".78In view of the many other influencing factorssuch as the castor angle, moment of inertia ofthe vehicle, width of t

16、he tyre contact surface,etc. a fundamental explanation of thischaracteristic is provided.The overall vehicle handling is alsoconsiderably more harmonious with thedouble pivot spring strut axle designed withslightly positive kingpin offset.Likewise, realization of the virtual "pivot axle"ha

17、s a favourable effect on the package spacefor the brake discs and brake callipers.In the case of the single-joint or pivot axle, thewheel control joint is largely determined by thesize of the kingpin offset. Since the kingpinoffset should be as small as possible, thewheel control joint must be locat

18、ed as fartowards the outside as possible. This however2 - Pivot axle/steering axleresults in problems concerning the packagespace for the brake disc and brake calliper. Onthe double pivot spring strut axle the positionof the control arm and tension strut withrespect to each other determine the size

19、of thekingpin offset.The pivot points of the control arm orwishbone and tension strut at the swivelbearing can therefore be selected such that nospace problems are encountered for the brakesystem.3 - Double pivot spring axle/determining the lower pivot pointInitially, it was thought that a negative

20、kingpinoffset should always be selected.However, when taking into consideration theself-stabilizing effect of a negative kingpinoffset in connection with asymmetricalbreaking forces, this presumption is justifiedonly under uniform deceleration conditions inthe stationary or steady range. In theunste

21、ady case, i.e. at the start of the breakingprocedure, 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.884 -Index Ex

22、planation Index Explanation1 Front axle carrier 6 Tension strut2 Wheel hub 7 Stabilizer bar3 Stabilizer link 8 Swivel bearing4 Control arm 9 Hydraulic mount5 Rack-and-pinion steering 10 Spring strutBoth tension struts are mounted with have, as it were, merged to form one. Thehydraulic mounts in the

23、front axle carrier. resulting advantage of the double pivot or jointspring strut axle is improved directionalIn addition, the distance of the tension strutstability in the high speed range and a lowerand control arm pivot points at the swiveltendency to steering instability in the lowerbearing large

24、ly determines the vertical forcesped range insignificant for LDS.lever arm.Compared to that of the control arm, the ballThe greater the joints of the tension strut andjoint guide joint of the tension strut is raisedcontrol arm are from each other at the swivelat the swivel bearing, thus providing ef

25、fectivebearing, the greater the weight reset force.anti-dive control. A further advantage of thisOn the single-joint axle, the distance is arrangement is that this tension strut mountgenerally zero as the two joints of this axle on the axle carrier can be arranged at98approximately the same level wi

26、th respect to The double pivot spring strut axle on the otherthe mounting at the swivel bearing and does hand features a frame which additionallynot have to be lowered. This is of particular provides significant stiffening of the front end.benefit to a large overhang angle. In addition, itis possibl

27、e to lower the control arm mount onthe axle carrier side, thus enabling a lower rollcentre.Technical dataThe single-joint axle features only one type ofcross brace as the axle carrier.Description Value Description ValueTotal toe-in 14 Kingpin offset 4mmTrack width 1493 mm Wheel lock 41° 22Cambe

28、r -12 Wheel lock, outer 33° 29Kingpin inclination 13° 56 Press-in depth 37 mmCaster angle 7° 2 Tyre size 185/60 R 16Caster 19.5 mm108E87 Rear axleGeneral It is designed as a multi-link independent rearsuspension axle with 5 different link arms.The designation "HA 5" does not

29、 refer to theThe newly developed rear axle with thefive links but rather represents thedevelopment designation "HA 5" is used forconsecutive development designation used atthe first time in the E87.BMW see models.Advantages5 - E87 Rear axleThe names of the individual links are defined inth

30、e following graphic.118Components of the rear axleIndex Description Index Description1 Rear axle carrier 6 Stabilizer link2 Thrust rod 7 Track link3 Traction strut 8 Semi-trailing arm4 Wheel hub 9 Camber link5 Control arm 10 Wheel carrier1286 - Rear axle from rear left top and from front left bottom

31、1387 - Top view of rear axle, leftVarious links of HA 5The top view of the two upper links blue in theillustration form a triangle as do the two lowerlinks purple in the illustration.The rear link orange in the illustrationrepresents the track rod.1488 - Rear axle carrier from rightIndex Description

32、 Index Description1 Semi-trailing arm 4 Track link2 Traction strut 5 Camber link3 Control armAdvantages of the new rear axle manufacturing the entire axle from highstrength steel and the HA 5 rear axle does notThe right-hand wheel carrier with the fivehave an excessively high weight.different links

33、of the HA 5 is shown in forwarddirection.The rear axle carrier and the links are made - Lightweight designfrom high strength steel. The wheel carrier isA bending moment occurs only in the cambercast from GGG 40.link as the spring and damper are supportedCompared to the previous rear axles, the HA 5

34、on this link. The remaining four links are notoffers the following advantages: subjected to moments of force thus enablinga lightweight and rigid design.Thanks to the straight design of the links andthe connection by means of ball joints, apart- Manufacturing costs from the camber link, all links tr

35、ansmit onlytensile and compressive forces.The lower costs are attributed to the fact thatConsequently, the wheel control with this axlethe use of high strength steel has made itis subject to only minimal elasticity and is verypossible to reduce the wall thicknesses of theprecise.rear axle carrier an

36、d of the links.Compared to the integral IV, a considerablesaving potential has been exploited by - Production158The HA 5 rear axle can be completely disadvantage of a dive motion while brakingpreassembled and adjusted with the brake and starting off is compensated by the tautsystem as well as the su

37、spension and suspension. The braking support anti-divedamping. This is a particular advantage for the realized on the E87 represents an optimumproduction plants as it reduces cycle times. compromise between comfort, safety anddriving dynamics requirements.- KinematicsThe use of five links enables fr

38、ee selection ofThe very small positive kingpin offsetthe pivot axle for the design layout. Thisguarantees insensitivity to longitudinal forcesmeans that the movement of the wheel ineven in connection with wide eraction with the suspension can beoptimized without compromise under braking,acc

39、eleration and lateral forces. This largelyThe relatively large caster ensures a defineddetermines all important variables such as toe,degree of lateral force understeering andcamber, brake support anti-dive angle, rolltherefore obliging vehicle handling. Thiscentre and roll centre change rate.method

40、 of vehicle stabilization offers thefastest response and is therefore also thebest.The change in toe see Fig. 6 as part of thesuspension action enables outstandingdirectional stability with a relatively shortwheelbase and exceptional self-steeringcharacteristics while cornering.The change in camber

41、as part of thesuspension action is selected such that anoptimum camber with respect to the roadsurface is always established while cornering.Nevertheless, the change in camber duringspring compression due to load is not toogreat as to cause increased tyre wear. As aresult, new lateral force potentia

42、ls are utilizedtogether with RSC tyres.The long design of the track link makes foroutstanding length tolerance insensitivity. Thelong track link also has a positive effect on thetoe-in characteristics over the spring travelrange.The low roll centre has a particularly beneficialeffect on the rolling

43、motion.The "propping" effect while cornering hasbeen largely minimized by improving the rollcentre change rate.The braking support has been set to 70 %.Racing cars generally have a support angle of0 % in order to constantly achieve imumcontact force. On these vehicles, the1689 - Toe charac

44、teristics over the rear axle spring rangeIndex Description Index Description1 Spring compression 3 Spring deflection2 Spring travel range mm 4 Track min.Toe-in change over spring Toe-in change under springtravel range under braking compression and deflectionforce without forceToe-in change over spri

45、ngtravel range under lateralforce- Crash requirements resulting in specific advantages particularly atlow impact speeds.The body side member had to be cranked to arelatively large extent in connection with the Added to this, the large rear axle carrier issemi-trailing arm and central link axle. This

46、 connected directly t the rigid frame sidebrought about disadvantages in connection member, allowing it to transmit the appliedwith a rear end impact. In contract, the HA 5 crash forces more favourable.rear axle permits a considerably morefavourable progression of the side member,178The semi-trailin

47、g arm features crash beading double flexible mounting provide outstandingin the semi-trailing arm of the HA 5 rear axle, insulation against road noise and tyre rollingsee Fig. 5 to ensure the fuel tank is not noise.damaged under any circumstances.Technical data- Rigidity/acousticsDescriptionThe rear

48、 axle carrier of the HA 5 rear axleWheelbase 2660 mmextends up to the rigid frame side members ofthe body with its axle mounting points andTrack width 1507 mmeven up to the sill with its thrust rods. ThisPress-in depth 37 mmprovides a very large support face for theTyre radius static 291 mmapplied f

49、orces and moments. The resultingadvantages include, on the one hand,Total toe-in 18considerably lower stress and strain on theCamber -1° 30body rear axle break-away and, on the otherhand, the option of designing the rear axlebearing mounts, which are wide apart,Settingrelatively soft. This arra

50、ngement and the10 - Track and camber settings rear viewIndex Description1 Track adjusting screw2 Camber adjusting screw188Suspension and damping11 - DamperIndex Description1 Mount2 Pin jointThe rear damper shock absorber on the E87is connected in a new way to the chassis. Themount 1 has a central nu

51、t and the lower pinjoint represents a new design at BMW. Thisarrangement provides great advantages inassembly only one nut and in production.The E87 will also be offered with the optionSA 226 "Sports suspension settings" as wellas SA 8SD "Sump guard" in certain country-specific v

52、ariants.198Electric steering lockHistoryElectric steering lock ELV access control unit CAS and the electricsteering lock ELV.Differing from the E65 that is not equippedwith a conventional steering wheel lock, for thefirst time, the "steering wheel lock function"will be realized by an elect

53、ric steering lock System and functional descriptionELV on the E87. The E65 is equippedTogether with the electric steering lock facilityexclusively with automatic transmission andELV, the steering column forms oneelectromechanical parking brake andcomponent and may only be replaced as atherefore sufficiently protected against plete unit. The EL