14-02-24 ATZ Lightweight Design Potential With Forging

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–

There are several developments in the

stee n ustry w t respect to mater a s n

w re an ars as we as n org ng

companies, all with the aim of supporting

customers n t e r g twe g t es gn

e orts 2 . However, eac n v ua

development provides merely an isolated

sout on, per aps w t on y neg g e

trans era ty to ot er areas o app ca-

tion. This is because solutions are devel-

oped in each case for the specific require-

ments n a ve c e an , even t en, t e

results may not be published at all.

A field analysis of the issue of “Light-

we g t Automot ve Des gn” p npo nts t e

most important projects to date, . It

becomes clear that the activities have dif-

erent n t ators stee n ustry, n v ua

stee manu acturers or supp ers, OEM .

However, the majority of projects deals

exc us ve y w t t e car o y or w t

g twe g t es gn so ut ons ase on

sheet metal; this is also reflected in how

g twe g t es gn s perce ve n t e

n ustry 3 . L g twe g t es gn potent a

in the powertrain and chassis is rarely

focussed on, and if it is considered, then

only by means of a solution approach at

system eve , or examp e owns z ng.

L g twe g t es gn potent a ac eve

hrough material or through forging oper-

at ons as not een ana yse to ate n

any arge pre-compet t ve o nt pro ect.

he steel manufacturing and forging

n ustry as t us set tse t e tas o

emonstrat ng es gn, mater a an pro-

duction engineering solutions, the success

o w c may e measure w t respect

o g twe g t es gn, cost an mp emen-

ation potential.

15 forging companies and nine steel man-

ufacturers have joined forces in the “The

L g twe g t Forg ng In t at ve” un er

e ausp ces o t e German For-g ng

Association (Industrieverband Massivum-

ormung e. V. – IMU an t e VDE

stee nst tute 6 . W t out raw ng on

ublic funding, the companies are mak-

ng mu t atera nanc ng ava a e to

ena e t e rst wor ng step o t e n t a-

ive to be taken, namely a lightweight

DR.-ING. HANS-WILLI RAEDT

is Vice President Advanced Engineering

t the Hirschvogel Automotive Group

in Denklingen (Germany).

DIPL.-ING. FRANK WILKE

is Vice President Technical Customer

ervice at the Deutsche Edelstahl-

werke GmbH in Siegen (Germany).

DIPL.-ING. DIPL.-WIRT.-ING.

HRISTIAN-SIMON ERNST

is Project Manager at the Institut

für Kraftfahrzeuge (ika) of RWTHAachen University (Germany).

DEVELOPMENT LIGHTWEIGHT DESIGN

40



design potential study. This is carried out

y the automotive engineering research

nst tute, Forsc ungsgese sc a t Kra t-

a rwesen m H Aac en a . T s s y

far the largest pre-competitive joint pro-

ect o t ese two n ustr es to ate.

A ve c e w t on y ow m eage was

rocured as a reference (significant

ser es vo ume, m e c ass estate car,

ese , ou e-c utc transm ss on, a -

wheel drive) and systematically disas-

sembled by the fka. The parts were do-

cumente n a ata ase mages, we g t,

mens ons an mater a . Dur ng seve-

ral workshops, experts of the participat-

ng compan es came toget er to wor on

g twe g t es gn proposa s. A propos-

als were classified with respect to their

g twe g t es gn potent a , t e est -

ate cost eve opment an t e ant c -

pated implementation efforts, and then

recorded in the database. In this way,

quant a e resu ts may e assesse n

severa mens ons n t e ata ase.

provides an overview of the procedure.

REFERENCE VEHICLE

The overall results of the lightweight

es gn stu y con ucte y T e L g t-

we g t Forg ng In t at ve are s own n. From a forging perspective, it is pri-

marily parts from the powertrain (injec-

t on, eng ne, transm ss on, trans er gear-

box, drive shafts) and the chassis which

are open to g twe g t es gn eas.

Some potent a s a so seen n t e car

body, mainly in the area of the fastening

elements.

T e g twe g t es gn eas t us con-

centrate on a re erence as s o 838 g,

which is approximately 48 % of the entire

ve c e. It s ou e ment one t at some

ve c e components contr ut ng great y

to weight cannot be produced by forging.

For t s reason, parts suc as t e eng ne

oc , cy n er ea , gear ox ous ng

and large-area basic chassis parts made

94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13

TKSNewSteelBody

WorldAutoSteel

WorldAutoSteel

Magna

InCarInnovative Car

EUCAR

Project

TKS

ULSABUltraLight Steel Auto Body

FutureSteelVehicle WorldAutoSteel

FEV/EDAG

CULTCars´ Ultralight Technologies

ULSASUltraLight Steel Auto Suspension WorldAutoSteel

ULSACUltraLight Steel Auto Closures

WorldAutoSteel

Consortium (Lead)

SuperLIGHT-CarSustainable Production Technologies for CO

2-Emission Reduced Light weight Car concepts

ULSAB-AVCUltraLight Steel Auto Body – Advanced Vehicle Technology

LDV Mass ReductionLight-Duty Vehicle Mass Reduction and Cost Analysis – Midsize Crossover Utility Vehicle

Year

Overview of large automotive lightweight design projects (Sources: Lightweight design potential study ofThe Lightweight Forging Initiative, fka)

THE LIGHTWEIGHT FORGING INITIATIVE

AUTOMOTIVE LIGHTWEIGHT DESIGN

POTENTIAL WITH FORGING

Forging processes (hot, warm and cold) are used to produce several important components in automotive

engineering applications. When awarding contracts, the lowest price is often the decisive criterion;

innovations are either not enquired about, or part and system development is already so far advanced at

the time of the enquiry that it is too late to incorporate lightweight design proposals. The LightweightForging Initiative was set up to highlight to the professional world the contributions which forging makes to

the automotive megatrend of lightweight design.

3I2014 Volume 116 41



rom s eet meta were not ana yse or

t e r g twe g t es gn potent a , as t e

possibilities offered by forging cannot be

emp oye n a cost-e c ent way.

In tota , a g twe g t es gn potent a

of 42 kg was identified. The lightweight

ideas submitted identified an average

g twe g t es gn potent a o 0 % or

the components analysed.

Idea classification according to cost

mpact an mp ementat on e orts s

shown in . The experts estimate that

some ideas will lead to both a reduction

n we g t as we as costs qu c w ns .

Ot er eas emonstrate a g twe g t

design potential which is expected to

nvo ve somew at g er costs an

ncrease eve opment e orts.

As part of the lightweight design

potent a stu y, 399 eas were generate

ase on t e parts n t e re erence ve -

cle. These may be categorised as ideas

re at ng to mater a , es gn or concept.

From t ese, a sma se ect on s a e

outlined in the following. To provide a

well-rounded picture of what the indus-

try can ac eve, n v ua g twe g t

design solutions will also be presented

which were not developed specifically

or t e re erence ve c e, ut were

already being used in other applications.

The lightweight design ideas described

o not c a m to e u y eve ope so u-

t ons. On t e one an , a er ng eve o

development efforts has flowed into these

proposa s. On t e ot er an , some pro-

posa s w e ace w t system requ re-

ments which are not known among the

part c pat ng stee manu acturers an org-

ng compan es. One t ng w c a t e

proposals have in common, however, is

t at t ey s ou not e v ewe as a cr t -

c sm o t e eng neer ng ac evements o

those who developed the reference vehicle.

Rat er, t ey s ou revea poss t es

w t respect to es gn, mater a an pro-

duction engineering for generating light-

we g t es gn, as we as prov e mpetus

an a ow convent ona proce ures to

undergo scrutiny. The lightweight design

potential stated as a percentage in the fol-

ow ng re ates to t e opt m se we g t

t s means, t e ser a component s x %

heavier than the optimised part).

T ere are many new eve opments n

the area of steel materials for forgings.

Ba n t c gra es, or examp e, are

appearing on the market which can be

processed just as cost efficiently as dis-

pers on- ar en ng stee s, t s means

without additional heat treatment, but

w c ac eve mec an ca va ues com-

para e to quenc e an tempere

steels, [1, 7]. By using these steels,

lightweight design potential may be lev-

erage n an econom c way. One exam-

p e s t e tra er coup ng w c may e

dimensioned with less weight using a

stronger an , at t e same t me, toug er

stee .

Compared to steel, the use of light-

we g t meta s may ea to g twe g t

es gn so ut ons n some cases., r g t,

shows a chassis bearing on the rear axle.

Here, a sw tc was ma e rom stee to

high-strength aluminium with a larger

contact surface. Furthermore, the part

as a o ow es gn w t nterna un er-

cut. Both may be implemented cost-

effectively and easily by means of cold

org ng.

However, other developments using

steel also hold considerable lightweight

es gn potent a , too. T e use o asten-

ng e ements w t a g er st rengt c ass

could make a significant contribution to

g twe g t es gn ue to t e arge num-

er o suc parts n ve c es. T s wou

e possible in cases where the strength

c ass s t e pr nc pa es gn cr ter on an

ot, or examp e, t e strengt o t e part

o be fastened.

Reference vehicle:125 kW / 170 PS2.0 l turbo-DI Diesel engine,

double-clutch transmission, all-wheel drive,total mass: 1740 kg

3. Listing and naming all individual parts

Verbrennungs -motor Getriebe

4. Analysis of individual parts

5. Weight of assemblies and systems

6. Photo documentation

Parking gear

(22108020001)

7. Database implementation with proposals for

lightweight design potential

Fahrzeuggesamtgewicht

9 %

16 %

16 %59 %

21 %

31 %

8 %

22 %

18 %

Antriebswellen

Ausgleichs-undVerteilergetriebe

Drehmomentwandler

Verbrennungsmotor

Lenksystem

Bremssystem

Räder und Reifen

Hinterachse

Vorderachse

Gewichtsbilanzierung Fahrzeugbereich Antrieb

Gewichtsbilanzierung Antriebsstrang

399,45 kg

Gewichtsbilanzierung Fahrwerk

284,21 kg

Referenzfahrzeug:

125 kW/170 PSTurbo-DI Dieselaggregat

DSGGetriebeAllradantrieb

Gesamtmasse: 1.740 kg

6%

16%

39%

23 %

16 %Antriebsstrang

Fahrwerk

Elektronik(6%)Ausstattung(16%)Karosserie (39%)

53%

13%

34%

0%

28%

6%

34%

32%

Festigkeitsklassen

8%

20%

3%

1%2%

4%

15%

31%

17%

Antriebsstrang

Schraubentypen

13,15 kg

Schraubentypen

Festigkeitsklassen

Fahrwerk

23%

10%

21%

46%13,15 kg 9,76 kg

Festigkeitsklassen allerSchrauben

Gesamt

Übersicht derSchraubentypen

22,92 kgFestigkeitsklassenichtangegeben

Festigkeitsklasse12.9



29%

7%

3%

1%3%

14%

43%

12%

14%

1%

1%4%

3%5%

10%

23%

27%

M18

M5

Sonstige

M7

M8

M16

M6

M14

M10

M12

22,92 kg9,76 kg

Tür,Sitz,

Gurt,

AHK

: ISO views: Detailed views

: Installation position,where necessary

: Digital removal of

manufacturer logo

1. Determining the total vehicle weight

ChassisCombustion

engine

Trans-

mission

Door, seat,belt, trailercoupling

2. Disassembling the entire vehicle

&

795.92 kg

Other

2.96 kg

Chassis13.55 kg

Powertrain

25,58 kg

Reference weight

838.00 kg-42.08 kg

Potential of

lightweight forging

0%

19 %

100 %

100 %

15%

16 %

16 %

6 %

939 %

23 %

Electronics

Interior

Drive

Chassis

Car body: Three workshops

: 65 experts from 30 companies and

research institutes

: Analysis of approx. 3500 parts from the

powertrain, chassis and other areas

: 399 ideas for lightweight potential in various

types of lightweight design approaches

: Documentation in the fka benchmarking database

: Lightweight design potential of 42.08 kg

for the areas identified

838.00 kg

Focus

of this

study

Procedure of the lightweight design potential study (Sources: Lightweight design potential study of

The Lightweight Forging Initiative, fka, RWTH Aachen)

Results of the lightweight design potential study (Sources: Lightweight design potential study of

The Lightweight Forging Initiative, fka, RWTH Aachen)


42



upper e t s ows geometr ca opt m -

sations on a crankshaft. In the area of

he pin bearings, recesses may be forged

nto t e part. A roug ca cu at on o

mbalance shows that this can lead to

aterial savings on the counterweights,

oo.

Geometr es w c are not rotat ona y

symmetric may be produced easily by

eans o org ng. upper r g t s ows

a yw ee w t poc ets at t ree s tes on

he circumference. A solution involving

ac n ng a one wou not a ow t s

g twe g t es gn potent a to e

exploited or would only do so at higher

costs, as m ng t ese poc ets wou e

expens ve.

(lower right) uses the example

o a connect ng ro to emonstrate

the potential of increasing the strength

class of a fastening element. At the

same pre-stress ng orce, t e screw can

be designed smaller, leading to a reduc-

tion in the dimensions of the connect-

ng ro . Part cu ar y we g t re uct ons

ac eve on t e connect ng ro resu t n

reater secondary effects in the engine

ear ngs, a ancer s a ts .

A t ona g twe g t es gn potent a

ay be tapped by fully exploiting the

orm ng poss t es o ere y org ng.

T s s s own n ower e t . In t s

case, it is important to consider materi-

a s w c perm t cons era e upsett ng

o t e stee w t out caus ng a rop n

their load-bearing capacity [8].

Ot er geometr ca poss t es a ow

more e ect ve mens on ng an t us

lead to parts which are smaller and can

bear greater load. One example of this is

s own n . Here, t e gears o t e er-

ential pinions are continually optimised

with respect to load-bearing capacity.

But a so t e poss ty o connect ng

forged gear teeth to a flange, which is

not possible with milled gears, increases

t e oa - ear ng capac ty o t ese parts,

a ow ng sma er an t us g ter

dimensioning.

T e same s true o t e spee gear n

upper r g t . Here, too, t e start ng po nt

was a classic, pure rotationally symmetric

geometry n t e connect on etween t e

gear r m an u . On t e one an , st -

ening radial arms were produced. On the

ot er, mater a was remove etween

t ese arms y means o punc ng to

achieve maximum weight savings.

A t ona potent a on spee gears s

s own n ower r g t . Here, t e pos-

sibility of reducing the wall thickness

below the tooth ends is identified. In the

case o crowne teet w c ear t e

load in the centre, the main bending

load of the teeth lies in the centre of the

toot . It s ou t us e poss e to use

ess mater a at t e toot en s to support

the bending load of the tooth.

Gearw ee s are attract ng part cu ar

attent on ue to t e g tota num er

thereof in transmissions. Accordingly, ower e t s ows a t ona opt m sa-

t on ac eve t roug a non-rotat ona y

symmetric design of the gear rim con-

nect on w t re uce wa t c nesses.

Depen ng on t e org ng ac t es

available (press forces, number of stages,

possibility of single or multiple piercing),

erent org ng compan es w arr ve at

different solution approaches with

respect to g twe g t es gn n or er to

re uce t e rotat ng masses n part cu ar.

These will need to be given greater atten-

tion, as their impact on fuel consump-

t on s espec a y g . e t s ows t e nput s a t n t e

transfer gearbox. Here, the lightweight

es gn potent a s ent e e ow t e

ypo gears. It s t us poss e to orge

a recess which does not need to be

mac ne , epen ng on m a ance

requ rements. Furt ermore, a o e can e

introduced into the shaft centre. While

800

840

830

820

810

430

0

W e i g h t [ k g ]

Starting

weight

838 kg

Other

154 kg

Chassis

285 kg

Power-

train

399 kg

796 kg

-42.0 kg

-15.7 kg -16.6 kg

-25.5 kg

-38.6 kg

Lightweight

design with

forging

Constant

costs and

medium

lightweight

potential

Combination

of lightweight

design

and costs

Full

utilisation

of lightweight

design

potential

Expanded

lightweight

design

potential

Max. implementation potential

High implementation potential for volume segment

Full utilisation of lightweight design potential

Optimum

between light-

weight design

and costs

-16 kg

-25 kg

-42 kg

Classification of the lightweight design ideas (Sources: Lightweight design potential of The Lightweight

Forging Initiative, fka)

: Material substitution steel aluminium

: Hollow design

: Use of bainitic instead

of dispersion-

hardening steel

Higher strength at

higher toughness level

:

: ∆m > 10 %

Chassis bearing

500

700

900

1100

1300

AFP

38MnVS6

16MnCr5mod

(H2)

20MnCrMo7

S t r e n g t h [ M P a ]

Rp0,2

[MPa]

Rm [MPa]

Material lightweight design potential (Sources: GMH, EZM, Hirschvogel, A+E Keller)

3I2014 Volume 116 3



t e atter oes generate a sma a t ona

e ort n so t mac n ng, as t e o e can-

not be produced by means of forging, it

s ou nevert e ess prove cost-e c ent

w en ca cu at ng “€ per g”. (right) shows an output flange. The

g twe g t es gn proposa encom-

passes t e o ow ng po nts: T e externa

geometry deviates from the rotational

symmetry. Pockets are forged into the

part an t e nterna geometry s rawn

deeper without increasing the stresses in

the external undercut. The proposal with

respect to t e ourna certa n y nee s to

st e assesse n more eta . It s

assumed that the inner race of the bear-

ng oes not necessar y nee to e us

w t t e ange, ut t at n v ua con-

tact surfaces are sufficient. These may

e pro uce eas y y means o org ng.

An mportant c ass s part s t e w ee

hub. Depending on the wheel bearing

generat on, t e unct ona ntegrat on o

t e ant - r ct on ear ngs rect y on t e

wheel hub have already led to weight sav-

ings; this was the case in the reference

ve c e ana yse . T e g twe g t es gn

proposal shown in (left) represents a

arge we g t re uct on. However, ue to

ts o es gn, t a so a s un er t e cate-

gory of suggestions involving signifi-

cantly higher implementation efforts.

Furt ermore, r g t s ows an a most

revo ut onary g twe g t es gn ea. T e

hexagon on nuts and bolts is a highly clas-

s c, a most con c es gn e ement. It may

e ev ate rom y expo t ng t e es gn

possibilities of cold forging. Although, per

part, on y a ew grams are save , t e g

num er o suc asten ng e ements means

that the lightweight design advantage mul-

t p es to a correspon ng egree n t e

ve c e. We g t sav ngs o up to 20 %,

depending on the size of the nuts, are

stated for this solution [9].

Lightweight design generated by means

of concept changes is highly effective, as

t s o a srupt ve rat er t an ncremen-

ta c aracter. However, t s can a so

magnify the implementation obstacles. s ows a g twe g t es gn proposa

w ose mp ementat on ur es st nee

to be tested out. The lightweight design

proposa oresees t at torque trans er s

ac eve v a H rt gears, w c may e

produced ready-for-assembly by means

of forging both on the output shaft as

we as on t e tr po . T e proposa t us

not only leads to a reduction in weight of

33.5 % but also to the omission of the

we ng process an to a re uct on o

effort in vehicle assembly.

The results outlined above highlight the

nnovat on o t e stee an org ng n us-

try. Assess ng mater a , es gn an org-

ing innovations demonstrates that a sig-

n cant we g t re uct on o 2 g appears

poss e on t e ve c e ana yse . Secon -

ary lightweight design potential [10] has

ot yet een ta en nto account. W t

espect to t e g twe g t es gn poten-

ial, the areas of powertrain and chassis

are of equal importance as the car body.

Stee mater a s an org ng tec no ogy

ay be used to achieve lightweight

design, with the cost per kilogram light-

we g t es gn y ng e ow t at ncurre

or many new types o manu actur ng

echnologies. Some lightweight design

otent a even prom ses cost neutra ty.

s g twe g t es gn t us as a roa

mpact and can contribute significantly to

e uc ng t e tota CO2 em ss ons.

o ut se t ese g twe g t es gn eas,

t is necessary to include material and forg-

∆m = 600 g (4.6 %)Non-rotationally symmetric

geometries

Equivalent stress

σV [MPa]

0

500

400

300

200

100

∆m = 189 g (20 %)

No increase in maximum stress in part

Series

Series

Potential

Recesses

on pin bearings

Potential

Crankshaft

Flywheel

: Use of higher strength screws

: M8 M7

: Lower conrod thickness / width

: ∆m ~ 1 kg kg possible with

secondary effects

Connecting rodCommon rail

: Non-rotationally

symmetric

geometry

Piercings:

Increased load-

bearing capacity

through

: Further developed

gear geometries

: Connection of the

teeth to the flange

:

: Stiffening radialarms

Deep pockets

Thin wall

thicknesses

:

:

: Reduction in wallthicknesses in

areas with low

stresses

: ∆m = 172 g (51 %)

Series

Potential

Differential pinions Speed gear

Speed gearSpeed gear

Lightweight design potential on engine parts (Sources: dp Bharat Forge, Hammerwerk Fridingen,

Kamax, Hirschvogel)

Lightweight design potential on transmission parts (Sources: Metaldyne, metallumform, Seissenschmidt,

Sona BLW Präzisionsschmiede)


44



ng potent a n t e ear y p ases o system

an part eve opment. Here, t ere are

tried-and-tested simultaneous engineering

processes. However, t ese nee to e use

or cons era y more components t an s

currently the case. The purchasing process

should begin during earlier phases of

eve opment, name y w en t e g t-

weight design proposals of the supplier

can still flow from material or production

eng neer ng nto part es gn.

In this study, The Lightweight Forging

Initiative has determined that not only is

t ere potent a to e tappe , ut a so

t at t ere s a nee or researc . For

example, the correlation between the

c ean ness o t e stee an t e at gue

strengt nee s to e etter quant e

even for applications beyond anti-friction

ear ngs n or er to trans er new stee

manu actur ng tec no og es nto g t-

weight design potential. To address these

an ot er ssues, a ea tec no ogy pro-

ect s e ng app e or at t e A F an

alliance of research associations). Cur-

rently (January 2014), this project is in

t e assessment p ase.

Future activities of The Lightweight

Forg ng In t at ve w nc u e commun -

cat on o t e resu ts w t n t e n ustry,

partly by means of a conference event at

the end of 2014. Furthermore, discus-

s ons w e e on cont nu ng t e suc-

cess u an cooperat ve co a orat on on

an electr ic vehicle, for example, or on

ra s ng co a orat on to a g o a eve .

REFERENCES

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Neue massivumgeformte Stähle, energieeffiziente

Lösungen für leistungsfähigere Bauteile. In: ATZ 114

(2012), No. 3, pp. 200-205

[2] http://www.massiverleichtbau.de/downloads/

informationen-zum-thema-Leichtbau-in-der-massiv-

umformung/

[3] Friedrich, H. E. (Hrsg.): Leichtbau in der

Fahrzeugtechnik. Braunschweig: Vieweg, 2013

[4] www.massiverleichtbau.de[5] www.metalform.de

[6] www.stahl-online.de

[7] Engineer, S.; et al.: Technological Properties of the

New High Strength Bainitic Steel 20MnCrMo7. Confer-

ence “SCT Steels in Cars and Trucks”, Salzburg, 2011

[8] Raedt, H.-W.; Herz, M.; Schuster, A.: Ausfälle

durch verformte Mangansulfide. In: Konstruktion

2012, Heft 1/2, S. IW 8-9

[9] Unseld, P.; Kertesz, L.; Meßmer, G.:

Geometrischer und stofflicher Leichtbau durch im

Kaltumformverfahren hergestellte mechanische

Verbindungselemente, Conference “Neuere Entwick-

lungen in der Massivumformung”, Stuttgart, 2013

(available in english)

[10] Malen, D. E.; Göbbels, R.; Wohlecker, R.: Sec-

ondary Mass Changes in Vehicle Design Estimation

and Application. WorldAutoSteel, 2013

: Lower wall thicknessbelow teeth

Drilles hollow space:

: ∆m = 510 g

(approx. 25 %)

σV [MPa]

0

450

900

1350

18002250: Non-rotationally symmetricexternal geometry

Pockets forged into part

Internal contour deeper

Hardened journal not round

Constant maximum stress in part

Torsional stiffness

decreases by 14 %

:

:

:

::

: ∆m = 213 g (21 %)

Series

Potential

Series

Potential

Input shaft Outout flange

Lightweight design potential in the remaining power train (Sources: Seissenschmidt, Hirschvogel)

: Recesses at sites without functional

relevance

Verification of strength in simulation

and test

:

: ∆m = 5.6 g (16 %)

: Non-rotationally symmetric

external geometry

Journal with recesses

Wheel rim centering via contact

surfaces instead of via ring

Stiffness optimised internal

and flange contour

:

:

:

: ∆m = 717 g (67 %)

0

500

750

250

σV [MPa]

Series Potential

S er ies P ot en tial

1000

Potential

Lightweight design potential in the chassis (Sources: Hirschvogel, HEWI)

: Replacement of screw flange

connection with Hirth gear pairing

Omission of welded connection of

sheet metal flange/tripod

Replacement of six individual

screws with a union nut

Reduction in assembly efforts

Hirth gear is proven to be highly

capable of bearing loads in a small

assembly space

:

:

:

:

: ∆m = 828 g (33.5 %)

Series Potential

One example of conceptual lightweight design potential (Source: Hirschvogel)

3I2014 Volume 116 45

Documents

14-02-24 ATZ Lightweight Design Potential With Forging