Mechanical Joining Technology in modern Vehicles' Material Mix

Wolfgang ObermannDirector Marketing Systems

Emhart Teknologies

2

Overview

Car body joining technologies

Modular equipment design

Self Piercing Riveting (SPR)

semi-hollow rivet

solid punch rivet

Clinching

Blind riveting

3

Mechanical Joining - Characteristics Self Piercing Riveting (SPR)

Joining technology for many materials (thin sheet, high strength sheet metal, Aluminium)Substitutes spot weldingNo pre-punchingVery high joint strengthComposite design possible2 or more layers can be rivetedSelf piercing riveting in combination with glue can beeffectedCold joining technology

4

Three Technologies in One System

Self Piercing Riveting (SPR)

Self Piercing Rivet Solid Punch Rivet

Clinching

Joining element Forming

Front lid / tailgate

RoofDoorsCar bodyUnder body

Visual area

5

Shear Test Comparison of Joining Methods

0

1

2

3

4

5

6

0 1 2 3 4 5 6 7elongation (mm)

forc

e (k

N)

Stanznieten Ø5,3x5 H4 Vollnieten Ø5x4,2 ES Clinchen

Scherzugvergleich der Fügeverfahren Stanznieten, Vollnieten und Clinchen

Stempelseitiges Material: DX54D 1,5 mm (Rm: 270 - 330 N/mm 2)Matrizenseitiges Material: AlMg4,5Mn 1,5 mm (Rm: 255 N/mm 2)

6

Peel Test Comparison of Joining Methods

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

0 1 2 3 4 5 6 7 8 9elongation (mm)

forc

e (k

N)

Stanznieten Ø5,3x5 H4 Vollnieten Ø5x4,2 ES Clinchen

Schälzugvergleich der Fügeverfahren Stanznieten, Vollnieten und Clinchen

Stempelseitiges Material: DX54D 1,5 mm (Rm: 270 - 330 N/mm 2)Matrizenseitiges Material: AlMg4,5Mn 1,5 mm (Rm: 255 N/mm2)

Self Piercing Rivetingwith Semi-hollow Rivet

8

Quality-related characteristics of a Self Piercing Riveting Joint

StrengthShear tension forcesPeel forces

Evaluation of an OK-joint(1) Interlock x (min. 0,20 mm)(2) Interlock y(3) Remaining material thickness (min. 0,15 mm)(4) Adjacent rivet headThe area out of undercut (1) and penetration depth (2) results in the stability of a self piercing riveting joint. The larger this area, the higher the stability of the joint. In order to avoid a piercing through of the rivet, a remaining material thickness (3) is necessary.To prevent corrosion between rivet and plate, the rivet head radius (4) should lie against the die side of the plate.

11

22

33

44

9

Application Engineering / Joint Investigation

Alu-Alu, Alu-Steel, Alu-Magnesium-Steel, Steel-Steel, Steel-Magnesium,…

Rivet C 3,35 x 4 C 3,35 x 4,5 C 3,35 x 5 C 5,3 x 4 C 5,3 x 5

min. total plate thickness 1,80 mm 2,00 mm 2,50 mm 2,00 mm 2,20 mm

max. upperplate thickness 1,40 mm 1,60 mm 2,00 mm 1,60 mm 2,00 mm

min. lowerplate thickness 1,00 mm 1,00 mm 1,00 mm 1,20 mm 1,00 mm

Rivet C 5,3 x 6 C 5,3 x 6,5 C 5,3 x 7 C 5,3 x 7,5 C 5,3 x 8

min. total plate thickness 2,50 mm 3,00 mm 3,50 mm 4,00 mm 4,50 mm

max. upper plate thickness 2,30 mm 2,50 mm 3,00 mm 3,00 mm 3,00 mm

min. lowerplate thickness 1,00 mm 1,20 mm 1,20 mm 1,30 mm 1,30 mm

10

High Strength Steel Applications

0

0,5

1

1,5

2

2,5

3

3,5

100 320 600 1000 1600

MPa

mm

Limits of SPR process: Max plate thickness / strength

Current strength limit for sheets on die side 600 MPa for volume production

Strength < 320MPa 320-560 MPA 560-1000MPa > 1000MPA

Steel Type Mild High strength Ultra High strength Mega High strength

Overview steel classifications (IFUM, University Hannover)

11

Rivet Geometries

C - Type P - Type HSS - Type

Top: DX54D (1,5 mm)Bottom: AA5754 (3,0 mm)

Mild Steels, Medium Steels, Aluminum, Magnesium, Plastic

Top: DP1000 (1,5 mm)Bottom:AA5754 (3,0 mm)

Enlarged outer diameter;optimized cutting edgechamfer below rivet head

Ultra and Mega High Strength Steels

Top: DP600 (1,5 mm)Bottom: AA5754 (3,0 mm)

Reduced inner diameter; stiffercutting edge; chamfer below rivet head

Mild Steels, Medium Steels, High Strength SteelsPure Steel joints and in combination with Aluminum bottom material

Solid Punch Riveting

13

Quality-related characteristics of a Solid Punch Riveting Joint

(1) Filled upper flute

(2) Head excess length

In order to achieve best results with the solid riveting technique, at least one flute should be filled with die-sided material. This is done with the help of the die that presses the material into the solid riveting geometry by means of punching.

1

22

1

Clinch Process

15

Quality-Relevant Characteristics of a Clinching Joint

(1) Interlock (min. 0,10 mm)(2) Neck width(3) Remaining material thickness (min. 0,40 mm)

The interlock size and the neck width define the stability of a joint. The remaining material thickness is used as a measurable process control parameter.

1

2

3

Joint Investigation

17

Application Engineering / Joint Investigation

Determination of rivet and die geometriesVerification of requiredstrenghtsC-frame specification Acessibility study

One System for Three Processes

19

Equipment Configuration - Modularity

Solid Punch rivets

Self piercing rivets

ClinchingERT Setting Tool

Modular constructionaccording to customer requirement

ERC ControlStandard TUCKER-control concept

FeedingERF for self piercing rivetsEPF for solid rivets

20

Force[kN]

10

20

30

40

50

3 6 9 12 15 24 33

Nosepiececontact

18 21 27 30 Punch path (mm) after nosepiece contact point

minsheet thickness

max sheet thickness

Preclamping springis activated

Rivet contactpoint

Preclamping springSpiral spring

Trigger for plate thicknessmeasurement

plate thickness measuring viasleeve position

Rivetsignature

Pressure path

Envelopecurve

Trigger for rivetlenght measurement

Setting path

minrivet length

max rivet length

Sequence of a riveting operation

21

Requirements in Volume Production – Parameter Monitoring

Force path measurement

Due to overlapping results no chance to detect NOK joints

Counter Start : 18225Counter End : 18924

Counter Start : 18925Counter End : 19483

22

Requirements in Volume Production – Parameter Monitoring

Mathematic result evaluation

identic data to slide 21

Clear separation between OK and NOK

23

Requirements in Volume Production – Data Management

POP Blind Rivet

25

Blind Rivet Technology

Blind riveting in Carbon Fibre

Requirements

High Pull-together capability

Reduced surface/edge pressure

Reduced hole bearing

High pull out resistance

High Corrosion resistance � only Stainless A4

High shear & tensile strength

High mandrel head retention

Good waterresistance

Grip range as much as possible

Rivet Setting with conventional equipment

26

Finding Solutions

No Go Critera

Limited in Application

Feature Vgrip Vgrip Plastics LSR TVD Closed End Multigripconventional POP

rivet

(Ø 4,8mm Metal-rivet; Ø 6,8mm VG-plastic)

Shape Blind head

Surface/ Edge pressure low very low low low high high

max. breakload ~ 8000 N ~ 670 N 4300 N 7900 N

Material Mandrel , Body A4/A4 Plastic/Plastic Steel/Steel ZiNi A2/A2

Pull-together capability good low good low bad bad

Grip Range 3mm 2mm 5mm 2mm

Water resistance good good no very good no

Mandrel head loosening force (at Room Temp.) > 1000 N >1000 N min. 0 N min. 0 N

Shear Strength(at Room Temp.) 4000 N 2015 N 2000 N 4300 N

Tensile Strength(at Room Temp.) 4500 N 600 N 2500 N 4800 N

Resistance to temperature very good low very good very good

Rivet length l max(at 2-4mm grip thickness) 13,2 mm 18,5 mm 19,5 mm 12,3 mm

Diameter Blindhead (Rivet set in application) 7,3 mm 9,5 mm 14,2 mm 6,6 mm

27

VGrip Setting Process

28

VERTRAULICH – Alle Rechte vorbehalten

Ø Studie: Metal VG-Stud / Sample: A2 DIN EN ISO 3506-1

Future Prospects

Emhart TeknologiesTucker GmbH

Max-Eyth-Str. 135394 Giessen

Tel. +49 641 405-0Fax +49 641 405-300

emhart.europe@bdk.comwww.emhart.eu