Fastening Technique for Hybrid Auto Body Structures Ralf Birkelbach, EJOT GmbH & Co. KG

Fastening Technique for Hybrid Auto Body Structures Ralf Birkelbach, EJOT GmbH & Co. KG EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 1

Content Design and material changes in automotive industry Joining requirement specification Basic fastener development: Fastener design and assembly principles Automotive applications with clearance hole Further developments: Optimized screw design and assembly principles Automotive applications without any hole Multi layer applications EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 2

Design and material changes in automotive industry Steel Aluminum Glass Plastics Others Quelle: Cluster Neue Werkstoffe in Bayern 2006 EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 4

Design and material changes in automotive industry Various stages of light weight design in the body in white structure Al- Die cast Al- Extruded profile Al- Sheet St High strength (22MnB5) Structure Steel Hang- ons Steel Structur Steel Hang- ons Al Structure Steel plate parts Al Hang- ons Al Structure Al/Steel plate parts Al Source: AUDI AG Hang- ons Al EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 5

Content Design and material changes in automotive industry Joining requirement specification Basic developments: Fastener design and assembly principles Automotive applications with clearance hole Further developments: Optimized screw design and assembly principles Automotive applications without any hole Multi layer applications EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 6

Joining Requirement Specification Joining different materials together (with minimized preparation) Solutions for fixing, attachement and structural (high strength) joints Assembly with and without adhesive between the layers One side access for fixing into aluminum extrusions (e. g. Space-framedesign) Accurate assembly without distortion High dynamic resistance Crash safety Fully automated assembly process High reliability / process control Multi layer applications EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 7

FDS screw design Head with recess inside / outside Usable thread length Thread forming part Flowdrilling section Point (tip) of the screw EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 9

Stages of the FDS assembly 1. Warming up the sheet metal by axial end load and high speed 1. 2. 3. 2. Penetration into the material 3. Forming of the extrusion 4. Chipless forming of a female machine thread 4. 5. 6. 5. Installation 6. Tightening with the pre-set torque EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 10

Torque plot of an FDS joint torque (Nm) T s 1. Forming of the extrusion 2. Thread forming 3. Engagement of full threads 4. Tightening 1. T T T i 2. 4. 3. T i = installation Torque T T = tightening Torque T S = stripping Torque time (sec.) EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 11

System for fullautomated FDS Robot-assembly (left) and feeding system (right) EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 12

Fully automated FDS assembly (with clearance hole) 1. 2. 3. 4. 5. 6. n: speed M: torque F: endload Finding Warm up Draft forming Thread forming Drive in Tightening EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 13

FDS Example in Aluminum (with clearance hole) EN AW-5754 t=1,15 mm EN AW-6082-T6 t=3.2 mm EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 14

Series Applications with Selfpiercing and Extruding Screws EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 16

Application examples (with clearance hole) Lamborghini Gallardo: fully automated assembly at Thyssen Krupp Drautz Fixation of the base plate (1 mm) onto Aluminum body frame (3 mm) 160 FDS M5 x 18 without pilot hole source: Audi AG EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 17

Application examples (with clearance hole) Ferrari California: assembly of the tunnel Assembly of 100 FDS M5x18 screws without pilot hole into: Aluminium profile with thicknesses: - 1,25mm EN AW-6181-A T4-1,5mm EN AW-6181-A T4-2,0mm EN AW-6063 T6-3,9mm EN AW-6063 T6 Clamped part: Aluminium die-cast material - 2mm C611 T5 with 7mm clearance hole EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 18

Application examples (with clearance hole) Audi TT Coupe/Roadster: fully automated robot assembly in the body in white production Robot-assembly (12 systems) for 229 FDS M5 screws (255 for Roadster) without pilot hole into: Aluminium profile: thickness 1,5 up to 3,5mm Aluminium die-cast material up to 3mm Clearance hole diam.: 7mm 80% of the FDS assembly into aluminium profile 75% in combination with adhesive (no adhesive in the clearance hole) source: Audi AG EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 19

Application examples (with clearance hole) Audi TT Coupe/Roadster: fully automated robot assembly in the body in white production Material mix assembly Steel plate 1,2 mm on aluminium profile 2,5 mm EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 20

Application examples (with clearance hole) Audi TT Coupe/Roadster: fully automated robot assembly in the body in white production Fixation of aluminium sheet 1,15mm on - 1,5 mm aluminium frame rail - 3 mm aluminium die-cast - 2 mm aluminium cross beam with different tightening torques A-pillar Fixation of car body shell 1,15 mm on aluminium die-cast 3 mm Demo Video EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 21

Further optimized FDS screw design Head with recess outside / inside Increased underhead bulge Usable thread length Thread forming part Flowdrilling section Point (tip) of the screw EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 23

Process steps of FDS assembly without part preparation = Downholder 1. 2. 3. Heating Penetrating Extrusion forming 4. 5. 6. Thread forming Engagement of full threads Tightening EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 24

Assembly principles Material combination and downholder design for assembly without clearance hole Fastening direction Clamped part (without clearence hole) Installation part Note: Preferred material combination: Thin on Thick and/or. weak on hard Adjustable downholder force EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 25

Fully automated FDS assembly (without holes) 1. 2. 3. 4. 5. 6. n: speed M: torque F: endload EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 26 Finding Warm up Draft forming Thread forming Drive in Tightening

FDS Example in Aluminum (without holes) EN AW-5754 t=1.5mm EN AW-6082-T6 t=3.8mm Demo Video EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 27

Application examples (without holes) Audi R8: Fully automated robot assembly in the body in white production Assembly of 310 FDS M5 screws without pilot and clearance hole into: Aluminium profile: thickness 1,5 up to 3,5mm Aluminium die-cast: up to 3mm Max. clamped part thickness 1,15mm source: Audi AG EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 29

Application examples (without holes) Audi R8: Fully automated robot assembly in the body in white production EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 30

Application examples (without holes) Audi A8 (D4): FDS Screw M5x20 Fully automated robot assembly in the body in white production Assembly: Installation parts: - 1,0 bis 4,8mm Aluminium profile - 2,5 bis 3,5mm Aluminium die-cast Clamped parts: - Aluminium (with and mostly without clearance hole) 740 FDS M5 x 20 (per car) 18 joints as 3-layers source: Audi AG EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 31

Guideline and recommendations Preferred conditions: clamped part thickness <= installation part thickness clamped part thickness max. 30% higher than underhead bulge clamped part hardness <= installation part hardness max. tensile strength installation part: ~ 800 MPa Advantages: no hole operation at all no consideration of tolerances structure fixing with or without adhesive one side access assembly Disadvantage: special headstyle required screw more expensive than with ordinary headsytle EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 32

Multi layer FDS screw design Head with recess outside / inside Increased underhead buldge Usable thread length Thread forming part Calibration part Flowdrilling section Point (tip) of the screw EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 34

Multi-layer application (3-layer Material Mix Aluminum/Steel) FDS M5x25 Installation part: HC 340 LA (2mm) Clamped part 1: Aluminium EN AW-6181 (1,5mm) Clamped part 2: Aluminium EN AW-6181 (1,5mm) Ti Ts t Process (Nm) (Nm) (sec.) end EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 35

Multi- layer application (3- layer stack-up of Aluminum) FDS M5x25 Installation part: Aluminium EN AW-6181 (2,0mm) Clamped part 1: Aluminium EN AW-6181 (1,5mm) Clamped part 2: Aluminium EN AW-6181 (1,5mm) Ti Ts t Process (Nm) (Nm) (sec.) end EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 36

Multi- layer application (4- layer stack-up of Aluminum) FDS M5x25 Installation part: Aluminium EN AW-6181 (1,5mm) Clamped part 1: Aluminium EN AW-6181 (1,5mm) Clamped part 2: Aluminium EN AW-6181 (1,5mm) Clamped part 3: Aluminium EN AW-6181 (1,5mm) Ti Ts t Process (Nm) (Nm) (sec.) end EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 37

Multi layer FDS screw design Head with recess outside / inside Increased underhead buldge Can and is also being used Usable for the thread 2 layer length joints Thread forming part Calibration part Flowdrilling section Point (tip) of the screw EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 38

Fulfillment of Joining Requirement Specification Joining different materials together Solutions for fixing, attachement and structural joints Assembly with and without adhesive between the layers One side access for fixing into aluminum extrusions (e. g. Space-framedesign) Accurate assembly without distortion High dynamic resistance Crash safety Fully automated assembly process High reliability / process control Multi layer applications EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 39

Thank you for your Attention! www.ejot.de EJOT GmbH & Co. KG April 2012 Ralf Birkelbach Folie 40