Fair EuroBLECH
|
|
EJOT FDS® direct assembly without pre-hole Visite EJOT at EuroBLECH Fair in Hannover Hall 13; Stand C72 - 21.-25. October 2008 Modern space frame structures have high demands on the joining technology in the body shell work because of the composite construction and the oftentimes one-sided accessibility. While the clamped components for joining the EJOT FDS® screw to the Audi TT where still pre-punched, this pre-punching was omitted for the Audi R8. For this the fastening parameters where adjusted and the geometry of the FDS® screw below the screw head was optimised, since a small amount of the material flows towards the fastening direction. While in the past this through hole was used for taking up the displaced material it is now being absorbed by the increased space below the screw head. |
|
To fasten the FDS® screw it is fed automatically into the nozzle of the robot guided fastening equipment. Prior to the actual fastening the retainer, which is positioned in front of the mouthpiece, pushes on the joining location in order to minimise cracking between the two components during the fastening process. The spindle speed is increased simultaneously to the application of the axial load. The screw point pierces both components and forms a metric female thread without chips. When the screw head connects to the surface the displaced material is taken up by the screw head. Until reaching the tightening torque the screw clamps the two components and ensures a much stronger joint due to the larger thread engagement. |
|
|
|
The material arrangement when fastening without pilot hole should be "thin in thick" or "soft in hard" respectively, since higher tightening torques can be reached and gaps between the two components can be minimised. The screw can be loosened again without damage, which is an advantage especially in the case of repairs or for recycling. In this way 310 EJOT FDS® screws are fastened in the Audi R8 series without pilot hole fully automated in the body shell assembly. |
|
The EJOT SHEETtracs® is a self tapping screw designed for a safe joint in thin sheet metals with a pre-formed pilot hole. The reduced flank angle of 45° creates a more stable female thread compared to common 60° threads. This feature increases the torque level and enables a safe assembly in thin sheet metal.
Features and benefits of the EJOT SHEETtracs® screw
|
|
