Product category:
Automation and assembly equipment
News Release from: Weber Automatic Assembly Systems | Subject: RSF automatic screwdriving equipment
Edited by the Manufacturingtalk Editorial
Team on 29 August 2007
Flow drill screws replace BIW rivets and
welding
Using flow drill screws rather than rivets or welding in BIW vehicle assembly, enables tough joints to be achieved faster and more efficiently, without affecting the strength or long term integrity.
Automatic Weber screwdriving systems are ensuring a tougher body assembly for the Audi TT car Weber Automatic Assembly Systems' latest RSF automatic screwdriving equipment is being used as part of an innovative method of fixing vehicle body panels at the Audi TT production line in Ingolstadt, Germany
This article was originally published on Manufacturingtalk on 18 Feb 2008 at 8.00am (UK)
Related stories
Control technology boosts screwdriving performance
An innovative control system gives line engineers complete control of all automated screwdriving parameters, with the ability to produce an almost infinite variety of programs.
Manual screwdriver has automatic feeding
A new low cost manual hand screwdriver with automatic feeding offers an accessible method of achieving increased production levels in a wide range of industrial applications.
RSF uses flow drill screws, rather than rivets or welding, to achieve tough joints faster and more efficiently, without affecting the strength or long term integrity of the vehicle.
Many of the body panels on the current Audi TT are manufactured from aluminium.
Formed sheet panels or extrusion profiles have to be joined both together, and to other materials, used in the overall vehicle construction.
Further reading
Screwdriving unit integrates process control
A screwdriving control unit allows the operator to input freely configurable process parameters to achieve integrated programmable cycle control.
Step conveyor improves assembly line times
A step conveyor, with feed unit and control module is designed to improve throughput times, productivity and profits at assembly shops undertaking production line screwdriving tasks.
Dual function machine speeds IC engine assembly
A special purpose machine, designed for the automatic insertion of valve seats and guides has was designed and built within three months and has reduced cylinder head assembly times.
The method of fixing chosen by Audi's engineers is to use self-piercing and extruding flow drilling screws (FDS), from EJOT.
These fasteners are applied using specially developed Weber automatic screwdriving systems, which are fitted to each of 15 production robots operating on the body in white (BIW) assembly line.
The Weber RSF screw-driving system is a modular, self-contained unit, which interfaces directly with the host robot to ensure accurate and repeatable positioning.
It uses an advanced sensor system to ensure that each screw is inserted with consistent torque and depth.
The RSF systems automatically positions itself using a linear transducer to measure the initial compression as the unit comes into contact with the surface of the vehicle.
It then sorts and blow-feeds individual screws to a combined screwdriving spindle and chuck, or nose-piece, unit.
The system then advances each screw, increasing the speed of rotation to 5,000 rev/min and the force applied to 1.5kN.
This action effectively causes localised heating and enables each screw to pierce the panel surface and then form a thread without using a pilot hole or generating of swarf or other debris inside the panel.
Once the threads are formed the speed is reduced, to just 200 rev/min, and the screw is driven home, with a long thread engagement creating a tough, long lasting join.
The entire operation is typically completed within 3-4s.
The RSF system incorporates a specially designed spindle drive mechanism, with a dynamic servo controller and a low mass, three phase synchronous motor; this is capable of extremely rapid start/stop operation, of handling high speeds and loads, and is maintenance-free.
In addition, a separate measurement transducer is used to monitor applied torque, plus speed, angle and direction of rotation, with the measured data being fed back to a controller, enabling screwdriving parameters to be changed instantly.
The spindle and chuck unit are extended and retracted pneumatically.
* Standard and interchangeable - further benefit of the system is that the various components and assemblies used on all 15 of the RSF machines are standard and interchangeable.
It helps Audi reduce still further its maintenance and staff training costs.
An additional off-line unit has also been installed for training purposes.
Weber Assembly Automation Systems' UK managing director, James Mayo, explained: "Our design and engineering team in Germany worked closely with Audi over a number of months to develop a solution that met the specific demands of the new TT production line.
In particular, the complex space frame body shape and the location of the panel fixing points meant that in many instances it was only possible to access fixing points from one side of each panel, precluding the use of conventional fixing methods.
In addition, it was important to carry out each fixing operation quickly and consistently, to maximise productivity without affecting build quality.
The solution developed by our team, based on our proven RSF technology, is compact, relatively lightweight and extremely reliable, requiring minimal long term maintenance, yet provides exceptional levels of accuracy, repeatability and overall performance.".
• Weber Automatic Assembly Systems: contact details and other news
• Email this article to a colleague
• Register for the free Manufacturingtalk email newsletter
• Manufacturingtalk Home Page
Search the Pro-Talk network of sites
