Product category:
Machine Safety Monitoring and Control
News Release from: Pilz Automation Technology | Subject: Programmable safety systems
Edited by the Engineeringtalk Editorial
Team on 29 June 2004
Ford updates safety on press lines
Ford has made extensive use of Pilz programmable safety systems and SafetyBus p fieldbus technologies to upgrade its press lines in Genk, Belgium, for Mondeos and Transits.
Ford has made extensive use of Pilz programmable safety systems and SafetyBus p fieldbus technologies to upgrade its press lines in Genk, Belgium, for Mondeos and Transits As a result of changes to the law relating to machinery safety on production plants, car manufacturers are required to adapt existing machinery in their plants to meet the new regulations
This article was originally published on Engineeringtalk on 20 Dec 2006 at 8.00am (UK)
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This presents a tremendous challenge for press shops, as presses are among the most expensive investments within car plants.
At the same time, in terms of their basic mechanics they are also one of the longest lasting types of production machinery in this area.
It was against this background that Ford decided to comply with the new standards at its press shop in Genk, Belgium, not just by implementing mechanical changes, but by an electrical upgrade of the safety technology - on all 300 presses.
Upgraded with Pilz PSS 3000 programmable safety systems, all the presses now comply with the very latest technical safety regulations.
The individual presses were upgraded gradually, while production was running.
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This required hardware and software to be highly standardised early on in the commissioning stage, so that processes in all project phases, including approval, could be optimised to ensure no risk to the availability of production.
In terms of programming the safety systems, all the different press types in the plant were accommodated within a single safety program.
Subroutines for the different press types are quick and easy to activate via coding at the inputs on the programmable safety systems.
This has the advantage that all presses can be operated via one safety program with a fixed CRC check sum, which protects the program from unwanted modifications.
Optimisation in this area not only made approval by external auditors so much easier, but also saved costs as the process took less time.
These advantages are also beneficial in the day-to-day running of the press lines, as the cyclical checks provide a form of self-maintenance.
As a result of the positive experiences gained from this project, additional upgrades were carried out using the some procedure at the press shops in Cologne, Saarlouis and Valencia.
Of the 8.3 million vehicles produced by Ford each year, about 2.2 million are destined for Europe, which corresponds to a market share of 11%.
This makes Ford the third-largest car manufacturer in Europe.
As part of new manufacturing concepts, Ford invested in new press lines in Cologne and, in 2003, Saarlouis, where all the attention is concentrated.
In Saarlouis, Germany, a new compact crossbar transfer press from Schuler produces large body parts for the Ford Focus C-Max; for example, the left or right side panel or even dual parts such as the left and right door.
The press force is 62,500kN, and the dimensions of the press are impressive, at 40m long, 8m wide and 10.50m high, with the depth of the press bed being 6m.
Equally, an electrical driving power of approximately 1000kW speaks for itself.
A newly developed workpiece transport system within the press line has replaced the transfer system between the press levels, which was driven via mechanically controlled disc cams.
One of the features of this system is the ability to increase the output of pressed parts thanks to the electrically controlled servo axes, which optimise transportation in respect of the different tools.
The system is very flexible, enabling simple adaptation to the respective tool.
Up to 200 different tool sets can be managed simultaneously.
A press of this scale needs to have an appropriate number of safety functions in order to guarantee the protection of operating personnel and plant at all times.
The main hazards or risks on the press emanate from the press slide, automation devices such as the modular tool transfer, tool conveyors and the waste chutes.
The safety of the press is guaranteed via a range of appropriate measures.
These include access control by enclosing the plant, guards, lift gates during tool change and light guards, as well as other optical sensors.
These are supplemented by mechanical locks and emergency stop functions.
Other key measures to reduce the potential risk include safely controlling the press slide through a press safety valve and safely locking the die cushion.
This is all achieved through approved standard software blocks within the programmable safety system, in compliance with the standards.
In brief, the following are used to safely monitor the press: at total of 18 emergency stops, 16 lift gates, 13 safety gates, five light guards, one press safety valve, five scrap flaps, 10 tool conveyors and 21 transfer locks.
The high number of safety functions, the large mechanical dimensions and limited space in the control cabinet were the key factors in Ford's decision to select a decentralised control concept, based on the safe fieldbus system SafetyBus p.
Safe operation of the plant is guaranteed by a total of eight PSS SB 3006 DP-S programmable safety systems, approximately 100 decentralised safe input/output modules and seven bridges, which enable safe data exchange between two separate SafetyBus p networks.
Another potential hazard comes from the tool conveyors on the press, which travel in and out of the press automatically during a tool change.
The end limits of the tool conveyor need to be monitored, and this is achieved via safe magnetic switches from the Pilz PSEN product range.
Like all the other sensors, the magnetic switches are connected directly to the decentralised I/O modules on the safe bus system.
This safety concept and the modular structure of the presses meant not only that the technical installation criteria could be met, but also that the engineering costs could be reduced, thanks to shorter design times and, above all, shorter on-site installation times.
Operators also have access to a comprehensive diagnostic package, which minimises downtimes thanks to targeted fault diagnostics.
Ford and Schuler clearly recognised the benefits to be gained from the use of decentralised fieldbus technology, even for safety-related control, and implemented appropriate systems rigorously.
They now have an overall safety concept that is based on the universal use of components from one supplier.
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