Design of Modus steering column, made it necessary to monitor the 'slide load' in relation to the distance the column is extended, something the existing inspection system could not do
Probably the most safety critical component on a motor vehicle is the steering, with brakes a close second.
So, any company that manufactures steering components must be one hundred per cent confident that its products meet the highest quality standards.
When ZF Steering Systems Nacam UK, one of Europe's leading manufacturers of car steering components, won the contract to supply adjustable steering columns for the new Renault Modus it had to solve a new quality assurance problem.
Because of the design of the Modus steering column, it was necessary to monitor the 'slide load' in relation to the distance the column is extended, not simply the force needed, something the existing inspection system could not do.
Working with Kistler Instruments, Nacam UK designed an automatic test rig that monitors the force needed to extend and retract the telescopic column in relation to distance.
The force is measured throughout the length of travel by a Kistler piezoelectric precision force sensor and distance by a linear displacement transducer.
Both parameters are fed into a Kistler CoMo Net system that monitors the data and rejects any column not within specification.
The CoMo Net system, mounted in a control cabinet adjacent to the test station, is programmed using a standard lap top computer to compare the measured force and distance with pre-set values.
Any column that falls outside specification is disassembled and reusable components returned to the assembly process to ensure maximum productivity and minimise wastage.
With two shifts per day for five days each week, cost-effective, 100% testing of these safety critical components is only possible by using an automated system.
Currently, Nacam UK is using eight Kistler CoMo Net systems and has plans to install a further five or six in the near future.
Nacam's manufacturing manager, Sean Bishop, says that reliable, 100% testing is essential, not only to protect the company's reputation for product quality, whilst keeping tight control of production costs, but also because just one out of spec column delivered to the customer can result in a whole batch of hundreds being rejected.
The Kistler CoMo Net systems is making it possible for Nacam UK to meet the highest QA standards, without compromising productivity.
