MONITORING SYSTEM ENSURES QUALITY OF
SAFETY CRITICAL ASSEMBLY.
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 Limited, 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, www.kistler.com, 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.
Kistler Instruments is one of the worlds leading manufacturers
of piezoelectric and piezoresistive precision sensors covering
acceleration, force, pressure and torque. Established in
Wintherthur (Switzerland) in 1957, Kistler is represented in over
50 countries and has subsidiaries in Germany, France, Italy, UK,
Japan, USA, China, Korea and Singapore.
Heavy investment in research and development, 15% of staff
worldwide are engaged in research and development, has
generated a number of innovations using piezoelectric,
piezoresistive and capacitive techniques to provide solutions
to numerous force, pressure and acceleration measuring problems.
These innovations include the world's first commercial quartz sensor,
two-wire constant current technology to integrate sensors with
microelectronic circuitry, high-temperature pressure sensors for
use up to 400 deg C and three-component force measuring sensors.
For more information, please contact :-
Kistler Instruments Ltd.
13 Murrell Green Business Park, London Road, Hook RG27 9GR
Tel: +44 (0)1256 741550
Fax: +44 (0)1256 741551