MacDonald Humfrey Automation (MHA) and sister company Exmac Automation have
joined forces to help automotive engineering specialist Ricardo create a
state-of-the-art 600 square metre assembly facility to build its first ever
high-performance engine at Ricardo's Technical Centre in West Sussex. Providing
a near cleanroom production environment the facility has the capacity to produce
4000 engines annually across two daily shifts. Its core is a ten-station
vertical conveyor mini-line supported by incoming materials inspection and
line-side delivery of components. Each station is equipped with a sophisticated
MacDonald Humfrey 'Human Machine Interface' (HMI) providing guidance to each
operator on the precise sequence of operations required at each stage of
assembly' to ensure No Fault Forward' (NFF) assembly. Tools at each station are
instrumented to provide data directly into a central warranty database for each
engine, providing complete finished product traceability.
Each line station is interlocked via its HMI to ensure that all operations and
checks have been successfully completed and recorded before the line can be
indexed and the engine moved forward to the next station.
Says Ricardo's Dave Thompson: "Exmac understood our brief, asked the right
questions and provided their own engineering ideas to help us achieve our
objectives. Because space couldn't accommodate a continuous loop line, designing
the conveying system proved particularly challenging, as did the relatively slow
50-minute Total Average Cycle Time (TACT) required for the low - eight engines
per shift - production volume and the 'no-faults-forward' culture.
To meet the specification within the space available Exmac designed a compact
10-station back-to-back manual line that takes up very little floor space in the
new building. The system allows Ricardo to load engine blocks onto the line and
rotate them at any of the stations, and indexes manually to allow greater
control over the assembly process.
Engine blocks are fixed to lightweight trolleys using a vertically mounted slew
ring and quick release plate, that allows it to be rotated through 360 degrees
whilst is locked in place to allow complete access for operators. Engines start
their build sequence at station 1 and when all assembly functions are completed
the control system allows a stop to retract for the operator to push the trolley
(running in a steel track) to a holding position until station 2 is clear. The
trolley is then pushed to station 2 where it is again held in place for that
station's assembly functions to be carried out ...and so on to station 10.
A latched turn-post at each end of the line (providing a swing-gate effect)
allows trolleys be re-directed to the opposite side of the line after assembly
operations at station 5 are completed. When a trolley reaches station 10 the
engine block has been transformed into a fully assembled, complete engine.
The Exmac-designed mechanical locking systems locate and secure trolleys at each
station until the MacDonald Humfrey HMI system confirms that operators have
completed all required tasks at each station, and assembly can continue on a
If an engine needs to be reworked, trolley and engine can be moved to a holding
position at the end of the line. When work is completed, both are returned to
station 1 (via the turntable if necessary) and then moved to the appropriate
station to allow the engine to continue its build programme.
Commenting for Ricardo, Dave Thompson says a great deal of thought has gone into
the way the line operates, and has resulted in a number of innovations,
including a novel low-cost method of rotating the engine using a
battery-operated electric drill, fitted with a special socket that is attached
to the gearbox, enabling the engine to be positioned wherever it is needed.
The bespoke MHA Human Machine Interface' provides Ricardo production engineers
with a list of operations that they can vary and configure themselves. For
example, not only are they able to set task-by-task instructions showing
assembly operators how to build the engine, they also include time allocated to
each task, DC tooling operations, air tests, and gasket glue plotting. In
addition, the HMI integrates all operations and confirms - with a time and date
stamp - that all tasks have been completed. Effectively this means that every
single operation - including every bolt to be tightened - has its own programme!
Detailed on-screen information and visual aids are shown at each of the ten
stations and data is fed to an MHA pick-to-light system to ensure efficient
error-proof component picking.
The facility was specified, designed, constructed and commissioned in just 18
months despite Ricardo insisting on an aesthetic approach to the design, in
order to present an attractive and technically advanced visitor environment for
Ricardo's international customers.
Summing up, Paul Crosbie of MHA says: "The combination of a robust Exmac
handling system and complex MHA control system, has more than exceeded Ricardo's
overall performance expectations."
For further information contact:
Marcus Hunter, Exmac Automation Gregory's Bank, Worcester WR3 8AB
Tel: 01905 721500, Fax: 01905 721539
Email: http://MH@exmac.co.uk, Web: www.exmacautomation.co.uk