A NEW ZEALAND exporter of metal-based components and assemblies to Australia and worldwide has halved machinery set up times, boosted production, and enhanced workplace safety by adopting hydraulic workholding technology.
Crighton Engineering and Manufacturing of Auckland has employed a compact formation of six Enerpac 5.2kN swing clamps to replace manual jig setup to produce load cell components in a Mazak V414-32 CNC mill.
Powered by a quick-acting Enerpac PA135 air-hydraulic pump, the 350-bar (5,000psi) hydraulics have reduced the setup operation from a two-stage, four-hour operation, to a simplified one-stage operation taking half that time.
"There's no possibility of components slipping out, as with the manual setup - or workers getting tired or components slipping out in manual setup, so safety is enhanced and production losses are curtailed," says production engineer Mike Renner.
"Precision and repeatability of the operation are very very good, which benefits customers.
"We used to be able to produce three machined components an hour on that machine and now we can do five, so our efficiency is very high, which is a benefit to customers and producers alike,” he said.
Mr Renner adopted the Enerpac workholding equipment after consulting Paykel engineering with his needs and receiving a recommendation from Mr Gavin Norrington.
Crightons uses the Enerpac equipment to hold 600mm and 800mm cold-machined aluminium load cell bars, which require machining of loading points at each end.
The jig used to machine the bars has initially been used for one shift a day, with further efficiencies possible as production expands.
Enerpac's Australasian national production automation manager John Maudson - who works with Enerpac New Zealand territory manager Neville Stuart in supporting distributors such as Paykel - says Crighton's use of hydraulic clamping shows how automation can substantially benefit lower-volume specialised production.
"Some people think production automation is something only for the big companies, but applications such as this show how practical, down-to-earth equipment can earn substantial gains in productivity for specialist producers such as Crightons.
"The major benefit of hydraulic workholding is the enormous time saved in clamping and unclamping the components. When we compare the time required for hydraulic clamping with that required for manual clamping the gain is no less than 90 to 95 per cent. This is attainable even in limited scale operations, as Crightons demonstrates.
"Equally as important as the time advantage is the positional accuracy of hydraulic clamping systems. The clamping forces are constant, resulting in very precise positioning and clamping. This ensures identical processing procedures and guaranteed quality. Rejection rates due to distortion will be insignificant, which means producers such as Crightons can produce world-class results.
"A third advantage offered by hydraulic clamping is optimum use of clamping space due to compact standard components and the ability to clamp in manually inaccessible areas. This can increase the number of components that can be clamped and processed simultaneously on one fixture," John Maudson said.