Test Rigs to Save Lives

An innovative Enerpac test rig that simulates 20G crash forces for vehicle seat manufacturing safety is expected to save lives. Jackson Enterprises, New Zealand’s leading van seating and interior specialist – which is involved in the conversion of standard vans into specialist passenger transport vehicles – has put a premium on safety by designing its own test rig that can suddenly impose more than three tons of force when trialing seat structure and seat belt anchoring points.

Forces such as this translate into more than 20G – or 20 times the force of gravity. “There was no such test in New Zealand so we made our own test rig,” said Managing Director Peter Jackson. “The only other option was to send each conversion to Australia for testing.”

“We wanted to impose 2250kg at the occupant centre of gravity and about 500kg at the seat frame centre of gravity. The ram load would be required to reach a peak of as high as 3100kg within between 0.5 seconds and 1.0 seconds and maintain it for a minimum of one second,” said Mr Jackson, who called in hydraulic specialist and Enerpac distributor Jonel Hydraulics to help design the project.

“We convert a lot of vehicles – Toyota HiAce, Mazda E2000, Nissans, Ford Transits, VWs, Mercedes Vito – so we wanted it to be versatile and accurate. Not only do we do minibus vehicles such as airport buses, but also we do major conversions on wheelchair vehicles for people with disabilities, so safety is always at a premium.

“In the interests of our customers, we also wanted to ensure the seats and mountings were properly engineered – neither under-engineered, leading to failure, nor over-engineered, leading to excess weight , complexity and cost.”

Working with Jonel Hydraulics George Pavletich, the company engineered a test rig incorporating a rugged 1.12 kW Enerpac ZE4 electric pump of a type typically subjected to heavy service demands around factories and mine sites. This was coupled to an accumulator through a manifold and controlled via cartridge valves so that a surge of force could be delivered to the two high force cylinders especially designed by Jonel Hydraulics for this task of simulating about 20G of force. The control system had to be able to accommodate pressure and load while accommodating a travel of 300mm during the test.

“We deal with a lot of seat types from Europe and Asia, so it is very useful to have this tool on site so we can do a wide range of our own tests. Jonel were fantastic and George worked on it progressively with us to build up its versatility to achieve our test objectives and ensure the right engineering and optimum safety for our customers. It wasn’t a straightforward job, as it required specific technical knowledge and the commitment to our operations to understand what we wanted and to translate that into reality. Jonel did this very well – the rig is becoming very versatile in service.”

Jackson said the company which has specialised since 1979 in the supply of van interior conversions for Minibuses – including standard and wheelchair accessible, commercial and trade person’s vehicles has always set high safety standards. Compliance with safety regulations is overseen by an Independent Registered engineer. This ensures work complies with New Zealand Safety Standards. Jackson Enterprises is committed to continuous improvement of products and standards and is accredited to the internationally recognised quality standard Telarc registered Q-Base. The company is also a member of the New Zealand Bus and Coach Association and VANZ Group.

Pavletich said the innovative project had been an exciting one for the company. “Its not often you get to benchmark new safety standards for a specific industry so Jacksons have done a tremendous job and its been good to work closely with them” he added.

Jonel Hydraulics is a major Australasian distributor of Enerpac products and the only authorised Enerpac service agent in the North Island. In addition to the transport sector, Jonel has been servicing industries including building and construction, earthmoving, forklift, manufacturing, materials handling and primary production and other major industrial markets for twenty five years. Their services include workshop and mobile servicing of hydraulic equipment, supply and remanufacture of hydraulic cylinders and other tools, honing, hose repairs and assistance with all aspects of specifying and design of hydraulic systems.

Enerpac is a major supplier of high-pressure (700 bar) hydraulic equipment with over 50 years experience. Its ranges of 700 Bar (10,000 psi) precision hydraulic cylinders, tools and safety equipment is complemented by professional bolting
technology being introduced to address the needs of industry, including mining and energy, infrastructure construction, manufacturing, pipelines, mobile machinery, tracked and heavy vehicles, cranage and fixed plant.