Connected (physically, that is).

One of the black spots in automotive engineering is the connector. Whether it be electronics or plumbing, joining two things together is always going to be a weak spot. While there have been a number of solutions provided for vehicle electrics/electronics, the connector has remained little changed when it comes to pipes, principally because the technology is straightforward and well known. However, with the drive to reduce costs, decrease weight and improve manufacturing processes, what was the right answer in the past is not necessarily the best one now.

With its roots in heavy-duty industrial applications, British company Oystertec (York; www.oystertec.com) has come up with a novel, simple and cheaper way of connecting two pipes together that it says will revolutionize the automotive industry once it becomes accepted. Such claims, of course, have been heard before from other companies over the years, but in Oystertec's case, it seems to have developed the perfect solution.

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As the manufacturer of fluid connectors built to take up to 500 bar, the 200-bar maximum found in the braking system or the 150 bar required in the power steering of a car present little problem. "The knowledge we have gained from our industrial applications stood us in good stead when developing fluid connectors for the automotive industry," says Brendan Johnston, director of Oystertec's automotive division. "It is certainly more useful than developing a product from a domestic application, like a hose pipe connector which only requires 2 bar. What has been different, though, is the very rigorous testing that has been carried out at every level and by every company on our products."

The basis of Oystertec's fluid connectors, which can be used on all the fluid systems on a vehicle, is so simple that it beggars belief that it has not been "discovered" before. Replacing the flange and bolt that serve as the basis of all connectors currently in use is a retaining ring and positional locking cap on one tube that lock onto the cavity housing on the other tube. Should this sound too complex, the retaining ring and locking cap are no more than two small components made out of plastic while the cavity housing is the specially shaped female into which they lock. On hearing the word "plastic," it immediately causes consternation when it comes to connectors, but Oystertec's rings are durable and made from the same nylon material used in various under-hood applications. They are made to withstand temperatures from -40[degrees]C to +250[degrees]C.

Apart from being a more simple and elegant solution to fluid connection, this solution also has massive implications on other accounts. Because the flange and bolt have been deleted from the equation, the space required for the connector is reduced. While this may be of little significance when it comes to a single connection, where there are multiple applications, such as on a power steering system, the space saved is substantial.

While this is not always taken into account by the purchasing department, the cost of manufacturing is also reduced. Instead of having power tools on the line doing up the bolts, the insertion force, which ranges from 50N (11 lb f) to 67 N (15 lb f), means that it can be easily done by hand. "This ensures not only a fast, smooth and reliable connection, but also a simple, consistent and effortless fit at every stage of the system assembly operation," says Johnston.

A secondary advantage is that it is impossible to not complete the connection without it being immediately apparent. While a bolt can be cross-threaded into place by an inattentive operator, the connector is either connected or not; there is no half measure. If the retaining ring has not been correctly clicked into place, the positional locking cap will not click into place. To ensure that it is also visible, and drawing on feedback from the Japanese, who have been studying the product with a view to taking out a license, the retaining ring is likely to be a bright yellow, which completely disappears from view when correctly locked into place.

"As it is a thread-less design, no assembly tools are needed to fit it," says Johnston. "This ensures that the costly assembly problems of over and under tightening and cross-threading of current threaded fittings are completely eliminated."

Because this is such a different solution, Oystertec has had to go that extra mile--or few miles--to prove its products' worth. While the connectors have been undergoing tests by a variety of major tier-ones and OEMs, it has put its connectors through tests that include 800,000 cycles without failure at 128 bar (1,856 psi), a burst test up to 800 bar (11,600 psi) without failure and tensile testing ranging from 5300 N to 6000 N (1,200 lb-ft to 1,350 lb-ft). It has also placed connectors on a number of vehicles for everyday use.

Although Oystertec owns IBP, a company that manufactures fluid connectors for industrial applications, it regards itself as an "innovations company" and is in the business of selling licenses. Already Dana has signed a technology transfer license agreement to acquire the technical knowledge, manufacturing capabilities and assembly detailing of this high pressure, multi-fluid systems, quick-to-connect connector, and there are others in the pipeline.

"Oystertec's new connector assembly technology also delivers systems commonality, stock reduction, labor and space saving benefits," says Johnston. "These are features that together with its fluid systems simplification capabilities, weight savings and reduced assembly errors can all be delivered directly to the assembly line."

By William Kimberley, Editor

Automotive Engineer, [e-mail]