11 Июля 2019

Continental developing self-inflating tyre tech

Having to pull over to reinflate your tyres after a session of dune-cresting or pumping up your tyres before the Christmas road trip to Gran’s may soon be a thing of the past.

As part of a general project called The Intelligent Tyre, German automotive parts giant Continental is working on a wheel that would also let you, say, inflate your tyres before a track day and also reduce pressures to normal levels before the drive home — without having to stop anywhere.

“We have the vision that tyres should adapt to the changing road conditions,” Continental engineer Christoph Berger told carsales.com in Hanover this week.

“Today you have to choose a sporting tyre, you have to choose an off-road tyre, you have to choose a comfortable tyre and we think in the future the tyre could adapt to different road conditions, different vehicle conditions and also to the driver’s needs.”

“It’s important that the footprint of the tyre is always on the road, and you can ensure that by making sure the inflation pressure is correct. Today you have to go the gas station to alter your tyres pressures.”

Continental’s radical solution is a wheel that can increase or reduce tyre pressures on demand, or if the vehicle load is altered noticeably, or if there is a warning from a passing car that road conditions ahead have changed.

The wheel unveiled at Continental’s TechWeek exhibition has five spokes but three of them are hollow with covers hiding the cavities.

Inside one of the spokes is a tiny pump, with related electronics, while inside a second spoke is the system control unit and the third hollow spoke houses the battery to power the pump.

Berger said the delicate-looking equipment has so far withstood the centrifugal forces that a wheel develops at speed, although he is quick to add it hasn’t been V-maxxed on a Veyron.

In fact, there may not be so much equipment – nor as much centrifugal force — involved in future if planned developments bear fruit.

“The battery is in the wheel just for this prototype, but in the future [there will be] no battery anymore. We want energy transferred wirelessly to the wheel,” said Berger.

Continental is already using induction to produce illuminated hi-viz vests, in which the vest’s battery is charged when the wearer sits on a vehicle seat.

“That’s an example of wireless energy transfer. Those guys are also working on the technical issue of getting energy into the rotating wheel without any contact.”

As for the centrifugal forces, the project team has set itself a major challenge: it wants to build the pump and control unit into the wheel hub, where centrifugal forces are much reduced.

However, that plan may be stymied by an issue already apparent with the current layout.

“You saw the compressor is not very big. We want a bigger compressor,” Berger said.

“Today we can increase the pressure by 0.55 bar [8psi] in three minutes. In future we want to it a little bit faster, but it is not changing within seconds.”

While Continental has a focus on premium vehicles, which often bring the issue of high speed and centrifugal force, Berger says emerging tyre markets where speeds are more modest may offer a market opportunity in future.

“When we are looking at autonomous driving and self-driving vehicles, centrifugal force is not that big a topic anymore because the vehicle dynamics are quite low, so they are not fast driving or fast cornering. Acceleration is not that fast.”

And there may be a practical application in fleet management or with the rise of car-share programs.