Full hydraulic and hydraulic assisted steering

[Dave W]

Assuming those regulations have been adopted they would suggest that it is possible to get full hydra steer approved.

The amount of control required should the "energy supply" fail is defined as:

In the event of a failure of the energy source of the control transmission, it shall be possible to carry out at least 24 "figure of eight" manoeuvres, where each loop of the figure is 40 m diameter at 10 km/h speed and at the performance level given for an intact system in paragraph 6. The test manoeuvres shall begin at an energy storage level given in paragraph 5.3.3.5.

Which the correct steering valve type with the mechanical pump built in should be able to comply with.

The only potential snagging point in those regulations I can find is with the requirement (for approval) for a warning signal in the event of a failure. Whilst it does say that:

In the case of a motor vehicle, an increase in steering force is considered to be a warning indication; in the case of a trailer, a mechanical indicator is permitted.

For "full-power steering" (which is what hydra steer would be classified as) though it may be necessary to include a pressure warning switch that lights a warning on the dash should the hydraulic pressure fail. (See section 5.4.2. Special provisions for full-power steering equipment ). That should be simple enough to implement anyway with an adjustable pressure switch in the line from the pump.

[o_teunico]

"The intention of the Regulation is to establish uniform provisions for the layout and performance of steering systems fitted to vehicles used on the road. Traditionally the major requirement has been that the main steering system contains a positive mechanical link between the steering control, normally the steering wheel, and the road wheels in order to determine the path of the vehicle. The mechanical link, if amply dimensioned, has been regarded as not being liable to failure.

Advancing technology, coupled with the wish to improve occupant safety by elimination of the mechanical steering column, and the production advantages associated with easier transfer of the steering control between left and right hand drive vehicles, has led to a review of the traditional approach and the Regulation is now amended to take account of the new technologies. Accordingly it will now be possible to have steering systems in which there is not any positive mechanical connection between the steering control and the road wheels."

Does anyone know the equivalent EC regulation for this?

[Tom A]

Does anyone know the equivalent EC regulation for this?

That would be 70/311/EEC as last amended by 1999/7/EC. EC motor vehicle regulations are aligned with UN Regs (UN regs used to be known as UN ECE regs. The ECE stands for Economic Commission for Europe).

The only caution I'd give is that these are the regulations that the major motor manufacturers must comply with. Whether the average fettler can go to an IVA armed with a copy of this reg and demonstrate full compliance is another matter entirely.....