Adjustable flow-control valve for the self-energising electro-hydraulic brake

AbstractThis paper presents the design and performance of an electrically adjustable flow control valve. It is designed specifically for the self-energising electro-hydraulic brake which requires small volume flows, a fail-safe open characteristic, a leakage tight closed position, simple control by just one solenoid, good dynamics, and repeatability.The valve concept is based on a conventional pressure compensator design usually found in flow-control valves. The measuring orifice used to sense the flow through the valve is typically constant. In the presented design it is made adjustable using a hydro-mechanical pilot servo mechanism. The pilot is actuated by a proportional solenoid. The paper explains static flow equations used to parameterise the design. Dynamic simulation is used to validate the design before manufacturing. Measurements of the prototype show a good match with the simulation.Measurements of the main characteristics of the valve are shown, specifically the dynamic response to a step inpu...