Contactless fuel flow gauge for vehicles - has reciprocating piston switching over electromagnetic valves when it approaches proximity switches

摘要

The fuel gauge comprises a four-way magnetic valve (5) which is interposed between the fuel pump and the engine of the vehicle. In a central chamber joining the four orifices of the magnetic valves is a piston (1) which can be reciprocated between pairs of valve orifices (X) (Y). Diagonal pairs (A, D) of valves are open when the other pair is closed and vice versa. When the piston is displaced in one direction by fuel flow, it triggers one or other of two proximity detectors (2a, b). This has the effect of changing over the function of the respective pair of valves. The switching frequency of the valves is proportional to the flow volume of fuel. The device is contact-less and only very small losses occur due to piston friction.