Fuel flow measuring device for IC engine - has sensor to detect position of the free piston pumping fuel

摘要

The internal combustion engine has a fuel flow measuring system incorporated in the fuel pump. A free piston (25) slides in a cylinder (24) and is surrounded by a capacitor type sensor (37). The upper chamber (24a) is exposed to cyclic pressure from a main piston (2) driven by a cam from a rotating shaft (6). This pressure drives the free piston downwards against the spring (26) and expels fuel in the chamber (24b) out through the passageway (27). The pressure generated by the main piston (2) drops suddenly when the edge (18) of a groove on the main piston clears an orifice (19). The spring then drives the free piston upwards to draw in more fuel through the passageway (36). The position of the free piston and its stroke are sensed by the sensor (37) which sends a signal to a computer which then calculates the fuel flow.