DEVICE FOR CONTROLLING AIR FUEL RATIO OF INTERNAL COMBUSTION ENGINE

PURPOSE:To improve the fuel consumption efficiency, exhaust performance, and operability of an internal combustion engine, by correcting the air intake quantity of the engine so that an appropriate air fuel ratio can be realized with respect to the quantity of fuel supplied to the engine. CONSTITUTION:Laser light from a laser light source 8 is irradiated upon a fuel passage 5a so that the laser light can traverse the passage 5a, through an optical fiber 12 and microlens 10. This flow rate detecting section 7 catches scattered light produced when a tracer passes through the laser light by means of the microlens 10 and introduces the caught scattered light advancing through the optical fiber 12 in the opposite direction to the laser light to a photoelectric converter 11 after separating the scattered light by means of a beam splitter 9. At the photoelectric converter 11 the caught scattered lights are converted into electric signals corresponding to their intensity and the moving speed of the tracer, namely, the flowing speed or flow rate of the fuel is calculated by an arithmetic device 13. The calculated result is supplied to a control circuit 6 as a fuel quantity signal.