| 摘要 |
PURPOSE:To measure the suction air quantity of an internal combustion engine, and to generate an air quantity signal to a fuel jet control computer, by detecting directly vibration numbers of vibration generated by a flow of a fluid, of a vibrator placed in a flow duct. CONSTITUTION:A photodetecting part 7 on which a spot 8a of irradiated laser light 8 is projected uses a light position detecting photoelectric converting element having a function for detecting a position of the spot 8a as the center of gravity of light intensity, irrespective of size of the spot 8a. At the time of measurement, a vibrator 6 is vibrated by vibration numbers (namely, a value proportional to a flow rate) proportional to a flow velocity (namely, a value proportional to a flow rate since the sectional area is constant), and a shadow of the vibrator 6 of the spot 8a by the laser light 8 is also vibrated on a photodetecting face 7c by vibration numbers. The spot 8a on the photodetecting face 7c of the laser light 8 is stopped at a fixed position at all times, irrespective of a flow of a fluid, but a shadow of the vibrator 6 in the spot 8a is influenced only by a flow velocity and is vibrated. The light center of gravity is vibrated in conformity with vibration of the vibrator 6. The vibration of this light center of gravity is outputted as a ripple voltage of an arithmetic part 9 from the photodetecting part 7. |
