| 摘要 |
PURPOSE:To eliminate a measurement error even in an operating region where a suction pulsation is signification and improve the precision of an air/fuel ratio control, by detecting a regular wave of short relative period correctly proportional to a flow and performing arithmetic operation of sucked air volume. CONSTITUTION:A vortex detection circuit 6 which outputs a voltage value corresponding to a pressure change following the generation of a vortex and a karman's vortex street generating element 3 arranged in a suction passage upstreams of a throttle valve are provided and sucked air volume is calculated on the basis of the frequency of this detected signal. In this case, a detection circuit 8 for a change in the frequency detected wave by the Karman's vortex stream is provided, so that arithmetic operation for a sucked air volume is carried out based on only the detection frequency of a relatively short period wave portion. |
