| 摘要 |
PURPOSE:To set an enlarged dynamic range for measuring flow rate, by providing a means which calculates the flow rate of air or mixed air by information on the sectional area of flow path of the mixed air and the pressure of the flow path. CONSTITUTION:When air flows in a Venturi 3 part at a velocity of flow V, a pressure difference P form the atmosphere at the part is approximately proportional to V<2> and if this pressure is detected by a pressure sensor 4, the flow velocity V of the air can be calculated. Eventually, the product of the flow velocity V and a sectional area A of the Venturi part 3 becomes a flow rate of the air. As the flow rate of the air depends on the opening degree of a throttle valve 11 and the number of revolutions of an internal combustion engine, if the number of revolutions of the engine is confirmed, it is easy to set up roughly a standard whether the air flow rate is much or little. Namely, a control unit 6 operates outputs of the sensor 4 and a sensor 7 for revolvution number and jets fuels from a fuel jetting valve 5 so as to fill the most suitable mixed air in a mixer 2. |
