| 摘要 |
<p>PURPOSE:To achieve a higher measuring accuracy of a flow rate of an intake air, by providing a circular throttle section having an inner surface comprising a cylinder surface and a tapered surface on a surrounding wall of a suction path on the upstream of a heating resistor. CONSTITUTION:An intake flow rate measuring apparatus 10 has a ring member 11 which composes a circular throttle section in proximity to a hollow member 2 in such a manner as to be inserted into a surrounding wall of an air suction path 3 on the upstream of the hollow member 2 provided with a heating resistor Rh and a temperature compensation resistance Rk facing each other. The ring member 11 has a cylinder surface 11a with a fixed opening area having a reduced path area and a tapered surface 11c with a path area expanding gradually toward the downstream being smoothly linked to a downstream end thereof. This can reduce a difference between an average flow velocity of an air intake flowing through an intake manifold due to a pressure loss at the throttle section and an intake flow velocity at a part provided with the heating resistor Rh thereby achieving a higher measuring accuracy of an intake flow rate.</p> |
