| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an apparatus for measuring the air flow rate with high accuracy by suppressing disturbance of air flow in a bypath through a simple structure. SOLUTION: A bypath 34 comprises an upstream channel 34a for passing the air from an intake port 31d in one radial direction of an air channel 2, a downstream channel 34b for passing the air in the opposite radial direction to the upstream channel 34a disposed in parallel with the upstream channel 34a on the downstream side thereof, and a channel 34c communicating between the upstream channel 34a and the downstream channel 34b. A corner part 35 facing the joint between the upstream channel 34a and the downstream channel 34b is formed into a smooth concave face having arcuate cross-section. Since generation of vortexes in the air flow passing a heat-sensitive resistor 25 and a heating resistor 26 arranged in the vicinity of the corner part 35 or disturbance of the air flow can be suppressed, fluctuation in the output of air flow rate being detected by the heat-sensitive resistor 25 and the heating resistor 26 can be suppressed and the air flow rate can be detected with high accuracy.</p> |
