Patent ID: 8707771
Filing Date: 2014-04-29
Classification: G01F,G01M

Abstract:
1. An airflow measuring device comprising: a case protruded in a duct and configured to receive a part of air flowing through the duct; a sensor accommodated in the case, the sensor being configured to conduct heat transfer with air received in the case and to send an electric signal according to a flow amount of air in the duct, wherein the case has the first passage has a throttle at a downstream of a branch position where the second passage is branched from the first passage, the first passage is configured to exhaust air into the duct while throttling air at the throttle, the throttle has a throttle wall surface having a normal vector directed toward an inside of the throttle, the case has a reference cross section including the branch position, the reference cross section being perpendicular to a passage axis of the duct, the case is configured to move air along a flow-direction vector into the second passage at the branch position, the reference cross section includes a reference vector, which is formed by vertically projecting the flow-direction vector on the reference cross section, a width direction is perpendicular to both a flow direction of air in the throttle and the reference vector, and the throttle wall surface has a specific region, in which