INTAKE AIR FLOW RATE MEASURING DEVICE, AND MANUFACTURING METHOD THEREOF

To provide an intake air flow rate measuring device 100 capable of avoiding failure that deteriorates detection accuracy of humidity caused by transfer of heat outside of an intake air duct D to a temperature detection element.SOLUTION: A separator cross-section area α1 is provided in a smaller size than a root part cross-section area β1. A separator α is disposed at a place directly hit by intake air flowing inside an intake air duct D. Since the separator cross-section area α1 is small, heat resistance of the separator α is increased. Further, since the separator cross-section area α1 is small, heat capacity of the separator α is reduced, and the separator α is forcibly cooled according to the intake air passing through inside the intake air duct D. Accordingly, a heat blocking effect is obtained due to the separator α, and therefore, heat inside an engine room does not reach a humidity detection element disposed in a humidity sensor 12. Thus, failure that deteriorates detection accuracy of humidity caused by heat outside the intake air duct D can be avoided so that humidity of the intake air can be measured with high accuracy.SELECTED DRAWING: Figure 1 【課題】吸気ダクトＤの外部の熱が温度検出素子に伝わることによって湿度の検出精度が悪化する不具合を回避できる吸気流量測定装置１００を提供する。【解決手段】分断部断面積α１が根元部断面積β１より小さく設けられる。分断部αが吸気ダクトＤの内部を流れる吸気に直接あたる所に配置される。分断部断面積α１が小さいことで分断部αの熱抵抗が大きくなる。また、分断部断面積α１が小さいことで、分断部αの熱容量が小さくなり、分断部αが吸気ダクトＤの内部を通過する吸気によって強制的に冷やされる。これにより、分断部αによる熱の遮断効果が得られるため、エンジンルーム内の熱が湿度センサ１２に設けた湿度検出素子に到達しない。このため、吸気ダクトＤの外部の熱によって湿度の検出精度が悪化する不具合を回避でき、吸気の湿度を高精度に測定できる。【選択図】 図１