Thermal flow sensor supporting element having a gradually increased portion between its distal ends

摘要

A flow rate detector has a detection pipe (26) disposed in a fluid channel (21), a supporting member (27) for supporting a thermosensitive flow rate sensor (28) being provided in the detection pipe (26). The supporting member (27) has a sensor holding portion (27a) which has a predetermined width and a broadening portion (27b) which is adjacent to one end of the sensor holding portion (27a) and the width of which gradually increases from the distal end thereof toward the sensor holding portion (27a). The flow rate sensor (28) is built in a side surface of the sensor holding portion (27a) such that it is exposed in the detection pipe (26).