| 摘要 |
PROBLEM TO BE SOLVED: To easily make a periphery of a flow rate detection sensor fitted to a sensor fixation part airtight.SOLUTION: A sensor fixation part 24 including a cylindrical part 26 to which a flow rate detection sensor 29 is fixed has first and second flange parts 27a, 27b formed on both sides thereof. The first flange part 27a has a larger external diameter than that of the other second flange part 27b. A cover member 23 which covers the sensor fixation part 24 is in a short cylindrical shape, and has an external diameter substantially equal to the external diameter of the first flange part 27a and an internal diameter a little larger than the external diameter of the second flange part 27b. A tip part side of the cover member 23 which abuts against the first flange part 27a is opened, and a circular wall part 30 is provided behind a rear end part located on the second flange part 27b. The tip part of the cover member 23 abuts against a seal material 33 on an inner side face of the first flange part 27a, and a wall part 30 of the cover member 23 abuts against a seal member 38 on an outer side face of the second flange part 27b. |
