| 摘要 |
<p>PURPOSE:To minimize the output fluctuation of a heating resistance body and also minimize dispersion in the quality of individual air meters for internal combustion engine. CONSTITUTION:The air feed passage of an internal combustion engine is formed of two systems of a main passage and a sub-passage 4, and a heating resistance body (hot-wire element) 5 is mounted on the sub-passage 4. A round part 40 and a tapered part 4E continued to the round part are provided on the inlet opening part of the sub-passage 4. When the center line X1 of a casting surface is off from the center line X2 of working at the time of machining the cylindrical passage of the sub-passage 4, the edge form is never changed by the off- centering since the cylindrical surface is crossed with the tapered surface, and the angle of a border part 4E is equalized over the whole circumference. Therefore, the air flowing into the sub-passage smoothly makes contact with the hot-wire element 5, an increase in output error and output noise is never caused. The dispersion between products is also minimized.</p> |
