| 摘要 |
<p>PURPOSE:To protect a heat ray detection element from flame and impact air due to backfiring of the engine by providing a passage member with a heat ray detection element parallel in a main intake passage while a means of avoiding the backfiring mounted on the downstream thereof. CONSTITUTION:A passage member 2 having a passage in the direction of a main air intake flow is provided in a cylindrical main intake passage 1. A heat ray detec- tion element 3a as temperature measuring resistance element and a hot-wire detec- tion element 3b as temperature compensating resistance element are mounted with a suport member 4 therein to detect mass of air sucked while an oval avoiding member 5 is provided on the side of an outlet of the passage member 2 by way of connection plates 6a and 6b. This avoids the application of mechanical shock on or attachment of unburned carbon particles to the hot-wire detection element 3 with a direct attack of a reverse air during the backfiring of the engine thereby enabling an adequate measurement of the flow rate of an air intake for a long time.</p> |
