| 摘要 |
<p>PURPOSE:To prevent exhaust gas from flowing back to an air cleaner when a lead valve for a secondary air passage becomes out of order and to inform the driver of the fact, by providing a temperature fuse in a passage that connects a negative pressure passage with the atmosphere side. CONSTITUTION:Usually the lead valve 16 is opened and closed suitably. However when it becomes out of order, and is remained open, a heat sensitive part 24 of the temperature fuse 20 is fused and broken at this temperature. Then, the passage 18 closed at the heat sensitive part 24 is opened. Thus since the left side of the diaphragm 8 becomes at the atmospheric pressure, a valve body 10 is seated on a valve seat 12 by the force of a spring 11, and the part between ports 13, 14, is cut off, that is, communication of the secondary air passage 15 and the air cleaner 5 is cut off. At this time, the temperature fuse 20 acts as a switch, and due to this the lamp 32 is lit to inform the driver of the fact.</p> |
