| 摘要 |
PURPOSE:To maintain measuring accuracy of a flow rate control valve for a long period by installing a means provided with a function to catch particles, such as carbon included in the spitting gas from an engine at a downstream position remoter than intake flow rate control valve on the way of a by-pass passage. CONSTITUTION:When spitting gas enters into a by-pass passage 9, the spitting gas flows in the second pipe body 9B, a trap 18, and the first pipe body 9A in the passage line 9' on the downstream of a flow rate control valve 10. During this flow process, the pipe body 9B and a trap inner wall 18' face each other through a very small clearance 21, so that gas which flows out of the pipe body 9B increases its flow speed by the throttling action of the clearance 21, collides with the trap inner wall 18', and its flow direction suddenly changes to an opening edge 19 side of the pipe body 9A side. Due to the collision and the flow speed changes, heavy particles, such as carbon adhere to the trap inner wall 18' by inertia, accumulating inside the trap. As a result, foreign materials do not adhere between a measuring valve part 11a and a valve seat 14a. |
