| 摘要 |
PURPOSE:To prevent releasing of gasoline vapor, by providing a first orifice at an intermediate portion between a purge pipe and a valve chamber of a vacuum control valve connected to an altitude compensating valve, and providing a second orifice in the purge pipe, so that the amount of purged gas can be varied. CONSTITUTION:A vacuum chamber 18 connected to an air chamber 3 of an altitude compensating valve 1 and a valve seat 19 connected to a canister 28 are separated from each other by a diaphragm 17. The valve seat 19 is opened when a changeover valve 20 fixed to the diaphragm 17 is moved upward in the vacuum chamber 18. Further, a first orifice 24 is provided between the valve seat 19 and a purge pipe 22 which connects the valve seat 19 to a vacuum generating section of an engine (not shown), and a second orifice 25 having a larger sectional area than the first orifice 24 is provided in the puge pipe 22 on the downsteam side of the first orifice 24. With such an arrangement, releasing of gasoline vaport on a high ground is prevented by changing the amount of purged gas according to the altitude by means of a vacuum control valve 16. |
