| 摘要 |
The gas-return valve 7 comprises a valve with a valve-head and a valve-stem. A spring-loaded diaphragm 9 is fixed to said valve stem, and on one face of the diaphragm there acts, in suction chamber 11, a suction derived through a transfer duct 13 from a pneumatic controller 14. The pneumatic controller 14 has two chambers 23, 24 separated by a diaphragm 19, the first chamber 24 of which communicating, firstly and permanently, with the transfer duct 13 and, secondly and alternatively in dependence upon, and as governed by, differences in instantaneous pressure, either, with the induction pipe 2 at a location upstream of the throttle valve 3, or, with atmosphere; the second chamber 23 being in permanent communication with a location on the downstream side of the throttle valve 3. In this way the pressures transmitted to the valve 7 through the transfer duct 13 from the pneumatic controller 14 are governed by differences in instantaneous pressures at locations on the upstream and downstream sides, respectively, of the throttle valve 3 in the engine induction passage. <IMAGE> |
