| 摘要 |
<p>PURPOSE:To prevent after-burning and other problems of an engine of the type in which supply of secondary air is effected by the use of pulsation of exhaust gas flow, by providing a control valve which is closed when differential pressure acted in two chambers of a differential pressure responsive means exceeds a predetermined value at the time of decelerating engine. CONSTITUTION:During steady operation of engine, control valve 11 is kept in its opened position by spring 18 since pressure acted in chambers 15, 16 of diaphragm means 13 communicated to the intake passage via vacuum passage 17 is balanced with each other, so that secondary air is passed from air inlet passage 9 to outlet passage 10 through a reed valve 6 that is opened by the function of pulsation of exhaust gas flow and then furnished to the exhaust system. At the time of decelerating engine, on the other hand, diaphragm 14 is displaced to the left in the drawing and control valve 11 is resultantly closed, since a relatively high vacuum is acted directly in chamber 15 whereas it is acted in chamber 16 with some delay through orifice 20. Thereafter, when suction vacuum acted in chamber 16 is increased and pressure in these two chambers 15, 16 is balanced, control valve 11 is opened again.</p> |
