| 摘要 |
PURPOSE:To operate a control valve means for controlling recirculation of exhaust gas in reliable manner also at a high ground where back pressure is lowered, through provision of a control valve unit which is operated differently with change in the height of the ground while controlling supply of vacuum from a vacuum reserving tank to the control valve means for controlling recirculation of exhaust gas. CONSTITUTION:At a high ground, throttle (26) opening of carburetor is slightly increase so as to compensate for reduction of air density and resultant lowering of engine output, so that vacuum at vacuum port 25 is lowered. Vacuum supplied from the vacuum port 25 is reserved in reservoir tank 108. When the vacuum supplied from port 25 is lowered with increasing of throttle (26) opening, vacuum is supplied from tank 108 to control valve 30 for controlling recirculation of exhaust gas, via control valve means 90 operatively connected to height compensating means 110, and the exhaust gas is recirculated until vacuum in tank 108 is comsumed completely. |
