| 摘要 |
<p>PURPOSE:To prevent the vibrations and noises of the titled engine when the engine is idling or stopped and to protect the engine at the time when the air sucking pressure of the engine rises too high by a method wherein when it is detected that the pressure in the air sucking pipe exceeds a predetermined value due to the pressure of supercharged air, an air sucking pipe throttle valve is driven at its intermediate position. CONSTITUTION:In case where the engine is operated at low temperatures without the necessity of increasing the fuel quantity or in case where the engine is in a no load operation condition without the necessity of stepping on the acceleration pedal, an acceleration switch 28 is closed and a relay switch 27 is opened to keep a negative pressure changeover valve 13 deenergized so that a port A is made to communicate with a port B and a negative pressure is introduced into a first diaphragm chamber 8. Accordingly, a butterfly valve 3 shifts to its intermediate position shown by a hypothetical line 1 and sucked air is choked by the valve in that condition. In this case, as the engine is in a no load operation condition, the number of revolutions of the engine is small and further, in the case of the instant engine which has a high compression efficiency, it is possible to prevent the compression force of the engine from increasing excessively by choking the sucked air to about 10-30%, to thereby reduce the vibrations and noises of the engine.</p> |
