| 摘要 |
PURPOSE:To realize improvement of drivability of an engine while preventing its emission from worsening, by limiting the opening of a throttle valve through a dashpot and changing a condition of the dashpot operative or inoperative in accordance with a condition of the engine. CONSTITUTION:In case of low temperature of cooling water when a water temperature switch 40 is turned on, an electric current is conducted to flow in a coil 39, and a shifting valve 37 is moved leftward against a spring 38 to close a selector passage 34. In consequence, when a throttle valve 7 is closed, a chamber 14 in a dashpot 9 is communicated to the outside air through an orifice 49 in a delay valve 46, and a piston 15 is gradually lowered to prevent a rapid close of the throttle valve 7. While in case of high cooling water temperature, if the water temperature switch 40 is turned off, the shifting valve 37 both opens the selector passage 34 and closes a selector passage 35. In consequence, negative pressure in an intake passage 43 is introduced into the chamber 14, and the piston 15 is lowered through a diaphragm 12 to a position the piston is not contacted to a cam body 8, then the dashpot 9 is changed to an inoperative condition. |
