| 摘要 |
PURPOSE:To reduce the quantity of exhaust gas flowing back at the time of a low load driving and prevent the reduction of the air fuel ratio by arranging a negative pressure quantity adjusting valve device in an exhaust gas flow-back control device of an internal combustion engine. CONSTITUTION:An exhaust passage (not shown) is communicated with a suction passage 1 via an exhaust gas flowing back passage 2 provided with a flow-back quantity control valve 3. In a negative pressure chamber 5 of a flow-back quantity control device 4 which opens or closes the valve 3, there is introduced a suction negative pressure directly above a throttle valve 13 when it is fully closed. An adjusting valve device 15 partitions and forms a chamber 24 opening to the atmospheric air, a control pressure chamber 23 and a pressure chamber 22 by means of large and small diaphragms 20 and 19. In the atmospheric air chamber there is provided a valve member 21 which performs opening or closing of the negative pressure passage 12 for the atmospheric air. The control chamber 23 is communicated with the atmospheric only at the time of a low pressure operation by a solenoid valve device 34 operated by a control mechanism 40 receiving a signal from a detector 41. A Venturi negative pressure of the passage 2 is introduced into the pressure chamber 22. |
