| 摘要 |
PURPOSE:To improve the starting performance of an engine, by providing a check valve for permitting fluid to flow only from the side of a pressure chamber to the side of an intake passage located on the downstream side of the pressure chamber in a negative-pressure passage communicated with the pressure chamber in a pressure responsive apparatus which determines the opening of a by-pass valve according to the level of pressure acted in the pressure chamber interlocked with the by-pass valve. CONSTITUTION:Through provision of a position sensor 38 for detecting the opening of a by- pass valve 20, the engine speed is controlled to be equal to a desired engine speed by controlling the opening of the by-pass valve 20 according to the deviation between an aimed opening determined on the basis of deviation of the engine speed and the actual opening detected by the position sensor 38 at the time of idling operation of an engine. With such an arrangement, it is enabled to control the engine speed extremely promptly and to slove the problems such as engine stall during idling operation. Further, since a check valve 33 permitting fluid to flow only from the side of a first solenoid valve 32 to the side of an intake passage 8 is provided in a negative-pressure passage 28, gas in a pressure chamber 26 is drawn toward the intake passage 8 via the first solenoid valve 32 when the absolute value of the negative pressure in the manifold is large even at the time of cranking an engine for starting the same when the negative pressure in the manifold is low, and this state is maintained by the check valve 33. Therefore, a relatively high negative pressure is acted in the pressure chamber 26 even at the time of starting, so that the starting performance of an engine can be improved. |
