| 摘要 |
PURPOSE:To enhance an intake inertia effect by simplified construction, by arranging high speed use intake passages, provided for neighboring cylinders, to adjoin each other while said passages to join with each other in the upstream of an opening and closing valve and substantially decreasing an intake pipe length when an engine is in high speed operation, in the case of the engine equipped with the opening and closing valve in the high speed use intake passage. CONSTITUTION:An engine inducts intake, after it passes through a throttle valve 14, to each cylinder from a surge tank 8 via a low speed use intake passage and a high speed use intake passage for every cylinder. The high speed use intake passages for the neighboring cylinders are arranged adjoining each other, and each passage provides an opening and closing valve 10 opened and closed by a diaphragm device 16. A partition 9a between the neighboring high speed use intake passages is connected in the upstream of the opening and closing valves 10. When the engine is in high speed operation at a predetermined load or more, the engine, switching the negative pressure and the positive pressure by a negative pressure selector valve 17, opens the valves 10 by the diaphragm device 16. Here the both high speed use intake passages, whose connection part 6c provides a function as the extension part of the surge tank 8, become an intake pipe length suitable for that when the engine is in high speed operation. |
