| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an intake manifold having the small intake resistance of an intake pipe in all rotational ranges of an engine. SOLUTION: Unbent parts 4a, 4b on both end sides of an intake pipe 4 of an intake manifold 1 are formed of inelastic members, and a bent part 4c bent between both ends 4a, 4b is formed of an elastic member. A pipe-shaped variable mechanism 5 provided with an upper side pinching plate 6 and a lower side pinching plate 7 capable of being approached to and separated from each other is provided on the bent part 4c, a servomotor 13 is controlled on the basis of a command of a controller, and the separation distance between the upper side pinching plate 6 and the lower side pinching plate 7 is controlled. The engine speed is detected by a speed sensor. When the engine speed is lower than the specified speed, the separation distance between both pinching plates 6, 7 is increased to make the sectional shape of the bent part 4c into a circular shape, while, when the engine speed is higher than the specified speed, the separation distance between both pinching plates 6, 7 is decreased to make the sectional shape of the bent part 4c into an elliptic flat shape.</p> |
