| 摘要 |
<p>PURPOSE:To enhance the rigidity of an entire duct and prevent the duct from being crushed by a negative pressure or the like by forming the duct of rubber or plastic used for the suction system or the like of an internal combustion engine and interposing a reinforcement member between opposite internal surfaces of a large curvature radius portion of the duct. CONSTITUTION:A suction duct 11 made of rubber or plastic is formed in a 3-dimensionally curved shape with a cross section extending laterally to show an ellipsoid. Straight line portions 11a, 11a at the front and rear and a curved portion 11b in the center of the duct of a large radius are provided at their internal opposite large curvature radius central portions with opposite pair of holding grooves 13, 13 between projections extending along the axial direction of the duct. Reinforcement members 15 are disposed in the holding groove 14.</p> |
