| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a resin throttle body 5 wherein the deformation of the bore inner diameter of a bore inner tube 31 due to the molding contraction of a bore outer tube 32 is suppressed by specifying the shape of an annular plate connection part 33 between the bore inner tube 31 and the bore outer tube 32 of a bore wall portion 6 in a double tube structure, to be optimum. <P>SOLUTION: In the throttle body 5, the thickness (plate thickness) in the direction of the center axis of the annular plate connection part 33 between the bore inner tube 31 and the bore outer tube 32 is set to be smaller than the minimum thickness in the radial direction of each of the bore inner tube 31 and the bore outer tube 32 around the annular plate connection part 33. Thereby, the length (plate width) in the radial direction of the annular plate connection part 33 of the bore wall portion 6 in the double tube structure is greater and the thickness (plate thickness) in the direction of the center axis of the annular plate connection part 33 is smaller. Thus, the rigidity or strength of the annular plate connection part 33 is lowered more greatly than that of each of the bore inner tube 31 and the bore outer tube 32, and so the influence of the the molding contraction of the bore outer tube 32 is hardly transferred to the bore inner tube 31 to suppress the deformation of the bore inner diameter of the bore inner tube 31. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
