| 摘要 |
PROBLEM TO BE SOLVED: To maintain appropriate fitting force for a long period of time by a method wherein spreading deformation of a fitting part of an inner cylinder is inhibited even though intensive pushing in force acts on concerning a cap backward insertion fitting structure. SOLUTION: A cap is composed of a metallic outer cylinder 7 and a synthetic resin made inner cylinder 8. A plurality of projected parts 81 are arranged on an inner peripheral surface of an opening end of the inner cylinder 8. An annular recessed part 2 to which the projected parts 81 fit by sinking is provided onto an outer peripheral surface of a tail end part of a shaft cylinder 1. A slant control wall 5 is provided in front of the annular recessed part 2. A clearance S between a crest part of the control wall 5 and an inner peripheral surface of the outer cylinder 7 is set to be less than a wall thickness T in a radial direction of the projected part 81 of the inner cylinder 8. |
