| 摘要 |
PROBLEM TO BE SOLVED: To restrain a situation in which a neck tube is damaged owing to to stain or the like at execution of manufacturing processes or micro damages generated during long-distance transportation or the like, by optimizing a compression stress layer existing in the neck tube, to the best of its possibility. SOLUTION: The neck tube with flare 1 is composed of a straight-tube part 2 with a uniform diameter having an open end part 4 at an end in a direction of an axis Z, and a flare part 3 connected to the other end part 5 in the axis Z direction of the straight-tube part. A compression stress layer, extending from the open end part 4 out of both end parts 4, 5 of the straight tube part 2 toward the central part side in Z direction with a length of 10 mm or longer, is formed on a first ring-shaped area 7. The first ring-shaped area 7 is confined within 20 mm from respective end parts 4 (5) of the straight-tube part 2 in Z axis direction, toward the center part side in axial direction, and the maximum compression stress value at the compression stress layer is made 7 MPa or less and 2.5 MPa or more. COPYRIGHT: (C)2005,JPO&NCIPI
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