| 摘要 |
PROBLEM TO BE SOLVED: To provide a connection structure for a writing utensil member, the connection structure being for air-tightly fitting an inner tube having a partition wall therein in a radial direction into an outer tube, the connection structure being capable of decreasing a pressing force for fitting even when an outer surface of an area on which the partition wall is formed is a fitting part.SOLUTION: There is provided a connection structure for a writing utensil member, which the connection structure fits an inner tube 3 having a partition wall 34 therein into an outer tube to air-tightly engage and prevent two members from slipping off. The inner tube 3 is provided with an annular rib 32 for fitting formed on an outer surface of an area on which the partition wall 34 is formed, and in front of the annular rib 32 an annular contact surface 31 formed for air-tight. The annular rib 32 is divided into plural arc-shaped rib pieces 5 by plural cutting parts 4 formed. A center angle of an arc formed with a peak of each rib piece 5 along a virtual circle of periphery of the annular rib 32 ranges between 40° to 50°, and the sum of the center angles ranges between 160° to 200°. |
