| 摘要 |
PROBLEM TO BE SOLVED: To provide a ballpoint pen capable of providing a sufficient ink outflow property, and surely guiding a rod part to a center part of an ink outflow space.SOLUTION: An inward front end edge 4 is formed at the front end of a metallic tip body 2. A plurality of inward projecting parts for a ball reception seat is formed on an inner surface of the tip body 2 behind the front end edge 4. An ink outflow space 51 radially extending to the outside in the radial direction from the center part is formed among the inward projecting parts. A rod part 71 for energizing a ball 3 forward and tightly fitting the ball 3 to the inner surface of the front end edge 4 is inserted into the ink outflow space 51. The plurality of inward projecting parts for a ball reception seat are called first inward projecting parts 5. A plurality of second inward projecting parts 6 are formed on the inner surface of the tip body 2 on the rear side relative to the first inward projecting parts 5. The second inward projecting parts 6 are located on the rear side among the first inward projecting parts 5. Carbonaceous film(s) are (is) formed on the inner surface of the front end edge 4 and/or the surface of the ball 3. |
