| 摘要 |
PROBLEM TO BE SOLVED: To enable a seal ring including a cut in one circumferential portion and having a square cross-section to be molded without mechanical processing and to exhibit excellent sealing performance.SOLUTION: A seal ring S is integrally injection-molded into an entire shape in which a cut 5 is open using a thermoplastic resin composition. In the shape at a time of molding, a ring body 1 of the seal ring S includes a region 13 provided on an opposite side to the cut 5 to have a maximum curvature radius R13, and the ring body 1 is set such that curvature radii R1 and R2 are gradually reduced in circumferential directions M1 and M1 from the region 13 having the maximum dimension to a first end portion 11 and a second end portion 12, respectively and that the first end portion 11 and the second end portion 12 have the minimum curvature radii R11 and R12, respectively. Furthermore, the ring body 1 is a true circle in use by reducing curvature radii of outer circumferential surfaces of a first convex portion 21 and a second convex portion 22 from a state in which the ring body 1 is not a true circle, the cut 5 is open, and the curvature radii of the outer circumferential surfaces are identical to the curvature radii R1 and R2, respectively. |
