| 摘要 |
PURPOSE:To reduce the difference in resin density as little as possible between the vicinity of both side edges of an inner shell, a front edge and the vicinity of an upper edge by setting a resin filling part at the center part of the inner shell and slitting both sides of the resin filling part. CONSTITUTION:A resin filled into a die from a resin filling part 20 is guided to a protruding line in the die for forming slits 29 and flows toward the front edge 21a of a part 21 corresponding to a seat and toward the upper edge 22c of a part 22 corresponding to a back rest. Then, a part of the flow bypasses the lower ends 29a and the upper ends 29b of the slits 29 and is guided to left and right side edge 28a, of an inner shell 2. Accordingly, the length of a path from the resin filling part 20 to the front edge 21a and the upper edge 22c and the length of path from the resin filling part 20 to both side edges 28a are equalized: this produces no large difference in resin density between the vicinity of the side edge 28a, the front edge 21a and the vicinity of the upper edge. Accordingly, an inconvenience that an internal stress remains due to a contraction strain when the resin is hardened can be effectively suppressed. |
