| 摘要 |
PURPOSE:To abolish a deflashing process by preparing a closed cavity with the 1st mold, the 2nd mold and a cylindrical metal and providing a little drawn portion in a clamped rubber injecting passage. CONSTITUTION:An inner cylindrical metal and an outer one 28, 30 are pressed between a top force 10 and a bottom force 14 in the axial direction to prepare a ringed and closed cavity 62. A vertical injecting passage 64 is provided, a draft is given and a drawn portion 6 is provided in an inlet section to prevent the injected material from flowing backward to the side of the passage 64 even when injecting pressure is removed. Rubber material is expanded in the process of vulcanization but no clearance occurs by pushing a clamper 50 at both ends of the inner and outer cylindrical metals 28 and 30 and on the top and the bottom force 10 and 14, therefore, no whisker flashes appear near both ends of the outer cylindrical metal 30 and the like. Expansion escapes to the upper stream side of the injecting passage 64 and a projection 70 in the form of a lump occurs on the opening section. This is cut by a chuck claw 72 and the like at the drawing section 66 to enable automatic cutting of useless rubber section 74. |
