| 摘要 |
PURPOSE:To obtain a V-ribbed belt which has neither a weld defect nor concentration of bubbles, by a method wherein a flowing distance of a molding material is made short by corresponding to a space between gates each by providing a plurality of gates in a circumferential direction of an annular cavity at intervals. CONSTITUTION:A molding material streamed into a runner 21 through a sprue 19 is split into two bands of a clockwise direction and counterclockwise direction of a peripheral direction by colliding with a protrusion 23 positioning directly below the sprue 19. The molding material is streamed away into a cavity 15 through gates 22 each by repeating such actuation as to split the same into one flowing in the peripheral direction as it is and one flowing into the cavity 15 every time the same meets respectively with the gates 22. Therefore, it becomes that the molding materials streamed in through the gates 22, 22 adjoining to each other collide with each other. However, since a space between the gates is narrow, collision is generated immediately after an inflow of the molding material into the cavity 15, the molding material is filled out into the cavity 15 under a state where the molding materials streamed into the cavity through the gates 22 each collide speedily with each other prior to curing and meet each other, and a V-ribbed belt free from a weld defect is obtained. |
