| 摘要 |
PURPOSE:To produce sufficient fitting pressure between a rim and a tire to easily load the tire to the rim by specifying the relationship between the number of piano wires in the lateral direction and the number of piano wires in the longitudinal direction in a rectangular cross-section of a bead core. CONSTITUTION:A tire has two or more belt layers and one or more carcass layers. A bead wire 10 is formed by winding one piano wire 12. In this case, the bead wire 10 is almost rectangular in cross-section, and for example, five piano wires are arranged in the lateral direction, and four piano wires are arranged in the longitudinal direction. Besides, figures show a starting place of winding. The relationship between the number NS of piano wires in the lateral direction and the number NT of piano wires in the longitudinal direction is set to : NS > NT. Thus, when a fixed substantially effective powerful strength can be obtained, loss of the length of the piano wire is reduced, and sufficient fitting pressure between a rim and a tire can be obtained. Further, since the number of piano wires in the lateral direction is smaller than the number of piano wires in the longitudinal direction. loading of the tire to the rim can be easily performed. |
