| 摘要 |
PURPOSE:To obtain a steel cord having improved adhesivity to rubber and fatigue resistance, prolonged tire life and improved productivity, quality and reliability by remarkably reducing and optimizing the linear contact angle between a core element wire and a side element wire and optimizing the gap between the side element wires. CONSTITUTION:The objective steel cord has a two-layer twisted structure consisting of a core strand 1a formed by twisting 2-3 core element wires 1 and an outer layer 2a composed of 6-8 side element wires 2 twisted around the circumference of the core strand. The twisting direction of the core strand is same as that of the outer layer and the linear contact angle alpha is adjusted to 1.5-4.5 deg.. The element wire diameter of the core element wire (D1) is made to be smaller than that of the side element wire (D2) and the gap Smm between the side element wires is adjusted to satisfy the relation 0.025<S=(D0+D1+D 2)XSin(180/N)-D2<0.07 wherein D0 is the core diameter of the core strand and N is the number of element wires of the side element wire. Each element wire is made of a high carbon steel. |
