To provide a steel cord for reinforcing rubber, which reduces the cord diameter and suppressing a dimensional change while ensuring adhesiveness between the cord and the rubber and to provide a pneumatic radial tire using the steel cord.
The steel cord 10 used in a belt layer 6 is obtained by twisting 5 side wires 12 having the same wire diameter as a core wire 11 together on the outside of the one core wire 11 subjected to helical preforming and arranging the wires. The steel cord has a flat structure in which the circumscribed circle C11 of the core wire 11 and the circumscribed circle C12 of the side wires 12 form an elliptical shape, respectively. The torsional direction of the core wire 11 is the same as the twisting direction of the side wires 12 and the preforming pitch of the core wire 11 is the same as the twisting pitch of the side wires 12. The minor axis ds of the circumscribed circle C11 of the core wire 11 is ds>d to the wire diameter d. The minor diameter Ds of the circumscribed circle C12 of the side wires 12 is Ds<3d and the major diameter D1 of the circumscribed circle C12 of the side wires 12 is D1>3.6d. The ratio of the minor diameter Ds to the major diameter D1 is D1/Ds>1.2.
COPYRIGHT: (C)2008,JPO&INPIT
| JP2000255210A | 2000-09-19 | |||
| JP2002087017A | 2002-03-26 | |||
| JP2000177311A | 2000-06-27 | |||
| JPH0967784A | 1997-03-11 |
| WO2000053436A1 | 2000-09-14 |
Takashi Noguchi
Kazuhiko Saishita