Patent ID: 11858297
Assignee: THE YOKOHAMA RUBBER CO., LTD.
Field: Transport (Mechanical engineering)
Classification: CPC B  Y | IPC B

Claim 0:
1. A pneumatic tire, comprising:
a pair of bead portions;
a pair of bead cores disposed one in each bead portion, each one of the pair of bead cores being formed by a bead wire being wound a plurality of times in a tire circumferential direction;
a carcass layer including each end portion being folded back on a respective one of the pair of bead cores from inside to outside in a tire lateral direction;
a cover member covering each bead core and being disposed on a respective folded back laterally inner side of the carcass layer;
a steel cord reinforcing layer disposed one adjacent to each folded back laterally outer side of the carcass layer; and
an organic fiber reinforcement disposed one adjacent to a laterally outer surface of each steel cord reinforcing layer, each organic fiber reinforcement having at least one organic fiber reinforced layer; and
a rim cushion rubber disposed one adjacent to a laterally outer surface of each organic fiber reinforcement and including a bead base portion and a bead outer surface portion, the bead base portion forming a contour of an inner surface of the respective bead portion in a tire radial direction, and the bead outer surface portion forming a contour of an outer surface of the respective bead portion in the tire lateral direction continuous to the outer end of the bead base portion in the tire lateral direction via an intersection point, wherein
in a meridian cross-section under a state with the pneumatic tire not mounted on a rim, each bead portion a line segment being parallel with an innermost bottom side of the bead core in the tire radial direction and passing through an outermost outer projection point of the bead core in the tire lateral direction is specified as a first line segment, a line segment being orthogonal with the first line segment at a position of the outer projection point is specified as a second line segment, a line segment being orthogonal with the first line segment and passing through the intersection point of the rim cushion rubber is specified as a third line segment, a number n of the organic fiber reinforced layer is from 1 to 3, and a thickness d per each of the at least one organic fiber reinforced layer is from 0.7 mm to 1.2 mm,
a distance A between the second line segment and the third line segment is from n×d+2.0 mm to n×d+4.0 mm,
a shortest distance B between an innermost inner projection point of the bead core in the tire lateral direction and a carcass cord of the carcass layer is from 0.6 mm to 1.4 mm, and
a shortest distance C between an innermost end of the bottom side of the bead core in the tire lateral direction and a carcass cord of the carcass layer is from 1.2 mm to 2.2 mm.