Pneumatic tire

A pneumatic tire, comprising:

• bead cores formed by annularly and multiply winding one or a plurality of bead wires;
• a carcass layer formed of a carcass ply of a single layer or a plurality of layers, the carcass layer being turned back so as to wrap the bead cores and extended between the bead cores;
• a rim cushion rubber disposed along a turned back portion of the carcass layer to constitute a rim fitting surface of a bead portion;
• the turned back portion of the carcass layer contacting a body portion of the carcass layer in a cross-sectional view in a tire meridian direction to form a closed region surrounding the bead cores;
• a rubber occupancy ratio in the closed region being in a range of 15% or less;
• the bead cores having a predetermined wire arrangement structure formed by arranging wire cross sections of the bead wires in the cross-sectional view in the tire meridian direction;
• a tangential line, contact points, a midpoint of the contact points, and a gauge being defined, the tangential line contacting an innermost layer in a tire radial direction and the wire cross sections innermost and outermost in a tire lateral direction in the wire arrangement structure from the rim fitting surface side, the contact points of the tangent line being on the innermost and the outermost wire cross sections, the gauge being in the tire radial direction from the midpoint to the rim fitting surface;
• a rate of change ΔGm of the gauge between before and after mounting on a rim being in a range from 10% or more to 60% or less;
• a layer in which a number of arrangements of the wire cross sections is a maximum in the wire arrangement structure being defined as a maximum arrangement layer;
• a number of layers of the wire cross sections outward in the tire radial direction with respect to the maximum arrangement layer being greater than a number of layers of the wire cross sections inward in the tire radial direction with respect to the maximum arrangement layer;
• a number of arrangements of the wire cross sections in each layer outward in the tire radial direction with respect to the maximum arrangement layer monotonically decreasing outward in the tire radial direction from the maximum arrangement layer;
• a number of arrangements of the wire cross sections in the innermost layer in the tire radial direction in the wire arrangement structure being smaller than a number of arrangements of the wire cross sections in the maximum arrangement layer;
• and
• the number of arrangements of the wire cross sections in the layer in which the number of arrangements of the wire cross sections is the maximum being less than a total number of layers of the wire cross sections in the wire arrangement structure;
• wherein
• in the cross-sectional view in the tire meridian direction, a bead base of the rim fitting surface is formed by connecting two types of linear portions with mutually different inclination angles,
• a first extension line of the linear portion on a bead heel side and a second extension line of the linear portion on a bead toe side of the bead base of the rim fitting surface are defined, and
• inclination angles α, β of the first and second extension lines with respect to the tangent line have a relationship 0.5≤β/α≤2.3.

A pneumatic tire, comprising:

• bead cores formed by annularly and multiply winding one or a plurality of bead wires;
• a carcass layer formed of a carcass ply of a single layer or a plurality of layers, the carcass layer being turned back so as to wrap the bead cores and extended between the bead cores;
• a rim cushion rubber disposed along a turned back portion of the carcass layer to constitute a rim fitting surface of a bead portion;
• the turned back portion of the carcass layer contacting a body portion of the carcass layer in a cross-sectional view in a tire meridian direction to form a closed region surrounding the bead cores;
• a rubber occupancy ratio in the closed region being in a range of 15% or less;
• the bead cores having a predetermined wire arrangement structure formed by arranging wire cross sections of the bead wires in the cross-sectional view in the tire meridian direction;
• a tangential line, contact points, a midpoint of the contact points, and a gauge being defined, the tangential line contacting an innermost layer in a tire radial direction and the wire cross sections innermost and outermost in a tire lateral direction in the wire arrangement structure from the rim fitting surface side, the contact points of the tangent line being on the innermost and the outermost wire cross sections, the gauge being in the tire radial direction from the midpoint to the rim fitting surface;
• a rate of change ΔGm of the gauge between before and after mounting on a rim being in a range from 10% or more to 60% or less;
• an outer side reinforcing rubber having a rubber hardness higher than a rubber hardness of the rim cushion rubber, the outer side reinforcing rubber being disposed between the turned back portion of the carcass layer and the rim cushion rubber;
• a radial height H3 from a measurement point of the tire inner diameter RD to an end portion outward of the outer side reinforcing rubber in the tire radial direction and a tire cross-sectional height SH having a relationship 0.10≤H3/SH≤0.30;
• and
• the outer side reinforcing rubber extending outward in the tire radial direction with respect to an end portion of the turned back portion of the carcass layer, and the outer side reinforcing rubber covering the end portion of the turned back portion of the carcass layer from outward in the tire lateral direction;
• wherein
• an amount of overlap H5 between the outer side reinforcing rubber and the bead core in the tire radial direction has a relationship 0.05≤H5/H1≤1.00 to a radial height H1 of the bead cores;
• and
• a length T1 of a perpendicular line drawn from an end portion of the turned back portion of the carcass layer to an outer surface of a tire side portion and a thickness T2 of the outer side reinforcing rubber on the perpendicular line have a relationship 0.50≤T2/T1≤0.90.