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US 12,365,205 B2Granted
Pneumatic tire
AssigneeThe Yokohama Rubber Co., Ltd.
InventorKoji Nishio
Life of this patent
Estimating the term…
Abstract
In a pneumatic tire, a bead filler is on an outer circumference of a bead core, a carcass turned up end is inward of an outer diameter side end of the bead filler, the carcass end is spaced from a carcass body, a steel reinforcement is in each bead, a sidewall rubber extends from the sidewall to the bead, and a support layer is between the bead filler and the sidewall rubber to cover the carcass end and an end of the steel reinforcement, the support layer extending toward an outer diameter side and contacting the carcass body on an outer diameter side of the bead filler outer diameter side end, and a 100% modulus of the support layer is at least 1.5 times that of the bead filler, and the sidewall rubber, the bead filler and the sidewall rubber being adjacent to the support layer.
Claims19
A pneumatic tire, comprising:
- a tread portion extending in a tire circumferential direction and having an annular shape;
- a pair of sidewall portions respectively disposed on both sides of the tread portion;
- a pair of bead portions each disposed on an inner side in a tire radial direction of the sidewall portions;
- and
- a carcass layer mounted between the pair of bead portions and comprising a plurality of steel cords, the carcass layer being turned up around a bead core of each of the bead portions from a tire inner side to a tire outer side,
- a bead filler being disposed on an outer circumference of the bead core of each of the bead portions, a turned up end portion of the carcass layer being disposed on a radially inner side with respect to a radially outer side end portion of the bead filler, the turned up end portion of the carcass layer being spaced apart from a body portion of the carcass layer, a steel reinforced layer that comprises a plurality of steel cords being disposed in each of the bead portions in such a manner as to wrap around the carcass layer, the bead core, and the bead filler, and a sidewall rubber layer exposed on a tire outer surface being disposed from the sidewall portion to the bead portion, and
- a rubber reinforcing support layer being disposed between the bead filler and the sidewall rubber layer in such a manner as to cover a turned up end portion of the carcass layer and an end portion of the steel reinforced layer while, on an outer side of the bead core in the tire width direction, extending only on one side of each of the carcass layer and the steel reinforced layer, the rubber reinforcing support layer at least extending from a position lateral to the bead core toward a radially outer side and contacting the body portion of the carcass layer at a position on a radially outer side with respect to a radially outer side end portion of the bead filler, and a 100% modulus KM100 of the rubber reinforcing support layer being at least 1.5 times as large as each of a 100% modulus BFM100 of the bead filler and a 100% modulus SM100 of the sidewall rubber layer, the bead filler and the sidewall rubber layer being adjacent to the rubber reinforcing layer, wherein
- the distance Ph from the center of the bead core to the turned up end portion of the carcass layer and a distance Sho from the center of the bead core to the end portion of the steel reinforced layer satisfies a relationship 5.0 mm≤Ph-Sho≤12.0 mm, and
- a distance Ph from a center of the bead core to the turned up end portion of the carcass layer ranges from 26.0 mm to 40.0 mm, the shortest distance TBF from the turned up end portion of the carcass layer to the body portion of the carcass layer is 11.0 mm or more, and the shortest distance T1 from the turned up end portion of the carcass layer to the outer surface of the bead portion is 7.0 mm or more.
6 more elements
A pneumatic tire, comprising:
- a tread portion extending in a tire circumferential direction and having an annular shape;
- a pair of sidewall portions respectively disposed on both sides of the tread portion;
- a pair of bead portions each disposed on an inner side in a tire radial direction of the sidewall portions;
- and
- a carcass layer mounted between the pair of bead portions and comprising a plurality of steel cords, the carcass layer being turned up around a bead core of each of the bead portions from a tire inner side to a tire outer side,
- a bead filler being disposed on an outer circumference of the bead core of each of the bead portions, a turned up end portion of the carcass layer being disposed on a radially inner side with respect to a radially outer side end portion of the bead filler, the turned up end portion of the carcass layer being spaced apart from a body portion of the carcass layer, a steel reinforced layer that comprises a plurality of steel cords being disposed in each of the bead portions in such a manner as to wrap around the carcass layer, the bead core, and the bead filler, and a sidewall rubber layer exposed on a tire outer surface being disposed from the sidewall portion to the bead portion, and
- a rubber reinforcing support layer being disposed between the bead filler and the sidewall rubber layer in such a manner as to cover a turned up end portion of the carcass layer and an end portion of the steel reinforced layer while, on an outer side of the bead core in the tire width direction, extending only on one side of each of the carcass layer and the steel reinforced layer, the rubber reinforcing support layer at least extending from a position lateral to the bead core toward a radially outer side and contacting the body portion of the carcass layer at a position on a radially outer side with respect to a radially outer side end portion of the bead filler, and a 100% modulus KM100 of the rubber reinforcing support layer being at least 1.5 times as large as each of a 100% modulus BFM100 of the bead filler and a 100% modulus SM100 of the sidewall rubber layer, the bead filler and the sidewall rubber layer being adjacent to the rubber reinforcing layer, wherein
- the distance Ph from the center of the bead core to the turned up end portion of the carcass layer and a distance Sho from the center of the bead core to the end portion of the steel reinforced layer satisfies a relationship 5.0 mm≤Ph-Sho≤12.0 mm, and
- the rubber reinforcing support layer comprises a crack suppression layer contacting the turned up end portion of the carcass layer and an end portion of the steel reinforced layer, and a rubber reinforcing body layer contiguous with the crack suppression layer, the crack suppression layer has an elongation at break KCEB of 300% or more, and a 100% modulus KmM100 of the rubber reinforcing body layer is greater than a 100% modulus KcM100 of the crack suppression layer.
6 more elements
Dependencies are inferred from the claim text.