Run-flat tire
AssigneeThe Yokohama Rubber Co., Ltd.
InventorShunya Harada
Life of this patent
Estimating the term…
Abstract
A run-flat tire includes: sipes formed in blocks; a belt reinforcing layer on an outer side in a radial direction of a belt layer; and a side reinforcing rubber in sidewall portions, wherein a density of the sipes in a center block is from 0.10 cords/mm or greater to 0.30 cords/mm or smaller, the belt reinforcing layer includes a center reinforcing portion in which more center reinforcing portions are stacked at a center region than at positions other than the center region, a width Wc of the center reinforcing portion is within 0.5 Gr≤Wc≤2.5 Gr with respect to a thickness Gr of the side reinforcing rubber at the tire maximum width position, and an average width of the width Wc of the center reinforcing portion is from 50% or greater to 90% or smaller of a width of the center block.
Claims11
A run-flat tire, comprising:
- a tread portion;
- a plurality of blocks defined in the tread portion by a plurality of main grooves and a plurality of lug grooves formed in the tread portion;
- a plurality of sipes formed in the plurality of blocks to extend in a tire width direction;
- a sidewall portion disposed on both sides in the tire width direction of the tread portion;
- a belt layer disposed in the tread portion;
- a belt reinforcing layer disposed on an outer side in a tire radial direction of the belt layer;
- a tread rubber layer disposed on an outer side in the tire radial direction of the belt reinforcing layer in the tread portion;
- and
- a side reinforcing rubber disposed in the sidewall portion,
- a density in a tire circumferential direction of the plurality of sipes formed in a center block which is the block closest to a tire equatorial plane among the plurality of blocks being larger than a density in the tire circumferential direction of the plurality of sipes formed in shoulder blocks which are the blocks located on outermost sides in the tire width direction,
- a density in the tire circumferential direction of the plurality of sipes formed in the center blocks being within a range from 0.10 sipes/mm or greater to 0.30 sipes/mm or smaller,
- a width in the tire width direction of the center block being within a range from 7% or greater to 20% or smaller of a development width of the tread portion,
- the belt reinforcing layer comprising a center reinforcing portion, which is a portion in which more belt reinforcing layers are stacked at a position of a center region, which is a region in the tire width direction where the center block is located, than at positions other than the center region,
- a width Wc in the tire width direction of the center reinforcing portion of the belt reinforcing layer being within a range of 0.5 Gr≤Wc≤2.5 Gr with respect to a thickness Gr of the side reinforcing rubber at a tire maximum width position, and
- an average width of the width Wc of the center reinforcing portion being within a range from 50% or greater to 90% or smaller of a width in the tire width direction of the center block.
Dependencies are inferred from the claim text.