US 12,030,344 B2
Tire
Takashi Sugiura, Kobe (JP)
Assigned to SUMITOMO RUBBER INDUSTRIES, LTD., Hyogo (JP)
Filed by SUMITOMO RUBBER INDUSTRIES, LTD., Hyogo (JP)
Filed on Jul. 2, 2021, as Appl. No. 17/366,261.
Claims priority of application No. 2020-115856 (JP), filed on Jul. 3, 2020.
Prior Publication US 2022/0001697 A1, Jan. 6, 2022
Int. Cl. B60C 11/00 (2006.01); B60C 11/01 (2006.01); B60C 11/12 (2006.01); B60C 11/13 (2006.01)
CPC B60C 11/0083 (2013.01) [B60C 11/01 (2013.01); B60C 11/1236 (2013.01); B60C 11/1281 (2013.01); B60C 11/1323 (2013.01); B60C 11/1353 (2013.01); B60C 2200/06 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A tire comprising:
a tread portion provided with a plurality of circumferential grooves extending continuously in the tire circumferential direction, and a plurality of land regions divided by the plurality of circumferential grooves,
the plurality of land regions including a crown land region on a tire equator, shoulder land regions extending axially inwardly from respective tread edges, and middle land regions between the respective shoulder land regions and the crown land region,
the ground contacting top surface of the crown land region comprising a crown axial central portion defined as including a center position in a tire axial direction of the crown land region,
the ground contacting top surface of each of the middle land regions comprising a middle axial inner portion defined as extending from an axially inner edge of the ground contacting top surface, and a middle axial outer portion defined as extending from an axially outer edge of the ground contacting top surface, and
the ground contacting top surface of each of the shoulder land regions comprising a shoulder axial inner portion defined as extending from an axially inner edge of the ground contacting top surface, and a shoulder axial central portion defined as including a center position in the tire axial direction of the shoulder land region,
wherein
in a meridian cross-section of the tire including a rotational axis of the tire,
a radius Rmi of curvature of the middle axial inner portion is substantially equal to a radius Rcc of curvature of the crown axial central portion,
a radius Rsc of curvature of the shoulder axial central portion is in a range from 0.90 to 1.10 times a radius Rmo of curvature of the middle axial outer portion,
the radius Rsc of curvature of the shoulder axial central portion and the radius Rmo of curvature of the middle axial outer portion are smaller than the radius Rcc of curvature of the crown axial central portion and the radius Rmi of curvature of the middle axial inner portion, and
a radius Rsi of curvature of the shoulder axial inner portion is smaller than the radius Rsc of curvature of the shoulder axial central portion and the radius Rmo of curvature of the middle axial outer portion,
wherein
each of the shoulder land regions has an axially outer side surface curved concavely toward an inside in the tire axial direction, and
a minimum radius Rsw of curvature of the axially outer side surface is smaller than the radius Rsi of curvature of the shoulder axial inner portion,
wherein
in the meridian cross-section of the tire including the rotational axis of the tire, the axially outer side surface comprises a radially outer portion extending linearly and radially inwardly from the tread edge, and an arc-shaped portion extending radially inwardly from the radially outer portion, the radially outer portion and the arc-shaped portion are connected with each other smoothly without forming an inflection point, and said minimum radius Rsw of curvature occurs in the arc-shaped portion,
the circumferential grooves include a shoulder circumferential groove disposed on each side of the tire equator to separate between the shoulder land region and the middle land region, and
the shoulder circumferential groove and the arc-shaped portion on a same side of the tire equator are disposed such that a virtual line parallel with an arc profile of the shoulder axial central portion passes through both a bottom of the shoulder circumferential groove and an outermost point of the arc-shaped portion in the tire axial direction,
wherein
the shoulder circumferential groove has a groove bottom comprising an axially inner portion axially inside a groove center line of the shoulder circumferential groove, and an axially outer portion axially outside the groove center line of the shoulder circumferential groove, and
in the meridian cross-section of the tire, the groove bottom is curved so that a radius of curvature of the axially inner portion is larger than a radius of curvature of the axially outer portion.
 
18. A tire comprising:
a tread portion provided with a plurality of circumferential grooves extending continuously in the tire circumferential direction, and a plurality of land regions divided by the plurality of circumferential grooves,
the plurality of land regions including a crown land region on a tire equator, shoulder land regions extending axially inwardly from respective tread edges, and middle land regions between the respective shoulder land regions and the crown land region,
the ground contacting top surface of the crown land region comprising a crown axial central portion defined as including a center position in a tire axial direction of the crown land region,
the ground contacting top surface of each of the middle land regions comprising a middle axial inner portion defined as extending from an axially inner edge of the ground contacting top surface, and a middle axial outer portion defined as extending from an axially outer edge of the ground contacting top surface, and
the ground contacting top surface of each of the shoulder land regions comprising a shoulder axial inner portion defined as extending from an axially inner edge of the ground contacting top surface, and a shoulder axial central portion defined as including a center position in the tire axial direction of the shoulder land region,
wherein
in a meridian cross-section of the tire including a rotational axis of the tire,
a radius Rmi of curvature of the middle axial inner portion is substantially equal to a radius Rcc of curvature of the crown axial central portion,
a radius Rsc of curvature of the shoulder axial central portion is in a range from 0.90 to 1.10 times a radius Rmo of curvature of the middle axial outer portion,
the radius Rsc of curvature of the shoulder axial central portion and the radius Rmo of curvature of the middle axial outer portion are smaller than the radius Rcc of curvature of the crown axial central portion and the radius Rmi of curvature of the middle axial inner portion,
a radius Rsi of curvature of the shoulder axial inner portion is smaller than the radius Rsc of curvature of the shoulder axial central portion and the radius Rmo of curvature of the middle axial outer portion,
each of the shoulder land regions includes an axially outer side surface that comprises a radially outer portion extending linearly and radially inwardly from one of the respective tread edges, and an arc-shaped portion extending radially inwardly from the radially outer portion and curved concavely toward an axially inside, and
the radially outer portion and the arc-shaped portion are connected with each other smoothly without forming an inflection point,
wherein
the circumferential grooves include a shoulder circumferential groove disposed on each side of the tire equator to separate between the shoulder land region and the middle land region,
the shoulder circumferential groove has a groove bottom comprising an axially inner portion axially inside a groove center line of the shoulder circumferential groove, and an axially outer portion axially outside the groove center line of the shoulder circumferential groove, and
in the meridian cross-section of the tire, the groove bottom is curved so that a radius of curvature of the axially inner portion is larger than a radius of curvature of the axially outer portion, and
the shoulder circumferential groove and the arc-shaped portion on a same side of the tire equator are disposed such that a virtual line parallel with an arc profile of the shoulder axial central portion passes through both a bottom of the shoulder circumferential groove and an outermost point of the arc-shaped portion in the tire axial direction.
 
19. A tire comprising:
a tread portion provided with a plurality of circumferential grooves extending continuously in the tire circumferential direction, and a plurality of land regions divided by the plurality of circumferential grooves,
the plurality of land regions including a crown land region on a tire equator, shoulder land regions extending axially inwardly from respective tread edges, and middle land regions between the respective shoulder land regions and the crown land region,
the ground contacting top surface of the crown land region comprising a crown axial central portion defined as including a center position in a tire axial direction of the crown land region,
the ground contacting top surface of each of the middle land regions comprising a middle axial inner portion defined as extending from an axially inner edge of the ground contacting top surface, and a middle axial outer portion defined as extending from an axially outer edge of the ground contacting top surface, and
the ground contacting top surface of each of the shoulder land regions comprising a shoulder axial inner portion defined as extending from an axially inner edge of the ground contacting top surface, and a shoulder axial central portion defined as including a center position in the tire axial direction of the shoulder land region,
wherein
in a meridian cross-section of the tire including a rotational axis of the tire,
a radius Rmi of curvature of the middle axial inner portion is substantially equal to a radius Rcc of curvature of the crown axial central portion,
a radius Rsc of curvature of the shoulder axial central portion is substantially equal to a radius Rmo of curvature of the middle axial outer portion,
the radius Rsc of curvature of the shoulder axial central portion and the radius Rmo of curvature of the middle axial outer portion are smaller than the radius Rcc of curvature of the crown axial central portion and the radius Rmi of curvature of the middle axial inner portion, and
a radius Rsi of curvature of the shoulder axial inner portion is smaller than the radius Rsc of curvature of the shoulder axial central portion and the radius Rmo of curvature of the middle axial outer portion,
wherein
each of the shoulder land regions includes an axially outer side surface that comprises a radially outer portion extending linearly and radially inwardly from one of the respective tread edges, and an arc-shaped portion extending radially inwardly from the radially outer portion and curved concavely toward an axially inside, and
the radially outer portion and the arc-shaped portion are connected with each other smoothly without forming an inflection point,
a minimum radius Rsw of curvature of the axially outer side surface is smaller than the radius Rsi of curvature of the shoulder axial inner portion, wherein
the circumferential grooves include a shoulder circumferential groove disposed on each side of the tire equator to separate between the shoulder land region and the middle land region,
the shoulder circumferential groove has a groove bottom comprising an axially inner portion axially inside a groove center line of the shoulder circumferential groove, and an axially outer portion axially outside the groove center line of the shoulder circumferential groove, and
in the meridian cross-section of the tire, the groove bottom is curved so that a radius of curvature of the axially inner portion is larger than a radius of curvature of the axially outer portion, and
the shoulder circumferential groove and the arc-shaped portion on a same side of the tire equator are disposed such that a virtual line parallel with an arc profile of the shoulder axial central portion passes through both a bottom of the shoulder circumferential groove and an outermost point of the arc-shaped portion in the tire axial direction.