Pneumatic tire having lug grooves
AssigneeBridgestone Corporation
InventorAkiyoshi Shimizu
Life of this patent
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Abstract
A component Fin toward an axial inner direction of the tire which is an opposite direction from an axial outer direction of the tire is applied to a force acting on a kicking end 16B of a land portion 16. With this, abrasion of the kicking end of the land portion can be moderated, and a biased abrasion resistance can be enhanced. A groove wall 20 of a lug groove 14 is provided with a step portion 22, a tread side groove width WA in a tread side of the step portion is widened toward an axial outer side of the tire, and a width WS of the step portion 22 is increased toward the axial outer side of the tire, thereby suppressing the lift from the road surface 26 at the tread-in end 16A of the land portion 16.
Claims5
A pneumatic tire having lug grooves arranged in a tread in a direction intersecting a circumferential direction of the tire and arranged in the circumferential direction of the tire, and land portions divided by the lug grooves, wherein
- when a distance from a ground-contact end to a tire equatorial plane is defined as L in a state in which the tire is assembled to a normal rim and a normal internal pressure is charged into the tire and a normal load is applied to the tire,
- in a region where a distance from the tire equatorial plane to an axial outer side of the tire is in a range of from 0.45L to 0.55L,
- a step portion which is a boundary between a tread side groove wall and a tire center side groove wall is respectively provided on both sides of the lug groove,
- an average groove width at the tread side of the step portions is widened toward the axial outer side of the tire and a width of the step portion is increased toward the axial outer side of the tire, and
- the tread side groove walls at a tread-in end and a kicking end of the land portion are inclined in opposite directions to each other with respect to an axial direction of the tire,
- wherein a depth position where the step portion is formed is a position of from 0.3 to 0.7 times of a groove depth of the lug groove from the tread side to the tire center side, and
- wherein in a region where the distance from the tire equatorial plane is in a range of from 0.55L to the axial outer side of the tire:
- an average width of the lug groove is substantially constant, and
- an average width between the tire center side groove walls is decreased toward the axial outer side of the tire.
A pneumatic tire having lug grooves arranged in a tread in a direction intersecting a circumferential direction of the tire and arranged in the circumferential direction of the tire, and land portions divided by the lug grooves, wherein
- when a distance from a ground-contact end to a tire equatorial plane is defined as L in a state in which the tire is assembled to a normal rim and a normal internal pressure is charged into the tire and a normal load is applied to the tire,
- in a region where a distance from the tire equatorial plane to an axial outer side of the tire is in a range of from 0.45L to 0.55L,
- a step portion which is a boundary between a tread side groove wall and a tire center side groove wall is respectively provided on both sides of the lug groove,
- an average groove width at the tread side of the step portions is widened toward the axial outer side of the tire and a width of the step portion is increased toward the axial outer side of the tire, and
- the tread side groove walls at a tread-in end and a kicking end of the land portion are inclined in opposite directions to each other with respect to an axial direction of the tire,
- wherein a depth position where the step portion is formed is a position of from 0.3 to 0.7 times of a groove depth of the lug groove from the tread side to the tire center side, and
- wherein a groove width between the tread side groove walls and a groove width between the tire side groove walls continuously increase from a groove bottom to a tread side of the tire;
- and
- wherein in a region where the distance from the tire equatorial plane is in a range of from 0.55L to the axial outer side of the tire:
- an average width of the lug groove is substantially constant, and
- an average width between the tire center side groove walls is decreased toward the axial outer side of the tire.
Dependencies are inferred from the claim text.