Abstract:
A pneumatic tire in which: a carcass layer is laid between paired bead sections; a belt layer is buried, on the outer peripheral side of the carcass layer, in a tread section; and multiple main grooves extending in a tire circumferential direction are provided in the tread section. In the pneumatic tire, a maximum groove depth of each of the main grooves is 8.5 mm to 15.0 mm, a ratio α of a section height SH of an actual tire to a section height SHstd calculated from a tire size is set in a range of 0.97≦α≦0.99, a contact area ratio is 65% to 70% under a measurement condition where an air pressure is 200 kPa and a load is 50% of a load carrying ability with the air pressure of 200 kPa, and an average contact pressure P is 300 kPa to 400 kPa under the measurement condition. The tire achieves enhanced wet performance without increasing tire weight.
Abstract:
A pneumatic tire is configured such that: paired first main grooves extending in a tire circumferential direction are provided on the two sides of a tire equator line in a tread portion, respectively; a distance between a center position of each first main groove and the tire equator line is set at 8% to 20% of a ground contact width W; a first land portion is defined between these first main grooves; multiple sub-grooves each having a curved shape are formed in each of both edge portions of the first land portion at intervals in the tire circumferential direction; one end of each sub-groove is opened to the corresponding first main groove, and the other end of the sub-groove is terminated inside the first land portion; a rib portion continuously extending in the tire circumferential direction is formed in an area of the first land portion on the tire equator line; and a relation between a length (L) of a center line of each sub-groove and a pitch length (P) of the sub-grooves in the tire circumferential direction satisfies 1.1×P≦L≦2.0×P.
Abstract:
Provided is a pneumatic tire which achieves both of excellent wet traction and wear resistance from an early stage to an advanced stage of wear. Multiple dent parts are formed, at certain intervals in a tire circumferential direction, in both side walls of each of at least two land portions of multiple land portions being formed in a tread surface and extending in the tire circumferential direction. Each of the dent parts has a smaller depth than main grooves that define the land portion where this dent part is formed. Multiple sipes are formed to traverse the land portion in a tire width direction between the right and left dent parts opposed to each other. Each of the sipes has a greater depth in both end regions opening to the dent parts than in a center region thereof.
Abstract:
In a pneumatic tire, a rotating direction of the tire is specified. A plurality of sipes are formed in land parts. Each of the sipes has a substantially zigzag shape formed by a string of multiple V-shaped parts in a plan view of a tread part, so that a falling amount of the land parts in the rotating direction of the tire differs from that of the land parts in a reverse direction, against an outside force generated when the tire lands on the ground. Besides, a direction of the V-shaped part of the sipe is set so that the falling amount of the land parts in the rotating direction of the tire is smaller than that in the reverse direction.
Abstract:
Provided are a tire forming mold which enables damage on ribs and blocks of a tire to be effectively prevented when the tire is removed from the tire forming mold in spite of a simple structure thereof, and a pneumatic tire producing method using the same. The tire forming mold according to the present invention is a two-division type of tire forming mold, including a mold main body for forming one side of the tire, wherein the mold main body is provided with a movable part which constitutes a part of a tread forming surface in the direction of the circumference thereof while the tire forming mold is being closed, and which can be moved while the tire is being removed from the tire forming mold.
Abstract:
Provided are a tire forming mold which enables damage on ribs and blocks of a tire to be effectively prevented when the tire is removed from the tire forming mold in spite of a simple structure thereof, and a pneumatic tire producing method using the same. The tire forming mold according to the present invention is a two-division type of tire forming mold, including a mold main body for forming one side of the tire, wherein the mold main body is provided with a movable part which constitutes a part of a tread forming surface in the direction of the circumference thereof while the tire forming mold is being closed, and which can be moved while the tire is being removed from the tire forming mold.
Abstract:
A pneumatic tire is configured such that: paired first main grooves extending in a tire circumferential direction are provided on the two sides of a tire equator line in a tread portion, respectively; a distance between a center position of each first main groove and the tire equator line is set at 8% to 20% of a ground contact width W; a first land portion is defined between these first main grooves; multiple sub-grooves each having a curved shape are formed in each of both edge portions of the first land portion at intervals in the tire circumferential direction; one end of each sub-groove is opened to the corresponding first main groove, and the other end of the sub-groove is terminated inside the first land portion; a rib portion continuously extending in the tire circumferential direction is formed in an area of the first land portion on the tire equator line; and a relation between a length (L) of a center line of each sub-groove and a pitch length (P) of the sub-grooves in the tire circumferential direction satisfies 1.1×P≦L≦2.0×P.
Abstract:
A pneumatic tire has no spew or no spew trace on a sidewall surface of the pneumatic tire and reduces air resistance. The tire includes a plurality of dimple-like recesses and a plurality of linear valley portions. The dimple-like recesses are provides in a first region including a tire maximum width position of the sidewall surface of the tire. The linear valley portions which are formed by serration of the sidewall surface, extend linearly in one direction in the first region and provided around each of the recesses so as to enclose each of the recesses. When a size of an occupied area of each of the recesses on the sidewall surface is represented by an equivalent diameter of a circle, an interval distance between the linear valley portions is smaller than the equivalent diameter.