Toyo Tire Rubber Co., Ltd.

Bird Stopper Co., Ltd.

Osaka Winton Co., Ltd.

Hiroaki Sugimoto

Yoshiro Sumiya

Yuichi Nakamura

Harunobu Suita

Shinichi Kaji

A pneumatic tire comprising a shoulder land portion and a narrow groove, the narrow groove comprises a first enlarged portion enlarging a groove width at a groove bottom only on the sacrificed portion side, a second enlarged portion being formed adjacently on the tread face side of the first enlarged portion and enlarging a groove width only on the sacrificed portion side, a projection portion being formed between the first enlarged portion and the second enlarged portion while projecting toward the main body land portion from an inner wall on the sacrificed land portion side, and a flat face portion having a depth, from the tread face, of 30% or more of a groove depth of the narrow groove, and having an inner wall on the sacrificed land portion side and an inner wall on the main body land portion side.

Pneumatic tire with tread having narrow groove

In a pneumatic tire in which a tread with a plurality of groovesandincluding main groovesextending in the tire circumferential direction formed and in which blockis formed on shoulder portions of tread T by groovesandon intersection line L between a surface of tread T and a surface of side portion S, the first sipesextending in the tire circumferential direction R are formed, and the depth direction of the sipesandis parallel to tire equatorial plane C, and the sipesare deeper than the sipesand the sipesare wider than the sipesand height difference between a surface of wearing regionand a surface of side portion S is not greater than 2.0 mm.

Pneumatic tire having wearing region sandwiched by first and second sipes

To provide a method capable of easily analyzing frictional energy of a rolling tire, in-plane pressure Pxy(L) and vertical pressure Pz(L) at one point of a tread produced by rolling the tire are measured, static frictional force R(L) is calculated and the frictional energy is calculated by determining a portion corresponding to the static frictional force R(L) equal to or larger than a primary maximum value as a slipping region LR.

Method of analyzing frictional energy of rolling tire

A rubber filler in the tire bead portions is formed by a hard rubber filler having JIS A hardness of at least 85, and a soft rubber filler having JIS A hardness of 65-75. An outer end C of the interface between the hard and soft rubber fillers is placed to be higher than the upper end of a rim flange and at least 10 mm lower than an end D of a turned-up steel cord carcass, in a cross section of the bead portion of the tire. Further, 1.0 La.ltoreq.Lb.ltoreq.2.0 La, where Lb represents the distance B-E from an inner-surface-side end B of the interface between a rubber bead cover and carcass topping rubber of a carcass ply to an inner-surface-side end E of the interface between the hard and soft rubber fillers, and where La represents the distance D-A from the end D of the turned-up carcass to an outer-surface-side end A of the interface between the rubber bead cover and the carcass topping rubber.

Pneumatic radial tire for heavy load with rubber filler comprising hard

Bird repellent apparatus

A pneumatic tire for trucks, buses, etc. having a tread profile, before inflation, which has a first circular arc forming a tread center area and second circulr arcs forming shoulder ribs at both sides of the first circular arc, the first and second circular arcs intersecting together at a point from which the shoulder rib starts to extend and inwardly of which there is a 1/4 tread width point from a tread center axis, the first and second circular arcs having an inner radial divergence, between an inside wall top of an outermost main groove and the intersecting point, of up to 3 mm and an outer edge divergence, between an outer edge of the shoulder rib and an elongated line of the first circular arc, of up to 10 mm, whereby a good river wear resistance is attained. The tire has a belt portion, below the tread portion, including a working belt ply composite and preferably has such a tread rubber thickness to an uppermost working belt ply that is larger at an end of the uppermost working belt ply than at the tread center axis.

Growing community of inventors

Osaka, Japan

Hiroaki Sugimoto