The Yokohama Rubber Co., Ltd.

Hiraku Kouda

Tatsuro Shinzawa

Takanori Uemura

Takayuki Shiraishi

Atsushi Tanno

Jun Matsuda

Masaaki Nagayasu

Ryohei Takemori

Yuki Sasaya

Kenichi Sato

Masaaki Miyoshi

Noriyoshi Koyama

Masahiro Ishida

Noboru Kuwahara

Automobile tire

In a pneumatic tire including main grooves extending in a tire circumferential direction in a tread portion, and including a sipe extending in a tire lateral direction on a rib defined by the main grooves, the sipe includes an edge on a leading side and an edge on a trailing side, chamfered portions shorter than a sipe length of the sipe are formed on respective edges, non-chamfered regions on which no other chamfered portion exists exist on portions opposing to respective chamfered portions in the sipe, a maximum depth x (mm) of the sipe and a maximum depth y (mm) of the chamfered portion satisfy x&#xd7;0.1&#x2264;y&#x2264;x&#xd7;0.3+1.0, and a sipe width of the sipe is constant in a range from an end portion positioned inside in a tire radial direction of the chamfered portion to a groove bottom of the sipe.

Pneumatic tire

In a pneumatic tire, a sipe includes an edge on a leading side and an edge on a trailing side; the edge and the edge each include a chamfered portion shorter than a sipe length of the sipe; a non-chamfered region in which other chamfered portions are not present is provided at portions facing the chamfered portions of the sipe; and for all chamfered portions, including at least the chamfered portions of the sipe, formed on grooves other than main grooves, with a ground contact width being equally divided into three in the tire lateral direction, a total projected area Aof chamfered portions provided in a center region centrally located in the tire lateral direction and each of total projected areas Aof chamfered portions provided in shoulder regions located on either side of the center region satisfy a relationship A&#x3c;A.

A pneumatic tire is provided. A rib includes a lug groove that opens at a first end portion to one of the main grooves and terminates at a second end portion within the rib, a first sipe that opens at a first end portion to the one of the main grooves the lug groove opens to and opens at a second end portion to the lug groove, and a second sipe that opens at a first end portion to another main groove located on the opposite side of the one of the main grooves the lug groove opens to and opens at a second end portion to the lug groove; and the first sipe and the second sipe each include a chamfered portion on the edge on the leading side or the edge on the trailing side.

In a pneumatic tire, a sipe includes an edge on a leading side and an edge on a trailing side; the edge on the leading side and the edge on the trailing side each include a chamfered portion shorter than a sipe length of the sipe; a non-chamfered region in which other chamfered portions are not present is provided at portions facing the chamfered portions of the sipe; and for all chamfered portions, including at least the chamfered portions of the sipe, formed on grooves other than main grooves, a total projected area Aof the chamfered portions located on a vehicle mounting inner side and a total projected area Aof the chamfered portions located on a vehicle mounting outer side satisfy a relationship A&#x3e;A.

A pneumatic tire is provided with a sipe including an edge on a leading side and an edge on a trailing side. The edge on the leading side and the edge on the trailing side each include a chamfered portion shorter than a sipe length of the sipe. A non-chamfered region in which other chamfered portions are not present is provided at portions facing the chamfered portions of the sipe. For all chamfered portions, including at least the chamfered portions of the sipe, formed on grooves other than main grooves, a total volume Sof the chamfered portions located on a vehicle mounting inner side and a total volume Sof the chamfered portions located on a vehicle mounting outer side satisfy a relationship S&#x3e;S.

Provided is a pneumatic tire. A sipe is formed, on each of a leading side edge and a trailing side edge, with a chamfered portion shorter than a sipe length of a sipe, a non-chamfered region in which no other chamfered portion is present is provided in a part facing each of the chamfered portions, at least one end of the sipe communicates with the auxiliary groove, one end of the chamfered portion adjacent to the auxiliary groove in the rib communicates with the auxiliary groove, a maximum depth&#xd7;(mm) of the sipe and a maximum depth y (mm) of the chamfered portion satisfy a relationship x&#xd7;0.1&#x2264;y&#x2264;x&#xd7;0.3+1.0, and a sipe width W of the sipe is constant in a range from an end positioned in the radial direction inside the chamfered portion to a groove bottom of the sipe.

In a pneumatic tire, a sipe includes an edge on a leading side and an edge on a trailing side; the edge and the edge each include a chamfered portion shorter than a sipe length of the sipe; a non-chamfered region in which other chamfered portions are not present is provided at portions facing the chamfered portions of the sipe; and for all chamfered portions, including at least the chamfered portions of the sipe, formed on grooves other than main grooves, with a ground contact width being equally divided into three in the tire lateral direction, a total volume Sof chamfered portions provided in a center region centrally located in the tire lateral direction and each of total volumes Sof chamfered portions provided in shoulder regions located on either side of the center region satisfy a relationship S&#x3c;S.

Provided is a pneumatic tire including a plurality of main grooves extending in the tire circumferential direction in a tread portion and including a sipe extending in a tire width direction on a rib defined by a main groove, the sipe includes a leading side edge and a trailing side edge, a chamfered portion shorter than a sipe length of the sipe is formed in each of the leading side edge and the trailing side edge, a non-chamfered region including no other chamfered portion is present in a part facing each chamfered portion of the sipe, and the rib includes an intersecting groove intersecting with at least one out of the sipe and the chamfered portion.

A rib of a pneumatic tire includes a first sipe extending from one of main grooves positioned on both sides of the rib and a second sipe extending from another one of the main grooves, one end portion of the first and second sipes terminating within the rib. The first and second sipes form a pair of sipes including edges on leading and trailing sides. Chamfered portions shorter than a total sipe length of the pair of sipes are formed on respective edges and non-chamfered regions exist on portions opposing respective chamfered portions in the pair of sipes. A maximum depth x (mm) of the sipes and a maximum depth y (mm) of the chamfered portion satisfy x&#xd7;0.1&#x2264;y&#x2264;x&#xd7;0.3+1.0. A sipe width is constant in a range from a portion positioned inside in a tire radial direction of the chamfered portion to a bottom of the sipes.

A pneumatic tire is provided. In a meridian cross-section, an external contour shape of the bead core is a polygon formed by common tangent lines of a plurality of circumferential portions of a bead wire, the external contour shape includes a single vertex located toward the outside in a tire radial direction, an internal angle formed by two sides sandwiching the vertex is an acute angle, a bottom side of the external contour shape is inclined with respect to the tire lateral direction by from 2&#xb0; to 9&#xb0;, and the carcass layer is bent and folded back along a circumference of the bead core in a bead portion, a folded back portion of the carcass layer from a position of an outer end of the bead core in the tire radial direction extends toward a sidewall portion in contact with a body portion.

Of layers configuring a bead core of a pneumatic tire, the width Wof one of the layers including the greatest number of rows, the width W, Wof other of the layers located respectively innermost and outermost in the radial direction satisfy W&#x3e;Wand W&#x2264;0.5&#xd7;W. The position of width Wis inward in the radial direction of the center of the bead core. A carcass is folded and curved along the bead core and extends toward sidewalls where a folded back portion of the carcass contacts a body of the carcass. A rubber occupancy ratio in a closed region formed by the body and the folded back portion is 0.1% to 15%. The cross-sectional area Sand hardness Hof a filler outward of the carcass in the lateral direction, and the cross-sectional area Sand the hardness Hof the side reinforcing layer satisfy 0.12&#x2264;(S&#xd7;H)/(S&#xd7;H)&#x2264;0.50.

Provided is a pneumatic tire. A sipe includes, on each of a leading side edge and a trailing side edge, a chamfered portion and a non-chamfered region in which no other chamfered portion is present. A maximum depth of the chamfered portion is shallower than a maximum depth of the sipe, and a width of the sipe is substantially constant. In a cross-sectional view perpendicular to a lengthwise direction of the sipe, at least one chamfered portion has a profile line that projects outwards in the radial direction beyond a chamfer reference line connecting the end portions of the chamfered portion, and a cross-sectional area of a chamfered region that is surrounded by the profile line, the sipe, and a tread contact surface of a tread portion is smaller than a cross-sectional area of a reference region surrounded by the chamfer reference line, the sipe, and the tread contact surface.

Provided is a pneumatic tire. A sipe includes, on each of a leading side edge and a trailing side edge, a chamfered portion and a non-chamfered region including no other chamfered portion. The maximum depth of the chamfered portion is shallower than the maximum depth of the sipe, and the sipe width is substantially constant. In a cross-sectional view, at least one chamfered portion includes a profile line that is convex inward in a tire radial direction with respect to a chamfer reference line connecting both ends of the chamfered portion; and a cross-sectional area of a chamfered region that is surrounded by the profile line, the sipe, and a tread contact surface of a tread portion is equal to or greater than a cross-sectional area of a reference region, the reference region being surrounded by the chamfer reference line, the sipe, and the tread contact surface.

In a cross-section of a pneumatic tire, a contour of the bead core is a polygon formed by tangent lines of circumferential portions of a bead wire, the contour includes a vertex with an acute angle and a bottom side opposite the vertex, the carcass layer is folded back along a circumference of the bead core in a bead portion, a folded back portion of the carcass layer from an outer end of the bead core extends in the radial direction, and a distance in the radial direction between a center of an arc profile of a tire outer surface and a straight line extending in the lateral direction through the vertex is within 20% of a radius r of the arc, and a distance in the lateral direction between the center of the arc and a straight line extending in the radial direction through the vertex is within 2r&#xb1;0.4r.

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Hiratsuka, Japan

Hiraku Kouda