Toyo Tire Corporation

Toyo Tire Rubber Co., Ltd.

Kunihiko Nagai

Akina Kouuchi

A pneumatic tire includes a pair of bead cores; a pair of bead fillers; a carcass ply that is suspended between the pair of bead cores; a side wall rubber that is arranged on a tire-outer-surface-side of the carcass ply and constitutes a tire outer surface; a chafer layer that is rolled up from a tire-inner-surface-side to the tire-outer-surface-side of the carcass ply around the bead cores and the bead fillers; and a pad rubber that is arranged between the side wall rubber and the carcass ply to be adjacent to a rolled-up end of the chafer layer in a tire width direction, the pad rubber having a modulus value higher than that of the side wall rubber. The pad rubber includes a constant thickness portion having a substantially constant thickness over a range of 7% or more but not exceeding 26% of a tire reference cross-section height.

Pneumatic tire

A pneumatic tire includes a pair of bead cores; a pair of bead fillers; a carcass ply; a side wall rubber; a chafer layer that is rolled up on an outer surface of the carcass ply; and a pair of support rubbers that is located between the side wall rubber and the carcass ply and arranged such that a rolled-up end of the chafer layer is sandwiched from both sides in a tire width direction. The pair of support rubbers includes a tape rubber located inside in the tire width direction and a rear pad rubber located outside in the tire width direction. A modulus value of the tape rubber is higher than a modulus value of the side wall rubber. A modulus value of the rear pad rubber is higher than the modulus value of the tape rubber.

A method of manufacturing a pneumatic tire including forming a green case by cylindrically winding a tire component member which includes at least one layer of a carcass ply. The green tire is shaped by expanding the green case into a toroidal shape with the supply of a fluid into the green case so that the green case adheres to a tread ring arranged radially outside the green case. The green tire is subjected to vulcanization molding within a mold die. During the shaping of the green tire, the fluid is supplied in accordance with a pressure profile which changes in a stepwise manner. The pressure profile is set such that a former stage pressure which allows the green case to expand to 35% to 40% of a full expansion amount is set lower than a final stage pressure in a final stage.

Method of manufacturing pneumatic tire, shaping device and pneumatic tire

A tire has a cap rubber formed of nonconductive rubber and forms a ground surface, and a conductive portion provided in at least one side end portion of a pair of side end portions in both ends in a tire width direction. The conductive portion is formed of a conductive rubber, and reaches a side surface of the cap rubber from the ground surface through an inner portion of the cap rubber. The conductive portion is relatively small in a thickness in the ground surface and a side surface of the cap rubber, is relatively large in the maximum thickness of an intermediate portion between the ground surface and the side surface of the cap rubber, and is formed into a crescent shape which is curved into an outer side in a tire width direction and an outer side in a radial direction, in a tire meridian cross section.

A tire has a cap rubber formed of nonconductive rubber and forms a ground surface, and a conductive portion provided in at least one side end portion of a pair of side end portions in both ends in a tire width direction. The conductive portion is formed of a conductive rubber, and reaches a side surface of the cap rubber from the ground surface through an inner portion of the cap rubber. The conductive portion is relatively small in a thickness in the ground surface and a side surface of the cap rubber, is relatively large in the maximum thickness of an intermediate portion between the ground surface and the side surface of the cap rubber, and is formed into a crescent shape which is curved into an inner side in a tire width direction and an inner side in a radial direction, in a tire meridian cross section.

A tire has a cap rubber formed of a nonconductive rubber and forms a ground surface, and a conductive portion provided in at least one side end portion of a pair of side end portions in both ends in a tire width direction. The conductive portion is formed of a conductive rubber, and reaches a side surface of the cap rubber from the ground surface through an inner portion of the cap rubber. The conductive portion is the smallest in thickness in the ground surface, is relatively large in thickness in the side surface of the cap rubber, is gradually increased in thickness from the ground surface to the side surface of the cap rubber, and is formed into a trumpet shape which is curved into an inner side in a tire width direction and an inner side in a radial direction, in a tire meridian cross section.

A method of manufacturing a pneumatic tire including forming a green case by cylindrically winding a tire component member which includes at least one layer of a carcass ply. A green tire is shaped by expanding the green case into a toroidal shape with the supply of a fluid into the green case so that the green case adheres to a tread ring arranged radially outside the green case. The green tire is subjected to vulcanization molding within a mold die. During the shaping of the green tire, the fluid is supplied in accordance with a pressure profile which changes in a stepwise manner. The pressure profile is set such that a former stage expansion rate in a former stage is set to slower than a final stage expansion rate in a final stage.

A method for manufacturing a cord included rubber sheet has an arrangement step and a cutting step. In the arrangement step, a band-like material of a cord included rubber sheet is supplied to a processing table, and a portion to be cut is arranged onto a groove. In the cutting step, the band-like material is cut by pressing the pressure cutting die, and the cord included rubber sheet having a predetermined length is obtained. A leading end of the pressure cutting die enters the groove and a die surface of the pressure cutting die contacts with an opening edge of the groove, in the cutting step, and a cut surface of the cord is coated with the rubber of the band-like material in a process that the die surface comes into contact with the opening edge after the leading end contacts with the band-like material.

Method of manufacturing cord included rubber sheet

Provided is a pneumatic tire having the structure where a carcass ply is wound around bead cores from the outside in the tire width direction to the inside in the tire width direction, and both end portions of an inner liner extend between beads and the carcass ply. A lightweight and highly rigid tire can be acquired. The tire can also enhance steering stability performance thereof. The pneumatic tire includes: a pair of left and right beads including bead cores; a carcass ply extending between the bead cores; and an inner linerdisposed on an inner peripheral side of the carcass ply, wherein the carcass plyis wound around the bead coresfrom the outside in the tire width direction to the inside in the tire width direction, and both end portions of the inner linerextend between the beads and the carcass ply.

Pneumatic tire and method of manufacturing the same

A pneumatic tire has a tread rubber provided in an outer side of a carcass layer in a tread portion. the tread rubber has a cap portion which is formed by a non-conductive rubber and constructs a ground-contacting surface, a base portion which is provided in an inner side in the tire diametrical direction of the cap portion, and a conductive portion which is formed by a conductive rubber and extends in a thickness direction of the tread rubber so as to reach a bottom surface of the tread rubber from the ground-contacting surface. A thickness of the conductive portion is made relatively large in a center portion in the thickness direction of the tread rubber, and the thickness of the conductive portion is made relatively small in both end portions in the thickness direction of the tread rubber.

Pneumatic tire with tread having cap portion, base portion and conductive portion

A pneumatic tire has a plurality of upper surface sipes formed on an upper surface of the block and arranged in parallel so as to be spaced in a sipe width direction, and a wall surface sipe extending along a tire diametrical direction in a wall surface positioned in a longitudinal direction of the upper surface sipe. The wall surface sipe is arranged between a pair of adjacent the upper surface sipes.

Pneumatic tire with tread having upper surface sipes and wall surface sipes

A pneumatic tire has an upper surface sipe formed on an upper surface of the block, a first wall surface sipe formed in a first wall surface of the block and extending in a direction intersecting the upper surface sipe, and a second wall surface sipe formed in a second wall surface which is adjacent to the first wall surface, and extending in a direction intersecting the upper surface sipe and the first wall surface sipe.

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Osaka, Japan

Kunihiko Nagai