Abstract: When a tire that is mounted on a specified rim, inflated to an internal pressure of 50 kPa, and placed in a no-load state is viewed as a cross-section from the tire meridian direction, a position of 1.30×Hf on an outer surface of a sidewall portion, taking a rim flange height (Hf) of the specified rim as a reference, is defined as a point (P), a foot of a normal line (L) drawn from the point (P) to a carcass line of a main body portion (131) of a carcass layer (13) is defined as a point (M), and a point of intersection of the normal line (L) and a carcass line of a folded back portion (132) of the carcass layer (13) is defined as a point (T). At this time, a distance (a) mm from the point (M) to the point (T), a distance (b) mm from the point (T) to the point (P), and a specified load (x) kN have relationships such that a=0.019×x+13.3 and b=0.052×x+21.6, with a tolerance of not less than 0% and not more than 20%.

Abstract: This pneumatic tire (1) includes: a pair of bead cores (11, 11); a carcass layer (13) extending between the pair of bead cores (11, 11); and a belt layer (14) including a laminate of at least four belt plies (141 to 144) having steel belt cords covered with coating rubber, the belt layer being disposed on the outer side in a tire radial direction of the carcass layer (13). An inter-cord distance (Ga) between an outermost layer belt ply (fourth belt (144)) and an adjacent belt ply (third belt (143)) has a relationship such that 0.80?Ga/?max?1.80 with respect to a maximum value (?max) of outer diameters (?4, ?3) of belt cords (1441, 1431) in the outermost layer belt ply (144) and the adjacent belt ply (143).

Abstract: This pneumatic tire (1) includes: a pair of bead cores (11, 11); a carcass layer (13) extending between the pair of bead cores (11, 11); and a belt layer (14) including a laminate of at least four belt plies (141 to 144) having steel belt cords covered with coating rubber, the belt layer being disposed on the outer side in a tire radial direction of the carcass layer (13). An inter-cord distance (Ga) between an outermost layer belt ply (fourth belt (144)) and an adjacent belt ply (third belt (143)) has a relationship such that 0.80?Ga/?max?1.80 with respect to a maximum value ((max) of outer diameters (?4, ?3) of belt cords (1441, 1431) in the outermost layer belt ply (144) and the adjacent belt ply (143).

Abstract: When a tire that is mounted on a specified rim, inflated to an internal pressure of 50 kPa, and placed in a no-load state is viewed as a cross-section from the tire meridian direction, a position of 1.30×Hf on an outer surface of a sidewall portion, taking a rim flange height (Hf) of the specified rim as a reference, is defined as a point (P), a foot of a normal line (L) drawn from the point (P) to a carcass line of a main body portion (131) of a carcass layer (13) is defined as a point (M), and a point of intersection of the normal line (L) and a carcass line of a folded back portion (132) of the carcass layer (13) is defined as a point (T). At this time, a distance (a) mm from the point (M) to the point (T), a distance (b) mm from the point (T) to the point (P), and a specified load (x) kN have relationships such that a=0.019×x+13.3 and b=0.052×x+21.6, with a tolerance of not less than 0% and not more than 20%.

Abstract: A pneumatic tire includes two cross belts having codes forming 5 to 30 degrees to a tire circumferential direction; a circumferential reinforcing layer having a width smaller than the cross belts, and having codes forming 0 to 5 degrees to the tire circumferential direction; and a carcass located inside, in a tire diameter direction, relative to a cross belt being inside among the cross belts. At 100% internal inflation pressure, a distance X1 between an equatorial plane and an outer edge of the circumferential reinforcing layer is 60% to 75% of a distance W between the equatorial plane and an outermost section of the carcass, and at 5% internal inflation pressure, a distance Y between the equatorial plane and a separation section of the carcass and a belt outwardly adjoining the carcass is 95% to 105% of a distance X2 between the equatorial plane and the outer edge.

Abstract: In a pneumatic tire for heavy load including a circumferentially-formed groove running in a tire circumferential direction on a surface of a tread part, when a pneumatic pressure equivalent to a normal inner pressure is applied with reference to a case where a pneumatic pressure equivalent to an inner pressure of kPa is applied, a radius growth in a tire radial direction at a crown center of the tread part and in the circumferentially-formed groove located at the most lateral side in a tire width direction is made to be less than 0.3%.

Abstract: The present invention provides a pneumatic tire that inhibits any fatigue rupture at an edge portion of a circumferential-direction reinforcing belt layer and also inhibits any separation at an edge portion of crossed belt layers. In the pneumatic tire, at least two crossed belt layers are disposed on the outer circumferential side of a carcass layer in a tread portion. At least one circumferential-direction reinforcing belt layer with a width smaller than those of the crossed belt layers is disposed between the crossed belt layers. Moreover, a stress relaxation layer of a rubber composition having a fixed thickness is disposed between the crossed belt layers while lying adjacent to an edge portion of and outside, in the width directions of, the circumferential-direction reinforcing belt layer.

Abstract: In a pneumatic tire, 48%?HB/HA?52%, 98%?HC/HA?100%, 108%?WB/WA?115%, and 55%?WC/WA?75% are satisfied, where, when a line from a position A of rim height FH in tire width direction is X-axis and a line in tire radial direction via center crown CL is Y-axis, WA is distance of a half of tire base width, WB is distance from the Y-axis to a maximum width position P of a carcass layer, WC is distance from the Y-axis to an inflection point Q of the carcass layer, HA is distance from the X-axis to a peak R of the carcass layer on the center crown CL, HB is distance from the X-axis to the maximum width position P, and HC is distance from the X-axis to the inflection point Q.

Abstract: In a pneumatic tire, a belt layer includes six superposed belt members. The edge of the fourth belt member on the tire-width direction outer side and the edge of the sixth belt member on the tire-width direction outer side are at approximately the same position in a tire width direction.

Abstract: A pneumatic tire includes two cross belts having codes forming 5 to 30 degrees to a tire circumferential direction; a circumferential reinforcing layer having a width smaller than the cross belts, and having codes forming 0 to 5 degrees to the tire circumferential direction; and a carcass located inside, in a tire diameter direction, relative to a cross belt being inside among the cross belts. At 100% internal inflation pressure, a distance X1 between an equatorial plane and an outer edge of the circumferential reinforcing layer is 60% to 75% of a distance W between the equatorial plane and an outermost section of the carcass, and at 5% internal inflation pressure, a distance Y between the equatorial plane and a separation section of the carcass and a belt outwardly adjoining the carcass is 95% to 105% of a distance X2 between the equatorial plane and the outer edge.

Abstract: Provided is a method of producing a pneumatic tire, which makes it possible to prevent, in forming a circumferential reinforcement layer by using a jointless material including one or more steel cords coated with rubber, occurrence of air pockets caused by variation in positions of wrapping of the jointless material. The method of producing a pneumatic tire includes forming a circumferential reinforcement layer in a way that while being oriented in the tire circumferential direction, a jointless material is wrapped helically in the tire axial direction around the outer peripheral side of a carcass layer in a tread portion, the jointless material including one or a plurality of steel cords coated with rubber. In the method, a lateral cross-sectional shape of the jointless material is formed substantially as a parallelogram, and a range of an inclination angle ? of the parallelogram is set to 5°???20°.

Abstract: The present invention provides a pneumatic tire that inhibits any fatigue rupture at an edge portion of a circumferential-direction reinforcing belt layer and also inhibits any separation at an edge portion of crossed belt layers. In the pneumatic tire, at least two crossed belt layers are disposed on the outer circumferential side of a carcass layer in a tread portion. At least one circumferential-direction reinforcing belt layer with a width smaller than those of the crossed belt layers is disposed between the crossed belt layers. Moreover, a stress relaxation layer of a rubber composition having a fixed thickness is disposed between the crossed belt layers while lying adjacent to an edge portion of and outside, in the width directions of, the circumferential-direction reinforcing belt layer.

Abstract: In a pneumatic tire, 48%?HB/HA?52%, 98%?HC/HA?100%, 108%?WB/WA?115%, and 55%?WC/WA?75% are satisfied, where, when a line from a position A of rim height FH in tire width direction is X-axis and a line in tire radial direction via center crown CL is Y-axis, WA is distance of a half of tire base width, WB is distance from the Y-axis to a maximum width position P of a carcass layer, WC is distance from the Y-axis to an inflection point Q of the carcass layer, HA is distance from the X-axis to a peak R of the carcass layer on the center crown CL, HB is distance from the X-axis to the maximum width position P, and HC is distance from the X-axis to the inflection point Q.

Abstract: In a pneumatic tire for heavy load including a circumferentially-formed groove running in a tire circumferential direction on a surface of a tread part, when a pneumatic pressure equivalent to a normal inner pressure is applied with reference to a case where a pneumatic pressure equivalent to an inner pressure of kPa is applied, a radius growth in a tire radial direction at a crown center of the tread part and in the circumferentially-formed groove located at the most lateral side in a tire width direction is made to be less than 0.3%.

Abstract: In a pneumatic tire, a belt layer includes six superposed belt members. The edge of the fourth belt member on the tire-width direction outer side and the edge of the sixth belt member on the tire-width direction outer side are at approximately the same position in a tire width direction.