Pneumatic tire
A pneumatic tire 1 including a belt layer ( 20 ) having a belt ply ( 21 ) and a belt reinforcing layer ( 30 ) having belt reinforcing ply ( 31 ) in which organic fiber cords are arranged in a tire circumferential direction, in which the belt ply ( 21 ) has an in-plane rigidity of 4.0 [kN/inch] or more in a tire width direction, and A, B, C, and D satisfy relationships represented by the following Expression (I) and Expression (II), 2 . 0 ≤ C / ( A × ( 90 - B ) ) Expression ( I ) Expression (II): 8.0≤D/(A×(90−B))≤30.0 where: A [N/inch] is a bending load per unit width of a sheet of the belt ply ( 21 ); B [deg] is a belt angle; C [N/25 mm] is a product of a load at 2% elongation of each organic fiber cord and the number of the organic fiber cords; and D [N/25 mm] is a product of a load at 5% elongation of the organic fiber cord and the number of the organic fiber cords.
1 . A pneumatic tire comprising:
a carcass;
a belt layer arranged on an outer circumference of a crown of the carcass; and
a belt reinforcing layer arranged on an outer circumference of the belt layer, wherein
the belt layer has a belt ply in which steel cords are arranged at an angle to a tire circumferential direction,
the belt reinforcing layer has a belt reinforcing ply on the outer circumference of the belt layer, the belt reinforcing ply having organic fiber cords arranged in the tire circumferential direction,
the belt ply has an in-plane rigidity of 4.0 [kN/inch] or more and 10.0 [kN/inch] or less in a tire width direction, and
A, B, C, and D satisfy relationships represented by the following Expression (I) and Expression (II),
2
.
0
≤
C
/
(
A
×
(
90
-
B
)
)
Expression
(
I
)
8.
≤
D
/
(
A
×
(
90
-
B
)
)
≤
3
0
.
0
Expression
(
II
)
where: A [N/inch] is a bending load per unit width of a sheet of the belt ply;
B [deg] is an angle of the steel cords in the belt layer with respect to the tire circumferential direction;
C [N/25 mm] is a product of a load [N] at 2% elongation of each of the organic fiber cords and the number of the organic fiber cords implanted in the belt reinforcing ply [cords/25 mm]; and
D [N/25 mm] is a product of a load [N] at 5% elongation of each of the organic fiber cords and the number of the organic fiber cords implanted in the belt reinforcing ply [cords/25 mm].
2 . The pneumatic tire according to claim 1 , wherein C is 1100 or less.
3 . The pneumatic tire according to claim 1 , wherein D is 2000 or more.
4 . The pneumatic tire according to claim 1 , wherein X is 9.0 or more and 25.0 or less, where X [kN/inch] is the in-plane rigidity in the extending direction of the steel cords of the belt ply.
5 . The pneumatic tire according to claim 1 , wherein a ratio (Y/A) of Y to A is 1.0 or more, where Y [kN/inch] is the in-plane rigidity in the tire width direction of the belt ply.
6 . The pneumatic tire according to claim 1 , wherein each organic fiber cord is a composite fiber cord formed by twisting yarn made of aliphatic polyamide fibers with yarn made of aromatic polyamide fibers.
7 . The pneumatic tire according to claim 1 , wherein A, B, and C satisfy 3.0≤C/(A×(90−B))≤8.0.
8 . The pneumatic tire according to claim 1 , wherein A, B, and D satisfy 10.0≤D/(A×(90−B))≤20.0.
9 . The pneumatic tire according to claim 1 , wherein C is 500 or more and 900 or less.
10 . The pneumatic tire according to claim 1 , wherein D is 2500 or more and 3000 or less.
11 . The pneumatic tire according to claim 1 , wherein a filament diameter of each steel cord is 0.14 mm or more and 0.21 mm or less.