PNEUMATIC TIRE
Provided is a pneumatic tire that can provide improved communication performance of a transponder while ensuring durability of the tire. In a pneumatic tire including a tread portion extending in a tire circumferential direction and having an annular shape, a pair of sidewall portions respectively disposed on both sides of the tread portion, and a pair of bead portions each disposed on an inner side of the pair of sidewall portions in a tire radial direction, a transponder is embedded in one of the sidewall portions, the transponder is covered with a coating layer, a relative dielectric constant of the coating layer is lower than a relative dielectric constant of a peripheral rubber member adjacent to the coating layer, and a total thickness Gac of the coating layer and a maximum thickness Gar of the transponder satisfy a relationship 1.1≤Gac/Gar≤3.0.
1 . A pneumatic tire, comprising:
a tread portion extending in a tire circumferential direction and having an annular shape;
a pair of sidewall portions respectively disposed on both sides of the tread portion; and
a pair of bead portions each disposed on an inner side of the pair of sidewall portions in a tire radial direction;
a transponder being embedded in one of the pair of sidewall portions, the transponder being covered with a coating layer, a relative dielectric constant of the coating layer being lower than a relative dielectric constant of a peripheral rubber member adjacent to the coating layer, and a total thickness Gac of the coating layer and a maximum thickness Gar of the transponder satisfying a relationship; 1.1≤Gac/Gar≤3.0.
2 . The pneumatic tire according to claim 1 , wherein
the transponder comprises a substrate and antennas extending from both ends of the substrate,
the transponder extends along the tire circumferential direction, and
a distance L between an end of the antennas in the tire circumferential direction and an end of the coating layer in the tire circumferential direction ranges from 2 mm to 20 mm.
3 . The pneumatic tire according to claim 1 , wherein
the transponder comprises a substrate and antennas extending from both ends of the substrate, and
the antennas extend within a range of ±20° with respect to the tire circumferential direction.
4 . The pneumatic tire according to claim 1 , wherein a center of the transponder in a thickness direction is disposed within a range of from 25% to 75% of the total thickness Gac of the coating layer from a surface on one side of the coating layer in a thickness direction.
5 . The pneumatic tire according to claim 1 , wherein the coating layer is made of elastomer or rubber and has a relative dielectric constant of 7 or less.
6 . The pneumatic tire according to claim 1 , wherein a center of the transponder in a length direction is disposed 10 mm or more spaced from a splice portion of a tire component in the tire circumferential direction.
7 . The pneumatic tire according claim 1 , wherein the transponder is disposed between a position of 15 mm outer side in the tire radial direction from an upper end of a bead core of one of the bead portions and a tire maximum width position.
8 . The pneumatic tire according to claim 2 , wherein
the transponder comprises a substrate and antennas extending from both ends of the substrate, and
the antennas extend within a range of ±20° with respect to the tire circumferential direction.
9 . The pneumatic tire according to claim 8 , wherein a center of the transponder in a thickness direction is disposed within a range of from 25% to 75% of the total thickness Gac of the coating layer from a surface on one side of the coating layer in a thickness direction.
10 . The pneumatic tire according to claim 9 , wherein the coating layer is made of elastomer or rubber and has a relative dielectric constant of 7 or less.
11 . The pneumatic tire according to claim 10 , wherein a center of the transponder in a length direction is disposed 10 mm or more spaced from a splice portion of a tire component in the tire circumferential direction.
12 . The pneumatic tire according to claim 11 , wherein the transponder is disposed between a position of 15 mm outer side in the tire radial direction from an upper end of a bead core of one of the bead portions and a tire maximum width position.