JP7698183B2 - Pneumatic tires - Google Patents

Description

The present invention relates to a pneumatic tire having an embedded transponder covered by a coating layer, and more specifically, to a pneumatic tire that makes it possible to improve the durability of the transponder while maintaining the durability of the tire.

It has been proposed to embed an RFID tag (transponder) in a pneumatic tire (see, for example, Patent Document 1). When embedding a transponder in a tire, if the physical properties of the covering layer for protecting the transponder are inappropriate, the durability of the tire or transponder cannot be sufficiently ensured. In other words, if the elastic modulus of the covering layer is too low, the protective effect of the transponder is impaired, and if the elastic modulus of the covering layer is too high, stress concentration occurs near the edges of the covering layer, leading to damage to the tire.

Japanese Unexamined Patent Publication No. 7-137510

The object of the present invention is to provide a pneumatic tire that makes it possible to improve the durability of the transponder while ensuring the durability of the tire.

In order to achieve the above object, a pneumatic tire of the present invention includes a tread portion extending in a circumferential direction of the tire to form an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on the radially inward side of the sidewall portions, the pneumatic tire having a transponder embedded in the tire and covered by a covering layer, the covering layer having a secant modulus at 20°C at 10% deformation in the range of 0.5 MPa to 5.0 MPa ,
the storage modulus E'c(20°C) of the coating layer at 20°C is in the range of 2 MPa to 12 MPa;
the transponder is embedded outside of the carcass layer in the tire width direction, a storage modulus E'c(20°C) of the covering layer at 20°C and a storage modulus E'out(20°C) of a rubber member having the largest storage modulus at 20°C among rubber members located outside of the transponder in the tire width direction satisfy a relationship of 0.1≦E'c(20°C)/E'out(20°C)≦1.5,
The center of the transponder is disposed 10 mm or more away from the splice portion of the tire constituent members in the tire circumferential direction .

In the present invention, the transponder is covered with a covering layer, and the secant modulus of elasticity at 20°C at 10% deformation of the covering layer is set within the above range, so that it is possible to fully exert the protective effect of the covering layer on the transponder while avoiding stress concentration near the edges of the covering layer. This makes it possible to improve the durability of the transponder while ensuring the durability of the tire.

In the pneumatic tire of the present invention, the relative dielectric constant of the coating layer is preferably 7 or less. This ensures the radio wave permeability of the transponder and improves the communication performance of the transponder.

The storage modulus E'c (20°C) of the coating layer at 20°C is preferably in the range of 2 MPa to 12 MPa. This effectively improves the durability of the transponder while ensuring the durability of the tire.

The transponder is embedded outside the carcass layer in the tire width direction, and it is preferable that the storage modulus at 20°C E'c(20°C) of the covering layer and the storage modulus at 20°C E'out(20°C) of the rubber member with the largest storage modulus at 20°C among the rubber members located outside the transponder in the tire width direction satisfy the relationship 0.1≦E'c(20°C)/E'out(20°C)≦1.5. This makes it possible to effectively improve the durability of the transponder while ensuring the durability of the tire.

The coating layer is preferably made of rubber or elastomer and 20 phr or more of white filler. This allows the dielectric constant of the coating layer to be relatively low, effectively improving the communication performance of the transponder.

It is preferable that the white filler contains 20 phr to 55 phr of calcium carbonate. This allows the dielectric constant of the coating layer to be relatively low, effectively improving the communication performance of the transponder.

It is preferable that the center of the transponder is located at least 10 mm away from the splice portion of the tire component in the tire circumferential direction. This can effectively improve the durability of the tire.

It is preferable that the transponder is disposed between a position 15 mm radially outward from the upper end of the bead core of the bead portion and the maximum tire width position. This allows the transponder to be disposed in an area where the stress amplitude during running is small, effectively improving the durability of the transponder and preventing a decrease in tire durability.

It is preferable that the distance between the cross-sectional center of the transponder and the tire surface is 1 mm or more. This effectively improves the durability of the tire and improves the tire's resistance to external damage.

The thickness of the coating layer is preferably 0.5 mm to 3.0 mm. This effectively improves the transponder's communication performance without causing unevenness on the tire surface.

The transponder has an IC board that stores data and an antenna that transmits and receives data, and the antenna is preferably spiral-shaped. This allows it to follow the deformation of the tire while it is running, improving the durability of the transponder.

In the present invention, the secant modulus at 10% deformation is calculated based on a stress-elongation curve measured at a specified temperature and a tensile speed of 500 mm/min using a dumbbell-shaped test piece of type 3 in accordance with JIS-K6251. However, if a dumbbell-shaped test piece of type 3 cannot be taken from a tire, a test piece of another shape may be used. The storage modulus E' is measured in accordance with JIS-K6394 using a viscoelasticity spectrometer in a tensile deformation mode at a specified temperature, a frequency of 10 Hz, an initial strain of 10%, and a dynamic strain of ±2%.

1 is a meridian half cross-sectional view showing a pneumatic tire according to an embodiment of the present invention. FIG. 2 is a meridian cross-sectional view illustrating the pneumatic tire of FIG. 1 . FIG. 2 is an equatorial cross-sectional view that illustrates the pneumatic tire of FIG. 1 . 2 is an enlarged cross-sectional view showing a transponder embedded in the pneumatic tire of FIG. 1. 1A and 1B are perspective views showing a transponder that can be embedded in a pneumatic tire according to the present invention. FIG. 2 is an explanatory diagram showing radial positions of transponders in a test tire.

The configuration of the present invention will be described in detail below with reference to the attached drawings. Figures 1 to 4 show a pneumatic tire according to an embodiment of the present invention.

As shown in FIG. 1, the pneumatic tire of this embodiment has a tread portion 1 that extends in the circumferential direction of the tire and forms an annular shape, a pair of sidewall portions 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3 arranged on the radially inner side of the sidewall portions 2.

Between a pair of bead portions 3, at least one carcass layer 4 (one layer in FIG. 1) is mounted, which is made of a plurality of carcass cords arranged in the radial direction. The carcass layer 4 is covered with rubber. As the carcass cords constituting the carcass layer 4, organic fiber cords such as nylon and polyester are preferably used. An annular bead core 5 is embedded in each bead portion 3, and a bead filler 6 made of a rubber composition with a triangular cross section is arranged on the outer periphery of the bead core 5.

On the other hand, multiple belt layers 7 (two layers in FIG. 1) are embedded on the tire outer circumferential side of the carcass layer 4 in the tread portion 1. The belt layers 7 include multiple reinforcing cords that are inclined with respect to the tire circumferential direction, and are arranged so that the reinforcing cords cross each other between the layers. In the belt layers 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set in the range of 10° to 40°, for example. Steel cords are preferably used as the reinforcing cords of the belt layers 7.

At least one belt cover layer 8 (two layers in FIG. 1) is arranged on the tire outer periphery side of the belt layer 7, in which reinforcing cords are arranged at an angle of, for example, 5° or less with respect to the tire circumferential direction, in order to improve high-speed durability. In FIG. 1, the belt cover layer 8 located on the inner side in the tire radial direction constitutes a full cover that covers the entire width of the belt layer 7, and the belt cover layer 8 located on the outer side in the tire radial direction constitutes an edge cover layer that covers only the ends of the belt layer 7. As the reinforcing cords of the belt cover layer 8, organic fiber cords such as nylon and aramid are preferably used.

In the above pneumatic tire, both ends 4e of the carcass layer 4 are folded back from the inside to the outside of the tire around each bead core 5, and are arranged to encase the bead core 5 and the bead filler 6. The carcass layer 4 includes a main body portion 4A that extends from the tread portion 1 through each sidewall portion 2 to each bead portion 3, and a rolled-up portion 4B that is rolled up around the bead core 5 in each bead portion 3 and extends toward each sidewall portion 2.

An inner liner layer 9 is disposed along the carcass layer 4 on the inner surface of the tire. A cap tread rubber layer 11 is disposed in the tread portion 1, a sidewall rubber layer 12 is disposed in the sidewall portion 2, and a rim cushion rubber layer 13 is disposed in the bead portion 3.

In addition, in the above pneumatic tire, a transponder 20 is embedded in a portion on the outer side of the carcass layer 4 in the tire width direction. The transponder 20 extends along the tire circumferential direction. The transponder 20 may be arranged so as to be inclined in the range of -10° to 10° with respect to the tire circumferential direction. As shown in FIG. 4, the transponder 20 is covered by a covering layer 23. This covering layer 23 covers the entire transponder 20 by sandwiching both the front and back sides of the transponder 20. The covering layer 23 may be made of a rubber having the same physical properties as the rubber constituting the sidewall rubber layer 12 or the rim cushion rubber layer 13, or may be made of a rubber having different physical properties.

As the transponder 20, for example, an RFID (Radio Frequency Identification) tag can be used. As shown in Figs. 5(a) and (b), the transponder 20 has an IC board 21 that stores data and an antenna 22 that transmits and receives data in a non-contact manner. By using such a transponder 20, information about the tire can be written or read at appropriate times, and the tire can be managed efficiently. RFID is an automatic recognition technology that is composed of a reader/writer with an antenna and a controller, and an ID tag with an IC board and an antenna, and can wirelessly communicate data.

The overall shape of the transponder 20 is not particularly limited, and may be, for example, columnar or plate-shaped as shown in Figs. 5(a) and (b). In particular, the columnar transponder 20 shown in Fig. 5(a) is preferable because it can follow the deformation of the tire in each direction. In this case, the antenna 22 of the transponder 20 protrudes from both ends of the IC board 21 and has a spiral shape. This allows it to follow the deformation of the tire during driving, improving the durability of the transponder 20. Furthermore, communication can be ensured by appropriately changing the length of the antenna 22.

In a pneumatic tire configured in this manner, the secant modulus of elasticity at 20°C at 10% deformation of the coating layer 23 that covers the transponder 20 is set to a range of 0.5 MPa to 5.0 MPa. In particular, it is preferable that the secant modulus of elasticity at 20°C at 10% deformation of the coating layer 23 be in the range of 2.0 MPa to 4.0 MPa.

In the above-mentioned pneumatic tire, the transponder 20 is covered by the covering layer 23, and the secant modulus of elasticity at 20°C at 10% deformation of the covering layer 23 is set within the above-mentioned range, so that the covering layer 23 can fully protect the transponder 20 while avoiding stress concentration near the edges of the covering layer 23. This makes it possible to improve the durability of the transponder 20 while ensuring the durability of the tire.

Here, if the secant modulus of elasticity at 20°C at 10% deformation of the coating layer 23 is lower than the lower limit, the coating layer 23 is excessively soft, and is compressed as the tire deforms, making the transponder 20 more susceptible to damage. Conversely, if the secant modulus of elasticity at 20°C at 10% deformation of the coating layer 23 is higher than the upper limit, stress concentration occurs near the edge of the coating layer 23 when the tire deforms, making it easier for peeling to occur at the interface between the coating layer 23 and the rubber member adjacent to the coating layer 23.

Furthermore, in the above-mentioned pneumatic tire, the transponder 20 is embedded outside the carcass layer 4 in the tire width direction, so there is no tire component that blocks radio waves when the transponder 20 communicates, and the communication properties of the transponder 20 can be ensured well. When the transponder 20 is embedded outside the carcass layer 4 in the tire width direction, the transponder 20 can be disposed between the rolled-up portion 4B of the carcass layer 4 and the rim cushion rubber layer 13, or between the carcass layer 4 and the sidewall rubber layer 12. As another structure, the transponder 20 can also be disposed between the rolled-up portion 4B of the carcass layer 4 and the bead filler 6, or between the main body portion 4A of the carcass layer 4 and the bead filler 6.

In the above-mentioned pneumatic tire, the storage modulus E'c (20°C) of the coating layer 23 at 20°C is preferably in the range of 2 MPa to 12 MPa. By setting the physical properties of the coating layer 23 in this way, the durability of the transponder 20 can be effectively improved.

Here, if the storage modulus E'c (20°C) of the coating layer 23 at 20°C is lower than the lower limit, the rigidity of the coating layer 23 will be low, and the protective properties will be reduced. Conversely, if the storage modulus E'c (20°C) of the coating layer 23 at 20°C is higher than the upper limit, the rigidity of the coating layer 23 will be high, the coating layer 23 will be brittle, and the coating layer 23 will be more likely to break, which will make the transponder 20 more likely to be damaged.

It is preferable that the storage modulus E'c (20°C) of the coating layer 23 at 20°C and the storage modulus E'c (60°C) of the coating layer 23 at 60°C satisfy the relationship 1.0≦E'c (20°C)/E'c (60°C)≦1.5. By setting the physical properties of the coating layer 23 in this way, the temperature dependency of the coating layer 23 becomes low (the coating layer 23 is less likely to generate heat), so that the coating layer 23 does not soften even if the tire temperature rises during high-speed driving, and the durability of the transponder 20 can be effectively improved.

In the above-mentioned pneumatic tire, among the rubber members (sidewall rubber layer 12 and rim cushion rubber layer 13 in FIG. 1) located on the outer side of the transponder 20 in the tire width direction, the rubber member (hereinafter sometimes referred to as the outer member) with the largest storage modulus E'out (20°C) at 20°C corresponds to the rim cushion rubber layer 13. Note that the rubber member (outer member) with the largest storage modulus at 20°C does not include the covering layer 23 that covers the transponder 20.

In a structure in which the transponder 20 is embedded outside the carcass layer 4 in the tire width direction, it is preferable that the storage modulus E'out (20°C) at 20°C of the outer member and the storage modulus E'c (20°C) at 20°C of the covering layer 23 satisfy the relationship 0.1≦E'c (20°C)/E'out (20°C)≦1.5. In particular, it is preferable that the relationship 0.15≦E'c (20°C)/E'out (20°C)≦1.30 is satisfied. This makes it possible to effectively improve the durability of the transponder 20 while ensuring the durability of the tire.

Here, if the value of E'c(20°C)/E'out(20°C) is smaller than the lower limit, the rigidity of the coating layer 23 decreases, and the protective properties decrease. Conversely, if the value of E'c(20°C)/E'out(20°C) is larger than the upper limit, the rigidity of the coating layer 23 increases, the coating layer 23 becomes brittle, and the coating layer 23 becomes more susceptible to fracture, which makes the transponder 20 more susceptible to damage.

The coating layer 23 is preferably composed of rubber or elastomer and 20 phr or more of white filler. By configuring the coating layer 23 in this manner, the dielectric constant of the coating layer 23 can be made relatively low compared to when carbon is contained, and the communication properties of the transponder 20 can be effectively improved. In this specification, "phr" means parts by weight per 100 parts by weight of the rubber component (elastomer).

The white filler constituting the coating layer 23 preferably contains 20 phr to 55 phr of calcium carbonate. This allows the relative dielectric constant of the coating layer 23 to be relatively low, effectively improving the communication performance of the transponder 20. However, if the white filler contains an excessive amount of calcium carbonate, it becomes brittle and the strength of the coating layer 23 decreases, which is not preferable. In addition to calcium carbonate, the coating layer 23 can optionally contain 20 phr or less of silica (white filler) or 5 phr or less of carbon black. When a small amount of silica or carbon black is used in combination, the relative dielectric constant of the coating layer 23 can be reduced while maintaining the strength of the coating layer 23.

The dielectric constant of the coating layer 23 is preferably 7 or less, and more preferably 2 to 5. By appropriately setting the dielectric constant of the coating layer 23 in this way, radio wave permeability when the transponder 20 emits radio waves can be ensured, and the communication performance of the transponder 20 can be effectively improved. The dielectric constant of the rubber constituting the coating layer 23 is 860 MHz to 960 MHz at room temperature. Here, the room temperature conforms to the standard conditions of the JIS standard, which are 23±2°C and 60%±5% RH. The dielectric constant of the rubber is measured by the capacitance method after being treated at 23°C and 60% RH for 24 hours. The above-mentioned range of 860 MHz to 960 MHz corresponds to the currently allocated frequency of UHF RFID, but if the above-mentioned allocated frequency is changed, the dielectric constant of the range of the allocated frequency can be specified as above.

The thickness t of the covering layer 23 is preferably 0.5 mm to 3.0 mm, and more preferably 1.0 mm to 2.5 mm. Here, the thickness t of the covering layer 23 is the rubber thickness at a position including the transponder 20, and is, for example, the rubber thickness obtained by adding up the thickness t1 and the thickness t2 on a straight line passing through the center of the transponder 20 and perpendicular to the tire surface (in FIG. 4, the tire outer surface) as shown in FIG. 4. By appropriately setting the thickness t of the covering layer 23 in this way, the communication performance of the transponder 20 can be effectively improved without causing unevenness on the tire surface. Here, if the thickness t of the covering layer 23 is thinner than 0.5 mm, the effect of improving the communication performance of the transponder 20 cannot be obtained, and conversely, if the thickness t of the covering layer 23 exceeds 3.0 mm, unevenness occurs on the tire surface, which is undesirable in terms of appearance. The cross-sectional shape of the covering layer 23 is not particularly limited, but for example, a triangle, a rectangle, a trapezoid, or a spindle shape can be adopted. The covering layer 23 in FIG. 4 has a substantially spindle-shaped cross-sectional shape.

In the above pneumatic tire, the transponder 20 is preferably arranged between a position P1 15 mm outward in the tire radial direction from the upper end 5e (the outer end in the tire radial direction) of the bead core 5 and a position P2 at which the tire is at its maximum width, as an arrangement region in the tire radial direction. That is, the transponder 20 is preferably arranged in the region S1 shown in FIG. 2. When the transponder 20 is arranged in the region S1, the transponder 20 is located in an area where the stress amplitude during running is small, so that the durability of the transponder 20 can be effectively improved, and further, the durability of the tire is not reduced. Here, if the transponder 20 is arranged on the inner side in the tire radial direction than the position P1, the transponder 20 tends to be close to metal members such as the bead core 5, and therefore the communication performance of the transponder 20 tends to deteriorate. On the other hand, if the transponder 20 is arranged on the outer side in the tire radial direction than the position P2, the transponder 20 is located in an area where the stress amplitude during running is large, and the transponder 20 itself is easily damaged, and the interfacial peeling around the transponder 20 is likely to occur, which is not preferable.

As shown in FIG. 3, there are a number of splice sections on the circumference of the tire, which are formed by overlapping the ends of tire constituent members. FIG. 3 shows the tire circumferential position Q of each splice section. It is preferable that the center of the transponder 20 is located 10 mm or more away from the splice section of the tire constituent member in the tire circumferential direction. That is, the transponder 20 is preferably located in the region S2 shown in FIG. 3. Specifically, it is preferable that the IC board 21 constituting the transponder 20 is located 10 mm or more away from the position Q in the tire circumferential direction. Furthermore, it is more preferable that the entire transponder 20 including the antenna 22 is located 10 mm or more away from the position Q in the tire circumferential direction, and it is most preferable that the entire transponder 20 in a state covered with the covering rubber is located 10 mm or more away from the position Q in the tire circumferential direction. In addition, it is preferable that the tire constituent member located away from the transponder 20 is the sidewall rubber layer 12 or the rim cushion rubber layer 13, or the carcass layer 4, which are located adjacent to the transponder 20. By positioning the transponder 20 away from the splice portion of the tire components in this way, tire durability can be effectively improved.

In the embodiment of FIG. 3, the tire circumferential positions Q of the splice portions of each tire component are arranged at equal intervals, but this is not limited to the embodiment. The tire circumferential positions Q can be set at any position, and in any case, the transponder 20 is arranged so as to be 10 mm or more away from the splice portions of each tire component in the tire circumferential direction.

As shown in FIG. 4, the distance d between the cross-sectional center of the transponder 20 and the tire surface is preferably 1 mm or more. By separating the transponder 20 from the tire surface in this manner, the durability of the tire can be effectively improved and the tire's resistance to external damage can be improved. In the embodiment of FIG. 4, the distance d is the distance between the cross-sectional center of the transponder 20 and the tire outer surface, but when the transponder 20 is positioned close to the inner liner layer 9, the distance d is the distance between the cross-sectional center of the transponder 20 and the tire inner surface. In particular, the distance d between the cross-sectional center of the transponder 20 and the tire outer surface is preferably 2 mm or more.

In the above embodiment, an example is shown in which the terminal 4e of the turned-up portion 4B of the carcass layer 4 is positioned near the upper end 6e of the bead filler 6, but this is not limited to this, and the terminal 4e of the turned-up portion 4B of the carcass layer 4 can be positioned at any height.

In a pneumatic tire with a tire size of 265/40ZR20 and a tread portion extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on the tire radial inner side of these sidewall portions, a transponder is embedded outside the carcass layer in the tire width direction, and the transponder is covered by a coating layer. Tires of Comparative Examples 1-2 and Examples 1-11 were manufactured with the tire radial position of the transponder, the secant modulus of elasticity at 20°C at 10% deformation of the coating layer, the storage modulus of the coating layer E'c (20°C), E'c (20°C)/E'out (20°C), the relative dielectric constant of the coating layer, and the thickness of the coating layer set as shown in Table 1.

In Comparative Examples 1-2 and Examples 1-11, a columnar transponder was used, the distance in the tire circumferential direction from the center of the transponder to the splice portion of the tire constituent member was set to 10 mm, and the distance from the center of the cross section of the transponder to the outer surface of the tire was set to 2 mm or more.

In Table 1, the radial positions of the transponders correspond to positions A through E shown in Figure 6.

These test tires were evaluated for tire durability and transponder performance (communication and durability) using the following test methods, and the results are shown in Table 1.

Durability (tires and transponders):
Each test tire was mounted on a standard rim wheel, and a running test was performed using a drum test machine under conditions of an air pressure of 120 kPa, 102% of the maximum load, and a running speed of 81 km, and the running distance when the tire broke was measured. The evaluation results were expressed as an index with Comparative Example 1 being 100. The higher the index value, the better the durability of the tire. Furthermore, for each test tire after the run, the transponder was checked for communication and damage, and the case where communication was possible and there was no damage was indicated as "◎ (excellent)", the case where communication was possible but there was damage was indicated as "○ (good)", and the case where communication was impossible was indicated as "× (not possible)".

Communication (transponder):
For each test tire, a reader/writer was used to carry out communication with the transponder. Specifically, the longest distance over which communication was possible was measured with the reader/writer output at 250 mW and a carrier frequency of 860 MHz to 960 MHz. The evaluation results were expressed as an index with Comparative Example 1 being 100. The higher the index value, the better the communication performance.

As can be seen from Table 1, the pneumatic tires of Examples 1 to 11 had a well-balanced improvement in tire durability and transponder durability compared to Comparative Examples 1 and 2.

In Comparative Example 1, the secant modulus of elasticity at 20°C at 10% deformation of the coating layer was too low, so the durability of the transponder was poor. In Comparative Example 2, the secant modulus of elasticity at 20°C at 10% deformation of the coating layer was too high, so the durability of the tire was poor.

REFERENCE SIGNS LIST 1 tread portion 2 sidewall portion 3 bead portion 4 carcass layer 5 bead core 6 bead filler 7 belt layer 12 sidewall rubber layer 13 rim cushion rubber layer 20 transponder 23 covering layer CL tire center line

Claims (8)

A pneumatic tire including a tread portion extending in a circumferential direction of the tire to form an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on the radially inner side of the sidewall portions,
a transponder is embedded in a tire, the transponder is covered with a covering layer, and a secant elastic modulus at 20°C at 10% deformation of the covering layer is in a range of 0.5 MPa to 5.0 MPa;
the storage modulus E'c(20°C) of the coating layer at 20°C is in the range of 2 MPa to 12 MPa;
the transponder is embedded outside of the carcass layer in the tire width direction, a storage modulus E'c(20°C) of the covering layer at 20°C and a storage modulus E'out(20°C) of a rubber member having the largest storage modulus at 20°C among rubber members located outside of the transponder in the tire width direction satisfy a relationship of 0.1≦E'c(20°C)/E'out(20°C)≦1.5,
A pneumatic tire, characterized in that the center of the transponder is disposed 10 mm or more away from the splice portion of the tire constituent members in the tire circumferential direction . The pneumatic tire according to claim 1, characterized in that the dielectric constant of the coating layer is 7 or less. 3. The pneumatic tire according to claim 1, wherein the coating layer is made of a rubber or elastomer and 20 phr or more of a white filler. 4. The pneumatic tire of claim 3 , wherein the white filler comprises 20 phr to 55 phr of calcium carbonate. 5. The pneumatic tire according to claim 1 , wherein the transponder is disposed between a position 15 mm radially outward from an upper end of a bead core of the bead portion and a maximum width position of the tire. 6. The pneumatic tire according to claim 1 , wherein the distance between the center of a cross section of the transponder and the surface of the tire is 1 mm or more. The pneumatic tire according to any one of claims 1 to 6 , characterized in that the covering layer has a thickness of 0.5 mm to 3.0 mm. 8. The pneumatic tire according to claim 1 , wherein the transponder has an IC board for storing data and an antenna for transmitting and receiving data, and the antenna is spiral-shaped.

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