tire

Abstract

We provide a tire that improves tire durability while also improving the communication capabilities of the transponder. [Solution] In a standard grounding state, the tire cross section at the position directly below the ground and the tire cross section at the position opposite to the position directly below the ground are superimposed, and the intersection point Pa where the carcass bodies 4A at the position directly below the ground and the position opposite to the position directly below the ground intersect at the sidewall portion 2, the intersection point Pb between the radial line Lr at the position directly below the ground and the carcass body 4A, the peripheral A of the carcass body 4A between the intersection point Pa and the intersection point Pb at the position directly below the ground, the point Pc on the carcass body 4A at the position directly below the ground moved from the intersection point Pa in the opposite direction to the intersection point Pb by a length of twice the peripheral A, and the intersection point Pd of the straight lines Lb and Lc drawn perpendicular to the carcass body 4A passing through the intersection point Pb and point Pc at the position directly below the ground, are identified, and the transponder 20 is embedded in the region S defined by the straight lines Lb and Lc at the sidewall portion 2 of the tire cross section directly below the ground.

Description

[Technical Field]

[0001] The present invention relates to a tire in which a transponder is embedded, and more particularly to a tire that improves the durability of the tire while improving the communication performance of the transponder. [Background technology]

[0002] In pneumatic tires, it has been proposed to embed RFID tags (transponders) within the tire (see, for example, Patent Document 1). However, in tires with embedded transponders in this way, there is a problem that the transponder and the tire may fail due to differences in rigidity between the transponder and the tire components, or due to deformation of the tire itself. On the other hand, if the transponder is embedded in a location close to the carcass layer, which is made of highly rigid steel cord, there is a problem that the communication performance of the transponder deteriorates. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-137510 [Overview of the project] [Problems that the invention aims to solve]

[0004] The objective of the present invention is to provide a tire that improves tire durability while improving the communication performance of the transponder. [Means for solving the problem]

[0005] The present invention, for achieving the above objective, comprises a tread portion extending in the circumferential direction of the tire and forming an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a pair of bead portions arranged radially inward of the sidewall portions, wherein a carcass layer containing a plurality of steel cords is mounted between the pair of bead portions, and the carcass layer is wound up from the inside to the outside of the tire around the bead core of each bead portion, and the tire comprises a carcass body extending between the pair of bead cores and a winding portion connected to the carcass body, wherein in a standard contact state in which the tire is assembled to a regular rim, filled with regular internal pressure, and subjected to a load of 100% of the regular load and statically in contact with a plane, the centerlines of each tire coincide with the tire cross-section at the position directly below the ground contact point and the tire cross-section at the opposite position directly below the ground contact point, and the central portions of the tread surfaces of each tread portion are in contact. The carcass bodies are superimposed in such a manner, and the intersection point Pa where the carcass bodies at the ground contact position and the opposing ground contact position intersect at the sidewall portion is identified, the intersection point Pb between the carcass body and a radial line drawn in the tire radial direction from the end of the winding portion at the ground contact position is identified, the peripheral A of the carcass body between the intersection point Pa and the intersection point Pb at the ground contact position is identified, the point Pc on the carcass body at the ground contact position is moved from the intersection point Pa in the opposite direction to the intersection point Pb by a length of twice the peripheral A, and the intersection point Pd of the straight lines Lb and Lc drawn perpendicular to the carcass body passing through the intersection point Pb and point Pc at the ground contact position is identified, and the transponder is embedded in the region defined by the straight lines Lb and Lc on the sidewall portion of the tire cross section at the ground contact position. [Effects of the Invention]

[0006] The inventors of this invention conducted extensive research on tires in which transponders are embedded, based on evaluations using actual tires and simulations. As a result, they discovered that the positional relationship between the transponder and the tire components greatly affects durability and communication performance, leading to the present invention.

[0007] In other words, in this invention, when embedding a transponder in a tire, the transponder is embedded in a region defined by straight lines Lb and Lc, which are determined by superimposing the tire cross-section at the position directly below the ground contact point in the standard ground contact condition with the tire cross-section at the position opposite to the ground contact point. Since this region is a region where the strain on the tire is small, embedding a transponder in this region does not worsen the durability of the tire. Moreover, the transponder can be positioned at a distance from the winding end of the carcass layer. This makes it possible to improve the durability of the tire while improving the communication performance of the transponder.

[0008] In the tire of the present invention, it is preferable that the transponder is positioned outside the carcass layer in the tire width direction. This effectively improves the communication performance of the transponder.

[0009] It is preferable that the transponder be positioned in the region defined by the straight lines Ld and Lb drawn from the tire's maximum width position toward the intersection point Pd at the point directly below the tire's contact point in a standard contact condition. This allows the transponder to be separated from the tread surface, thereby preventing damage to the transponder due to tire trauma or impact during contact, and improving the transponder's durability.

[0010] The minimum distance between the transponder and the outer surface of the tire is preferably in the range of 3 mm to 15 mm. This allows the transponder to be separated from the outer surface of the tire, thereby preventing damage to the transponder due to tire stress and effectively improving the durability of the transponder.

[0011] In a standard contact condition, the height of the carcass layer's raised edge at the point directly opposite the point of contact is preferably in the range of 1.1 to 3.5 times the height of the rim flange. This effectively improves the tire's durability.

[0012] In the region defined by the straight lines Lb and Lc specified in the side wall portion directly below the ground connection, the number of steel cords measured in a direction orthogonal to the extension direction of the steel cords in the carcass layer is preferably 20 cords / 50 mm to 45 cords / 50 mm. Thereby, while effectively improving the communication performance of the transponder, the durability of the tire can be effectively improved.

[0013] The transponder is covered by a coating layer, and the coating layer is preferably composed of a rubber or elastomer containing 20 phr or more of a white filler. Thereby, compared with the case of containing carbon, the relative permittivity of the coating layer can be lowered, and the communication performance of the transponder can be effectively improved.

[0014] The white filler preferably contains 20 phr to 55 phr of calcium carbonate. Thereby, the relative permittivity of the coating layer can be lowered, and the communication performance of the transponder can be effectively improved.

[0015] The transponder is covered by a coating layer, and the storage elastic modulus E'c(20°C) of the coating layer at 20°C and the storage elastic modulus E'a(20°C) of the rubber member adjacent to the outside in the tire width direction of the transponder preferably satisfy the relationship of 0.15 ≦ E'c(20°C) / E'a(20°C) ≦ 1.30. Thereby, since the physical properties of the coating layer and the rubber member adjacent to the coating layer become close, the stress dispersion effect during running can be obtained, and the durability of the transponder can be effectively improved.

[0016] A bead filler is disposed on the outer periphery of the bead core of each bead portion. The bead filler is composed of a lower filler disposed adjacent to the outside in the tire radial direction of the bead core and an upper filler disposed adjacent to the outside in the tire radial direction of the lower filler. The upper filler has a lower modulus than the lower filler, and the transponder is preferably disposed so as to abut on the upper filler. Thereby, since the stress is relaxed, the durability of the transponder can be improved.

[0017] A bead filler is placed on the outer circumference of the bead core of each bead section, and the tire cross-sectional height h SEC and the height of the bead filler h BF This means that 0.35 ≤ h BF / h SEC It is preferable that the relationship ≤ 0.55 is satisfied, and 0.40 ≤ h BF / h SEC It is more preferable to satisfy the relationship ≤0.50. This allows for an effective improvement in tire durability.

[0018] In this invention, each dimension is measured when the tire is mounted on a standard rim and filled to the standard internal pressure. "Standard rim" refers to the rim defined for each tire by the standard, which includes the standard on which the tire is based. For example, it is the standard rim for JATMA, the "Design Rim" for TRA, or the "Measuring Rim" for ETRTO. "Standard internal pressure" refers to the air pressure defined for each tire by the standard, which includes the standard on which the tire is based. For JATMA, it is the maximum air pressure. For TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES". For ETRTO, it is "INFLATION PRESSURE". "Standard load" refers to the load defined for each tire by the standard, which includes the standard on which the tire is based. For JATMA, it is the maximum load capacity. For TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES". For ETRTO, it is "LOAD CAPACITY".

[0019] In this invention, the storage modulus E' is measured in accordance with JIS K6394:2007 using a viscoelastic spectrometer under the specified conditions of tensile deformation mode, temperature, frequency of 10 Hz, initial strain of 10%, and dynamic strain of ±2%. [Brief explanation of the drawing]

[0020] [Figure 1] This is a meridian cross-sectional view showing a heavy-duty pneumatic tire according to an embodiment of the present invention. [Figure 2] Figure 1 is a cross-sectional view showing the bead portion of a pneumatic tire. [Figure 3] Figure 1 is a cross-sectional view showing a standard contact condition that satisfies predetermined conditions when the pneumatic tire is mounted on the rim. [Figure 4] (a) and (b) are superimposed images of the tire cross-section at the position directly below the ground contact point and the tire cross-section at the opposite position directly below the ground contact point of the pneumatic tire in Figure 3. (a) shows the entirety of both tire cross-sections, and (b) shows the main part of the tire cross-section at the position directly below the ground contact point. [Figure 5] (a) and (b) show examples of transponders usable in the present invention, where (a) is a perspective view and (b) is a cross-sectional view. [Modes for carrying out the invention]

[0021] The configuration of the present invention will be described in detail below with reference to the attached drawings. Figures 1 to 4 show a heavy-duty pneumatic tire according to an embodiment of the present invention.

[0022] As shown in Figure 1, the pneumatic tire T of this embodiment comprises 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 radially inward of these sidewall portions 2.

[0023] Between a pair of bead sections 3, at least one carcass layer 4 (one layer in Figure 1) is mounted, consisting of multiple carcass cords arranged radially. This carcass layer 4 includes multiple carcass cords (steel cords) extending in the tire's radial direction and has a structure that is wound up from the inside to the outside of the tire around the bead core 5 located in each bead section 3. Therefore, the carcass layer 4 has a carcass body 4A extending between the pair of bead cores 5 and a winding portion 4B connected to this carcass body 4A. A bead filler 6 made of a rubber composition with a triangular cross-section is arranged on the outer circumference of the bead core 5. The bead filler 6 consists of a lower filler 6A that abuts the bead core 5 and an upper filler 6B located radially outside the lower filler 6A, with the upper filler 6B being softer than the lower filler 6A.

[0024] Multiple belt layers (four in Figure 1) are embedded on the radially outer side of the carcass layer 4 in the tread section 1. Each belt layer 7 contains multiple belt cords (steel cords) that are inclined with respect to the circumferential direction of the tire. These belt layers 7 consist of two central main belt layers 72 and 73 where the belt cords intersect each other, and auxiliary belt layers 71 and 74 positioned inside and outside these main belt layers 72 and 73 in the radial direction of the tire. The inclination angle of the belt cords constituting the main belt layers 72 and 73 with respect to the circumferential direction of the tire is set to a range of, for example, 10° to 35°, and the inclination angle of the belt cords constituting the auxiliary belt layers 71 and 74 with respect to the circumferential direction of the tire is set to a range of, for example, 10° to 75°.

[0025] As shown in Figure 2, each bead portion 3 has a steel reinforcement layer 8 containing multiple reinforcing cords (steel cords) arranged to enclose the carcass layer 4, bead core 5, and bead filler 6. Two organic fiber reinforcement layers 9 are arranged on the outer side of the steel reinforcement layer 8 in the tire width direction. Each of the organic fiber reinforcement layers 9 contains multiple organic fiber cords (e.g., nylon cords) aligned in one direction, and these organic fiber cords constituting the organic fiber reinforcement layers 9 are oriented to intersect each other between layers.

[0026] The positional relationship between the end 4e of the carcass layer 4 and the end 8e of the steel reinforcement layer 8 is not limited to those shown in Figures 1-4. Alternatively, the end 4e of the carcass layer 4 can be positioned inward in the tire width direction compared to the outer end 8e of the steel reinforcement layer 8 in the width direction, and the end 4e of the carcass layer 4 can be positioned outward in the tire radial direction compared to both ends 8e of the steel reinforcement layer 8.

[0027] In the above-described pneumatic tire, a tread rubber layer 11 exposed to the outer surface of the tire is arranged in the tread portion 1, a side rubber layer 12 exposed to the outer surface of the tire is arranged in the sidewall portion 2, and a rim cushion rubber layer 13 exposed to the outer surface of the tire is arranged in the bead portion 3. In addition, an inner liner layer 14 is arranged inside the carcass layer 4, along the carcass body 4A of the carcass layer 4, and is exposed to the inner surface of the tire.

[0028] In the above-described pneumatic tire, a transponder 20 is embedded in the tire. More preferably, the transponder 20 is embedded in the sidewall portion 2 or the bead portion 3. The transponder 20 only needs to be located at one point in the sidewall portion 2 or the bead portion 3 on at least one side. Furthermore, it is preferable that the transponder 20 is arranged to extend along the circumferential direction of the tire.

[0029] When embedding the transponder 20 in the tire, the transponder 20 is positioned as follows. The pneumatic tire T shown in Figure 3 is mounted on a regular rim, filled with the regular internal pressure, and subjected to a load of 100% of the regular load, and is in static contact with the plane M. This state is defined as the standard contact state. In this standard contact state, the position on the lower side of the rim R is defined as the position directly below the contact point, and the position on the upper side of the rim R (i.e., opposite the position directly below the contact point) is defined as the position opposite the position directly below the contact point. In other words, the position directly below the contact point and the position opposite the position directly below the contact point are circumferential positions on the circumference of the tire in the standard contact state that face each other, and each position can be identified by the lower and upper cross-sections when the entire tire is cut in a plane perpendicular to the plane M and containing the tire rotation axis.

[0030] In this standard grounding condition, at the position directly below the ground and the position opposite the ground, as shown in Figures 4(a) and (b), the tire cross-section at the position directly below the ground (solid line cross-section in Figure 4(a)) and the tire cross-section at the position opposite the ground (dashed line cross-section in Figure 4(a)) are superimposed so that the centerlines CL of each tire coincide and the central parts of the tread surfaces of each tread section 1 are in contact, and various points and lines are identified as follows. Specifically, the point where the carcass bodies 4A at the ground contact position and the opposite ground contact position intersect each other at the sidewall portion 2 is defined as intersection Pa, the intersection point of the radial line Lr drawn from the end 4e of the winding portion 4B at the ground contact position in the tire radial direction with the carcass body 4A is defined as intersection Pb, the carcass peripheral of the carcass body 4A between intersection Pa and intersection Pb at the ground contact position is defined as peripheral A, the point obtained by moving twice the length of peripheral A from intersection Pa to the carcass body 4A at the ground contact position in the opposite direction from intersection Pb is defined as point Pc, the lines drawn perpendicular to the carcass body 4A passing through intersection Pb and point Pc at the ground contact position are defined as line Lb and line Lc, respectively, and the intersection point of these lines Lb and line Lc is defined as intersection Pd. At this time, the transponder 20 is placed in the region S defined by line Lb and line Lc on the sidewall portion 2 of the tire cross-section at the ground contact position. In Figure 4(b), the shaded area within the tire cross-section directly below the ground contact point indicates the region S where the transponder 20 can be placed, based on the provisions described above.

[0031] In the area where the transponder 20 can be placed, it is preferable to place the transponder 20 outside the carcass layer 4 in the tire width direction, particularly from the viewpoint of improving the communication performance of the transponder 20. This means placing it in a more limited area outside the carcass body 4A of the carcass layer 4 in the tire width direction, as shown in the shaded area of ​​Figure 4(b). By placing it in such a limited area, the carcass layer 4, which is made of steel cords, becomes less susceptible to interference during communication of the transponder 20.

[0032] For example, an RFID (Radio Frequency Identification) tag can be used as the transponder 20. As shown in Figures 5(a) and (b), the transponder 20 has an IC board 21 for storing data and an antenna 22 for contactlessly transmitting and receiving data. By using such a transponder 20, information about tires can be written to or read in a timely manner, and tires can be managed efficiently. RFID is an automatic identification technology that consists of a reader / writer having an antenna and a controller, and an ID tag having an IC board and an antenna, and is capable of exchanging data wirelessly.

[0033] The overall shape of the transponder 20 is not particularly limited, but a columnar transponder 20 as shown in Figure 5(a) is preferable because it can follow the deformation of the tire in all directions. In this case, the antenna 22 of the transponder 20 protrudes from each end of the IC substrate 21 and has a spiral shape. This allows it to follow the deformation of the tire during driving and improves the durability of the transponder 20. Furthermore, communication can be ensured by appropriately changing the length of the antenna 22.

[0034] Furthermore, it is preferable that the entire transponder 20 is covered with a coating layer 23. This coating layer 23 covers the entire transponder 20 by sandwiching both the front and back surfaces of the transponder 20 between two rubber sheets, for example. By protecting the transponder 20 with the coating layer 23 in this way, the adhesion and durability of the transponder 20 can be improved.

[0035] In the pneumatic tire described above, the transponder 20 is embedded in the tire in a region S defined by straight lines Lb and Lc, which are determined by superimposing the tire cross-section at the position directly below the ground contact point in a standard ground contact state with the tire cross-section at the position opposite to the ground contact point. Since this region S is a region where the strain on the tire is small, embedding the transponder 20 in this region S does not worsen the durability of the tire. Moreover, the transponder 20 can be positioned at a distance from the winding end 4e of the carcass layer 4. This makes it possible to improve the durability of the tire while improving the communication performance of the transponder 20.

[0036] In the above-described pneumatic tire, it is preferable that the transponder 20 be positioned in the region defined by the straight lines Ld and Lb drawn from the tire's maximum width position P toward the intersection point Pd, at the position directly below the point of contact in the standard contact state. This region refers to the area inward in the tire radial direction (upper side of the figure) from the straight line Ld within the region S shown in Figure 4(b). By positioning the transponder 20 in this manner, the transponder 20 can be separated from the tread surface of the tread portion 1, thereby preventing damage to the transponder 20 due to tire trauma or impact during contact, and improving the durability of the transponder 20.

[0037] The shortest distance d (see Figure 2) between the transponder 20 and the outer surface of the tire should ideally be in the range of 3 mm to 15 mm. By setting this shortest distance d appropriately, the transponder 20 can be separated from the outer surface of the tire, thereby preventing damage to the transponder 20 due to tire stress and effectively improving the durability of the transponder 20.

[0038] In the standard grounding condition, at the position directly below the ground, the height h4 of the rolled-up end 4e of the carcass layer 4 is equal to the height h of the rim flange RF. RFIt is preferable that it is in the range of 1.1 times to 3.5 times with respect to (see FIG. 3). By appropriately setting the height h4 of the wound-up end portion 4e in this way, the durability of the tire can be effectively improved. Here, when it is 1.1 times or more, the effect of improving the communication performance of the transponder 20 is high, and when it is 3.5 times or less, the effect of improving the durability of the tire is high. Note that the height h RF of the rim flange RF is the height in the tire radial direction from the tire inner diameter position (i.e., the rim outer diameter position) to the outermost side in the tire radial direction of the rim flange RF, and the height h4 of the wound-up end portion 4e of the carcass layer 4 is the height in the tire radial direction from the tire inner diameter position to the wound-up end portion 4e.

[0039] Also, in the region S defined by the straight line Lb and the straight line Lc in the sidewall portion 2 directly under the ground contact, the number of steel cords of the carcass layer 4 measured in the direction orthogonal to the extension direction of the steel cords of the carcass layer 4 is preferably 20 cords / 50 mm to 45 cords / 50 mm. By appropriately setting the number of steel cords of the carcass layer 4 in this way, the durability of the tire can be effectively improved while effectively improving the communication performance of the transponder 20. Here, when the number of steel cords of the carcass layer 4 is 20 or more, the effect of improving the durability of the tire is high, and when the number of steel cords of the carcass layer 4 is 45 or less, the effect of improving the communication performance of the transponder 20 is high.

[0040] In the above pneumatic tire, the tire section height h SEC and the height h BF of the bead filler 6 preferably satisfy the relationship of 0.35 ≤ h BF / h SEC ≤ 0.55, and more preferably satisfy the relationship of 0.40 ≤ h BF / h SEC ≤ 0.50 (see FIG. 1). By appropriately setting the ratio h BF / h SEC in this way, the durability of the tire can be effectively improved. Here, the ratio h BF / h SECBy setting the ratio to 0.35 or higher, the bending rigidity near the bead portion 3 can be improved, and the strain near the bead portion 3 can be reduced, thereby improving the durability of the tire at the location where the transponder 20 is placed. BF / h SEC By setting this to 0.55 or less, the tire's durability can be improved while suppressing the concentration of strain in the flexible zone. Note that the tire section height h SEC h is the height in the radial direction of the tire, from the inner diameter position of the tire (i.e., the outer diameter position of the rim) to the maximum diameter position of the tire, and is the height of the bead filler 6. BF This is the height in the radial direction of the tire, from the inner diameter position of the tire to the upper end position of the bead filler 6.

[0041] Furthermore, the bead filler 6 is composed of a lower filler 6A and an upper filler 6B, with the upper filler 6B having a lower modulus than the lower filler 6A, and the transponder 20 is positioned to be in contact with the upper filler 6B. This relieves stress, thereby improving the durability of the transponder 20. The modulus of each filler is the tensile stress at 100% elongation measured at a temperature of 20°C, in accordance with JIS K6251:2017.

[0042] In the above-described pneumatic tire, the coating layer 23 is preferably composed of rubber or elastomer containing 20 phr or more of white filler. This allows for a lower dielectric constant of the coating layer 23 compared to the case where carbon is included, and effectively improves the communication performance of the transponder 20. In this specification, "phr" means parts by weight per 100 parts by weight of rubber component (elastomer).

[0043] The white filler constituting this coating layer 23 preferably contains calcium carbonate in a concentration of 20 phr to 55 phr. This allows the 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, reducing the strength of the coating layer 23, which is undesirable. In addition to calcium carbonate, the coating layer 23 may optionally contain silica (white filler) of 20 phr or less, or carbon black of 5 phr or less. When small amounts of silica or carbon black are used in combination, the dielectric constant of the coating layer 23 can be reduced while maintaining its strength.

[0044] In the above-described pneumatic tire, it is preferable that the storage modulus E'c(20°C) of the coating layer 23 at 20°C and the storage modulus E'a(20°C) of the rubber member adjacent to the outer side of the transponder 20 in the tire width direction (if the transponder 20 is equipped with the coating layer 23, this is the rubber member adjacent to the outer side of the coating layer 23 in the tire width direction, for example, the side rubber layer 12) satisfy the relationship 0.15 ≤ E'c(20°C) / E'a(20°C) ≤ 1.30. This makes the physical properties of the coating layer 23 and the rubber member adjacent to the coating layer 23 (for example, the side rubber layer 12) similar, thereby obtaining a stress distribution effect during driving, enhancing the protective effect of the transponder 20, and improving the durability of the transponder 20. Here, if E'c(20°C) / E'a(20°C) falls outside the above range, the stress distribution effect when the tire is used at room temperature decreases. [Examples]

[0045] In a pneumatic tire with a tire size of 245 / 70R19.5, comprising a tread section, a pair of sidewall sections, and a pair of bead sections, a carcass layer containing carcass cords made of steel cords is mounted between the pair of bead sections, four belt layers containing belt cords made of steel cords are arranged on the radially outer side of the carcass layer in the tread section, and the carcass layer is wound up from the inside to the outside of the tire around the bead core of each bead section, with a carcass body extending between the pair of bead cores and a winding section connected to the carcass body, a conventional example and tires of Examples 1 to 48 were manufactured with a transponder embedded in the tire, differing only in the structure related to the transponder.

[0046] In these conventional examples and the tires of Examples 1 to 48, the arrangement of the transponder within region S1, the positional relationship in the width direction with the carcass layer, the arrangement of the transponder within region S2, the shortest distance d, the position of the winding end of the carcass layer, the number of carcass cords, the presence or absence of a rubber coating layer, the carbon black content of the coating layer, the silica content of the coating layer, the calcium carbonate content of the coating layer, the ratio of the coating layer to the adjacent rubber member E'c(20℃) / E'a(20℃), the presence or absence of contact with the upper filler, and the ratio h BF / h SEC The parameters were set as shown in Tables 1 to 4. In the conventional example and the tires of Examples 1 to 48, the bead filler consists of a lower filler and an upper filler, with the upper filler having a lower modulus than the lower filler. In conventional tires, the transponder is located between the inner liner layer and the steel reinforcement layer, embedded near the edge of the steel reinforcement layer.

[0047] The durability and transponder communication performance of these test tires were evaluated using the following test methods, and the results are shown in Tables 1 to 4.

[0048] In Tables 1-4, "positional relationship in the width direction with respect to the carcass layer" and "presence or absence of contact with the upper filler" both indicate the positional relationship with respect to the transponder. "Placement of the transponder within region S1" means whether or not it is placed in region S defined by the straight lines Lb and Lc on the sidewall at the position directly below the ground contact point. "Placement of the transponder within region S2" means whether or not it is placed in the region of region S that is radially inward from the straight line Ld. "Position of the rolled-up end of the carcass layer" is the height h of the rim flange at the position directly opposite the ground contact point in the standard ground contact condition. RF The ratio of the height h4 of the winding end of the carcass layer to (h4 / h RF This indicates that...

[0049] The durability and transponder communication performance of these test tires were evaluated using the following test methods, and the results are shown in Tables 1 to 4.

[0050] Durability: Each test tire was mounted on a standard rim (rim size 19.5 x 7.50), inflated to 850 kPa, and mounted on a drum testing machine (drum diameter: 1707 mm). An initial load was set to 100% of the JATMA maximum load, and a running test was conducted in accordance with UN.R54 certified test conditions. The distance traveled when a tire or transponder failure occurred was measured. The evaluation results are shown as an index with the conventional example set to 100. A higher index value indicates better durability of the tire and transponder.

[0051] Transponder communication capabilities: For each test tire, communication with the transponder was performed using a reader / writer. Specifically, the longest possible communication distance was measured using a reader / writer with an output of 250mW and a carrier frequency of 860MHz to 960MHz. The evaluation results are shown as an index with the conventional example set to 100. A higher index value indicates better transponder communication performance.

[0052] [Table 1]

[0053] [Table 2]

[0054] [Table 3]

[0055] [Table 4]

[0056] As can be seen from Tables 1 to 4, the pneumatic tires of Examples 1 to 48 were able to improve the durability of the tires while improving the communication performance of the transponders compared to conventional examples.

[0057] This disclosure encompasses the following inventions [1] to

[11] . The invention [1] provides a tire comprising a tread portion extending in the circumferential direction of the tire and forming an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a pair of bead portions arranged radially inward of the sidewall portions, wherein a carcass layer containing a plurality of steel cords is mounted between the pair of bead portions, and the carcass layer is wound up from the inside to the outside of the tire around the bead core of each bead portion, and the tire comprises a carcass body extending between the pair of bead cores and a winding portion connected to the carcass body, wherein the tire is mounted on a regular rim, filled with regular internal pressure, and subjected to a load of 100% of the regular load, in a standard contact state in which the tire is statically in contact with a plane, the tire cross section at the position directly below the contact point and the tire cross section at the opposite position directly below the contact point are superimposed such that the centerlines of each tire coincide and the central portions of the tread surfaces of each tread portion are in contact, The tire is characterized in that it identifies an intersection point Pa where the carcass bodies at the position directly below the ground and the position opposite the position directly below the ground intersect at the sidewall portion, a point Pb at the intersection of a radial line drawn in the tire radial direction from the end of the winding portion at the position directly below the ground with the carcass body, a peripheral A of the carcass body between the intersection point Pa and the intersection point Pb at the position directly below the ground, a point Pc on the carcass body at the position directly below the ground moved from the intersection point Pa in the opposite direction from the intersection point Pb by a length of twice the peripheral A, and a point Pd at the intersection point Lb and Lc drawn perpendicular to the carcass body passing through the intersection point Pb and point Pc, respectively at the position directly below the ground, and a transponder is embedded in the region defined by the line Lb and the line Lc in the sidewall portion of the tire cross section at the position directly below the ground. Invention [2] is the tire according to Invention [1], characterized in that the transponder is positioned outward in the tire width direction from the carcass layer. Invention [3] is a tire according to Invention [1] or [2], characterized in that the transponder is positioned in a region defined by a straight line Ld drawn from the position of the maximum tire width toward the intersection point Pd and a straight line Lb at the position directly below the ground in the standard grounding state. Invention [4] is a tire according to any one of Inventions [1] to [3], characterized in that the shortest distance between the transponder and the outer surface of the tire is in the range of 3 mm to 15 mm. Invention [5] is a tire according to any one of Inventions [1] to [4], characterized in that, in the standard ground contact condition, the height of the rolled-up end of the carcass layer at the position directly below the ground contact point is in the range of 1.1 to 3.5 times the height of the rim flange. Invention [6] is a tire according to any one of Inventions [1] to [5], characterized in that the number of steel cords measured in a direction perpendicular to the extension direction of the steel cords of the carcass layer in the region defined by the straight line Lb and the straight line Lc identified in the sidewall portion at the position directly below the ground is 20 cords / 50 mm to 45 cords / 50 mm. Invention [7] is a tire according to any one of Inventions [1] to [6], characterized in that the transponder is covered by a coating layer, and the coating layer is made of rubber or elastomer containing 20 phr or more of white filler. Invention [8] is a tire according to Invention [7], characterized in that the white filler contains 20 phr to 55 phr of calcium carbonate. Invention [9] is a tire according to any one of Inventions [1] to [8], characterized in that the transponder is covered with a coating layer, and the storage modulus of elasticity E'c(20°C) of the coating layer at 20°C and the storage modulus of elasticity E'a(20°C) of a rubber member adjacent to the outer side of the transponder in the tire width direction satisfy the relationship 0.15 ≤ E'c(20°C) / E'a(20°C) ≤ 1.30. Invention

[10] is a tire according to any one of Inventions [1] to [9], characterized in that a bead filler is arranged on the outer circumference of the bead core of each bead portion, and the bead filler is composed of a lower filler arranged adjacent to the outer side of the bead core in the tire radial direction and an upper filler arranged adjacent to the outer side of the lower filler in the tire radial direction, the upper filler has a lower modulus than the lower filler, and the transponder is arranged to contact the upper filler. The invention

[11] is characterized in that a bead filler is placed on the outer circumference of the bead core of each bead section, and the tire section height h SEC and the height h of the bead filler BF toga 0.35 ≤ h BF / h SEC The tire is characterized by satisfying the relationship ≤ 0.55, as described in any of the inventions [1] to

[10] . [Explanation of Symbols]

[0058] 1. Tread section 2 Sidewall section 3. Bead section 4. Carcass layer 4A Carcass Body 4B Winding section 4e End (winding end) 5 Bead core 6. Bead Filler 6A Lower filler 6B Upper filler 7 Belt layer 8. Steel reinforcement layer 20 transponders CL tire centerline Lb,Lc,Ld straight line Lr radial line Pa,Pb,Pc,Pd points T pneumatic tire

Claims

1. A tire comprising a tread portion extending in the circumferential direction of the tire and forming an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a pair of bead portions arranged radially inward of these sidewall portions, wherein a carcass layer containing a plurality of steel cords is mounted between the pair of bead portions, and the carcass layer is wound up from the inside to the outside of the tire around the bead core of each bead portion, and the tire has a carcass body extending between the pair of bead cores and a winding portion connected to the carcass body, In the standard contact state, where the tire is mounted on a regular rim, filled to the regular internal pressure, and subjected to a load of 100% of the regular load, and statically in contact with a flat surface, the tire cross-section at the position directly below the contact point and the tire cross-section at the opposite position directly below the contact point are superimposed so that the centerlines of each tire coincide and the central portions of the tread surfaces of each tread are in contact. The intersection point Pa where the carcass bodies at the ground-level position and the opposing ground-level position intersect at the sidewall portion, The intersection point Pb of the radial line drawn from the end of the winding portion at the position directly below the ground contact point in the tire radial direction with the carcass body, The peripheral A of the carcass body between the intersection Pa and the intersection Pb at the position directly below the ground, On the carcass body at the position directly below the ground, a point Pc is obtained by moving from the intersection Pa to a point Pb in the opposite direction to the intersection Pb by a length twice the length of the peripheral A, Identify the intersection point Pd of the straight line Lb and the straight line Lc drawn perpendicularly to the carcass body, passing through the intersection point Pb and point Pc at the grounding position, A tire characterized in that a transponder is embedded in the sidewall portion of the tire cross-section at the position directly below the ground contact point, in a region defined by the straight line Lb and the straight line Lc.

2. The tire according to claim 1, characterized in that the transponder is positioned outward in the tire width direction from the carcass layer.

3. The tire according to claim 1 or 2, characterized in that the transponder is positioned in a region defined by a straight line Ld and a straight line Lb drawn from the tire's maximum width position toward the intersection point Pd at the position directly below the ground in the standard grounding state.

4. The tire according to claim 1, characterized in that the shortest distance between the transponder and the outer surface of the tire is in the range of 3 mm to 15 mm.

5. The tire according to claim 1 or 2, characterized in that, at the position directly below the ground in the standard grounding condition, the height of the rolled-up end of the carcass layer is in the range of 1.1 to 3.5 times the height of the rim flange.

6. The tire according to claim 1 or 2, characterized in that the number of steel cords measured in a direction perpendicular to the extension direction of the steel cords of the carcass layer in the region defined by the straight line Lb and the straight line Lc identified in the sidewall portion at the position directly below the ground is 20 cords / 50 mm to 45 cords / 50 mm.

7. The tire according to claim 1 or 2, characterized in that the transponder is covered by a coating layer, and the coating layer is made of rubber or elastomer containing 20 phr or more of white filler.

8. The tire according to claim 7, characterized in that the white filler contains 20 phr to 55 phr of calcium carbonate.

9. The tire according to claim 1 or 2, characterized in that the transponder is covered with a coating layer, and the storage modulus of elasticity E'c(20°C) of the coating layer at 20°C and the storage modulus of elasticity E'a(20°C) of a rubber member adjacent to the outer side of the transponder in the tire width direction satisfy the relationship 0.15 ≤ E'c(20°C) / E'a(20°C) ≤ 1.

30.

10. The tire according to claim 1 or 2, wherein a bead filler is arranged on the outer circumference of the bead core of each bead portion, and the bead filler is composed of a lower filler arranged adjacent to the outer side of the bead core in the tire radial direction and an upper filler arranged adjacent to the outer side of the lower filler in the tire radial direction, wherein the upper filler has a lower modulus than the lower filler and the transponder is arranged to contact the upper filler.

11. A bead filler is placed on the outer circumference of the bead core of each bead section, and the tire cross-sectional height h SEC and the height h of the bead filler BF toga 0.35 ≤ h BF / h SEC The tire according to claim 1 or 2, characterized in that it satisfies the relationship ≤ 0.55.

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