Conductive tire

Abstract

The present invention provides a tire having a tread and a pair of sidewalls extending from each of the two axial ends of the tread, at least the radially innermost ply being provided with an edge cover made of an electrically conductive rubber composition and covering at least the radially inner face of the radially innermost ply, according to the invention, the radially innermost ply is arranged in the carcass and extends up to an axial distance L, the at least one sidewall, together with the carcass, extends towards the underneath of the radially innermost ply up to an axial distance Le, the axial distance L being greater than the axial distance Le, and the edge cover provided with the radially innermost ply has a portion in contact with the carcass, the axial distance L being at least 10.0 mm greater than the axial distance Le.

Description

Technical Field

[0001] The present invention relates to a tire. In particular, the present invention relates to a tire having improved electrical conductivity while maintaining manufacturing efficiency. Background Art

[0002] At present, tires designed to run at high speeds, in particular tires for passenger vehicles, usually include an additional ply with cords oriented in the circumferential direction. This ply can be placed above the ply of the crown reinforcement at an angle that is also commonly used. In this structure, this ply with cords oriented in the circumferential direction is the radially outermost ply of the crown of the tire.

[0003] In recent years, for economic and environmental reasons, tires are required to be fuel efficient. As a means of obtaining such tires, it is of interest to reduce the rolling resistance of the tire. As a method of obtaining a tire by effectively reducing the rolling resistance, it has been proposed to reduce the hysteresis loss (which is the main cause of rolling resistance). Since the manufacture of materials with reduced hysteresis loss has a negative impact on manufacturing efficiency, tire manufacturers are seeking to maintain overall manufacturing efficiency, and one of the ways to achieve this manufacturing efficiency is to reduce the amount of semi-finished materials in the factory.

[0004] EP0931676 discloses a pneumatic tire in which, in each tire shoulder region between the sidewall region and the tread region, there is a circumferentially extending ply support strip radially arranged between the carcass ply and the innerliner, the ply support strip comprising a rubber compound and including short discontinuous fibrillated aramid fibers in an amount between 7 and 15 parts by weight per 100 parts by weight of rubber.

[0005] EP2749434 discloses a pneumatic tire comprising a pair of sidewalls, the outer ends of the sidewalls being located on the inner side of the ends of the belt layers in the axial direction so that the buffer layer is bonded together with the sidewalls. US2017 / 120682 discloses a tire comprising a crown reinforcement comprising two working crown layers having different axial widths. A layer C of a rubber compound is arranged between the ends of the working crown layers. A second layer S of a polymer compound is in contact with at least one working crown layer and a carcass reinforcement comprising a circumferential reinforcing element layer radially arranged between the two working crown layers. In the meridian plane, the distance d between the end of the axially narrowest working layer and the working layer separated by layer C is is the diameter of the reinforcing element. The second layer S is composed of a filled elastomer blend having a macroscopic dispersion coefficient Z ≥ 65 and a maximum tan (δ) value of less than 0.100. Its complex dynamic shear modulus G* measured in a return cycle at 10% and 60°C is greater than 1.35 MPa. US2014 / 230986 discloses a tire that achieves weight reduction without reducing internal pressure retention performance. The tire includes an inner liner located inside the carcass. The inner liner includes a first inner liner and a pair of second inner liners, the first inner liner extending on one bead and the other bead and extending along the inner side of the carcass between one bead and the other bead, and the pair of second inner liners extend substantially inward in the radial direction from the end of the belt layer along the first inner liner. The second inner liner is located between the first inner liner 66 and the carcass. The first inner liner is formed by a cross-linked first rubber composition. The base rubber of the first rubber composition includes butyl rubber. Each second inner liner is formed by a cross-linked second rubber composition. The base rubber of the second rubber composition includes diene rubber.

[0006] However, using the solutions disclosed in these documents, the electrical conductivity of the tire will be reduced and thus lead to exceeding the standard resistance threshold, since the sidewalls cut off the conductive path. This situation becomes particularly important when using low hysteresis loss compositions to be incorporated into the calendered mix of the belt layer. It is therefore desirable to improve the electrical conductivity of the tire by reducing the number of semi-finished products, without reducing the manufacturing efficiency of such tires.

[0007] Therefore, there is a need for a tire that provides improved conductivity by reducing the number of semi-finished products without reducing manufacturing efficiency.

[0008] definition:

[0009] A "radial direction / orientation" is a direction / orientation perpendicular to the axis of rotation of the tire. This direction / orientation corresponds to the thickness orientation of the tire.

[0010] An "axial direction / orientation" is a direction / orientation parallel to the tire's axis of rotation.

[0011] A "circumferential direction / orientation" is a direction / orientation that is tangential to any circle centered on the axis of rotation. This direction / orientation is perpendicular to the axial direction / orientation and the radial direction / orientation.

[0012] "Tyre" means all types of resilient tyres, whether or not subjected to internal pressure.

[0013] “Tread” of a tire means the mass of rubber material bounded by lateral surfaces and two major surfaces, one of which is intended to come into contact with the ground when the tire rolls.

[0014] A "ply" is a layer of material such as nylon, polyester or steel arranged parallel to each other at a given spacing in the form of cables, threads or strands and coated with a rubber material.

[0015] "Conductivity" is assessed by measuring the electrical resistance of the tire according to the WdK 110 test, with lower resistance meaning higher conductivity. Summary of the invention

[0016] It is therefore an object of the present invention to provide a tire that provides improved electrical conductivity by reducing the number of semi-finished products without reducing manufacturing efficiency.

[0017] The present invention provides a tire, the tire having a tread and a pair of sidewalls, the tread being intended to contact the ground through a contact surface during rolling, the pair of sidewalls extending from each of the two axial ends of the tread, the tire comprising at least one cord layer arranged radially inside the tread, the at least one cord layer comprising a plurality of parallel reinforcing elements, the reinforcing elements extending at an angle A relative to the tire circumferential orientation, the angle A being greater than 10 degrees, the tire further comprising a carcass arranged radially inside the at least one cord layer, at least the radially innermost cord layer of the at least one cord layer being provided with an edge covering layer, the edge covering layer being composed of The at least one sidewall is made of a conductive rubber composition and covers at least the radial innermost ply in the at least one ply and extends to an axial distance L measured from the axial end of the radial innermost ply in the at least one ply, at least one sidewall extends together with the carcass toward below the radial innermost ply in the at least one ply to an axial distance Le measured from the axial end of the radial innermost ply in the at least one ply, the axial distance L is greater than the axial distance Le, and the edge covering layer provided on the radial innermost ply in the at least one ply has a portion in contact with the carcass, and the axial distance L is at least 10.0 mm greater than the axial distance Le.

[0018] This arrangement provides improved conductivity by reducing the number of semi-finished products without reducing manufacturing efficiency.

[0019] Since at least one sidewall extends together with the carcass toward below the radially innermost ply in at least one ply layer, the sidewall can be used to replace the material arranged below the radially innermost ply in at least one ply layer having a sequential tire structure, thereby improving manufacturing efficiency by reducing the number of semi-finished products.

[0020] Since at least the radially innermost ply among at least one ply is provided with an edge cover layer which covers at least the radially inner surface of the radially innermost ply among at least one ply, separation between the ply and the carcass can be avoided, thereby improving durability performance.

[0021] Since the edge cover layer made of the conductive rubber composition provided in the radially innermost ply of at least one ply has a portion in contact with the carcass, charges can pass through the carcass through the edge cover layer, thereby improving the conductivity of the tire.

[0022] Since the axial distance L is greater than the axial distance Le by at least 10.0 mm, the electrical conductivity of the tire can be improved.

[0023] If the axial distance L is less than the axial distance Le of 10.0 mm, there is a risk that the contact between the edge cover layer and the carcass is insufficient to create a sufficient conductive path.

[0024] The distance L is preferably at least 11.0 mm greater than the axial distance Le, more preferably at least 12.0 mm greater than the axial distance Le, and still more preferably at least 15.0 mm greater than the axial distance Le.

[0025] In another preferred embodiment, the axial distance Le is at most equal to 15.0 mm.

[0026] If the axial distance Le is greater than 15.0 mm, there is a risk that the overall width of the semi-finished product for the sidewall is too large, thereby reducing manufacturing efficiency. By setting the axial distance Le to at most 15.0 mm, the manufacturing efficiency of such tires can be improved.

[0027] This axial distance Le is preferably equal to at most 13.0 mm, more preferably equal to at most 12.0 mm, still more preferably equal to at most 10.0 mm.

[0028] In another preferred embodiment, the edge cover layer further covers the axially outermost and radially outer sides of the radially innermost ply in at least one ply up to an axial distance L or less measured from the axial end of the radially innermost ply in at least one ply.

[0029] According to this arrangement, since the edge cover layer covering the axially outermost and radially outer sides can prevent not only separation between the carcass but also separation between the carcasses, durability performance can be improved.

[0030] In another preferred embodiment, the tire is provided with at least two radially adjacent plies, and each of the at least two plies is provided with an edge covering layer covering an edge portion of each ply.

[0031] According to this arrangement, since the edge cover layer covering the edge portion of each of the at least two plies can prevent not only separation between the plies and the carcass but also separation between the plies themselves, durability performance can be improved.

[0032] In another preferred embodiment, the edge cover layer of one of the radially adjacent plies has a portion in contact with the edge cover layer of the other of the radially adjacent plies.

[0033] According to this arrangement, since the edge covering layer covering the edge portion of each of the radially adjacent plies can prevent not only the separation between the plies and the carcass, but also the separation between the plies, while enhancing the conductive path leading to the carcass, the durability performance and the conductivity can be further improved simultaneously.

[0034] In another preferred embodiment, the volume resistivity of the conductive rubber composition constituting the edge cover layer is at most equal to 5.00×10 5 Ω·cm.

[0035] If the volume resistivity of the conductive rubber composition is greater than 5.00×105Ω.cm, there is a risk that the edge cover layer cannot effectively serve as a conductive path to the carcass. By setting the volume resistivity of the conductive rubber composition to at most 5.00×105Ω.cm, the conductivity of the tire can be improved.

[0036] The volume resistivity of the conductive rubber composition constituting the edge cover layer is preferably equal to at most 4.00×10 5 Ω·cm, more preferably equal to at most 3.75×10 5 Ω·cm.

[0037] In another preferred embodiment, the tire further comprises at least one electrically conductive path leading to the contact surface.

[0038] According to this arrangement, the electrical conductivity of the tyre can be further improved, since the electric charges can also reach the ground through at least one conductive path leading to the contact surface.

[0039] According to the above arrangement, it is possible to provide a tire that provides improvement in electrical conductivity by reducing the number of semi-finished products without reducing manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Other characteristics and advantages of the invention emerge from the following description made with reference to the accompanying drawings which illustrate, by way of non-limiting example, embodiments of the invention.

[0041] In these drawings:

[0042] - Figure 1 is a schematic cross-sectional view of a tire according to a first embodiment of the present invention;

[0043] - Figure 2 To display Figure 1 An enlarged schematic diagram of the portion shown in II;

[0044] - Figure 3 A tire according to a second embodiment of the present invention corresponds to Figure 1 An enlarged schematic diagram of the portion shown in II;

[0045] - Figure 4 For a tire according to the prior art corresponding to Figure 1 An enlarged schematic diagram of the portion shown in II. DETAILED DESCRIPTION

[0046] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0047] Will refer to Figure 1 and Figure 2 A tire 1 according to a first embodiment of the present invention will be described.

[0048] Figure 1 is a schematic cross-sectional view of a tire according to a first embodiment of the present invention. Figure 2 To display Figure 1 The enlarged schematic diagram of the part shown in II in FIG. Figure 1 and Figure 2 Portions other than those shown in the figure are typical radial tire structures, and thus descriptions of these portions will be omitted.

[0049] The tire 1 is a tire having a tread 4 and a pair of sidewalls 6 ( Figure 1 The tire 1 is a tire of the present invention (only one of which is shown in the figure), the tread 4 is intended to contact the ground through the contact surface 41 during rolling, the pair of sidewalls 6 extends from each of the two axial ends of the tread 4, and the tire 1 includes at least one cord layer 3 arranged radially inside the tread 4, the at least one cord layer 3 includes a plurality of parallel reinforcing elements (not shown), and the reinforcing elements extend at an angle A (not shown) relative to the tire circumferential orientation, when applied to passenger vehicle tires, the angle A is greater than 10 degrees and generally less than 45 degrees. In this embodiment, the tire 1 includes two cord layers 3a, 3b, and the angle A is 25 degrees.

[0050] like Figure 1 and Figure 2 As shown, the tire 1 further comprises a carcass 2 which is arranged radially inside the at least one carcass layer 3 .

[0051] like Figure 2As shown, at least the radially innermost ply 3a of at least one ply 3 is provided with an edge covering layer 5, which is made of a conductive rubber composition and covers at least the radially inner face of the radially innermost ply 3a of at least one ply 3 and extends to an axial distance L measured from an axial end of the radially innermost ply 3a of at least one ply 3, and at least one sidewall 6 extends together with the carcass 2 toward the bottom of the radially innermost ply 3a of at least one ply 3 to an axial distance Le measured from an axial end of the radially innermost ply 3a of at least one ply 3. The axial distance L is greater than the axial distance Le. The axial distance L is at least 10.0 mm greater than the axial distance Le. The axial distance Le is at most equal to 15.0 mm. In the present embodiment, the axial distance Le is 7.0 mm, and the axial distance L is 16.0 mm greater than the axial distance Le.

[0052] like Figure 2 As shown, the edge cover layer 5 further covers the axially outermost and radially outer sides of the radially innermost ply 3a in the at least one ply 3 up to an axial distance L or less measured from the axial end of the radially innermost ply 3a in the at least one ply 3.

[0053] like Figure 2 As shown, the radially innermost ply 3 a of at least one of the plies 3 is provided with an edge covering layer 5 having a portion in contact with the carcass 2 .

[0054] The volume resistivity of the conductive rubber composition constituting the edge cover layer 5 is at most 5.00×10 5 Ω·cm. In this embodiment, the volume resistivity of the conductive rubber composition constituting the edge cover layer 5 is 3.50×10 5 Ω·cm.

[0055] Since at least one sidewall 6 extends together with the carcass 2 toward below the radially innermost ply 3a in at least one ply 3, the sidewall 6 can be used to replace the material arranged below the radially innermost ply 3a in at least one ply 3 having a sequential tire structure, thereby improving manufacturing efficiency by reducing the number of semi-finished products.

[0056] Since at least the radially innermost ply 3a in at least one ply 3 is provided with an edge covering layer 5, and the edge covering layer 5 at least covers the radially inner surface of the radially innermost ply 3a in at least one ply 3, separation between the ply 3 and the carcass 2 can be avoided, thereby improving the durability performance.

[0057] Since the edge cover layer 5 made of a conductive rubber composition provided in the radially innermost ply 3a of at least one ply 3 has a portion in contact with the carcass 2, charges can pass through the carcass 2 through the edge cover layer 5, thereby improving the conductivity of the tire 1.

[0058] Since the axial distance L is greater than the axial distance Le by at least 10.0 mm, the electrical conductivity of the tire 1 can be improved.

[0059] If the axial distance L is less than the axial distance Le of 10.0 mm, there is a risk that the contact between the edge cover layer 5 and the carcass 2 is insufficient to produce a sufficient conductive path.

[0060] The distance L is preferably at least 11.0 mm greater than the axial distance Le, more preferably at least 12.0 mm greater than the axial distance Le, and still more preferably at least 15.0 mm greater than the axial distance Le.

[0061] Since the axial distance Le is at most equal to 15.0 mm, the manufacturing efficiency of such a tire 1 can be improved.

[0062] If the axial distance Le is greater than 15.0 mm, there is a risk that the overall width of the semi-finished product for the sidewall 6 is too large, thereby reducing manufacturing efficiency.

[0063] This axial distance Le is preferably equal to at most 13.0 mm, more preferably equal to at most 12.0 mm, still more preferably equal to at most 10.0 mm.

[0064] Since the edge covering layer 5 further covers the axially outermost and radially outer portions of the radially innermost ply 3a in at least one ply 3 up to an axial distance L or less measured from the axial end of the radially innermost ply 3a in at least one ply 3, the durability performance can be improved because the edge covering layer 5 covering the axially outermost and radially outer portions can prevent not only separation between the ply 3 and the carcass 2 but also separation between the plies 3.

[0065] Since the volume resistivity of the conductive rubber composition constituting the edge cover layer 5 is at most equal to 5.00×10 5 Ω·cm, the conductivity of the tire 1 can be improved.

[0066] If the volume resistivity of the conductive rubber composition is greater than 5.00×10 5 Ω·cm, there is a risk that the edge cover layer 5 may not effectively serve as a conductive path to the carcass 2 .

[0067] The volume resistivity of the conductive rubber composition constituting the edge cover layer 5 is preferably equal to at most 4.00×10 5 Ω·cm, more preferably equal to at most 3.75×10 5 Ω·cm.

[0068] Will refer to Figure 3 A tire 21 according to a second embodiment of the present invention will be described. Figure 3 A tire according to a second embodiment of the present invention corresponds to Figure 1This is an enlarged schematic diagram of the portion shown in II. Figure 3 Apart from the arrangement shown, the structure of this second embodiment is similar to that of the first embodiment and will therefore be referred to herein. Figure 3 Give a description.

[0069] like Figure 3 As shown, the tire 21 is a tire having a tread 24 and a pair of sidewalls 26 ( Figure 3 The tire 21 is a tire of the present invention (only one of which is shown in the figure), wherein the tread 24 is intended to contact the ground through the contact surface 241 during rolling, the pair of sidewalls 26 extending from each of the two axial ends of the tread 24, and the tire 21 includes at least one ply 23 radially arranged inside the tread 24, the at least one ply 23 including a plurality of parallel reinforcing elements (not shown), the reinforcing elements extending at an angle A (not shown) relative to the tire circumferential orientation, when applied to passenger vehicle tires, the angle A is greater than 10 degrees and generally less than 45 degrees. In the present embodiment, the tire 21 includes two plies 23a, 23b, and the angle A is 27 degrees.

[0070] like Figure 3 As shown, the tire 21 further includes a carcass 22 disposed radially inside the at least one carcass layer 23 .

[0071] like Figure 3 As shown, at least the radially innermost ply 23a of at least one ply 23 is provided with an edge covering layer 25, which is made of a conductive rubber composition and covers at least the radially inner face of the radially innermost ply 23a of at least one ply 23 and extends to an axial distance L measured from an axial end of the radially innermost ply 23a of at least one ply 23, and at least one sidewall 6 extends together with the carcass 22 toward the bottom of the radially innermost ply 23a of at least one ply 23 to an axial distance Le measured from an axial end of the radially innermost ply 23a of at least one ply 23. The axial distance L is greater than the axial distance Le. The axial distance L is at least 10.0 mm greater than the axial distance Le. The axial distance Le is at most equal to 15.0 mm.

[0072] like Figure 3 As shown, the tire 21 is provided with at least two radially adjacent plies 23a, 23b, and each of the at least two plies 23 is provided with an edge covering layer 25 covering an edge portion of each ply 23a, 23b. The tire 21 further includes at least one conductive path (not shown) leading to the contact surface 241.

[0073] like Figure 3As shown, the edge covering layer 25 of one of the radially adjacent plies 23a, 23b has a portion in contact with the edge covering layer 25 of the other of the radially adjacent plies 23a, 23b.

[0074] Since the tire 21 is provided with at least two radially adjacent plies 23a, 23b, and each of the at least two plies 23 is provided with an edge covering layer 25 covering an edge portion of each ply 23a, 23b, durability performance can be improved because the edge covering layer 25 covering an edge portion of each of the at least two plies 23 can prevent not only separation between the plies 23 and the carcass 22, but also separation between the plies 23.

[0075] Since the edge covering layer 25 of one of the radially adjacent plies 23 has a portion in contact with the edge covering layer 25 of another of the radially adjacent plies, the durability performance and the conductivity can be further improved at the same time, because the edge covering layer 25 covering the edge portion of each of the radially adjacent plies 23 can not only prevent the separation between the plies 23 and the carcass 22, but also prevent the separation between the plies 23 while enhancing the conductive path leading to the carcass 22.

[0076] Since the tire 21 further includes at least one conductive path leading to the contact surface 241 , the conductivity of the tire 21 can be further improved because the electric charges can reach the ground through the at least one conductive path leading to the contact surface 241 .

[0077] The structure of at least one conductive path leading to the contact surface 241 can be any form known to those skilled in the art. The rubber composition constituting at least one conductive path leading to the contact surface 241 can be the same as the rubber composition constituting the edge cover layer 25. At least one conductive path leading to the contact surface 241 can extend beyond the radial innermost side of the tread 24.

[0078] The present invention is not limited to the described and illustrated embodiments, and various modifications may be made without departing from the framework thereof.

[0079] [ Figure 4 ] Figure 4 For a tire according to the prior art corresponding to Figure 1 The enlarged schematic diagram of the part shown in II in FIG. Figure 4In the present invention, a tire 101 has a tread 104 and a pair of sidewalls 106, wherein the tread 104 is intended to contact the ground through a contact surface 1041 during rolling, and the pair of sidewalls 106 extend from each of the two axial ends of the tread 104. The tire 101 includes at least one carcass layer 103 (two carcass layers 103a and 103b in this prior art) radially arranged on the inner side of the tread 104, and the at least one carcass layer 103 includes a plurality of parallel reinforcing elements (not shown), and the reinforcing elements extend at an angle A relative to the tire circumferential orientation, and the angle A is greater than 10 degrees. The tire 101 is The first step includes a carcass 102 disposed radially inside at least one ply 103, at least a radially innermost ply 103a in at least one ply 103 is provided with an edge covering layer 105, the edge covering layer 105 is made of a conductive rubber composition and covers at least a radially inner surface of the radially innermost ply 103a in at least one ply 103, at least one sidewall 106 extends together with the carcass 102 toward the bottom of the radially innermost ply in at least one ply 103, and the edge covering layer 105 disposed on the radially innermost ply in at least one ply 103 has no portion in contact with the carcass 102. The radially outermost ply 103b in at least one ply 103 is not provided with an edge covering layer.

[0080] In order to verify the effects of the present invention, two types of tires applied to the examples of the present invention and other types of reference tires were prepared.

[0081] Example 1 is a tire as described in the first embodiment above. Example 2 is also a tire as described in the first embodiment above, wherein the tire uses a low hysteresis loss composition to form a calendered mixture of the belt layer (cord layer). Reference 1 is a tire according to the prior art; it has substantially the same structure as Example 1, but the edge covering layer provided in the radially innermost cord layer does not have a portion in contact with the carcass. Reference 2 is also a tire according to the prior art, wherein the tire uses a low hysteresis loss composition to form a calendered mixture of the belt layer (cord layer). Unless otherwise noted, all examples and references are made of the same rubber-based material (a typical rubber-based material for passenger vehicle tires). The tire size of the examples and references is 245 / 45R18, mounted on an 8.0J×18 conductive rim, and inflated to 200 kPa.

[0082] Conductivity test:

[0083] The resistance of the tire is measured according to WdK 110 by placing the assembly of the test tire and rim on a steel plate, applying a load of 595 kg to the tire, then passing a current of 1000 V between the rim and the steel plate, and reading the resistance with a high resistance meter.

[0084] The results are shown in Table 1. In this Table 1, the results indicated by "×" mean a threshold value higher than 108Ω, "G" means 108Ω or less, and "V" means 107Ω or less.

[0085] [Table 1]

[0086] Example 1 Example 2 Reference 1 Reference 2 resistance V G × ×

[0087] As can be seen from Table 1, the examples show an improvement in electrical conductivity represented by electrical resistance, while improving manufacturing efficiency by reducing the number of semi-finished products, which cannot be achieved by the tires disclosed in the prior art.

[0088] Reference numerals list

[0089] 1. 21 tires

[0090] 2.22 carcass

[0091] 3. 23 ply

[0092] 4.24 tread

[0093] 41, 241 contact surface

[0094] 5.25 Edge Covering Layer

[0095] 6, 26 sidewall

Claims

1. A tire (1), comprising a tread (4) and a pair of sidewalls (6), the tread (4) being intended to come into contact with the ground via a contact surface (41) during rolling, the pair of sidewalls (6) extending from each of the two axial ends of the tread (4), the tire (1) comprising at least one ply (3) radially arranged on the inside of the tread (4), the at least one ply (3) comprising a plurality of parallel reinforcing elements, the reinforcing elements extending at an angle A relative to the circumferential orientation of the tire, the angle A being greater than 10 degrees, the tire (1) further comprising a carcass (2) radially arranged on the inside of the at least one ply (3), at least the radially innermost ply of the at least one ply (3) being provided with an edge covering layer (5), the edge covering layer The layer (5) is made of a conductive rubber composition and covers at least the radial inner surface of the radially innermost ply in at least one ply (3) and extends to an axial distance L measured from the axial end of the radially innermost ply in at least one ply (3), at least one sidewall (6) extends together with the carcass (2) toward the bottom of the radially innermost ply in at least one ply (3) to an axial distance Le measured from the axial end of the radially innermost ply in at least one ply (3), the axial distance L is greater than the axial distance Le, and the edge covering layer (5) provided on the radially innermost ply in at least one ply (3) has a portion in contact with the carcass (2), and the tire is characterized in that the axial distance L is at least 10.0 mm greater than the axial distance Le.

2. The tire (1) according to claim 1, wherein: The axial distance Le is at most equal to 15.0 mm.

3. The tire (1) according to claim 1 or claim 2, wherein: The edge covering layer (5) further covers the axially outermost and radially outer sides of the radially innermost ply in at least one ply layer (3) up to an axial distance L or less measured from an axial end of the radially innermost ply in at least one ply layer (3).

4. The tire (1) according to any one of claims 1 to 3, wherein: The tire (1) is provided with at least two radially adjacent plies (3), and each of the at least two plies (3) is provided with an edge covering layer (5) covering an edge portion of each ply (3).

5. The tire (1) according to claim 4, wherein: The edge covering layer (5) of one of the radially adjacent carcass plies (3) has a portion in contact with the edge covering layer (5) of the other of the radially adjacent carcass plies (3).

6. The tire (1) according to any one of claims 1 to 5, wherein: The volume resistivity of the conductive rubber composition constituting the edge cover layer (5) is at most equal to 5.00×10 5 Ω·cm.

7. The tire (1) according to any one of claims 1 to 6, wherein: The tire (1) further comprises at least one electrically conductive path leading to the contact surface (41).

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