Pneumatic tire

Abstract

To provide a pneumatic tire which improves mud traction performance and cut resistance performance while suppressing increase of tire mass.SOLUTION: A pneumatic tire is given in which a plurality of protectors 10 are formed. The protector 10 includes: a first protector 11; and a second protector 12 adjacent thereto through a groove-like part 13. A tie-bar 15 is formed in the groove-like part 13 to connect the first protector 11 with the second protector 12. The tie-bar 15 is formed partially in a tire radial direction area of the groove-like part 13. A protrusion height of the tie-bar 15 is smaller than protrusion heights of the first protector 11 and the second protector 12. Each of the first protector 11 and the second protector 12 includes: an inside part 20; and an outside part 21 that is positioned at the outer side in the tire radial direction relative to the inside part 20. A maximum length of the inside part 20 in a tire circumferential direction is larger than a maximum length of the outside part 21 in the tire circumferential direction. The tie-bar 15 is connected with the inside part 20 and not connected with the outside part 21.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to pneumatic tires.

Background Art

[0002] Patent Document 1 below describes a pneumatic tire provided with a plurality of side grooves and a plurality of side blocks partitioned by the side grooves in a side region. The pneumatic tire of Patent Document 1 is said to improve running performance and cut resistance on unpaved roads including muddy ground.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In pneumatic tires that run on rough roads such as muddy ground, a plurality of protectors are provided on the sidewall portion in order to enhance the cut resistance and mud performance of the sidewall portion. Such protectors have the problem of increasing the tire mass.

[0005] The present disclosure has been devised in view of the above problems, and the main object thereof is to provide a pneumatic tire capable of enhancing mud traction performance and cut resistance while suppressing an increase in tire mass.

Means for Solving the Problems

[0006] The present disclosure relates to a pneumatic tire, comprising a first buttress portion extending radially inward from a first tread edge. A plurality of protectors that bulge outward in the tire axial direction are formed in the first buttress portion. The protector includes a first protector and a second protector adjacent to the first protector via a groove-shaped portion extending in the tire radial direction therebetween. A tie bar that connects the first protector and the second protector is formed in the groove-shaped portion. The tie bar is partially formed in a tire radial direction region of the groove-shaped portion. The tie bar has a bulge height smaller than the bulge heights of the first protector and the second protector.

Advantages of the Invention

[0007] By adopting the above configuration, the pneumatic tire of the present disclosure can enhance the mud traction performance and cut resistance performance while suppressing an increase in tire mass.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a tire meridian cross-sectional view including a tire rotation axis (not shown) in a normal state of the pneumatic tire (hereinafter sometimes simply referred to as "tire") 1 of the present embodiment. In FIG. 1, as a preferred embodiment, a pneumatic tire mounted on a 4WD vehicle or the like capable of traveling on rough ground is shown. However, it goes without saying that the present disclosure can also be applied to the tire 1 including those for light trucks and heavy loads.

[0010] The "normal state" is a no-load state in which the tire 1 is rim-mounted on a normal rim (not shown) and filled with a normal internal pressure. In this specification, unless otherwise specified, the dimensions and the like of each part of the tire 1 are values measured in this normal state.

[0011] The "normal rim" is a rim defined for each tire in a standard system including the standard on which the tire 1 is based. For example, in the case of JATMA, it is the "standard rim", in the case of TRA, it is the "Design Rim", and in the case of ETRTO, it is the "Measuring Rim".

[0012] The "normal internal pressure" is the air pressure defined for each tire in a standard system including the standard on which the tire 1 is based. In the case of JATMA, it is the "maximum air pressure", in the case of TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and in the case of ETRTO, it is the "INFLATION PRESSURE".

[0013] Inside the tire 1 of the present embodiment, tire components such as a carcass 6 and a belt layer 7 are arranged. Known aspects are appropriately adopted for these tire components.

[0014] In this embodiment, the tire 1 includes a first buttress portion 4A that extends radially inward from the first tread end To in the tire radius direction. Further, the tire 1 includes, for example, a second buttress portion 4B that extends radially inward from the second tread end Ti in the tire radius direction. Since the second buttress portion 4B is formed in the same manner as the first buttress portion 4A, its description is omitted. Note that the second buttress portion 4B may be formed in a manner different from the first buttress portion 4A.

[0015] The first tread end To and the second tread end Ti are defined as the outermost ground contact positions in the tire axis direction when a normal load is applied to the tire 1 in the normal state and the camber angle is grounded on the plane at 0 degrees. A tread portion 2 is formed between the first tread end To and the second tread end Ti.

[0016] The "normal load" is the load defined for each tire by the standard. For JATMA, it is the maximum load capacity; for TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES"; for ETRTO, it is "LOAD CAPACITY".

[0017] FIG. 2 is a perspective view of the first buttress portion 4A. FIG. 3 is a front view of the first buttress portion 4A. As shown in FIGS. 1 to 3, a plurality of protectors 10 that bulge outward in the tire axis direction are formed in the first buttress portion 4A of this embodiment. The protector 10 includes a first protector 11 and a second protector 12 adjacent to the first protector 11 via a groove-shaped portion 13 that extends in the tire radius direction therebetween.

[0018] In the groove portion 13, a tie bar 15 that connects the first protector 11 and the second protector 12 is formed. Such a tie bar 15 enhances the circumferential rigidity of the first protector 11 and the second protector 12, etc., and enhances the cut resistance of the first buttress portion 4A as well as preventing chipping of the protector 10. Further, by increasing the rigidity of the first protector 11 and the second protector 12 by the tie bar 15, the shearing force on the mud road surface using the protector 10 increases, and the mud traction performance is improved.

[0019] The tie bar 15 is partially formed in the tire radial direction region 13R of the groove portion 13. Also, the tie bar 15 has a raised height h2 (shown in FIG. 7) that is smaller than the raised height h1 of the first protector 11 and the second protector 12. Such a tie bar 15 can suppress an increase in tire mass.

[0020] In the first buttress portion 4A, a recess 16 that is recessed inward in the tire axial direction is provided. In this embodiment, the recess 16 extends continuously in the tire circumferential direction. Although not particularly limited, the tire radial width w1 of the recess 16 is 1.0 to 3.0 mm. The depth d1 (shown in FIG. 7) of the recess 16 is 0.5 to 2.0 mm. Such a recess 16 gives a change to the visual appearance of the first buttress portion 4A and enhances the appearance performance. The depth d1 of the recess 16 is the depth from the outer surface 8A of the shoulder block 8R described later.

[0021] In this embodiment, the protector 10 is disposed radially inward of the recess 16. The protector 10 is formed, for example, only from a plurality of protector pairs 10A each including a first protector 11 and a second protector 12. Note that the protector 10 is not limited to such a mode, and may include a third protector (not shown) having a shape different from that of the first protector 11 and the second protector 12.

[0022] Each of the first protector 11 and the second protector 12 includes an inner portion 20 and an outer portion 21 located radially outside the inner portion 20 in the tire radius direction. Note that the inner portion 20 and the outer portion 21 are separated by a tire circumferential direction line n passing through an intersection point T of an outer edge portion 36 and an intermediate edge portion 38, which will be described later (shown in FIG. 5).

[0023] The maximum length Wa in the tire circumferential direction of the inner portion 20 is formed to be larger than the maximum length Wb in the tire circumferential direction of the outer portion 21. Such an inner portion 20 increases the rigidity of the outer portion 21 that is likely to come into contact with mud or the like, thereby further enhancing the mud traction performance and cut resistance performance. In addition, the appearance performance of the protector 10 is enhanced.

[0024] In each protector 10, the maximum length Wb of the outer portion 21 is desirably 50% or more of the maximum length Wa of the inner portion 20, more desirably 60% or more, desirably 80% or less, and more desirably 70% or less. Thereby, the above-described action is effectively exerted. In the present embodiment, the maximum length Wa of the inner portion 20 is 23.9 to 33.9 mm.

[0025] When the first battless portion 4A is viewed from the front, in the tire circumferential direction, the inner portion 20A of the first protector 11 is L-shaped and protrudes on the side opposite to the groove portion 13 with respect to the outer portion 21A. Further, in the tire circumferential direction, the inner portion 20B of the second protector 12 is reverse L-shaped and protrudes on the side opposite to the groove portion 13 with respect to the outer portion 21B. In other words, each of the first protector 11 and the second protector 12 includes an open region K that is open radially outward in the tire radius direction and on the side opposite to the groove portion 13 in the tire circumferential direction at the position where the inner portion 20 and the outer portion 21 are connected. Also in such an open region K, a shearing force against mud or the like is exerted, so that the mud traction performance is enhanced. The L-shape and the reverse L-shape in this specification mean that an angle α1 between a straight line P1 connecting both ends of an inner peripheral edge 30, which will be described later, and a straight line P2 connecting both ends of an inward edge 32 (shown in FIG. 4), and an angle α2 between a straight line P3 connecting both ends of an outer edge portion 36, which will be described later, and a straight line P4 connecting both ends of an intermediate edge portion 38 (shown in FIG. 5) are 80 to 120 degrees.

[0026] As shown in FIG. 2, each of the first protector 11 and the second protector 12 includes a side surface 25 rising from the outer surface 4s of the first buttless portion 4A and an outer surface 26 connecting the outer end 25e in the tire axial direction of the side surface 25. In this specification, the outer surface 4s means a surface that smoothly extends except for local irregularities including raised marks such as trademarks and concavo-convex patterns in the normal state. In this embodiment, the outer surface 4s forms the groove bottom 13s of the groove-shaped portion 13.

[0027] FIG. 4 is an enlarged view of FIG. 3. As shown in FIG. 4, the outer end 25e of the side surface 25 forms a side edge 28 where the side surface 25 and the outer surface 26 intersect. Each of the side edges 28 of the first protector 11 and the second protector 12 includes an inner peripheral edge 30, an outer peripheral edge 31, an inward edge 32, and an outward edge 33 in this embodiment. The inner peripheral edge 30 extends in the tire circumferential direction along the innermost side in the tire radial direction of each protector 11, 12, for example. The outer peripheral edge 31 extends in the tire circumferential direction along the outermost side in the tire radial direction of each protector 11, 12. The inward edge 32 is adjacent to the groove-shaped portion 13 by connecting the first end 30e of the inner peripheral edge 30 and the first end 31e of the outer peripheral edge 31. The outward edge 33 forms an open region K by connecting the second end 30i of the inner peripheral edge 30 and the second end 31i of the outer peripheral edge 31.

[0028] The inner peripheral edge 30A of the first protector 11 and the inner peripheral edge 30B of the second protector 12 extend so as to form a single virtual line X, an arc-shaped virtual line X in this embodiment. Such inner peripheral edges 30A, 30B suppress a decrease in shear force when traveling on muddy ground, thereby enhancing mud traction performance. In this specification, "extending so as to form the single virtual line" means that not only are the inner peripheral edges 30A, 30B located on a single straight line or an arc with a single radius of curvature, but also those in which the maximum separation distance (not shown) between the virtual line X and each of the inner peripheral edges 30A, 30B is within 2 mm are included. In this embodiment, the virtual line X is inclined with respect to the tire circumferential direction. Note that the virtual line X includes straight lines and arc-shaped lines, but does not include broken lines and wavy lines.

[0029] The outer peripheral edges 31 of each of the first protector 11 and the second protector 12 form, for example, a recess 16. In the present embodiment, the outer peripheral edges 31 of each of the first protector 11 and the second protector 12 are formed on the tire circumferential direction line n.

[0030] FIG. 5 is an enlarged view of FIG. 3. As shown in FIG. 5, the inner edge 32A of the first protector 11 includes a first edge 34 and a second edge 35. The first edge 34 extends linearly from the first end 31e of the outer peripheral edge 31 inward in the tire radial direction, for example. The second edge 35 is continuous with the first edge 34 and is inclined at an angle larger than that of the first edge 34 with respect to the tire radial direction. Although not particularly limited, the angle α3 between the first edge 34 and the second edge 35 is formed as an obtuse angle. Such an inner edge 32A increases the groove width inside the groove portion 13 in the tire radial direction. The angle α3 is preferably 100 to 130 degrees. The inner edge 32B of the second protector 12 extends linearly in the tire radial direction.

[0031] In the present embodiment, the first edge 34 of the first protector 11 and the inner edge 32B of the second protector 12 extend in parallel. As a result, the rigidity step between the first protector 11 and the second protector 12 is reduced, so that a high shearing force can be exerted against mud or the like. In this specification, the term "parallel" means that not only the difference in the angle with respect to the tire radial direction between each other is 0 degree, but also within 5 degrees.

[0032] Each outer edge 33 includes an outer edge portion 36 extending from the outer peripheral edge 31, an inner edge portion 37 extending from the inner peripheral edge 30, and an intermediate edge portion 38 connecting the outer edge portion 36 and the inner edge portion 37. The outer edge portion 36, the inner edge portion 37, and the intermediate edge portion 38 extend linearly, for example. In each outer edge 33, in the present embodiment, an open region K is formed by the outer edge portion 36 and the intermediate edge portion 38. In each protector 11, 12, the intermediate edge portion 38 is inclined inward in the tire radial direction toward the side opposite to the circumferential direction of the groove portion 13. As a result, the volume of mud or the like that can be dug up by the intermediate edge portion 38 and the outer edge portion 36 increases, so that the mud traction performance and the cut resistance performance are enhanced.

[0033] FIG. 6 is an enlarged view of FIG. 3. As shown in FIG. 6, the tie bar 15 is connected to the inner portion 20. The tie bar 15 is connected to, for example, the inner portion 20A of the first protector 11 and the inner portion 20B of the second protector 12. Such a tie bar 15 enhances the rigidity of the inner portion 20 and improves the cut resistance performance and the mud traction performance. Further, the tie bar 15 is not connected to the outer portion 21. As a result, the outer portion 21 having relatively low rigidity maintains the deformation due to the rotation of the tire 1, so that the mud or the like in the groove portion 13 sandwiched between the two outer portions 21 is smoothly discharged.

[0034] The tie bar 15 includes, for example, an inner edge 15A and an outer edge 15B. The inner edge 15A and the outer edge 15B extend in the tire circumferential direction. In the present embodiment, the inner edge 15A is connected to a position 40 where the first edge portion 34 and the second edge portion 35 are continuous. The outer edge 15B is disposed outside the inner edge 15A in the tire radial direction. The inner edge 15A and the outer edge 15B extend parallel to each other, for example. In the present embodiment, the inner edge 15A and the outer edge 15B extend parallel to the virtual line X.

[0035] The tire radial length L1 of the tire 15 is preferably 50% or less of the tire radial length La of the groove portion 13. Thereby, since the decrease in the volume of the groove portion 13 is suppressed, an increase in the tire mass can be suppressed. In order to enhance the mud traction performance and cut resistance performance while suppressing an increase in the tire mass, the length L1 of the tire 15 is preferably 20% or more of the length La of the groove portion 13, more preferably 22% or more, further preferably 30% or less, and still more preferably 28% or less. The length L1 of the groove portion 13 is, in this specification, the larger one of the tire radial lengths of the inner edges 32A and 32B that form the groove portion 13.

[0036] FIG. 7 is a cross-sectional view taken along line A-A of FIG. 6. As shown in FIG. 7, the difference (h1a - h2) between the raised height h1a of the first protector 11 and the raised height h2 of the tire 15, and the difference (h1b - h2) between the raised height h1b of the second protector 12 and the raised height h2 of the tire 15 are both preferably 0.5 mm or more. Thereby, the action of suppressing an increase in the tire mass is effectively exerted. In order to enhance the mud traction performance and cut resistance performance, the differences (h1a - h2) and (h1b - h2) are both more preferably 1.0 mm or more, preferably 2 mm or less, and more preferably 1.5 mm or less.

[0037] The raised height h1a of the first protector 11 and the raised height h1b of the second protector 12 are both preferably 1.0 mm or more, more preferably 1.5 mm or more, preferably 5.0 mm or less, and more preferably 4.0 mm or less.

[0038] The raised height h1a of the first protector 11 and the raised height h1b of the second protector 12 are the same in this embodiment. The raised height h1a of the first protector 11 and the raised height h1b of the second protector 12 may be different.

[0039] As shown in FIGS. 1 and 2, the tread portion 2 includes a shoulder land portion 8 on the inner side in the tire axial direction from the first tread end To. The shoulder land portion 8 is divided into a plurality of shoulder blocks 8R by a plurality of shoulder lateral grooves 9 connected to the first tread end To.

[0040] FIG. 8 is a front view of the first buttress portion 4A. As shown in FIG. 8, in this embodiment, the shoulder block 8R includes an outer surface 8A that extends inward in the tire axial direction from the first tread end To and forms the first buttress portion 4A. The outer surface 8A includes, for example, a pair of block edges 39 that are spaced apart in the tire circumferential direction and extend in the tire radial direction. Each block edge 39 connects the first tread end To and the recess 16 and extends linearly. Each block edge 39 includes a first block edge 39a that forms the shoulder lateral groove 9 and a second block edge 39b that is more inclined with respect to the tire radial direction than the first block edge 39a. The second block edge 39b is inclined, for example, toward the first block edge 39a side toward the inner side in the tire radial direction.

[0041] In this embodiment, the shoulder lateral groove 9 extends outward in the tire axial direction from the first tread end To. In other words, the shoulder lateral groove 9 also extends to the first buttress portion 4A. As a result, a pair of groove edges 9a, 9a that extend in the longitudinal direction of the shoulder lateral groove 9 are formed in the first buttress portion 4A. In this embodiment, each groove edge 9a extends linearly. Each groove edge 9a is connected to the recess 16, for example.

[0042] The groove-shaped portion 13 is disposed at a position that at least partially overlaps with a projection region R1 obtained by projecting the shoulder lateral groove 9 inward in the tire radial direction. The projection region R1 is a region surrounded by a pair of extension lines 9e obtained by extending each groove edge 9a inward in the tire radial direction. In FIG. 8, the projection region R1 is shown by hatching. In this embodiment, the entire groove-shaped portion 13 is disposed at a position that overlaps with the projection region R1.

[0043] The width Wg of the groove portion 13 is desirably 90% or more, more desirably 95% or more, of the groove width Ws of the shoulder transverse groove 9, desirably 110% or less, and more desirably 105% or less. Since the width Wg of the groove portion 13 is 90% or more of the groove width Ws of the shoulder transverse groove 9, the mud traction performance can be enhanced. Since the width Wg of the groove portion 13 is 110% or less of the groove width Ws of the shoulder transverse groove 9, the cut resistance performance can be maintained at a high level. The width Wg of the groove portion 13 is desirably, for example, 20% to 40% of the maximum length Wa (shown in FIG. 3) of the inner portion 20. Further, the groove width Ws of the shoulder transverse groove 9 is desirably 3.7 to 9.7 mm.

[0044] The outer portion 21 is disposed at a position that at least partially overlaps with the projection area R2 obtained by projecting the shoulder block 8R inward in the tire radial direction. The projection area R2 is an area surrounded by a pair of tire radial lines s1 passing through the inner ends 39i of the respective block edges 39 of the shoulder block 8R. In FIG. 8, the projection area R2 is shown by hatching. In the present embodiment, the entire outer portion 21 is disposed at a position overlapping with the projection area R2. More specifically, the entire outer portions 21 of the first protector 11 and the second protector 12 are disposed at positions overlapping with the respective projection areas R2. Thereby, the apparent rigidity between the protector 10 and the shoulder block 8R increases, and the mud traction performance further improves.

[0045] Figure 9(a) is a front view of the protector pair 10A of another embodiment. Figure 9(b) is a cross-sectional view taken along line B-B of Figure 9(a). The same components as those of the protector pair 10A in this embodiment may be denoted by the same reference numerals and their description may be omitted. As shown in Figures 9(a) and 9(b), in this embodiment, the inner portion 20 is provided with a border portion 40 extending along the side surface 25 (side edge 28) on the outer surface 26. In this embodiment, the border portion 40 is formed as a rib 40R protruding from the outer surface 26. Such a border portion 40 gives a change to the visibility of the protector 10 and improves the appearance performance. Note that the border portion 40 is preferably arranged in each of the inner portions 20 of the first protector 11 and the second protector 12. Also, it is desirable that the border portion 40 is not formed in the outer portion 21. Further, the border portion 40 may be formed of, for example, two ribs 40R extending along the side surface 25 (not shown).

[0046] Figure 9(c) is a cross-sectional view taken along line B-B of Figure 9(a) of another embodiment. The same components as those of the protector pair 10A in this embodiment may be denoted by the same reference numerals and their description may be omitted. As shown in Figure 9(c), the border portion 40 in this embodiment is formed as a groove-like body 40G recessed from the outer surface 26. Such a border portion 40 also gives a change to the visibility of the protector 10 and improves the appearance performance.

[0047] As described above, the particularly preferred embodiments of the present disclosure have been described in detail. However, the present disclosure is not limited to the illustrated embodiments and can be implemented in various forms with modifications.

Example

[0048] A tire having the basic structure shown in Figure 1 and having the buttress portion shown in Figure 2 was manufactured, and their mud traction performance, cut resistance performance, tire mass, and appearance performance were evaluated. The test methods and common specifications are as follows. Tire size: 265 / 65R18 Rim: 8.0J Internal pressure: 230 kPa In each example, Wg and wa are the same.

[0049] <Mud traction performance> Each test tire was mounted on all four wheels of a four-wheel drive vehicle with a displacement of 3500 cc. Then, a test driver drove the vehicle on a test course with a muddy road surface, and the driving characteristics regarding traction at this time were evaluated by the sense of the test driver. The results are shown in scores with Comparative Example 1 set as 100. The larger the numerical value, the greater the traction and the better the mud performance.

[0050] <Cut resistance performance> Using the above vehicle, after a test driver drove about 1500 km on a rocky road surface including rocks and gravel, etc., the cut resistance performance was evaluated by the sense based on the depth and length of the cut scars generated on the outer surface of the treadless part. The results are shown in scores with Comparative Example 1 set as 100. The larger the numerical value, the smaller the cut scars and the better the cut resistance.

[0051] <Tire mass> The mass of the first treadless part of each test tire was measured. The results are shown in an index with the reciprocal of the mass (kg) of Comparative Example 1 set as 100. The larger the numerical value, the smaller the mass and the better it is. Note that tires with a small mass are excellent in rolling resistance performance.

[0052] <Appearance performance> Ten test drivers evaluated the beauty and visibility of the first treadless part by the sense. The results are shown in scores (average score of ten people) with Comparative Example 1 set as 100. The larger the numerical value, the better the appearance performance. The test results are shown in Table 1. Note that a test tire with any one of the cut resistance performance, mud performance, and tire mass of the test results being 95 or less is unqualified. Also, the border part of Example 15 is in the mode shown in Fig. 9(b).

[0053]

Table 1

[0054]

Table 2

[0055] As a result of the tests, it was confirmed that the tires of the examples had improved cut resistance and mud performance compared to the tires of the conventional examples. Also, it was confirmed that an increase in the tire mass was suppressed in the tires of the examples.

[0056] [Appendix] The present disclosure includes the following aspects.

[0057] [Disclosure 1] A pneumatic tire, comprising a first buttress portion extending radially inward in the tire radius direction from a first tread end, wherein a plurality of protectors that bulge outward in the tire axial direction are formed in the first buttress portion, the protector includes a first protector and a second protector adjacent to the first protector with a groove-shaped portion extending in the tire radius direction therebetween, a tie bar that connects the first protector and the second protector is formed in the groove-shaped portion, the tie bar is partially formed in a tire radius direction region of the groove-shaped portion, the tie bar has a bulge height smaller than bulge heights of the first protector and the second protector, a pneumatic tire. [Disclosure 2] The pneumatic tire according to Disclosure 1, wherein a tire radius direction length of the tie bar is 50% or less of a tire radius direction length of the groove-shaped portion. [Disclosure 3] The pneumatic tire according to Disclosure 1 or 2, wherein a difference (h1a - h2) between a bulge height h1a of the first protector and a bulge height h2 of the tie bar and a difference (h1b - h2) between a bulge height h1b of the second protector and the bulge height h2 of the tie bar are both 0.5 mm or more. [Disclosure 4] The raised height h1a of the first protector and the raised height h1b of the second protector are both 1.0 to 5.0 mm, and the pneumatic tire according to any one of Disclosures 1 to 3 of the present disclosure. [Disclosure 5] On the tread portion inward in the tire axial direction from the first tread end, a shoulder land portion is provided. The shoulder land portion is divided into a plurality of shoulder blocks by a plurality of shoulder lateral grooves connected to the first tread end. The groove-shaped portion is arranged at a position overlapping at least a part of the projection area obtained by projecting the shoulder lateral groove inward in the tire radial direction, and the pneumatic tire according to any one of Disclosures 1 to 4 of the present disclosure. [Disclosure 6] The width of the groove-shaped portion is 90% to 110% of the groove width of the shoulder lateral groove, and the pneumatic tire according to Disclosure 5 of the present disclosure. [Disclosure 7] Each of the first protector and the second protector includes an inner portion and an outer portion located outside the inner portion in the tire radial direction. The maximum length in the tire circumferential direction of the inner portion is larger than the maximum length in the tire circumferential direction of the outer portion, and the pneumatic tire according to any one of Disclosures 1 to 6 of the present disclosure. [Disclosure 8] The tie bar is connected to the inner portion, and the pneumatic tire according to Disclosure 7 of the present disclosure. [Disclosure 9] In a front view of the first buttress portion, The inner portion of the first protector is L-shaped protruding to the side opposite to the groove-shaped portion with respect to the outer portion in the tire circumferential direction. The inner portion of the second protector is reverse L-shaped protruding to the side opposite to the groove-shaped portion with respect to the outer portion in the tire circumferential direction, and the pneumatic tire according to Disclosure 7 or 8 of the present disclosure. [Disclosure 10] Each of the first protector and the second protector includes a side surface rising from the outer surface of the first buttress portion and an outer surface connecting the outer end in the tire axial direction of the side surface. The pneumatic tire according to any one of 7 to 9 of the present disclosure, wherein the inner portion is provided with a border portion extending along the side surface on the outer surface.

Description of Signs

[0058] 1 Pneumatic tire 10 Protector 11 First protector 12 Second protector 13 Grooved portion 13R Tire radial direction region 15 Tyber

Claims

1. A pneumatic tire, comprising a first buttress portion extending radially inward from a first tread end, wherein a plurality of protectors rising outward in the tire axial direction are formed in the first buttress portion, the protector includes a first protector and a second protector adjacent to the first protector with a groove-shaped portion extending in the tire radial direction therebetween, a tie bar connecting the first protector and the second protector is formed in the groove-shaped portion, the tie bar is partially formed in the tire radial direction region of the groove-shaped portion, the tie bar has a rising height smaller than the rising heights of the first protector and the second protector, each of the first protector and the second protector includes an inner portion and an outer portion located radially outside the inner portion, the maximum length in the tire circumferential direction of the inner portion is greater than the maximum length in the tire circumferential direction of the outer portion, the tie bar is connected to the inner portion, the tie bar is not connected to the outer portion, a pneumatic tire.

2. A pneumatic tire, comprising a first buttress portion extending radially inward from a first tread end, wherein a plurality of protectors rising outward in the tire axial direction are formed in the first buttress portion, the protector includes a first protector and a second protector adjacent to the first protector with a groove-shaped portion extending in the tire radial direction therebetween, a tie bar connecting the first protector and the second protector is formed in the groove-shaped portion, the tie bar is partially formed in the tire radial direction region of the groove-shaped portion, the tie bar has a rising height smaller than the rising heights of the first protector and the second protector, each of the first protector and the second protector includes an inner portion and an outer portion located radially outside the inner portion, the maximum length in the tire circumferential direction of the inner portion is greater than the maximum length in the tire circumferential direction of the outer portion, each of the first protector and the second protector includes a side surface rising from the outer surface of the first buttress portion and an outer surface intersecting the side surface at a side edge which is the outer end in the tire axial direction of the side surface, the inner portion is provided with a beaded portion extending on the outer surface, The edge portion is spaced apart from the side edge and extends along the side edge. Pneumatic tire. **Claim 3** A pneumatic tire, comprising a first buttress portion extending radially inward in the tire radius direction from a first tread end, wherein a plurality of protectors protruding outward in the tire axial direction are formed in the first buttress portion, the protector includes a first protector and a second protector adjacent to the first protector via a groove-shaped portion extending in the tire radius direction therebetween, a tie bar connecting the first protector and the second protector is formed in the groove-shaped portion, the tie bar is partially formed in a tire radius direction region of the groove-shaped portion, the tie bar has a raised height smaller than the raised heights of the first protector and the second protector, each of the first protector and the second protector includes an inner portion and an outer portion located radially outside the inner portion in the tire radius direction, the maximum length in the tire circumferential direction of the inner portion is larger than the maximum length in the tire circumferential direction of the outer portion, each of the first protector and the second protector includes a side surface rising from an outer surface of the first buttress portion and an outer surface intersecting the side surface at a side edge that is an outer end in the tire axial direction of the side surface, the inner portion is provided with an edge portion extending on the outer surface, the edge portion is a groove-shaped body recessed from the outer surface, Pneumatic tire. **Claim 4** A pneumatic tire, comprising a first buttress portion extending radially inward in the tire radius direction from a first tread end, wherein a plurality of protectors protruding outward in the tire axial direction are formed in the first buttress portion, the protector includes a first protector and a second protector adjacent to the first protector via a groove-shaped portion extending in the tire radius direction therebetween, a tie bar connecting the first protector and the second protector is formed in the groove-shaped portion, the tie bar is partially formed in a tire radius direction region of the groove-shaped portion, the tie bar has a raised height smaller than the raised heights of the first protector and the second protector, each of the first protector and the second protector includes an inner portion and an outer portion located radially outside the inner portion in the tire radius direction, the maximum length in the tire circumferential direction of the inner portion is larger than the maximum length in the tire circumferential direction of the outer portion, Each of the first protector and the second protector includes a side surface rising from the outer surface of the first buttress portion and an outer surface intersecting the side surface at a side edge which is the outer end in the tire axial direction of the side surface. The inner portion is provided with a border portion extending on the outer surface. The border portion is not formed on the outer portion. Pneumatic tire.

5. The pneumatic tire according to any one of claims 1 to 4, wherein the length of the tiber in the tire radial direction is 50% or less of the length of the groove portion in the tire radial direction.

6. The pneumatic tire according to any one of claims 1 to 5, wherein the difference (h1a - h2) between the raised height h1a of the first protector and the raised height h2 of the tiber, and the difference (h1b - h2) between the raised height h1b of the second protector and the raised height h2 of the tiber are both 0.5 mm or more.

7. The pneumatic tire according to any one of claims 1 to 6, wherein the raised height h1a of the first protector and the raised height h1b of the second protector are both 1.0 to 5.0 mm.

8. On the tread portion, a shoulder land portion is provided on the inner side in the tire axial direction from the first tread end. The shoulder land portion is divided into a plurality of shoulder blocks by a plurality of shoulder cross grooves connected to the first tread end. The pneumatic tire according to any one of claims 1 to 7, wherein the groove portion is arranged at a position overlapping at least a part of the projection region obtained by projecting the shoulder cross groove inward in the tire radial direction.

9. The pneumatic tire according to claim 8, wherein the width of the groove portion is 90% to 110% of the groove width of the shoulder cross groove.

10. The pneumatic tire according to any one of claims 2 to 9, wherein the tiber is connected to the inner portion.

11. Each of the first protector and the second protector includes a side surface rising from the outer surface of the first buttress portion and an outer surface connecting the outer ends in the tire axial direction of the side surface. The pneumatic tire according to claim 1, wherein the inner portion is provided with a border portion extending along the side surface on the outer surface.

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