Motorcycle tires for use on uneven surfaces

Abstract

The present invention provides a motorcycle tire for use on uneven terrain. In the motorcycle tire for use on uneven terrain, excellent traction performance and cornering performance are exhibited. The motorcycle tire for use on uneven terrain has a tread portion (2). The tread portion (2) includes: a base surface (8) and a plurality of pattern blocks (10) protruding from the base surface (8) toward the outer side of the tire radial direction. At least one of the plurality of pattern blocks (10) includes a convex pattern block (15). The convex pattern block (15) includes: a pattern block body (16) and at least one convex portion (17) extending along the tire circumferential direction with a width smaller than the tire axial direction of the pattern block body (16). At least the convex portion (17) of the convex pattern block (15) is connected to the base surface (8) via a first base portion (21).

Description

Technical Field

[0001] The present invention relates to a tire for a motorcycle used on uneven terrain. Background Art

[0002] Patent Document 1 below proposes a pneumatic tire for motorcycles used on uneven terrain, in which a convex portion is provided on a crown pattern block. The convex portion protrudes from the pattern block body of the crown pattern block toward the rear ground contact side in the rotation direction of the tire. The convex portion increases the edge component in the tire circumferential direction. In addition, the convex portion supports the crown pattern block on the rear ground contact side, suppresses excessive tilting of the crown pattern block in the tire circumferential direction, and provides large traction.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-060347

[0004] In recent years, due to the improvement of vehicle performance, further improvement of traction performance and cornering performance is desired. The inventors have repeatedly conducted various studies on this point and found that by improving the lug-bearing blocks, traction performance and cornering performance can be further improved, and finally completed the present invention. Summary of the invention

[0005] The present invention has been conceived in view of the above-mentioned actual situation, and a main object of the present invention is to provide a motorcycle tire for use on uneven terrain with excellent traction performance and cornering performance.

[0006] The present invention is a motorcycle tire for use on uneven terrain having a tread portion, the tread portion comprising: a base surface, and a plurality of pattern blocks protruding from the base surface toward the outer side in the tire radial direction, at least one of the plurality of pattern blocks comprising a pattern block with fins, the pattern block with fins comprising: a pattern block body, and at least one fin portion extending in the tire circumferential direction with a width smaller than that of the pattern block body in the tire axial direction, at least the fin portion of the pattern block with fins being connected to the base surface via a first base portion locally enlarged along the cross section of the base surface.

[0007] In the motorcycle tire for use on uneven terrain of the present invention, it is preferable that the block main body of the lug-bearing block is connected to the base surface via a second base portion having a cross section locally enlarged along the base surface.

[0008] In the motorcycle tire for use on uneven terrain of the present invention, it is preferable that the first base portion and the second base portion are provided so as to continuously surround the outer circumference of the lug block.

[0009] In the motorcycle tire for use on uneven terrain of the present invention, it is preferred that the raised height of the first base portion is 5% to 50% of the total height of the lug-bearing block.

[0010] Preferably, in the motorcycle tire for use on uneven terrain of the present invention, the first base portion includes an outer side surface extending along the base surface, and an intersection angle between the side surface of the lug block and the outer side surface is 90 to 130 degrees.

[0011] In the motorcycle tire for use on rough terrain of the present invention, it is preferred that the first base portion has a stepped profile in a cross section perpendicular to the base surface.

[0012] In the motorcycle tire for use on uneven terrain of the present invention, it is preferable that a protruding width of the first base portion from the tread block along the base surface is smaller than a width of the tread portion in the tire axial direction.

[0013] In the motorcycle tire for use on rough terrain of the present invention, preferably, the tread portion is designated in a rotational direction of the tire, and the convex piece portion is provided on a rear ground contacting side of the block body in the rotational direction.

[0014] In the motorcycle tire for use on uneven terrain of the present invention, the finned block preferably includes a first fin portion on one side in the tire axial direction and a second fin portion on the other side in the tire axial direction.

[0015] Preferably, in the motorcycle tire for use on uneven terrain of the present invention, the first fin portion is connected to one axial side of the block body, and the second fin portion is connected to the other axial side of the block body.

[0016] In the motorcycle tire for use on uneven terrain of the present invention, it is preferable that the fin portion includes a third fin portion provided between the first fin portion and the second fin portion.

[0017] The motorcycle tire for use on uneven terrain of the present invention can exhibit excellent traction performance and cornering performance by adopting the above-mentioned structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a cross-sectional view showing one embodiment of a motorcycle tire for use on rough terrain according to the present invention.

[0019] Figure 2 Yes means Figure 1 An expanded view of the tread pattern of the tread portion.

[0020] Figure 3 yes Figure 2 An enlarged stereoscopic view of the tread block with lugs.

[0021] Figure 4 yes Figure 2An enlarged top view of the tread block with lugs.

[0022] Figure 5 yes Figure 4 BB line cross-sectional view.

[0023] Figure 6 It is an enlarged plan view of a crown block and a middle block according to another embodiment of the present invention.

[0024] Figure 7 It is a development view of the tread portion of a motorcycle tire for use on uneven terrain according to a comparative example.

[0025] Description of Reference Numerals

[0026] 2... tread portion; 8... base surface; 10... pattern block; 15... pattern block with convex piece; 16... pattern block body; 17... convex piece portion; 21... first base portion. DETAILED DESCRIPTION

[0027] Hereinafter, one embodiment of the present invention will be described based on the drawings.

[0028] exist Figure 1 1 is a cross-sectional view of a motorcycle tire for use on rough terrain (hereinafter, sometimes simply referred to as a “tire”) 1 in a normal state, showing one embodiment of the present invention. Figure 2 It is a development view showing a tread pattern of the tread portion 2 of the tire 1 . Figure 1 yes Figure 2 It is an AA line cross-sectional view and a meridian cross-sectional view containing the tire rotation axis.

[0029] "Normal state" refers to a state in which the tire is assembled on a regular rim and filled with a regular internal pressure, and is unloaded, when various specifications of the tire are specified. When various specifications of the tire are not specified, the normal state is a standard usage state corresponding to the purpose of use of the tire and refers to an unloaded state. In this specification, unless otherwise specified, the dimensions of various parts of the tire are values ​​measured under the normal state. In addition, regarding the dimensions of various parts of the tire, when there are slight differences depending on the measurement position, unless otherwise specified, the dimensions shown in this specification refer to the center value between the minimum value and the maximum value. In addition, each structure described in this specification allows for normal errors contained in rubber molded products.

[0030] "Regular rims" refer to rims that have specifications specified for each tire in a standard system that includes the specifications that the tire complies with, such as "standard rims" in JATMA, "design rims" in TRA, and "measuring rims" in ETRTO.

[0031] "Normal internal pressure" refers to the air pressure specified for each tire in the specification system that includes the specifications to which the tire is based. If it is JATMA, it is the "maximum air pressure". If it is TRA, it is the maximum value recorded in the table "TIRE LOAD LIMITS ATVARIOUS COLD INFLATION PRESSURES". If it is ETRTO, it is "INFLATION PRESSURE".

[0032] like Figure 1 As shown, the tire 1 of the present invention is suitable for use as a tire for off-road motorcycle competition. The tire of this embodiment is suitable for use as a tire for the rear wheel of an off-road motorcycle. However, it is not limited to such a form. For the tread portion 2 of the tire 1 of this embodiment, in the cross section, its outer surface is curved into an arc shape that bulges outward in the tire radial direction.

[0033] The tire 1 of the present embodiment includes, for example, a carcass 6 and a tread reinforcing layer 7. These may be appropriately configured as known structures.

[0034] like Figure 2 As shown, the tread portion 2 has, for example, a directional pattern that specifies the rotation direction R. The rotation direction R is indicated by text or symbols, for example, on the sidewall portion 3 ( Figure 1 However, the present invention is not limited to such a form. In addition, in several figures of this specification, the rotation direction R is indicated by an arrow.

[0035] The tread portion 2 is divided into, for example, a crown region Cr, a middle region Mi, and a shoulder region Sh.

[0036] The crown region Cr is a region having a width of 1 / 3 of the tread development width TWe centered at the tire equator C. The shoulder region Sh is a region having a width of 1 / 6 of the tread development width TWe from each tread end Te toward the tire equator C. The middle region Mi is a region between the crown region Cr and the shoulder region Sh.

[0037] The developed tread width TWe is the distance between the tread ends Te and Te in the tire axial direction when the tread portion 2 is developed into a plane. The tread end Te refers to the axially outer edge of the block included in the axially outermost block row among the blocks arranged in the tread portion 2.

[0038] The tread portion 2 includes a base surface 8 and a plurality of pattern blocks 10 that protrude from the base surface 8 toward the outer side in the tire radial direction. The pattern blocks 10 of the present embodiment include a plurality of crown pattern blocks 11, a plurality of intermediate pattern blocks 12, and a plurality of shoulder pattern blocks 13. The centroid of the tread of the crown pattern block 11 is located in the crown region Cr. In a preferred embodiment, the crown pattern block 11 is arranged on the tire equator C. The centroid of the tread of the intermediate pattern block 12 is located in the intermediate region Mi. In addition, the intermediate pattern block 12 is adjacent to the crown pattern block 11. The centroid of the tread of the shoulder pattern block 13 is located in the shoulder region Sh. In addition, the shoulder pattern block 13 is adjacent to the intermediate pattern block 12.

[0039] The axial width of the crown block 11 is, for example, 20% to 30% of the tread development width TWe. The axial width of the middle block 12 is, for example, 10% to 20% of the tread development width TWe. The axial width of the shoulder block 13 is, for example, 8% to 15% of the tread development width TWe. However, the present invention is not limited to such a form.

[0040] At least one of the plurality of blocks 10 includes a finned block 15. In the present embodiment, the crown block 11 and the middle block 12 constitute the finned block 15.

[0041] At least some of the blocks 10 of the present embodiment are connected via a base portion 20 having a locally enlarged cross section along the base surface 8. In the drawings of the blocks viewed from above in this specification, the base portion 20 is colored to facilitate understanding.

[0042] exist Figure 3 An enlarged stereoscopic view of a lug pattern block 15 is shown in FIG. Figure 4 FIG. 1 shows an enlarged top view of a lug pattern block 15. In addition, Figure 3 and Figure 4 The lug-bearing block 15 shown corresponds to the crown block 11 in the present embodiment.

[0043] like Figure 3 and Figure 4 As shown, the lug block 15 includes a block body 16 and at least one lug portion 17 extending in the tire circumferential direction with a width smaller than that of the block body 16 in the tire axial direction.

[0044] At least the fin portion 17 of the finned block 15 is connected to the base surface 8 via a first base portion 21 whose cross section along the base surface 8 is locally enlarged.

[0045] The tire of the present invention can exhibit excellent traction performance and cornering performance by adopting the above-mentioned structure. The following mechanism is presumed as the reason for this.

[0046] The tire 1 of the present invention suppresses the tread block 10 from tilting in the tire circumferential direction by the convex piece 17. Therefore, the traction performance is improved. In addition, since the convex piece 17 includes an edge extending in the tire circumferential direction, it provides friction in the tire axial direction, which is also beneficial to the improvement of the cornering performance.

[0047] Furthermore, in the present invention, since the first base portion 21 increases the rigidity of the fin portion 17 , further improvements in traction performance and cornering performance can be expected.

[0048] The following describes a more detailed structure of the present embodiment. In addition, the structure described below is not an essential element of the present invention, but a structure representing a specific form of the present embodiment. Therefore, it is obvious that the present invention can exert the above-mentioned effects even without the structure described below. In addition, even if any one of the structures described below is applied alone in the tire of the present invention having the above-mentioned characteristics, it is expected that the performance corresponding to each structure will be improved. Moreover, in the case of applying several of the structures described below in combination, it is expected that the performance of the combination corresponding to each structure will be improved.

[0049] like Figure 4 As shown, for example, the circumferential length L2 of the lug block 15 of the present embodiment is smaller than the axial length L1 of the tire. Specifically, the circumferential length L2 of the lug block 15 is preferably 60% to 90% of the axial length L1 of the tire. Such a lug block 15 is beneficial for improving traction performance.

[0050] The block body 16 includes a first side surface 23 facing the front ground contact side (hereinafter referred to as the "front ground contact side") facing the rotation direction R, and a second side surface 24 facing the rear ground contact side (hereinafter referred to as the "rear ground contact side") facing the rotation direction R. The first side surface 23 is, for example, recessed toward the rear ground contact side. For example, two planes 23a that are inclined opposite to each other with respect to the tire axial direction are connected via a ridge line, thereby constituting the first side surface 23 of the present embodiment. The angle of the aforementioned plane 23a with respect to the tire axial direction is, for example, 5 to 25°. Such a first side surface 23 exerts a large reaction force when pushing away mud and soil when driving on uneven ground.

[0051] The second side surface 24 includes a portion extending along the aforementioned plane of the first side surface 23. In addition, the convex piece 17 is connected to the second side surface 24. That is, the convex piece 17 is provided on the rear ground contact side in the rotation direction R of the pattern block body 16. Such a convex piece 17 effectively prevents the pattern block from falling to the rear ground contact side, and exhibits excellent traction performance.

[0052] The side surface 25a on one side of the tire axial direction and the side surface 25b on the other side of the pattern block body 16 extend parallel to the tire circumferential direction. Such side surfaces generate a reaction force in the tire axial direction during cornering, thereby improving the cornering performance. However, the present invention is not limited to such a form.

[0053] The finned block 15 of the present embodiment includes, for example, a plurality of fin portions 17 . Figure 3 and Figure 4 The tread block 15 (crown block 11) shown has three treads 17. Specifically, the tread block 15 includes a first tread 26 on one side in the tire axial direction, a second tread 27 on the other side in the tire axial direction, and a third tread 28 provided therebetween.

[0054] The first fin portion 26 is connected to the side surface 25a on one side in the tire axial direction of the block body 16. The second fin portion 27 is connected to the side surface 25b on the other side in the tire axial direction of the block body 16. The first fin portion 26 and the second fin portion 27 have substantially the same shape.

[0055] The third fin portion 28 is connected to the central portion of the tread block main body 16 in the tire axial direction. In the present embodiment, the crown block 11 is arranged at the tire equator C, and the third fin portion 28 included in the crown block 11 is arranged on the tire equator C. In a more preferred embodiment, the centroid of the tread surface of the tread block is located in a region where the third fin portion 28 extends parallel to the tire circumferential direction toward the first contact side. Thus, the third fin portion 28 effectively suppresses the tilting of the tread block main body 16, and exhibits excellent traction performance.

[0056] To ensure the above effect, the third fin 28 has a tire circumferential length greater than the first and second fins 26 and 27. The third fin 28 protrudes further back than the first and second fins 26 and 27.

[0057] The width W2 of the third fin portion 28 in the tire axial direction is, for example, greater than the widths of the first fin portion 26 and the second fin portion 27 in the tire axial direction. Specifically, the width W2 of the third fin portion 28 is, for example, 130% to 200% of the width W1 of the first fin portion 26. Thus, the third fin portion 28 suppresses the tilting of the block body 16, and prevents mud and dirt from being retained around the finned block 15 by appropriately deforming the first fin portion 26 and the second fin portion 27.

[0058] The block body 16 of the lug block 15 is connected to the base surface 8 (shown in FIG. 8 ) via a second base portion 22 having a locally enlarged cross section along the base surface 8. Figure 2 and Figure 3, the same below. ) are connected. Thus, in the present embodiment, the first base portion 21 and the second base portion 22 are provided in a manner to continuously surround the outer periphery of the lug-bearing pattern block 15.

[0059] The first base portion 21 and the second base portion 22 increase the rigidity of the root portion of the lug block 15, thereby effectively improving the traction performance and the turning performance. In addition, the first base portion 21 and the second base portion 22 prevent the lug block 15 from being buried in the road surface on a soft road surface. Such an action can prevent the increase in the running resistance of the tire and prevent mud and soil from being retained around the lug block 15.

[0060] The second base portion 22 has substantially the same structure as the first base portion 21 at least in a cross section perpendicular to the base surface 8. Therefore, the structure of the first base portion 21 described below can be applied to the second base portion 22.

[0061] exist Figure 5 Shown in Figure 4 BB line cross-sectional view. In addition, Figure 5 8 is a diagram showing a cross section of the first base portion 21 perpendicular to the base surface 8. Figure 5 As shown, the first base portion has a stepped profile in the cross section. The profile of the first base portion 21 is preferably a step of three or less steps, and the profile of the first base portion 21 in this embodiment is a step of one step.

[0062] The raised height h2 of the first base portion 21 is 5% to 50%, preferably 5% to 15%, of the total height h1 of the lug block 15. Such a first base portion 21 can maintain the ease with which the lug block 15 penetrates the road surface and improve the rigidity of the lug block 15.

[0063] It is preferred that the protruding width W3 of the first base portion 21 from the lug block 15 along the base surface 8 is smaller than the lug portion 17 ( Figure 4 In the present embodiment, the protruding width W3 of the first base portion 21 is the width W1 (indicated in the figure) of the first convex piece 26 in the tire axial direction. Figure 4 Such a first base portion 21 can improve the rigidity of the fin portion 17 without excessively impairing the amount of penetration of the fin-bearing block 15 into the road surface.

[0064] The first base portion 21 includes an outer side surface 21a extending along the base surface 8. The intersection angle θ1 between the side surface of the lug block 15 and the outer side surface 21a is, for example, 90 to 130°, preferably 90 to 100°. Thus, the lug block 15 easily penetrates the road surface, improving traction performance and cornering performance.

[0065] like Figure 2 As shown in FIG. 1 , the middle block 12 of the present embodiment is configured as a lug block 15. The middle block 12 includes, for example, a first lug portion 26 on one side in the tire axial direction and a second lug portion 27 on the other side in the tire axial direction. On the other hand, the middle block 12 does not include the third lug portion 28. Such a middle block 12 can be deformed appropriately more easily than the crown block 11, and mud and soil are prevented from being retained around it.

[0066] The length of the first fin portion 26 and the second fin portion 27 of the middle block 12 in the tire circumferential direction is smaller than the length of the third fin portion 28 of the crown block 11 in the tire circumferential direction. The length of the first fin portion 26 and the second fin portion 27 of the middle block 12 in the tire circumferential direction is the same as the length of the first fin portion 26 and the second fin portion 27 of the crown block 11 in the tire circumferential direction. As a result, the change in traction during straight travel and during cornering becomes linear.

[0067] The side surface of the middle block 12 facing the first contact side in the rotation direction R is inclined toward the first contact side, for example, as it moves from the tire equator C side toward the tread end Te side. In addition, the centroid of the tread of the middle block 12 is located closer to the first contact side than the centroid of the tread of the crown block 11. Thus, the middle block 12 guides mud and soil pushed to the tire equator C side to the crown block 11 side, and the mud and soil are further pushed away by the crown block 11. Therefore, the traction performance is further improved.

[0068] It is preferred that the length L3 of the middle pattern block 12 in the tire axial direction is smaller than the length L4 of the crown pattern block 11 in the tire axial direction (with Figure 4 The tread blocks 15 have the same length L1 in the tire axial direction. ) Specifically, the length L3 of the middle block 12 is 50% to 80% of the length L4 of the crown block 11.

[0069] The shoulder pattern block 13 of the present embodiment is configured as a non-convex pattern block that does not include the above-mentioned convex portion 17, for example. The tread of the shoulder pattern block 13 is, for example, rectangular, preferably trapezoidal. The tread of the shoulder pattern block 13 of the present embodiment includes two edges extending parallel to the tire circumferential direction. The length of the shoulder pattern block 13 in the tire circumferential direction increases toward the tread end Te side. For such a shoulder pattern block 13, since its rigidity increases toward the tread end Te side, it is possible to make the responsiveness when the camber angle of the vehicle body increases linear.

[0070] The shoulder block 13 is provided with a base portion 20 having a locally enlarged cross section along the base surface 8 on the base surface 8 side. The structure of the first base portion 21 described above can be applied to the base portion 20. For such a shoulder block 13, the rigidity of the root portion is high, which is useful for improving the cornering performance.

[0071] The shoulder block 13 of this embodiment does not have a base portion 20 on the side surface on the tread end Te side, but has a base portion 20 in other areas. Such a shoulder block 13 is easy to bend appropriately toward the tread end Te side, so the driver can easily understand the movement of the vehicle body during turning at a near maximum camber angle.

[0072] The tread portion 2 includes, for example, a crown bar 31 and a shoulder bar 32. The crown bar 31 is formed by protruding from the base surface 8 and connects the crown pattern block 11 with the middle pattern block 12. The shoulder bar 32 is formed by protruding from the base surface 8 and connects the shoulder pattern block 13 with the middle pattern block 12. In addition, the height of each bar in this embodiment is smaller than the height of the above-mentioned base portion 20. In this embodiment, the pattern blocks connected by each bar are integrated to improve the traction performance.

[0073] exist Figure 6 FIG. 2 shows an enlarged top view of the crown block 11 and the middle block 12 according to another embodiment of the present invention. Figure 6 As shown, the tread block 15 of the present invention may be provided with only the first base portion 21, for example, without the second base portion. Such a tread block 15 can increase the amount of penetration of the block body 16 into the road surface.

[0074] As mentioned above, although the form of the tire for motorcycles used on uneven terrain of the present invention has been described in detail, the present invention is not limited to the above-mentioned specific embodiment, and can be implemented by changing into various forms.

[0075] [Example]

[0076] Based on the specifications in Table 1, a prototype with Figure 2 The rear tire of a motorcycle used for uneven ground with the basic pattern of Figure 7 As shown in FIG. 1 , a tire in which each pattern block a is connected to the base surface b without passing through the base portion is produced. Figure 2 The tires shown have substantially the same tread pattern. The traction performance and cornering performance of each test tire were tested. The common specifications and test methods of each test tire are as follows.

[0077] Vehicle used: 450cc off-road motorcycle racing vehicle

[0078] Tire size: 120 / 80-19

[0079] - Rim size: 2.15WM

[0080] Internal pressure: 80kPa

[0081] The test method is as follows.

[0082] <Traction performance>

[0083] The traction performance of the test vehicle when running on uneven ground was evaluated by the sensory organs of the test riders. The results were expressed as a score with the comparative example being 100, and a larger value indicates a better traction performance.

[0084] <Cornering performance>

[0085] The test riders evaluated the turning performance of the test vehicle on uneven ground using their sense organs. The results were expressed as a score with the comparative example being 100, with a larger value indicating a better turning performance.

[0086] The test results are shown in Table 1.

[0087]

Table 1

[0088]

[0089] As shown in Table 1, it can be confirmed that the tires of Examples exhibit excellent traction performance and cornering performance.

Claims

1. A motorcycle tire for use on uneven terrain, having a tread portion, characterized in that: The tread portion includes: a base surface, and a plurality of pattern blocks protruding from the base surface toward the outer side in the tire radial direction. The plurality of pattern blocks include at least one pattern block with a convex plate, The convex block includes: a block body and at least one convex portion extending in the tire circumferential direction with a width smaller than the axial width of the block body. At least the fin portion of the finned block is connected to the base surface via a first base portion having a locally enlarged cross section along the base surface, The finned block includes, as the fin portion, a first fin portion on one side in the tire axial direction, a second fin portion on the other side in the tire axial direction, and a third fin portion provided between the first fin portion and the second fin portion.

2. The motorcycle tire for use on uneven terrain according to claim 1, characterized in that: The block body of the lug-bearing block is connected to the base surface via a second base portion having a locally enlarged cross section along the base surface.

3. The motorcycle tire for use on uneven terrain according to claim 2, characterized in that: The first base portion and the second base portion are provided so as to continuously surround the outer periphery of the lug-bearing block.

4. The motorcycle tire for use on uneven terrain according to any one of claims 1 to 3, characterized in that: The protrusion height of the first base portion is 5% to 50% of the total height of the lug-bearing pattern block.

5. The motorcycle tire for use on uneven terrain according to any one of claims 1 to 3, characterized in that: The first base portion includes an outer side surface extending along the base surface, The intersection angle between the side surface of the lug-bearing pattern block and the outer side surface is 90 to 130 degrees.

6. The motorcycle tire for use on uneven terrain according to any one of claims 1 to 3, characterized in that: The first base portion has a stepped profile in a cross section perpendicular to the base surface.

7. The motorcycle tire for use on uneven terrain according to any one of claims 1 to 3, characterized in that: A protruding width of the first base portion from the lug block along the base surface is smaller than a width of the lug portion in the tire axial direction.

8. The motorcycle tire for use on uneven terrain according to any one of claims 1 to 3, characterized in that: The tread portion is designated in the direction of rotation of the tire, The convex piece portion is provided on a rear ground contact side of the block body in the rotation direction.

9. The motorcycle tire for use on uneven terrain according to any one of claims 1 to 3, characterized in that: The first convex piece is connected to the side surface of the pattern block body on one side of the tire axial direction. The second convex piece portion is connected to the side surface of the block body on the other side in the tire axial direction.

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