tire

Abstract

To provide a tire improved in on-ice performance and load durability.SOLUTION: The present invention relates to a tire including a tread part 2. The tread part 2 includes a plurality of circumferential grooves 3, a plurality of lateral grooves 10, and a plurality of first blocks 13. A first sipe 15 is provided in each first blocks 13. The first sipe 15 extends in a zigzag shape in both a cross section orthogonal to a sipe length direction and a cross section parallel to a ground contact surface of the first block 13. The first sipe 15 is divided by a tie-bar 18 into a first part 16 and a second part 17. A circular first widening part 21 communicates with a sipe bottom part 16d of the first part 16, and the first widening part 21 extends in a zigzag shape. A circular second widening part 22 communicates with a sipe bottom part 17d of the second part 17, and the second widening part 22 extends in a zigzag shape. The first widening part 21 and the second widening part 22 do not communicate with each other.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a tire. [Background Art]

[0002] Patent Document 1 below proposes a pneumatic tire intended for use in winter. The outer shoulder land portion of this tire is divided into a plurality of outer shoulder blocks by a plurality of outer shoulder lateral grooves extending in the tire axial direction. At least one of the outer shoulder blocks is divided into a first block piece on an outer tread edge side and a second block piece on an inner tread edge side by a first narrow longitudinal groove extending in the tire circumferential direction. A plurality of first sipes are provided on the first block piece, and a plurality of second sipes are provided on the second block piece. Furthermore, the total number of second sipes in the second block piece is larger than the total number of first sipes in the first block piece. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2021-195051 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In recent years, further improvement in performance on ice has been demanded for tires provided with sipes in the tread portion that are intended for use in winter. On the other hand, in the tire, due to the falling of the land portion caused by contact load, strain is likely to occur at the bottom portion of the sipe, and consequently cracks starting from the bottom portion are likely to occur. Therefore, improvement is also demanded for the durability of the sipe bottom against contact load (hereinafter referred to as "load durability") of the tire.

[0005] Furthermore, in recent years, with the spread of hybrid vehicles that use both engines and motors, and EV vehicles that run solely on motors, noise during vehicle operation has been significantly reduced. For this reason, there is a need to reduce noise caused by sipes in the aforementioned tires.

[0006] This invention was conceived in view of the above circumstances, and its main objective is to provide a tire with improved ice performance, load durability, and noise performance. [Means for solving the problem]

[0007] The present invention relates to a tire having a tread portion, the tread portion comprising a plurality of circumferential grooves extending continuously in the circumferential direction of the tire, a plurality of transverse grooves extending in the axial direction of the tire, and a plurality of first blocks, each of the plurality of first blocks having at least one first sipe, the first sipe extending in a zigzag pattern in both a cross section perpendicular to the sipe length direction and a cross section parallel to the tread surface of the first block, each of the first sipes being divided in the sipe length direction into at least a first portion and a second portion by at least one tie bar that locally rises outward in the radial direction of the tire from the bottom of the sipe and terminates before the tread surface, and the bottom of each of the first portion and the second portion of the sipe is The tire has a first widening section that extends in a zigzag pattern in a cross section parallel to the tread surface of the first block, the bottom of the sipe of the first portion is connected to the first widening section which has a circular cross-section, the first widening section has a groove width greater than the width of the first portion, and the first widening section extends in a zigzag pattern along the bottom of the sipe of the first portion in a plan view of the tread, and the bottom of the sipe of the second portion is connected to the second widening section which has a circular cross-section, the second widening section has a groove width greater than the width of the second portion, and the second widening section extends in a zigzag pattern along the bottom of the sipe of the second portion in a plan view of the tread, and the first widening section and the second widening section are not connected to each other. [Effects of the Invention]

[0008] By adopting the above configuration, the tire of the present invention can improve ice performance, load durability, and noise performance. [Brief explanation of the drawing]

[0009] [Figure 1] This is an exploded view of the tire tread portion of one embodiment of the present invention. [Figure 2] Figure 1 is a cross-sectional view of the tread area. [Figure 3] This is an enlarged view of multiple first blocks in Figure 1. [Figure 4] This is an enlarged perspective view conceptually illustrating the space divided by the first sipe. [Figure 5] This is a cross-sectional view along line AA in Figure 3. [Figure 6] This is a cross-sectional view of the first block of the first sipe in Figure 3, parallel to the tread surface. [Figure 7] Figure 3 is a cross-sectional view along line BB. [Modes for carrying out the invention]

[0010] One embodiment of the present invention will be described below with reference to the drawings. Figure 1 is an exploded view of the tread portion 2 of the tire 1 of this embodiment. As shown in Figure 1, the tire 1 of the present invention is intended for use in winter. The tire 1 of this embodiment is used, for example, as a pneumatic tire for a passenger car. However, the present invention is not limited to this embodiment and may be applied, for example, to heavy-duty tires.

[0011] The tread portion 2 includes a plurality of circumferential grooves 3 that extend continuously in the circumferential direction of the tire between two tread ends Te, and a plurality of land portions 4 divided by these circumferential grooves 3.

[0012] The tread edge Te corresponds to the outermost axial contact point of the tire when tire 1 in its normal state is loaded with 70% of its normal load, has a camber angle of 0°, and is in contact with a flat surface.

[0013] The aforementioned "normal condition" refers, in the case of pneumatic tires for which various standards are defined, to a state in which the tire is mounted on a standard rim, filled to the standard internal pressure, and under no load. For tires for which various standards are not defined, or for non-pneumatic tires, the aforementioned normal condition means a standard operating condition according to the intended use of the tire, in which it is not mounted on a vehicle and under no load. Unless otherwise specified in this specification, the dimensions of each part of the tire are values ​​measured under the aforementioned normal condition. Furthermore, unless otherwise specified in this specification, known methods may be appropriately applied to the measurement method of the aforementioned dimensions.

[0014] A "standard rim" is the rim defined for each tire within the standards system that the tire is based on. For example, it is the "standard rim" for JATMA, the "Design Rim" for TRA, and the "Measuring Rim" for ETRTO.

[0015] "Regular internal pressure" refers to the air pressure specified for each tire by each standard within the tire standard system, including the standard on which the tire is based. For JATMA, it is the "maximum air pressure," for TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES," and for ETRTO, it is the "INFLATION PRESSURE."

[0016] "Regular load" refers to the load specified for each tire within the standard system, including the standard on which the tire is based, in the case of pneumatic tires for which various standards are defined. For example, it is the "maximum load capacity" for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "LOAD CAPACITY" for ETRTO. For tires for which various standards are not defined, "regular load" refers to the maximum load that can be applied when using the tire, in accordance with the above standards.

[0017] The tread portion 2 of the present embodiment is provided with four circumferential grooves 3. These circumferential grooves 3 are composed of two crown circumferential grooves 5 and two shoulder circumferential grooves 6. The two crown circumferential grooves 5 are arranged so as to sandwich the tire equator C. The two shoulder circumferential grooves 6 are arranged so as to sandwich the two crown circumferential grooves 5. However, the present invention is not limited to such an embodiment.

[0018] The circumferential grooves 3 can adopt various forms, such as those extending linearly in the tire circumferential direction and those extending in a zigzag shape.

[0019] Fig. 2 shows a cross-sectional view of the tread portion 2. Fig. 2 conceptually shows a cross-section of the tread portion 2, and cross-sections of sipes and lateral grooves observed in a plan view of the tread portion 2 are omitted in Fig. 2. As shown in Fig. 2, the groove width of the circumferential groove 3 is desirably at least 3 mm or more. The maximum groove width W1 of the circumferential groove 3 is, for example, 2.0% to 5.0% of the tread width TW (shown in Fig. 1). Further, the maximum depth d1 of the circumferential groove 3 is, for example, 5 to 15 mm. The tread width TW corresponds to the distance in the tire axial direction from one tread edge Te to the other tread edge Te in the normal state.

[0020] As shown in Fig. 1, the tread portion 2 of the present embodiment is divided into five land portions 4 by the aforementioned circumferential grooves 3. These five land portions 4 are composed of one crown land portion 7, two middle land portions 8, and two shoulder land portions 9. The crown land portion 7 is defined between the two crown circumferential grooves 5. The middle land portion 8 is defined between the crown circumferential groove 5 and the shoulder circumferential groove 6. The shoulder land portion 9 is defined on the axially outer side of the shoulder circumferential groove 6 in the tire axial direction, and includes the tread edge Te.

[0021] The tread portion 2 of the present invention is provided with a plurality of lateral grooves 10. As a result, each land portion 4 is configured as a row of blocks including a plurality of blocks 11 separated by the lateral grooves 10. The tread portion 2 also includes a plurality of first blocks 13. The plurality of first blocks 13 in this embodiment are included in the shoulder land portion 9. Therefore, the plurality of first blocks 13 constitute the tread edge Te.

[0022] Figure 3 shows an enlarged view of a plurality of first blocks 13. The plurality of first blocks 13 shown in Figure 3 are included in the left shoulder land area 9 of Figure 1. As shown in Figure 3, each of the plurality of first blocks 13 is provided with at least one first sipe 15. In a preferred embodiment, each of the plurality of first blocks 13 in this embodiment is provided with a plurality of first sipes 15.

[0023] In this specification, "sipe" refers to a notched element having a minute width, where the width between two opposing inner walls is 1.5 mm or less. A chamfered portion may be provided at the opening of the sipe. Furthermore, as will be described later, a widened portion is connected to the bottom of the first sipe 15.

[0024] Figure 4 shows an enlarged perspective view conceptually illustrating the space partitioned by the first sipe 15. In Figure 4, the space is lightly dotted. Figure 5 shows a cross-sectional view of the first sipe 15 perpendicular to the sipe length direction. Note that Figure 5 is a cross-sectional view including the first widening section 21, which will be described later, and corresponds to the cross-sectional view along line AA in Figure 3. Figure 6 shows a cross-sectional view of the first sipe 15 parallel to the tread surface of the first block 13. As shown in Figures 4 to 6, the first sipe 15 of the present invention extends in a zigzag pattern in both the cross-section perpendicular to the sipe length direction and the cross-section parallel to the tread surface of the first block 13.

[0025] Figure 7 shows a cross-sectional view of the first sipe 15 along its length. Figure 7 corresponds to the cross-sectional view of line BB in Figure 3. In Figure 7, the ridge lines 20 that divide the irregularities in the sipe wall are conceptually shown by dashed lines. As shown in Figure 7, the first sipe 15 is divided into at least a first section 16 and a second section 17 along the length of the sipe by at least one tie bar 18. The tie bar 18 rises locally outward in the tire radial direction from the bottom of the sipe and terminates before the tread surface 13s of the first block 13. In the region between the tie bar 18 and the tread surface 13s of the first block 13, a virtual line (not shown) obtained by extending the center line of the tie bar 18 in the width direction outward in the tire radial direction forms the boundary between the first section 16 and the second section 17.

[0026] As shown in Figure 4, the bottom of the sipes of the first section 16 and the second section 17 extend in a zigzag pattern in a cross-section parallel to the tread surface 13s of the first block 13 (shown in Figure 5). Also, as shown in Figures 4 and 5, the bottom of the sipe 16d of the first section 16 is connected to a first widening section 21, which has a circular cross-section. The first widening section 21 has a groove width greater than the width of the first section 16. Furthermore, as shown in Figures 4 and 6, the first widening section 21 extends in a zigzag pattern along the bottom of the sipe 16d of the first section 16 in a plan view of the tread.

[0027] Similarly, as shown in Figure 4, a second widening section 22, which has a circular cross-section, is connected to the bottom 17d of the sipe of the second section 17. The second widening section 22 has a groove width greater than the width of the second section 17. Also, as shown in Figures 4 and 6, the second widening section 22 extends in a zigzag pattern along the bottom 17d of the sipe of the second section 17 in a plan view of the tread. Furthermore, the first widening section 21 and the second widening section 22 are not connected to each other. By adopting the above configuration, the tire 1 of the present invention can improve ice performance, load durability, and noise performance. The reason for this is as follows.

[0028] As described above, the first sipe 15 of the tire 1 of the present invention extends in a zigzag shape. Furthermore, the first sipe 15 is divided into a first part 16 and a second part 17 by a tie bar 18. When a ground load is applied to the first block 13, the opposing sipe walls of the first sipe 15 interlock firmly, maintaining the rigidity of the first block 13. The tie bar 18 also helps to maintain the rigidity of the first block 13. As a result, the collapse of the first block 13 is effectively suppressed, distortion at the bottom of the first sipe 15 is suppressed, and load durability is improved.

[0029] Furthermore, as shown in Figure 4, the first sipe 15 of the present invention includes a first widening portion 21 and a second widening portion 22, both of which have a circular cross-section and are not connected to each other. Therefore, even if the first block 13 collapses, the strain is dispersed at the bottom of the first sipe 15, thereby suppressing damage.

[0030] Furthermore, because the collapse of the first block 13 is suppressed by the mechanism described above, a large contact area is secured when driving on ice, and a large frictional force can be obtained on the ice due to the edge effect of the first sipe 15. In addition, since the first sipe 15 includes the first widening section 21 and the second widening section 22, the first sipe 15 exhibits excellent water absorption performance, further enhancing ice performance.

[0031] Furthermore, in the present invention, since the first widening section 21 and the second widening section 22 extend in a zigzag shape, the movement of air within these widening sections is inhibited, and consequently, noise associated with the opening and closing of the sipes can be reduced. For these reasons, the tire 1 of the present invention can improve noise performance, ice performance, and load durability.

[0032] The configuration of this embodiment will be described in more detail below. Note that each configuration described below represents a specific aspect of this embodiment. Therefore, it goes without saying that the present invention can achieve the above-described effects even without the configurations described below. Furthermore, even if any one of the configurations described below is applied individually to a tire of the present invention having the above-described features, an improvement in performance corresponding to each configuration can be expected. Moreover, if several of the configurations described below are applied in combination, a combined improvement in performance corresponding to each configuration can be expected.

[0033] As shown in Figure 1, when the tread portion 2 is divided into four equal parts in the tire axial direction, the tread portion 2 is divided into two outer regions 2A, which are the area on the tread edge Te side, and two inner regions 2B, which are the area on the tire equator C side, it is desirable that the multiple first blocks 13 are located in the land portion 4 included in the outer region 2A. In this embodiment, the first blocks 13 are included in the shoulder land portion 9, and the multiple first blocks 13 constitute the tread edge Te. As a result, the first sipes 15 are located in the shoulder land portion 9, where the ground pressure tends to be high, thus reliably improving load durability.

[0034] As shown in Figure 3, it is desirable that a single first block 13 is provided with a plurality of first sipes 15. In this embodiment, a single first block 13 is provided with four first sipes 15, each first sipe 15 traversing the first block 13 in the tire axial direction. In addition, the first block 13 in this embodiment is not provided with any sipes or grooves other than the first sipes 15. However, the present invention is not limited to this embodiment, and for example, the first block 13 may be provided with longitudinal grooves extending in the tire circumferential direction. It should be noted that although the figures in this specification describe the configuration of a single first sipe 15, these configurations can be extended to each of the first sipes 15 described above.

[0035] The spacing ta between two adjacent first sipes 15 in the circumferential direction of the tire (corresponding to the distance between the sipe centerlines in the circumferential direction of the tire) is, for example, 3.0 to 7.0 mm, preferably 4.0 to 6.0 mm. This allows for excellent ice performance while suppressing uneven wear of the first block 13.

[0036] As shown in Figure 5, the first sipe 15 extends radially in the tire with a constant width W2 in its cross-section. Furthermore, as shown in Figure 6, the first sipe 15 also extends in the sipe length direction while maintaining the constant width W2 described above. That is, the first sipe 15 in this embodiment extends with a constant width W2 throughout its entire length. The width W2 is preferably 1.0 mm or less, and more preferably 0.2 to 0.7 mm. This improves load durability and ice performance in a balanced manner. However, the present invention is not limited to this embodiment, and unavoidable errors in rubber products such as tires may be tolerated. For this reason, the width of the first sipe 15 may vary depending on the measurement position. In this case, the ratio W2M / W2m of the maximum value W2M to the minimum value W2m (not shown) of the width of the first sipe 15 is preferably 2.0 or less. Furthermore, the maximum value W2M is preferably 0.4 to 0.7 mm. The aforementioned minimum value W2m is preferably 0.2 to 0.4 mm.

[0037] As shown in Figure 7, the maximum depth d3 from the tread surface 13s of the first block 13 to the bottom of the first widening section 21 is 4.0 to 9.0 mm. Similarly, the maximum depth d4 from the tread surface of the first block 13 to the bottom of the second widening section 22 is 4.0 to 9.0 mm. This allows for a good balance between load durability and ice performance. In a preferred embodiment, the depths d3 and d4 described above are the same.

[0038] The tie bar 18 is positioned, for example, in the central region when the first sipe 15 is divided into three equal parts along its length. In a more desirable embodiment, the tie bar 18 in this embodiment is preferably positioned to include the center position of the first sipe 15 along its length. This suppresses local deformation of the first sipe 15 and provides excellent load resistance.

[0039] The tie bar 18 in this embodiment extends in the tire radial direction with a constant width, for example. The outer end portion 18a of the tie bar 18 in the tire radial direction has a convex, arc-shaped outer surface toward the tread surface 13s. The maximum width W5 of the tie bar 18 in a cross section along the length of the first sipe 15 is, for example, 0.5 to 5.0 mm.

[0040] The height h1 from the bottom of the first widening section 21 to the outer end of the tie bar 18 in the tire radial direction is preferably 30% or more, more preferably 40% or more, preferably 80% or less, and more preferably 70% or less of the maximum depth d3 from the tread surface 13s of the first block 13 to the bottom of the first widening section 21. Such a tie bar 18 helps to improve load durability and ice performance in a balanced way.

[0041] As shown in Figure 4, the first widening section 21 extends in a zigzag pattern along the sipe length direction of the first sipe 15 while maintaining a circular area in its cross-section. Furthermore, the first widening section 21 extends in a zigzag pattern along its entire length. As a result, the first widening section 21 is configured as a zigzag-bent tubular shape, except for the portion communicating with the first sipe 15. In addition, the convergence of the circular centers in the cross-section of the first widening section 21 forms the central axis of the first widening section 21, and this central axis extends in a zigzag pattern. The second widening section 22 is similar.

[0042] As shown in Figure 6, in a cross-section parallel to the tread surface 13s of the first block 13, the zigzag shape of the first widening section 21 and the second widening section 22 includes a zigzag corner 28 bent at an obtuse angle. However, the present invention is not limited to this embodiment, and the zigzag shape of the first widening section 21 and the second widening section 22 may include an arc-shaped zigzag corner. Such first widening section 21 and second widening section 22 make it less likely for the zigzag corner to become the starting point of cracks, and further improve load durability.

[0043] In this embodiment, the first widening section 21 and the second widening section 22 have substantially the same configuration. Therefore, the zigzag pitch of the first widening section 21 is equal to the zigzag pitch of the second widening section 22. However, in the present invention, the zigzag pitch of the first section 16 may differ from the zigzag pitch of the second section 17, so the zigzag pitch of the first widening section 21 may differ from the zigzag pitch of the second widening section 22. In such an embodiment, the water absorption and the degree of interlocking of the two sipe walls can be made different in the first section 16 and the second section 17, allowing for fine adjustment of the balance between ice performance and load durability.

[0044] As shown in Figure 5, the diameter L1 in the cross-section of the first widening section 21 is preferably 2.0 times or more, more preferably 3.0 times or more, preferably 6.0 times or less, and more preferably 5.0 times or less, the width in the cross-section of the first sipe 15. This allows for excellent dimolding properties during tire production while achieving the effects described above. In this embodiment, "width in the cross-section of the first sipe 15" refers to a constant width W2, and if the width differs depending on the measurement position, it refers to the maximum width.

[0045] From a similar viewpoint, the diameter of the cross-section of the second widening section 22 is preferably 2.0 times or more, more preferably 3.0 times or more, preferably 6.0 times or less, and more preferably 5.0 times or less, the width of the cross-section of the first sipe 15.

[0046] As shown in Figure 4, the ratio of the volume V1 of the first widened section 21 to the volume V2 of the second widened section 22, V1 / V2, is approximately 0.8 to 1.2, and in this embodiment, these volumes are substantially the same.

[0047] In another embodiment, the first widening portion 21 is positioned closer to the tread edge Te than the second widening portion 22, and the volume V1 of the first widening portion 21 may be larger than the volume V2 of the second widening portion 22. In this case, the volume V1 is preferably 120% to 150% of the volume V2. In this embodiment, the first widening portion 21 closer to the tread edge Te can exhibit excellent water absorption, thereby enhancing ice performance, and furthermore, an improvement in wandering performance can be expected.

[0048] In yet another embodiment, the first widening portion 21 is positioned closer to the tread edge Te than the second widening portion 22, and the volume V1 of the first widening portion 21 may be smaller than the volume V2 of the second widening portion 22. In this case, the volume V1 is preferably 50% to 80% of the volume V2. In this embodiment, because the volume of the first widening portion 21 closer to the tread edge Te is small, the rigidity near the tread edge Te is improved, and load durability is improved.

[0049] As shown in Figure 2, the tread portion 2 of this embodiment includes a cap rubber layer Cg and a base rubber layer Bg. The cap rubber layer Cg constitutes the tread surface of the tread portion 2. The base rubber layer Bg is positioned radially inward of the cap rubber layer Cg. The rubber hardness of the cap rubber layer Cg is, for example, 40 to 65°. The base rubber layer Bg has a higher rubber hardness than the cap rubber layer Cg. The rubber hardness of the base rubber layer Bg is, for example, 50 to 75°. In this specification, rubber hardness refers to the hardness measured by a durometer type A in an environment of 23°C, in accordance with JIS-K6253.

[0050] In this embodiment, the distance t2 from the tread surface of the tread portion 2 to the boundary 25 between the cap rubber layer Cg and the base rubber layer Bg is set to 30% to 70% of the total thickness t1 of the tread rubber. On the other hand, as shown in Figure 5, the minimum distance t3 in the tire radial direction from the boundary 25 to the bottom of the first widened portion 21 and the second widened portion 22 is 0.5 mm or more, preferably 1.0 to 4.0 mm. This effectively suppresses the peeling of the rubber at the boundary 25 caused by deformation of the first widened portion 21 and the second widened portion 22.

[0051] Although a tire according to one embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiments described above and can be implemented in various modified forms.

[0052] [Note] The present invention includes the following embodiments.

[0053] [Invention 1] A tire having a tread portion, The tread portion includes a plurality of circumferential grooves extending continuously in the tire circumferential direction, a plurality of lateral grooves extending in the tire axial direction, and a plurality of first blocks. Each of the aforementioned plurality of first blocks is provided with at least one first sipe, The first sipe extends in a zigzag pattern in both a cross-section perpendicular to the sipe's length and a cross-section parallel to the tread surface of the first block. Each of the first sipes is divided in the longitudinal direction of the sipe into at least a first portion and a second portion by at least one tie bar that locally rises outward in the radial direction of the tire from the bottom of the sipe and terminates before the tread surface. The bottom of the sipe of each of the first and second portions extends in a zigzag pattern in a cross-section parallel to the tread surface of the first block, A first widening portion, having a circular cross-section, is connected to the bottom of the sipe of the first portion, and the first widening portion has a groove width greater than the width of the first portion, and in a plan view of the tread, the first widening portion extends in a zigzag pattern along the bottom of the sipe of the first portion. A second widening section, whose cross-section is circular, is connected to the bottom of the sipe of the second portion, and the second widening section has a groove width greater than the width of the second portion, and in a plan view of the tread, the second widening section extends in a zigzag pattern along the bottom of the sipe of the second portion. The first widening section and the second widening section are not in communication with each other. tire. [2nd Invention] The tire according to the present invention 1, wherein in a cross-section parallel to the tread surface of the first block, the zigzag shape of the first widening portion and the second widening portion includes an arc-shaped zigzag corner. [Invention 3] The tire according to invention 1 or 2, wherein the zigzag pitch of the first widening portion is equal to the zigzag pitch of the second widening portion. [4th Invention] The tire according to invention 1 or 2, wherein the zigzag pitch of the first widening portion is different from the zigzag pitch of the second widening portion. [5th ​​Invention] The tire according to invention 1 or 2, wherein the first widening portion extends in a zigzag pattern over its entire length. [Invention 6] The tire according to invention 1 or 2, wherein the plurality of first blocks constitute the tread end of the tread portion. [7th Invention] The tire according to invention 1 or 2, wherein the height from the bottom of the first widening section to the outer end of the tie bar in the tire radial direction is 30% to 80% of the maximum depth from the tread surface of the first block to the bottom of the first widening section. [8th Invention] The tire according to invention 1 or 2, wherein the width of the tie bar in a cross-section along the longitudinal direction of the first sipe is 0.5 to 5.0 mm. [Invention 9] The tread portion includes a cap rubber layer that constitutes its tread surface, and a base rubber layer disposed radially inward of the cap rubber layer and having a greater hardness than the cap rubber layer. The tire according to invention 1 or 2, wherein at least a portion of the first widening portion and the second widening portion are disposed within the base rubber layer. [Invention 10] The tire according to the present invention, wherein the minimum distance in the radial direction of the tire from the boundary between the cap rubber layer and the base rubber layer to the bottom of the first widened portion and the second widened portion is 0.5 mm or more. [Explanation of Symbols]

[0054] 2 Tread section 3 Circumferential groove 10 Yokomizo 13. Block 1 15. First Sipe 16 Part 1 16d Sipe bottom of the first section 17 Part 2 17d Sipe bottom of the second section 18 Tie Bar 21. First widening section 22. Second widening section

Claims

1. A tire having a tread portion, The tread portion includes a plurality of circumferential grooves extending continuously in the tire circumferential direction, a plurality of lateral grooves extending in the tire axial direction, and a plurality of first blocks. Each of the aforementioned plurality of first blocks is provided with at least one first sipe, The first sipe extends in a zigzag pattern in both a cross-section perpendicular to the sipe's length and a cross-section parallel to the tread surface of the first block. Each of the first sipes is divided in the lengthwise direction of the sipe into at least a first portion and a second portion by at least one tie bar that locally rises outward in the radial direction of the tire from the bottom of the sipe and terminates before the tread surface. The bottom of the sipe of the first and second portions extends in a zigzag pattern in a cross-section parallel to the tread surface of the first block. A first widening portion, having a circular cross-section, is connected to the bottom of the sipe of the first portion, and the first widening portion has a groove width greater than the width of the first portion, and in a plan view of the tread, the first widening portion extends in a zigzag pattern along the bottom of the sipe of the first portion. A second widening section, whose cross-section is circular, is connected to the bottom of the sipe of the second portion, and the second widening section has a groove width greater than the width of the second portion, and in a plan view of the tread, the second widening section extends in a zigzag pattern along the bottom of the sipe of the second portion. The first widening section and the second widening section are not in communication with each other. tire.

2. The tire according to claim 1, wherein in a cross-section parallel to the tread surface of the first block, the zigzag shape of the first widened portion and the second widened portion includes an arc-shaped zigzag corner.

3. The tire according to claim 1 or 2, wherein the zigzag pitch of the first widened portion is equal to the zigzag pitch of the second widened portion.

4. The tire according to claim 1 or 2, wherein the zigzag pitch of the first widened portion is different from the zigzag pitch of the second widened portion.

5. The tire according to claim 1 or 2, wherein the first widening portion extends in a zigzag pattern over its entire length.

6. The tire according to claim 1 or 2, wherein the plurality of first blocks constitute the tread end of the tread portion.

7. The tire according to claim 1 or 2, wherein the height from the bottom of the first widening portion to the outer end of the tie bar in the tire radial direction is 30% to 80% of the maximum depth from the tread surface of the first block to the bottom of the first widening portion.

8. The tire according to claim 1 or 2, wherein the width of the tie bar in a cross-section along the length of the first sipe is 0.5 to 5.0 mm.

9. The tread portion includes a cap rubber layer that constitutes its tread surface, and a base rubber layer disposed radially inward of the cap rubber layer and having a greater hardness than the cap rubber layer. The tire according to claim 1 or 2, wherein at least a portion of the first widened portion and the second widened portion is disposed within the base rubber layer.

10. The tire according to claim 9, wherein the minimum distance in the radial direction of the tire from the boundary between the cap rubber layer and the base rubber layer to the bottom of the first widened portion and the second widened portion is 0.5 mm or more.

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