tire

Abstract

To provide a tire capable of exhibiting excellent on-snow performance.SOLUTION: Provided is a tire with a tread part 2. A first edge 16 in a peripheral direction groove 3 extends at an angle of 30° or less in a tire axial direction to a first side A1 in a tire peripheral direction of a connection part 15. A second edge 17 and a third edge 18 in the peripheral direction groove 3 are arranged to a second side A2 in the tire peripheral direction of the connection part 15. The third edge 18 is arranged inside in the tire axial direction from the second edge 17. The second edge 17 and the third edge 18 are inclined in opposite directions to each other with respect to the tire peripheral direction, and also extend in a direction moving closer to each other toward the second side A2 from the first side A1. A crown lateral groove 10 is connected to the first side A1 of the connection part, and a groove width W2 of the peripheral direction groove 3 at the closest position where the second edge 17 and the third edge 18 are closest to each other is smaller than a groove width W1 of the crown lateral groove on an extension line of the first edge.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This disclosure relates to tires.

Background Art

[0002] In Patent Document 1 below, a tire for an SUV assumed for off-road driving has been proposed. By specifying the crown block, it is expected to improve the grip performance on locked road surfaces and snow-mud road surfaces while maintaining the durability of the crown block.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, there has been an increasing demand for further improvement in snow performance of tires, especially for improvement in traction performance and braking performance on snow.

[0005] This disclosure has been devised in view of the above actual situation, and the main object is to provide a tire that can exhibit excellent snow performance.

Means for Solving the Problems

[0006] This disclosure relates to a tire having a tread portion, the tread portion including a tread end, at least one circumferential groove extending in a zigzag pattern continuously in the circumferential direction of the tire between the tread end and the tire equator, and a plurality of crown transverse grooves extending from the circumferential groove toward the tire equator, the circumferential groove including a connecting portion to which the plurality of crown transverse grooves are connected, each of the connecting portions including a first edge, a second edge and a third edge that are separated from each other, the first edge extending from the first side of the connecting portion in the circumferential direction of the tire at an angle of 30° or less with respect to the tire axis, and the second edge and the The third edge is positioned on the second side of the connecting portion in the tire circumferential direction, and is positioned further inward in the tire axial direction than the second edge, and the second and third edges are inclined in opposite directions with respect to the tire circumferential direction and extend toward each other from the first side toward the second side, and the crown lateral groove is connected to the first side of the connecting portion, and the groove width W2 of the circumferential groove at the closest approach position where the second and third edges are closest is smaller than the groove width W1 of the crown lateral groove on the extension of the first edge, in this tire. [Effects of the Invention]

[0007] The tire disclosed herein, by adopting the above configuration, can exhibit excellent performance on snow. [Brief explanation of the drawing]

[0008] [Figure 1] This is an exploded view of the tread portion of a tire according to one embodiment of the present disclosure. [Figure 2] This is an enlarged view of the circumferential grooves in Figure 1. [Figure 3] This is a magnified view of the connection point in Figure 2. [Figure 4] Figure 1 is an enlarged view of the Crown Land area. [Figure 5] Figure 4 is an enlarged view of the first crown block. [Figure 6] Figure 4 is an enlarged view of the second crown block. [Figure 7]Figure 1 is an enlarged view of the shoulder area. [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of the present disclosure will be described 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 this embodiment is suitably used, for example, as a pneumatic tire for an SUV that is also intended for off-road driving. However, the tire 1 of this disclosure is not limited to this embodiment.

[0010] The tread portion 2 of the tire 1 in this embodiment includes two tread ends Te, at least one circumferential groove 3, and a plurality of crown lateral grooves 10. The tread portion 2 in this embodiment has a pattern that is point-symmetric with respect to a point on the tire equator C. Therefore, the pattern elements between one tread end Te and the tire equator C and the pattern elements between the other tread end Te and the tire equator C have substantially the same configuration, except that their orientation in the circumferential direction of the tire is opposite. However, the tire 1 of this disclosure is not limited to this embodiment.

[0011] The tread edge Te is the outermost contact point in the axial direction 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.

[0012] "Normal condition" refers to the state in the case of pneumatic tires for which various standards are defined, where the tire is mounted on a normal rim, filled to the normal internal pressure, and under no load. For tires for which various standards are not defined, or for non-pneumatic tires, the normal condition refers to the standard operating condition according to the intended use of the tire, and is under no load. Unless otherwise specified in this specification, the dimensions of each part of the tire are values ​​measured under normal condition. Furthermore, unless otherwise specified in this specification, known methods may be appropriately applied to the measurement methods of the aforementioned dimensions and material composition.

[0013] A "standard rim" is the rim specified for each tire within the standard 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.

[0014] "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."

[0015] "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.

[0016] The circumferential grooves 3 extend in a zigzag pattern continuously in the circumferential direction of the tire between the tread edge Te and the tire equator C. The tread portion 2 of this embodiment is provided with two circumferential grooves 3 flanking the tire equator C. The crown lateral groove 10 of this embodiment connects these two circumferential grooves 3. Furthermore, the tread portion 2 of this embodiment includes a crown land portion 4 divided between the two circumferential grooves 3 and a shoulder land portion 5 divided on the tread edge Te side of the circumferential grooves 3.

[0017] The circumferential groove 3 includes, for example, a portion inclined at an angle of 10 to 40° with respect to the tire circumferential direction. The tire axial distance L3 from the tire equator C to the inner end in the tire axial direction of the circumferential groove 3 (the end closest to the tire equator C) is, for example, 5% to 15% of the tread width TW. Also, the tire axial distance L4 from the tire equator C to the outer end in the tire axial direction of the circumferential groove 3 (the end closest to the tread end Te) is, for example, 25% to 35% of the tread width TW. Note that the tread width TW is the maximum tire axial distance from one tread end Te to the other tread end Te in the normal state.

[0018] FIG. 2 shows an enlarged view of one circumferential groove 3 (the circumferential groove 3 on the left side in FIG. 1) of FIG. 1. As shown in FIG. 2, the circumferential groove 3 includes connection portions 15 to which a plurality of crown cross grooves 10 are respectively connected.

[0019] FIG. 3 shows an enlarged view of one connection portion 15. In FIG. 3, dots are provided on the connection portion 15. As shown in FIG. 3, each of the connection portions 15 includes a first edge 16, a second edge 17, and a third edge 18 that are separated from each other. The first edge 16 extends at an angle θ1 of 30° or less with respect to the tire axial direction on the first side A1 (the lower side in each figure of this specification) in the tire circumferential direction of the connection portion 15. The second edge 17 and the third edge 18 are arranged on the second side A2 (the upper side in each figure of this specification) in the tire circumferential direction of the connection portion 15. Also, the third edge 18 is arranged closer to the tire axial inner side than the second edge 17.

[0020] The second edge 17 and the third edge 18 are inclined in opposite directions with respect to the tire circumferential direction and extend in a direction approaching each other from the first side A1 to the second side A2.

[0021] Furthermore, in this disclosure, the crown lateral groove 10 is connected to the first side A1 of the connection portion 15. This configuration means that, at least, the crown lateral groove 10 is connected to the connection portion 15 on the first side A1 than the second edge 17 and the third edge 18. Also, the crown lateral groove 10 crosses the extension of the first edge 16. The groove width W2 of the circumferential groove 3 at the closest approach position where the second edge 17 and the third edge 18 are closest is smaller than the groove width W1 of the crown lateral groove 10 on the extension of the first edge 16. The tire 1 of this disclosure can exhibit excellent snow performance by adopting the above configuration. The mechanism is as follows.

[0022] At the connection point 15 between the circumferential groove 3 and the crown lateral groove 10, the formation of hard snow columns can be expected when driving on snow. Furthermore, the snow columns compacted at the connection point 15 are sheared by the first edge 16 positioned at the aforementioned angle θ1, thereby providing a large reaction force (snow column shear force) in the circumferential direction of the tire.

[0023] Furthermore, in this disclosure, the groove width W1 of the crown lateral groove 10 and the groove width W2 of the circumferential groove 3 are defined as described above. As a result, when driving on snow, the snow in the crown lateral groove 10 and the connecting portion 15 moves towards the second edge 17 and third edge 18 using the rotation of the tire, and is strongly compressed between these edges. This action further increases the reaction force described above, thereby improving braking performance and traction performance on snow. The tire 1 of this disclosure can exhibit excellent snow performance through the above mechanism.

[0024] 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 this disclosure 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 this disclosure 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.

[0025] In this embodiment, the first edge 16, the second edge 17, and the third edge 18 are each connected to groove walls arranged at an angle of 15° or less with respect to the tire radial direction (not shown). However, the disclosure is not limited to this embodiment, and these edges may also be connected to chamfered surfaces arranged at an angle of 30 to 60° with respect to the tire radial direction, for example.

[0026] In a plan view of the tread, the first edge 16 is configured as a linearly extending line segment. The length L5 of the first edge 16 (the so-called peripheral length along the length of the sipe) is, for example, 5% to 10% of the tread width TW (shown in Figure 1, and the same applies hereafter). Furthermore, the angle θ1 of the first edge 16 with respect to the tire axis is preferably 10 to 20°. Such a first edge 16 can provide snow column shear force in a well-balanced manner in the circumferential and axial directions of the tire.

[0027] In a plan view of the tread, the second edge 17 is composed of a linearly extending line segment. The length L6 of the second edge 17 in the tire axial direction (the so-called peripheral length along the length of the sipe) is, for example, 80% to 120% of the length L5 of the first edge 16.

[0028] As shown in Figure 2, the first edge 16 and the second edge 17 extend in a direction that approaches each other from the tire equator C side toward the tread edge Te side. The angle θ2 between the first edge 16 and the second edge 17 is, for example, 30 to 40°. Furthermore, it is desirable that the minimum distance La between the first edge 16 and the second edge 17 is greater than the groove width W1 (shown in Figure 3). Specifically, it is desirable that the distance La is 130% to 170% of the groove width W1. This arrangement of the first edge 16 and the second edge 17 allows the snow in the connection portion 15 to be strongly compressed in the tire axial direction when driving on snow, and also prevents snow from getting stuck in the connection portion 15.

[0029] The third edge 18 is configured, for example, as part of the edge of a block adjacent to the tire equator C side of the circumferential groove 3. The angle θ3 between the second edge 17 and the third edge 18 is, for example, acute, preferably 60 to 80°, and more preferably 65 to 75°. Such second edge 17 and third edge 18 can firmly compact the snow within the connection 15 and can prevent snow from getting stuck within the connection 15.

[0030] As shown in Figure 3, the groove width W2 of the circumferential groove 3 is preferably 30% or more, more preferably 50% or more, preferably 90% or less, and more preferably 80% or less of the groove width W1 of the crown lateral groove 10. This makes it difficult for snow to accumulate in the connection part 15, and excellent snow performance is maintained over time.

[0031] As shown in Figure 2, the circumferential groove 3 of this embodiment includes a plurality of convex groove portions 20 that are curved in a direction that is convex toward the tread edge Te side. In this embodiment, the convex groove portions 20 and the aforementioned connecting portion 15 are arranged alternately in the circumferential direction of the tire. The convex groove portions 20 also include a first groove portion 21 and a second groove portion 22. The first groove portion 21 is connected to the first side A1 of the connecting portion 15. The second groove portion 22 of the convex groove portion 20 is connected to a crown lateral groove 10 that is different from the crown lateral groove 10 connected to the aforementioned connecting portion 15. The convex groove portion 20 including the first groove portion 21 and the second groove portion 22 can strongly compress snow inside, further improving snow performance.

[0032] The groove width W3 at the point closest to the connection point 15 of the first groove 21 is preferably larger than the groove width W2 (shown in Figure 3). Specifically, the groove width W3 is 130% to 170% of the groove width W2. Such a first groove 21 helps to improve both handling stability on dry surfaces (hereinafter sometimes simply referred to as "handling stability") and snow performance in a balanced manner.

[0033] The convex groove section 20 includes, for example, a narrow section 20a in the central part of the tire circumferential direction, where the groove width is smaller than that of other parts. The groove width W4 of the narrow section 20a is, for example, 80% to 120% of the groove width W2 (shown in Figure 3). Such a narrow section 20a can further compact the snow within the convex groove section 20 when driving on snow.

[0034] Figure 4 shows an enlarged view of the crown land portion 4. As shown in Figure 4, the crown lateral groove 10 is inclined toward the first side A1 toward the tire equator C from the circumferential groove 3 shown in Figure 2. The crown lateral groove 10 also alternately includes a first crown lateral groove 11 communicating with the connecting portion 15 and a second crown lateral groove 12 communicating with the convex groove portion 20 in the circumferential direction of the tire. The first crown lateral groove 11 is curved, for example, in a direction that is convex toward the first side A1. The second crown lateral groove 12 is curved, for example, in a direction that is convex toward the second side A2. Such first and second crown lateral grooves 11 and 12 provide snow column shear force in multiple directions, which helps to exhibit excellent snow performance.

[0035] The crown land portion 4 is provided with a crown longitudinal groove 13 that connects the first crown transverse groove 11 and the second crown transverse groove 12. The crown longitudinal groove 13 is, for example, located on the tire equator C and is inclined at an angle of 5 to 15° with respect to the circumferential direction of the tire.

[0036] The crown land portion 4 alternately comprises a first region 4A and a second region 4B in the circumferential direction of the tire, each divided by a plurality of crown lateral grooves 10. The first region 4A includes a first crown block 26 having a first tread surface 26a. In this embodiment, the first region 4A is composed of one first crown block 26. The second region 4B includes at least one second crown block 27 having a second tread surface 27a. Preferably, one second region 4B includes two or more second crown blocks 27, and in this embodiment, the second region 4B is composed of two second crown blocks 27. The second crown blocks 27 are divided by circumferential grooves 3, crown lateral grooves 10, and crown longitudinal grooves 13, and are adjacent to the first crown block 26 via the crown lateral grooves 10.

[0037] Figure 5 shows an enlarged plan view of the first crown block 26. As shown in Figure 5, in a plan view of the tread, the first crown block 26 is arranged such that the longest possible straight line 30 that can be drawn on the first tread surface 26a has an angle θ4 with respect to the tire axis that is less than 45°. Also, the first tread surface 26a of the first crown block 26 has a maximum length L2 in the direction perpendicular to the longest straight line 30 that is 50% or less of the length L1 of the longest straight line 30. Such a first crown block 26 is easily deformable in the circumferential direction of the tire, and can strongly compact the snow in the crown lateral groove 10 when driving on snow, which helps to improve snow performance.

[0038] Figure 6 shows an enlarged plan view of the second crown block 27. As shown in Figure 6, the second tread surface 27a of the second crown block 27 is a polygonal shape from which multiple equal-diagonal lines 35 can be drawn, dividing the second tread surface 27a into two parts having an area of ​​45% or more. The equal-diagonal lines include the longest diagonal line 36 and the shortest diagonal line 37. The longest diagonal line 36 means the one with the longest length among the multiple equal-diagonal lines 35. The shortest diagonal line 37 means the one with the shortest length among the multiple equal-diagonal lines 35. In this specification, a polygonal shape includes both a convex polygonal shape in which all interior angles are less than 180°, and a concave polygonal shape that includes interior angles greater than 180°. In this embodiment, the first tread surface 26a and the second tread surface 27a are concave polygonal shapes.

[0039] In this embodiment, it is desirable that the length L7 of the maximum diagonal 36 is 160% or less of the length L8 of the minimum diagonal 37. Such a second crown block 27 has greater rigidity in the tire circumferential direction compared to the first crown block 26, and can maintain handling stability on dry road surfaces.

[0040] As shown in Figure 4, the first crown block 26 is provided, for example, on the tire equator C, and the second crown block 27 is provided one on each side of the tire equator C in the direction of the tire axis. However, the present disclosure is not limited to such embodiments.

[0041] As shown in Figure 5, from the viewpoint of ensuring snow column shear force in the tire axial direction, the angle θ5 of the maximum straight section 30 with respect to the tire axial direction is, for example, 30° or more. Also, the length L1 of the maximum straight section 30 is, for example, 35% to 55% of the tread width TW (shown in Figure 1). Such a first crown block 26 helps to improve both handling stability and snow performance in a balanced way.

[0042] In the first crown block 26, the length L2 is, for example, 25% to 50% of the length L1 of the maximum straight section 30, preferably 30% to 40%. This suppresses uneven wear of the first crown block 26 while achieving the above-mentioned effects.

[0043] The first crown block 26 includes a main portion 40 and sub-parts 41 connected to both sides of the main portion 40 in the tire axial direction. The main portion 40 includes two edges 40a extending parallel to each other. The sub-parts 41 include two edges 41a extending toward each other toward the tire axial end of the first crown block 26. The angle θ6 between the two edges 41a of the sub-parts 41 is, for example, 30 to 60°, preferably 40 to 50°. With such a first crown block 26, when driving on snow, the sub-parts 41 can deform appropriately to expel snow from the circumferential grooves 3 and the crown lateral grooves 10, and can maintain excellent snow performance.

[0044] As shown in Figure 6, in the second crown block 27, it is desirable that the length L8 of the minimum diagonal 37 is 60% or more of the length L7 of the maximum diagonal 36. This reduces the anisotropy of the rigidity of the second crown block 27, resulting in a well-balanced improvement in traction performance and cornering performance on dry surfaces.

[0045] In this embodiment, the longest straight line 30 of the first tread surface 26a (shown in Figure 5) and the longest diagonal 36 of the second tread surface 27a are inclined in the same direction with respect to the tire axis. The angle θ7 of the longest diagonal 36 of the second tread surface 27a with respect to the tire circumferential direction is, for example, 45° or less, and preferably 30 to 40°. The angle θ8 of the shortest diagonal 37 of the second crown block 27 with respect to the tire axis is, for example, 45° or less, and preferably 5 to 15°. However, the second crown block 27 is not limited to this embodiment.

[0046] The maximum length L10 of the second tread surface 27a of the second crown block 27 in the tire circumferential direction is preferably 130% to 150% of the length L9 (shown in Figure 4) of the first tread surface 26a of the first crown block 26 on the tire equator C. This ensures the circumferential rigidity of the second crown block 27 and improves traction performance on dry surfaces.

[0047] From the viewpoint of ensuring cornering performance on dry surfaces, it is desirable that the maximum length L11 of the second tread surface 27a of the second crown block 27 in the tire axial direction be 60% to 80% of the aforementioned length L10 of the second tread surface 27a of the second crown block 27.

[0048] Preferably, the second crown block 27 includes a crown recess 28 in which the side wall on the crown lateral groove 10 side is partially recessed. In a preferred embodiment, of the two second crown blocks 27 included in the second region 4B, one second crown block 27 includes a crown recess 28 on the first side A1 in the tire circumferential direction, and the other second crown block 27 includes a crown recess 28 on the second side A2 in the tire circumferential direction. This further improves snow performance.

[0049] As shown in Figure 4, the first crown block 26 and the second crown block 27 are each provided with a plurality of crown sipes 29. The crown sipes 29 are preferably, for example, locally bent. Such crown sipes 29 can improve snow performance while maintaining the rigidity of the first crown block 26 and the second crown block 27. In this specification, "sipe" means a groove-like body having a small width (meaning a recess having a longitudinal direction) in which the width between the two inner walls is 1.5 mm or less. The sipe may include a chamfered portion at the opening or a so-called flask bottom with an increased width at the bottom.

[0050] Figure 7 shows an enlarged view of the shoulder land portion 5 of Figure 1. The shoulder land portion 5 includes, for example, a plurality of shoulder blocks 45 separated by a plurality of shoulder lateral grooves 44 extending in the direction of the tire axis.

[0051] It is desirable that at least one of the shoulder lateral grooves 44 extends from the aforementioned connection portion 15 of the circumferential groove 3 toward the tread edge Te. Such shoulder lateral grooves 44, together with the connection portion 15, help to improve snow performance.

[0052] The shoulder block 45 preferably includes a shoulder recess 46 in which the side wall on the circumferential groove 3 side is partially recessed. Such a shoulder recess 46 can further improve snow performance.

[0053] The shoulder block 45 is provided with multiple shoulder sipes 47. Ideally, the shoulder sipes 47 should be locally bent. Such shoulder sipes 47 can improve snow performance while maintaining the rigidity of the shoulder block 45.

[0054] Although a tire according to one embodiment of the present disclosure has been described in detail above, the present disclosure is not limited to the specific embodiment described above and can be implemented in various modified forms.

[0055] [Note] This disclosure includes the following aspects.

[0056] [Disclosure 1] A tire having a tread portion, The tread portion includes a tread edge, at least one circumferential groove extending in a zigzag pattern continuously in the circumferential direction of the tire between the tread edge and the tire equator, and a plurality of crown lateral grooves extending from the circumferential groove toward the tire equator. The circumferential groove includes a connecting portion to which each of the plurality of crown transverse grooves is connected. Each of the aforementioned connection portions includes a first edge, a second edge, and a third edge that are separated from each other. The first edge extends from the first side of the connecting portion in the circumferential direction of the tire at an angle of 30° or less with respect to the tire axis. The second edge and the third edge are arranged on the second side of the connecting portion in the tire circumferential direction. The third edge is positioned further inward in the tire axial direction than the second edge. The second edge and the third edge are inclined in opposite directions with respect to the circumferential direction of the tire and extend toward each other from the first side toward the second side. The crown lateral groove is connected to the first side of the connection portion, The groove width W2 of the circumferential groove at the closest approach position where the second edge and the third edge are closest is smaller than the groove width W1 of the crown transverse groove on the extension of the first edge. tire. [Disclosure 2] The tire according to Disclosure 1, wherein the groove width W2 is 30% to 90% of the groove width W1. [Disclosure 3] The tire according to Disclosure 1, wherein the groove width W2 is 50% to 80% of the groove width W1. [Disclosure 4] The tire according to any one of disclosures 1 to 3, wherein the angle of the first edge with respect to the tire axis is 10 to 20°. [Disclosure 5] The first edge and the second edge extend in a direction that approaches each other from the tire equator side toward the tread edge side, The tire according to any one of disclosures 1 to 4, wherein the minimum distance La between the first edge and the second edge is greater than the groove width W1. [Disclosure 6] The tire according to any one of disclosures 1 to 5, wherein each of the first edge, the second edge, and the third edge has a series of groove walls arranged at an angle of 15° or less with respect to the tire radial direction. [Disclosure 7] The circumferential groove includes a first groove portion that is connected to the first side of the connecting portion, The tire according to any one of disclosures 1 to 6, wherein the groove width W3 at the closest point of the first groove to the connection portion is greater than the groove width W2. [Disclosure 8] The tire according to any one of disclosures 1 to 7, wherein the circumferential groove includes a portion inclined at an angle of 10 to 40° with respect to the circumferential direction of the tire. [Disclosure 9] The tire according to any one of disclosures 1 to 8, wherein the crown lateral groove is inclined toward the first side from the circumferential groove toward the tire equator. [Disclosure 10] The tire according to any one of disclosures 1 to 9, wherein the tread portion includes at least one shoulder lateral groove extending from the connection portion toward the tread end. [Explanation of Symbols]

[0057] 2 Tread section 3 Circumferential groove 10 Crown lateral groove 15 Connection part 16. First Edge 17. Second Edge 18 Third Edge W1 Groove width of the crown lateral groove on the extension of the first edge W2 Groove width of the circumferential groove at the closest approach position A1 First side in the circumferential direction of the tire Te tread section C Tire Equator

Claims

1. A tire having a tread portion, The tread portion includes a tread edge, at least one circumferential groove extending in a zigzag pattern continuously in the circumferential direction of the tire between the tread edge and the tire equator, and a plurality of crown lateral grooves extending from the circumferential groove toward the tire equator. The circumferential groove includes a connecting portion to which each of the plurality of crown transverse grooves is connected. Each of the aforementioned connecting portions includes a first edge, a second edge, and a third edge that are separated from each other. The first edge extends from the first side of the connecting portion in the circumferential direction of the tire at an angle of 30° or less with respect to the tire axis. The second edge and the third edge are arranged on the second side of the connecting portion in the tire circumferential direction. The third edge is positioned further inward in the tire axial direction than the second edge. The second edge and the third edge are inclined in opposite directions with respect to the circumferential direction of the tire and extend toward each other from the first side toward the second side. The crown lateral groove is connected to the first side of the connection portion, The groove width W2 of the circumferential groove at the closest approach position where the second edge and the third edge are closest is smaller than the groove width W1 of the crown transverse groove on the extension of the first edge. The angle of the first edge with respect to the tire axis is 10 to 20°. tire.

2. A tire having a tread portion, The tread portion includes a tread edge, at least one circumferential groove extending in a zigzag pattern continuously in the circumferential direction of the tire between the tread edge and the tire equator, and a plurality of crown lateral grooves extending from the circumferential groove toward the tire equator. The circumferential groove includes a connecting portion to which each of the plurality of crown transverse grooves is connected. Each of the aforementioned connecting portions includes a first edge, a second edge, and a third edge that are separated from each other. The first edge extends from the first side of the connecting portion in the circumferential direction of the tire at an angle of 30° or less with respect to the tire axis. The second edge and the third edge are arranged on the second side of the connecting portion in the tire circumferential direction. The third edge is positioned further inward in the tire axial direction than the second edge. The second edge and the third edge are inclined in opposite directions with respect to the circumferential direction of the tire and extend toward each other from the first side toward the second side. The crown lateral groove is connected to the first side of the connection portion, The groove width W2 of the circumferential groove at the closest approach position where the second edge and the third edge are closest is smaller than the groove width W1 of the crown transverse groove on the extension of the first edge. The groove width W2 is 50% to 80% of the groove width W1. The first edge and the second edge extend in a direction that approaches each other from the tire equator side toward the tread edge side, The minimum distance La between the first edge and the second edge is greater than the groove width W1. tire.

3. The tire according to claim 1, wherein the groove width W2 is 30% to 90% of the groove width W1.

4. The tire according to any one of claims 1 to 3, wherein each of the first edge, the second edge, and the third edge has a series of groove walls arranged at an angle of 15° or less with respect to the radial direction of the tire.

5. The circumferential groove includes a first groove portion connected to the first side of the connecting portion, The tire according to any one of claims 1 to 4, wherein the groove width W3 at the point closest to the connection portion of the first groove is greater than the groove width W2.

6. The tire according to any one of claims 1 to 5, wherein the circumferential groove includes a portion inclined at an angle of 10 to 40° with respect to the circumferential direction of the tire.

7. The tire according to any one of claims 1 to 6, wherein the crown lateral groove is inclined toward the first side toward the tire equator from the circumferential groove.

8. The tire according to any one of claims 1 to 7, wherein the tread portion includes at least one shoulder lateral groove extending from the connecting portion toward the tread end.

Images