tire

Abstract

To provide a tire capable of improving on-ice performance and noise performance.SOLUTION: There is provided a tire having a tread part. In each first pitch region 18, a ratio D1 / Pa of a shortest distance D1 between a first shoulder mechanism 31 and a first crown lateral mechanism 11, and a first pitch length Pa of the first pitch region 18, satisfies a following formula (1) or (2), and a ratio D2 / Pa of a shortest distance D2 between a second shoulder lateral groove 32 and a second crown lateral groove 12, and the first pitch length Pa, satisfies a following formula (3) or (4): the formula 1 is 0%<D1 / Pa≤5%; the following formula 2 is 28%≤D1 / Pa≤34%; the following formula 3 is 0%<D2 / Pa≤5%; the following formula 4 is 28%≤D2 / Pa≤34%, where T / L>0.022 is satisfied, and T is a total number of the first pitch regions, and L is a tire circumferential length.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a tire.

Background Art

[0002] Patent Document 1 below describes a radial tire for heavy loads having a tread portion. In this tread portion, a central longitudinal main groove passing through the tire equator and outer longitudinal main grooves on both sides thereof are provided. As a result, the tread surface is divided into four ribs. Each rib is provided with a plurality of transverse grooves. It is expected that the performance on ice and snow will be improved by these transverse grooves.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, as the area ratio (sea ratio) of the transverse grooves in the tread portion increases, the performance on ice and snow improves, but there is a problem that the pitch noise caused by the transverse grooves increases when driving on a dry road surface.

[0005] The present disclosure has been devised in view of the above actual situation, and the main object is to provide a tire capable of improving the performance on ice and snow and the noise performance.

Means for Solving the Problems

[0006] The present disclosure relates to a tire having a tread portion, wherein the tread portion has a tread pattern in which one pitch region constituting a pattern unit is arranged in the tire circumferential direction. The one pitch region includes a first tread end, a second tread end arranged on the opposite side in the tire axial direction of the first tread end, a plurality of circumferential grooves continuously extending in the tire circumferential direction between the first tread end and the second tread end, and a plurality of lateral grooves. The plurality of circumferential grooves include a first shoulder circumferential groove continuously extending in the tire circumferential direction on the first tread end side, and a crown circumferential groove continuously extending in the tire circumferential direction adjacent to the first shoulder circumferential groove. The plurality of lateral grooves include a plurality of first shoulder lateral grooves extending from the first shoulder circumferential groove toward the first tread end side and terminating without reaching the first tread end, a plurality of second shoulder lateral grooves extending from the first tread end toward the first shoulder circumferential groove side and terminating without reaching the first shoulder circumferential groove, a plurality of first crown lateral grooves extending from the crown circumferential groove toward the first shoulder circumferential groove side and terminating without reaching the first shoulder circumferential groove, and a plurality of second crown lateral grooves extending from the first shoulder circumferential groove toward the crown circumferential groove side and terminating without reaching the crown circumferential groove. The first shoulder lateral grooves and the second shoulder lateral grooves are alternately arranged in the tire circumferential direction in the one pitch region, the first crown lateral grooves and the second crown lateral grooves are alternately arranged in the tire circumferential direction in the one pitch region, and in each one pitch region, the ratio D1 / Pa of the shortest distance D1 in the tire circumferential direction between the first shoulder lateral groove and the first crown lateral groove to the one pitch length Pa in the tire circumferential direction of the one pitch region satisfies the following formula (1) or (2), and the ratio D2 / Pa of the shortest distance D2 in the tire circumferential direction between the second shoulder lateral groove and the second crown lateral groove to the one pitch length Pa satisfies the following formula (3) or (4). 0% < D1 / Pa ≦ 5% (where T / L ≦ 0.022)…(1) 28% ≦ D1 / Pa ≦ 34% (where T / L > 0.022)…(2) 0% < D2 / Pa ≦ 5% (where T / L ≦ 0.022)…(3) 28% ≤ D2 / Pa ≤ 34% (where T / L > 0.022) ... (4) Here, T: Total number of pitch regions L: Tire circumference [Effects of the Invention]

[0007] By adopting the above configuration, the tires disclosed herein can improve both ice and snow performance and noise performance. [Brief explanation of the drawing]

[0008] [Figure 1] This is an exploded view of the tread portion of a tire showing one embodiment of the present disclosure. [Figure 2] This is an enlarged view of the first shoulder land area and the first crown land area in Figure 1. [Figure 3] Figure 1 shows enlarged views of the first and second shoulder land areas. [Figure 4] Figure 1 shows enlarged views of the first shoulder and second crown areas. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described below with reference to the drawings. It should be understood that the drawings contain exaggerations and representations that differ from the actual structural proportions in order to aid in understanding the content of the disclosure. Furthermore, the same or common elements are denoted by the same reference numerals throughout each embodiment, and redundant explanations are omitted. Moreover, the specific configurations shown in the embodiments and drawings are for the purpose of understanding the content of this disclosure, and this disclosure is not limited to the specific configurations shown.

[0010] Figure 1 is an exploded view of the tread portion 2 of a tire 1 showing one embodiment of the present disclosure. As shown in Figure 1, the tire 1 of the present disclosure is suitably used, for example, as a pneumatic tire for heavy loads. However, the present disclosure is not limited to such uses.

[0011] [Tread area] The tread portion 2 of this embodiment has a tread pattern in which 1-pitch regions 18 constituting pattern constituent units are arranged in the circumferential direction of the tire.

[0012] The 1-pitch region 18 is the region between the first virtual line 18a and the second virtual line 18b, which is separated from the first virtual line 18a by the same distance as the average 1-pitch length Pa. The 1-pitch length Pa corresponds to the distance in the circumferential direction of the tire between the groove centerlines of two adjacent crown lateral grooves 10 (for example, a pair of first crown lateral grooves 11, 11, or a pair of second crown lateral grooves 12, 12). If this distance (1-pitch length) changes in the axial direction of the tire, it corresponds to the intermediate distance. The average 1-pitch length (hereinafter sometimes simply referred to as "1-pitch length") Pa means the average of the 1-pitch lengths of multiple crown lateral grooves 10 that extend around the entire circumference of the tire.

[0013] The first virtual line 18a and the second virtual line 18b extend parallel to the tire axis direction, from one shoulder circumferential groove 5 to the other shoulder circumferential groove 5. The positions of the first virtual line 18a and the second virtual line 18b in the tire circumferential direction are not particularly limited. The first virtual line 18a is a virtual line that passes through the end of the groove centerline of any one crown lateral groove 10. The second virtual line 18b is a virtual line that passes through the end of the groove centerline of a crown lateral groove 10 adjacent to the crown lateral groove 10 in the tire circumferential direction through which the first virtual line 18a passes.

[0014] Each pitch region 18 is composed of two tread ends Te, Te, a plurality of circumferential grooves 3 extending continuously in the tire circumferential direction between the two tread ends Te, Te, a plurality of land portions 4 divided into the plurality of circumferential grooves 3, and a plurality of lateral grooves 19. The two tread ends Te, Te are composed of a first tread end Te1 and a second tread end Te2 located on the opposite side of the tire axial direction from the first tread end Te1.

[0015] The two tread edges Te, Te (in this example, the first tread edge Te1 and the second tread edge Te2) respectively correspond to the edges of the contact surface when 100% of the normal load is applied to the tire 1 in the normal state and the tread portion 2 is grounded on a plane at a camber angle of 0°.

[0016] The "normal state" means that in the case of a pneumatic tire with various specifications defined, the tire is rim-mounted on a normal rim and filled with a normal internal pressure, and moreover, it is in a no-load state. In the case of a tire without various defined specifications or a non-pneumatic tire, the "normal state" means a standard usage state according to the purpose of use of the tire, which means the state of not being mounted on a vehicle and being no-load. In this specification, unless otherwise specified, the dimensions, etc. of each part of the tire are values measured in the above normal state.

[0017] The "normal rim" is the rim defined for each tire in the specification system including the specifications on which the tire is based. For example, in the case of JATMA, it is the "standard rim", in the case of TRA, it is the "Design Rim", and in the case of ETRTO, it is the "Measuring Rim".

[0018] The "normal internal pressure" is the air pressure defined for each tire in the specification system including the specifications on which the tire is based. In the case of JATMA, it is the "maximum air pressure", in the case of TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and in the case of ETRTO, it is the "INFLATION PRESSURE".

[0019] For pneumatic tires with various standards defined, the "normal load" is the load defined for each tire in the standard system including the standards on which the tire is based. For JATMA, it is the "maximum load capacity"; for TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES"; for ETRTO, it is the "LOAD CAPACITY". Also, for tires without various standards defined, the "normal load" refers to the maximum applicable load in using the tire, in accordance with the above standards.

[0020] [Circumferential groove] The plurality of circumferential grooves 3 includes the shoulder circumferential groove 5 and the crown circumferential groove 6. In the tread portion 2 of the present embodiment, a pair of shoulder circumferential grooves 5 provided so as to sandwich the tire equator C, and one crown circumferential groove 6 arranged inside the shoulder circumferential groove 5 in the tire axial direction are provided. Thereby, the tire 1 of the present embodiment is configured as a so-called 4-rib tire in which the tread portion 2 is divided into four land portions 4 by three circumferential grooves 3. Note that the present disclosure is not limited to such a mode.

[0021] Each circumferential groove 3 extends, for example, in a zigzag shape in the tire circumferential direction. The groove widths W1, W3 of each circumferential groove 3 are preferably, for example, 2.5% to 6.0% of the tread width TW. The depth (not shown) of each circumferential groove 3 is preferably, for example, 10 to 25 mm in the case of the heavy-duty tire of the present embodiment. The tread width TW is the distance in the tire axial direction between the two tread ends Te, Te (in this example, the first tread end Te1 and the second tread end Te2) in the normal state.

[0022] The crown circumferential groove 6 is provided, for example, on the tire equator C. The distance L1 in the tire axial direction from the tire equator C to the groove center line of the shoulder circumferential groove 5 is, for example, 20% to 35% of the tread width TW. However, the arrangement of the circumferential grooves 3 is not limited to such a range.

[0023] The pair of shoulder circumferential grooves 5 in this embodiment include a first shoulder circumferential groove 5A that extends continuously in the tire circumferential direction on the first tread end Te1 side and a second shoulder circumferential groove 5B that extends continuously in the tire circumferential direction on the second tread end Te2 side.

[0024] [Rikube] The multiple land sections 4 include shoulder land sections 8 and crown land sections 9. The shoulder land section 8 is divided on the tire axial side of the shoulder circumferential groove 5 and includes the tread edge Te. The crown land section 9 is divided between the shoulder circumferential groove 5 and the crown circumferential groove 6. The tread section 2 of this embodiment is composed of two shoulder land sections 8 and two crown land sections 9.

[0025] The two shoulder portions 8 of this embodiment are composed of a first shoulder portion 8A located on the first tread end Te1 side and a second shoulder portion 8B located on the second tread end Te2 side.

[0026] The shoulder land portion 8 (first shoulder land portion 8A, second shoulder land portion 8B) is provided with multiple shoulder longitudinal narrow grooves 43 that connect the first shoulder transverse groove 31 and the second shoulder transverse groove 32, and the third shoulder transverse groove 33 and the fourth shoulder transverse groove 34. This further improves resistance to uneven wear.

[0027] The first shoulder land portion 8A and the second shoulder land portion 8B are provided with a plurality of shoulder sipes 40 extending in the direction of the tire axis. These plurality of shoulder sipes 40 can provide frictional force in the circumferential direction of the tire on icy and snowy road surfaces, enabling excellent performance on icy and snowy surfaces. In this specification, "sipe" means a small-width cut, where the width between two sipe walls in the sipe body is 2.0 mm or less.

[0028] The two crown sections 9 of this embodiment are composed of a first crown section 9A adjacent to the first shoulder section 8A and a second crown section 9B adjacent to the second shoulder section 8B.

[0029] The crown land portion 9 (first crown land portion 9A, second crown land portion 9B) is provided with, for example, multiple crown longitudinal grooves 23. The crown longitudinal grooves 23 extend in a zigzag pattern along the circumferential direction of the tire and connect the first crown lateral groove 11 and the second crown lateral groove 12, or the third crown lateral groove 13 and the fourth crown lateral groove 14. Such crown longitudinal grooves 23 can provide frictional force in the axial direction of the tire on icy and snowy surfaces, and help to improve performance on icy and snowy surfaces.

[0030] The first crown section 9A and the second crown section 9B are provided with multiple crown sipes 20. These multiple crown sipes 20 can provide frictional force in the circumferential direction of the tire on icy and snowy surfaces, enabling excellent performance on icy and snowy roads.

[0031] [Yokomizo] The multiple lateral grooves 19 in this embodiment include crown lateral grooves 10 and shoulder lateral grooves 30. The maximum groove width W4 of these crown lateral grooves 10 and shoulder lateral grooves 30 is, for example, 60% to 90% of the maximum groove width W3 of the crown circumferential grooves 6, from the viewpoint of improving ice and snow performance and resistance to uneven wear in a balanced manner.

[0032] [Shoulder groove] The shoulder lateral groove 30 of this embodiment includes a plurality of first shoulder lateral grooves 31, a plurality of second shoulder lateral grooves 32, a plurality of third shoulder lateral grooves 33, and a plurality of fourth shoulder lateral grooves 34.

[0033] Multiple first shoulder lateral grooves 31 extend from the first shoulder circumferential groove 5A toward the first tread edge Te1, and terminate without reaching the first tread edge Te1. Multiple first shoulder lateral grooves 31 have a discontinuous end within the first shoulder land portion 8A.

[0034] Multiple second shoulder lateral grooves 32 extend from the first tread end Te1 toward the first shoulder circumferential groove 5A, and terminate without reaching the first shoulder circumferential groove 5A. Multiple second shoulder lateral grooves 32 have a discontinuous end within the first shoulder land portion 8A.

[0035] The first shoulder lateral groove 31 and the second shoulder lateral groove 32 are arranged alternately in the circumferential direction of the tire within a single pitch region 18. These first shoulder lateral groove 31 and the second shoulder lateral groove 32 provide frictional force in multiple directions on icy and snowy surfaces, improving performance on icy and snowy roads.

[0036] The first shoulder lateral groove 31 is inclined, for example, in the same direction as the first crown lateral groove 11 with respect to the tire axis. The second shoulder lateral groove 32 extends, for example, at an angle of 5° or less with respect to the tire axis. Such first shoulder lateral grooves 31 and second shoulder lateral grooves 32 help ensure wandering performance on icy and snowy road surfaces.

[0037] Multiple third shoulder lateral grooves 33 extend from the second shoulder circumferential groove 5B toward the second tread end Te2, and terminate without reaching the second tread end Te2. Multiple third shoulder lateral grooves 33 have a broken end within the second shoulder land portion 8B.

[0038] Multiple fourth shoulder lateral grooves 34 extend from the second tread end Te2 towards the second shoulder circumferential groove 5B, and terminate without reaching the second shoulder circumferential groove 5B. Multiple fourth shoulder lateral grooves 34 have a discontinuous end within the second shoulder land portion 8B.

[0039] The third shoulder lateral groove 33 and the fourth shoulder lateral groove 34 are arranged alternately in the circumferential direction of the tire within a single pitch region 18. These third shoulder lateral groove 33 and fourth shoulder lateral groove 34 provide frictional force in multiple directions on icy and snowy surfaces, improving performance on icy and snowy roads.

[0040] The third shoulder lateral groove 33 is inclined, for example, in the same direction as the third crown lateral groove 13 with respect to the tire axis. The fourth shoulder lateral groove 34 extends, for example, at an angle of 5° or less with respect to the tire axis. Such third shoulder lateral grooves 33 and fourth shoulder lateral grooves 34 help ensure wandering performance on icy and snowy road surfaces.

[0041] [Crown lateral groove] The crown lateral groove 10 of this embodiment includes a plurality of first crown lateral grooves 11, a plurality of second crown lateral grooves 12, a plurality of third crown lateral grooves 13, and a plurality of fourth crown lateral grooves 14.

[0042] Multiple first crown lateral grooves 11 extend from the crown circumferential groove 6 toward the first shoulder circumferential groove 5A, and terminate without reaching the first shoulder circumferential groove 5A. Multiple first crown lateral grooves 11 in this embodiment have a terminated end within the first crown land portion 9A.

[0043] Multiple second crown lateral grooves 12 extend from the first shoulder circumferential groove 5A toward the crown circumferential groove 6, and terminate without reaching the crown circumferential groove 6. In this embodiment, multiple second crown lateral grooves 12 have a discontinuous end within the first crown land portion 9A.

[0044] The first crown lateral groove 11 and the second crown lateral groove 12 are arranged alternately in the circumferential direction of the tire within a single pitch region 18. These first crown lateral groove 11 and the second crown lateral groove 12 provide frictional force in multiple directions on icy and snowy surfaces, improving performance on icy and snowy roads.

[0045] The first crown groove 11 and the second crown groove 12 are preferably inclined in opposite directions relative to the tire axis, for example. The angle between the first crown groove 11 and the second crown groove 12 with respect to the tire axis is, for example, 5 to 15°. Such first crown groove 11 and second crown groove 12 can provide frictional force in multiple directions on icy and snowy road surfaces.

[0046] Multiple third crown lateral grooves 13 extend from the crown circumferential groove 6 toward the second shoulder circumferential groove 5B, and terminate without reaching the second shoulder circumferential groove 5B. In this embodiment, multiple third crown lateral grooves 13 have a discontinuous end within the second crown land portion 9B.

[0047] Multiple fourth crown lateral grooves 14 extend from the second shoulder circumferential groove 5B toward the crown circumferential groove 6, and terminate without reaching the crown circumferential groove 6. In this embodiment, multiple fourth crown lateral grooves 14 have a discontinuous end within the second crown land portion 9B.

[0048] The third crown lateral groove 13 and the fourth crown lateral groove 14 are arranged alternately in the circumferential direction of the tire within a single pitch region 18. These third crown lateral groove 13 and fourth crown lateral groove 14 provide frictional force in multiple directions on icy and snowy surfaces, improving performance on icy and snowy roads.

[0049] The third crown lateral groove 13 and the fourth crown lateral groove 14 are preferably inclined in opposite directions relative to the tire axis, for example. The angle of the third crown lateral groove 13 and the fourth crown lateral groove 14 with respect to the tire axis is, for example, 5 to 15°. Such third crown lateral groove 13 and fourth crown lateral groove 14 can provide frictional force in multiple directions on icy and snowy road surfaces.

[0050] [Relationship between the shortest distance between horizontal grooves and the length of one pitch] Figure 2 is an enlarged view of the first shoulder land area 8A and the first crown land area 9A of Figure 1. In each pitch region 18, the ratio D1 / Pa of the shortest distance D1 in the tire circumferential direction between the first shoulder lateral groove 31 and the first crown lateral groove 11 to the pitch length Pa in the tire circumferential direction of the pitch region 18 satisfies the following equation (1) or (2). Furthermore, the ratio D2 / Pa of the shortest distance D2 in the tire circumferential direction between the second shoulder lateral groove 32 and the second crown lateral groove 12 to the pitch length Pa satisfies the following equation (3) or (4). Figures 1 and 2 illustrate the case where the ratio T / L of the total number T of pitch regions 18 to the tire circumferential length L is 0.017. 0% < D1 / Pa ≤ 5% (provided that T / L ≤ 0.022) … (1) 28% ≤ D1 / Pa ≤ 34% (provided that T / L > 0.022) … (2) 0% < D2 / Pa ≤ 5% (provided that T / L ≤ 0.022) … (3) 28% ≤ D2 / Pa ≤ 34% (provided that T / L > 0.022) … (4) Here, T: Total number of one - pitch regions L: Tire circumference

[0051] The shortest distance D1 in this embodiment is specified as the shortest distance in the tire circumferential direction between the groove center line of the first shoulder lateral groove 31 and the groove center line of the first crown lateral groove 11. The shortest distance D2 in this embodiment is specified as the shortest distance in the tire circumferential direction between the groove center line of the second shoulder lateral groove 32 and the groove center line of the second crown lateral groove 12.

[0052] Generally, for the passing noise measurement value used to evaluate the noise performance during dry - road surface driving, the sound pressure is weighted by frequency by an A - filter (auditory correction). Therefore, in the frequency band below 0.5 kHz or above 1.25 kHz, the measured sound pressure value becomes relatively low, while in the frequency band of 0.5 - 1.25 kHz, the measured sound pressure value tends to become relatively high. For this reason, if there is a peak of the pitch sound emphasized at 0.5 - 1.25 kHz, the OA value may exceed the standard upper limit.

[0053] For example, when the ratio T / L of the total number (total number in the tire circumferential direction) T of one - pitch regions 18 to the tire circumference L is 0.022, the frequency of the primary - component pitch sound generated from tire 1 during driving at 70 km / h is obtained as 0.428 kHz based on the following formula (13). Frequency of primary - component pitch sound (kHz) = 70 (km / h) ÷ (3.6 × L) × 1000 × T … (13)

[0054] When the ratio T / L is 0.022 or less, the pitch length Pa becomes relatively larger. As a result, in the pitch region 18, there tends to be fewer combinations of lateral grooves 19, 19 that open in the same direction in the tire axial direction (for example, the second shoulder lateral groove 32 and the second crown lateral groove 12 that open on the first tread edge Te1 side) that have aligned phases in the tire circumferential direction. In this way, when the phases of lateral grooves 19 that open in the same direction are not aligned, the pitch sound of the first component becomes smaller (smaller than 0.428 kHz), and a sound pressure peak (0.5~1.25 kHz) appears in the pitch sound of the higher-order components.

[0055] In this embodiment, when the ratio T / L is 0.022 or less, the ratio D1 / Pa of the shortest distance D1 in the tire circumferential direction between the first shoulder lateral groove 31 and the first crown lateral groove 11 that open on the second tread end Te2 (shown in Figure 1) side and the pitch length Pa is set to 0% to 5%. Furthermore, the ratio D2 / Pa of the shortest distance D2 in the tire circumferential direction between the second shoulder lateral groove 32 and the second crown lateral groove 12 that open on the first tread end Te1 side and the pitch length Pa is set to 0% to 5%.

[0056] As a result, the first shoulder lateral groove 31 and the first crown lateral groove 11 approach each other in the circumferential direction of the tire, and the second shoulder lateral groove 32 and the second crown lateral groove 12 approach each other. Therefore, the peak of the sound pressure of the higher-order component pitch sound is shifted towards the first-order component pitch sound, reducing the pitch sound and improving noise performance. In order to effectively exert this effect, the ratio D1 / Pa and ratio D2 / Pa are preferably 4% or less, and more preferably 3% or less.

[0057] On the other hand, when the ratio T / L is greater than 0.022, the pitch length Pa becomes relatively smaller. As a result, in the pitch region 18, there tends to be a greater number of combinations where the phases in the circumferential direction of the tire are aligned for the lateral grooves 19, 19 that open in the same direction in the tire axis direction (for example, the second shoulder lateral groove 32 and the second crown lateral groove 12). When the phases of the lateral grooves 19 that open in the same direction are aligned in this way, the pitch sound of higher-order components becomes smaller (smaller than 0.428 kHz), and a sound pressure peak (0.5~1.25 kHz) appears in the pitch sound of first-order components.

[0058] In this embodiment, when the ratio T / L is greater than 0.022, the ratio D1 / Pa, which is the shortest distance D1 between the first shoulder lateral groove 31 and the first crown lateral groove 11 and the pitch length Pa, is set to 28% to 34%. Furthermore, the ratio D2 / Pa, which is the shortest distance D2 between the second shoulder lateral groove 32 and the second crown lateral groove 12 and the pitch length Pa, is set to 28% to 34%.

[0059] As a result, the first shoulder lateral groove 31 and the first crown lateral groove 11 are spaced apart from each other in the circumferential direction of the tire, and the second shoulder lateral groove 32 and the second crown lateral groove 12 are also spaced apart from each other. Therefore, the peak of the sound pressure of the first-order component pitch sound is shifted towards the higher-order component pitch sound, reducing the pitch sound and improving noise performance. In order to effectively exert this effect, the ratio D2 / Pa is preferably 30% or more, and also preferably 32% or less.

[0060] Thus, the tire 1 of this embodiment can reduce pitch noise caused by the lateral grooves 19 without reducing the landsea ratio of the 1-pitch region 18 excluding the multiple circumferential grooves 3, thereby improving both ice and snow performance and noise performance. The landsea ratio of the 1-pitch region 18 excluding the multiple circumferential grooves 3 is the ratio of the total area of ​​the outer surface of the 1-pitch region 18, which is filled with the circumferential grooves 3 and the lateral grooves 19, to the sum of the areas of the lateral grooves 19 located at the same height as the tread surface of the 1-pitch region 18.

[0061] Figure 3 is an enlarged view of the first shoulder land area 8A and the second shoulder land area 8B of Figure 1. In this embodiment, it is desirable that in each pitch region 18, the ratio D3 / Pa of the shortest distance D3 in the tire circumferential direction between the first shoulder lateral groove 31 and the fourth shoulder lateral groove 34 to the pitch length Pa satisfies the following formula (5) or (6). Furthermore, it is preferable that the ratio D4 / Pa of the shortest distance D4 in the tire circumferential direction between the second shoulder lateral groove 32 and the third shoulder lateral groove 33 to the pitch length Pa satisfies the following formula (7) or (8). 31% ≤ D3 / Pa ≤ 37% (where T / L ≤ 0.022) ... (5) 4% ≤ D3 / Pa ≤ 6% (where T / L > 0.022) ... (6) 31% ≤ D4 / Pa ≤ 37% (where T / L ≤ 0.022) ... (7) 4% ≤ D4 / Pa ≤ 6% (where T / L > 0.022) ... (8) Here, T: Total number of pitch regions L: Tire circumference

[0062] In this embodiment, the shortest distance D3 is defined as the shortest distance in the tire circumferential direction between the groove centerline of the first shoulder lateral groove 31 and the groove centerline of the fourth shoulder lateral groove 34. In this embodiment, the shortest distance D4 is defined as the shortest distance in the tire circumferential direction between the groove centerline of the second shoulder lateral groove 32 and the groove centerline of the third shoulder lateral groove 33.

[0063] In this embodiment, when the ratio T / L is 0.022 or less, the ratio D3 / Pa of the shortest distance D3 in the tire circumferential direction between the first shoulder lateral groove 31 and the fourth shoulder lateral groove 34 that open on the second tread edge Te2 side, and the pitch length Pa, is set to 31% to 37%. Furthermore, the ratio D4 / Pa of the shortest distance D4 in the tire circumferential direction between the second shoulder lateral groove 32 and the third shoulder lateral groove 33 that open on the first tread edge Te1 side, and the pitch length Pa, is set to 31% to 37%. As a result, the first shoulder lateral groove 31 and the fourth shoulder lateral groove 34 are spaced apart from each other in the tire circumferential direction, and the second shoulder lateral groove and the third shoulder lateral groove are also spaced apart from each other.

[0064] When the ratio T / L is 0.022 or less, equations (1) and (3) above are satisfied, and the first shoulder lateral groove 31 and the first crown lateral groove 11 are close together in the circumferential direction of the tire, and the second shoulder lateral groove 32 and the second crown lateral groove 12 are close together in the circumferential direction of the tire. As a result, by separating the first shoulder lateral groove 31 and the fourth shoulder lateral groove 34 from each other, and separating the second shoulder lateral groove 32 and the third shoulder lateral groove 33 from each other, the pitch sound of the first component is suppressed from becoming excessively loud. Thus, the noise performance is improved. In order to effectively exert this effect, the ratios D3 / Pa and D4 / Pa are preferably 33% or more, and preferably 35% or less.

[0065] On the other hand, if the ratio T / L is greater than 0.022, the ratio D3 / Pa of the shortest circumferential distance D3 between the first shoulder groove 31 and the fourth shoulder groove 34 and the pitch length Pa is set to 4% to 6%. Furthermore, the ratio D4 / Pa of the shortest circumferential distance D4 between the second shoulder groove 32 and the third shoulder groove 33 and the pitch length Pa is set to 4% to 6%. As a result, the first shoulder groove 31 and the fourth shoulder groove 34 approach each other in the circumferential direction of the tire, and the second shoulder groove 32 and the third shoulder groove 33 approach each other.

[0066] When the ratio T / L is greater than 0.022, equations (2) and (4) above are satisfied, and the first shoulder lateral groove 31 and the first crown lateral groove 11 are spaced apart in the circumferential direction of the tire, and the second shoulder lateral groove 32 and the second crown lateral groove 12 are spaced apart in the circumferential direction of the tire. Therefore, by bringing the first shoulder lateral groove 31 and the fourth shoulder lateral groove 34 closer together, and the second shoulder lateral groove 32 and the third shoulder lateral groove 33 closer together, the pitch sound of higher-order components is suppressed from becoming excessively loud. Thus, noise performance is improved. In order to effectively exert this effect, the ratios D3 / Pa and D4 / Pa are preferably 4.5% or more, and preferably 5.5% or less.

[0067] Figure 4 is an enlarged view of the first shoulder land area 8A and the second crown land area 9B of Figure 1. In this embodiment, in each pitch region 18, the ratio D5 / Pa of the shortest distance D5 in the tire circumferential direction between the first shoulder lateral groove 31 and the fourth crown lateral groove 14 to the pitch length Pa is preferably satisfied by the following formula (9) or (10). The ratio D6 / Pa of the shortest distance D6 in the tire circumferential direction between the second shoulder lateral groove 32 and the third crown lateral groove 13 to the pitch length Pa is preferably satisfied by the following formula (11) or (12). 28% ≤ D5 / Pa ≤ 34% (where T / L ≤ 0.022) ... (9) 33% ≤ D5 / Pa ≤ 39% (where T / L > 0.022) ... (10) 28% ≤ D6 / Pa ≤ 34% (where T / L ≤ 0.022) ... (11) 33% ≤ D6 / Pa ≤ 39% (where T / L > 0.022) ... (12) Here, T: Total number of pitch regions L: Tire circumference

[0068] The shortest distance D5 is identified as the shortest circumferential distance between the groove centerline of the first shoulder lateral groove 31 and the groove centerline of the fourth crown lateral groove 14. The shortest distance D6 is identified as the shortest circumferential distance between the groove centerline of the second shoulder lateral groove 32 and the groove centerline of the third crown lateral groove 13.

[0069] In this embodiment, when the ratio T / L is 0.022 or less, the ratio D5 / Pa of the shortest circumferential distance D5 between the first shoulder lateral groove 31 and the fourth crown lateral groove 14 that open on the second tread end Te2 side, and the pitch length Pa, is set to 28% to 34%. Furthermore, the ratio D6 / Pa of the shortest circumferential distance D6 between the second shoulder lateral groove 32 and the third crown lateral groove 13 that open on the first tread end Te1 side, and the pitch length Pa, is set to 28% to 34%. As a result, in the circumferential direction of the tire, the positions of the third crown lateral groove 13 and the fourth crown lateral groove 14 are different from the positions of the first crown lateral groove 11, the second crown lateral groove 12, and the first to fourth shoulder lateral grooves 31 to 4th shoulder lateral grooves 34 that satisfy the above equations (1), (3), (5), and (7).

[0070] The third crown groove 13 and the fourth crown groove 14 can suppress a further increase in the primary component pitch sound, which is amplified by the proximity of the first shoulder groove 31 and the first crown groove 11, and the proximity of the second shoulder groove 32 and the second crown groove 12. Furthermore, the third crown groove 13 and the fourth crown groove 14 can suppress a further increase in the higher-order component pitch sound, which is amplified by the separation of the first shoulder groove 31 and the fourth shoulder groove 34, and the separation of the second shoulder groove 32 and the third shoulder groove 33. Therefore, noise performance is improved. In order to effectively exert these effects, the ratios D5 / Pa and D6 / Pa are preferably 30% or more, and preferably 32% or less.

[0071] On the other hand, if the ratio T / L is greater than 0.022, the ratio D5 / Pa of the shortest circumferential distance D5 between the first shoulder groove 31 and the fourth crown groove 14 to the pitch length Pa is set to 33% to 39%. Furthermore, the ratio D6 / Pa of the shortest circumferential distance D6 between the second shoulder groove 32 and the third crown groove 13 to the pitch length Pa is set to 33% to 39%. As a result, in the circumferential direction of the tire, the positions of the third crown groove 13 and the fourth crown groove 14 are different from the positions of the first crown groove 11, the second crown groove 12, and the first to fourth shoulder grooves 31 to 4th shoulder grooves 34 that satisfy equations (2), (4), (6), and (8) above.

[0072] The third crown groove 13 and the fourth crown groove 14 can suppress a further increase in higher-order pitch sounds that are amplified by the separation between the first shoulder groove 31 and the first crown groove 11, and the separation between the second shoulder groove 32 and the second crown groove 12. Furthermore, the third crown groove 13 and the fourth crown groove 14 can suppress a further increase in primary-order pitch sounds that are amplified by the proximity of the first shoulder groove 31 and the fourth shoulder groove 34, and the proximity of the second shoulder groove 32 and the third shoulder groove 33. Therefore, noise performance is improved. In order to effectively exert these effects, the ratios D5 / Pa and D6 / Pa are preferably 35% or more, and preferably 37% or less.

[0073] The land-sea ratio is preferably set to 7% to 15%. Setting the land-sea ratio to 7% or higher improves performance on ice and snow. On the other hand, setting the land-sea ratio to 15% or lower suppresses the increase in pitch noise caused by the lateral grooves 19. For this reason, the land-sea ratio is preferably 9% or higher, and also preferably 13% or lower.

[0074] It is preferable that the total number of lateral grooves 19 within a pitch region 18 be set to six or more. Setting the total number of lateral grooves 19 to six or more provides frictional force in multiple directions on icy and snowy road surfaces, improving performance on icy and snowy surfaces. On the other hand, a large total number of lateral grooves 19 can lead to an increase in pitch noise caused by the lateral grooves 19. For this reason, it is preferable that the total number of lateral grooves 19 be set to ten or less.

[0075] The depth of the lateral grooves 19 (not shown) is preferably set to 50% to 95% of the depth of the circumferential grooves 3 (not shown). Setting the depth of the lateral grooves 19 to 95% or less of the depth of the circumferential grooves 3 suppresses an increase in the groove volume of the lateral grooves 19, thereby reducing pitch noise. On the other hand, setting the depth of the lateral grooves 19 to 50% or more of the depth of the circumferential grooves 3 ensures sufficient groove volume and maintains ice and snow performance. From this viewpoint, the depth of the lateral grooves 19 is preferably 90% or less of the depth of the circumferential grooves 3, and more preferably 55% or more.

[0076] Within each land area 4, the shortest distance D7 between adjacent pairs of lateral grooves 19 in the circumferential direction of the tire (for example, the shortest distance between the first shoulder lateral groove 31 and the second shoulder lateral groove 32) is preferably set to 40% to 60% of the pitch length Pa. Setting the shortest distance D7 to 40% or more of the pitch length Pa suppresses adjacent pairs of lateral grooves 19, 19 in the circumferential direction of the tire from getting too close together, preventing an increase in the primary component of pitch noise and uneven wear energy (uneven wear). On the other hand, setting the shortest distance D7 to 60% or less of the pitch length Pa suppresses adjacent pairs of lateral grooves 19 from getting too far apart, preventing uneven wear energy. This suppresses uneven wear in the tread area 2 (land area 4).

[0077] The length L10 of the lateral groove 19 in the tire axial direction is preferably set to 6% to 15% of the tread width TW (shown in Figure 1). Setting the length L10 to 15% or less of the tread width TW suppresses an increase in the groove volume of the lateral groove 19, thereby reducing the peak of sound pressure. On the other hand, setting the length of the lateral groove 19 to 6% or more of the tread width ensures sufficient groove volume and maintains ice and snow performance. To effectively achieve these effects, the length L10 is preferably 13% or less of the tread width TW, and more preferably 8% or more of the tread width TW.

[0078] The ratio W4 / Pa of the groove width W4 (shown in Figure 1) to the pitch length Pa of the lateral groove 19 is preferably set to 9% to 13%. Setting the ratio W4 / Pa to 13% or less suppresses an increase in the groove volume of the lateral groove 19, thereby reducing the peak sound pressure. On the other hand, setting the ratio W4 / Pa to 9% or more ensures sufficient groove volume for the lateral groove 19, maintaining performance on ice and snow. From this viewpoint, the ratio W4 / Pa is preferably 12% or less, and preferably 10% or more.

[0079] Although particularly preferred embodiments of this disclosure have been described in detail above, this disclosure is not limited to the illustrated embodiments and can be modified and implemented in various ways. [Examples]

[0080] The tires shown in Figure 1 were prototyped based on the specifications in Table 1 (Examples 1 to 3 and Comparative Example). For each prototype tire, ice and snow performance, noise performance, and resistance to uneven wear were evaluated. The specifications of each tire were identical except for the configuration described in Table 1, and the tire size, etc., are as follows. The test method is as follows. The test results are shown in Table 1. Tire size: 275 / 80R22.5 Rim size: 7.50 x 22.5 Internal pressure: 800kPa Vehicle: 10-ton truck (2-D type) with a 5-ton load. Tire mounting position: All wheels Total number of pitch regions T: 53 Tire circumference L: 3178 (mm) T / L:0.017

[0081] <Ice and snow performance> The time required to travel 200m on an S-shaped road consisting of a series of curves with a radius of curvature of 30m on an icy or snowy surface was measured. The results are expressed as an index with the reciprocal of the time in Example 3 set to 100, and a higher value indicates better performance on ice and snow. An index of 60 or higher indicates excellent performance on ice and snow.

[0082] <Noise performance> Using the vehicle described above, it was driven on a straight test course in accordance with ECE R117, with the engine off and the gear in neutral. A microphone was placed 7.5m laterally from the centerline of the course and 1.2m above the test surface. The maximum noise level dBA was measured at a speed of 60km / h at the point closest to the microphone. A lower value indicates better noise performance, and a value of 74dBA or less indicates excellent noise performance.

[0083] <Abrasion resistance> Using the vehicle described above, either the test tire or the control tire was driven until 50% wear was achieved on the crown of the tire. The occurrence of heel-and-toe wear in the blocks separated by lateral grooves was then measured and evaluated using a three-point method. A higher numerical value indicates better performance.

[0084] [Table 1]

[0085] The test results showed that Examples 1-3 exhibited ice and snow performance equivalent to the comparative example, and furthermore, their noise performance was improved compared to the comparative example. Therefore, Examples 1-3 were able to improve both ice and snow performance and noise performance. In addition, Example 3, in which the shortest distance D7 / Pa of the pair of lateral grooves, the length L10 / Pa of the lateral grooves, and the groove width W4 / Pa of the lateral grooves were set within a preferred range, showed improved resistance to uneven wear compared to Examples 1 and 2, in which these were not set within a preferred range.

[0086] [Note] This disclosure includes the following aspects.

[0087] [Disclosure 1] A tire having a tread portion, The tread portion has a tread pattern in which one-pitch regions constituting pattern constituent units are arranged in the circumferential direction of the tire. The aforementioned pitch region includes a first tread end, a second tread end located on the opposite side of the first tread end in the tire axial direction, a plurality of circumferential grooves extending continuously in the tire circumferential direction between the first tread end and the second tread end, and a plurality of transverse grooves. The plurality of circumferential grooves include a first shoulder circumferential groove that extends continuously in the tire circumferential direction along the first tread end, and a crown circumferential groove that extends continuously in the tire circumferential direction adjacent to the first shoulder circumferential groove. The aforementioned multiple transverse grooves are A plurality of first shoulder lateral grooves extending from the first shoulder circumferential groove toward the first tread end and terminating without reaching the first tread end, A plurality of second shoulder transverse grooves that extend from the first tread end toward the first shoulder circumferential groove side and terminate without reaching the first shoulder circumferential groove; A plurality of first crown transverse grooves that extend from the crown circumferential groove toward the first shoulder circumferential groove side and terminate without reaching the first shoulder circumferential groove; A plurality of second crown transverse grooves that extend from the first shoulder circumferential groove toward the crown circumferential groove side and terminate without reaching the crown circumferential groove, wherein the first shoulder transverse grooves and the second shoulder transverse grooves are alternately arranged in the tire circumferential direction in the one pitch region, the first crown transverse grooves and the second crown transverse grooves are alternately arranged in the tire circumferential direction in the one pitch region, in each one pitch region, the ratio D1 / Pa of the shortest circumferential distance D1 between the first shoulder transverse groove and the first crown transverse groove in the tire circumferential direction to the one pitch length Pa in the tire circumferential direction of the one pitch region satisfies the following formula (1) or (2), the ratio D2 / Pa of the shortest circumferential distance D2 between the second shoulder transverse groove and the second crown transverse groove in the tire circumferential direction to the one pitch length Pa satisfies the following formula (3) or (4), A tire. 0% < D1 / Pa ≦ 5% (where T / L ≦ 0.022)...(1) 28% ≦ Dl / Pa ≦ 34% (where T / L > 0.022)...(2) 0% < D2 / Pa ≦ 5% (where T / L ≦ 0.022)...(3) 28% ≦ D2 / Pa ≦ 34% (where T / L > 0.022)...(4) Here, T: The total number of one pitch regions L: Tire circumference [Disclosure 2] The circumferential groove includes a second shoulder circumferential groove that continuously extends in the tire circumferential direction on the second tread end side, The plurality of transverse grooves, It includes a plurality of third shoulder lateral grooves that extend from the second shoulder circumferential groove toward the second tread end and terminate without reaching the second tread end, A plurality of fourth shoulder lateral grooves extending from the second tread end toward the second shoulder circumferential groove and terminating without reaching the second shoulder circumferential groove, The third shoulder lateral groove and the fourth shoulder lateral groove are arranged alternately in the tire circumferential direction within the 1-pitch region. In each of the aforementioned one-pitch regions, the ratio D3 / Pa of the shortest distance D3 in the tire circumferential direction between the first shoulder lateral groove and the fourth shoulder lateral groove to the one-pitch length Pa satisfies the following formula (5) or (6): The tire according to Disclosure 1, wherein the ratio D4 / Pa of the shortest distance D4 in the tire circumferential direction between the second shoulder lateral groove and the third shoulder lateral groove to the pitch length Pa satisfies the following formula (7) or (8). 31% ≤ D3 / Pa ≤ 37% (where T / L ≤ 0.022) ... (5) 4% ≤ D3 / Pa ≤ 6% (where T / L > 0.022) ... (6) 31% ≤ D4 / Pa ≤ 37% (where T / L ≤ 0.022) ... (7) 4% ≤ D4 / Pa ≤ 6% (where T / L > 0.022) ... (8) Here, T: Total number of pitch regions L: Tire circumference [Disclosure 3] The circumferential groove includes a second shoulder circumferential groove that extends continuously in the tire circumferential direction along the second tread end. The aforementioned multiple transverse grooves are A plurality of third crown transverse grooves extend from the crown circumferential groove toward the second shoulder circumferential groove and terminate without reaching the crown circumferential groove, It includes a plurality of fourth crown transverse grooves that extend from the second shoulder circumferential groove toward the crown circumferential groove and terminate without reaching the crown circumferential groove. The third crown lateral groove and the fourth crown lateral groove are arranged alternately in the tire circumferential direction within the 1-pitch region. In each of the aforementioned pitch regions, the ratio D5 / Pa of the shortest distance D5 in the tire circumferential direction between the first shoulder lateral groove and the fourth crown lateral groove to the pitch length Pa satisfies the following formula (9) or (10): The tire according to disclosure 1 or 2, wherein the ratio D6 / Pa of the shortest distance D6 in the tire circumferential direction between the second shoulder lateral groove and the third crown lateral groove to the 1 pitch length Pa satisfies the following formula (11) or (12). 28% ≤ D5 / Pa ≤ 34% (where T / L ≤ 0.022) ... (9) 33% ≤ D5 / Pa ≤ 39% (where T / L > 0.022) ... (10) 28% ≤ D6 / Pa ≤ 34% (where T / L ≤ 0.022) ... (11) 33% ≤ D6 / Pa ≤ 39% (where T / L > 0.022) ... (12) Here, T: Total number of pitch regions L: Tire circumference [Disclosure 4] The tire according to any one of disclosures 1 to 3, wherein the landsea ratio of the 1-pitch region excluding the plurality of circumferential grooves is 7% to 15%. [Disclosure 5] The tire according to any one of disclosures 1 to 4, wherein the total number of lateral grooves within the pitch region is 6 or more. [Disclosure 6] The tire according to any one of paragraphs 1 to 5 of this disclosure, wherein the depth of the lateral groove is 50% to 95% of the depth of the circumferential groove. [Disclosure 7] The tire according to any one of disclosures 1 to 6, wherein the shortest distance between a pair of adjacent lateral grooves in the circumferential direction of the tire is 40% to 60% of the 1-pitch length Pa. [Disclosure 8] The tire according to any one of disclosures 1 to 7, wherein the length of the lateral groove in the tire axial direction is 6% to 15% of the tread width. [Explanation of Symbols]

[0088] 1 tire 2 Tread section 11. First Crown Cross Groove 12. Second Crown Cross Groove 18 1 pitch area 31. First shoulder lateral groove 32 Second shoulder lateral groove

Claims

1. A tire having a tread portion, The tread portion has a tread pattern in which one-pitch regions constituting pattern constituent units are arranged in the circumferential direction of the tire. The aforementioned pitch region includes a first tread end, a second tread end located on the opposite side of the first tread end in the tire axial direction, a plurality of circumferential grooves extending continuously in the tire circumferential direction between the first tread end and the second tread end, and a plurality of transverse grooves. The plurality of circumferential grooves include a first shoulder circumferential groove that extends continuously in the tire circumferential direction along the first tread end, and a crown circumferential groove that extends continuously in the tire circumferential direction adjacent to the first shoulder circumferential groove. The aforementioned multiple transverse grooves are A plurality of first shoulder lateral grooves extending from the first shoulder circumferential groove toward the first tread end and terminating without reaching the first tread end, A plurality of second shoulder lateral grooves extending from the first tread end toward the first shoulder circumferential groove and terminating without reaching the first shoulder circumferential groove, A plurality of first crown transverse grooves extending from the crown circumferential groove toward the first shoulder circumferential groove and terminating without reaching the first shoulder circumferential groove, It includes a plurality of second crown transverse grooves that extend from the first shoulder circumferential groove toward the crown circumferential groove and terminate without reaching the crown circumferential groove, The first shoulder lateral groove and the second shoulder lateral groove are arranged alternately in the tire circumferential direction within the one-pitch region. The first crown lateral groove and the second crown lateral groove are arranged alternately in the tire circumferential direction within the 1-pitch region. In each of the aforementioned one-pitch regions, the ratio D1 / Pa of the shortest distance D1 in the tire circumferential direction between the first shoulder lateral groove and the first crown lateral groove to the one-pitch length Pa in the tire circumferential direction of the one-pitch region satisfies the following formula (1) or (2): The ratio D2 / Pa of the shortest distance D2 in the tire circumferential direction between the second shoulder lateral groove and the second crown lateral groove to the pitch length Pa satisfies the following formula (3) or (4): tire. 0% < D1 / Pa ≤ 5% (where T / L ≤ 0.022) ... (1) 28% ≤ D1 / Pa ≤ 34% (where T / L > 0.022) ... (2) 0% < D2 / Pa ≤ 5% (where T / L ≤ 0.022) ... (3) 28% ≤ D2 / Pa ≤ 34% (where T / L > 0.022) ... (4) Here, T: Total number of 1 pitch areas L: Tire circumference

2. The circumferential groove includes a second shoulder circumferential groove that extends continuously in the tire circumferential direction along the second tread end. The aforementioned multiple transverse grooves are It includes a plurality of third shoulder lateral grooves that extend from the second shoulder circumferential groove toward the second tread end and terminate without reaching the second tread end, A plurality of fourth shoulder lateral grooves extending from the second tread end toward the second shoulder circumferential groove and terminating without reaching the second shoulder circumferential groove, The third shoulder lateral groove and the fourth shoulder lateral groove are arranged alternately in the tire circumferential direction within the 1-pitch region. In each of the aforementioned one-pitch regions, the ratio D3 / Pa of the shortest distance D3 in the tire circumferential direction between the first shoulder lateral groove and the fourth shoulder lateral groove to the one-pitch length Pa satisfies the following formula (5) or (6): The tire according to claim 1, wherein the ratio D4 / Pa of the shortest distance D4 in the tire circumferential direction between the second shoulder lateral groove and the third shoulder lateral groove to the pitch length Pa satisfies the following formula (7) or (8). 31% ≤ D3 / Pa ≤ 37% (where T / L ≤ 0.022) ... (5) 4% ≤ D3 / Pa ≤ 6% (where T / L > 0.022) ... (6) 31% ≤ D4 / Pa ≤ 37% (where T / L ≤ 0.022) ... (7) 4% ≤ D4 / Pa ≤ 6% (where T / L > 0.022) ... (8) Here, T: Total number of 1 pitch areas L: Tire circumference

3. The circumferential groove includes a second shoulder circumferential groove that extends continuously in the tire circumferential direction along the second tread end. The aforementioned multiple transverse grooves are A plurality of third crown transverse grooves extend from the crown circumferential groove toward the second shoulder circumferential groove and terminate without reaching the second shoulder circumferential groove, It includes a plurality of fourth crown transverse grooves that extend from the second shoulder circumferential groove toward the crown circumferential groove and terminate without reaching the crown circumferential groove. The third crown lateral groove and the fourth crown lateral groove are arranged alternately in the tire circumferential direction within the 1-pitch region. In each of the aforementioned one-pitch regions, the ratio D5 / Pa of the shortest distance D5 in the tire circumferential direction between the first shoulder lateral groove and the fourth crown lateral groove to the one-pitch length Pa satisfies the following formula (9) or (10): The tire according to claim 1 or 2, wherein the ratio D6 / Pa of the shortest distance D6 in the tire circumferential direction between the second shoulder lateral groove and the third crown lateral groove to the pitch length Pa satisfies the following formula (11) or (12). 28% ≤ D5 / Pa ≤ 34% (where T / L ≤ 0.022) ... (9) 33% ≤ D5 / Pa ≤ 39% (where T / L > 0.022) ... (10) 28% ≤ D6 / Pa ≤ 34% (where T / L ≤ 0.022) ... (11) 33% ≤ D6 / Pa ≤ 39% (where T / L > 0.022) ... (12) Here, T: Total number of 1 pitch areas L: Tire circumference

4. The tire according to any one of claims 1 to 3, wherein the landsea ratio of the one-pitch region excluding the plurality of circumferential grooves is 7% to 15%.

5. The tire according to any one of claims 1 to 4, wherein the total number of lateral grooves within the pitch region is six or more.

6. The tire according to any one of claims 1 to 5, wherein the depth of the lateral groove is 50% to 95% of the depth of the circumferential groove.

7. The tire according to any one of claims 1 to 6, wherein the shortest distance between a pair of adjacent lateral grooves in the circumferential direction of the tire is 40% to 60% of the pitch length Pa.

8. The tire according to any one of claims 1 to 7, wherein the length of the lateral groove in the tire axial direction is 6% to 15% of the tread width.

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