JP4481092B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that can be used for all seasons.

  All-season tires are required to balance the performance on snow with dry and wet running performance at a high level.

As a tread pattern of a conventional all-season tire, for example, a tread pattern as described in Patent Document 1 is representative.
Japanese Patent No. 3229953

  In a configuration like the current pattern, in order to ensure on-snow performance, a lug groove having a relatively large angle with respect to the circumferential direction is inserted, and the number of narrow grooves equally placed in the block is increased. Although this method aims to ensure performance, attempts to improve on-snow performance with this method will lead to a decrease in block rigidity and a decrease in dry and wet handling performance.

  Moreover, since the angle of the lug groove is close to the tire width direction, it is disadvantageous for drainage performance.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a pneumatic tire that can improve performance on snow while ensuring dry performance and wet performance.

In order to achieve the above object, a pneumatic tire according to claim 1 is provided with a tread disposed between both sidewalls and in contact with a road surface, and a plurality of circumferential grooves provided on the tread and extending along a tire circumferential direction. And extending from the outermost circumferential groove in the tire width direction toward the tire equatorial plane so as to terminate in the land portion , and is inclined at an angle of 25 to 65 degrees with respect to the tire circumferential direction and spaced in the tire circumferential direction. A plurality of lug grooves arranged in the tire width direction center side of the lug groove, and a short circumferential groove extending in the tire circumferential direction and terminating in the land portion. A plurality of lug compartment land portions that are sandwiched between lug grooves and that have a dimension in a direction along the lug groove that is longer than a dimension in a direction perpendicular to the longitudinal direction of the lug groove are arranged along the tire circumferential direction. Composed by Has a lug compartment land row of at least one row, the lug compartment land portion, the lug groove and extends parallel to the auxiliary grooved closed two when grounded groove width is set narrower than the lug groove A lug central region that is sandwiched between the lug narrow grooves and extends continuously at a constant width without being divided in the tire width direction; provided on both sides of the lug central region in the tire circumferential direction; the auxiliary lug narrow groove; A circumferential lug edge region composed of a plurality of small sub-lag land portions that are partitioned by a plurality of lug edge partial grooves that divide the direction edge portion into a plurality of directions along the lug grooves. It is said.

  Next, the operation of the pneumatic tire according to claim 1 will be described.

  First, since a plurality of circumferential grooves extending along the tire circumferential direction are arranged on the tread, basic drainage properties, straight running stability during dry and wet traveling are ensured.

  By disposing a plurality of lug grooves that are inclined at an angle of 25 to 65 degrees with respect to the tire circumferential direction, drainage performance higher than that of an all-season tire can be exhibited.

  Here, when the angle of the lug groove with respect to the tire circumferential direction is less than 25 degrees, the lug compartment land portion row becomes very thin, and there is a concern that the motion performance is deteriorated.

  On the other hand, when the angle of the lug groove with respect to the tire circumferential direction exceeds 65 degrees, there is no merit for drainage performance.

  Therefore, the lug groove is preferably inclined within an angle range of 25 to 65 degrees with respect to the tire circumferential direction.

  The lug groove, which has a relatively small inclination angle with respect to the tire circumferential direction, is advantageous for drainage performance, but is disadvantageous for running on snow. By forming a plurality of lug edge partial slits on both edges of the edge and the stepping edge, it is possible to compensate for the disadvantageous parts when running on snow and to improve cornering performance, braking performance, and traction performance on snow. .

  Here, it is preferable that the lug section land portion is set relatively wide in advance so as to cut an edge (narrow groove).

  By dividing the wide lag section land part in the tire circumferential direction with the auxiliary lug narrow groove parallel to the lug groove, it is possible to make the block rigidity effective for running on snow, with the auxiliary lug narrow groove and the lug edge partial groove By partitioning the small sub-lag land, cornering performance on snow can be improved.

  Furthermore, the lug section land portion is divided into three in the circumferential direction by the auxiliary lug narrow groove, and both edge portions have a function that works mainly on traction and braking performance during snow travel.

The central part sandwiched between the auxiliary lug narrow grooves maintains high rigidity without being cut by the narrow grooves, so that it is possible to suppress the collapse of the small sub-land on both edges when driving on dry, wet and snowy. It is possible to reduce the block rigidity, that is, it is possible to cut an edge (lug edge partial cut groove) more effective for running on snow.
Also, when the groove walls facing each other of the auxiliary lug narrow grooves come into contact with each other at the time of ground contact, the circumferential center portion of the lug section land portion supports the small sub-lag land portions on both sides in the tire circumferential direction within the tire ground contact surface. Unnecessary deformation of the small sub-lag land is suppressed.

  The invention according to claim 2 is the pneumatic tire according to claim 1, wherein the width when the lug central region is measured in a direction perpendicular to the longitudinal direction of the lug groove is W1, and the circumferential lug edge portion. W2 / W1 is set in the range of 0.5 to 1.5 when the width when the region is measured in the direction perpendicular to the longitudinal direction of the lug groove is W2. .

  Next, the operation of the pneumatic tire according to claim 2 will be described.

  By setting the ratio W2 / W1 between the width W1 of the lug center region and the width W2 of the circumferential lug edge region within the range of 0.5 to 1.5, the circumferential rigidity of each region is substantially uniform. It is possible to suppress uneven wear caused by rolling of the tire.

  The pneumatic tire according to claim 3 is the pneumatic tire according to claim 1 or 2, wherein an angle formed between the lug groove and the lug edge partial cut groove connected to the lug groove is 30 degrees. It is characterized by being set above.

  Next, the operation of the pneumatic tire according to claim 3 will be described.

  If the angle formed by the lug groove and the lug edge partial cut groove is less than 30 degrees, the small sub-lag land portion has an acute angle portion, and there is a concern about deterioration of performance on snow and uneven wear due to a decrease in block rigidity.

  Therefore, it is preferable that the angle formed by the lug groove and the lug edge partial cut groove is 30 degrees or more.

  The pneumatic tire according to claim 4 is the pneumatic tire according to any one of claims 1 to 3, wherein a groove width of the lug edge partial groove is a groove width of the adjacent lug groove. It is characterized by being set within a range of 5 to 80% of the above.

  Next, the operation of the pneumatic tire according to claim 4 will be described.

  If the groove width of the lug edge partial groove is less than 5% of the groove width of the adjacent lug groove, the shear force of the snow column formed by entering the lug edge partial groove when running on snow is insufficient, and effective on snow The performance cannot be demonstrated.

  On the other hand, if the groove width of the lug edge partial cut groove exceeds 80% of the groove width of the adjacent lug groove, the drainage effect of the lug groove deteriorates and the dryness caused by the rigidity reduction (due to volume reduction) of the small sub-lag land portion , Wet and snow maneuverability will be reduced.

  Therefore, it is preferable to set the groove width of the lug edge partial cut groove within a range of 5 to 80% of the groove width of the adjacent lug groove.

  Invention of Claim 5 is a pneumatic tire of any one of Claim 1 thru | or 4, The tire circumferential direction edge part of the said lug division land part is 1-7 lug edge parts. It is characterized by being divided by a groove.

  Next, the operation of the pneumatic tire according to claim 5 will be described.

  The tire circumferential direction edge of the lug compartment land part determines the number of divisions depending on the size of the block and the degree of snow performance to be obtained, but the number of lug edge partial grooves on one tire circumferential edge is If the number is eight or more, the rigidity of the edge portion of the lug compartment land portion is significantly reduced, which causes dryness, wet performance, and uneven wear.

  Therefore, the number of lug edge partial grooves is preferably 7 or less.

The pneumatic tire according to claim 6 is the pneumatic tire according to any one of claims 1 to 5 , wherein the lug groove extends outward in the tire width direction so as to open at a tread end. A block row extending in the tire circumferential direction is formed in each of the tread central region and a tread shoulder region located on the outer side in the tire width direction of the tread central region.

Next, the operation of the pneumatic tire according to claim 6 will be described .

  The lug groove extends outward in the tire width direction so as to open at the tread end, and a block row extending in the tire circumferential direction is formed in each of the tread central region and the tread shoulder region located outside the tread central region in the tire width direction. This will ensure the snow performance required for all-season tires.

The invention according to claim 7 is the pneumatic tire according to any one of claims 1 to 6 , wherein a land portion sandwiched between the lug grooves is at least in the tire circumferential direction by the auxiliary lug narrow grooves. It is characterized by being divided into two sub-blocks.

Next, the operation of the pneumatic tire according to claim 7 will be described .

  Since the land portion sandwiched between the lug grooves is divided into at least two sub-blocks in the tire circumferential direction by the auxiliary lug narrow grooves, higher on-snow performance can be exhibited.

As described above, since the pneumatic tire according to claim 1 has the above-described configuration, it has an excellent effect that the performance on snow can be improved while ensuring the dry performance and the wet performance. Moreover, it has the outstanding effect that the unnecessary deformation | transformation of a small sublag land part can be suppressed.

  Since the pneumatic tire according to claim 2 is configured as described above, it has an excellent effect that uneven wear caused by rolling of the tire can be suppressed.

  Since the pneumatic tire according to claim 3 has the above-described configuration, it has an excellent effect that the block rigidity of the small sub-lag land portion can be reliably ensured.

  Since the pneumatic tire according to claim 4 has the above-described configuration, it has an excellent effect that the performances of dry, wet, and snow can be balanced at a high level.

  Since the pneumatic tire according to claim 5 has the above-described configuration, it has an excellent effect that the performances of dry, wet, and snow can be balanced at a high level.

Since the pneumatic tire according to claim 6 has the above-described configuration, it has an excellent effect that the snow performance necessary for the all-season tire can be ensured.

Moreover, since the pneumatic tire according to claim 7 has the above-described configuration, it has an excellent effect that higher performance on snow can be exhibited.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  A pneumatic tire 10 according to an embodiment of the present invention will be described with reference to FIGS.

  The pneumatic tire 10 has a size of 205 / 55R16, and the internal structure is the same as that of a normal radial tire.

  As shown in FIG. 1, the tread 12 of the pneumatic tire 10 of the present embodiment has a first circumferential groove 14, a second circumferential groove 16, and a third circumferential groove from the inside to the outside when the vehicle is mounted. 18 is formed.

  Here, in the pneumatic tire 10, the left side in the drawing is the inside when the vehicle is mounted, and the right side in the drawing is the outside when the vehicle is mounted.

  In the present embodiment, the center region 20 is between the first circumferential groove 14 and the third circumferential groove 18 of the tread 12, and the inner side of the first circumferential groove 14 when mounted on the vehicle (the arrow IN direction side) is the inner shoulder region. 22, the outer side (arrow OUT direction side) of the third circumferential groove 18 when the vehicle is mounted is referred to as an outer shoulder region 24.

  Connected to the second circumferential groove 16 is a first lug groove 26 that intersects with the first circumferential groove 14 and extends upward and inclining toward the tread end 12E on the inner side when the vehicle is mounted.

  An inner shoulder block 28 is defined in the inner shoulder region 22 by the first circumferential groove 14 and the first lug groove 26.

  The inner shoulder block 28 is formed with a lateral narrow groove 30 extending parallel to the first lug groove 26 and a narrow groove 32 extending along the circumferential direction of the vertical tire.

  On the other hand, in the central region 20, the first block 34 is partitioned by the first circumferential groove 14, the second circumferential groove 16, and the first lug groove 26 on the inner shoulder region side of the second circumferential groove 16. Has been.

  A lateral narrow groove 36 extending in parallel with the first lug groove 26 is formed in the center of the first block 34 in the tire axial direction.

  The central lug 20 and the outer shoulder area 24 extend from the outer tread end 12E when mounted on the vehicle to the third circumferential groove 18 so as to incline to the vicinity of the second circumferential groove 16 and extend to the left. A groove 38 is formed.

  A short circumferential groove 40 extending in parallel with the tire equatorial plane CL is connected to the end of the second lug groove 38 on the tread center side.

  An outer shoulder block 42 is defined in the outer shoulder region 24 by the third circumferential groove 18 and the second lug groove 38.

  The outer shoulder block 42 is formed with a lateral narrow groove 44 extending parallel to the second lug groove 38 and a narrow groove 46 extending along the circumferential direction of the vertical tire.

  Here, in this embodiment, in the land part arrange | positioned between the 2nd circumferential groove 16 and the 3rd circumferential groove 18 of the center area | region 20, the 2nd lug groove 38 and the 2nd lug groove 38 are The space between the two is called a lag compartment land portion 48.

  Two auxiliary lug narrow grooves 50 that are parallel to the second lug groove 38 are formed in the lug compartment land portion 48.

  The auxiliary lug narrow groove 50 has one end connected to the short circumferential groove 40 and the other end connected to the third circumferential groove 18.

  Further, the auxiliary lug narrow groove 50 is set to a groove width such that groove walls facing each other at the time of ground contact (that is, the groove closes at the time of ground contact).

  The lug compartment land portion 48 is formed long along the longitudinal direction of the second lug groove 38.

  The lug section land portion 48 is divided into three regions in the tire circumferential direction by two auxiliary lug narrow grooves 50. In the present embodiment, the lug center region 51 is located at the center and the circumferential lug edges are located on both sides thereof. This will be referred to as area 52.

  As shown in FIG. 2, the width when the lug center region 51 is measured in the direction perpendicular to the longitudinal direction of the second lug groove 38 is W1, and the circumferential lug edge region 52 is in the longitudinal direction of the second lug groove 38. It is preferable that W2 / W1 is set within a range of 0.5 to 1.5 when the width when measured in the orthogonal direction is W2.

  The lug center region 51 continuously extends between the third circumferential groove 18 and the short circumferential groove 40 without forming a narrow groove or the like.

  Next, in the circumferential lug edge region 52, the auxiliary lug narrow groove 50, and a plurality of lug edge partial grooves 54 that divide the tire circumferential edge portion into a plurality along the second lug groove 38, A plurality of small sub-lag land portions 56 are partitioned.

  In one circumferential lug edge region 52, the number of lug edge partial grooves 54 is preferably in the range of 1 to 7.

  The angle θ (measured on the narrow angle side) formed by the second lug groove 38 and the lug edge partial cut groove 54 is preferably set to 30 degrees or more.

  Further, the groove width W3 of the lug edge partial cut groove 54 is preferably set within a range of 5 to 80% of the groove width W4 of the adjacent second lug groove 38.

  In the pneumatic tire 10 of the present embodiment, the first circumferential groove 14, the second circumferential groove 16, the third circumferential groove 18, the first lug groove 26, the second lug groove 38, and the short circumferential groove 40 are used. The groove depth of the lug edge partial cut groove 54 is 8.5 mm. The groove widths of the first circumferential groove 14, the second circumferential groove 16, and the third circumferential groove 18 are 7.5 to 9 mm. The angle of the lug edge partial groove 54 with respect to the tire circumferential direction is 50 degrees, and the angle θ of the lug edge partial groove 54 with respect to the second lug groove 38 is 65 degrees. The groove width W3 of the lug edge partial cut groove 54 is set to 45% of the groove width W4 of the adjacent second lug groove 38.

The widths of the lateral narrow groove 30, the narrow groove 32, the lateral narrow groove 36, the lateral narrow groove 44, the narrow groove 46, and the auxiliary lug narrow groove 50 are each 0.5 mm, which is a groove width that is closed when grounding.
(Function)
Next, the effect | action of the pneumatic tire 10 of this embodiment is demonstrated.

  In the pneumatic tire 10 of the present embodiment, the tread 12 is provided with three circumferential grooves including a first circumferential groove 14, a second circumferential groove 16, and a third circumferential groove 18 extending along the tire circumferential direction. As a result of the arrangement, basic drainage performance, straight running stability during dry and wet running are ensured.

  Since the second lug groove 38 that is inclined at an angle of 25 to 65 degrees with respect to the tire circumferential direction is disposed on the tread 12, higher drainage performance than that of a conventional all-season tire can be exhibited.

  If the angle of each lug groove with respect to the tire circumferential direction is less than 25 degrees, the lug partition land portion 48 between the lug grooves becomes very thin, and there is a concern that the motion performance is deteriorated due to insufficient rigidity.

  On the other hand, when the angle of each lug groove with respect to the tire circumferential direction exceeds 65 degrees, there is no merit for drainage performance.

  Reducing the inclination angle of the second lug groove 38 with respect to the tire circumferential direction is advantageous for drainage performance, but disadvantageous for running on snow. However, in the pneumatic tire 10 of the present embodiment, a plurality of lug edge partial cut grooves 54 are formed on both edge portions of the kicking edge and the stepping edge of the lug section land portion 48, so that when running on snow The disadvantageous part can be compensated, and cornering performance, braking performance, and traction performance on snow can be improved.

  In addition, the lug compartment land portion 48 set wide can be divided into three in the tire circumferential direction by two auxiliary lug narrow grooves 50 parallel to the second lug groove 38, so that the block rigidity effective for running on snow can be obtained. The cornering performance on snow can be improved by dividing the plurality of small sub-lag land portions 56 by the narrow grooves 50 and the lug edge partial cut grooves 54.

  Further, by dividing the lug section land portion 48 into three, both edge portions in the tire circumferential direction of each of the divided land portions (the lug central region 51 and the circumferential lug edge region 52) are mainly used during snow traveling. It has a function that works effectively for traction and braking performance

  The lug central region 51 maintains a high rigidity state without being cut by a narrow groove, so that it is possible to suppress the collapse of the small sub-lag land portions 56 on both sides in the tire circumferential direction when traveling on dry, wet, and snow. It is possible to reduce the block rigidity of 56, that is, it is possible to cut an edge (lug edge partial groove 54) more effective for running on snow.

  By setting the ratio W2 / W1 between the width W1 of the lug center region 51 and the width W2 of the circumferential lug edge region 52 within the range of 0.5 to 1.5, the rigidity in the circumferential direction of each region is set. It can be made substantially uniform, and uneven wear caused by rolling of the tire can be suppressed.

  When the angle θ formed by the second lug groove 38 and the lug edge partial cut groove 54 is less than 30 degrees, the small sub-lag land portion 56 has an acute angle portion, and the deterioration of the on-snow performance and the uneven wear property due to the decrease in block rigidity. There are concerns.

  When the groove width W3 of the lug edge partial groove 54 is less than 5% of the groove width W4 of the adjacent second lug groove 38, the shear force of the snow column formed by entering the lug edge partial groove 54 when traveling on snow. Will not be able to demonstrate effective on-snow performance.

  On the other hand, when the groove width W3 of the lug edge partial groove 54 exceeds 80% of the groove width W4 of the adjacent second lug groove 38, the drainage effect of the second lug groove 38 is deteriorated, and the rigidity of the small sub-lag land portion 56 is increased. Dry, wet, and snow maneuverability due to the decrease is reduced.

  Note that if the number of lug edge partial slits is 8 or more with respect to one tire circumferential edge, the rigidity of the edge of the lug partition land will be significantly reduced, resulting in a decrease in dry and wet performance. Abrasion is reduced.

  At the time of ground contact, the auxiliary lug narrow groove 50 is closed, and the lug center region 51 of the lug partition land portion 48 supports the small sub-lag land portions 56 on both sides in the tire circumferential direction within the tire ground contact surface. Deformation is suppressed.

Necessary for all-season tires, since the first lug groove 26 and the second lug groove 38 extend from the tire width direction center to the tire width direction outer side so as to open to the tread end 12E and substantially traverse the entire tread 12. Snow performance can be secured.
(Test example)
In order to confirm the effect of the present invention, a conventional pneumatic tire and a pneumatic tire of an example to which the present invention was applied were prepared, and an actual vehicle test was performed.

  Below, the tread pattern of the pneumatic tire of the conventional example used for the test is demonstrated according to FIG.

  As shown in FIG. 3, the tread 100 has a circumferential groove 102 formed in the center and circumferential grooves 104 formed on both sides thereof.

  The land portion between the circumferential groove 102 and the circumferential groove 104 connects the lug groove 106, the lug groove 106, and the lug groove 106 whose inclination angle with respect to the tire equatorial plane CL decreases toward the tire equatorial plane CL. A rib 110 and a block 112 are defined by a lug groove 108 inclined in a direction opposite to the lug groove 106.

  A sipe 114 and a sipe 116 are formed on the rib 110, and a sipe 118 and a sipe 120 are formed on the block 112.

  A rib 122 is defined on the outer side of the circumferential groove 104 in the tire width direction. The rib 122 extends from the tread end 100E toward the circumferential groove 104, and terminates in the block. A lug groove 126 is formed which is disposed on the extension line and terminates in the block. Sipes 128, 130, and 132 are formed on the rib 122.

  Note that the pneumatic tires used in the tests all had a size of 205 / 55R16 and an internal pressure of 230 kPa. The load was equivalent to two passengers.

The test method and evaluation method will be described below.
-Feeling on snow: Comprehensive evaluation of braking performance, starting performance and cornering performance on a test course on a snowy road surface. The evaluation was expressed as an index with the conventional example being 100. In addition, it shows that it is excellent in performance, so that the numerical value of an index | exponent is large.
-Snow brake: Measures the braking distance when full braking is performed from 40km / h on snow. The evaluation was expressed as an index with the reciprocal of the braking distance of the conventional example as 100. In addition, it shows that it is excellent in performance, so that the numerical value of an index | exponent is large.
・ Snow traction: Measure acceleration time from starting at a distance of 50m on snow. The evaluation was expressed as an index with the reciprocal of the acceleration time of the conventional example as 100. In addition, it shows that it is excellent in performance, so that the numerical value of an index | exponent is large.
-Wet hydroplaning property: Feeling of hydroplaning limit speed when passing through a wet road with a depth of 5mm.
-Dry maneuvering stability: I drove sports on various circuit modes in a dry circuit course. The evaluation was a feeling evaluation of the test driver, and an index display with the conventional example being 100. In addition, it shows that it is excellent in performance, so that the numerical value of an index | exponent is large.
-Wet handling stability: We ran sports on various circuit modes in a wet circuit course. The evaluation was a feeling evaluation of the test driver, and an index display with the conventional example being 100. In addition, it shows that it is excellent in performance, so that the numerical value of an index | exponent is large.

  The results of the test are as described in Table 1 below.

  From the test results, it can be seen that the pneumatic tire of the example to which the present invention is applied has all the above-mentioned performances improved as compared with the pneumatic tire of the conventional example.

It is a top view of the tread of the pneumatic tire concerning one embodiment of the present invention. FIG. 2 is an enlarged plan view of a lug compartment land portion shown in FIG. 1. It is a top view of the tread of the pneumatic tire concerning a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pneumatic tire 12 Tread 14 1st circumferential groove 16 2nd circumferential groove 18 3rd circumferential groove 20 Tread center area 26 1st lug groove 28 Inner shoulder block 34 block 38 2nd lug groove 42 Outer shoulder block 48 Lug Land segment 50 Auxiliary lug narrow groove 51 Central lug region 52 Circumferential lug edge region 54 Lug edge partial groove 56 Small sub-lag land

Claims (7)

A tread disposed between both sidewalls and in contact with the road surface, a plurality of circumferential grooves provided on the tread and extending along the tire circumferential direction;
Extends from the outermost circumferential groove in the tire width direction toward the tire equatorial plane so as to terminate in the land , and is inclined at an angle of 25 to 65 degrees with respect to the tire circumferential direction and spaced in the tire circumferential direction. A plurality of lug grooves, and a short circumferential groove extending from the end of the lug groove in the tire width direction center side along the tire circumferential direction and terminating in the land portion ,
The tread includes a lug partition land portion that is sandwiched between the lug grooves and has a dimension in a direction along the lug grooves that is longer than a dimension in a direction perpendicular to the longitudinal direction of the lug grooves in the tire circumferential direction. Having at least one row of lug compartment land sections arranged by arranging a plurality of
The lug section land portion is sandwiched between two auxiliary lug narrow grooves that extend in parallel with the lug groove and have a groove width narrower than the lug groove and that are in contact with the groove walls facing each other at the time of ground contact. A lug center region continuously extending with a constant width without being divided in the tire width direction, provided on both sides of the lug center region in the tire circumferential direction, the auxiliary lug narrow groove, and a tire circumferential direction edge portion as the lug groove A pneumatic tire characterized by having a circumferential lug edge region composed of a plurality of small sub-lag land portions divided by a plurality of lug edge partial slits that are divided into a plurality of pieces in a direction along the direction. The width when the lug central region is measured in the direction orthogonal to the longitudinal direction of the lug groove is W1, and the width when the circumferential lug edge region is measured in the direction orthogonal to the longitudinal direction of the lug groove is W2. The pneumatic tire according to claim 1, wherein W2 / W1 is set within a range of 0.5 to 1.5. The pneumatic tire according to claim 1 or 2, wherein an angle formed by the lug groove and the lug edge partial cut groove connected to the lug groove is set to 30 degrees or more. The groove width of the lug edge partial cut groove is set within a range of 5 to 80% of the groove width of the adjacent lug groove. 4. Pneumatic tire described in 2. The air according to any one of claims 1 to 4, wherein a tire circumferential edge of the lug section land portion is divided by 1 to 7 lug edge partial grooves. Enter tire. The lug groove extends outward in the tire width direction so as to open at the tread end, and extends in the tire circumferential direction in the tread central region and the tread shoulder region located outside the tread central region in the tire width direction. The pneumatic tire according to any one of claims 1 to 5, wherein the pneumatic tire is formed. 7. The land portion sandwiched between the lug grooves is divided into at least two sub-blocks in the tire circumferential direction by the auxiliary lug narrow grooves. Pneumatic tire described in 2.

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