JP2015168301A - pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire in which blocks included in a block row of a tread shoulder part have a plurality of types of pitches, which can be improved in uniformity and improved in travel performance in a muddy place (mud performance).SOLUTION: In the pneumatic tire which has a plurality of blocks 15 that are divided by circumferential grooves 13 and lug grooves 14 in at least a tread shoulder part 12, in which the plurality of blocks 15 are arranged so as to have a plurality of types of pitches P in a tire circumference direction, radially protruding parts 16 are formed on sites respectively on extended lines of the lug grooves 14 in a region C between an end part A in a tire width direction of a tread part 1 and a tire maximum width position B, and radially recessed parts 17 are formed on sites respectively outside in the tire width direction of the blocks 15 in the region C, while circumferentially protruding parts 18 are formed between adjacent radially protruding parts 16.

Description

  The present invention relates to a pneumatic tire, and more specifically, in a pneumatic tire in which blocks included in a block row of a tread shoulder portion have a plurality of types of pitches, while improving uniformity and running performance in a muddy place (mud performance) It is related with the pneumatic tire which made it possible to improve.

  In a pneumatic tire, in order to reduce pattern noise caused by the tread pattern, the pitch of the blocks included in the block row formed on the tread surface is changed (specifically, the tire circumferential length of the block, The width of the lug grooves arranged between the blocks is changed) (see, for example, Patent Document 1). However, in such a tire, since the block rigidity varies between blocks having different pitches, the uniformity is deteriorated, and unpleasant vibration is likely to occur during traveling, and there is a problem in that riding comfort is reduced. . In particular, a mud tire mainly intended to travel on a rough road such as a muddy area is designed to have a large groove volume in the tread portion, and this tendency becomes remarkable.

  On the other hand, in a muddy area, the road surface is soft, so the side part on the tread part side also tends to contact the road surface. In addition to this, the tire is in contact with the road surface by setting the air pressure to fill the tire low. The area is increased so that mud can be chewed efficiently. Therefore, it has been proposed to improve the running performance (mud performance) in a muddy place by providing a protrusion extending from the lug groove to the tire maximum width position on the side portion in the mud tire (for example, Patent Documents). 2). However, such protrusions do not necessarily have an effect of improving the mud performance, and further improvements are required.

JP 2003-237317 A JP 2013-124046 A

  An object of the present invention is to improve uniformity and improve running performance (mud performance) in a muddy place in a pneumatic tire in which blocks included in a block row of a tread shoulder portion have a plurality of pitches. It is to provide a pneumatic tire.

  In order to achieve the above object, a pneumatic tire according to the present invention includes a tread portion that extends in the tire circumferential direction to form an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and the sidewall portions. A circumferential groove extending in the tire circumferential direction and a lug groove extending in the tire width direction at least in a tread shoulder portion located on the outer side in the tire width direction of the tread portion. A pneumatic tire in which the plurality of blocks are arranged so as to have a plurality of types of pitches in the tire circumferential direction, and the tire width direction end portion of the tread portion and the tire maximum width A radial convex portion that protrudes from the surface of the sidewall portion and extends in the tire radial direction at a portion on the extension line of each lug groove in the region between the positions. Formed in the tire width direction outer side of each block in the region between the tire width direction end portion of the tread portion and the tire maximum width position and extending in the tire radial direction, respectively, with respect to the surface of the sidewall portion While forming the radial recessed part to perform, the circumferential convex part which protruded from the surface of the sidewall part and extended in the tire circumferential direction was formed between the adjacent radial convex parts.

  In the present invention, as described above, the radial convex portions are respectively formed on the extended lines of the lug grooves in the region between the tire width direction end portion of the tread portion and the tire maximum width position, and the tire of the tread portion is formed. Since the radial recesses are formed in the tire width direction outside portion of each block in the region between the width direction end and the tire maximum width position, the difference in the circumferential length of the block and the groove width of the lug groove Therefore, the difference in block rigidity due to the tire can be reduced, and the uniformity of the tire can be improved. In addition, a circumferential convex portion is formed between adjacent radial convex portions, and the radial convex portion, the radial concave portion, and the circumferential convex portion bite mud when traveling in a muddy area. The traveling property (mud performance) in the muddy place can be improved by the cooperation of the portion, the radial concave portion, and the circumferential convex portion.

  In this invention, it is preferable that the volume of a radial direction convex part is so large that the groove width of a lug groove is large, and the volume of a radial direction recessed part is so large that the tire circumferential direction length of a block is large. Thereby, the difference in the circumferential rigidity of the tread surface is further relaxed, which is advantageous in improving uniformity.

  In this invention, it is preferable that the protrusion height of a radial direction convex part is 3 mm-15 mm, the depth of a radial direction recessed part is 1 mm-3 mm, and the protrusion height of a circumferential direction convex part is 3 mm-15 mm. By setting to such a range, uniformity can be improved and mud performance can be effectively improved.

  In this invention, it is preferable that the protrusion height of a radial direction convex part is so large that the groove width of a lug groove is large, and the depth of a radial direction recessed part is so large that the tire circumferential direction length of a block is large. Thereby, the difference in the circumferential rigidity of the tread surface is further relaxed, which is advantageous in improving uniformity.

  In the present invention, the protruding height of the radial convex portion is the largest on the tread portion side and is reduced toward the tire maximum width position side, and the depth of the radial concave portion is the largest on the tread portion side and is directed toward the tire maximum width position side. It is preferable to be smaller. As a result, the protruding amount of the radial convex portion or the concave amount of the radial concave portion near the tread surface that contacts the ground during the muddy road running in the sidewall portion becomes larger, making it easier to bite mud and improving mud performance. To be advantageous.

  In this invention, it is preferable that the protrusion height of the circumferential direction convex part is larger than another part in the part which this circumferential direction convex part overlaps with a radial direction recessed part. As a result, the circumferential convex portion can easily bite mud, which is advantageous for improving the mud performance.

It is a meridian half section view showing a pneumatic tire according to an embodiment of the present invention. 1 is a perspective view showing a part of a pneumatic tire according to an embodiment of the present invention. 1 is a side view of a pneumatic tire according to an embodiment of the present invention. It is XX arrow sectional drawing of FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 4 of a pneumatic tire according to another embodiment of the present invention.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

  The pneumatic tire of the present invention illustrated in FIG. 1 includes a tread portion 1 that extends in the tire circumferential direction and has an annular shape, a pair of sidewall portions 2 that are disposed on both sides of the tread portion 1, and sidewall portions 2. And a pair of bead portions 3 arranged on the inner side in the tire radial direction. In FIG. 1, CL indicates the tire equator.

  A single carcass layer 4 is mounted between the pair of left and right bead portions 3, and end portions of the carcass layer 4 are folded around the bead core 5 from the inside to the outside of the tire. A bead filler 6 having a triangular cross section made of rubber is disposed on the outer peripheral side of the bead core 5. On the outer peripheral side of the carcass layer 4 in the tread portion 1, two belt layers 7 and 8 are arranged over the entire tire circumference. The belt layers 7 and 8 include reinforcing cords made of, for example, steel cords, the reinforcing cords are inclined at an angle of, for example, 10 ° to 40 ° with respect to the tire circumferential direction, and the reinforcing cords cross each other between the layers. Is arranged. Further, a belt reinforcing layer 9 is disposed on the outer peripheral side of the belt layers 7 and 8. The belt reinforcing layer 9 includes a reinforcing cord made of an organic fiber cord such as nylon or aramid, and the reinforcing cord is arranged at an angle of, for example, 5 ° or less with respect to the tire circumferential direction.

  The present invention is applied to such a general pneumatic tire, but its specific structure is not limited to the basic structure described above.

  When the tread surface 10 which is the outer surface of the tread portion 1 is divided into a tread center portion 11 on the tire equator CL side and a tread shoulder portion 12 on both outer sides in the tire width direction, in the present invention, at least the tread shoulder portion 12 is A circumferential groove 13 extending in the tire circumferential direction and a lug groove 14 extending in the tire width direction are provided, and a plurality of blocks 15 are defined by the circumferential groove 13 and the lug groove 14. In the present invention, the structure of the groove / land portion formed in the tread center portion 11 is not particularly limited. However, in the embodiment of FIG. 1, the circumferential groove 13 and the lug groove 14 are similar to the tread shoulder portion 12. A plurality of blocks 15 are partitioned.

The plurality of blocks 15 (15A, 15B, 15C) partitioned and formed in the tread shoulder portion 12 constitute a block row arranged in the tire circumferential direction as illustrated in FIG. 2, and constitute this block row. The pitches P (P _A , P _B , P _C ) of the blocks 15A, 15B, 15C are not constant. That is, the block 15 (15A, 15B, 15C) is configured to have a plurality of types of pitches P (P _A , P _B , P _C ) in the tire circumferential direction. The pitch P is a distance from one end of the block 15 in the tire circumferential direction to one end of the adjacent block 15 in the tire circumferential direction, and is adjacent to the tire circumferential length L of the block 15 and the block 15 on one side. This corresponds to the sum of the groove widths W of the lug grooves 14 to be performed.

  In the present invention, with respect to the lug groove 14 and the block 15, the radial convex portion 16 and the radial concave portion 17 are formed in the region C between the tire width direction end portion A and the tire maximum width position B of the tread portion 1. And the circumferential direction convex part 18 is formed. The radial protrusions 16 are formed so as to protrude from the surface of the sidewall portion 2 at positions on the extension lines of the lug grooves 14 in the region C and extend in the tire radial direction. The radial recesses 17 are formed in the regions C on the outer side in the tire width direction of the respective blocks 15 so as to be recessed with respect to the surface of the sidewall portion 2 and extend in the tire radial direction. On the other hand, the circumferential convex portion 18 is formed so as to protrude from the surface of the sidewall portion 2 between the adjacent radial convex portions 16 and 16 and to extend in the tire circumferential direction.

  Thus, since the radial convex portion 16, the radial concave portion 17, and the circumferential convex portion 18 are formed in the region C, the outer side in the tire width direction of the lug groove 14 which is an element for reducing the rigidity in the tread surface 10 is formed. Radial direction convex part 16 which is an element which increases rigidity is arranged in a part, and a radial direction which is an element which decreases rigidity in a part of tire 15 in the tire width direction outside block 15 which is an element which increases rigidity in tread surface 10 Since the concave portion 17 is disposed, the difference in the block rigidity due to the difference in the pitch P of the block 15 is alleviated by the radial convex portion 16 and the radial concave portion 17, and the tire uniformity can be improved. Moreover, since the radial convex part 16 and the radial concave part 17 and the circumferential convex part 18 bite mud when traveling in the muddy ground, the radial convex part 16, the radial concave part 17, and the circumferential convex part 18. This can improve the runnability (mud performance) in the muddy area.

In the schematic diagram shown in FIG. 3, the pitches P _A , P _B , and P _C of the blocks 15A, 15B, and 15C are different from each other, and the magnitude relationship is P _A <P _B <P _C. Also, lug grooves 14A, 14B, the groove width W _A of 14C, W _B, W _C, and block 15A, 15B, 15C tire circumferential direction length L _A of the, L _B, L _C likewise different from each other, the magnitude relationship The groove width has a relationship of W _A <W _B <W _C , and the circumferential length has a relationship of L _A <L _B <L _C. When the pitch P (groove width W, circumferential length L) has such a magnitude relationship, the volumes of the radial protrusions 16 and the radial recesses 17 are preferably changed according to the pitch P of the blocks 15. . That is, the larger the groove width W of the lug groove 14 or the length L in the tire circumferential direction of the block 15, the larger the volumes of the radial convex portion 16 and the radial concave portion 17 may be.

Specifically, as shown in FIG. 3, the radial convex portion 16A located on the extension line of the lug groove 14A (groove width W _A ) and the radial direction located on the extension line of the lug groove 14B (groove width W _B ) The volume of the radial convex portion 16C located on the extension line of the convex portion 16B and the lug groove 14C (groove width W _C ) is different, and the diameter depends on the size relationship of the groove width (W _A <W _B <W _C ). The volume of the directional protrusions 16A to 16C may be in the relationship of the radial protrusion 16A <the radial protrusion 16B <the radial protrusion 16C. Similarly, the radial concave portion 17 is also positioned on the outer side in the tire width direction of the block 15A (circumferential length L _A ) in the radial direction of the radial concave portion 17A and the block 15B (circumferential length L _B ). The volume of the radial recess 17C located on the outer side in the tire width direction of the radial recess 17B and the block 15C (circumferential length L _C ) is different, and the size relationship of the circumferential length (L _A <L _B <L _C ), The volume of the radial recesses 17A to 17C may be in the relationship of the radial recess 17A <the radial recess 17B <the radial recess 17C.

  Thus, by setting the volume of the radial protrusion 16 and the radial recess 17 according to the pitch P of the block 15 (the groove width W of the lug groove 14 and the circumferential length L of the block 15), the groove width W An element for increasing the rigidity (ie, the radial convex portion 16 having a large volume) is disposed at the outer side in the tire width direction of the lug groove 14 where the rigidity is increased and the rigidity is decreased, and the circumferential length L is increased and the rigidity is increased. Since an element (that is, a radial concave portion 17 having a large volume) that further reduces rigidity is arranged at a portion outside the tire width direction of the block 15 that becomes larger, the circumferential rigidity difference of the tread surface 10 is further increased. It is relaxed and it is advantageous for improvement of uniformity.

The volume of the radial projection 16 and the radial recess 17 is, for example, the same as the projection height of the radial projection 16 and the depth of the radial recess 17, while the radial projection 16 and the radial recess 17. It may be set by changing the circumferential length of 17. That is, as illustrated in FIG. 3, the circumferential length of the radial convex portion 16A is T _A , the circumferential length of the radial convex portion 16B is T _B , and the circumferential length of the radial convex portion 16C is T when is _C, the magnitude of the circumferential length of the radial protrusions 16A - 16C by the relationship _{T a <T B <T C} , the volume of the radial protrusions 16A - 16C, the radial The relationship of convexity 16A <radial convexity 16B <radial convexity 16C can be set. Similarly, regarding the radial recess 17, the circumferential length of the radial recess 17A is t _A , the circumferential length of the radial recess 17B is t _B , and the circumferential length of the radial recess 17C is t _C. When the relationship between the circumferential lengths of the radial recesses 17A to 17C is set to a relationship of t _A <t _B <t _C , the volume of the radial recesses 17A to 17C is set to the radial recess 17A <radial direction. The relationship of the recess 17B <the radial recess 17C can be set.

  Since the circumferential convex part 18 should just be able to chew mud with the radial convex part 16 and the radial concave part 17, without connecting with the radial convex part 16 like embodiment of FIG. An end portion in the tire circumferential direction of the circumferential convex portion 18 may be separated from the radial convex portion 16 or may terminate in the circumferential concave portion 17. However, since the radial direction convex part 16 can be reinforced when the circumferential direction convex part 18 connects the adjacent radial direction convex part 16, durability of these convex parts can be improved.

  The circumferential direction convex part 18 should just form one row between the adjacent radial direction convex parts 16 and 16 so that it may illustrate in FIGS. 1-3, but you may provide multiple rows | lines. In particular, when providing a plurality of circumferential protrusions 18, it is preferable to provide two to three rows. Thereby, since the element which chews mud increases, mud performance can be improved. However, if the circumferential protrusions 18 are in four or more rows, the groove volume in the region C is reduced, so that the mud performance cannot be sufficiently improved.

  The radial protrusion 16 preferably extends along an extension line of the lug groove 14 and may be inclined within a range of, for example, ± 30 ° with respect to the tire radial direction.

  The radial convex portion 16 and the radial concave portion 17 can be formed in various shapes such as a triangular shape and an elliptical shape in addition to being formed in a rectangular shape as illustrated in FIG. Further, it may be formed to extend in a zigzag shape in the radial direction. Moreover, it may be a shape that is divided in the middle in the radial direction and intermittently extends in the radial direction.

  As illustrated in FIG. 4, the protruding height of the radial convex portion 16 from the surface of the sidewall portion 2 is H, the depth of the radial concave portion 17 from the surface of the sidewall portion 2 is D, and the circumferential convex portion. 18 where the protruding height from the surface of the sidewall portion 2 is h, the protruding height H of the radial convex portion 16 is 3 mm to 15 mm, the depth D of the radial concave portion 17 is 1 mm to 3 mm, and the circumferential convexity It is preferable to set the protrusion height h of the portion 18 in the range of 3 mm to 15 mm. By setting to such a range, uniformity can be improved and mud performance can be effectively improved.

  At this time, if the protruding height H of the radial protrusion 16 is smaller than 3 mm, the difference in tread rigidity cannot be sufficiently reduced, so that the effect of improving uniformity is reduced and the effect of biting mud is also reduced. Therefore, the mud performance cannot be improved sufficiently. If the protruding height H of the radial convex portion 16 is greater than 15 mm, the rigidity increase due to the radial convex portion 16 becomes too large, and the uniformity is reduced instead. If the depth D of the radial recess 17 is less than 1 mm, the difference in tread rigidity cannot be sufficiently reduced, so that the effect of improving uniformity is reduced and the effect of biting mud is also reduced. Cannot be improved sufficiently. If the depth D of the circumferential recess 17 is greater than 3 mm, the reduction in rigidity due to the radial recess 17 becomes too large, and the uniformity decreases instead. If the protrusion height h of the circumferential protrusion 18 is smaller than 3 mm, the effect of biting the mud is reduced, and the mud performance cannot be sufficiently improved. If the protrusion height h of the circumferential protrusion 18 is greater than 15 mm, the protrusion of the circumferential protrusion 18 becomes too large, and the durability of the circumferential protrusion 18 decreases.

  As described above, the volume of the radial convex portion 16 and the radial concave portion 17 can be set by changing the circumferential length T of the radial convex portion 16 and the circumferential length t of the radial concave portion 17. However, in addition to the circumferential lengths T and t, the protrusion height H of the radial protrusion 16 and the depth D of the radial recess 17 are further changed to the groove width W of the lug groove 14 and the circumferential length of the block 15. It can be changed according to L. That is, the projection height H of the radial protrusion 16 is increased as the groove width W of the lug groove 14 is increased, and the depth D of the radial recess 17 is increased as the tire circumferential length L of the block 15 is increased. . Thereby, the difference in the circumferential rigidity of the tread surface is further relaxed, which is advantageous in improving uniformity.

  The protruding height H of the radial convex portion 16 and the depth D of the radial concave portion 17 do not necessarily have to be constant. For example, the protruding height H of the radial convex portion 16 is the largest on the tread portion 1 side and It is also possible to make the depth D smaller toward the large position B, and the depth D of the radial recess 17 to be largest on the tread portion 1 side and smaller toward the tire maximum width position B side. When traveling in a muddy area, the portion close to the tread portion 1 of the sidewall portion 2 is also grounded. Thus, by setting the protruding height H and the depth D in this manner, Since the protruding amount of the radial convex portion 16 and the concave amount of the radial concave portion 17 at the portion that contacts the ground during running on the ground are increased, mud can be easily bitten and the mud performance is improved.

  The protrusion height h of the circumferential convex portion 18 is not necessarily constant. For example, as illustrated in FIG. 5, the circumferential convex portion 18 has a portion where the circumferential convex portion 18 overlaps the radial concave portion 17. The protruding height h ′ can be made larger than the protruding height h of other portions of the circumferential protrusion 18. Thereby, since the circumferential direction convex part 18 becomes easy to chew mud, it becomes advantageous to the improvement of a mud performance.

  The tire size 265 / 65R17 112S has the cross-sectional structure of FIG. 1, and the presence / absence, position, width, protrusion height / depth of each of the radial protrusions and the radial recesses, the presence / absence of the circumferential protrusions, the width, Eight types of tires of Conventional Example 1, Comparative Examples 1-2, and Examples 1-5 with different protrusion heights as shown in Table 1 were manufactured.

  In each example, three types of blocks having different pitches are repeatedly arranged, the number of pitches is 70, the block having the largest block pitch (hereinafter referred to as a large block) is 42 mm, and the second largest block. (Hereinafter referred to as a medium block) is 36 mm, the smallest block (hereinafter referred to as a small block) is 30 mm, and the pitch ratio is 1.4. In addition, the groove width of the lug groove is 7.5 mm for the largest lug groove (hereinafter referred to as a large lug groove), 6.5 mm for the second largest lug groove (hereinafter referred to as a middle lug groove), and the smallest lug groove (hereinafter referred to as a lug groove). , The small lug groove) is 5.0 mm, and the tire circumferential length of the block is 37 mm for the large block, 31 mm for the medium block, and 25 mm for the small block. Moreover, in any example, the shape of a radial direction convex part, a radial direction recessed part, and a circumferential direction convex part is the shape illustrated in FIG.

  In Table 1, the width and depth of the radial convex portion and the radial concave portion are the radial convex portions at positions corresponding to the large lug groove, middle lug groove, small lug groove, large block, medium block, and small block, respectively. And the radial recesses are individually described. In Examples 4 and 5 in which the protrusion height of the radial protrusion changes, the protrusion height is the largest on the tread surface side and the protrusion height is the smallest on the bead side. Is expressed as “maximum protrusion height (protrusion height on the tread portion side) → minimum protrusion height (protrusion height on the bead portion side)”. In the column of the protrusion height of the circumferential convex portion, the height of the portion where the circumferential convex portion overlaps the radial concave portion is shown in parentheses.

  These test tires were evaluated for uniformity and mud performance by the following evaluation methods, and the results are also shown in Table 1.

Uniformity Each test tire is mounted on a wheel with a rim size of 17 × 8.0J, filled with air pressure of 230 kPa, and in accordance with JIS D4233, RFV is measured using an indoor drum tester (drum diameter 1707 mm). Therefore, it was evaluated as uniformity. The evaluation results are shown as an index with Conventional Example 1 as 100. The larger the index value, the better the uniformity.

Mud performance Each test tire is assembled to a wheel with a rim size of 17 x 8.0J, filled with regular internal pressure, mounted on a test vehicle (four-wheel drive vehicle) with a displacement of about 2700cc, and a test course consisting of muddy ground is 30km / h. The vehicle traveled at a speed of ˜60 km / h, and a sensory evaluation was conducted by seven expert panelists on steering performance during lane change and cornering and steering stability during straight travel. The evaluation results are shown as an index with Comparative Example 1 as 100. The larger the index value, the better the steering stability.

  As can be seen from Table 1, the tires of Examples 1 to 5 have improved uniformity and mud performance in comparison with Conventional Example 1.

  On the other hand, in Comparative Example 1 in which the positional relationship between the radial protrusions and the radial recesses was reversed, the block rigidity difference could not be suppressed, and the uniformity deteriorated. Moreover, the comparative example 2 which does not have a circumferential direction convex part was not able to fully improve the mud performance.

DESCRIPTION OF SYMBOLS 1 Tread part 2 Side wall part 3 Bead part 4 Carcass layer 5 Bead core 6 Bead filler 7,8 Belt layer 9 Belt reinforcement layer 10 Tread surface 11 Tread center part 12 Tread shoulder part 13 Circumferential groove 14 Lug groove 15 Block 16 Radial direction Convex part 17 Radial concave part 18 Circumferential convex part CL Tire equator

Claims (6)

An annular tread portion extending in the tire circumferential direction, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on the inner side in the tire radial direction of the sidewall portions. A plurality of blocks defined by a circumferential groove extending in the tire circumferential direction and a lug groove extending in the tire width direction on at least a tread shoulder portion located on the outer side in the tire width direction of the tread portion. In the pneumatic tire arranged so that the block has a plurality of pitches in the tire circumferential direction,
A radial convex portion that protrudes from the surface of the sidewall portion and extends in the tire radial direction is formed at a portion on the extension line of each lug groove in a region between the tire width direction end portion of the tread portion and the tire maximum width position. In addition, each of the blocks in the region between the tire width direction end portion of the tread portion and the tire maximum width position in the tire width direction outer side is recessed with respect to the surface of the sidewall portion and extends in the tire radial direction. While forming a radial recessed part, the pneumatic tire characterized by forming the circumferential convex part which protrudes from the surface of a sidewall part between the said adjacent radial convex parts, and extended in a tire circumferential direction.   2. The air according to claim 1, wherein the volume of the radial protrusion is larger as the groove width of the lug groove is larger, and the volume of the radial recess is larger as the tire circumferential length of the block is larger. Enter tire.   The protruding height of the radial convex portion is 3 mm to 15 mm, the depth of the radial concave portion is 1 mm to 3 mm, and the protruding height of the circumferential convex portion is 3 mm to 15 mm. 2. The pneumatic tire according to 2.   The protrusion height of the radial protrusion is increased as the groove width of the lug groove is increased, and the depth of the radial recess is increased as the tire circumferential length of the block is increased. The pneumatic tire according to 2 or 3.   The protruding height of the radial convex portion is the largest on the tread portion side and decreases toward the tire maximum width position side, and the radial concave portion depth is the largest on the tread portion side and decreases toward the tire maximum width position side. The pneumatic tire according to claim 1, wherein the pneumatic tire is a tire.   The pneumatic projection according to any one of claims 1 to 5, wherein the protrusion height of the circumferential convex portion is larger than the other portion in a portion where the circumferential convex portion overlaps the radial concave portion. tire.

Images