JP6056330B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that improves steering stability at high speed running and durability at high speed running with a camber.

  Conventionally, for example, in Patent Document 1, at least one carcass and belt layer, and a belt cover layer in which a reinforcing cord made of an organic fiber cord is spirally wound around the tire radial direction outside the belt layer in the tire radial direction. And a tread portion having a tread surface having a different tread surface ratio across the tire equatorial plane, wherein the tread surface has a tire diameter on a side having a smaller groove area ratio across the tire equatorial plane in the meridional section. A pneumatic tire having a tread profile in which the outermost position in the direction is arranged and the amount of depression of the tread profile from the outermost position in the tire radial direction to the tire radial direction at each outermost end in the tire width direction is equally described. Has been.

  The pneumatic tire described in Patent Document 1 includes a tread portion having a tread surface having a different groove area ratio across the tire equator plane, so that drainage is performed on the side having a larger groove area ratio (that is, the side having more grooves). Performance can be obtained, and steering stability on a dry road surface can be obtained on the side having a small groove area ratio (that is, a side having few grooves and high rigidity), so that both drainage performance and steering stability can be achieved. Moreover, according to this pneumatic tire, the tread surface has a tread profile in which the outermost position in the tire radial direction is arranged on the side where the groove area ratio is small across the tire equatorial plane in the meridional section, that is, on the side where the rigidity of the tread portion is high. Since the contact pressure is increased on the high-rigidity side to make the contact pressure uniform throughout the contact area, the rigidity of the tread part that sandwiches the tire equator surface without deteriorating durability at high speeds The deterioration of conicity caused by the difference can be suppressed.

JP 2011-230699 A

  In recent years, there has been a demand for both handling stability at high speed and durability at high speed with camber. Here, in order to ensure steering stability, it is effective to project the rib contour outward in the tire radial direction from the tread surface contour so as to improve the ground contact property of the rib formed in the tread portion. On the other hand, in the case of application to a vehicle with a camber, since the contact length becomes longer on the inner rib than the outer rib on the tire equator when the vehicle is mounted, durability at high speed tends to decrease. . For this reason, it is difficult to achieve both steering stability at high speed and durability at high speed with camber.

  The present invention has been made in view of the above, and an object of the present invention is to provide a pneumatic tire that can achieve both steering stability at high speed running and durability at high speed running with a camber.

  In order to solve the above-described problems and achieve the object, the pneumatic tire of the first invention is provided along the tire circumferential direction by at least three main grooves extending along the tire circumferential direction on the tread surface. In a pneumatic tire in which at least four extending ribs are formed and a direction inside and outside the vehicle is specified when the vehicle is mounted, at least one of the ribs in a region outside the vehicle from the tire equator plane is the tread surface. Projecting outward in the tire radial direction from the contour line, and at least one of the ribs inside the vehicle from the tire equatorial plane is recessed in the tire radial direction from the contour line, and the center of the radius of curvature of the line of the recess is It is located outside the tread surface in the tire radial direction.

  According to this pneumatic tire, since at least one of the ribs protrudes outward in the tire radial direction from the contour line on the outside of the vehicle, the grounding property of the ribs is improved, so that the steering stability during high speed driving is improved. can do. In addition, at least one of the ribs on the inner side of the vehicle is recessed inward in the tire radial direction from the contour line, so that excessive grounding of the ribs is mitigated, so that the ground contact length is uniform between the ribs and high speed with camber Durability in running can be improved. As a result, it is possible to achieve both handling stability at high speed and durability at high speed with camber.

  The pneumatic tire according to a second aspect of the present invention is the pneumatic tire according to the first aspect, wherein the rib arranged in the region outside the vehicle from the tire equatorial plane and sandwiched between the main grooves is in the tire radial direction from the contour line. The rib that protrudes outward and is located in the vehicle inner side than the tire equator plane and is sandwiched between the main grooves is recessed inward in the tire radial direction from the contour line, and the radius of curvature of the line of the recess is The center is located outside the tread surface in the tire radial direction.

  According to this pneumatic tire, since at least one of the ribs protrudes outward in the tire radial direction from the contour line on the outside of the vehicle, the grounding property of the ribs is improved, so that the steering stability during high speed driving is improved. can do. Since the ribs disposed between the main grooves are caused most by the improvement of the ground contact property of the ribs, it is possible to further improve the steering stability during high speed traveling. In addition, at least one of the ribs on the inner side of the vehicle is recessed inward in the tire radial direction from the contour line, so that excessive grounding of the ribs is mitigated, so that the ground contact length is uniform between the ribs and high speed with camber Durability in running can be improved. Since the ribs placed between the main grooves are the most attributable to alleviating excessive ground contact, the contact length between the ribs is made more uniform, and the durability at high speed running with a camber can be further improved. it can. As a result, it is possible to remarkably obtain the effect of achieving both handling stability at high speed and durability at high speed with camber.

  Further, in the pneumatic tire according to a third aspect, in the first aspect, the four main ribs are formed by the three main grooves, and the center main groove at the center in the tire width direction on the tire equator plane. Is disposed, the rib disposed between the main grooves on the vehicle outer side of the center main groove protrudes outward in the tire radial direction from the contour line, and the main groove on the vehicle inner side of the center main groove. The rib disposed between the grooves is recessed inward in the tire radial direction with respect to the contour line, and the center of the radius of curvature of the line of the recess is positioned on the outer side in the tire radial direction with respect to the tread surface.

  According to this pneumatic tire, when the four main ribs are formed by the three main grooves and the center main groove in the center in the tire width direction is arranged on the tire equator plane, Since the rib disposed between the main grooves protrudes outward in the tire radial direction with respect to the contour line, the ground contact property of the rib is improved, so that the steering stability during high speed running can be improved. Since the ribs disposed between the main grooves are caused most by the improvement of the ground contact property of the ribs, it is possible to further improve the steering stability during high speed traveling. Moreover, since the ribs that are sandwiched between the main grooves on the vehicle inner side of the center main groove are dented inward in the tire radial direction from the contour line, excessive grounding of the ribs is alleviated, so that the ground contact length between each rib is reduced. It is made uniform and the durability in high-speed traveling with a camber can be improved. Since the ribs placed between the main grooves are the most attributable to alleviating excessive ground contact, the contact length between the ribs is made more uniform, and the durability at high speed running with a camber can be further improved. it can. As a result, it is possible to remarkably obtain the effect of achieving both handling stability at high speed and durability at high speed with camber.

  In the pneumatic tire according to a fourth aspect of the present invention, in the first aspect, the five ribs are formed by the four main grooves, and a center rib in the center in the tire width direction is disposed on the tire equatorial plane. The rib disposed between the main grooves adjacent to the vehicle outer side of the center rib protrudes outward in the tire radial direction from the contour line, and adjacent to the vehicle inner side of the center rib. The rib disposed between the main grooves is recessed inward in the tire radial direction from the contour line, and the center of the radius of curvature of the line of the recess is positioned on the outer side in the tire radial direction from the tread surface. To do.

  According to this pneumatic tire, when five ribs are formed by the four main grooves and the center rib in the tire width direction center is arranged on the tire equator plane, the center rib is adjacent to the vehicle outer side. Then, by projecting the ribs disposed between the main grooves to the outer side in the tire radial direction from the contour line, the ground contact property of the ribs is improved, so that the steering stability during high speed traveling can be improved. Since the rib disposed adjacent to the outer side of the center rib and sandwiched between the main grooves is caused most by the improved grounding property of the rib, the steering stability during high speed traveling can be further improved. In addition, the ribs that are arranged adjacent to the inner side of the center rib and sandwiched between the main grooves are recessed inwardly in the tire radial direction from the contour line, so that excessive grounding of the ribs is alleviated. The length is made uniform, and the durability in high-speed traveling with a camber can be improved. The ribs placed between the main ribs adjacent to the inner side of the center rib are caused by alleviating excessive grounding, so the grounding length is more uniform between the ribs, and the camber can be operated at high speed. The durability can be further improved. As a result, it is possible to remarkably obtain the effect of achieving both handling stability at high speed and durability at high speed with camber.

  In the pneumatic tire according to a fifth aspect of the present invention, in the first aspect, the six main ribs are formed by the five main grooves, and the center main groove at the center in the tire width direction on the tire equator plane. Is disposed, the at least one rib disposed on the outer side of the center main groove and sandwiched between the main grooves protrudes outward in the tire radial direction from the contour line, and the inner side of the center main groove in the vehicle The at least one rib disposed between the main grooves is recessed inward in the tire radial direction with respect to the contour line, and the center of the radius of curvature of the recessed line is positioned on the outer side in the tire radial direction with respect to the tread surface. It is characterized by that.

  According to this pneumatic tire, when six ribs are formed by five main grooves, and the center main groove in the center in the tire width direction is arranged on the tire equator surface, the vehicle outer side of the center main groove Since the rib disposed between the main grooves protrudes outward in the tire radial direction with respect to the contour line, the ground contact property of the rib is improved, so that the steering stability during high speed running can be improved. Since the ribs disposed between the main grooves are caused most by the improvement of the ground contact property of the ribs, it is possible to further improve the steering stability during high speed traveling. Moreover, since the ribs that are sandwiched between the main grooves on the vehicle inner side of the center main groove are dented inward in the tire radial direction from the contour line, excessive grounding of the ribs is alleviated, so that the ground contact length between each rib is reduced. It is made uniform and the durability in high-speed traveling with a camber can be improved. Since the ribs placed between the main grooves are the most attributable to alleviating excessive ground contact, the contact length between the ribs is made more uniform, and the durability at high speed running with a camber can be further improved. it can. As a result, it is possible to remarkably obtain the effect of achieving both handling stability at high speed and durability at high speed with camber.

  The pneumatic tire according to a sixth aspect of the present invention is the pneumatic tire according to any one of the second to fifth aspects, further comprising a ground end on a shoulder rib on the vehicle inner side than the main groove on the innermost side of the vehicle. When P1 is set, P2 is an opening end of the main groove on the innermost side of the vehicle closer to the vehicle inner side, and P3 is an opening end of the main groove on the innermost side of the vehicle closer to the outer side of the vehicle. , P1, P2, and P3 are recessed inward in the tire radial direction from the contour line of the curvature radius passing through P1, P2, and P3, and the center of the curvature radius of the line of the recess is located on the outer side in the tire radial direction from the tread surface.

  According to this pneumatic tire, the ground contact area of the shoulder rib is recessed inward in the tire radial direction from the contour line, so that it synergizes with the effect of mitigating excessive ground contact of the rib inside the vehicle. It is possible to further improve durability.

  The pneumatic tire according to a seventh aspect is characterized in that, in the fourth aspect, the center rib protrudes outward in the tire radial direction from the contour line.

  According to this pneumatic tire, by projecting the center rib outward in the tire radial direction from the contour line, it synergizes with the effect of improving the ground contact property of the rib on the outside of the vehicle, so the handling stability at high speeds is further improved. can do.

  The pneumatic tire according to an eighth aspect of the present invention is the pneumatic tire according to the seventh aspect, wherein the pneumatic tire has a grounding end on a shoulder rib on the inner side of the vehicle with respect to the main groove on the innermost side of the vehicle. When the opening end near the vehicle inner side of the main groove is P2, and the opening end of the main groove near the vehicle outer side is P3, the distance between P1 and P2 of the shoulder rib is P1, P2, P3. It is characterized in that it is recessed inward in the tire radial direction from the contour line of the radius of curvature that passes, and the center of the radius of curvature of the line of the recess is located on the outer side in the tire radial direction from the tread surface.

  According to this pneumatic tire, the center rib protrudes outward in the tire radial direction from the contour line, and synergizes with the effect of improving the ground contact property by the rib on the outer side of the vehicle, so that the driving stability during high speed driving is further improved. Can do. In addition, by denting the ground contact area of the shoulder rib to the inside in the tire radial direction than the outline, it synergizes with the effect of mitigating excessive ground contact of the rib on the inside of the vehicle, so the durability at high speed with camber is further improved Can be improved. As a result, it is possible to remarkably obtain the effect of achieving both handling stability at high speed and durability at high speed with camber.

  A pneumatic tire according to a ninth aspect of the present invention is the pneumatic tire according to any one of the second to eighth aspects, wherein the pneumatic tire is disposed between the main groove in a region outside the vehicle from the tire equatorial plane and is positioned more than the contour line. In the rib protruding outward in the radial direction, the protruding amount is 0.7 [%] or more and 2.0 [%] or less of the width of the rib, and the main groove in a region inside the vehicle from the tire equatorial plane In the rib that is disposed between the ribs and is recessed inward in the tire radial direction from the contour line, the amount of the recess is 0.7% or more and 2.0% or less of the width of the rib. And

  According to this pneumatic tire, by defining the protruding amount of the rib and the recessed amount of the rib with respect to each width, it is possible to achieve compatibility between handling stability at high speed and durability at high speed with a camber. Highly maintainable.

  The pneumatic tire according to a tenth aspect of the invention is the sixth or eighth aspect of the invention, wherein the pneumatic tire is disposed between the main grooves in a region outside the vehicle from the tire equator plane, and is located on the outer side in the tire radial direction from the contour line. In the protruding rib, the protruding amount is 0.7 [%] or more and 2.0 [%] or less of the width of the rib, and is disposed between the main groove in a region inside the vehicle from the tire equatorial plane. In the rib that is recessed in the tire radial direction from the contour line, the amount of the recess is 0.7% or more and 2.0% or less of the width of the rib, and the shoulder rib is further recessed. The amount is 1.0 [%] or more and 3.0 [%] or less with respect to the width between P1 and P2.

  According to this pneumatic tire, by defining the protruding amount of the rib, the recessed amount of the rib, and the recessed amount of the shoulder rib with respect to the respective widths, the handling stability at the high speed traveling and the high speed traveling with the camber are performed. High compatibility with durability can be maintained.

  The pneumatic tire according to an eleventh aspect is the pneumatic tire according to the seventh aspect, wherein the pneumatic tire is disposed between the main grooves in a region outside the vehicle from the tire equator plane and protrudes outward in the tire radial direction from the contour line. In the rib, the protruding amount is 0.7 [%] or more and 2.0 [%] or less of the width of the rib, and the rib is disposed between the main groove in a region on the vehicle inner side than the tire equator plane. In the rib recessed inward in the tire radial direction from the contour line, the amount of the recess is 0.7 [%] or more and 2.0 [%] or less of the width of the rib, and the protruding amount of the center rib is It is characterized by being 1.0 [%] or more and 2.5 [%] or less of the width of the center rib.

  According to this pneumatic tire, by defining the protruding amount of the rib, the recessed amount of the rib, and the protruding amount of the center rib with respect to each width, the handling stability at high speed driving and the high speed driving with camber are achieved. High compatibility with durability can be maintained.

  The pneumatic tire according to a twelfth aspect is the pneumatic tire according to the eighth aspect, wherein the pneumatic tire is disposed between the main grooves in a region outside the vehicle from the tire equator plane and protrudes outward in the tire radial direction from the contour line. In the rib, the protruding amount is 0.7 [%] or more and 2.0 [%] or less of the width of the rib, and the rib is disposed between the main groove in a region on the vehicle inner side than the tire equator plane. In the rib recessed inward in the tire radial direction from the contour line, the amount of the recess is 0.7 [%] or more and 2.0 [%] or less of the width of the rib, and the protruding amount of the center rib is The width of the center rib is 1.0 [%] or more and 2.5 [%] or less, and the shoulder rib has a dent amount of 1.0 [%] or more and 3.0 [%] with respect to the width between P1 and P2. %] Or less.

  According to this pneumatic tire, by defining the rib protrusion amount, the rib recess amount, the shoulder rib recess amount, and the center rib protrusion amount with respect to the respective widths, the steering stability in high-speed running and High compatibility with durability at high speed with camber can be maintained.

  The pneumatic tire according to the present invention can achieve both steering stability at high speed and durability at high speed with camber.

FIG. 1 is a meridional sectional view of a pneumatic tire according to an embodiment of the present invention. FIG. 2 is a meridional sectional view of a tread portion of another example of the pneumatic tire according to the embodiment of the present invention. FIG. 3 is a meridional sectional view of a tread portion of another example of the pneumatic tire according to the embodiment of the present invention. FIG. 4 is a meridional sectional view of a tread portion of another example of the pneumatic tire according to the embodiment of the present invention. FIG. 5 is a meridional sectional view of a tread portion of another example of the pneumatic tire according to the embodiment of the present invention. FIG. 6 is a meridional sectional view of a tread portion of another example of the pneumatic tire according to the embodiment of the present invention. FIG. 7 is an enlarged meridian cross-sectional view of the tread portion of the pneumatic tire according to the embodiment of the present invention. FIG. 8 is a meridional cross-sectional enlarged view of the tread portion of the pneumatic tire according to the embodiment of the present invention. FIG. 9 is an enlarged meridian cross-sectional view of the tread portion of the pneumatic tire according to the embodiment of the present invention. FIG. 10 is an enlarged meridian cross-sectional view of the tread portion of the pneumatic tire according to the embodiment of the present invention. FIG. 11 is a chart showing the results of the performance test of the pneumatic tire according to the example of the present invention. FIG. 12 is a chart showing the results of the performance test of the pneumatic tire according to the example of the present invention. FIG. 13 is a chart showing the results of the performance test of the pneumatic tire according to the example of the present invention.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same. Further, a plurality of modifications described in this embodiment can be arbitrarily combined within the scope obvious to those skilled in the art.

  1 is a meridional sectional view of a pneumatic tire according to the present embodiment, and FIGS. 2 to 6 are meridional sectional views of tread portions of other examples of the pneumatic tire according to the present embodiment. FIG. 10 is an enlarged meridian cross-sectional view of the tread portion of the pneumatic tire according to the present embodiment.

  In the following description, the tire radial direction refers to a direction orthogonal to the rotation axis (not shown) of the pneumatic tire 1, and the tire radial direction inner side refers to the side toward the rotation axis in the tire radial direction, the tire radial direction outer side. Means the side away from the rotation axis in the tire radial direction. Further, the tire circumferential direction refers to a direction around the rotation axis as a central axis. Further, the tire width direction means a direction parallel to the rotation axis, the inner side in the tire width direction means the side toward the tire equator plane (tire equator line) CL in the tire width direction, and the outer side in the tire width direction means the tire width direction. Is the side away from the tire equatorial plane CL. The tire equatorial plane CL is a plane that is orthogonal to the rotation axis of the pneumatic tire 1 and passes through the center of the tire width of the pneumatic tire 1. The tire width is the width in the tire width direction between the portions located outside in the tire width direction, that is, the distance between the portions farthest from the tire equatorial plane CL in the tire width direction. The tire equator line is a line along the tire circumferential direction of the pneumatic tire 1 on the tire equator plane CL. In the present embodiment, the same sign “CL” as that of the tire equator plane is attached to the tire equator line.

  As shown in FIG. 1, the pneumatic tire 1 according to the present embodiment includes a tread portion 2, shoulder portions 3 on both sides thereof, and a sidewall portion 4 and a bead portion 5 that are sequentially continuous from the shoulder portions 3. Yes. The pneumatic tire 1 includes a carcass layer 6, a belt layer 7, and a belt reinforcing layer 8.

  The tread portion 2 is made of a rubber material (tread rubber), is exposed at the outermost side in the tire radial direction of the pneumatic tire 1, and the surface thereof is the contour of the pneumatic tire 1. A tread surface 21 is formed on the outer peripheral surface of the tread portion 2, that is, on the tread surface that contacts the road surface during traveling. The tread surface 21 extends in the tire circumferential direction and has three or more straight main grooves parallel to the tire equator line CL (three in FIG. 1, four in FIG. 2, and five in FIG. 3). The main groove 22 is provided. The tread surface 21 extends along the tire circumferential direction by the plurality of main grooves 22 and has four or more ribs 23 parallel to the tire equator line CL (four in FIG. 1 and five in FIG. 2). (In FIG. 3, the number is 6). Although not clearly shown in the drawing, the tread surface 21 is provided with a lug groove that is formed with a groove depth shallower than the main groove 22 and intersects the main groove 22 in each rib 23. The rib 23 is divided into a plurality in the tire circumferential direction by lug grooves. Further, the lug groove is formed to open to the outer side in the tire width direction on the outermost side in the tire width direction of the tread portion 2. Note that the lug groove may have either a form communicating with the main groove 22 or a form not communicating with the main groove 22.

  The shoulder portion 3 is a portion on both outer sides in the tire width direction of the tread portion 2. Further, the sidewall portion 4 is exposed at the outermost side in the tire width direction of the pneumatic tire 1. The bead unit 5 includes a bead core 51 and a bead filler 52. The bead core 51 is formed by winding a bead wire, which is a steel wire, in a ring shape. The bead filler 52 is a rubber material disposed in a space formed by folding the end portion in the tire width direction of the carcass layer 6 at the position of the bead core 51.

  The carcass layer 6 is configured such that each tire width direction end portion is folded back from the tire width direction inner side to the tire width direction outer side by a pair of bead cores 51 and is wound around in a toroidal shape in the tire circumferential direction. It is. The carcass layer 6 is formed by coating a plurality of carcass cords (not shown) arranged in parallel at an angle in the tire circumferential direction with an angle with respect to the tire circumferential direction being along the tire meridian direction. The carcass cord is made of organic fibers (polyester, rayon, nylon, etc.). The carcass layer 6 is provided as at least one layer.

  The belt layer 7 has a multilayer structure in which at least two belts 71 and 72 are laminated, and is disposed on the outer side in the tire radial direction which is the outer periphery of the carcass layer 6 in the tread portion 2 and covers the carcass layer 6 in the tire circumferential direction. It is. The belts 71 and 72 are made by coating a plurality of cords (not shown) arranged in parallel at a predetermined angle (for example, 20 degrees to 30 degrees) with a coat rubber with respect to the tire circumferential direction. The cord is made of steel or organic fiber (polyester, rayon, nylon, etc.). Further, the overlapping belts 71 and 72 are arranged so that the cords intersect each other.

  The belt reinforcing layer 8 is disposed on the outer side in the tire radial direction which is the outer periphery of the belt layer 7 and covers the belt layer 7 in the tire circumferential direction. The belt reinforcing layer 8 is formed by coating a plurality of cords (not shown) arranged in parallel in the tire circumferential direction (± 5 degrees) in the tire width direction with a coat rubber. The cord is made of steel or organic fiber (polyester, rayon, nylon, etc.). The belt reinforcing layer 8 shown in FIG. 1 is disposed so as to cover the end of the belt layer 7 in the tire width direction. The configuration of the belt reinforcing layer 8 is not limited to the above, and is not clearly shown in the figure. However, the belt reinforcing layer 8 is configured to cover the entire belt layer 7 or has two reinforcing layers, for example, on the inner side in the tire radial direction. The reinforcing layer is formed so as to be larger in the tire width direction than the belt layer 7 and is disposed so as to cover the entire belt layer 7, and the reinforcing layer on the outer side in the tire radial direction is disposed so as to cover only the end portion in the tire width direction of the belt layer 7. Alternatively, for example, a configuration in which two reinforcing layers are provided and each reinforcing layer is disposed so as to cover only the end portion in the tire width direction of the belt layer 7 may be employed. That is, the belt reinforcing layer 8 overlaps at least the end portion in the tire width direction of the belt layer 7. The belt reinforcing layer 8 is provided by winding a strip-shaped strip material (for example, a width of 10 [mm]) in the tire circumferential direction.

  In the pneumatic tire 1 of the present embodiment, the direction inside and outside the vehicle is specified when the vehicle is mounted. In the tread portion 2, the inner side of the vehicle is referred to as the vehicle inner side and the outer side of the vehicle is referred to as the outer side of the vehicle with reference to the tire equatorial plane CL. The designation of the direction with respect to the vehicle inner side and the vehicle outer side is not clearly shown in the drawing, but is indicated by, for example, an index provided on the sidewall portion 4. In addition, designation | designated of a vehicle inner side and a vehicle outer side is not restricted to the case where it mounts | wears with a vehicle. For example, when the rim is assembled, the direction of the rim with respect to the inside and outside of the vehicle is determined in the tire width direction. For this reason, when the pneumatic tire 1 is assembled with a rim, the orientation with respect to the vehicle inner side and the vehicle outer side is designated in the tire width direction.

  In addition, by designating the inside / outside direction of the vehicle when the vehicle is mounted, the rib 23 of the tread portion 2 described above is located in a region outside the vehicle from the tire equatorial plane CL as shown in FIGS. Let it be rib 23out, and let it be rib 23in in the area inside the vehicle. More specifically, as shown in FIGS. 1 to 6, a rib 23out on the vehicle outer side than the main groove 22 on the outermost side of the vehicle is a vehicle outer shoulder rib 23out-sh, and the inner groove 22 on the vehicle inner side of the main groove 22 on the innermost side of the vehicle. The rib 23in is referred to as a vehicle inner shoulder rib 23in-sh. As shown in FIGS. 2 and 6, the rib 23 whose center in the tire width direction is disposed on the tire equatorial plane CL is defined as a center rib 23ce. Further, as shown in FIG. 4, even if the tire is arranged on the tire equatorial plane CL, the center in the tire width direction is not arranged on the tire equatorial plane CL, and the area outside the vehicle exceeds 50%. Let the rib 23 currently made be the rib 23out of the area | region outside a vehicle. Although not shown in the figure, the center in the tire width direction is not arranged on the tire equator plane CL even if it is arranged on the tire equator plane CL, and it is arranged in an area inside the vehicle exceeding 50%. Let the rib 23 currently done be the rib 23in of the area | region inside a vehicle. Further, as shown in FIGS. 1, 3, and 5, the main groove 22 disposed on the tire equatorial plane CL is defined as a center main groove 22ce.

  In such a pneumatic tire 1, when new, at least one rib 23out, 23out-sh in a region outside the vehicle from the tire equatorial plane CL protrudes outward in the tire radial direction from the contour line L of the tread surface 21. At least one rib 23in, 23in-sh inside the vehicle from the equator plane CL is recessed inward in the tire radial direction from the contour line L, and the center S of the radius of curvature of the recessed line is the tire diameter from the tread surface 21. Located outside in the direction.

  Here, the contour line L is adjacent to both sides of the ribs 23out and 23in in the tire width direction in the meridional section in the case of the ribs 23out and the ribs 23in disposed between the main grooves 22 as shown in FIG. An arc that passes through at least three of the four open ends P in the two main grooves 22 and can be drawn with the maximum curvature radius with the center on the inner side in the tire radial direction of the tread surface 21. In addition, as shown in FIG. 8, the contour line L is a shoulder rib 23in-sh or shoulder rib 23in-sh (in FIG. 8, the shoulder rib 23in-sh is shown). sh (23out-sh) has a grounding end T, the grounding end T is P1, and an opening end near the vehicle inner side (vehicle outer side) of the main groove 22 on the vehicle innermost side (vehicle outermost side) is P2. When the opening end of the innermost (vehicle outermost) main groove 22 near the vehicle outer side (vehicle inner side) is P3, it passes through P1, P2, P3 and has a radius of curvature having a center on the inner side in the tire radial direction of the tread surface 21. The arc. The shoulder rib 23in-sh is recessed inward in the tire radial direction from the contour line L between P1 and P2, and the center S of the radius of curvature of the line of the recess is positioned on the outer side in the tire radial direction from the tread surface 21. To do. Further, the shoulder rib 23out-sh protrudes outward in the tire radial direction from the contour line L between P1 and P2.

  In addition, as shown in FIG. 9 (in FIG. 9, rib 23out is shown), when chamfering C is given to the opening end of the main groove 22, the end point located on the outermost side in the tire radial direction is defined as the opening end. A line L is defined.

  Note that the ground contact edge T means that the tread surface 21 of the tread portion 2 of the pneumatic tire 1 is a road surface when the pneumatic tire 1 is assembled on a regular rim, filled with a regular internal pressure and a regular load is applied. In the contact area, both outermost ends in the tire width direction are continuous in the tire circumferential direction.

  The regular rim is “standard rim” defined by JATMA, “Design Rim” defined by TRA, or “Measuring Rim” defined by ETRTO. The normal internal pressure is “maximum air pressure” defined by JATMA, the maximum value described in “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “INFLATION PRESSURES” defined by ETRTO. The normal load is “maximum load capacity” defined by JATMA, a maximum value described in “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “LOAD CAPACITY” defined by ETRTO.

  Thus, in the pneumatic tire 1 of the present embodiment, at least one rib 23out, 23out-sh in the region outside the vehicle from the tire equatorial plane CL protrudes outward in the tire radial direction from the contour line L of the tread surface 21. The at least one rib 23in, 23in-sh inside the vehicle from the tire equatorial plane CL is recessed inward in the tire radial direction from the contour line L, and the center S of the radius of curvature of the line of the recess is from the tread surface 21. Located on the outside in the tire radial direction.

  According to the pneumatic tire 1, at least one of the ribs 23out and 23out-sh protrudes outward in the tire radial direction from the contour line L on the outer side of the vehicle, thereby improving the ground contact property of the ribs 23out and 23out-sh. Therefore, it is possible to improve the steering stability during high speed traveling. Moreover, at least one of the ribs 23in and 23in-sh is located on the inner side of the vehicle so that the center S of the radius of curvature of the recessed line is positioned on the outer side in the tire radial direction than the tread surface 21. Since the excessive contact of the ribs 23in and 23in-sh is eased by indenting in the direction inner side, the contact length between the ribs 23 (the length in the tire circumferential direction in the region where the tread surface 21 contacts the road surface) is uniform. It becomes possible to improve durability at high speed traveling with a camber. As a result, it is possible to achieve both steering stability at high speed running and durability at high speed running with a camber.

  Further, in the pneumatic tire 1 of the present embodiment, the ribs 23out arranged in the region outside the vehicle from the tire equatorial plane CL and sandwiched between the main grooves 22 protrude outward in the tire radial direction from the contour line L, and A rib 23in disposed in the vehicle inner side of the tire equatorial plane CL and sandwiched between the main grooves 22 is recessed inward in the tire radial direction from the contour line L, and the center S of the curvature radius of the line of the recess is the tread. It is preferable to be located on the outer side in the tire radial direction from the surface 21.

  According to the pneumatic tire 1, the grounding property of the rib 23out is improved by causing the rib 23out to protrude outward in the tire radial direction from the contour line L on the outer side of the vehicle, so that the steering stability during high speed traveling is improved. It becomes possible to do. The ribs 23out disposed between the main grooves 22 are most likely due to the improved grounding performance of the ribs 23out, so that it is possible to further improve the steering stability during high-speed traveling. In addition, at least one of the ribs 23in is recessed inward in the tire radial direction from the contour line L so that the center S of the radius of curvature of the recessed line is positioned on the outer side in the tire radial direction from the tread surface 21 on the vehicle inner side. As a result, excessive grounding of the ribs 23in is alleviated, so that the grounding length is made uniform between the ribs 23, and durability at high speed traveling with a camber can be improved. The ribs 23in disposed between the main grooves 22 are most attributable to alleviating excessive grounding, so that the grounding length is more uniform between the ribs 23 and the durability at high speed traveling with a camber is further improved. It becomes possible to do. As a result, it is possible to obtain a remarkable effect of achieving both steering stability at high speed running and durability at high speed running with a camber.

  In the pneumatic tire 1 of the present embodiment, four ribs 23 are formed by the three main grooves 22, and the center main groove 22ce at the center in the tire width direction is disposed on the tire equatorial plane CL. A rib 23out disposed between the main groove 22 and the center main groove 22ce on the vehicle outer side protrudes outward in the tire radial direction from the contour line L, and is disposed between the center main groove 22ce and the main groove 22 on the vehicle inner side. It is preferable that the rib 23in is recessed inward in the tire radial direction with respect to the contour line L, and the center S of the radius of curvature of the line of the recess is positioned on the outer side in the tire radial direction with respect to the tread surface 21.

  According to this pneumatic tire 1, when four ribs 23 are formed by the three main grooves 22, and the center main groove 22ce at the center in the tire width direction is disposed on the tire equatorial plane CL, Since the rib 23out disposed between the main groove 22 and the main groove 22ce on the outer side of the main groove 22ce protrudes outward in the tire radial direction from the contour line L, the grounding property of the rib 23out is improved. It becomes possible to improve the property. The ribs 23out disposed between the main grooves 22 are most likely due to the improved grounding performance of the ribs 23out, so that it is possible to further improve the steering stability during high-speed traveling. Moreover, since the rib 23in disposed between the main groove 22 and the inner side of the center main groove 22ce is recessed inward in the tire radial direction from the contour line L, excessive grounding of the rib 23in is alleviated. It is possible to make the ground contact length uniform between 23 and improve the durability in high-speed traveling with a camber. The ribs 23in disposed between the main grooves 22 are most attributable to alleviating excessive grounding, so that the grounding length is more uniform between the ribs 23 and the durability at high speed traveling with a camber is further improved. It becomes possible to do. As a result, it is possible to obtain a remarkable effect of achieving both steering stability at high speed running and durability at high speed running with a camber.

  Further, in the pneumatic tire 1 of the present embodiment, when the five ribs 23 are formed by the four main grooves 22 and the center rib 23ce at the center in the tire width direction is disposed on the tire equatorial plane CL, A rib 23out disposed adjacent to the outer side of the center rib 23ce and sandwiched between the main grooves 22 protrudes outward in the tire radial direction from the contour line L, and is sandwiched between the center ribs 23ce and adjacent to the inner side of the vehicle. It is preferable that the rib 23in disposed in the step is recessed inward in the tire radial direction with respect to the contour line L, and the center S of the curvature radius of the concave line is positioned on the outer side in the tire radial direction with respect to the tread surface 21.

  According to this pneumatic tire 1, when five ribs 23 are formed by the four main grooves 22, and the center rib 23ce at the center in the tire width direction is arranged on the tire equatorial plane CL, the center rib Since the rib 23out, which is disposed adjacent to the outer side of the 23ce vehicle and sandwiched between the main grooves 22, protrudes outward in the tire radial direction from the contour line L, the grounding property of the rib 23out is improved. Stability can be improved. The rib 23out disposed between the center rib 23ce and the main groove 22 adjacent to the vehicle outer side of the center rib 23ce is most attributable to the improvement of the ground contact property of the rib 23out, so that the steering stability during high speed traveling is further improved. Is possible. In addition, since the rib 23in disposed adjacent to the inner side of the main groove 22 adjacent to the vehicle inner side of the center rib 23ce is recessed inward in the tire radial direction from the contour line L, excessive grounding of the rib 23in is alleviated. The ground contact length is made uniform between the ribs 23, and it becomes possible to improve the durability in high-speed traveling with a camber. The ribs 23in disposed between the center ribs 23ce and the main grooves 22 adjacent to the inner side of the vehicle are most likely to alleviate excessive grounding. Therefore, the grounding length is more uniform between the ribs 23, and the camber It is possible to further improve the durability at high speed running. As a result, it is possible to obtain a remarkable effect of achieving both steering stability at high speed running and durability at high speed running with a camber.

  In the pneumatic tire 1 of the present embodiment, when the five ribs 23 are formed by the four main grooves 22 and the center rib 23ce at the center in the tire width direction is disposed on the tire equatorial plane CL. The center rib 23ce preferably protrudes outward in the tire radial direction from the contour line L together with the rib 23out disposed between the main groove 22 and adjacent to the vehicle outer side of the center rib 23ce.

  According to this pneumatic tire 1, since the center rib 23ce protrudes outward in the tire radial direction from the contour line L, it synergizes with the effect of improving the ground contact of the rib 23out on the outside of the vehicle. It becomes possible to improve the property.

  Further, in the pneumatic tire 1 of the present embodiment, six ribs 23 are formed by the five main grooves 22, and the center main groove 22ce in the tire width direction center is disposed on the tire equatorial plane CL. In addition, at least one rib 23out disposed between the main groove 22 and the center main groove 22ce on the vehicle outer side protrudes outward in the tire radial direction from the contour line L, and is sandwiched between the main groove 22 and the center main groove 22ce on the vehicle inner side. It is preferable that at least one of the ribs 23in is recessed inward in the tire radial direction with respect to the contour line L, and the center S of the radius of curvature of the concave line is positioned on the outer side in the tire radial direction with respect to the tread surface 21.

  According to this pneumatic tire 1, when five ribs 23 are formed by the five main grooves 22, and the center main groove 22ce at the center in the tire width direction is disposed on the tire equatorial plane CL, By projecting at least one rib 23out arranged outside the main groove 22ce between the main grooves 22 to the outside in the tire radial direction from the contour line L, the grounding property of the rib 23out is improved. It is possible to improve the steering stability of the vehicle. The ribs 23out disposed between the main grooves 22 are most likely due to the improved grounding performance of the ribs 23out, so that it is possible to further improve the steering stability during high-speed traveling. In addition, since the at least one rib 23in disposed on the inner side of the center main groove 22ce and sandwiched between the main grooves 22 is recessed inward in the tire radial direction from the contour line L, excessive grounding of the rib 23in is alleviated. The ground contact length is made uniform between the ribs 23, and it is possible to improve the durability in high-speed traveling with a camber. The ribs 23in disposed between the main grooves 22 are most attributable to alleviating excessive grounding, so that the grounding length is more uniform between the ribs 23 and the durability at high speed traveling with a camber is further improved. It becomes possible to do. As a result, it is possible to obtain a remarkable effect of achieving both steering stability at high speed running and durability at high speed running with a camber.

  In the case where six ribs 23 are formed by the five main grooves 22 and the center main groove 22ce at the center in the tire width direction is disposed on the tire equatorial plane CL, the center main groove 22ce is located outside the vehicle. At least one rib 23out disposed between the main grooves 22 protrudes outward in the tire radial direction from the contour line L, and the innermost rib on the vehicle disposed between the main grooves 22 inside the center main groove 22ce. It is preferable in order to obtain the above effect remarkably that 23 in is recessed inward in the tire radial direction from the contour line L, and the center S of the radius of curvature of the line of the recess is positioned in the outer side of the tread surface 21 in the tire radial direction. .

  Further, in the pneumatic tire 1 of the present embodiment, the ribs 23out arranged to be sandwiched between the main grooves 22 on the vehicle outer side are protruded outward in the tire radial direction from the contour line L, and are sandwiched between the main grooves 22 on the vehicle inner side. After the rib 23in to be arranged is recessed inward in the tire radial direction from the contour line L, the shoulder rib 23in-sh on the vehicle inner side than the main groove 22 on the innermost side of the vehicle has a grounding end T. When T is P1, the opening end of the innermost main groove 22 on the inner side of the vehicle is P2, and the opening end of the innermost main groove 22 on the outer side of the vehicle is P3, P1 of the shoulder rib 23in-sh -P2 is recessed inward in the tire radial direction from the contour line L of the radius of curvature passing through P1, P2 and P3, and the center S of the radius of curvature of the concave line is located on the outer side in the tire radial direction from the tread surface 21. Preferably to .

  According to the pneumatic tire 1, the ground contact area of the shoulder rib 23 in-sh is recessed inward in the tire radial direction from the contour line L, thereby synergistic with the effect of mitigating excessive ground contact of the rib 23 in on the vehicle inner side. Therefore, it is possible to further improve the durability at high speed traveling with a camber.

  Further, in the pneumatic tire 1 of the present embodiment, the ribs 23out arranged to be sandwiched between the main grooves 22 on the vehicle outer side are protruded outward in the tire radial direction from the contour line L, and are sandwiched between the main grooves 22 on the vehicle inner side. The rib 23in to be disposed is recessed inward in the tire radial direction from the contour line L, and the center rib 23ce is further protruded outward in the tire radial direction from the contour line L. The inner shoulder rib 23in-sh has a grounding end T, the grounding end T is P1, the opening end closer to the vehicle inner side of the innermost main groove 22 is P2, and the vehicle in the innermost main groove 22 of the vehicle When the opening end on the outer side is P3, the distance between P1 and P2 of the shoulder rib 23in-sh is recessed inward in the tire radial direction from the contour line L of the radius of curvature passing through P1, P2, and P3. Half curvature It is preferable that the center S of is located in the tire radial direction outer side than the tread surface 21.

  According to this pneumatic tire 1, since the center rib 23ce protrudes outward in the tire radial direction from the contour line L, it synergizes with the effect of improving the ground contact by the rib 23out on the outside of the vehicle. It becomes possible to improve the property. Moreover, since the ground contact area of the shoulder rib 23in-sh is recessed inward in the tire radial direction with respect to the contour line L, it synergizes with the effect of mitigating excessive ground contact of the rib 23in inside the vehicle. It becomes possible to further improve the durability. As a result, it is possible to obtain a remarkable effect of achieving both steering stability at high speed running and durability at high speed running with a camber.

  Further, as shown in FIG. 7, the pneumatic tire 1 of the present embodiment is arranged in a rib 23out that is disposed between the main grooves 22 in a region outside the vehicle from the tire equatorial plane CL and protrudes from the contour line L. The protrusion amount (maximum protrusion amount) G1 is not less than 0.7% and not more than 2.0% of the width of the rib 23out, and is sandwiched in the main groove 22 in a region on the vehicle inner side than the tire equatorial plane CL. In the rib 23in that is disposed at the inner side in the tire radial direction with respect to the contour line L, the dent amount (maximum dent amount) D1 is 0.7 [%] or more and 2.0 [%] or less of the width of the rib 23in. It is preferable that

  The width of the ribs 23out and 23in refers to the arc length of the contour line L between the open ends PP of the main grooves 22 sandwiching the ribs 23out and 23in as shown in FIG.

  According to this pneumatic tire 1, by defining the protruding amount G1 of the rib 23out and the recessed amount D1 of the rib 23in with respect to the respective widths, the handling stability at high speed and the durability at high speed with camber are achieved. It is possible to maintain a high level of compatibility.

  Further, as shown in FIG. 7, the pneumatic tire 1 of the present embodiment is arranged in a rib 23out that is disposed between the main grooves 22 in a region outside the vehicle from the tire equatorial plane CL and protrudes from the contour line L. The protrusion amount (maximum protrusion amount) G1 is not less than 0.7% and not more than 2.0% of the width of the rib 23out, and is sandwiched in the main groove 22 in a region on the vehicle inner side than the tire equatorial plane CL. In the rib 23in that is disposed at the inner side in the tire radial direction with respect to the contour line L, the dent amount (maximum dent amount) D1 is 0.7 [%] or more and 2.0 [%] or less of the width of the rib 23in. Further, as shown in FIG. 8, the recess amount D2 of the shoulder rib 23in-sh inside the vehicle is 1.0 [%] or more and 3.0 [%] or less with respect to the width between P1 and P2. It is preferable.

  In addition, the width | variety of the shoulder rib 23in-sh means the arc length of the outline L between P1-P2, as shown in FIG.

  According to this pneumatic tire 1, by controlling the protrusion amount G1 of the ribs 23out, the recess amount D1 of the ribs 23in, and the recess amount D2 of the shoulder ribs 23in-sh with respect to the respective widths, the steering at high speed running is performed. It is possible to maintain a high degree of compatibility between stability and durability in high-speed driving with a camber.

  Further, as shown in FIG. 7, the pneumatic tire 1 of the present embodiment is arranged in a rib 23out that is disposed between the main grooves 22 in a region outside the vehicle from the tire equatorial plane CL and protrudes from the contour line L. The protrusion amount (maximum protrusion amount) G1 is not less than 0.7% and not more than 2.0% of the width of the rib 23out, and is sandwiched in the main groove 22 in a region on the vehicle inner side than the tire equatorial plane CL. In the rib 23in that is disposed at the inner side in the tire radial direction with respect to the contour line L, the dent amount (maximum dent amount) D1 is 0.7 [%] or more and 2.0 [%] or less of the width of the rib 23in. Further, as shown in FIG. 10, it is preferable that the protruding amount G2 of the center rib 23ce is 1.0 [%] or more and 2.5 [%] or less of the width of the center rib 23ce.

  As shown in FIG. 10, the width of the center rib 23ce refers to the arc length of the contour line L between the open ends PP of the main grooves 22 sandwiching the center rib 23ce.

  According to this pneumatic tire 1, by defining the protrusion amount G1 of the rib 23out, the recess amount D1 of the rib 23in, and the protrusion amount G2 of the center rib 23ce with respect to the respective widths, steering stability at high speed running is achieved. It is possible to maintain a high degree of compatibility with durability at high speed with a camber.

  Further, as shown in FIG. 7, the pneumatic tire 1 of the present embodiment is arranged in a rib 23out that is disposed between the main grooves 22 in a region outside the vehicle from the tire equatorial plane CL and protrudes from the contour line L. The protrusion amount (maximum protrusion amount) G1 is not less than 0.7% and not more than 2.0% of the width of the rib 23out, and is sandwiched in the main groove 22 in a region on the vehicle inner side than the tire equatorial plane CL. In the rib 23in that is disposed at the inner side in the tire radial direction with respect to the contour line L, the dent amount (maximum dent amount) D1 is 0.7 [%] or more and 2.0 [%] or less of the width of the rib 23in. Further, as shown in FIG. 8, the recess amount D2 of the shoulder rib 23in-sh inside the vehicle is 1.0% or more and 3.0% or less with respect to the width between P1 and P2. Furthermore, as shown in FIG. It is preferable protrusion amount G2 of e is 1.0 [%] of the width of the center rib 23ce than 2.5 [%] or less.

  According to this pneumatic tire 1, the protrusion amount G1 of the rib 23out, the recess amount D1 of the rib 23in, the recess amount D2 of the shoulder rib 23in-sh, and the protrusion amount G2 of the center rib 23ce are defined for each width. This makes it possible to maintain a high degree of compatibility between handling stability at high speed and durability at high speed with camber.

  11 to 13 are charts showing the results of the performance test of the pneumatic tire according to this example. In this example, performance tests on high speed maneuverability (steering stability during high speed driving) and high speed durability with camber (durability during high speed driving with camber) are performed for multiple types of pneumatic tires with different conditions. It was broken.

  In this test, a pneumatic tire having a tire size of 295 / 35R21 was used as a test tire.

  The method for evaluating high-speed maneuverability is as follows. The test tire is assembled on a rim of 21 × 10 J, filled with air pressure 260 [kPa], mounted on a test vehicle (passenger vehicle with displacement of 4800 [cc]), and dried. It runs on a road test course, and it is evaluated by a sensory evaluation by one skilled test driver regarding steering performance during lane change and cornering and stability during straight travel. This sensory evaluation is indicated by an index based on a conventional pneumatic tire as a reference (100), and the higher this index is, the better the steering stability is.

  The high-speed durability evaluation method with camber is as follows. The test tire is assembled on a rim of 21 × 10 J, filled with air pressure of 340 [kPa], applied with a load of 7.65 [kN], and a camber angle of −2.7. [Degree], the drum endurance tester took over and traveled at the following speed step, and the speed when the tester detected a tire failure was measured. Then, using the conventional pneumatic tire as a reference, it was evaluated how many steps were improved or how many steps were reduced. Here, +1 step indicates that the vehicle can travel for 20 [min] at +10 [km / h], and +0.5 step indicates that the vehicle can travel for 10 [min] at +10 [km / h].

Step 0: Travel time 0 [min] ... Speed 0 [km / h]
Step 1 ... Running time 1 [min] ... Speed 0 to 190 [km / h]
Step2: Travel time 5 [min] ... Speed 190 [km / h]
Step3: Travel time 5 [min] ... Speed 240 [km / h]
Step 4: Travel time 10 [min] ... Speed 250 [km / h]
Step 5: Travel time 10 [min] ... Speed 260 [km / h]
Step 6: Travel time 10 [min] ... Speed 270 [km / h]
Step 7: Travel time 20 [min] ... Speed 280 [km / h]
Step 8: Travel time 20 [min] ... Speed 290 [km / h]
Step 9: Travel time 20 [min] ... Speed 300 [km / h]
Step 10: Travel time 20 [min] ... Speed 310 [km / h]
Thereafter, speed is increased by +1 step (+10 [km / h], 20 [min] travel) until failure

  FIG. 11 shows the rib structure of FIG. In FIG. 11, in the pneumatic tire of Conventional Example 1, each rib does not protrude and is not recessed. In the pneumatic tire of Comparative Example 1, the outer ribs of the vehicle protrude, but the other ribs do not protrude and are not recessed. In the pneumatic tire of Comparative Example 2, the ribs arranged inside the vehicle are recessed, but the other ribs do not protrude and are not recessed. In the pneumatic tire of Comparative Example 3, the vehicle outer rib and the rib arranged on the vehicle inner side protrude. In the pneumatic tire of Comparative Example 4, the vehicle inner rib and the vehicle outer rib are recessed.

  In FIG. 11, in the pneumatic tires of Examples 1 to 14, the ribs arranged on the vehicle outer side protrude, and the ribs arranged on the vehicle inner side are recessed. In the pneumatic tires of Examples 3 to 7 and Examples 10 to 14, the protruding amount of the ribs and the recessed amount of the ribs are within the specified ranges.

  FIG. 12 shows the rib structure of FIG. In FIG. 12, in the pneumatic tire of Conventional Example 2, each rib does not protrude and is not recessed. In the pneumatic tire of Comparative Example 5, the vehicle outer rib and the center rib protrude, but the other ribs do not protrude and are not recessed. In the pneumatic tire of Comparative Example 6, the ribs arranged inside the vehicle except the center rib are recessed, but the other ribs do not protrude and are not recessed. In the pneumatic tire of Comparative Example 7, the vehicle outer rib and the rib arranged on the vehicle inner side protrude. In the pneumatic tire of Comparative Example 8, the vehicle outer rib and the rib disposed on the vehicle inner side are recessed.

  In FIG. 12, in the pneumatic tires of Examples 15 to 28, the ribs arranged on the vehicle outer side protrude, and the ribs arranged on the vehicle inner side are recessed. In the pneumatic tires of Examples 17 to 21 and Examples 24 to 28, the protruding amount of the ribs and the recessed amount of the ribs are within the specified ranges.

  FIG. 13 shows the rib structure of FIG. In FIG. 13, in the pneumatic tire of Conventional Example 3, each rib does not protrude and is not recessed. In the pneumatic tire of Comparative Example 9, the shoulder-side vehicle outer rib protrudes, but the other ribs do not protrude and are not recessed. In the pneumatic tire of Comparative Example 10, the shoulder side vehicle inner rib and the vehicle inner shoulder rib are recessed, but the other ribs do not protrude and are not recessed. In the pneumatic tire of Comparative Example 11, the shoulder side vehicle outer rib, the shoulder side vehicle inner rib, and the vehicle inner shoulder rib protrude. In the pneumatic tire of Comparative Example 12, the shoulder side vehicle outer rib, the shoulder side vehicle inner rib, and the vehicle inner shoulder rib are recessed.

  In FIG. 12, in the pneumatic tires of Examples 29 to 45, the ribs arranged on the vehicle outer side protrude, and the ribs arranged on the vehicle inner side are recessed. In the pneumatic tires of Examples 31 to 37 and Examples 40 to 45, the protruding amount of the ribs and the recessed amount of the ribs are within the specified ranges.

  And as shown to the test result of FIGS. 11-13, it turns out that the high-speed stability and the high-speed durability with a camber are improved in the pneumatic tire of Example 1- Example 45.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Tread part 21 Tread surface 22 Main groove 22ce Center main groove 23 Rib 23out Vehicle outer side rib 23out-sh Vehicle outer side shoulder rib 23in Vehicle inner side rib 23in-sh Vehicle inner side shoulder rib 23ce Center rib CL tire Equatorial plane L Contour line P, P2, P3 Open end of main groove S Center of radius of curvature T (P1) Grounding end

Claims (12)

At least four ribs extending along the tire circumferential direction are formed by at least three main grooves extending along the tire circumferential direction on the tread surface, and the direction inside and outside the vehicle when the vehicle is mounted is designated. And at least one of the ribs in a region outside the vehicle from the tire equator plane protrudes outward in the tire radial direction from the contour line of the tread surface, and at least one of the ribs inside the vehicle from the tire equator plane has the contour. A pneumatic tire that is recessed to the inside in the tire radial direction from the line, and the center of the radius of curvature of the line of the recess is located outside the tread surface in the tire radial direction,
The rib disposed on the outer side of the vehicle from the tire equator plane and sandwiched between the main grooves protrudes outward in the tire radial direction from the contour line, and is a region on the inner side of the vehicle from the tire equator plane. The rib disposed between the main grooves is recessed in the tire radial direction inner side than the contour line, and the center of the radius of curvature of the line of the recess is located on the outer side in the tire radial direction from the tread surface,
The shoulder rib on the vehicle inner side of the main groove on the innermost side of the vehicle has a grounding end, the grounding end is P1, the opening end closer to the vehicle inner side of the main groove on the innermost side of the vehicle is P2, and the innermost side of the vehicle When the opening end near the vehicle outer side of the main groove is P3, the interval between the shoulder ribs P1 and P2 is recessed inward in the tire radial direction from the contour line of the radius of curvature passing through P1, P2 and P3. air-filled tire you characterized in that the center of the radius of curvature of the line is located in the tire radial direction outer side than the tread surface. At least four ribs extending along the tire circumferential direction are formed by at least three main grooves extending along the tire circumferential direction on the tread surface, and the direction inside and outside the vehicle when the vehicle is mounted is designated. And at least one of the ribs in a region outside the vehicle from the tire equator plane protrudes outward in the tire radial direction from the contour line of the tread surface, and at least one of the ribs inside the vehicle from the tire equator plane has the contour. A pneumatic tire that is recessed to the inside in the tire radial direction from the line, and the center of the radius of curvature of the line of the recess is located outside the tread surface in the tire radial direction,
The rib disposed on the outer side of the vehicle from the tire equator plane and sandwiched between the main grooves protrudes outward in the tire radial direction from the contour line, and is a region on the inner side of the vehicle from the tire equator plane. The rib disposed between the main grooves is recessed in the tire radial direction inner side than the contour line, and the center of the radius of curvature of the line of the recess is located on the outer side in the tire radial direction from the tread surface,
In the rib that is arranged between the main groove in the region outside the vehicle from the tire equator plane and protrudes outward in the tire radial direction from the contour line, the protruding amount is 0.7 [%] of the width of the rib. The amount of dents in the rib that is 2.0% or less and that is disposed between the main grooves in the vehicle inner side area than the tire equator plane and is recessed inward in the tire radial direction from the contour line. air-filled tire characterized by but 0.7% of the width of the ribs to 2.0 [%] or less. At least four ribs extending along the tire circumferential direction are formed by at least three main grooves extending along the tire circumferential direction on the tread surface, and the direction inside and outside the vehicle when the vehicle is mounted is designated. And at least one of the ribs in a region outside the vehicle from the tire equator plane protrudes outward in the tire radial direction from the contour line of the tread surface, and at least one of the ribs inside the vehicle from the tire equator plane has the contour. A pneumatic tire that is recessed to the inside in the tire radial direction from the line, and the center of the radius of curvature of the line of the recess is located outside the tread surface in the tire radial direction,
The three of the main groove, are formed four said ribs, if Center main groove in the tire width direction center on the tire equatorial plane are arranged, the main groove in the vehicle outer side of the center main groove The ribs disposed between the main line and the rib protrude outside the contour line in the tire radial direction, and the rib disposed between the main grooves on the vehicle inner side of the center main groove is in the tire radial direction from the contour line. recessed inwardly, air-filled tire, characterized in that the recess of the radius of curvature of the center line is located in the tire radial direction outer side than the tread surface. At least four ribs extending along the tire circumferential direction are formed by at least three main grooves extending along the tire circumferential direction on the tread surface, and the direction inside and outside the vehicle when the vehicle is mounted is designated. And at least one of the ribs in a region outside the vehicle from the tire equator plane protrudes outward in the tire radial direction from the contour line of the tread surface, and at least one of the ribs inside the vehicle from the tire equator plane has the contour. A pneumatic tire that is recessed to the inside in the tire radial direction from the line, and the center of the radius of curvature of the line of the recess is located outside the tread surface in the tire radial direction,
When the five ribs are formed by the four main grooves, and the center rib in the tire width direction center is disposed on the tire equator plane, the main groove is adjacent to the vehicle outer side of the center rib. The ribs disposed between the center ribs protrude outward in the tire radial direction from the contour line, and the ribs disposed between the main grooves adjacent to the vehicle inner side of the center rib are tired from the contour line. recessed radially inward, air-filled tire you, characterized in that the recess of the radius of curvature of the center line is located in the tire radial direction outer side than the tread surface. At least four ribs extending along the tire circumferential direction are formed by at least three main grooves extending along the tire circumferential direction on the tread surface, and the direction inside and outside the vehicle when the vehicle is mounted is designated. And at least one of the ribs in a region outside the vehicle from the tire equator plane protrudes outward in the tire radial direction from the contour line of the tread surface, and at least one of the ribs inside the vehicle from the tire equator plane has the contour. A pneumatic tire that is recessed to the inside in the tire radial direction from the line, and the center of the radius of curvature of the line of the recess is located outside the tread surface in the tire radial direction,
The five of the main groove, are formed the rib of six, when the centers main groove in the tire width direction center on the tire equatorial plane are arranged, the main groove in the vehicle outer side of the center main groove The at least one rib disposed between the main line protrudes outward in the tire radial direction from the contour line, and the at least one rib disposed between the main groove on the vehicle inner side of the center main groove is the contour. recessed in the tire radial direction inner side than the line, the air-filled tire you, characterized in that the radius of curvature of the center of the recess of the line is located in the tire radial direction outer side than the tread surface. The shoulder rib on the vehicle inner side of the main groove on the innermost side of the vehicle has a grounding end, the grounding end is P1, the opening end closer to the vehicle inner side of the main groove on the innermost side of the vehicle is P2, and the innermost side of the vehicle When the opening end near the vehicle outer side of the main groove is P3, the interval between the shoulder ribs P1 and P2 is recessed inward in the tire radial direction from the contour line of the radius of curvature passing through P1, P2 and P3. The pneumatic tire according to any one of claims 3 to 5, wherein the center of the curvature radius of the line is located on the outer side in the tire radial direction from the tread surface.   The pneumatic tire according to claim 4, wherein the center rib protrudes outward in the tire radial direction from the contour line.   The shoulder rib on the vehicle inner side of the main groove on the innermost side of the vehicle has a grounding end, the grounding end is P1, the opening end closer to the vehicle inner side of the main groove on the innermost side of the vehicle is P2, and the innermost side of the vehicle When the opening end near the vehicle outer side of the main groove is P3, the interval between the shoulder ribs P1 and P2 is recessed inward in the tire radial direction from the contour line of the radius of curvature passing through P1, P2 and P3. The pneumatic tire according to claim 7, wherein the center of the curvature radius of the line is located on the outer side in the tire radial direction from the tread surface. In the rib that is arranged between the main groove in the region outside the vehicle from the tire equator plane and protrudes outward in the tire radial direction from the contour line, the protruding amount is 0.7 [%] of the width of the rib. The amount of dents in the rib that is 2.0% or less and that is disposed between the main grooves in the vehicle inner side area than the tire equator plane and is recessed inward in the tire radial direction from the contour line. the pneumatic tire according to but one of claims 3-8, characterized in that the 0.7% of the rib width to 2.0 [%] or less.   In the rib that is arranged between the main groove in the region outside the vehicle from the tire equator plane and protrudes outward in the tire radial direction from the contour line, the protruding amount is 0.7 [%] of the width of the rib. The amount of dents in the rib that is 2.0% or less and that is disposed between the main grooves in the vehicle inner side area than the tire equator plane and is recessed inward in the tire radial direction from the contour line. Is not less than 0.7 [%] and not more than 2.0 [%] of the width of the rib, and the recess amount of the shoulder rib is not less than 1.0 [%] and not less than 3.0 with respect to the width between P1 and P2. The pneumatic tire according to claim 6 or 8, wherein the pneumatic tire is [%] or less.   In the rib that is arranged between the main groove in the region outside the vehicle from the tire equator plane and protrudes outward in the tire radial direction from the contour line, the protruding amount is 0.7 [%] of the width of the rib. The amount of dents in the rib that is 2.0% or less and that is disposed between the main grooves in the vehicle inner side area than the tire equator plane and is recessed inward in the tire radial direction from the contour line. Is not less than 0.7% and not more than 2.0% of the width of the rib, and the protrusion amount of the center rib is not less than 1.0% and not less than 2.5% of the width of the center rib. The pneumatic tire according to claim 7, wherein:   In the rib that is arranged between the main groove in the region outside the vehicle from the tire equator plane and protrudes outward in the tire radial direction from the contour line, the protruding amount is 0.7 [%] of the width of the rib. The amount of dents in the rib that is 2.0% or less and that is disposed between the main grooves in the vehicle inner side area than the tire equator plane and is recessed inward in the tire radial direction from the contour line. Is not less than 0.7% and not more than 2.0% of the width of the rib, and the protrusion amount of the center rib is not less than 1.0% and not less than 2.5% of the width of the center rib. The indentation of the shoulder rib according to claim 8, wherein the shoulder rib has a dent amount of 1.0% to 3.0% with respect to the width between P1 and P2. tire.

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