JP5018293B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire that can reduce the rolling resistance of the tire while maintaining the durability performance of the tire.

  In recent years, pneumatic tires are required to reduce rolling resistance of tires from the viewpoint of improving fuel efficiency. At the same time, it is required to maintain the durability of the tire.

  As a conventional pneumatic tire related to this problem, a technique described in Patent Document 1 is known. A conventional pneumatic tire (heavy duty tire) is a carcass in which a body portion extending from a tread portion to a bead core of a bead portion through a sidewall portion is integrally provided with a folded portion that folds the periphery of the bead core from the inner side to the outer side in the tire axial direction. A heavy-duty tire having a carcass having a ply, wherein the bead portion tapers from the outer surface of the bead core to the outer side in the tire radial direction between the main body portion and the folded portion of the carcass ply and the main body portion. A bead apex rubber having an inner surface facing the outer side and an outer surface facing the outer side in the tire axial direction, an inner end side in the tire radial direction is connected to the outer surface of the bead apex rubber, and an outer end along the main body portion A packing rubber extending in a tapered shape on the outer side in the tire radial direction; and the packing rubber disposed on the outer side in the tire axial direction of the packing rubber. An outer sidewall rubber that forms the outer surface of the bead apex rubber, a loss tangent tan δ of the bead apex rubber is 0.10 to 0.20, a complex elastic modulus E * is 45 to 65 MPa, and a loss tangent tan δ of the packing rubber is 0.03 to 0.09, the complex elastic modulus E * is 3.4 to 3.8 MPa, the loss tangent tan δ of the outer sidewall rubber is 0.065 to 0.125, and the complex elastic modulus E * is 3.0. It is characterized by being -3.4 MPa.

JP 2002-178724 A

  An object of the present invention is to provide a pneumatic tire capable of reducing the rolling resistance of the tire while maintaining the durability performance of the tire.

  In order to achieve the above object, a pneumatic tire according to the present invention includes a pair of bead cores, a bead filler disposed on the outer side in the tire radial direction of the bead core, and a tire disposed between the bead cores. A pneumatic tire comprising: a carcass layer wound outward in the width direction and enclosing the bead core; and a sidewall rubber that is disposed on the outer side in the tire width direction of the bead filler and the carcass layer 4 and constitutes a sidewall portion of the tire. The bead filler is made of a rubber material having tan δ (20 [° C.]) smaller than that of the sidewall rubber, and the first filler portion is disposed so as to wrap around the rolled-up end portion of the carcass layer; From a rubber material having tan δ (20 [° C.]) larger than one filler part And a second filler portion disposed between the first filler portion and the bead core, and a sectional area A of the first filler portion and a tire diameter of the bead core in a sectional view in the tire meridian direction. The cross-sectional area X of the region L from the outer end in the direction to the tire maximum width position P has a relationship of 0.50 ≦ A / X ≦ 0.90, and from the end R in the tire radial direction of the bead core. The tire from the distance h in the tire radial direction to the winding end portion Q of the carcass layer and the end R in the tire radial direction of the bead core to the point S in the tire width direction in the maximum thickness portion of the first filler portion. The distance H in the radial direction has a relationship of 0.75 ≦ h / H ≦ 1.25.

  In the pneumatic tire according to the present invention, (1) the first filler portion of the carcass layer is made of a rubber material having a tan δ (20 [° C.]) smaller than that of the sidewall rubber (soft rubber layer). Thus, the rolled-up end portion Q of the carcass layer is wrapped. Further, the first filler portion, which is a soft rubber layer, is disposed in the region L from the bead core to the maximum width position of the sidewall portion, and the cross-sectional area ratio A / X of the first filler portion in this region L is optimized. Therefore, the tire rigidity in this region L is reduced with respect to the tread portion. As a result, the sidewall portion can be easily eccentrically deformed when the tire rolls, so that there is an advantage that the rolling resistance of the tire is effectively reduced. (2) Ratio h / the distance h from the end R of the bead core to the rolled-up end Q of the carcass layer and the distance H from the end R of the bead core to the point S of the maximum thickness portion of the first filler portion By optimizing H, the cross-sectional area of the 2nd filler part arrange | positioned between a bead core and a 1st filler part is ensured appropriately. Thereby, there exists an advantage by which durability of a bead part is ensured and the durability performance of a tire is maintained appropriately.

  Moreover, in the pneumatic tire according to the present invention, the first filler portion has a substantially rhombus shape eccentric to the inner side in the tire radial direction in a sectional view in the tire meridian direction.

  In this pneumatic tire, due to the eccentric shape of the first filler portion, the sidewall portion can be positively deformed eccentrically when the tire rolls. Thereby, there exists an advantage by which the rolling resistance of a tire is reduced more effectively.

  In the pneumatic tire according to the present invention, the first filler portion is made of a single rubber material.

  In this pneumatic tire, there is an advantage that the type of rubber material used for the bead portion is reduced as compared with a configuration in which the wound end portion Q of the carcass layer is sandwiched between a pair of filler portions made of different rubber materials. is there.

  In the pneumatic tire according to the present invention, the first filler portion has a tan δ (20 [° C.]) of 0.14 or less and a modulus of 1 [MPa] or more and 5 [MPa] or less (100 [%]). ) And an elongation at break of 300 [%] or more.

  In this pneumatic tire, since the physical property value of the first filler portion is optimized, the tire rigidity in the region L is appropriately reduced. Thereby, there exists an advantage by which the rolling resistance of a tire is reduced.

  In the pneumatic tire according to the present invention, the width D of the maximum thickness portion of the first filler portion and the inner side in the tire width direction of the maximum thickness portion of the first filler portion in a cross-sectional view in the tire meridian direction The distance d from the point S to the winding end Q of the carcass layer has a relationship of 0.4 ≦ d / D ≦ 0.7.

  In this pneumatic tire, the positional relationship between the maximum thickness portion of the first filler portion and the rolled-up end portion Q of the carcass layer is optimized, so that the sidewall portion can be appropriately eccentrically deformed during tire rolling. Thereby, there exists an advantage by which the rolling resistance of a tire is reduced.

  Further, in the pneumatic tire according to the present invention, in a sectional view in the tire meridian direction, by a virtual line l passing through the winding end portion Q of the carcass layer and the end portion T on the outer side in the tire radial direction of the first filler portion. When the first filler part is divided into two parts, the cross-sectional area a1 of the part of the first filler part located on the inner side in the tire width direction from the virtual line l and the part of the first filler part located on the outer side in the tire width direction And the cross-sectional area a2 of 0.4 ≦ a1 / a2 ≦ 0.7.

  In this pneumatic tire, since the distribution of the cross-sectional area of the first filler portion is optimized with respect to the rolled-up end portion Q of the carcass layer, the sidewall portion can be appropriately eccentrically deformed when the tire rolls. Thereby, there exists an advantage by which the rolling resistance of a tire is reduced.

  In the pneumatic tire according to the present invention, (1) the first filler portion 31 of the carcass layer 4 is made of a rubber material having a tan δ (20 [° C.]) smaller than that of the sidewall rubber 7 (soft rubber layer). The wound-up end portion Q of the carcass layer 4 is wrapped by the one filler portion 31. Further, the first filler portion, which is a soft rubber layer, is disposed in the region L from the bead core to the maximum width position of the sidewall portion, and the cross-sectional area ratio A / X of the first filler portion in this region L is optimized. Therefore, the tire rigidity in this region L is reduced with respect to the tread portion. As a result, the sidewall portion can be easily eccentrically deformed when the tire rolls, so that there is an advantage that the rolling resistance of the tire is effectively reduced. (2) Ratio h / the distance h from the end R of the bead core to the rolled-up end Q of the carcass layer and the distance H from the end R of the bead core to the point S of the maximum thickness portion of the first filler portion By optimizing H, the cross-sectional area of the 2nd filler part arrange | positioned between a bead core and a 1st filler part is ensured appropriately. Thereby, there exists an advantage by which durability of a bead part is ensured and the durability performance of a tire is maintained appropriately.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

  FIG. 1 is a sectional view in the tire meridian direction showing a pneumatic tire according to an embodiment of the present invention. 2 and 3 are enlarged sectional views showing bead fillers of the pneumatic tire shown in FIG. FIG. 4 is a chart showing the results of the performance test of the pneumatic tire according to the example of the present invention.

[Pneumatic tire]
The pneumatic tire 1 includes a bead core 2, a bead filler 3, a carcass layer 4, a belt layer 5, a tread rubber 6, and a sidewall rubber 7 (see FIG. 1). The bead core 2 has an annular structure and is configured as a pair of left and right. The bead filler 3 is disposed on the outer periphery of the bead core 2 in the tire radial direction and reinforces the bead portion of the tire. The carcass layer 4 is bridged in a toroidal shape between the left and right bead cores 2 and 2 to constitute a tire skeleton. Further, both end portions of the carcass layer 4 are wound and locked outward in the tire width direction (tire tread direction) so as to wrap the bead core 2. Further, rubber members are provided at both ends of the carcass layer 4 to cover each end. The belt layer 5 includes a plurality of stacked belt members 51 to 53 and is disposed on the outer periphery in the tire radial direction of the carcass layer 4. The tread rubber 6 is disposed on the outer circumference in the tire radial direction of the carcass layer 4 and the belt layer 5 to constitute a tread portion of the tire. The sidewall rubber 7 is disposed on the outer side in the tire width direction of the carcass layer 4 to constitute a sidewall portion of the tire.

[Bead filler]
Moreover, the bead filler 3 is comprised by the 1st filler part (soft rubber layer) 31 and the 2nd filler part (hard rubber layer) 32 (refer FIG. 1 and FIG. 2). The first filler portion 31 is made of a rubber material having tan δ (20 [° C.]) smaller than that of the sidewall rubber 7, and is disposed so as to wrap around the rolled-up end portion Q of the carcass layer 4. The second filler portion 32 is made of a rubber material having tan δ (20 [° C.]) larger than that of the first filler portion 31 and is disposed between the first filler portion 31 and the bead core 2.

  For example, in this embodiment, the first filler portion 31 and the second filler portion 32 are made of rubber materials having different materials (see FIG. 2). Further, tan δ (20 [° C.]) of the first filler portion 31 is set smaller than tan δ (20 [° C.]) of the second filler portion 32. For this reason, the first filler portion 31 is made of a softer rubber material than the second filler portion 32. Further, a cut portion is provided on the inner side in the tire radial direction of the first filler portion 31, and the winding end portion Q of the carcass layer 4 is sandwiched in this portion. Thereby, the winding-up end portion Q of the carcass layer 4 is wrapped by the first filler portion 31 from both the inside and the outside in the tire width direction. Further, the second filler portion 32 is disposed so as to be wrapped in the rolled-up portion of the carcass layer 4. Further, the second filler portion 32 is arranged on the outer side in the tire radial direction than the bead core 2 and on the inner side in the tire radial direction (bead toe side) than the first filler portion 31.

  Here, in this pneumatic tire 1, from a sectional view in the tire meridian direction, (1) from the cross-sectional area A of the first filler portion 31 and the end of the bead core 2 in the tire radial direction to the tire maximum width position P. The cross-sectional area X of the region L has a relationship of 0.50 ≦ A / X ≦ 0.90 (see FIG. 2). That is, the first filler portion 31 that is a soft rubber layer is disposed in the region L from the bead core 2 to the maximum width position of the sidewall portion, and the installation ratio (A / X) of the first filler portion 31 in this region L Is optimized.

  Further, in the tire meridian cross-sectional view, (2) the distance in the tire radial direction from the outer end R of the bead core 2 to the winding end Q of the carcass layer 4 is defined as h (see FIG. 2). . Further, the distance in the tire radial direction from the end R on the inner side in the tire radial direction of the bead core 2 to the point S on the inner side in the tire width direction in the maximum thickness portion of the first filler portion 31 is defined as H. At this time, the ratio h / H between the distance h and the distance H has a relationship of 0.75 ≦ h / H ≦ 1.25. That is, the ratio h between the distance h from the end portion R of the bead core 2 to the rolled-up end portion Q of the carcass layer 4 and the distance H from the end portion R of the bead core 2 to the point S of the maximum thickness portion of the first filler portion 31. / H is optimized.

  In addition, the largest thickness part of the 1st filler part 31 means the largest dimension concerning the axial direction of the bead filler 3 which has a cyclic structure. For example, in this embodiment, the first filler portion 31 has a substantially rhombus shape in a cross-sectional view in the tire meridian direction, and the maximum thickness portion of the first filler portion 31 is configured by corner portions of the rhombus shape. Has been. Further, the first filler portion 31 wraps the rolled-up end portion Q of the carcass layer 4 at the maximum thickness portion.

[effect]
In this pneumatic tire 1, (1) the first filler portion 31 of the carcass layer 4 is made of a rubber material having a tan δ (20 [° C.]) smaller than that of the sidewall rubber 7 (soft rubber layer). The winding end portion Q of the carcass layer 4 is wrapped by the portion 31. Further, the first filler portion 31 is disposed in the region L from the bead core 2 to the maximum width position of the sidewall portion (see FIG. 2), and the cross-sectional area ratio A / X of the first filler portion 31 in this region L is Since it is optimized, the tire rigidity in this region L is reduced with respect to the tread portion. As a result, the sidewall portion can be easily eccentrically deformed when the tire rolls, so that there is an advantage that the rolling resistance of the tire is effectively reduced. For example, when A / X <0.50, the tire rigidity in the region L is not sufficiently reduced, and therefore it is difficult to obtain an effect of reducing the tire rolling resistance. Further, when 0.90 <A / X, there is a problem that the rigidity of the sidewall portion is not ensured.

  Further, (2) the distance h from the end R of the bead core 2 to the winding end Q of the carcass layer 4 and the distance H from the end R of the bead core 2 to the point S of the maximum thickness portion of the first filler portion 31; By optimizing the ratio h / H, the cross-sectional area of the second filler portion 32 disposed between the bead core 2 and the first filler portion 31 is appropriately secured (see FIG. 2). Thereby, there exists an advantage by which durability of a bead part is ensured and the durability performance of a tire is maintained appropriately. For example, when h / H <0.75, the arrangement space of the second filler portion 32 is reduced and the cross-sectional area of the second filler portion 32 is insufficient, so that the durability of the bead portion is not ensured. Moreover, in 1.25 <h / H, since the arrangement space of the 1st filler part 31 reduces and the cross-sectional area of the 1st filler part 31 reduces, the reduction effect of the rolling resistance of a tire reduces.

  Further, in the configuration (2), the position of the winding end portion Q of the carcass layer 4 and the maximum width position of the first filler portion 31 are arranged at substantially the same position (0.75 ≦ h / H ≦ 1.25). Therefore, the thickness of the first filler portion 31 decreases from the rolled-up end portion Q of the carcass layer 4 toward the tire maximum width position of the sidewall portion (see FIG. 2). As a result, the sidewall portion can be more easily eccentrically deformed when the tire rolls, so that there is an advantage that the rolling resistance of the tire is effectively reduced.

[Additional matter 1]
In the pneumatic tire 1, it is preferable that the first filler portion 31 has a substantially rhombus shape that is eccentric inward in the tire radial direction in a sectional view in the tire meridian direction (see FIGS. 1 and 2). In such a configuration, due to the eccentric shape of the first filler portion 31, the sidewall portion can be positively deformed eccentrically during tire rolling. Thereby, there exists an advantage by which the rolling resistance of a tire is reduced more effectively.

  For example, in this embodiment, the first filler portion 31 has a substantially rhombus shape that is long in the tire radial direction and narrow in the tire width direction in a cross-sectional view in the tire meridian direction, and the center (the rhomboid shape) (Intersection of diagonal lines) is decentered inward in the tire radial direction (see FIG. 2). Further, the first filler portion 31 has a notch portion provided from the apex on the inner side in the tire radial direction of the rhombus shape toward the center portion, and the winding end portion Q of the carcass layer 4 is sandwiched by this notch portion. . At this time, the winding end portion Q of the carcass layer 4 is substantially in the same position with respect to the maximum width position of the first filler portion 31. Therefore, the center of the rhombus shape of the first filler portion 31 is substantially at the same position as the rolled-up end portion Q of the carcass layer 4, and from this position toward the outer side in the tire radial direction (maximum width position P side of the sidewall portion). The thickness of the first filler portion 31 is reduced. With this configuration, the sidewall portion can be positively deformed eccentrically when the tire rolls.

  Moreover, in this pneumatic tire 1, it is preferable that the 1st filler part 31 consists of a single rubber material (refer FIG. 2). That is, the rolled-up end portion Q of the carcass layer 4 is wrapped by the first filler portion 31 made of a single rubber material. In such a configuration, the type of rubber material used for the bead portion is reduced as compared with a configuration (not shown) in which the rolled-up end portion Q of the carcass layer is sandwiched between a pair of filler portions made of different rubber materials. There are advantages.

  For example, in this embodiment, as described above, the first filler portion 31 is made of a single rubber material, and a notch portion is formed at the inner end in the tire radial direction of the first filler portion 31 (FIG. 2). And the winding-up edge part Q of the carcass layer 4 is inserted | pinched by this notch part.

[Additional matter 2]
Moreover, in this pneumatic tire 1, the first filler portion has a tan δ (20 [° C.]) of 0.14 or less, a modulus of 1 [MPa] or more and 5 [MPa] or less (at 100 [%] extension), It preferably has a breaking elongation of 300 [%] or more. Further, these physical property values (modulus and elongation at break) conform to the provisions of JISK6251. In such a configuration, since the physical property value of the first filler portion 31 is optimized, the tire rigidity in the region L is appropriately reduced. Thereby, there exists an advantage by which the rolling resistance of a tire is reduced.

  In this embodiment, the first filler part 31 has the physical property values described above, and the second filler part 32 has a tan δ (20 [° C.]) of 0.14 or more, and 5 [MPa] or more and 18 [ MPa] modulus (at 100 [%] elongation) and 200 [%] elongation at break (see FIG. 2). Further, the sidewall rubber 7 has a tan δ (20 [° C.]) of 0.14 to 0.25, a modulus of 4 [MPa] or less (at 100 [%] elongation), 300 [%] to 700 [ %] Has the following elongation at break.

  In the pneumatic tire 1, the width D of the maximum thickness portion of the first filler portion 31 and the point on the inner side in the tire width direction of the maximum thickness portion of the first filler portion 31 in a sectional view in the tire meridian direction. The distance d from S to the winding end Q of the carcass layer 4 preferably has a relationship of 0.4 ≦ d / D ≦ 0.7 (see FIG. 2). That is, the rolled-up end portion Q of the carcass layer 4 is disposed at the approximate center of the maximum thickness portion of the first filler portion 31. In such a configuration, the positional relationship between the maximum thickness portion of the first filler portion 31 and the winding end portion Q of the carcass layer 4 is optimized, so that the sidewall portion can be appropriately eccentrically deformed during tire rolling. Thereby, there exists an advantage by which the rolling resistance of a tire is reduced.

  Further, in the pneumatic tire 1, the first filler is represented by an imaginary line l that passes through the winding end portion Q of the carcass layer 4 and the end portion T of the first filler portion in the tire radial direction in a sectional view in the tire meridian direction. When the part 31 is divided into two parts, the cross-sectional area a1 of the part 311 of the first filler part 31 located on the inner side in the tire width direction from the virtual line l and the part 312 of the first filler part 31 located on the outer side in the tire width direction. The cross-sectional area a2 preferably has a relationship of 0.4 ≦ a1 / a2 ≦ 0.7 (see FIG. 3). In other words, the cross-sectional area of the first filler portion 31 is approximately bisected in the tire width direction by the virtual line l. In such a configuration, the distribution of the cross-sectional area of the first filler portion 31 is optimized with respect to the rolled-up end portion Q of the carcass layer 4, so that the sidewall portion can be appropriately eccentrically deformed during tire rolling. Thereby, there exists an advantage by which the rolling resistance of a tire is reduced.

[performance test]
In this example, performance tests on (1) rolling resistance and (2) durability performance were performed on a plurality of pneumatic tires with different conditions (see FIG. 4). In this performance test, a pneumatic tire having a tire size of 275 / 80R22.5 is assembled to a rim having a rim size of 22.5 × 7.50.

  (1) In a performance test relating to rolling resistance (low rolling resistance performance), a pneumatic tire is subjected to the maximum air pressure and maximum load specified by JATMA. Then, an indoor drum tester is used to measure rolling resistance at 60 [km / h], 80 [km / h], and 100 [km / h]. And based on this measurement result, index evaluation with a conventional pneumatic tire (conventional example) as a reference (100) is performed. This evaluation is more preferable as the index value is larger.

  (2) In the performance test related to durability performance, a pneumatic tire is loaded with a load of 140 [%] of the specified internal pressure specified by JATMA and a specified load. The indoor drum tester is used to travel 30,000 [km] at a traveling speed of 45 [km / h]. And after this driving | running | working, the separation which generate | occur | produced around the winding-up edge part Q of the carcass layer 4 is observed. Then, based on the observation result, index evaluation using the conventional example as a reference (100) is performed. Evaluation is so preferable that the numerical value is large.

  In the conventional pneumatic tire, the bead filler includes a first filler portion and a second filler portion. And the 1st filler part is arrange | positioned only in the tire width direction inner side from the winding-up edge part of a carcass layer, and the 2nd filler part is arrange | positioned between the 1st filler part and the bead core.

  In the pneumatic tires 1 of Invention Examples 1 to 5, the bead filler 3 is composed of the first filler portion 31 and the second filler portion 32 (see FIG. 2). The first filler portion 31 of the bead filler 3 is disposed so as to wrap around the rolled-up end portion Q of the carcass layer 4, and the second filler portion 32 is disposed between the first filler portion 31 and the bead core 2. Yes.

  In the pneumatic tires of the conventional example and the inventive examples 1 to 5, the first filler portion is made of a rubber material having a tan δ (20 [° C.]) of 0.10 and a modulus of 100 [%] of 4 [MPa] when stretched. It is configured. Further, the second filler portion is made of a rubber material having a tan δ (20 [° C.]) of 0.20 and a modulus of 100 [%] of 10 [MPa] when stretched. Further, the sidewall rubber is made of a rubber material having a tan δ (20 [° C.]) of 0.15 and a 100 [%] modulus at 3 [MPa] elongation.

  As shown in the test results, in the pneumatic tires 1 of Invention Examples 1 to 5, it is understood that the rolling resistance of the tire is reduced while maintaining the durability performance of the tire (see FIG. 4). Further, when Invention Examples 1, 3, 4 and Comparative Example 1 are compared, the rolling resistance of the tire is improved by optimizing the cross-sectional area ratio A / X of the first filler portion 31 in the region L (see FIG. 1). It can be seen that is effectively reduced. Further, when Invention Examples 2 and 3 are compared with Comparative Example 2 and Invention Examples 1 and 5 are compared with Comparative Example 3, the distance from the end R of the bead core 2 to the winding-up end Q of the carcass layer 4 By optimizing the ratio h / H between h and the end portion R of the bead core 2 to the point H of the maximum thickness portion of the first filler portion 31, the durability of the tire is maintained. It can be seen that the rolling resistance is effectively reduced.

  As described above, the pneumatic tire according to the present invention is useful in that the rolling resistance of the tire can be reduced while maintaining the durability performance of the tire.

It is sectional drawing of the tire meridian direction which shows the pneumatic tire concerning the Example of this invention. It is an expanded sectional view which shows the bead filler of the pneumatic tire described in FIG. It is an expanded sectional view which shows the bead filler of the pneumatic tire described in FIG. It is a graph which shows the result of the performance test of the pneumatic tire concerning the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Bead core 3 Bead filler 31 1st filler part 32 2nd filler part 4 Carcass layer 5 Belt layers 51-53 Belt material 6 Tread rubber 7 Side wall rubber

Claims (6)

A pair of bead cores, a bead filler disposed on the outer side in the tire radial direction of the bead core, a carcass layer that is disposed between the bead cores and is wound up on the outer side in the tire width direction so as to wrap around the bead core; A pneumatic tire comprising a bead filler and a sidewall rubber disposed outside the carcass layer 4 in the tire width direction and constituting a sidewall portion of the tire,
A first filler portion, wherein the bead filler is made of a rubber material having a tan δ (20 [° C.]) smaller than that of the sidewall rubber, and is disposed so as to wrap around the rolled-up end portion of the carcass layer; A second filler portion made of a rubber material having a larger tan δ (20 [° C.]) and disposed between the first filler portion and the bead core, and
In a cross-sectional view in the tire meridian direction, the cross-sectional area A of the first filler portion and the cross-sectional area X of the region L from the outer end in the tire radial direction of the bead core to the tire maximum width position P are 0.50 ≦ A /X≦0.90, and the distance h in the tire radial direction from the end R in the tire radial direction of the bead core to the winding-up end Q of the carcass layer and the end in the tire radial direction of the bead core The distance H in the tire radial direction from the portion R to the point S on the inner side in the tire width direction in the maximum thickness portion of the first filler portion has a relationship of 0.75 ≦ h / H ≦ 1.25. Pneumatic tires.   2. The pneumatic tire according to claim 1, wherein the first filler portion has a substantially rhombic shape eccentric inward in the tire radial direction in a cross-sectional view in the tire meridian direction.   The pneumatic tire according to claim 1 or 2, wherein the first filler portion is made of a single rubber material.   The first filler portion has a tan δ (20 [° C.]) of 0.14 or less, a modulus of 1 [MPa] or more and 5 [MPa] or less (at 100 [%] extension), and a breaking elongation of 300 [%] or more. The pneumatic tire according to any one of claims 1 to 3, further comprising:   In a sectional view in the tire meridian direction, the width D of the maximum thickness portion of the first filler portion and the winding end portion of the carcass layer from the point S on the inner side in the tire width direction in the maximum thickness portion of the first filler portion The pneumatic tire according to claim 1, wherein the distance d to Q has a relationship of 0.4 ≦ d / D ≦ 0.7.   When the first filler portion is divided into two by a virtual line 1 passing through a winding end portion Q of the carcass layer and an end portion T on the outer side in the tire radial direction of the first filler portion in a sectional view in the tire meridian direction In addition, the cross-sectional area a1 of the first filler portion located on the inner side in the tire width direction from the imaginary line l and the cross-sectional area a2 of the first filler portion located on the outer side in the tire width direction are 0.4 ≦ a1. The pneumatic tire according to claim 1, having a relationship of /a2≦0.7.

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