Pneumatic tire

Abstract

Provided is a pneumatic tire capable of improving low fuel consumption performance by reducing air resistance during running. 【Solution means】The present invention is a pneumatic tire 1 including a ground contact surface 3a extending from a first ground contact end Te1 to a second ground contact end Te2, and a first side outer surface 6a extending inward in the tire radial direction from the first ground contact end Te1. The tread portion 3 has a first shoulder circumferential groove 4A and a first shoulder land portion 5A defined by the first shoulder circumferential groove 4A and the first ground contact end Te1. The ground contact surface 3a has a first virtual line L1, which is a tangent line at the intermediate position Pm in the tire axial direction of the first shoulder land portion 5A, having a first angle θ1 of 74 to 80° with respect to the tire radial direction. The first side outer surface 6a has a second virtual line L2, which is a tangent line at the first position P1, having a second angle θ2 of 36 to 40° with respect to the tire radial direction. The distance t in the tire radial direction between the first ground contact end Te1 and the tire equator C is 2% to 6% of the ground contact width TW.

Description

Technical Field

[0001] The present invention relates to pneumatic tires.

Background Art

[0002] Conventionally, various pneumatic tires having specific profiles have been proposed. For example, Patent Document 1 below proposes a pneumatic tire that can achieve both noise performance and low fuel consumption performance by including a profile in which the portion from the maximum width position of the tire to the outer end position has a single radius of curvature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in addition to the rolling resistance that the pneumatic tire of Patent Document 1 has improved, the resistance related to low fuel consumption performance includes air resistance during running. Further improvement has been expected for the air resistance during running even in the pneumatic tire of Patent Document 1.

[0005] The present invention has been devised in view of the above actual situation, and the main object thereof is to provide a pneumatic tire that can improve low fuel consumption performance by reducing air resistance during running.

Means for Solving the Problems

[0006] The present invention relates to a pneumatic tire having a profile defined on an outer surface in a tire meridian cross section in a normal state which is a non-loaded state where the tire is mounted on a standard rim and adjusted to a standard internal pressure. The profile includes a ground contact surface of a tread portion extending from a first ground contact end to a second ground contact end, and a first side outer surface of a sidewall portion extending inward in the tire radial direction from the first ground contact end. A first position is defined on the first side outer surface at a distance of 15% of the tire section height from the tire equator of the ground contact surface inward in the tire radial direction. The tread portion has a first shoulder circumferential groove extending in the tire circumferential direction on the most first ground contact end side between the tire equator and the first ground contact end, and a first shoulder land portion defined by the first shoulder circumferential groove and the first ground contact end. The ground contact surface is such that a first virtual line which is a tangent line at an intermediate position in the tire axial direction of the first shoulder land portion inclines inward in the tire radial direction toward the outside in the tire axial direction. The first virtual line has a first angle of 74 to 80° with respect to the tire radial direction. The first side outer surface is such that a second virtual line which is a tangent line at the first position inclines in the same direction as the first virtual line with respect to the tire radial direction. The second virtual line has a second angle of 36 to 40° with respect to the tire radial direction. The ground contact surface has a ground contact width which is the distance in the tire axial direction between the first ground contact end and the second ground contact end. The distance in the tire radial direction between the first ground contact end and the tire equator is 2% to 6% of the ground contact width. It is a pneumatic tire.

Advantages of the Invention

[0007] By having the above-described configuration, the pneumatic tire of the present invention can reduce the air resistance during running, and as a result, can improve the low fuel consumption performance.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Best Mode for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a tire meridian cross-sectional view showing the profile 2 of the pneumatic tire 1 in a normal state of the present embodiment. Here, the "normal state" is a no-load state in which the pneumatic tire 1 is rim-mounted on a normal rim R and adjusted to a normal internal pressure. Hereinafter, unless otherwise specified, the dimensions and the like of each part of the pneumatic tire 1 are values measured in this normal state.

[0010] The "normal rim R" is, when there is a standard system including the standard on which the pneumatic tire 1 is based, the rim defined for each tire by the standard. For example, in the case of JATMA, it is the "standard rim", in the case of TRA, it is the "Design Rim", and in the case of ETRTO, it is the "Measuring Rim". The "normal rim R" is, when there is no standard system including the standard on which the pneumatic tire 1 is based, the rim that can be rim-mounted and does not cause air leakage, and among them, it is the rim with the smallest rim diameter and the smallest rim width.

[0011] The "normal internal pressure" is, when there is a standard system including the standard on which the pneumatic tire 1 is based, the air pressure defined for each tire by each standard. In the case of JATMA, it is the "maximum air pressure", in the case of TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and in the case of ETRTO, it is the "INFLATION PRESSURE". The "normal internal pressure" is, when there is no standard system including the standard on which the pneumatic tire 1 is based, the air pressure determined for each tire by the manufacturer or the like.

[0012] As shown in FIG. 1, the pneumatic tire 1 is suitably used, for example, as a passenger car tire. The pneumatic tire 1 of the present embodiment has a profile 2 defined by the outer surface in the tire meridian cross section in the normal state. The profile 2 of the present embodiment includes a ground contact surface 3a of the tread portion 3 extending from the first ground contact end Te1 to the second ground contact end Te2.

[0013] The ground contact surface 3a has, for example, a tire equator C that is an intermediate position in the tire axial direction between the first ground contact end Te1 and the second ground contact end Te2, and a ground contact width TW that is the distance in the tire axial direction between the first ground contact end Te1 and the second ground contact end Te2. It is desirable that the first ground contact end Te1 is located at a distance t inside the tire radius direction from the tire equator C.

[0014] Here, the "first ground contact end Te1" and the "second ground contact end Te2" are the outermost ground contact positions in the tire axial direction when 70% of the normal load is applied to the pneumatic tire 1 in the normal state and it contacts the plane with a camber angle of 0°.

[0015] The "normal load" is the load determined for each tire when there is a standard system including the standard on which the pneumatic tire 1 is based. For JATMA, it is the "maximum load capacity", for TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and for ETRTO, it is the "LOAD CAPACITY". The "normal load" is the load determined for each tire by the manufacturer or the like as the maximum applicable load when using the pneumatic tire 1 when there is no standard system including the standard on which the pneumatic tire 1 is based.

[0016] The tread portion 3 of the present embodiment has a plurality of circumferential grooves 4 extending in the tire circumferential direction and a plurality of land portions 5 separated by the plurality of circumferential grooves 4. The plurality of circumferential grooves 4 may, for example, extend linearly in the tire circumferential direction, may extend in a zigzag shape, or may be a mixture of those extending linearly and those extending in a zigzag shape. Such a tread portion 3 helps to achieve both the rigidity and drainage performance of the land portion 5.

[0017] The plurality of circumferential grooves 4 of the present embodiment include a first shoulder circumferential groove 4A that extends most toward the first grounding end Te1 in the tire circumferential direction between the tire equator C and the first grounding end Te1. The plurality of land portions 5 of the present embodiment include a first shoulder land portion 5A separated by the first shoulder circumferential groove 4A and the first grounding end Te1.

[0018] It is desirable that a first virtual line L1, which is a tangent line at the intermediate position Pm in the tire axial direction of the first shoulder land portion 5A, inclines inward in the tire radial direction toward the outside in the tire axial direction on the ground contact surface 3a. Such a ground contact surface 3a helps to smooth the flow of air during running from the tread portion 3 to the sidewall portion 6 described later and suppress the separation of air.

[0019] Here, the intermediate position Pm of the first shoulder land portion 5A is a position that is separated by a distance W1 / 2, which is half of the maximum width W1 in the tire axial direction of the first shoulder land portion 5A, inward in the tire axial direction from the first grounding end Te1.

[0020] FIG. 2 is an enlarged view of part A of FIG. 1. As shown in FIG. 2, the first virtual line L1 of the present embodiment is inclined at a first angle θ1 with respect to the tire radial direction. The first angle θ1 is preferably 74° or more. By the first angle θ1 being 74° or more, excessive deformation during grounding can be suppressed and the rolling resistance can be reduced. From such a viewpoint, the first angle θ1 is more preferably 76° or more, and still more preferably 77° or more.

[0021] The first angle θ1 is preferably 80° or less. When the first angle θ1 is 80° or less, the air flow during running from the tread portion 3 to the sidewall portion 6 described later becomes smooth, air separation is suppressed, and the air resistance during running can be reduced. From such a viewpoint, the first angle θ1 is more preferably 78° or less, and still more preferably 77° or less.

[0022] From these, the first angle θ1 is preferably 74 to 80°, more preferably 76 to 78°, and still more preferably 77°. Note that the combination of the upper limit value and the lower limit value of these numerical ranges can be arbitrarily selected.

[0023] As shown in FIG. 1, the profile 2 of the present embodiment includes a first side outer surface 6a of the sidewall portion 6 extending inward in the tire radial direction from the first ground contact end Te1, and a first bead outer surface 7a of the bead portion 7 located inward in the tire radial direction of the first side outer surface 6a.

[0024] On the first side outer surface 6a of the present embodiment, a first position P1 is defined at a distance D1 of 15% of the tire section height SH inward in the tire radial direction from the tire equator C of the ground contact surface 3a. It is desirable that the second virtual line L2, which is a tangent line at the first position P1 on the first side outer surface 6a, inclines in the same direction as the first virtual line L1 with respect to the tire radial direction. Such a first side outer surface 6a helps to smooth the air flow during running from the tread portion 3 to the sidewall portion 6 and suppress air separation.

[0025] As shown in FIG. 2, the second virtual line L2 of the present embodiment inclines at a second angle θ2 with respect to the tire radial direction. The second angle θ2 is preferably 36° or more. When the second angle θ2 is 36° or more, the air flow during running from the tread portion 3 to the sidewall portion 6 becomes smooth, air separation is suppressed, and the air resistance during running can be reduced. From such a viewpoint, the second angle θ2 is more preferably 37° or more, and still more preferably 38° or more.

[0026] The second angle θ2 is preferably 40° or less. By having the second angle θ2 be 40° or less, it is possible to suppress the separation of air on the outer side in the tire radial direction of the sidewall portion 6 and reduce the air resistance during running. From such a viewpoint, the second angle θ2 is more preferably 39° or less, and even more preferably 38° or less.

[0027] From these facts, the second angle θ2 is preferably 36 - 40°, more preferably 37 - 39°, and even more preferably 38°. Note that the combinations of the upper limit value and the lower limit value of these numerical ranges can be arbitrarily selected.

[0028] As shown in FIG. 1, the distance t in the tire radial direction between the first grounding end Te1 and the tire equator C is preferably 2% or more of the grounding width TW. By having the distance t be 2% or more of the grounding width TW, the flow of air during running from the tread portion 3 to the sidewall portion 6 becomes smooth, the separation of air is suppressed, and the air resistance during running can be reduced. From such a viewpoint, the distance t between the first grounding end Te1 and the tire equator C is more preferably 3% or more of the grounding width TW.

[0029] The distance t between the first grounding end Te1 and the tire equator C is preferably 6% or less of the grounding width TW. By having the distance D2 be 6% or less of the grounding width TW, excessive deformation during grounding can be suppressed and the rolling resistance can be reduced. From such a viewpoint, the distance t between the first grounding end Te1 and the tire equator C is more preferably 5% or less of the grounding width TW.

[0030] From these facts, the distance t between the first grounding end Te1 and the tire equator C is preferably 2% - 6% of the grounding width TW, and more preferably 3% - 5%. Note that the combinations of the upper limit value and the lower limit value of these numerical ranges can be arbitrarily selected.

[0031] Due to the synergistic effect of the above components, the pneumatic tire 1 having Profile 2 of the present embodiment can reduce the air resistance during driving, and as a result, can improve the low fuel consumption performance.

[0032] In a more preferred aspect, the standard rim R has a first rim end R1 which is the end on the first grounding end Te1 side, a second rim end R2 which is the end on the second grounding end Te2 side, and a maximum width RW which is the distance in the rim width direction between the first rim end R1 and the second rim end R2.

[0033] The pneumatic tire 1 of the present embodiment does not have a rim guard in the sidewall portion 6. Such a pneumatic tire 1 can reduce the air resistance during driving because there is no rim guard that has a large impact on the air resistance.

[0034] The pneumatic tire 1 preferably has a tire cross-sectional width SW that is 6 mm or more larger than the maximum width RW in the rim width direction of the standard rim R. Such a pneumatic tire 1 can suppress the standard rim R from contacting a curb or the like even without a rim guard, and can achieve both durability performance and low fuel consumption performance. Here, the tire cross-sectional width SW is the maximum width in Profile 2 and does not include local protrusions or rim guards.

[0035] The distance d in the tire radial direction between the first rim end R1 and the first bead outer surface 7a is preferably 3 mm or less. Such a first bead outer surface 7a can suppress the generation of turbulent flow between the first rim end R1 and the first bead outer surface 7a, and can reduce the air resistance during driving by maintaining the kinetic energy of the air.

[0036] The maximum width W1 in the tire axial direction of the first shoulder land portion 5A is preferably 20% or more of the ground contact width TW. When the maximum width W1 of the first shoulder land portion 5A is 20% or more of the ground contact width TW, the air that has flowed in due to the influence of the vehicle during running can be smoothly flowed into the first shoulder circumferential groove 4A, thereby reducing the air resistance during running. By arranging the first shoulder circumferential groove 4A at a position with high ground pressure, it also helps to increase the running speed at which the hydroplaning phenomenon occurs. From such a perspective, the maximum width W1 of the first shoulder land portion 5A is more preferably 22% or more of the ground contact width TW.

[0037] The maximum width W1 in the tire axial direction of the first shoulder land portion 5A is preferably 30% or less of the ground contact width TW. When the maximum width W1 of the first shoulder land portion 5A is 30% or less of the ground contact width TW, it is possible to suppress an excessive increase in the rigidity of the first shoulder land portion 5A, improve the handling stability performance of the pneumatic tire 1, and also help to improve the drainage performance on the outer side in the tire axial direction. From such a perspective, the maximum width W1 of the first shoulder land portion 5A is more preferably 28% or less of the ground contact width TW.

[0038] From these facts, the maximum width W1 in the tire axial direction of the first shoulder land portion 5A is preferably 20% to 30% of the ground contact width TW, and more preferably 22% to 28%. It should be noted that the combination of the upper limit value and the lower limit value of these numerical ranges can be arbitrarily selected.

[0039] On the first side outer surface 6a, it is desirable to define a second position P2 that is at a distance D2 of 25% of the tire section height SH from the tire equator C inward in the tire radial direction, and a third position P3 that is at a distance D3 of 19 mm from the tire equator C inward in the tire radial direction. On the first side outer surface 6a of the present embodiment, a fourth position P4 located inward in the tire radial direction of the virtual intersection point Pv of the first virtual line L1 and the second virtual line L2 is defined.

[0040] As shown in FIG. 2, it is desirable that the distance D4 in the tire radial direction between the first position P1 and the second position P2 is equal to the distance D4 in the tire radial direction between the first position P1 and the fourth position P4. In this case, the first position P1 is an intermediate position in the tire radial direction between the second position P2 and the fourth position P4. Such a first position P1 is suitable as a representative point of the outer region in the tire radial direction of the first side outer surface 6a.

[0041] FIG. 3 is a schematic view of a mold M for molding the pneumatic tire 1. As shown in FIGS. 1 to 3, the mold M of the present embodiment includes a tread mold M1 for molding the tread portion 3 and a side mold M2 for molding the sidewall portion 6. The pneumatic tire 1 has, for example, a mold parting line ML between the tread mold M1 and the side mold M2.

[0042] As shown in FIG. 2, the mold parting line ML preferably includes a stepped portion 8 having a height h of 0.4 mm or less. Such a stepped portion 8 can suppress the generation of cracks starting from the mold parting line ML and improve the durability performance of the pneumatic tire 1.

[0043] Further, since the height h of the stepped portion 8 is 0.4 mm or less, an increase in air resistance during running can be suppressed, and the low fuel consumption performance of the pneumatic tire 1 can be improved. Here, the height h of the stepped portion 8 is the maximum value of the height protruding in a direction orthogonal to the first side outer surface 6a from the first side outer surfaces 6a on both sides of the stepped portion 8 in the tire radial direction.

[0044] The stepped portion 8 of the mold parting line ML is preferably located between the second position P2 and the third position P3. By the stepped portion 8 being located outside the second position P2 in the tire radial direction, a decrease in the air flow velocity near the maximum width position of the first side outer surface 6a can be suppressed, and the air resistance during running can be reduced.

[0045] Since the step portion 8 is located radially inward of the tire than the third position P3, it is possible to suppress a decrease in the flow velocity of the air near the buttress on the outer side in the tire radial direction of the first side outer surface 6a, and reduce the air resistance during running.

[0046] As shown in FIG. 1, for the pneumatic tire 1 of the present embodiment, in the tire axial direction, the mounting direction on the vehicle is specified. The first grounding end Te1 of the present embodiment is located outside the vehicle when mounted on the vehicle. The second grounding end Te2 is preferably located inside the vehicle when mounted on the vehicle. Such a pneumatic tire 1 can define at least the profile 2 on the outer side of the vehicle, which has a large influence on air resistance, into a shape with low air resistance, and can improve the fuel efficiency performance.

[0047] The circumferential groove 4 of the present embodiment includes a second shoulder circumferential groove 4B that extends in the tire circumferential direction on the side closest to the second grounding end Te2 between the tire equator C and the second grounding end Te2. The circumferential groove 4 includes, for example, a first crown circumferential groove 4C that extends in the tire circumferential direction between the tire equator C and the first shoulder circumferential groove 4A, and a second crown circumferential groove 4D that extends in the tire circumferential direction between the tire equator C and the second shoulder circumferential groove 4B. Such a circumferential groove 4 is excellent in drainage performance and helps to improve the wet performance of the pneumatic tire 1. Note that the circumferential groove 4 is not limited to four, and may be, for example, three or less, or five or more.

[0048] The land portion 5 of the present embodiment has a second shoulder land portion 5B defined by the second shoulder circumferential groove 4B and the second grounding end Te2. The land portion 5 preferably includes a first middle land portion 5C defined by the first shoulder circumferential groove 4A and the first crown circumferential groove 4C, and a second middle land portion 5D defined by the second shoulder circumferential groove 4B and the second crown circumferential groove 4D. The land portion 5 includes, for example, a crown land portion 5E defined by the first crown circumferential groove 4C and the second crown circumferential groove 4D. Such a land portion 5 is excellent in rigidity and helps to improve the handling stability performance of the pneumatic tire 1.

[0049] Profile 2 of the present embodiment includes a second side outer surface 6b of a sidewall portion 6 extending inward in the tire radial direction from a second grounding end Te2, and a second bead outer surface 7b of a bead portion 7 located inward of the second side outer surface 6b in the tire radial direction.

[0050] Profile 2 may be formed symmetrically in the tire axial direction, for example, about the tire equator C. In this case, the grounding surface 3a of the second shoulder land portion 5B, the second side outer surface 6b, and the second bead outer surface 7b are each symmetrically shaped with the grounding surface 3a of the first shoulder land portion 5A, the first side outer surface 6a, and the first bead outer surface 7a. Such a pneumatic tire 1 can reduce air resistance during running inside the vehicle and further improve fuel efficiency performance.

[0051] As described above, particularly preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiments and can be implemented in various forms.

Example

[0052] A pneumatic tire of tire size 215 / 45R20 having the profile of FIG. 1 was prototyped based on the specifications in Table 1. The prototyped pneumatic tires in the normal state were mounted on a drum tester, and their rolling resistances were measured based on the force method of ISO28580. The results of the rolling resistance test are shown as an index with Comparative Example 1 being 100, and the larger the numerical value, the smaller the rolling resistance.

[0053] Also, using a pneumatic tire model of the same tire size as the prototyped pneumatic tire, aerodynamic simulations of the front wheels were performed when mounted on a passenger vehicle model, and their air resistance coefficients were obtained. The results of the air resistance test are shown as an index with Comparative Example 1 being 100, and the larger the numerical value, the smaller the air resistance during running.

[0054] The test results are shown in Table 1.

Table 1

[0055] As a result of the tests, it was confirmed that the pneumatic tire of the example maintains equivalent rolling resistance compared to the comparative example while reducing the air resistance during running, and improves the low fuel consumption performance evaluated by the total of the rolling resistance and the air resistance.

[0056] [Supplementary Note] The present invention is as follows.

[0057] [Invention 1] A pneumatic tire, having a profile defined by an outer surface in a tire meridian cross-section in a normal state of a tire in a no-load state assembled to a standard rim and adjusted to a standard internal pressure, wherein the profile includes a ground contact surface of a tread portion extending from a first ground contact end to a second ground contact end, and a first side outer surface of a sidewall portion extending inward in the tire radial direction from the first ground contact end, a first position defined on the first side outer surface at a distance of 15% of the tire cross-sectional height inward in the tire radial direction from the tire equator of the ground contact surface is defined, the tread portion has a first shoulder circumferential groove extending in the tire circumferential direction on the most first ground contact end side between the tire equator and the first ground contact end, and a first shoulder land portion defined by the first shoulder circumferential groove and the first ground contact end, a first virtual line which is a tangent line at an intermediate position in the tire axial direction of the first shoulder land portion inclines inward in the tire radial direction toward the outside in the tire axial direction, the first virtual line has a first angle of 74 to 80° with respect to the tire radial direction, a second virtual line which is a tangent line at the first position on the first side outer surface inclines in the same direction as the first virtual line with respect to the tire radial direction, the second virtual line has a second angle of 36 to 40° with respect to the tire radial direction, the ground contact surface has a ground contact width which is a distance in the tire axial direction between the first ground contact end and the second ground contact end, The distance in the tire radial direction between the first grounding end and the tire equator is 2% to 6% of the grounding width. Pneumatic tire.

[0058] [Invention 2] The pneumatic tire according to Invention 1, having a tire cross-sectional width that is 6 mm or more greater than the maximum width in the rim width direction of the standard rim.

[0059] [Invention 3] The profile includes a first bead outer surface of a bead portion located inside the first side outer surface in the tire radial direction. The pneumatic tire according to Invention 1 or 2, wherein the distance in the tire radial direction between the first rim end, which is the end on the first grounding end side of the standard rim, and the first bead outer surface is 3 mm or less.

[0060] [Invention 4] It has a mold parting line between a tread mold for molding the tread portion and a side mold for molding the sidewall portion. The pneumatic tire according to any one of Inventions 1 to 3, wherein the mold parting line includes a stepped portion having a height of 0.4 mm or less.

[0061] [Invention 5] On the first side outer surface, a second position that is 25% of the tire cross-sectional height away from the tire equator in the inner side in the tire radial direction and a third position that is 19 mm away from the tire equator in the inner side in the tire radial direction are defined. The pneumatic tire according to Invention 4, wherein the stepped portion is located between the second position and the third position.

[0062] [Invention 6] On the first side outer surface, a fourth position located inside the virtual intersection of the first virtual line and the second virtual line in the tire radial direction is defined. The pneumatic tire according to Invention 5, wherein the first position is an intermediate position in the tire radial direction between the second position and the fourth position.

[0063] [The present invention 7] The mounting orientation on the vehicle is specified, The first grounding end is located outside the vehicle when mounted on the vehicle, and the pneumatic tire according to any one of the first to sixth aspects of the present invention.

Explanation of reference numerals

[0064] 1 Pneumatic tire 3 Tread portion 3a Ground contact surface 4A First shoulder circumferential groove 5A First shoulder land portion 6a First side outer surface

Claims

1. A pneumatic tire, having a profile defined on an outer surface in a tire meridian cross-section in a normal state which is a non-loaded state where it is mounted on a standard rim and adjusted to a standard internal pressure, wherein the profile includes a ground contact surface of a tread portion extending from a first ground contact end to a second ground contact end and a first side outer surface of a sidewall portion extending inward in the tire radial direction from the first ground contact end, wherein a first position is defined on the first side outer surface, which is at a distance of 15% of the tire cross-sectional height from the tire equator of the ground contact surface inward in the tire radial direction, wherein the tread portion has a first shoulder circumferential groove extending in the tire circumferential direction on the most first ground contact end side between the tire equator and the first ground contact end, and a first shoulder land portion defined by the first shoulder circumferential groove and the first ground contact end, wherein a first virtual line, which is a tangent line at an intermediate position in the tire axial direction of the first shoulder land portion, inclines inward in the tire radial direction toward the outside in the tire axial direction, wherein the first virtual line has a first angle of 74 to 80° with respect to the tire radial direction, wherein the first side outer surface inclines in the same direction as the first virtual line with respect to the tire radial direction, with a second virtual line, which is a tangent line at the first position, wherein the second virtual line has a second angle of 36 to 40° with respect to the tire radial direction, wherein the ground contact surface has a ground contact width which is a distance in the tire axial direction between the first ground contact end and the second ground contact end, wherein a distance in the tire radial direction between the first ground contact end and the tire equator is 2% to 6% of the ground contact width, A pneumatic tire.

2. The pneumatic tire according to claim 1, having a tire cross-sectional width that is 6 mm or more greater than the maximum width in the rim width direction of the standard rim.

3. wherein the profile includes a first bead outer surface of a bead portion located inward in the tire radial direction of the first side outer surface, wherein a distance in the tire radial direction between a first rim end, which is an end on the first ground contact end side of the standard rim, and the first bead outer surface is 3 mm or less. The pneumatic tire according to claim 1 or 2.

4. having a mold parting line between a tread mold for molding the tread portion and a side mold for molding the sidewall portion, wherein the mold parting line includes a stepped portion having a height of 0.4 mm or less. The pneumatic tire according to claim 1 or 2.

5. On the outer surface of the first side, a second position is defined at a distance of 25% of the tire section height from the tire equator toward the inner side in the tire radial direction, and a third position is defined at a distance of 19 mm from the tire equator toward the inner side in the tire radial direction. The stepped portion is located between the second position and the third position. The pneumatic tire according to claim 4.

6. On the outer surface of the first side, a fourth position is defined inside the virtual intersection of the first virtual line and the second virtual line in the tire radial direction. The first position is an intermediate position in the tire radial direction between the second position and the fourth position. The pneumatic tire according to claim 5.

7. The mounting orientation on the vehicle is specified. The first grounding end is located outside the vehicle when mounted on the vehicle. The pneumatic tire according to claim 1 or 2.

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