pneumatic tires

Abstract

Pneumatic tires (1), comprising: a cylindrical ring-shaped structure (100) arranged around an axis of rotation (AX); a carcass section (120) including a rubber-coated cord, wherein at least one section of the carcass section (120) is arranged on an outside of the annular structure (100) in a direction parallel to the axis of rotation (AX); and a rubber layer including a tread section (10), wherein at least one section of the rubber layer is arranged on an outside of the annular structure (100) in a beam direction to the axis of rotation (AX), wherein the conditions SW / OD ≤ 0.30 1.0 ≤ BW / W ≤ 1.1 0.82 ≤ W / SW ≤ 0.90 are fulfilled, where SW is a total tire width and OD is a tire outer diameter, where W is a width of a ground contact area (G) of the tread section (10), and BW is a measure of the ring-shaped structure (100) in the direction parallel to the axis of rotation (AX).

Description

Technical field

[0001] The present invention relates to a passenger car pneumatic tire with lower fuel consumption. State of the art

[0002] To improve the fuel consumption of hybrid vehicles (HV), electric vehicles (EV), and similar vehicles, pneumatic tires with reduced rolling resistance are offered. Particularly in recent years, with increasing environmental awareness, there has been a growing demand for pneumatic tires designed for improved fuel efficiency.

[0003] As a means of reducing the rolling resistance of a pneumatic tire, a technology for reducing the air resistance around the tire by reducing the overall width (SW) and the forward projection area of ​​a pneumatic tire is known (see e.g. patent document 1). List of oppositions patent literature Patent document 1: WO 2011 / 135774 A1 Patent document 2: EP 2 565 054 A1 Patent document 3: EP 2 554 402 A1 Patent document 4: DE 10 2012 208 873 A1 Summary of the invention: Technical problem

[0004] However, the application of the aforementioned methods results in a pneumatic tire with a narrow overall width and therefore a narrow ground contact area. To achieve a certain load capacity, the outer diameter (OD) must then be increased. Consequently, the tire track length of such a pneumatic tire is relatively long.

[0005] While a pneumatic tire with a large tire footprint has significantly improved water drainage properties (WET behavior) due to its small ground contact width, lateral force (CF) and steering stability may decrease.

[0006] In light of the foregoing, an objective of the present invention is to provide a pneumatic tire that is able to reduce rolling resistance and improve the steering stability behavior which is reduced by the reduction of rolling resistance. Solution to the problem

[0007] A pneumatic tire will be provided to solve the aforementioned problems, and the pneumatic tire includes: a cylindrical ring-shaped structure arranged around an axis of rotation; a carcass section including a rubber-coated cord, wherein at least one section of the carcass section is arranged on the outside of the ring-shaped structure in a direction parallel to the axis of rotation; and A rubber layer including a tread section, wherein at least one section of the rubber layer is arranged on an outer surface of the annular structure in a radial direction relative to the axis of rotation. For such a pneumatic tire, the following conditions apply: SW / OD≤0.30 1.0≤BW / W≤1.1 0.82≤W / SW≤0.90 fulfilled, where SW is an overall tire width and OD is a tire outer diameter, where W is a width of a ground contact area of ​​the tread section, and BW is a measure of the ring-shaped structure in the direction parallel to the axis of rotation.

[0008] A ground contact surface of the running surface section and an outer surface of the ring-shaped structure, which points outwards in the direction of the beam with respect to the axis of rotation, are preferably parallel to the axis of rotation.

[0009] Preferably, 0.14 × (OD - RD) / 2SW + 0.65 ≤ W / SW ≤ 0.14 × (OD - RD) / 2SW + 0.76 is satisfied, where W is a width of a ground contact area of ​​the tread section and RD is a rim diameter of the tire.

[0010] The ring-shaped structure preferably includes a large number of through holes.

[0011] The ring-shaped structure is preferably formed by a strip-shaped metal plate, the end sections of which are welded together, and the requirements 150 GPa ≤ E ≤ 250 GPa, and 0.2 mm ≤ Tb ≤ 0.8 mm are preferably met, where E is the Young's modulus of the metal and Tb is the thickness of the plate.

[0012] The rubber layer preferably comprises a main groove formed in the tread section, which runs around the axis of rotation, and an inner surface which points in a direction opposite to the ground contact surface of the tread section, and 0.05 ≤ Tu / T1 ≤ 0.15 is preferably fulfilled, wherein T1 represents a first thickness of the rubber layer, which is a distance measure from the ground contact surface of the tread section to the inner surface, and Tu is a second thickness of the rubber layer, which is a distance measure from a lower surface of the main groove to the inner surface.

[0013] The rubber layer preferably comprises a narrow groove designed to surround the axis of rotation in an edge region which includes an edge section of the ground contact area of ​​the tread section in the direction parallel to the axis of rotation; a center point of the edge region in the direction parallel to the axis of rotation is preferably aligned with the edge section of the ground contact area, and DW = 0.1W is preferably satisfied, where W is the width of a ground contact area of ​​the tread section and DW is a width of the edge section.

[0014] The ring-shaped structure preferably comprises a recessed and projecting section on at least one section of the end sections of the ring-shaped structure in the direction parallel to the axis of rotation.

[0015] Preferably, the grooves in the tread section form an asymmetrical pattern, and the ground contact area is preferably designed such that 10% ≤ GR ≤ 25%, GRo < GRi, and 0.1 ≤ (GRi - GRo) / GR ≤ 0.6 are satisfied, where GR represents a groove area ratio in the ground contact area of ​​the tread section, GRi a groove area ratio in an inner tire area Ai, and GRo a groove area ratio in an outer tire area Ao, wherein the inner tire area Ai, when a pneumatic tire is mounted on a vehicle, represents an area within the ground contact area on a vehicle side of a tire equator line, and the outer tire area Ao, when a pneumatic tire is mounted on a vehicle, represents an area within the ground contact area on a side opposite the vehicle side of the tire equator line.

[0016] A plurality of transverse grooves running perpendicular to a tire circumference direction are preferably provided in the tread section, and 1.1 ≤ GRLi / GRLo ≤ 1.9 is preferably fulfilled, where GRL represents a groove area ratio of the transverse grooves in the ground contact area, GRLo a groove area ratio of the transverse grooves in the outer tire area Ao and GRLi a groove area ratio of the transverse grooves in the inner tire area Ai.

[0017] The transverse grooves are preferably arranged at intervals in the circumferential direction of the tire, and 1 < Pi / Po ≤ 2 is preferably fulfilled, where Pi represents a number of transverse grooves arranged in the inner tire area Ai, and Po represents a number of transverse grooves arranged in the outer tire area Ao around a complete circumference of the tread section of the pneumatic tire.

[0018] A longitudinal groove extending in the circumferential direction of the tire is preferably arranged in an outer inner tire area Aoi and not in an outer tire area Aoo, wherein the outer inner tire area Aoi represents an area on the side of the tire equator line of the tire outer area Ao with a width corresponding to 25% of a ground contact width, and the outer tire outer area Aoo represents an area of ​​the tire outer area Ao excluding the outer inner tire area Aoi.

[0019] An inner longitudinal groove, which is a longitudinal groove running in the circumferential direction of the tire, is preferably provided in the inner tire area Ai; an outer longitudinal groove, which is a longitudinal groove running in the circumferential direction of the tire, is preferably provided in the outer tire area Ao; and 1 ≤ GRBi / GRBo ≤ 2 is preferably satisfied, wherein GRBi represents a groove area ratio of the inner longitudinal groove in the inner tire area Ai and GRBo represents a groove area ratio of the outer longitudinal groove in the outer tire area Ao.

[0020] Advantageous effects of the invention: The pneumatic tire according to the present invention is able to reduce rolling resistance and improve the steering stability behavior, which is reduced by the reduction of rolling resistance.

[0021] The accompanying drawings and the description of preferred embodiments of this invention will further facilitate understanding of this invention. Brief description of the drawings Fig. Figure 1 is a meridian cross-sectional view of a pneumatic tire according to a first embodiment. Fig. Figure 2 is an enlarged view of a tire section according to the first embodiment. Fig. Figure 3 is a diagram showing an example of a carcass section according to the first embodiment. Fig. Figure 4 is a diagram showing an example of a tread section according to the first embodiment. Fig. Figure 5 is a diagram illustrating an example of a method for producing a ring-shaped structure according to the first embodiment. Fig.Figure 6 is a diagram illustrating an example of the process for producing the ring-shaped structure according to the first embodiment. Fig. Figure 7 is a diagram illustrating an example of the process for producing the ring-shaped structure according to the first embodiment. Fig. Figure 8 is a diagram showing an example of an area around a welded section of the ring-shaped structure according to the first embodiment. Fig. Figure 9 is a diagram that schematically illustrates an example of a ring-shaped structure according to a second embodiment. Fig. Figure 10 is a diagram that schematically illustrates an example of a ring-shaped structure according to a third embodiment. Fig. Figure 11 is a diagram that schematically illustrates an example of a ring-shaped structure according to a fourth embodiment. Fig.Figure 12 is a diagram that schematically illustrates an example of a ring-shaped structure according to a fifth embodiment. Fig. Figure 13 is a diagram that schematically illustrates an example of a ring-shaped structure according to a sixth embodiment. Fig. Figure 14 is a unfolded view showing a section of a tread section of the pneumatic tire according to a seventh embodiment. Fig. Figure 15 is a unfolded view showing a section of a tread section of the pneumatic tire according to a modified example of the seventh embodiment. Fig. Figure 16 is a unfolded view showing a section of a tread section of a pneumatic tire of a prior art example. Description of embodiments: First embodiment

[0022] The following is an explanation of a pneumatic tire 1 according to embodiments of the present invention with reference to the drawings. Fig. Figure 1 is a meridian cross-sectional view of the pneumatic tire 1 according to the embodiment of the present invention. Fig. Figure 2 is an enlarged meridional cross-sectional view of a section of the pneumatic tire 1 according to the embodiment of the present invention. It should be noted that the pneumatic tire 1 according to the present embodiment has a meridional cross-sectional shape similar to that of a pneumatic tire according to the prior art. Here, the meridional cross-sectional shape of the pneumatic tire refers to the cross-sectional shape of the pneumatic tire as it appears on a plane perpendicular to the equatorial plane of the tire CL.

[0023] The description below uses an XYZ Cartesian coordinate system and describes the positional relationship of each section with respect to this system. Any direction in a horizontal plane is defined as an X-axis direction, any direction perpendicular to the X-axis direction in the horizontal plane as a Y-axis direction, and any direction perpendicular to each of the X-axis directions and the Y-axis direction as a Z-axis direction. Additionally, the rotation (tilt) directions about the X-axis, Y-axis, and Z-axis are defined as θX, θY, and θZ directions, respectively.

[0024] The pneumatic tire 1 is ring-shaped. When the tire 1 is inserted, its interior is filled with air. In the following description, the pneumatic tire 1 will also simply be referred to as tire 1.

[0025] In the present embodiment, a rotation axis (a central axis) AX of a tire 1 runs parallel to the Y-axis. The Y-axis direction is a vehicle width direction or a width direction of the tire 1. The rotation direction (equivalent to the θY direction) of the tire 1 (rotation axis AX of the tire 1) can also be referred to as the circumferential direction. The X-axis direction and the Z-axis direction are radial directions with respect to the rotation axis (central axis) AX. The radial direction with respect to the rotation axis (central axis) AX can also be referred to as the radial direction. The ground on which the tire 1 rolls (travels) is approximately parallel to an XY plane.

[0026] Fig. 1 and Fig. Figure 2 shows views of tire 1 in meridian cross-sections through which the axis of rotation AX passes. As in Fig. 1 and Fig.As shown in Figure 2, the tire 1 has a cylindrical ring-shaped structure 100 around the axis of rotation (central axis) AX; a carcass section 120, of which at least one section is arranged on the outside of the ring-shaped structure 100 in the Y-axis direction; a tread rubber layer 11 with a tread section 10, of which at least one section is arranged on the outside of the ring-shaped structure 100 in the direction of travel with respect to the axis of rotation AX; and sidewall sections 3 that protect the carcass section 120.

[0027] The ring-shaped structure 100 is a cylindrical element. The ring-shaped structure 100 is an element (a reinforcing element) that maintains the shape of the tire 1. The ring-shaped structure 100 has an outer surface 100A and an inner surface 100B. The outer surface 100A faces outwards in the direction of the beam with respect to the axis of rotation AX. The inner surface 100B faces in the opposite direction to the outer surface 100A. The outer surface 100A and the inner surface 100B are each parallel to the Y-axis (axis of rotation AX).

[0028] Carcass section 120 is a component (reinforcing element) that forms the frame of the tire 1. Carcass section 120 contains a cord (reinforcing material). The cord of carcass section 120 can be referred to as carcass cord. Carcass section 120 consists of a cord layer (a layer of reinforcing material) including the cord. Carcass section 120 acts as a pressure vessel when the tire 1 is filled with gas (air).

[0029] Fig. Figure 3 is an enlarged view of a section of carcass section 120. As in Fig.As shown in Figure 3, carcass section 120 has a rubber 120R and cords 120F covered with rubber 120R. The cords 120F contain organic fibers. The rubber 120R covering the cords 120F can be referred to as coating rubber or covering rubber. It should be noted that carcass section 120 may contain polyester cords 120F, polyamide cords 120F containing an aliphatic backbone, polyamide cords 120F containing exclusively an aromatic backbone, or rayon cords 120F.

[0030] As in Fig.As shown in Figure 2, at least one section of the carcass section 120 is arranged on the outside of the annular structure 100 in the Y-axis direction. In the present embodiment, at least one section of the carcass section 120 is arranged on the side of the inner surface 100B of the annular structure 100. At least one section of the carcass section 120 is arranged on the inside of the annular structure 100 in the direction of rotation with respect to the AX axis. At least one section of the carcass section 120 is arranged such that it faces the inner surface 100B of the annular structure 100. The carcass section 120 comprises an outer surface 120A that faces the inner surface 100B of the annular structure 100. The inner surface 100B of the annular structure 100 contacts at least one section of the outer surface 120A of the carcass section 120. The annular structure 100 and the carcass section 120 are connected to each other.

[0031] The carcass section 120 is supported by bead sections 2. The bead sections 2 are arranged on both sides of the carcass section 120 in the Y-axis direction. The carcass section 120 is folded back at the bead sections 2. The bead sections 2 are elements (reinforcing elements) that fix both ends of the carcass section 120 in the Y-axis direction. The bead sections 2 fix the tire 1 to the rim of a wheel. The bead sections 2 are a bundle of steel wires. It should be noted that the bead sections 2 can consist of a bundle of carbon steel wires. In the present embodiment, an inner liner 140 is provided on the inside of the carcass section 120. The inner liner 140 prevents the gas inside the tire 1 from escaping.

[0032] The tread rubber layer 11 encompasses the carcass section 10. The tread rubber layer 11 protects the carcass section 120. The tread rubber layer 11 is a cylindrical element. At least one section of the tread rubber layer 11 is arranged around the carcass section 120. The tread rubber layer 11 has an outer surface 11A and an inner surface 11B. The outer surface 11A faces outwards in the direction of the beam with respect to the axis of rotation AX. The inner surface 11B faces in the opposite direction to the outer surface 11A. The outer surface 11A and the inner surface 11B are each parallel to the Y-axis (axis of rotation AX).

[0033] The outer surface 11A is a ground contact surface that makes contact with the ground. The tread rubber layer 11 comprises the ground contact surface (outer surface) 11A, which comes into contact with the ground, main grooves 40 in at least one section of the ground contact surface 11A, which surround the axis of rotation AX, and the inner surface 11B, which points in the opposite direction to the ground contact surface 11A. Under rainy conditions and the like, the main grooves 40 can channel water (water drainage properties) away from between the tire 1 and the ground as the tire 1 rolls over the water-covered ground. In the present embodiment, the main groove 40 refers to a groove arranged in the tread rubber layer 11 with a depth of 2.5 mm or more and a width of 4 mm or more.

[0034] The tread rubber layer 11 contains natural rubber, synthetic rubber, carbon black, sulfur, zinc oxide, a crack-preventing material, a vulcanization accelerator and an anti-aging agent.

[0035] At least one section of the tread rubber layer 11 is arranged on the side of the outer surface 100A of the annular structure 100. At least one section of the tread rubber layer 11 is arranged on the outside of the annular structure 100 in the direction of the beam with respect to the axis of rotation AX. At least one section of the tread rubber layer 11 is arranged on the outer surface 100A of the annular structure 100. At least one section of the inner surface 11B of the tread rubber layer 11 faces the outer surface 100A of the annular structure 100. The outer surface 100A of the annular structure 100 contacts at least one section of the inner surface 11B of the tread rubber layer 11. The annular structure 100 and the tread rubber layer 11 are connected to each other.

[0036] In the present embodiment, the axis of rotation AX, the outer surface 100A of the ring-shaped structure 100, the inner surface 100B of the ring-shaped structure 100, the ground contact surface 11A of the tread rubber layer 11 and the inner surface 11B of the tread rubber layer 11 are essentially parallel to each other.

[0037] It should be noted that in the present embodiment, the ground contact surface 11A and the outer surface 100A are parallel, which also means that the distance between the ground contact surface 11A and the outer surface 100A is the same in the direction of the circumference and width of the tire 1. Furthermore, the ground contact surface 11A and the outer surface 100A are parallel, which means that the difference between the maximum and minimum distance between the ground contact surface 11A and the outer surface 100A in the direction of the circumference and width of the tire 1 is 0.3 mm or less. The ratios between the ground contact area 11A and the inner surface 11B, the ratios between the ground contact area 11A and the inner surface 100B, the ratios between the inner surface 11B and the outer surface 100A, the ratios between the inner surface 11B and the inner surface 100B, and the ratios between the outer surface 100A and the inner surface 100B are also similar.

[0038] The sidewall sections 3 protect the carcass section 120. The sidewall sections 3 are arranged on both sides of the tread rubber layer 11 in the Y-axis direction.

[0039] In the present embodiment, SW / OD≤0.30 fulfilled, where SW indicates the overall tire width and OD indicates the tire's outer diameter.

[0040] In the present embodiment, it is further 1.0≤ BW / W≤1.1 fulfilled, where W specifies a ground contact width corresponding to the width of the ground contact area of ​​the ground contact surface 11A, and BW represents a dimension (width) of the ring-shaped structure 100 in the Y-axis direction parallel to the rotation axis AX.

[0041] In the present embodiment, it is further 0.82≤W / SW≤0.90 fulfilled.

[0042] The tire width SW refers to the overall width of the tire 1, in other words, the maximum dimension of the tire 1 in the Y-axis direction parallel to the axis of rotation AX. In the present embodiment, the tire width SW refers to the distance between the furthest section (surface) on the +Y side of the sidewall section 3, which is located on the +Y side of the tread rubber layer 11, and the furthest section (surface) on the -Y side of the sidewall section 3, which is located on the -Y side. For example, if a design (marking, component) is arranged on the surface of the sidewall section 3, which is located on the +Y side of the tread rubber layer 11 and projects from the surface of this sidewall section 3 to the +Y side, the furthest section on the +Y side of the sidewall section 3 comprises the end section of the design.Similarly, in the case of a design arranged on the surface of the sidewall section 3 located on the -Y-side of the tread rubber layer 11 projecting from the surface of this sidewall section 3 to the -Y-side, the section furthest away from the -Y-side of the sidewall section 3 comprises the end section of the design. The tire width SW specifically refers to the width from one sidewall section 3 to the other, including any designs on the sidewall sections 3, when the tire 1 is mounted on a rim, inflated to 230 kPa (so that the dimensions of tire 1 are predetermined), and unloaded.

[0043] The tire outer diameter OD refers to the outer diameter of tire 1 when tire 1 is mounted on a rim, inflated to 230 kPa (so that the dimensions of tire 1 are predetermined) and unloaded.

[0044] The ground contact width W refers to the width of the ground contact area of ​​the ground contact surface 11A; in other words, a maximum dimension (maximum width) of the ground contact area in the Y-axis direction parallel to the axis of rotation AX. The ground contact area of ​​the ground contact surface 11A refers to the portion of the ground contact surface that comes into contact with the ground when the tire 1 is mounted on a rim and inflated to 230 kPa (so that the dimensions of tire 1 are predetermined), and a load corresponding to 80% of the load capacity is applied.

[0045] If formula (1A) is satisfied, in other words, if the tire width SW is reduced and thus the forward contact patch is smaller, the air resistance around the tire 1 is reduced. As a result, fuel consumption is improved. Furthermore, in the present embodiment, since the tire 1 has the ring-shaped structure 100, a reduction in steering stability due to the reduced tire width SW is prevented or minimized.

[0046] In the present embodiment, due to the parallelism of the ground contact surface 11A and the outer surface 100A to the axis of rotation AX, the stiffness distribution in the tread rubber layer 11 is uniform in the lateral direction. Consequently, localized deformation of the tread rubber layer 11 is prevented or minimized, thus reducing rolling resistance. Fuel consumption is improved accordingly.

[0047] Furthermore, if formula (2A) is satisfied, the rolling resistance of tire 1 can be reduced and favorable steering stability achieved. For example, if BW / W is greater than 1.1, steering stability may be reduced. If BW / W is less than 0.9, the bending deformation at the end sections of the ground contact area of ​​the ground contact surface 11A is increased. Consequently, the rolling resistance is increased, and thus fuel consumption may not be improved.

[0048] Furthermore, if formula (3A) is satisfied, the rolling resistance of tire 1 can be reduced and favorable steering stability can be achieved. If, for example, W / SW is greater than 0.90, the ground contact area is larger, thus increasing the deformation of the ground contact area 11A. As a result, the rolling resistance of tire 1 is not sufficiently reduced. If W / SW is less than 0.65, steering stability is reduced.

[0049] In the present embodiment, it is further 0.14×(OD−RD) / 2SW + 0.65≤W / SW≤0.14×(OD−RD) / 2SW + 0.76 fulfilled, where RD represents a rim diameter of the tire (inner diameter).

[0050] The aspect ratio of tire 1 is (OD - RD) / 2SW. Formula (4A) shows that W / SW varies depending on the aspect ratio. To maintain rolling resistance and also efficiently improve steering stability, the ground contact width W is specified according to the aspect ratio in the present embodiment. The tire 1 with a low value of (OD - RD) / 2SW (low aspect ratio) exhibits superior steering stability compared to the tire 1 with a high value of (OD - RD) / 2SW (high aspect ratio). Thus, rolling resistance can be maintained by appropriately reducing the ground contact width W, and a reduction in steering stability can also be prevented or minimized.

[0051] In the present embodiment, it is further 0.05≤Tu / T1≤0.15 fulfilled, where T1 represents a thickness of the tread rubber layer 11, specifically a distance measure from the ground contact surface 11A to the inner surface 11B, and Tu represents a thickness of the tread rubber layer 11, specifically a distance measure from a lower surface 40B of the main groove 40 to the inner surface 11B.

[0052] In particular, 0.08≤Tu / T1≤0.12 fulfilled.

[0053] Thickness T1 and thickness Tu are dimensions in the Z-axis direction perpendicular to the rotation axis AX. In other words, thickness T1 and thickness Tu are vertical thicknesses.

[0054] In the present embodiment, the rigidity of the tire 1 is increased by the ring-shaped structure 100. Accordingly, even if the thickness Tu is small relative to the thickness T1 of the tread rubber layer 11, as shown in formula (5A), cracking in the tread rubber layer 11 is prevented or minimized. Furthermore, by specifying the thickness T1 and the thickness Tu of the tread rubber layer 11 as shown in formula (5A), the water runoff properties can be reduced while simultaneously maintaining favorable steering stability. Thus, for example, the desired dynamic properties of tire 1, such as cornering behavior, can be achieved. Rolling resistance can also be effectively reduced.

[0055] It should be noted that in the present embodiment, the annular structure 100 can be coated with either a rubber layer, including the tread rubber layer 11 or the sidewall sections 3, a surface pretreatment material, and an adhesive. In other words, in the tire 1 according to this embodiment, the annular structure 100 is not exposed.

[0056] Fig.Figure 4 shows a view (unfolded view) illustrating an example of the ground contact area 11A of the tire 1. The tread rubber layer 11 includes an edge region ER, which encompasses an edge section Eg of the ground contact area of ​​the ground contact surface 11A in the Y-axis direction parallel to the axis of rotation AX. The center position of the edge region ER is aligned with the edge region Eg of the ground contact surface in the Y-axis direction parallel to the axis of rotation AX. The tread rubber layer 11 includes narrow grooves 30 in the edge region ER. The narrow grooves 30 are formed circumferentially around the axis of rotation AX. The narrow grooves 30 are narrower than the main grooves 40. The width of the main grooves 40 and the narrow grooves 30 is a dimension in the Y-axis direction. In the present embodiment, the narrow groove 30 refers to a groove arranged in the tread rubber layer 11 with a depth of 2 mm to 4 mm (both values ​​inclusive).

[0057] In the present embodiment, DW=0.1 W fulfilled, where DW represents a width of the boundary region ER.

[0058] If tire 1 is provided with the ring-shaped structure 100, the load on the tread rubber layer 11 in or near the edge region Rg may increase. Accordingly, the rolling resistance can be reduced and fuel consumption improved by arranging the narrow grooves 30 parallel to the tire equator line CL in the edge region ER, which includes the edge region Rg, as shown in formula (6A).

[0059] Next, an example of a method for producing the ring-shaped structure 100 according to the present embodiment is described. Fig. 5, Fig. 6 and Fig. Figure 7 shows views of the example of the process for producing the ring-shaped structure 100. As in Fig.As shown in Figure 5, a strip-shaped (rectangular) metal plate 20 is prepared. The plate 20 includes projections 22 that extend transversely from both sides (see arrow S) and are arranged longitudinally at a first end section 20TL and a second end section 20TL (see arrow C).

[0060] Then, as in Fig.Figure 6 shows the end sections 20TL of the plates 20 joined longitudinally and then welded together. The end section 20TL is preferably oriented perpendicular to the longitudinal direction of plate 20. Welding methods that can be used include gas welding (oxygen-acetylene welding), arc welding, tungsten inert gas (TIG) welding, plasma welding, MIG welding (metal inert gas welding), electroslag welding, electron beam welding, laser welding, ultrasonic welding, and the like. Thus, the ring-shaped structure 100 can be easily produced by welding the end sections 20TL of the plates 20 together. It should be noted that after welding, the plate 20 can be subjected to either heat treatment or rolling. Such treatment improves the strength of the ring-shaped structure 100. For example,When using precipitation-hardened stainless steel, the heat treatment includes heating at 500°C for 60 minutes. However, the heat treatment conditions are not limited to the above and can be modified as needed to achieve the desired properties.

[0061] Next, as in Fig.Figure 7 shows that the protrusions 22 present after welding are removed. This produces the ring-shaped structure 100. It should be noted that if the ring-shaped structure 100 is to be heat-treated, the heat treatment should preferably be carried out after the removal of the protrusions 22. Since the heat treatment strengthens the ring-shaped structure 100, the protrusions 22 are easier to remove before the heat treatment and the like. After the ring-shaped structure 100 has been manufactured, an unvulcanized tread rubber layer 11 is applied around the outside of the ring-shaped structure 100. The carcass section 120 is also attached to the ring-shaped structure 100. This creates a tire blank. The tire blank is then vulcanized, and the tread rubber layer 11 and the ring-shaped structure 100 are bonded together to form the tire 1.

[0062] Fig.Figure 8 is a side view of the area around the welded section 201 of the annular structure 100, which is joined by welding. As shown in Fig. As shown in Figure 8, the welded section 201 has a greater thickness than the thickness Tb of the sections surrounding the welded section 201. The thickness Tb of the surrounding sections corresponds to the thickness Tb of the plate 20. The thickness Tb is the thickness of the annular structure 100 in sections, excluding the sections in which the welded section 201 is formed. The thickness Tb also denotes the distance from the outer surface 100A to the inner surface 100B.

[0063] As described above, the ring-shaped structure 100 is manufactured using a metal material. In the present embodiment, 150 GPa≤E≤250 GPa. fulfilled, where E represents the elastic modulus (Young's modulus) of the metal material from which the ring-shaped structure 100 (plate 20) is made.

[0064] In particular, 170 GPa≤E≤210 GPa fulfilled.

[0065] In the present embodiment, it is further 0.2 mm≤Tb≤0.8 mm. fulfilled, where Tb represents the thickness of plate 20.

[0066] In particular, 0.4 mm≤Tb≤0.6 mm. fulfilled.

[0067] In this embodiment, the tensile strength of the metal material of the ring-shaped structure 100 is between 900 MPa and 1800 MPa (both values ​​inclusive).

[0068] Tire 1, which fulfills formulas (7A) and (8A), exhibits reduced rolling resistance and unchanged service life. Steering stability is also improved. Since tire 1 also has a large outer diameter, the ring-shaped structure 100 with its comparatively high rigidity is preferentially used.

[0069] With a modulus of elasticity E of less than 150 GPa, the deformation of the ground contact area of ​​the tread rubber layer 11 increases; thus, it is difficult to reduce rolling resistance. With a modulus of elasticity E of more than 250 GPa, the flexural stiffness increases, thereby reducing the area of ​​the ground contact zone and increasing the ground contact pressure. Consequently, it is difficult to reduce rolling resistance. Furthermore, the effect of improving steering stability is diminished due to the insufficient area in the ground contact zone.

[0070] With a thickness Tb of less than 0.2 mm, the deformation of the ground contact area of ​​the tread rubber layer 11 increases; this makes it difficult to reduce rolling resistance. Furthermore, reducing the thickness Tb may not result in sufficient service life. With a thickness Tb of more than 0.8 mm, the flexural stiffness increases, thus reducing the area of ​​the ground contact zone and increasing the ground contact pressure. Consequently, it is difficult to reduce rolling resistance. Moreover, the effect of improving steering stability is diminished due to the insufficient area in the ground contact zone.

[0071] The ring-shaped structure 100 can be made of at least one of the following materials: spring steel, high-strength steel, stainless steel, and titanium. The titanium may be a titanium alloy. In the present embodiment, the ring-shaped structure 100 contains stainless steel. Stainless steel is highly corrosion-resistant. The values ​​of the modulus of elasticity E and the tensile strength described above can be achieved with stainless steel.

[0072] If the ring-shaped structure 100 is manufactured from stainless steel, at least one of the materials classified according to Japanese Industrial Standard (JIS) G4303 can be used: martensitic stainless steel, ferritic stainless steel, austenitic stainless steel, austenitic-ferritic two-phase stainless steel, and precipitation-hardenable stainless steel. Using such a stainless steel will result in a ring-shaped structure 100 with superior elongation strength and toughness.

[0073] Next, an embodiment of the present invention is described. The inventors of this invention manufactured tires 1 according to the embodiment described above and carried out evaluation tests on the tires 1 with regard to the fuel economy index and steering stability. In addition, tires according to the prior art example and comparative example 1 were manufactured, and evaluation tests were also carried out on the tires with regard to the fuel economy index and steering stability.

[0074] The evaluation test for the fuel economy index was carried out by mounting the tires on a compact car with front-wheel drive and an engine displacement of 1500 cm³. 3The test was carried out, and the vehicle completed 50 laps on a 2 km test track at a speed of 100 km / h. The improvement in fuel efficiency was measured against the fuel consumption rate of the tires from the comparison example (reference tires), with the comparison example assigned a reference value of 100. Higher index values ​​indicate better fuel consumption.

[0075] The steering stability evaluation test was carried out by mounting the tires on a standard rim and then mounting the tires on a passenger car with an engine displacement of 1500 cm³. 3The test was conducted in which the vehicle completed three laps on a 1 km test track with lane changes. The driving feel was evaluated by three experienced drivers. The average score for each tire was expressed as an index value, based on a reference value of 100 for the average evaluation score of the tire (reference tire) for driving feel from the comparison example. Higher scores indicate superior steering stability.

[0076] Table 1 shows the results of the evaluation tests for the tire according to the embodiment of this invention and for the tires (reference tires) according to the prior art example and comparative example 1. In the prior art example, the SW / OD value was 0.32. In comparative example 1, the SW / OD value was 0.24. In the embodiment, the SW / OD value was 0.24. [Table 1-I] (Table 1) Example of the state of the art Comparative example 1 Example of implementation SW(mm) 205 165 165 aspect ratio 55 55 55 RD (inch) 16 20 20 OD (mm) 632 695 695 SW / OD 0,32 0,24 0,24 Ring-shaped structure Unavailable Unavailable Available Ground contact area and ring-shaped structure parallel to the axis of rotation? - - Yes BW / W 0,98 0,98 1,00 W / SW 0,82 0,82 0,87 Fuel economy index 100 101,5 102,5 Steering stability 100 90 105

[0077] In Table 1, the "absence" of the "ring-shaped structure" means that the belt layer is a conventional belt layer with arranged cords. The "presence" of the "ring-shaped structure" means that the belt layer is the ring-shaped structure 100 according to this invention. In other words, in Table 1, the tires according to the prior art example and Comparative Example 1 did not include the ring-shaped structure 100 according to this invention. The tire according to the embodiment includes the ring-shaped structure 100 according to this invention. The tires of the prior art example and Comparative Example 1 included a typically used belt layer with arranged cords instead of the ring-shaped structure 100.

[0078] In Table 1, answering "Yes" to the question "Ground contact area and ring-shaped structure parallel to the axis of rotation?" means that the ground contact area 11A of the tread section 10 and the outer surface 100A of the ring-shaped structure 100 are parallel to the axis of rotation AX. Answering "No" to the question "Ground contact area and ring-shaped structure parallel to the axis of rotation?" means that the ground contact area 11A of the tread section 10 and the outer surface 100A of the ring-shaped structure 100 are not parallel to the axis of rotation AX.

[0079] As shown in Table 1, formulas (2A), (3A) and (4A) were satisfied in the prior art example, but formula (1A) was not. Furthermore, the prior art example did not include the ring-shaped structure 100.

[0080] For comparison example 1, formula (1A), formula (2A), formula (3A) and formula (4A) were satisfied, however, the ring-shaped structure 100 was not provided.

[0081] Formulas (1A), (2A) and (3A) were fulfilled in the exemplary embodiment, however, formula (4A) was not fulfilled. Furthermore, in the exemplary embodiment, the ground contact surface 11A of the tread section 10 and the outer surface 100A of the ring-shaped structure 100 were parallel to the axis of rotation AX.

[0082] As shown in Table 1, the tire according to the embodiment had better fuel economy indices than the tires according to the prior art example and the comparative example 1.

[0083] As shown in Table 1, the tire according to the embodiment demonstrated better steering stability than the tire according to comparison example 1.

[0084] As shown in Table 1, the embodiment exhibited better fuel economy indices than the prior art example and the comparative example 1, in which the ring-shaped structure 100 was not present.

[0085] As shown in Table 1, the embodiment exhibited the same or better steering stability than the prior art example and Comparative Example 1, in which the ring-shaped structure 100 was not present.

[0086] As described above, according to this embodiment, the tires 1 provided with the ring-shaped structure 100, whose ratio of tire width SW to tire outer diameter OD is specified such that formula (1A) is satisfied, can reduce the rolling resistance of the tires 1 and thus improve fuel consumption. Furthermore, the tires 1 provided with the ring-shaped structure 100 can prevent or minimize a reduction in steering stability. Thus, according to this embodiment, it can be achieved that the tires 1 exhibit the desired dynamic properties.

[0087] Furthermore, in the present embodiment, due to the parallelism of the ground contact surface 11A and the outer surface 100A to the axis of rotation AX, the stiffness distribution in the tread rubber layer 11 is uniform in the lateral direction. Consequently, localized deformation of the tread rubber layer 11 is prevented or minimized, thus reducing rolling resistance. Fuel consumption is improved accordingly.

[0088] Furthermore, in the present embodiment, the ratio between the ground contact width W and the width BW of the ring-shaped structure 100 is predetermined such that formula (2A) is satisfied. As a result, the rolling resistance of the tire 1 is reduced, and thus improved steering stability can be achieved.

[0089] In the present embodiment, the ratio between the ground contact width W and the tire width SW is predetermined such that formula (3A) is satisfied. As a result, the rolling resistance of tire 1 is reduced, and thus improved steering stability can be achieved.

[0090] In the present embodiment, as shown in formula (4A), W / SW is varied depending on the aspect ratio (OD - RD) / 2SW of the tire 1. Consequently, the rolling resistance can be maintained and the steering stability effectively improved. Tire 1 with a low aspect ratio exhibits superior steering stability compared to tire 1 with a high aspect ratio. Therefore, the rolling resistance can be maintained by appropriately reducing the ground contact width W, and a reduction in steering stability can also be prevented or minimized.

[0091] Furthermore, according to this embodiment, the ratio between the thickness T1 and the thickness Tu of the tread rubber layer 11 is predetermined such that formula (5A) is satisfied. Consequently, if the thickness of the tread rubber layer 11 is suppressed, cracking in the tread rubber layer 11 can be prevented or minimized, and the desired dynamic properties of the tire 1 can be achieved.

[0092] According to this embodiment, the rolling resistance can be reduced by arranging the narrow grooves 30 parallel to the tire equator line CL in the edge region ER with the width DW, as shown in formula (6A), and thus fuel consumption can be improved.

[0093] Furthermore, according to this embodiment, the modulus of elasticity E and the thickness Tb of the ring-shaped structure 100 are specified such that formula (7A) and formula (8A) respectively are satisfied. As a result, the rolling resistance of tire 1 is reduced, and thus the service life of tire 1 is ensured. Second embodiment

[0094] A second embodiment is described. In the description below, sections identical or substantially equivalent to the embodiment described above are designated with the same reference numerals, and descriptions of these sections are either simplified or omitted. Examples of the ring-shaped structure are described in the embodiments described below.

[0095] Fig. Figure 9 is a perspective view illustrating an example of a ring-shaped structure 101 according to the present embodiment. As shown in Fig.As illustrated in Figure 9, the annular structure 101 includes a section with depressions and projections 50 at at least one end in the lateral direction (direction parallel to the axis of rotation AX) of the annular structure 101. The section with depressions and projections 50 is provided on each side of the annular structure 101 in the lateral direction. The projections of the section with depressions and projections 50 are tapered. The section with depressions and projections 50 forms a so-called saw blade shape. In the present embodiment, the dimension We of the section with depressions and projections 50 in the lateral direction is in the range of 5 mm to 40 mm, inclusive.

[0096] If at least one section of the tread rubber layer 11 is arranged on each side of the annular structure 101 in the width direction, the section with depressions and projections 50 can engage in the tread rubber layer 11. As a result, the connection between the annular structure 101 and the tread rubber layer 11 is strengthened.

[0097] Furthermore, the provision of the section with indentations and protrusions 50 prevents or minimizes a sudden change in stiffness at the end sections of the tire 1 in the lateral direction. This is particularly effective when the ring-shaped structure 101 has a narrow width.

[0098] The ring-shaped structure 101 is cylindrical and therefore deforms slightly in the direction of the beam relative to the axis of rotation AX (bending slightly in the direction of the Z-axis), but not in the direction parallel to the axis of rotation AX (high stiffness). Accordingly, the stiffness with respect to the direction parallel to the axis of rotation AX can be unbalanced. In the present embodiment, the ring-shaped structure 101 deforms slightly in the direction parallel to the axis of rotation AX due to the section with depressions and projections 50. This prevents or minimizes unbalanced stiffness. Third embodiment

[0099] A third embodiment is described. Fig. Figure 10 is a perspective view illustrating an example of a ring-shaped structure 102 according to the present embodiment. Fig.The ring-shaped structure 102 has an outer surface 102A, an inner surface 102B and a plurality of through holes 4 that penetrate the outer surface 102A and the inner surface 102B.

[0100] In the present embodiment, the through holes 4 are arranged with equal spacing between them in the width direction of the annular structure 102. Furthermore, the through holes 4 are arranged with equal spacing between them in the circumferential direction of the annular structure 102. The through holes 4 are arranged with the same density in both the width and circumferential directions of the annular structure 102.

[0101] In the present embodiment, at least one section of the tread rubber layer 11, which is bonded to the outer surface 102A of the annular structure 102, can contact the carcass section 120, which is bonded to the inner surface 102B of the annular structure 102 by means of the through holes 4. When the adhesive (the adhesive layer) is applied to at least one of the surfaces (inner surface 11B of the tread rubber layer 11 and / or outer surface 120A of the carcass section 120), at least one section of the inner surface 11B of the tread rubber layer 11 and the outer surface 120A of the carcass section 120 are bonded to each other by the adhesive (the adhesive layer) via the through holes 4.This strengthens both the connection between the tread rubber layer 11 and the ring-shaped structure 102 and the connection between the ring-shaped structure 102 and the carcass section 120, thus improving the service life of the tire 1.

[0102] Furthermore, the stiffness of the ring-shaped structure 102 is adjustable via the through-holes 4. For example, the stiffness of the ring-shaped structure 102 can be adjusted by changing the number or size of the through-holes 4. For example, the through-holes 4 prevent excessive cornering stiffness and thus improve steering stability. Fourth embodiment

[0103] A fourth embodiment is described. Fig. Figure 11 is a perspective view illustrating an example of a ring-shaped structure 103 according to the present embodiment. Fig.11 includes the ring-shaped structure 103, the section with depressions and projections 50, and the multitude of through holes 4. Referring to Fig. 9 described components and those with reference to Fig. The 10 described components can be combined in this way. Fifth embodiment

[0104] A fifth embodiment is described. Fig. Figure 12 is a perspective view illustrating an example of a ring-shaped structure 104 according to the present embodiment. Fig.The annular structure 104 includes a plurality of through holes 4. Furthermore, the annular structure 104 includes recesses 5. The recesses 5 can also be referred to as notched sections 5. The recesses 5 are provided on each side of the annular structure 104 in the width direction. The recesses 5 are arranged with a gap between them in the circumferential direction of the annular structure 104. If at least one section of the tread rubber layer 11 is arranged on each side of the annular structure 104 in the width direction, at least one section of the tread rubber layer 11 can be wedged in the recesses 5. This strengthens the bond between the annular structure 104 and the tread rubber layer 11. Sixth embodiment

[0105] A sixth embodiment is described. Fig.Figure 13 is a perspective view illustrating an example of a ring-shaped structure 105 according to the present embodiment. Fig.13 The annular structure 105 includes the plurality of through holes 4. Furthermore, the through holes 4 are arranged with equal intervals between them in the circumferential direction of the annular structure 105. The through holes 4 are also arranged with a space between them in the width direction of the annular structure 105. Finally, the through holes 4 are arranged with unequal spaces between them in the width direction of the annular structure 105. In the present embodiment, the space between the through holes 4 located near the edges of the annular structure 105 is smaller in the width direction than the space between the through holes 4 in a central region of the annular structure 105.It should be noted that in the width direction of the ring-shaped structure 105, the space between the through holes 4 arranged near the edges of the ring-shaped structure 105 may be larger than the space between the through holes 4 in the middle area of ​​the ring-shaped structure 105.

[0106] In the present embodiment, the connection between the tread rubber layer 11 and the ring-shaped structure 105 and the connection between the ring-shaped structure 105 and the carcass section 120 can also be reinforced by means of the through holes 4. Seventh embodiment

[0107] A seventh embodiment is described. In the description below, sections identical or substantially equivalent to those described above are designated with the same reference numerals, and descriptions of these sections are either simplified or omitted.

[0108] In the following description, "tire radial direction" refers to the direction perpendicular to the rotation axis AX of the pneumatic tire 1. The term "tire circumferential direction" refers to the direction of rotation around the rotation axis AX (see Fig.14). Furthermore, “tire width direction” refers to the direction parallel to the tire rotation axis. The term tire equator plane CL refers to a plane perpendicular to the rotation axis AX of the pneumatic tire 1 and passing through a center point in the tire width direction of the pneumatic tire 1. The term tire equator line refers to a line along the circumferential direction of the pneumatic tire 1 that lies on the tire equator plane CL. In this specification and the drawings, the same reference symbol CL is used for the tire equator line as for the tire equator plane.

[0109] The pneumatic tire 1 of the present embodiment is provided with a pair of bead sections 2, sidewall sections 3 which are continuous with the bead sections, and a tread section 10 which connects the sidewall sections 3 in the tire meridian cross-section.

[0110] It should be noted that in this invention the internal structure of the pneumatic tire is not specifically limited. The internal structure of the pneumatic tire varies depending on the desired performance and design of the pneumatic tire and is preferably determined through tests, simulations, and the like to meet various requirements.

[0111] The pneumatic tire 1 according to the present embodiment is designed such that the ratio between the total width (nominal width) SW and the outer diameter OD of the pneumatic tire 1 is given by the following relationship: SW / OD≤0.3 fulfilled. formula <1> is equivalent to formula (1A).

[0112] It should be noted that in this invention, the overall width SW is equal to the width from one sidewall section to the other, including any designs on the sidewall section, when the pneumatic tire 1 is mounted on a rim, inflated to 230 kPa (an internal pressure that can be adjusted at the user's discretion) to define the dimensions of the pneumatic tire 1, and is unloaded. The outer diameter OD is the outer diameter of the tire at this time. It should be noted that the internal pressure of 230 kPa described above is chosen for the purpose of defining the dimensions of the pneumatic tire. Thus, it should be clarified that inflation to an internal pressure of 230 kPa is not required for the application of this invention, and the pneumatic tire 1 inflated according to this invention to an internal pressure within the typically used range will exhibit the effects of this invention.

[0113] The rim used in the present invention has a rim diameter compatible with the inner diameter of the pneumatic tire 1 and has a nominal rim width corresponding to the specified rim width Rm (mm) shown in Table 2 and Table 3, which is closest to the value (Rm = K1 × Sn) resulting from the product of the nominal tire cross-sectional width Sn and the coefficient K1, which is determined according to the aspect ratio of the tire mounted on the rim as described in the correspondence table (Table 1) according to ISO 4000-1:2001. [Table 2] (Table 2) aspect ratio K1 20-25 0,92 30-40 0,90 45 0,85 50-55 0,80 60-70 0,75 75-95 0,70 [Table 3] (Table 3) Nominal rim width Rm (mm) 3 76,2 3,5 88,9 4 101,6 4,5 114,3 5 127 5,5 139,7 6 152,4 6,5 165,1 7 177,8 7,5 190,5 8 203,2 8,5 215,9 9 228,6 9,5 241,3 10 254

[0114] Fig. Figure 14 is a unfolded view illustrating a section of the tread section 10 of the pneumatic tire 1 according to an embodiment of the present invention. Fig.In section 14, when describing pneumatic tire 1, it is assumed that the side to the right of the tire equator line CL, when the tire is mounted on the vehicle, is the vehicle side, and the side to the left of the tire equator line CL, when the tire is mounted on the vehicle, is the side opposite the vehicle side. In other words, in the description of this specification and the drawings, pneumatic tire 1 is mounted on the left side of the vehicle.

[0115] In the tread section 10 of the pneumatic tire 1 of the present embodiment, four longitudinal grooves 12A, 12B, 12C and 12D are formed, extending in the circumferential direction, and rib sections 14A, 14B, 14C, 14D and 14E are formed, which are defined by the longitudinal grooves 12A, 12B, 12C and 12D. In the rib sections 14A, 14B, 14C, 14D, 14E, the transverse grooves 16A, 16B, 16C, 16D, 16E are formed. The transverse grooves 16A, 16B, 16C, 16D, 16E are grooves 12, 16 arranged to run transversely to the tire's circumferential direction in the tread section 10 and differ from the longitudinal grooves 12A, 12B, 12C, 12D. It should be noted that in the present specification, the longitudinal grooves 12 and the transverse grooves 16 are collectively referred to as grooves 12, 16, and in this invention, the longitudinal grooves 16 are grooves with a width of 1.5 to 8 mm (both values ​​inclusive). As in Fig.Figure 14 illustrates that the configuration of the grooves 12, 16 and the web sections 14 forms an asymmetrical pattern on the tread section 10.

[0116] The pneumatic tire 1 according to the present embodiment is designed such that in the ground contact area G of the tread section 10, the groove area ratio GR of the ground contact area, the ground contact groove area ratio GRi of the inner tire area Ai and the ground contact groove area ratio GRo of the outer tire area Ao satisfy the following relationships: 10(%)≤GR≤25(%). GRo <GRi 0.1≤(GRi−GRo) / GR≤0.6.

[0117] In this invention, the ground contact area G refers to the portion of the ground contact surface that comes into contact with the ground when the pneumatic tire 1 is mounted on the rim described above, inflated to an internal pressure of 230 kPa, and a load corresponding to 80% of the load capacity is applied. The ground contact width W refers to the maximum width within the ground contact area in the tire width direction. The ground contact length W refers to the maximum length within the ground contact area in the tire circumference direction. Furthermore, in this invention, the load capacity is defined according to ISO 4000-1:1994.For a size for which the load capacity index is not specified in the ISO standard described above, the load capacity can be determined by a separate calculation, taking into account compliance with the standards of the respective country. In this case, the load capacity is calculated based on the standards of the respective country. Therefore, in the present invention, the load capacity for each tire size is calculated from the following calculation equation (c), which is published in "Calculation of Load Capacity" in the notes to JIS D 4202-1994, and which is the calculation equation for the actual load capacity used in the JIS standard. X=K×2.735×10−5×p0.585×Sd1.39×(DR−12.7+Sd) where X = load capacity (kg) K = 1.36 P = 230 (= air pressure (kPa)) Sd = 0.93 × S 0,75 - 0.637d S 0,75 = S × ((180°- Sin -1 ((Rm / S)) / 131.4°) S = designed cross-sectional width (mm) R m = Rim width corresponding to the designed cross-sectional width (mm) d = (0.9 - aspect ratio (-)) × S 0,75 - 6.35 D R = Reference value for the rim diameter (mm)

[0118] Furthermore, the groove area ratio GR refers to the ratio of the groove area to the sum of the web section area and the groove area within the ground contact area G (= ground contact area).

[0119] Furthermore, as in Fig.As illustrated in Figure 14, the inner tire area Ai refers to an area within the ground contact area G on the vehicle side of the tire equator line CL with half the width of the ground contact width W when the tire 1 is mounted on a vehicle. The outer tire area Ao refers to an area within the ground contact area on the side of the tire equator line CL opposite the vehicle side with half the width of the ground contact width W. The ground contact groove area ratio GRi in the inner tire area Ai is the ratio of the groove area to the sum of the rib section area and the groove area in the inner tire area Ai. The ground contact groove area ratio GRo in the outer tire area Ao is the ratio of the groove area to the sum of the rib section area and the groove area in the outer tire area Ao.

[0120] According to the pneumatic tire 1 of the present embodiment, the following actions and effects can be achieved. (1) The pneumatic tire 1 according to the present embodiment is designed such that the ratio of the total width SW to the outer diameter OD corresponds to the relationship in formula <1> This is fulfilled. Accordingly, the overall width SW to outer diameter OD is small compared to a typical-sized pneumatic tire (e.g., 205 / 55R16 (SW / OD = 0.32)). Because of this, the frontal contact patch of the pneumatic tire 1 is small, thus reducing the tire's air resistance and rolling resistance. Conversely, if the overall width SW is simply reduced, the load capacity of the pneumatic tire 1 is also reduced. However, by fulfilling the formula... <1> The outer diameter OD is large in relation to the overall width SW, so that the reduction of the load capacity can be prevented or minimized. (2) The pneumatic tire 1 according to the present embodiment is designed such that the groove area ratio GR, with reference to the ground contact area, assumes a value in the range which is given in the formula described above. <2> This area of ​​the groove area ratio GR is specified. This range is set low compared to a typical pneumatic tire. Thus, by increasing the area in which the rib sections 14 are in contact with the ground, the stiffness of the tread section 10 is increased, and steering stability can therefore be improved. It should be noted that if the groove area ratio GR is above 25%, the stiffness of the tread section 10 is reduced, so that sufficient lateral grip cannot be guaranteed, and steering stability can only be improved with difficulty. In addition, if the overall width SW is small, as described above, the water drainage properties are improved.However, if the groove area ratio GR falls below 10%, the grooves 12 and 16 provided in the tread section 10 are reduced; consequently, water cannot be adequately drained from the ground contact area G. As a result, it is difficult to maintain the water drainage properties with respect to the overall tire design. (3) The pneumatic tire 1 according to the present embodiment is designed such that the groove area ratio GR in the ground contact area G, the ground contact groove area ratio GRo in the outer area of ​​the tire Ao and the ground contact groove area ratio GRi in the inner area of ​​the tire Ai correspond to the formulas <3> and <4> fulfill. Consequently, the grooves provided in the outer area Ao of the tire are reduced more than those in the inner area Ai. As described in point (2) above, the pneumatic tire 1 according to this embodiment can prevent or minimize a reduction in water drainage properties due to the comparatively low groove area ratio GR by designing the ground contact groove area ratio GRi in the inner area Ai to be higher than the ground contact groove area ratio GRo in the outer area Ao.Furthermore, the area of ​​the rib sections 14 located in the outer tire area Ao, which are in contact with the ground, is larger than that of the rib sections in the inner tire area Ai. Consequently, the stiffness of the rib section 10 in the outer tire area Ao is high. Accordingly, sufficient lateral grip can be achieved and steering stability improved. It should be noted that with regard to formula <4> If ((GRi - GRo) / GR) is less than 0.1, a deterioration in water drainage properties cannot be sufficiently prevented. If ((GRi - GRo) / GR) is greater than 0.6, the block stiffness of the tread section 10 in the inner tire area Ai decreases excessively and steering stability may be reduced. (4) As described in (1), the pneumatic tire 1 according to the present embodiment has a comparatively large outer diameter OD and a comparatively narrow overall width SW compared to a typical-sized pneumatic tire. Accordingly, reduced space requirements, improvements in design, and the like are to be expected.

[0121] Furthermore, the groove area ratios GR, GRi and GRo satisfy in particular the following relationships: 15%≤GR≤22% and / or 0.2 ≤ (GRi - GRo) / GR ≤ 0.4. This is the case because the water drainage properties are prevented or minimized, and the stiffness of the tread section 10 in the outer tire area Ao is increased; thus, high steering stability can be achieved.

[0122] Here, as in Fig.As shown in Figure 14, the multitude of transverse grooves 16 are arranged in the tread section 10. With respect to a groove area ratio GRL of the transverse grooves 16 (the ratio of the groove area of ​​the transverse grooves 16 to the sum of the rib section area and the groove area (= ground contact area) within the ground contact area G), a groove area ratio GRLo of the transverse grooves 16 in the outer tire area Ao and a groove area ratio GRLi of the transverse grooves 16 in the inner tire area Ai preferably exhibit a relationship which 1.1≤GRLi / GRLo≤1.9. This is the case because, on the one hand, a deterioration of water drainage properties can be prevented or minimized, and on the other hand, steering stability can be significantly improved by increased block stiffness and road contact area. It should be noted that if (GRLi / GRLo) is less than 1.1, the deterioration of water drainage properties is not sufficiently prevented or minimized. If (GRLi / GRLo) is greater than 1.9, the block stiffness of the tread section 10 in the inner tire area Ai decreases significantly, and steering stability may be reduced.

[0123] Furthermore, around the entire circumference of the tread section 10 of the pneumatic tire 1 according to this embodiment, the circumferentially spaced transverse grooves 16 have the following ratio between the number Pi of transverse grooves 16A, 16B, which are arranged in the outer tire area Ao, and the number Po of transverse grooves 16C, 16D, 16E, which are arranged in the inner tire area Ai: 1≤Pi / Po≤2..

[0124] This is due to the fact that by arranging more transverse grooves 16 in the inner tire area Ai than in the outer tire area Ao improvements in water drainage properties are to be expected, and furthermore, that by increasing block stiffness and increasing the ground contact area, the deterioration of water drainage properties can be largely prevented or minimized and steering stability can also be improved.

[0125] Furthermore, for a similar reason as in formula <6> The number of transverse grooves 16C, 16D, 16E arranged in the inner area Ai of the tire is specified, preferably between 40 and 80, inclusive of both values. It should be noted that the number of transverse grooves 16C, 16D, 16E refers to the total number of grooves around the entire circumference of the tire, including those transverse grooves 16C, 16D, 16E that are aligned and arranged side by side with the greatest spacing between them in the direction of the tire circumference.

[0126] Furthermore, as in Fig.As shown in Figure 14, in the tread section 10, as described above, the longitudinal grooves 12C, 12D (corresponding to the inner longitudinal grooves) are arranged in the inner tire area Ai, and the longitudinal grooves 12A, 12B (corresponding to the outer longitudinal grooves) are arranged in the outer tire area Ao. With such a design, the groove area ratio GRBi of the longitudinal grooves 12C, 12D arranged in the inner tire area Ai and the groove area ratio GRBoi of the longitudinal grooves 12A, 12B arranged in the outer tire area Ao preferably have a ratio that satisfies the following formula: 1≤GRBi / GRBoi≤2.

[0127] This is because the deterioration of the water drainage properties can be further prevented or minimized by increasing the groove area ratio GRBi of the longitudinal grooves 12C, 12D arranged in the inner tire area Ai.

[0128] As described above, both the longitudinal grooves 12 and the transverse grooves 16 are arranged in the tread section 10 of the pneumatic tire 1 of the present embodiment. However, according to this invention, the grooves 12, 16 are arranged in the tread section 10 of the pneumatic tire 1 and the ground contact area G of the pneumatic tire is designed to at least Formula <2> to formula <4> to fulfill. In other words, either the longitudinal grooves 12 or the transverse grooves 16 are arranged in the tread section 10 of the pneumatic tire 1 of the present invention such that at least formula <2> to formula <4> is fulfilled. Modified example

[0129] Fig. Figure 15 is a flattened view illustrating a section of the tread of a pneumatic tire according to a modified example of the embodiment of the present invention. Here, the outer inner tire area Aoi and the outer tire area Aoo are shown with reference to Fig. 15 specified. The outer inner tire area Aoi represents an area on the side of the tire equator line CL of the tire outer area Ao with a width of 25% of the ground contact width W. The outer outer tire area Aoo represents an area on the side of a ground contact edge in the tire width direction of the tire outer area Ao excluding the outer inner tire area Aoi. The outer outer tire area Aoo has a width of 25% of the width of the ground contact width W.

[0130] Here, as in Fig.As illustrated in Figure 15, the longitudinal groove 12A, which runs in the circumferential direction of the tire, is preferably arranged in the outer inner tire area Aoi, and preferably no longitudinal grooves 12 are arranged in the outer tire area Aoo. This is because, by ensuring the distance in the tire width direction from the ground contact edge GE to the longitudinal groove 12A in the outer tire area Ao, the rigidity of the tread section 10 in the tire width direction can be increased and steering stability during cornering can be improved. Examples

[0131] For the exemplary implementations, various performance tests were carried out on tires with regard to the rolling resistance coefficient (RRC) index, the fuel economy index, steering stability, and resistance to aquaplaning (water drainage properties) on pneumatic tires that had met various conditions.

[0132] In these performance tests, each test tire was mounted on a rim of a compatible size, as described above, and inflated to an internal pressure of 230 kPa for the respective vehicle tests.

[0133] The following is a description of the test procedures for the performance tests that were carried out on the test tires. Fuel efficiency performance

[0134] The test tires were fitted to a front-wheel drive vehicle with an engine displacement of 1800 cm³. 3 The vehicle was mounted, driven for 50 laps at a speed of 100 km / h on a 2 km test track, and the fuel consumption improvement rate was measured relative to the fuel consumption rate of a prior art example, with the prior art example assigned a reference value of 100. Higher index values ​​indicate better fuel consumption. Steering stability

[0135] The test tires were mounted on a standard rim and attached to a passenger car (engine capacity 1800 cm³). 3 The tires were mounted, and the handling during lane changes was evaluated by three experienced drivers over three laps of a 2 km test track. The evaluation results for the average score for each test tire were expressed as an index, with the average score for handling from comparison example 1 set to 100. Higher scores indicate superior steering stability. Resistance to aquaplaning

[0136] Aquaplaning resistance was assessed by conducting a straight-line aquaplaning test, measuring the speed at which aquaplaning occurred. In this straight-line aquaplaning test, the test vehicle was driven into a water basin with a water depth of 10 mm while the speed was increased, and the tire slip ratio was measured. The speed at which the slip ratio reached 10% was taken as the speed at which aquaplaning occurred. In this test, the measurement results from examples other than the prior art example were expressed as an index, with the measurement results of the prior art example set to 100. In these embodiments, higher index values ​​indicate better aquaplaning resistance.

[0137] The following is a description of each of the test tires and the results of the performance tests. Performance tests for fuel economy index, steering stability, and aquaplaning resistance were carried out on the pneumatic tires according to the prior art and embodiments 7 to 18 (note: embodiments 1 to 6 are missing). Table 4 shows numerical values ​​for the dimensions of each test tire and the results of the performance tests. [Table 4-I] State of the art example Example 7 Example 8 Example 9 Example 10 Nominal width (total width) SW 205 165 165 165 165 aspect ratio 55 55 55 55 55 Inner diameter RD (inches) 16 20 20 20 20 Outer diameter OD (mm) 632 695 695 695 695 SW / OD 0,32 0,24 0,24 0,24 0,24 Ring-shaped structure Unavailable Available Available Available Available GR (%) 30 8 30 20 20 (GRi - GRo) / GR 0,00 0,35 0,35 0,00 0,70 GRLi / GRLo 1,0 1,5 1,5 1,5 1,5 Pi / Po 1,0 1,5 1,5 1,5 1,5 Outer position of the longitudinal groove Aoi, Aoo Aoi Aoi Aoi Aoi GRBi / GRBo 1,0 1,5 1,5 1,5 1,5 Fuel economy index 100,0 102,5 103,0 103,0 103,0 Steering stability 100 115 100 110 105 Aquaplaning performance 115 100 105 102 107 [Table 4-II] Example 11 Example 12 Example 13 Example 14 Nominal width (total width) SW 165 165 165 165 aspect ratio 55 55 55 55 Inner diameter RD (inches) 20 20 20 20 Outer diameter OD (mm) 695 695 695 695 SW / OD 0,24 0,24 0,24 0,24 Ring-shaped structure Available Available Available Available GR (%) 20 20 20 20 (GRi - GRo) / GR 0,35 0,35 0,35 0,35 GRLi / GRLo 1,0 2,0 1,5 1,5 Pi / Po 1,5 1,5 1,0 2,1 Outer position of the longitudinal groove Aoi Aoi Aoi Aoi GRBi / GRBo 1,5 1,5 1,5 1,5 Fuel economy index 103,0 103,0 103,0 103,0 Steering stability 110 105 110 105 Aquaplaning performance 102 107 103 107 [Table 4-III] Example 15 Example 16 Example 17 Example 18 Nominal width (total width) SW 165 165 165 165 aspect ratio 55 55 55 55 Inner diameter RD (inches) 20 20 20 20 Outer diameter OD (mm) 695 695 695 695 SW / OD 0,24 0,24 0,24 0,24 Ring-shaped structure Available Available Available Available GR (%) 20 20 20 20 (GRi - GRo) / GR 0,35 0,35 0,35 0,35 GRLi / GRLo 1,5 1,5 1,5 1,5 Pi / Po 1,5 1,5 1,5 1,5 Outer position of the longitudinal groove Aoo Aoi Aoi Aoi GRBi / GRBo 1,5 0,9 2,1 1,5 Fuel economy index 102,5 103,0 103,0 103,0 Steering stability 110 110 105 110 Aquaplaning performance 107 105 110 110

[0138] In Table 4, the "absence" of the "ring-shaped structure" means that the belt layer is a conventional belt layer with arranged cords. The "presence" of the "ring-shaped structure" means that the belt layer is the ring-shaped structure 100 according to this invention. In other words, in Table 4, the tires according to the prior art example did not include the ring-shaped structure 100 according to this invention. The tires according to embodiments 7 to 18 included the ring-shaped structure 100 according to this invention. The tires of the prior art example included a typically used belt layer with arranged cords instead of the ring-shaped structure 100.

[0139] Furthermore, in the category of Table 4, “Outer position of the longitudinal groove”, “Aoi” means that the longitudinal groove 12 is located in the outer inner tire area Aoi, “Aoo” means that the longitudinal groove 12 is located in the outer outer tire area Aoo, and “Aoi, Aoo” means that the longitudinal groove 12 is located in the outer inner tire area Aoi and in the outer outer tire area Aoo.

[0140] The pneumatic tire, following a state-of-the-art example, had a tire size of 205 / 55R16, and the value for (SW / OD) was 0.32, which means that formula <1> was not fulfilled. Furthermore, the pneumatic tire according to the prior art example did not include the ring-shaped structure. The tread section of the pneumatic tire according to the prior art example exhibited the in Fig. 16 illustrated tread pattern patterns.

[0141] The pneumatic tires according to embodiments 7 to 18 had a tire size of 165 / 55R20, and the value for (SW / OD) was 0.24, which means that formula <1> was fulfilled. For the tread section 10 of the pneumatic tires according to embodiments 7 to 18, tread profile patterns were based on the one in Fig. 16 illustrated tread pattern patterns, adapted to the respective tire size, are provided.

[0142] The pneumatic tire according to the prior art served as a reference tire for steering stability. In the present invention, this means that for steering stability testing, a tire whose size was changed to a narrow width and large diameter to reduce rolling resistance, and thus a tire with reduced steering stability, was used as the reference. Subsequently, the pneumatic tires according to exemplary embodiments were evaluated to determine the extent to which steering stability was improved compared to the prior art example.

[0143] Here, the tread section of the pneumatic tires was provided with a tread profile pattern based on the tread profile pattern of the prior art example, according to exemplary embodiments and the prior art example (in Fig.16 illustrated tread pattern patterns) and adapted to the dimensional parameters such as the groove area ratio (GR) set for each of the test tires. As shown in Fig. As can be seen from the tread pattern pattern illustrated in 14, the pneumatic tire was designed according to exemplary embodiments with a tread pattern based on the one shown in Fig. 16 illustrated tread profile patterns were provided, and the groove area of ​​the longitudinal grooves 12 and the transverse grooves 16, the number and position in the tire width direction of the longitudinal grooves 12, and the like were adapted to the dimensional parameters of the individual test tires.

[0144] As can be seen from Table 4, the prior art example did not satisfy the formula. <1> , formula <2> , formula <3> , formula <4> , formula <5> , formula <6> and formula <7> Furthermore, the prior art example did not include the ring-shaped structure. Furthermore, the prior art example was provided with the longitudinal groove 12 in the outer inner tire area Aoi and in the outer tire area Aoo.

[0145] The embodiment 7 fulfilled formula <1> , formula <3> , formula <4> , formula <5> , formula <6> and formula <7> , but not formula <2> . Exemplary embodiment 7 had a GR of 8%. Furthermore, exemplary embodiment 7 comprised the ring-shaped structure. Exemplary embodiment 7 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0146] The embodiment 8 fulfilled formula <1> , formula <3> , formula <4> , formula <5> , formula <6> and formula <7> , but not formula <2> . Exemplary embodiment 8 had a GR of 30%. Furthermore, exemplary embodiment 8 comprised the ring-shaped structure. Exemplary embodiment 8 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0147] Example 9 fulfills formula <1> , formula <2> , formula <3> , formula <5> , formula <6> and formula <7> , but not formula <4> In embodiment 9, (GRi - GRo) / GR was 0.00. Furthermore, embodiment 9 included the ring-shaped structure. Embodiment 9 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0148] The embodiment 10 fulfilled formula <1> , formula <2> , formula <3> , formula <5> , formula <6> and formula <7> , but not formula <4> In embodiment 10, (GRi - GRo) / GR was 0.70. Furthermore, embodiment 10 included the ring-shaped structure. Embodiment 10 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0149] The embodiment 11 fulfilled formula <1> , formula <2> , formula <3> , formula <4> , formula <6> and formula <7> , but not formula <5> In embodiment 11, the value for W / SW was 1.0. Furthermore, embodiment 11 included the ring-shaped structure. Embodiment 11 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0150] The embodiment 12 fulfilled formula <1> , formula <2> , formula <3> , formula <4> , formula <6> and formula <7> , but not formula <5> In embodiment 12, the value for W / SW was 2.0 (not included in the scope of protection). Furthermore, embodiment 12 included the ring-shaped structure. Embodiment 12 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0151] The embodiment 13 fulfilled formula <1> , formula <2> , formula <3> , formula <4> , formula <5> and formula <7> , but not formula <6> In embodiment 13, the value for Pi / Po was 1.0. Furthermore, embodiment 13 included the ring-shaped structure. Embodiment 13 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0152] The embodiment 14 fulfilled formula <1> , formula <2> , formula <3> , formula <4> , formula <5> and formula <7> , but not formula <6> In embodiment 14, the value for Pi / Po was 2.1. Furthermore, embodiment 14 included the ring-shaped structure. Embodiment 14 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0153] The embodiment 15 fulfilled formula <1> , formula <2> , formula <3> , formula <4> , formula <5> , formula <6> and formula <7> . Exemplary embodiment 15 comprised the ring-shaped structure. Exemplary embodiment 15 was provided with the longitudinal groove 12 in the outer tire area Aoo, but it was not provided with the longitudinal groove 12 in the outer tire area Aoi.

[0154] The embodiment 16 fulfilled formula <1> , formula <2> , formula <3> , formula <4> , formula <5> and formula <6> , but not formula <7> In embodiment 16, the value for GRBi / GRBo was 0.9. Furthermore, embodiment 16 included the ring-shaped structure. Embodiment 16 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0155] The embodiment 17 fulfilled formula <1> , formula <2> , formula <3> , formula <4> , formula <5> and formula <6> , but not formula <7> In embodiment 17, the value for GRBi / GRBo was 2.1. Furthermore, embodiment 17 included the ring-shaped structure. Embodiment 17 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0156] The embodiment 18 fulfilled formula <1> , formula <2> , formula <3> , formula <4> , formula <5> , formula <6> and formula <7> Furthermore, embodiment 18 comprised the ring-shaped structure. Embodiment 18 was provided with the longitudinal groove 12 in the outer inner tire area Aoi, but it was not provided with the longitudinal groove 12 in the outer tire area Aoo.

[0157] According to the results of the performance tests shown in Table 4, the pneumatic tires according to embodiments 7 to 18, in which formula <1> The higher fuel economy indices were achieved compared to the state of the art. Furthermore, the results of the performance tests within the tested tire sizes confirmed that the 165 / 55R20 tire size showed a sufficient improvement in fuel consumption compared to the 205 / 55R16 tire size, as shown in Table 4.

[0158] Furthermore, according to the results of the performance tests shown in Table 4, the pneumatic tires according to embodiments 11 to 18, in which formula <1> to formula <4> The tires demonstrated fuel economy indices and steering stability that were superior to those of state-of-the-art tires. In other words, these test tires were able to reduce rolling resistance and improve the steering stability that would otherwise be reduced by the lower rolling resistance.

[0159] It should be noted that the groove area ratio GR of the pneumatic tire according to embodiment 7 (the tire in which formula <2> (not fulfilled), was exceptionally low (GR = 8%). This resulted in good steering stability, but significantly reduced resistance to aquaplaning.

[0160] Furthermore, according to the results of the performance tests shown in Table 4, the pneumatic tires according to embodiments 13 to 18, in which formula <1> to formula <5> The requirements were met, resulting in higher steering stability and greater resistance to aquaplaning.

[0161] According to the results of the performance tests shown in Table 4, the pneumatic tires according to embodiments 15 to 18, in which formula <1> to formula <6> The requirements were met, resulting in higher steering stability and greater resistance to aquaplaning.

[0162] According to the results of the performance tests shown in Table 4, as can be seen from embodiment 15 and embodiment 18, the pneumatic tire according to embodiment 18, which had a longitudinal groove in the outer inner tire area Aoi, exhibited superior steering stability and resistance to aquaplaning compared to the pneumatic tire according to embodiment 15, which did not have the longitudinal groove in the outer tire area Aoi.

[0163] Furthermore, as can be seen from the results of the performance tests shown in Table 4, the pneumatic tire according to embodiment 18, in which formula <1> to formula <7> were fulfilled, exhibiting superior resistance to aquaplaning compared to the pneumatic tires according to embodiments 16 and 17, where, although formula <1> to formula <6> were fulfilled, formula <7> however, this was not the case.

[0164] It should be noted that the invention has been described with regard to specific embodiments. However, various modifications and changes are possible for those skilled in the art without deviating from the scope and spirit of the present invention.

[0165] The present invention is described below. (1) Pneumatic tires with an asymmetric pattern formed by grooves in a tread section, wherein SW / OD ≤ 0.30 is satisfied, where SW / OD represents a ratio between a total width SW and an outer diameter OD of the pneumatic tire, and the ground contact area is designed such that 10% ≤ GR ≤ 25%, GRo < GRi, and 0.1 ≤ (GRi - GRo) / GR ≤ 0.6 is satisfied, where GRi represents a groove area ratio in an inner tire area Ai, and GRo represents a groove area ratio in an outer tire area Ao, where the inner tire area Ai is an area within the ground contact area on one side of a vehicle of a tire equator line when the pneumatic tire is mounted on a vehicle, and the tire outer area Ao represents an area within the ground contact area on one side of the tire equator line opposite the side of the vehicle when the pneumatic tire is mounted on a vehicle. (2) Pneumatic tires according to (1), wherein a plurality of transverse grooves extending transversely to a tire circumferential direction are provided in the tread section, and 1.1≤GRLi / GRLo≤1.9 is fulfilled, where GRL represents a groove area ratio of the transverse grooves in the ground contact area, GRLo a groove area ratio of the transverse grooves in the outer tire area Ao and GRLi a groove area ratio of the transverse grooves in the inner tire area Ai. (3) Pneumatic tires according to (2), wherein the transverse grooves are arranged at intervals in the circumferential direction of the tire, and 1 <Pi / Po≤2 is satisfied, where Pi represents a number of transverse grooves arranged in the inner tire area Ai, and Po represents a number of transverse grooves arranged in the outer tire area Ao around a complete circumference of the tread section of the pneumatic tire. (4) Pneumatic tires according to one of points (1) to (3), wherein a longitudinal groove running in the direction of the tire circumference is provided in an outer inner tire area Aoi and not in an outer tire area Aoo, wherein the outer inner tire area Aoi represents an area on the side of the tire equator line of the outer tire area Ao with a width corresponding to 25% of a ground contact width, and the outer outer tire area Aoo represents an area of ​​the outer tire area Ao excluding the outer inner tire area Aoi. (5) Pneumatic tires according to one of points (1) to (4), wherein an inner longitudinal groove, which is a longitudinal groove running in the circumferential direction of the tire, is provided in the inner area Ai of the tire; an outer longitudinal groove, which is a longitudinal groove running in the circumferential direction of the tire, is provided in the outer area Ao of the tire; and 1≤GRBi / GRBo≤2 is fulfilled, where GRBi represents a groove area ratio of the inner longitudinal groove in the tire interior Ai and GRBo represents a groove area ratio of the outer longitudinal groove in the tire exterior Ao.

[0166] It should be noted that the first to seventh embodiments described above can optionally be combined. For example, the belt layer of tire 1 described in the seventh embodiment can be in the ring-shaped structure 100 described in the first to sixth embodiments. Specifically, tires 1 including the ring-shaped structure 100 described in the first to sixth embodiments, the carcass section 120, and the tread rubber layer 11 can have the formula described in the seventh embodiment. <1> fulfill and the tread section 10 of this tread rubber layer 11 can formula <2> to formula <4> fulfill. Furthermore, the tread section 10 of the tire 1 described in the first to sixth embodiments can fulfill at least one of the following formulas: Formula <5> , formula <6> and formula <7> , which is described in the seventh embodiment.This tire 1 can also comprise at least one of the ring-shaped structures described in the second to sixth embodiments. Furthermore, these tires 1 can satisfy at least one of the formulas (1A) to (8B) described in the first embodiment. REFERENCE MARK LIST: 1 tire (pneumatic tire) 4 through holes 10 tread section 11 Tread rubber layer 11A Ground contact area 11B Inner surface 12 Longitudinal groove (groove) 16 transverse groove (groove) 30 Narrow groove 40 Main groove Section 50 with depressions and protrusions 100 ring-shaped structure 100A outdoor area 100B internal surface 120 carcass sections AX Rotation axis AI tire interior Ao Tire Exterior G Ground contact area GR groove area ratio GRi groove area ratio in the inner area of ​​the tire Large groove area ratio in the outer area of ​​the tire OD outer diameter SW Total width

Claims

[1] Pneumatic tires (1), comprising: a cylindrical ring-shaped structure (100) arranged around an axis of rotation (AX); a carcass section (120) including a rubber-coated cord, wherein at least one section of the carcass section (120) is arranged on an outside of the annular structure (100) in a direction parallel to the axis of rotation (AX); and a rubber layer including a tread section (10), wherein at least one section of the rubber layer is arranged on an outside of the annular structure (100) in a beam direction to the axis of rotation (AX), wherein the conditions SW / OD≤0.30 1.0≤BW / W≤1.1 0.82≤W / SW≤0.90 are fulfilled, where SW is a total tire width and OD is a tire outer diameter, where W is a width of a ground contact area (G) of the tread section (10), and BW is a measure of the ring-shaped structure (100) in the direction parallel to the axis of rotation (AX). [2] Pneumatic tire (1) according to claim 1, wherein a ground contact surface (11A) of the tread section (10) and an outer surface (100A) of the ring-shaped structure (100), which points outwards in the direction of the beam with respect to the axis of rotation (AX), are parallel to the axis of rotation (AX). [3] Pneumatic tires (1) according to claim 1 or 2, wherein 0.14×(OD−RD) / 2SW+0.65≤W / SW≤0.14×(OD−RD) / 2SW+0.76 is satisfied, where W represents a width of a ground contact area (G) of the tread section (10) and RD represents a rim diameter of the tire (1). [4] Pneumatic tire (1) according to any one of claims 1 to 3, wherein the ring-shaped structure (100) comprises a plurality of through holes. [5] Pneumatic tire (1) according to any one of claims 1 to 4, wherein the ring-shaped structure (100) is formed by a strip-shaped metal plate, the end sections of which are welded together, and 150 GPa ≤ E ≤ 250 GPa, and 0.2 mm ≤ Tb ≤ 0.8 mm are satisfied, where E represents the elastic modulus (Young's modulus) of the metal and Tb represents the thickness of the plate. [6] Pneumatic tire (1) according to any one of claims 1 to 5, wherein the rubber layer comprises: a main groove (40) formed in the tread section (10) which runs around the axis of rotation (AX), and an inner surface (11B, 100B) which points in a direction opposite to the ground contact surface (11A) of the tread section (10), and 0.05≤Tu / T1≤0.15 is satisfied, wherein T1 represents a first thickness of the rubber layer, the first thickness corresponding to a distance measure from the ground contact surface (11A) of the tread section (10) of the inner surface, and Tu represents a second thickness of the rubber layer, the second thickness corresponding to a distance measure from a lower surface of the main groove (40) to the inner surface. [7] Pneumatic tire (1) according to any one of claims 1 to 6, wherein the rubber layer comprises a narrow groove (30) designed to surround the axis of rotation (AX) in a marginal area which includes a marginal section of the ground contact area (G) of the tread section (10) in the direction parallel to the axis of rotation (AX); a center point of the edge region is aligned in the direction parallel to the axis of rotation (AX) according to the edge section of the ground contact area (G), and DW = 0.1W is satisfied, where W is the width of a ground contact area (G) of the tread section (10) and DW is a width of the edge section. [8] Pneumatic tire (1) according to any one of claims 1 to 7, wherein the annular structure (100) comprises a recess and projection section on at least one section of the end sections of the annular structure (100) in the direction parallel to the axis of rotation (AX). [9] Pneumatic tire (1) according to one of claims 1 to 8, wherein the grooves in the tread section (10) form an asymmetric pattern and the ground contact area (G) is designed such that 10%≤GR≤25% GRo <GRi, and 0.1≤(GRi−GRo) / GR≤0.6 is fulfilled where GR represents a groove area ratio in the ground contact area (G) of the tread section (10), GRi a groove area ratio in an inner tire area (Ai), and GRo a groove area ratio in an outer tire area (Ao), wherein the inner area (Ai) of a pneumatic tire (1) mounted on a vehicle represents an area within the ground contact area (G) on one side of the vehicle of a tire equator line, and the outer area (Ao) of a pneumatic tire (1) mounted on a vehicle represents an area within the ground contact area (G) on one side opposite the side of the vehicle of the tire equator line. [10] Pneumatic tire (1) according to claim 9, wherein a multitude of transverse grooves (16) which run transversely to a tire circumference direction are provided in the tread section (10), and 1.1 ≤ GRLi / GRLo ≤ 1.9 is fulfilled, where GRL represents a groove area ratio of the transverse grooves (16) in the ground contact area (G), GRLo represents a groove area ratio of the transverse grooves (16) in the outer tire area (Ao) and GRLi represents a groove area ratio of the transverse grooves (16) in the inner tire area (Ai). [11] Pneumatic tire (1) according to claim 10, wherein the transverse grooves (16) are arranged at intervals in the direction of the tire circumference, and 1 <Pi / Po≤2 is satisfied, where Pi represents a number of transverse grooves (16) arranged in the inner area (Ai) of the tire, and Po represents a number of transverse grooves (16) arranged in the outer area (Ao) of the tire around a complete circumference of the tread section (10) of the pneumatic tire (1). [12] Pneumatic tire (1) according to one of claims 9 to 11, wherein a longitudinal groove (12) extending in the circumferential direction of the tire is provided in an outer inner tire area (Aoi) and not in an outer outer tire area (Aoo), wherein the outer inner tire area (Aoi) represents an area on the side of the tire equator line of the outer tire area (Ao) with a width corresponding to 25% of a ground contact width, and the outer outer tire area (Aoo) represents an area of ​​the outer tire area (Ao) excluding the outer inner tire area (Aoi). [13] Pneumatic tire (1) according to one of claims 9 to 12, wherein an inner longitudinal groove (12), which is a longitudinal groove (12) extending in the circumferential direction of the tire, is provided in the inner area (Ai) of the tire; an outer longitudinal groove (12), which is a longitudinal groove (12), which runs in the circumferential direction of the tire, is provided in the outer area of ​​the tire (Ao); and 1≤GRBi / GRBo≤2 is fulfilled, where GRBi represents a groove area ratio of the inner longitudinal groove (12) in the inner area of ​​the tire (Ai) and GRBo represents a groove area ratio of the outer longitudinal groove (12) in the outer area of ​​the tire (Ao).

Images