TIRES

Abstract

Tires (1), comprising: a plurality of main circumferential grooves (21, 22, 23, 24) provided in a tread section (2), the plurality of main circumferential grooves (21, 22, 23, 24) extending in the tire circumferential direction; and a plurality of rib sections (20C, 20Ma, 20Mb, 20Sa, 20Sb), which are defined by the majority of main circumferential grooves (21, 22, 23, 24), comprising the majority of web sections (20C, 20Ma, 20Mb, 20Sa, 20Sb): a central rib section (20C) that is closest to the equatorial plane (CL) of the tire (1); a first shoulder bridge section (20Sa) that is defined by ground contact edges (T IN , T OUT ) on both sides relating to a tire width direction in relation to the equatorial plane (CL) of the tire (1) a ground contact edge (T OUT ) includes; and a first middle bridge section (20Ma) between the first shoulder bridge section (20Sa) and the central bridge section (20C), wherein in a meridian cross-sectional view of the tire (1) a line forming a single arc passes through a ground contact edge located in the first shoulder rib section (20Sa), a midpoint (P CL ) a length of the central rib section (20C) in the tire width direction and a midpoint (P OUT ) a length of the first middle rib section (20Ma) in the tire width direction, is defined as a first virtual profile (PR1), an end section of the central rib section (20C) on one side of the first central rib section (20Ma) is recessed towards an inner side in the tire radial direction relative to the first virtual profile (PR1), an end section of the first middle rib section (20Ma) on one side of the central rib section (20C) is recessed relative to the first virtual profile (PR1) towards the inner side in the tire radial direction, a depression amount (CR1) of the end section of the central rib section (20C) on the side of the first middle rib section (20Ma) is greater than a depression amount (MR2) of the end section of the first middle rib section (20Ma) on the side of the central rib section (20C), and in the meridional cross-sectional view of the tire (1) a distance between intersection points (E, E') of the first virtual profile (PR1) and extension lines (KMS, KMS') that are on the side of the central rib section (20C) of groove walls (KM, KM') of main circumferential grooves (22, 23) adjacent to both end sections of the central rib section (20C) in the tire width direction is defined as Wc, and a ground contact edge of the central rib section (20C) is located on a side that is further inboard than a position at a distance of 0.03Wc from the end section of the central rib section (20C) on the side of the first middle bridge section (20Ma).

Description

Technical field

[0001] The present invention relates to a tire. State of the art

[0002] In general, good steering stability can be achieved through a suitable tire contact patch shape. Patent document 1 discloses a technology for improving the contact patch shape by projecting the rib section towards the outer side in the tire radial direction, relative to the standard contour line of the entire tread section. Patent document 2 discloses a tire with an asymmetric tread pattern that improves steering performance. Patent document 3 discloses a tire in which edges of the rib section extending in the tire width direction are formed with arcuate surfaces around a center point within the rib section, thereby reducing the ground contact load concentration at the edges of the rib section. List of oppositions patent literature Patent Document 1: JP 5387707 B Patent document 2: DE 10 2010 040 647 A1 Patent document 3: EP 3 042 791 A1 Brief description of the invention: Technical problem

[0003] The tire described in patent document 1 includes a rib section that projects towards the outer side in the tire's radial direction. However, since the projection amount is not large, the contact patch shape cannot be significantly improved, and there is still room for improvement with regard to achieving compatible steering stability performance in both dry and wet conditions.

[0004] The present invention was made in light of the foregoing, and it is an object of the present invention to provide a tire with which both steering stability performance on dry surfaces and steering stability performance on wet surfaces can be achieved in a compatible manner. Solution to the problem

[0005] To solve the problems and fulfill the objective, a tire according to a particular aspect of the present invention is a tire comprising: a plurality of major circumferential grooves provided in a tread section, the plurality of major circumferential grooves extending in a tire circumferential direction; and a plurality of rib sections defined by the plurality of major circumferential grooves, the plurality of rib sections comprising: a central rib section located closest to an equatorial plane of the tire; a first shoulder rib section comprising a ground contact edge on both sides related to a tire width direction with respect to the equatorial plane of the tire; and a first intermediate rib section between the first shoulder rib section and the central rib section, wherein, in a meridional cross-sectional view of a tire, a linewhich, in a single arc, connects a ground contact edge located in the first shoulder rib section, a midpoint of a length of the central rib section in the tire width direction, and a midpoint of a length of the first middle rib section in the tire width direction, is defined as a first virtual profile; an end section of the central rib section on one side of the first middle rib section is recessed towards an inner side in the tire radial direction relative to the first virtual profile; an end section of the first middle rib section on one side of the central rib section is recessed towards the inner side in the tire radial direction relative to the first virtual profile.a depression amount of the end section of the central rib section on the side of the first central rib section is greater than a depression amount of the end section of the first central rib section on the side of the central rib section, and in the meridional cross-sectional view of the tire, a distance between the intersection points of the first virtual profile and from the groove walls of circumferentially extending main grooves adjacent to both end sections of the central rib section relative to a tire width direction, emanating extension lines on the side of the central rib section is defined as Wc, and a ground contact edge of the central rib section is located on a side that is further inboard than a position at a distance of 0.03Wc from the end section of the central rib section on the side of the first central rib section.

[0006] Preferably, in the meridional cross-sectional view of the tire, a distance between the intersection points of the first virtual profile and extension lines extending from groove walls on sides of the first central rib section of main circumferential grooves adjacent to both end sections of the first central rib section relative to a tire width direction is defined as Wa, and a ground contact edge of the first central rib section is located on a side that is further inboard than a position at a distance of 0.03Wa from the end section of the first central rib section on the side of the central rib section.

[0007] Preferably, the difference between the indentation amount of the end section of the central web section on the side of the first middle web section and the indentation amount of the end section of the first middle web section on the side of the central web section is 0.1 mm or more and 0.8 mm or less.

[0008] Preferably, the groove width of the main circumferential groove adjacent to the end section of the central rib section, relative to the tire width direction, is equal to or greater than the groove width of a main circumferential groove adjacent to the first shoulder rib section.

[0009] Preferably, the length of the central rib section in the tire width direction is 105% or 120% or less than the length of the first central rib section in the tire width direction.

[0010] Preferably, an end section of the first shoulder rib section on the inner side in the tire width direction relative to the first virtual profile is recessed in the direction of the inner side in the tire radial direction, and a recession amount of the end section of the central rib section on an outer side in the tire width direction is greater than a recession amount of the end section of the first shoulder rib section on the inner side in the tire width direction.

[0011] Preferably, an end section of the first middle rib section on one side of the first shoulder rib section is recessed relative to the first virtual profile in the direction of the inner side in the tire radial direction, and a recession amount of the end section of the first middle rib section on the side of the first shoulder rib section is equal to or greater than a recession amount of the end section of the first shoulder rib section on one side of the first middle rib section.

[0012] Preferably, the first shoulder rib section includes a lug groove extending in the tire width direction, the lug groove includes a chamfer in the groove depth direction and groove width direction, and a chamfer in the groove width direction is greater than a chamfer in the groove depth direction.

[0013] Preferably, the tire further includes: a second shoulder rib section including a further ground contact edge extending from the ground contact edges on both sides in the tire width direction with respect to the equatorial plane of the tire; and a second central rib section between the second shoulder rib section and the central rib section, wherein, in the meridional cross-sectional view of a tire, a line connecting in a single arc a ground contact edge located in the second shoulder rib section, the midpoint of the length of the central rib section in the tire width direction, and a midpoint of a length of the second central rib section in the tire width direction is defined as a first virtual profile.an end section of the central rib section on one side of the second central rib section relative to the second virtual profile is recessed towards an inner side in the tire radial direction, an end section of the second central rib section on one side of the central rib section relative to the second virtual profile is recessed towards the inner side in the tire radial direction, a recession amount of the end section of the central rib section on the side of the second central rib section is greater than a recession amount of the end section of the second central rib section on the side of the central rib section, and in the meridional cross-sectional view of the tire, a distance between the intersection points of the second virtual profile and the groove walls of circumferentially extending main grooves adjacent to both end sections of the central rib section relative to the tire width direction.outgoing extension lines on the side of the central web section are defined as Wc', and a ground contact edge of the central web section is arranged on a side that is further inboard than a position at a distance of 0.03Wc' from the end section of the central web section on the side of the second central web section.

[0014] Preferably, in the meridian cross-sectional view of the tire, a distance between the intersection points of the second virtual profile and extension lines extending on the side of the second central rib section of groove walls of the main circumferential grooves adjacent to both end sections of the second central rib section relative to the tire width direction is defined as Wb, and a ground contact edge of the second central rib section is located on a side that is further inboard than a position at a distance of 0.03Wb from the end section of the second central rib section on the side of the central rib section.

[0015] Preferably, the difference between the indentation amount of the end section of the central web section on the side of the second middle web section and the indentation amount of the end section of the second middle web section on the side of the central web section is 0.1 mm or more and 0.8 mm or less.

[0016] Preferably, the groove width of the main circumferential groove, which borders the end section of the central rib section in the direction of the tire width, is equal to or greater than the groove width of a main circumferential groove, which borders the second shoulder rib section.

[0017] Preferably, the length of the central rib section in the tire width direction is 105% or 120% or less than the length of the second central rib section in the tire width direction.

[0018] Preferably, an end section of the second shoulder rib section on the inner side in the tire width direction is recessed relative to the second virtual profile in the direction of the inner side in the tire radial direction, and a recession amount of the end section of the central rib section on the outer side in the tire width direction is greater than a recession amount of the end section of the second shoulder rib section on the inner side in the tire width direction.

[0019] Preferably, an end section of the second middle rib section on one side of the second shoulder rib section is recessed relative to the second virtual profile in the direction of the inner side in the tire radial direction, and a recession amount of the end section of the second middle rib section on the side of the second shoulder rib section is equal to or greater than a recession amount of the end section of the second shoulder rib section on one side of the second middle rib section.

[0020] Preferably, the second shoulder rib section includes a lug groove extending in the tire width direction, the lug groove includes a chamfer in the groove depth direction and groove width direction, and a chamfer in the groove width direction is greater than a chamfer in the groove depth direction.

[0021] Preferably, the rubber from which the tread section is formed has a hardness of 65 or more at 20 °C. Advantageous effects of the invention

[0022] The tire according to the present invention can achieve both dry steering stability performance and wet steering stability performance in a compatible manner. Brief description of the drawings Fig. Figure 1 is a cross-sectional view in a tire meridional direction illustrating a tire according to an embodiment of the present invention. Fig. 2 is a top view showing an example of a tread surface of the in Fig. 1 illustrated tire. Fig. Figure 3 is a diagram describing the midpoint of a bridge section. Fig. Figure 4 is a diagram describing the midpoint of another bridge section. Fig.Figure 5 is a diagram describing a depression at the end section of a web section. Fig. Figure 6 is a diagram describing a depression at the end section of a bridge section. Fig. Figure 7 is a diagram describing a depression at the end section of a bridge section. Fig. Figure 8 is a diagram describing a depression at the end section of a bridge section. Fig. Figure 9 is an enlarged meridian cross-sectional view of a central bridge section, a middle bridge section, and a shoulder bridge section. Fig. Figure 10 is a diagram illustrating an example of a cross-section of a stud groove of a shoulder bridge section. Fig. Figure 11 is a diagram illustrating an example of a cross-section of a stud groove of a shoulder bridge section. Fig.Figure 12 is a diagram illustrating an example of a contact surface shape of the tire according to the present embodiment. Fig. Figure 13 is a diagram illustrating an example of a tire contact patch shape according to a comparative example. Description of embodiments

[0023] Embodiments of the present invention are described in detail below with reference to the drawings. In the embodiments described below, identical or similar components to those of other embodiments have identical reference numerals, and descriptions of these components are either simplified or omitted. The present invention is not limited by the embodiments. Components of the embodiments include elements that are essentially identical or that can be easily interchanged and devised by a person skilled in the art. It should be noted that the configurations described below can be combined as desired. Furthermore, various omissions, substitutions, and modifications to the configurations can be made within the scope of protection of the present invention. Tires

[0024] Fig.Figure 1 is a cross-sectional view in a tire meridional direction illustrating a tire according to an embodiment of the present invention. Fig. Figure 1 is a cross-sectional view of a half-area in the tire radial direction. Fig. 2 is a top view showing an example of a tread surface of the in Fig. 1 illustrated tire 1 illustrated. Fig. 1 and Fig. Figure 2 also illustrates a radial tire for a passenger car as an example of a tire.

[0025] In Fig.1 is a cross-section in the tire meridian direction, defined as a cross-section of the tire 1 along a plane that includes an axis of rotation of the tire 1 (not illustrated). Furthermore, an equatorial plane CL of the tire is defined as a plane perpendicular to the tire axis of rotation and passing through a midpoint between measurement points of a tire cross-sectional width specified by JATMA (Japan Automobile Tire Manufacturers Association). The equatorial plane CL of the tire refers to a plane that is perpendicular to the axis of rotation of the pneumatic tire 1 and passes through the center of a tire width of the tire 1.

[0026] In the following, the tire radial direction refers to the direction perpendicular to the tire's axis of rotation (not illustrated). An inner side in the tire radial direction refers to the side closer to the axis of rotation in the tire radial direction. An outer side in the tire radial direction refers to the side away from the axis of rotation in the tire radial direction. Furthermore, a tire circumferential direction refers to the circumferential direction with the axis of rotation as its central axis. Additionally, a tire width direction refers to a direction parallel to the axis of rotation. An inner side in the tire width direction refers to the side closer to the tire's equatorial plane CL (tire equatorial line) in the tire width direction, and an outer side in the tire width direction refers to the side away from the tire's equatorial plane CL in the tire width direction.

[0027] Furthermore, an outer side and an inner side (in the direction of tire width) are defined as vehicle width directions when the tire is mounted on a vehicle. Additionally, left and right areas delimited by the equatorial plane CL of the tire are defined as an outer area (in the direction of tire width) and an inner area (in the direction of tire width), respectively. The tire also includes a mounting direction indicator (not illustrated) that specifies the mounting direction of the tire relative to a vehicle. Examples of the mounting direction indicator include a mark and a depression / protrusion on a sidewall section of the tire. For example, Regulation No.Regulation 30 of the Economic Commission for Europe (ECE R30) stipulates that a vehicle mounting direction indicator must be provided on the sidewall section on the outer side in the direction of vehicle width if the tire is mounted on a vehicle.

[0028] In Fig. 1 is a point T OUT A ground contact edge on the outer side in the direction of vehicle width. A point T IN The ground contact edge is located on the inner side of the tire in the direction of vehicle width. The ground contact edges refer to the two outermost edges in the direction of tire width within an area where a tread surface 3 of a tread section 2 of the tire 1 comes into contact with the road surface when the tire 1 is mounted on a specified rim, inflated to a specified internal pressure, and loaded with 70% of a specified load. The ground contact edge is continuous in the circumferential direction of the tire.

[0029] The specified rim refers to a "standard rim" specified by JATMA, a "measurement rim" specified by the Tire and Rim Association, Inc. (TRA), or a "measurement rim" specified by the European Tyre and Rim Technical Organisation (ETRTO). Furthermore, the specified internal pressure refers to a "maximum inflation pressure" specified by JATMA, the maximum value in "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" as specified by the TRA, or "INFLATION PRESSURES" as specified by the ETRTO. Furthermore, the specified load refers to a "maximum load capacity" according to JATMA specifications, the maximum value in "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" according to TRA specifications, or a "LOAD CAPACITY" according to ETRTO specifications.However, in the case of a car tire, JATMA specifies a specified internal pressure of 180 kPa, and the specified load is 88% of the maximum load capacity at the specified internal pressure.

[0030] The tread surface 3 is provided with a plurality of main circumferential grooves 21, 22, 23, and 24. A plurality of rib sections 20C, 20Ma, 20Mb, 20Sa, and 20Sb are defined by the main circumferential grooves 21, 22, 23, and 24. Rib section 20C is the central rib section closest to the equatorial plane of the tire CL. When a main circumferential groove is provided on the equatorial plane of the tire CL, the rib sections on both sides of the main circumferential groove, relative to the tire width direction, are the rib sections closest to the equatorial plane of the tire CL, i.e., the central rib sections. Rib section 20Sa is a first shoulder rib section forming a ground contact edge T. OUTthe ground contact edges T OUT and T IN on both sides relative to the tire width direction and the equatorial plane of the tire CL. 20Ma designates a first middle rib section located between the first shoulder rib section 20Sa and the central rib section 20C. Rib section 20Sb is a second shoulder rib section that includes a different ground contact edge T. IN from the ground contact edges T OUT and T INon both sides relative to the tire width direction with respect to the equatorial plane of the tire CL. The rib section 20Mb is a second middle rib section between the second shoulder rib section 20Sb and the central rib section 20C. The rib sections 20C, 20Ma, 20Mb, 20Sa and 20Sb can each be a rib-like rib section extending circumferentially in the direction of the tire or a rib section enclosing block rows subdivided by a groove extending in the direction of the tire width.

[0031] The tire 1 has a ring structure with the tire axis of rotation at its center and includes a pair of bead cores 11, 11, a pair of bead fillers 12, 12, a carcass layer 13, a belt layer 14, a tread rubber 15, a pair of sidewall rubbers 16, 16 and a pair of rim cushion rubber layers 17, 17 (see Fig. 1).

[0032] The pair of bead cores 11, 11 includes one or more bead wires made of steel, wound multiple times in a ring shape, and embedded in bead sections 10 to configure the core of the left and right bead sections 10. The pair of bead fillers 12, 12 is arranged on the outer side of the pair of bead cores 11, 11 in the tire radial direction to reinforce the bead sections 10.

[0033] The carcass layer 13 has a single-layer structure enclosing a single carcass ply, or a multi-layer structure enclosing multiple layered carcass plies. The carcass layer 13 extends in a torus shape between the left and right bead cores 11 and 12, forming the support structure of the tire. Furthermore, both end sections of the carcass layer 13 are folded over towards the outer side (in the direction of the tire width) to enclose the bead cores 11 and the bead fillers 12, and are fixed in place. The carcass layer 13 is produced by covering multiple carcass cord threads, made of steel or an organic fiber material (e.g., aramid, nylon, polyester, or rayon), with a coating rubber and applying a rolling process to the carcass cord threads. The cord thread angle is 80 degrees or more and 100 degrees or less.The cord thread angle is defined as the inclination angle of the carcass cord thread in the longitudinal direction with respect to the tire's circumferential direction.

[0034] In the configuration of Fig. 1 The carcass layer 13 has a single-layer structure including a single carcass ply, and a folded section 132 of it extends along the outer circumferential surface of a body section 131. A terminal end section of the folded section 132 is enclosed between the belt layer 14 and the body section 131.

[0035] The belt layer 14 is formed by stacking a plurality of belt layers and is arranged around the outer circumference of the carcass layer 13. The belt layer 14 includes a pair of cross belts 141, 142, a belt cover 143, and a belt edge cover 144. In this example, a plurality of belt covers 143 are provided.

[0036] The pair of cross-belts 141, 142 is produced by covering a plurality of belt cord threads, made of steel or an organic fiber material, with coating rubber and applying a rolling process to the belt cord threads. The cord thread angle has an absolute value of 15 degrees or more and 55 degrees or less. Furthermore, the pair of cross-belts 141, 142 has cord thread angles (defined as the longitudinal inclination angle of the belt cord threads with respect to the tire's circumferential direction) with opposite signs and is layered such that the longitudinal directions of the belt cord threads intersect (so-called cross-ply structure). The pair of cross-belts 141, 142 is also layered on an outer side of the carcass layer 13 in the tire's radial direction.

[0037] The belt cover 143 and the belt edge covers 144 are manufactured by coating a plurality of belt cover cord threads, made of steel or an organic fiber material, with coating rubber and have a cord thread angle of 0 degrees or more and 10 degrees or less as an absolute value. Furthermore, for example, a strip material is formed from one or more belt cover cord threads covered with coating rubber, and the belt cover 143 and the belt edge covers 144 are manufactured by repeatedly and spirally wrapping this strip material around the outer circumferential surfaces of the cross belts 141, 142 in the direction of the tire circumference.Furthermore, the belt cover 143 is arranged so that it completely covers the cross belts 141, 142, and the pair of belt edge covers 144, 144 is arranged so that it covers the left and right edge sections of the cross belts 141, 142 from the outer side in the tire radial direction.

[0038] The tread rubber 15 is arranged on the outer circumference of the carcass layer 13 and the belt layer 14 in the radial direction of the tire and forms a tread section 2 of the tire. Shoulder sections 8 are arranged at both end sections of the tread section 2 in the direction of the tire width.

[0039] The pair of sidewall rubbers 16, 16 is each arranged on the outer side of the carcass layer 13 in the direction of tire width and forms a left and a right sidewall section 30. For example, in the configuration of Fig.1. The end section of the sidewall rubber 16 is arranged on the outer side (in the tire radial direction) in the lower layer of the tread rubber 15 and is located between the belt layer 14 and the carcass layer 13. However, no such restriction is intended, and the end section of the sidewall rubber 16 on the outer side (in the tire radial direction) may be arranged in the outer layer of the tread rubber 15 and exposed in a support section (not illustrated). The support section is a non-ground contact area of ​​the connecting section between the profile of the tread section 2 and the profile of the sidewall section 30.

[0040] The pair of rim pad rubbers 17, 17 extends from an inner side of the left and right bead core 11, 11 in the tire radial direction and the folded-over sections 132 of the carcass layer 13 to the outer side in the tire width direction and forms rim mating surfaces of the bead sections 10. The rim mating surface is a contact surface of the bead section 10 with the rim flange (not illustrated).

[0041] The inner liner 18 is an air permeation prevention layer located on the inner surface of the tire and covering the carcass layer 13. It suppresses oxidation caused by the exposure of the carcass layer 13 and also prevents air from escaping the tire. Furthermore, the inner liner 18 is made, for example, of a rubber compound containing butyl rubber as the main component, a thermoplastic resin, and a thermoplastic elastomer compound containing an elastomer component mixed with the thermoplastic resin. Tread pattern

[0042] As in Fig.As illustrated in Figure 2, the tire 1 includes in the tread surface the plurality of main circumferential grooves 21, 22, 23 and 24 extending in the tire circumferential direction, and the plurality of rib sections 20C, 20Ma, 20Mb, 20Sa and 20Sb defined by these main circumferential grooves 21, 22, 23 and 24.

[0043] As in Fig. As illustrated in Figure 2, the rib section 20C, which is closest to the equatorial plane of the tire CL, is the central rib section. The rib section 20Sa, which forms the ground contact edge T OUT The first shoulder rib section is the section that includes the outer side (in the direction of vehicle width) with respect to the equatorial plane of the tire, CL. The rib section between the central rib section 20C and the first shoulder rib section 20Sa is the first central rib section 20Ma. The rib section 20Sa, which includes the ground contact edge T OUTThe second shoulder rib section is the section that includes the inner side (in the direction of vehicle width) with respect to the equatorial plane of the tire, CL. The rib section between the central rib section 20C and the second shoulder rib section 20Sa is the second central rib section 20Ma.

[0044] As in Fig. As illustrated in Figure 2, each rib section can be provided with a lug groove. The lug groove is a transverse groove that extends in the direction of the tire's width and opens when the tire comes into contact with the ground, thus acting as a groove. The first shoulder rib section 20Sa includes a lug groove L1. One end section of the lug groove L1 terminates at the first shoulder rib section 20Sa. The other end section of the lug groove L1 extends to the outer side of the ground contact edge T in the direction of the vehicle's width. OUTThe first central bridge section 20Ma is provided with a tunnel groove L2. One end section of tunnel groove L2 is open towards the main circumferential groove 21. The other end section of tunnel groove L2 is open towards the main circumferential groove 22. The central bridge section 20C is provided with a tunnel groove L3. One end section of tunnel groove L3 terminates at the central bridge section 20C. The other end section of tunnel groove L3 is open towards the main circumferential groove 22. The second central bridge section 20Mb includes tunnel grooves L4 and L5. One end section of tunnel groove L4 and one end section of tunnel groove L5 terminate at the second central bridge section 20Mb. The other end section of tunnel groove L4 is open towards the main circumferential groove 23. The other end section of tunnel groove L5 is open towards the main circumferential groove 24. The second shoulder bridge section 20Sb is equipped with a stud groove L6.One end section of the lug groove L6 terminates at the second shoulder rib section 20Sb. The other end section of the lug groove L6 extends to the inner side of the ground contact edge T in the direction of vehicle width. IN The drainage capacity can be ensured by providing these tunnel grooves L1 to L6.

[0045] Here, the groove width of the main circumferential groove 23, which adjoins the end section of the central rib section 20C (relative to the tire width direction), is preferably equal to or greater than the groove width of the main circumferential groove 21, which adjoins the first shoulder rib section 20Sa. Furthermore, the groove width of the main circumferential groove 23 is equal to or greater than the groove width of the main circumferential groove 24, which adjoins the second shoulder rib section 20Sb. If the main circumferential groove is provided at the equatorial plane of the tire CL, the groove width of the main circumferential groove is preferably equal to or greater than the groove width of the main circumferential groove that adjoins the shoulder rib section. By making the groove width of the main circumferential groove that collects the water drained in the central rib section 20C greater than the groove width of the other main circumferential grooves, the drainage capacity can be further improved.

[0046] The main circumferential grooves 21, 22, 23, and 24 have a groove width of 4.0 mm or more and 24.6 mm or less, and a groove depth of 5.5 mm or more and 8.0 mm or less. The main circumferential grooves 21, 22, 23, and 24 can be grooves with a wear indicator or narrow grooves without a wear indicator.

[0047] The groove width is measured as the distance between opposing groove walls within a groove opening section when the tire is mounted on a specified rim, inflated to a specified internal pressure, and in an unloaded state. In a configuration where the groove opening section includes a recessed or chamfered section, the groove width is measured using the intersections of the tread contact surface and extensions of the groove walls as measuring points, in a cross-sectional view parallel to the groove width direction and the groove depth direction.

[0048] Groove depth is measured as the distance from the tread surface to a position of maximum groove depth when the tire is mounted on a specified rim, inflated to the specified internal pressure, and unloaded. Additionally, in a configuration where a groove base partially includes depressions / protrusions or a sipe, the groove depth is measured excluding the partial depressions / protrusions or the sipe. tread rubber

[0049] The hardness of the rubber from which the tread section 2 is made is preferably 65 or higher. If the hardness of the rubber from which the tread section 2 is made is lower than that specified above, the bulged section of the rib segment, which has a non-ground contact area under normal load, will be compressed under high load. This is undesirable because the non-ground contact area becomes small, and the effectiveness of achieving both wet and dry steering stability performance in a compatible manner is reduced. The hardness specified above is the JIS A hardness, i.e., the durometer hardness measured at a temperature of 20 °C using a type A durometer according to JIS K 6253. Virtual profile

[0050] Back to Fig. 1, where a line forming a single arc connects the three points of the ground contact edge T OUT, which is located on the first shoulder rib section 20Sa in the direction of tire width, of the center point P CL the length of the central rib section 20C in the direction of tire width and the center point P OUT The length of the first central rib section 20Ma, connecting in the tire width direction, is defined as a first virtual profile PR1. The first virtual profile PR1 is a virtual profile on the outer side of the tire's equatorial plane CL in the vehicle width direction. Furthermore, a line that connects the three points of the ground contact edge T in a single arc is defined. IN , which is located on the second shoulder rib section 20Sb on the inner side in the direction of tire width, of the center point P CL the length of the central rib section 20C in the direction of tire width and the center point P INThe length of the second central rib section 20Mb, connected in the tire width direction, is defined as a second virtual profile PR2. The second virtual profile PR2 is a virtual profile on the inner side of the tire's equatorial plane CL, in the vehicle width direction. center point of a bridge section

[0051] Here, the midpoint of the bridge section is defined as follows. Fig. Figure 3 is a diagram to describe the midpoint of the bridge section. Fig. Figure 3 illustrates a meridian cross-section of the second central bridge section 20Mb as an example of the bridge section. Fig.3. The end section of the second central rib section 20Mb on the side of the main circumferential groove 24, i.e., on the outer side in the direction of vehicle width, is defined as T1. Furthermore, the end section of the second central rib section 20Mb on the side of the main circumferential groove 23, i.e., on the inner side in the direction of vehicle width, is defined as T2. The distance between end section T1 and end section T2 is a length LM of the second central rib section 20Mb in the tire width direction. The intersection of the normal H from the midpoint PM of length LM to the road contact surface RM of the second central rib section 20Mb and the road contact surface RM is the midpoint P. IN of the second middle web section 20Mb. The midpoint PCL of the central web section 20C and the midpoint P OUT of the in Fig.The first central web section 20Ma, illustrated in 1, is also defined in the same way as above.

[0052] In the Fig. In the 3 illustrated example, the maximum projection position of the second middle bridge section is 20Mb and the midpoint is P. IN together. However, the midpoint of a bridge section, defined as described above, does not always coincide with the maximum projection position of the bridge section.

[0053] If a chamfer or recess is provided at the end section of the web section, the midpoint is defined as follows. Fig. Figure 4 is a diagram illustrating the midpoint of another bridge section. Fig. Figure 4 illustrates a meridian cross-section of another second middle bridge section 20Mb'. As in Fig.As illustrated in Figure 4, a chamfer M is provided at the inner end section of the second central rib section 20Mb' in the direction of the vehicle width. The midpoint of a rib section exhibiting the chamfer M is defined as follows. The intersection point T3 of an extension line KMS originating from a groove wall KM and an extension line RMS originating from a road contact surface RM' is defined as a virtual edge. The distance between the end section T1 and the intersection point T3 is a length LM' of the second central rib section 20Mb' in the tire width direction. The intersection point of a normal H from a midpoint PM' of length LM' to the road contact surface RM' of the second central rib section 20Mb' and the road contact surface RM' is the midpoint P. IN' of the second middle web section 20Mb. The midpoint is defined in the same way as above if a recess is provided at the end section of the web section. Recess at the end section of a bridge section

[0054] Fig. Figures 5 to 8 are views describing a depression at an end section of the web section. Fig. Figure 5 illustrates a meridian cross-section of the first central bridge section 20Ma as an example of the bridge section. Fig. 5 are the end sections of the first central rib section 20Ma relative to the first virtual profile PR1, recessed towards the inner side in the tire radial direction. Fig.5. The indentation amount (maximum value) of the first virtual profile PR1 at the outer end section of the first central rib section 20Ma, relative to the tire width direction, is defined as MR1. Furthermore, the indentation amount (maximum value) of the first virtual profile PR1 at the inner end section of the first central rib section 20Ma, relative to the tire width direction, is defined as MR2. As in Fig. As illustrated in Figure 5, in the meridian cross-section view both end sections of the first middle rib section 20Ma are recessed towards the inner side in the tire radial direction, so that the first middle rib section 20Ma has a convex shape.

[0055] As in Fig.As illustrated in Figure 6, the outer end section of the central rib section 20C, in the vehicle width direction, is also recessed towards the inner side (in the tire width direction) relative to the first virtual profile PR1 in the same manner as described above. The recession depth (maximum value) from the first virtual profile PR1 at the outer end section of the central rib section 20C, in the vehicle width direction, is defined as CR1. The inner end of the central rib section 20C, in the vehicle width direction, is also recessed towards the inner side (in the tire width direction) relative to the second virtual profile PR2, in the same manner as described above. The recession depth (maximum value) from the second virtual profile PR2 at the inner end section of the central rib section 20C, in the vehicle width direction, is defined as CR2. As shown in Fig.As illustrated in Figure 6, in the meridian cross-sectional view both end sections of the central rib section 20C, which are related to the tire width direction, are recessed towards the inner side in the tire radial direction, so that the central rib section 20C has a convex shape.

[0056] As in Fig.As illustrated in Figure 6, the outer end section of the second central rib section 20Mb, in the direction of vehicle width, is also recessed towards the inner side, in the direction of tire width, relative to the second virtual profile PR2, in the same manner as described above. The recession depth (maximum value) from the second virtual profile PR2 at the outer end section of the second central rib section 20Mb, in the direction of vehicle width, is defined as MR3. The inner end section of the second central rib section 20Mb, in the direction of vehicle width, is also recessed towards the inner side, in the direction of tire width, relative to the second virtual profile PR2, in the same manner as described above. The recession depth (maximum value) from the second virtual profile PR2 at the inner end section of the second central rib section 20Mb, in the direction of vehicle width, is defined as MR3. As in Fig.As illustrated in Figure 6, in the meridian cross-section view both end sections of the second middle rib section 20Mb are recessed towards the inner side in the tire radial direction, so that the second middle rib section 20Mb has a convex shape.

[0057] As in Fig. As illustrated in Figure 6, the inner end section of the shoulder rib section 20Sa, in the direction of vehicle width, is also recessed towards the inner side relative to the first virtual profile PR1 in the same manner as described above. The recession amount (maximum value) from the first virtual profile PR1 at the inner end section of the shoulder rib section 20Sa, in the direction of vehicle width, is defined as SR1. In the meridian cross-sectional view, both end sections of the shoulder rib section 20Sa are recessed towards the inner side in the tire radial direction, so that the shoulder rib section 20Sa has a convex shape.

[0058] As in Fig.As illustrated in Figure 6, the outer end section of the shoulder rib section 20Sb, in the direction of vehicle width, is also recessed towards the inner side (in the tire radial direction) relative to the second virtual profile PR2 in the same manner as described above. The recession amount (maximum value) from the second virtual profile PR2 at the outer end section of the shoulder rib section 20Sb, in the direction of vehicle width, is defined as SR2. In the meridian cross-sectional view, both end sections of the shoulder rib section 20Sb are recessed towards the inner side (in the tire radial direction), so that the shoulder rib section 20Sb has a convex shape.

[0059] If one considers Fig.6. Here, the indentation amount CR1 at the outer end section of the central rib section 20C (in the direction of vehicle width) is greater than the indentation amount MR2 at the inner end section of the first central rib section 20Ma (in the direction of vehicle width). Furthermore, the indentation amount CR2 at the inner end section of the central rib section 20C (in the direction of vehicle width) is greater than the indentation amount MR3 at the outer end section of the second central rib section 20Mb (in the direction of vehicle width). By deepening the central rib section 20C in this way, the drainage characteristics of the central rib section, which has the worst drainage properties, can be improved. The wet steering stability performance can be improved by increasing the ground contact pressure, and the stiffness of the rib section is not reduced, so the dry steering stability performance can be maintained.As a further countermeasure, it is conceivable to enlarge the groove area of ​​the lug groove to increase the ground contact pressure. However, this is not preferable because the stiffness of the rib section decreases and the dry steering stability performance deteriorates. The indentation amount MR1 at the outer end section of the first central rib section 20Ma (in other words, the end section on the side of the shoulder rib section 20Sa) is preferably equal to or greater than the indentation amount SR1 at the inner end section of the shoulder rib section 20Sa (in other words, the end section on the side of the first central rib section 20Ma).Furthermore, the indentation amount MR4 at the inner end section of the second middle web section 20Mb in the direction of vehicle width (in other words, the end section on the side of the shoulder web section 20Sb) is preferably equal to or greater than the indentation amount SR2 at the outer end section of the shoulder web section 20Sb in the direction of vehicle width (in other words, the end section on the side of the second middle web section 20Mb).

[0060] If we consider again Fig.5. The intersection points of the first virtual profile PR1 and the extension lines KMS1 and KMS2, which extend from the groove walls KM1 and KM2 of the first central rib section 20Ma of the main circumferential grooves 21 and 22, adjacent to both end sections of the first central rib section 20Ma in the tire circumferential direction, are defined as E1 and E2, respectively. Furthermore, the distance between the intersection point E1 and the intersection point E2 in the tire width direction is defined as Wa. Here, the ground contact edge of the first central rib section 20Ma is positioned on a side of the first central rib section 20Ma that is further inboard in the tire width direction than a position at a distance of 0.03Wa from each of the two end sections of the first central rib section 20Ma.This means that points B1 and B2, which are projected in the normal direction to the first virtual profile PR1 from points A1 and A2, which have been moved by a distance of 0.03Wa along the first virtual profile PR1 from the intersection points E1 and E2 to the middle of the first middle web section 20Ma, onto the first middle web section 20Ma, have no contact with the ground.

[0061] The same applies to those referring to Fig. 6 described end sections of the second middle rib section 20Mb, relating to the tire width direction. That is, as in Fig.As illustrated in Figure 7, the intersection points of the second virtual profile PR2 and the extension lines KMS3 and KMS4, which extend from the groove walls KM3 and KM4 of the second central rib section 20Mb of the main circumferential grooves 23 and 24, adjacent to both end sections of the second central rib section 20Mb in the tire circumferential direction, are defined as E3 and E4, respectively. Furthermore, the distance between intersection point E3 and intersection point E4 in the tire width direction is defined as Wb. Here, the ground contact edge of the second central rib section 20Mb lies on a side of the second central rib section 20Mb that is further inboard in the tire width direction than a position at a distance of 0.03Wb from each of the two end sections of the second central rib section 20Mb.This means that points B3 and B4, which are projected in the normal direction to the second virtual profile PR2 from points A3 and A4, which have been moved by a distance of 0.03Wb along the second virtual profile PR2 from the intersection points E3 and E4 to the middle of the second middle web section 20Mb, have no contact with the ground.

[0062] The same applies to those referring to Fig. 6 described, referring to the end sections of the central rib section 20C in the direction of the tire width. In other words, the intersection of the first virtual profile PR1 and the extension line KMS, which extends from the groove wall KM of the main circumferential groove 22, which adjoins the outer end section of the central rib section 20C in the direction of the vehicle width, is as described in Fig.Figure 8 illustrates this and is defined as E. Furthermore, the intersection of the first virtual profile PR1 and the extension line KMS', which extends from the groove wall KM' of the main circumferential groove 23, adjacent to the inner end section of the central rib section 20C in the direction of the vehicle width, on the side of the central rib section 20C, is defined as E'. Then the distance between the intersection point E and the intersection point E' in the direction of the tire width is defined as Wc.

[0063] Here, the ground contact edge of the central rib section 20C lies on a side of the central rib section 20C that is further inward in the tire width direction than a position 0.03Wc from either of the two end sections of the central rib section 20C. In other words, point B, which is projected onto the central rib section 20C from point A (moved 0.03Wc along the first virtual profile PR1 from intersection E to the center of the central rib section 20C) in the normal direction to the first virtual profile PR1, does not make contact with the ground. Furthermore, point B', which is projected onto the central rib section 20C from point A' (moved 0.03Wc along the first virtual profile PR1 from intersection E' to the center of the central rib section 20C) in the normal direction to the first virtual profile PR1, does not make contact with the ground.

[0064] In the reference to Fig. In the example described in section 8, it is assumed that the first virtual profile PR1 and the second virtual profile PR2 are identical. If the first virtual profile PR1 and the second virtual profile PR2 are different, then in Fig. 8 the intersection point of the extension line KMS' originating from the groove wall KM' and the second virtual profile PR2 the intersection point E'.

[0065] If the second virtual profile PR2 is used as a reference for the inner side in the direction of vehicle width, then in Fig.8 The intersection of the second virtual profile PR2 and the extension line KMS', which extends from the groove wall KM' of the main circumferential groove 23, adjacent to the inner end section of the central rib section 20C in the vehicle width direction, on the side of the central rib section 20C, is E'. Assuming that the distance between the intersection E and the intersection E' in the tire width direction is Wc', then point B', which is projected in the normal direction to the second virtual profile PR2 from point A', which has been moved by a distance of 0.03Wc' along the second virtual profile PR2 from the intersection E' to the center of the central rib section 20C, does not come into contact with the ground.This means that the ground contact edge of the central rib section 20C is located on a side that is further inward in the tire width direction than a position at a distance of 0.03Wc' from the end section of the central rib section 20C on the side of the middle rib section. That is, if the second virtual profile PR2 is used as a reference, then... Fig. 8. “Abstand Wc” is replaced by “Abstand Wc’” and “0.03Wc” by “0.03Wc’”.

[0066] In Fig.6. The difference between the indentation depth CR1 and the indentation depth MR2 is preferably 0.1 mm or more and 0.8 mm or less. The difference between the indentation depth CR2 and the indentation depth MR3 is preferably 0.1 mm or more and 0.8 mm or less. A difference in indentation depth that is too small is not preferred, as it impairs the drainage performance of the central web section 20C. The difference in indentation depth is more preferably 0.2 mm or more and 0.8 mm or less. If the difference in indentation depth is within this range, the drainage performance can be further improved. If the difference in indentation depth is too large, the soil contact pressure of the central web section 20C increases excessively, resulting in uneven soil contact.This is not preferable because the lateral force when steering on a dry road surface, which has a large contact area, especially under microscopic view, is not effectively transferred to the road surface, leading to a deterioration of dry steering stability performance. Width of the bridge section

[0067] In Fig.6. The width of the central rib section 20C, i.e., the width in the tire width direction, is defined as Wc. The width of the first central rib section 20Ma, i.e., the width in the tire width direction, is defined as Wa. The width of the second central rib section 20Mb, i.e., the width in the tire width direction, is defined as Wb. The width Wc is the distance between intersection E and intersection E' in the tire width direction. The width Wa is the distance between intersection E1 and intersection E2 in the tire width direction. The width Wb is the distance between intersection E3 and intersection E4 in the tire width direction.

[0068] The width Wc of the central rib section 20C is preferably 105% or more and 120% or less of the widths Wa and Wb of the adjacent first central rib section 20Ma and second central rib section 20Mb. In other words, it is preferable that Wc / Wa, i.e., the ratio between the width Wc and the width Wa, is 1.05 or more and 1.20 or less. Furthermore, it is preferable that Wc / Wb, i.e., the ratio between the width Wc and the width Wb, is 1.05 or more and 1.20 or less. By making the length of the central rib section 20C, which has a large ground contact length in the tire width direction, greater than that of the adjacent rib section, dry steering stability performance can be ensured while maintaining drainage performance. A Wc / Wa ratio and a Wc / Wb ratio greater than 1.20 impair drainage performance and are not preferred. cleat groove

[0069] Fig. Figure 9 is an enlarged meridian cross-sectional view of the central bridge section 20C, the middle bridge section 20Ma, and the shoulder bridge section 20Sa. As in Fig. As illustrated in Figure 9, the shoulder rib section 20Sa is provided with a lug groove L1. The middle rib section 20Ma is provided with a lug groove L2. The central rib section 20C is provided with a lug groove L3. By providing these lug grooves L1, L2, and L3, the drainage performance is improved. Therefore, the wet steering stability performance can be further enhanced.

[0070] Furthermore, it is preferable that the groove opening sections of the tunnel grooves L1, L2, and L3 be provided with chamfers. In particular, the tunnel groove L1 of the shoulder bridge section 20Sa has a significant effect on the drainage capacity. Therefore, it is preferable that the groove opening section of the tunnel groove L1 be chamfered.

[0071] Fig. 10 and Fig. Figure 11 shows an example of a cross-section of the stud groove of the shoulder bridge section 20Sa. As in Fig. As illustrated in Figure 10, chamfers M11 and M12 are provided at the opening section of the tunnel groove L1a. The angles θ1 and θ2 of chamfers M11 and M12 of tunnel groove L1a with respect to the road contact surface of the web section 20Sa are both 45 degrees. Therefore, the length MD of chamfers M11 and M12 in the groove depth direction and the length MW of chamfers M11 and M12 in the groove width direction are identical.

[0072] Furthermore, the chamfers M13 and M14, as in Fig.Figure 11 illustrates this, provided at the opening section of the lug groove L1b. The angles θ3 and θ4 of the chamfers M13 and M14 of the lug groove L1b with respect to the road contact surface of the rib section 20Sa are both, for example, 27 degrees. Therefore, the length MW of the chamfers M13 and M14 in the groove width direction is greater than the length MD of the chamfers M13 and M14 in the groove depth direction. As described above, the length MW in the groove width direction of the chamfers M13 and M14 of the lug groove L1 is greater than the length MD in the groove depth direction, thus improving drainage performance. Therefore, both wet steering stability performance and dry steering stability performance can be achieved in a compatible manner. Examples of contact surface shapes

[0073] Fig. Figure 12 is a diagram illustrating an example of the contact patch shape of the tire according to the present embodiment. The diagram shown in Fig. The 12 illustrated areas correspond to the respective bridge sections, which are described in the document with reference to Fig. The tread section 2 described in section 2 is provided. Fig. 12 corresponds to an area of ​​40C, the central web section 20C in Fig.2. A 40Ma area corresponds to the first central rib section 20Ma, and a 40Mb area corresponds to the second central rib section 20Mb. A 40Sa area corresponds to the first shoulder rib section 20Sa, and a 40Sb area corresponds to the second shoulder rib section 20Sb. Since, as described above, the tread depths of the first virtual profile PR1 and the second virtual profile PR2 are appropriately defined at the end sections of the respective rib sections, the length of area 40C is the longest in the circumferential direction of the tire, and the lengths of areas 40Sa and 40Sb, which correspond to the shoulder rib sections in the circumferential direction of the tire, are relatively short. Therefore, the balance of each area is good. Consequently, the drainage performance of the section corresponding to the main circumferential groove can be improved.

[0074] Fig.Figure 13 is a diagram illustrating an example of the contact patch shape of the tire according to a comparative example. Fig. Figure 13 illustrates an example of the contact surface shape when the indentation values ​​of the first virtual profile PR1 and the second virtual profile PR2 are not appropriately defined at the end sections of the respective web sections. Fig. Figure 13 illustrates an area 50C corresponding to the central bridge section, an area 50Ma corresponding to the first middle bridge section, an area 50Mb corresponding to the second middle bridge section, an area 50Sa corresponding to the first shoulder bridge section, and an area 50b corresponding to the second shoulder bridge section.

[0075] With reference to Fig. 13 is the area of ​​the section corresponding to the tunnel groove, in each area smaller than in the case of Fig. 12. Therefore, in the case of Fig.13. It is difficult to improve the drainage performance. Compared to the lengths of the areas in the circumferential direction of the tire, the length of area 50C, which corresponds to the central rib section 20C in the circumferential direction of the tire, is shorter than the length of area 50Mb, which corresponds to the second central rib section 20Mb in the circumferential direction of the tire. Furthermore, the length of area 50Sa, which corresponds to the rib section of the first shoulder in the circumferential direction of the tire, is relatively long. As described above, the balance of the lengths of each area in the circumferential direction of the tire is poor. Therefore, it is difficult to improve the dry steering stability performance and the wet steering stability performance. Brief description

[0076] As described above, a structure is employed in which the end portion of the central rib section and the end portion of the middle rib section on both sides of the main circumferential groove are recessed towards the inner side in the direction of the tire circumference, relative to the virtual profile. The recession depth of the former end portion is greater than that of the latter end portion, and a region of 0.03Wc (or 0.03Wc') of the end portion of the central rib section on the side of the middle rib section does not contact the ground, thus ensuring a suitable contact patch shape for the tire. This structure can improve both dry and wet steering stability performance.

[0077] Since dry and wet steering stability performance is particularly effective on the outer side of the vehicle (in the direction of vehicle width), the application of the aforementioned structure can improve both dry and wet steering stability performance, at least on this side. Furthermore, the application of the aforementioned structure to the inner side of the vehicle (in the direction of vehicle width) can improve both dry and wet steering stability performance.

[0078] In the aforementioned structure, the bulge of the central rib section, which requires drainage capacity, is larger than the bulge of the adjacent section, and the width of the main circumferential groove bordering the central rib section is relatively wide. As a result, water can be effectively channeled from the rib section into the main circumferential groove. Furthermore, due to the increased bulge, the end portion of the central rib section (relative to the tire width direction) does not make contact with the ground, thus reducing the actual ground contact area, increasing ground contact pressure, and improving wet steering stability. Increasing the bulges of all rib sections would improve wet steering stability but worsen dry steering stability because the ground contact area would be too small.According to the aforementioned structure, dry steering stability performance and wet steering stability performance can be improved. Examples

[0079] In the present example, tests for dry and wet steering stability performance were conducted on a variety of tire types under different conditions (see Tables 1 to 6). For these tests, 255 / 35ZR19 (96Y) 19×9J pneumatic tires were mounted on a predetermined rim and inflated to a pressure of 230 kPa. One vehicle was a 3500 cc FR sedan. A sensory evaluation of dry and wet steering stability performance was performed on a test track by a test driver on a predetermined road surface and at a predetermined speed. The evaluation was performed using index values, with the reference (100) assigned to the conventional example tire, and a higher value indicating better performance. If the rating is 95 or higher, the required performance for the tire is assured.

[0080] The tires of Examples 1 to 31 include a plurality of main circumferential grooves provided in the tread section and extending in the circumferential direction of the tire, and a plurality of rib sections defined by the plurality of main circumferential grooves, and on an outer side area of ​​the vehicle, a central rib section closest to an equatorial plane of the tire, a first shoulder rib section which includes a ground contact edge on both sides with respect to the equatorial plane of the tire, based on the tire width direction.and a first central rib section is provided between the first shoulder rib section and the central rib section. In the tires of Examples 1 to 31, on the outside of the vehicle, the end section of the central rib section on the side of the first central rib section is recessed relative to the first virtual profile towards the inner side in the tire radial direction, a recession amount of the end section of the central rib section on the side of the central rib section is recessed relative to the first virtual profile towards the inner side in the tire radial direction, a recession amount of the end section of the central rib section on the side of the first central rib section is greater than a recession amount of the end section of the first central rib section on the side of the central rib section, and if, in the tire meridian cross-sectional view, the distance between the intersection points of the first virtual profile and the extension lines,The ground contact edge of the central rib section, which extends from the groove walls of the main circumferential grooves adjacent to both end sections of the central rib section in the tire width direction, is defined as Wc on the sides of the central rib section. This is located on a side that is further inboard than a position at a distance of 0.03Wc from the end section of the central rib section on the first side of the central rib section.

[0081] Furthermore, in the tires of Examples 17 to 31, on the inside of the vehicle, the end section of the central rib segment on the side of the second central rib segment is recessed relative to the second virtual profile towards the inner side in the tire radial direction; the end section of the second central rib segment on the side of the central rib segment is recessed relative to the second virtual profile towards the inner side in the tire radial direction; the recession amount of the end section of the central rib segment on the side of the second central rib segment is greater than the recession amount of the end section on the side of the central rib segment of the second central rib segment; and if, in the tire meridian cross-sectional view, the distance between the intersection points of the second virtual profile and the extension lines extending from the groove walls of the main circumferential grooves is greater than ... on the cross-sectional section sides of the tire meridian cross-sectional view, the distance between the intersection points of the second virtual profile and the extension lines extending from the groove walls of the main circumferential grooves is greater than the recession amount of the second central rib segment.which extend to both end sections of the central rib section, defined in the tire width direction as Wc', the ground contact edge of the central rib section is located on a side that is further inward than a position at a distance of 0.03Wc' from the end section of the central rib section on the second side of the central rib section.

[0082] In the conventional example tire, the depth of the virtual tread pattern is uniform. In the comparative example 1 tire, the depth of the end section of the central rib segment on the side of the second central rib segment is smaller than the depth of the end section of the second central rib segment on the side of the central rib segment. In the tires of comparative examples 3 and 4, the depth of the end section of the central rib segment on the side of the second central rib segment is identical to the depth of the end section of the second central rib segment on the side of the central rib segment.In the tire of comparison example 2, the ground contact edge of the central rib section is positioned on a side that is further outward than a position at a distance of 0.03Wc from the end of the central rib section on the side of the first central rib section. If the depression amount in Table 1 is a negative value, it indicates the projection amount.

[0083] According to the tires of Examples 1 to 31, satisfactory results are achieved if, at least on the outside of the vehicle, the end section of the central rib segment on the side of the first central rib segment is recessed relative to the first virtual profile towards the inner side in the tire radial direction, the end section of the first central rib segment on the side of the central rib segment is recessed relative to the first virtual profile towards the inner side in the tire radial direction, and the recession amount of the end section of the central rib segment on the side of the first central rib segment is greater than the recession amount of the end section of the first central rib segment on the side of the central rib segment.and if, in the meridian cross-sectional view on the sides of the central rib section, the distance between the intersection points of the first virtual profile and the extension lines on the sides of the central rib section, extending from the groove walls of the main circumferential grooves adjacent to both end sections of the central rib section relative to the tire width direction, is defined as Wc, then the ground contact edge of the central rib section lies on a side that is further inboard than a position at a distance of 0.03Wc from the end section of the central rib section on the first side of the central rib section.

[0084] Furthermore, it can be seen from the tires of Examples 17 to 31 that satisfactory results are achieved if, on the inside of the vehicle, the end section of the central rib segment on the side of the second central rib segment is recessed relative to the second virtual profile towards the inner side in the tire radial direction, the end section of the second central rib segment on the side of the central rib segment is recessed relative to the second virtual profile towards the inner side in the tire radial direction, the recession amount of the end section of the central rib segment on the side of the second central rib segment is greater than the recession amount of the end section of the second central rib segment on the side of the central rib segment, and if, in the meridian cross-sectional view on the sides of the central rib segment, the distance between the intersection points of the first virtual profile and the extension lines,The ground contact edge of the central rib section, which extends from the groove walls of the main circumferential grooves adjacent to both end sections of the central rib section and is defined as Wc in the tire width direction, lies on a side that is further inboard than a position at a distance of 0.03Wc from the end section of the central rib section on the first side of the central rib section. [Table 1] Table 1-I State of the art example Example 1 Comparative example 1 Comparative example 2 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,2 0,7 0,4 0,7 Maximum indentation amount MR2 [mm] of the end section of the middle web section on the side of the central web section 0,2 0,4 0,7 0,4 Difference (CR1 - MR2) [mm] 0 0,3 -0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,2 0,4 0,7 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,2 0,4 0,7 0,4 Difference (MR1 - SR1) [mm] 0 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Outer side Inner side Inner side Outer side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Outer side Inner side Inner side Outer side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,2 0,7 0,4 0,7 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,2 0,4 0,7 0,4 Difference (CR2 - MR3) [mm] 0 0,3 -0,3 0,3 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,2 0,4 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,2 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Outside inside inside inside The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Outer side Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 200 tread rubber hardness 75 75 75 75 Dry steering stability performance 100 100 100 100 Wet steering stability performance 100 120 100 100 Table 1-II Comparative example 3 Comparative example 4 Example 2 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,4 1,5 0,5 Maximum indentation amount MR2 [mm] of the end section of the middle web section on the side of the central web section 0,4 1,5 0,4 Difference (CR1 - MR2) [mm] 0 0 0,1 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 1,5 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 1,5 0,4 Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,4 1,5 0,5 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 1,5 0,4 Difference (CR2 - MR3) [mm] 0 0 0,1 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. inside inside inside The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 90 100 Wet steering stability performance 100 120 110 [Table 2] Table 2-I Example 3 Example 4 Example 5 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,6 1,2 1,3 Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,2 0,8 0,9 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,6 1,2 1,3 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR2 - MR3) [mm] 0,2 0,8 0,9 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 100 95 Wet steering stability performance 120 125 125 Table 2-II Example 6 Example 7 Example 8 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the central bridge section / 100 102 110 groove adjacent to shoulder bridge section [%] Width of central web section WC / Width of middle web section Wa [%] 110 110 103 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR2 - MR3) [mm] 0,3 0,3 0,3 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of the central walkway section WC / Width of the 110 110 110 middle bridge section Wb[%] Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 100 100 Wet steering stability performance 110 115 110 [Table 3] Table 3-I Example 9 Example 10 Example 11 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 105 120 122 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR2 - MR3) [mm] 0,3 0,3 0,3 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 100 100 Wet steering stability performance 120 120 110 Table 3-II Example 12 Example 13 Example 14 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0 Difference (MR1 - SR1) [mm] 0 0 0,4 The ground contact edge of the central bridge section lies at 0.03W. Inner side Inner side Inner side inner side or outer side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR2 - MR3) [mm] 0,3 0,3 0,3 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies at a value of 0.03W. Inner side Inner side Inner side inner side or outer side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 63 65 75 Dry steering stability performance 100 100 100 Wet steering stability performance 110 118 115 [Table 4] Table 4-I Example 15 Example 16 Example 17 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on 0,4 0,4 0,4 the side of the middle web section Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 100 150 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,4 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,7 Difference (CR2 - MR3) [mm] 0,3 0,3 -0,3 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,7 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,7 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the off-center bridge section lies Inner side Inner side Inner side in relation to 0.03W on the inside or outside The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 100 100 Wet steering stability performance 115 118 118 Table 4-II Example 18 Example 19 Example 20 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum depth SR1 [mm] of the end section 0,4 0,4 0,4 of the shoulder strap section on the side of the middle strap section Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,4 1,5 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 1,5 Difference (CR2 - MR3) [mm] 0,3 0 0 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 1,5 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 1,5 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Outer side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Outer side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 100 99 Wet steering stability performance 118 118 120 [Table 5] Table 5-I Example 21 Example 22 Example 23 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,5 0,6 1,2 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR2 - MR3) [mm] 0,1 0,2 0,8 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 100 100 Wet steering stability performance 119 120 121 Table 5-II Example 24 Example 25 Example 26 Outer side in the direction of vehicle width Maximum indentation CR1 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 1,3 0,7 0,7 Maximum indentation amount MR3 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR2 - MR3) [mm] 0,9 0,3 0,3 Depth MR4 [mm] of the end section of the middle web section on 0,4 0,4 0,4 the side of the shoulder strap section Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 100 102 Width of central web section WC / Width of middle web section Wb [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 100 100 Wet steering stability performance 121 119 120 [Table 6] Table 6-I Example 27 Example 28 Example 29 In vehicle widths- Maximum indentation CR1 [mm] of the end section of the central web section 0,7 0,7 0,7 outer side on the side of the middle web section Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR1 - SR1) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 0,7 Maximum indentation MR3 [mm] of the end section of the middle web section 0,4 0,4 0,4 on the side of the central bridge section Difference (CR2 - MR3) [mm] 0,3 0,3 0,3 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 0,4 Difference (MR4 - SR2) [mm] 0 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 110 Width of central web section WC / Width of middle web section Wb [%] 103 105 120 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 200 tread rubber hardness 75 75 75 Dry steering stability performance 100 100 100 Wet steering stability performance 119 120 120 Table 6-II Example 30 Example 31 In-Vehicle Maximum depth CR1 [mm] of the end section 0,7 0,7 width-oriented outer side of the central bridge section on the side of the middle bridge section Maximum indentation CR1 [mm] of the end section of the middle web section on the side of the central web section 0,4 0,4 Difference (CR1 - MR2) [mm] 0,3 0,3 Maximum indentation amount MR1 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 Maximum indentation SR1 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0,4 Difference (MR1 - SR1) [mm] 0 0 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 Width of central web section WC / Width of middle web section Wa [%] 110 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 Inner side (in the direction of vehicle width) Maximum indentation CR2 [mm] of the end section of the central web section on the side of the middle web section 0,7 0,7 Maximum depth MR3 [mm] of the end section 0,4 0,4 of the middle section of the bridge on the side of the central section of the bridge Difference (CR2 - MR3) [mm] 0,3 0,3 Depth MR4 [mm] of the end section of the middle web section on the side of the shoulder web section 0,4 0,4 Maximum indentation SR2 [mm] of the end section of the shoulder bridge section on the side of the middle bridge section 0,4 0 Difference (MR4 - SR2) [mm] 0 0,4 The ground contact edge of the central bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side The ground contact edge of the middle bridge section lies on the inner or outer side with respect to 0.03W. Inner side Inner side Width of the groove adjacent to the central web section / shoulder web section [%] 110 110 Width of central web section WC / Width of middle web section Wb [%] 122 110 Bevel width MW of the shoulder lug groove / bevel depth MD [%] 200 200 tread rubber hardness 75 75 Dry steering stability performance 100 100 Wet steering stability performance 119 120 List of reference symbols 1 tire 2. Tread section 3. Tread surface 8 Shoulder section 10 bead section 11 bead core 12 bead fillers 13 Carcass layer 14 Belt layer 15 tread rubber 16 side wall rubber 17 Wheel rim pad rubber 18 Inner Soul 20C Central Bridge Section 20Ma First middle section of the bridge 20Mb Second middle bridge section 20Sa First shoulder bridge section 20Sb Second shoulder strap section 21, 22, 23, 24 Main circumferential groove 30 side wall section CL Equatorial plane of the tire L1, L1a, L1b, L2, L3, L4, L5, L6 lug groove PR1 First virtual profile PR2 Second virtual profile T IN , T OUT ground contact edge

Claims

[1] Tires (1), comprising: a plurality of main circumferential grooves (21, 22, 23, 24) provided in a tread section (2), the plurality of main circumferential grooves (21, 22, 23, 24) extending in the tire circumferential direction; and a plurality of rib sections (20C, 20Ma, 20Mb, 20Sa, 20Sb), which are defined by the majority of main circumferential grooves (21, 22, 23, 24), comprising the majority of web sections (20C, 20Ma, 20Mb, 20Sa, 20Sb): a central rib section (20C) that is closest to the equatorial plane (CL) of the tire (1); a first shoulder bridge section (20Sa) that is defined by ground contact edges (T IN , T OUT ) on both sides relating to a tire width direction in relation to the equatorial plane (CL) of the tire (1) a ground contact edge (T OUT ) includes; and a first middle bridge section (20Ma) between the first shoulder bridge section (20Sa) and the central bridge section (20C), wherein in a meridian cross-sectional view of the tire (1) a line forming a single arc passes through a ground contact edge located in the first shoulder rib section (20Sa), a midpoint (P CL ) a length of the central rib section (20C) in the tire width direction and a midpoint (P OUT ) a length of the first middle rib section (20Ma) in the tire width direction, is defined as a first virtual profile (PR1), an end section of the central rib section (20C) on one side of the first central rib section (20Ma) is recessed towards an inner side in the tire radial direction relative to the first virtual profile (PR1), an end section of the first middle rib section (20Ma) on one side of the central rib section (20C) is recessed relative to the first virtual profile (PR1) towards the inner side in the tire radial direction, a depression amount (CR1) of the end section of the central rib section (20C) on the side of the first middle rib section (20Ma) is greater than a depression amount (MR2) of the end section of the first middle rib section (20Ma) on the side of the central rib section (20C), and in the meridional cross-sectional view of the tire (1) a distance between intersection points (E, E') of the first virtual profile (PR1) and extension lines (KMS, KMS') that are on the side of the central rib section (20C) of groove walls (KM, KM') of main circumferential grooves (22, 23) adjacent to both end sections of the central rib section (20C) in the tire width direction is defined as Wc, and a ground contact edge of the central rib section (20C) is located on a side that is further inboard than a position at a distance of 0.03Wc from the end section of the central rib section (20C) on the side of the first middle bridge section (20Ma). [2] Tire (1) according to claim 1, wherein in the meridian cross-sectional view of the tire (1) a distance between the intersection points (E1, E2) of the first virtual profile (PR1) and the extension lines (KMS1, KMS2) extending from the groove walls (KM1, KM2) on the sides of the first central rib section (20Ma) of the main circumferential grooves (21, 22) adjoining both end sections of the first central rib section (20Ma) in the tire width direction is defined as Wa, and a ground contact edge of the first central rib section (20Ma) is arranged on a side that is further inboard than a position at a distance of 0.03Wa from the end section of the first central rib section (20Ma) on the side of the central rib section (20C). [3] Tires (1) according to claim 1 or 2, wherein the difference between the indentation amount (CR1) of the end section of the central rib section (20C) on the side of the first central rib section (20Ma) and the indentation amount (MR2) of the end section of the first central rib section (20Ma) on the side of the central rib section (20C) is 0.1 mm or more and 0.8 mm or less. [4] Tire (1) according to any one of claims 1 to 3, wherein in the tire width direction a groove width of the main circumferential groove (23) adjacent to the end section of the central rib section (20C) is equal to or greater than a groove width of a main circumferential groove (21) adjacent to the first shoulder rib section (20Sa). [5] Tire (1) according to any one of claims 1 to 4, wherein the length of the central rib section (20C) in the tire width direction is 105% or 120% or less than the length of the first central rib section (20Ma) in the tire width direction. [6] Tires according to any one of claims 1 to 5, wherein an end section of the first shoulder rib section (20Sa) on the inner side in the tire width direction relative to the first virtual profile (PR1) is recessed towards the inner side in the tire radial direction, and a depression amount (CR1) of the end section of the central rib section (20C) on an outer side in the direction of tire width is greater than a depression amount (SR1) of the end section of the first shoulder rib section (20Sa) on the inner side in the direction of tire width. [7] Tires (1) according to claim 6, wherein an end section of the first middle rib section (20Ma) on one side of the first shoulder rib section (20Sa) is recessed relative to the first virtual profile (PR1) towards the inner side in the tire radial direction, and a depression amount (MR1) of the end section of the first middle bridge section (20Ma) on the side of the first shoulder bridge section (20Sa) is equal to or greater than a depression amount (SR1) of the end section of the first shoulder bridge section (20Sa) on one side of the first middle bridge section (20Ma). [8] Tires (1) according to any one of claims 1 to 7, wherein the first shoulder rib section (20Sa) includes a lug groove (L1b) extending in the direction of tire width, the tunnel groove (L1b) includes a chamfer (M13, M14) in a groove depth direction and a groove width direction, and a chamfer length (MW) towards the groove width is greater than a chamfer length towards the groove depth (MD). [9] Tires (1) according to any one of claims 1 to 8, further comprising: a second shoulder strap section (20Sb) extending from the ground contact edges (T IN , T OUT ) on both sides relating to the tire width direction with respect to the equatorial plane (CL) of the tire (1) a different ground contact edge (T IN ) includes; and a second middle bridge section (20Mb) between the second shoulder bridge section (20Sb) and the central bridge section (20C), wherein in the meridian cross-sectional view of the tire (1) a line which in a single arc a ground contact edge which is located in the second shoulder rib section (20Sb) the midpoint (P CL ) the length of the central rib section (20C) in the direction of tire width and a center point (P IN) a length of the second middle rib section (20Mb) in the tire width direction, is defined as a second virtual profile (PR2), an end section of the central rib section (20C) on one side of the second middle rib section (20Mb) is recessed relative to the second virtual profile (PR2) towards the inner side in the tire radial direction, an end section of the second middle rib section (20Mb) on one side of the central rib section (20C) is recessed relative to the second virtual profile (PR2) towards the inner side in the tire radial direction, a depression amount (CR2) of the end section of the central web section (20C) on the side of the second middle web section (20Mb) is greater than a depression amount (MR3) of the end section of the second middle web section (20Mb) on the side of the central web section (20C), and in the meridian cross-sectional view of the tire (1) a distance in the tire width direction between the intersection points (E, E') of the second virtual profile (PR2) and the extension lines (KMS, KMS') extending on the sides of the rib section from the groove walls (KM, KM') of the main circumferential grooves (22, 23) adjacent to both end sections of the central rib section (20C) is defined as Wc', and a ground contact edge of the central rib section (20C) is arranged on a side that is further inboard than a position at a distance of 0.03Wc' from the end section of the central rib section (20C) on the side of the second central rib section (20Mb). [10] Tire (1) according to claim 9, wherein in the meridian cross-sectional view of the tire (1) a distance between the intersection points (E3, E4) of the second virtual profile (PR2) and the extension lines (KMS3, KMS4) extending on the sides of the second central rib section (20Mb) from the groove walls (KM3, KM4) of the main circumferential grooves (23, 24) adjacent to both end sections of the second central rib section (20Mb) in the tire width direction is defined as Wb, and a ground contact edge of the second central rib section (20Mb) is arranged on a side that is further inboard than a position at a distance of 0.03Wb from the end section of the second central rib section (20Mb) on the side of the central rib section (20C). [11] Tires (1) according to claim 9 or 10, wherein the difference between the indentation amount (CR2) of the end section of the central rib section (20C) on the side of the second middle rib section (20Mb) and the indentation amount (MR3) of the end section of the second middle rib section (20Mb) on the side of the central rib section (20C) is 0.1 mm or more and 0.8 mm or less. [12] Tire (1) according to any one of claims 9 to 11, wherein a groove width of the main circumferential groove (23) adjacent to the end section of the central rib section (20C) is equal to or greater in the tire width direction than a groove width of a main circumferential groove (24) adjacent to the second shoulder rib section (20Sb). [13] Tire (1) according to any one of claims 9 to 12, wherein the length of the central rib section (20C) in the tire width direction is 105% or 120% or less than the length of the second central rib section (20Mb) in the tire width direction. [14] Tire (1) according to any one of claims 9 to 11, wherein an end section of the second shoulder rib section (20Sb) on the inner side in the tire width direction relative to the second virtual profile (PR2) is recessed towards the inner side in the tire radial direction, and a recession amount (CR2) of the end section of the central rib section (20C) on the outer side in the tire width direction is greater than a recession amount (SR2) of the end section of the second shoulder rib section (20Sb) on the inner side in the tire width direction. [15] Tire (1) according to claim 14, wherein an end section of the second middle rib section (20Mb) on one side of the second shoulder rib section (20Sb) is recessed relative to the second virtual profile (PR2) towards the inner side in the tire radial direction, and a recession amount (MR4) of the end section of the second middle rib section (20Mb) on the side of the second shoulder rib section (20Sb) is equal to or greater than a recession amount (SR2) of the end section of the second shoulder rib section (20Sb) on one side of the second middle rib section (20Mb). [16] Tires (1) according to any one of claims 9 to 15, wherein the second shoulder rib section (20Sb) includes a lug groove (L6) that extends in the direction of the tire width, the trough groove (L6) includes a chamfer in a groove depth direction and a groove width, and The chamfer length towards the groove width is greater than the chamfer length towards the groove depth. [17] Tire (1) according to any one of claims 1 to 16, wherein the rubber forming the tread section (2) has a hardness of 65 or more at 20 °C.

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