Pneumatic radial tire for passenger vehicle

Abstract

Provided is a pneumatic radial tire for a passenger vehicle in which a cross-sectional width (SW) of the tire and an outer diameter (OD) of the tire satisfy a predetermined relationship, the carcass having a first tire width direction portion in which the carcass cords are disposed in a radial manner and a second tire width direction portion in which the carcass cords are disposed in a radial manner and in which the carcass cords are disposed in a radial manner. And a second tire width direction portion in which the carcass cord extends at an angle with respect to the tire circumferential direction, the second tire width direction portion being located in a tire width direction half that is located outside when the tire is mounted on a vehicle, and the second tire width direction portion being located in a tire width direction half that is located outside when viewed from the tire radial outer side. The carcass cords and the belt cords of the carcass main body section in the second tire width direction section extend in directions intersecting each other.

Description

Technical Field

[0001] The present disclosure relates to a pneumatic radial tire for a passenger vehicle. Background Art

[0002] As a pneumatic radial tire for passenger cars that improves fuel efficiency, the applicant has proposed a narrow-width, large-diameter pneumatic radial tire for passenger cars having a predetermined relationship between the cross-sectional width SW and the outer diameter OD of the tire (for example, Patent Document 1). In addition, in the narrow-width, large-diameter pneumatic radial tire for passenger cars, in order to reduce weight and further improve fuel efficiency, it has also been proposed to use only one inclined belt layer in which the belt cords are inclined relative to the tire circumferential direction (see, for example, Patent Document 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: WO 2011 / 135774 A1

[0006] Patent Document 2: Japanese Patent Application Publication No. 2020-093674 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, when only one inclined belt layer is used, since the rigidity in the extending direction of the belt cords will be high and the tread rubber will not be able to stretch in said direction, as shown in FIG. Figure 1 As schematically shown, the shape of the ground contact pitch will deteriorate, which may lead to a decrease in the driving performance of the tire. In particular, the fact that the section width SW of the tire is small and the fact that narrow-width, large-diameter pneumatic radial tires for passenger cars such as those described above are often used at high internal pressures also lead to deterioration in the shape of the ground contact pitch.

[0009] Therefore, an object of the present disclosure is to provide a pneumatic radial tire for a passenger vehicle which can reduce the weight of the tire by having only one inclined belt layer while also improving the shape of the ground contact patch to control the degradation of the driving performance of the tire.

[0010] Solutions for solving problems

[0011] The main points of this disclosure are as follows:

[0012] (1) A pneumatic radial tire for a passenger vehicle, comprising

[0013] a pair of bead portions;

[0014] a carcass consisting of one or more carcass plies made of rubber-coated carcass cords; and

[0015] The belt portion is arranged on the outer side of the crown portion of the carcass in the tire radial direction and is composed of only one inclined belt layer, wherein the inclined belt layer is composed of a belt ply, and the belt ply is made of rubber-coated belt cords extending at an angle relative to the tire circumferential direction, wherein

[0016] The cross-sectional width SW of the tire is less than 165 (mm),

[0017] The ratio of the cross-sectional width SW of the tire to the outer diameter OD of the tire is 0.26 or less, or the cross-sectional width SW (mm) of the tire and the outer diameter OD (mm) of the tire satisfy the relational expression:

[0018] OD(mm)≥-0.0187×SW(mm) 2 +9.15×SW(mm)-380(mm),

[0019] The carcass has a first tire width direction portion where the carcass cords are arranged in a meridian direction and a second tire width direction portion where the carcass cords extend at an angle with respect to the tire circumferential direction.

[0020] The carcass includes a carcass main body portion extending from the bead portion to the inner side of the belt portion in the tire radial direction.

[0021] The second tire width direction portion is located in the tire width direction half portion located on the outer side when the tire is mounted on a vehicle, and

[0022] The carcass cords of the carcass main portion and the belt cords in the second tire width direction portion extend in directions intersecting each other when viewed from the tire radial direction outer side.

[0023] Here, “extending in directions intersecting each other” means not only a case where the cords intersect when viewed from the outside in the tire radial direction, but also includes a case where the cords intersect when the carcass cords or the belt cords are extended.

[0024] As used herein, the term "rim" refers to a standard rim of an applicable size described or that may be described in the future in an industrial standard effective for a region where tires are produced and used (such as the JATMA Yearbook of JATMA (Japan Automobile Tire Manufacturers Association) in Japan, the standard manual of ETRTO (European Tire and Rim Technical Organization) in Europe, and the yearbook of TRA (Tire and Rim Association) in the United States) (that is, the "rim" of the above-mentioned "wheel" includes current sizes as well as sizes to be described in the future in the above-mentioned industrial standards. An example of a "size to be described in the future" may be a size listed as "future development" in the 2013 edition of ETRTO), however, for sizes not listed in these industrial standards, the term "rim" refers to a rim having a width corresponding to the bead width of the tire.

[0025] In addition, the term "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel of applicable size and ply grade as described in the above-mentioned JATMA Yearbook and other industrial standards. In the case of a size not listed in the above-mentioned industrial standards, the term "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is installed.

[0026] Furthermore, the term "maximum load" refers to a load corresponding to the above-mentioned maximum load capacity.

[0027] Effects of the Invention

[0028] According to the present disclosure, it is possible to provide a pneumatic radial tire for a passenger vehicle which can reduce the weight of the tire by having only one inclined belt layer while improving the shape of the ground contact patch to control the degradation of the driving performance of the tire. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In the attached figure:

[0030] Figure 1 is a diagram schematically illustrating the shape of a ground contact patch when a tire has only one inclined belt layer;

[0031] Figure 2 is a schematic diagram illustrating the cross-sectional width SW and the outer diameter OD of a tire;

[0032] Figure 3 is a cross-sectional view in the tire width direction of a pneumatic radial tire for a passenger vehicle according to one embodiment of the present disclosure;

[0033] Figure 4 is a diagram schematically illustrating the structure of a carcass, a belt portion, and a cap layer;

[0034] Figure 5is a diagram schematically illustrating another carcass structure;

[0035] Figure 6 is a diagram schematically illustrating an improvement in the shape of a ground contact surface;

[0036] Figure 7 is a diagram schematically illustrating another example of the structure of a carcass, a belt portion, and a cap layer;

[0037] Figure 8 is a diagram illustrating a configuration of an RFID; and

[0038] Fig. 9 It is a cross-sectional view in the tire width direction of a pneumatic radial tire for a passenger vehicle according to a modification. DETAILED DESCRIPTION

[0039] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0040] Figure 2 It is a schematic diagram illustrating the cross-sectional width SW and the outer diameter OD of the tire.

[0041] A pneumatic radial tire for a passenger vehicle (hereinafter, simply referred to as a "tire") according to one embodiment of the present disclosure has a tire section width SW of less than 165 mm, and a ratio SW / OD of the tire section width SW to the outer diameter OD is 0.26 or less, and thus has a narrow width and large diameter shape. By making the tire section width SW narrower relative to the outer diameter OD of the tire, air impedance can be reduced, and by making the outer diameter OD of the tire larger relative to the tire section width SW, deformation of the tread rubber in the area near the contact surface of the tire is controlled and rolling impedance can be reduced, and by these means, the fuel efficiency of the tire can be improved. The ratio SW / OD is preferably 0.25 or less, and more preferably 0.24 or less.

[0042] The above ratio is preferably satisfied when the tire internal pressure is 200 kPa or more, more preferably satisfied when the tire internal pressure is 220 kPa or more, and even more preferably satisfied when the tire internal pressure is 280 kPa or more. This is because the rolling resistance can be reduced. On the other hand, it is preferred that the above ratio is satisfied when the tire internal pressure is 350 kPa or less. This is because the ride comfort can be improved.

[0043] Here, the section width SW of the tire is preferably 105 to 145 mm, and more preferably 115 to 135 mm.

[0044] Furthermore, when the section width SW and the outer diameter OD of the tire satisfy the above ratio, the aspect ratio of the tire is preferably 45 to 70, and more preferably 45 to 65.

[0045] The specific tire size is not particularly limited, but can be, for example, 105 / 50R16, 115 / 50R17, 125 / 55R20, 125 / 60R18, 125 / 65R19, 135 / 45R21, 135 / 55R20, 135 / 60R17, 135 / 60R18, 135 / 60R19, 135 / 65R19, 145 / 45R21, 145 / 55R2 Any size in 0, 145 / 60R16, 145 / 60R17, 145 / 60R18, 145 / 60R19, 145 / 65R19, 155 / 45R18, 155 / 45R21, 155 / 55R18, 155 / 55R19, 155 / 55R21, 155 / 60R17, 155 / 65R18, 155 / 70R17, 155 / 70R19.

[0046] Alternatively, the section width SW of the tire is less than 165 mm, and the section width SW (mm) and the outer diameter OD (mm) of the tire satisfy the relational expression:

[0047] OD(mm)≥-0.0187×SW(mm)2+9.15×SW(mm)-380,

[0048] Therefore, the tire has a shape of narrow width and large diameter.

[0049] By satisfying the above relational expressions, air resistance and rolling resistance can be reduced, thereby improving the fuel efficiency of the tire.

[0050] In the third aspect, regarding the cross-sectional width SW and the outer diameter OD of the tire, when the above relational expression is satisfied, the ratio SW / OD is preferably 0.26 or less, more preferably 0.25 or less, and even more preferably 0.24 or less. This is because the fuel efficiency of the tire can be further improved.

[0051] The above relational expression and ratio are preferably satisfied when the tire internal pressure is 200 kPa or more, more preferably satisfied when the tire internal pressure is 220 kPa or more, and even more preferably satisfied when the tire internal pressure is 280 kPa or more. This is because the rolling resistance can be reduced. On the other hand, it is preferred that the above relational expression and ratio are satisfied when the tire internal pressure is 350 kPa or less. This is because the ride comfort can be improved.

[0052] Here, the section width SW of the tire is preferably 105 to 145 mm, and more preferably 115 to 135 mm.

[0053] Furthermore, when the section width SW and the outer diameter OD of the tire satisfy the above relationship, the aspect ratio of the tire is preferably 45 to 70, and more preferably 45 to 65.

[0054] The specific tire size is not particularly limited, but can be, for example, 105 / 50R16, 115 / 50R17, 125 / 55R20, 125 / 60R18, 125 / 65R19, 135 / 45R21, 135 / 55R20, 135 / 60R17, 135 / 60R18, 135 / 60R19, 135 / 65R19, 145 / 45R21, 145 / 55R2 Any size in 0, 145 / 60R16, 145 / 60R17, 145 / 60R18, 145 / 60R19, 145 / 65R19, 155 / 45R18, 155 / 45R21, 155 / 55R18, 155 / 55R19, 155 / 55R21, 155 / 60R17, 155 / 65R18, 155 / 70R17, 155 / 70R19.

[0055] The tire of this embodiment is a pneumatic radial tire for passenger cars. The tire is particularly suitable for use as a tire for a personal motor vehicle.

[0056] Figure 3 1 is a cross-sectional view in the tire width direction of a pneumatic radial tire for a passenger vehicle according to one embodiment of the present disclosure. Figure 3 The figure shows a cross-sectional view of a tire in its reference condition, with the tire mounted on a rim, filled to a specified internal pressure and without a load. Figure 3 As shown, the tire 1 includes a carcass 3, which is composed of one or more carcass plies, and the carcass plies are made of rubber-coated carcass cords. In addition, the tire 1 includes a belt portion 4 and a tread 5 in sequence on the tire radially outer side of the crown portion of the carcass 3, and the belt portion 4 is composed of only one inclined belt layer, and the inclined belt layer is composed of a belt ply, and the belt ply is made of rubber-coated belt cords extending at an angle relative to the tire circumferential direction.

[0057] In this example, a bead core 2a is embedded in each bead portion 2. In the present disclosure, the cross-sectional shape and material of the bead core 2a are not particularly limited, and can be made to have a structure commonly used in pneumatic radial tires for passenger cars. In the present disclosure, the bead core 2a can be divided into a plurality of small bead cores. Alternatively, in the present disclosure, the bead portion 2 can be constructed without a bead core 2a.

[0058] In the example shown, the tire 1 has a bead filler 2b having a substantially triangular cross section outside the bead core 2a in the tire radial direction. The cross-sectional shape of the bead filler 2b is not limited to this example, and the material is also not limited to this example. Alternatively, the tire can be lightweighted by omitting the bead filler 2b.

[0059] In this embodiment, the tire 1 may also have a rim protection portion. In addition, in this embodiment, the bead portion 2 may also have additional components, such as a rubber layer or a cord layer for reinforcement purposes. These additional components may be arranged at various positions relative to the carcass 3 and the bead filler 2b.

[0060] exist Figure 3 In the example shown, the carcass 3 is composed of a single carcass ply. On the other hand, in the present disclosure, the number of carcass plies is not particularly limited and may be two or more layers. Figure 4 As shown, the carcass 3 has a first tire width direction portion 301 and a second tire width direction portion 302, in which the carcass cords are arranged in a meridian, in which the carcass cords extend at an angle relative to the tire circumferential direction, and in which the second tire width direction portion 302 is located in the tire width direction half (in the example shown, only a part of the tire half) located on the outside when the tire is mounted on a vehicle. Figure 3In the example shown, the carcass 3 has a carcass main body portion 3a extending in a ring shape between the pair of bead portions 2 and a carcass folded-back portion 3b folded back from the carcass main body portion 3a around the bead core 2a. The carcass main body portion 3a extends from the bead portion 2 to the radially inner side of the belt portion 4. On the other hand, in the present disclosure, the carcass folded-back portion 3b may be wound around the bead core 2a, or may be sandwiched between a plurality of separate small bead cores. The end 3c of the carcass folded-back portion 3b is located radially outside of the tire at the radially outer end of the bead filler 2b, and is located radially inside of the tire at the position of the maximum width of the tire. This makes it possible to lightweight the tire while maintaining the rigidity of the sidewall portion. On the other hand, in the present disclosure, the end 3c of the carcass folded-back portion 3b may be located radially inside of the tire at the radially outer end of the bead filler 2b, or it may be located radially outside of the tire at the position of the maximum width of the tire. Alternatively, it may be an encapsulation structure in which the end 3c of the carcass folded portion 3b is located inside the end of the belt portion 4 (e.g., the end of the belt layer 4b) in the tire width direction, so that the end 3c of the carcass folded portion 3b is located between the carcass main body portion 2a and the belt portion 4 in the tire radial direction. In addition, when the carcass 3 is composed of a plurality of carcass plies, the position of the end 3c of the carcass folded portion 3b (e.g., the position in the tire radial direction) may be the same or different between the carcass plies. There is no particular limitation on the number of carcass cords per unit width in the carcass 3, but, for example, it may be in the range of 20 to 60 cords / 50 mm. In addition, the carcass cord may adopt various structures. For example, in the tire radial direction, the carcass maximum width position may be close to the bead portion 2 side or to the tread portion 5 side. For example, the carcass maximum width position may be set in the range of 50% to 90% of the cross-sectional height of the tire from the bead base line to the tire radial outside. The above-mentioned "meridian configuration" refers to a configuration in which the carcass cords extend at an angle of 85° or more, and preferably 90°, relative to the tire circumferential direction. Figure 4 As shown, due to the folding of the carcass, the inclination direction of the belt cords in the second tire width direction portion 302 is opposite between the carcass main portion 3a and the carcass folding portion 3b, as shown in the figure. Figure 3 As shown, the carcass 3 may be constructed to span between the pair of bead portions 2 in an annular shape. Figure 5As schematically shown in FIG. 1 , the carcass 3 may be constructed to have: a first carcass 351 extending from the bead portion 2 in the tire width direction half located on the outside when the tire is mounted on the vehicle to the tire radial inner side of the belt portion; and a second carcass 352 extending from the bead portion 2 in the tire width direction half located on the inside when the tire is mounted on the vehicle to the tire radial inner side of the belt portion. In addition, in order to improve the rigidity of the tire located on the outside when the tire is mounted on the vehicle, as shown in the figure, the second carcass 352 may have a radial extension portion 352a extending from the tire radial outer side to the tire radial inner side along the first carcass 351 and terminating at the tire width inner side of the bead portion in the tire width direction half located on the outside when the tire is mounted on the vehicle, or in order to make the tire lighter, the second carcass 352 may be constructed to have no radial extension portion 352a.

[0061] In the tire of the present embodiment, it is preferred that the tire has only one inclined belt layer, the inclined belt layer is composed of a belt ply made of rubber-coated belt cords extending at an angle relative to the tire circumferential direction, and the tire width direction width of the belt layer is 90% to 115% of the ground contact width, particularly preferably 100% to 105% of the ground contact width. It will be noted that the "ground contact width" refers to the distance between the ground contact ends E in the tire width direction. The "ground contact ends" refer to both ends of the tire ground contact surface in the tire width direction when the tire is mounted on the rim, filled with a specified internal pressure, and loaded with a maximum load.

[0062] In the present embodiment, as the belt cord of the belt layer, a metal cord, in particular a steel cord, is most preferably used, but non-metal cords such as organic fiber cords (e.g., Kevlar (registered trademark) etc.) may also be used. The steel cord is mainly made of steel, and may also contain various trace elements such as carbon, manganese, silicon, phosphorus, sulfur, copper and chromium. In the present embodiment, the belt cord of the belt layer may be a monofilament cord, a cord made of a plurality of filaments arranged in parallel, or a cord made of a plurality of filaments twisted together. Various twisting structures may be used, and the cross-sectional structure, twisting pitch, twisting direction and distance between adjacent filaments may also be changed. In addition, cords made of twisted filaments of different materials may also be used, and there is no particular limitation on the cross-sectional structure, and various twisting structures such as single twist, layer twist and multi-twist may be used.

[0063] In the present embodiment, the inclination angle of the belt cords in the belt layer relative to the tire circumferential direction is preferably 10° or more. In the present embodiment, the inclination angle of the belt cords in the belt layer relative to the tire circumferential direction is preferably a high angle, specifically 20° or more, particularly in the range of 20° to 45° relative to the tire circumferential direction. This is because, by making the inclination angle 20° or more, the rigidity in the tire width direction can be increased, and the steering stability performance, especially the steering stability performance during cornering, can be improved. In addition, this is because the rolling resistance is reduced by reducing the shear deformation of the interlayer rubber.

[0064] Here, in this embodiment, if Figure 4 As shown in FIG. 1 , when viewed from the outer side of the tire radial direction, the carcass cords and the belt cords of the carcass main portion 3a in the second tire width direction portion 302 extend in directions crossing each other. The inclination angle of the carcass cords of the carcass main portion 3a in the second tire width direction portion 302 relative to the tire circumferential direction is greater than the inclination angle of the belt cords relative to the tire circumferential direction. The inclination angle of the carcass cords of the carcass main portion 3a in the second tire width direction portion 302 relative to the tire circumferential direction is preferably 70° to 88°, more preferably 76° to 84°.

[0065] In the illustrated example, the end portion of the belt portion 4 is located in the first tire width direction portion 301. In the illustrated example, the width of the cap layer 8 in the tire width direction is smaller than the width of the belt portion 4 in the tire width direction.

[0066] Preferably, the tire width direction inner end of the second tire width direction portion 302 is located 10% to 40% away from the tire width direction end of the belt portion 4 toward the tire width direction outer side.

[0067] In the example shown, the tread rubber constituting the tread 5 is composed of a single layer. On the other hand, in the present embodiment, the tread rubber constituting the tread 5 can be formed by laminating a plurality of rubber layers in the tire radial direction. The plurality of rubber layers may have different loss tangents, moduli, hardness, glass transition temperatures, materials, etc. In addition, the thickness ratio of the plurality of rubber layers in the tire radial direction may vary in the tire width direction, and the bottom of the circumferential main groove, etc. may also be made of a rubber layer different from the peripheral area. In addition, the tread rubber constituting the tread 5 may be formed by a plurality of rubber layers different in the tire width direction. The plurality of rubber layers may have different loss tangents, moduli, hardness, glass transition temperatures, materials, etc. In addition, the width ratio of the plurality of rubber layers in the tire width direction may vary in the tire radial direction, and only a limited area (such as only the area near the circumferential main groove, only the area near the ground contact end, only the shoulder land portion, or only the central land portion, etc.) may have a rubber layer different from the peripheral area.

[0068] The tire 1 of this embodiment has an inner liner 7 on the inner surface 6 of the tire (referred to as the inner surface 6 of the tire for short), and the thickness of the inner liner 7 is preferably about 1.5 mm to 2.8 mm. This is because it can effectively reduce the noise inside the vehicle between 80 and 100 Hz. The air permeability coefficient of the rubber composition constituting the inner liner 7 is preferably 1.0×10 -14 cc·cm / (cm 2 ·s·cmHg) or greater and 6.5×10 -10 cc·cm / (cm 2 ·s·cmHg) or less.

[0069] like Figure 3 As shown, the tire has one or more (one in the example shown) cover layers 8 on the outer side of the belt portion 4 in the tire radial direction.

[0070] The cap layer 8 is composed of a strip-shaped member composed of rubber-coated cords arranged substantially in parallel and spirally wound in the tire circumferential direction. In the example shown, the width of the cap layer 8 in the tire width direction is smaller than the width of the belt portion 4 in the tire width direction. As for the cord of the cap layer 8, for example, an organic fiber cord can be used.

[0071] The effects of the pneumatic radial tire for a passenger vehicle according to the present embodiment will be described below.

[0072] The pneumatic radial tire for a passenger car in the present embodiment is a narrow width large diameter tire having a cross-sectional width SW of less than 165 mm among narrow width large diameter tires satisfying the above relationship expression between the cross-sectional width SW and the outer diameter of the tire. According to this tire, air resistance can be particularly reduced, and rolling resistance can also be reduced, so that the fuel efficiency of the tire can be improved.

[0073] Here, in the present embodiment, the tire has a belt portion composed of only one inclined belt layer, and therefore the tread rubber is less likely to be deformed in the inclined direction ( Figure 4 In connection with this, the tire of the present embodiment further has a first tire width direction portion 301 and a second tire width direction portion 302, in which the carcass cords are arranged in a meridian configuration, and in the second tire width direction portion 302, the carcass cords extend at an angle relative to the tire circumferential direction, and when viewed from the radially outer side of the tire, the carcass cords of the carcass main portion 3a in the second tire width direction portion 302 and the belt cords extend in directions intersecting each other. For this reason, the carcass cords of the carcass main portion 3a in the second tire width direction portion 302 are subjected to a force attempting to restore the meridian configuration, which can promote the tread rubber in the direction of the force ( Figure 4 In this way, the difficulty of stretching the tread rubber in the inclined direction of the belt cord can be further reduced, such as Figure 6 As schematically shown in , the shape of the contact patch is improved, thereby improving handling stability and other driving performances.

[0074] Here, it is preferable that the inclination angle of the carcass cords of the carcass main body portion 3a in the second tire width direction portion 302 with respect to the tire circumferential direction is greater than the inclination angle of the belt cords with respect to the tire circumferential direction. This is because by making the inclination angle of the carcass cords of the carcass main body portion 3a in the second tire width direction portion 302 with respect to the tire circumferential direction greater than the inclination angle of the belt cords with respect to the tire circumferential direction, both rigidity for supporting the load and lateral rigidity and torsional deformation for correcting the shape of the ground contact patch can be achieved.

[0075] Furthermore, it is preferred that the carcass cord of the carcass main body portion 3a in the second tire width direction portion 302 has an inclination angle of 70° to 88° relative to the tire circumferential direction. This is because by setting the inclination angle to 70° or more, both torsional deformation and rigidity can be achieved simultaneously, while by setting the inclination angle to 88° or less, sufficient restoring force against torsion can be generated. For the same reason, it is even more preferred that the above inclination angle is 76° to 84°.

[0076] Furthermore, it is preferred that the position of the inner end in the tire width direction of the second tire width direction portion 302 is spaced from the tire width direction end (end in the same tire width direction half) of the belt portion 4 toward the tire width direction outer side by 10% to 40% of the tire width direction width of the belt portion 4. This is because, by setting the interval to 10% or more, the effect of correcting the shape of the ground contact surface of the entire tire width direction half located on the inner side when the tire is mounted on the vehicle can be obtained, and by setting the interval to 40% or less, both torsional deformation and rigidity can be achieved. For the same reason, it is further preferred that the position of the inner end in the tire width direction of the second tire width direction portion 302 is spaced from the tire width direction end of the belt portion 4 toward the tire width direction outer side by 20% to 30% of the tire width direction width of the belt portion 4.

[0077] like Figure 7 As shown, preferably, the carcass also has a third tire width direction portion 303 different from the second tire width direction portion 302, in which the carcass cords extend at an angle relative to the tire circumferential direction, the third tire width direction portion 303 is located in the tire width direction half located on the inner side when the tire is mounted on a vehicle, and when viewed from the radially outer side of the tire, the carcass cords and belt cords of the carcass main body portion 3a in the third tire width direction portion 303 extend in directions intersecting each other. Even in the tire width direction half located on the inner side when the tire is mounted on a vehicle, the force in the third tire width direction portion 303 that attempts to restore the meridian configuration of the carcass cords in the carcass main body portion 3a has the effect of promoting the tread rubber in the direction of the force ( Figure 7 The effect of stretching the tread rubber in the upper right and lower left directions can be further reduced, and the difficulty of stretching the tread rubber in the inclined direction of the belt cord can be further reduced. Therefore, the shape of the ground contact surface can be further improved to further improve the driving performance.

[0078] It will be noted that the pneumatic radial tire for a passenger vehicle may be mounted on the left wheel of the vehicle, and the belt cords may extend from the lower left to the upper right when viewed from the radially outer side of the tire ( Figure 7 ), or may be installed on the right wheel of the vehicle, and the belt cords may extend from the lower right to the upper left when viewed from the radially outer side of the tire.

[0079] In addition, the carcass 3 can span between the pair of bead portions 2 in a ring shape. Alternatively, the carcass 3 can have a first carcass 351 and a second carcass 352, the first carcass 351 extending from the bead portion 2 in the tire width direction half located on the outside when the tire is installed on the vehicle to the radial inside of the belt portion 4, and the second carcass 352 extending from the bead portion 2 in the tire width direction half located on the inside when the tire is installed on the vehicle to the radial inside of the belt portion 4.

[0080] In addition, if Fig. 9 As shown, the distance in the tire radial direction between a straight line m1 passing through a point on the tread surface at the tire equatorial plane and parallel to the tire width direction and a straight line m2 passing through the ground contact end E and parallel to the tire width direction is defined as the drop height L. CR When the tread width of the tire is defined as TW, the ratio L is preferably CR / TW is greater than 0.045. This allows the crown shape to be relatively round, and thereby the shape of the ground contact patch can be made rounder, with the ground contact length in the shoulder portion being shorter than the ground contact length in the center portion. This prevents the shape of the ground contact patch from becoming too narrow when the camber angle changes, and further controls the degradation of the shape of the ground contact patch. "Ground contact end" refers to the two ends of the ground contact patch (the portion in contact with the road surface) of the tire when the tire is mounted on the rim, filled with a specified internal pressure, and loaded with a maximum load. "Tread width" refers to the distance between the ground contact ends of the tire when the tire is mounted on the rim, filled with a specified internal pressure, and unloaded.

[0081] <Tire and rim assembly>

[0082] Here, a tire and rim assembly is formed by mounting the above-mentioned pneumatic radial tire for passenger vehicles on a rim. According to this tire and rim assembly, the same effects as those explained for the above-mentioned pneumatic radial tire for passenger vehicles can be obtained. At this time, the internal pressure of the tire and rim assembly is preferably 200 kPa or more, more preferably 220 kPa or more, and even more preferably 280 kPa or more. This is because, by increasing the internal pressure, rolling resistance can be further reduced. On the other hand, the internal pressure of the tire and rim assembly is preferably 350 kPa or less because this improves ride comfort.

[0083] <How to use pneumatic radial tires for passenger cars>

[0084] The method for using the pneumatic radial tire for a passenger car uses the above-mentioned pneumatic radial tire for a passenger car. According to the method for using the pneumatic radial tire for a passenger car, the same effects as those described above for the pneumatic radial tire for a passenger car can be obtained. At this time, it is preferred to use the pneumatic radial tire for a passenger car when the internal pressure is 200 kPa or more, and it is even more preferred to use the pneumatic radial tire for a passenger car when the internal pressure is 220 kPa or more, and it is even more preferred to use the pneumatic radial tire for a passenger car when the internal pressure is 280 kPa or more. This is because the rolling resistance can be further reduced by increasing the internal pressure. On the other hand, it is preferred to use the pneumatic radial tire for a passenger car when the internal pressure is 350 kPa or less because this improves the ride comfort.

[0085] <Example of Communication Device>

[0086] like Figure 8 As shown, the tire may include an RF tag as a communication device 500. The RF tag has an IC chip and an antenna. For example, the RF tag can be configured by being sandwiched between multiple components of the same type or different types constituting the tire. In this way, it is easier to attach the RF tag when producing the tire, and the productivity of the tire with the RF tag can be improved. In this example, the RF tag can be configured between, for example, a bead filler and other components adjacent to the bead filler. The RF tag can be buried in any component constituting the tire. In this way, compared with configuring the RF tag by being sandwiched between multiple components constituting the tire, the load on the RF tag can be reduced, thereby improving the durability of the RF tag. In this example, the RF tag can be buried in rubber components such as tread rubber and sidewall rubber. It is preferred that the RF tag is not configured at a position that is a boundary between components having different levels of rigidity in the peripheral length direction, and the peripheral length direction is a direction along the outer surface of the tire when viewed in a tire width direction section. In this way, the RF tag is not configured at a position where the skew is likely to be concentrated based on the rigidity step difference. This reduces the load on the RF tag, thereby improving the durability of the RF tag. In this example, it is preferred that the RF tag is not arranged at a position that is a boundary between the edge of the carcass and a member adjacent to the carcass edge (e.g., sidewall rubber, etc.) when viewed in a cross section in the tire width direction, for example. The number of RF tags is not limited. The tire may have only one RF tag, or it may have two or more RF tags. Here, the RF tag is explained as an example of a communication device, but a communication device other than an RF tag may also be used.

[0087] The RF tag can be configured in, for example, the tread portion of the tire. In this way, the RF tag will not be damaged by the side cut of the tire. The RF tag can be configured in, for example, the center of the tread in the tire width direction. The center of the tread is a position in the tread portion where distortion is less likely to be concentrated. In this way, the load applied to the RF tag can be reduced, thereby improving the durability of the RF tag. This also makes it possible to prevent differences in communication with the RF tag from both outer sides of the tire in the tire width direction. In this example, in the tire width direction, the RF tag can be configured within, for example, 1 / 2 of the tread width centered on the tire equatorial plane. In the tire width direction, the RF tag can be configured at, for example, the end of the tread. If the position of the reader that communicates with the RF tag is predetermined, the RF tag can be configured at, for example, the end of the tread on a side close to the reader. In this example, in the tire width direction, the RF tag can be configured within, for example, 1 / 4 of the tread width with the tread end as the outer end.

[0088] The RF tag can be configured on the tire inner cavity side of a carcass including, for example, one or more carcass plies spanning between the bead portions. In this way, the RF tag becomes less likely to be damaged by external impacts of the tire, or less likely to be damaged by, for example, side cuts or nail punctures. As an example, the RF tag can be configured to be in close contact with the surface of the carcass facing the tire inner cavity. As another example, when there is another component on the tire inner cavity side of the carcass, the RF tag can be configured between the carcass and the other component located on the tire inner cavity side of the carcass. The other component located on the tire inner cavity side of the carcass is, for example, an inner liner forming the inner surface of the tire. As another example, the RF tag can be attached to the inner surface of the tire facing the tire inner cavity. By attaching the RF tag to the inner surface of the tire, it is easy to attach the RF tag to the tire, and it is also easy to check and replace the RF tag. In other words, the convenience of attachment and maintenance of the RF tag can be improved. In addition, by attaching the RF tag to the inner surface of the tire, the RF tag can be prevented from becoming the core of the tire failure compared to the structure in which the RF tag is buried inside the tire. Furthermore, when the carcass has a plurality of carcass plies and there is a position where the plurality of carcass plies overlap, the RF tag may be arranged between the overlapping carcass plies.

[0089] For example, the RF tag can be configured in the tread portion of the tire on the radially outer side of the belt portion, and the belt portion is composed of only one belt cord layer. As an example, the RF tag can be configured to be in close contact with the belt portion on the radially outer side of the tire relative to the belt portion. In addition, as another example, when a reinforcing belt layer is provided, the RF tag can be configured to be in close contact with the reinforcing belt layer on the radially outer side of the tire relative to the reinforcing belt layer. In addition, as another example, the RF tag can be buried in the tread rubber on the radially outer side of the belt portion. By arranging the RF tag on the outer side of the belt portion in the tread portion of the tire, the communication with the RF tag from the radially outer side of the tire of the tire is less likely to be interfered by the belt portion. Therefore, the communication with the RF tag from the radially outer side of the tire of the tire can be improved. In addition, the RF tag can be configured in the tread portion of the tire, for example, on the radially inner side of the belt portion. In this way, the radially outer side of the RF tag is covered by the belt portion, so the RF tag becomes less likely to be damaged by the impact from the tread surface or by nail puncture. As an example in this regard, the RF tag may be arranged between the belt portion and the carcass located on the inner side of the belt portion in the tire radial direction.

[0090] The RF tag can be configured at a position such as in the sidewall portion or bead portion of the tire. For example, the RF tag can be configured on the sidewall portion or bead portion of the side, such as close to a reader that can communicate with the RF tag. This improves the communication between the RF tag and the reader. As an example, the RF tag can be configured between the carcass and the sidewall rubber or between the tread rubber and the sidewall rubber. The RF tag can be configured in the tire radial direction, for example, between the tire maximum width position and the tread surface position. Through this construction, compared with the construction in which the RF tag is configured on the tire radial inner side of the tire maximum width position, the communication with the RF tag from the tire radial outer side of the tire can be improved. The RF tag can be configured on the tire radial inner side of the tire maximum width position, for example. Through this construction, the RF tag is configured near the bead portion with high rigidity. This reduces the load applied to the RF tag, thereby improving the durability of the RF tag. As an example, the RF tag can be configured in a position adjacent to the bead core in the tire radial direction or the tire width direction. Skew is less likely to be concentrated near the bead core, which reduces the load on the RF tag, thereby improving the durability of the RF tag. In particular, it is preferred that the RF tag is arranged on the radially inner side of the tire at the maximum width position of the tire and on the radially outer side of the bead core of the bead portion. With this construction, the durability of the RF tag can be improved, and the communication between the RF tag and the reader is less likely to be interfered by the bead core, thereby improving the communication performance of the RF tag. In addition, when the sidewall rubber is composed of a plurality of rubber members of the same or different types adjacent to each other in the tire radial direction, the RF tag can be arranged to be sandwiched between the plurality of rubber members constituting the sidewall rubber. The RF tag can be arranged on, for example, the outer surface of the sidewall rubber.

[0091] The RF tag can be configured to be sandwiched between the bead filler and the member adjacent to the filling filler, for example. According to this configuration, the RF tag can be placed at a position where strain is less likely to be concentrated due to the disposal of the bead filler. This reduces the load applied to the RF tag, thereby improving the durability of the RF tag. The RF tag can be configured between the bead filler and the carcass, for example. The part of the carcass that sandwiches the RF tag between the carcass and the bead filler can be located outside the tire width direction relative to the bead filler, or inside the tire width direction relative to the bead filler. If the part of the carcass that sandwiches the RF tag between the carcass and the bead filler is located outside the tire width direction relative to the bead filler, the load applied to the RF tag due to the impact or damage from the tire width direction outside of the tire can be even more reduced, thereby improving the durability of the RF tag. In addition, the bead filler can have a portion adjacent to the sidewall rubber configuration. In this case, the RF tag can be configured to be sandwiched between the bead filler and the sidewall rubber. In addition, the bead filler can also have a portion adjacent to the rubber bead chafer configuration. In this case, the RF tag can be configured to be sandwiched between the bead filler and the rubber bead chafer.

[0092] The RF tag can be configured to be, for example, sandwiched between the rubber bead packer and the sidewall rubber. According to this construction, the RF tag can be placed at a position where strain is less likely to concentrate due to the placement of the rubber bead packer. This reduces the load applied to the RF tag, thereby improving the durability of the RF tag. The RF tag can be configured to be, for example, sandwiched between the rubber bead packer and the carcass. According to this construction, the load applied to the RF tag due to impact and damage from the rim can be reduced. Therefore, the durability of the RF tag can be improved.

[0093] The RF tag can be configured to be, for example, sandwiched between a wire bead filler and another member adjacent to the wire bead filler on the outside or inside of the wire bead filler in the tire width direction. According to this configuration, the position of the RF tag is less likely to change when the tire is deformed. This reduces the load applied to the RF tag when the tire is deformed, thereby improving the durability of the RF tag. Another member adjacent to the wire bead filler on the inside or outside of the tire width direction may be a rubber member, such as a rubber bead filler. In addition, another member adjacent to the wire bead filler on the inside or outside of the tire width direction may be a carcass.

[0094] A belt reinforcement layer may be provided on the tire radially outer side of the belt portion. For example, the belt reinforcement layer may be made by continuously spirally winding a cord made of polyethylene terephthalate around the tire in the tire circumferential direction. -2 N / tex or more tension applied adhesive treatment to make the cord, the elastic modulus under 29.4N load measured at 160°C can be 2.5mN / dtex% or more. In addition, the belt reinforcement layer can be configured to cover the entire belt portion, or it can be configured to cover only the two ends of the belt portion. In addition, the winding density per unit width of the belt reinforcement layer can be changed according to the position in the width direction. According to this configuration, road noise and flat spots can be reduced without reducing high-speed durability.

[0095] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, in the above examples, we have shown a case with a single cover layer, but in order to make the tire lightweight, it is also possible to have a structure without a cover layer.

[0096] [Contribution to the Sustainable Development Goals (SDGs) led by the United Nations]

[0097] SDGs are proposed to realize a sustainable society. One embodiment of the present disclosure is considered to be a technology that can contribute to "No. 12_Ensuring sustainable consumption and production patterns" and "No. 13_Climate change and specific countermeasures".

[0098] Reference numerals list

[0099] 1 Pneumatic radial tires for passenger cars (tire)

[0100] 2 Bead section

[0101] 2a Bead core

[0102] 2b Bead filler

[0103] 3 Carcass

[0104] 301 First tire width direction portion

[0105] 302 Second tire width direction portion

[0106] 303 Third tire width direction portion

[0107] 4 Belt

[0108] 5 Tread

[0109] 6 Tire inner surface

[0110] 7 Lining

[0111] 8 Covering layer

[0112] 500 communication device

[0113] CL Tire equatorial plane

Claims

1. A pneumatic radial tire for a passenger vehicle, comprising: a pair of bead portions; a carcass consisting of one or more carcass plies made of rubber-coated carcass cords; and The belt portion is arranged on the outer side of the crown portion of the carcass in the tire radial direction and is composed of only one inclined belt layer, wherein the inclined belt layer is composed of a belt ply, and the belt ply is made of rubber-coated belt cords extending at an angle relative to the tire circumferential direction, wherein The cross-sectional width SW of the tire is less than 165 (mm), The ratio of the cross-sectional width SW of the tire to the outer diameter OD of the tire is 0.26 or less, or the cross-sectional width SW (mm) of the tire and the outer diameter OD (mm) of the tire satisfy the relational expression: OD (mm) ≥ -0.0187 × SW (mm) 2 +9.15×SW(mm)-380(mm), The carcass has a first tire width direction portion, in which the carcass cords are arranged meridianally, and a second tire width direction portion, in which the carcass cords extend at an angle relative to the tire circumferential direction. The carcass includes a carcass main body portion extending from the bead portion to the inner side of the belt portion in the tire radial direction. The second tire width direction portion is located in the tire width direction half located on the outer side when the tire is mounted on the vehicle, and The carcass cords of the carcass main portion and the belt cords in the second tire width direction portion extend in directions intersecting each other when viewed from the tire radial direction outer side.

2. The pneumatic radial tire for a passenger vehicle according to claim 1, wherein: The inclination angle of the carcass cords of the carcass main portion in the second tire width direction portion with respect to the tire circumferential direction is greater than the inclination angle of the belt cords with respect to the tire circumferential direction.

3. The pneumatic radial tire for a passenger vehicle according to claim 1 or 2, wherein: The inclination angle of the carcass cords of the carcass main portion in the second tire width direction portion with respect to the tire circumferential direction is 70° to 88°.

4. The pneumatic radial tire for a passenger vehicle according to any one of claims 1 to 3, wherein: The tire width direction inner end of the second tire width direction portion is located 10% to 40% away from the tire width direction end of the belt portion toward the tire width direction outer side.

5. The pneumatic radial tire for a passenger vehicle according to any one of claims 1 to 4, wherein: The pneumatic radial tire for a passenger vehicle is installed on the left wheel of the vehicle. When viewed from the radially outer side of the tire, the belt cords extend from the lower left to the upper right. The carcass further has a third tire width direction portion different from the second tire width direction portion, in which the carcass cords extend at an angle with respect to the tire circumferential direction, The third tire width direction portion is located in the tire width direction half portion located on the inner side when the tire is mounted on the vehicle, and The carcass cords of the carcass main portion and the belt cords in the third tire width direction portion extend in directions intersecting each other when viewed from the tire radial direction outer side.

6. The pneumatic radial tire for a passenger vehicle according to any one of claims 1 to 5, wherein: The carcass spans between the pair of bead portions in a ring shape.

7. The pneumatic radial tire for a passenger vehicle according to any one of claims 1 to 5, wherein: The carcass has a first carcass and a second carcass, the first carcass extending from a bead portion in a tire widthwise half located on the outside when the tire is mounted on a vehicle to the radial inside of the belt portion, and the second carcass extending from a bead portion in a tire widthwise half located on the inside when the tire is mounted on a vehicle to the radial inside of the belt portion.

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