WO2015170478A1 - Pneumatique radial pour véhicules de tourisme - Google Patents

Pneumatique radial pour véhicules de tourisme Download PDF

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Publication number
WO2015170478A1
WO2015170478A1 PCT/JP2015/002327 JP2015002327W WO2015170478A1 WO 2015170478 A1 WO2015170478 A1 WO 2015170478A1 JP 2015002327 W JP2015002327 W JP 2015002327W WO 2015170478 A1 WO2015170478 A1 WO 2015170478A1
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Prior art keywords
tire
width direction
groove
circumferential main
width
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PCT/JP2015/002327
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English (en)
Japanese (ja)
Inventor
慎太郎 畠中
勲 桑山
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株式会社ブリヂストン
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Publication of WO2015170478A1 publication Critical patent/WO2015170478A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/02—Carcasses
    • B60C9/04—Carcasses the reinforcing cords of each carcass ply arranged in a substantially parallel relationship
    • B60C9/08—Carcasses the reinforcing cords of each carcass ply arranged in a substantially parallel relationship the cords extend transversely from bead to bead, i.e. radial ply
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/03—Tread patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/03—Tread patterns
    • B60C11/13—Tread patterns characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
    • Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction 

Definitions

  • the present invention relates to a pneumatic radial tire for passenger cars.
  • the applicant of the present invention has a specific relationship between the tire internal pressure, the cross-sectional width (SW), and the tire outer diameter (OD), that is, a narrow width (narrow tire cross-sectional width), a large diameter.
  • the technique concerning the pneumatic radial tire for passenger cars (large tire outer diameter) is proposed (for example, patent document 1).
  • the narrow and large diameter tires described above have room for further reduction in rolling resistance, and are also desired to be used as tires for all seasons.
  • an object of the present invention is to provide a pneumatic radial tire for a passenger car that can achieve both rolling resistance and performance on snow.
  • the present inventor has intensively studied to solve the above problems. That is, in such a tire, since the tire width is narrow and the tire is used at a high internal pressure, the contact pressure increases, and the crushing deformation (deformation in which the tread rubber compressed in the tire radial direction swells in the tire width direction) also increases. . Further, in such a tire, since the ground contact width becomes small, deformation of the outermost land portion when the vehicle is mounted due to wiping force (force that pulls both ends of the tread inward in the tire width direction when the tire is running) increases. Accordingly, the deformation concentrates on the groove bottom of the outermost circumferential main groove when the vehicle is mounted, which partitions the outermost land portion when the vehicle is mounted. Hereinafter, this will be described in detail with reference to FIG.
  • the groove bottom portion of the groove wall on the outer side in the tire width direction of the circumferential main groove 91 provided on the tread 90 which is the outermost side when the vehicle is mounted is particularly narrow and large in diameter and has a high internal pressure.
  • the groove bottom of the groove wall is shear-deformed (in FIG. 1, schematically shown by a parallelogram), and the groove wall bulges inward in the tire width direction. It will be deformed.
  • this deformation amount is indicated by a tread rubber (indicated by a broken diagonal line in FIG. 1) on the inner side in the tire width direction from the innermost position in the tire width direction of the outermost land portion when the vehicle is mounted. ) And the amount of deformation increases as the volume of the tread rubber increases. Also, the groove bottom portion of the circumferential main groove 91 undergoes shear deformation (shown schematically in FIG. 1 as a parallelogram) due to crushing deformation, and the groove bottom is the tire. It will be deformed to bulge radially outward. Since these deformations cause energy loss, the rolling resistance is deteriorated.
  • the snow column shear force for improving the performance on snow depends on the groove volume of the circumferential main groove 91.
  • the edge effect for improving the performance on snow depends on the edge pressure by the edge 92 on the inner side in the tire width direction defined by the circumferential main groove 91 which becomes a main contact surface when a slip angle is given. To do.
  • the present inventor has studied a method for solving the above-mentioned problems. As a result, the inventors have obtained new knowledge that the intended purpose can be achieved advantageously, and have completed the present invention.
  • the pneumatic radial tire for a passenger car includes a carcass formed of a ply of a radial arrangement code straddling a toroidal shape between a pair of bead portions, When the tire is incorporated in the rim and the internal pressure is 250 kPa or more, When the tire cross-sectional width SW is less than 165 (mm), the ratio SW / OD of the tire cross-sectional width SW to the outer diameter OD (mm) is 0.26 or less, When the cross-sectional width SW of the tire is 165 (mm) or more, the cross-sectional width SW and the outer diameter OD (mm) of the tire are a relational expression, OD ⁇ 2.135 ⁇ SW + 282.3 The filling, The tire has one or more circumferential main grooves extending in the tire circumferential direction on the tread surface, In the tire width direction cross section when the tire is mounted on the rim
  • the angle ⁇ in (°) formed by the groove wall on the inner side in the tire width direction with respect to the tire radial direction is such that the groove wall on the outer side in the tire width direction defined by the outermost circumferential main groove is in the tire radial direction. Larger than the angle ⁇ out (°) formed, The groove wall on the inner side in the tire width direction defined by the outermost circumferential main groove is inclined inward in the tire width direction from the inner side in the tire radial direction to the outer side.
  • rim is an industrial standard that is effective in the region where tires are produced and used. and Rim Technical Organization's STANDARDDS MANUAL, TRA (The Tire and Rim Association, Inc.) YEAR BOOK, etc. (Measuring Rim, Design Rim in TRA's YEAR BOOK). Also included) size that may be included in the case of size not listed in the industry standard, it refers to a rim having a width corresponding to the bead width of the tire.
  • the “internal pressure defined for each vehicle on which a tire is mounted” refers to the air pressure corresponding to the maximum load load determined in the industry standard or in the future, and is not described in the industry standard. In this case, when the maximum number of occupants is assumed, the air pressure corresponding to the load applied to the tire with the highest load among the four wheels is assumed.
  • ⁇ in is positive when the groove wall on the inner side in the tire width direction defined by the outermost circumferential main groove is inclined inward in the tire width direction from the inner side in the tire radial direction toward the outer side in the tire radial direction. To do.
  • ⁇ out the case where the groove wall on the outer side in the tire width direction defined by the outermost circumferential main groove is inclined outward in the tire width direction from the inner side in the tire radial direction to the outer side in the tire radial direction.
  • the magnitude of ⁇ in is larger than the magnitude of ⁇ out” means that the absolute value of ⁇ in is larger than the absolute value of ⁇ out.
  • a pneumatic radial tire for a passenger car according to a second aspect of the present invention is a pneumatic radial tire for a passenger car provided with a carcass made of a ply of a radial arrangement code straddling a toroidal shape between a pair of beads.
  • the cross-sectional width SW and the outer diameter OD (mm) of the tire are expressed by a relational expression: OD ⁇ ⁇ 0.0187 ⁇ SW 2 + 9.15 ⁇ SW-380
  • the tire has one or more circumferential main grooves extending in the tire circumferential direction on the tread surface, The tire is attached to the rim, and the internal pressure specified for each vehicle on which the tire is attached is filled, In the cross section in the tire width direction when it is in an unloaded state, Of the one or more circumferential main grooves extending in the tire circumferential direction, the tire width of the outermost circumferential main groove located on the outermost side in the tire width direction in one half of the tire width direction with the tire equatorial plane as a boundary The angle ⁇ in (°) formed by the groove wall on the inner side with respect to the tire radial direction is the angle ⁇ out (° formed by the groove wall on the outer side in the
  • a pneumatic radial tire for a passenger car (hereinafter, also simply referred to as a tire) is a radial tire including a carcass made of a ply of a radial arrangement cord straddling a toroidal shape between a pair of bead portions.
  • the tire cross-sectional width SW (mm) and the tire outer diameter OD (mm) satisfy the following relationship.
  • the tire of this embodiment when the tire of this embodiment is incorporated in a rim and the internal pressure is 250 kPa or more, and the tire cross-sectional width SW is less than 165 (mm), the tire cross-sectional width SW and the outer diameter OD (mm)
  • the ratio SW / OD of the tire is 0.26 or less, or the tire cross-sectional width SW is 165 (mm) or more
  • the tire cross-sectional width SW and the outer diameter OD (mm) are expressed by a relational expression, OD ⁇ 2.135 ⁇ SW + 282.3 is satisfied (hereinafter also referred to as relational expression (1)).
  • the tire Since the cross-sectional width SW and the outer diameter OD (mm) of the tire have the above relationship, the tire has a narrow width and a large diameter, improves the rolling resistance performance of the tire (reduces the rolling resistance value), and The tire can be reduced in weight.
  • the internal pressure of the tire is preferably 250 kPa or more, and more preferably 250 to 350 kPa.
  • the contact length tends to increase, but by increasing the contact length to 250 kPa or more, the increase in the contact length is suppressed, the deformation amount of the tread rubber is reduced, and the rolling resistance is further reduced. Because it can.
  • FIG. 3 is a view showing a tread pattern of a tire according to an embodiment of the present invention.
  • this tire has one or more (three in the illustrated example) circumferential main grooves 2 (2 a, 2 b, 2 c) extending in the tire circumferential direction on the tread surface 1.
  • one circumferential main groove 2a is disposed in one half of the tire width direction on one side with the tire equatorial plane CL as a boundary, and the circumferential main groove 2a includes three circumferential main grooves. 2 has the largest groove width.
  • two circumferential main grooves 2b and 2c are arranged in the other half of the tire width direction on the other side with the tire equatorial plane CL as a boundary.
  • this tire is divided into four land portions 3a, 3b, 3c, 3d in the illustrated example, which are partitioned by three circumferential main grooves 2a, 2b, 2c and a tread end TE in the illustrated example. have.
  • FIG. 4 shows the position in the outermost part in the tire width direction in one half of the tire width direction with the tire equatorial plane CL as a boundary among the three circumferential main grooves 2a, 2b, 2c extending in the tire circumferential direction. It is a figure which shows the tire width direction cross-sectional shape of the outermost circumferential direction main groove 2a to do.
  • the groove wall 21 on the inner side in the tire width direction defined by the outermost circumferential main groove 2 a is inclined inward in the tire width direction from the inner side in the tire radial direction to the outer side.
  • the angle ⁇ in formed by the groove wall 21 on the inner side in the tire width direction defined by the outermost circumferential main groove 2a with respect to the tire radial direction is 15 ° in this example.
  • the angle ⁇ out formed by the groove wall 22 on the outer side in the tire width direction defined by the outermost circumferential main groove 2a with respect to the tire radial direction is 0 ° in this example.
  • the angle ⁇ in (15 ° in this example) formed by the groove wall 21 on the inner side in the tire width direction of the outermost circumferential main groove 2a with respect to the tire radial direction is the maximum.
  • the groove wall 22 on the outer side in the tire width direction of the outer circumferential main groove 2a is larger than the angle ⁇ out (0 ° in this example) formed with respect to the tire radial direction.
  • the circumferential main grooves 2b and 2c have a symmetrical shape in the tire width direction cross section as shown in FIG. 6, and are partitioned by these circumferential main grooves 2b and 2c.
  • the groove wall on the inner side in the tire width direction is inclined inward in the tire width direction from the inner side to the outer side in the tire radial direction, the inclination angle of the groove wall with respect to the tire radial direction is 5 °, and these circumferential directions
  • the groove wall on the outer side in the tire width direction defined by the main grooves 2b and 2c is inclined outward in the tire width direction from the inner side in the tire radial direction to the outer side, and the inclination angle of the groove wall with respect to the tire radial direction is 5 °.
  • the angle ⁇ in Is relatively larger than the angle ⁇ out
  • the edge pressure at the inner edge in the tire width direction partitioned by the circumferential main groove 2a can be increased, and the turning performance on snow can be improved.
  • the angle ⁇ in is relatively larger than the angle ⁇ out, Since the width of the groove bottom is reduced, the shear deformation of the groove bottom can be reduced.
  • the size of the angle ⁇ out is relatively smaller than the size of the angle ⁇ in, the volume of the tread rubber portion located on the inner side in the tire width direction of the outermost land portion of the outermost land portion when the vehicle is mounted is reduced. (In the example shown in FIGS. 4 and 5, there is no tread rubber portion on the inner side in the tire width direction from the innermost position in the tire width direction of the outermost land portion when the vehicle is mounted), and shear deformation at the groove bottom portion of the groove wall is reduced. can do.
  • the angle ⁇ out is relatively smaller than the angle ⁇ in, the cross-sectional area of the circumferential main groove 2a is compared in the case where the groove width (opening width) of the circumferential main groove 2a is constant. Can be ensured, the snow column shearing force can be secured, and the turning performance on snow can be secured. 4 and 5, even if the angle ⁇ out is positive, the angle ⁇ out is relatively smaller than the angle ⁇ in, and therefore the groove width (opening) of the circumferential main groove 2a. When the width is considered to be constant, the width of the groove bottom of the circumferential main groove 2a is reduced, and shear deformation of the groove bottom is reduced. As described above, according to the tire of this embodiment, both rolling resistance and performance on snow can be achieved.
  • the angle ⁇ out may be 0 ° as shown in FIG. 4, may be negative as shown in FIG. 5, or may be positive.
  • the angles ⁇ in and ⁇ out preferably satisfy ⁇ 5 ° ⁇ ⁇ out ⁇ 3 ° and 10 ° ⁇ ⁇ in ⁇ 20 °.
  • the angle ⁇ in By setting the angle ⁇ in to 10 ° or more, the above-described edge pressure can be further increased.
  • the angle ⁇ in to 20 ° or less the cross-sectional area of the circumferential main groove 2a is secured, This is because the snow column shear force can be further secured.
  • the protrusion 4 it is preferable to provide the protrusion 4 only on the groove bottom portion on the groove wall side on the outer side in the tire width direction of the outermost circumferential main groove 2a.
  • the protrusion 4 has a rectangular shape in a cross-sectional view in the tire width direction, and has a side wall that is inclined from the inner side in the tire radial direction to the outer side in the tire width direction. is doing.
  • the bottom surface of the protrusion 4 is wider than the upper surface of the protrusion 4, and such a shape can effectively suppress deformation of the groove bottom.
  • the maximum width in the tire width direction of the protrusion 4 is w1 (mm)
  • the maximum height in the tire radial direction is h1 (mm)
  • the protrusion 4
  • the cross-sectional area in the tire width direction cross section is S1 (mm 2 )
  • w1 ⁇ h1 / 2 ⁇ S1 ⁇ w1 ⁇ h1
  • S1 ⁇ w1 ⁇ h1 / 2 it is preferable to satisfy.
  • S1 ⁇ w1 ⁇ h1 / 2 the reinforcing effect by the protrusions 4 can be enhanced and the shear deformation of the groove bottom can be further suppressed.
  • S1 ⁇ w1 ⁇ h1 the groove This is because the volume can be secured and the snow column shear force can be secured.
  • the outermost circumference when the tire is mounted on the rim filled with the internal pressure defined for each vehicle on which the tire is mounted, and in an unloaded state.
  • the groove width of the opening of the direction main groove 2a is w2 (mm) and the maximum groove depth is h2 (mm)
  • the ratio w1 / w2 to 1/6 or more and the ratio h1 / h2 to 1/8 or more, the reinforcing effect by the protrusion 4 can be enhanced and the shear deformation at the groove bottom can be further suppressed.
  • the ratio w1 / w2 to 1/8 or less and the ratio h1 / h2 to 1/5 or less
  • the groove volume can be secured and the snow column shear force can be secured. .
  • the outermost circumferential main groove 2a located on the outermost side in the tire width direction is separated from the tread end TE by a distance of 15% to 25% of the tread width TW.
  • the outermost circumferential main groove 2a is separated from the tread end TE by a distance of 15% or more of the tread width TW, thereby ensuring the width in the tire width direction of the outermost land portion in the tire width direction. Steering stability on the road surface can be ensured, while the outermost circumferential main groove 2a is separated from the tread end TE by a distance of 25% or less of the tread width TW, thereby providing a slip angle.
  • the “tread end” means that a tire is mounted on a rim, filled with an internal pressure defined for each vehicle on which the tire is mounted, and is defined by the above industrial standards, or a maximum load load determined in the future, or In the case of a size that is not described in the above industrial standards, when the maximum number of passengers is assumed, when a load is applied to the tire with the highest load among the four wheels, the contact surface will be grounded to the road surface.
  • the outermost position in the tire circumferential direction is the outermost position in the tire width direction
  • “tread width” is the distance in the tire width direction between the tread ends TE.
  • the outermost circumferential main groove 2a located on the outermost side in the tire width direction preferably has a larger groove width than the other circumferential main grooves 2a, 2b. This is because the snow column shear force can be improved efficiently by increasing the groove area of the outer circumferential main groove when the vehicle is mounted so that the contact length becomes longer when the slip angle is applied.
  • the groove width (opening width) of the outermost circumferential main groove 2a located on the outermost side in the tire width direction is preferably 6 to 9% of the tread width TW.
  • the groove width of the outermost circumferential main groove refers to the groove width when a tire is mounted on a rim and an internal pressure defined for each vehicle on which the tire is mounted is filled and no load is applied.
  • a plurality of widthwise grooves 5 extending in the tire width direction and a plurality of widthwise sipes 6 extending in the tire width direction are alternately arranged in the tire circumferential direction in the land portion 3 a.
  • This width direction groove 5 it is possible to secure snow column shearing force and improve snow traction performance and snow braking performance.
  • the edge component with respect to the tire circumferential direction can be secured by the width direction sipe 6.
  • the land portion 3b has a plurality of widthwise grooves 7 extending in the tire width direction at intervals in the tire circumferential direction. Thereby, snow column shear force is ensured and snow traction performance and snow brake performance can be improved. Further, the land portion 3b is provided with width direction sipes 8 that are inclined and extend in the tire width direction at intervals in the tire circumferential direction, thereby securing an edge component in the tire circumferential direction and the tire width direction. be able to. Further, in this example, a single circumferential sipe 9 extending in the tire circumferential direction is formed in the land portion 3b, whereby an edge component in the tire width direction can be secured.
  • the land portion 3c has a plurality of width-direction sipes 10 extending incline in the tire width direction at intervals in the tire circumferential direction. Thereby, the edge component with respect to the tire circumferential direction and the tire width direction can be ensured.
  • the land portion 3d has a plurality of widthwise grooves 11 extending in the tire width direction at intervals in the tire circumferential direction. Thereby, snow column shear force is ensured and snow traction performance and snow brake performance can be improved. Further, a plurality of width direction sipes 12 extending in the tire width direction are provided in the land portion 3d at intervals in the tire circumferential direction, whereby an edge component in the tire circumferential direction can be ensured. Further, in this example, a single circumferential sipe 13 extending in the tire circumferential direction is formed in the land portion 3d, whereby an edge component in the tire width direction can be secured.
  • the cross-sectional width SW and the outer diameter OD (mm) of the tire are expressed by the relational expression (2), OD ⁇ ⁇ 0.0187 ⁇ SW 2 + 9.15 ⁇ SW-380 Can also be satisfied.
  • the internal pressure of the tire is preferably 250 kPa or more, and more preferably 250 to 350 kPa.
  • the tire size of the pneumatic radial tire for passenger cars of the present invention is specifically 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 / 55R20, 145 / 60R16, 145 / 60R17, 145 / 60R18, 145 / 60R19, 145 / 65R19, 155 / 45R18, 155 / 45R21, 155 / 55R18, 155 / 55R19, 155 / 55R21, 155 / 60R17, 155 / 65R13, 155 / 65R18, 155 / 70R17, 155 / 70R19, 165 / 45R22, 165
  • the groove volume ratio (groove volume V2 / tread rubber volume V1) is preferably 20% or less, and the negative ratio (ratio of groove area to tread tread area) is 20% or less. It is preferable. These values are lower than the standard values for conventional size pneumatic radial tires for passenger cars. In order to improve the wet performance, it is a general idea to increase the groove amount. However, a pneumatic radial for a passenger car having a narrow and large diameter that satisfies the above relational expression (1) and / or (2).
  • the groove volume ratio is, for example, the tire diameter at the center in the tire width direction at the inner side in the tire width direction from the both ends in the width direction of the maximum width belt layer having the maximum width in the tire width direction of the belt layer.
  • the ratio is defined as V2 / V1. Is done.
  • the pattern is mainly composed of rib-like land portions that are partitioned in the tire width direction by TE.
  • the rib-shaped land portion refers to a land portion extending in the tire circumferential direction without having a width-direction groove traversing in the tire width direction, and the rib-shaped land portion is a width-direction groove terminating in the sipe or the rib-shaped land portion. May have.
  • a negative rate is obtained between the tire width direction half of the vehicle mounting inner side and the vehicle mounting outer side with the tire equator plane CL as a boundary. A difference may be provided.
  • the shoulder rib-shaped land portions various configurations can be adopted for the shoulder rib-shaped land portions divided by the outermost circumferential main groove in the tire width direction and the tread end TE.
  • the width in the tire width direction of the shoulder rib-shaped land portion on the vehicle mounting outside and inside can be changed.
  • the width in the tire width direction of the shoulder rib-shaped land portion outside the vehicle mounting is larger than the width in the tire width direction of the shoulder rib-shaped land portion inside the vehicle mounting.
  • the buckling is suppressed and the cornering power is improved.
  • the tire is mounted on the vehicle, it is preferable to provide an end opening groove extending from the circumferential main groove to the vehicle mounting inner side. Specifically, as shown in FIG. 9, at least one half of the tread surface with the tire equatorial plane CL as a boundary is adjacent to the tread end TE and has a distance in the tread width direction from the tread end TE.
  • the tread end side main groove 40 extending in the tread circumferential direction and spaced apart by 25% or more of the tread width TW is adjacent to the tread end side land portion defined by the tread end side main groove 40 and the tread end TE.
  • One of the portions 41 preferably has at least one end opening groove 42 extending from the tread end side main groove 40 in the tread width direction and staying in the adjacent land portion 41.
  • the groove 43 in FIG. 9 is a shallow groove having a groove depth smaller than that of the main groove.
  • the deformation of the tread and the belt due to the compressive stress is suppressed as compared with the case where the one end opening groove 42 is not provided or the case where the one end opening groove 42 does not extend to the outside of the vehicle. Furthermore, since the one end opening groove 42 stays in the land portion, the rigidity against the tensile stress inside the vehicle mounting becomes higher compared to the case where the one end opening groove 42 extends to the vehicle mounting inner side. Belt deformation is suppressed.
  • the tire is shown in the tire width direction cross section as shown in FIG.
  • a straight line parallel to the tire width direction passing through the point P on the tread surface on the equator plane CL is defined as m1
  • a straight line passing through the ground contact E and parallel to the tire width direction is defined as m2.
  • distance and the fall height L CR, when the tread width of the tire and TW, the ratio L CR / TW preferably set to 0.045 or less.
  • the crown portion of the tire is flattened (flattened), the contact area increases, the input (pressure) from the road surface is relaxed, and the tire radial direction is reduced.
  • the deflection rate can be reduced, and the durability and wear resistance of the tire can be improved.
  • the “ground contact E” is defined for each vehicle in which a tire is mounted on a rim, filled with a maximum air pressure specified for each vehicle on which the tire is mounted, and placed vertically on a flat plate. This refers to both end points in the tire width direction on the contact surface with the flat plate when a weight corresponding to the maximum load is applied.
  • the tread rubber may be formed by laminating a plurality of different rubber layers in the tire radial direction.
  • the plurality of rubber layers those having different tangent loss, modulus, hardness, glass transition temperature, material and the like can be used.
  • the ratio of the thickness in the tire radial direction of the plurality of rubber layers may be changed in the tire width direction, or only the circumferential main groove bottom or the like may be a rubber layer different from the periphery thereof.
  • the tread rubber may be formed of a plurality of rubber layers different in the tire width direction.
  • the plurality of rubber layers those having different tangent loss, modulus, hardness, glass transition temperature, material and the like can be used.
  • the ratio of the width of the plurality of rubber layers in the tire width direction may be changed in the tire radial direction, and only in the vicinity of the circumferential main groove, only in the vicinity of the tread end TE, only in the shoulder land portion, only in the center land portion. Only a limited part of the area can be a rubber layer different from the surrounding area.
  • the tire of the present invention preferably has an inclined belt layer composed of a rubberized layer of cords extending incline with respect to the tire circumferential direction.
  • the inclined belt layer may be only one layer.
  • the shape of the ground contact surface during turning tends to be distorted.
  • an inclined belt layer extending in a direction in which the cords cross each other between two or more layers.
  • a belt structure in which two belt layers form an inclined belt layer is most preferable.
  • the width in the tire width direction of the maximum width inclined belt layer having the largest width in the tire width direction is preferably 90% to 115% of the tread width TW, and is 100% to 105% of the tread width TW. It is particularly preferred.
  • a metal cord particularly a steel cord is most commonly used as the belt cord of the inclined belt layer, but an organic fiber cord can also be used.
  • the steel cord is mainly composed of steel and can contain various trace contents such as carbon, manganese, silicon, phosphorus, sulfur, copper, and chromium.
  • a monofilament cord or a cord obtained by twisting a plurality of filaments can be used as the belt cord of the inclined belt layer.
  • Various designs can be adopted for the twist structure, and various cross-sectional structures, twist pitches, twist directions, and distances between adjacent filaments can be used.
  • the cord which twisted the filament of a different material can also be used, and it does not specifically limit as a cross-sectional structure, Various twisted structures, such as a single twist, a layer twist, a double twist, can be taken.
  • the inclination angle of the belt cord of the inclined belt layer is preferably 10 ° or more with respect to the tire circumferential direction.
  • the inclination angle of the belt cord of the inclined belt layer is preferably set to a high angle, specifically 35 ° or more with respect to the tire circumferential direction, and particularly within a range of 55 ° to 85 ° with respect to the tire circumferential direction. .
  • This is because by setting the inclination angle to 35 ° or more, the rigidity in the tire width direction can be increased, and in particular, the steering stability performance during cornering can be improved.
  • the rolling resistance performance can be improved by reducing the shear deformation of the interlayer rubber.
  • the tire of the present invention can have a circumferential belt composed of one or more circumferential belt layers outside the inclined belt layer in the tire radial direction.
  • the circumferential belt has a tire circumferential rigidity per unit width of the central region C including the tire equatorial plane CL, and other regions. It is preferably higher than the tire circumferential rigidity per unit width.
  • FIG. 11 schematically shows an example of the belt structure, in which circumferential belt layers 53 and 54 are laminated on the outer side in the tire radial direction of the inclined belt layers 51 and 52, and in the central region C, the circumferential belt layer 53 and 54 overlap each other in the tire radial direction.
  • the tire circumferential rigidity per unit width of the central region C can be determined as a unit of other regions. It can be higher than the tire circumferential rigidity per width.
  • the tread in a tire having increased rigidity in the tire circumferential direction in the central region including the tire equatorial plane CL, the tread has a land portion continuous in the tire circumferential direction in the region including at least the tire equatorial plane CL of the tread surface. It is preferable to have. If the circumferential main groove is disposed on or near the tire equator plane CL, the rigidity of the tread in the region may be reduced, and the contact length in the land portion defining the circumferential main groove may be extremely short. Therefore, it is preferable to dispose land portions (rib-shaped land portions) continuous in the tire circumferential direction over a certain region including the tire equatorial plane CL from the viewpoint of improving noise performance without reducing cornering power.
  • FIG. 12 schematically shows another example of the belt structure, in which one circumferential belt layer 63 is laminated on the outer side in the tire radial direction of the two inclined belt layers 61 and 62.
  • the inclined belt layer is inclined in two layers having different widths in the tire width direction.
  • the inclination angle ⁇ 1 with respect to the tire circumferential direction of the cord that includes at least the belt layer and forms the widest inclined belt layer, and the inclination angle ⁇ 2 with respect to the tire circumferential direction of the cord that forms the narrowest inclined belt layer are 35 ° ⁇ ⁇ 1 It is preferable that ⁇ 85 °, 10 ° ⁇ ⁇ 2 ⁇ 30 °, and ⁇ 1> ⁇ 2 are satisfied.
  • Many tires having an inclined belt layer having a belt cord inclined at an angle of 35 ° or more with respect to the tire circumferential direction have first, second and third vibration modes in the cross-sectional direction in a high frequency range of 400 Hz to 2 kHz.
  • the tread surface Since the tread surface has a shape that vibrates greatly uniformly, a large radiated sound is generated. Therefore, if the tire circumferential direction rigidity of the tread tire width direction central region is locally increased, the tread tire width direction central region becomes difficult to spread in the tire circumferential direction, and the spread of the tread surface in the tire circumferential direction is suppressed. As a result, radiated sound can be reduced.
  • FIG. 13 schematically shows another example of the belt structure, in which one circumferential belt layer 73 is laminated on the outer side in the tire radial direction of the two inclined belt layers 71 and 72.
  • the circumferential belt layer is preferably highly rigid, and more specifically, the tire circumference.
  • the contact surface tends to have a substantially triangular shape, that is, a shape in which the contact length in the circumferential direction varies greatly depending on the position in the tire width direction.
  • a highly rigid circumferential belt layer by using a highly rigid circumferential belt layer, the ring rigidity of the tire is improved, and deformation in the tire circumferential direction is suppressed. Deformation is also suppressed, and the ground contact shape is less likely to change.
  • the eccentric rigidity is promoted by improving the ring rigidity, and the rolling resistance is simultaneously improved. The effect of improving the rolling resistance is particularly large in a pneumatic radial tire for a passenger car having a narrow width and a large diameter that satisfies the above relational expressions (1) and / or (2).
  • the inclination angle of the inclined belt layer with respect to the tire circumferential direction of the belt cord is a high angle, specifically 35 ° or more.
  • the contact length may be reduced depending on the tire due to the increased rigidity in the tire circumferential direction. Therefore, by using a high-angle inclined belt layer, it is possible to reduce the out-of-plane bending rigidity in the tire circumferential direction, increase the elongation in the tire circumferential direction of the rubber when the tread surface is deformed, and suppress the decrease in the contact length. it can.
  • a wavy cord may be used for the circumferential belt layer in order to increase the breaking strength.
  • a high elongation cord (for example, elongation at break is 4.5 to 5.5%) may be used.
  • various materials can be used for the circumferential belt layer.
  • Typical examples include rayon, nylon, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), aramid, and glass fiber.
  • Carbon fiber, steel, etc. can be used. From the viewpoint of weight reduction, an organic fiber cord is particularly preferable.
  • the cord of the circumferential belt layer may be a monofilament cord, a cord in which a plurality of filaments are combined, or a hybrid cord in which filaments of different materials are combined.
  • the number of circumferential belt layers to be driven can be in the range of 20 to 60/50 mm, but is not limited to this range.
  • the distribution of rigidity, material, number of layers, driving density, etc. can be given in the tire width direction.
  • the number of circumferential belt layers can be increased only at the end in the tire width direction.
  • the number of circumferential belt layers can be increased only in the center portion.
  • the circumferential belt layer can be designed to be wider or narrower than the inclined belt layer.
  • the width in the tire width direction can be 90% to 110% of the maximum width inclined belt layer having the largest width in the tire width direction among the inclined belt layers.
  • the circumferential belt layer is configured as a spiral layer.
  • the carcass maximum width position can be brought closer to the bead portion side or closer to the tread side.
  • the carcass maximum width position can be provided in the range of 50% to 90% relative to the tire cross-section height on the outer side in the tire radial direction from the bead base portion.
  • the carcass can adopt various structures.
  • the number of carcass shots can be in the range of 20 to 60 pieces / 50 mm, but is not limited thereto.
  • the folded end of the carcass can be positioned on the inner side in the tire radial direction of the end of the bead filler in the tire radial direction, and the folded end of the carcass is positioned in the tire radial direction from the outer end of the bead filler in the tire radial direction or the maximum tire width position. It can be located on the outer side, and in some cases, it can extend to the inner side in the tire width direction from the end in the tire width direction of the inclined belt layer. Furthermore, when the carcass is constituted by a plurality of carcass plies, the position of the carcass folded end in the tire radial direction can be varied. In addition, a structure in which a plurality of bead core members are sandwiched or wound around a bead core without using a carcass folded portion can be employed.
  • the tire side portion In a pneumatic radial tire for a passenger car having a narrow and large diameter that satisfies the above relational expression (1) and / or (2), it is preferable to make the tire side portion thin.
  • “To thin the tire side portion” means, for example, that the cross-sectional area S1 of the bead filler in the tire width direction is 1 to 4 times the cross-sectional area S2 of the bead core in the tire width direction.
  • the ratio Ts / Tb between the gauge Ts of the sidewall portion at the tire maximum width portion and the bead width Tb at the tire radial direction center position of the bead core can be 15% or more and 40% or less.
  • the ratio Ts / Tc between the gauge Ts of the sidewall portion in the tire maximum width portion and the diameter Tc of the carcass cord can be set to 5 or more and 10 or less.
  • the gauge Ts is the sum of the thicknesses of all members such as rubber, a reinforcing member, and an inner liner. In the case where the bead core is divided into a plurality of small bead cores by the carcass, the distance between the innermost end in the width direction and the outermost end of all the small bead cores is Tb.
  • the tire maximum width position can be provided in the range of 50% to 90% in comparison with the tire cross-section height, on the outer side in the tire radial direction from the bead base portion.
  • the tire of the present invention may have a structure having a rim guard.
  • the tire according to the present invention may have a structure without a bead filler.
  • the bead core can adopt various structures such as a circular cross section and a polygonal cross section.
  • a structure in which the carcass is wound around the bead core a structure in which the carcass is sandwiched between a plurality of bead core members may be employed.
  • the bead portion may be further provided with a rubber layer, a cord layer, or the like for the purpose of reinforcement or the like.
  • additional members can be provided at various positions with respect to the carcass and the bead filler.
  • the thickness of the inner liner from the viewpoint of reducing in-vehicle noise of 80-100 Hz. Specifically, it is preferably about 1.5 mm to 2.8 mm thicker than usual (about 1.0 mm). It has been found that pneumatic radial tires for passenger cars with narrow and large diameters satisfying the above relational expression (1) and / or (2) tend to deteriorate the in-vehicle noise of 80-100 Hz especially when high internal pressure is used. Yes. By increasing the thickness of the inner liner, it is possible to improve vibration damping and reduce in-vehicle noise of 80-100 Hz. In addition, since the loss which contributes to rolling resistance is small compared with other members, such as a tread, an inner liner can improve noise performance, suppressing deterioration of rolling resistance to the minimum.
  • the inner liner can be formed of a film layer mainly composed of a resin in addition to a rubber layer mainly composed of butyl rubber.
  • a porous member in order to reduce cavity resonance noise, can be disposed on the tire inner surface, or electrostatic flocking can be performed.
  • the tire of the present invention can also be provided with a sealant member for preventing air leakage during puncture on the tire inner surface.
  • the pneumatic radial tire for passenger cars of the present invention can also be a side-reinforced run-flat tire having a crescent-shaped reinforcing rubber in the tire side portion.
  • a side-reinforced run-flat tire when a side-reinforced run-flat tire is used, it is possible to achieve both run-flat durability and fuel efficiency by adopting a simplified side part. it can.
  • the side portion and the tread portion are This is based on the knowledge that the deformation is relatively small, while the deformation is relatively large from the shoulder portion to the buttress portion. This deformation is in contrast to the relatively large deformation at the side portion in the conventional size.
  • FIG. 14 is a tire width direction cross-sectional view of a tire according to an embodiment of the present invention when the tire of the present invention is a run-flat tire.
  • the folded end A of the carcass folded portion is located on the inner side in the tire radial direction from the maximum tire width position P.
  • the tire is assembled in the rim, filled with a predetermined internal pressure,
  • the maximum tire radial direction length of the side reinforcing rubber 81 in the tire width direction cross section in the reference state as a load is H1
  • the outermost point in the tire radial direction of the bead filler is connected to the outermost point in the tire radial direction of the bead core.
  • FIG. 15 is a tire width direction cross-sectional view of a tire according to another embodiment of the present invention when the tire of the present invention is a run-flat tire.
  • the tire has a maximum width in the tire width direction among one or more belt layers in a cross section of the tire width direction in a reference state in which the tire is incorporated into the rim, filled with a predetermined internal pressure, and is unloaded.
  • the half width in the tire width direction of the belt layer is WB, and the circumferential main groove 101 on the outermost side in the tire width direction among the one or more circumferential main grooves from the tire width direction end of the belt layer having the largest width in the tire width direction.
  • the distance in the tire width direction to the center position in the tire width direction is WG, it is preferable that the relational expression 0.5 ⁇ WG / WB ⁇ 0.8 is satisfied.
  • Each tire is a pneumatic radial tire for a passenger car including a carcass made of a ply of a radial arrangement code straddling a toroidal shape between a pair of bead portions.
  • Each tire has a tire size of 165 / 60R19 and satisfies OD ⁇ 2.135 ⁇ SW + 282.3 and OD ⁇ ⁇ 0.0187 ⁇ SW 2 + 9.15 ⁇ SW-380.
  • Each tire has the tread pattern shown in FIG.
  • Each of the above tires was mounted on a rim having a rim size of 5.5J-19, the internal pressure was set to 300 kPa, and the following tests for evaluating the rolling resistance value and turning performance on snow were performed.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Tires In General (AREA)

Abstract

La présente invention concerne un pneumatique radial pour véhicules de tourisme, caractérisé en ce qu'il est pourvu d'une carcasse qui s'étend au plan toroïdal entre une paire de parties de talon et qui comprend des couches de câbles disposés radialement. Le pneumatique radial pour véhicules de tourisme est en outre caractérisé en ce que : quand le pneumatique est monté sur une jante applicable et que la pression interne est établie de façon à être d'au moins 250 kPa, la largeur (SW) de section transversale du pneumatique et le diamètre externe (OD) du pneumatique satisfont une expression relationnelle prescrite ; et dans une section transversale du pneumatique dans le sens de la largeur, l'angle (θin) (°) formé entre la direction radiale du pneumatique et une paroi de rainure interne dans le sens de la largeur du pneumatique, ladite paroi de rainure interne étant démarquée dans la rainure principale périphérique située le plus à l'extérieur, parmi les principales rainures périphériques s'étendant le long du pneumatique dans la direction périphérique, qui est positionné sur le côté le plus à l'extérieur dans le sens de la largeur du pneumatique, est supérieur à l'angle (θout) (°) formé entre la direction radiale du pneumatique et une paroi de rainure externe dans le sens de la largeur du pneumatique, ladite paroi de rainure externe étant démarquée dans la rainure principale périphérique située le plus à l'extérieur.
PCT/JP2015/002327 2014-05-07 2015-05-07 Pneumatique radial pour véhicules de tourisme WO2015170478A1 (fr)

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Cited By (2)

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US20180370290A1 (en) * 2017-06-27 2018-12-27 Sumitomo Rubber Industries, Ltd. Tire
EP3960504A1 (fr) * 2020-08-31 2022-03-02 Sumitomo Rubber Industries, Ltd. Pneumatique

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JP6881088B2 (ja) * 2017-06-27 2021-06-02 住友ゴム工業株式会社 タイヤ
JP7069995B2 (ja) * 2018-04-10 2022-05-18 住友ゴム工業株式会社 タイヤ
JP7275780B2 (ja) * 2019-04-03 2023-05-18 住友ゴム工業株式会社 タイヤ
JP7275778B2 (ja) * 2019-04-03 2023-05-18 住友ゴム工業株式会社 タイヤ

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JP2011183993A (ja) * 2010-03-10 2011-09-22 Bridgestone Corp 空気入りタイヤ
JP2012254654A (ja) * 2011-06-07 2012-12-27 Bridgestone Corp タイヤ
JP2013039899A (ja) * 2011-08-19 2013-02-28 Bridgestone Corp 空気入りタイヤ

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JP2011183993A (ja) * 2010-03-10 2011-09-22 Bridgestone Corp 空気入りタイヤ
JP2012254654A (ja) * 2011-06-07 2012-12-27 Bridgestone Corp タイヤ
JP2013039899A (ja) * 2011-08-19 2013-02-28 Bridgestone Corp 空気入りタイヤ

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180370290A1 (en) * 2017-06-27 2018-12-27 Sumitomo Rubber Industries, Ltd. Tire
EP3421263A1 (fr) * 2017-06-27 2019-01-02 Sumitomo Rubber Industries, Ltd. Pneumatique
CN109130709A (zh) * 2017-06-27 2019-01-04 住友橡胶工业株式会社 轮胎
CN109130709B (zh) * 2017-06-27 2022-03-11 住友橡胶工业株式会社 轮胎
EP3960504A1 (fr) * 2020-08-31 2022-03-02 Sumitomo Rubber Industries, Ltd. Pneumatique
US11865871B2 (en) 2020-08-31 2024-01-09 Sumitomo Rubber Industries, Ltd. Tire

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