Tire

Abstract

A tire (1) is provided with a plurality of shoulder lug grooves (311) extending beyond a tire ground contact end (T) to a shoulder reinforcement. In addition, the plurality of shoulder lug grooves (311) have protrusions (5) that protrude from the groove bottoms of the shoulder lug grooves (311) and are disposed further to the outside in the tire width direction than the tire ground contact end (T). The distance (D1) in the tire width direction from the tire ground contact end (T) to the protruding portion (5) is within the range of 0.02 < = D1 / SH < = 0.15 with respect to the tire cross-sectional height (SH).

Description

Technical Field

[0001] This invention relates to a tire, and more specifically, to a tire that improves performance on mud and snow. Background Technology

[0002] In recent years, in addition to dry and wet performance requirements, all-terrain tires have also been required to improve performance on mud and snow during off-road driving. As a prior art tire related to this issue, the technology described in Patent Document 1 is known.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-142370 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The purpose of this invention is to provide a tire that can improve performance on mud and snow.

[0008] means for solving problems

[0009] To achieve the above objectives, the tire of the present invention has a plurality of shoulder lateral grooves extending beyond the tire contact end to the shoulder reinforcement portion, characterized in that the plurality of shoulder lateral grooves have protrusions that protrude from the bottom of the shoulder lateral grooves and are positioned further outward in the tire width direction than the tire contact end.

[0010] Invention Effects

[0011] In the tire of the present invention, (1) the shoulder lateral grooves have protrusions, thereby improving the function of expelling mud and snow from the shoulder lateral grooves during off-road driving. Furthermore, (2) since the protrusions are positioned further outward in the tire width direction than the tire contact patch end, the groove volume of the shoulder lateral grooves in the tire contact patch area is ensured, thereby improving the tire's traction performance. Thus, it has the advantage of improving the tire's performance on mud and snow. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view showing the tire along the radial direction of an embodiment of the present invention.

[0013] Figure 2 It means Figure 1 A top view of the tread surface of the tire.

[0014] Figure 3 It means Figure 2 A side view of the shoulder reinforcement of the tire.

[0015] Figure 4 It means Figure 2 A cross-sectional view of the shoulder reinforcement of the tire.

[0016] Figure 5 It means Figure 2 An enlarged top view of the shoulder reinforcement of the tire.

[0017] Figure 6 It means Figure 3 An explanatory diagram of the protruding part of the shoulder transverse groove.

[0018] Figure 7 It means Figure 3 An explanatory diagram of the protruding part of the shoulder transverse groove.

[0019] Figure 8 These are graphs showing the performance test results of tires according to embodiments of the present invention.

[0020] Figure 9 These are graphs showing the performance test results of tires according to embodiments of the present invention. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to this embodiment. Furthermore, the constituent elements of this embodiment include elements that are replaceable while maintaining the identity of the invention, and the replacement is obvious. Moreover, the various modifications described in this embodiment can be arbitrarily combined within the scope that is obvious to those skilled in the art.

[0022] [tire]

[0023] Figure 1 This is a cross-sectional view of tire 1 in the radial direction according to an embodiment of the present invention. This view shows a cross-sectional view of a single-sided region of the tire's radial direction. In this embodiment, a pneumatic radial tire for light trucks will be described as an example of a tire.

[0024] In this figure, the tire radial section is defined as the section cut from the tire in a plane including the tire's axis of rotation (not shown). Furthermore, the tire equatorial plane CL is defined as a plane passing through the midpoint of the tire's section width as specified by JATMA and perpendicular to the tire's axis of rotation. Additionally, the tire width direction is defined as parallel to the tire's axis of rotation, and the tire radial direction is defined as perpendicular to the tire's axis of rotation.

[0025] Tire 1 has a ring-shaped structure centered on the tire's axis of rotation, comprising: a pair of bead cores 11, 11; a pair of sidewall cores 12, 12; a carcass layer 13; a belt layer 14; a tread compound 15; a pair of sidewall compounds 16, 16; and a pair of rim protectors 17, 17 (see reference). Figure 1 ).

[0026] A pair of bead cores 11, 11 are formed by repeatedly winding one or more bead wires made of steel in a loop, and are embedded in the bead portion to form the cores of the left and right bead portions. A pair of sidewall cores 12, 12 are respectively disposed on the radial outer periphery of the tire of the pair of bead cores 11, 11 to reinforce the bead portion.

[0027] The carcass layer 13 has a single-layer structure formed by a single carcass ply or a multi-layer structure formed by stacking multiple carcass ply layers, and is arranged in a ring between the left and right bead cores 11, 12 to form the tire skeleton. Furthermore, the two ends of the carcass layer 13 are rolled back and secured to the outside in the tire width direction, enclosing the bead core 11 and the sidewall core 12. Additionally, the carcass ply of the carcass layer 13 is constructed by rolling multiple ply cords made of steel or organic fiber materials (e.g., aramid, nylon, polyester, rayon, etc.) covered with overlay rubber, and has a cord angle of 80 degrees to 100 degrees (defined as the angle of inclination of the length direction of the ply cord relative to the tire circumference).

[0028] The belt layer 14 is formed by stacking multiple belt ply layers 141 to 144 and is arranged around the outer periphery of the carcass layer 13. The belt ply layers 141 to 144 include a pair of cross belts 141 and 142 and multiple cover layers 143 and 144.

[0029] The pair of cross belts 141 and 142 are constructed by coating multiple belt cords made of steel or organic fiber material with coated rubber and then rolling them, and have a cord angle of 15 degrees or more and 55 degrees or less in absolute value (defined as the angle of inclination of the length direction of the belt cord relative to the tire circumference). Furthermore, the pair of cross belts 141 and 142 have cord angles of different signs, causing the length directions of the belt cords to intersect and overlap each other (a so-called oblique cross configuration). Moreover, the pair of cross belts 141 and 142 are stacked and arranged on the radially outer side of the tire carcass layer 13.

[0030] The cover layer 143 is constructed by covering cover layer cords made of steel or organic fiber material with rubber coating, and has a cord angle of 0-10 degrees in absolute value. Furthermore, the cover layer 143 may be a strip-shaped profile formed by covering one or more cover layer cords with rubber coating, and this strip-shaped profile is spirally wound multiple times in the tire circumferential direction around the outer circumferential surface of the cross belts 141, 142. Moreover, multiple cover layers 143 are arranged to cover the entire area of ​​the cross belts 141, 142.

[0031] The tread rubber 15 is disposed on the radial outer periphery of the tire carcass layer 13 and the belt layer 14 to form the tread portion of the tire 1. Made of a rubber material with excellent contact properties and weather resistance, it is exposed on the entire outer periphery of the tire to form the tread surface. A pair of sidewall rubbers 16, 16 are respectively disposed on the outer side of the tire carcass layer 13 in the tire width direction to form the left and right sidewall portions. A pair of rim protectors 17, 17 extend radially outward from the inner side of the left and right bead cores 11, 11 and the rolled-back portion of the tire carcass layer 13, forming the rim mating surface of the bead portion.

[0032] [Tread surface]

[0033] Figure 2 It means Figure 1 This is a top view of the tread surface of the tire 1. The figure shows the tread surface of an all-season tire with mud and snow markings "M+S". The tread surface is indicated by the symbol 'tread surface'. In this figure, the tire circumferential direction refers to the direction about the tire's axis of rotation. Furthermore, the reference numeral T indicates the tire contact patch end, and the dimension symbol TW indicates the tire contact patch width. Additionally, in this figure, tire 1 has a tread surface that is approximately point-symmetric with a centerline point on the tire's equatorial plane CL; therefore, some reference numerals for the constituent elements in the right-hand region of the figure are omitted.

[0034] like Figure 2 As shown, the tire 1 has multiple circumferential main grooves 21 and 22 extending along the tire circumference on the tread surface, and multiple annular land portions 31 to 33 divided by these circumferential main grooves 21 and 22. The circumferential main grooves 21 and 22 have annular structures that extend continuously throughout the entire circumference of the tire.

[0035] For example, in Figure 2In its configuration, tire 1 includes: a pair of shoulder main grooves 21, 21 and a pair of central main grooves 22, 22; and a pair of shoulder circumferential grooves 31, 31 and three rows of intermediate circumferential grooves 32, 33, 32. However, it is not limited to this; tire 1 may also have three circumferential main grooves and four rows of circumferential grooves, or five or more circumferential main grooves and six or more rows of circumferential grooves (illustrations omitted). In these cases, the pair of shoulder main grooves 21, 21 are the outermost main grooves in the tire width direction, each defined by the left and right regions bounded by the tire equatorial plane CL. Furthermore, the central main groove (illustrations omitted) is defined as the main groove located closer to the tire equatorial plane CL than the shoulder main grooves 21, 21.

[0036] The main groove is defined as a groove that has the obligation to display a wear indicator as specified in JATMA. In addition, the main groove has a groove width of 3.0 mm to 13 mm and a groove depth of 8.0 mm to 16 mm.

[0037] Regarding the groove width, it is measured as the distance between the opposing groove walls on the tread tread opening under no-load conditions, with the tire mounted on a specified rim and filled with a specified internal pressure. In structures where the groove opening has a notch or chamfer, the groove width is measured with the intersection of the extension line of the tread tread surface and the extension line of the groove wall in a cross-sectional view parallel to the groove depth direction in the groove width direction as the endpoint.

[0038] Regarding groove depth, it is measured as the distance from the tread surface to the bottom of the groove under no-load conditions, with the tire mounted on a specified rim and inflated to the specified internal pressure. Furthermore, groove depth is measured without considering structures with localized unevenness or sipes at the bottom.

[0039] The specified rim refers to the "standard rim" as defined by JATMA, the "design rim" as defined by TRA, or the "measuring rim" as defined by ETRTO. Furthermore, the specified inflator refers to the "maximum tire pressure" as defined by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" as defined by TRA, or the "inflation pressure" as defined by ETRTO. Additionally, the specified load refers to the "maximum load capacity" as defined by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" as defined by TRA, or the "load capacity" as defined by ETRTO. However, in JATMA, when the tire is a passenger car tire, the specified internal pressure is 180 kPa, and the specified load is 88% of the maximum load capacity at the specified internal pressure.

[0040] The circumferential revetments 31-33 consist of a pair of shoulder circumferential revetments 31, 31 and three rows of intermediate circumferential revetments 32, 33, 32. The shoulder circumferential revetments 31, 31 are defined as the circumferential revetments on the outer side of the tire width direction, defined by the main shoulder grooves 21, 21. Furthermore, the pair of shoulder circumferential revetments 31, 31 are positioned in the left and right regions bounded by the tire equatorial plane CL. The intermediate circumferential revetments 32, 33 are defined as the circumferential revetments positioned between the pair of shoulder circumferential revetments 31, 31.

[0041] In addition, Figure 2 In its configuration, tire 1 has a point-symmetric tread pattern with a center point on the tire equatorial plane CL. However, it is not limited to this. Tire 1 may also have a line-symmetric tread pattern centered on the tire equatorial plane CL, a directional tread pattern in the direction of tire rotation, or a left-right asymmetrical tread pattern (illustrations omitted).

[0042] In addition, Figure 2 In its configuration, the circumferential main grooves 21 and 22 have a sawtooth shape or a bent shape with amplitude in the tire width direction. However, it is not limited to this; the circumferential main grooves 21 and 22 may also have a straight shape, or a wave shape or a stepped shape with amplitude in the tire width direction (illustrations omitted).

[0043] In addition, Figure 2In the tire shoulder ring portion 31, the maximum ground contact width Wb1 is within the range of 0.15≤Wb1 / TW≤0.30 relative to the tire ground contact width TW, preferably within the range of 0.17≤Wb1 / TW≤0.25.

[0044] Regarding the ground contact width of the rim, it is measured as the straight-line distance along the tire's axial direction on the contact surface between the rim and the flat plate when the tire is mounted on a specified rim and a specified internal pressure is applied, while the tire is placed perpendicular to the flat plate in a stationary state and a load corresponding to a specified load is applied.

[0045] Regarding tire contact width (TW), it is measured as the straight-line distance along the tire's axial direction on the contact surface between the tire and the flat plate when the tire is mounted on a specified rim and a specified internal pressure is applied, while the tire is placed perpendicular to the flat plate in a stationary state and a load corresponding to the specified load is applied.

[0046] The tire contact point T is defined as the position of the maximum axial width of the tire on the contact surface between the tire and the flat plate when the tire is mounted on a specified rim and a specified internal pressure is applied, while the tire is placed perpendicular to the flat plate in a stationary state and a load corresponding to a specified load is applied.

[0047] [Tire shoulder perimeter]

[0048] Figures 3-5 It means Figure 2 Side view of the shoulder reinforcement of the tire 1 ( Figure 3 ), sectional view ( Figure 4 ) and enlarged top view ( Figure 5 In these figures, Figure 3 This is a top view of a tire shoulder ring 31 as seen from the side of the tire. Figure 4 This is a diagram showing the unfolded shape of the shoulder lateral grooves 311 outside the tire contact patch. Figure 5 A cross-sectional view showing the shoulder lateral groove 311 along the length of the groove.

[0049] like Figure 2 As shown, the shoulder ring portion 31 has multiple shoulder lateral grooves 311 and multiple shoulder tread blocks 312.

[0050] like Figure 2As shown, the shoulder lateral groove 311 opens towards the main shoulder groove 21 at one end, extends beyond the tire contact patch end T and along the tire width direction to the shoulder reinforcement. Furthermore, multiple shoulder lateral grooves 311 are arranged at predetermined intervals in the tire circumferential direction. Additionally, the shoulder lateral groove 311 has a groove width of 3.0 mm to 17.0 mm, preferably 5.0 mm to 15.0 mm, and a groove depth of 8.0 mm to 17.0 mm, preferably 10.0 mm to 16.0 mm (dimension markings omitted in the figure) within the tire contact patch. Furthermore, the maximum groove width W11_max of the shoulder lateral groove 311 (refer to...) Figure 4 ) relative to the maximum groove width Wm of the main groove 21 on the tire shoulder (refer to Figure 2 The value should be within the range of 1.35 ≤ W11_max / Wm ≤ 1.85, preferably within the range of 1.45 ≤ W11_max / Wm ≤ 1.75. Furthermore, the maximum groove depth H11_max of the shoulder lateral groove 311 (refer to...) Figure 5 The maximum groove depth Hm (illustration omitted) of the main groove 21 of the tire shoulder is in the range of 0.75≤H11_max / Hm≤1.00, preferably in the range of 0.80≤H11_max / Hm≤0.98.

[0051] For example, in Figure 2 In its composition, such as Figure 4 and Figure 5 As shown, the shoulder lateral groove 311 has a shape that widens towards the outer side in the tire width direction, and has a maximum groove width W11_max and a maximum groove depth H11_max at the tire contact end T. Furthermore, the shoulder lateral groove 311 extends beyond the tire contact end T and reaches the mold dividing position M.

[0052] The dividing position M of the mold is defined as the position corresponding to the connecting part of the dividing mold of the tire forming mold, and is located in the shoulder reinforcement of the tire. A rib-like protrusion is formed at the dividing position M of the mold. This rib-like protrusion is composed of residual rubber embedded during tire vulcanization and extends circumferentially along the tire. Specifically, the dividing mold (not shown) consists of a first forming mold that moves in and out radially to form the tread portion and left and right second forming molds that move in and out axially to form the sidewall portion, thereby forming a rib-like protrusion with a width of approximately 2 mm to 3 mm at the dividing position M of the mold.

[0053] In addition, Figure 4 In the figure, the extension length L11 of the shoulder lateral groove 311 outside the tire contact patch relative to the tire section height SH (refer to...) Figure 1The value should be within the range of 0.15 ≤ L11 / SH ≤ 0.25, preferably within the range of 0.17 ≤ L11 / SH ≤ 0.22. This improves tire traction during off-road driving. For example, in Figure 4 In the configuration, the shoulder lateral groove 311 extends beyond the tire contact end T and to the dividing position M of the mold, and the dividing position M of the mold is within the range of the L11 / SH ratio mentioned above.

[0054] Regarding the extension length L11 of the shoulder lateral groove 311, the measurement is the extension length of the shoulder lateral groove 311 in the tire width direction when viewed from above.

[0055] The tire section height SH is the distance of half the difference between the tire's outer diameter and the rim diameter. It is measured under no-load conditions while the tire is mounted on a specified rim and a specified internal pressure is applied.

[0056] In addition, Figure 4 In the tire contact patch, the width W11' of the shoulder lateral groove 311 outside the tire contact patch is within the range of 0.80 ≤ W11' / W11_max ≤ 1.20 relative to the maximum width W11_max of the shoulder lateral groove 311 inside the tire contact patch, and preferably within the range of 0.95 ≤ W11' / W11_max ≤ 1.05. For example, in Figure 4 In the configuration, the width W11' of the shoulder lateral groove 311 is set to be approximately constant in the shoulder reinforcement.

[0057] In addition, Figure 5 In this configuration, the groove depth H11 of the shoulder lateral groove 311 outside the tire contact surface is within the range of 0.10 ≤ H11' / H11_max ≤ 1.00 relative to the maximum groove depth H11_max of the shoulder lateral groove 311 inside the tire contact surface, and preferably within the range of 0.15 ≤ H11' / H11_max ≤ 1.00. For example, in Figure 5 In the configuration, the groove depth H11' of the shoulder lateral groove 311 gradually decreases from the tire contact end T towards the mold dividing position M.

[0058] like Figure 2 As shown, the shoulder tread blocks 312 are divided by a plurality of shoulder lateral grooves 311. In addition, the plurality of shoulder tread blocks 312 are arranged at a predetermined interval in the tire circumferential direction to form a single tread block row.

[0059] It should be noted that, in Figure 1 In its composition, such as Figure 3 As shown, tire 1 has sidewall tread blocks 4. The sidewall tread blocks 4 are tread blocks that protrude from the side of the tire, and they are especially useful for protecting the tire sidewall from external damage when driving off-road.

[0060] [The raised part at the bottom of the shoulder lateral groove]

[0061] Figure 6 and Figure 7 It means Figure 3 Explanatory diagrams of the protrusion 5 of the shoulder lateral groove 311. In these diagrams, Figure 6 This is a top view showing a single protrusion 5. Figure 7 A cross-sectional view showing the protrusion 5 along the length of the shoulder lateral groove 311.

[0062] like Figure 2 and Figure 3 As shown, the shoulder lateral groove 311 has a protrusion 5. (As indicated...) Figure 4 As shown, the protrusion 5 is positioned further outward in the tire width direction than the tire contact patch end T, and is arranged in an island-like configuration separated from the groove wall of the shoulder lateral groove 311. Furthermore, as... Figure 5 As shown, it protrudes from the bottom of the shoulder lateral groove 311.

[0063] In this configuration, (1) the shoulder lateral groove 311 has a protrusion 5, thereby improving the function of mud and snow removal from the shoulder lateral groove 311 during off-road driving. Furthermore, (2) since the protrusion 5 is positioned further outward in the tire width direction than the tire contact patch end, the groove volume of the shoulder lateral groove 311 in the tire contact patch area is ensured, thereby improving the tire's traction performance. Thus, the tire's performance in mud and snow is improved.

[0064] For example, in Figure 2 In the configuration, the left and right shoulder lateral grooves 311, 311 each have a single protrusion 5 outside the tire contact surface. However, it is not limited to this; only one shoulder lateral groove 311 may have a protrusion 5 (illustration omitted). Furthermore, in Figure 2 In the configuration, each of the multiple shoulder lateral grooves 311 has a protrusion 5. However, it is not limited to this, and only a portion of the multiple shoulder lateral grooves 311 may have a protrusion 5 (illustration omitted).

[0065] In addition, Figure 4 In this design, the extension length L5 of the protrusion 5 in the tire width direction is within the range of 0.05 ≤ L5 / SH ≤ 0.15 relative to the tire section height SH, preferably within the range of 0.06 ≤ L5 / SH ≤ 0.12. This lower limit ensures the extension length L5 of the protrusion 5, thereby ensuring its mud and snow removal function. The upper limit reduces tire vulcanization defects caused by excessively large protrusions, thus ensuring tire productivity.

[0066] Regarding the extension length L5 of the protrusion 5, it is measured as the extension length in the tire width direction when the shoulder lateral groove 311 is viewed from above.

[0067] In addition, Figure 4 In the middle, the distance D1 from the tire contact patch T to the protrusion 5 in the tire width direction is relative to the tire profile height SH (refer to...). Figure 1 The distance D1 is within the range of 0.02 ≤ D1 / SH ≤ 0.15, preferably within the range of 0.07 ≤ D1 / SH ≤ 0.11. This lower limit ensures the distance D1 from the tire contact patch T to the protrusion 5, thereby ensuring the tire's traction performance within the contact patch. The upper limit ensures the mud and snow removal function of the protrusion 5.

[0068] The distance D1 of the protrusion 5 is measured as the distance between the shoulder lateral grooves 311 in the tire width direction when viewed from above.

[0069] In addition, Figure 4 In this design, the distance D2 from the wall of the shoulder lateral groove 311 to the protrusion 5 is within the range of 0.20 ≤ D2 / W11' ≤ 0.40 relative to the groove width W11' of the shoulder lateral groove 311 outside the tire contact surface, and preferably within the range of 0.30 ≤ D2 / W11' ≤ 0.37. This optimizes the distance D2 from the wall of the shoulder lateral groove 311 to the protrusion 5, thereby ensuring the improved mud and snow performance provided by the protrusion 5.

[0070] The distance D2 of the protrusion 5 is measured as the distance between the shoulder lateral grooves 311 in the tire width direction when viewed from above.

[0071] In addition, Figure 4 In the figure, the distance Dm from the dividing position M of the mold to the protrusion 5 is relative to the tire section height SH (refer to...). Figure 1 The value is within the range of 0.10 ≤ Dm / SH ≤ 0.50, preferably within the range of 0.20 ≤ Dm / SH ≤ 0.40. This ensures the improved performance on mud and snow surfaces provided by the protrusion 5.

[0072] The distance Dm from the protrusion 5 is measured as the distance between the shoulder lateral grooves 311 in the tire width direction when viewed from above.

[0073] In addition, Figure 4 In this configuration, the maximum width W5_max of the protrusion 5, relative to the width W11' of the shoulder lateral groove outside the tire contact patch, is within the range of 0.25 ≤ W5_max / W11' ≤ 0.45, and preferably within the range of 0.32 ≤ W5_max / W11' ≤ 0.40. This ensures the improved performance on mud and snow provided by the protrusion 5.

[0074] The maximum width W5_max of the protrusion 5 is measured as the width of the top surface of the protrusion 5 relative to the direction perpendicular to the tire width direction when viewed from above in the shoulder lateral groove 311.

[0075] In addition, such as Figure 4 As shown, the protrusion 5 is formed by connecting a wide portion 51 and a narrow portion 52, with the narrow portion 52 positioned outward in the tire width direction. Therefore, the protrusion 5 has a shape that narrows in width towards the outward side in the tire width direction. This improves the mud and snow removal efficiency of the protrusion 5. Furthermore, as... Figure 5 As shown, the height H51 of the convex portion 5 (refer to Figure 7 The speed decreases monotonically towards the outer edge of the tire width direction.

[0076] In addition, Figure 6 In this configuration, the extension length L51 of the wide portion 51 in the tire width direction is within the range of 0.35 ≤ L51 / L5 ≤ 0.55 relative to the extension length L5 of the protrusion 5, preferably within the range of 0.40 ≤ L51 / L5 ≤ 0.45. Furthermore, the width W51 of the wide portion 51 is within the range of 0.90 ≤ W51 / W5_max ≤ 1.00 relative to the maximum width W5_max of the protrusion 5, preferably within the range of 0.97 ≤ W51 / W5_max ≤ 1.00. This ensures the volume of the protrusion 5, thereby ensuring the mud and snow removal function provided by the protrusion 5.

[0077] In addition, Figure 6 In this configuration, the extension length L52 of the narrow portion 52 in the tire width direction is within the range of 0.30 ≤ L52 / L5 ≤ 0.50 relative to the extension length L5 of the protrusion 5, preferably within the range of 0.37 ≤ L52 / L5 ≤ 0.45. Furthermore, the width W52 of the narrow portion 52 is within the range of 0.30 ≤ W52 / W5_max ≤ 0.50 relative to the maximum width W5_max of the protrusion 5, preferably within the range of 0.40 ≤ W52 / W5_max ≤ 0.48. This ensures the volume of the protrusion 5, thereby ensuring the mud and snow removal function provided by the protrusion 5.

[0078] Regarding the extension lengths L51 and L52 of the wide portion 51 and the narrow portion 52, the measured lengths are the extension lengths of the shoulder lateral grooves 311 in the tire width direction when viewed from above.

[0079] Regarding the widths W51 and W52 of the wide portion 51 and the narrow portion 52, the measurement is the width of the top surface of the protrusion 5 of the shoulder lateral groove 311 relative to the direction perpendicular to the tire width direction when viewed from above.

[0080] For example, in Figure 4 In its composition, such as Figure 6As shown, the protrusion 5 has a shape in which its width tapers outward in the tire width direction. Furthermore, the angle of inclination (dimension markings omitted in the figure) of the connection between the wide portion 51 and the narrow portion 52, i.e., the tapered narrowing portion, is within a range of 30 degrees to 50 degrees relative to the length direction of the protrusion 5. This improves the mud and snow removal efficiency of the protrusion 5.

[0081] In addition, Figure 5 In its composition, such as Figure 7 As shown, the thickness of the protrusion 5 gradually decreases towards the outer side in the tire width direction. Furthermore, the location of the maximum thickness of the protrusion 5 is preferably positioned at the venting location of the tire forming mold. This reduces vulcanization defects in the protrusion 5.

[0082] In addition, Figure 7 In the process, the maximum thickness H5_max of the protrusion 5 is within the range of 0.8 [mm] ≤ H5_max ≤ 1.5 [mm]. The lower limit ensures the mud and snow removal performance of the protrusion 5, while the upper limit reduces vulcanization failures of the protrusion 5.

[0083] In addition, Figure 7 In the process, the thickness H5 of the protrusion 5, relative to the depth H11' of the shoulder lateral groove 311 at the location of the protrusion 5, is in the range of 0.02 ≤ H5 / H11' ≤ 0.50, preferably in the range of 0.25 ≤ H5 / H11' ≤ 0.45. The thickness H5 of the protrusion 5 is in the range of 0.4 [mm] ≤ H5 ≤ 3.0 [mm], preferably in the range of 0.5 [mm] ≤ H5 ≤ 1.5 [mm]. Furthermore, the minimum thickness H5_min of the protrusion 5, relative to the maximum thickness H5_max of the protrusion 5, is in the range of 0.40 ≤ H5_min / H5_max ≤ 0.60. Figure 7 In the configuration, the thickness of the protrusion 5 gradually decreases towards the outer side in the tire width direction. Therefore, the protrusion 5 has a maximum thickness H5_max at one edge and a minimum thickness H5_min at the other edge.

[0084] The thickness H5 of the protrusion 5 is measured as the distance from the bottom of the shoulder groove 311 to the top surface or edge of the protrusion 5.

[0085] [Shallow groove in the shoulder reinforcement]

[0086] exist Figure 2 In its composition, such as Figure 3 As shown, tire 1 has a shallow groove 6. The shallow groove 6 is formed in a region further outward in the tire width direction than the tire contact patch end, i.e., the shoulder reinforcement, and extends along the tire circumferential direction, thereby connecting with the shoulder lateral groove 311 at at least one end. In this configuration, during off-road driving, the tire's snow and mud performance is improved by the edge action of the shallow groove 6.

[0087] For example in Figure 3 In its construction, the shallow groove 6 has a bent shape and extends along the tire circumference to connect adjacent shoulder lateral grooves 311, 311. Furthermore, the connection between the shallow groove 6 and the shoulder lateral groove 311 overlaps with the protrusion 5 when projected onto the tire circumference. This improves the tire's performance in snow and mud.

[0088] In addition, Figure 4 In the shallow groove 6, the groove width W6 relative to the groove width W11' of the shoulder lateral groove 311 outside the tire contact surface is in the range of 0.50 ≤ W6 / W11' ≤ 1.20, preferably in the range of 0.60 ≤ W6 / W11' ≤ 1.10. Furthermore, the groove width W6 of the shallow groove 6 is in the range of 7.0 [mm] ≤ W6 ≤ 12.0 [mm], preferably in the range of 8.5 [mm] ≤ W6 ≤ 10.5 [mm]. Furthermore, in... Figure 7 In the middle, the groove depth H6 of the shallow groove 6 is in the range of 0.35≤H6 / H11'≤0.55 relative to the groove depth H11' of the shoulder lateral groove 311 outside the tire contact surface, preferably in the range of 0.40≤H6 / H11'≤0.50.

[0089] [Effect]

[0090] As described above, [1] the tire 1 has a plurality of shoulder lateral grooves 311 extending beyond the tire contact end T and to the shoulder reinforcement (see reference). Figure 2 and Figure 3 In addition, the multiple shoulder lateral grooves 311 have protrusions 5 that protrude from the bottom of the shoulder lateral grooves 311 and are located further outward in the tire width direction than the tire contact end T.

[0091] In this configuration, (1) the shoulder lateral groove 311 has a protrusion 5, thereby improving the function of mud and snow removal from the shoulder lateral groove 311 during off-road driving. Furthermore, (2) since the protrusion 5 is positioned further outward in the tire width direction than the tire contact patch end, the groove volume of the shoulder lateral groove 311 in the tire contact patch area is ensured, thereby improving the tire's traction performance. Thus, it has the advantage of improving the tire's performance on mud and snow.

[0092] Furthermore, [2] in this tire 1, in the tire 1 described in [1] above, the distance D1 from the tire contact end T to the protrusion 5 in the tire width direction (refer to...) Figure 4 ) relative to the tire section height SH (refer to Figure 1The value is within the range of 0.02≤D1 / SH≤0.15. It has the following advantages: the lower limit ensures the distance D1 from the tire contact point T to the protrusion 5, thereby ensuring the traction performance of the tire in the contact area; the upper limit ensures the mud and snow removal function of the protrusion 5.

[0093] Furthermore, [3] in this tire 1, in the tire 1 described in [1] or [2] above, the extension length L5 of the protrusion 5 in the tire width direction (refer to) Figure 4 ) relative to the tire section height SH (refer to Figure 1 The value is within the range of 0.05≤L5 / SH≤0.15. This has the following advantages: the lower limit ensures the extension length L5 of the protrusion 5, thereby ensuring the mud and snow removal function of the protrusion 5; the upper limit reduces tire vulcanization failure caused by excessive protrusion, thereby ensuring tire productivity.

[0094] Furthermore, [4] in this tire 1, in any one of the tires [1] to [3] above, the extension length L11 of the shoulder lateral groove 311 outside the tire contact surface (refer to) Figure 4 ) relative to the tire section height SH (refer to Figure 1 The value is within the range of 0.15≤L11 / SH≤0.25. Therefore, it has the advantage of improving tire traction when driving off-road.

[0095] Furthermore, [5] in this tire 1, in any one of the tires [1] to [4] above, the distance D2 from the groove wall of the shoulder lateral groove 311 to the protrusion 5 is within the range of 0.20 ≤ D2 / W11' ≤ 0.40 relative to the groove width W11' of the shoulder lateral groove 311 outside the tire contact surface (refer to...). Figure 4 Therefore, it has the following advantages: the distance D2 from the groove wall of the shoulder groove 311 to the protrusion 5 is optimized, thereby ensuring the improved mud and snow performance brought about by the protrusion 5.

[0096] Furthermore, [6] in this tire 1, in any one of the tires [1] to [5] above, the maximum width W5_max of the protrusion 5 is within the range of 0.25≤W5_max / W11'≤0.45 relative to the groove width W11' of the shoulder lateral groove 311 outside the tire contact surface (refer to...). Figure 4 Therefore, it has the advantage of ensuring the improved performance on mud and snow caused by the protrusion 5.

[0097] Furthermore, [7] in this tire 1, in any one of [1] to [6] above, the protrusion 5 is formed by connecting the wide portion 51 and the narrow portion 52, and the narrow portion 52 is arranged outward in the tire width direction (see reference). Figure 4Therefore, it has the advantage of improving the mud and snow removal function brought about by the protrusion 5.

[0098] Furthermore, [8] in this tire 1, in any one of [1] to [7] above, the protrusion 5 is formed by connecting the wide portion 51 and the narrow portion 52, and the extension length L51 of the wide portion 51 in the tire width direction is in the range of 0.35≤L51 / L5≤0.55 relative to the extension length L5 of the protrusion 5 (refer to...). Figure 6 Therefore, the volume of the protrusion 5 is ensured, thereby ensuring the mud and snow removal functions provided by the protrusion 5.

[0099] Furthermore, [9] in this tire 1, in any one of [1] to [8] above, the protrusion 5 is formed by connecting the wide portion 51 and the narrow portion 52, and the width W52 of the narrow portion 52 is in the range of 0.30≤W52 / W5_max≤0.50 relative to the maximum width W5_max of the protrusion 5 (see reference). Figure 6 Therefore, the volume of the protrusion 5 is ensured, thereby ensuring the mud and snow removal functions provided by the protrusion 5.

[0100] Furthermore,

[10] in this tire 1, in any one of the tires [1] to [9] above, the thickness H5 of the protrusion 5 is in the range of 0.4 [mm] ≤ H5 ≤ 3.0 [mm] (refer to) Figure 7 It has the following advantages: the lower limit ensures the mud and snow removal performance of the protrusion 5, and the upper limit reduces vulcanization failure of the protrusion 5.

[0101] Furthermore,

[11] in this tire 1, in any one of the tires [1] to

[10] above, the thickness of the protrusion 5 gradually decreases outward toward the tire width direction. As a result, it has the advantage of reducing vulcanization defects of the protrusion 5.

[0102] Furthermore,

[12] in any one of the tires [1] to

[11] above, the tire 1 has a shallow groove 6 formed in a region further outward in the tire width direction than the tire contact end T, and extends along the tire circumferential direction, thereby connecting with the shoulder lateral groove 311 at at least one end (see reference). Figure 3 Furthermore, the connection between the shallow groove 6 and the shoulder lateral groove 311 overlaps with the protrusion 5 when viewed in the circumferential direction of the tire. This provides the advantage of improved tire performance on snow and mud.

[0103] [Applicable to]

[0104] It should be noted that, in this embodiment, as described above, a pneumatic tire is used as an example of a tire. However, it is not limited to this, and the configuration described in this embodiment can be applied to other tires as will be obvious to those skilled in the art. Other tires include, for example, airless tires and solid tires.

[0105] Example

[0106] Figure 8 and Figure 9 These are graphs showing the performance test results of tires according to embodiments of the present invention.

[0107] In this performance test, the performance of various test tires on mud and snow was evaluated. Test tires with a size of 265 / 70R17 121 / 118S were mounted on rims with a size of 17×8J, and internal pressures of 450 kPa for the front tires and 550 kPa for the rear tires, along with JATMA-specified loads, were applied to the tires. Furthermore, the test tires were mounted on all wheels of an SUV (Sport Utility Vehicle), i.e., a 4WD vehicle, which served as the test vehicle.

[0108] In the evaluation of performance on mud and snow, the test vehicle was driven on a specified muddy road surface, and the test driver conducted a sensory evaluation related to traction. This evaluation was carried out using an index with a comparative example as a baseline (100), with higher values ​​indicating better performance.

[0109] The test tire in the embodiment has Figures 1-5 The tire shoulder lateral groove 311 has an island-shaped protrusion 5 at the bottom of the groove outside the tire contact surface. Furthermore, the tire section height SH is 186 mm. Additionally, the groove length L11 of the shoulder lateral groove 311 outside the tire contact surface is 32 mm, and the groove width W11' is 10.5 mm, 12.5 mm, or 14.5 mm. Furthermore, the groove depth H11' of the shoulder lateral groove 311 at the location of the protrusion 5 is 2.2 mm.

[0110] The comparative example test tire is the same as the test tire of Example 1, in which the convex portion 5 extends along the entire length of the shoulder lateral groove 311 and intersects with the tire contact end T.

[0111] As the test results show, the test tires in the embodiment exhibit improved performance in mud and snow.

[0112] Explanation of reference numerals in the attached figures

[0113] 1: Tire; 11: Bead core; 12: Sidewall core; 13: Carcass layer; 14: Belt layer; 141, 142: Cross belts; 143: Belt cover layer; 15: Tread rubber; 16: Sidewall rubber; 17: Rim protector; 21: Shoulder main groove; 22: Central main groove; 31: Shoulder circumferential groove; 311: Shoulder lateral groove; 312: Shoulder tread block; 32: Central circumferential groove; 4: Sidewall tread block; 5: Raised section; 51: Wide section; 52: Narrow section; 6: Shallow groove.

Claims

1. A tire having a plurality of shoulder lateral grooves extending beyond the tire contact patch and into a shoulder reinforcement portion. Its features are, The plurality of shoulder lateral grooves have protrusions that protrude from the bottom of the shoulder lateral grooves and are positioned further outward in the tire width direction than the tire contact patch end.

2. The tire according to claim 1, wherein, The distance D1 from the tire contact point to the protrusion in the tire width direction is within the range of 0.02 ≤ D1 / SH ≤ 0.15 relative to the tire profile height SH.

3. The tire according to claim 1 or 2, wherein, The extension length L5 of the protrusion in the tire width direction is within the range of 0.05≤L5 / SH≤0.15 relative to the tire section height SH.

4. The tire according to any one of claims 1 to 3, wherein, The extension length L11 of the shoulder lateral groove outside the tire contact surface is within the range of 0.15≤L11 / SH≤0.25 relative to the tire section height SH.

5. The tire according to any one of claims 1 to 4, wherein, The distance D2 from the wall of the shoulder lateral groove to the protrusion is within the range of 0.20 ≤ D2 / W11' ≤ 0.40 relative to the width W11' of the shoulder lateral groove outside the tire contact surface.

6. The tire according to any one of claims 1 to 5, wherein, The maximum width W5_max of the protrusion is within the range of 0.25≤W5_max / W11'≤0.45 relative to the width W11' of the shoulder lateral groove outside the tire contact surface.

7. The tire according to any one of claims 1 to 6, wherein, The protrusion is formed by connecting the wide portion and the narrow portion, and the narrow portion is positioned outward in the tire width direction.

8. The tire according to any one of claims 1 to 7, wherein, The protrusion is formed by connecting the wide portion and the narrow portion, and the extension length L51 of the wide portion in the tire width direction is in the range of 0.35≤L51 / L5≤0.55 relative to the extension length L5 of the protrusion.

9. The tire according to any one of claims 1 to 8, wherein, The protrusion is formed by connecting the wide portion and the narrow portion, and the width W52 of the narrow portion is in the range of 0.30≤W52 / W5_max≤0.50 relative to the maximum width W5_max of the protrusion.

10. The tire according to any one of claims 1 to 9, wherein, The thickness H5 of the protrusion is in the range of 0.4 [mm] ≤ H5 ≤ 3.0 [mm].

11. The tire according to any one of claims 1 to 10, wherein, The thickness of the protrusion gradually decreases outwards in the tire width direction.

12. The tire according to any one of claims 1 to 11, wherein the tire has a shallow groove formed in a region further outward in the tire width direction than the tire contact patch end, and extends circumferentially along the tire, thereby connecting with a shoulder lateral groove at at least one end, and When the connection between the shallow groove and the shoulder lateral groove is projected onto the tire circumferential direction, it overlaps with the convex part.

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