Pneumatic tires

Abstract

Provided is a pneumatic tire that improves chipping damage resistance, snow braking performance, snow handling performance, pattern noise performance, and drainage performance in a well-balanced manner. The tread pattern of the pneumatic tire (10) includes more than three circumferential main grooves extending along the circumference of the tire, a land portion divided by the circumferential main grooves, and a sipe pattern provided on the land portion. At least one of the edges of the land portion on both sides of the tire width direction is a serrated edge. The serrated edge has a serrated shape with a concave and convex shape whose position in the tire width direction changes periodically. The sipe pattern is a composite sipe pattern having a two-dimensional portion and a three-dimensional portion, and the three-dimensional portion is connected to the serrated edge.

Description

Technical Field

[0001] The present invention relates to pneumatic tires. Background Art

[0002] Patent Document 1 discloses a pneumatic tire that achieves both drainage performance and uneven wear resistance. In Patent Document 1, a recessed portion is provided in a groove wall of a main groove, and a sipe communicating with the recessed portion and a shallow groove communicating without the recessed portion are provided.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-43208 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The pneumatic tire of Patent Document 1 does not consider the improvement of braking performance on snowy roads, i.e., snow braking performance, and steering stability performance on snowy roads, i.e., snow steering performance, and there is room for improvement. In addition, pattern noise performance and chipping damage resistance performance also need to be considered.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pneumatic tire having improved chipping damage resistance, snow braking performance, snow handling performance, pattern noise performance, and drainage performance in a well-balanced manner.

[0009] Technical solutions to solve problems

[0010] In order to solve the above-mentioned problems and achieve the purpose, a pneumatic tire of a certain scheme of the present invention is a pneumatic tire with a tread pattern, wherein the tread pattern includes: more than 3 circumferential main grooves, wherein the more than 3 circumferential main grooves extend along the circumference of the tire; a land portion, wherein the land portion is divided by 2 of the more than 3 circumferential main grooves; and a sipe pattern, wherein the sipe pattern is arranged on the land portion, and at least one of the edges on both sides of the land portion in the tire width direction is a serrated edge, and the serrated edge has a serrated shape with a concave and convex shape whose position in the tire width direction changes periodically, and the sipe pattern is a composite sipe pattern having a two-dimensional portion and a three-dimensional portion, and the three-dimensional portion is connected to the serrated edge.

[0011] Preferably, a ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.25 or more and 0.75 or less.

[0012] Preferably, when the land portion is a shoulder land portion including a ground contact edge, a ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.25 or more and 0.65 or less.

[0013] Preferably, when the land portion is a shoulder land portion including a ground contact end portion, the shoulder land portion has a plurality of shoulder transverse grooves extending from the inner side in the tire width direction toward the outer side in the tire width direction, and the plurality of shoulder transverse grooves extend from the circumferential main groove at least to the ground contact end portion.

[0014] Preferably, a ratio of a distance between the zigzag-shaped protrusions in the tire circumferential direction to a length of the zigzag-shaped edges between adjacent shoulder lateral grooves in the tire circumferential direction is 0.15 or more and 0.55 or less.

[0015] Preferably, when the land portion is a shoulder land portion including a ground contact edge, the land portion has two or more of the composite sipes and three or more of the zigzag-shaped protrusions between adjacent shoulder lateral grooves.

[0016] Preferably, when the land portion is a shoulder land portion including a ground contact edge, a ratio of a length twice the amplitude of the zigzag shape in the tire width direction to a ground contact width of the shoulder land portion in the tire width direction is 0.02 or more and 0.15 or less.

[0017] Preferably, when the land portion is a land portion not including a ground contact edge portion, a ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.40 or more and 0.75 or less.

[0018] Preferably, when the land portion is a land portion not including a ground contact end portion, the land portion has a plurality of transverse grooves extending from the inner side in the tire width direction toward the outer side in the tire width direction, and the plurality of transverse grooves penetrate the land portion.

[0019] Preferably, a ratio of a distance between the zigzag-shaped protrusions in the tire circumferential direction to a length of an edge of the zigzag shape between adjacent lateral grooves in the tire circumferential direction is 0.15 or more and 0.55 or less.

[0020] Preferably, when the land portion is a land portion that does not include a ground contact edge portion, a ratio of an amplitude of the zigzag shape in the tire width direction to a width of the land portion in the tire width direction is 0.03 or more and 0.15 or less.

[0021] Preferably, when the land portion is a land portion that does not include a ground contact end portion, the land portion includes two or more of the composite sipes and three or more of the serrated convex portions between adjacent lateral grooves.

[0022] Preferably, in the case where the land portion is a land portion that does not include a ground contact end portion, when the distance in the tire circumferential direction between the connection portions of two or more of the composite sipe patterns provided between adjacent transverse grooves and connected to the circumferential main groove on the inner side in the tire width direction is set to Ls1, Ls2, ..., Lsn (n is a natural number greater than 3), Ls1<Lsn.

[0023] Preferably, in the case where the land portion is a land portion that does not include a ground contact end portion, when the distances in the circumferential direction of the tire between the connecting portions of the plurality of sipes provided between adjacent transverse grooves and connected to the circumferential main groove on the inner side in the tire width direction are set to Ls1, Ls2, ..., Lsn (n is a natural number greater than 3), and the distances in the circumferential direction of the tire between the convex portions of the connecting portions of the plurality of sipes provided between adjacent transverse grooves and connected to the circumferential main groove on the outer side in the tire width direction are set to Lz1, Lz2, ..., Lzn (n is a natural number greater than 3), Ls1<Lz1 and Lsn>Lzn.

[0024] Preferably, the composite sipe is connected to a maximum amplitude position of the sawtooth-shaped edge.

[0025] Effects of the Invention

[0026] According to the present invention, it is possible to obtain the effect of improving chipping damage resistance performance, snow braking performance, snow handling performance, pattern noise performance, and drainage performance in a well-balanced manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional view in the tire meridian direction showing a pneumatic tire according to an embodiment of the present invention.

[0028] Figure 2 It is shown Figure 1 A development view of an example of a tread pattern of a pneumatic tire is shown.

[0029] Figure 3 Yes Figure 2 The diagram shows an enlarged view of a portion of a middle land portion of a tread pattern.

[0030] Figure 4 Yes Figure 2 The diagram shows an enlarged view of a portion of a middle land portion of a tread pattern.

[0031] Figure 5 It is a plan view showing an example of a sipe.

[0032] Figure 6 Yes Figure 2The diagram shows an enlarged view of a portion of a middle land portion of a tread pattern.

[0033] Figure 7 Yes Figure 2 The diagram shows an enlarged view of a portion of a middle land portion of a tread pattern.

[0034] Fig. 8A Yes Figure 2 A diagram showing an enlarged portion of a middle land portion of the tread pattern shown.

[0035] Figure 8B Yes Fig. 8A A diagram showing an enlarged portion of the diagram.

[0036] Fig. 9A It is a diagram showing another example of the intermediate land portion.

[0037] Fig. 9B Yes Fig. 9A A diagram showing an enlarged portion of the diagram.

[0038] Fig. 10A It is a diagram showing another example of the intermediate land portion.

[0039] Fig. 10B Yes Fig. 10A A diagram showing an enlarged portion of the diagram.

[0040] Fig.11 It is shown Figure 2 A cross-sectional view of an example of a three-dimensional portion of a composite sipe.

[0041] Fig.12 It is along Figure 5 A cross-sectional view of the extension direction of the sipe pattern. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. In the following description of each embodiment, the same reference numerals are used for components that are the same or equivalent to other embodiments, and the description thereof is simplified or omitted. The present invention is not limited by each embodiment. In addition, the components of each embodiment include components that can be replaced and easily replaced by those skilled in the art or substantially the same components. The multiple variations described in the embodiment can be arbitrarily combined within the scope that is obvious to those skilled in the art. In addition, the omission, replacement or change of the configuration can be performed within the scope that does not depart from the gist of the invention.

[0043] [Pneumatic tires]

[0044] Figure 1 It is a cross-sectional view in the tire meridian direction showing a pneumatic tire according to an embodiment of the present invention. Figure 1A cross-sectional view of a single side region of the tire radial direction is shown. Figure 1 , a radial tire for a passenger car is shown as an example of a pneumatic tire.

[0045] The cross section in the meridian direction of the tire refers to the cross section when the tire is cut with a plane containing the tire rotation axis (not shown in the figure). In addition, the reference numeral CL is the tire equatorial plane, which refers to a plane passing through the center point of the tire in the direction of the tire rotation axis and perpendicular to the tire rotation axis. The tire radial direction refers to the direction orthogonal to the rotation axis (not shown) of the pneumatic tire 10, the inner side in the tire radial direction refers to the side facing the rotation axis in the tire radial direction, and the outer side in the tire radial direction refers to the side away from the rotation axis in the tire radial direction. In addition, the tire circumferential direction refers to the circumferential direction with the above-mentioned rotation axis as the center axis. In addition, the tire width direction refers to the direction parallel to the above-mentioned rotation axis. The inner side in the tire width direction refers to the side facing the tire equatorial plane CL in the tire width direction, and the outer side in the tire width direction refers to the side away from the tire equatorial plane CL in the tire width direction.

[0046] The tire equatorial plane CL is a plane that is orthogonal to the rotation axis of the pneumatic tire 10 and passes through the center of the tire width of the pneumatic tire 10. The tire width is the width of the tire width direction between the portions located at the outer sides in the tire width direction, that is, the distance between the portions farthest from the tire equatorial plane CL in the tire width direction. The tire equatorial line is a line located on the tire equatorial plane CL and along the tire circumferential direction of the pneumatic tire 10. In the present embodiment, the tire equatorial line is denoted by the same reference numeral "CL" as the tire equatorial plane.

[0047] like Figure 1 As shown, a pneumatic tire 10 of the present embodiment includes a tread portion 1 extending in a circumferential direction of the tire and having an annular shape, a pair of sidewall portions 2, 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3, 3 arranged on the inner side of the sidewall portions 2 in the tire radial direction.

[0048] A carcass layer 4 is provided between a pair of bead portions 3, 3. The carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction and folded back from the inside to the outside of the tire around a bead core 5 disposed at each bead portion 3. A bead filler 6 composed of a rubber composition having a triangular cross-section is disposed on the outer periphery of the bead core 5.

[0049] On the other hand, a plurality of belt layers 7 are buried on the outer peripheral side of the carcass layer 4 at the tread portion 1. These belt layers 7 include a plurality of reinforcing cords inclined relative to the tire circumferential direction, and are arranged so that the reinforcing cords intersect each other between the layers. In the belt layer 7, the inclination angle of the reinforcing cords relative to the tire circumferential direction is set, for example, in the range of 10 degrees to 40 degrees. As the reinforcing cords of the belt layer 7, steel cords are preferably used. On the outer peripheral side of the belt layer 7, for the purpose of improving high-speed durability, at least one belt covering layer 8 is arranged in which the reinforcing cords are arranged at an angle of, for example, less than 5 degrees relative to the tire circumferential direction. As the reinforcing cords of the belt covering layer 8, organic fiber cords such as nylon and aramid are preferably used.

[0050] In addition, the above-mentioned tire internal structure is a representative example of a pneumatic tire and is not limited thereto.

[0051] [Tread]

[0052] Figure 2 It is shown Figure 1 FIG. 1 is a development view of an example of a tread pattern of a pneumatic tire 10 shown in FIG. Figure 1 and Figure 2 In the figure, the reference symbol T represents the tire grounding end.

[0053] like Figure 2 As shown, the pneumatic tire 10 of this example has four circumferential main grooves 11A, 11B, 12A, and 12B in the tread portion 1. The circumferential main grooves 12A and 12B extend in the tire circumferential direction at positions outside the tire equatorial plane CL in the tire width direction. The circumferential main groove 11A extends in the tire circumferential direction at a position closer to the tire equatorial plane CL than the circumferential main groove 12A. The circumferential main groove 11B extends in the tire circumferential direction at a position closer to the tire equatorial plane CL than the circumferential main groove 12B.

[0054] The circumferential main grooves 11A, 11B, 12A and 12B are circumferential grooves having wear indicators indicating the end of wear, and generally have a groove width of 5.0 [mm] or more and a groove depth of 7.5 [mm] or more. In addition, the groove width and groove depth of the circumferential main grooves 11A, 11B, 12A and 12B are not limited to the above ranges.

[0055] The lateral grooves described below refer to lateral grooves having a groove width of 2.0 [mm] or more and a groove depth of 3.0 [mm] or more. The sipes described below refer to cuts formed in the land portion and generally have a groove width of less than 1.5 [mm].

[0056] exist Figure 2In the embodiment of the present invention, the central land portion Rc is divided by two circumferential main grooves 11A and 11B. In addition, the middle land portion Rm is divided by two circumferential main grooves 11A and 12A, and the other middle land portions Rm are divided by two circumferential main grooves 11B and 12B. The outer side of the circumferential main groove 12A in the tire width direction becomes the shoulder land portion Rs. The outer side of the circumferential main groove 12B in the tire width direction becomes the other shoulder land portion Rs. In addition, when there are three circumferential main grooves, the central land portion Rc is not provided, but the tread portion is composed of the middle land portions Rm on both sides of the equator line CL and the shoulder land portions Rs on the outer side of the middle land portion Rm in the tire width direction.

[0057] The central land portion Rc (hereinafter sometimes referred to as the land portion Rc) is located on the tire equator line CL. The land portion Rc has a plurality of sipes 15. The sipes 15 extend in the tire circumferential direction and the tire width direction. One end of the sipe 15 is connected to the circumferential main groove 11A, and the other end of the sipe 15 is connected to the circumferential main groove 11B. The sipe 15 is a through sipe that penetrates the land portion Rc. In addition, in this example, the edges on both sides of the land portion Rc are straight line shapes.

[0058] The middle land portion Rm (hereinafter sometimes referred to as the land portion Rm) has a plurality of transverse grooves 13. The transverse grooves 13 extend in the tire width direction and the tire circumferential direction. One end of the transverse groove 13 opens to the circumferential main groove 11A or 11B. The other end of the transverse groove 13 opens to the circumferential main groove 12A or 12B. The land portion Rm has a plurality of sipes 16 between adjacent transverse grooves 13. The sipes 16 extend in the tire circumferential direction and the tire width direction. One end of the sipe 16 is connected to the circumferential main groove 11A or 11B, and the other end of the sipe 16 is connected to the circumferential main groove 12A or 12B. The sipe 16 is a through sipe that penetrates the land portion Rm.

[0059] In this example, the outer edge of the land portion Rm in the tire width direction, that is, the edge on the circumferential main groove 12A or 12B side, is a sawtooth shape. The sawtooth shape is a shape with concavities and convexities whose positions in the tire width direction periodically change. The inner edge of the land portion Rm in the tire width direction, that is, the edge on the circumferential main groove 11A or 11B side, is a straight line shape without concavities and convexities.

[0060] The shoulder land portion Rs (hereinafter sometimes referred to as the land portion Rs) has a plurality of transverse grooves 14A, 14B. The transverse grooves 14A, 14B extend in the tire width direction from the inner side in the tire width direction toward the outer side in the tire width direction. The transverse grooves 14A, 14B extend from the circumferential main groove 12A or 12B to the position outside the tire ground contact end T. The land portion Rs has a plurality of sipes 17 between the transverse grooves 14A and the transverse grooves 14B. The sipes 17 extend in the tire width direction. One end of the sipe 17 is connected to the circumferential main groove 12A or 12B, and the other end of the sipe 17 is connected to the decorative groove 18 outside the tire ground contact end T.

[0061] [Sipe pattern]

[0062] exist Figure 2 In the embodiment, the sipes 15, 16 and 17 are composite sipes having a two-dimensional portion (so-called plane sipe) and a three-dimensional portion (so-called solid sipe). The two-dimensional portion refers to a portion of the sipe wall having a straight shape when the sipe is observed in a cross-section perpendicular to the longitudinal direction of the sipe. The three-dimensional portion refers to a portion of the sipe wall having a shape bent in the sipe width direction when the sipe is observed in a cross-section perpendicular to the longitudinal direction of the sipe. By these sipes 15, 16 and 17, the edge components of the land portions Rc, Rm and Rs are ensured, and the traction of the pneumatic tire 10 is improved.

[0063] exist Figure 2 In the embodiment, the section within the region 20A of the sipe 15 is a three-dimensional section. The section outside the region 20A of the sipe 15 is a two-dimensional section. The section within the region 20B of the sipe 16 is a three-dimensional section. The section outside the region 20B of the sipe 16 is a two-dimensional section. The section within the region 20C of the sipe 17 is a three-dimensional section. The section outside the region 20C of the sipe 17 is a two-dimensional section.

[0064] The two-dimensional portion has a sipe wall surface that is a straight line shape when viewed in any cross-section with the sipe length direction as the normal direction (including the sipe width direction and the sipe depth direction). The three-dimensional portion has a sipe wall surface that has a bending shape with an amplitude in the sipe width direction when viewed in a cross-section with the sipe length direction as the normal direction and when viewed in a cross-section with the sipe depth direction as the normal direction. Compared with the two-dimensional portion, the three-dimensional portion has a stronger meshing force of the opposing sipe wall surfaces, so it has the function of strengthening the rigidity of the land portion. By increasing the rigidity of the serrated portion of the land portion, the chipping damage resistance performance can be improved.

[0065] Here, when focusing on the land portion Rm divided by the circumferential main groove 11A and the circumferential main groove 12A, the edge on the side of the circumferential main groove 12A is serrated. That is, one side of the edge of the land portion Rm in the tire width direction is serrated. In addition, there is a region 20B on the side of the edge having a serrated shape. That is, the three-dimensional portion of the sipe 16 is connected to the serrated edge. Therefore, the land portion Rm improves the snow performance due to the edge effect of the serrated shape. Moreover, the sipe 16 of the portion connected to the circumferential main groove 12A on the side of the serrated edge becomes a three-dimensional portion, so the block rigidity of the serrated portion is increased, and the chipping damage resistance performance is improved.

[0066] In addition, when focusing on the land portion Rs, the edge on the side of the circumferential main groove 12A is serrated. That is, one side of the edge of the land portion Rs in the tire width direction is serrated. In addition, there is a region 20C on the side of the serrated edge. That is, the three-dimensional portion of the sipe 17 is connected to the serrated edge. Therefore, the land portion Rs has improved snow performance due to the edge effect of the serrated shape. Moreover, the sipe 17 of the portion connected to the circumferential main groove 12A on the serrated edge side becomes a three-dimensional portion, so the block rigidity of the serrated portion is increased, and the chipping damage resistance performance is improved.

[0067] [Shoulder land]

[0068] Figure 3 Yes Figure 2 FIG. 1 is an enlarged view of a portion of the shoulder land portion Rs of the tread pattern shown. Figure 3 In the embodiment, the land portion Rs on the outer side of the circumferential main groove 12B in the tire width direction has a sipe 17. The length (i.e., width) of the three-dimensional portion of the sipe 17 in the tire width direction is set to Ws2. The length Ws2 is the length (i.e., width) in the tire width direction from the edge of the circumferential main groove 12B of the land portion Rs to the end of the three-dimensional portion of the sipe 17 on the outer side in the tire width direction. In addition, the length from the edge of the circumferential main groove 12B of the land portion Rs to the ground contact end T, that is, the ground contact width of the land portion Rs in the tire width direction is set to Ws1. At this time, the ratio Ws2 / Ws1 is preferably greater than 0.25 and less than 0.65. When the ratio Ws2 / Ws1 is less than 0.25, sufficient block rigidity cannot be obtained, which hinders the improvement of chipping damage resistance performance. When the ratio Ws2 / Ws1 exceeds 0.65, the block rigidity becomes too high and the pattern noise worsens, so it is not preferred.

[0069] exist Figure 3 In the tire, the land portion Rs has a plurality of shoulder transverse grooves 14A and 14B extending from the circumferential main groove 12B on the inner side in the tire width direction toward the outer side in the tire width direction. The plurality of shoulder transverse grooves 14A and 14B preferably extend at least to the ground contact end T. By extending the plurality of shoulder transverse grooves 14A and 14B to the ground contact end T, drainage performance can be improved.

[0070] In the land portion Rs, the length of the zigzag edge between the adjacent shoulder transverse grooves 14A and 14B in the tire circumferential direction is set to Ls1. In addition, the distance between the zigzag protrusions in the tire circumferential direction is set to Ls2. At this time, the ratio Ls2 / Ls1 is preferably greater than 0.15 and less than 0.55. When the ratio Ls2 / Ls1 is less than 0.15, the zigzag concavoconvex becomes too fine and becomes easily defective, which is not preferred. When the ratio Ls2 / Ls1 exceeds 0.55, the edge effect cannot be fully obtained, and the snow performance is not improved.

[0071] Moreover, in the land portion Rs, the ground contact width in the tire width direction is set to Ws1. In addition, in the land portion Rs, the length of twice the amplitude of the serrated shape of the edge on the side of the circumferential main groove 12B in the tire width direction is set to Ws3. The length Ws3 is the length (i.e., the width) of the serrated convex portion in the tire width direction. At this time, the ratio Ws2 / Ws1 is preferably greater than 0.02 and less than 0.15. When the ratio Ws2 / Ws1 is less than 0.02, no edge effect is generated and the snow performance is not improved. When the ratio Ws2 / Ws1 exceeds 0.15, drainage will be hindered and wet performance will be reduced.

[0072] Furthermore, although the land portion Rs on the tire width direction outer side of the circumferential main groove 12B has been described above, the same description is also applicable to the land portion Rs on the tire width direction outer side of the circumferential main groove 12A.

[0073] [Middle land]

[0074] Figure 4 Yes Figure 2 The figure is an enlarged view of a portion of the middle land portion Rm of the tread pattern shown. Figure 4 In the embodiment, the maximum width of the land portion Rm in the tire width direction is set to W1. Figure 4 In the embodiment, the distance from the connection portion of the sipe 16 connected to the circumferential main groove 12A to the end of the zone 20B in the tire width direction of the three-dimensional section is set to Wc2. At this time, the ratio Wc2 / W1 is preferably greater than 0.40 and less than 0.75. When the ratio Wc2 / W1 is less than 0.40, sufficient block rigidity cannot be obtained, and the chipping damage resistance performance will not be improved. When the ratio Wc2 / W1 exceeds 0.75, the block rigidity becomes too high and the pattern noise worsens, so it is not preferred.

[0075] Figure 5 1 is a plan view showing an example of the sipe pattern 16. Figure 5 In the embodiment, one end of the sipe 16 is connected to the circumferential main groove 11A, and the other end is connected to the circumferential main groove 12A. Figure 5 The sipe pattern 16 of this example is composed of straight portions ST1, ST2 and ST3 and curved portions C1 and C2. The straight portion ST1 is arranged on the side of the circumferential main groove 11A, that is, on the inner side in the tire width direction. The straight portion ST1 is connected to the edge of the land portion Rm on the inner side in the tire width direction. The straight portion ST3 is arranged on the side of the circumferential main groove 12A, that is, on the outer side in the tire width direction. The straight portion ST3 is connected to the edge of the land portion Rm on the outer side in the tire width direction. The length of the straight portion ST1 in the extension direction is shorter than the length of the straight portion ST3 in the extension direction.

[0076] One end of the straight portion ST1 is connected to the circumferential main groove 11A, and the other end of the straight portion ST1 is connected to one end of the bent portion C1. The other end of the bent portion C1 is connected to the straight portion ST2. One end of the straight portion ST3 is connected to the circumferential main groove 12A, and the other end of the straight portion ST3 is connected to one end of the bent portion C2. The other end of the bent portion C2 is connected to the straight portion ST2. By providing the bent portion C1 between the straight portion ST1 and the straight portion ST2, and providing the bent portion C2 between the straight portion ST2 and the straight portion ST3, the sipe 16 has a substantially Z-shaped shape. The Z-shaped shape refers to a shape including at least two bent portions, and the straight portions are connected to each other through the bent portions. In addition, the Z-shaped shape may also include an S-shaped shape composed of a circular arc. In the following description, the straight portion ST1 close to the equatorial plane CL among the straight portion ST1 and the straight portion ST3 is sometimes referred to as the inner straight portion, and the straight portion ST3 far from the equatorial plane CL is sometimes referred to as the outer straight portion.

[0077] Figure 6 Yes Figure 2 The figure is an enlarged view of a portion of the middle land portion Rm of the tread pattern shown. Figure 6 In the block formed by adjacent transverse grooves 13 among the plurality of transverse grooves 13 that penetrate the land portion Rm, the length of the zigzag edge between the adjacent transverse grooves 13 in the tire circumferential direction is set to L1. The distance between the zigzag convex portions in the tire circumferential direction is set to L2. The ratio L2 / L1 of the distance L2 to the length L1 is preferably greater than 0.15 and less than 0.55. When the ratio L2 / L1 is greater than 0.55, the edge effect cannot be fully obtained and the snow performance is not improved, so it is not preferred. When the ratio L2 / L1 is less than 0.15, the zigzag concave and convex becomes too fine and becomes easily defective, so it is not preferred. In addition, the length L1 of the zigzag edge in the tire circumferential direction is measured with the corner of the intersection of the transverse groove 13 and the circumferential main groove 12A as a reference.

[0078] In addition, Figure 6 In the tire width direction, the maximum width of the land portion Rm is set to W1. The length (i.e., width) in the tire width direction from the connection point of the sipe 16 connected to the circumferential main groove 11A on the inner side in the tire width direction to the end point K1 on the outer side in the tire width direction of the inner straight portion ST1 is set to W2. In the block formed by the adjacent transverse grooves 13 among the plurality of transverse grooves 13 penetrating the land portion Rm, the width of twice the amplitude of the zigzag shape in the tire width direction is set to W3. The width W3 is the distance between the corners 21 and 22 of the opening of the sipe 16 in the tire width direction.

[0079] At this time, the ratio W2 / W1 of the width W2 to the width W1 is preferably greater than 0.10 and less than 0.40. When the ratio W2 / W1 is less than 0.10, the edge effect becomes small and the snow performance is reduced, which is not preferred. When the ratio W2 / W1 is greater than 0.40, the bending portion C1 becomes close to the serration portion, and the chipping damage resistance performance is poor, which is not preferred.

[0080] The ratio W3 / W2 of the width W3 to the width W2 is preferably 0.15 or more and 0.45 or less. When the ratio W3 / W2 is less than 0.15, the edge effect of the zigzag groove becomes small, and the snow performance is reduced, which is not preferred. When the ratio W3 / W2 is greater than 0.45, the drainage is reduced, and the edge effect of the sipe 16 is also reduced, so the snow performance is reduced, which is not preferred.

[0081] In addition, the ratio W3 / W1 of the width W3 to the maximum width W1 of the land portion Rm in the tire width direction is preferably 0.03 or more and 0.15 or less. When the ratio W3 / W1 is greater than 0.15, drainage is impeded and drainage performance is reduced, which is not preferred. When the ratio W3 / W1 is less than 0.03, no edge effect is generated and snow performance is not improved, which is not preferred.

[0082] In the land portion Rm, it is preferred that two or more sipes 16 are provided between adjacent transverse grooves 13, and three or more serrated convex portions are provided between adjacent transverse grooves 13. If the number of sipes 16 between adjacent transverse grooves 13 is less than two, the number of serrated convex portions decreases, and the snow performance is not improved, which is not preferred.

[0083] In addition, Figure 6 In the embodiment, the straight line portions ST3 of the plurality of sipes 16 are parallel to each other. Here, parallel means that the angle formed by two straight lines L16 obtained by extending the center lines of the two sipes 16 is within ±5°. When the two straight lines L16 are completely parallel, the angle formed by the two straight lines L16 is 0°.

[0084] Moreover, in Figure 6 In the embodiment, the plurality of transverse grooves 13 are parallel to each other. Here, parallel means that the angle formed by two straight lines L13 obtained by extending the center lines of the two transverse grooves 13 is within ±5°. When the two straight lines L13 are completely parallel, the angle formed by the two straight lines L13 is 0°.

[0085] Figure 7 Yes Figure 2 The figure is an enlarged view of a portion of the middle land portion Rm of the tread pattern shown. Figure 7, the distances between the zigzag-shaped protrusions between adjacent transverse grooves 13 are set to Lz1, Lz2, ..., Lzn (n is a natural number greater than or equal to 3). The distance Lz1 and the distance Lzn are distances in the tire circumferential direction measured with different transverse grooves 13 as reference. At this time, the ratio Lzmin / Lzmax of the shortest distance Lzmin to the longest distance Lzmax among the distances Lz1 to Lzn is preferably greater than 0.50. That is, it is preferred that the ratio of the minimum value of the distance between the zigzag-shaped protrusions to the maximum value of the distance between the zigzag-shaped protrusions is greater than 1.05. The ratio Lzmin / Lzmax being greater than 0.50 means that the distances between the protrusions are arranged in an unequal manner. By unequally arranging the distances between the protrusions to different distances, the dispersion of the sound generated when the pneumatic tire 10 contacts the road surface becomes good, and the pattern noise is good. In addition, the minimum value of the distances Lz1, Lz2, ..., Lzn is 3.0 [mm].

[0086] In addition, Figure 7 In the embodiment, the distances in the tire circumferential direction of the connection portions between the plurality of sipes 16 provided between adjacent transverse grooves 13 and connected to the circumferential main groove 11A on the inner side in the tire width direction are respectively set to Ls1, Ls2, ..., Lsn (n is a natural number greater than 3). The distances Ls1, Ls2, ..., Lsn are all distances in the tire circumferential direction measured with reference to the connection portion of the inner straight portion ST1 connected to the circumferential main groove 11A. The distance Ls1 and the distance Lsn are distances in the tire circumferential direction measured with reference to mutually different transverse grooves 13. At this time, the relationship between the distance Ls1 and the distance Lsn is preferably Ls1<Lsn. That is, it is preferred that, in the tire circumferential direction, the distance Lsn at the other end is longer than the distance Ls1 at one end. By changing the distance of the inner straight portion ST1 of the Z-shaped sipe 16, the edge effect can be exerted at a wider angle, and the snow performance can be improved. In addition, the minimum value of the distances Ls1, Ls2, ..., Lsn is 2.5 [mm].

[0087] exist Figure 7In the tire circumferential distance between the convex parts of the connection parts connected to the circumferential main groove 12A on the outside in the tire width direction between the plurality of sipes 16 provided between adjacent transverse grooves 13 are respectively set to Lz1, Lz2, ..., Lzn (n is a natural number greater than 3). The distance Lz1 and the distance Ls1 are the distances in the tire circumferential direction measured with the same transverse groove 13 as a reference. Since the same transverse groove 13 is used as a reference, the distance Lz1 and the distance Ls1 become the relationship between the inside and the outside in the tire width direction, and the two are located at corresponding positions. In addition, the distance Lzn and the distance Lsn are the distances in the tire circumferential direction measured with the same transverse groove 13 as a reference. Since the same transverse groove 13 is used as a reference, the distance Lzn and the distance Lsn become the relationship between the inside and the outside in the tire width direction, and the two are located at corresponding positions. At this time, it is preferred that Ls1<Lz1 and Lsn>Lzn. That is, it is preferable that, in the relationship between the distance Ls1 and the distance Lz1 at the corresponding positions in the tire circumferential direction, the distance Lz1 at the outer position in the tire width direction is greater than the distance Ls1 at the inner position in the tire width direction. By making the distance Lz1 greater than the distance Ls1, the length of the sipe in the extension direction becomes longer, so the edge effect becomes larger and the snow performance is improved. In addition, it is preferable that, in the relationship between the distance Lsn and the distance Lzn at the corresponding positions in the tire circumferential direction, the distance Lzn at the outer position in the tire width direction is smaller than the distance Lsn at the inner position in the tire width direction. By making the distance Lzn smaller than the distance Lsn, the length of the sipe in the extension direction becomes longer, so the edge effect becomes larger and the snow performance is improved.

[0088] exist Figure 7 In the embodiment, the sipe 16 is connected to the maximum amplitude position of the width W3 which is twice the amplitude in the tire width direction of the serrated edge. Thus, when stress is applied in the tire circumferential direction, the stress applied to the protruding portion that is easily damaged can be dispersed along the groove wall of the sipe 16, and the chipping damage resistance performance is improved. For example, when stress is applied in the tire circumferential direction as shown by arrow YA, the stress can be dispersed along the groove wall of the sipe 16 as shown by arrow YB. Thus, the chipping damage resistance performance of the protruding portion that is easily damaged is improved.

[0089] Fig. 8A Yes Figure 2 The diagram shows an enlarged view of a portion of a middle land portion Rm of the tread pattern. Figure 8B Yes Fig. 8A A portion of the image is enlarged. Fig. 8A and Figure 8BIn the embodiment, the two bent portions C1 and C2 of the sipe 16 are arranged at a position closer to the tire width direction than the center line RL passing through the center of the land portion Rm in the tire width direction. The bent portion C2 of the two bent portions C1 and C2 is located closer to the center line RL than the bent portion C1. The boundary between the bent portion C2 and the straight portion ST3 is the end point K2. The distance between the end point K2 and the center line RL in the tire width direction is set to Db. The ratio Db / W1 of the distance Db to the maximum width W1 of the land portion Rm in the tire width direction is preferably greater than 0 and less than 0.40.

[0090] Here, the length in the tire circumferential direction from the connection point 23 of the sipe 16 connected to the circumferential main groove 11A on the inner side in the tire width direction to the end point K2 on the inner side in the tire width direction of the outer straight portion ST3 is set to L3. The ratio L3 / L1 of the length L3 to the length L1 is preferably greater than 0.15 and less than 0.45. When the ratio L3 / L1 is greater than 0.45, the number of sipes cannot be increased, so the snow performance is not improved, which is not preferred. When the ratio L3 / L1 is less than 0.15, the length of the portion connecting the straight portion ST1 and the straight portion ST3 extending from the two edge sides of the land portion Rm (i.e., the bent portion C1, the straight portion ST2 and the bent portion C2) becomes shorter, the edge effect is reduced, and the snow performance is not improved, which is not preferred.

[0091] In addition, the ratio L3 / W1 of the length L3 to the maximum width W1 is preferably greater than 0.15 and less than 0.65. When the ratio L3 / W1 is less than 0.15, the edge effect becomes small and the snow performance is reduced, which is not preferred. When the ratio L3 / W1 is greater than 0.65, the number of sipes cannot be increased and the snow performance is not improved, which is not preferred.

[0092] Fig. 9A 1 is a diagram showing another example of the middle land portion Rm. Fig. 9B Yes Fig. 9A A portion of the image is enlarged. Fig. 9A and Fig. 9B In the sipes 16A and 16B, the bent portions C1 and C2 are arranged at positions on the inner side in the tire width direction than the center line RL passing through the center of the land portion Rm in the tire width direction. In the sipes 16A, the bent portion C2 of the two bent portions C1 and C2 is located closer to the center line RL than the bent portion C1. The boundary between the bent portion C2 and the straight portion ST3 is the end point K2. The distance between the end point K2 and the center line RL in the tire width direction is set to Dba. The ratio Dba / W1 of the distance Dba to the maximum width W1 of the land portion Rm in the tire width direction is preferably greater than 0 and less than 0.40.

[0093] In addition, in the sipe 16B, the bent portion C1 of the two bent portions C1 and C2 is located closer to the center line RL than the bent portion C2. The boundary between the bent portion C1 and the straight portion ST1 is the end point K1. The distance between the end point K1 and the center line RL in the tire width direction is set to Dbb. The ratio Dbb / W1 of the distance Dbb to the maximum width W1 of the land portion Rm in the tire width direction is preferably greater than 0 and less than 0.40.

[0094] Fig. 10A 1 is a diagram showing another example of the middle land portion Rm. Fig. 10B Yes Fig. 10A A portion of the image is enlarged. Fig. 10A and Fig. 10B , the bent portion C1 of the sipe 16C is arranged at a position closer to the inside in the tire width direction than the center line RL passing through the center of the land portion Rm in the tire width direction. The bent portion C2 of the sipe 16B is located on the center line RL. More specifically, the end point K2 that is the boundary between the bent portion C2 and the straight portion ST3 is located on the center line RL. In this case, the distance between the end point K2 and the center line RL in the tire width direction is 0, so the ratio Db / W1=0. The same is true for the bent portion C2 of the sipe 16D.

[0095] Therefore, in Fig. 10A and Fig. 10B In the case of , the following condition is also satisfied: the ratio of the distance in the tire width direction between the bent portion C2 close to the center line RL passing through the midpoint position in the tire width direction of the land portion Rm and the center line RL to the width of the land portion Rm in the tire width direction is greater than 0 and less than 0.40. In addition, one of the two bent portions C1 and C2 may be provided at a position closer to the tire width direction than the center line RL passing through the midpoint position in the tire width direction of the land portion Rm, and the other bent portion may be located on the center line RL.

[0096] By making the ratio of the distance in the tire width direction of the center line RL of the bending point of the bending portion of the two bending portions C1 and C2 close to the midpoint position of the center line RL passing through the land portion Rm is greater than 0 and less than 0.40 relative to the maximum width W1 of the land portion Rm in the tire width direction, the following effect can be obtained. That is, by providing a serrated groove and a roughly Z-shaped sipe pattern 16, the edge effect is increased. When the roughly Z-shaped bending point is close to the serrated portion, the rigidity of the block near the serrated portion is reduced, and chipping damage may occur. Therefore, by arranging the bending point and the serrated portion of the sipe pattern 16 at separated positions, it is possible to take into account both snow performance and chipping damage resistance.

[0097] In addition, the groove width is measured as the maximum value of the distance between the groove walls on the left and right sides of the groove opening in an unloaded state in which the tire is mounted on a specified rim and filled with a specified internal pressure. In a structure in which the land portion has a notch or a chamfered portion at the edge, the groove width is measured based on the intersection of the tread surface and the extension line of the groove wall when the cross-section is observed with the groove length direction as the normal direction. In addition, in a structure in which the groove extends in a zigzag or wavy shape along the tire circumferential direction, the groove width is measured based on the center line of the amplitude of the groove wall.

[0098] The tire ground contact edge T is defined as the maximum axial width position of the tire at the contact surface between the tire and the flat plate when the tire is mounted on a specified rim and given a specified internal pressure, and is placed vertically relative to the flat plate in a static state and a load corresponding to a specified load is applied.

[0099] Here, the prescribed rim refers to the "Applicable Rim" prescribed by JATMA, the "Design Rim" prescribed by TRA, or the "Measuring Rim" prescribed by ETRTO. In addition, the prescribed internal pressure refers to the "Maximum Air Pressure" prescribed by JATMA, the maximum value of the "TIRE LOAD LIMITS AT VARIOUSCOLD INFLATION PRESSURES" prescribed by TRA, or the "INFLATION PRESSURES" prescribed by ETRTO. In addition, the prescribed load refers to the "Maximum Load Capacity" prescribed by JATMA, the maximum value of the "TIRE LOAD LIMITS AT VARIOUSCOLD INFLATION PRESSURES" prescribed by TRA, or the "LOADCAPACITY" prescribed by ETRTO. However, in JATMA, in the case of a tire for a passenger car, the internal pressure is specified to be 180 [kPa], and the load is specified to be 88 [%] of the maximum load capacity.

[0100] [Three-dimensional part of the composite sipe]

[0101] Fig.11 It is shown Figure 2 2 is a cross-sectional view of an example of a three-dimensional portion of the composite sipe 16 in FIG. Fig.11 1 is a diagram showing a cross section obtained by cutting a section of a three-dimensional portion of a composite sipe 16 along a plane perpendicular to the extending direction (i.e., the longitudinal direction) of the sipe. Fig.11In FIG. 1 , the length in the sipe depth direction from the open end 9A of the composite sipe 16 to the tread surface to the groove bottom 9B, that is, the groove depth is DS. The groove width of the composite sipe 16 (that is, the sipe width) is Ts.

[0102] The vicinity of the open end 9A of the composite sipe 16 is a straight portion 9 along the sipe depth direction. The composite sipe 16 is formed into a shape that is bent or bent relative to the sipe depth direction. The amplitude in the sipe width direction that is bent or bent around the line 9L obtained by extending the center line of the straight portion 9 is As. The ratio As / Ts of the amplitude As to the groove width Ts is preferably greater than 0.40 and less than 0.80. When the ratio As / Ts exceeds 0.80, the mold's shedding property deteriorates during vulcanization molding, causing a malfunction, and is therefore not preferred. When the ratio As / Ts is less than 0.40, it is not possible to suppress the fall, and the block rigidity does not increase, so the wear resistance does not improve, and is therefore not preferred.

[0103] In addition, Fig.11 In the figure, one cycle of the bending or folding of the composite sipe 16 is S. The composite sipe 16 preferably has a bending shape or a folding shape with one or more cycles and three or less cycles. When it is less than one cycle, the effect of suppressing the collapse is insufficient and the block rigidity is not increased, which is not preferred. When it exceeds three cycles, the mold release property deteriorates during vulcanization molding, causing failure, which is not preferred.

[0104] also, Figure 2 The other composite sipes 15 and 17 in the embodiment also have the same structure as the composite sipe 16 described above.

[0105] [Groove depth]

[0106] Fig.12 It is along Figure 5 A cross-sectional view of the sipe 16 in the extending direction. Fig.12 The two-dimensional part and the three-dimensional part are not distinguished in the figure. The ratio DS / Dg of the groove depth DS of the sipe 16 to the groove depth Dg of the circumferential main groove 11A is preferably 0.50 or more and 0.85 or less. When the ratio DS / Dg is greater than 0.85, the block rigidity is reduced and the wear resistance is reduced, which is not preferred. When the ratio DS / Dg is less than 0.50, the snow performance is reduced, which is not preferred.

[0107] like Fig.12As shown in FIG. 1 , a bottom raised portion 160 is provided at a connection portion of the sipe 16 connected to the circumferential main groove 11A. The ratio DS1 / DS of the groove depth DS1 of the sipe 16 at the bottom raised portion 160 to the groove depth DS of the sipe 16 is preferably 0.50 or more and 0.85 or less. When the ratio DS1 / DS is greater than 0.85, the block rigidity is reduced and the wear resistance is reduced, which is not preferred. When the ratio DS1 / DS is less than 0.50, the snow performance is reduced, which is not preferred.

[0108] [Modifications]

[0109] The above description is based on the case where there are four circumferential main grooves 11A, 11B, 12A and 12B. It is sufficient to have three or more circumferential main grooves. Figure 2 The structure in which the two circumferential main grooves 11A and 11B are one and the center land portion Rc does not exist is obtained.

[0110] [Example]

[0111] Tables 1 to 4 are tables showing the results of performance tests of the pneumatic tires of the present invention. In the performance tests, different pneumatic tires were evaluated for chipping damage resistance, snow braking performance, snow handling performance, and drainage performance. In these performance tests, a test tire of a size of 225 / 65R17 102H was mounted on a rim of a rim size of 17×7.0J, and an air pressure of 230 [kPa] was applied. In addition, as a test vehicle, a FF (Front engine Front drive) SUV (Sport Utility Vehicle) vehicle with a displacement of 2500 [cc] was used.

[0112] The chipping damage resistance is evaluated by running around on an off-road route, measuring the number of defects on the tread surface after 450 weeks of running and indexing. The evaluation is evaluated by an index with the conventional example 1 described below as the reference (100). The larger the value, the better.

[0113] The snow braking performance is evaluated by indexing the braking distance at a speed of 30 km / h on a snowy road surface. The evaluation is evaluated by an index with the conventional example 1 described later as a reference (100). The larger the value, the better.

[0114] The snow handling performance is evaluated by indexing the test driver's sense of handling stability on a snowy road surface. The evaluation is evaluated by an index with the conventional example 1 described later as a reference (100). The larger the value, the better.

[0115] The pattern noise performance is evaluated by measuring the in-vehicle sound in a vehicle traveling at 100 [km / h]. The entire frequency band of the in-vehicle sound is taken as the object. The evaluation is performed by using the noise measurement value [dB] based on the existing example 1 described later (0 [dB]). The smaller the value, the better.

[0116] The drainage performance was evaluated by running in a pool of water with a depth of 10±1 [mm], measuring the speed at which the slip rate reached 10% and 15%, and comparing it with the index of the conventional example 1 described later as 100. This evaluation was evaluated by the index with the conventional example 1 as the reference (100). The larger the value, the better.

[0117] The pneumatic tires of Examples 1 to 22 are tires as follows: at least one of the edges on both sides of the tire width direction of the land portion divided by two circumferential main grooves is in a serrated shape, and the sipe pattern arranged on the land portion is a composite sipe pattern having a two-dimensional portion and a three-dimensional portion, and the three-dimensional portion is connected to the serrated edge.

[0118] In Examples 1 to 22, settings were made as shown in Tables 1 to 4. That is, pneumatic tires having a ratio Ws2 / Ws1 of 0.25 or more and 0.65 or less with respect to the shoulder land portion and pneumatic tires not having such a ratio, pneumatic tires having a ratio Ls2 / Ls1 of 0.15 or more and 0.55 or less with respect to the shoulder land portion and pneumatic tires not having such a ratio, pneumatic tires having a ratio Ws3 / Ws1 of 0.02 or more and 0.15 or less with respect to the shoulder land portion and pneumatic tires not having such a ratio, pneumatic tires having a ratio Wc2 / W1 of 0.40 or more and 0.75 or less with respect to the middle land portion and pneumatic tires not having such a ratio, pneumatic tires having a ratio L2 / L1 of 0.15 or more and 0.55 or less with respect to the middle land portion and pneumatic tires not having such a ratio, and pneumatic tires having a ratio Wc3 / W1 of 0.03 or more and 0.15 or less with respect to the middle land portion and pneumatic tires not having such a ratio were prepared, respectively.

[0119] The pneumatic tire of the prior art example 1 is a tire having a land portion with a serrated edge on one side in the tire width direction, and the sipes provided on the land portion are 2D sipes as a whole. The pneumatic tire of the prior art example 2 is a tire having a land portion with a serrated edge on both sides in the tire width direction, and the sipes provided on the land portion are 3D sipes as a whole.

[0120] In addition, in Tables 1 to 4, "2D" of the sipe shape indicates that the sipe is a sipe consisting of only a two-dimensional portion. "3D" of the sipe shape indicates that the sipe is composed of only a three-dimensional portion. "2D+3D" of the sipe shape indicates a composite sipe consisting of a two-dimensional portion and a three-dimensional portion.

[0121] These pneumatic tires were evaluated for chipping damage resistance, snow braking performance, snow handling performance, pattern noise performance, and drainage performance by the above-mentioned evaluation methods. The results are collectively shown in Tables 1 to 4.

[0122] As shown in Tables 1 to 4, good results were obtained when the ratio Ws2 / Ws1 of the shoulder land portion was 0.25 or more and 0.65 or less, the ratio Ls2 / Ls1 of the shoulder land portion was 0.15 or more and 0.55 or less, the ratio Ws3 / Ws1 of the shoulder land portion was 0.02 or more and 0.15 or less, the ratio Wc2 / W1 of the middle land portion was 0.40 or more and 0.75 or less, the ratio L2 / L1 of the middle land portion was 0.15 or more and 0.55 or less, and the ratio Wc3 / W1 of the middle land portion was 0.03 or more and 0.15 or less.

[0123] [Table 1]

[0124] (Table 1)

[0125] Existing example 1 Existing Example 2 Example 1 Example 2 Example 3 Example 4 Main groove shape Sawtooth Serrated on both sides Sawtooth Sawtooth Sawtooth Sawtooth Sipe shape 2D 3D 2D+3D 2D+3D 2D+3D 2D+3D The shape of the sipes connected to the main groove 2D 3D 3D 3D 3D 3D Ratio of shoulder land portion Rs Ws2 / Ws1 - 1.00 0.47 0.23 0.25 0.45 Ratio of shoulder land portion Rs Ls2 / Ls1 0.34 0.34 0.34 0.34 0.34 0.34 Ratio of shoulder land portion Rs Ws3 / Ws1 0.06 0.06 0.06 0.06 0.06 0.06 Ratio of middle land portion Rm Wc2 / W1 - 1.00 0.50 0.38 0.38 0.38 The ratio of the middle land portion Rm is L2 / L1 0.41 0.41 0.41 0.41 0.41 0.41 Ratio of middle land portion Rm Wc3 / W1 0.06 0.06 0.06 0.06 0.06 0.06 Chip damage resistance 100 112 110 102 104 106 Snow braking performance 100 112 110 110 110 110 Snow handling performance 100 112 110 102 104 106 Pattern Noise Performance 0.0 +0.8 0.0 0.0 0.0 0.0 Drainage performance 100 95 100 100 100 100

[0126] [Table 2]

[0127] (Table 2)

[0128]

[0129] [Table 3]

[0130] (Table 3)

[0131]

[0132] [Table 4]

[0133] (Table 4)

[0134]

[0135] Description of Reference Numerals

[0136] 1 Tread

[0137] 2 Sidewall

[0138] 3 Bead section

[0139] 4 Carcass layer

[0140] 5 Bead core

[0141] 6 Bead filler

[0142] 7 Belt

[0143] 8 Belt Cover

[0144] 10 Pneumatic tires

[0145] 11A, 11B, 12A, 12B Circumferential main groove

[0146] 13 horizontal slot

[0147] 14A, 14B horizontal groove

[0148] 15, 16, 17 sipes

[0149] 18 Decoration Slots

[0150] As Amplitude

[0151] CL Tire equatorial plane

[0152] Rc Central Land

[0153] Rm Middle Land

[0154] Rs shoulder land

[0155] T Tire contact end

[0156] Ts Slot width

Claims

1. A pneumatic tire, the pneumatic tire being a pneumatic tire having a tread pattern, characterized in that: The tread pattern comprises: More than three circumferential main grooves, wherein the more than three circumferential main grooves extend along the circumference of the tire; a land portion, the land portion being divided by two of the three or more circumferential main grooves or being provided at the outermost sides of the circumferential main grooves in the tire width direction; and a sipe pattern, wherein the sipe pattern is provided on the land portion, The land portion has a plurality of transverse grooves extending from the inner side in the tire width direction toward the outer side in the tire width direction. At least one of the edges of the land portion on both sides in the tire width direction is a serrated edge, The serrated edge has a serrated shape having concave portions and convex portions whose positions in the tire width direction periodically change. The recessed portion of the sawtooth edge connects the sipes, The convex portion of the serrated edge is formed at an extended end of one groove wall of the sipe connected to the concave portion. The end of one groove wall of the transverse groove becomes the convex portion of the serrated edge. The sipe pattern is a composite sipe pattern having a two-dimensional portion and a three-dimensional portion, The two-dimensional portion refers to a portion of the sipe wall surface having a straight line shape when the sipe is viewed in section perpendicular to the longitudinal direction of the sipe. The three-dimensional portion is a portion of a sipe wall surface having a shape bent in the sipe width direction when the sipe is viewed in section perpendicular to the sipe length direction. The section of the sipe other than the section of the three-dimensional section is the section of the two-dimensional section, The three-dimensional portion is directly connected to one edge of the land portion without passing through the two-dimensional portion. The two-dimensional portion is connected to the other edge of the land portion, The three-dimensional portion of the sipe connected to the serrated edge is connected to the concave portion of the serrated edge, A ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.25 or more and 0.75 or less.

2. The pneumatic tire according to claim 1, characterized in that: When the land portion is a shoulder land portion including a ground contact edge portion, A ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.25 or more and 0.65 or less.

3. The pneumatic tire according to claim 1 or 2, characterized in that: When the land portion is a shoulder land portion including a ground contact edge portion, The plurality of transverse grooves are shoulder transverse grooves, The plurality of shoulder transverse grooves extend from the circumferential main groove at least to the ground contact end portion.

4. The pneumatic tire according to claim 3, characterized in that: A ratio of a distance between the zigzag-shaped protrusions in the tire circumferential direction to a length of the zigzag-shaped edges between adjacent shoulder lateral grooves in the tire circumferential direction is 0.15 or more and 0.55 or less.

5. The pneumatic tire according to claim 3, characterized in that: When the land portion is a shoulder land portion including a ground contact edge portion, The land portion has two or more of the composite sipes and three or more of the serrated convex portions between adjacent shoulder lateral grooves.

6. The pneumatic tire according to claim 3, characterized in that: When the land portion is a shoulder land portion including a ground contact edge portion, A ratio of a length twice the amplitude of the zigzag shape in the tire width direction to a ground contact width of the shoulder land portion in the tire width direction is 0.02 or more and 0.15 or less.

7. The pneumatic tire according to claim 1, wherein: In the case where the land portion is a land portion that does not include a ground contact end portion, A ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.40 or more and 0.75 or less.

8. The pneumatic tire according to claim 1 or 7, characterized in that: In the case where the land portion is a land portion that does not include a ground contact end portion, The plurality of transverse grooves penetrate the land portion.

9. The pneumatic tire according to claim 8, characterized in that: A ratio of a distance between the zigzag-shaped protrusions in the tire circumferential direction to a length of an edge of the zigzag shape between adjacent lateral grooves in the tire circumferential direction is 0.15 or more and 0.55 or less.

10. The pneumatic tire according to claim 1 or 7, characterized in that: In the case where the land portion is a land portion that does not include a ground contact end portion, A ratio of an amplitude of the sawtooth shape in the tire width direction to a width of the land portion in the tire width direction is 0.03 or more and 0.15 or less.

11. The pneumatic tire according to claim 8, wherein: In the case where the land portion is a land portion that does not include a ground contact end portion, The land portion has two or more of the composite sipes and three or more of the serrated convex portions between adjacent lateral grooves.

12. The pneumatic tire according to claim 11, characterized in that In the case where the land portion is a land portion that does not include a ground contact end portion, When the distances in the tire circumferential direction between the connection portions of two or more of the composite sipes provided between adjacent transverse grooves and connected to the circumferential main groove on the inner side in the tire width direction are set to Ls1, Ls2, ..., Lsn, Ls1<Lsn, and n is a natural number greater than or equal to 3.

13. The pneumatic tire according to claim 11, wherein: In the case where the land portion is a land portion that does not include a ground contact end portion, When the circumferential distances between the connecting portions of the plurality of sipes arranged between adjacent transverse grooves and connected to the circumferential main groove on the inner side of the tire width direction are set to Ls1, Ls2, ..., Lsn, and the circumferential distances between the convex portions of the connecting portions of the plurality of sipes arranged between adjacent transverse grooves and connected to the circumferential main groove on the outer side of the tire width direction are set to Lz1, Lz2, ..., Lzn, Ls1<Lz1 and Lsn>Lzn, and n is a natural number greater than 3.

14. A pneumatic tire, the pneumatic tire being a pneumatic tire having a tread pattern, characterized in that: The tread pattern comprises: More than three circumferential main grooves, wherein the more than three circumferential main grooves extend along the circumference of the tire; a land portion, the land portion being divided by two of the three or more circumferential main grooves or being provided at the outermost sides of the circumferential main grooves in the tire width direction; and a sipe pattern, wherein the sipe pattern is provided on the land portion, The land portion has a plurality of transverse grooves extending from the inner side in the tire width direction toward the outer side in the tire width direction. At least one of the edges of the land portion on both sides in the tire width direction is a serrated edge, The serrated edge has a serrated shape having concave portions and convex portions whose positions in the tire width direction periodically change. The recessed portion of the sawtooth edge connects the sipes, The convex portion of the serrated edge is formed at an extended end of one groove wall of the sipe connected to the concave portion. The end of one groove wall of the transverse groove becomes the convex portion of the serrated edge. The sipe pattern is a composite sipe pattern having a two-dimensional portion and a three-dimensional portion, The two-dimensional portion refers to a portion of the sipe wall surface having a straight line shape when the sipe is viewed in section perpendicular to the longitudinal direction of the sipe. The three-dimensional portion is a portion of a sipe wall surface having a shape bent in the sipe width direction when the sipe is viewed in section perpendicular to the sipe length direction. The three-dimensional portion of the sipe connected to the serrated edge is directly connected to the concave portion of the serrated edge without passing through the two-dimensional portion, The two-dimensional portion is connected to an edge without jagged edges, When the land portion is a shoulder land portion including a ground contact edge portion, The shoulder land portion has a plurality of shoulder lateral grooves extending from the inner side in the tire width direction toward the outer side in the tire width direction. The plurality of shoulder transverse grooves extend from the circumferential main groove at least to the ground contact end portion. A ratio of a distance between the zigzag-shaped protrusions in the tire circumferential direction to a length of the zigzag-shaped edges between adjacent shoulder lateral grooves in the tire circumferential direction is 0.15 or more and 0.55 or less.

15. The pneumatic tire according to claim 14, characterized in that A ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.25 or more and 0.75 or less.

16. The pneumatic tire according to claim 14 or 15, characterized in that: When the land portion is a shoulder land portion including a ground contact edge portion, A ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.25 or more and 0.65 or less.

17. The pneumatic tire according to claim 14 or 15, characterized in that: When the land portion is a shoulder land portion including a ground contact edge portion, The land portion has two or more of the composite sipes and three or more of the serrated convex portions between adjacent shoulder lateral grooves.

18. The pneumatic tire according to claim 14 or 15, characterized in that: When the land portion is a shoulder land portion including a ground contact edge portion, A ratio of a length twice the amplitude of the zigzag shape in the tire width direction to a ground contact width of the shoulder land portion in the tire width direction is 0.02 or more and 0.15 or less.

19. A pneumatic tire, the pneumatic tire being a pneumatic tire having a tread pattern, characterized in that: The tread pattern comprises: More than three circumferential main grooves, wherein the more than three circumferential main grooves extend along the circumference of the tire; a land portion, the land portion being divided by two of the three or more circumferential main grooves or being provided at the outermost sides of the circumferential main grooves in the tire width direction; and a sipe pattern, wherein the sipe pattern is provided on the land portion, The land portion has a plurality of transverse grooves extending from the inner side in the tire width direction toward the outer side in the tire width direction. At least one of the edges of the land portion on both sides in the tire width direction is a serrated edge, The serrated edge has a serrated shape having concave portions and convex portions whose positions in the tire width direction periodically change. The recessed portion of the sawtooth edge connects the sipes, The convex portion of the serrated edge is formed at an extended end of one groove wall of the sipe connected to the concave portion. The end of one groove wall of the transverse groove becomes the convex portion of the serrated edge. The sipe pattern is a composite sipe pattern having a two-dimensional portion and a three-dimensional portion, The two-dimensional portion refers to a portion of the sipe wall surface having a straight line shape when the sipe is viewed in section perpendicular to the longitudinal direction of the sipe. The three-dimensional portion is a portion of a sipe wall surface having a shape bent in the sipe width direction when the sipe is viewed in section perpendicular to the sipe length direction. The three-dimensional portion of the sipe connected to the serrated edge is directly connected to the concave portion of the serrated edge without passing through the two-dimensional portion, The two-dimensional portion is connected to an edge without jagged edges, In the case where the land portion is a land portion that does not include a ground contact end portion, The plurality of transverse grooves penetrate the land portion.

20. The pneumatic tire according to claim 19, wherein: In the case where the land portion is a land portion that does not include a ground contact end portion, A ratio of a width of the three-dimensional portion in the tire width direction to a ground contact width of the land portion in the tire width direction is 0.40 or more and 0.75 or less.

21. The pneumatic tire according to claim 19 or 20, characterized in that: A ratio of a distance between the zigzag-shaped protrusions in the tire circumferential direction to a length of an edge of the zigzag shape between adjacent lateral grooves in the tire circumferential direction is 0.15 or more and 0.55 or less.

22. The pneumatic tire according to claim 19 or 20, characterized in that: In the case where the land portion is a land portion that does not include a ground contact end portion, A ratio of an amplitude of the sawtooth shape in the tire width direction to a width of the land portion in the tire width direction is 0.03 or more and 0.15 or less.

23. The pneumatic tire according to claim 19 or 20, characterized in that: In the case where the land portion is a land portion that does not include a ground contact end portion, The land portion has two or more of the composite sipes and three or more of the serrated convex portions between adjacent lateral grooves.

24. The pneumatic tire according to claim 23, wherein: In the case where the land portion is a land portion that does not include a ground contact end portion, When the distances in the tire circumferential direction between the connection portions of two or more of the composite sipes provided between adjacent transverse grooves and connected to the circumferential main groove on the inner side in the tire width direction are set to Ls1, Ls2, ..., Lsn, Ls1<Lsn, and n is a natural number greater than or equal to 3.

25. The pneumatic tire according to claim 23, wherein: In the case where the land portion is a land portion that does not include a ground contact end portion, When the circumferential distances between the connecting portions of the plurality of sipes arranged between adjacent transverse grooves and connected to the circumferential main groove on the inner side of the tire width direction are set to Ls1, Ls2, ..., Lsn, and the circumferential distances between the convex portions of the connecting portions of the plurality of sipes arranged between adjacent transverse grooves and connected to the circumferential main groove on the outer side of the tire width direction are set to Lz1, Lz2, ..., Lzn, Ls1<Lz1 and Lsn>Lzn, and n is a natural number greater than 3.

26. The pneumatic tire of claim 1, 2, 7, 14, 15, 19 or 20, wherein: The composite sipe is connected to the maximum amplitude position of the sawtooth-shaped edge.

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