Tire

Abstract

The present application provides a tire that improves performance on snow and noise performance. The tire has a tread portion (2). A first intermediate transverse groove (11) is provided in an intermediate land portion (7) of the tread portion (2). The first intermediate transverse groove (11) includes a first groove portion (31), a second groove portion (32) inclined in the same direction as the first groove portion (31), and a third groove portion (33) located between the first groove portion (31) and the second groove portion (32) and inclined in the opposite direction to the first groove portion (31) with respect to the tire axial direction. The groove width of the first groove portion (31) increases from the third groove portion (33) toward the outside in the tire axial direction. The groove width of the second groove portion (32) increases from the third groove portion (33) toward the inside in the tire axial direction.

Description

Technical Field

[0001] This invention relates to tires. Background Technology

[0002] Patent document 1 discloses a tire with multiple first lateral grooves on the first land portion of the tread. When the tire travels on ice and snow, it compacts and shears snow and ice within the grooves of the first lateral grooves, thereby generating greater traction.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2018-203117

[0004] The aforementioned tires have a tendency to generate significant noise due to the first lateral groove, and efforts are being made to improve this. Summary of the Invention

[0005] The present invention was made in view of the above-mentioned actual situation, and its main objective is to provide a tire that improves snow performance and noise performance.

[0006] The tire of the present invention has a tread portion, the tread portion comprising: a plurality of circumferential grooves extending continuously along the tire circumference between a first tread end and a second tread end, and a plurality of land portions divided by the plurality of circumferential grooves, the plurality of land portions including an intermediate land portion disposed between the first tread end and the tire equator, the intermediate land portion having at least one first intermediate transverse groove completely traversing the intermediate land portion along the tire axial direction, the first intermediate transverse groove comprising: a first groove portion inclined relative to the tire axial direction from a first end outside the tire axial direction, a second groove portion inclined relative to the tire axial direction from a second end inside the tire axial direction in the same direction as the first groove portion, and a third groove portion located between the first groove portion and the second groove portion and inclined relative to the tire axial direction in the opposite direction to the first groove portion, the groove width of the first groove portion increasing from the third groove portion side toward the tire axial direction outward, and the groove width of the second groove portion increasing from the third groove portion side toward the tire axial direction inward.

[0007] In the tire of the present invention, preferably, the maximum width of the first intermediate transverse groove is 120% to 200% of the width of the third groove.

[0008] Preferably, in the tire of the present invention, the first intermediate transverse groove includes: a first intermediate reinforcing rib raised at the bottom of the groove on the first end side, and a second intermediate reinforcing rib raised at the bottom of the groove on the second end side.

[0009] Preferably, in the tire of the present invention, at least one second intermediate transverse groove is provided in the intermediate land portion, which is completely transverse to the intermediate land portion along the tire axis, and the second intermediate transverse groove is inclined in the same direction as the first groove relative to the tire axis.

[0010] Preferably, in the tire of the present invention, the intermediate land portion is provided with: a first recess connected to the end of the second intermediate transverse groove on the outer side of the tire axial direction, and a second recess connected to the end of the second intermediate transverse groove on the inner side of the tire axial direction, wherein the first recess and the second recess open at the contact surface of the intermediate land portion and the side of the tire axial direction, respectively.

[0011] Preferably, in the tire of the present invention, the first recess extends from the end of the second intermediate transverse groove on the outer side of the tire axial direction to one side of the tire circumferential direction, and the second recess extends from the end of the second intermediate transverse groove on the inner side of the tire axial direction to the other side of the tire circumferential direction.

[0012] Preferably, in the tire of the present invention, at least one first interruption groove extending along the tire axial direction is provided in the intermediate land portion, the outer end of the first interruption groove in the tire axial direction is connected to the first recess, and the inner end of the first interruption groove in the tire axial direction is interrupted in the contact surface of the intermediate land portion.

[0013] Preferably, in the tire of the present invention, at least one second interruption groove extending along the tire axial direction is provided in the intermediate land portion, the inner end of the second interruption groove in the tire axial direction is connected to the second recess, and the outer end of the second interruption groove in the tire axial direction is interrupted in the contact surface of the intermediate land portion.

[0014] The tire of the present invention, by adopting the above-described structure, can improve snow performance and noise performance. Attached Figure Description

[0015] Figure 1 This is a unfolded view of the tread section of a tire according to one embodiment of the present invention.

[0016] Figure 2 yes Figure 1 An enlarged view of the central land area.

[0017] Figure 3 yes Figure 2 A sectional view along line AA.

[0018] Figure 4 yes Figure 2 Enlarged view of the central patterned block and the central horizontal groove.

[0019] Figure 5 yes Figure 2 BB line section view.

[0020] Figure 6 yes Figure 2 CC-line sectional view.

[0021] Figure 7 yes Figure 1Enlarged view of the land portion of the calf's crown.

[0022] Figure 8 yes Figure 7 DD-line sectional view.

[0023] Figure 9 yes Figure 7 Enlarged view of the tire tread pattern blocks and the transverse grooves of the tire tread.

[0024] Figure 10 yes Figure 7 EE line section view.

[0025] Figure 11 yes Figure 1 Enlarged view of the land area of ​​the fetal shoulder.

[0026] Figure 12 This is a unfolded diagram of the tread of a comparative example tire.

[0027] Figure 13 It is a unfolded diagram of the tire tread that serves as a benchmark for comparing noise performance.

[0028] Explanation of reference numerals in the attached figures: 2…tread portion; 3…circumferential groove; 4…land portion; 7…intermediate land portion; 11…first intermediate transverse groove; 31…first groove; 32…second groove; 33…third groove; T1…first tread end; T2…second tread end. Detailed Implementation

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a developed view of the tread portion 2 of a tire 1 according to one embodiment of the present invention. The tire 1 of this embodiment is a winter tire designed for driving on snow and ice, and is suitable for use as a pneumatic tire for SUVs and light trucks, for example. However, the present invention is not limited to this embodiment, and can also be applied to pneumatic tires for heavy loads and non-air tires that do not have pressurized air filled inside the tire.

[0030] like Figure 1 As shown, the tread portion 2 of the present invention includes: a plurality of circumferential grooves 3 extending continuously along the tire circumference between the first tread end T1 and the second tread end T2, and a plurality of land portions 4 divided by the aforementioned circumferential grooves 3. The tire 1 of this embodiment is configured as a tire with a tread portion 2 consisting of four circumferential grooves 3 and five land portions 4, a so-called five-pattern tire. However, the present invention is not limited to this configuration.

[0031] The first tread end T1 and the second tread end T2 are respectively equivalent to the ends of the contact surfaces when the tire 1 in its normal state is subjected to a normal load, causing the tread portion 2 to contact the ground plane at a 0° camber angle.

[0032] "Standard condition" refers to the state where, for pneumatic tires of various specifications, the tire and rim are assembled on a standard rim and filled with the standard internal pressure, and there is no load. For tires without specified specifications or non-pneumatic tires, the above-mentioned standard condition means the standard operating condition corresponding to the tire's intended use, unmounted on a vehicle and without load. In this manual, unless otherwise specified, the dimensions of the tire are values ​​measured under the above-mentioned standard condition.

[0033] "Standard rim" refers to a rim with a specified specification for each tire within a specification system that includes the specifications on which the tire is based. For example, if it is JATMA, it is "standard rim"; if it is TRA, it is "Design Rim"; and if it is ETRTO, it is "Measuring Rim".

[0034] "Standard internal pressure" refers to the air pressure specified for each tire within the specification system, including the tire's base specifications. For JATMA, it is the "maximum air pressure"; for TRA, it is the maximum value recorded in the table "TIRE LOAD LIMITS ATVARIOUS COLD INFLATION PRESSURES"; and for ETRTO, it is "INFLATION PRESSURE".

[0035] "Regular load" refers to the load specified for each tire within a specification system, including the specifications the tire is based on, when various sizes of pneumatic tires are defined. For JATMA tires, it's "maximum load capacity"; for TRA tires, it's the maximum value recorded in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES"; and for ETRTO tires, it's "LOAD CAPACITY". Furthermore, when tire sizes are not specified, "regular load" refers to the maximum load that the tire can withstand when using the aforementioned specifications.

[0036] The circumferential groove 3 includes two shoulder circumferential grooves 5 and two crown circumferential grooves 6. One shoulder circumferential groove 5 is provided between the first tread end T1 and the tire equator C, and another is provided between the second tread end T2 and the tire equator C. The two crown circumferential grooves 6 are provided with the tire equator C separated by one side. Thus, one crown circumferential groove 6 is provided between one shoulder circumferential groove 5 and the tire equator C, and another is provided between the other shoulder circumferential groove 5 and the tire equator C.

[0037] The tire axial distance L1 from the tire equator C to the center line of the shoulder circumferential groove 5 is preferably 25% to 35% of the tread width TW. The tire axial distance L2 from the tire equator C to the center line of the crown circumferential groove 6 is preferably 5% to 15% of the tread width TW. Furthermore, the tread width TW is the tire axial distance from the first tread end T1 to the second tread end T2 in the above-described normal state.

[0038] In this embodiment, each circumferential groove 3 extends in a straight line parallel to the tire circumference, for example. Each circumferential groove 3 may also extend in a wavy shape, for example.

[0039] The groove width W1 of each circumferential groove 3 is preferably at least 3 mm. In addition, the groove width W1 of each circumferential groove 3 is preferably, for example, 3.0% to 7.0% of the tread width TW.

[0040] The plurality of land sections 4 include two intermediate land sections 7, one crown land section 8, and two shoulder land sections 9. One intermediate land section 7 is provided between the first tread end T1 and the tire equator C, and another is provided between the tire equator C and the second tread end T2. Thus, the intermediate land section 7 is divided between the shoulder circumferential groove 5 and the crown circumferential groove 6.

[0041] The crown land portion 8 is adjacent to the inner side of the intermediate land portion 7 via the circumferential groove 3. The crown land portion 8 is divided between two crown circumferential grooves 6. The shoulder land portion 9 is adjacent to the outer side of the intermediate land portion 7 via the circumferential groove 3. The shoulder land portion 9 is divided on the outer side of the shoulder circumferential groove 5 and includes a first tread end T1 or a second tread end T2.

[0042] In this embodiment, the two intermediate land portions 7 have identical structures. Hereinafter, one intermediate land portion 7 will be described, but the other intermediate land portion 7 will be described similarly. Furthermore, the two shoulder land portions 9 also have identical structures, and the structure of one shoulder land portion 9 described in this specification can be applied to the other shoulder land portion 9.

[0043] exist Figure 2 The diagram shows an enlarged view of the intermediate land section 7. Multiple intermediate lateral grooves 10 are provided in the intermediate land section 7. The intermediate lateral grooves 10 include a first intermediate lateral groove 11 and a second intermediate lateral groove 12, which have different shapes when viewed from above the tire tread. The first intermediate lateral groove 11 and the second intermediate lateral groove 12 completely traverse the intermediate land section 7 along the tire axial direction.

[0044] The first intermediate transverse groove 11 of the present invention includes a first groove portion 31, a second groove portion 32, and a third groove portion 33. The first groove portion 31 extends from a first end 11a on the outer side of the first intermediate transverse groove 11 relative to the tire axial direction and is inclined relative to the tire axial direction. The second groove portion 32 extends from a second end 11b on the inner side of the first intermediate transverse groove 11 relative to the tire axial direction and is inclined relative to the tire axial direction in the same direction as the first groove portion 31. The third groove portion 33 is located between the first groove portion 31 and the second groove portion 32 and is inclined relative to the tire axial direction in the opposite direction to the first groove portion 31.

[0045] In this invention, the width of the first groove 31 increases from the side of the third groove 33 toward the outer axial direction of the tire. The width of the second groove 32 increases from the side of the third groove 33 toward the inner axial direction of the tire. By adopting the above structure in this invention, snow performance and noise performance can be improved. The reason for this is speculated to be the following mechanism.

[0046] In this invention, the first intermediate transverse groove 11 includes the aforementioned third groove 33, thereby hindering the movement of air inside the first intermediate transverse groove 11, reducing pump noise, and thus improving noise performance.

[0047] Furthermore, in this invention, the width of the first groove 31 and the second groove 32 increases from the third groove 33 side, thereby reducing air turbulence at the confluence of the first intermediate transverse groove 11 and the circumferential groove 3, and also reducing noise. Additionally, when driving on snow, the first intermediate transverse groove 11, including the aforementioned first groove 31 and second groove 32, can strongly compact the snow internally, providing greater snow column shear force. In this invention, it is believed that this mechanism can improve both snow performance and noise performance.

[0048] The structure of this embodiment will now be described in more detail. Furthermore, each structure described below represents a specific state of this embodiment. Therefore, the present invention can achieve the aforementioned effects even without the structures described below. Moreover, even when any one of the structures described below is applied individually to the tire of the present invention possessing the above features, an improvement in the performance corresponding to each structure can be expected. Furthermore, when several of the structures described below are applied in combination, an improvement in the combined performance corresponding to each structure can be expected.

[0049] In this embodiment, it includes a plurality of intermediate tread blocks 15 divided by a plurality of intermediate transverse grooves 10 that completely traverse the intermediate land portion 7 along the tire axis.

[0050] exist Figure 3 The middle shows Figure 2 A sectional view along line AA. (e.g.) Figure 3As shown, at least one of the intermediate transverse grooves 10 includes a first intermediate reinforcing rib 16 raised at the bottom of the groove at the end on the outer side of the tire axial direction, and a second intermediate reinforcing rib 17 raised at the bottom of the groove at the end on the inner side of the tire axial direction. In this embodiment, each intermediate transverse groove 10 is configured to include the first intermediate reinforcing rib 16 and the second intermediate reinforcing rib 17. This effectively maintains the rigidity of the intermediate land portion 7 and improves handling stability on dry roads (hereinafter, sometimes simply referred to as "handling stability").

[0051] like Figure 2 As shown, the plurality of intermediate tread blocks 15 include: a contact surface 15s, a first intermediate longitudinal edge 15a extending circumferentially along the outer side of the tire axial direction at the contact surface 15s, and a second intermediate longitudinal edge 15b extending circumferentially along the inner side of the tire axial direction at the contact surface 15s.

[0052] exist Figure 4 The image shows an enlarged view of the central patterned block 15 and the central horizontal groove 10. Additionally, in... Figure 4 In the middle, points are formed in the first intermediate tie 16 and the second intermediate tie 17. For example... Figure 4 As shown, at least one first intermediate groove 21 and at least one second intermediate groove 22 are provided on the ground surface 15s of at least one intermediate patterned block 15. The first intermediate groove 21 extends from the first intermediate longitudinal edge 15a and includes an interrupted end 21a within the ground surface 15s. The second intermediate groove 22 extends from the second intermediate longitudinal edge 15b and includes an interrupted end 22a within the ground surface 15s.

[0053] In this specification, "groove" refers to a cutting element with a small width, and the width between two inner walls extending approximately parallel to each other is 1.5 mm or less. Furthermore, "approximately parallel" means that the angle between the two inner walls is 10° or less. The width of the groove is preferably 0.5 to 1.5 mm, more preferably 0.4 to 1.0 mm. In other types of grooves, at least one of the two groove edges may be formed by a chamfer. Additionally, the bottom of the flask with a width exceeding 1.5 mm may be connected to the bottom of the groove.

[0054] The interrupted end 21a of the first intermediate sipe 21 is located axially inside the tire than the first intermediate reinforcing bar 16. The interrupted end 22a of the second intermediate sipe 22 is located axially outside the tire than the second intermediate reinforcing bar 17, and axially inside the tire than the interrupted end 21a of the first intermediate sipe 21. This ensures sufficient length for both the first intermediate sipe 21 and the second intermediate sipe 22, maintaining snow performance.

[0055] As a preferred embodiment, in this embodiment, within the contact surface 15s of at least one intermediate tread block 15, no grooves or sipes are provided in a first region 23 that is axially inner to the tire than the interrupted end 21a of the first intermediate sipe 21 and axially outer to the tire than the interrupted end 22a of the second intermediate sipe 22. Therefore, the rigidity and contact area of ​​the intermediate tread block 15 are sufficiently ensured. Consequently, when cornering on a dry road surface, even with an increased slip angle, the cornering characteristics do not change drastically, resulting in excellent handling stability. Furthermore, the aforementioned first region 23 is the area within the contact surface 15s of the intermediate tread block 15 between an imaginary line 21b extending parallel to the tire circumference through the interrupted end 21a of the first intermediate sipe 21 and another imaginary line 22b extending parallel to the tire circumference through the interrupted end 22a of the second intermediate sipe 22.

[0056] like Figure 2 As shown, the intermediate pattern block 15 in this embodiment is provided with two first intermediate grooves 21 and two second intermediate grooves 22. The first intermediate grooves 21 and the second intermediate grooves 22 extend in a serrated shape. Such first intermediate grooves 21 and second intermediate grooves 22 can maintain the rigidity of the intermediate pattern block 15 and improve its snow performance.

[0057] The tire axial length L3 of the first intermediate sipe 21 and the tire axial length L4 of the second intermediate sipe 22 are, for example, 25% to 40% of the tire axial width W2 of the intermediate tread block 15. Furthermore, the aforementioned length L3 of the first intermediate sipe 21 is the tire axial length L5 of the first intermediate reinforcing rib 16 (e.g., ...). Figure 3 (as shown) 150% to 300%. Similarly, the aforementioned length L4 of the second intermediate groove 22 is the tire axial length L6 of the second intermediate brace 17 (as shown). Figure 3 (As shown) 1.5 to 3.0 times. Such a first intermediate cutter groove 21 and a second intermediate cutter groove 22 improve snow performance and noise performance in a balanced way.

[0058] The first intermediate sipe 21 and the second intermediate sipe 22 are inclined in the same direction relative to the tire axis. The angle between the first intermediate sipe 21 and the second intermediate sipe 22 and the tire axis is, for example, 20 to 35°. Furthermore, when the sipes extend in a serrated shape, the angle is measured at the center line of the serration's amplitude. When driving on snow, such first intermediate sipes 21 and second intermediate sipes 22 can also provide friction in the tire axis.

[0059] exist Figure 5 The middle shows Figure 2 The BB-line sectional view. Furthermore, although it is believed that the folded-back portion of the serrations in the first intermediate groove 21 of the actual object appears as an ridge line, in... Figure 5 The middle part is omitted. For example... Figure 5 As shown, the depth of the central portion 25 of the first intermediate sipe 21 along the tire axial direction is greater than the depth of the ends 26 on both sides of the tire axial direction. Therefore, the maximum depth d2 of the first intermediate sipe 21 is formed in the central portion 25. The maximum depth d2 of the first intermediate sipe 21 is, for example, 65% to 85% of the depth d1 of the shoulder circumferential groove 5. Furthermore, the depth d3 of the ends 26 of the first intermediate sipe 21 is, for example, 50% to 70% of the maximum depth d2. With this design, the central portion 25 of the first intermediate sipe 21 can be easily and moderately opened, providing greater friction on snow and ice. Additionally, the second intermediate sipe 22 has the same cross-sectional shape as the first intermediate sipe 21, thus the structure of the first intermediate sipe 21 can be applied to the second intermediate sipe 22.

[0060] like Figure 4 As shown, the first region 23 does not have grooves or sipes, nor any other small recesses. Therefore, the first region 23 forms a flat contact surface. The tire axial length L7 of the first region 23 is equal to the tire axial width W2 of the intermediate tread block 15 (e.g., ...). Figure 2 As shown (and the same applies below), the length of the first region 23 is 20% to 40%. This ensures the rigidity of the intermediate tread block 15 and provides excellent handling stability. In addition, when multiple first intermediate sipes 21 of different lengths are configured, and when multiple second intermediate sipes 22 of different lengths are configured, the first region 23 is determined in a way that minimizes the tire axial length of the first region 23.

[0061] like Figure 3 As shown, the tire axial length L5 of the first intermediate rib 16 and the length L6 of the second intermediate rib 17 are preferably 10% to 20% of the width W2 of the intermediate tread block 15. Furthermore, when the tire axial lengths of the first intermediate rib 16 and the second intermediate rib 17 vary in the tire radial direction, the lengths L5 and L6 are measured at the center position in the tire radial direction. More preferably, in this embodiment, the first intermediate rib 16 and the second intermediate rib 17 are configured with substantially the same shape.

[0062] The depths d5 from the ground plane of the intermediate patterned block 15 to the outer surface of the first intermediate tie rod 16 and d6 from the ground plane of the intermediate patterned block 15 to the outer surface of the second intermediate tie rod 17 are 65% to 85% of the maximum depth d4 of the intermediate transverse groove 10. In a more preferred embodiment, the aforementioned depths d5 and d6 are respectively less than the maximum depth d2 of the first intermediate groove 21 (e.g., ...). Figure 5 As shown below, and the same applies below), and is greater than the depth d3 of the end 26 of the first intermediate groove 21 in the tire axial direction (as shown below). Figure 5(As shown, the same applies below). This depth configuration achieves the aforementioned effects and helps to suppress uneven wear of the intermediate pattern block 15.

[0063] like Figure 4 As shown, the first intermediate transverse groove 11 has at least one bend 27. In this embodiment, the first intermediate transverse groove 11 includes two bends 27. Furthermore, the second intermediate transverse groove 12 does not include any bends. In this embodiment, the intermediate land portion 7 is alternately provided with the first intermediate transverse groove 11 and the second intermediate transverse groove 12 along the tire circumference. Additionally, both the first intermediate transverse groove 11 and the second intermediate transverse groove 12 possess… Figure 3 The cross-sectional shape shown.

[0064] Preferably, the bent portion 27 is located axially between the interrupted end 21a of the first intermediate sipe 21 and the interrupted end 22a of the second intermediate sipe 22. This prevents localized deformation of the intermediate tread block 15, resulting in excellent handling stability.

[0065] like Figure 2 As shown, the first intermediate transverse groove 11 has its maximum width at either the first end 11a or the second end 11b. Furthermore, the third groove 33 extends with a constant width. The maximum width W3 of the first intermediate transverse groove 11 is preferably 120% to 200% of the width W4 of the third groove 33. This results in a balanced improvement in both noise performance and snow performance.

[0066] like Figure 4 As shown, the tire axial length L8 of the first groove 31 and the tire axial length L9 of the second groove 32 are, for example, 35% to 45% of the tire axial width W2 of the contact patch of the intermediate tread block 15. Furthermore, the tire axial length L10 of the third groove 33 is, for example, 10% to 30% of the aforementioned width W2 of the intermediate tread block 15.

[0067] The angle of the first groove 31 or the second groove 32 relative to the tire axial direction is, for example, 25 to 45°. The angle of the third groove 33 relative to the tire axial direction is, for example, 50 to 65°. The angle between the first groove 31 and the third groove 33, and the angle between the second groove 32 and the third groove 33, are, for example, 80 to 110°, preferably 90 to 110°. When driving on snow, this configuration of the grooves can generate harder snow columns within the grooves, providing greater snow column shearing force, and can suppress snow clogging within the grooves.

[0068] The second intermediate transverse groove 12 is inclined, for example, in the same direction as the first groove 31 of the first intermediate transverse groove 11 relative to the tire axis. In this embodiment, the second intermediate transverse groove 12 is inclined at an angle of 10 to 30°.

[0069] like Figure 2As shown, a first recess 41 and a second recess 42 are provided in the intermediate land portion 7. The first recess 41 extends from the end of the second intermediate transverse groove 12 on the outer side of the tire axial direction toward one side of the tire circumferential direction (the upper side in the figures of this specification). The second recess 42 extends from the end of the second intermediate transverse groove 12 on the inner side of the tire axial direction toward the other side of the tire circumferential direction (the lower side in the figures of this specification).

[0070] exist Figure 6 The diagram shows a cross-section of the first recess 41 and the second recess 42. Figure 2 A CC-line sectional view. For example... Figure 6 As shown, the first recess 41 and the second recess 42 each open at the contact surface of the intermediate land portion 7 and at the side of the tire axial direction. Thus, the first recess 41 and the second recess 42 include: an inner wall surface 40a extending parallel to the tire radial direction, and a bottom surface 40b extending parallel to the contact surface of the intermediate land portion 7. The tire axial length L11 of the first recess 41 and the second recess 42 at the contact surface of the intermediate land portion 7 is, for example, 5% to 15% of the width W2 of the contact surface 15s of the intermediate tread block 15.

[0071] The depth d7 of the first recess 41 and the second recess 42 is, for example, 60% to 75% of the depth d1 of the shoulder circumferential groove 5. In a more preferred embodiment, such as... Figure 4 As shown, the bottom surface of the first recess 41 and the first intermediate tie rod 16 (as shown) Figure 2 The outer surfaces of the second recess 42 (as shown) are connected to the same plane. Furthermore, the bottom surface of the second recess 42 is connected to the second intermediate tie 17 (as shown). Figure 2 The outer surfaces of the snow column (as shown) are connected by the same plane. Thus, when driving on snow, the second intermediate transverse groove 12, the first recess 41, and the second recess 42 become a single unit to form a larger snow column, which can provide greater snow column shear force.

[0072] like Figure 2 As shown, at least one first interruption groove 43 extending axially along the tire is provided in the intermediate land portion 7. The outer end of the first interruption groove 43 in the tire axial direction is connected to a first recess 41, and the inner end in the tire axial direction is interrupted within the contact surface of the intermediate land portion 7. Preferably, the first interruption groove 43 is connected to the circumferential end of the first recess 41. Such a first interruption groove 43 can reduce pump noise, maintain noise performance, and improve snow performance.

[0073] The axial length L12 of the first tread groove 43 is, for example, 25% to 35% of the width W2 of the intermediate tread block 15. Such a first tread groove 43 can improve snow performance and noise performance in a balanced way.

[0074] At least one second interruption groove 44 extending along the tire axial direction is provided in the intermediate land portion 7. The inner end of the second interruption groove 44 in the tire axial direction is connected to the second recess 42, and the outer end in the tire axial direction is interrupted in the contact surface of the intermediate land portion 7.

[0075] The tire axial length of the second groove 44 can be the same as the length L12 of the first groove 43.

[0076] The bottom surface of the first interruption groove 43 is connected to the bottom surface of the first recess 41 by the same plane. The bottom surface of the second interruption groove 44 is connected to the bottom surface of the second recess 42 by the same plane. Such a first interruption groove 43 and a second interruption groove 44 can suppress local deformation of the intermediate pattern block 15, which helps to improve handling stability.

[0077] exist Figure 7 The middle shows Figure 1 An enlarged view of the land portion 8 of the tire crown. (See image below.) Figure 7 As shown, the crown land portion 8 includes a plurality of crown tread blocks 55 divided by a plurality of crown lateral grooves 50 that run completely across the crown land portion 8 along the tire axial direction.

[0078] Multiple tread grooves 50 are oriented relative to the tire axial direction toward the central tread groove 10 ( Figure 2 (As shown) tilted in the opposite direction. As a result, the pumping sound generated by the intermediate transverse groove 10 and the crown transverse groove 50 is easily turned into white noise, thereby improving noise performance.

[0079] The lateral grooves 50 include, for example, a first lateral groove 51 and a second lateral groove 52, which have different shapes when viewed from above. In this embodiment, the first lateral groove 51 and the second lateral groove 52 are alternately arranged in the tire circumferential direction.

[0080] The first lateral groove 51 extends along the tire axial direction with a constant groove width, for example. The first lateral groove 51 includes a steeply inclined portion 51a disposed at the center of the tire axial direction, and gently inclined portions 51b connected to both sides of the steeply inclined portion 51a. The angle of the steeply inclined portion 51a relative to the tire axial direction is, for example, 40 to 60°. The gently inclined portion 51b is inclined in the same direction as the steeply inclined portion 51a relative to the tire axial direction. The gently inclined portion 51b is disposed at a smaller angle relative to the tire axial direction than the steeply inclined portion 51a. The angle of the gently inclined portion 51b relative to the tire axial direction is, for example, 20 to 30°. The length of one gently inclined portion 51b in the tire axial direction is 40% to 50% of the total length of the lateral groove 50. Furthermore, the aforementioned angles and lengths are measured along the centerline of the groove. With such steeply inclined portions 51a and gently inclined portions 51b, air movement is difficult within the groove of the lateral groove 50, thus reducing pump noise.

[0081] The second lateral crown groove 52 includes, for example, a central portion 52a along the tire axial direction and a wide portion 52b connected to the central portion 52a. The wide portion 52b has, for example, a groove width larger than that of the central portion 52a. The groove width of the wide portion 52b is, for example, 150% to 250% of the groove width of the central portion 52a. In this embodiment, a chamfered portion 53 is formed in the wide portion 52b, thereby creating a larger groove width in the wide portion 52b. Such a second lateral crown groove 52 can evenly improve snow performance and handling stability.

[0082] exist Figure 8 The middle shows Figure 7 A DD-line sectional view. For example... Figure 8 As shown, the lateral groove 50 includes a first lateral groove 61 raised at the bottom of the groove at the end on the first tread end T1 side, and a second lateral groove 62 raised at the bottom of the groove at the end on the second tread end T2 side. Such a first lateral groove 61 and a second lateral groove 62 help improve handling stability.

[0083] The tire axial length L13 of the first tread band 61 and the tire axial length L14 of the second tread band 62 are respectively the tire axial width W5 of the contact surface 55s of the tread block 55. Figure 7 (as shown) 25% to 35%. In a more preferred embodiment, the length L13 of the first crown brace 61 is preferably greater than the length L5 of the first intermediate brace 16. Figure 3 (As shown). Similarly, preferably, the length L14 of the second crown brace 62 is greater than the length L6 of the second intermediate brace 17. Figure 3 (As shown). This rationalizes the rigidity balance of the crown land portion 8 and the intermediate land portion 7, further improving handling stability. Furthermore, in this embodiment, the first crown transverse groove 51 and the second crown transverse groove 52 each include a first crown brace 61 and a second crown brace 62.

[0084] like Figure 7 As shown, the plurality of tread pattern blocks 55 include: a contact surface 55s, a first longitudinal edge 55a extending along the tire circumference at the first tread end T1 side of the contact surface 55s, and a second longitudinal edge 55b extending along the tire circumference at the second tread end T2 side of the contact surface 55s.

[0085] exist Figure 9 The image shows an enlarged view of the tread pattern block 55 and the tread groove 50. Additionally, in... Figure 9 In this context, points are formed in the first crown reinforcement 61 and the second crown reinforcement 62. For example... Figure 9As shown, at least one first tread groove 63 and at least one second tread groove 64 are provided on the contact surface 55s of at least one tread block 55. The first tread groove 63 extends from the longitudinal edge 55a of the first tread and includes an interrupted end 63a within the contact surface 55s. The second tread groove 64 extends from the longitudinal edge 55b of the second tread and includes an interrupted end 64a within the contact surface 55s. Such first tread grooves 63 and second tread grooves 64 can maintain the rigidity of the tread block 55 and improve snow performance.

[0086] The interrupted end 64a of the second crown sipe 64 is located closer to the longitudinal edge 55a of the first crown than the interrupted end 63a of the first crown sipe 63. In a further preferred embodiment, when viewed from above, the interrupted end 63a of the first crown sipe 63 is positioned to overlap with the area where the second crown brace 62 is extended parallel to the tire circumferential direction. Similarly, when viewed from above, the interrupted end 64a of the second crown sipe 64 is positioned to overlap with the area where the first crown brace 61 is extended parallel to the tire circumferential direction. This suppresses uneven wear on the crown land portion 8.

[0087] exist Figure 10 The middle shows Figure 7 A sectional view along the EE line. Furthermore, it is believed that on the inner wall of the first crown sipe 63 of the actual object, the folded-back portion of the serrations of the sipe appears as an ridge line, but... Figure 10 The middle part is omitted. For example... Figure 10 As shown, the first crown groove 63 includes: a first portion 66 communicating with the circumferential groove 6 of the crown, a second portion 67 including an interrupted end 63a, and a third portion 68 between the first portion 66 and the second portion 67. The first portion 66 has a shallower depth than the third portion 68. The depth d8 of the first portion 66 is 50% to 70% of the depth d10 of the third portion 68. Furthermore, the second portion 67 has a shallower depth than the first portion 66. The depth d9 of the second portion 67 is 20% to 35% of the depth d10 of the third portion 68. The third portion 68 constitutes the maximum depth of the first crown groove 63. This first crown groove 63 helps to improve snow performance and handling stability in a balanced way. Additionally, the second crown groove 64 has the same cross-sectional shape as the first crown groove 63. Therefore, the structure of the first crown groove 63 described above can be applied to the second crown groove 64.

[0088] like Figure 7As shown, a longitudinal tread groove 70 extending circumferentially between the first tread groove 63 and the second tread groove 64 is provided on the tread tread block 55. In this embodiment, the longitudinal tread groove 70 is connected to both the first tread groove 63 and the second tread groove 64. However, the longitudinal tread groove 70 may not be connected to the aforementioned grooves. The longitudinal tread groove 70, for example, has a depth smaller than that of the first tread groove 63 and the second tread groove 64. The maximum depth of the longitudinal tread groove 70 is 20% to 35% of the maximum depth of the first tread groove 63. In a preferred embodiment, the longitudinal tread groove 70 is configured with the same depth as the second portion 67 of the first tread groove 63. Such a longitudinal tread groove 70 can suppress uneven wear of the tread tread block 55 and improve cornering performance on snow and ice.

[0089] The tread pattern block 55 includes a first tread pattern block 56 and a second tread pattern block 57 with different configurations of tread longitudinal grooves 70. A tread longitudinal groove 70 is provided on the first tread pattern block 56 at a position axially aligned with the center of the tire surface relative to the first tread pattern block 56, near the first tread longitudinal edge 55a. A tread longitudinal groove 70 is provided on the second tread pattern block 57 at a position axially aligned with the center of the tire surface relative to the second tread pattern block 57, near the second tread longitudinal edge 55b. In a preferred embodiment, the first tread pattern block 56 and the second tread pattern block 57 are alternately arranged in the tire circumferential direction. This suppresses localized deformation and provides excellent handling stability.

[0090] exist Figure 11 The middle shows Figure 1 An enlarged view of the tire shoulder land area 9. (See image below.) Figure 11 As shown, the shoulder land portion 9 includes multiple shoulder tread blocks 76 divided by multiple shoulder lateral grooves 75 that run completely across the shoulder land portion 9 along the tire axial direction.

[0091] The tire shoulder tread block 76 is provided with a plurality of shoulder grooves 77 extending in a serrated manner. In a more preferred embodiment, the two ends of the shoulder grooves 77 are interrupted within the tire shoulder tread block 76. Such shoulder grooves 77 help to improve snow performance and handling stability in a balanced manner.

[0092] The tire of one embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment described above, but can be implemented in various ways.

[0093] [Example]

[0094] Based on the specifications in Table 1, a prototype with... Figure 1 The basic pattern size is for a 265 / 70R17 tire. Additionally, as a comparative example, such as... Figure 12As shown, a tire with a first groove b and a second groove c forming the first intermediate lateral groove a with a constant groove width was prototyped. The comparative example tire, apart from the above, is actually similar to... Figure 1 The tires shown are the same.

[0095] In addition, the tire used as a benchmark for comparing noise performance (the benchmark tire), such as Figure 13 As shown, a tire was prototyped in which the first intermediate transverse groove d is inclined in a certain direction and extends with a constant groove width.

[0096] The snow performance and noise performance of each test tire were tested. The common specifications and test methods for each test tire are as follows.

[0097] Wheel rim installation: 17×8J

[0098] Tire internal pressure: 410 kPa

[0099] Test vehicle: 4000cc engine, four-wheel drive vehicle

[0100] Tire mounting location: All wheels

[0101] <Snow Performance>

[0102] The driving performance of the test vehicles on snow was evaluated based on the driver's senses. The results were scored with the snow performance of the comparative example set at 100; the higher the score, the better the snow performance.

[0103] <Noise Performance>

[0104] The maximum sound pressure level of the exterior noise was measured when the test vehicle was traveling at 70 km / h on a dry road surface. The result was that the difference in sound pressure level with the reference tire, i.e., the reduction in sound pressure level, was expressed by an exponent with the reduction in sound pressure level of the comparative example set to 100. The larger the exponent, the lower the maximum sound pressure level of the noise, and the better the noise performance.

[0105] [Table 1]

[0106]

[0107] The test results confirm that the tires in this embodiment maintain snow performance and improve handling stability on dry roads.

Claims

1. A tire having a tread pattern, characterized in that, The tread portion includes: a plurality of circumferential grooves extending continuously along the tire circumference between the first tread end and the second tread end, and a plurality of land portions divided by the plurality of circumferential grooves. The plurality of land portions include: an intermediate land portion disposed between the first tread end and the tire equator, and a crown land portion adjacent to the intermediate land portion via the circumferential groove on the inner side of the tire axial direction. The intermediate land portion is provided with at least one first intermediate transverse groove and at least one second intermediate transverse groove that completely traverse the intermediate land portion along the tire axis. The land portion of the tire crown has multiple tread grooves that completely traverse the land portion of the tire crown along the tire axial direction. The first intermediate transverse groove includes: a first groove portion inclined relative to the tire axis from a first end on the outer side of the tire axis; a second groove portion inclined relative to the tire axis from a second end on the inner side of the tire axis in the same direction as the first groove portion; and a third groove portion located between the first groove portion and the second groove portion and inclined relative to the tire axis in the opposite direction to the first groove portion. The width of the first groove increases from the third groove side toward the outer axial direction of the tire. The width of the second groove increases from the third groove side toward the axial inward side of the tire. The second intermediate transverse groove is inclined in the same direction as the first groove relative to the tire axis. The lateral grooves of the tire crown are inclined in the opposite direction to the first groove relative to the tire axis. The intermediate land portion is provided with: a first recess that connects to the outer end of the second intermediate transverse groove on the tire axial direction, and a second recess that connects to the inner end of the second intermediate transverse groove on the tire axial direction. The first recess and the second recess open at the contact surface of the intermediate land portion and at the side of the tire axial direction, respectively. The depth of the first recess and the second recess is 60% to 75% of the depth of the shoulder circumferential groove.

2. The tire according to claim 1, characterized in that, The maximum width of the first intermediate transverse groove is 120% to 200% of the width of the third groove.

3. The tire according to claim 1 or 2, characterized in that, The first intermediate transverse groove includes: a first intermediate tie rod raised at the bottom of the groove on the first end side, and a second intermediate tie rod raised at the bottom of the groove on the second end side.

4. The tire according to claim 1, characterized in that, The first recess extends from the end of the second intermediate transverse groove on the outer side of the tire axial direction to one side of the tire circumferential direction. The second recess extends from the end of the second intermediate transverse groove on the inner side of the tire axial direction to the other side of the tire circumferential direction.

5. The tire according to claim 1 or 4, characterized in that, At least one first interruption groove extending along the tire axis is provided in the intermediate land portion. The outer end of the first interrupted groove in the tire axial direction is connected to the first recess, and the inner end of the tire axial direction is interrupted within the contact surface of the intermediate land portion.

6. The tire according to claim 1 or 4, characterized in that, At least one second interruption groove extending along the tire axis is provided in the intermediate land portion. The inner end of the second interrupted groove on the tire axial direction is connected to the second recess, and the outer end of the tire axial direction is interrupted within the contact surface of the intermediate land portion.

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