CN108437703B - tire - Google Patents
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- CN108437703B CN108437703B CN201810148854.2A CN201810148854A CN108437703B CN 108437703 B CN108437703 B CN 108437703B CN 201810148854 A CN201810148854 A CN 201810148854A CN 108437703 B CN108437703 B CN 108437703B
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- crown
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- shoulder
- block
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/032—Patterns comprising isolated recesses
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0339—Grooves
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
本发明提供一种可发挥出优异的湿地性能及耐不均匀磨损性能的轮胎。具有胎面部(2)的轮胎。胎面部(2)包括在轮胎周向上连续延伸的一对胎冠主槽(3)、和一对胎冠主槽(3)之间所划分出的胎冠陆地部(10)。胎冠陆地部(10)通过将一对胎冠主槽(3)之间连接的多个胎冠横槽(14)所划分出的多个胎冠花纹块(15)。胎冠花纹块(15)中的至少一个设置有呈波状延伸且将所述胎冠横槽(14)间连接的胎冠刀槽花纹(30)。
The present invention provides a tire that can exhibit excellent wet performance and uneven wear resistance. A tire with a tread portion (2). The tread portion (2) includes a pair of crown main grooves (3) extending continuously in the tire circumferential direction, and a crown land portion (10) defined between the pair of crown main grooves (3). The crown land portion (10) is a plurality of crown blocks (15) divided by a plurality of crown transverse grooves (14) connecting a pair of crown main grooves (3). At least one of the crown blocks (15) is provided with a crown sipe (30) extending in a wave shape and connecting the crown transverse grooves (14).
Description
Technical Field
The present invention relates to a tire capable of exhibiting excellent wet performance and uneven wear resistance.
Background
Various tires having a tread portion provided with a plurality of crown blocks have been proposed (for example, see patent document 1 below). Generally, there is a greater tendency for ground-contact pressure to act on the crown blocks. Therefore, the crown block tends to be worn early and unevenly. On the other hand, in order to improve such defects, there is a tendency to lower the wet performance in the case of enlarging the crown block.
The inventors found, as a result of various experiments, that the wet performance and the uneven wear resistance can be improved in a balanced manner by improving sipes provided on crown blocks.
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 2015-089796
Disclosure of Invention
Problems to be solved by the invention
The present invention has been made in view of the above problems, and a main object thereof is to provide a tire that can exhibit excellent wet performance and uneven wear resistance.
Means for solving the problems
The present invention is a tire having a tread portion including a pair of crown main grooves extending continuously in a tire circumferential direction and a crown land portion partitioned between the pair of crown main grooves, the crown land portion including a plurality of crown blocks partitioned by a plurality of crown lateral grooves connecting between the pair of crown main grooves, at least one of the crown blocks being provided with a crown sipe extending in a wavy manner and connecting between the crown lateral grooves.
In the tire according to the present invention, it is preferable that the tread portion is assigned a rotation direction, and each of the crown blocks has a V-shape in which the crown block is oriented to project toward a land side in the rotation direction.
In the tire according to the present invention, it is preferable that the crown block has a first block wall facing the crown lateral groove on a first land side in the rotation direction and a second block wall facing the crown lateral groove on a second land side in the rotation direction, and the first block wall has a first inclined portion inclined with respect to the tire axial direction, a second inclined portion inclined in a direction opposite to the first inclined portion with respect to the tire axial direction, and a recessed portion disposed between the first inclined portion and the second inclined portion and recessed toward the second land side.
In the tire of the present invention, it is preferable that the depressed portion has a V shape opposite to the crown block.
In the tire of the present invention, preferably, the crown sipes are connected to the dimples.
In the tire according to the present invention, preferably, the tread portion includes shoulder main grooves continuously extending in the tire circumferential direction on the tire axial direction outer sides of the crown main grooves, and the crown main grooves and the shoulder main grooves each extend in a zigzag shape.
In the tire of the present invention, it is preferable that the shoulder main groove includes a first portion having a larger groove width than a maximum groove width of the crown main groove, and a second portion having a smaller groove width than a maximum groove width of the crown main groove.
In the tire of the present invention, it is preferable that the maximum angle of the shoulder main groove with respect to the tire circumferential direction is larger than the maximum angle of the crown main groove with respect to the tire circumferential direction.
In the tire according to the present invention, it is preferable that the tread portion includes a center land portion defined between the crown main groove and the shoulder main groove and a shoulder land portion defined on the outer side of the shoulder main groove in the tire axial direction, the center land portion includes a plurality of center blocks defined by a plurality of center lateral grooves connecting between the crown main groove and the shoulder main groove, the shoulder land portion includes a plurality of shoulder blocks defined by a plurality of shoulder lateral grooves extending outward in the tire axial direction from the shoulder main groove, and the center blocks have hexagonal treads.
In the tire of the present invention, preferably, the crown block includes two crown block pieces partitioned by the crown sipes, an area Sm of a tread surface of the middle block is smaller than an area Sc of a tread surface of one of the crown block pieces, and a sum of the area Sm and the area Sc is 1.5 to 2.5 times an area Ss of a tread surface of the shoulder block.
In the tire of the present invention, preferably, the intermediate lateral groove has a larger groove width than the crown lateral groove, and the shoulder lateral groove has a larger groove width than the intermediate lateral groove.
Effects of the invention
The tread portion of the tire of the present invention includes a pair of crown main grooves extending continuously in the tire circumferential direction, and a crown land portion defined between the pair of crown main grooves. The crown land portion includes a plurality of crown blocks divided by a plurality of crown transverse grooves connecting between the pair of crown main grooves. At least one of the crown pattern blocks is provided with a crown sipe which extends in a wavy manner and connects the crown transverse grooves.
The tread sipes improve the frictional force on the wet road surface by the edges thereof, thereby exhibiting excellent wet performance. The crown sipes of the present invention extend in a wavy manner and connect the crown transverse grooves to each other, and therefore not only can secure the edge portions in the tire circumferential direction but also can secure the edge portions in the tire axial direction. Therefore, the turning performance and the traction performance during wet traveling can be improved.
Further, the crown sipes are essentially closed when the crown blocks are in contact with the ground. Thus, one block piece and the other block piece divided by the crown sipe can be supported by each other. Therefore, the rigidity of the appearance of the crown block can be improved, and even the uneven wear resistance can be maintained. In particular, the crown sipe of the present invention extends in a wave shape, and therefore the sipe walls are firmly engaged with each other, so that it is possible to exert an excellent supporting effect with respect to the force in the tire circumferential direction. Therefore, deformation of the crown block during driving and braking can be suppressed, and uneven wear resistance can be effectively maintained.
Drawings
Fig. 1 is a development view of a tread portion of a tire according to an embodiment of the present invention.
Fig. 2 is an enlarged view of the crown land portion of fig. 1.
FIG. 3 is an enlarged view of the crown block of FIG. 2.
Fig. 4 (a) is a cross-sectional view taken along line a-a of fig. 2, and fig. 4 (b) is an enlarged view of the crown sipe.
Fig. 5 is an enlarged view of the middle land portion of fig. 1.
Fig. 6 is a sectional view taken along line B-B of fig. 5.
Fig. 7 is an enlarged view of the shoulder land portion of fig. 1.
FIG. 8 (a) is a sectional view taken along line C-C of FIG. 7, and FIG. 8 (b) is a sectional view taken along line D-D of FIG. 7
Fig. 9 is a developed view of a tread portion of a tire of a comparative example.
Detailed Description
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Fig. 1 is a developed view showing a tread portion 2 of a tire 1 according to an embodiment of the present invention. The tire 1 of the present embodiment can be used for various tires such as a pneumatic tire for passenger cars and heavy loads, and a non-pneumatic tire in which the inside of the tire is not filled with pressurized air. The tire 1 of the present embodiment is preferably used as a heavy load pneumatic tire, for example.
As shown in fig. 1, a tire 1 of the present invention has a tread portion 2 in which a rotation direction R is specified. The rotation direction R is indicated by characters or symbols on the side wall (not shown), for example.
The tread portion 2 is provided with a crown main groove 3 and a shoulder main groove 4 which extend continuously in the tire circumferential direction. One crown main groove 3 is provided on each side of the tire equator C. A shoulder main groove 4 is provided between one crown main groove 3 and the tread end Te and between the other crown main groove 3 and the tread end Te, respectively.
In the case of a pneumatic tire, the tread end Te is the following position: when the rim is assembled to a regular rim (not shown), filled with a regular internal pressure, and a regular tire 1 in an unloaded state is loaded with a regular load, and is in a flat ground contact position at a camber angle of 0 °, the tire is in the most axially outward ground contact position.
The "regular Rim" is a Rim defined for each tire in a specification system including a specification based on the tire, and is, for example, "standard Rim" in case of JATMA, "Design Rim" in case of TRA, and "Measuring Rim" in case of ETRTO.
The "normal internal PRESSURE" is an air PRESSURE specified for each TIRE in a specification system including a specification based on the TIRE, and is "maximum air PRESSURE" in JATMA, a maximum value described in a table "TIRE LOAD conditions AT TIREs PRESSURE maintenance systems" in TRA, and "INFLATION PRESSURE" in ETRTO.
The "normal LOAD" is a LOAD specified for each TIRE in the internal specification system including the specification based on the TIRE, and is "maximum LOAD CAPACITY" in JATMA, a maximum value described in the table "TIRE LOAD limit AT variation color establishment tests" in TRA, and "LOAD CAPACITY" in ETRTO.
The crown main grooves 3 preferably extend, for example, in a zigzag shape. The inclination angle θ 1 of the saw-tooth of the crown main groove 3 is preferably 3 to 7 °, for example, with respect to the maximum inclination in the tire circumferential direction.
The crown main groove 3 is preferably, for example, such that the distance L1 in the tire axial direction from the tire equator C to the groove center line is 0.15 to 0.25 times the tread width TW. The tread width TW is a distance in the tire axial direction from one tread end Te to the other tread end in the normal state.
The crown main groove 3 preferably has a groove width W1 of 3 to 5% of the tread width TW, for example.
The shoulder main grooves 4 extend, for example, in a zigzag shape. The inclination angle θ 2 of the zigzag of the shoulder main groove 4 with respect to the tire circumferential direction is preferably larger than the angle θ 1 of the crown main groove 3, for example. Specifically, the angle θ 2 is preferably, for example, 8 to 12 °. Such a shoulder main groove 4 can exhibit excellent drainage.
In the shoulder main groove 4 of the present embodiment, for example, the amplitude of the groove edge 4b on the tread end Te side is larger than the amplitude of the groove edge 4a on the tire equator C side. Such shoulder main grooves 4 are advantageous in that the groove edges 4a, 4b are uniformly worn.
The shoulder main groove 4 is preferably, for example, such that a distance L2 in the tire axial direction from the tire equator C to the groove center line is 0.30 to 0.40 times the tread width TW.
The shoulder main groove 4 has a groove width W2 of 3 to 6% of the tread width TW, for example. Preferably, the shoulder main grooves 4 include a first portion 4A of a larger groove width than the maximum groove width of the crown main groove 3 and a second portion 4B of a smaller groove width than the maximum groove width of the crown main groove 3. Such shoulder main grooves 4 can generate pumping noise of a different frequency from the crown main grooves 3. Therefore, the noise generated by the crown main groove 3 and the shoulder main groove 4 can be whitened.
In the case of a heavy load pneumatic tire, the crown main groove 3 and the shoulder main groove 4 preferably have a groove depth of 20 to 25mm, for example. Such crown main grooves 3 and shoulder main grooves 4 can exhibit excellent wet performance.
The tread portion 2 is provided with the above-described crown main groove 3 and shoulder main groove 4, whereby a crown land portion 10, a pair of intermediate land portions 11, and a pair of shoulder land portions 12 can be defined.
An enlarged view of the crown land portion 10 is illustrated in fig. 2. As shown in fig. 2, the crown land portion 10 is divided between a pair of crown main grooves 3. The crown land portion 10 is divided into a plurality of rows of crown blocks 15 by a plurality of crown transverse grooves 14.
An enlarged view of crown block 15 is illustrated in fig. 3. As shown in fig. 3, at least one of the crown blocks 15 is provided with a crown sipe 30 extending in a wave shape and connecting the crown transverse grooves 14. Thus, the crown block 15 comprises two crown block pieces 20 divided by the crown sipes 30. In the present specification, the term "sipe" refers to an indentation having a width of 2.0mm or less.
The crown sipes 30 can improve the frictional force on a wet road surface by the edges thereof, thereby exhibiting excellent wet performance. The crown sipes 30 of the present invention extend in a wavy manner and connect the crown transverse grooves 14 to each other, and therefore not only can secure the edge portions in the tire circumferential direction but also can secure the edge portions in the tire axial direction. Therefore, the turning performance and the traction performance during wet traveling can be improved.
Moreover, the crown sipe 30 is essentially closed when the crown block 15 is in contact with the ground. Thus, one crown block piece 20 and the other crown block piece 20 divided by the crown sipes 30 can support each other. Therefore, the rigidity of the appearance of the crown block 15 can be improved, and even the uneven wear resistance can be maintained. In particular, the crown sipe 30 of the present invention extends in a wave shape, and therefore the sipe walls are firmly engaged with each other, so that an excellent supporting effect with respect to the force in the tire circumferential direction can be exerted. Therefore, deformation of the crown block 15 during driving and braking can be suppressed, and uneven wear resistance can be effectively maintained.
The crown sipes 30 are preferably provided at positions where the area ratio of the tread surfaces of the two crown block pieces 20 becomes 0.8 to 1.2, for example. The crown sipe 30 of the present embodiment is provided, for example, in the center portion of the crown block 15 in the tire axial direction. Preferably, the crown sipes 30 divide the crown blocks 15 into two crown block pieces 20 having treads of substantially the same area. Thus, the two crown block pieces 20 are liable to wear equally, and even improve uneven wear resistance.
The width W5 of the crown sipe 30 may be 2.0mm or less, but is preferably 1.8mm or less, more preferably 1.6mm or less, and is preferably 0.5mm or more, more preferably 0.8mm or more, and still more preferably 1.2mm or more. Such a crown sipe 30 can improve the wet performance and the uneven wear resistance in a balanced manner.
A cross-sectional view of the crown sipe 30 of fig. 2 taken along line a-a is illustrated in fig. 4 (a). As shown in fig. 4 (a), the crown sipe 30 preferably has a depth d2 that is 0.85 to 1.00 times the depth d1 of the crown main groove 3, for example. Such a crown sipe 30 is advantageous in exhibiting excellent wet performance.
An enlarged view of the crown sipe 30 of fig. 3 is illustrated in fig. 4 (b). As shown in fig. 4 (b), the crown sipe 30 extends in the tire circumferential direction while making an amplitude in the tire axial direction. Preferably, the crown sipes 30 extend, for example, in a sinusoidal manner. However, the crown sipes 30 are not limited to this form, and include, for example, forms extending in various wave shapes such as triangular wave, rectangular wave, and trapezoidal wave.
The crown sipes 30 preferably extend, for example, with a smaller amplitude than the crown main grooves 3 extending in a zigzag shape. The peak-to-peak amplitude a1 of the centerline 30c of the crown sipe 30 is preferably 1.0mm or more, more preferably 1.3mm or more, and preferably 2.0mm or less, more preferably 1.7mm or less. Such a crown sipe 30 can suppress uneven wear of the edge thereof and can secure the edge portion in the tire axial direction.
The crown sipes 30 preferably extend, for example, at a smaller wavelength than the crown main grooves 3 (shown in fig. 1) extending in a zigzag shape. The wavelength λ 1 of the crown sipe 30 is preferably, for example, 16.0mm or more, more preferably 20.0mm or more, and preferably 30.0mm or less, more preferably 26.0mm or less. Such a crown sipe 30 can suppress uneven wear of the edges thereof, and can strongly engage sipe walls opposing each other with each other, and can even improve the rigidity of the appearance of the crown block 15.
As shown in fig. 2, the crown transverse groove 14 connects the pair of crown main grooves 3. The crown lateral groove 14 of the present embodiment is, for example, V-shaped in a projecting direction toward the first land side in the rotation direction R. The "crown lateral groove is V-shaped" includes, for example, not only a mode in which the groove center line is bent in a V-shape, but also a mode in which the groove center line is smoothly curved in a convex direction toward the ground-contacting side (for example, an arc shape).
The crown transverse groove 14 of the present embodiment includes, for example, a first groove portion 16 and a second groove portion 17 extending in opposite directions with respect to the tire axial direction. The first groove portion 16 and the second groove portion 17 communicate with each other through a connecting portion 18. The first groove portion 16 and the second groove portion 17 are preferably inclined at an angle θ 3 of 10 to 20 ° with respect to the tire axial direction, for example.
The connecting portion 18 is provided, for example, at the center portion (for example, on the tire equator C) in the tire axial direction of the crown transverse groove 14. As another aspect of the present invention, the connecting portion 18 may be provided at a position offset to one side in the tire axial direction with respect to the tire equator C.
The crown transverse groove 14 preferably has a groove width W6 of 0.8 to 1.2 times the crown main groove 3, for example. At least the first groove portion 16 and the second groove portion 17 in the crown transverse groove 14 of the present embodiment have a constant groove width in the longitudinal direction thereof.
The crown block 15 of the present embodiment has, for example, a lateral length shape in which the maximum lateral width W3 in the tire axial direction is larger than the maximum longitudinal width W4 in the tire circumferential direction. The maximum banner width W3 is preferably 1.3 to 1.7 times the maximum vertical width W4. Such a crown block 15 has high lateral rigidity, thereby contributing to excellent steering stability.
The crown block 15 is preferably, for example, V-shaped in a projecting direction toward the ground contacting side in the rotation direction R. "crown block 15 is V-shaped" means, for example, that the profile of the two first block walls 21 and second block walls 22 of crown block 15 facing crown transverse groove 14 includes a convex shape toward the ground-contacting side. The first block wall 21 is a block wall facing the crown transverse groove 14 on the ground-contacting side, and the second block wall 22 is a block wall facing the crown transverse groove 14 on the ground-contacting side in the rotation direction R. The first block wall 21 and the second block wall 22 are not limited to the shape of a flat bend, and may be, for example, a smoothly curved shape (for example, curved in an arc shape).
As shown in fig. 3, the first block wall 21 of the present embodiment includes, for example, a first inclined portion 23 and a second inclined portion 24 inclined in opposite directions with respect to the tire axial direction, and a recessed portion 25 therebetween. The angle θ 4 between the first inclined portion 23 and the second inclined portion 24 is preferably, for example, 150 to 160 °. The first inclined portion 23 and the second inclined portion 24 of the present embodiment extend in a planar shape, for example, but are not limited to this embodiment.
The recessed portion 25 is recessed toward the rear landing side in the rotation direction R, for example. The depressed portion 25 is advantageous for suppressing the chipping and wear of the end portion on the land-first side in the rotation direction R of the crown block 15. Preferably, the recesses 25 are connected to the crown sipes 30. Thereby, uneven wear of the end portion on the ground-contacting side of the crown sipe 30 can be suppressed.
Preferably, the concave portion 25 has a V shape opposite to the crown block 15. The recess 25 is formed of, for example, two planes inclined in opposite directions to each other. The angle θ 9 between the two planes is, for example, 125 to 135 °. Such recessed portion 25 can further suppress chipping and uneven wear of the top portion of the land-first side of the crown block 15.
The second block wall 22 has, for example, a third inclined portion 26 and a fourth inclined portion 27 inclined in opposite directions to each other with respect to the tire axial direction. The third inclined portion 26 and the fourth inclined portion 27 in the present embodiment extend in a planar shape, for example, but are not limited to such an embodiment. The third inclined portion 26 is inclined, for example, in the same direction as the first inclined portion 23 of the first block wall 21, and preferably extends along the first inclined portion 23. The fourth inclined portion 27 is inclined, for example, in the same direction as the second inclined portion 24 of the first block wall 21, and preferably extends along the second inclined portion 24.
Preferably, the crown sipe 30 is preferably connected to the crown portion 28 formed by the third inclined portion 26 and the fourth inclined portion 27 of the second block wall 22. This can suppress uneven wear of the end portion on the rear land side in the rotation direction R of the crown sipe 30.
The crown block 15 preferably has, for example, a pair of block lateral walls 29 projecting outward in the axial direction of the tire. Such crown blocks 15 have a high lateral rigidity, contributing to further improvement in the steering stability.
An enlarged view of the mid-land portion 11 is illustrated in fig. 5. As shown in fig. 5, the intermediate land portion 11 is divided between the crown main groove 3 and the shoulder main groove 4. The intermediate land portion 11 includes a plurality of intermediate blocks 35 defined by a plurality of intermediate lateral grooves 34.
The intermediate lateral groove 34 is preferably inclined at an angle θ 5 of 10 to 20 ° with respect to the tire axial direction, for example. The intermediate lateral groove 34 of the present embodiment is inclined toward the rear landing side in the rotation direction R from the crown main groove 3 toward the shoulder main groove 4. Such intermediate lateral grooves 34 can guide water in the wet running groove to the outside in the tire axial direction.
The intermediate lateral groove 34 extends linearly, for example. The intermediate transverse grooves 34 have, for example, a larger groove width W7 as compared to the crown transverse grooves 14 (shown in fig. 2). In order to improve wet performance, the groove width W7 of the intermediate transverse groove 34 is preferably 1.15 to 1.25 times the groove width W6 of the crown transverse groove 14, for example.
A cross-sectional view of the intermediate transverse slot 34 along line B-B is illustrated in fig. 6. As shown in fig. 6, the intermediate lateral groove 34 includes a first groove wall 34a on the first landing side and a second groove wall 34b on the rear landing side in the rotation direction R. The first groove wall 34a is disposed at an angle θ 6 of 3 to 7 degrees with respect to the tire radial direction, for example. The second groove wall 34b is arranged at a larger angle θ 7 than the angle θ 6 with respect to the tire radial direction, for example. The angle θ 7 is preferably 9 to 13 °, for example. Such intermediate lateral grooves 34 are advantageous in suppressing the serration (inelandtoe) wear of the intermediate blocks 35.
The intermediate transverse grooves 34 preferably have a groove depth d3 of, for example, 0.90 to 1.00 times the crown main groove 3. The groove depth d3 of the intermediate transverse groove 34 in this embodiment is the same as the crown main groove 3. Such intermediate horizontal grooves 34 can further improve the wet performance.
As shown in fig. 5, the intermediate block 35 preferably has a substantially hexagonal tread surface, for example. The "substantially hexagonal tread surface" refers to, for example, the chamfered portion 36 that allows the corners of the block to be slightly lacking.
The tread surface area Sm of the middle block 35 is preferably smaller than the tread surface area Sc of one crown block piece 20. Specifically, the area Sm is preferably 0.80 to 0.90 times the area Sc. Such intermediate blocks 35 can be uniformly worn together with the crown block pieces 20, and thus can exhibit excellent uneven wear resistance.
An enlarged view of the shoulder land portion 12 is illustrated in fig. 7. As shown in fig. 7, the shoulder land portion 12 is divided on the outer side in the tire axial direction of the shoulder main groove 4. The shoulder land portion 12 includes, for example, a plurality of shoulder blocks 40 defined by a plurality of shoulder lateral grooves 39.
The shoulder lateral groove 39 is preferably, for example, such that the groove width W8 increases toward the tire axial direction outer side. Such shoulder transverse grooves 39 can smoothly guide the water in the grooves to the outside in the tire axial direction during wet running.
In order to further enhance the above-described effects, the shoulder lateral grooves 39 preferably have a larger groove width than the intermediate lateral grooves 34, for example. More specifically, the shoulder lateral groove 39 has a larger groove width across its entire area as compared with the intermediate lateral groove 34.
Fig. 8 (a) shows a cross-sectional view of the shoulder transverse groove 39 taken along line C-C. Fig. 8 (b) shows a cross-sectional view of the shoulder cross groove 39 taken along line D-D. The D-D line cross section is a cross section closer to the tread end Te side than the C-C line cross section. As shown in fig. 8 (a) and (b), the shoulder lateral groove 39 preferably has a pair of groove walls 39a inclined at an angle θ 8 of 10 to 25 ° with respect to the tire radial direction, for example.
More preferably, the angle θ 8 of the groove wall 39a of the shoulder lateral groove 39 with respect to the tire radial direction increases toward the tire axial direction outer side. Such shoulder transverse grooves 39 can exhibit excellent drainage properties, and can further improve the wet performance.
The shoulder lateral groove 39 preferably has a groove depth d4 of 0.20 to 0.30 times the shoulder main groove 4, for example. Such shoulder transverse grooves 39 can improve the rigidity of the shoulder land portion 12 while maintaining the wet performance, and can improve the steering stability.
As shown in fig. 7, the shoulder block 40 includes, for example, an inner side wall 41 curved to project inward in the tire axial direction, and a flat outer side wall 42 along the tire circumferential direction. Accordingly, the shoulder blocks 40 preferably have substantially pentagonal tread surfaces, for example. The "substantially pentagonal tread" refers to, for example, a chamfered portion 43 that allows a slight lack of the block corner, or a recessed portion 44 provided in the side wall.
Preferably, the outer sidewall 42 is provided with a recess 44 recessed inward in the tire axial direction. Such an outer sidewall 42 is advantageous in exerting excellent offset resistance.
The tread surface area Ss of the shoulder block 40 is preferably larger than the tread surface area Sm of the middle block 35 (shown in fig. 5), for example. Specifically, the area Ss is preferably 1.05 to 1.15 times the area Sm. This can suppress the slippage of the shoulder block 40 during running of the tire.
As shown in fig. 1, the sum Sm + Sc of the area Sm of the tread surface of the middle block 35 and the area Sc of the tread surface of the crown block piece 20 is preferably 1.5 times or more, more preferably 1.8 times or more, and preferably 2.5 times or less, more preferably 2.2 times or less, of the area Ss of the tread surface of the shoulder block 40. Such blocks can appropriately apply a ground contact pressure acting on the crown block 15 during running of the tire, and can suppress sliding of the shoulder blocks, and can even exert excellent uneven wear resistance.
While the tire according to the embodiment of the present invention has been described in detail, the present invention is not limited to the specific embodiment described above, and can be implemented in various forms.
[ examples ] A method for producing a compound
A heavy duty pneumatic tire having the dimension 11R22.5 of the basic pattern of fig. 1 was tried out. As a comparative example, a tire not provided with a crown sipe as shown in fig. 9 was produced in a trial. Each of the tires was tested for wet performance, uneven wear resistance, and heel-and-toe (heel-and-toe) wear. The common mode and test method for each test tire are as follows.
Assembling a rim: 8.25X 22.5
Tire internal pressure: 720kPa
< wetland Performance >
The passage time of the test vehicle when it passed through the test route having a total length of 10m was measured under the following conditions. The results are expressed by an index in which the passage time of the comparative example is set to 100. The smaller the value, the better.
Testing the vehicle: 10t truck (2-D vehicle)
And (3) loading state: the front part of the objective table is in a semi-loading state
Testing tire assembly position: all-wheel
Road surface: asphalt with water film having thickness of 5mm
The starting method comprises the following steps: the clutch is connected to start in a fixed manner at 2-1500 rpm.
< uneven wear resistance >
After the crown block of one tire of the rear wheel in the test vehicle was run until 50% worn, the ratio Wc/Ws of the amount of wear Wc of the crown block to the amount of wear Ws of the shoulder block was measured. The result is represented by an index with the ratio Wc/Ws being 1 set as 100. The closer the index is to 100, the more uniformly the crown and shoulder blocks are worn, and the more excellent uneven wear resistance is exhibited.
< heel and toe wear >
The amount of heel and toe wear of the crown block was measured after the crown block of one of the rear wheels in the test vehicle was driven until 10% wear. The results show that as an index for setting the comparative example to 100, a smaller value is better.
The results of the test are shown in table 1.
[ TABLE 1 ]
[ TABLE 2 ]
[ TABLE 3 ]
As a result of the test, it was confirmed that the tires of examples exhibited excellent wet performance and uneven wear resistance.
Description of the symbols
2 tread portion
3 crown main groove
10 crown land portion
14 crown transverse groove
15 crown pattern block
30 crown sipes.
Claims (9)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017027251A JP6838421B2 (en) | 2017-02-16 | 2017-02-16 | tire |
| JP2017-027251 | 2017-02-16 |
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| Publication Number | Publication Date |
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| CN108437703A CN108437703A (en) | 2018-08-24 |
| CN108437703B true CN108437703B (en) | 2021-11-02 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201810148854.2A Active CN108437703B (en) | 2017-02-16 | 2018-02-13 | tire |
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| JP (1) | JP6838421B2 (en) |
| CN (1) | CN108437703B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| JP7225824B2 (en) * | 2019-01-22 | 2023-02-21 | 住友ゴム工業株式会社 | tire |
| JP7346960B2 (en) * | 2019-07-16 | 2023-09-20 | 住友ゴム工業株式会社 | tire |
| JP6901025B1 (en) * | 2020-05-01 | 2021-07-14 | 住友ゴム工業株式会社 | tire |
| JP7516849B2 (en) * | 2020-05-14 | 2024-07-17 | 住友ゴム工業株式会社 | tire |
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| CN101878120A (en) * | 2007-11-28 | 2010-11-03 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN101992660A (en) * | 2009-08-21 | 2011-03-30 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN102555679A (en) * | 2010-11-05 | 2012-07-11 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN102689568A (en) * | 2011-03-25 | 2012-09-26 | 住友橡胶工业株式会社 | Heavy duty pneumatic tire |
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| JP3113343B2 (en) * | 1991-10-23 | 2000-11-27 | 住友ゴム工業株式会社 | Pneumatic tire |
| JP4559179B2 (en) * | 2004-10-06 | 2010-10-06 | 株式会社ブリヂストン | Pneumatic tire |
| FR2894183B1 (en) * | 2005-12-06 | 2008-02-15 | Michelin Soc Tech | TIRE TREAD FOR PNEUMATIC HEAVY WEIGHT |
| JP4510906B2 (en) * | 2008-05-08 | 2010-07-28 | 住友ゴム工業株式会社 | Pneumatic tire |
| JP4996670B2 (en) * | 2009-11-10 | 2012-08-08 | 住友ゴム工業株式会社 | Pneumatic tire |
| FR2978377B1 (en) * | 2011-07-28 | 2014-12-26 | Michelin Soc Tech | SCULPTURE FOR CIVIL ENGINE VEHICLE TIRES |
| JP5480869B2 (en) * | 2011-10-26 | 2014-04-23 | 住友ゴム工業株式会社 | Heavy duty pneumatic tire |
| JP5841568B2 (en) * | 2013-07-12 | 2016-01-13 | 住友ゴム工業株式会社 | Pneumatic tire |
| JP5852627B2 (en) * | 2013-11-07 | 2016-02-03 | 住友ゴム工業株式会社 | Heavy duty tire |
| FI125377B (en) * | 2014-01-17 | 2015-09-15 | Nokian Renkaat Oyj | Vehicle tire |
| FR3017075B1 (en) * | 2014-02-03 | 2016-02-12 | Michelin & Cie | TIRE TREAD TIRE FOR HEAVY WEIGHT |
| JP6114724B2 (en) * | 2014-08-26 | 2017-04-12 | 住友ゴム工業株式会社 | Heavy duty pneumatic tire |
| JP6417226B2 (en) * | 2015-01-26 | 2018-10-31 | 住友ゴム工業株式会社 | Pneumatic tire |
| CN205168067U (en) * | 2015-11-26 | 2016-04-20 | 厦门正新橡胶工业有限公司 | Modified bicycle tire tread arabesquitic |
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| JP2008149768A (en) * | 2006-12-14 | 2008-07-03 | Bridgestone Corp | Pneumatic tire |
| CN101878120A (en) * | 2007-11-28 | 2010-11-03 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN101992660A (en) * | 2009-08-21 | 2011-03-30 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN102555679A (en) * | 2010-11-05 | 2012-07-11 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN102689568A (en) * | 2011-03-25 | 2012-09-26 | 住友橡胶工业株式会社 | Heavy duty pneumatic tire |
| CN103608192A (en) * | 2011-06-24 | 2014-02-26 | 株式会社普利司通 | Motorcycle pneumatic tire |
| JP2014218106A (en) * | 2013-05-02 | 2014-11-20 | 株式会社ブリヂストン | Tire |
| CN105383225A (en) * | 2014-08-26 | 2016-03-09 | 住友橡胶工业株式会社 | heavy duty pneumatic tire |
| CN105751824A (en) * | 2015-01-07 | 2016-07-13 | 住友橡胶工业株式会社 | Pneumatic tire |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6838421B2 (en) | 2021-03-03 |
| CN108437703A (en) | 2018-08-24 |
| JP2018131111A (en) | 2018-08-23 |
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