CN113043797B - Tire with a tire body - Google Patents
Tire with a tire body Download PDFInfo
- Publication number
- CN113043797B CN113043797B CN202011493690.0A CN202011493690A CN113043797B CN 113043797 B CN113043797 B CN 113043797B CN 202011493690 A CN202011493690 A CN 202011493690A CN 113043797 B CN113043797 B CN 113043797B
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- China
- Prior art keywords
- sipe
- tire
- circumferential groove
- groove
- crown
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Classifications
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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
- B60C11/13—Tread patterns characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping
- B60C11/1307—Tread patterns characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping with special features of the groove walls
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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
-
- 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
- B60C2011/0341—Circumferential grooves
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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
- B60C11/13—Tread patterns characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping
- B60C11/1307—Tread patterns characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping with special features of the groove walls
- B60C2011/133—Tread patterns characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping with special features of the groove walls comprising recesses
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
- Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction
Abstract
In a tire having a circumferential groove with a recess provided in the groove wall, noise performance is improved. A tire has a tread portion (2). At least 1 circumferential groove (8) extending continuously in the tire circumferential direction and 2 land portions (9) adjacent to Zhou Xianggou (8) are provided in the tread portion (2). The circumferential groove (8) comprises at least one recess (10) provided in at least one of the two groove walls. The concave part (10) is recessed to the outside in the groove width direction compared with the groove edge of the circumferential groove which appears on the tread surface of the tread part (2). A sipe (11) communicating with the recess (10) is provided on the tread surface of the land part (9). A sipe edge part (11 e) of the sipe (11) is formed by a chamfer part (12).
Description
Technical Field
The present invention relates to tires.
Background
Patent document 1 proposes a tire in which a tread portion is provided with a main groove extending continuously in a tire circumferential direction. The groove wall of the main groove is provided with a concave portion recessed in the groove width direction of the main groove. The concave portion ensures an opening area of the main groove at a tread surface of the tread portion even if the tread portion is worn. Thus, excellent wet performance is exhibited for a long period of time.
Patent document 1: japanese patent laid-open publication 2016-196218
However, recent tires are required to have improved noise performance. Therefore, a tire having a circumferential groove with a recess provided in the groove wall, such as the tire of patent document 1, is also required to further improve noise performance.
Disclosure of Invention
The present invention has been made in view of the above-described problems, and an object of the present invention is to improve noise performance in a tire having a circumferential groove in which a recess is provided in a groove wall.
The present invention provides a tire having a tread portion, wherein at least 1 circumferential groove extending continuously in a tire circumferential direction and 2 land portions adjacent to the circumferential groove are provided in the tread portion, the circumferential groove includes at least one concave portion provided in at least one groove wall of both groove walls, the concave portion is recessed outward in a groove width direction than a groove edge of the circumferential groove in which a tread surface of the tread portion appears, a sipe communicating with the concave portion is provided in a tread surface of the land portion, and a sipe edge portion of the sipe is formed by a chamfer portion.
In the tire of the present invention, it is preferable that the length of the sipe in the tire axial direction is larger than the maximum depth of the concave portion from the groove edge.
In the tire of the present invention, it is preferable that the circumferential groove includes the concave portions provided on one groove wall and the concave portions provided on the other groove wall alternately in the groove length direction.
In the tire of the present invention, it is preferable that the maximum chamfer depth of the chamfer portion is 20% to 50% of the maximum height in the tire radial direction of the concave portion.
In the tire of the present invention, it is preferable that the circumferential groove includes an outer crown circumferential groove adjacent to the tire equator, the outer crown circumferential groove includes a 1 st groove wall on the tread end side and a 2 nd groove wall on the tire equator side, the concave portion includes a plurality of 1 st concave portions provided on the 1 st groove wall and a plurality of 2 nd concave portions provided on the 2 nd groove wall, the land portion to which the 1 st groove wall belongs is provided with the sipe communicating with the 1 st concave portion, and the land portion to which the 2 nd groove wall belongs is not provided with the sipe.
In the tire of the present invention, it is preferable that the 1 st concave portion communicates with the sipe at a position different from a maximum depth position of the 1 st concave portion.
In the tire of the present invention, it is preferable that the sipe in communication with the 1 st concave portion is a full open type entirely intersecting the land portion.
In the tire according to the present invention, it is preferable that the circumferential groove includes an inner crown circumferential groove adjacent to the tire equator, the inner crown circumferential groove includes a plurality of concave portions provided on both side groove walls, and the concave portions of the inner crown circumferential groove communicate with the sipes.
In the tire of the present invention, it is preferable that the sipe communicating with the concave portion of the inner crown circumferential groove is a half-open type in which an end portion on the opposite side to the concave portion is interrupted in the land portion.
In the tire according to the present invention, it is preferable that the land portion includes a crown land portion adjacent to a tire equator side of the inner crown circumferential groove, and an inner intermediate land portion adjacent to the crown land portion with the inner crown circumferential groove interposed therebetween, a plurality of crown sipes communicating with the inner crown circumferential groove are provided in the crown land portion, a plurality of 1 st inner intermediate sipes communicating with the inner crown circumferential groove are provided in the inner intermediate land portion, and the crown sipes and the 1 st inner crown sipes are inclined in opposite directions with respect to each other in the tire axial direction.
In the tire of the present invention, it is preferable that the length of the crown sipe in the tire axial direction is longer than the length of the 1 st inner intermediate sipe in the tire axial direction.
In the tire of the present invention, it is preferable that the circumferential groove includes an inner shoulder circumferential groove adjacent to one tread end, the inner shoulder circumferential groove includes a plurality of concave portions provided on both side groove walls, and the concave portions of the inner shoulder circumferential groove communicate with non-chamfer sipes having no chamfer portion.
In the tire according to the present invention, it is preferable that the land portion includes an inner intermediate land portion adjacent to a tire equator side of the inner shoulder circumferential groove, and an inner shoulder land portion adjacent to the inner intermediate land portion across the inner shoulder circumferential groove, a plurality of 2 nd inner intermediate sipes communicating with the inner shoulder circumferential groove are provided in the inner intermediate land portion, a plurality of inner shoulder sipes communicating with the inner shoulder circumferential groove are provided in the inner shoulder land portion, and the number of the inner shoulder sipes provided in the inner shoulder land portion as a whole is greater than the number of the 2 nd inner intermediate sipes provided in the inner intermediate land portion as a whole.
In the tire of the present invention, it is preferable that the inner shoulder sipe is fully open so as to completely intersect the inner shoulder land portion.
The circumferential groove of the tire of the present invention includes at least one concave portion provided in at least one of the both side groove walls. The concave portion is recessed outward in the groove width direction than a groove edge of the circumferential groove which appears on the tread surface of the tread portion. Even in a state where the tread portion is worn, the concave portion can secure the capacity of the circumferential groove, thereby improving the wet performance.
In the tire of the present invention, the tread surface of the land portion is provided with a sipe in communication with the concave portion. Such a sipe reduces the compression of air in the circumferential groove when the circumferential groove is grounded, and can reduce noise in the circumferential groove. In the sipe according to the present invention, since the sipe edge portion is formed by the chamfer portion, the striking noise when the sipe edge portion is grounded can be reduced. By these actions, the tire of the present invention can exert excellent noise performance.
Drawings
Fig. 1 is an expanded view showing a tread portion according to an embodiment of the present invention.
Fig. 2 is an enlarged view of the outboard crown circumferential groove, crown land portion, and outboard intermediate land portion of fig. 1.
Fig. 3 is a cross-sectional view taken along line A-A of fig. 2.
Fig. 4 is a sectional view taken along line B-B of fig. 2.
Fig. 5 is a cross-sectional view taken along line C-C of fig. 2.
Fig. 6 is an enlarged view of the outboard middle pocket of fig. 2.
Fig. 7 is a sectional view taken along line D-D of fig. 6.
Fig. 8 is a sectional view taken along line E-E of fig. 6.
FIG. 9 is an enlarged view of the inboard crown circumferential groove, the inboard shoulder circumferential groove, the crown land portion, the inboard mid land portion, and the inboard shoulder land portion of FIG. 1.
Fig. 10 is an enlarged view of the crown sipe of fig. 9.
Fig. 11 is a cross-sectional view taken along line F-F of fig. 10.
Fig. 12 is a sectional view taken along line G-G of fig. 10.
Fig. 13 is an enlarged view of the 1 st inner intermediate pocket of fig. 9.
Fig. 14 is a sectional view taken along line H-H of fig. 13.
Fig. 15 is a sectional view taken along line I-I of fig. 13.
Fig. 16 is a sectional view taken along line J-J of fig. 9.
Fig. 17 is a sectional view taken along line K-K of fig. 9.
Fig. 18 is a sectional view taken along line L-L of fig. 9.
Fig. 19 is a cross-sectional view taken along line M-M of fig. 1.
Fig. 20 is a cross-sectional view taken along line N-N of fig. 1.
Description of the reference numerals
2 … tread portions; 8 … circumferential grooves; 9 … land portion; 10 … recess; 11 … knife slot; 11e … pocket edge portions; 12 … chamfer.
Detailed Description
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the following embodiments and specific configurations shown in the drawings are for understanding the content of the present invention, and the present invention is not limited to the specific configurations shown in the drawings.
In the present embodiment, a pneumatic tire for a car, preferably a pneumatic radial tire, is shown as the tire 1.
As shown in fig. 1, the tire 1 of the present embodiment is preferably oriented for mounting to a vehicle. Thereby, the tread portion 2 is defined as an inner tread end Ti and an outer tread end To. The inner tread end Ti is intended to be located on the vehicle inner side when mounted to the vehicle. The outer tread end To is intended To be located outside the vehicle when mounted To the vehicle. The direction of attachment to the vehicle is shown, for example, in a sidewall portion (not shown) of the tire 1.
In the present specification, the inner tread end Ti and the outer tread end To are defined as the inner and outer contact positions of the tread portion 2 at the outermost sides in the tire axial direction in the normal load loaded state of the tire 1.
In the present specification, the term "normal load loading state" means a state in which the tire 1 in a normal internal pressure state assembled on a normal rim (not shown) and filled with a normal internal pressure is loaded with a normal load and grounded on a plane in a state in which the camber angle is 0 °. Unless otherwise specified, the dimensions of each portion of the tire 1 are determined in the normal internal pressure state.
In the present specification, the term "regular Rim" refers to a Rim that defines a standard for each tire in a standard system including a standard according to which the tire is based, and is, for example, "standard Rim" in the case of JATMA, "Design Rim" in the case of TRA, and "Measuring Rim" in the case of ETRTO.
In the present specification, the "normal internal pressure" refers to the air pressure of each specification defined for each tire in the specification system including the specification according to which the tire is based, and is "highest air pressure" in the case of JATMA, the maximum value described in table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in the case of TRA, and "INFLATION PRESSURE" in the case of ETRTO.
In the present specification, the term "normal LOAD" refers to a LOAD of each specification defined for each tire in a specification system including specifications according to which the tire is based, and is "maximum LOAD CAPACITY" in the case of JATMA, the maximum value described in table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in the case of TRA, and "LOAD CAPACITY" in the case of ETRTO.
As shown in fig. 1, at least 1 circumferential groove 8 extending continuously in the tire circumferential direction and at least 2 land portions 9 adjacent to the circumferential groove 8 are provided in the tread portion 2 of the tire 1. The tread portion 2 of the present embodiment includes a plurality of circumferential grooves 8 and a plurality of land portions 9 partitioned by the circumferential grooves 8.
Each circumferential groove 8 has a sufficiently large groove width such that a pair of groove walls do not contact each other in the ground plane in the normal load state. Thus, the circumferential groove 8 has a groove width of, for example, 2.5mm or more, preferably 3.0mm or more, and more preferably 3.5mm or more. Similarly, the maximum depth of the circumferential groove is, for example, 5.0mm or more, preferably 6.0mm or more. Such circumferential grooves provide the basic drainage properties of the tire 1.
In the present embodiment, the circumferential groove 8 is composed of 4 pieces of inner crown circumferential groove 3A, inner shoulder circumferential groove 4A, outer crown circumferential groove 3B, and outer shoulder circumferential groove 4B. These circumferential grooves 8 extend linearly along the tire circumferential direction, for example. Specifically, the circumferential groove 8 has a pair of groove edges extending straight along the tire circumferential direction in the ground contact surface of the tread portion 2. In other embodiments, the circumferential groove 8 may extend in a wavy or zigzag shape.
The inner crown circumferential groove 3A is disposed between the tire equator C and the inner tread end Ti. The inner shoulder circumferential groove 4A is disposed between the inner crown circumferential groove 3A and the inner tread end Ti. The outer crown circumferential groove 3B is disposed between the tire equator C and the outer tread end To. The outer shoulder circumferential groove 4B is disposed between the outer crown circumferential groove 3B and the outer tread end To.
The tread portion 2 of the present embodiment is formed with 5 land portions 9 partitioned by the circumferential grooves 8 described above. The land portion 9 is constituted by a crown land portion 5, an inner intermediate land portion 6A, an inner shoulder land portion 7A, an outer intermediate land portion 6B, and an outer shoulder land portion 7B. The width of each land portion 9 in the tire axial direction is preferably 10% or more of the tread ground contact width TW, for example. Further, the tread ground contact width TW is a distance in the tire axial direction between the inner tread end Ti and the outer tread end To in the normal internal pressure state.
The crown land portion 5 is formed between the inner crown circumferential groove 3A and the outer crown circumferential groove 3B. The inner intermediate land portion 6A is formed between the inner crown circumferential groove 3A and the inner shoulder circumferential groove 4A so as to be adjacent to the inner tread end Ti side of the crown land portion 5 via the inner crown circumferential groove 3A. The inner shoulder land portion 7A is adjacent to the inner tread end Ti side of the inner intermediate land portion 6A across the inner shoulder circumferential groove 4A, and is formed between the inner shoulder circumferential groove 4A and the inner tread end Ti.
The outer intermediate land portion 6B is adjacent To the outer tread end To side of the crown land portion 5 across the outer crown circumferential groove 3B, and is formed between the outer crown circumferential groove 3B and the outer shoulder circumferential groove 4B. The outer shoulder land portion 7B is adjacent To the outer tread end To side of the outer intermediate land portion 6B across the outer shoulder circumferential groove 4B, and is formed between the outer shoulder circumferential groove 4B and the outer tread end To.
As a drawing explaining an embodiment of the circumferential groove 8, fig. 2 shows an enlarged view of the outer crown circumferential groove 3B, the crown land portion 5, and the outer intermediate land portion 6B. Figure 3 shows a cross-sectional view along line A-A of figure 2. Fig. 4 shows a cross-sectional view along line B-B of fig. 2. As shown in fig. 2 to 4, the circumferential groove 8 includes at least one recess 10 provided in at least one of the groove walls. The concave portion 10 is recessed outward in the groove width direction than the edge of the circumferential groove 8 which appears on the tread surface of the tread portion 2. Even if the tread portion 2 wears, the concave portion 10 ensures an opening area of the circumferential groove 8 at the tread surface of the tread portion 2. Thus, excellent wet performance is exhibited for a long period of time.
As shown in fig. 2, in the present invention, a sipe 11 communicating with a recess 10 is provided in the tread surface of a land portion 9. Such a sipe 11 can reduce noise in the circumferential groove 8 by relaxing compression of air in the circumferential groove 8 when the circumferential groove 8 is grounded.
Fig. 5 shows a cross-sectional view along line C-C of fig. 2. As shown in fig. 5, the sipe edge portion 11e of the sipe 11 of the present invention is formed by a chamfer portion 12. This can prevent a large ground pressure from locally acting on the sipe edge portion 11e, and therefore can reduce striking noise when the sipe edge portion 11e is grounded. In addition, in the case of a sipe having no chamfer portion, the corner portion formed by the sipe wall and the land portion vibrates when the land portion is stepped on (when the tread surface including the sipe is separated from the land portion), and this tends to cause high-frequency noise. In the present invention, the chamfer 12 prevents the vibration, thereby suppressing high-frequency noise. From these effects, the tire 1 of the present invention can exert excellent noise performance.
The structure of the present embodiment will be described in more detail below. As shown in fig. 2, the circumferential groove 8 of the present embodiment includes concave portions 10 provided on one groove wall and concave portions 10 provided on the other groove wall alternately in the groove length direction. Hereinafter, the groove wall on the outer tread end To side of the groove walls of the circumferential groove 8 may be referred To as the 1 st groove wall, and the groove wall on the inner tread end Ti side may be referred To as the 2 nd groove wall. In addition, the recess 10 provided in the 1 st groove wall may be referred to as a 1 st recess 16, and the recess provided in the 2 nd groove wall may be referred to as a 2 nd recess 17.
The amount of the recess 10 recessed from the rim gradually decreases from the maximum depth position of the most recessed outward in the groove width direction toward both sides in the tire circumferential direction. Thus, a contour 10d (indicated by a broken line in fig. 2) showing the bottom surface of the recess 10 in the groove width direction is formed on the circular arc.
The length L1 of the recess 10 in the tire circumferential direction is, for example, 1.0 to 3.0 times the width W1 of the land portion 9 in the tire axial direction in which the recess 10 is provided. Further, the 1 st concave portion 16 and the 2 nd concave portion 17 overlap in the tire circumferential direction. The overlapping length L2 of the 1 st concave portion 16 and the 2 nd concave portion 17 in the tire circumferential direction is 20% to 40% of the length L1 of the concave portion 10. The arrangement of the concave portions 10 improves the wet performance when the tread portion 2 is worn.
As shown in fig. 3 and 4, the maximum depth d1 of the concave portion 10 from the groove edge is 10% to 30% of the groove width W2 of the circumferential groove 8 in which the concave portion 10 is provided. The maximum height h1 of the recess 10 in the tire radial direction is, for example, 60% to 80% of the depth d2 of the circumferential groove 8. Such a recess 10 improves the wet performance and the steering stability in a balanced manner.
As shown in fig. 5, a main body 13 is connected to the chamfer 12 at the inner side in the tire radial direction in the sipe 11. In the present specification, the "sipe" means a small-width incision such that at least a part of the pair of sipe walls 13W of the main body 13 are in contact with each other in the ground plane in the normal load state, and for example, the width W3 of the main body 13 is 1.5mm or less, preferably 1.0mm or less.
The chamfer 12 is formed by an inclined surface obtained by cutting the corner formed by the groove wall 13w of the main body 13 and the tread of the land 9 in an inclined manner. In other embodiments, the chamfer 12 may be formed as an arc-shaped arc or a rectangular recess (both not shown). In addition to the above-described effects, the chamfer portion 12 contributes to an improvement in impact-absorbing ability of the land portion, thereby improving riding comfort. The structure of the chamfer 12 described here can be applied to a chamfer of each pocket described later.
The angle of the inclined surface of the chamfer 12 with respect to the normal line of the tire is, for example, 30 to 60 °. Such a chamfer 12 also contributes to improvement of noise performance and riding comfort. The tire normal line is an imaginary line extending parallel to the tire radial direction.
From the viewpoint of improving the noise performance and the steering stability in a balanced manner, the maximum chamfer depth d3 of the chamfer portion 12 is, for example, 20 to 50%, preferably 30 to 40% of the maximum height h1 of the recessed portion in the tire radial direction.
As shown in fig. 2, the length of the sipe 11 in the tire axial direction is at least greater than the maximum depth of the recess 10 from the groove edge. This ensures the above-described effects.
The outer crown circumferential groove 3B of the present embodiment includes a 1 st groove wall 3B1 on the outer tread end To side and a 2 nd groove wall 3B2 on the tire equator C side. An outer intermediate sipe 21 is provided in the outer intermediate land portion 6B to which the 1 st groove wall 3B1 of the outer crown circumferential groove 3B belongs as the sipe 11 communicating with the 1 st concave portion 16. In addition, no sipe communicating with the 2 nd concave portion 17 is provided in the crown land portion 5 to which the 2 nd groove wall 3B2 of the outer crown circumferential groove 3B belongs. Thus, the striking sound at the time of the edge grounding belonging to the 1 st groove wall 3B1 and the striking sound at the time of the edge grounding belonging to the 2 nd groove wall 3B2 are liable to be whitened, and the noise performance is improved.
The 1 st concave portion 16 of the outer crown circumferential groove 3B preferably communicates with the outer intermediate sipe 21 at a position different from the maximum depth position of the 1 st concave portion 16, for example. In the present embodiment, the 1 st concave portion 16 of the outer crown circumferential groove 3B communicates with 2 outer intermediate sipes 21 in the above-described embodiment. More specifically, the 2 outer intermediate sipes 21 are disposed at the maximum depth position of the 1 st concave portion 16. Thereby, the noise performance is further improved.
The outer intermediate sipe 21 is, for example, a fully open type that completely crosses the outer intermediate land portion 6B. The outer intermediate sipe 21 contributes to suppressing noise at the time of grounding and appropriately promoting deformation of the outer intermediate land portion 6B to further improve riding comfort.
In the present embodiment, the outer intermediate sipe 21 is inclined with respect to the tire axial direction, for example. In a preferred embodiment, the outer intermediate sipe 21 extends in a single circular arc or straight line from its inner end 21i in the tire axial direction to its outer end 21o in the tire axial direction. According to this configuration, the outer intermediate sipe 21 can be gradually grounded to the road surface, and thus noise during running can be further reduced. Further, the rigidity of the outer intermediate land portion 6B gradually changes in the tire circumferential direction, so the riding comfort improves.
The angle of the outer intermediate sipe 21 with respect to the tire axial direction is, for example, in the range of 5 to 40 °, and more preferably in the range of 5 to 30 °. This improves the riding comfort and the wear resistance in a balanced manner.
Fig. 6 shows an enlarged view of the outer intermediate sipe 21 of fig. 2. Fig. 7 shows a sectional view of fig. 6 taken along line D-D. Fig. 8 shows a sectional view along line E-E of fig. 6. As shown in fig. 6 to 8, the chamfer portions 21a are formed at the sipe edge portions on both sides of the outer intermediate sipe 21. More specifically, the outer intermediate sipe 21 is constituted by a main body portion 21b and a chamfer portion 21a constituting the sipe.
The chamfer portion 21a has a chamfer width 21W1. As shown in fig. 6 and 7, the chamfer width 21W1 is measured from the groove wall of the main body 21b to the groove edge 21e thereof in a direction perpendicular to the longitudinal direction of the main body 21 b.
In the present embodiment, the chamfer width 21W1 at both ends of the outer intermediate sipe 21 is configured to be larger than the chamfer width 21W1 of the longitudinal center portion 21c of the outer intermediate sipe 21. Here, the central portion 21c means a portion of the central 10% of the length of the outer intermediate sipe 21. This improves wear resistance and noise performance in a balanced manner. In addition, with the above configuration, the rigidity of the central portion of the outer intermediate land portion 6B can be improved, and further the steering stability can be improved.
The chamfer width 21W1 of the chamfer portion 21a increases from the central portion 21c toward the inner end 21i and the outer end 21o, respectively. As a preferred embodiment, the chamfer width 21W1 continuously increases. As a further preferred embodiment, as shown in fig. 6, the chamfer width 21W1 preferably increases continuously so that the sipe edge portion 21e describes an arc (preferably a single arc) protruding toward the main body portion 21b side. With this structure, the abrasion resistance of the outer intermediate land portion 6B is further improved.
On the other hand, if the chamfer width 21W1 becomes too large, the wear resistance may be deteriorated. From such a viewpoint, the chamfer width 21W1 is, for example, in the range of 0.8 to 3.0mm, more preferably in the range of 1.0 to 2.5 mm. In the chamfer width 21W1 of each chamfer portion 21a, the maximum value is preferably 1.5 times or more, more preferably 2.0 to 3.0 times the minimum value.
As shown in fig. 8, the chamfer portion 21a has a chamfer depth 21D1. The chamfer depth 21D1 is the length in the tire radial direction from the ground contact surface of the outer intermediate land portion 6B to the inner edge 21f in the tire radial direction of the chamfer portion 21 a. When the chamfer depth 21D1 is increased, the effect of improving riding comfort is improved, but there is a tendency that noise during running is increased. In the present embodiment, as shown in fig. 8, the chamfer depth 21D1 at the inner end 21i and the outer end 21o of the outer intermediate sipe 21 is configured to be larger than the chamfer depth 21D1 of the central portion 21c of the outer intermediate sipe 21.
According to the above configuration, the increase in the ground contact pressure at the both side edge portions of the outer intermediate land portion 6B can be suppressed, so that the impact noise is reduced, and the riding comfort is further improved. In contrast, the center portion 21c of the outer intermediate sipe 21 having a small chamfer depth 21D1 maintains the rigidity of the outer intermediate land portion 6B high, thereby suppressing deterioration of the wear resistance of the outer intermediate land portion 6B. This effect becomes more significant in combination with the above-described preferred structure of the chamfer width 21W 1.
In the present embodiment, the chamfer depth 21D1 of the chamfer portion 21a increases from the center portion 21c toward the inner end 21i and the outer end 21o, respectively. As a preferred embodiment, the chamfer depth 21D1 continuously increases. As a further preferred embodiment, the chamfer depth 21D1 is preferably continuously increased in such a manner that the inner side edge 21f bulges toward the tire radial direction outer side. With this structure, riding comfort is improved, and wear resistance of the outer intermediate land portion 6B is further improved.
On the other hand, if the chamfer depth 21D1 becomes too large, there is a concern that the wear resistance is deteriorated. From such a viewpoint, the chamfer depth 21D1 is, for example, in the range of 0.8 to 3.0mm, more preferably in the range of 1.0 to 2.5 mm. The maximum value is preferably 1.5 times or more, more preferably 2.0 to 3.0 times the minimum value, in the chamfer depth 21D1 of each chamfer portion 21 a.
As shown in fig. 7, in order to satisfy riding comfort and quietness in a high dimension, the opening width 21W2 of the outer intermediate sipe 21 at the ground plane including the chamfer portion 21a is preferably in the range of 2.4 to 6.0mm, for example, and more preferably in the range of 3.0 to 5.0 mm.
As shown in fig. 8, the depth 21D2 of the outer intermediate sipe 21 increases toward the outer crown circumferential groove 3B. Since the outer intermediate land portion 6B is likely to act with a larger ground contact pressure on the tire equator C side, the riding comfort is further improved by increasing the depth at the inner end 21i of the outer intermediate sipe 21. On the other hand, by reducing the depth at the outer end 21o of the outer intermediate sipe 21, the resistance against a large lateral force at the time of turning is improved, and the wear resistance is improved. In the present embodiment, the depth of the outer intermediate sipe 21 is changed stepwise including a step, but may be changed continuously, as a preferable embodiment.
In a particularly preferred embodiment, in the outer intermediate sipe 21, the depth at the inner end 21i is 65% to 85% of the maximum depth of the outer crown circumferential groove 3B, and the depth at the outer end 21o is 45% to 65% of the maximum depth of the outer crown circumferential groove 3B. This improves the riding comfort and the wear resistance in a more balanced manner.
As shown in fig. 2, the outer intermediate land portion 6B of the present embodiment is not provided with grooves and sipes other than the outer intermediate sipe 21 described above. This improves the rigidity of the outer intermediate land portion 6B, and thus exhibits excellent steering stability.
Fig. 9 shows an enlarged view of the inner crown circumferential groove 3A, the inner shoulder circumferential groove 4A, the crown land portion 5, the inner intermediate land portion 6A, and the inner shoulder land portion 7A. As shown in fig. 9, the inner crown circumferential groove 3A includes 1 st concave portions 23 of 1 st groove wall 3A1 provided on the outer tread end To side and 2 nd concave portions 24 of 2 nd groove wall 3A2 provided on the inner tread end Ti side alternately in the groove length direction. The 1 st concave portion 23 and the 2 nd concave portion 24 of the inner crown circumferential groove 3A can be configured as the concave portion 10 described above.
The concave portions 10 of the inner crown circumferential groove 3A communicate with the sipes 11, respectively. The sipe 11 communicating with each concave portion 10 of the inner crown circumferential groove 3A is, for example, a half-open type in which an end portion on the opposite side to the concave portion 10 is interrupted in a land portion. Such a sipe 11 contributes to improvement of noise performance and steering stability.
A plurality of crown sipes 25 are provided in the crown land portion 5 and communicate with the inner crown circumferential groove 3A. The crown sipe 25 communicates with the 1 st concave portion 23 of the inner crown circumferential groove 3A. Crown sipe 25 may also include a sipe not in communication with recess 1. Sup. St 23.
Crown sipe 25 preferably communicates with a location of recess 1, 23, other than the location of maximum depth. This improves the abrasion resistance.
The crown sipe 25 extends, for example, linearly. Crown sipe 25 is inclined with respect to the tire axial direction, for example. The crown sipe 25 is inclined in the same direction as the outer intermediate sipe 21 (shown in fig. 2) with respect to the tire axial direction, and the angle of the crown sipe 25 with respect to the tire axial direction is, for example, 5 to 40 °, preferably 5 to 30 °.
The crown sipe 25 preferably crosses the tire equator C, for example. The length L3 of the crown sipe 25 in the tire axial direction is, for example, 70% to 90% of the width W4 of the crown land portion 5 in the tire axial direction.
Fig. 10 shows an enlarged plan view of crown sipe 25. Fig. 11 is a cross-sectional view taken along line F-F of fig. 10. Fig. 12 is a sectional view taken along line G-G of fig. 10. As shown in fig. 10 to 12, sipe edge portions 25e on both sides of the crown sipe 25 are formed by chamfer portions 25a, respectively. More specifically, the crown sipe 25 is constituted by a main body portion 25b and a chamfer portion 25a constituting the sipe.
The chamfer portion 25a has a chamfer width 25W1. As shown in fig. 10 and 11, the chamfer width 25W1 is measured from the groove wall of the main body 25b to the groove edge 25e thereof in a direction perpendicular to the longitudinal direction of the main body 25 b. The chamfer portion 25a has a chamfer depth 25D1, which is the length in the tire radial direction from the ground contact surface to the inner edge 25f of the chamfer portion 25 a.
In the present embodiment, as shown in fig. 10, the chamfer width 25W1 of the chamfer portion 25a increases from the closed end 25o toward the open end 25 i. In a preferred embodiment, the chamfer width 25W1 may also increase continuously. In a further preferred embodiment, the sipe edge portion 25e may be formed so as to extend linearly while being inclined with respect to the main body portion 25b, so that the chamfer width 25W1 may be continuously increased at a constant rate. This can increase the rigidity of the central portion of the crown land portion 5, and can obtain superior steering stability.
As shown in fig. 12, the chamfer depth 25D1 of the chamfer portion 25a increases from the closed end 25o toward the open end 25 i. In a preferred embodiment, the chamfer depth 25D1 may also increase continuously. In a further preferred embodiment, the chamfer depth 25D1 may also increase continuously at a constant rate in such a way that the inner edge 25f is inclined with respect to the ground plane and extends linearly. Such a structure exhibits the same operational effects as described above.
The chamfer width 25W1 and the chamfer depth 25D1 are, for example, in the range of 0.8 to 3.0mm, and more preferably in the range of 1.0 to 2.5 mm.
As shown in fig. 11, in order to satisfy riding comfort and noise performance in a high dimension, the opening width 25W2 of the crown sipe 25 at the ground contact surface 5a including the chamfer 25a is preferably in the range of 2.4 to 6.0mm, and more preferably in the range of 3.0 to 5.0mm, for example.
As shown in fig. 12, the depth 25D2 of the crown sipe 25 increases toward the inner crown circumferential groove 3A. Such a crown sipe 25 effectively improves the shock absorbing capability of the inner crown circumferential groove 3A side of the crown land portion 5 where the ground contact pressure is easily increased, thereby further improving the riding comfort. Further, since the depth of the crown sipe 25 on the closed end 25o side is relatively small, an increase in noise during running can be suppressed. In the present embodiment, the depth of the crown sipe 25 is changed stepwise including 2 or more steps as a preferable embodiment, but may be changed continuously.
If the depth 25D2 of the crown sipe 25 becomes too large, there is a concern that noise during traveling caused by the crown sipe 25 increases. From such a viewpoint, the maximum value of the depth 25D2 of the crown sipe 25 is, for example, 90% or less, more preferably in the range of 50% to 85% of the maximum depth of the inner crown circumferential groove 3A.
As shown in fig. 9, the inner intermediate land portion 6A is provided with a plurality of 1 st inner intermediate sipes 27 communicating with the inner crown circumferential groove 3A. In the present embodiment, each 1 st inner intermediate sipe 27 communicates with the 2 nd concave portion 24 of the inner crown circumferential groove 3A. Such a disposition of the sipe reliably improves noise performance.
The 1 st 2 nd concave portion 24 communicates with, for example, 2 1 st inner intermediate pockets 27. In the present embodiment, the 2 1 st inner intermediate sipes 27 communicate with each other so as to sandwich the maximum depth position of the 2 nd concave portion 24. Thereby, each 1 st inner intermediate sipe 27 communicates with a position different from the maximum depth position of the 2 nd concave portion 24.
The 1 st inner intermediate sipe 27 and the crown sipe 25 alternately communicate with the inner crown circumferential groove 3A in the tire circumferential direction. This suppresses excessive deformation of the land portion, and improves steering stability.
The 1 st inner intermediate sipe 27 extends linearly, for example. The 1 st inner intermediate sipe 27 is inclined with respect to the tire axial direction, for example. Medial 1 st intermediate sipe 27 and crown sipe 25 are preferably inclined in opposite directions relative to the tire axis. The angle of the 1 st inner intermediate sipe 27 with respect to the tire axial direction is, for example, 5 to 40 °, preferably 5 to 30 °.
The length L4 of the 1 st inner intermediate sipe 27 in the tire axial direction is, for example, 35% or more, more preferably 40% or more, and still more preferably less than 60% of the width W5 of the inner intermediate land portion 6A in the tire axial direction. In a preferred embodiment, the length L3 of the crown sipe 25 in the tire axial direction is greater than the above-mentioned length L4 of the 1 st inner intermediate sipe 27. This improves riding comfort.
Fig. 13 is an enlarged plan view of the 1 st inner intermediate pocket 27. Fig. 14 is a sectional view taken along line H-H of fig. 13. Fig. 15 is a sectional view taken along line I-I of fig. 13. As shown in fig. 13 to 15, the sipe edge portions on both sides of the 1 st inner intermediate sipe 27 are formed by chamfer portions 27a, respectively. More specifically, the 1 st inner intermediate sipe 27 is constituted by a main body portion 27b and a chamfer portion 27a constituting the sipe.
The chamfer portion 27a has a chamfer width 27W1. As shown in fig. 13 and 14, the chamfer width 27W1 is measured from the groove wall of the main body 27b to the groove edge 27e thereof in a direction perpendicular to the longitudinal direction of the main body 27 b. The chamfer portion 27a has a chamfer depth 27D1, which is the length in the tire radial direction from the ground contact surface 6a to the inner edge 27f of the chamfer portion 27 a.
In the present embodiment, as shown in fig. 13, the chamfer width 27W1 of the chamfer portion 27a increases from the closed end 27o toward the open end 27 i. The chamfer width 27W1 may also continuously increase. In a further preferred embodiment, as shown in fig. 13, the chamfer width 27W1 may be continuously increased at a constant ratio so that the sipe edge portion 27e is inclined with respect to the main body portion 27b and linearly extends. This can increase the rigidity of the central portion of the inner intermediate land portion 6A, and can achieve superior steering stability.
As shown in fig. 15, the chamfer depth 27D1 of the chamfer portion 27a increases from the closed end 27o toward the open end 27 i. Such a structure functions in the same manner as described above. In a preferred embodiment, the chamfer depth 27D1 may also increase continuously. In a further preferred embodiment, as shown in fig. 8, the chamfer depth 27D1 may also be continuously increased at a constant ratio in a manner inclined with respect to the ground plane and extending in a straight line. Such a structure exhibits the same operational effects as described above.
The chamfer width 27W1 is, for example, in the range of 0.8 to 3.0mm, more preferably in the range of 1.0 to 2.5 mm. The chamfer depth 27D1 is, for example, in the range of 0.8 to 3.0mm, more preferably in the range of 1.0 to 2.5 mm. Thus, the noise performance is improved in balance with the steering stability.
As shown in fig. 14, in order to satisfy riding comfort and quietness in a high dimension, the opening width 27W2 of the 1 st inner intermediate sipe 27 at the ground plane including the chamfer portion 27a is preferably in the range of 2.4 to 6.0mm, more preferably in the range of 3.0 to 5.0mm, for example.
As shown in fig. 15, the depth 27D2 of the 1 st inner intermediate sipe 27 increases toward the inner crown circumferential groove 3A. This improves the riding comfort and noise performance. In the present embodiment, the depth of the 1 st inner intermediate sipe 27 is shown as being constant after gradually increasing and is opened to the inner crown circumferential groove 3A as a preferable embodiment, but may be continuously changed.
If the depth 27D2 of the 1 st inner intermediate sipe 27 becomes excessively large, there is a concern that noise during traveling caused by the 1 st inner intermediate sipe 27 increases. From such a viewpoint, the maximum value of the depth 27D2 of the 1 st inner intermediate sipe 27 is, for example, 90% or less, more preferably 50% to 95% of the maximum depth of the inner crown circumferential groove 3A.
As shown in fig. 9, the inner shoulder circumferential groove 4A includes 1 st concave portions 31 of 1 st groove wall 4A1 provided on the outer tread end To side and 2 nd concave portions 32 of 2 nd groove wall 4A2 provided on the inner tread end Ti side alternately in the tire circumferential direction. The 1 st concave portion 31 and the 2 nd concave portion 32 of the inner shoulder circumferential groove 4A can be configured as the concave portion 10 described above.
The concave portions 10 of the inner shoulder circumferential grooves 4A communicate with the sipes 11, respectively. The concave portions 10 of the inner shoulder circumferential grooves 4A preferably communicate with the non-chamfer sipes 33 that do not include the chamfer portions 12. This increases the friction force at the edge of each sipe, thereby improving the wet performance.
The sipe 11 communicating with the 1 st concave portion 31 of the inner shoulder circumferential groove 4A is, for example, a half-open type in which an end portion on the opposite side from the concave portion 10 is interrupted in the land portion. The sipe 11 communicating with the 2 nd recess 32 of the inner shoulder circumferential groove 4A is, for example, a fully open type that completely crosses the land portion. Such a disposition of the sipe 11 contributes to improvement of noise performance and steering stability.
The inner intermediate land portion 6A is provided with a plurality of 2 nd inner intermediate sipes 35 communicating with the inner shoulder circumferential groove 4A. In the present embodiment, the 1 st inner intermediate sipe 27 and the 2 nd inner intermediate sipe 35 are alternately provided in the groove length direction. The arrangement of the sipes maintains the abrasion resistance of the inner intermediate land portion 6A, and improves the wet performance.
The 2 nd inner intermediate sipe 35 preferably communicates with a position different from the maximum depth position of the 1 st concave portion 31. This improves the abrasion resistance.
The 2 nd inner intermediate sipe 35 is inclined with respect to the tire axial direction, for example. The 2 nd inner intermediate sipe 35 is preferably inclined with respect to the tire axial direction in the same direction as the 1 st inner intermediate sipe 27. The angle of the 2 nd inner intermediate sipe 35 with respect to the tire axial direction is, for example, 5 to 40 °, and more preferably 5 to 30 °. In a particularly preferred embodiment, the 2 nd inner intermediate sipe 35 extends parallel to the 1 st inner intermediate sipe 27.
Fig. 16 shows a sectional view of fig. 9 taken along line J-J. As shown in fig. 16, in the present embodiment, the 2 nd inner intermediate sipe 35 is not provided with a chamfer portion, and is constituted only by a main body portion 35b constituting the sipe. In the 2 nd inner intermediate sipe 35, the sipe wall of the main body portion 35b intersects the ground plane substantially at a right angle (for example, 90 ° ± 3 °).
Fig. 17 shows a cross-sectional view of fig. 9 taken along line K-K. As shown in fig. 17, the depth 35D2 of the 2 nd inner intermediate sipe 35 increases toward the inner shoulder circumferential groove 4A. Such a 2 nd inner intermediate sipe 35 effectively improves the impact-absorbing capability on the inner shoulder circumferential groove 4A side of the inner intermediate land portion 6A where the ground contact pressure is easily increased, thereby further improving the riding comfort. Further, since the depth of the 2 nd inner intermediate sipe 35 on the closed end 35i side is relatively small, an increase in noise during traveling can be suppressed. In the present embodiment, the depth of the 2 nd inner intermediate sipe 35 is shown as being constant after gradually increasing and is opened to the inner shoulder circumferential groove 4A as a preferable embodiment, but may be continuously changed.
The depth 35D2 of the 2 nd inner intermediate sipe 35 is preferably 50% to 95% of the maximum depth of the inner crown circumferential groove 3A, for example. Thus, the noise performance is improved in balance with the steering stability.
As shown in fig. 9, the inner shoulder land portion 7A is provided with a plurality of inner shoulder sipes 38 communicating with the inner shoulder circumferential groove 4A. The inner shoulder sipes 38 are fully open, completely intersecting the inner shoulder land portion 7A. The number of inner shoulder sipes 38 provided in the inner shoulder land portion 7A is greater than the number of 2 nd inner intermediate sipes 35 provided in the inner intermediate land portion 6A. Specifically, the number of the inner shoulder sipes 38 is 2.0 to 2.5 times the number of the 2 nd inner intermediate sipes 35. This improves riding comfort and wet performance.
The inboard shoulder sipes 38 are inclined relative to the tire axial direction. The inner shoulder sipes 38 are inclined, for example, substantially entirely in a direction opposite to the 2 nd inner intermediate sipe 35 with respect to the tire axial direction. The angle of the inner shoulder sipes 38 with respect to the tire axial direction is, for example, 3 to 15 °, preferably 3 to 10 °. The inner shoulder sipe 38 is preferably inclined toward the same direction as the 2 nd inner intermediate sipe 35 at the end portion on the inner shoulder circumferential groove 4A side.
In the present embodiment, half of the inner shoulder sipes 38 are arranged to smoothly continue with the 2 nd inner intermediate sipe 35 via the inner shoulder circumferential groove 4A. Specifically, when the center line of each sipe is extended along the shape of each sipe in the inner shoulder circumferential groove 4A in the center of the inner shoulder sipe 38 and the 2 nd inner intermediate sipe 35 adjacent to each other in the tire axial direction in a plan view of the tread, both extension lines intersect each other or are separated by 2mm or less. According to this structure, the rigidity of the inner and outer land portions of the inner shoulder circumferential groove 4A is optimized, and excellent riding comfort can be obtained.
Fig. 18 shows a sectional view of fig. 9 taken along line L-L. As shown in fig. 18, each of the inner shoulder sipes 38 includes a 1 st portion 38a extending from the inner shoulder circumferential groove 4A, a 2 nd portion 38b communicating with the inner tread end Ti and having a greater depth than the 1 st portion 38a, and a 3 rd portion 38c disposed therebetween. The 3 rd portion 38c has a large change in depth per unit length as compared with the 1 st portion 38a and the 2 nd portion 38 b. In the present embodiment, the depth of the 3 rd portion 38c continuously varies. Such an inner shoulder sipe 38 does not excessively reduce the rigidity of the inner shoulder land portion 7A on the inner side in the tire axial direction, and can improve riding comfort.
In order to effectively exert the above-described function, the width 38aW in the tire axial direction of the 1 st portion 38a is preferably 10% or more, more preferably 15% or more, preferably 50% or less, and even more preferably 40% or less of the width W6 in the tire axial direction of the inner shoulder land portion 7A. From the same point of view, the depth of the 1 st portion 38a is, for example, in the range of 5% to 30%, preferably 10% to 25%, of the maximum depth of the inner shoulder circumferential groove 4A.
The depth of the 2 nd portion 38b continuously decreases toward the inner tread end Ti. Further, the 2 nd portion 38b passes beyond the inner tread end Ti toward the tire axial outside. The inner shoulder sipe 38 including the 2 nd portion 38b can ensure flexibility of the inner shoulder land portion 7A even when the tread surface is shifted toward the inner tread end Ti at the time of cornering, and thus improve riding comfort.
In order to improve riding comfort without deteriorating steering stability, the maximum depth of the 2 nd portion 38b is, for example, 50% or more, preferably 60% or more, for example, 90% or less, preferably 80% or less of the maximum depth of the inner shoulder circumferential groove 4A.
As shown in fig. 1, the difference between the contact pressures applied to the land portion adjacent to the outer shoulder circumferential groove 4B is large when the land portion is straight and when the land portion is cornering. Therefore, the land portion is preferably high in rigidity in terms of improvement of steering stability. From such a viewpoint, the recess is not disposed on the groove wall of the outer shoulder circumferential groove 4B of the present embodiment. This improves the rigidity of the land portion, and can exhibit excellent steering stability.
The 1 st outer shoulder sipe 41 and the 2 nd outer shoulder sipe 42 alternately are provided in the outer shoulder land portion 7B in the tire circumferential direction. The 1 st outer shoulder sipe 41 is fully open. The 2 nd outboard shoulder sipe 42 is half-open.
The 1 st outer shoulder sipe 41 is inclined with respect to the tire axial direction, for example. The 1 st outer shoulder sipe 41 of the present embodiment is inclined in the same direction as the outer intermediate sipe 21 with respect to the tire axial direction. The angle of the 1 st outer shoulder sipe 41 with respect to the tire axial direction is, for example, 3 to 15 °, preferably 3 to 10 °.
In the present embodiment, the 1 st outer shoulder sipe 41 is disposed at a position smoothly continuous with the outer intermediate sipe 21 via the outer shoulder circumferential groove 4B. Specifically, when the center line of each sipe is extended along the shape of each sipe in the outer shoulder circumferential groove 4B in the centering of the 1 st outer shoulder sipe 41 and the outer intermediate sipe 21 adjacent to each other in the tire axial direction in a plan view of the tread, both extension lines intersect each other or are separated by 2mm or less. According to this structure, the rigidity of the inner and outer land portions of the outer shoulder circumferential groove 4B is optimized, and more excellent riding comfort and wear resistance are obtained.
Fig. 19 shows a cross-sectional view of fig. 1 taken along line M-M. As shown in fig. 19, each 1 st outer shoulder sipe 41 includes a 1 st portion 41a extending from the outer shoulder circumferential groove 4B, a 2 nd portion 41B communicating with the outer tread end To and having a depth greater than the 1 st portion 41a, and a 3 rd portion 41c disposed therebetween. The 3 rd portion 41c has a larger depth change per unit length than the 1 st portion 41a and the 2 nd portion 41 b. In the present embodiment, the depth of the 3 rd portion 41c continuously varies. Such 1 st outer shoulder sipe 41 can improve riding comfort without excessively decreasing the rigidity of the outer shoulder land portion 7B on the inner side in the tire axial direction.
In order to effectively exert the above-described function, the width 41aW of the 1 st portion 41a in the tire axial direction is preferably 10% or more, more preferably 15% or more, preferably 50% or less, and even more preferably 40% or less of the width W7 of the outer shoulder land portion 7B in the tire axial direction. Similarly, in order to effectively perform the above-described function, the depth of the 1 st portion 41a is, for example, 5% to 30%, preferably in the range of 10% to 25% of the maximum depth of the outer shoulder circumferential groove 4B.
The depth of the 2 nd portion 41b continuously decreases toward the outer tread end To. In addition, the 2 nd portion 41b passes beyond the outer tread end To toward the tire axial direction outer side. The 1 st outer shoulder sipe 41 including such a 2 nd portion 41B can ensure flexibility of the outer shoulder land portion 7B even in a state where the ground contact surface is displaced toward the outer tread end To at the time of turning, and improve riding comfort.
In order to improve riding comfort without deteriorating steering stability, the maximum depth of the 2 nd portion 41B is, for example, 50% or more, preferably 60% or more, for example, 90% or less, preferably 80% or less of the maximum depth of the outer shoulder circumferential groove 4B.
As shown in fig. 1, the 2 nd outer shoulder sipe 42 is inclined with respect to the tire axial direction, for example. The 2 nd outer shoulder sipe 42 of the present embodiment is inclined in the same direction as the 1 st outer shoulder sipe 41 with respect to the tire axial direction. The angle of the 2 nd outer shoulder sipe 42 with respect to the tire axial direction is, for example, 3 to 15 °, preferably 3 to 10 °. In a more preferred embodiment, the 2 nd outer shoulder sipe 42 preferably extends parallel to the 1 st outer shoulder sipe 41. As a result, in the outer shoulder land portion 7B, the deformation behavior upon contact with the ground becomes stable, and the riding comfort is further improved.
Fig. 20 shows a cross-sectional view of fig. 1 taken along line N-N. As shown in fig. 20, each 2 nd outer shoulder sipe 42 extends outward in the tire axial direction from its inner end 42i in the tire axial direction. In the present embodiment, the depth of the 2 nd outer shoulder sipe 42 continuously decreases toward the tire axial outer side. Even when the ground contact surface is displaced toward the outer tread end To during cornering, the 2 nd outer shoulder sipe 42 can ensure flexibility of the outer shoulder land portion 7B, thereby improving riding comfort.
The distance L5 in the tire axial direction from the outer shoulder circumferential groove 4B to the inner end 42i of the 2 nd outer shoulder sipe 42 is, for example, 10% to 40% of the width W7 in the tire axial direction of the outer shoulder land portion 7B.
The maximum depth of the 2 nd outer shoulder sipe 42 is, for example, 50% to 90% of the maximum depth of the outer shoulder circumferential groove 4B. This improves the riding comfort and the steering stability in a balanced manner.
The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described specific disclosure, and various modifications and implementations are possible within the scope of the technical ideas described in the scope of the claims. For example, the intermediate land portion and the shoulder land portion according To the scope of the claims of the present invention may be applied To the outer intermediate land portion 6B and the outer shoulder land portion 7B on the outer tread end To side, respectively.
[ example ]
Based on the use of Table 1, pneumatic tires for passenger cars having a size 225/45R18 of the basic pattern of FIG. 1 were produced. In addition, as comparative example 1, a tire having the basic pattern of fig. 1 was produced, and the concave portion of the groove wall disposed in the circumferential groove was not communicated with the sipe, and the chamfer portion was not formed in the sipe edge portion in all the sipes. As comparative example 2, a tire having the basic pattern of fig. 1 was produced on trial, and no chamfer was formed in the sipe edge portion in all sipes. The tires of comparative examples 1 and 2 have substantially the same structure as the tires of examples except for the above-described structure. The noise performance and steering stability of each test tire were tested. The common specifications and test methods of the respective test tires are as follows.
And (3) mounting a rim: 18X 7.5J
Tire internal pressure: 240kPa
Tire mounting position: all-wheel
Testing the vehicle: rear wheel drive vehicle with 2500cc exhaust
Noise performance >
The above test vehicle was caused to travel at a speed of 80km/h on a test route (ISO road surface) with the engine stopped. Then, the maximum level dB (a) of the passing noise was measured by a microphone provided at a position spaced 7.5m from the running center line and 1.2m from the road surface. The results are shown in table 1 by scores of 100 in comparative example 1. The larger the value, the more excellent the noise performance.
< steering stability >)
The steering stability of the vehicle during the circulating road running using the above test was evaluated by the driver's sense. The results are shown in table 1 by scores of 100 in comparative example 1. The larger the value, the more excellent the steering stability.
The results of the test are shown in table 1.
[ Table 1 ]
As a result of the test, it was confirmed that the tire of the example exhibited excellent noise performance. In addition, it can be confirmed that the tire of the example maintains steering stability.
Claims (13)
1. A tire having a tread portion with an inner tread end located on the vehicle inner side when mounted to a vehicle and an outer tread end located on the vehicle outer side when mounted to a vehicle, characterized in that,
At least 1 circumferential groove extending continuously in the tire circumferential direction and 2 land portions adjacent to the circumferential groove are provided in the tread portion,
the circumferential groove includes at least one recess provided in at least one of the two side groove walls,
the concave portion is recessed to the outside in the groove width direction than the groove edge of the circumferential groove which appears on the tread surface of the tread portion,
a knife groove communicated with the concave part is arranged on the tread of the land part,
the sipe edge portion of the sipe is formed by a chamfer portion,
the circumferential groove includes an outer crown circumferential groove adjacent to a tire equator and disposed between the tire equator and the outer tread end,
the outer crown circumferential groove includes a 1 st groove wall on the tread end side and a 2 nd groove wall on the tire equator side,
the concave parts comprise a plurality of 1 st concave parts arranged on the 1 st groove wall and a plurality of 2 nd concave parts arranged on the 2 nd groove wall,
the land portion to which the 1 st groove wall belongs is provided with the sipe communicating with the 1 st concave portion,
the land portion to which the 2 nd groove wall belongs is not provided with the sipe communicating with the 2 nd recess.
2. A tire as in claim 1, wherein,
The sipe has a length in the tire axial direction that is greater than a maximum depth of the recess from the tire axial direction of the rim.
3. Tyre according to claim 1 or 2, characterized in that,
the circumferential groove includes the concave portions provided on one groove wall and the concave portions provided on the other groove wall alternately in the groove length direction.
4. Tyre according to claim 1 or 2, characterized in that,
the maximum chamfer depth of the chamfer portion is 20 to 50% of the maximum height of the recessed portion in the tire radial direction.
5. Tyre according to claim 1 or 2, characterized in that,
the 1 st concave portion communicates with the sipe at a position different from a maximum depth position of the 1 st concave portion in the tire axial direction from the rim.
6. Tyre according to claim 1 or 2, characterized in that,
the sipe in communication with the 1 st recess is fully open entirely transverse to the land portion.
7. Tyre according to claim 1 or 2, characterized in that,
the circumferential groove includes an inner crown circumferential groove adjacent to a tire equator and disposed between the tire equator and the inner tread end,
the inner crown circumferential groove comprises a plurality of concave parts respectively arranged on two side groove walls,
The concave parts of the inner crown circumferential grooves are respectively communicated with the cutter grooves.
8. The tire of claim 7 wherein the tire is formed from a thermoplastic material,
the sipe communicating with the concave portion of the inner crown circumferential groove is a half-open type in which an end portion on the opposite side to the concave portion is interrupted in the land portion.
9. The tire of claim 7 wherein the tire is formed from a thermoplastic material,
the land portion includes a crown land portion adjacent to a tire equator side of the inner crown circumferential groove, and an inner intermediate land portion adjacent to the crown land portion across the inner crown circumferential groove,
a plurality of crown knife grooves communicated with the inner crown circumferential grooves are arranged on the crown land part,
a plurality of 1 st inner middle knife grooves communicated with the inner crown circumferential groove are arranged on the inner middle land part,
the crown sipe and the 1 st inner crown sipe are inclined in opposite directions relative to the tire axial direction.
10. Tire according to claim 9, wherein,
the length of the tire axial direction of the crown sipe is greater than the length of the tire axial direction of the 1 st inner middle sipe.
11. Tire according to claim 9, wherein,
The circumferential groove comprises an inboard shoulder circumferential groove adjacent one tread end,
the inner shoulder circumferential groove includes a plurality of the concave portions provided on both side groove walls,
the concave portions of the inner shoulder circumferential grooves communicate with non-chamfer sipes that do not have the chamfer portion, respectively.
12. Tyre according to any one of claims 1, 2, 8, 10, 11,
the land portion includes an inner intermediate land portion adjacent to a tire equator side of the inner shoulder circumferential groove, and an inner shoulder land portion adjacent to the inner intermediate land portion across the inner shoulder circumferential groove,
a plurality of 2 nd inner middle sipes communicated with the inner shoulder circumferential grooves are arranged on the inner middle land part,
a plurality of inner shoulder knife grooves communicated with the inner shoulder circumferential grooves are arranged on the inner shoulder land part,
the number of inner shoulder sipes provided on the inner shoulder land portion is greater than the number of 2 nd inner intermediate sipes provided on the inner intermediate land portion.
13. Tire according to claim 12, wherein,
the inboard shoulder blade groove is fully open completely transverse to the inboard shoulder land portion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019236952A JP7074120B2 (en) | 2019-12-26 | 2019-12-26 | tire |
| JP2019-236952 | 2019-12-26 |
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| CN113043797A CN113043797A (en) | 2021-06-29 |
| CN113043797B true CN113043797B (en) | 2023-10-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202011493690.0A Active CN113043797B (en) | 2019-12-26 | 2020-12-17 | Tire with a tire body |
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| JP (1) | JP7074120B2 (en) |
| CN (1) | CN113043797B (en) |
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| EP3842263B1 (en) * | 2019-12-27 | 2023-07-12 | Sumitomo Rubber Industries, Ltd. | Tyre |
| JP2023134123A (en) | 2022-03-14 | 2023-09-27 | 住友ゴム工業株式会社 | tire |
| JP2023134124A (en) | 2022-03-14 | 2023-09-27 | 住友ゴム工業株式会社 | tire |
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| JPH03157208A (en) * | 1989-11-13 | 1991-07-05 | Bridgestone Corp | Pneumatic radial tire for high speed traveling |
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Also Published As
| Publication number | Publication date |
|---|---|
| JP2021104746A (en) | 2021-07-26 |
| JP7074120B2 (en) | 2022-05-24 |
| CN113043797A (en) | 2021-06-29 |
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