阅读说明：本技术 轮胎 (Tyre for vehicle wheels ) 是由 中岛幸一 于 2019-12-11 设计创作，主要内容包括：本发明的轮胎能够提高雪路性能。轮胎(1)在胎面部(2)设置有具有踏面(3a)的花纹块(3)。在花纹块(3)设置有：倒角部(7),其将纵壁面(3b)、横壁面(3c)以及踏面(3a)相交的角部(3k)倾斜地切掉而形成；和倒角边缘(8),其为倒角部(7)与踏面(3a)相交而形成。在倒角部(7)设置有从踏面(3a)向轮胎径向内侧延伸的多个第一凹部(9)。第一凹部(9)分别沿倒角边缘(8)的长度方向具有摆幅。(The tire of the invention can improve snow road performance. A tread portion (2) of a tire (1) is provided with a pattern block (3) having a tread surface (3 a). The pattern block (3) is provided with: a chamfered section (7) formed by obliquely cutting out a corner section (3k) where the vertical wall surface (3b), the horizontal wall surface (3c), and the tread surface (3a) intersect; and a chamfered edge (8) formed by the intersection of the chamfered portion (7) and the tread (3 a). A plurality of first recesses (9) extending from the tread surface (3a) to the inner side in the tire radial direction are provided in the chamfered section (7). The first recesses (9) each have a swing in the longitudinal direction of the chamfered edge (8).)

1. A tire comprising a tread portion, characterized in that,

the tread part is provided with a pattern block with a tread,

the block includes: a vertical wall surface that is connected to the tread surface and extends in the tire circumferential direction; and a lateral wall surface connected to the tread surface and extending in the tire axial direction,

the pattern block is provided with: a chamfered portion formed by obliquely cutting off a corner at which the vertical wall surface, the horizontal wall surface, and the tread surface intersect; and a chamfered edge formed by the intersection of the chamfered portion and the tread surface,

the chamfered portion is provided with a plurality of first recessed portions extending inward in the tire radial direction from the tread surface,

the first recesses have a swing in a length direction of the chamfered edge, respectively.

2. The tire according to claim 1,

the tread is provided with an interruption groove extending from an outer end of the first recess in the tire radial direction and forming a terminal end in the block.

3. A tire comprising a tread portion, characterized in that,

the tread part is provided with a pattern block with a tread,

the block includes: a vertical wall surface that is connected to the tread surface and extends in the tire circumferential direction; and a lateral wall surface connected to the tread surface and extending in the tire axial direction,

the pattern block is provided with: a chamfered portion formed by cutting off a corner portion where the vertical wall surface, the horizontal wall surface, and the tread surface are butted; and a chamfered edge formed by the intersection of the chamfered portion and the tread surface,

a plurality of second recesses extending in a longitudinal direction of the chamfered edge are provided at the chamfered portion,

the second recesses each have a swing in a direction orthogonal to the chamfered edge.

4. A tyre according to any one of claims 1 to 3,

the tread portion having a first tread end and a second tread end,

the pattern block is formed as follows: a first shoulder block disposed closest to the first tread end side, and a second shoulder block disposed closest to the second tread end side.

5. Tire according to claim 4,

the chamfered portion of the first shoulder block is provided on a first side of the first shoulder block in the tire circumferential direction,

the chamfered portion of the second shoulder block is provided on a second side of the second shoulder block in the tire circumferential direction opposite to the first side.

6. A tyre according to any one of claims 1 to 5,

the angle between the chamfering part and the tread is 5-70 degrees.

7. A tyre according to anyone of claims 1 to 6,

the depth of the first concave part or the second concave part is 0.5-3 mm.

8. Tire according to any one of claims 1 to 7,

the cross section of the first concave part or the second concave part, which is perpendicular to the length direction of the first concave part or the second concave part, is V-shaped.

9. Tire according to any one of claims 1 to 7,

the first concave portion or the second concave portion has a circular arc-shaped cross section perpendicular to the longitudinal direction thereof.

10. Tire according to any one of claims 1 to 7,

the first concave portion or the second concave portion has a polygonal shape having a cross section perpendicular to the longitudinal direction thereof and being a quadrangle or more.

11. Tire according to any one of claims 1 to 10,

the tire circumferential direction length of the chamfered portion and the tire axial direction length of the chamfered portion are 10% to 50% of the tire circumferential direction length of the block.

Technical Field

The present invention relates to a tire having a block in a tread portion.

Background

Patent document 1 listed below describes a tire in which two raised portions are provided on the surface of a reinforcing portion, the two raised portions being arranged adjacent to each other in the tread circumferential direction from the side of a sidewall toward the end of a tread. The hump of such a tire exerts an edge effect, thereby improving traction performance on a snowy road surface.

Patent document 1: international publication No. 2013/150783

In recent years, further improvement in snow performance of tires has been desired. After various experiments, the inventors of the present invention found that improvement of a tread portion having a large ground contact pressure is suitable for improvement of snow road performance.

Disclosure of Invention

The present invention has been made in view of the above-described problems, and a main object thereof is to provide a tire capable of improving snow performance.

The tire of the present invention includes a tread portion, wherein a block having a tread is provided in the tread portion, the block including: a vertical wall surface that is connected to the tread surface and extends in the tire circumferential direction; and a lateral wall surface connected to the tread surface and extending in the tire axial direction, the pattern block being provided with: a chamfered portion formed by obliquely cutting off a corner at which the vertical wall surface, the horizontal wall surface, and the tread surface intersect; and a chamfered edge formed by the intersection of the chamfer and the tread surface, wherein the chamfered portion is provided with a plurality of first recesses extending inward in the tire radial direction from the tread surface, and each of the first recesses has a swing in the longitudinal direction of the chamfered edge.

In the tire of the present invention, it is preferable that the tread surface is provided with an interruption groove extending from an outer end of the first concave portion in the tire radial direction and forming a terminal end in the block.

The tire of the present invention includes a tread portion, wherein a block having a tread is provided in the tread portion, the block including: a vertical wall surface that is connected to the tread surface and extends in the tire circumferential direction; and a lateral wall surface connected to the tread surface and extending in the tire axial direction, the pattern block being provided with: a chamfered portion formed by cutting off a corner portion where the vertical wall surface, the horizontal wall surface, and the tread surface are butted; and a chamfered edge formed by the intersection of the chamfered portion and the tread surface, wherein the chamfered portion is provided with a plurality of second recesses extending in a longitudinal direction of the chamfered edge, and each of the second recesses has a swing in a direction orthogonal to the chamfered edge.

In the tire of the present invention, preferably, the tread portion has a first tread end and a second tread end, and the block is formed such that: a first shoulder block disposed closest to the first tread end side, and a second shoulder block disposed closest to the second tread end side.

In the tire of the present invention, it is preferable that the chamfered portion of the first shoulder block is provided on a first side of the first shoulder block in the tire circumferential direction, and the chamfered portion of the second shoulder block is provided on a second side of the second shoulder block opposite to the first side in the tire circumferential direction.

In the tire of the present invention, preferably, an angle between the chamfered portion and the tread surface is 5 to 70 degrees.

In the tire of the present invention, preferably, the first concave portion or the second concave portion has a depth of 0.5 to 3 mm.

In the tire of the present invention, it is preferable that the first concave portion or the second concave portion has a V-shaped cross section perpendicular to the longitudinal direction thereof.

In the tire according to the present invention, it is preferable that the first concave portion or the second concave portion has an arc-shaped cross section perpendicular to the longitudinal direction thereof.

In the tire according to the present invention, it is preferable that the first concave portion or the second concave portion has a polygonal shape having a cross section perpendicular to the longitudinal direction thereof and being a quadrangle or more.

In the tire of the present invention, the tire circumferential direction length of the chamfered portion and the tire axial direction length of the chamfered portion are preferably 10% to 50% of the tire circumferential direction length of the block.

The block of the tire of the present invention is provided with: a chamfered portion formed by obliquely cutting off a corner portion where the vertical wall surface, the horizontal wall surface, and the tread surface intersect; and a chamfered edge formed by the intersection of the chamfered portion and the tread surface. The chamfered portion is provided with a plurality of first recessed portions extending inward in the tire radial direction from the tread surface. Such chamfered portions and first recesses increase the volume of the snow pillars formed on the vertical wall surfaces and the lateral wall surfaces, and therefore a large snow pillar can be formed.

The first recesses have a swing in a length direction of the chamfered edge, respectively. Such a first concave portion can catch snow in the chamfered portion without discharging the snow when the block is in contact with the ground. Thereby, a strong snow column is formed at the chamfered portion.

Therefore, the tire of the present invention can improve the snow column shearing force at the tread portion on which a large ground contact pressure acts, and thus has excellent snow road performance.

Drawings

Fig. 1 is a perspective view of a block of a tire according to an embodiment of the present invention.

Fig. 2 is a front view of the chamfered portion of fig. 1.

Fig. 3 (a) is a sectional view taken along line a-a of fig. 2, and (b) and (c) are sectional views of other embodiments of the first recess.

Fig. 4 is a development view of a tread portion provided with the block of fig. 1.

Fig. 5 is a perspective view of a block of another embodiment.

Fig. 6 is a perspective view of a block of still another embodiment.

Fig. 7 (a) is a perspective view of a block provided with a second concave portion, and (b) is a front view of a chamfered portion of (a).

Description of reference numerals: 1 … tire; 2 … tread portion; 3a … tread; 3b … longitudinal wall surface; 3c … transverse wall; 3k … corner; 7 … chamfer; 8 … chamfering the edges; 9 … first recess.

Detailed Description

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a perspective view of a block 3 provided in a tread portion 2 of a tire 1 of the present embodiment. Fig. 1 shows a block 3 of a pneumatic tire 1 for a passenger vehicle as a preferred embodiment. However, the present invention can be applied to, for example, a pneumatic tire 1 for heavy load or other types of tires 1.

As shown in fig. 1, in the present embodiment, the block 3 is formed in a substantially rectangular parallelepiped shape. The block 3 is not limited to this form, and the tread surface 3a that contacts the road surface can be selected from various shapes such as a polygonal shape and a V-shape.

The block 3 of the present embodiment includes, for example: the tire has a tread surface 3a, a vertical wall surface 3b connected to the tread surface 3a and extending in the tire circumferential direction, and a lateral wall surface 3c connected to the tread surface 3a and extending in the tire axial direction.

The vertical wall surface 3b is formed as, for example, a groove wall 4a of a vertical groove 4 extending in the tire circumferential direction provided in the tread portion 2. The lateral wall surface 3c is formed as, for example, a groove wall 5a of a lateral groove 5 extending in the tire axial direction provided in the tread portion 2. In the present specification, the term "extend in the tire circumferential direction" is not limited to extending parallel to the tire circumferential direction, and preferably extends at an angle of 45 degrees or less, more preferably at an angle of 30 degrees or less, and still more preferably at an angle of 15 degrees or less with respect to the tire circumferential direction. Similarly, the term "extend in the tire axial direction" is not limited to a form extending parallel to the tire axial direction, and preferably extends at an angle of 45 degrees or less, more preferably 30 degrees or less, and still more preferably 15 degrees or less with respect to the tire axial direction.

The block 3 of the present embodiment is provided with: a chamfered portion 7 formed by obliquely cutting off a corner portion 3k where the vertical wall surface 3b, the horizontal wall surface 3c, and the tread surface 3a intersect; and a chamfered edge 8 formed by the intersection of the chamfered portion 7 and the tread surface 3 a. Such chamfered portions 7 further increase the volume of the snow pillars formed on the vertical wall surfaces 3b and the horizontal wall surfaces 3c (the vertical grooves 4 and the horizontal grooves 5), and thus a large snow pillar can be formed. In the present embodiment, the chamfered portion 7 is formed in a triangular shape.

The chamfered portion 7 of the present embodiment is provided with a plurality of first recesses 9 extending inward in the tire radial direction from the tread surface 3 a. Such first concave portion 9 further increases the volume of the snow pillar formed on the vertical wall surface 3b and the lateral wall surface 3 c.

Fig. 2 is a front view of the chamfered portion 7. As shown in fig. 1 and 2, each first recess 9 has a swing in the longitudinal direction f1 of the chamfered edge 8. Such a first concave portion 9 can trap snow in the chamfered portion 7 without discharging the snow when the block 3 is in contact with the ground. This forms a strong snow column in the chamfered portion 7 of the present embodiment. Therefore, in the tire 1 of the present embodiment, the tread portion 2 on which a large ground contact pressure acts exerts a high snow column shearing force, and therefore snow road performance is improved. In the present specification, a direction orthogonal to the chamfered edge 8 (hereinafter, may be simply referred to as "orthogonal direction") is referred to as f 2.

The first recess 9 of the present embodiment extends from the chamfered edge 8 to the inner end 7i of the chamfered portion 7 in the tire radial direction. The first recess 9 is not limited to this, and may be formed so as to terminate without reaching the inner end 7i, for example. The effective effect is exhibited if the height H1 in the tire radial direction of the first recessed portion 9 is 80% or more of the height Ha in the tire radial direction of the chamfered portion 7.

The first recess 9 includes: a recess wall 12 extending in the depth direction from the chamfered portion 7, and longitudinal edges 13 (shown in fig. 3) disposed on both sides of the recess wall 12 in the longitudinal direction f1 and extending in the tire radial direction.

In the present embodiment, the first concave portions 9 are continuously arranged so as to contact each other in the longitudinal direction f 1. Such a first recess 9 increases the volume of the snow column.

Fig. 3 (a) is a sectional view taken along line a-a of fig. 2 (a cross section perpendicular to the longitudinal direction of the first recess 9). As shown in fig. 3 (a), the first recess 9 has a V-shaped cross section, for example. The first recessed portion 9 is easy to discharge snow in the recessed portion by the recessed portion wall 12, and therefore snow road performance is improved. In the present embodiment, the recess wall 12 extends linearly while being inclined in the depth direction from both the longitudinal edges 13.

Fig. 3 (b) and (c) are cross-sections of the first recess 9 of other embodiments. As shown in fig. 3b, the first concave portion 9 may have an arc shape, for example, and as shown in fig. 3c, the first concave portion 9 may have a polygonal shape such as a square or more (as shown in fig. 3c, a pentagonal shape). In the mode shown in fig. 3 (b) and (c), the volume of the snow column formed in the first recess 9 is further increased.

The depth d of the first recess 9 is preferably 0.5 to 3 mm. In the case where the depth d of the first recess 9 is less than 0.5mm, there is a possibility that snow cannot be efficiently captured. When the depth d of the first recess 9 exceeds 3mm, the rigidity of the chamfered portion 7 adjacent to the first recess 9 may be reduced, and the snow column formed in the first recess 9 and the chamfered portion 7 may not be firmly formed. The depth d is the maximum depth of the first recess 9.

As shown in fig. 1 or 2, in the present embodiment, the depth d of the first recessed portion 9 gradually decreases toward the tire radial direction inner side. Such a first recess 9 suppresses a decrease in rigidity of the inner end 7i side of the chamfered portion 7, and can form a strong snow column. From the same viewpoint, the width w1 of the first recessed portion 9 in the longitudinal direction f1, for example, gradually decreases toward the tire radial direction inner side. Further, the width w1 of the first concave portion 9 gradually decreases toward the bottom in the depth direction.

The swing center line 9c of the first recess 9 extends from the chamfered edge 8 toward the inner end 7i of the chamfered portion 7. Such a first recess 9 maintains the length of the longitudinal edge 13 of the first recess 9 to be large, and therefore exhibits a high snow column shearing force.

Although not particularly limited, in order to effectively exhibit the above-described effects, the maximum swing α of the first concave portion 9 is preferably 10% to 15% of the half wavelength λ of the first concave portion 9.

The chamfered portion 7 is not particularly limited, but for example, the length La in the tire circumferential direction and the length Lb in the tire axial direction of the chamfered portion 7 are preferably 10% to 50% of the length L in the tire circumferential direction of the block 3. When the length La and the length Lb of the chamfered portion 7 are less than 10% of the length L of the block 3, the volume of the snow pillar formed by the chamfered portion 7 is reduced, and the snow pillar shearing force may not be increased. When the length La and the length Lb of the chamfered portion 7 exceed 50% of the length L of the block 3, the block 3 may have a reduced rigidity, and the snow pillar formed by the chamfered portion 7 may not be firmly compacted. Therefore, the length La in the tire circumferential direction of the chamfered portion 7 and the length Lb in the tire axial direction of the chamfered portion 7 are more preferably 20% to 40% of the length L in the tire circumferential direction of the block 3.

From the same viewpoint, the height Ha in the tire radial direction of the chamfered portion 7 is preferably 80% to 95%, more preferably 85% to 90%, of the height H of the block 3.

The angle theta between the chamfered portion 7 and the tread surface 3a is preferably 5 to 70 degrees. When the angle θ is 5 degrees or less, the volume of the snow column formed by the chamfered portion 7 may be reduced. When the angle θ exceeds 70 degrees, the effect of compacting snow in the chamfered portion 7 may be reduced, and the shearing force exerted by the chamfered portion 7 may be reduced. In the present specification, the angle θ is an angle between the tread surface 3a and an imaginary line n passing through an inner end 7i of the chamfered portion 7 and a vertex 8a on the chamfered edge 8.

In the present embodiment, the block 3 is provided with the interruption groove 11 extending from the outer end 9e of the first concave portion 9 in the tire radial direction and forming a terminal end in the tread surface 3 a. Such an interruption groove 11 promotes the deformation of the first recess 9 and promotes the discharge of snow in the recess, in addition to the enhancement of the snow column shearing force.

The interruption groove 11 of the present embodiment is provided in plural, and extends from each of the first concave portions 9. In the present embodiment, the respective interrupt grooves 11 extend in the same direction. The interruption groove 11 extends, for example, in the tire axial direction. Such an interruption groove 11 exerts a large traction property with respect to a snow road.

Although not particularly limited, in order to suppress excessive reduction in rigidity of the block 3, the width w2 (maximum width) of the interruption groove 11 is preferably smaller than the width w1 of the first recessed portion 9. The width w2 of the interruption groove 11 is preferably 40% to 100% of the width w1 of the first recessed portion 9, for example.

Fig. 4 is a development view of the entire tread portion 2 including the block 3 of the present embodiment. As shown in fig. 4, the tread portion 2 has a first tread end Te (left side in the figure) and a second tread end Ti (right side in the figure).

The "tread end" Te and Ti are defined as: when a normal load is applied to a tire 1 in a normal state in which a rim is assembled to a normal rim and a no-load state is filled with a normal internal pressure, and the tire is grounded at a ground contact position closest to both sides in the axial direction of the tire when the tire is grounded on a plane at a camber angle of 0 degrees. In a normal state, the distance between the tread ends Te and Ti in the tire axial direction is defined as a tread width TW. Unless otherwise specified, the dimensions and the like of each portion of the tire 1 are values measured in a normal state.

The "regular Rim" is a Rim that defines a specification for each tire in a specification system including the specification under which the tire 1 conforms, and is, for example, "standard Rim" in the case of JATMA, "Design Rim" in the case of TRA, or "Measuring Rim" in the case of ETRTO.

The "normal internal PRESSURE" is an air PRESSURE specified for each tire in a specification system including the specification to which the tire 1 conforms, and is "maximum air PRESSURE" in case of JATMA, the maximum value described in the table "relating to" related PRESSURE AT variable atmospheric PRESSURE requirements "in case of TRA, and" relating PRESSURE requirements "in case of ETRTO. When the tire is a passenger car, the normal internal pressure is 180 kPa.

The "normal LOAD" is a LOAD specified for each tire in a specification system including the specification under which the tire 1 conforms, and is "maximum LOAD CAPACITY" in the case of JATMA, the maximum value described in the table "tirload limit AT variable availability requirements" in the case of TRA, and "LOAD CAPACITY" in the case of ETRTO. When the tire 1 is a passenger car, the normal load is a load corresponding to 88% of the above load.

In the tread portion 2 of the present embodiment, the block 3 is formed such that: a first shoulder block 3A disposed on the side closest to the first tread end Te, and a second shoulder block 3B disposed on the side closest to the second tread end Ti. In the present embodiment, the first shoulder blocks 3A and the second shoulder blocks 3B are arranged in the tire circumferential direction.

In the first shoulder block 3A of the present embodiment, the chamfered portion 7 is provided on a first side (lower side in fig. 4) of the first shoulder block 3A in the tire circumferential direction. In the second shoulder block 3B of the present embodiment, the chamfered portion 7 is provided on a second side (upper side in fig. 4) of the second shoulder block 3B in the tire circumferential direction opposite to the first side. In such a tread portion 2, when the tire 1 rotates in any direction in the tire circumferential direction, the chamfered portion 7 exerts the same shearing force. In addition, the chamfered portions 7 of the first shoulder block 3A and the second shoulder block 3B may be provided on the same side in the tire circumferential direction. In this embodiment, the same shearing force is exerted by the chamfered portions 7 on both sides in the tire axial direction.

The tread portion 2 of the present embodiment is provided with: one or more longitudinal main grooves 4A continuously extending in the tire circumferential direction are provided, and in the present embodiment, three longitudinal main grooves 4A are provided. Thereby, a strip-shaped land portion 6 extending in the tire circumferential direction is provided between the vertical main grooves 4A. The tread portion 2 is not limited to such an embodiment, and various embodiments can be adopted.

Fig. 5 is a perspective view of the block 3 provided with the first concave portion 9 of the other embodiment. In fig. 5, the same components as those of the present embodiment are denoted by the same reference numerals, and the description thereof is omitted. As shown in fig. 5, in this embodiment, the first recesses 9 adjacent to each other in the longitudinal direction f1 are arranged to provide a gap s formed by cutting out the chamfered edge 8. In such a manner, the rigidity of the block 3 is maintained higher.

Fig. 6 is a perspective view of the block 3 provided with the first concave portion 9 of still another embodiment. In fig. 6, the same components as those of the present embodiment are denoted by the same reference numerals, and the description thereof is omitted. As shown in fig. 6, in the present embodiment, the width w1 in the longitudinal direction f1 is formed uniformly along the tire radial direction. The first recesses 9 are formed to have the same depth (not shown) along the tire radial direction. Such first concave portions 9 also increase the volume of the snow pillars formed on the vertical wall surfaces 3b and the horizontal wall surfaces 3c, and therefore a large snow pillar can be formed. In the present embodiment, the swing center line 9c of the first concave portion 9 extends parallel to the orthogonal direction f 2.

Fig. 7 (a) is a perspective view of a block 3 according to another embodiment. Fig. 7 (b) is a front view of the chamfered portion 7 provided in the block 3 of fig. 7 (a). As shown in fig. 7 (a) and (b), the chamfered portion 7 is provided with a plurality of second recesses 10 extending in the longitudinal direction f1 of the chamfered edge 8.

Each second recess 10 has a swing in the orthogonal direction f 2. Even when the block 3 is in contact with the ground, such a second recessed portion 10 can capture snow that is easily discharged from the chamfered portion 7 without discharging the snow, and therefore a strong snow column is formed in the chamfered portion 7. The swing center line 10c of the second recess 10 extends, for example, parallel to the longitudinal direction f 1. The width w1, the depth (not shown) and the ratio of the half wavelength λ to the amplitude a of the second concave portion 10 are preferably formed in the same range as the first concave portion 9. The second concave portion 10 is preferably formed in an arc shape, a polygonal shape having a square or more, or a V shape so that a cross section perpendicular to the longitudinal direction thereof is the same as that of the first concave portion 9.

Although the tire according to the embodiment of the present invention has been described in detail above, the present invention is not limited to the above specific embodiment, and can be implemented by being modified into various embodiments.

(examples)

Tires having the basic pattern of fig. 4 and a size of 215/60R16 were produced in a trial based on the specifications of table 1, and snow performance of each of the test tires was tested. The common specification and test method of each tire are as follows.

Width w1 of first or second recess: 3.4mm

Maximum swing a/half wavelength λ of the first or second recess: 11.5% (chamfered edge side), 11.9% (inner end side of chamfered part)

Height Ha of chamfered portion/block height H: 67 percent

Length of chamfered portion La/length of block L: 32 percent of

Length Lb of chamfered portion/length L of block: 32 percent of

< snow road Performance >

Each tire was mounted on an all-wheel of a front-wheel-drive passenger vehicle having an exhaust gas volume of 1500cc under the following conditions, and a test driver allowed the vehicle to travel on a test course on a snowy road surface. The test driver evaluated the driving characteristics related to the steering wheel responsiveness, the traction performance, the grip performance, and the like at this time by the sense. The results are expressed as a score of 100 for comparative example 1. The larger the value, the better.

Rim (all-wheel): 16X 6.5J

Internal pressure (full wheel): 240kPa

TABLE 1

The results of the test can confirm that: the tires of the examples had excellent snow performance.