阅读说明：本技术 轮胎 (Tyre for vehicle wheels ) 是由 八木健太 于 2021-05-20 设计创作，主要内容包括：本发明提供能够发挥优异的冰上转弯性能的轮胎。轮胎具有胎面部(2)。胎面部(2)包括由周向沟(3)划分出的第1陆地部(11)、和横穿第1陆地部(11)的多条第1横沟(16)。第1陆地部(11)包括由第1横沟(16)划分出的多个第1花纹块(18)。在至少一个第1花纹块(18)形成有刀槽花纹(25)、和将第1花纹块(18)在轮胎周向上断开的第2横沟(20)。第2横沟(20)包括相对于轮胎轴向朝第1方向倾斜的一对两端部(21)、和位于两端部(21)之间并且朝与第1方向相反的第2方向倾斜的中央部(22)。(The invention provides a tire capable of exerting excellent on-ice turning performance. The tire has a tread portion (2). The tread portion (2) includes a 1 st land portion (11) defined by the circumferential groove (3), and a plurality of 1 st lateral grooves (16) crossing the 1 st land portion (11). The 1 st land portion (11) includes a plurality of 1 st blocks (18) partitioned by the 1 st lateral grooves (16). A sipe (25) and a 2 nd lateral groove (20) for cutting off the 1 st block (18) in the tire circumferential direction are formed in at least one 1 st block (18). The 2 nd lateral groove (20) includes a pair of both end portions (21) inclined in the 1 st direction with respect to the tire axial direction, and a central portion (22) located between the both end portions (21) and inclined in the 2 nd direction opposite to the 1 st direction.)

1. A tire having a tread portion,

said tyre being characterized in that it is provided with a tread band,

the tread portion includes a 1 st land portion divided by a circumferential groove continuously extending in a tire circumferential direction, and a plurality of 1 st lateral grooves crossing the 1 st land portion,

the 1 st land portion includes a plurality of 1 st blocks partitioned by the 1 st lateral grooves,

a sipe and a 2 nd lateral groove for cutting off the 1 st block in the tire circumferential direction are formed in at least one of the 1 st blocks,

the 2 nd lateral groove includes a pair of both end portions inclined in a 1 st direction with respect to the tire axial direction, and a central portion located between the both end portions and inclined in a 2 nd direction opposite to the 1 st direction.

2. The tire according to claim 1,

the width of the 2 nd lateral groove is smaller than the width of the 1 st lateral groove.

3. Tire according to claim 1 or 2,

the width of each of the pair of end portions is larger than the width of the central portion.

4. A tyre according to anyone of claims 1 to 3,

the length of each of the pair of end portions in the tire axial direction is smaller than the length of the central portion in the tire axial direction.

5. A tyre according to anyone of claims 1 to 4,

the 1 st horizontal grooves are respectively inclined towards the 2 nd direction.

6. A tyre according to anyone of claims 1 to 5,

the angle of the central part relative to the axial direction of the tire is larger than that of the 1 st transverse groove relative to the axial direction of the tire.

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

the maximum depth of the central portion is less than the maximum depth of the sipe.

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

the sipe is inclined toward the 1 st direction.

9. A tyre according to anyone of claims 1 to 8,

the sipe does not communicate with the 2 nd lateral groove.

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

the sipe is a 3-dimensional shaped sipe extending in a wavy shape in a longitudinal direction and a depth direction thereof.

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

the angle of the 1 st transverse groove relative to the axial direction of the tire is 20-40 degrees.

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

the angle of the central portion with respect to the axial direction of the tire is 50-70 degrees.

13. Tire according to any one of claims 1 to 12,

the angle between the two end parts and the axial direction of the tire is 20-40 degrees.

14. The tire according to any one of claims 1 to 13,

the tire is assigned an orientation for installation to a vehicle,

the tread portion includes an inner tread end located on an inner side of the vehicle when mounted to the vehicle,

the 1 st land portion is provided between the tire equator and the inner tread end.

15. Tire according to any one of claims 1 to 14,

the tread portion includes a plurality of the circumferential grooves,

the circumferential groove includes an inner crown circumferential groove adjacent to the tire equatorial side of the 1 st land portion,

the inboard crown circumferential groove has a maximum groove width among the plurality of circumferential grooves.

Technical Field

The present invention relates to a tire.

Background

Patent document 1 listed below proposes a pneumatic tire in which an outer shoulder block is provided with a longitudinal groove and a sidewall groove. The pneumatic tire increases the edge component in the tire circumferential direction by the longitudinal cut groove, and improves cornering performance on an ice road.

Patent document 1: japanese patent laid-open publication No. 2013-082308

In recent years, further improvement in turning performance on ice has been demanded for tires on the premise of use in winter.

The inventors have found that a water film on ice can be effectively removed by improving the shape of a lateral groove or a sipe, and the like, and have completed the present invention.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and a main object thereof is to provide a tire capable of exhibiting excellent on-ice cornering performance.

The present invention is a tire having a tread portion, wherein the tread portion includes a 1 st land portion defined by circumferential grooves continuously extending in a tire circumferential direction, and a plurality of 1 st lateral grooves crossing the 1 st land portion, the 1 st land portion includes a plurality of 1 st blocks defined by the 1 st lateral grooves, a sipe is formed in at least one of the 1 st blocks, and a 2 nd lateral groove for dividing the 1 st block in the tire circumferential direction, and the 2 nd lateral groove includes a pair of both end portions inclined in a 1 st direction with respect to a tire axial direction, and a central portion positioned between the both end portions and inclined in a 2 nd direction opposite to the 1 st direction.

Preferably: in the tire according to the present invention, the width of the 2 nd lateral groove is smaller than the width of the 1 st lateral groove.

Preferably: in the tire of the present invention, the groove width of each of the pair of end portions is larger than the groove width of the central portion.

Preferably: in the tire of the present invention, the length of each of the pair of end portions in the tire axial direction is smaller than the length of the center portion in the tire axial direction.

Preferably: in the tire of the present invention, the 1 st lateral grooves are inclined in the 2 nd direction, respectively.

Preferably: in the tire of the present invention, an angle of the central portion with respect to the tire axial direction is larger than an angle of the 1 st lateral groove with respect to the tire axial direction.

Preferably: in the tire of the present invention, the maximum depth of the central portion is smaller than the maximum depth of the sipe.

Preferably: in the tire of the present invention, the sipe is inclined in the 1 st direction.

Preferably: in the tire of the present invention, the sipe does not communicate with the 2 nd lateral groove.

Preferably: in the tire of the present invention, the sipe is a 3-dimensional sipe extending in a wavy shape in the longitudinal direction and the depth direction thereof.

Preferably: in the tire of the present invention, the angle of the 1 st lateral groove with respect to the axial direction of the tire is 20 to 40 °.

Preferably: in the tire of the present invention, the angle of the central portion with respect to the axial direction of the tire is 50 to 70 °.

Preferably: in the tire of the present invention, the angle between the two end portions and the tire axial direction is 20 to 40 °.

For the tire of the present invention, it is preferable that: the direction of mounting to the vehicle is designated, the tread portion includes an inner tread end located on the inner side of the vehicle when mounted to the vehicle, and the 1 st land portion is provided between the tire equator and the inner tread end.

Preferably: in the tire of the present invention, the tread portion includes a plurality of the circumferential grooves, the circumferential grooves include an inner crown circumferential groove adjacent to the tire equator side of the 1 st land portion, and the inner crown circumferential groove has the largest groove width among the plurality of circumferential grooves.

The tire of the present invention can exhibit excellent on-ice cornering performance by adopting the above-described structure.

Drawings

Fig. 1 is a development view of a tread portion of a tire according to an embodiment of the present invention.

Fig. 2 is an enlarged view of the 1 st land portion of fig. 1.

Fig. 3 is an enlarged view of the 2 nd lateral groove of fig. 2.

Fig. 4 is a sectional view taken along line a-a of fig. 2.

Fig. 5 is a sectional view taken along line B-B of fig. 2.

FIG. 6 is an enlarged perspective view of the sipe walls of the sipe of FIG. 2.

Fig. 7 is an enlarged view of the 1 st, 2 nd and 3 rd land portions of fig. 1.

Fig. 8 is an enlarged view of the 4 th and 5 th lands of fig. 1.

Fig. 9 is an enlarged view of the 1 st land portion of another embodiment of the present invention.

Fig. 10 is an enlarged view of the 1 st land portion of another embodiment of the present invention.

Fig. 11 is an enlarged view of the 1 st land portion of the tire of the comparative example.

Description of the reference numerals

2 … tread portion; 3 … circumferential grooves; 11 … part 1 land; 16 … transverse 1 groove; 18 … block 1; 20 … transverse groove 2; 21 … two ends; 22 … center; 25 … sipes.

Detailed Description

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

Fig. 1 is a developed view of a tread portion 2 of a tire 1 of the present embodiment. As shown in fig. 1, the tire 1 of the present embodiment is used as a pneumatic tire for a passenger car, for example, on the premise of being used in winter. However, the tire 1 of the present invention is not limited to such an embodiment.

The tire 1 of the present embodiment has, for example, a tread portion 2 in which a direction of mounting to a vehicle is designated. For example, the direction of attachment to the vehicle is indicated by characters and symbols on the side wall (not shown).

The tread portion 2 is composed of 4 circumferential grooves 3 continuously extending in the tire circumferential direction between an outer tread end To and an inner tread end Ti, and 5 land portions 4 partitioned by the circumferential grooves 3. That is, the tire 1 of the present invention is configured as a so-called 5-rib tire. However, the tire 1 of the present invention is not limited to such an embodiment, and may be a so-called 4-rib tire including 3 circumferential grooves 3 and 4 land portions 4, for example.

The outer tread end To is a tread end intended To be located on the vehicle outer side when the vehicle is installed, and the inner tread end Ti is a tread end intended To be located on the vehicle inner side when the vehicle is installed. The outer tread end To and the inner tread end Ti correspond To the tire axial outermost ground contact positions when the tire 1 in a normal state is loaded with a normal load and ground on a plane at a 0 ° camber angle, respectively.

The "normal state" is a state in which, when pneumatic tires of various specifications are specified, the tires are assembled on a normal rim and the normal internal pressure and no load are applied. In the case of tires of which various specifications are not defined, or non-pneumatic tires, the normal state refers to a standard usage state according to the purpose of use of the tire and a no-load state. In the present specification, unless otherwise specified, the dimensions of each portion of the tire and the like are values measured in the above-described normal state. In addition, the respective structures described in the present specification allow for usual errors included in rubber molded articles.

The "regular Rim" is a Rim that is specified for each tire in a specification system including specifications to which the tire conforms, and for example, JATMA indicates "standard Rim", TRA indicates "Design Rim", and ETRTO indicates "Measuring Rim".

The "normal internal PRESSURE" is an air PRESSURE that is specified for each TIRE in a specification system including specifications that the TIRE conforms to, and indicates "maximum air PRESSURE" in the case of JATMA, a maximum value described in a table "TIRE LOAD conditions AT TIREs cool stability requirements" in the case of TRA, and indicates "stability requirements" in the case of ETRTO.

The "normal LOAD" is a LOAD that is specified for each TIRE in a specification system including specifications to which the TIRE conforms when pneumatic TIREs of VARIOUS specifications are specified, and indicates "maximum LOAD CAPACITY" in the case of JATMA, a maximum value described in a table "TIRE LOAD conditions AT vehicles color stability requirements" in the case of TRA, and "LOAD CAPACITY" in the case of ETRTO. In the case of tires of which various specifications are not defined, or non-pneumatic tires, "normal load" means a load that acts on one tire in a normal use state of the tire. The "standard use state" refers to a state in which a tire is mounted on a standard vehicle according to the purpose of use of the tire and is stationary on a flat road surface in a state in which the vehicle can run.

The circumferential grooves 3 include, for example, an inboard crown circumferential groove 5, an inboard shoulder circumferential groove 6, an outboard crown circumferential groove 7, and an outboard shoulder circumferential groove 8. The inner crown circumferential groove 5 is provided between the tire equator C and the inner tread end Ti. An inboard shoulder circumferential groove 6 is provided between the inboard crown circumferential groove 5 and the inboard tread end Ti. The outer crown circumferential groove 7 is provided between the tire equator C and the outer tread end To. An outboard shoulder circumferential groove 8 is provided between the outboard crown circumferential groove 7 and the outboard tread end To.

The circumferential groove 3 may be formed in various forms such as a groove extending linearly in the tire circumferential direction or a groove extending in a zigzag shape. In the present embodiment, the inner crown circumferential groove 5, the inner shoulder circumferential groove 6, and the outer shoulder circumferential groove 8 extend linearly in parallel in the tire circumferential direction. On the other hand, the outer crown circumferential groove 7 extends in a zigzag shape. However, the tire 1 of the present invention is not limited to such an embodiment.

The distance L1 in the tire axial direction from the groove center line of the outer shoulder circumferential groove 8 or the inner shoulder circumferential groove 6 to the tire equator C is, for example, 20% to 35% of the tread width TW. The distance L2 in the tire axial direction from the groove center line of the outer crown circumferential groove 7 or the inner crown circumferential groove 5 to the tire equator C is, for example, 3% to 15% of the tread width TW. In a preferred form, the distance in the tire axial direction from the groove center line of the inner crown circumferential groove 5 to the tire equator C is greater than the distance in the tire axial direction from the groove center line of the outer crown circumferential groove 7 to the tire equator C. The tread width TW is a distance in the tire axial direction from the outer tread end To the inner tread end Ti in the normal state.

The width W1 of the circumferential groove 3 is preferably at least 3 mm. In a preferred embodiment, the groove width W1 of the circumferential groove 3 is 2.0% to 5.0% of the tread width TW. In the present embodiment, of the 4 circumferential grooves 3, the inner crown circumferential groove 5 has the largest groove width.

The land portion 4 includes the 1 st land portion 11. The 1 st land portion 11 is preferably provided, for example, between the tire equator C and the inner tread end Ti. The 1 st land portion 11 of the present embodiment is divided between the inner crown circumferential groove 5 and the inner shoulder circumferential groove 6.

Fig. 2 shows an enlarged view of the 1 st land portion 11. As shown in fig. 2, the 1 st land portion 11 is provided with a plurality of 1 st lateral grooves 16 that cross the 1 st land portion 11. Thus, the 1 st land portion 11 includes a plurality of 1 st blocks 18 divided by the 1 st lateral grooves 16.

A plurality of sipes 25 and a 2 nd lateral groove 20 that breaks the 1 st block 18 in the tire circumferential direction are formed in at least one of the 1 st blocks 18. The 2 nd lateral groove 20 of the present embodiment breaks the 1 st block 18 by extending from the inner crown circumferential groove 5 to the inner shoulder circumferential groove 6.

In the present specification, the "sipe" refers to a cut element having a minute width, and a width between two mutually opposing groove walls is 0.6mm or less. The width of the sipe is preferably 0.1 to 0.5mm, and more preferably 0.2 to 0.4 mm. The sipe of the present embodiment has the above width in the above range over the entire depth thereof. In the present specification, a cut element including a region having a width of 0.6mm or less over 50% or more of the entire depth thereof in a cross section of the cut element is treated as a sipe (sipe including a groove element) even if the region having a width exceeding 0.6mm is partially included. In addition, in a cross section of a certain cut element, a cut element including a region having a width greater than 0.6mm over 50% or more of the entire depth thereof is treated as a groove (a groove including a sipe element) even if the cut element includes a region having a width of 0.6mm or less locally.

An enlarged view of the 2 nd lateral groove 20 is shown in fig. 3. As shown in fig. 3, the 2 nd lateral groove 20 includes a pair of both end portions 21 inclined in the 1 st direction with respect to the tire axial direction, and a central portion 22 located between the both end portions 21 and inclined in the 2 nd direction opposite to the 1 st direction. In the present specification, "inclined in the 1 st direction" means an inclined state toward the upper right, and "inclined in the 2 nd direction" means an inclined state toward the lower right. The tire 1 of the present invention can exhibit excellent on-ice cornering performance by adopting the above-described structure. The reason for this is assumed to be the following mechanism.

When running on ice, the tire 1 of the present invention breaks the water film on ice in the tire circumferential direction by the 1 st lateral groove 16. On the other hand, since the 2 nd lateral groove 20 includes the central portion 22 and both end portions 21, the edge of the 2 nd lateral groove 20 includes a portion protruding toward one side in the tire circumferential direction and a portion protruding toward the other side in the tire circumferential direction. Therefore, the edge of the 2 nd lateral groove 20 can further break the water film that the 1 st lateral groove 16 breaks in the tire axial direction. In addition, the water film interrupted by the 1 st and 2 nd lateral grooves 16 and 20 is effectively absorbed by the sipe 25. By such an action, the edges of the grooves and sipes can exert a large frictional force even on ice. Further, the edges of the center portion 22 and both end portions 21 of the 2 nd lateral groove 20 provide a frictional force in the tire axial direction, and therefore the on-ice cornering performance is improved.

Hereinafter, a more detailed configuration of the present embodiment will be described. Each configuration described below represents a specific embodiment of the present embodiment. Therefore, it is needless to say that the above-described effects can be exhibited even if the present invention does not have the configuration described below. Further, even if any one of the respective configurations described below is applied to the tire of the present invention having the above-described features alone, improvement in performance according to the respective configurations can be expected. When a plurality of the respective structures described below are applied in a composite manner, improvement in the performance of the composite according to the respective structures can be expected.

As shown in fig. 2, each of the plurality of 1 st lateral grooves 16 is inclined in the same direction with respect to the tire axial direction. The 1 st horizontal grooves 16 of the present embodiment are inclined in the 2 nd direction, respectively. The angle theta 1 of the 1 st lateral groove 16 with respect to the tire axial direction is, for example, 20 to 40 deg. Such a 1 st lateral groove 16 can provide a frictional force in the tire axial direction on ice.

The 1 st lateral groove 16 of the present embodiment extends linearly with a constant groove width, for example. The width W2 of the 1 st lateral groove 16 is, for example, 1.0 to 8.0mm, preferably 2.0 to 6.0 mm.

In fig. 4 is shown a cross-sectional view along line a-a of fig. 2. As shown in FIG. 4, the maximum depth d1 of the 1 st lateral groove 16 is, for example, 3.0 to 11.0mm, preferably 6.0 to 9.5 mm.

The groove bottom surface of the 1 st lateral groove 16 includes, for example, a projecting portion 16a partially projecting outward in the tire radial direction. The projecting portion 16a is provided, for example, at an end of the 1 st lateral groove 16 in the tire axial direction, and in the present embodiment, at an end of the 1 st lateral groove 16 on the inner crown circumferential groove 5 side. The height h1 of the protrusion 16a in the tire radial direction is, for example, 0.5 to 2.0 mm. The length of the projecting portion 16a in the tire axial direction is preferably 30% or less, more preferably 5% to 15% of the length of the 1 st lateral groove 16 in the tire axial direction. Such a projection 16a can prevent debris of snow and ice from being jammed in the 1 st lateral groove 16.

As shown in fig. 2, a chamfered portion 28a that obliquely continues to the tread surface of the 1 st block 18 is formed at an acute outer corner 28 formed by the 1 st lateral groove 16 and the inner crown circumferential groove 5. Such a chamfered portion 28a contributes to an improvement in rigidity of the 1 st block 18.

The width of the 2 nd lateral groove 20 is smaller than the width W2 of the 1 st lateral groove 16. Specifically, the maximum groove width W3 of the 2 nd lateral groove 20 is formed at one of the pair of both end portions 21, and the groove width W3 is smaller than the groove width W2 of the 1 st lateral groove 16. The width W3 of the 2 nd lateral groove 20 is 40-60% of the width W2 of the 1 st lateral groove 16. Such a 2 nd lateral groove 20 contributes to improving the on-ice cornering performance and the steering stability on a dry road surface (hereinafter, sometimes simply referred to as "steering stability") in a well-balanced manner.

As shown in fig. 3, the center portion 22 of the 2 nd lateral groove 20 passes through the center position in the tire axial direction of the 1 st land portion 11 (shown in fig. 2), for example. The length L3 of the center portion 22 in the tire axial direction is 25% to 45% of the width W4 of the 1 st land portion 11 in the tire axial direction (as shown in fig. 2, the same applies hereinafter). In this specification, the length of the groove is measured at the groove center line.

The central portion 22 is inclined at a constant angle with respect to the tire axial direction, for example, and extends linearly. The angle θ 2 of the central portion 22 with respect to the tire axial direction is preferably larger than the angle θ 1 of the 1 st lateral groove 16 with respect to the tire axial direction (as shown in fig. 2). Specifically, the angle of the central portion 22 is 50 to 70 °, preferably 55 to 65 °.

As shown in fig. 2, the groove width W5 of the central portion 22 constitutes the minimum groove width of the 2 nd lateral groove 20. The groove width W5 of the central portion 22 is, for example, greater than 0.6mm and 3.0mm or less. The central portion 22 of the present embodiment is configured as a narrow groove having a groove width of more than 0.6mm and 2.0mm or less, for example. Thereby, the two groove walls facing each other at the center portion 22 contact each other, and the rigidity of the 1 st block 18 is improved. Therefore, the 1 st block 18 can be suppressed from toppling, thereby improving the steering stability.

Preferably, the depth of the central portion 22 is less than the depth of the 1 st lateral groove 16. In a more preferred embodiment, the maximum depth of the central portion 22 is less than the maximum depth of the sipe 25. The depth of the central portion 22 is preferably 20% to 40% of the depth of the sipe 25. The depth of the central portion 22 is, for example, 0.2 to 5.0mm, preferably 0.5 to 3.0 mm. This can improve the on-ice turning performance and the steering stability in a well-balanced manner.

The two ends 21 of the present embodiment are constituted by a 1 st end 23 connected to the inner crown circumferential groove 5 and a 2 nd end 24 connected to the inner shoulder circumferential groove 6. The 1 st end 23 and the 2 nd end 24 are inclined at a constant angle with respect to the tire axial direction and extend linearly. Thus, the 2 nd lateral groove 20 of the present embodiment is configured to include an N-shaped lateral groove having a central portion 22, a 1 st end portion 23 extending from the central portion 22 to the inner crown circumferential groove 5, and a 2 nd end portion 24 extending from the central portion 22 to the inner shoulder circumferential groove 6.

As shown in fig. 3, the angle θ 3 of the both end portions 21 with respect to the tire axial direction is, for example, 10 to 50 °, preferably 20 to 40 °. The angle theta 4 between the central portion 22 and the 1 st end portion 23 and the angle theta 5 between the central portion 22 and the 2 nd end portion 24 are each 70 to 110 deg., preferably 80 to 100 deg.. This makes it easier for the edge of the 2 nd lateral groove 20 to cut off the water film on ice, thereby improving the on-ice turning performance.

The groove width W6 of the both ends 21 is, for example, larger than 0.6mm and 5.0mm or less. The groove width W6 of the both ends 21 of the present embodiment is, for example, 1.0 to 4.0mm, preferably 2.0 to 3.0 mm. In a more preferred embodiment, the groove width W6 of each of the pair of end portions 21 is larger than the groove width W5 of the central portion 22. Specifically, the groove width W6 is 2.0 to 3.5 times the groove width W5. The width of the 2 nd end 24 is smaller than the width of the 1 st end 23. Such both end portions 21 can effectively improve the on-ice turning performance.

In order to improve the ice turning performance and the steering stability in a well-balanced manner, the length L4 in the tire axial direction of each of the pair of end portions 21 is, for example, longer than the length L3 in the tire axial direction of the central portion 22. The length L4 in the tire axial direction of each of the pair of both end portions 21 is, for example, 25% to 40% of the width W4 in the tire axial direction of the 1 st land portion 11.

A cross-sectional view along line B-B of fig. 2 is shown in fig. 5. As shown in fig. 5, the depth of the both end portions 21 is preferably smaller than the depth of the 1 st lateral groove 16 and larger than the depth of the central portion 22. The maximum depth of the end portions 21 is, for example, 2.0 to 7.0mm, preferably 3.0 to 7.0 mm.

The 1 st end 23 and the 2 nd end 24 are formed to have a greater depth from the central portion 22 toward the end of the 2 nd lateral groove 20. In a preferred form, the maximum depth d2 of the 1 st end 23 is greater than the maximum depth d3 of the 2 nd end 24. Thereby, the rigidity of the 1 st block 18 becomes greater toward the inner tread end Ti side, thus resulting in an improvement in steering stability on a dry road surface.

As shown in fig. 2, the 1 st block 18 is provided with a plurality of sipes 25 inclined with respect to the tire axial direction. In the present embodiment, at least 1 of the sipes 25 is inclined in the 1 st direction, and in a preferred embodiment, each sipe 25 provided in the 1 st block 18 is inclined in the 1 st direction. The angle of each sipe 25 with respect to the tire axial direction is, for example, 10 to 50 °, and preferably 20 to 40 °. Such sipes 25 cooperate with the 1 st lateral grooves 16 and the 2 nd lateral grooves 20 to provide frictional force in a plurality of directions, thereby improving the turning performance on ice.

In the present embodiment, each sipe 25 extends in a zigzag shape. In this case, the above-mentioned inclination direction and angle are determined by the inclination direction and angle of the straight line connecting both ends of the sipe.

Preferably, at least 1 sipe 25 is not in communication with a 2 nd lateral groove 20. In a more preferred aspect, each sipe 25 provided in the 1 st block 18 does not communicate with the 2 nd lateral groove 20. The distance between one end of each sipe 25 and the 2 nd lateral groove 20 is, for example, 0.5 to 2.0mm, preferably 0.8 to 1.2 mm. This can sufficiently secure the length of each sipe 25, and can maintain the rigidity of the 1 st block 18.

An enlarged perspective view showing the sipe wall 25w of the sipe 25 is shown in fig. 6. As shown in fig. 6, each sipe 25 of the present embodiment is, for example, a 3D (3-dimensional) sipe extending in a wavy manner in the longitudinal direction and the depth direction thereof. Thereby, when the two opposing groove walls 25w contact each other, the apparent rigidity of the 1 st block 18 can be improved, so that the steering stability can be improved. However, the present invention is not limited to such an embodiment, and the sipe 25 may extend linearly in the longitudinal direction and the depth direction, for example.

In order to improve the turning performance on ice and the steering stability on a dry road surface in a well-balanced manner, the depth of the sipe 25 is, for example, 2.0 to 9.0mm, preferably 4.0 to 8.0 mm.

As shown in fig. 1, the tread portion 2 of the present embodiment includes a 2 nd land portion 12, a 3 rd land portion 13, a 4 th land portion 14, and a 5 th land portion 15 in addition to the 1 st land portion 11 described above. The 2 nd land portion 12 is adjacent to the 1 st land portion 11 on the inner tread end Ti side, and is divided between the inner shoulder circumferential groove 6 and the inner tread end Ti. The 3 rd land portion 13 is adjacent To the outer tread end To side of the 1 st land portion 11, and is divided between the outer crown circumferential groove 7 and the inner crown circumferential groove 5. The 4 th land portion 14 is adjacent To the 3 rd land portion 13 on the outer tread end To side, and is divided between the outer crown circumferential groove 7 and the outer shoulder circumferential groove 8. The 5 th land portion 15 is adjacent To the 4 th land portion 14 on the outer tread end To side, and is divided between the outer shoulder circumferential groove 8 and the outer tread end To.

Fig. 7 shows an enlarged view of the 1 st land portion 11, the 2 nd land portion 12, and the 3 rd land portion 13. As shown in fig. 7, a plurality of inner shoulder lateral grooves 30 are provided in the 2 nd land portion 12 so as to cross the 2 nd land portion 12. Thus, the 2 nd land portion 12 includes a plurality of inboard shoulder blocks 31.

The inboard shoulder lateral groove 30 is inclined, for example, in the 1 st direction. The angle of the inner shoulder lateral groove 30 with respect to the tire axial direction is, for example, 5 to 15 °. In a more preferred embodiment, the angle of the inner shoulder lateral groove 30 with respect to the tire axial direction is smaller than the angle of the 1 st lateral groove 16 with respect to the tire axial direction. Such an inboard shoulder transverse groove 30 can improve traction performance on ice.

The inboard shoulder cross groove 30 includes a 1 st furrow edge 30a and a 2 nd furrow edge 30 b. The 1 st furrow edge 30a extends linearly, for example. The 2 nd furrow edge 30b is, for example, bent in a zigzag shape. More specifically, the 2 nd furrow edge 30b includes a gently inclined edge 30c and a steeply inclined edge 30d alternately in the longitudinal direction thereof. The gently inclined edge 30c extends in the tire axial direction. The steep-inclined edge 30d has a larger angle with respect to the tire axial direction than the gentle-inclined edge 30 c. In addition, the steep incline edge 30d has a length less than the length of the gentle incline edge 30 c. The inner shoulder lateral groove 30 having the 2 nd groove edge 30b can fix snow and ice chips therein.

In the present embodiment, a region in which the end portion of the inner shoulder lateral groove 30 on the inner shoulder circumferential groove 6 side extends in parallel in the tire axial direction overlaps at least a part of the end portion of the 1 st lateral groove 16 on the inner shoulder circumferential groove 6 side. Thus, the inboard shoulder cross groove 30 and the 1 st cross groove 16 cooperate with each other to improve traction performance on ice.

The inner shoulder blocks 31 are provided with inner shoulder sipes 32 extending in the tire circumferential direction. The inner-shoulder sipes 32 communicate between, for example, two inner-shoulder lateral sipes 30 adjacent in the tire circumferential direction. Such an inner shoulder sipe 32 provides a frictional force in the tire axial direction on ice.

The inner shoulder block 31 includes a first piece 33 divided between the inner shoulder circumferential groove 6 and the inner shoulder longitudinal narrow groove 32, and a 2 nd piece 34 divided on the inner tread end Ti side of the inner shoulder longitudinal narrow groove 32.

The first and 2 nd blades 33 and 34 are provided with a plurality of inside shoulder sipes 35 extending in a zigzag shape, respectively. Each inboard shoulder sipe 35 is, for example, inclined in the 1 st direction. In a preferred form, the angle of each inboard shoulder sipe 35 with respect to the axial direction of the tire is smaller than the angle of the sipe 25 provided in the 1 st block 18 with respect to the axial direction of the tire. This improves the on-ice turning performance and the on-ice traction performance in a well-balanced manner.

In a preferred aspect, the sipe interval of the plurality of inboard shoulder sipes 35 provided to the first segment 33 is preferably greater than the sipe interval of the plurality of sipes 25 provided to the 1 st block 18. In a more preferred embodiment, the sipe interval of the plurality of inboard shoulder sipes 35 provided in the 2 nd blade 34 is preferably larger than the sipe interval of the plurality of inboard shoulder sipes 35 provided in the first blade 33. Thereby, the rigidity of the 2 nd land portion 12 is greater than the rigidity of the 1 st land portion 11, so that the steering stability on a dry road surface is improved. Further, "sipe spacing" refers to the minimum distance between two sipes.

A plurality of crown transverse grooves 40 crossing the 3 rd land portion 13 are provided in the 3 rd land portion 13. Thus, the 3 rd land portion 13 includes a plurality of crown blocks 41 partitioned by the crown transverse grooves 40.

The crown transverse groove 40 is inclined, for example, in the 1 st direction. The crown transverse groove 40 is, for example, at an angle of 15 to 25 ° with respect to the axial direction of the tire. In a more preferred form, the crown transverse grooves 40 are at a smaller angle to the axial direction of the tire than the 1 st transverse groove 16. In addition, the crown groove 40 has a larger angle with respect to the tire axial direction than the inner-shoulder groove 30. Thus, the crown groove 40, the 1 st groove 16, and the inboard shoulder groove 30 cooperate to provide friction in multiple directions, thereby improving cornering performance and traction performance on ice.

Preferably, the end of the crown lateral groove 40 on the inner crown circumferential groove 5 side does not overlap a region where the end of the 1 st lateral groove 16 on the inner crown circumferential groove 5 side is extended in parallel in the tire axial direction. Preferably, the end of the crown lateral groove 40 on the inner crown circumferential groove 5 side overlaps with a region in which the 1 st end 23 of the 2 nd lateral groove 20 is extended in the longitudinal direction thereof. Thus, crown groove 40 cooperates with lateral groove 1 16 to improve traction on ice.

The crown lateral groove 40 preferably has a groove width that increases toward the outer tread end To at the end on the outer crown circumferential groove 7 side, for example. In such a crown side groove 40, snow and ice chips are hard to be clogged inside.

The crown block 41 is provided with, for example, 1 st and 2 nd interrupted grooves 43 and 44, and a plurality of crown sipes 45 extending in a zigzag shape.

The 1 st interrupting groove 43 extends from the inboard crown circumferential groove 5 and is interrupted within the crown block 41. The 2 nd interrupting groove 44 extends from the outer crown circumferential groove 7 and is interrupted in the crown block 41. The 1 st and 2 nd interrupting grooves 43 and 44 of the present embodiment are interrupted without reaching the center position of the crown block 41 in the tire axial direction. In addition, the 1 st interruption groove 43 and the 2 nd interruption groove 44 are inclined in the 2 nd direction, respectively. Such 1 st and 2 nd interruption grooves 43 and 44 contribute to the improvement of the turning performance on ice and the steering stability in a well-balanced manner.

Each crown sipe 45 is inclined, for example, in the 2 nd direction. The angle of the crown sipe 45 with respect to the axial direction of the tire is smaller than the angle of the sipe 25 provided in the 1 st block 18 with respect to the axial direction of the tire. Such a crown sipe 45 improves the cornering performance on ice and the traction performance in a well-balanced manner.

An enlarged view of the 4 th land portion 14 and the 5 th land portion 15 is shown in fig. 8. As shown in fig. 8, the 4 th land portion 14 is provided with a plurality of outer intermediate lateral grooves 46 that cross the 4 th land portion 14. Thus, the 4 th land portion 14 includes a plurality of outer intermediate blocks 47 defined by the outer intermediate lateral grooves 46.

The outer intermediate lateral grooves 46 are inclined, for example, in the 2 nd direction. The angle of the outer intermediate lateral groove 46 with respect to the tire axial direction is, for example, 15 to 25 °. In a more preferred embodiment, the angle of the outer intermediate lateral grooves 46 with respect to the tire axial direction is smaller than the angle of the 1 st lateral groove 16 with respect to the tire axial direction.

The outer intermediate blocks 47 are provided with outer intermediate interrupting grooves 48, and a plurality of outer intermediate sipes 49 extending in a zigzag shape.

The outer intermediate interruption groove 48 extends, for example, from the outer crown circumferential groove 7 and is interrupted within the outer intermediate block 47. The outer intermediate interruption groove 48 is inclined, for example, in the 2 nd direction. The angle of the outer intermediate cut-off groove 48 with respect to the tire axial direction is, for example, 10 to 20 °. Such outer middle interrupted groove 48 helps to maintain the rigidity of the outer middle block 47 and improve traction performance on ice.

As shown in fig. 1, the end of the outer intermediate interruption groove 48 on the outer crown circumferential groove 7 side preferably overlaps a region in which the end of the crown transverse groove 40 on the outer crown circumferential groove 7 side extends in parallel in the tire axial direction. Thus, the outboard intermediate breaking grooves 48 cooperate with the crown transverse grooves 40 to improve traction on ice.

As shown in FIG. 8, the outer intermediate sipes 49 are, for example, inclined in the 1 st direction. It is preferable that the angle of the outer intermediate sipe 49 with respect to the tire axial direction is smaller than the angle of the sipe 25 provided to the 1 st block 18 with respect to the tire axial direction. Such outer intermediate sipes 49 provide frictional forces in multiple directions, thereby contributing to improved on-ice cornering performance.

The 5 th land portion 15 is provided with a plurality of outer shoulder lateral grooves 50 that cross the 5 th land portion 15. Thus, the 5 th land portion 15 includes a plurality of outer shoulder blocks 51 partitioned by the outer shoulder lateral grooves 50.

The outer shoulder lateral groove 50 extends at an angle of 10 ° or less with respect to the tire axial direction, for example. In a preferred embodiment, the end of the outer shoulder lateral groove 50 on the outer shoulder circumferential groove 8 side preferably overlaps a region in which the end of the outer intermediate lateral groove 46 on the outer shoulder circumferential groove 8 side is extended in parallel in the tire axial direction.

The outer shoulder blocks 51 are provided with outer shoulder sipes 52 extending in the tire circumferential direction and a plurality of outer shoulder sipes 53 extending in a zigzag pattern.

The outer-shoulder sipes 52 communicate between the outer-shoulder lateral grooves 50 adjacent in the tire circumferential direction. The outboard shoulder sipes 52 are preferably, for example, partially curved. Such an outer shoulder sipe 52 can provide a frictional force on the tire circumference on ice.

Preferably, the angle of the outboard shoulder sipe 53 with respect to the tire axial direction is smaller than the angle of the sipe 25 provided in the 1 st block 18 with respect to the tire axial direction.

As shown in fig. 1, the land percentage of the tread portion 2 of the present embodiment is 70% to 90%, preferably 80% to 88%. This improves the on-ice cornering performance and steering stability on dry road surfaces in a well-balanced manner. In the present specification, the "land ratio" is a ratio of an area of an actual ground contact surface of the tread portion to an area of a ground contact surface of the tread portion 2 in a state where all of the grooves and sipes provided in the tread portion 2 are filled.

Another embodiment of the present invention will be described below. In the drawings showing another embodiment, the same reference numerals as those described above are given to the already-described elements, and the above-described configuration can be applied.

Fig. 9 and 10 show enlarged views of the 1 st land portion 11 according to another embodiment. In the embodiment shown in fig. 9, the angle θ 2 of the central portion 22 and the angle θ 3 of the both end portions 21 with respect to the tire axial direction are larger than the angle θ 1 of the 1 st lateral groove 16 with respect to the tire axial direction, respectively, with respect to the 2 nd lateral groove 20. Thereby, the on-ice turning performance is further improved.

In the embodiment shown in fig. 9, the angle θ 4 between the central portion 22 and the 1 st end portion 23 and the angle θ 5 between the central portion 22 and the 2 nd end portion 24 are acute angles, preferably 60 to 80 °. This makes it easy for the edges of the 2 nd horizontal grooves 20 to cut off the water film.

In the embodiment shown in fig. 10, the angle θ 2 of the central portion 22 and the angle θ 3 of the both end portions 21 with respect to the tire axial direction are smaller than the angle θ 1 of the 1 st lateral groove 16 with respect to the tire axial direction, respectively, with respect to the 2 nd lateral groove 20.

In the embodiment shown in fig. 10, an angle θ 4 between the central portion 22 and the 1 st end portion 23 and an angle θ 5 between the central portion 22 and the 2 nd end portion 24 are obtuse angles, preferably 130 to 150 °. This improves the rigidity of the 1 st block 18, and exhibits excellent steering stability.

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-described specific embodiment, and can be implemented in various forms by being modified.

[ examples ] A method for producing a compound

Tires having a size 195/65R15 of the basic tread pattern of fig. 1 were produced in a trial based on the specifications of table 1. As a comparative example, a tire having the 1 st land portion a shown in fig. 11 was prototyped. As shown in fig. 11, the block b divided into the 1 st land portion a in the comparative example is provided with an interruption groove d extending from the inner shoulder circumferential groove c and interrupted in the block b. The tire of the comparative example had a pattern substantially the same as the pattern shown in fig. 1, except for the above-described structure. The test tires were tested for on-ice cornering performance and steering stability on dry road surfaces. The general specifications and test methods of the respective test tires were as follows.

Mounting a rim: 15X 6.0JJ

Tire internal pressure: 230kPa for front wheel and 230kPa for rear wheel

Testing the vehicle: front wheel drive vehicle with displacement of 1500cc

Tire mounting position: all wheels

< performance of turning on ice >

The cornering performance of the above test vehicle when running on ice was evaluated by the driver's senses. The result is a score of 100 in comparative example, and the larger the value, the more excellent the on-ice bending performance.

< handling stability on dry road surface >

Using the above test vehicle, the steering stability when running on a dry road was evaluated by the driver's sense. The result is a score of 100 in comparative example, and the larger the numerical value, the more excellent the steering stability on the dry road surface.

The results of the tests are shown in table 1.

[ TABLE 1 ]

As shown in table 1, it was confirmed that each example having the 2 nd lateral groove of the present invention exhibited excellent on-ice turning performance. In addition, it can also be confirmed that the respective examples maintain steering stability on a dry road surface.

For the embodiment having the 1 st land portion shown in fig. 2, a test tire in which the length and depth of the center portion were changed was produced, and the above-described test was performed. Further, the width of the 1 st land portion and the depth of the sipe are common in each embodiment.

The results of the tests are shown in table 2.

[ TABLE 2 ]

As shown in table 2, it was confirmed that the length and depth of the central portion had a high correlation with the on-ice cornering performance and the steering stability on a dry road surface.