WO2015111359A1

WO2015111359A1 - Pneumatic tire

Info

Publication number: WO2015111359A1
Application number: PCT/JP2014/084434
Authority: WO
Inventors: 正剛久保田
Original assignee: 横浜ゴム株式会社
Priority date: 2014-01-21
Filing date: 2014-12-25
Publication date: 2015-07-30
Also published as: JP2015136975A; JP6364783B2

Abstract

A pneumatic tire is provided with a tread pattern having: a first circumferential-direction groove; a land part that is located outside the first circumferential-direction groove in a width direction of the tire, continuously extends over the entire circumference of the tire, and continuously extends outwardly in the width direction of the tire from the first circumferential-direction groove to an end of a contact area of the tire; a first slanting groove that extends, while slanting outwardly in the width direction of the tire, in a first direction along the circumferential direction of the tire from a position spaced from the first circumferential-direction groove outwardly in the width direction of the tire; a first lug groove extending from the outer end of the first slanting groove in the width direction of the tire to the end of the contact area; and a second slanting groove that extends from the land part spaced in the circumferential direction of the tire from the first slanting groove and the first lug groove to a connection between the first slanting groove and the first lug groove and is smaller in length than the first slanting groove in the circumferential direction of the tire.

Description

Pneumatic tire

The present invention relates to a pneumatic tire having a tread pattern formed in a tread portion.

In order to improve the wet performance of the pneumatic tire, a groove is provided in the tread portion of the tire. In order to improve the wet performance, it is necessary to increase the groove area ratio. On the other hand, when the groove area ratio is increased, noise during traveling increases. Further, when the groove area ratio is increased, the ground contact area is reduced, so that the grip force of the tire is reduced, and the steering stability may be reduced. For this reason, in order to reduce noise and improve steering stability, it is required to reduce the groove area ratio.
In order to satisfy such conflicting requirements, the width and number of tire circumferential grooves provided in the tread portion and the inclination angle and width of the lug grooves have been devised (for example, see Patent Document 1).

JP 2005-231430 A

By the way, there is a demand for using tires that can run on public roads for running on a circuit race course. In response to such demands, there are tires that have drainage grooves and can travel on public roads, but have fewer grooves and higher gripping power than general tires.
Generally, a tire having a drainage groove has a locally low rigidity portion at the groove portion. When such a tire is used on a race course, uneven wear of the tire occurs in a portion having low rigidity. When a vehicle is driven using tires with uneven wear, noise during driving tends to be greater than before the wear.
Then, an object of this invention is to provide the pneumatic tire which can suppress the noise by uneven wear.

One aspect of the present invention is a pneumatic tire. The pneumatic tire has a tread pattern in a tread portion, and the tread pattern is
A first circumferential groove extending in the tire circumferential direction and provided annularly over the entire circumference of the tire;
A land portion that is provided on the outer side in the tire width direction of the first circumferential groove and is continuous over the entire circumference of the tire, and a land portion that continues from the first circumferential groove to the tire ground contact end in the tire width direction;
A first inclined groove extending in the tire circumferential direction is inclined in the tire circumferential direction while starting from a position spaced from the first circumferential groove outward in the tire width direction and extending toward the first direction in the tire circumferential direction. A plurality of first inclined groove groups,
A first lug groove group in which a plurality of first lug grooves extending from the outer end in the tire width direction to the ground contact end of the first inclined grooves are provided in the tire circumferential direction;
Land between the first inclined groove and the first lug groove and the other first inclined groove and the other first lug groove adjacent to each other in the second direction opposite to the first direction in the tire circumferential direction. The first end in the tire circumferential direction and extending to the connecting portion between the first inclined groove and the first lug groove, and the length in the tire circumferential direction is shorter than the first inclined groove A second inclined groove group in which a plurality of second inclined grooves are provided in the tire circumferential direction;
Is provided.

Another aspect of the present invention is:
A pneumatic tire having a tread pattern in a tread portion,
The tread pattern is
A pair of first circumferential grooves extending in the tire circumferential direction, spaced apart across the tire center line, and provided annularly over the entire circumference of the tire;
A land portion that is provided on the outer side in the tire width direction of each of the first circumferential grooves, is continuous over the entire circumference of the tire, and is continuous from each of the first circumferential grooves to the tire ground contact edge on the outer side in the tire width direction;
A first inclined groove extending from the first circumferential direction toward the first direction in the tire circumferential direction and extending obliquely toward the outer side in the tire width direction is defined as a start end at a position spaced apart from each of the first circumferential grooves. A plurality of first inclined groove groups provided in a direction;
A first lug groove group in which a plurality of first lug grooves extending from the outer end in the tire width direction to the ground contact end of the first inclined grooves are provided in the tire circumferential direction;
Land between the first inclined groove and the first lug groove and the other first inclined groove and the other first lug groove adjacent to each other in the second direction opposite to the first direction in the tire circumferential direction. The first end in the tire circumferential direction and extending to the connecting portion between the first inclined groove and the first lug groove, and the length in the tire circumferential direction is shorter than the first inclined groove A second inclined groove group in which a plurality of second inclined grooves are provided in the tire circumferential direction;
Is provided.

Another aspect of the present invention is:
A pneumatic tire having a tread pattern in a tread portion,
The tread pattern is
A pair of first circumferential grooves extending in the tire circumferential direction, spaced apart across the tire center line, and provided annularly over the entire circumference of the tire;
A land portion that is provided on the outer side in the tire width direction of each of the first circumferential grooves, is continuous over the entire circumference of the tire, and is continuous from each of the first circumferential grooves to the tire ground contact edge on the outer side in the tire width direction;
With the position spaced apart from each of the first circumferential grooves on the outer side in the tire width direction as a starting end, and toward the first direction in the tire circumferential direction on the outer side in the tire width direction than one of the first circumferential grooves, The tire extends in the tire width direction outer side, and extends in the tire width direction outer side than the other of the first circumferential grooves in the direction opposite to the first direction in the tire circumferential direction and extends in the tire width direction outer side. A first inclined groove group provided with a plurality of inclined grooves in the tire circumferential direction;
A first lug groove group in which a plurality of first lug grooves extending from the outer end in the tire width direction to the ground contact end of the first inclined grooves are provided in the tire circumferential direction;
Land between the first inclined groove and the first lug groove and the other first inclined groove and the other first lug groove adjacent to each other in the second direction opposite to the first direction in the tire circumferential direction. The first end in the tire width direction outside one of the first circumferential grooves and extending to the connecting portion between the first inclined groove and the first lug groove toward the first direction in the tire circumferential direction. And extending to the connecting portion between the first inclined groove and the first lug groove in a direction opposite to the first direction in the tire circumferential direction on the outer side in the tire width direction than the other of the first circumferential groove, A second inclined groove group in which a plurality of second inclined grooves whose length in the direction is shorter than the first inclined grooves are provided in the tire circumferential direction;
Is provided.

An angle θ ₁ formed by a straight line connecting both ends of the first inclined groove and the tire circumferential direction is preferably 15 ° ≦ θ ₁ ≦ 40 °.
In addition, it is preferable that an absolute value of an angle θ ₃ formed by a straight line connecting both ends of the second inclined groove and a tire circumferential direction is 10 ° or less.

The distance in the tire circumferential direction between the start ends of the adjacent first inclined grooves is L1, and the tire circumferential direction between the start end of the first inclined groove and the start end of the second inclined groove connected to the first inclined groove is When the distance is L2, it is preferable that 0.3 ≦ L2 / L1 ≦ 0.7.
When the distance in the tire width direction from the first circumferential groove of the connecting portion is W1, and the distance in the tire width direction from the first circumferential groove at the start end of the first inclined groove is W2, It is preferable that 0.1 ≦ W2 / W1 ≦ 0.4.

A second lug groove extending in parallel with the first lug groove in a land part between two first lug grooves adjacent to each other in the tire circumferential direction, the land part being outside the second inclined groove in the tire width direction. Is preferably provided.

It is preferable that the width of the first inclined groove increases from the start end toward the connection portion.
Moreover, it is preferable that the width | variety of a said 2nd inclination groove | channel increases as it goes to the said connection part from the said start end.

It is preferable that the depth of the first inclined groove increases from the start end toward the connection portion.
Moreover, it is preferable that the depth of the said 2nd inclination groove | channel increases as it goes to the said connection part from the said start end.

The first inclined groove group, the first lug groove group, and the second inclined groove group are provided only on the outer side of the vehicle when a pneumatic tire is mounted on the tire center line. Is preferable.

With respect to the tire center line, one or a plurality of second circumferential grooves extending in the tire circumferential direction and annularly over the entire circumference of the tire are provided on the inner side of the vehicle when the pneumatic tire is mounted on the vehicle. It is preferable.

According to the above-described aspect, by providing the second inclined groove whose length in the tire circumferential direction is shorter than that of the first inclined groove, the portion having lower rigidity than the other portions of the land portion is dispersed in the tire circumferential direction. Can do. Thereby, uneven wear can be suppressed and noise during traveling can be improved.

1 is a perspective view showing a pneumatic tire 10 according to a first embodiment of the present invention. It is a development view showing

tread patterns

30A and 30B of pneumatic tire 10 which is a 1st embodiment of the present invention. It is a development view showing

tread patterns

30A and 30C of a pneumatic tire which is a second embodiment of the present invention. It is a development view showing

tread patterns

30A and 30D of a pneumatic tire which is a modification of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
(Whole tire description)
Hereinafter, the pneumatic tire of this embodiment will be described. FIG. 1 is a tire cross-sectional view showing a cross section of a pneumatic tire (hereinafter referred to as a tire) 10 of the present embodiment.
The tire 10 is, for example, a passenger car tire. Passenger car tires are tires defined in Chapter A of JATMA YEAR BOOK 2012 (Japan Automobile Tire Association Standard). In addition, the present invention can also be applied to small truck tires defined in Chapter B and truck and bus tires defined in Chapter C.
The numerical value of the dimension of each pattern element specifically explained below is a numerical example in the tire for passenger cars, and the pneumatic retirement according to the present invention is not limited to these numerical examples.

The tire circumferential direction described below refers to the direction of rotation of the tread surface (both rotation directions) when the tire 10 is rotated about the tire rotation axis, and the tire radial direction refers to the tire rotation axis. The radial direction extending orthogonally refers to the tire radial direction outer side, which is the side away from the tire rotation axis in the tire radial direction. The tire width direction means a direction parallel to the tire rotation axis direction, and the tire width direction outside means both sides of the tire 10 away from the tire center line CL.

(Tire structure)
The tire 10 has a pair of bead cores 11, a carcass ply layer 12, and a belt layer 14 as a skeleton material, and a tread rubber member 18, a side rubber member 20, and a bead filler rubber around these skeleton materials. It mainly includes a member 22, a rim cushion rubber member 24, and an inner liner rubber member 26.

The pair of bead cores 11 has an annular shape, and is disposed at both ends in the tire width direction and at inner ends in the tire radial direction.
The carcass ply layer 12 is composed of one or a plurality of carcass ply materials 12a and 12b in which organic fibers are covered with rubber. The carcass ply materials 12 a and 12 b are formed in a toroidal shape by being wound between a pair of bead cores 11.
The belt layer 14 includes a plurality of

belt members

14 a and 14 b and is wound around the outer side of the carcass ply layer 12 in the tire radial direction in the tire circumferential direction. The width in the tire width direction of the belt material 14a on the inner side in the tire radial direction is wider than the width of the belt material 14b on the outer side in the tire radial direction.
The

belt members

14a and 14b are members in which a steel cord is covered with rubber. The steel cord of the belt material 14a and the steel cord of the belt material 14b are arranged to be inclined at a predetermined angle, for example, 20 to 30 degrees with respect to the tire circumferential direction. The steel cord of the belt material 14a and the steel cord of the belt material 14b are inclined in directions opposite to each other with respect to the tire circumferential direction and cross each other. The belt layer 14 suppresses the expansion of the carcass ply layer 12 due to the filled air pressure.

A tread rubber member 18 is provided outside the belt layer 14 in the tire radial direction. Side rubber members 20 are connected to both ends of the tread rubber member 18. The tread rubber member 18 includes a two-layer rubber member including an upper layer tread rubber member 18a provided on the outer side in the tire radial direction and a lower layer tread rubber member 18b provided on the inner side in the tire radial direction. A rim cushion rubber member 24 is provided at the inner end in the tire radial direction of the side rubber member 20. The rim cushion rubber member 24 comes into contact with a rim on which the tire 10 is mounted. A bead filler rubber member 22 is provided outside the bead core 11 in the tire radial direction so as to be sandwiched between carcass ply layers 12 wound around the bead core 11. An inner liner rubber member 26 is provided on the inner surface of the tire 10 facing the tire cavity region filled with air surrounded by the tire 10 and the rim.
In addition, the tire 10 includes a belt cover layer 28 that covers the outer surface of the belt layer 14 in the tire radial direction. The belt cover layer 28 is made of organic fibers and rubber that covers the organic fibers.

Although the tire 10 has the tire structure shown in FIG. 1, the tire structure of the pneumatic tire of the present invention is not limited to this.

FIG. 2 is a development view showing the

tread patterns

30A and 30B of the pneumatic tire 10. FIG. As shown in FIG. 2, the tire 10 of the present invention has tread patterns 30 A and 30 B that are characteristic of the present invention formed on the tread portion T on both sides with respect to the tire center line CL. The tire 10 having the

tread patterns

30A and 30B can be suitably used for a tire for a passenger car. In particular, it can be suitably used when traveling on a circuit race course with a passenger car capable of traveling on public roads. Here, a case where the tread pattern 30A is disposed on the outer side in the vehicle width direction when mounted on the vehicle and the tread pattern 30B is disposed on the inner side in the vehicle width direction when mounted on the vehicle will be described.

The tire 10 of the present invention has a predetermined tire rotation direction, and is mounted on the vehicle so as to rotate in the tire rotation direction R of FIG. 2 when the vehicle moves forward. On the surface of the side rubber member 20 of the tire 10, symbols and information for specifying the direction of this rotational movement are displayed. When the tire 10 rotates in the tire rotation direction R, the tread portion T rotates from the top to the bottom in FIG. 2, and the position in contact with the road surface of the tread portion T moves from the bottom to the top in FIG.
In FIG. 2, the symbol CL indicates the center line of the tire. The

tread patterns

30A and 30B are in contact with the road surface in the tire width direction region indicated by the contact width W in a state where the tire 10 is mounted on the vehicle.

Here, the distance between the grounding ends E1 and E2 is the grounding width W. The ground contact ends E1 and E2 are at both ends of the ground contact surface in the tire width direction when the tire 10 is assembled to a specified rim, filled with a specified internal pressure, and grounded on a horizontal plane under the condition of 80% of the specified load. is there.

In the present invention, the tire width direction W refers to the direction of the rotation center axis of the tire 10 and is the left-right direction in FIGS. 1 and 2. Further, the tire circumferential direction C refers to the rotation direction R of the tire 10 and the opposite direction, and is a direction perpendicular to the paper surface of FIG. 1 and a vertical direction of FIG.
The

tread patterns

30A and 30B shown in FIG. 2 are provided on the opposite sides of the center line CL in the width direction. Each of the

tread patterns

30A and 30B includes a first circumferential groove 31, a first inclined groove group including a plurality of first inclined grooves 32, a first lug groove group including a plurality of first lug grooves 33, and a plurality of

tread patterns

30A and 30B. A second inclined groove group including the second inclined grooves 34.

A pair of first circumferential grooves 31 (the first circumferential groove 31 of the tread pattern 30A and the first circumferential groove 31 of the tread pattern 30B) that are separated from each other with the tire center line CL therebetween extend in the tire circumferential direction. It is provided annularly over the entire circumference. A first inclined groove group, a first lug groove group, and a second inclined groove group are provided in a region between the first circumferential groove 31 and the tire ground contact edge E1 or E2.
There are no other circumferential grooves on the outer side in the tire width direction than the first circumferential groove 31. The land portion 36 in the region between the first circumferential groove 31 and the tire ground contact edge E1 or E2 is continuous to the tire ground contact edge E1 or E2 without being divided in the tire width direction. For this reason, the ground contact area of the land portion 36 can be increased, and the steering stability can be improved.

A plurality of the first inclined grooves 32 are provided in the tire circumferential direction, and a position spaced outward from the first circumferential groove 31 in the tire width direction is a start end X, and the direction opposite to the tire rotation direction R (first direction) ) Toward the outer side in the tire width direction and extends to be inclined toward the outer side in the tire width direction, and is connected to the first lug groove 33 and the second inclined groove 34 at the outer end Y (connection portion Y) in the tire width direction.

A plurality of first lug grooves 33 are provided in the tire circumferential direction, from the respective outer ends in the tire width direction of the first inclined grooves 32 toward the direction opposite to the tire rotation direction R and toward the outer side in the tire width direction. It inclines and extends to the outer side in the tire width direction than the ground contact edge E1 or E2.

A plurality of second inclined grooves 34 are provided in the tire circumferential direction. One end of the second inclined groove 34 is connected to the first inclined groove 32 and the first lug groove 33 at a connection portion B between the first inclined groove 32 and the first lug groove 33. The second inclined groove 34 extends from the connecting portion B in the tire rotating direction R, and the first inclined groove 32 and the first lug groove 33 to which the second inclined groove is connected and the other first adjacent to the tire rotating direction R. It extends to a position W (starting end) that is separated from the inclined groove 32 and the first lug groove 33.
That is, the plurality of first inclined grooves are 32a, 32b, 32c,... In the order of the tire rotation direction R, the plurality of first lug grooves are 33a, 33b, 33c,. The inclined grooves are defined as 34a, 34b, 34c,. The first inclined groove 32a, the first lug groove 33a, and the second inclined groove 34a are connected by the connecting portion B1, and the first inclined groove 32b, the first lug groove 33b, and the second inclined groove 34b are connected by the connecting portion B2. Suppose that At this time, the second inclined groove 34a is different from the first inclined groove 32a and the first lug groove 33a to which the second inclined groove 34a is connected by the connecting portion B1 in the tire rotation direction R (the first tire circumferential direction first). In the direction opposite to the tire rotation direction R (first direction) from the connecting portion B2 of the other first inclined groove 32b and the other first lug groove 33b adjacent to each other in the second direction opposite to the direction). The position is the start end V1, and extends in the first direction to the connecting portion Y1 between the first inclined groove 32a and the first lug groove 33a.

The length of the second inclined groove 34 in the tire circumferential direction is shorter than that of the first inclined groove 32. For this reason, the start ends V1, V2,... Of the second inclined grooves 34 are arranged at intermediate positions between the start ends X1, X2,.
In the region 36 between the first circumferential groove 31 and the tire ground contact edge E1 or E2, in the vicinity of the start end X of the first inclined groove 32 and in the vicinity of the start end V of the second inclined groove 34. The part is less rigid than the other parts.
If the race course of a circuit is run using the pneumatic tire which does not have the 2nd inclined groove 34 but is provided only with the 1st inclined groove 32, in the part near the starting end X of the 1st inclined groove 32, Uneven wear of the land portion 36 occurs. Due to this uneven wear, noise during running is worsened.

On the other hand, in the present embodiment, by providing the second inclined groove 34 whose length in the tire circumferential direction is shorter than that of the first inclined groove 32, a portion having a lower rigidity than other portions of the land portion 36 is provided in the tire circumferential direction. Can be dispersed in the direction. Thereby, uneven wear can be suppressed and noise during traveling can be improved.
The tire circumferential positions of the start end X of the first inclined groove 32 and the start end V of the second inclined groove 34 of the tread pattern 30A, and the start end X and the second inclination of the first inclined groove 32 of the tread pattern 30B. It is preferable to shift the position of the start end V of the groove 34 in the tire circumferential direction. As a result, a portion having lower rigidity than the other portions of the land portion 36 can be further dispersed in the tire circumferential direction, uneven wear can be suppressed, and noise during traveling can be improved.

Here, the center point in the groove width direction at the start end X of the first inclined groove 32 (the tip when there is no groove width at the start point) and the groove width direction at the outer end Y in the tire width direction of the first inclined groove 32. of a straight line connecting the center point (center point of the connecting portion Y between the first lug grooves 33), when the angle between the tire circumferential direction and theta _1, it is preferable that 15 ° ≦ θ ₁ ≦ 40 ° . Hereinafter, this angle is referred to as an inclination angle of the first inclined groove 32. If the inclination angle theta ₁ of the first inclined groove 32 is less than 15 °, the rigidity of the portion is decreased surrounded by the first inclined groove 32 and the second inclined groove 34 of the land portion 36, there is a possibility that uneven wear occurs . On the other hand, when the inclination angle theta ₁ is greater than 40 °, it becomes insufficient effect of reducing noise.

The center point in the groove width direction at the inner end Y in the tire width direction of the first lug groove 33 (the center point of the connecting portion Y with the first inclined groove 32) and the center point in the groove width direction at the outer end Z in the tire width direction An angle θ ₂ formed by the connecting straight line and the tire circumferential direction is larger than an angle θ ₁ formed by the first inclined groove 32 and the tire width direction. Hereinafter, this angle θ ₂ is referred to as an inclination angle of the first lug groove 33. It is preferred that the inclination angle theta ₂ of the first lug grooves 33 is 70 ° ~ 80 °. If the inclination angle theta ₂ of the first lug grooves 33 is in the range of 70 ° ~ 80 °, the balance of the turning performance and braking performance of the tire is improved.

A center point in the groove width direction at the start end V of the second inclined groove 34 (a tip when there is no groove width at the start point) and a center point in the groove width direction at the outer end Y in the tire width direction of the first inclined groove 32 ( of a straight line connecting the center point) and the connecting portion Y between the first lug grooves 33, when the angle between the tire circumferential direction and theta _3, the absolute value of θ _{₃ |} θ ₃ | is, _| θ ₃ | ≦ 10 ° is preferable. Hereinafter, this angle θ _{3 is referred} to as an inclination angle of the second inclined groove 32. Incidentally, the sign of the inclination angle theta ₃ is when the starting point W of the second inclined groove 32 is inside the tire width direction than the connecting portion Y is positive, the start point W of the second inclined groove 32 is connected portion Y Is also negative when it is outside in the tire width direction.
When the absolute value of the inclination angle θ ₃ of the second inclined groove 34 is larger than + 10 °, the rigidity of the portion surrounded by the first inclined groove 32 and the second inclined groove 34 of the land portion 36 is lowered, and uneven wear occurs. There is a fear. On the other hand, if the inclination angle θ ₁ is smaller than −10 °, the effect of reducing noise becomes insufficient. Moreover, the drainage performance by the 2nd inclination groove 34 falls.

Here, the distance in the tire circumferential direction between the start end X1 of the first inclined groove 32a and the start end X2 of the first inclined groove 32b adjacent to the first inclined groove 32a is L1. Further, the distance in the tire circumferential direction between the start end X2 of the first inclined groove 32b and the start end V2 of the second inclined groove 34b connected to the first inclined groove 32b is L2. At this time, it is preferable that 0.3 ≦ L2 / L1 ≦ 0.7 from the viewpoint of dispersing the portion having low rigidity of the land portion 36 in the tire circumferential direction.

Further, the distance in the tire width direction from the first circumferential groove 31 to the tire width direction outer side end Y (connection portion Y) of the first inclined groove 32 is W1, and the first inclined groove 32 starts from the first circumferential groove 31. When the distance in the tire width direction to the end X is W2, it is preferable that 0.1 ≦ W2 / W1 ≦ 0.4. By setting the position of the start end X of the first inclined groove 32 in the tire width direction so that W2 / W1 falls within this range, the portion of the land portion 36 in the vicinity of the start end X of the first inclined groove 32 is set. Rigidity is not extremely reduced, uneven wear can be suppressed, and noise can be reduced.

It is preferable that the groove width of the first inclined groove 32 gradually increases from the start end X toward the connection portion Y and gradually decreases from the connection portion Y toward the start end X. Thereby, the fall of the rigidity of the land part 36 in the vicinity of the start end X can be suppressed.
Further, it is preferable that the depth of the first inclined groove 32 gradually increases from the start end X toward the connection portion Y and gradually decreases from the connection portion Y toward the start end X. Thereby, the fall of the rigidity of the land part 36 in the vicinity of the start end X can be suppressed.

Similarly, it is preferable that the groove width of the second inclined groove 34 gradually increases from the start end V toward the connection portion Y and gradually decreases from the connection portion Y toward the start end V. Thereby, the fall of the rigidity of the land part 36 in the vicinity of the start end V can be suppressed.
Moreover, it is preferable that the groove depth of the second inclined groove 34 gradually increases from the start end D toward the connection portion B and gradually decreases from the connection portion B toward the start end D. Thereby, the fall of the rigidity of the land part 36 in the vicinity of the start end V can be suppressed.

In addition, the 2nd lug groove 35 extended in parallel with the 1st lug groove 33 in the range which does not cross | intersect the 1st inclined groove 32 and the 2nd inclined groove 34 between the two 1st lug grooves 33 adjacent to a tire circumferential direction. May be provided. The second lug groove 35 shown in FIG. 2 extends from the position spaced from the second inclined groove 34 to the outer side in the tire width direction to the ground contact E1 or E2 in parallel with the first lug groove 33.
Here, the start end U of the second lug groove 35 is preferably displaced from the start end X of the first inclined groove 32 and the start end V of the second inclined groove 34 in the tire circumferential direction. When the second lug groove 35 is provided, the rigidity of the portion near the start end V of the land portion 36 becomes low. By shifting the position of the start end U from the position of the start end X and the start end V in the tire circumferential direction, the portion with low rigidity of the land portion 36 can be further dispersed in the tire circumferential direction, and uneven wear is suppressed. Noise during running can be further improved.

(Second Embodiment)
FIG. 3 is a plan development view of the tread pattern of the tire according to the second embodiment of the present invention. As shown in FIG. 3, in the present embodiment, the tread pattern 30A on the side arranged on the outer side in the width direction of the vehicle when mounted on the vehicle is the same as that of the first embodiment. The tread pattern 30C on the inner side in the width direction is different from the tread pattern 30B of the first embodiment.

In the present embodiment, the extending direction of the first inclined groove 32, the first lug groove 33, the second inclined groove 34, and the second lug groove 35 is opposite in the tread pattern 30A and the tread pattern 30C.
That is, in the tread pattern 30A, the first inclined groove 32 extends from the start end X in the direction opposite to the tire rotation direction R (upward in FIG. 3) and outward in the tire width direction, and the second inclined groove 24 extends from the start end V to the tire. The first lug groove 33 extends from the connecting portion Y in the direction opposite to the tire rotation direction R (upward in FIG. 3) and outward in the tire width direction. On the other hand, in the tread pattern 30C, the first inclined groove 32 extends from the start end X to the tire rotation direction R (downward in FIG. 3) and the tire width direction outside, and the second inclined groove 24 rotates from the start end V to the tire. The first lug groove 33 extends from the connecting portion Y in the tire rotation direction R (downward in FIG. 3) and outward in the tire width direction.

In this way, the tread pattern 30C may be formed so as to be rotationally symmetric with the tread pattern 30A around one point on the tire center line CL.
Also in the present embodiment, by providing the second inclined groove 34 whose length in the tire circumferential direction is shorter than that of the first inclined groove 32, a portion (first inclined groove 32 having lower rigidity than the other portions of the land portion 36 is provided. In the vicinity of the starting end X of the second inclined groove 34 and the portion in the vicinity of the starting end V of the second inclined groove 34) can be dispersed in the tire circumferential direction. Thereby, uneven wear can be suppressed and noise during traveling can be improved.
Further, the land portion 36 in the region between the first circumferential groove 31 and the tire ground contact edge E1 or E2 is continued to the tire ground contact edge E1 or E2 without being divided in the tire width direction, so that the land portion 36 is obtained. The ground contact area can be increased, and the steering stability can be improved.

(Modification)
FIG. 4 is a plan development view of a tread pattern of a tire according to a modification of the present invention. As shown in FIG. 4, in the present embodiment, the tread pattern 30A on the side arranged on the outer side in the width direction of the vehicle when mounted on the vehicle is the same as that of the first embodiment. The tread pattern 30D on the inner side in the width direction is different from the tread pattern 30B of the first embodiment. The tread pattern 30 D includes one or a plurality of second circumferential grooves 37 (37 A, 37 B) and a third lug groove group including a plurality of third lug grooves 38.

Also in the present modification, as in the first embodiment and the second embodiment, by providing the second inclined groove 34 whose tire circumferential length is shorter than the first inclined groove 32, A portion having a lower rigidity than the portion (a portion near the start end X of the first inclined groove 32 and a portion near the start end V of the second inclined groove 34) can be dispersed in the tire circumferential direction. Thereby, uneven wear can be suppressed and noise during traveling can be improved.
Further, by providing the tread pattern 30A on the outer side in the width direction of the vehicle, which has a greater influence on the steering stability than on the inner side in the width direction of the vehicle, between the first circumferential groove 31 and the tire ground contact end E1 on the outer side in the width direction of the vehicle. The land portion 36 in the region can be continued to the tire ground contact end E1 without being divided in the tire width direction, and the ground contact area of the land portion 36 on the outer side in the width direction of the vehicle can be increased, thereby improving the steering stability. can do.
Further, by providing one or a plurality of second circumferential grooves 37 (37A, 37B) in the tread pattern 30D on the inner side in the width direction of the vehicle, the vehicle has less influence on the steering stability than the outer side in the width direction of the vehicle. The groove area ratio in the inner portion in the width direction can be increased and the drainage performance can be improved.

[Experimental example]
In order to examine the effects of the

tread patterns

30A and 30B of the tire 10 of the present invention, tires provided with tread patterns having the specifications shown in Tables 1 and 2 below were produced and the tire performance was evaluated.

The tire size was 215 / 45R17.
In the tires of Examples 1 to 16, the first circumferential groove 31, the first inclined groove 32, the second inclined groove 34, and the first lug groove 33 are formed in the tread portion T. Table 1 shows the inclination angle θ ₁ of the first inclined groove 32 and the inclination angles θ ₃ , L2 / L1, and W2 / W1 of the second inclined groove 34, respectively.

In Comparative Example 1, only the first circumferential groove 31, the first inclined groove 32, and the first lug groove 33 are formed in the tread portion T. The inclination angle θ ₁ of the first inclined groove 32 is as shown in Table 1.
In Comparative Example 2, only the first circumferential groove 31, the second inclined groove 34, and the first lug groove 33 are formed in the tread portion T. The inclination angle θ ₃ of the second inclined groove 34 is as shown in Table 1.

As the tire performance of the prototype tires described above, the uneven wear performance and the in-vehicle noise performance of the worn tire were evaluated as follows.

[Uneven wear performance]
In order to evaluate the tire performance, a rear wheel drive vehicle having an engine displacement of 2000 cc class was used. The internal pressure condition was 230 (kPa) for both the front and rear wheels. After making 10 laps of the circuit course of 1km 6km with the above vehicle, the degree of uneven wear was evaluated by 10-point method by visual observation of 10 people. The tire of Comparative Example 1 was given 5 points and judged to be improved by 6 points or more.

[In-car noise performance of worn tires]
The tires used for the evaluation of uneven wear performance were mounted on the vehicle by a professional driver, and the interior noise was evaluated by a five-point method using the professional driver's feeling. The tire of Comparative Example 1 was given 3 points and judged to be improved by 4 points or more.
The evaluation results are shown in Tables 1 and 2.

Only the tire of Comparative Example 1 having only the first circumferential groove, the first inclined groove, and the first lug groove, and not having the second inclined groove, only the first circumferential groove, the second inclined groove, and the first lug groove. In the tires of Examples 1 to 16 having the first circumferential groove, the first inclined groove, the second inclined groove, and the first lug groove, in contrast to the tire of the comparative example 2 having the first inclined groove It can be seen that the uneven wear performance and the in-vehicle noise performance of the worn tire are improved.

Comparing Examples 1 to 4, it can be seen that when the inclination angle θ ₁ of the first inclined groove 32 is 15 ° ≦ θ ₁ ≦ 40 °, the partial wear performance and the in-vehicle noise performance of the worn tire are further improved.
Comparing Examples 5 to 8, it can be seen that when the absolute value of the inclination angle θ ₂ of the second inclined groove 34 is 10 ° or less, the uneven wear performance and the in-vehicle noise performance of the worn tire are further improved.
Comparing Examples 9 to 12, it can be seen that when L2 / L1 is 0.3 ≦ L2 / L1 ≦ 0.7, the uneven wear performance and the in-vehicle noise performance of the worn tire are further improved.
Comparing Examples 13 to 16, it can be seen that when W2 / W1 is 0.1 ≦ W2 / W1 ≦ 0.4, the uneven wear performance and the in-vehicle noise performance of the worn tire are further improved.

As mentioned above, although the pneumatic tire of this invention was demonstrated in detail, this invention is not limited to the said embodiment, Of course, in the range which does not deviate from the main point of this invention, you may make a various improvement and change. is there.

Axis rotation axis C tire circumferential direction CL center line E1, E2 contact end R tire rotation direction T tread portion W contact width 10 tire 11 bead core 12 carcass ply layer 14

belt layers

14a, 14b belt material 18 tread rubber member 18a first tread rubber Member 18b Second tread rubber member 20 Side rubber member 22 Bead filler rubber member 24 Rim cushion rubber member 26 Inner

liner rubber members

30A, 30B, 30C, 30D Tread pattern 31 First circumferential groove 32 First inclined groove 33 First lug groove 34 Second inclined groove 35 Second lug groove 36

Land portions

37, 37A, 37B Second circumferential groove 38 Lug groove

Claims

A pneumatic tire having a tread pattern in a tread portion,
The tread pattern is
A first circumferential groove extending in the tire circumferential direction and provided annularly over the entire circumference of the tire;
A land portion that is provided on the outer side in the tire width direction of the first circumferential groove and is continuous over the entire circumference of the tire, and a land portion that continues from the first circumferential groove to the tire ground contact end in the tire width direction;
A first inclined groove extending in the tire circumferential direction is inclined in the tire circumferential direction while starting from a position spaced from the first circumferential groove outward in the tire width direction and extending toward the first direction in the tire circumferential direction. A plurality of first inclined groove groups,
A first lug groove group in which a plurality of first lug grooves extending from the outer end in the tire width direction to the ground contact end of the first inclined grooves are provided in the tire circumferential direction;
Land between the first inclined groove and the first lug groove and the other first inclined groove and the other first lug groove adjacent to each other in the second direction opposite to the first direction in the tire circumferential direction. The first end in the tire circumferential direction and extending to the connecting portion between the first inclined groove and the first lug groove, and the length in the tire circumferential direction is shorter than the first inclined groove A second inclined groove group in which a plurality of second inclined grooves are provided in the tire circumferential direction;
A pneumatic tire comprising:
A pneumatic tire having a tread pattern in a tread portion,
The tread pattern is
A pair of first circumferential grooves extending in the tire circumferential direction, spaced apart across the tire center line, and provided annularly over the entire circumference of the tire;
A land portion that is provided on the outer side in the tire width direction of each of the first circumferential grooves, is continuous over the entire circumference of the tire, and is continuous from each of the first circumferential grooves to the tire ground contact edge on the outer side in the tire width direction;
A first inclined groove extending from the first circumferential direction toward the first direction in the tire circumferential direction and extending obliquely toward the outer side in the tire width direction is defined as a start end at a position spaced apart from each of the first circumferential grooves. A plurality of first inclined groove groups provided in a direction;
A first lug groove group in which a plurality of first lug grooves extending from the outer end in the tire width direction to the ground contact end of the first inclined grooves are provided in the tire circumferential direction;
Land between the first inclined groove and the first lug groove and the other first inclined groove and the other first lug groove adjacent to each other in the second direction opposite to the first direction in the tire circumferential direction. The first end in the tire circumferential direction and extending to the connecting portion between the first inclined groove and the first lug groove, and the length in the tire circumferential direction is shorter than the first inclined groove A second inclined groove group in which a plurality of second inclined grooves are provided in the tire circumferential direction;
A pneumatic tire comprising:
A pneumatic tire having a tread pattern in a tread portion,
The tread pattern is
A pair of first circumferential grooves extending in the tire circumferential direction, spaced apart across the tire center line, and provided annularly over the entire circumference of the tire;
A land portion that is provided on the outer side in the tire width direction of each of the first circumferential grooves, is continuous over the entire circumference of the tire, and is continuous from each of the first circumferential grooves to the tire ground contact edge on the outer side in the tire width direction;
With the position spaced apart from each of the first circumferential grooves on the outer side in the tire width direction as a starting end, and toward the first direction in the tire circumferential direction on the outer side in the tire width direction than one of the first circumferential grooves, The tire extends in the tire width direction outer side, and extends in the tire width direction outer side than the other of the first circumferential grooves in the direction opposite to the first direction in the tire circumferential direction and extends in the tire width direction outer side. A first inclined groove group provided with a plurality of inclined grooves in the tire circumferential direction;
A first lug groove group in which a plurality of first lug grooves extending from the outer end in the tire width direction to the ground contact end of the first inclined grooves are provided in the tire circumferential direction;
Land between the first inclined groove and the first lug groove and the other first inclined groove and the other first lug groove adjacent to each other in the second direction opposite to the first direction in the tire circumferential direction. The first end in the tire width direction outside one of the first circumferential grooves and extending to the connecting portion between the first inclined groove and the first lug groove toward the first direction in the tire circumferential direction. And extending to the connecting portion between the first inclined groove and the first lug groove in a direction opposite to the first direction in the tire circumferential direction on the outer side in the tire width direction than the other of the first circumferential groove, A second inclined groove group in which a plurality of second inclined grooves whose length in the direction is shorter than the first inclined grooves are provided in the tire circumferential direction;
A pneumatic tire comprising:
The pneumatic tire according to any one of claims 1 to 3, wherein an angle θ 1 formed by a straight line connecting both ends of the first inclined groove and a tire circumferential direction is 15 ° ≦ θ 1 ≦ 40 °.
The absolute value of the straight line and the angle theta 3 in the tire circumferential direction connecting the both ends of the second inclined groove is 10 ° or less, the pneumatic tire according to any one of claims 1 to 4.
The distance in the tire circumferential direction between the start ends of the adjacent first inclined grooves is L1, and the tire circumferential direction between the start end of the first inclined groove and the start end of the second inclined groove connected to the first inclined groove is The pneumatic tire according to any one of claims 1 to 5, wherein 0.3 ≦ L2 / L1 ≦ 0.7 when the distance is L2.
When the distance in the tire width direction from the first circumferential groove of the connecting portion is W1, and the distance in the tire width direction from the first circumferential groove at the start end of the first inclined groove is W2, 0. The pneumatic tire according to any one of claims 1 to 6, wherein 1≤W2 / W1≤0.4.
A second lug groove extending in parallel with the first lug groove in a land part between two first lug grooves adjacent to each other in the tire circumferential direction, the land part being outside the second inclined groove in the tire width direction. The pneumatic tire according to any one of claims 1 to 7, wherein is provided.
The pneumatic tire according to any one of claims 1 to 8, wherein a width of the first inclined groove increases from the start end toward the connection portion.
The pneumatic tire according to any one of claims 1 to 9, wherein a width of the first lug groove increases from the start end toward the connection portion.
The pneumatic tire according to any one of claims 1 to 9, wherein the depth of the first inclined groove increases from the start end toward the connection portion.
The pneumatic tire according to any one of claims 1 to 11, wherein a depth of the first lug groove increases from the start end toward the connection portion.
The first inclined groove group, the first lug groove group, and the second inclined groove group are provided only on the outer side of the vehicle when a pneumatic tire is mounted on the tire center line. The pneumatic tire according to any one of claims 1 to 12.
With respect to the tire center line, one or a plurality of second circumferential grooves extending in the tire circumferential direction and annularly over the entire circumference of the tire are provided on the inner side of the vehicle when the pneumatic tire is mounted on the vehicle. The pneumatic tire according to claim 13.