JP6953298B2 - Pneumatic tires - Google Patents

Description

The present invention relates to a pneumatic tire.

Conventionally, in a pneumatic tire, a plurality of sipes are arranged in a block in order to improve the performance on ice and snow (see, for example, Patent Document 1).

JP-A-2017-500247

In the above techniques, it is desired to further improve the performance on ice and snow.

An object of the present invention is to provide a pneumatic tire that has both performance on ice and performance on snow.

The gist structure of the present invention is as follows.
The pneumatic tire of the first aspect of the present invention has one or more circumferential main grooves extending in the tread circumferential direction and a plurality of widthwise grooves extending in the tread width direction on the tread tread.
A plurality of block-shaped land portions are partitioned by the one or more circumferential main grooves and tread ends and the plurality of width direction grooves.
The land portion comprises at least three widthwise sipes extending across the land portion in the tread width direction.
The width direction sipe is located between the first sipe located on one side of the tread circumferential direction, the second sipe located on the other side of the tread circumferential direction, and the first sipe and the second width direction sipe. , Consisting of at least one intermediate sipe,
The first block piece partitioned by the first sipe and the width groove, the second block piece partitioned by the second sipe and the width groove, and the first sipe or the second sipe. It has an intermediate block piece, which is partitioned by the intermediate sipe or between two adjacent intermediate sipe.
The sipe volume of the intermediate sipe is smaller than the sipe volume of the first sipe and the sipe volume of the second sipe.
According to the pneumatic tire of the first aspect of the present invention, both on-ice performance and on-snow performance can be achieved at the same time.
Here, the "tread end" means that the tire comes into contact with the road surface when the tire is assembled on the rim, filled with the specified internal pressure, and rolled with a load corresponding to the maximum load capacity applied. The outermost end in the tire width direction of the outer peripheral surface of the tire.
Further, "extending in the tread circumferential direction" means extending at an angle of 5 ° or less with respect to the tread circumferential direction, and in addition to the case of extending linearly in the tread circumferential direction, the case of extending in a zigzag shape or a curved shape, etc. Shall include.
The term "sipe" refers to a tire having an opening width of 1.5 mm or less on the tread tread when the tire is mounted on the rim, the specified internal pressure is applied, and no load is applied.

Here, "rim" is an industrial standard that is effective in the area where tires are produced and used. In Japan, JATMA (Japan Automobile Tire Association) JATMA YEAR BOOK, and in Europe, ETRTO (The European Tire and Rim). STANDARDS MANUAL of Technical Organization), YEAR BOOK of TRA (The Tire and Rim Association, Inc.) in the United States, etc., or will be described in the future. , TRA's YEAR BOOK refers to the Design Rim) (ie, the "rim" above includes sizes that may be included in the industry standards in the future in addition to the current size. "Sizes to be described in the future" As an example of the above, the size described as "FUTURE DEVELOPMENTS" in the 2013 edition of ETRTO can be mentioned.) However, in the case of a size not described in the above industrial standard, the width corresponding to the bead width of the tire is used. Refers to the rim.
In addition, the "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel in the applicable size / ply rating described in the above JATMA, etc., and has a size not described in the above industrial standard. In this case, the "specified internal pressure" shall mean the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tires are mounted. Further, the "maximum load" means a load corresponding to the maximum load capacity.

In the pneumatic tire of the first aspect of the present invention, the sipe volume of the intermediate sipe is preferably 30 to 70% of the sipe volume of the first sipe and the sipe volume of the second sipe.
According to this configuration, the performance on ice and the performance on snow can be further compatible.

In the pneumatic tire of the first aspect of the present invention, the maximum depth of the intermediate sipe in the tire radial direction is the maximum depth of the first sipe in the tire radial direction and the maximum depth of the second sipe in the tire radial direction. It is preferably 30 to 70% of the tire.
According to this configuration, the performance on ice and the performance on snow can be further compatible.

The pneumatic tire of the second aspect of the present invention has one or more circumferential main grooves extending in the tread circumferential direction and a plurality of widthwise grooves extending in the tread width direction on the tread tread.
A plurality of block-shaped land portions are partitioned by the one or more circumferential main grooves and tread ends and the plurality of width direction grooves.
The land portion comprises at least three widthwise sipes extending across the land portion in the tread width direction.
The width direction sipes are the first sipes located on one side of the tread circumferential direction, the second sipes located on the other side of the tread circumferential direction, and at least located between the first sipes and the second sipes. Consists of one intermediate sipe
The first block piece partitioned by the first sipe and the width groove, the second block piece partitioned by the second sipe and the width groove, and the first sipe or the second sipe. It has an intermediate block piece, which is partitioned by the intermediate sipe or between two adjacent intermediate sipe.
In a plan view of the tread tread, the area of the intermediate block piece is larger than the area of the first block piece and the area of the second block piece.
According to the pneumatic tire of the second aspect of the present invention, both the performance on ice and the performance on snow can be achieved at the same time.

The pneumatic tire of the third aspect of the present invention has one or more circumferential main grooves extending in the tread circumferential direction and a plurality of widthwise grooves extending in the tread width direction on the tread tread.
A plurality of block-shaped land portions are partitioned by the one or more circumferential main grooves and tread ends and the plurality of width direction grooves.
The land portion comprises at least three widthwise sipes extending across the land portion in the tread width direction.
The width direction sipes are the first sipes located on one side of the tread circumferential direction, the second sipes located on the other side of the tread circumferential direction, and at least located between the first sipes and the second sipes. Consists of one intermediate sipe
The first block piece partitioned by the first sipe and the width groove, the second block piece partitioned by the second sipe and the width groove, and the first sipe or the second sipe. It has an intermediate block piece, which is partitioned by the intermediate sipe or between two adjacent intermediate sipe.
The first sipe and the second sipe are two-dimensional sipe that extend linearly in the depth direction, and the intermediate sipe is a three-dimensional sipe having a portion that bends and extends in the depth direction.
or,
The first sipe, the second sipe, and the intermediate sipe are all three-dimensional sipe having a portion that bends and extends in the depth direction, and the bending cycle of the intermediate sipe in the depth direction is the same. It is shorter than the bending period of the first sipe and the second sipe in the depth direction.
According to the pneumatic tire of the third aspect of the present invention, both the performance on ice and the performance on snow can be achieved at the same time.

According to the present invention, both on-ice performance and on-snow performance can be achieved at the same time.

It is a top view which shows the tread tread surface of the pneumatic tire which concerns on one Embodiment of 1st Embodiment of this invention. It is a tread circumferential sectional view which shows typically the land part 4 of the tire which concerns on one Embodiment of 1st Embodiment of this invention. It is a tread circumferential sectional view which shows typically the land part 4 of the tire which concerns on one Embodiment of the 2nd aspect of this invention. It is a tread circumferential sectional view which shows typically the land part 4 of the tire which concerns on one Embodiment of the 3rd aspect of this invention. It is a tread circumferential sectional view which shows typically the land part 4 of the tire which concerns on other embodiment of the 3rd aspect of this invention. It is a tread circumferential sectional view which shows typically the land part 4 of the tire which concerns on a comparative example.

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

<First aspect>
FIG. 1 is a plan view showing a tread tread 1 of a pneumatic tire (hereinafter, also referred to as a tire) according to an embodiment of the first aspect of the present invention.
As shown in FIG. 1, this tire has one or more (four in the illustrated example) circumferential main grooves 2 extending in the tread circumferential direction and a plurality of widthwise grooves extending in the tread width direction on the tread tread 1. 3 and. The number of the circumferential main groove 2 and the width direction groove 3 is not limited to this example, and can be changed as appropriate.

The groove width (opening width) of the circumferential main groove 2 is not particularly limited, but can be, for example, 4 to 10 mm, and the depth (maximum depth) of the circumferential main groove 2 is not particularly limited. For example, it can be 5 to 10 mm.
The groove width (opening width) of the width direction groove 3 is not particularly limited, but can be, for example, 2 to 8 mm, and the depth (maximum depth) of the width direction groove 3 is not particularly limited. For example, it can be 3 to 10 mm. Further, the width direction groove 3 is preferably inclined at an angle of 0 to 45 ° with respect to the tread width direction.

Further, as shown in FIG. 1, a plurality of land rows (5 rows in the illustrated example) are formed by the circumferential main groove 2 and the tread end TE, and the circumferential main groove 2 and the tread end TE and a plurality of rows are formed. A plurality of block-shaped land portions 4 are partitioned by the width direction groove 3.

As shown in FIG. 1, each land portion 4 extends across the land portion 4 in the tread width direction (in the illustrated example, four in the land portion 4 of the outermost land portion row in the tread width direction). Other than that, the land area 4 has 5) width direction sipes 5. The width direction sipe 5 is located between the first sipe 5a located on one side of the tread circumferential direction, the second sipe 5b located on the other side of the tread circumferential direction, and between the first sipe 5a and the second sipe 5b. , At least one (in the illustrated example, two in the land 4 of the outermost land row in the tread width direction and three in the other land 4), consisting of an intermediate sipe 5c. In the illustrated example, the width direction sipe 5 is formed substantially parallel to the width direction groove 3, and is inclined at an angle of 0 to 45 ° with respect to the tread width direction, similarly to the width direction groove 3. Is preferable. Further, in this example, the widthwise sipes 5 are arranged at equal intervals so as to equally divide the block-shaped land portion 4 in the tread circumferential direction.

FIG. 2 is a tread circumferential sectional view schematically showing a land portion 4 of a tire according to an embodiment of the first aspect of the present invention.
As shown in FIG. 2, this tire is partitioned by a first sipe 5a and a width groove 3, a first block piece 6a, a second sipe 5b and a width groove 3, and a second block piece. It has a 6b and an intermediate block piece 6c partitioned by a first sipe 5a or a second sipe 5b and an intermediate sipe 5c, or between two adjacent intermediate sipe 5c.

In the example shown in FIG. 2, the maximum depth of the intermediate sipe 5c in the tire radial direction is shallower than the maximum depth of the first sipe 5a in the tire radial direction and the maximum depth of the second sipe 5b in the tire radial direction. As shown in FIG. 2, in this example, the maximum depths of the three intermediate sipes 5c in the tire radial direction are the same. Further, as shown in FIG. 2, in this example, the maximum depth of the first sipe 5a in the tire radial direction and the maximum depth of the second sipe 5b in the tire radial direction are the same.

Then, in this example, the extending lengths of the first sipe 5a, the second sipe 5b, and the intermediate sipe 5c are the same. Further, in this example, the sipe widths (opening widths) of the first sipe 5a, the second sipe 5b, and the intermediate sipe 5c are also the same. Therefore, in this example, the sipe volume of the intermediate sipe 5c is smaller than the sipe volume of the first sipe 5a and the sipe volume of the second sipe 5b.
As a result, the rigidity of the intermediate sipe 5c is higher than the rigidity of the first sipe 5a and the rigidity of the second sipe.

In particular, in the present embodiment, the maximum depth of the intermediate sipe 5c in the tire radial direction is 30 to 70% of the maximum depth of the first sipe 5a in the tire radial direction and the maximum depth of the second sipe 5b in the tire radial direction. Is.
In this example, the maximum depths of the three intermediate sipes 5c in the tire radial direction are the same, but when there are a plurality of intermediate sipes 5c, the maximum depths in the tire radial direction can be different. Further, in this example, the maximum depth in the tire radial direction of the first sipe 5a and the maximum depth in the tire radial direction of the second sipe 5b are the same, but the maximum depth in the tire radial direction can be different. In these cases, the maximum depth of the intermediate sipe 5c in the tire radial direction is in the range of 30 to 70% of the maximum depth of the first sipe 5a in the tire radial direction and the maximum depth of the second sipe 5b in the tire radial direction. It is preferable to make them different.

As described above, in the tire of the present embodiment of the first aspect of the present invention, the sipe volume of the intermediate sipe 5c is smaller than the sipe volume of the first sipe 5a and the sipe volume of the second sipe 5b.
Hereinafter, the action and effect of the tire of the present embodiment of the first aspect of the present invention will be described. As an example, a case where the first sipe 5a is on the stepping side will be described.

According to the tire of the present embodiment of the first aspect of the present invention, the sipe volume of the intermediate sipe 5c is smaller than the sipe volume of the first sipe 5a and the sipe volume of the second sipe 5b (particularly, the tire of the intermediate sipe 5c). Since the maximum depth in the radial direction is deeper than the maximum depth in the tire radial direction of the first sipe 5a and the maximum depth in the tire radial direction of the second sipe 5b), the first stepping side has the highest edge pressure. The first block piece 6a partitioned by the sipe 5a is likely to fall down, and the edge pressure can be effectively increased. On the other hand, since the intermediate block piece 6c partitioned by the intermediate block piece 5c has a relatively shallow maximum depth of the sipe, it is difficult to fall down and the ground contact area by the intermediate block piece 6c can be secured. As a result, it is possible to improve the performance on ice by achieving both the securing of the edge pressure and the securing of the ground contact area. Further, on the kicking side, which greatly contributes to the performance of biting snow, the second block piece 6b partitioned by the second sipe 5b has a relatively deep radial maximum depth of the second sipe 5b. It becomes easy to fall down and the performance on snow can be effectively improved.
As described above, according to the tire of the present embodiment of the first aspect of the present invention, both the performance on ice and the performance on snow can be achieved at the same time.
In the tire of the present embodiment, since the first sipe 5a and the second sipe 5b have the same maximum depth, sipe width, and extension length, the second sipe 5b is on the stepping side. Even in the case of, the same effect can be obtained. Therefore, tire rotation can extend the life of tires due to wear.

In the first aspect of the present invention, as in the above embodiment, the sipe volume of the intermediate sipe 5 is preferably 30 to 70% of the sipe volume of the first sipe 5a and the sipe volume of the second sipe 5b. ..
By setting the above numerical range to 30% or more, the intermediate sipe 5 can be prevented from disappearing early due to wear, while by setting the above numerical range to 70% or less, the above-mentioned edge pressure and ground contact can be prevented. This is because the effect of securing the area and improving the performance on ice can be more reliably exhibited.

Further, in the first aspect of the present invention, as in the above embodiment, the maximum depth of the intermediate sipe 5c in the tire radial direction is the maximum depth of the first sipe 5a in the tire radial direction and the second sipe 5b. It is preferably 30 to 70% of the maximum depth in the tire radial direction.
By setting the above numerical range to 30% or more, the intermediate sipe 5 can be prevented from disappearing early due to wear, while by setting the above numerical range to 70% or less, the above-mentioned edge pressure and ground contact can be prevented. This is because the effect of securing the area and improving the performance on ice can be more reliably exhibited.
Further, by adjusting the sipe volume at the maximum depth in the tire radial direction of the width direction sipe 5 without changing the extending length of the width direction sipe 5, the above effect can be obtained while ensuring the edge length. Because it can be done.

In the above embodiment, the maximum depth of the widthwise sipe 5 in the tire radial direction is made different between the first sipe 5a, the second sipe 5b, and the intermediate sipe 5c as described above, so that the intermediate sipe 5c The sipe volume is smaller than the sipe volume of the first sipe 5a and the sipe volume of the second sipe 5b, but either the sipe extension length, the sipe width (opening width), or the maximum radial depth of the sipe. By adjusting 1 or more, the sipe volume of the intermediate sipe 5c can be made smaller than the sipe volume of the first sipe 5a and the sipe volume of the second sipe 5b.

Further, in the tire of the first aspect, in at least one land portion 4, the sipe volume of the intermediate sipe 5c is made smaller than the sipe volume of the first sipe 5a and the sipe volume of the second sipe 5b as described above. However, as in the above embodiment, it is preferable that the sipe volume of the intermediate sipe 5c is smaller than the sipe volume of the first sipe 5a and the sipe volume of the second sipe 5b for all the land parts 4.
This is because the above effects can be obtained in all the land areas 4 and the performance on ice and the performance on snow can be surely achieved at the same time.

<Second aspect>
Next, the tire according to the embodiment of the second aspect of the present invention will be described. This tire has a tread tread 1 similar to that shown in FIG. 1, except for the sipe spacing of the width sipe 5.

FIG. 3 is a tread circumferential cross-sectional view schematically showing the land portion 4 of the tire according to the embodiment of the second aspect of the present invention.
As shown in FIG. 3, in this example, the maximum depths of the first sipe 5a, the second sipe 5b, and the intermediate sipe 5c in the tire radial direction are the same, and the sipe volume is also the same. It is different from the tire shown in.

Further, as shown in FIG. 3, the tire is partitioned by a first sipe 5a and a width direction groove 3, a first block piece 6a, a second sipe 5b and a width direction groove 3, and a second. It has a block piece 6b and an intermediate block piece 6c partitioned by a first sipe 5a or a second sipe 5b and an intermediate sipe 5c, or between two adjacent intermediate sipe 5c.

Then, as shown in FIG. 3, in this cross section, the tread circumferential length of the intermediate block piece 6c is larger than the tread circumferential length of the first block piece 6a and the tread circumferential length of the second block piece 6b. ..
In the plan view of the tread tread 1, the area of the intermediate block piece 6c is larger than the area of the first block piece 6a and the area of the second block piece 6b.
Hereinafter, the action and effect of the tire of the present embodiment of the second aspect of the present invention will be described. As an example, a case where the first sipe 5a is on the stepping side will be described.

According to the tire of the present embodiment of the second aspect of the present invention, the area of the intermediate block piece 6c is smaller than the area of the first block piece 6a and the area of the second block piece 6b in the plan view of the tread tread surface 1. (In particular, in the cross section shown in FIG. 3, the tread circumferential length of the intermediate block piece 6c is larger than the tread circumferential length of the first block piece 6a and the tread circumferential length of the second block piece 6b). On the stepping side where the edge pressure is high, the first block piece 6a having a relatively small area is likely to fall down, and the edge pressure can be effectively increased. On the other hand, since the area of the intermediate block piece 6c is relatively large, it is possible to secure a ground contact area. As a result, it is possible to improve the performance on ice by achieving both the securing of the edge pressure and the securing of the ground contact area. Further, on the kicking side, which greatly contributes to the performance of biting snow, the second block piece 6b has a relatively small area, so that it is easy to fall down and the performance on snow can be effectively improved.
As described above, according to the tire of the present embodiment of the second aspect of the present invention, both the performance on ice and the performance on snow can be achieved at the same time.
In the tire of the present embodiment, since the first block piece 6a and the second block piece 6b have the same area in the plan view of the tread tread surface 1, the second sipe 5b is the stepping side. Even in this case, the same effect can be obtained. Therefore, tire rotation can extend the life of tires due to wear.

Here, in the second aspect, in the plan view of the tread tread 1, the area of the intermediate block piece 6c is preferably 120 to 250% of the area of the first block piece 6a and the area of the second block piece 6b. ..
By setting the above numerical range to 120% or more, the minimum rigidity of the block piece can be secured, while by setting the above numerical range to 250% or less, the above-mentioned edge pressure and ground contact area can be secured. This is because the effect of enhancing the performance on ice can be more reliably exhibited.

<Third aspect>
Next, the tire according to the embodiment of the third aspect of the present invention will be described. This tire has the same configuration as that shown in FIG. 1 in the plan view of the tread tread surface 1.
FIG. 4 is a tread circumferential sectional view schematically showing a land portion 4 of a tire according to an embodiment of a third aspect of the present invention.
As shown in FIG. 4, in this example, the maximum depths of the first sipe 5a, the second sipe 5b, and the intermediate sipe 5c in the tire radial direction are the same, which is different from the tire shown in FIG. ing.
As shown in FIG. 4, this tire is partitioned by a first sipe 5a and a width groove 3, a first block piece 6a, a second sipe 5b and a width groove 3, and a second block piece. It has a 6b and an intermediate block piece 6c partitioned by a first sipe 5a or a second sipe 5b and an intermediate sipe 5c, or between two adjacent intermediate sipe 5c.

Here, as shown in FIG. 4, the first sipe 5a and the second sipe 5b are two-dimensional sipe extending linearly in the depth direction, and the intermediate sipe 5c bends and extends in the depth direction. It is a three-dimensional sipe having a part. In the illustrated example, each of the three intermediate sipes 5c has five bends.
In the three-dimensional sipe, the block pieces partitioned by the sipe are less likely to fall down than in the two-dimensional sipe due to the effect that the wall surfaces of the sipe mesh with each other.
Hereinafter, the action and effect of the tire of the present embodiment of the third aspect of the present invention will be described. As an example, a case where the first sipe 5a is on the stepping side will be described.

According to the tire of the present embodiment of the third aspect of the present invention, the first sipe 5a and the second sipe 5b are two-dimensional sipe extending linearly in the depth direction, and the intermediate sipe 5c is a depth. Since it is a three-dimensional sipe having a portion that bends and extends in the longitudinal direction, the first block piece 6a partitioned by the first sipe 5a easily collapses on the stepping side where the edge pressure is highest, and the edge pressure is reduced. Can be effectively enhanced. On the other hand, the intermediate block piece 6c partitioned by the intermediate sipe 5c is less likely to fall down, and the ground contact area of the intermediate block piece 6c can be secured. As a result, it is possible to improve the performance on ice by achieving both the securing of the edge pressure and the securing of the ground contact area. Further, on the kicking side, which greatly contributes to the performance of biting snow, the second block piece 6b partitioned by the second sipe 5b is likely to fall down, and the performance on snow can be effectively improved.
As described above, according to the tire of the present embodiment of the third aspect of the present invention, both the performance on ice and the performance on snow can be achieved at the same time.
In the tire of the present embodiment, since both the first sipe 5a and the second sipe 5b are two-dimensional sipe, the same effect can be obtained even when the second sipe 5b is on the stepping side. can. Therefore, tire rotation can extend the life of tires due to wear.
Here, in the above example, the bent portion has a shape having a corner portion in the cross-sectional view, but a smooth shape such as a sine wave is also included in the present invention.
In the present embodiment of the third aspect, the number of bent portions of the three-dimensional sipe, the magnitude of the bending amplitude, and the like can be appropriately changed.

Next, the tire according to another embodiment of the third aspect of the present invention will be described. This tire has the same configuration as that shown in FIG. 1 in the plan view of the tread tread surface 1.
FIG. 5 is a tread circumferential sectional view schematically showing a land portion 4 of a tire according to another embodiment of the third aspect of the present invention.
As shown in FIG. 5, in this example, the maximum depths of the first sipe 5a, the second sipe 5b, and the intermediate sipe 5c in the tire radial direction are the same, which is different from the tire shown in FIG. ing.
As shown in FIG. 5, this tire is partitioned by a first sipe 5a and a width groove 3, a first block piece 6a, a second sipe 5b and a width groove 3, and a second block piece. It has a 6b and an intermediate block piece 6c partitioned by a first sipe 5a or a second sipe 5b and an intermediate sipe 5c, or between two adjacent intermediate sipe 5c.

Here, as shown in FIG. 5, the first sipe 5a, the second sipe 5b, and the intermediate sipe 5c are all three-dimensional sipe having a portion that bends and extends in the depth direction, and the intermediate sipe 5c has a portion. The bending cycle in the depth direction is shorter than the bending cycle in the depth direction of the first sipe 5a and the second sipe 5b (the number of bending portions is three in the first sipe 5a and the second sipe 5b, and the intermediate sipe 5 in 5c). The bending amplitudes are all the same.
Here, since the bending cycle of the intermediate sipe 5c in the depth direction is shorter than the bending cycle of the first sipe 5a and the second sipe 5b in the depth direction, the block pieces 6c partitioned by the intermediate sipe 5c are relative to each other. Therefore, it is less likely to fall down than the block pieces 6a and 6b partitioned by the first sipe 5a and the second sipe 5b.
Hereinafter, the action and effect of the tire of another embodiment of the third aspect of the present invention will be described. As an example, a case where the first sipe 5a is on the stepping side will be described.

According to the tire of the present embodiment of the third aspect of the present invention, the bending cycle of the intermediate sipe 5c in the depth direction is shorter than the bending cycle of the first sipe 5a and the second sipe 5b in the depth direction. On the stepping side where the edge pressure is highest, the first block piece 6a partitioned by the first sipe 5a is likely to fall down, and the edge pressure can be effectively increased. On the other hand, the intermediate block piece 6c partitioned by the intermediate sipe 5c is less likely to fall down, and the ground contact area of the intermediate block piece 6c can be secured. As a result, it is possible to improve the performance on ice by achieving both the securing of the edge pressure and the securing of the ground contact area. Further, on the kicking side, which greatly contributes to the performance of biting snow, the second block piece 6b partitioned by the second sipe 5b is likely to fall down, and the performance on snow can be effectively improved.
As described above, according to the tire of the other embodiment of the third aspect of the present invention, both the performance on ice and the performance on snow can be achieved at the same time.
In the tire of the present embodiment, since the first sipe 5a and the second sipe 5b have the same bending cycle in the depth direction, the same applies even when the second sipe 5b is on the stepping side. It can exert an action effect. Therefore, tire rotation can extend the life of tires due to wear.

Although the embodiments of the first, second, and third aspects of the present invention have been described above, the present invention is not limited to the above embodiments. For example, with respect to the third aspect, in the example shown in FIG. 5, the bending cycle of the intermediate sipe 5c in the depth direction is shorter than the bending cycle of the first sipe 5a and the second sipe 5b in the depth direction. However, the same effect can be obtained by making the amplitude of the bent portion of the intermediate sipe 5c larger than the amplitude of the bent portion of the first sipe 5a and the second sipe 5b while keeping the bending period the same. Can be done. Similarly, the same effect can be obtained by making the number of bending portions of the intermediate sipe 5c larger than the number of bending portions of the first sipe 5a and the second sipe 5b while keeping the bending period and the magnitude of the amplitude the same. Can be played.
Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples.

In order to confirm the effect of the present invention, tires according to Invention Examples 1 to 6 and Comparative Examples 1 and 2 having a tire size of 195 / 65R15 were prototyped, filled with an internal pressure of 250 kN, and loaded with a load of 4 kN to perform the following braking performance on ice. And a test was conducted to evaluate the performance on snow. The specifications and evaluation results of each tire are shown in Table 1 below.

<Brake performance on ice>
In the test, the tires of Invention Examples 1 to 6 and Comparative Examples 1 and 2 were mounted on a passenger car, and a braking test and an acceleration test were performed on an ice road. In the braking test, the braking distance from the initial speed of 40 km / h until the vehicle became stationary with full braking was measured, and the average deceleration was calculated from the initial speed and the braking distance.
<Brake performance on snow>
In the test, the tires of Invention Examples 1 to 6 and Comparative Examples 1 and 2 were mounted on a passenger car, and a braking test and an acceleration test were performed on a snowy road. In the braking test, the braking distance from the initial speed of 40 km / h until the vehicle became stationary with full braking was measured, and the average deceleration was calculated from the initial speed and the braking distance.
Regarding these evaluation results, Invention Examples 1 to 5 and Comparative Example 1 are shown by exponential notation when the evaluation result of Comparative Example 1 is set to 100, and the larger the numerical value is, the better the braking performance on ice and the braking performance on snow. It shows that there is. Further, Invention Example 6 and Comparative Example 2 are shown in an exponential notation when the evaluation result of Comparative Example 2 is set to 100, and the larger the numerical value, the better the braking performance on ice and the braking performance on snow. ..

As shown in Table 1, it can be seen that the tires according to Invention Examples 1 to 5 were able to achieve both braking performance on ice and performance on snow as compared with the tires according to Comparative Example 1. Further, it can be seen that the tire according to Invention Example 6 was able to achieve both braking performance on ice and performance on snow as compared with the tire according to Comparative Example 2.

1: Tread tread, 2: Circumferential main groove, 3: Width groove, 4: Land,
5: Width direction sipe, 5a: 1st sipe, 5b: 2nd sipe, 5c: intermediate sipe,
6a: 1st block piece, 6b: 2nd block piece, 6c: 3rd block piece,
TE: Tread edge

Claims (5)

The tread tread has one or more circumferential main grooves extending in the tread circumferential direction and a plurality of widthwise grooves extending in the tread width direction.
A plurality of block-shaped land portions are partitioned by the one or more circumferential main grooves and tread ends and the plurality of width direction grooves.
The land portion comprises at least three flat plate width direction sipes extending across the land portion in the tread width direction so as to completely divide the land portion.
The width direction sipes are the first sipes located on one side of the tread circumferential direction, the second sipes located on the other side of the tread circumferential direction, and at least located between the first sipes and the second sipes. Consists of one intermediate sipe
The first block piece partitioned by the first sipe and the width groove, the second block piece partitioned by the second sipe and the width groove, and the first sipe or the second sipe. It has an intermediate block piece, which is partitioned by the intermediate sipe or between two adjacent intermediate sipe.
A pneumatic tire, wherein the sipe volume of the intermediate sipe is smaller than the sipe volume of the first sipe and the sipe volume of the second sipe. The pneumatic tire according to claim 1, wherein the sipe volume of the intermediate sipe is 30 to 70% of the sipe volume of the first sipe and the sipe volume of the second sipe. The maximum depth of the intermediate sipe in the tire radial direction is 30 to 70% of the maximum depth of the first sipe in the tire radial direction and the maximum depth of the second sipe in the tire radial direction, according to claim 1 or The pneumatic tire according to 2. The tread tread has one or more circumferential main grooves extending in the tread circumferential direction and a plurality of widthwise grooves extending in the tread width direction.
A plurality of block-shaped land portions are partitioned by the one or more circumferential main grooves and tread ends and the plurality of width direction grooves.
The land portion comprises at least three flat plate width direction sipes extending across the land portion in the tread width direction so as to completely divide the land portion.
The width direction sipes are the first sipes located on one side of the tread circumferential direction, the second sipes located on the other side of the tread circumferential direction, and at least located between the first sipes and the second sipes. Consists of one intermediate sipe
The first block piece partitioned by the first sipe and the width groove, the second block piece partitioned by the second sipe and the width groove, and the first sipe or the second sipe. It has an intermediate block piece, which is partitioned by the intermediate sipe or between two adjacent intermediate sipe.
A pneumatic tire, characterized in that, in a plan view of the tread tread, the area of the intermediate block piece is larger than the area of the first block piece and the area of the second block piece. The tread tread has one or more circumferential main grooves extending in the tread circumferential direction and a plurality of widthwise grooves extending in the tread width direction.
A plurality of block-shaped land portions are partitioned by the one or more circumferential main grooves and tread ends and the plurality of width direction grooves.
The land portion comprises at least three widthwise sipes extending across the land portion in the tread width direction.
The width direction sipes are the first sipes located on one side of the tread circumferential direction, the second sipes located on the other side of the tread circumferential direction, and at least located between the first sipes and the second sipes. Consists of one intermediate sipe
The first block piece partitioned by the first sipe and the width groove, the second block piece partitioned by the second sipe and the width groove, and the first sipe or the second sipe. It has an intermediate block piece, which is partitioned by the intermediate sipe or between two adjacent intermediate sipe .
Before Symbol first sipe and said second sipe, and the intermediate sipes are both a 3-dimensional sipes having a portion extending bent in the depth direction, the period of the bending of the depth direction of the intermediate sipe, A pneumatic tire characterized in that it is shorter than the bending period of the first sipe and the second sipe in the depth direction.

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