JP7600619B2 - tire - Google Patents

Description

The present invention relates to a tire.

The following Patent Document 1 proposes a pneumatic tire with multiple shoulder lateral grooves in the shoulder land area and multiple first middle lateral grooves in the first middle land area. The shoulder lateral grooves and the first middle lateral grooves are expected to maintain the performance on icy roads and improve the performance on snow.

JP 2015-013514 A

In recent years, tires intended for use in winter have been required to have improved braking and turning performance on snow. Meanwhile, with the recent improvement in vehicle maneuverability, there is a demand for tires to have even better turning performance on snow.

The present invention was devised in light of the above-mentioned circumstances, and its main objective is to provide a tire that can exhibit excellent cornering performance on snow while maintaining braking performance on snow.

The present invention relates to a tire having a tread portion, the tread portion including a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in the tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion arranged on the first tread edge side of the tire equator and divided into the circumferential grooves, the middle land portion including a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion, the middle lateral groove including a first groove portion extending in the tire axial direction on the first tread edge side and a second groove portion extending in the tire axial direction on the second tread edge side. , the second groove portion is displaced to one side in the tire circumferential direction relative to the first groove portion, so that the middle lateral groove includes a longitudinal edge extending along the tire circumferential direction between the edge of the first groove portion and the edge of the second groove portion, the middle block includes a first circumferential edge on the first tread edge side and a second circumferential edge on the second tread edge side, and the middle block is provided with an interrupted groove that extends from the first circumferential edge and has an interrupted end within the middle block, and the interrupted end of the interrupted groove is located on the first circumferential edge side of the longitudinal edge.

In the tire of the present invention, it is desirable that the length of the vertical edge in the tire circumferential direction is 40% to 60% of the groove width of the first groove portion.

In the tire of the present invention, it is desirable that the maximum depth of the middle lateral grooves is 40% to 60% of the maximum depth of the circumferential grooves.

In the tire of the present invention, it is desirable that the axial length of the interrupted groove is 40% to 60% of the axial length of the first groove portion.

In the tire of the present invention, the middle block is provided with a sipe pair in which two sipes are adjacent to each other in the tire axial direction, and it is preferable that the sipe pair includes a first middle sipe that extends from the first circumferential edge and has an end that is interrupted within the middle block, and a second middle sipe that extends from the second circumferential edge and has an end that is interrupted within the middle block.

In the tire of the present invention, it is desirable that the distance in the tire axial direction from the end of the first middle sipe to the end of the second middle sipe is 3% to 7% of the maximum width in the tire axial direction of the middle block.

In the tire of the present invention, it is preferable that the discontinuous end of the first middle sipe is located closer to the first circumferential edge than the longitudinal edge.

In the tire of the present invention, it is preferable that the middle block is provided with a third middle sipe that extends from the second circumferential edge and has an interrupted end within the middle block on the first circumferential edge side of the longitudinal edge.

In the tire of the present invention, it is desirable that the longitudinal edges extend at an angle of 5° or less relative to the tire circumferential direction.

In the tire of the present invention, the tread portion has a specified orientation for mounting on the vehicle, the first tread edge is on the outer side of the vehicle when mounted on the vehicle, the tread portion includes an outer shoulder land portion adjacent to the first tread edge side of the middle land portion via the circumferential groove, the outer shoulder land portion is provided with a plurality of outer shoulder lateral grooves that cross the outer shoulder land portion, and it is desirable that, in a plan view of the tread, the inner end in the tire axial direction of the outer shoulder lateral groove overlaps with a projected area obtained by extending the outer end in the tire axial direction of the interrupted groove in parallel to the tire axial direction.

In the tire of the present invention, it is preferable that the tread portion has a specified orientation for mounting on a vehicle, the first tread edge is on the outer side of the vehicle when mounted on the vehicle, the circumferential groove includes an outer crown circumferential groove adjacent to the second tread edge side of the middle land portion, and the outer crown circumferential groove includes a plurality of variable width portions in the tire circumferential direction where the groove width gradually decreases toward one side in the tire circumferential direction.

By adopting the above-mentioned configuration, the tire of the present invention is able to exhibit excellent cornering performance on snow while maintaining braking performance on snow.

1 is a development view of a tread portion of a tire according to one embodiment of the present invention. FIG. 2 is an enlarged view of the middle land portion of FIG. FIG. 3 is an enlarged view of the middle block and the middle lateral groove of FIG. 2 . FIG. 2 is an enlarged view of the inner middle land portion of FIG. 1 . FIG. 5 is an enlarged view of a lateral groove and a block of the inner middle land portion of FIG. 4 . 5 is a cross-sectional view taken along line AA in FIG. 4. 6 is a cross-sectional view taken along line BB in FIG. 5. 6 is a cross-sectional view taken along line CC of FIG. 5. FIG. 2 is an enlarged view of the outer shoulder land portion of FIG. 1 . FIG. 2 is an enlarged view of the inner shoulder land portion of FIG. 1 . FIG. 2 is an enlarged view of the crown land portion of FIG. FIG. 4 is an enlarged view of a middle land portion of a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Fig. 1 is a development view of a tread portion 2 of a tire 1 according to the present embodiment. As shown in Fig. 1, the tire 1 according to the present embodiment is used, for example, as a pneumatic tire for passenger cars intended for use in winter. However, the tire 1 of the present invention is not limited to such an embodiment.

The tire 1 of this embodiment has a tread portion 2 for which the mounting orientation on the vehicle is specified, for example. The mounting orientation on the vehicle is indicated, for example, by letters or marks on the sidewall portion (not shown). The tread portion 2 is also configured, for example, in an asymmetric pattern (meaning that the tread pattern is not line-symmetric with respect to the tire equator C). However, the tire 1 of the present invention is not limited to this aspect, and may be one for which the mounting orientation on the vehicle is not specified.

The tread portion 2 includes a first tread edge T1 and a second tread edge T2. In this embodiment, the first tread edge T1 is on the outer side of the vehicle when mounted on the vehicle, and the second tread edge T2 is on the inner side of the vehicle when mounted on the vehicle. The first tread edge T1 and the second tread edge T2 each correspond to the axially outermost contact positions of the tire when the tire 1 in a normal state is loaded with a normal load and contacts a flat surface with a camber angle of 0°.

In the case of pneumatic tires for which various standards are established, the "normal state" refers to a state in which the tire is mounted on a normal rim, inflated to the normal internal pressure, and unloaded. In the case of tires for which various standards are not established or non-pneumatic tires, the normal state refers to a standard usage state according to the intended use of the tire, and a state in which no load is applied. In this specification, unless otherwise specified, the dimensions of each part of the tire are values measured in the normal state.

A "genuine rim" is a rim that is specified for each tire by the standard system that includes the standard on which the tire is based. For example, in the case of JATMA, it is called a "standard rim," in the case of TRA, it is called a "design rim," and in the case of ETRTO, it is called a "measuring rim."

"Normal internal pressure" is the air pressure set for each tire by each standard in the standard system on which the tire is based. For JATMA, it is the "maximum air pressure." For TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES." For ETRTO, it is the "INFLATION PRESSURE."

In the case of pneumatic tires for which various standards are established, the "normal load" is the load that is established for each tire in the standard system including the standards on which the tire is based, and is the "maximum load capacity" for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "LOAD CAPACITY" for ETRTO. In addition, in the case of tires for which various standards are not established or non-pneumatic tires, the "normal load" refers to the load acting on a single tire in the standard mounting state of the tire. The "standard mounting state" refers to the state in which the tire is mounted on a standard vehicle corresponding to the intended use of the tire, and the vehicle is stationary on a flat road surface in a drivable state.

The tread portion 2 includes a plurality of circumferential grooves 3 that extend continuously in the tire circumferential direction between the first tread edge T1 and the second tread edge T2, and a plurality of land portions divided into the circumferential grooves 3. The tire 1 of this embodiment is configured as a so-called five-rib tire in which the tread portion 2 includes five land portions divided into four circumferential grooves 3. However, the present invention is not limited to this aspect, and for example, the tread portion 2 may be a so-called four-rib tire configured with three circumferential grooves 3 and four land portions.

The circumferential grooves 3 include, for example, an outer crown circumferential groove 5, an outer shoulder circumferential groove 4, an inner crown circumferential groove 6, and an inner shoulder circumferential groove 7. The outer crown circumferential groove 5 is provided between the tire equator C and the first tread edge T1. The outer shoulder circumferential groove 4 is provided between the outer crown circumferential groove 5 and the first tread edge T1. The inner crown circumferential groove 6 is provided between the tire equator C and the second tread edge T2. The inner shoulder circumferential groove 7 is provided between the inner crown circumferential groove 6 and the second tread edge T2.

The circumferential grooves 3 may be of various configurations, such as extending linearly around the tire circumferential direction or extending in a zigzag pattern. Specific configurations of this embodiment will be described later.

The axial distance L1 from the groove centerline of the outer shoulder circumferential groove 4 or the inner shoulder circumferential groove 7 to the tire equator C is, for example, 20% to 35% of the tread width TW. The axial distance L2 from the groove centerline of the outer crown circumferential groove 5 or the inner crown circumferential groove 6 to the tire equator C is, for example, 3% to 15% of the tread width TW. The tread width TW is the axial distance from the first tread edge T1 to the second tread edge T2 in the normal state.

The groove width W1 of the circumferential grooves 3 is preferably at least 3 mm. In a preferred embodiment, the groove width W1 of the circumferential grooves 3 is 2.0% to 6.0% of the tread width TW. In this embodiment, of the four circumferential grooves 3, the inner crown circumferential groove 6 has the largest groove width.

The land portion includes a middle land portion 12 that is divided into circumferential grooves 3. The middle land portion 12 is divided, for example, between an outer shoulder circumferential groove 4 and an outer crown circumferential groove 5. As a result, the middle land portion 12 is located on the outer side of the tire equator when mounted on a vehicle. However, when the present invention is applied to a tire for which the mounting orientation on a vehicle is not specified, the middle land portion 12 is not limited to the above position.

Furthermore, the land portion of this embodiment includes an outer shoulder land portion 11, a crown land portion 13, an inner middle land portion 14, and an inner shoulder land portion 15. The outer shoulder land portion 11 is located axially outward of the outer shoulder circumferential groove 4 and includes a first tread edge T1. The crown land portion 13 is located between the outer crown circumferential groove 5 and the inner crown circumferential groove 6. The inner middle land portion 14 is located between the inner shoulder circumferential groove 7 and the inner crown circumferential groove 6. The inner shoulder land portion 15 is located axially outward of the inner shoulder circumferential groove 7 and includes a second tread edge T2.

Figure 2 shows an enlarged view of the middle land portion 12. As shown in Figure 2, the middle land portion 12 includes a plurality of middle blocks 24 that are divided into a plurality of middle lateral grooves 20 that cross the middle land portion 12 in the tire axial direction.

3 shows an enlarged view of the middle lateral groove 20 and the middle block 24. As shown in FIG. 3, the middle lateral groove 20 includes a first groove portion 21 extending in the tire axial direction on the first tread edge T1 side, and a second groove portion 22 extending in the tire axial direction on the second tread edge T2 side. In addition, the second groove portion 22 is shifted to one side in the tire circumferential direction relative to the first groove portion 21, so that the middle lateral groove 20 includes a vertical edge 25 extending along the tire circumferential direction between the edge 21a of the first groove portion 21 and the edge 22a of the second groove portion 22.

The middle block 24 includes a first circumferential edge 24a on the first tread edge T1 side and a second circumferential edge 24b on the second tread edge T2 side. The middle block 24 is also provided with an interrupted groove 26 that extends from the first circumferential edge 24a and has an interrupted end 26a within the middle block 24. In the present invention, the interrupted end 26a of the interrupted groove 26 is located closer to the first circumferential edge 24a than the vertical edge 25. By adopting the above configuration, the tire 1 of the present invention can exhibit excellent cornering performance on snow while maintaining braking performance on snow. The following mechanism is presumed to be the reason for this.

Since large ground pressure acts on the middle land area 12 during cornering, each groove arranged in the middle land area 12 contributes greatly to on-snow performance. For this reason, the grooves arranged in the middle land area 12 are specified in the present invention.

When driving on snow, the middle lateral grooves 20 compress snow inside to form snow pillars, which are then sheared to generate a reaction force (hereinafter, such a reaction force may be referred to as snow pillar shear force), thereby improving braking performance on snow. In addition, because the middle lateral grooves 20 include the above-mentioned vertical edges 25, a large snow pillar shear force is also generated in the axial direction of the tire, thereby improving cornering performance on snow.

The discontinuous grooves 26 also work in conjunction with the outer shoulder circumferential grooves 4 to exert a large snow column shear force when driving on snow, improving braking performance and cornering performance on snow.

Furthermore, in the present invention, since the interrupted groove 26 is interrupted closer to the first circumferential edge 24a than the longitudinal edge 25, the block piece 27 between the interrupted groove 26 and the first groove portion 21 is more likely to bend in the circumferential direction of the tire with the two longitudinal edges 25 of the middle lateral groove 20 as fulcrums. This makes it easier for the first groove portion 21 to open and close due to changes in ground pressure acting on the middle block. This action can prevent snow from clogging near the two longitudinal edges 25, allowing for sustained excellent turning performance on snow. It is presumed that this mechanism allows the present invention to maintain snow braking performance while providing excellent turning performance on snow.

The following describes the configuration of this embodiment in more detail. Each of the configurations described below represents a specific aspect of this embodiment. Therefore, it goes without saying that the present invention can achieve the above-mentioned effects even if it does not have the configurations described below. Furthermore, even if any one of the configurations described below is applied alone to a tire of the present invention having the above-mentioned characteristics, an improvement in performance corresponding to each configuration can be expected. Furthermore, when several of the configurations described below are applied in combination, a composite improvement in performance corresponding to each configuration can be expected.

As shown in FIG. 1, the outer shoulder circumferential groove 4 extends linearly with a constant groove width. On the other hand, the outer crown circumferential groove 5 includes multiple width-varying portions 5a in the tire circumferential direction, where the groove width gradually decreases toward one side in the tire circumferential direction. Similarly, the inner crown circumferential groove 6 also includes multiple width-varying portions 6a in the tire circumferential direction, where the groove width gradually decreases toward one side in the tire circumferential direction. The inner shoulder circumferential groove 7 also includes multiple width-varying portions 7a in the tire circumferential direction, where the groove width gradually decreases toward one side in the tire circumferential direction. The circumferential groove 3 including the width-varying portions can strongly compact the snow inside, which helps improve cornering performance on snow.

In a preferred embodiment, the width-changing portion 5a of the outer crown circumferential groove 5 gradually decreases in width in the first tire circumferential direction (upward in each figure of this specification). The width-changing portion 6a of the inner crown circumferential groove 6 and the width-changing portion 7a of the inner shoulder circumferential groove 7 gradually decrease in width in the second tire circumferential direction (downward in each figure of this specification), which is opposite to the first tire circumferential direction. Such an arrangement of the width-changing portions allows solid snow pillars to form in the circumferential groove 3 during both acceleration and deceleration.

As shown in FIG. 3, the middle lateral grooves 20 are inclined in a first direction (upward to the right in each figure in this specification) with respect to the tire axial direction. The angle of the middle lateral grooves 20 with respect to the tire axial direction (the angle between the first groove portion 21 and the second groove portion 22) is, for example, 45° or less, and preferably 15 to 25°. Such middle lateral grooves 20 are useful for improving not only braking performance on snow, but also cornering performance on snow.

The groove width W3 of the middle lateral grooves 20 is, for example, 15% to 25% of the maximum axial width W2 of the middle block 24. In this embodiment, the groove width of the first groove portion 21 is the same as the groove width of the second groove portion 22. The maximum depth of the middle lateral grooves 20 is 40% to 60% of the maximum depth of the circumferential grooves 3. Such middle lateral grooves 20 improve snow performance and steering stability on dry roads (hereinafter sometimes simply referred to as steering stability) in a well-balanced manner.

The axial length L3 of the first groove portion 21 is preferably 30% or more, more preferably 40% or more, and preferably 70% or less, more preferably 60% or less of the width W2 of the middle block 24. The axial length of the second groove portion 22 is also preferably defined within the range of the length L3 of the first groove portion 21 described above.

The two longitudinal edges 25 are preferably included in the central portion when the middle block 24 is divided into thirds in the axial direction by an imaginary plane extending parallel to the tire circumferential direction. The angle of the longitudinal edges 25 with respect to the tire circumferential direction is, for example, 10° or less, and preferably 5° or less. As a more preferable aspect, the longitudinal edges 25 of this embodiment are arranged parallel to the tire circumferential direction. Such longitudinal edges 25 provide a large reaction force in the axial direction of the tire when driving on snow, reliably improving cornering performance on snow.

To form a solid snow column in the middle lateral groove 20, it is desirable for the distance between the two longitudinal edges 25 in the tire axial direction to be small. For this reason, the distance between the two longitudinal edges 25 in the tire axial direction is desirably 10 mm or less, and more desirably 5 mm or less. In this embodiment, the distance is substantially zero. Therefore, in a plan view of the tread, the two longitudinal edges 25 are located on the same straight line.

The circumferential length L4 of one longitudinal edge 25 is preferably 30% or more, more preferably 40% or more, and preferably 70% or less, more preferably 60% or less of the groove width W3a of the first groove portion 21. Such a longitudinal edge 25 can achieve the above-mentioned effects while maintaining the drainage properties of the middle lateral groove 20.

The interrupted groove 26 has a groove width that gradually decreases from the outer shoulder circumferential groove 4 toward the interrupted end 26a. The maximum groove width W4 of the interrupted groove 26 is smaller than the groove width W3 of the middle lateral groove 20. Specifically, the groove width W4 of the interrupted groove 26 is 60% to 90% of the groove width W3 of the middle lateral groove 20. Such interrupted grooves 26 are useful for improving on-snow performance and steering stability in a well-balanced manner.

The interrupted grooves 26 are, for example, inclined in the first direction. The angle of the interrupted grooves 26 with respect to the tire axial direction is, for example, 45° or less, and preferably 10 to 25°.

The axial length L5 of the interrupted groove 26 is preferably 30% or more, more preferably 40% or more, and preferably 70% or less, more preferably 30% or less of the axial length L3 of the first groove portion 21.

As shown in FIG. 2, the middle block 24 is provided with a plurality of middle sipes 30. The middle sipes 30 are inclined, for example, in the first direction. The angle of the middle sipes 30 relative to the tire axial direction is, for example, 15 to 25 degrees. When the sipes extend in a wavy shape, the angle refers to the angle of an imaginary line connecting both ends of the sipe relative to the tire axial direction.

In this specification, a "sipe" refers to a cut element having a minute width, with the width between two opposing sipe walls being 0.6 mm or less. The width of the sipe is preferably 0.1 to 0.5 mm, and more preferably 0.2 to 0.4 mm. The sipe of this embodiment has the width in the above range throughout its entire depth. The sipe may be connected to a chamfered opening or flask bottom whose width is greater than the above range.

Each sipe in this embodiment extends, for example, in a wavy shape when viewed in plan of the tread. In this case, the peak-to-peak amplitude of the sipe is preferably 0.80 to 1.20 mm. Also, the wavelength of the sipe is preferably 2.0 to 5.0 mm. However, this is not limited to the above embodiment, and each sipe may extend linearly. Also, in a preferred embodiment, each sipe is configured as a so-called 3D sipe that extends wavy in cross section. Such sipes help maintain the rigidity of the land portion when opposing sipe walls come into contact with each other, and help improve steering stability on dry road surfaces.

At least one of the middle sipes 30 extends from the first circumferential edge 24a or the second circumferential edge 24b and has an end that is interrupted within the middle block 24. Such middle sipes 30 can improve braking performance on snow while maintaining the rigidity of the middle block 24.

In this embodiment, the middle block 24 is provided with a sipe pair 29 in which two sipes are adjacent to each other in the tire axial direction. This sipe pair 29 includes a first middle sipe 31 and a second middle sipe 32. The first middle sipe 31 extends from the first circumferential edge 24a and has an interrupted end 31a within the middle block 24. The interrupted end 31a is located, for example, closer to the first circumferential edge 24a than the longitudinal edge 25. The second middle sipe 32 extends from the second circumferential edge 24b and has an interrupted end 32a within the middle block 24. Such a sipe pair 29 also helps improve braking performance on ice.

The distance L6 (shown in FIG. 3) in the tire axial direction from the end 31a of the first middle sipe 31 to the end 32a of the second middle sipe 32 is 3% to 7% of the maximum axial width W2 of the middle block 24. Such a sipe pair 29 can ensure sufficient sipe length while maintaining the rigidity of the middle block 24.

The middle block 24 is provided with a third middle sipe 33. The third middle sipe 33 extends from the second circumferential edge 24b and has an interrupted end 33a within the middle block 24, closer to the first circumferential edge 24a than the two longitudinal edges 25. The axial length of the third middle sipe 33 is, for example, 60% to 80% of the width W2 of the middle block 24. Such third middle sipes 33 are useful for improving performance on ice and on snow.

The maximum depth of the third middle sipes 33 is greater than the maximum depth of the first middle sipes 31 and greater than the maximum depth of the second middle sipes 32. The maximum depth of the third middle sipes 33 is, for example, 130% to 150% of the maximum depth of the first middle sipes 31 or the second middle sipes 32. Such third middle sipes 33 are easier to open than the first middle sipes 31 and the second middle sipes 32, further improving performance on ice.

In this embodiment, the middle block 24 has a dimple 34 between the first groove portion 21 and the interrupted groove 26. This dimple 34 is recessed in an area surrounded by an edge of an ellipse that is elongated in the circumferential direction of the tire. Such a dimple 34 moderately reduces the rigidity of the middle block 24 and helps to prevent snow from clogging the middle lateral groove 20 and the interrupted groove 26.

Figure 4 shows an enlarged view of the inner middle land portion 14. As shown in Figure 4, the inner middle land portion 14 includes a plurality of blocks 36 separated by a plurality of lateral grooves 35.

Figure 5 shows an enlarged view of the lateral groove 35 and block 36 of the inner middle land portion 14. As shown in Figure 5, the block 36 includes an outer circumferential edge 36a and an inner circumferential edge 36b arranged on both sides of the tread surface, one lateral narrow groove 38 extending from the outer circumferential edge 36a to the inner circumferential edge 36b with a groove width smaller than that of the lateral groove 35, and multiple lateral sipes 40 with a width of 0.6 mm or less. In this embodiment, the outer circumferential edge 36a of the block 36 is located closer to the tire equator C than the inner circumferential edge 36b.

The groove width W5 of the horizontal narrow groove 38 is 1.0 to 2.0 mm. The maximum depth of the horizontal narrow groove 38 is 40% to 60% of the maximum depth of the horizontal groove 35.

The lateral sipes 40 include full-open sipes 41 that extend from the outer circumferential edge 36a to the inner circumferential edge 36b, and semi-open sipes 42 that extend from the outer circumferential edge 36a or the inner circumferential edge 36b and have an interrupted end 42a within the block 36.

Figure 6 shows a cross-sectional view of line A-A in Figure 4. As shown in Figure 6, the maximum depth d3 of the full-open sipe 41 is greater than the maximum depth d2 of the lateral narrow groove 38, and is smaller than the maximum depth d1 of the lateral groove 35. Similarly, the maximum depth d4 of the semi-open sipe 42 is greater than the maximum depth d2 of the lateral narrow groove 38, and is smaller than the maximum depth d1 of the lateral groove 35. In this embodiment, the configuration of the blocks 36 of the inner middle land portion 14 makes it possible to improve performance on snow and steering stability on dry roads while maintaining performance on ice. The following mechanism is presumed to be the reason for this.

As shown in FIG. 4, the lateral grooves 35 and the circumferential grooves 3 that communicate with them can form hard snow columns, which helps improve performance on snow. Furthermore, the lateral narrow grooves 38, which have a groove width of 1.0 to 2.0 mm and a depth of 40% to 60% of the lateral grooves 35, can form snow columns while minimizing the loss of rigidity of the blocks 36, providing snow column shear force. This improves performance on snow and steering stability on dry roads.

On the other hand, the full-open sipes 41 and the semi-open sipes 42 provide an edge component and maintain on-ice performance. In particular, the semi-open sipes 42 provide an edge component while maintaining the rigidity of the blocks 36, improving on-ice performance and steering stability in a well-balanced manner.

As shown in FIG. 6, by specifying the depth of the full-open sipes 41 and the semi-open sipes 42 as described above, the rigidity of the blocks 36 is maintained, while the block pieces 37 between the lateral grooves 35 and the lateral narrow grooves 38 are easily collapsed toward the lateral grooves 35. This makes it easier for the lateral narrow grooves 38 to open and close due to changes in ground pressure. Due to this action, even with the lateral narrow grooves 38 having a small groove width, solid snow pillars can be formed, and the snow pillars can be prevented from clogging in the grooves, improving performance on snow. In this embodiment, it is presumed that this mechanism makes it possible to improve performance on snow and steering stability on dry roads while maintaining performance on ice.

As shown in FIG. 5, the lateral grooves 35 extend linearly and inclined in the first direction. The angle of the lateral grooves 35 with respect to the axial direction of the tire is, for example, 15 to 25 degrees.

The maximum depth of the lateral grooves 35 is, for example, greater than the maximum depth of the middle lateral grooves 20. The depth of the lateral grooves 35 is, for example, 80% to 120% of the maximum depth of the circumferential grooves 3. In this embodiment, the depth of the lateral grooves 35 and the depth of the circumferential grooves 3 are the same.

The lateral narrow grooves 38 extend linearly, for example, inclined in the first direction. The angle of the lateral narrow grooves 38 with respect to the tire axial direction is, for example, 15 to 25°. In a desirable embodiment, the angle difference between the lateral grooves 35 and the lateral narrow grooves 38 is 5° or less, and in this embodiment, they are parallel. Such lateral narrow grooves 38 improve braking performance and cornering performance on ice and snow in a well-balanced manner.

As shown in FIG. 4, the multiple blocks 36 include a first block piece 43 and a second block piece 44 separated by a horizontal narrow groove 38. Furthermore, in at least one of the multiple blocks 36, the first block piece 43 and the second block piece 44 have substantially the same circumferential length in the tire. "Substantially the same" includes a case where the circumferential length of the first block piece 43 is 90% to 110% of the circumferential length of the second block piece 44. Hereinafter, such a block may be referred to as an equal block 46. The block 36 shown in FIG. 5 is an equal block 46.

In the equal-division block 46, one full-open sipe 41 and one semi-open sipe 42 are provided on each of the first block piece 43 and the second block piece 44. In this case, the full-open sipe 41 is provided adjacent to the lateral narrow groove 38. The semi-open sipe 42 is provided between the lateral groove 35 and the full-open sipe 41.

At least one of the multiple blocks 36 has a first block piece 43 whose circumferential length is different from the second block piece 44. Hereinafter, such a block may be referred to as an unequal block 47. In the unequal block 47 of this embodiment, for example, the second block piece 44 has a circumferential length that is approximately 50% to 80% of the circumferential length of the first block piece 43.

In the unequal block 47 of this embodiment, one full-open sipe 41 and one semi-open sipe 42 are provided on the first block piece 43. In this first block piece 43, the full-open sipe 41 is provided adjacent to the lateral narrow groove 38. The semi-open sipe 42 is provided between the lateral groove 35 and the full-open sipe 41.

The second block piece 44 of the unequal block 47 has only one semi-open sipe 42.

In this embodiment, the inner middle land portion 14 includes multiple equal blocks 46 and multiple unequal blocks 47 as described above, which makes the impact sound when the inner middle land portion 14 touches the ground a white noise, thereby achieving excellent noise performance.

The full-open sipes 41 and the semi-open sipes 42 are inclined, for example, in the first direction. The angle of the full-open sipes 41 and the semi-open sipes 42 with respect to the tire axial direction is, for example, 15 to 25 degrees.

As shown in FIG. 6, the maximum depth d3 of the full-open sipe 41 is 70% to 90% of the maximum depth d1 of the lateral groove 35. Such a full-open sipe 41 helps to improve on-ice performance while maintaining the rigidity of the block 36.

Figure 7 shows a cross-sectional view of line B-B in Figure 5. As shown in Figure 7, the full open sipe 41 includes a shallow bottom portion 41a with a raised bottom at the end on the inner shoulder circumferential groove 7 side. The depth d5 of the shallow bottom portion 41a is 30% to 40% of the maximum depth d3 of the full open sipe 41. Such a full open sipe 41 can improve on-ice performance while maintaining the rigidity of the block 36. Note that each sipe in this embodiment is configured as a 3D sipe, so the sipe wall has irregularities, but the irregularities are omitted in each drawing showing the sipe wall such as Figure 7 in this specification.

As shown in FIG. 4, in this embodiment, the outer circumferential edge 36a is located closer to the tire equator C than the inner circumferential edge 36b, and each semi-open sipe 42 is connected to the outer circumferential edge 36a. This makes it easier for the semi-open sipes 42 to open on the tire equator C side, preventing snow from clogging the inner crown circumferential groove 6.

The semi-open sipe 42 crosses, for example, the axial center position of the block 36. The axial length of the semi-open sipe 42 is, for example, 70% to 95% of the maximum axial width of the block 36.

As shown in FIG. 6, the maximum depth d4 of the semi-open sipe 42 is smaller than the maximum depth d3 of the full-open sipe 41. The depth d4 of the semi-open sipe 42 is, for example, 50% to 65% of the maximum depth d1 of the lateral groove 35. Such a semi-open sipe 42 can improve on-ice performance while maintaining the rigidity of the block 36.

Figure 8 shows a cross-sectional view of line CC in Figure 5. As shown in Figure 8, the semi-open sipe 42 includes a shallow bottom portion 42b with a raised bottom on the side of the discontinuous end 42a. In a more desirable embodiment, the semi-open sipe 42 includes a central shallow bottom portion 42c with a raised bottom on the outer circumferential edge 36a side of the shallow bottom portion 42b. Such a semi-open sipe 42 can more reliably maintain the rigidity of the block 36, and exhibits excellent driving stability.

As shown in FIG. 5, the block 36 of this embodiment has a dimple 48 between the semi-open sipe 42 and the inner shoulder circumferential groove 7. This dimple 48 is recessed in an area surrounded by an elliptical edge that is elongated in the tire circumferential direction. Such a dimple 48 moderately reduces the rigidity of the block 36 and can prevent snow from clogging the surrounding grooves.

Figure 9 shows an enlarged view of the outer shoulder land portion 11. As shown in Figure 9, the outer shoulder land portion 11 includes, for example, a plurality of outer shoulder blocks 51 separated by a plurality of outer shoulder lateral grooves 50.

The outer shoulder lateral groove 50 includes, for example, an inner groove portion 50a and an outer groove portion 50b. The inner groove portion 50a is connected, for example, to the outer shoulder circumferential groove 4 and is inclined in the first direction. The outer groove portion 50b is connected, for example, to the first tread edge T1 side of the inner groove portion 50a and is inclined in a second direction opposite to the first direction with respect to the tire axial direction. The outer shoulder lateral groove 50 including such an inner groove portion 50a and outer groove portion 50b improves snow braking performance and snow cornering performance in a well-balanced manner.

The angle of the inner groove portion 50a relative to the tire axial direction is, for example, 5 to 15°. The angle of the outer groove portion 50b relative to the tire axial direction is, for example, 5 to 15°. The outer groove portion 50b crosses the axial center position of the outer shoulder land portion 11. The axial length L7 of the outer groove portion 50b is, for example, 60% to 80% of the axial width W6 of the outer shoulder land portion 11.

In a plan view of the tread, the axially inner end 50c of the outer shoulder lateral groove 50 overlaps with a projected area obtained by extending the axially outer end 26b of the interrupted groove 26 parallel to the tire axial direction. Such outer shoulder lateral grooves 50 cooperate with the interrupted grooves 26 to form solid snow columns, further improving on-snow performance.

The outer shoulder block 51 is provided with a plurality of first outer shoulder sipes 53 and a plurality of second outer shoulder sipes 54. In this embodiment, the first outer shoulder sipes 53 are connected to the outer shoulder circumferential groove 4 and terminate within the outer shoulder block 51. The second outer shoulder sipes 54 are provided, for example, axially outward of the first outer shoulder sipe 53, and both ends terminate within the outer shoulder block 51. Such first outer shoulder sipes 53 and second outer shoulder sipes 54 improve steering stability on dry roads and performance on ice in a well-balanced manner.

In a more desirable embodiment, the number of second outer shoulder sipes 54 in one outer shoulder block 51 is preferably less than the number of first outer shoulder sipes 53. Such a sipe arrangement helps to suppress uneven wear near the first tread edge T1.

Figure 10 shows an enlarged view of the inner shoulder land portion 15. As shown in Figure 10, the inner shoulder land portion 15 is provided with a plurality of inner shoulder lateral grooves 55 and a plurality of inner shoulder interrupted grooves 56.

The inner shoulder lateral groove 55 crosses, for example, the inner shoulder land portion 15 in the tire axial direction. In this embodiment, the inner shoulder lateral groove 55 includes, for example, a first inclined groove portion 55a that extends from the inner shoulder circumferential groove 7 at an incline in the first direction, and a second inclined groove portion 55b that is connected to the first inclined groove portion 55a and extends at an incline in the second direction. Such an inner shoulder lateral groove 55 improves snow braking performance and snow cornering performance in a well-balanced manner.

The axial length L8 of the first inclined groove portion 55a is preferably, for example, 20% to 50% of the axial width W7 of the inner shoulder land portion 15.

In plan view of the tread, it is desirable that the axially inner end 55c of the inner shoulder lateral groove 55 overlaps with the area of the lateral narrow groove 38 provided in the inner middle land portion 14 extended along its length. Such an inner shoulder lateral groove 55 cooperates with the lateral narrow groove 38 to form solid snow columns, improving on-snow performance.

The inner shoulder interrupted groove 56 is connected to the inner shoulder circumferential groove 7 and has an interrupted end 56a within the inner shoulder land portion 15. In this embodiment, the inner shoulder interrupted groove 56 includes a portion that extends along the first inclined groove portion 55a and a portion that extends along the second inclined groove portion 55b. Such an inner shoulder interrupted groove 56 improves performance on snow and ice while suppressing uneven wear of the inner shoulder land portion 15.

In plan view of the tread, it is desirable that the axially inner end 56b of the inner shoulder-discontinuous groove 56 overlaps with the area obtained by extending the lateral groove 35 provided in the inner middle land portion 14 along its length.

The inner shoulder land portion 15 includes a plurality of inner shoulder blocks 57 that are divided into a plurality of inner shoulder lateral grooves 55. The inner shoulder blocks 57 are provided with a first inner shoulder sipe 58 and a second inner shoulder sipe 59.

The first inner shoulder sipe 58 in this embodiment, for example, communicates with the inner shoulder circumferential groove 7 and terminates within the inner shoulder block 57. The second inner shoulder sipe 59 is provided, for example, axially outboard of the first inner shoulder sipe 58, and both ends terminate within the inner shoulder block 57. Such first inner shoulder sipe 58 and second inner shoulder sipe 59 can improve on-ice performance while maintaining the rigidity of the inner shoulder block 57.

Figure 11 shows an enlarged view of the crown land portion 13. As shown in Figure 11, the crown land portion 13 includes a plurality of crown blocks 61 separated by a plurality of crown lateral grooves 60.

The crown lateral grooves 60 cross the crown land portion 13 in the tire axial direction. The crown lateral grooves 60 of this embodiment include, for example, a first crown groove portion 60a and a second crown groove portion 60b. The first crown groove portion 60a is connected, for example, to the outer crown circumferential groove 5 and is inclined in the first direction. The second crown groove portion 60b is connected, for example, to the inner crown circumferential groove 6 and is inclined in the second direction. Such crown lateral grooves 60 can strongly compact snow inside, further improving braking performance on snow.

The outer end portion 64 of the second crown groove portion 60b on the second tread edge T2 side overlaps, for example, with an area obtained by extending the second groove portion 22 of the middle lateral groove 20 along its length. The outer end portion 64 of the second crown groove portion 60b on the second tread edge T2 side overlaps, for example, with an area obtained by extending the end portion of the inner crown circumferential groove 6 side of the lateral groove 35 provided in the inner middle land portion 14 parallel to the tire axial direction.

The crown block 61 is provided with a first crown-interrupted groove 62 and a second crown-interrupted groove 63. The first crown-interrupted groove 62 extends, for example, from the crown lateral groove 60 and terminates within the crown block 61. The second crown-interrupted groove 63 extends from the inner crown circumferential groove 6 and terminates within the crown block 61. Such first crown-interrupted groove 62 and second crown-interrupted groove 63 can moderately reduce the rigidity of the crown block 61 and prevent snow from clogging the crown lateral groove 60 and the inner crown circumferential groove 6.

The crown block 61 is provided with a plurality of crown sipes 65. The crown sipes 65 are inclined, for example, in the second direction.

As shown in FIG. 1, the land ratio of the tread portion 2 is preferably, for example, 60% to 75%. In this specification, the land ratio means the ratio of the total area of the actual contact surface of the tread portion 2 to the total area of the virtual contact surface in which all the grooves of the tread portion are filled. Such a tread portion 2 improves performance on snow and steering stability while maintaining performance on ice.

From a similar perspective, the rubber hardness of the tread rubber constituting the tread portion 2 is, for example, 45 to 65°. Here, the rubber hardness refers to the durometer A hardness measured in an environment of 23°C using a durometer type A based on JIS-K6253.

The tire according to one embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment described above and can be modified and implemented in various ways.

A tire having a size of 195/65R15 and the basic tread pattern of FIG. 1 was prototyped based on the specifications of Tables 1 and 2. As a comparative example, a tire having a middle land portion a shown in FIG. 12 was prototyped. As shown in FIG. 12, the middle land portion a of the comparative example is provided with a plurality of middle lateral grooves b extending linearly. The middle lateral groove b of the comparative example does not have the first groove portion and the second groove portion of the present invention, and the two edges extend linearly. The comparative example tire has substantially the same pattern as that shown in FIG. 1, except for the above-mentioned configuration. Each test tire was tested for braking performance on snow and cornering performance on snow. The common specifications and test methods of each test tire are as follows.
Rim: 15 x 6.0JJ
Tire pressure: front wheel 200kPa, rear wheel 200kPa
Test vehicle: 1500cc engine, front-wheel drive Tire mounting position: all wheels

<Snow braking performance>
The braking performance of the test vehicle when it was driven on snow was evaluated by the driver. The results are expressed as a score based on the comparative example being 100, with a higher score indicating better braking performance on snow.

<Turning performance on snow>
The cornering performance of the test vehicle when it was driven on snow was evaluated by the driver. The results are expressed as a score based on the comparative example being 100, with a higher score indicating better cornering performance on snow.
The results of the tests are shown in Tables 1-2.

As shown in Table 1, it was confirmed that the tire of the present invention exhibits excellent cornering performance on snow while maintaining braking performance on snow.

2 Tread portion 12 Middle land portion 20 Middle lateral groove 21 First groove portion 22 Second groove portion 24 Middle block 24a First circumferential edge 24b Second circumferential edge 25 Longitudinal edge 26a Interrupted edge 26 Interrupted groove T1 First tread edge T2 Second tread edge

Claims (11)

A tire having a tread portion,
the tread portion includes a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in a tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion disposed on the first tread edge side relative to a tire equator and divided by the circumferential grooves,
The middle land portion includes a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion,
The middle lateral groove includes a first groove portion extending in the tire axial direction at the first tread end side and a second groove portion extending in the tire axial direction at the second tread end side,
the second groove portion is offset from the first groove portion to one side in the tire circumferential direction, so that the middle lateral groove includes a longitudinal edge extending in the tire circumferential direction between an edge of the first groove portion and an edge of the second groove portion,
the middle block includes a first circumferential edge on the first tread end side and a second circumferential edge on the second tread end side,
The middle block is provided with an interrupted groove extending from the first circumferential edge and having an interrupted end within the middle block,
The interrupted end of the interrupted groove is located closer to the first circumferential edge than the longitudinal edge,
The tread portion has a specified orientation for mounting on a vehicle,
The first tread edge is on the outer side of the vehicle when the tire is mounted on the vehicle,
the circumferential groove includes an outer crown circumferential groove adjacent to the second tread end side of the middle land portion,
The outer crown circumferential groove includes a plurality of width-changing portions in the tire circumferential direction, the width of which is gradually decreased toward one side in the tire circumferential direction.
tire. A tire having a tread portion,
the tread portion includes a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in a tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion disposed on the first tread edge side relative to a tire equator and divided by the circumferential grooves,
The middle land portion includes a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion,
The middle lateral groove includes a first groove portion extending in the tire axial direction at the first tread end side and a second groove portion extending in the tire axial direction at the second tread end side,
the second groove portion is offset from the first groove portion to one side in the tire circumferential direction, so that the middle lateral groove includes a longitudinal edge extending in the tire circumferential direction between an edge of the first groove portion and an edge of the second groove portion,
the middle block includes a first circumferential edge on the first tread end side and a second circumferential edge on the second tread end side,
The middle block is provided with an interrupted groove extending from the first circumferential edge and having an interrupted end within the middle block,
The interrupted end of the interrupted groove is located closer to the first circumferential edge than the longitudinal edge,
The length of the vertical edge in the tire circumferential direction is 40% to 60% of the groove width of the first groove portion,
The maximum depth of the middle lateral groove is 40% to 60% of the maximum depth of the circumferential groove.
tire. A tire having a tread portion,
the tread portion includes a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in a tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion disposed on the first tread edge side relative to a tire equator and divided by the circumferential grooves,
The middle land portion includes a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion,
The middle lateral groove includes a first groove portion extending in the tire axial direction at the first tread end side and a second groove portion extending in the tire axial direction at the second tread end side,
the second groove portion is offset from the first groove portion to one side in the tire circumferential direction, so that the middle lateral groove includes a longitudinal edge extending in the tire circumferential direction between an edge of the first groove portion and an edge of the second groove portion,
the middle block includes a first circumferential edge on the first tread end side and a second circumferential edge on the second tread end side,
The middle block is provided with an interrupted groove extending from the first circumferential edge and having an interrupted end within the middle block,
The interrupted end of the interrupted groove is located closer to the first circumferential edge than the longitudinal edge,
a maximum depth of the middle lateral groove is 40% to 60% of a maximum depth of the circumferential groove,
The axial length of the interrupted groove is 40% to 60% of the axial length of the first groove portion.
tire. A tire having a tread portion,
the tread portion includes a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in a tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion disposed on the first tread edge side relative to a tire equator and divided by the circumferential grooves,
The middle land portion includes a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion,
The middle lateral groove includes a first groove portion extending in the tire axial direction at the first tread end side and a second groove portion extending in the tire axial direction at the second tread end side,
the second groove portion is offset from the first groove portion toward one side in the tire circumferential direction, so that the middle lateral groove includes a longitudinal edge extending along the tire circumferential direction between an edge of the first groove portion and an edge of the second groove portion,
the middle block includes a first circumferential edge on the first tread end side and a second circumferential edge on the second tread end side,
The middle block is provided with an interrupted groove extending from the first circumferential edge and having an interrupted end within the middle block,
The interrupted end of the interrupted groove is located closer to the first circumferential edge than the longitudinal edge,
a maximum depth of the middle lateral groove is 40% to 60% of a maximum depth of the circumferential groove,
The longitudinal edge extends at an angle of 5° or less with respect to the circumferential direction of the tire.
tire. The middle block is provided with a sipe pair in which two sipes are adjacent to each other in the tire axial direction,
5. The tire according to claim 1, wherein the sipe pair includes a first middle sipe extending from the first circumferential edge and having an interrupted end within the middle block, and a second middle sipe extending from the second circumferential edge and having an interrupted end within the middle block. A tire having a tread portion,
the tread portion includes a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in a tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion disposed on the first tread edge side relative to a tire equator and divided by the circumferential grooves,
The middle land portion includes a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion,
The middle lateral groove includes a first groove portion extending in the tire axial direction at the first tread end side and a second groove portion extending in the tire axial direction at the second tread end side,
the second groove portion is offset from the first groove portion to one side in the tire circumferential direction, so that the middle lateral groove includes a longitudinal edge extending in the tire circumferential direction between an edge of the first groove portion and an edge of the second groove portion,
the middle block includes a first circumferential edge on the first tread end side and a second circumferential edge on the second tread end side,
The middle block is provided with an interrupted groove extending from the first circumferential edge and having an interrupted end within the middle block,
The interrupted end of the interrupted groove is located closer to the first circumferential edge than the longitudinal edge,
The middle block is provided with a sipe pair in which two sipes are adjacent to each other in the tire axial direction,
The sipe pair includes a first middle sipe extending from the first circumferential edge and having an interrupted end within the middle block, and a second middle sipe extending from the second circumferential edge and having an interrupted end within the middle block,
The distance in the tire axial direction from the end of the first middle sipe to the end of the second middle sipe is 3% to 7% of the maximum width in the tire axial direction of the middle block.
tire. A tire having a tread portion,
the tread portion includes a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in a tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion disposed on the first tread edge side relative to a tire equator and divided by the circumferential grooves,
The middle land portion includes a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion,
The middle lateral groove includes a first groove portion extending in the tire axial direction at the first tread end side and a second groove portion extending in the tire axial direction at the second tread end side,
the second groove portion is offset from the first groove portion to one side in the tire circumferential direction, so that the middle lateral groove includes a longitudinal edge extending in the tire circumferential direction between an edge of the first groove portion and an edge of the second groove portion,
the middle block includes a first circumferential edge on the first tread end side and a second circumferential edge on the second tread end side,
The middle block is provided with an interrupted groove extending from the first circumferential edge and having an interrupted end within the middle block,
The interrupted end of the interrupted groove is located closer to the first circumferential edge than the longitudinal edge,
The length of the vertical edge in the tire circumferential direction is 40% to 60% of the groove width of the first groove portion,
The middle block is provided with a sipe pair in which two sipes are adjacent to each other in the tire axial direction,
The sipe pair includes a first middle sipe extending from the first circumferential edge and having an interrupted end within the middle block, and a second middle sipe extending from the second circumferential edge and having an interrupted end within the middle block,
The middle block is provided with a third middle sipe extending from the second circumferential edge and having an interrupted end within the middle block on the first circumferential edge side relative to the longitudinal edge.
tire. A tire having a tread portion,
the tread portion includes a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in a tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion disposed on the first tread edge side relative to a tire equator and divided by the circumferential grooves,
The middle land portion includes a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion,
The middle lateral groove includes a first groove portion extending in the tire axial direction at the first tread end side and a second groove portion extending in the tire axial direction at the second tread end side,
the second groove portion is offset from the first groove portion to one side in the tire circumferential direction, so that the middle lateral groove includes a longitudinal edge extending in the tire circumferential direction between an edge of the first groove portion and an edge of the second groove portion,
the middle block includes a first circumferential edge on the first tread end side and a second circumferential edge on the second tread end side,
The middle block is provided with an interrupted groove extending from the first circumferential edge and having an interrupted end within the middle block,
The interrupted end of the interrupted groove is located closer to the first circumferential edge than the longitudinal edge,
The length of the interrupted groove in the tire axial direction is 40% to 60% of the length of the first groove portion in the tire axial direction,
The middle block is provided with a sipe pair in which two sipes are adjacent to each other in the tire axial direction,
The sipe pair includes a first middle sipe extending from the first circumferential edge and having an interrupted end within the middle block, and a second middle sipe extending from the second circumferential edge and having an interrupted end within the middle block,
The middle block is provided with a third middle sipe extending from the second circumferential edge and having an interrupted end within the middle block on the first circumferential edge side relative to the longitudinal edge.
tire. A tire having a tread portion,
the tread portion includes a first tread edge and a second tread edge, a plurality of circumferential grooves extending continuously in a tire circumferential direction between the first tread edge and the second tread edge, and a middle land portion disposed on the first tread edge side relative to a tire equator and divided by the circumferential grooves,
The middle land portion includes a plurality of middle blocks divided into a plurality of middle lateral grooves crossing the middle land portion,
The middle lateral groove includes a first groove portion extending in the tire axial direction at the first tread end side and a second groove portion extending in the tire axial direction at the second tread end side,
the second groove portion is offset from the first groove portion to one side in the tire circumferential direction, so that the middle lateral groove includes a longitudinal edge extending in the tire circumferential direction between an edge of the first groove portion and an edge of the second groove portion,
the middle block includes a first circumferential edge on the first tread end side and a second circumferential edge on the second tread end side,
The middle block is provided with an interrupted groove extending from the first circumferential edge and having an interrupted end within the middle block,
The interrupted end of the interrupted groove is located closer to the first circumferential edge than the longitudinal edge,
The middle block is provided with a sipe pair in which two sipes are adjacent to each other in the tire axial direction,
The sipe pair includes a first middle sipe extending from the first circumferential edge and having an interrupted end within the middle block, and a second middle sipe extending from the second circumferential edge and having an interrupted end within the middle block,
The middle block is provided with a third middle sipe that extends from the second circumferential edge and has an interrupted end within the middle block on the first circumferential edge side relative to the longitudinal edge,
The longitudinal edge extends at an angle of 5° or less with respect to the circumferential direction of the tire.
tire. The tire according to claim 6 , wherein the discontinued end of the first middle sipe is located closer to the first circumferential edge than the longitudinal edge. The tread portion has a specified orientation for mounting on a vehicle,
The first tread edge is on the outer side of the vehicle when the tire is mounted on the vehicle,
the tread portion includes an outer shoulder land portion adjacent to the first tread end side of the middle land portion with the circumferential groove interposed therebetween,
The outer shoulder land portion is provided with a plurality of outer shoulder lateral grooves crossing the outer shoulder land portion,
11. The tire according to claim 1, wherein, in a plan view of the tread, an axially inner end portion of the outer shoulder lateral groove overlaps with a projected area obtained by extending an axially outer end portion of the interrupted groove parallel to the tire axial direction.

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