JP7396891B2 - pneumatic tires - Google Patents

Description

The present disclosure relates to pneumatic tires.

Ruts are formed on the icy and snowy road surface. When changing lanes from a state where the tires are running along ruts, the tires need to overcome the ruts. Winter pneumatic tires such as studless tires are required to have the ability to overcome ruts on icy and snowy roads.

In the pneumatic tire described in Patent Document 1, V-shaped sipes are formed in the area outside the contact surface of the land portion. When a tire crosses a rut, the area outside the contact surface of the land comes into contact with the wall of the rut, and the sipes scratch the wall of the rut, making it easier for the tire to cross the rut.

However, further improvement in rut-crossing performance is desired.

Japanese Patent Application Publication No. 2006-312383

The present disclosure provides a pneumatic tire that can improve performance over ruts.

The pneumatic tire of the present disclosure includes a shoulder block extending from an inner contact patch area to an outer contact patch area, and the outside contact patch area of the shoulder block includes a first groove and a second groove spaced apart in the width direction of the tire. A protrusion is formed between the first groove and the second groove, and each of the first groove and the second groove has a surface inclined with respect to the surface of the protrusion. .

A plan view showing an example of the tread surface of the pneumatic tire of the present disclosure Perspective view showing shoulder block Diagram showing the contact status between tires and road surface Cross-sectional view of A1-A1 part in Figure 2 Cross-sectional view of A2-A2 part in Figure 2 Enlarged perspective view showing the area around the corner of the ground plane

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

FIG. 1 is a plan view of a tread surface Tr provided in a pneumatic tire PT (hereinafter also simply referred to as "tire PT") of the present embodiment. The vertical direction in FIG. 1 corresponds to the tire circumferential direction CD, and the horizontal direction in FIG. 1 corresponds to the tire width direction WD. As shown in FIG. 1, the tread pattern formed on the tread surface Tr is a block pattern.

The pneumatic tire PT includes a center block row 10 in which a plurality of center blocks 1 are arranged in the tire circumferential direction CD at the center of the tread surface Tr in the tire width direction. In this embodiment, the center block row 10 is provided on the tire equator TE. The tread surface Tr is provided with four main grooves 61 to 64 that extend continuously in the tire circumferential direction CD, of which a pair of main grooves 62 and 64 located across the tire equator TE are located in the center block. Column 10 is divided. The center block row 10 is divided into a plurality of center blocks 1 by lateral grooves 11 extending in the tire width direction.

The pneumatic tire PT includes a pair of shoulder block rows 20, 20 in which a plurality of shoulder blocks 2 are arranged in the tire circumferential direction CD at both ends of the tread surface Tr in the tire width direction. The shoulder block row 20 is divided into a plurality of shoulder blocks 2 by lateral grooves 11 extending in the tire width direction. The tire PT also includes quarter block rows 40, 40 in which a plurality of quarter blocks 4 are arranged in the tire circumferential direction between the center block row 10 and the shoulder block row 20. The quarter block row 40 is divided into a plurality of quarter blocks 4 by lateral grooves 11 extending in the tire width direction. In this way, the tread surface Tr is divided into five block rows 10, 20, and 40 by the four main grooves 61 to 64. Although the center block 1, the pair of shoulder blocks 2, and the pair of quarter blocks 4 each form a quadrilateral (quadrilateral) in plan view, they are not limited to this, and various shapes can be adopted.

A plurality of sipes 12 are formed in the center block 1. The sipe 12 is formed by a cut having a width of 1.0 mm or less. Although the sipe 12 is formed as a wave-shaped sipe, it is not limited to this, and may be, for example, a straight sipe. Although both ends of the sipe 12 are closed, one or both ends may be opened into a groove (the main grooves 62, 64 or the lateral groove 11). The sipe 12 may be a two-dimensional sipe whose shape does not change along the depth direction, or a three-dimensional sipe including a portion whose shape changes along the depth direction.

Sipes 22 and 42 are formed in the shoulder block 2 and the quarter block 4, respectively.

The contact edge CE is the outermost position of the contact patch in the width direction of the tire when the tire PT is mounted on a regular rim, filled with the regular internal pressure, placed vertically on a flat road surface, and the regular load is applied. It is. The ground plane inner region Ai is an area that becomes a ground plane between the pair of ground ends CE.

A regular rim is a rim defined for each tire by the standard in the standard system that includes the standard on which the tire is based, for example, a standard rim for JATMA, and a "Measuring Rim" for TRA and ETRTO. Regular internal pressure is the air pressure specified for each tire by each standard in the standard system including the standard on which the tire is based, and for JATMA it is the maximum air pressure, and for TRA it is the air pressure specified in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES". ”, if it is ETRTO, it is “INFLATION PRESSURE”. Note that if the tire is for a passenger car, the pressure is 180 kPa, and if the tire is marked as Extra Load or Reinforced, the pressure is 220 kPa. The regular load is the load specified for each tire by each standard in the standard system including the standard on which the tire is based, and for JATMA it is the maximum load capacity, for TRA it is the maximum value listed in the table above, For ETRTO, it is "LOAD CAPACITY", but if the tire is for a passenger car, it is 88% of the corresponding load of internal pressure.

FIG. 2 is a perspective view showing the shoulder block 2. As shown in FIG. As shown in FIGS. 1 and 2, the shoulder block 2 extends from the inner ground plane area Ai to the outer ground plane area Ao. As shown in FIG. 2, the shoulder block 2 extends to an annular projection 50 formed on the side surface of the tire. As shown in FIGS. 1 and 2, the area Ao outside the ground contact surface of the shoulder block 2 has a first groove 23 and a second groove 24 spaced apart in the tire width direction WD. The first groove 23 and the second groove 24 extend in the tire circumferential direction CD. A protrusion 25 is formed between the first groove 23 and the second groove 24 . In this embodiment, the first groove 23 is open at both ends of the shoulder block 2 in the tire circumferential direction, but it may be closed within the shoulder block 2. The shapes of the first groove 23 and the second groove 24 may be changed. In addition, in this embodiment, although the protrusion 25 protrudes beyond the tire profile, it does not need to protrude from the tire profile.

In this embodiment, the first groove 23 and the second groove 24 are V-shaped grooves extending in a V-shape with the peaks facing inward in the tire width direction. The protrusion 25 is a V-shaped protrusion extending in a V-shape with a peak facing inward in the tire width direction. As a result, since the first groove 23, the second groove 24, and the protrusion 25 are V-shaped, the tire is easily held by the grooves 23, 24 and the protrusion 25 that bite into the wall of the rut when overcoming the rut. It is possible to improve the performance of overcoming ruts 30. Of course, the first groove 23 and the second groove 24 may be V-shaped grooves extending in a V-shape with the peaks facing outward in the tire width direction.

FIG. 3 is a diagram showing the state of contact between the tire and the road surface. FIG. 3 shows a cross section of the tire PT and a road surface with ruts 30. Since the rut 30 has a wall surface with a height H, when the tire PT rides over the rut 30, the area Ao outside the ground contact surface comes into contact with the wall surface of the rut 30. At this time, the first groove 23, the second groove 24, and the protrusion 25 bite into the wall surface of the rut 30, so that the performance of overcoming the rut 30 is improved.

FIG. 4 is a sectional view taken along line A1-A1 in FIG. FIG. 5 is a sectional view taken along line A2-A2 in FIG. FIG. 2 is a cross section that crosses the first groove 23 and the second groove 24 at right angles. As shown in FIGS. 4 and 5, the first groove 23 and the second groove 24 each have surfaces 23a, 23b, 24a, and 24b that are inclined with respect to the surface of the protrusion 25. If there are sloped surfaces 23a, 23b, 24a, and 24b, the first groove 23 and the second groove 24 will be opened wider than sipes made of parallel wall surfaces, making it easier for snow to dig into them. . A surface 23a forming the first groove 23 and surfaces 24a and 24b forming the second groove 24 are flat in cross section of the groove. The surface 23b forming the first groove 23 is a curved surface. If at least a portion of the surfaces forming the first groove 23 and the second groove 24 have a flat surface, the openings will inevitably become larger, making it easier for the wall surfaces of the ruts 30 to dig into the grooves. As shown in FIG. 5, the groove width W1 of the first groove 23 is 3.6 mm, and the depth is 0.5 mm. The groove width W2 of the second groove 24 is 2.6 mm, and the depth is 0.5 mm. It is not limited to this. In order for the first groove 23, the second groove 24, and the protrusion 25 to bite into the wall surface of the rut 30 and to effectively exhibit the ability to overcome the rut, the groove width of each groove 23, 24 is 2.5 mm. The depth of each of the grooves 23 and 24 is preferably 0.5 mm or more. In order to ensure the rigidity of the protrusion 25 and improve the performance of overcoming the ruts 30, the width of the protrusion 25 is preferably 5 mm or more.

As shown in FIGS. 1, 2, and 6, the shoulder block 2 is partitioned by a lateral groove 11, and the shoulder block 2 has block wall surfaces 26 on both sides in the tire circumferential direction CD. A corner of the ground plane of the shoulder block 2 is cut out by a first notch 27. The first notch 27 is open to the ground plane, the block wall surface 26, and the area outside the ground plane Ao. Since the corners of the ground contact surface are cut out by the first notch portions 27, the edges within the ground contact surface can be increased, and snow traction performance is improved. In particular, as shown in FIG. 6, the first notch 27 forms an edge 27a along the tire circumferential direction CD. Compared to the case where the edge 27a is inclined in the tire circumferential direction CD, the edge length can be increased the most, and snow traction performance can be improved. Furthermore, since the edge 27a has a scratching effect when riding over the ruts 30, the rut riding performance can be improved. Of course, the edge formed by the first notch 27 may be inclined with respect to the tire circumferential direction CD. Moreover, although the first notch 27 is provided in the round portion where the ground contact edge exists in the tire meridian cross section, the present invention is not limited thereto. Even if the meridian cross-sectional shape of the tire is a square shape in which the ground contact end is a bending point, the first notch 27 can be formed in the ground contact surface.

In order to increase the edge and improve snow traction performance, it is sufficient that at least one first notch 27 is provided within the ground contact surface. In this embodiment, a plurality of (two in the embodiment) first notches 27 are provided. The corner portion of the ground plane of the shoulder block 2 is cut out in a step-like manner by a plurality (two) of first notches 27 . By cutting out the ground plane in a step-like manner, the edge is effectively increased.

As shown in FIG. 1, FIG. 2, FIG. 4, and FIG. It is bounded by The pair of second notches 28 are arranged on both sides of the top surface 21 in the tire circumferential direction. The pair of second notches 28 can be omitted. When the tire is stopped, snow may come into contact with the area Ao outside the contact patch. In that case, snow comes into contact with and gets caught in either of the pair of second notches 28 that constrict the top surface 21, which may improve snow traction performance at the time of starting.

As described above, the pneumatic tire of the present embodiment includes the shoulder block 2 extending from the inner contact patch area Ai to the outer contact patch area Ao, and the outer contact patch area Ao of the shoulder block 2 is spaced apart in the tire width direction WD. A protrusion 25 is formed between the first groove 23 and the second groove 24, and each of the first groove 23 and the second groove 24 has a first groove 23 and a second groove 24. , it is preferable to have surfaces 23a, 23b, 24a, and 24b that are inclined with respect to the surface of the protrusion 25.

The area Ao outside the ground contact surface of the shoulder block 2 is an area that comes into contact with the wall surface of the rut 30 when riding over the rut 30. Then, first grooves 23 and second grooves 24 spaced apart in the tire width direction WD are formed in the area Ao outside the ground contact surface that contacts the wall surface of the rut 30, and the first grooves 23 and the second grooves 24 are Since each has surfaces 23a, 23b, 24a, and 24b that are inclined with respect to the surface of the protrusion 25, the wall surfaces of the ruts 30 can easily dig into the grooves 23 and 24. Moreover, the protrusion 25 formed between the first groove 23 and the second groove 24 can easily bite into the wall surface of the rut 30, making it possible to improve the performance of overcoming the rut 30.

As in this embodiment, each of the first groove 23 and the second groove 24 preferably extends in a V-shape with the peak facing outward or inward in the tire width direction. As a result, since each of the first groove 23 and the second groove 24 is a V-shaped groove, the tire is held by the grooves 23 and 24 and the protrusion 25 that bite into the wall surface of the rut 30 when overcoming the rut 30. This makes it possible to improve the performance of overcoming the ruts 30.

As in this embodiment, the shoulder block 2 has block wall surfaces 26 on both sides in the tire circumferential direction CD, and the shoulder block 2 has a first notch 27 that opens to the ground contact surface, the block wall surface 26, and the area outside the ground contact surface Ao. It is preferable that the corner of the ground plane of the shoulder block 2 is cut out by a first notch 27. As a result, since the corners of the ground contact surface are cut out by the first notches 27, the edge 27a can be increased in the ground contact surface, and the snow traction performance can be improved.

As in this embodiment, it is preferable that the first notch 27 forms an edge 27a along the tire circumferential direction CD. This increases the edge 27a within the ground contact surface and improves snow traction performance. Furthermore, since the edge 27a exhibits a scratching effect when getting over the ruts 30, it is possible to improve the ability to get over the ruts 30.

As in the present embodiment, it is preferable that a plurality of first notches 27 are formed, and the corners of the ground plane of the shoulder block 2 are cut out in a step-like manner by the plurality of first notches 27. This makes it possible to increase the edge and improve snow traction performance.

As in the present embodiment, the top surface 21 on the inner side in the tire width direction than the first groove 23 in the area Ao outside the ground contact surface of the shoulder block 2 is formed by a pair of second notches 28 disposed on both sides in the tire circumferential direction. It is preferable that it is closed. As a result, when snow comes into contact with the area outside the ground contact surface when stopped, the snow comes into contact with either of the pair of second notches 28 constricting the top surface 21 and gets caught, causing snow traction when starting. There is.

Although the embodiments of the present disclosure have been described above based on the drawings, it should be understood that the specific configuration is not limited to these embodiments. The scope of the present disclosure is indicated not only by the description of the embodiments described above but also by the claims, and further includes all changes within the meaning and scope equivalent to the claims.

It is possible to apply the structure adopted in each of the above embodiments to any other embodiment. The specific configuration of each part is not limited to the embodiment described above, and various modifications can be made without departing from the spirit of the present disclosure.

It is possible to apply the structure adopted in each of the above embodiments to any other embodiment.

2... Shoulder block, 23... First groove, 24... Second groove, 25... Protrusion, 23a, 23b, 24a, 24b... Inclined surface, 26... Block wall surface, 27... First notch, 27a... Edge , 28...Second notch, Ai...Area within the ground plane, Ao...Area outside the ground plane

Claims (5)

Equipped with a shoulder block extending from the area inside the ground plane to the area outside the ground plane,
The area outside the ground contact surface of the shoulder block has a first groove and a second groove spaced apart in the tire width direction, a protrusion is formed between the first groove and the second groove, Each of the first groove and the second groove has a surface inclined with respect to the surface of the protrusion,
Each of the first groove and the second groove extends in a V-shape when viewed along the tire width direction, and the peak portion of the V-shape faces outward or inward in the tire width direction. pneumatic tires. Equipped with a shoulder block extending from the area inside the ground plane to the area outside the ground plane,
The area outside the ground contact surface of the shoulder block has a first groove and a second groove spaced apart in the tire width direction, a protrusion is formed between the first groove and the second groove, Each of the first groove and the second groove has a surface inclined with respect to the surface of the protrusion,
The shoulder block has block wall surfaces on both sides in the tire circumferential direction,
The shoulder block has a first notch that opens to a ground plane, a wall surface of the block, and an area outside the ground plane,
In the pneumatic tire, a corner of the contact surface of the shoulder block is cut out by the first notch. The pneumatic tire according to claim 2 , wherein the first notch portion forms an edge along the tire circumferential direction. A plurality of the first notches are formed,
The pneumatic tire according to claim 2 or 3 , wherein a corner of a ground contact surface of the shoulder block is cut out in a stepped manner by the plurality of first notches. Equipped with a shoulder block extending from the area inside the ground plane to the area outside the ground plane,
The area outside the ground contact surface of the shoulder block has a first groove and a second groove spaced apart in the tire width direction, a protrusion is formed between the first groove and the second groove, Each of the first groove and the second groove has a surface inclined with respect to the surface of the protrusion,
A pneumatic tire, wherein a top surface of the shoulder block in the area outside the ground contact surface on the inner side in the tire width direction than the first groove is narrowed by a pair of second notches arranged on both sides in the tire circumferential direction.

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