JPH07276917A - Tire - Google Patents

Abstract

PURPOSE:To provide both anti-skid action and improved wondering action on road surfaces with trails, etc. CONSTITUTION:A recessed side buttress part 6 extending at a steep angle of alpharelative to a road surface 5 and a protruded side buttress part 7 extending at a gentle angle of beta are provided in the form of mixing with each other in circumferential direction. Also the edges 8 and 9 of these both buttresses 6 and 7 are arranged on the same circumference. Thus both the anti-skid action by the recessed side buttress part 6 and the wondering improving action by the protruded side buttress part 7 can be obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a tire.

[0002]

2. Description of the Related Art Conventionally, in a tire, an edge of a shoulder portion formed circumferentially between a tread surface and a buttress surface is made as close as possible to a vertical angle to prevent skidding during a curve run, etc. Things are often done. However, when this is done, when traveling on a rutted road surface such as a snowy road or a mud road, sudden wobbling occurs when a sharp edge comes into contact with or overruns the inner wall of the rut, resulting in poor wandering performance. The difficulty arises.

Therefore, particularly in the shoulder portion of a snow road tire or the like, an outer peripheral side gently sloping surface that rises at a relatively gentle angle from the road surface is provided, and a space between the outer peripheral side gently sloping surface and the buttress surface is provided. In some cases, a so-called "two-step inclination" structure is used in which the connection is made with a steeply inclined surface on the inner peripheral side having a relatively steep angle (for example, in Japanese Patent Laid-Open No. 5-294114,
Some of this type of technology has been adopted).

[0004]

However, by doing so, after all, with respect to the road surface, a gently sloping surface on the outer peripheral side,
That is, since the edge is raised by the edge having a gentle angle, the side slipping property is increased (slip easily). Thus, it was difficult to achieve both prevention of skid and improvement of wandering performance.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a tire capable of preventing skidding and having excellent wandering property even on a rutted road surface. And

[0006]

In order to achieve the above object, the present invention takes the following technical means. That is, the present invention is a tire in which a concave side buttress portion rising at a steep angle from the road surface and a convex side buttress portion rising at a steeper angle from the road surface are mixedly formed in the circumferential direction of the shoulder portion, and the convex side buttress portion is formed. Is positioned so as to sandwich both sides in the circumferential direction of the concave side buttress portion, and the edge where the concave side buttress portion intersects the tread surface and the edge where the convex side buttress portion intersects the tread surface are provided on the same circumference. The concave buttress portion and the convex buttress portion are partitioned by an axial sipe that extends to the tread surface.

It is preferable to form an axial sipe on each tread surface adjacent to the concave buttress portion and the convex buttress portion. It is preferable that the axial sipe formed on the tread surface adjacent to the convex buttress portion is formed to a depth substantially the same as that of the concave buttress portion in the convex buttress portion.

[0008] The convex buttress portion has a two-stage slant including an outer peripheral side gently inclined surface rising from the edge of the tread surface and an inner peripheral side steeply inclined surface connecting the outer peripheral side gently inclined surface and the buttress surface. May be configured.

[0009]

The concave buttress portion that mainly prevents skidding by having a steep edge and the convex buttress portion that mainly improves wandering performance by having a gentle angle edge are formed on the same circumference. Since it is provided as described above, the skid prevention effect and the wandering property improving effect can be surely obtained according to the traveling road surface condition.

In particular, since the convex buttress portion sandwiches the concave buttress portion, it is possible to scratch or scrape the inner wall of the rut on the circumferential surface (front and rear surfaces in the rotational direction) of the convex buttress portion. Since the concave buttress portion and the convex buttress portion are partitioned by the axial sipe, the rigidity of the shoulder portion is lowered, the road surface is better fitted, and uneven wear does not occur.

The rigidity of the shoulder portion can also be reduced by providing each tread surface adjacent to the concave buttress portion and the convex buttress portion or the convex buttress portion itself with an axial sipe. By forming the convex-side buttress portion in a two-step inclined configuration, the wandering performance can be further enhanced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment of a tire 1 according to the present invention, and 2 is a shoulder portion formed by an intersection of a tread surface 3 and a buttress surface 4.
On the shoulder portion 2, there are a concave buttress portion 6 that rises at a steep angle α with respect to the road surface 5, and a convex buttress portion 7 that rises at an angle β that is looser than the concave buttress portion 6. Is provided.

The convex side buttress portion 7 is positioned so as to sandwich both sides (front and rear in the rotational direction) of the concave side buttress portion 6 in the circumferential direction, and a combination of these three forms one shoulder block. ing. Each of the shoulder blocks is defined by the lateral groove 3a, and the concave buttress portion 6 is formed to have substantially the same depth as the lateral groove 3a.

The edge 8 where the concave buttress portion 6 intersects the tread surface 3 and the edge 9 where the convex buttress portion 7 intersects the tread surface 3 are provided on the same circumference. For this reason, when traveling on a curve or the like, since the concave side buttress portion 6 has the steep angle edge 8 as described above, a high gripping force with respect to the road surface 5 is exerted and an effect of preventing skidding is exerted. Become. Of course, the edge 9 of the convex-side buttress portion 7 can simultaneously provide the skid-preventing action. On the other hand, when running on a rutted road surface,
Since the convex-side buttress portion 7 has the gentle-angled edge 9 as described above, the convex-side buttress portion 7 comes into contact with the inner wall of the rut earlier than the concave-side buttress portion 6, whereby the rut It has the effect of improving wandering performance by making it possible to get over and straight ahead. Not only that, the circumferential surface (front and rear surfaces in the rotational direction) of the convex-side buttress portion 7 causes a scratching or scraping action on the inner wall of the rut, so that strong traction and braking action can be obtained. .

In this way, the skid-preventing action and the wandering property improving action can be reliably obtained according to the traveling road surface condition. Concave side buttress 6
The convex-side buttress portion 7 and the convex-side buttress portion 7 are defined by an axial sipe 10 that extends to the tread surface 3. This sipe 10
Has the same depth as the concave-side buttress portion 6. This makes it possible to reduce the rigidity of the shoulder portion 2 (make it flexible), improve the familiarity with the road surface 5, and enhance the grip force. In addition, uneven wear can be prevented from occurring.

FIG. 3 shows a second embodiment of the tire 1 according to the present invention. The difference from the first embodiment is that the tread surfaces adjacent to the concave buttress portion 6 and the convex buttress portion 7 are different from each other. 3 is that axial sipes 11 and 12 are formed. The sipe 12 provided on the tread surface 3 adjacent to the convex-side buttress portion 7 maintains a constant cut width with respect to the surface (the buttress surface 4) of the convex-side buttress portion 7, and the concave-side buttress portion. It is formed to a depth position substantially the same as 6. Further, the sipe 11 provided on the tread surface 3 adjacent to the concave side buttress portion 6 has the same cutting angle as that of the sipe 12, and therefore, the depth of the concave side buttress portion 6 is half the depth or slightly deeper than that. It is formed (toward the center of the tire).

Also in these sipes 11 and 12, it is useful for lowering the rigidity of the shoulder portion 2 to improve grip performance and prevent uneven wear. FIG. 4 shows a third embodiment of the tire 1 according to the present invention. In this embodiment, the convex buttress portion 7 has an outer peripheral side gently sloping surface 13 rising from an edge 9 of the tread surface 3, The gently sloping surface 13 on the outer peripheral side and the steeply sloping surface 14 on the inner peripheral side connecting the buttress surface 4 form a two-step inclination. Here, the position that divides the two-step inclination is located on the tire inner diameter side that is approximately half the main groove depth from the tread surface, and it is desirable to be on the inner diameter side from this, and in the embodiment, the main groove (lateral groove) 3a At a depth of 20 mm, the division boundary position is 11 from the tread surface side.
It is set to mm.

By adopting such a constitution, the wandering property can be improved in the studless tire. That is, the studless tire has a structure in which the effect of the on-snow performance can be further exhibited up to 1/2 of the tire main groove depth. The boundary position of the above-mentioned two-step inclination is matched with this effect, and if it is located at a place of about 1/2, the improvement of wandering property when traveling on snow is added and the traveling stability is greatly improved. Further, the concave side buttress portion 6 is formed to have a large circumferential dimension, and an axial sipe 15 is formed in the middle portion thereof over the entire depth of the concave side buttress portion 6. Other configurations and operations are substantially the same as those in the first embodiment.

The test results of the second embodiment (see FIG. 3) using the substitute road surface (testing device) are as follows. The tire size used is 11 / 70R22.5 (price number 14), and the rim size is 22.5 x 7.5.
It is 0. The air pressure was 9.00 kgf / cm ² and the load was 2725 kgf. As a comparative example (conventional), the same structure as the second example was used except that the concave side buttress portion 6 and the sipes 10 to 12 were not provided.

As a result, it was confirmed that when the camber angle was 3 to 4 ° or more, there was no skid and the ruts could be successfully overcome. In the present invention,
The pattern formed on the tread surface 3 is not limited in any way. Besides the open type penetrating the sipes 10, 11, 12, 15 etc. in the axial direction, the closed type with both ends closed or one end The type may be such that one side is open and the other side is closed.

Uses of the tire 1 (for large vehicles, industrial vehicles,
(For winter, for race, etc.) is not limited.

[0022]

The present invention has the above-described structure, and has a concave buttress portion that mainly prevents sideslip by having a sharp angle edge and a wandering performance mainly by having a gentle angle edge. The convex buttresses to be raised are provided so that their edges are on the same circumference, so that a skid prevention effect and a wandering improvement effect can be obtained reliably depending on the road surface condition on which the vehicle is traveling. Becomes

In particular, since the convex buttress portion sandwiches the concave buttress portion, it is possible to obtain the scratching or scraping action of the inner wall of the rut by the convex buttress portion, and it is of course possible to effectively exhibit the wandering performance. It is also possible to obtain strong traction and braking action. Between the concave buttress portion and the convex buttress portion, or the tread surface adjacent to each of these buttress portions, or when forming the axial sipe in the convex buttress portion itself, the rigidity of the shoulder portion can be reduced, so that the road surface You get a better fit and therefore a higher grip. Also, uneven wear can be prevented.

If the convex buttress portion has a two-step slant structure, the wandering performance can be further enhanced.

[Brief description of drawings]

FIG. 1 is a front sectional view (corresponding to the sectional view taken along the line AA of FIG. 2) showing a first embodiment according to the present invention.

FIG. 2 is a perspective view of a main part of the tire according to the first embodiment.

FIG. 3 is an enlarged perspective view of essential parts showing a second embodiment according to the present invention.

FIG. 4 is a perspective view of an essential part showing a third embodiment according to the present invention.

[Explanation of symbols]

1 tire 2 shoulder part 3 tread surface 4 buttress surface 5 road surface 6 concave buttress part 7 convex buttress part 8 edge of concave buttress part 9 edge of convex buttress part 10 sipes (concave buttress part and convex buttress part and 11 Sipe (of the tread surface adjacent to the concave buttress portion) 12 Sipe (of the tread surface adjacent to the convex buttress portion) 13 Outer peripheral side gently sloping surface 14 Inner peripheral steep surface

Claims (4)

[Claims] 1. A concave buttress portion (6) rising at a steep angle (α) from a road surface (5) and an angle (β) looser than this.
In the tire in which the convex side buttress portion (7) that rises up in the circumferential direction of the shoulder portion (2) are mixedly formed, the convex side buttress portion (7) is formed on both sides of the concave side buttress portion (6) in the circumferential direction. An edge (8) where the concave buttress portion (6) intersects the tread surface (3) and an edge (9) where the convex buttress portion (7) intersects the tread surface (3) while being positioned for sandwiching. Are provided on the same circumference, and the concave buttress portion (6) and the convex buttress portion (7) are provided.
The axial sipe (1
A tire characterized by being divided by 0). 2. An axial sipe (11, 12) is formed on each tread surface (3) adjacent to the concave buttress portion (6) and the convex buttress portion (7). The tire according to claim 1. 3. An axial sipe (12) formed on a tread surface (3) adjacent to the convex buttress portion (7).
The tire according to claim 2, wherein the convex buttress portion (7) is formed to a depth substantially the same as that of the concave buttress portion (6). 4. The outer peripheral gentle slope (13), in which the convex buttress portion (7) rises from an edge (9) of the tread surface (3), the outer peripheral gentle slope (13) and the buttress surface. The tire according to claim 1, wherein a two-step inclination is formed with the inner peripheral side steeply sloping surface (14) connecting between (4).