WO2013015408A1

WO2013015408A1 - Tyre

Info

Publication number: WO2013015408A1
Application number: PCT/JP2012/069151
Authority: WO
Inventors: 慶一加藤
Original assignee: 株式会社ブリヂストン
Priority date: 2011-07-27
Filing date: 2012-07-27
Publication date: 2013-01-31

Abstract

A tyre wherein a lug groove which communicates with a central circumferential direction groove and extends in the tread width direction is formed in the region on the central circumferential direction groove side of the central rib-shaped land part. A first sipe only which extends in the tread width direction and is narrower than the lug groove is formed in the region on the shoulder circumferential direction groove side of the central rib-shaped land part. A shoulder sipe only which communicates with the shoulder circumferential direction groove and extends in the tread width direction is formed in the region on the shoulder circumferential direction groove side of the shoulder-rib-shaped land part.

Description

tire

The present invention relates to a tire provided with a plurality of rib-like land portions continuous in the tire circumferential direction.

Conventionally, in a pneumatic tire (hereinafter referred to as a tire) mounted on an automobile or the like, various tread patterns are used in order to improve performance on a wet road while suppressing uneven wear. For example, as tires for heavy-duty vehicles such as trucks and buses, tires having zigzag circumferential grooves extending in the tire circumferential direction and having a constant amplitude in the tread width direction on the tire equator line are known. (See Patent Document 1).

Also, a sipe extending in the tread width direction is formed in the block-like land portion adjacent to the zigzag circumferential groove. According to such a tire, by setting the depth of the circumferential groove within a predetermined range, the traction on the wet road is improved and unnecessary deformation of the block-shaped land portion is suppressed. It is supposed to be suppressed.

However, with recent improvements in the performance of automobiles such as trucks and buses, tires that have excellent wear resistance while ensuring various performances on wet roads have been demanded.

JP-A-6-191235

In the tire according to the first feature, in a region including the tire equator line, a central circumferential groove extending in the tire circumferential direction, and a shoulder circumferential groove extending in the tire circumferential direction on the outer side in the tread width direction than the central circumferential groove And are formed. A central rib-shaped land portion continuous in the tire circumferential direction is provided between the central circumferential groove and the shoulder circumferential groove. A shoulder rib-like land portion continuous in the tire circumferential direction is provided on the outer side in the tread width direction of the shoulder circumferential groove. A lug groove that communicates with the central circumferential groove and extends in the tread width direction is formed in a region on the central circumferential groove side of the central rib-shaped land portion. In the region on the shoulder circumferential groove side of the central rib-shaped land portion, only a first sipe that extends in the tread width direction and is narrower than the lug groove is formed. Only a shoulder sipe that communicates with the shoulder circumferential groove and extends in the tread width direction is formed in a region on the shoulder circumferential groove side of the shoulder rib-shaped land portion.

Drawing 1 is a partial plane development view of the tread of pneumatic tire 10 concerning an embodiment. FIG. 2 is a partially enlarged plan view of a tread of the pneumatic tire 10 according to the embodiment. FIG. 3 is a partial plan view of a tread of the pneumatic tire 10A according to the modified example. FIG. 4 is a partially enlarged plan view of the tread of the pneumatic tire 10A according to the modified example.

Next, the tire (pneumatic tire) according to the embodiment will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

Therefore, specific dimensions should be determined in consideration of the following explanation. Moreover, the part from which the relationship and ratio of a mutual dimension differ also in between drawings may be contained.

(1) Schematic Configuration of Pneumatic Tire FIG. 1 is a partial plan development view of a tread of the pneumatic tire 10 according to the present embodiment. As shown in FIG. 1, a central circumferential groove 20 and a shoulder circumferential groove 30 are formed in the pneumatic tire 10. The pneumatic tire 10 can be suitably used particularly for a small truck having a load capacity of about 1 to 1.5 t. The pneumatic tire 10 may be filled with an inert gas such as nitrogen gas instead of air. Moreover, in FIG. 1, the thin line part means the area | region which does not touch a road surface at the time of a regular internal pressure and a regular load.

Central circumferential groove 20, in the region including the tire equator line CL, a linear groove extending in the tire circumferential direction D _C.

The shoulder circumferential groove 30 is formed on the outer side in the tread width direction _DT than the central circumferential groove 20. Shoulder circumferential groove 30 is also a straight groove extending in the tire circumferential direction D _C.

Between the central circumferential groove 20 and the shoulder circumferential groove 30, the central rib-like land portion 40 continuing in the tire circumferential direction D _C is provided. Central rib-like land portion 40 is a land portion of the rib shape extending along the tire circumferential direction D _C (straight).

Further, in the tread width direction D _T of the shoulder circumferential grooves 30, shoulder rib-like land portion 50 continuing in the tire circumferential direction D _C is provided. Shoulder rib-like land portion 50 is also a land portion of the rib (linear) extending along the tire circumferential direction D _C. The shoulder rib-like land portion 50, extends from the outer tread width direction D _{T (tread),} a shoulder groove 300 extending along the middle of the tire circumferential direction D _C is formed.

(2) Shape of Land Part FIG. 2 is a partially enlarged plan view of the tread of the pneumatic tire 10. As shown in FIG. 2, a lug groove 100 that communicates with the central circumferential groove 20 and extends in the tread width direction _DT is formed in a region on the central circumferential groove 20 side of the central rib-shaped land portion 40. The lug groove 100 does not necessarily have to be parallel to the tread width direction DT, and may be formed to have an angle of 30 degrees or less with respect to the tread width direction DT.

A first sipe 110 that extends in the tread width direction _DT and has a narrower groove width than the lug groove 100 is formed in a region on the shoulder circumferential groove 30 side of the central rib-shaped land portion 40. Only the first sipe 110 and the hook-shaped sipe 130 are formed in the region on the shoulder circumferential groove 30 side of the central rib-shaped land portion 40. The hook-shaped sipe 130 is a hook-shaped sipe having substantially the same groove width as that of the first sipe 110 and communicates with the lug groove 100.

Here, the region on the shoulder circumferential groove side refers to a portion facing the circumferential groove in a range of about 10 to 30% of the width of each land portion. In addition, the lug groove is a width in the width direction projected in the width direction, which means a groove having a length of 30% or more of the grounded land portion, and a width that keeps opening when grounded. Say something with. The typical width is about 2 to 10 mm.

A second sipe 120 extending in the tread width direction _DT is formed between the adjacent lug grooves 100. One end of the second sipe 120 communicates with the central circumferential groove 20. On the other hand, the other end of the central circumferential groove 20 terminates in the central rib land portion 40.

The lug groove 100 communicates with the circumferential narrow groove 150. Circumferential narrow groove 150 extending in the tire circumferential direction _{D C.} The circumferential narrow groove 150 does not necessarily extend in the tire circumferential direction DC, and may be formed at an angle of 30 degrees or less with respect to the tire circumferential direction DC. The groove width of the circumferential narrow groove 150 is narrower than the groove width of the lug groove 100.

Only a shoulder sipe 200 that communicates with the shoulder circumferential groove 30 and extends in the tread width direction _DT is formed in a region on the shoulder circumferential groove 30 side of the shoulder rib-shaped land portion 50.

In the present embodiment, the first sipe 110, the second sipe 120, the bowl-shaped sipe 130, and the shoulder sipe 200 are set to 0.5 to 1.0 mm, which is larger than the groove width of the lug groove 100 or the circumferential narrow groove 150. narrow.

(3) Action / Effect According to the pneumatic tire 10, only the first sipe 110 and the saddle-shaped sipe 130 are formed in the region on the shoulder circumferential groove 30 side of the central rib-shaped land portion 40. Further, only the shoulder sipes 200 are formed in the region on the shoulder circumferential groove 30 side of the shoulder rib-shaped land portion 50. For this reason, since the lug groove | channel etc. with a wide groove | channel do not communicate with the shoulder circumferential groove | channel 30, it is hard to produce the turbulent flow of the rain water which entered the shoulder circumferential groove | channel 30, and drainage property improves. In particular, the suppression of such turbulent flow can effectively suppress the occurrence of the hydroplaning phenomenon.

Further, the lug groove 100 is formed only in the region on the central circumferential groove 20 side of the central rib-shaped land portion 40 and is not formed in the region on the shoulder circumferential groove 30 side of the central rib-shaped land portion 40. Uneven wear (center wear) in the land portion 40 can be effectively suppressed. Further, only the shoulder sipe 200 is formed on the shoulder circumferential groove 30 side of the shoulder rib-shaped land portion 50, and no lug groove is formed. For this reason, it is effective also in suppression of the heel & toe abrasion of the shoulder rib-shaped land part 50. FIG.

In the present embodiment, the second sipes 120 are formed between the lug grooves 100 adjacent to each other. One end of the second sipe 120 communicates with the central circumferential groove 20 and the other end of the central circumferential groove 20 terminates in the central rib-shaped land portion 40. For this reason, there are few elements used as a wear nucleus, and center wear can be controlled further.

In the present embodiment, a circumferential narrow groove 150 communicating with the lug groove 100 is formed. By such a circumferential narrow groove 150, rainwater that has entered the central circumferential groove 20 can be instantaneously drawn into the central rib-shaped land portion 40, and drainage, in particular, the occurrence of a hydroplaning phenomenon can be effectively performed. Can be suppressed.

Also, the lug groove 100 is disposed from the central circumferential groove side, which has relatively little influence on the uneven wear and drainage of the main groove, and is disposed so as to form an acute angle in the circumferential direction from the middle. Thereby, the effect by arrange | positioning lug grooves, such as surface drainage and a traction, can be acquired, obtaining the effect of this invention. Similarly, the shoulder groove 300 is also arranged from the outside of the tread surface and is arranged in the circumferential direction from the middle.

(4) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. Should not. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

For example, the embodiment can be changed as follows. Drawing 3 is a partial plane development view of the tread of pneumatic tire 10A concerning the example of change of an embodiment. Hereinafter, differences from the above-described pneumatic tire 10 will be mainly described. The central circumferential groove 20A, the shoulder circumferential groove 30A, the central rib-shaped land portion 40A, and the shoulder rib-shaped land portion 50A shown in FIG. 3 are the central circumferential groove 20, the shoulder circumferential groove 30, the center of the pneumatic tire 10. It corresponds to the rib-like land portion 40 and the shoulder rib-like land portion 50, respectively.

The central circumferential groove 20A and the shoulder circumferential groove 30A have a zigzag shape having a constant amplitude in the tread width direction _DT . As a result, the edge component in the tire width direction is increased in the center portion as compared with the case where the shoulder circumferential groove is linear. This improves the response to fine inputs during steering, resulting in improved steering stability.

FIG. 4 is a partially enlarged plan view of the tread of the pneumatic tire 10A. As shown in FIG. 4, a lug groove 100A communicates with the central circumferential groove 20A. In addition, a wedge-shaped groove 210 is formed between the shoulder circumferential groove 30A and the shoulder sipe 200A. The wedge-shaped groove 210 has a groove width that decreases from the shoulder circumferential groove 30A toward the shoulder sipe 200A.

According to the pneumatic tire 10A, even when the wedge-shaped groove 210 is formed, the number of elements that become wear nuclei can be reduced, which can contribute to suppression of uneven wear.

In the above-described embodiment, the

pneumatic tires

10 and 10A have been described as being suitable for use in a small truck having a load capacity of about 1 to 1.5 t. However, the scope of application of the present invention is such a small truck. It is not limited to pneumatic tires.

Thus, it goes without saying that the present invention includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is determined only by the invention specifying matters according to the scope of claims reasonable from the above description.

Note that the entire content of Japanese Patent Application No. 2011-164592 (filed on July 27, 2011) is incorporated herein by reference.

According to the characteristics of the present invention, it is possible to provide a tire having excellent uneven wear resistance while ensuring various performances on wet roads at a higher level.

Claims

In the region including the tire equator line, a central circumferential groove extending in the tire circumferential direction, and
A shoulder circumferential groove extending in the tire circumferential direction is formed on the outer side in the tread width direction than the central circumferential groove,
Between the central circumferential groove and the shoulder circumferential groove, a central rib-shaped land portion continuous in the tire circumferential direction is provided,
A tire provided with a shoulder rib-like land portion continuous in the tire circumferential direction on the outer side in the tread width direction of the shoulder circumferential groove,
In the region on the central circumferential groove side of the central rib-shaped land portion, a lug groove that communicates with the central circumferential groove and extends in the tread width direction is formed.
In the region on the shoulder circumferential groove side of the central rib-shaped land portion, only a first sipe extending in the tread width direction and having a groove width narrower than the lug groove is formed.
A tire in which only a shoulder sipe that communicates with the shoulder circumferential groove and extends in the tread width direction is formed in a region on the shoulder circumferential groove side of the shoulder rib-shaped land portion.
A second sipe extending in the tread width direction is formed between the lug grooves adjacent to each other,
2. The tire according to claim 1, wherein one end of the second sipe communicates with the central circumferential groove, and the other end of the second sipe terminates in the central rib-shaped land portion.
A circumferential narrow groove extending in the tire circumferential direction is formed in communication with the lug groove,
The tire according to claim 1 or 2, wherein a groove width of the circumferential narrow groove is narrower than a groove width of the lug groove.
The tire according to any one of claims 1 to 3, wherein the central circumferential groove and the shoulder circumferential groove have a zigzag shape having a constant amplitude in a tread width direction.
5. The wedge-shaped groove whose groove width becomes narrower from the shoulder circumferential groove toward the shoulder sipe is formed between the shoulder circumferential groove and the shoulder sipe. Tire described in.