JP5142325B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire (hereinafter referred to as “tire”), and more particularly, to a pneumatic tire in which the appearance of a tire is improved by improving a boundary portion between a sidewall portion and a tread portion.

  In general, a pneumatic tire for a passenger car is formed with a plurality of circumferential main grooves extending continuously in the tire circumferential direction at intervals in the width direction of the tread portion. Lug grooves extending in the width direction of the tread portion are formed on the ribs defined by the grooves, and at least the circumferential main grooves and the lug grooves form a tread pattern.

  In addition, the boundary between the sidewall portion and the tread portion is such that the lug groove continuous from the tread reaches the tread end portion and forms a boundary with the sidewall portion, or the lug groove is surrounded by the boundary with the sidewall portion. In general, a boundary is formed by connecting with a groove extending continuously in a direction.

On the other hand, it has been reported that a groove having a special shape or the like is provided in the tread shoulder portion, for example, to prevent uneven wear of the tire shoulder portion (Patent Document 1) and to improve the wandering property. (Patent Document 2).
JP-A-2-48202 JP-A-2-53607

  However, most conventional techniques for improving the tread portion pattern focus on improving the running performance, and do not relate to improving the appearance of the tire.

  That is, in a conventional tire 11 having a tread portion 12 and a pair of sidewall portions 13 and bead portions 14 that are continuous on both sides thereof as shown in FIG. 3, the lug groove 13 that continues from the tread portion 12 is a tread end portion. 20, the sidewall portion 13 and the boundary 20 are formed, or the tread portion 12 is connected to a groove (not shown) continuously extending in the circumferential direction at the boundary 20 with the sidewall portion 13. Since it looks wide, it can be seen as a tire with good exercise performance, but the sidewall 13 looks narrow, so the outer diameter of the tire looks small, and as a result, it looks like a tire with poor comfort. There was a problem.

  Therefore, an object of the present invention is to provide a pneumatic tire that appears to have both good exercise performance and riding comfort performance by improving the boundary portion between the sidewall portion and the tread portion.

  As a result of intensive studies to solve the above problems, the present inventor has found that the object can be achieved by providing a specific circumferential groove in the boundary portion between the sidewall portion and the tread portion. It came to be completed.

That is, the pneumatic tire of the present invention is a pneumatic tire including a tread portion and a pair of sidewall portions and bead portions that are continuous on both sides thereof.
The tread portion has at least a lug groove, and a narrow groove continuous in a circumferential direction at a portion closer to the tread portion than a boundary between the sidewall portion and the tread portion,
A rubber piece for maintaining the groove shape of the narrow groove is provided at an intersecting portion where the narrow groove and the lug groove intersect.

  In the pneumatic tire of the present invention, it is preferable that the cross-sectional shape of the circumferential narrow groove in the tire width direction is a curved surface, a triangle, or a trapezoid.

  According to the present invention, there is an effect that the tread portion can be seen widely and looks like a tire with good exercise performance, and the side portion also looks wide and looks like a tire with good riding comfort performance.

Hereinafter, embodiments of the present invention will be specifically described.
FIG. 1 is a perspective view of a pneumatic tire 1 according to a preferred embodiment of the present invention.

  A tire 1 shown in FIG. 1, which includes a tread portion 2 and a pair of sidewall portions 3 and bead portions 4 connected to both sides thereof, includes a lug groove 5 in the tread portion 2, and a boundary between the sidewall portion 3 and the tread portion 2. And a narrow groove 6 continuous in the circumferential direction at a portion closer to the tread portion 2 than the tread portion 2. Further, an intersection 7 where the narrow groove 6 and the lug groove 5 intersect is provided with a rubber piece 8 for maintaining the groove shape of the narrow groove 6. Accordingly, when the tire 1 is viewed from the side, the circumferential narrow groove 6 can be continuously recognized without being divided into the lug grooves 5, and the circumferential narrow groove 6 is formed between the sidewall portion 3 and the tread. As a result of being present in the portion closer to the tread portion 2 than the boundary with the portion 2, the tire sidewall portion 3 can be shown wider to the viewer, and an impression that the tire is comfortable to ride can be given.

  Moreover, it is preferable that the cross-sectional shape of the circumferential direction narrow groove 6 is a curved surface, a triangle, or a trapezoid. By forming the circumferential narrow groove 6 in this way, when light hits the bottom surface of the circumferential narrow groove 6, when the tire is viewed from the side when the vehicle is mounted due to reflection of this light, the circumferential narrow groove 6 6 becomes obvious, and the effect of increasing the tire outer diameter becomes remarkable.

  Furthermore, when the tire is viewed from the side when mounted on the vehicle, the lug groove 5 appears to reach the sidewall portion 3 beyond the circumferential narrow groove 6, so that the tread portion 2 can be seen widely and the tire has good exercise performance. Can give the impression that there is.

  2 is a cross-sectional view in the tire width direction at the intersection 7 of the circumferential narrow groove 6 and the lug groove 5 of the tire shown in FIG. The rubber piece 8 provided at the intersection 7 between the narrow groove 6 and the lug groove 5 has a substantially triangular shape as shown in the cross-sectional shape in the tire width direction of the wall 9 on the center side of the groove-shaped tire formed therein. It is preferable. By forming the wall portion 9 in this manner, the durability of the narrow groove 6 in the intersecting portion 7 can be enhanced, and the original function of the lug groove 5 is not impaired. Even if the wall 9 on the side of the groove-shaped side wall 3 of the narrow groove 6 in the rubber piece 8 is formed so as to fill the lug groove 5 with the rubber piece 8, it is no longer the end of the lug groove 5. There is an advantage that the original function of the lug groove 5 is not impaired, and the rubber piece 8 can be easily arranged by forming the lug groove 5 in this way. The material of the rubber piece 8 is preferably the same as that of the tread rubber from the viewpoint of adhesion to the tread rubber.

  In the illustrated tire 1, the tread portion 2 includes four circumferential main grooves 10, lug grooves 5 extending substantially in the tire width direction, various sipes, and the like, and a plurality of land portion rows are formed. In the present invention, the shape and number of grooves other than the circumferential narrow grooves 6 and the lug grooves 5 are not limited and can be appropriately selected.

  When the tire of the present invention shown in FIGS. 1 and 2 described above and the conventional tire shown in FIG. 3 are respectively mounted on an actual vehicle and the mounted tires are viewed from the side and front, it is clear that the tire of the present invention is clearly compared. There was an impression that the tire was superior to the conventional tire in terms of appearance and motor performance and ride comfort.

1 is a partial perspective view of a pneumatic tire according to a preferred embodiment of the present invention. FIG. 2 is an enlarged partial sectional view in the tire width direction of a lug groove portion of the tire shown in FIG. 1. It is a fragmentary perspective view of the conventional pneumatic tire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tire 2 Tread part 3 Side wall part 4 Bead part 5 Lug groove 6 (Circumferential direction) Fine groove 7 Crossing part 8 Rubber piece 9 Wall part 10 Circumferential main groove

Claims (2)

In a pneumatic tire including a tread portion and a pair of sidewall portions and bead portions that are continuous on both sides thereof,
The tread portion has at least a lug groove, and a narrow groove continuous in a circumferential direction at a portion closer to the tread portion than a boundary between the sidewall portion and the tread portion,
A pneumatic tire comprising a rubber piece for maintaining a groove shape of the narrow groove at an intersecting portion where the narrow groove and the lug groove intersect.   The pneumatic tire according to claim 1, wherein a cross-sectional shape of the circumferential narrow groove in a tire width direction is a curved surface, a triangle, or a trapezoid.

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