CN1899861A - Pneumatic tire for load - Google Patents

Abstract

The invention provides a pneumatic tire for load carrying. In the prior art, simply forming the height of the outermost rib lower than that of the adjacent ribs cannot completely prevent the abnormal wear of the outermost rib, and because the outermost rib has a simple Because of the structure of the tire, there is a problem that the abnormal wear phenomenon occurs rapidly after the middle period of tire wear. The present invention comprises a tread part (1), a sidewall part (2) and a bead part (3), and a decoupling groove (4) is formed on the shoulder part (10) of the tread part, and the outermost part divided by the decoupling groove The height of the rib (12) at the end is lower than that of the adjacent rib (11), wherein a stepped portion (41) is formed in the decoupling groove, so that the decoupling groove has at least two widths. This prevents abnormal wear on the shoulder ribs, prevents the grip performance of the tire from deteriorating after the middle stage of wear, and significantly prolongs the life of the tire.

Description

Pneumatic tires for trucks

technical field

The present invention relates to a pneumatic tire for heavy loads, and more particularly, to a pneumatic tire for heavy loads capable of preventing abnormal wear of shoulder ribs.

Background technique

In general, in pneumatic radial tires for trucks and buses, the wear performance and abnormal wear performance of the tire can be said to be the most important issues.

Radial tires for trucks can be roughly classified into a rib pattern and a block pattern according to the pattern shape of the tread portion.

Block tires have the advantage of making the braking performance of the vehicle better. The strip pattern tires make the vehicle's handling performance and stability good, without the inherent front and rear edge wear (Heel & Toe Wear) of block pattern tires, and the resistance to wear is better than that of block pattern tires.

However, the rib tire is mainly used on the front wheel axle, and when the direction of the vehicle is steered, since the tire slips in the lateral direction, there is a problem of abnormal wear caused by this phenomenon.

Abnormal wear such as lateral wear occurs when the ground contact pressure transmitted to the individual ribs formed in the tread portion is not uniform, or when the ground contact pressure is not uniform locally on the tire due to frequent vibrations when the vehicle is running (Also known as horizontal wear or RIVER wear) or stamping (パンチ) wear.

In particular, at the edge of the rib adjacent to the groove adjacent to the shoulder portion of the tread, vibration occurs when the tire is running, and there is a problem that the ribs are likely to be worn.

In order to prevent the above-mentioned problems, tire manufacturers such as Michelin and Goodyear have filed patent applications for tires in which decoupling grooves are formed at the outermost ends of the tire shoulders so that the The height of the outermost rib divided by the decoupling groove is formed lower than the height of the adjacent rib, thereby dispersing the stress concentrated on the outermost end.

However, in the invention of the above-mentioned patent application, simply making the height of the outermost rib lower than that of the adjacent ribs cannot completely prevent the occurrence of abnormalities in the outermost rib (including the decoupling groove) wear and tear.

In addition, it can be seen that since the outermost rib has a simple structure, there is a problem that the abnormal wear phenomenon occurs rapidly after the middle period of tire wear has passed.

Contents of the invention

The present invention was made in order to solve the above-mentioned conventional problems, and an object of the present invention is to provide a pneumatic tire for heavy trucks which improves the shape of the decoupling groove and can prevent abnormal wear of the shoulder ribs.

The pneumatic tire for heavy trucks of the present invention includes a tread portion, a sidewall portion, and a bead portion. Decoupling grooves are formed on shoulder portions of the tread portion, and the height ratio of the outermost rib divided by the decoupling grooves to that The height of adjacent ribs is low, and a stepped portion is formed in the decoupling groove so that the decoupling groove has at least two widths.

Description of drawings

What Fig. 1 shows is the partial perspective view of tire of the present invention;

Figure 2 is a partially enlarged cross-sectional view of the main part of the present invention.

Detailed ways

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a partial perspective view of the tire of the present invention, and Fig. 2 shows a partial enlarged cross-sectional view of the main part of the present invention.

As shown in Figures 1 and 2, the pneumatic tire for trucks according to the present invention includes a tread portion 1, a sidewall portion 2 and a bead portion 3, and a decoupling groove 4 is formed on the shoulder portion 10 of the tread portion 1. The height of the outermost rib 12 divided by the decoupling groove 4 is lower than that of the adjacent rib 11 . Wherein, a stepped portion 41 is formed in the decoupling groove 4 , so that the decoupling groove 4 is formed with at least two widths.

The height difference h between the rib 12 formed at the outermost end of the tread portion 1 and the adjacent rib 11 is preferably within a range of 10 to 30% of the depth D of the groove 15 . When the height difference h is less than 10% of the depth D of the groove 15, the stress concentrated on the outermost rib 12 cannot be effectively dispersed, and abnormal wear cannot be suppressed. When the height difference h is greater than 30% of the depth D of the groove 15 %, it will lose its role as a rib.

In addition, the width W of the outermost rib 12 is in the range of 5 to 10 mm, and the depth D1 of the lower section of the decoupling groove 4 with the small width W1 is in the range of 50 to 70% of the depth D of the groove 15. The depth D2 of the large width W2 part of the upper stage of the decoupling groove 4 formed by the stepped part 41 is in the range of 30% to 50% of the depth D of the groove 15, and the large width W2 of the upper stage of the decoupling groove 4 is at the most Within the range of 15-50% of the width W of the outer end rib, the small width W1 of the lower section of the decoupling groove 4 is within the range of 0.5-2 mm.

In the present invention having the above configuration, by making the height of the outermost rib 12 defined by the decoupling groove 4 lower than the height of the adjacent rib 11, the stress concentrated on the shoulder portion 10 can be dispersed when the tire rotates. , can suppress abnormal wear phenomenon. In addition, by forming the decoupling groove 4 in two stages with different widths W1 and W2, the width of the decoupling groove 4 decreases with wear, thereby improving crack resistance and prolonging the life of the tire.

The present invention is not limited to the above-mentioned embodiments, and can be variously modified and implemented within the range permitted by the technical concept of the present invention.

According to the present invention as described above, by improving the shape of the decoupling groove, it is possible to prevent abnormal wear on the shoulder ribs, to prevent the phenomenon that the grip performance of the tire is lowered after the middle stage of wear, and to greatly reduce the wear and tear of the tire. Significantly prolong tire life.

Claims (3)

1. Pneumatic tire for heavy vehicle, comprise fetus face (1), sidewall portion (2) and bead part (3), tire shoulder portion (10) at described fetus face (1) is formed with decoupling groove (4), the height of the rib (11) that the aspect ratio of the rib (12) of the outermost end of being divided by described decoupling groove (4) is adjacent is low, wherein, be formed with end difference (41) at described decoupling groove (4), make described decoupling groove (4) have two width at least.

2. Pneumatic tire for heavy vehicle according to claim 1 is characterized in that, the diff-H (h) that is formed on the rib (12) of outermost end of described fetus face (1) and the rib (11) that is adjacent is in 10～30% scope of the degree of depth (D) of groove (15).

3. Pneumatic tire for heavy vehicle according to claim 1 and 2, it is characterized in that, the width (W) of the rib of described outermost end (12) is in the scope of 5～10mm, the degree of depth (D1) of the little width (W1) of described decoupling groove (4) part is in 50～70% scope of the degree of depth (D) of groove (15), the degree of depth (D2) of the big width (W2) of described decoupling groove (4) part is in 30～50% scope of the degree of depth (D) of groove (15), the big width (W2) of described decoupling groove (4) epimere is in 15～50% scopes of outermost end rib width (W), and the little width (W1) of described decoupling groove (4) hypomere is in the scope of 0.5～2mm.

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