KR100792979B1 - Pneumatic Tires for Heavy Load Cars - Google Patents

Abstract

A pneumatic tire for a heavy vehicle is provided to raise heat dissipation efficiency of the tire by forming semi-grooves in the outermost rib to increase the sectional area of the outermost rib. A pneumatic tire for a heavy vehicle comprises a tread(1), a sidewall(2) and a bead section. The tread(1) has a shoulder section provided with a shoulder rib(4) distinguished by a groove(3). The shoulder rib(4) has a stepped portion lower than a tread a grounding line. The shoulder rib(4) is provided with a plurality of shoulder semi-ribs(41,42,43) that are prepared in the form of multi-step structure having a sequentially reduced height. A shoulder semi-groove(401) is formed between the shoulder semi-ribs(41,42). A shoulder semi-groove(402) is formed between the shoulder semi-ribs(42,43). A shoulder semi-groove(403) is formed between the shoulder semi-rib(43) and the outermost rib.

Description

Pneumatic tire for heavy vehicle

1 relates to a conventional tire

  (A) is an example of a tire having the shoulder block stepped lower than the neighboring block

  (B) shows the grounding state of the tire shown in (a) above.

Figure 2 is a cross-sectional view of the main portion of an embodiment of the present invention

3 is a cross-sectional view showing main parts of another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1. Tread

2. Sidewall

3. Groove

4. Shoulder rib

41, 42, 43.Shoulder Semi Rib

401, 402, 403. Shoulder Semi Groove

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heavy duty vehicle tire, and more particularly, to a tire formed by lowering the height of the outermost rib of a tread than the height of an adjacent rib.

Radial pneumatic tires have the thickest rubber thickness in the shoulder part of the tread, resulting in the greatest heat generation of tires while driving. Because of this heat generation, the rubber temperature easily rises above 100 degrees Celsius, which causes the rubber to harden and separation occurs between the belt layers at the bottom.

Thus, in the related art, as shown in FIG. 1A of the accompanying drawings, the height of the outermost tread block, which is the shoulder portion, is formed to be lower than that of the neighboring tread block, thereby reducing the thickness of the rubber layer to improve heat dissipation performance. However, in such a tire, due to the simple step of the shoulder portion, there is a discontinuity line (a) in the ground shape as shown in (b) of FIG. 1, which is attached, which is a crack of the bottom of the outermost groove, There is a defect that causes abnormal partial wear of the shoulder rib (Rib).

Accordingly, the present invention improves the grounding state of the outermost ribs by forming a step in multiple stages having a sequential height difference without placing one step as in the prior art in placing a step at the height of the outermost rib. To reduce the amount of momentum by preventing the ribs on the outside of the shoulder from contacting the ground, and to increase the cross-sectional area by forming semi grooves on the outermost ribs to improve heat dissipation performance and to greatly reduce the separation between the belt layers due to heat generation. When described with reference to the accompanying drawings, the present invention as follows.

Forming a shoulder rib 4 composed of a tread 1 and a sidewall 2 and a bead part (not shown in the drawings) and separated by a groove 3 on the shoulder side of the tread part 1, and a shoulder The rib 4 is designed to have a low step compared to the tread ground wire A. In the present invention, the shoulder rib 4 has one step compared to the tread ground wire A as in the prior art. Instead, as shown in the accompanying drawings, Figure 2, characterized in that formed by a multi-stage shoulder semi-ribbed (41, 42, 43) having a sequential height difference.

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In addition, the step between each of the shoulder semi-ribs 41, 42, 43 is that the step D1 of the first shoulder semi-groove 41 has a depth H from the tread ground line A to the bottom of the groove 3. It is preferable that it is 0.1 to 0.8 times, and the level difference (Example D2) of a lower shoulder semi-groove below is 0.1 to 0.8 times the level difference D1 of a next upper semi groove.

The present invention is further characterized by the formation of the shoulder-shaped microgrooves 401, 402, and 403 between the multi-stage shoulder semi-ribs 41, 42, and 43. The depth of the shoulder semi grooves 401 and 402 is preferably formed to be 1 to 2 times the step between the adjacent semi grooves.

The present invention, such as the rubber thickness is sequentially reduced to prevent the occurrence of tread ground width discontinuity line to prevent abnormal wear of the shoulder ribs, and by sequentially grounding in accordance with the grounding load, the effect of significantly improving the steering stability, shoulder Increasing the heat dissipation performance by reducing the rubber thickness of the secondary ribs, and by increasing the cross-sectional area by adopting a plurality of semi-grooves at the same time with a continuous step, there is an effect to maximize the heat dissipation performance.

Claims (5)

delete delete delete A shoulder rib 4 composed of a tread 1, a sidewall 2, and a bead part and separated by a groove 3 on the shoulder side of the tread part 1 is formed, and the shoulder rib 4 is a tread ground wire ( When the shoulder ribs 4 are formed of the multi-stage shoulder semi-ribs 41, 42, and 43 having a sequential height difference, the shoulder ribs 41, 42 of the multi-stage have , 43) a shoulder semi-groove (401, 402, 403) formed between the pneumatic tire for a heavy-duty vehicle. 5. The pneumatic tire according to claim 4, wherein the shoulder semi grooves (401, 402) have a depth of one to two times the step between adjacent two semi grooves.

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