KR101652558B1 - Pneumatic tire with improved uniformity of block stiffness - Google Patents

Abstract

The present invention relates to a pneumatic tire including a chamfer having a width and a depth proportional to a block size or a block stiffness ratio. According to the present invention, the chamfer size is adjusted according to the type of pitch, The braking performance can be improved by optimizing the block stiffness, and the uniformity of the pressure distribution in the ground plane can be minimized to minimize the block-to-block variation, which is also advantageous in the wear performance.

Description

[0001] Pneumatic tire with improved uniformity of block stiffness [

The present invention relates to a pneumatic tire having improved block stiffness uniformity, and more particularly, to a pneumatic tire including a chamfer having a size proportional to a block size or a stiffness ratio, thereby improving block stiffness uniformity.

BACKGROUND ART Automobile tires provide braking force by the relative frictional force with the ground during braking. 1A, the tread portion of a tire can be divided into a central portion 1 and shoulder portions 2a and 2b. The central portion 1 has a large role in driving, and the shoulder portions 2a and 2b are brakes The role of poetry is great. On the other hand, the pattern of the tire tread portion is formed by arranging the shapes having the same shape of pitch (10, 20) in the circumferential direction, and generally, the size of each pitch is designed to be about 3 to 5 in one tire, do.

In recent years, chambers have been formed in the side grooves of the shoulder to improve the braking performance, thereby increasing the ground contact area during braking and uniformly controlling the ground pressure distribution. Fig. 1B is a cross-sectional view taken along line X-X 'in Fig. 1A, in which a chamber portion 10a formed at one pitch is shown.

If chamfers are formed in the grooves of the same size, uniform stiffness can be maintained if the pitch of the tire blocks is one. However, if two or more different pitches are applied, the initially considered block stiffness is deformed, It may cause a heel and toe phenomenon which is unfavorable to the performance, and the ground pressure distribution may become uneven.

It is an object of the present invention to provide an air inlet radial tire which includes a chamfer having a size proportional to the block size of the tire tread portion, thereby improving the uniformity of the block stiffness and thereby exhibiting excellent braking performance and wear performance.

Another object of the present invention is to provide an air inlet radial tire which includes a chamfer having a size proportional to the stiffness of each block, thereby improving the uniformity of the block stiffness, thereby providing excellent braking performance and wear performance.

According to an aspect of the present invention,

Wherein the pitch comprises two or more pitches having different block sizes in a tread shoulder portion, the pitch comprising a chamfer having a width and a depth in the same ratio as the block size ratio.

The tire according to the present invention can improve the braking performance by adjusting the size of the chamfer according to the type of pitch to ensure the uniformity of the inter-block ground pressure and optimizing the block stiffness. In addition, uniform pressure distribution can be induced in the ground plane, minimizing block-to-block deviations, and also favoring abrasion performance.

1A is a plan view showing the pitch of a tire tread shoulder;
1B is a cross-sectional view taken along the line XX 'in FIG. 1A.
2 is a top view of a block illustrating chamfers formed in proportion to the block size of a small pitch, a medium pitch, and a large pitch according to one embodiment of the present invention.
3 is an excerpted cross-sectional view of a block illustrating chamfers formed in proportion to the block size of a small pitch, a medium pitch, and a large pitch according to an embodiment of the present invention.

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

Since the pitches of 3 to 5 types applied to the tire pattern are made up of blocks of different sizes, there is a difference in pitch size, which also causes a difference in the stiffness of the tire. Embodiments of the present invention are directed to a pneumatic tire comprising a chamfer having a block size ratio or a block stiffness ratio equal in size to a pitch having a different block size. According to the present invention, the braking function and the wear performance of the tire can be improved by including the chamfer having a size proportional to the block size or the block stiffness.

Figure 2 is a top view of a block illustrating chamfers 11a, 12a, 13a formed in proportion to the block size of small pitch 11, medium pitch 12, and large pitch 13 according to an embodiment of the present invention. to be. As shown in Fig. 2, the sizes of the chamfers 11a, 12a, and 13a are different from each other in proportion to the size of the block for each of the pitches 11, 12, and 13.

Figure 3 is an excerpt of a block showing chamfers 11a, 12a and 13a formed in proportion to the block size of the small pitch 11, medium pitch 12 and large pitch 13 according to an embodiment of the present invention. Sectional view. 3, the size of the chambers 11a, 12a and 13a means the width a and the depth beta of the chamfer, and the width a and the depth beta of the chamfer are equal to each other, They may be the same or different.

 In one embodiment of the invention, the block size of the small pitch 11: the block size of the medium pitch 12: when the block size of the large pitch 13 is 1: 1.3: 1.5, Chamfer 11a: Medium pitch chamfer 12a: Large pitch chamfer 13a can be determined at a ratio of 1: 1.3: 1.5.

According to another embodiment of the present invention, the width and depth of the chamfer are determined in proportion to the stiffness ratio of the pitch block. In this case, after measuring the stiffness between the blocks at each pitch, the width and depth of the chamfer can be determined in proportion to the measured value.

If the ratio of the chamfer size to the block size or the stiffness ratio of the pitch is formulated, the small pitch has a pitch ratio x (0.99 to 1), the medium pitch has a pitch ratio x (0.99 to 1.01) The pitch is in the range of the pitch ratio x (0.98 to 1.01). On the other hand, the ratio of the chamfer size to each pitch in the case of five types of pitches is the pitch ratio x (0.98 to 1) for medium pitch, the pitch ratio x (0.98 to 1.02) for medium pitch 1 and medium pitch 2, 1 and the large pitch 2 are in the range of the pitch ratio x (0.97 to 1.03). In one embodiment of the invention, medium pitch 1 and medium pitch 2 may have the same block size, and large pitch 1 and large pitch 2 may have the same block size.

In the present invention, the chamfer may be formed at both front and rear edges in the running direction of the block. Further, it may be formed only at one corner of the front or rear side, and the opposite corner may be maintained at a right angle. The cross-sectional shape of the chamfer may be a triangular or rounded round shape.

Hereinafter, the structure and effects of the present invention will be described in more detail with reference to specific examples. However, these examples are merely for the purpose of understanding the present invention more clearly and do not limit the scope of the present invention.

Example  One

The braking distance and the heel and toe when the ratio of the small size, the medium size and the large size in the ratio of 1: 1.29: 1.49 were measured in proportion to the block size of the pitch with the width and the depth of the chamfer having a triangular cross- Respectively.

Comparative Example  One

Table 1 shows the braking distance and the heel and toe when the width and depth of the chamfer having a triangular cross-sectional shape are set to 1 mm in the same manner regardless of the block size ratio of the pitch.

        * In parentheses, the index value Braking distance (m) Hill and toe measurement result (mm) Example 1 40.1 (101.2) 0.39 (104.09) Comparative Example 1 40.6 (100) 0.41 (100)

According to Table 1, it can be seen that the uniformity of the inter-block ground pressure can be secured in the case of Embodiment 1 in which the chamfer size is adjusted in proportion to the block size of the pitch, and the optimum design of the block stiffness is possible. Therefore, it is possible to minimize the block-to-block variation in the vehicle braking performance and the wear performance, and to prevent the abnormal wear.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, The facts will be apparent to those skilled in the art. Accordingly, the scope of protection of the present invention should be defined in the appended claims and their equivalents.

1: tread center portion 2a, 2b: tread shoulder portion
10, 11, 12, 13, 20: pitch 10a, 11a, 12a, 13a: chamfer

Claims (7)

A pneumatic tire comprising two or more pitches having different block sizes in a tread shoulder, wherein the pitch includes a chamfer having a width and a depth proportional to a block size ratio, Wherein the ratio of the chamfer size to the pitch of the small pitch is 0.99 to 1, the pitch of the medium pitch is 0.99 to 1.01, and the pitch of the large pitch is 0.98 to 1.01.
The pneumatic tire according to claim 1, wherein a block size ratio of the small pitch: medium pitch: large pitch is 1: 1.3: 1.5, and the width and depth ratio of the chamfer is 1: 1.3: 1.5.
A pneumatic tire comprising two or more pitches having different block sizes in a tread shoulder portion, wherein the pitch includes a chamfer having a width and a depth proportional to a block size ratio, and when the types of the pitch are five (0.98 to 1.02), medium pitch 1 and medium pitch 2 are pitch ratios (0.98 to 1.02), large pitch 1 and large pitch 2 are pitch ratios (0.97 to 1.03 ). ≪ / RTI > The pneumatic tire according to claim 1 or 3, wherein said width and depth are the same or different from each other.
delete The pneumatic tire according to any one of claims 1 to 3, wherein the chamfer is formed at both the front and rear edges in the running direction of the block.
The pneumatic tire according to claim 1 or 3, wherein the cross-sectional shape of the chamfer is a triangular or rounded round shape.

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