KR20150008551A

KR20150008551A - Pneumatic Radial Tire

Info

Publication number: KR20150008551A
Application number: KR20130082625A
Authority: KR
Inventors: 김학구
Original assignee: 한국타이어 주식회사
Priority date: 2013-07-15
Filing date: 2013-07-15
Publication date: 2015-01-23
Also published as: KR101541593B1

Abstract

The present invention relates to a pneumatic tire as a pneumatic radial tire comprising a tread, a side wall, and a bead part. The tread has multiple tread blocks and grooves formed thereon, wherein each of the tread blocks has a tie bar formed therebetween and consisting of a female tie bar and a male tie bar between which at least one puzzle-type kerf is formed. The tire according to the present invention is capable of largely improving the stiffness and the handling stability thereof without a separation due to abnormal abrasion and stress concentration.

Description

{Pneumatic Radial Tire}

The present invention relates to an air inlet radial tire, and more particularly, to an air inlet radial tire having an improved tie bar in a groove of a tread to maintain traction performance during wear / And more particularly to an air inlet radial tire having an improved tie bar capable of preventing cracking.

Generally, the pneumatic tire includes an inner liner constituting the inside of the tire, a carcass stacked on the outer periphery of the inner liner, a belt laminated on the outer periphery of the carcass, a tread , Both sidewalls constituting both sides of the tire, and both bead portions coupled to the wheel to maintain air pressure.

As shown in Fig. 1A, the tread portion 10 of this pneumatic tire has a plurality of longitudinal grooves 11 formed in the circumferential direction thereof and a plurality of transverse grooves 12 formed in the widthwise direction thereof , And a plurality of tread blocks (13) are formed by the grooves (11, 12).

When the tire is subjected to stress on the tread block 13, the block is distorted. In particular, when the tire runs on an unpaved road, stress is concentrated on the portion where the longitudinal grooves 11 and the lateral grooves 12 and the tread blocks 13 are connected The tread is prone to tearing.

In order to solve this problem, a tie bar 17 connecting the tread block 13 adjacent to the pneumatic tire and the tread block 13 is formed as shown in FIG. 1B to form the tread block 13, The tread block 13 can be prevented from being ruptured and abnormal wear can be prevented. Particularly in air-inlet radial tires such as trucks and buses, a tie bar 17 is formed between the blocks so as to serve as a bridge for increasing the rigidity by connecting blocks and blocks.

However, in the tire formed with such a tie bar, there is a problem that traction performance is deteriorated due to the ribbing between the tie bar 17 and the tread block 13 in the latter half of the wear. In the case of a transverse tie bar, as shown in FIG. 1B, the degree of freedom of the tread blocks is reduced due to the role of the strong tie bar 17 between the tread block and the tread block, and the tire receives a continuous load, The fatigue is accumulated in the marked area, and stress is concentrated at the connection point between the tread block and the tie bar, causing various cracks, and the tie bar may impair the rigidity of the tire, causing a problem in quality. On the other hand, if the height of the tie bar is lowered, the rolling performance is deteriorated due to the movement of the block, which gives an unstable feeling in terms of stability.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-described problems of the prior art and to provide a tie-bar cuff having a tie bar, The present invention provides a tire in which rigidity and steering stability of a tire are further improved by solving the problem of abnormal wear or degradation of traction performance by relieving stress concentration phenomenon by allowing a slight flow between bars.

According to one aspect of the present invention for achieving the above object,

A tread grounded on the road surface; Grooves formed in the tread, the grooves being formed in the tire circumferential direction and the transverse grooves formed in the tire width direction; The pneumatic tire includes tread blocks divided by the plurality of grooves. The pneumatic tire is characterized in that a plurality of grooves are provided between both ends of the tread blocks adjacent to the tread block and a center portion located between the tread blocks, wherein the tie bar is formed with an arm tie bar and a tie bar, and a puzzle cuff extending in the tire axial direction is formed between the arm tie bar and the water tie bar at the central portion, Wherein the tie bars have at least one recess, the water tie bar having at least one convex portion engaging one or more recesses of the arm tie bar.

The tires having the improved structure tie bars of the present invention are formed with tie bars having puzzle cuffs between the tread blocks to improve the stiffness in the main direction of the tires, And can provide a remarkable effect of preventing abnormal wear of a tire, preventing cracks due to stress concentration, and maintaining traction performance to the end of wear.

Further, according to the tire of the present invention, the degree of freedom of the tread block at the time of grounding can be increased to prevent the heel and the torsion, and the traction performance due to the ribbing between the tie bar and the block can be prevented in the middle of the wear, It is possible to provide an effect that can be achieved.

Unlike conventional tie bars, puzzle type tie bars provide a tie-bar-like function that maintains rigidity between existing blocks owing to the linkage between the tie bars, while at the same time having a stress relief effect, It is possible to significantly reduce the possibility of cracks between the tie bar and the block, which have occurred mainly in the tie bar.

Further, in the present invention, the connecting portion (both ends) between the tread block and the tie bar is formed as a curved surface, and when the stress concentration is set by setting the roundness (R value) It is possible to induce the concentrated stress that has occurred between bars to be naturally transferred to the tie bar connecting portion, thereby preventing cracks due to stress concentration.

Further, in the air inlet radial tire of the present invention, the arm tie bars and the tie tie bars hold each other, so that the rigidity of the tie bar can be maintained and the rolling improving effect can be maintained. It is possible to prevent the occurrence of cracks in the tie bar clearance area that can be generated by the continuous load.

In addition, when a height step is formed between the arm tie and the tie tie bar, the time for ribing can be delayed with respect to the existing tie bar, and even if the rib is advanced, So that it is possible to prevent perfect rib formation.

1A is a plan view showing a tread pattern shape of a general air inlet radial tire.
1B is a plan view showing a tread pattern shape of an air inlet radial tire having a tie bar.
2 is a plan view showing a tread pattern shape formed in a tread portion of an air inlet radial tire according to an embodiment of the present invention.
3A-3B are schematic perspective views showing the configuration of a tie bar of an air inlet radial tire of an embodiment of the present invention.
4A and 4B are schematic diagrams showing the shape of a puzzle cuff in another embodiment of the present invention.
5 is a schematic diagram for explaining the specifications of a puzzle cuff of an embodiment of the present invention.
6 is a schematic perspective view showing the configuration of a tie bar of an air inlet radial tire including a three-dimensional puzzle type cuff according to another embodiment of the present invention.
7 is a perspective sectional view of a tie bar having a three-dimensional puzzle cuff of an air inlet radial tire according to another embodiment of the present invention.

Hereinafter, an air inlet radial tire having the improved tie bar of the present invention will be described in more detail with reference to the drawings. In the drawings, parts not relating to the description are omitted for clarifying the present invention, and the same or similar components are denoted by the same reference numerals throughout the specification.

Fig. 2 is a plan view showing a tread pattern shape formed in a tread portion of an air inlet radial tire according to an embodiment of the present invention, and Figs. 3a-b and 4a-b are cross- Fig. 2 is a schematic perspective view showing a configuration of a tie bar of Fig.

The air inlet radial tire of the present invention comprises a tread portion, a side wall portion and a bead portion, and a plurality of tread blocks and a plurality of grooves are formed in the tread portion. 2, the tread pattern of the air inlet radial tire according to the present embodiment has a unit pattern shape formed within a unit pitch P repeated along the circumferential direction of the tire to form an entire tread pattern. The tread pattern is basically determined by the shape formed by the longitudinal grooves 11, the lateral grooves 12, and the tread blocks 13 partitioned by them.

Tie bars 14 are formed in the transverse grooves 12 for connecting the respective tread blocks 13 adjacent to each other in the circumferential direction of the tire. Thus, the tie bar 15 formed in the transverse groove 12 is configured to hold the tread blocks 13 together in the circumferential direction of the tire to prevent the occurrence of abnormal wear such as heels and tears between the blocks .

At least one tie bar is formed between the plurality of grooves, the tie bar having both end portions in contact with the adjacent tread blocks and a central portion positioned between the both end portions. The tie bar 14 is constituted by an arm tie bar 14 'and a male tie bar 14' ', and a puzzle cuff 15' extending in the axial direction of the tire between the arm tie bar and the water tie bar Is formed with one or more recesses 15 'which are in contact with one or more recesses 15' of the arm tie bars 14 ' The stitch has at least one convex portion 15 ".

The recess 15 'is longer than the length of the portion facing the puzzle-type cuff, and the length of the portion facing the puzzle-type cuff is longer than the length of the portion of the recess 15' The puzzle type tie bar 14 of the present invention is formed so that the concave portion 15 'of the arm tie bar 14' and the convex portion 15 'of the shoulder tie bar 14' 'are shorter than the length of the outer circumferential edge portion accommodated in the concave portion. 15 "are engaged with each other to hold each other, the stress concentration region of the rib, which is the connection portion between the tie bar and the tread block, is transferred on the connection while faithfully performing the tie bar maintaining the existing stiffness such as the rolling performance improvement The ability to reduce cracking can be reduced.

In the air inlet radial tire of the present invention, a puzzle-shaped tie bar connection portion shape is formed in a tie bar portion such as a blade and a cuff to be inserted into a conventional block at the time of mold production, and inserted into a groove back surface Thus, a puzzle-type tie bar can be manufactured by making a link between the tie bars.

The puzzle cuffs 15 of the tie bar 14 in the present invention may be one or more transverse puzzle cuffs or transverse and longitudinal puzzle cuffs.

The number of the concave portion 15 'of the arm tie bar 14' and the convex portion 15 '' of the water tie bar 14 '' in the air inlet radial tire of the present invention are not particularly limited, and FIGS. 4A and 4B The concave portion and the convex portion may be formed in plural.

5 is a schematic diagram for explaining the specifications of a puzzle cuff of an embodiment of the present invention. The depth h of the puzzle cuff 15 is in the range of about 75% to about 85% of the depth of the main groove. If the depth h of the puzzle-type cuff exceeds 85% of the depth of the main grooved portion, the drainability may deteriorate. If the depth h is less than 75%, the tie bar can not exhibit its function properly.

The tie bars 14 are formed with arm tie bars and tie tie bars on both sides with respect to the puzzle cuff 15, and the depths of the blocks of the arm tie bars and the suiting tie bars may be equal to each other or have steps. Case having a step is, as shown in Figure 5, the female tie bar and to increase the one of the tie bars (h ₁₎ has a height of 1.3 times to 1.6 times the tie bars of the other one of the height (h ₂₎ Lt; / RTI > When the tie bar 15 and the tie bar 15 are formed to connect between the tread blocks 13 they occupy most of the transverse grooves 12 and because of the height of the tie bars 14, The depth of the tread is reduced, and the traction performance may be deteriorated in the latter half of the tread. Therefore, if a step is formed between the arm tie and the tie bar height as described above, The tie bars can be sufficiently carried out while maintaining sufficient space.

5, in one embodiment of the present invention, a cavity 16 may be formed at the bottom of the puzzle cuff. That is, when the cavity 16 having a predetermined diameter is formed at the bottom of the puzzle cuff 15, stress concentration at the bottom of the puzzle cuff 15 formed in the tie bar 14 is relaxed, The occurrence can be suppressed.

In the present invention, the shape of the concave portion and the convex portion is not particularly limited, and any shape can be applied as long as the concave portion and the convex portion can hold each other such as a circular shape or an inverted trapezoid shape.

In another embodiment, the puzzle cuff 15 of the present invention may be a three-dimensional puzzle cuff formed with puzzle cuffs in both the width direction of the tire and the running direction of the tire. As shown in Fig. 6, the puzzle-type cuff 15 is not only a puzzle-like shape in plan view but also a puzzle shape in a side view to form a three-dimensional waveform. Alternatively, as shown in Fig. 7, the puzzle type cuff may have a puzzle shape with respect to the width direction of the tire and a puzzle shape with the shape of a wave shape in the running direction of the tire Dimensional puzzle type cuff.

As described above, according to the present invention, it is possible to optimize the shape of the tread pattern to improve traction and braking performance without affecting other performance of the tire. It is possible to run safely on snowy roads and ice roads, thereby ensuring stability of driving.

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, and that various changes and modifications may be made therein without departing from the spirit and scope of the invention. Accordingly, the true scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of protection of the present invention.

11: longitudinal groove 12: lateral groove
13: Tread block 14: Tie bars
14 ': Amanda Bar 14 ": Su Tai Bar
15: puzzle-type cuff 15 ': concave
15 ": convex portion 16: cavity

Claims

A tread grounded on the road surface; Grooves formed by longitudinal grooves formed in the tire circumferential direction and transverse grooves formed in the tire width direction in the tread; The pneumatic tire includes tread blocks divided by the plurality of grooves. The pneumatic tire is characterized in that a plurality of grooves are formed between both ends of the tread blocks adjacent to the tread block and a center portion located between the both ends, wherein the tie bar is formed with an arm tie bar and a tie bar, and a puzzle cuff extending in the tire axial direction is formed between the arm tie bar and the water tie bar at the central portion, Wherein the tie bar has at least one recess, the water tie bar having at least one convex portion engaging one or more recesses of the arm tie bar.

The puzzle-type cuff according to claim 1, wherein the concave portion is longer than the length of the portion facing the puzzle-type cuff, the length of the inner circumferential edge of the arm tie bar is longer than the length of the portion facing the puzzle- Characterized in that the outer radial tires are shorter than the gullies of the outer circumferential edges accommodated.

2. The air inlet radial tire of claim 1, wherein both ends are formed as curved surfaces, and the roundness R of both ends is greater than the roundness R of the ribs of the tie bar.

2. The air inlet radial tire of claim 1, wherein the puzzle cuff of the tie bars is at least one of a transverse puzzle cuff or a transverse and longitudinal puzzle cuff.

The tread according to claim 1, wherein the tie bars are constructed with arm tie bars and tie tie bars on both sides of a puzzle cuff, the depths of the blocks of the arm tie bars and the water tie bars being smaller than the depth of the tread blocks, tie bars and the number of height of one of the tie bars (h ₁₎ is the pneumatic radial tire characterized in that a height of 1.3 times to 1.6 times the tie bars of the other one of the height (h _2).

The air inlet radial tire according to claim 1, wherein a cavity is formed in a bottom portion of the puzzle cuff in the longitudinal direction of the puzzle cuff.

2. The air inlet radial tire according to claim 1, wherein the waveform of the puzzle cuff is a three-dimensional puzzle-type cuff formed in both the width direction of the tire and the running direction of the tire.

The air inlet radial tire according to claim 1, wherein the puzzle type cuff is a three-dimensional puzzle type cuff having a puzzle shape in the width direction of the tire and a waveform in the running direction of the tire.