KR101995794B1 - Heavy Duty Pneumatic Tire with Waved Groove - Google Patents

Abstract

The present invention relates to a pneumatic tire for a heavy load having a rib pattern, in which a wave-shaped groove having a depth varying in the circumferential direction of the tire is formed to solve various problems caused by a stone ejector structure for preventing stuck- The present invention relates to a pneumatic tire for a heavy load having a groove,
A pneumatic tire for a heavy load having a rib pattern, wherein a groove (G) having a constant width is formed along the circumferential direction of the tire, both side walls of the groove (G) are formed as inclined surfaces and the groove base has a constant curvature Wherein the middle point P of the groove base forms a continuous wave along the circumferential direction of the tire in the form of a horizontal wave in the range of a certain width with reference to the center line of the groove and the depth P of the middle point of the groove base Is continuously changed.

Description

Technical Field [0001] The present invention relates to a heavy duty pneumatic tire having a wavy groove,

BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to a pneumatic tire for a heavy load having a rib pattern, and more particularly to a pneumatic tire for a heavy load having a rib pattern, And more particularly to a pneumatic tire for a heavy load having a wavy groove.

In general, various types of tread patterns are formed in the tread portion of the tire for grounding and ground to secure a traction force, a braking force, and a driving force. The tread pattern of the tire includes a plurality of grooves formed along the circumferential direction of the tire.

Since the pneumatic tire for heavy load has many rigid roads as well as on unpaved roads, the tread portion has sufficient rigidity, so that a tread pattern of a rib structure in which a plurality of grooves are formed along the circumferential direction is formed on the tread portion, A belt layer consisting of a plurality of belts is provided at the bottom of the tread to provide rigidity.

In the pneumatic tire for a heavy load of the above-mentioned rib pattern, since the tread portion does not move during running due to the belt layer, when a stone or foreign matter is caught in the groove, the stone or foreign matter is not discharged to the outside, A stone piling phenomenon occurs. However, if the rock or foreign matter continues to travel without being removed, stones or foreign substances embedded in the grooves cause repetitive impact and friction between the side walls of the grooves. This impact and friction not only accelerates the wear of the groove bottom but also causes cracks in the grooves and belt separation that detaches the belt layer from the tread portion by damaging the uppermost belt in the event of a worn condition deteriorating It is becoming a major cause.

Accordingly, a technique relating to a heavy duty pneumatic tire having a square or circular stone eject bar in a groove for preventing stiction in a groove formed in the circumferential direction of the tire in the rib pattern has been devised.

However, in order to insert the anti-stone bar in the groove in the heavy-duty pneumatic tire having such a rib pattern, it is required that the bottom surface of the groove be larger than a certain size. Under the condition of a certain size or less, There is a problem.

In addition, a pneumatic tire for a heavy load, in which a stone-pinching prevention bar is inserted, causes micro-cracks due to repeated tensile and compression of the edge rubber of the stone-pinion prevention bar inserted into the groove of the tire when the ground contacts the tread surface There is a problem in that the anti-stone bar is released by such a micro crack, and there is a problem that after the middle of wear, the micro crack spreads into the groove according to the growth of micro crack and causes an accident.

In addition, the pneumatic tire for heavy load, in which the anti-stone bite prevention bar is inserted, is formed so that the tread rubber of the green case is filled in the anti-stone bite bar in the vulcanizing process, There is a problem that the belt durability is deteriorated due to local waving.

Meanwhile, as a result of investigation of the prior art related to the present invention, a large number of patent documents have been searched and some of them will be described as follows.

Patent Document 1 discloses an air inlet flat tire in which an annular concave surface is formed so as to extend radially inward in the width direction central portion of the crown portion so that the water film phenomenon can be effectively suppressed at the time of cornering.

Patent Document 2 discloses a tread pattern structure of a high performance tire comprising a plurality of circumferential main grooves, a transverse groove formed between the main grooves, and various shapes of blocks formed between the grooves, wherein at least one main groove of the circumferential main grooves The first slope and the second slope are continuously connected in a wave form and the linear groove is integrally formed on the lower side of the linear surface connected to the slopes, Discloses a tread pattern with three-dimensional waves and straight grooves in which the block stiffness and hydroplaning of the tread are well maintained.

Patent Literature 3 discloses that the longitudinal grooves formed in the circumferential direction of the tire at the time of traveling have a constant width and depth and continuously change the inclination angle of the right and left wall surfaces to a constant shape around the bottom center line, And a pneumatic tire for a heavy load capable of suppressing a reduction in tire durability life.

JP 1993-278408 A KR 10-0610676 B1 KR 10-2013-0115440 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pneumatic tire for a heavy load having a rib pattern, The prevention of the stuck-up prevention bar caused by the micro-cracks of the side of the bar to prevent the occurrence of the accident, and the occurrence of the accident caused by the enlargement of the crack due to the micro-crack growth. The present invention provides a pneumatic tire for a heavy load capable of preventing micro cracks in a base portion caused by a stuck-up prevention bar, and prevents waving phenomenon occurring in the width direction of a belt layer of a heavy- So as to improve the durability of the belt.

According to an aspect of the present invention, there is provided a pneumatic tire for a heavy load having a rib pattern, wherein grooves having a predetermined width are formed along the circumferential direction of the tire, both side walls of the groove are formed as inclined surfaces having a variable inclination angle In addition, the inclination angles of the groove base and both side walls meet and have a constant curvature. The center point of the groove base where the curvature and the tangent line of the groove base meet is parallel to the circumferential direction of the tire A continuous waveform is formed, and the depth of the midpoint of the groove base portion is continuously changed.

According to the pneumatic tire for heavy load having the wavy groove of the present invention, the width of the left and right direction waves formed by the groove base portion is 0.15 times or more and 0.5 times or less of the width of the groove top end.

According to the pneumatic tire for heavy load having the wavy groove of the present invention, the midpoint depth of the groove bottom forms a continuous wave along the circumferential direction of the tire in the form of a wave in the up-and-down direction, And the width of the wave in the vertical direction corresponding to the car is 0.25 times or more and 0.35 times or less of the maximum depth of the groove.

According to the pneumatic tire for heavy load having the wavy groove of the present invention, the wavelength of the vertical wave of the groove base portion is not less than 1 time and not more than 2 times the wavelength of the left and right wave.
According to the pneumatic tire for heavy load having the wavy groove of the present invention, the ribs of the rib pattern have center ribs located in the center of the tread width direction, a shoulder rib located on the tread shoulder, And the groove is formed between the center rib and the side rib located at the center of the tread width direction.

In the pneumatic tire for heavy duty with the wavy groove of the present invention, the middle point of the groove base forms a continuous wave in the form of a wave in the left and right direction, and the depth of the base midpoint continuously changes, It is possible to improve the problem that the insertion of the anti-stone bite bar is limited according to the width and the curvature size of the base portion in the existing heavy duty pneumatic tire.

In addition, it is possible to prevent the occurrence of stitches and foreign matter from being inserted into the grooves during traveling through the wave in the left and right direction of the grooves formed along the circumferential direction at the time of traveling the pneumatic tire for heavy load, thereby preventing separation trouble due to groove cracks, It is possible to improve the durability of the belt by preventing the phenomenon of local waving in the width direction of the belt caused by the vulcanization in the belt layer located at the lower portion of the groove.

In addition, as the wave-shaped groove is formed, the aesthetic effect on the appearance of the tire can be enhanced, and the top and bottom waves formed along the traveling direction can be harmonized with traveling noise during traveling of the tire, so that substantial tire noise is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a rib pattern tire in which a rocking-pin prevention bar is formed in a groove. Fig.
2 is a plan view of a heavy duty pneumatic tire having a wavy groove according to the present invention;
3 is an enlarged cross-sectional view taken along line AA in Fig. 2 showing a circumferential cross-sectional shape of a wave-like groove which is a substantial part of the present invention.
Fig. 4 is an enlarged cross-sectional view taken along the line BB in Fig. 2 showing the cross-sectional shape in the width direction of the wavy groove, which is a substantial part of the present invention;
FIG. 5 is a three-dimensional modeling shape of a wave-like groove which is a main part of the present invention; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a heavy duty pneumatic tire having a wavy groove according to the present invention will be described with reference to the accompanying drawings.

As shown in FIGS. 2 to 5, the heavy-duty pneumatic tire having a wavy groove according to the present invention is a heavy duty pneumatic tire having a rib pattern in which a plurality of grooves G are formed along a tire circumferential direction A groove G having a constant width along the circumference of the tire is formed, both side walls of the groove G are formed as inclined surfaces having variable inclination angles, and the groove base portion and the inclination angles of both side walls meet to have a constant curvature, And the center point P of the groove base portion formed by the tangent line of the groove base portion forms a continuous waveform along the circumferential direction of the tire in the form of a lateral wave in the range of a certain width with reference to the center line of the groove, Is continuously changed.

It is preferable that the width W1 of the wave in the left and right direction formed by the groove base portion is 0.15 times or more and 0.5 times or less of the groove upper end width W and is represented by the following equation 1.

When the width W1 of the left and right directional wave is less than 0.15 times the width of the groove top width W, the effect of the left and right directional wave is insignificant and the stone ejector function is hardly exhibited. The width W1 of the left and right directional wave is limited as shown in Equation (1), because the position (wavelength) of the wave is longer and the position of the groove base portion changes greatly and partial uneven wear may occur.

The depth of the middle point P of the groove base portion forms a continuous wave form in the vertical direction of the tire along the circumferential direction of the tire and the width D of the up and down direction wave corresponding to the depth difference of the middle point P of the groove base portion ') Is 0.25 times or more and 0.35 times or less the maximum groove depth (D), and it can be expressed by the following equation (2).

If the width D 'of the vertical wave is less than 25% of the groove maximum depth D, the effect is insignificant. If the width exceeds 35%, the height of the groove base becomes excessively high, It is possible to cause a crack to be easily brought into contact with the tire, resulting in deterioration of the traction performance of the tire, and it is disadvantageous in terms of mileage since the wearer feels as if the wear is over.

It is preferable that the wavelength N 'of the vertical wave of the groove base portion is not less than 1 times and not more than 2 times the wavelength N of the left and right wave, and can be expressed by the following equation (3).

또한, 리브 패턴의 리브는 트레드 폭 방향 중심에 위치하는 센터 리브와, 트레드 숄더에 위치하는 숄더 리브 및 상기 센터 리브와 숄더 리브 사이에 위치하는 사이드 리브로 이루어지고, 그루브는 트레드 폭방향 중심에 위치하는 센터 리브와 사이드 리브 사이에 형성되는 것이 바람직하다.

The ribs of the rib pattern are composed of a center rib located at the center of the tread width direction, a shoulder rib located at the tread shoulder, and a side rib positioned between the center rib and the shoulder rib, And is preferably formed between the center rib and the side rib.

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, It will be appreciated by those of ordinary skill in the art that numerous changes and modifications can be made to the present invention without departing from the scope of the present invention. And all such modifications and changes as fall within the scope of the present invention are therefore to be regarded as being within the scope of the present invention.

G ... Groove
R ... rib
P ... center of groove base
W ... groove top width
W1 ... width of left and right wave
D ... Groove Maximum depth
D '... Width of up and down wave
N ... Wavelength of left and right direction wave
N '... Wavelength of up and down wave

Claims (5)

In a heavy duty pneumatic tire having a rib pattern,
Grooves G having a constant width are formed along the circumferential direction of the tire,
Both side walls of the groove G are formed as inclined surfaces having a variable inclination angle and the groove base portion and the inclination angles of both side walls meet to have a constant curvature,
The center point P of the groove base portion where the curvature and the tangent line of the groove base meet is formed as a continuous wave along the circumferential direction of the tire in a wave form in the left and right direction in a range of a certain width with reference to the center line of the groove,
The depth of the center point P of the groove base portion forms a continuous waveform along the circumferential direction of the tire in the form of a wave in a vertical direction,
The width D 'of the vertical wave corresponding to the depth difference of the midpoint of the groove base is 0.25 times or more and 0.35 times or less of the groove maximum depth D,
Wherein the wavelength N 'of the vertical wave of the groove base portion is not less than 1 time and not more than 2 times the wavelength N of the lateral wave. The method according to claim 1,
Wherein a width (W1) of the left-right direction wave formed by the groove base portion is 0.15 times or more and 0.5 times or less of the groove top width (W). 3. The method according to claim 1 or 2,
The rib (R) of the rib pattern comprises a center rib located at the center of the tread width direction, a shoulder rib located at the tread shoulder, and a side rib positioned between the center rib and the shoulder rib,
Wherein the groove (G) is formed between the center rib and the side rib located at the center of the tread width direction. delete delete

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