JPH05605A - Tread-outer layer for pneumatic radial tire - Google Patents
Tread-outer layer for pneumatic radial tireInfo
- Publication number
- JPH05605A JPH05605A JP3181739A JP18173991A JPH05605A JP H05605 A JPH05605 A JP H05605A JP 3181739 A JP3181739 A JP 3181739A JP 18173991 A JP18173991 A JP 18173991A JP H05605 A JPH05605 A JP H05605A
- Authority
- JP
- Japan
- Prior art keywords
- sipe
- tire
- tread
- rotation axis
- blind end
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
- B60C11/1218—Three-dimensional shape with regard to depth and extending direction
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は空気入りラジアルタイヤ
に関し、タイヤのトレッドに設けられたサイプの盲端か
ら亀裂の発生を防止することができる形状のサイプを備
えたタイヤに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic radial tire, and more particularly to a tire provided with a sipe having a shape capable of preventing cracks from being generated from a blind end of a sipe provided on a tread of the tire.
【０００２】[0002]
【従来の技術】空気入りラジアルタイヤのトレッド表面
には、トレッドのグリップ力の向上、湿潤路面における
エッジ効果の増大、トレッドのブロック又はリブの剛性
調節によるトレッドの耐摩耗性の向上等を目的として、
狭い溝よりなるサイプが多数設けられている。これらの
サイプのうち、略タイヤの回転軸方向に設けられ、一端
がトレッドに周方向に沿って設けた縦溝の側壁またはバ
ットレス部に開放され、他端がトレッドのブロック又は
リブ内で盲端として行き止まりとなっているサイプは、
走行中のタイヤのトレッドに繰り返し加わる負荷によ
り、サイプの盲端部及び底部開口端部に大きな力が加わ
り、サイプの盲端部又は底部開口端部からトレッドゴム
に亀裂が発生することが多い。例えば図１に示すトレッ
ド１の踏面２からトレッド１に設けた縦溝３の側壁４、
又はトレッド１のサイド部５にかけて連続して開口する
サイプ６の場合には、トレッド１の踏面２のサイプ盲端
７及び縦溝３の側壁４又はサイド部５に開口するサイプ
６の底部開口端８から、それぞれ逆方向に延びる亀裂９
が発生する。即ち制動力が主として作用する従動輪に装
着したタイヤでは、踏面２のサイプ盲端７からタイヤの
回転方向斜め前方に向かって亀裂９が延び、縦溝３の側
壁４又はサイド部５に開口するサイプ底部開口端８から
はタイヤの回転方向斜め後方に向かって亀裂９が延び
る。一方駆動力が主として作用する駆動輪に装着したタ
イヤでは、踏面２のサイプ盲端７からタイヤの回転方向
斜め後方に向かって亀裂９が延び、縦溝３の側壁４又は
サイド部５に開口するサイプ底部開口端８からはタイヤ
の回転方向斜め前方に向かって亀裂９が延びる。従って
トレッド１に作用する力がサイプ６の末端に集中して、
その部分よりトレッドゴムが引き裂かれるようにして、
亀裂９が発生する。2. Description of the Related Art The tread surface of a pneumatic radial tire has the purpose of improving the grip of the tread, increasing the edge effect on wet road surfaces, and improving the wear resistance of the tread by adjusting the rigidity of the block or rib of the tread. ,
A large number of sipes, which are narrow grooves, are provided. Of these sipes, they are provided approximately in the rotational axis direction of the tire, one end is opened to the side wall or the buttress portion of the vertical groove provided along the circumferential direction on the tread, and the other end is a blind end in the block or rib of the tread. The sipe that has become a dead end as
Due to the repeated load applied to the tread of a running tire, a large force is applied to the blind end and the bottom opening end of the sipe, and the tread rubber is often cracked from the blind end or the bottom opening end of the sipe. For example, from the tread surface 2 of the tread 1 shown in FIG. 1 to the side wall 4 of the vertical groove 3 provided in the tread 1,
Alternatively, in the case of the sipe 6 that continuously opens to the side portion 5 of the tread 1, the sipe blind end 7 of the tread 2 of the tread 1 and the side wall 4 of the vertical groove 3 or the bottom opening end of the sipe 6 that opens to the side portion 5 Cracks 9 extending in opposite directions from 8
Occurs. That is, in the tire mounted on the driven wheel on which the braking force mainly acts, the crack 9 extends from the sipe blind end 7 of the tread surface 2 toward the diagonally forward direction of the tire, and opens in the side wall 4 or the side portion 5 of the vertical groove 3. A crack 9 extends from the opening end 8 of the bottom of the sipe toward the diagonally rearward side in the tire rotation direction. On the other hand, in the tire mounted on the drive wheel on which the driving force is mainly applied, a crack 9 extends from the sipe blind end 7 of the tread surface 2 obliquely rearward in the tire rotation direction and opens in the side wall 4 or the side portion 5 of the vertical groove 3. From the sipe bottom opening end 8, a crack 9 extends obliquely forward in the tire rotation direction. Therefore, the force acting on the tread 1 is concentrated at the end of the sipe 6,
Make the tread rubber torn from that part,
A crack 9 occurs.
【０００３】トレッド１の接地幅を４等分し、両側の接
地端１０に近いそれぞれ接地幅の４分の１の幅の部分を
ショルダー領域１１とし、その両側のショルダー領域１
１に挟まれた中央の部分をセンター領域１２とすると
き、これらのサイプ６の末端からの亀裂９は、トレッド
１の幅方向両側の接地端１０に近いショルダー領域１１
のサイプ６に特に多く発生する。The ground contact width of the tread 1 is divided into four equal parts, and a portion having a width of a quarter of the ground contact width close to the ground contact ends 10 on both sides is defined as a shoulder region 11, and the shoulder regions 1 on both sides thereof.
When the central portion sandwiched between 1 is the center region 12, the cracks 9 from the ends of these sipes 6 are shoulder regions 11 close to the ground contact ends 10 on both sides in the width direction of the tread 1.
It especially occurs in the sipe 6 of.
【０００４】上記のサイプ盲端７又はサイプ底部開口端
８等のサイプ６の末端から発生する亀裂９を防止する方
法としては、 サイプの深さを浅くし、或いは長さを
短くする方法、 トレッド踏面のサイプの盲端の幅を
拡げ、盲端部に丸孔状膨らみを形成することにより、氷
雪路及び湿潤路における駆動、制動性能の改善とトレッ
ドの偏摩耗防止を図ると共に、サイプ盲端からの亀裂を
も防止する方法（特開昭６１−２６１１０９号公報）、
サイプ自体の幅を厚くして、その盲端部に丸みを持
たせる方法、が知られている。As a method of preventing the crack 9 generated from the end of the sipe 6 such as the sipe blind end 7 or the sipe bottom opening end 8 described above, a method of reducing the depth or the length of the sipe, or a tread is used. By expanding the width of the blind end of the sipe on the tread and forming a round hole-shaped bulge at the blind end, the driving and braking performance on ice and snow roads and wet roads are improved and uneven wear of the tread is prevented, and the sipe blind end is To prevent cracks from the surface (JP-A-61-261109),
A method is known in which the width of the sipe itself is increased and the blind end thereof is rounded.
【０００５】[0005]
【発明が解決しようとする課題】上記従来のサイプ盲端
からの亀裂発生の防止法のうち、のサイプの深さ或い
は長さを小さくする方法はサイプの本来の目的である接
地性の改善、排水性の改善、偏摩耗防止等の効果が減殺
される。Among the conventional methods for preventing cracks from occurring from the blind end of the sipe, the method of reducing the depth or length of the sipe is to improve the grounding property, which is the original purpose of the sipe. The effects of improving drainage and preventing uneven wear are diminished.
【０００６】のサイプの盲端の幅を拡げ丸孔状膨らみ
を形成する方法は、タイヤ成形時の膨らみの加工が困難
であり、その加硫成形用金型の製作費が嵩む。In the method of expanding the width of the blind end of the sipe to form a round hole-shaped bulge, it is difficult to process the bulge at the time of tire molding, and the manufacturing cost of the vulcanization molding die increases.
【０００７】の又サイプを厚くして盲端に丸みを持た
せる方法は、サイプ盲端の丸みの加工が困難であり、サ
イプを厚くすると偏摩耗を生じやすくなる。Further, in the method of thickening the sipe so that the blind end has a roundness, it is difficult to process the roundness of the sipe blind end, and if the sipe is thickened, uneven wear is likely to occur.
【０００８】従って本発明は上記従来法の欠点がなくサ
イプの盲端からの亀裂の発生を防止することができる形
状のサイプを備えたタイヤのトレッド外皮を提供するこ
とを目的とする。SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a tread skin of a tire provided with a sipe having a shape capable of preventing the occurrence of cracks from the blind end of the sipe without the drawbacks of the above-mentioned conventional methods.
【０００９】[0009]
【課題を解決するための手段】上記目的を達成すべく、
本発明者は鋭意研究を重ねた結果、タイヤトレッドの上
記サイプ盲端７又は底部開口端８等のサイプ末端に亀裂
９を生ぜしめるように主として作用する力の方向、即ち
従来のタイヤでサイプ盲端７又は底部開口端８に生じた
亀裂９に対し略直角方向にサイプ６の末端近傍の部分を
屈曲させることにより、サイプ盲端７角部に過大な応力
として、一極集中的に加わっていた引裂力は、その大部
分が屈曲部から先の折れ曲がり部に沿う方向に単純な張
力として働くようになり、又その張力に対する変形代が
長くなるため、そのサイプ６が接地している間に加えら
れる定変位的負荷エネルギーはサイプ６に沿う歪部分に
広く分散して貯えられ、応力は小さくなって、定変位的
負に対する疲労耐久力が増大することになる。その結果
サイプ６の末端部分からの亀裂９の発生を防止しうるこ
とを見出し、本発明を完成するに至った。[Means for Solving the Problems] In order to achieve the above object,
As a result of intensive studies, the present inventor has found that the direction of the force mainly acting to cause the crack 9 at the sipe end such as the sipe blind end 7 or the bottom opening end 8 of the tire tread, that is, the sipe blind end in the conventional tire. By bending the portion near the end of the sipe 6 in a direction substantially perpendicular to the crack 9 generated at the end 7 or the bottom opening end 8, excessive stress is applied to the corners of the sipe blind end 7 in an extremely concentrated manner. Most of the tearing force acts as a simple tension in the direction along the bent portion from the bent portion to the front, and the deformation margin for the tension becomes long, so that the sipe 6 is grounded. The applied constant displacement load energy is widely dispersed and stored in the strained portion along the sipe 6, the stress is reduced, and the fatigue endurance against the constant displacement negative is increased. As a result, they have found that it is possible to prevent the occurrence of cracks 9 from the end portion of the sipe 6, and have completed the present invention.
【００１０】即ち、本発明はタイヤ回転軸を含む平面に
略平行に配列したカーカスコードと該カーカスコードの
外側に積層して該回転軸に垂直な平面に対して２０°以
内の角度で配列されたコードよりなる複数のベルト層を
有する空気入りラジアルタイヤにおいて、タイヤのトレ
ッドの接地幅を４等分して両側の各４分の１の部分をそ
れぞれショルダー領域とし、ショルダー領域により挟ま
れる中央部分をセンター領域とし、該ショルダー領域ま
たはセンター領域のタイヤ幅方向外側部分に配置された
リブに、タイヤ回転軸を含む平面に略平行に多数配列さ
れ、一端をタイヤサイド部に又はトレッドの縦溝の側壁
に開放され、踏面で他端が盲端に形成されたサイプの少
なくとも一部が、該サイド部又は該縦溝側壁のサイプ底
部開口端近傍でタイヤ周方向に鈍角に折れ曲がる折れ曲
がり部を有することを特徴とする空気入りラジアルタイ
ヤのトレッド外皮を要旨とする。That is, according to the present invention, a carcass cord arranged substantially parallel to a plane including a tire rotation axis and a carcass cord laminated on the outside of the carcass cord are arranged at an angle within 20 ° with respect to a plane perpendicular to the rotation axis. In a pneumatic radial tire having a plurality of belt layers composed of cords, the ground contact width of the tread of the tire is divided into four equal parts, and each one-quarter part on each side is defined as a shoulder region, and a central part sandwiched between the shoulder regions. A center region, the shoulder region or a rib arranged on the tire width direction outer side portion of the center region, a large number are arranged substantially parallel to a plane including the tire rotation axis, one end of the tire side portion or the vertical groove of the tread. At least a part of the sipe that is open to the side wall and has the other end formed as a blind end on the tread is located near the sipe bottom opening end of the side portion or the vertical groove side wall. And gist tread outer skin of the pneumatic radial tire characterized by having a bent portion bent at an obtuse angle in the ya circumferential direction.
【００１１】[0011]
【実施例】次に本発明の内容を図面により詳細に説明す
る。図２は本はのタイヤの断面図、図３は本発明の空気
入りラジアルタイヤのトレッド外皮の一例のトレッドパ
ターン図、図４は同トレッド外皮の斜視図である。トレ
ッド１の接地幅Ｗを４等分し、外側の各１／４の幅の部
分をショルダー領域１１、中心部の１／２の幅の部分を
センター領域１２とする。タイヤのトレッド１表面に
は、略タイヤの周方向に連続して延びる直線状又はジグ
ザグ状の縦溝３が複数本設けられている。ショルダー領
域１１の縦溝３とサイド部５に挟まれたショルダーリブ
１３には踏面２から接地端１０を経てサイド部５に連続
して開口し、タイヤ回転軸を含む平面に略平行なショル
ダーサイプ６ａを設ける。ショルダーサイプ６ａの踏面
２への開口部はショルダーリブ１３内でサイプ盲端７と
なり、その踏面２への開口部はサイプ盲端７近傍で鈍角
に折れ曲がり短い折れ曲がり部１５を形成する。その折
れ曲がりの角θ1 は３０〜６０度が好ましい。また折れ
曲がり部１５の長さｌ1 は踏面２に開口するサイプ６の
長さＬの２５〜６０％が好ましい。The contents of the present invention will now be described in detail with reference to the drawings. 2 is a cross-sectional view of the tire of FIG. 3, FIG. 3 is a tread pattern diagram of an example of the tread skin of the pneumatic radial tire of the present invention, and FIG. 4 is a perspective view of the tread skin. The ground contact width W of the tread 1 is divided into four equal parts, and each outer 1/4 width portion is defined as a shoulder area 11 and a central portion 1/2 width portion is defined as a center area 12. The surface of the tread 1 of the tire is provided with a plurality of linear or zigzag vertical grooves 3 that continuously extend in the circumferential direction of the tire. The shoulder rib 13 sandwiched between the vertical groove 3 and the side portion 5 of the shoulder region 11 is continuously opened to the side portion 5 from the tread surface 2 through the ground contact end 10 and is substantially parallel to a plane including the tire rotation axis. 6a is provided. The opening to the tread 2 of the shoulder sipe 6a becomes the sipe blind end 7 in the shoulder rib 13, and the opening to the tread 2 forms an obtuse bend near the sipe blind end 7 to form a short bend 15. The bending angle θ 1 is preferably 30 to 60 degrees. Further, the length l 1 of the bent portion 15 is preferably 25 to 60% of the length L of the sipe 6 opening to the tread 2.
【００１２】ショルダーサイプ６ａのサイド部５への開
口部もサイプ底部開口端８近傍で鈍角に折れ曲がって、
折れ曲がり部１５を形成し、その折れ曲がりの角θ2 は
３０〜６０度が好ましく、その折れ曲がり部１５の長さ
ｌ2 はサイド部５に開口するサイプ６の深さＨの２５〜
６０％が好ましい。サイプ盲端７近傍とサイプ底部開口
端８近傍のサイプ６の折れ曲がりの方向はタイヤ回転軸
を含む平面に対して互に同じ方向側に向ける。The opening of the shoulder sipe 6a to the side portion 5 is also bent at an obtuse angle in the vicinity of the opening end 8 of the sipe bottom portion,
The bent portion 15 is formed, and the angle θ 2 of the bent portion is preferably 30 to 60 degrees, and the length l 2 of the bent portion 15 is 25 to the depth H of the sipe 6 opening to the side portion 5
60% is preferable. The directions of bending of the sipe 6 near the sipe blind end 7 and near the sipe bottom opening end 8 are directed in the same direction with respect to the plane including the tire rotation axis.
【００１３】トレッド１のセンター領域１２の縦溝３に
挟まれたリブのうち、外側のリブ１６の縦溝３の内側側
壁４ａから踏面２に跨がる部分にも上記ショルダーサイ
プ６ａと略同様の形状のサイプ６を設ける。即ち内側側
壁４ａへの開口部のサイプ底部開口端８近傍及び踏面２
への開口部のサイプ盲端７のそれぞれ近傍で、鈍角に折
れ曲がり、折れ曲がり部１５を形成する。その折れ曲が
り部１５の折れ曲がり方向はショルダーサイプ６ａと同
じ方向とする。Of the ribs sandwiched by the vertical grooves 3 in the center region 12 of the tread 1, the portion extending from the inner side wall 4a of the vertical groove 3 of the outer rib 16 to the tread surface 2 is substantially the same as the shoulder sipe 6a. A sipe 6 of the shape is provided. That is, in the vicinity of the sipe bottom opening end 8 of the opening to the inner side wall 4a and the tread 2
An obtuse angle bend is formed near each of the sipe blind ends 7 of the openings to form a bend 15. The bending direction of the bent portion 15 is the same as that of the shoulder sipe 6a.
【００１４】ショルダーリブ１３の縦溝３側にも、踏面
２から縦溝３の稜線１４を経て縦溝の外側側壁４ｂに連
続して開口し、タイヤ回転軸を含む平面に略平行なサイ
プ６を設けることができる。このサイプ６にもショルダ
ーサイプ６ａと同様に折れ曲がり部１５を設けるのが好
ましい。図５のＡ矢視図に示すように、このサイプ６の
折れ曲がり部１５の折れ曲がり方向は、踏面２のサイプ
盲端７の折れ曲がり部１５を、タイヤ回転軸を含む平面
に対してショルダーサイプ６ａの折れ曲がり部１５と同
一方向に折り曲げ外側側壁４ｂの底部開口端８の折れ曲
がり部１５は、タイヤ回転軸を含む平面に対してショル
ダーサイプ６ａの折れ曲がり部１５と同じ方向に折り曲
げるのが好ましい。Also on the side of the vertical groove 3 of the shoulder rib 13, the sipe 6 is opened continuously from the tread surface 2 through the ridgeline 14 of the vertical groove 3 to the outer side wall 4b of the vertical groove, and is substantially parallel to the plane including the tire rotation axis. Can be provided. It is preferable that the sipe 6 also has a bent portion 15 similarly to the shoulder sipe 6a. As shown in the view from the arrow A of FIG. 5, the bending direction of the bending portion 15 of the sipe 6 is such that the bending portion 15 of the sipe blind end 7 of the tread 2 is located on the shoulder sipe 6a with respect to the plane including the tire rotation axis. Bending in the same direction as the bending portion 15 The bending portion 15 of the bottom opening end 8 of the outer side wall 4b is preferably bent in the same direction as the bending portion 15 of the shoulder sipe 6a with respect to the plane including the tire rotation axis.
【００１５】トレッド１のセンター領域１２の内側に設
ける回転軸方向のサイプ６にはその末端より亀裂９が生
ずる虞は少ないので、折れ曲がり部１５を設ける必要が
ない。Since the sipe 6 provided in the center region 12 of the tread 1 in the direction of the rotation axis is less likely to be cracked 9 from its end, the bent portion 15 need not be provided.
【００１６】本発明のトレッド外皮の折れ曲がり部１５
を有するサイプ６を形成するにはタイヤ成形用金型のリ
ブ形成用溝に図６に示すような形状のサイプ形成板１７
を植設する。サイプ形成板１７にはその２辺に沿って、
サイプ６の折れ曲がり部１５を形成するための屈曲部１
８を設ける。屈曲部１８への屈折点は若干丸みを持た
せ、サイプ６の屈折点に応力が集中しないようにするの
が望ましい。屈曲部１８はサイプ形成板１７の縁に平行
な一定幅ｄを有する必要はなく、折れ曲がり部１５がサ
イプ６の奥で幅ｄが狭くなるように形成してもよいし、
サイプ６のサイド部５、縦溝３側壁４又は踏面２に開口
する開口端近傍に相当する部分のみに三角形状に屈曲部
１８を設けてもよい。Bent portion 15 of the tread skin of the present invention
In order to form a sipe 6 having a sipe 6, a sipe forming plate 17 having a shape as shown in FIG.
To plant. On the sipe forming plate 17, along its two sides,
Bent portion 1 for forming bent portion 15 of sipe 6
8 is provided. It is desirable that the bending point on the bent portion 18 be slightly rounded so that stress is not concentrated on the bending point of the sipe 6. The bent portion 18 does not have to have a constant width d parallel to the edge of the sipe forming plate 17, and the bent portion 15 may be formed so that the width d becomes narrower inside the sipe 6.
The bent portion 18 may be provided in a triangular shape only in the side portion 5 of the sipe 6, the side wall 4 of the vertical groove 3, or the portion corresponding to the vicinity of the opening end opening to the tread surface 2.
【００１７】[0017]
【作用】本発明のタイヤを車輛に装着するには、制動力
が主として作用する従動輪には、車輛装着時に車輛外側
となるタイヤサイド部５のショルダーサイプ６ａの折れ
曲がり部１５が、タイヤの回転方向前方斜め向きになる
ように装着する。駆動力が主として作用する駆動輪に
は、車輛装着時に車輛外側となるタイヤサイド部５のシ
ョルダーサイプ６ａの折れ曲がり部１５が、タイヤの回
転方向後方斜め向きになるように装着する。In order to mount the tire of the present invention on a vehicle, the bent portion 15 of the shoulder sipe 6a of the tire side portion 5, which is on the outside of the vehicle when the vehicle is mounted, is attached to the driven wheel on which the braking force mainly acts. Wear it so that it is facing diagonally forward. The drive wheel, on which the driving force mainly acts, is mounted so that the bent portion 15 of the shoulder sipe 6a of the tire side portion 5, which is on the outside of the vehicle when the vehicle is mounted, is inclined rearward in the rotational direction of the tire.
【００１８】このようにタイヤを車輛に装着することに
より、図７の説明図に示すように、（ａ）に示す従来の
サイプ６では（ｂ）に示すようにショルダーサイプ６ａ
のサイプ盲端７及びサイプ底部開口端８に応力が集中す
る結果、そのサイプ末端部から応力によりゴムが引き裂
かれるようにして、応力の方向に対し略直角方向に亀裂
９が入る。By mounting the tires on the vehicle in this manner, as shown in the explanatory view of FIG. 7, in the conventional sipe 6 shown in FIG. 7A, the shoulder sipe 6a as shown in FIG.
As a result of the stress being concentrated on the sipe blind end 7 and the sipe bottom opening end 8 of the sipe, the rubber is torn from the end of the sipe, and a crack 9 is formed in a direction substantially perpendicular to the stress direction.
【００１９】（ｃ）の本発明の折れ曲がり部１５を有す
るサイプ６の場合は、（ｄ）に示すように折れ曲がりに
より応力の一点集中が緩和され、サイプ６の末端にゴム
を引き裂くように作用する応力が小さくなる。即ち
（ａ）に示す従来のタイヤでサイプ盲端７又は底部開口
端８に生じた亀裂９に対し略直角方向にサイプ６の末端
近傍の部分を屈曲させることにより、サイプ盲端７角部
に過大な応力として、一極集中的に加わっていた引裂力
は、その大部分が屈曲部から先の折れ曲がり部１５に沿
う方向に単純な張力として働くようになり、又その張力
に対する変形代が長くなるため、そのサイプ６が接地し
ている間に加えられる定変位的負荷エネルギーはサイプ
６に沿う歪部分に広く分散して貯えられ、サイプ盲端７
に引き裂くように働く応力は小さくなって、定変位的負
に対する疲労耐久力が増大することになる。その結果、
亀裂９の発生が殆どなくなる。In the case of the sipe 6 having the bent portion 15 of the present invention of (c), one point of stress is relaxed by the bending as shown in (d), and it acts so as to tear the rubber at the end of the sipe 6. The stress becomes small. That is, in the conventional tire shown in (a), a portion near the end of the sipe 6 is bent in a direction substantially perpendicular to the crack 9 generated in the sipe blind end 7 or the bottom opening end 8 to form a corner of the sipe blind end 7. As the excessive stress, the tearing force, which is applied extremely intensively, mostly acts as a simple tension in the direction along the bent portion 15 from the bent portion, and the deformation margin for the tension is long. Therefore, the constant displacement load energy applied while the sipe 6 is grounded is widely dispersed and stored in the strained portion along the sipe 6, and the sipe blind end 7
The stress that acts to tear apart becomes small and the fatigue endurance against constant displacement negative increases. as a result,
Almost no crack 9 is generated.
【００２０】駆動輪と従動輪ではトレッド１のサイプ６
末端部にかかる最も大きな応力方向が異なり、主として
制動力の作用する従動輪では、制動力によりタイヤ回転
方向前方斜めに張力が作用するのに対し、主として駆動
力の作用する駆動輪では、駆動力によりタイヤ回転方向
後方斜めに張力が作用するため、上記のごとく駆動輪と
従動輪でタイヤの装着方向を逆にすることにより、サイ
プ６の末端からの亀裂９の発生を効果的に防止すること
ができる。For driving and driven wheels, the sipe 6 of the tread 1
The direction of the largest stress applied to the end portion is different, and in the driven wheel where the braking force mainly acts, the tension acts diagonally forward in the tire rotation direction due to the braking force, whereas in the driving wheel where the driving force mainly acts, the driving force As a result, tension acts diagonally rearward in the tire rotation direction. Therefore, by reversely mounting the tires on the driving wheels and the driven wheels as described above, it is possible to effectively prevent the occurrence of cracks 9 from the ends of the sipes 6. You can
【００２１】このトレッド外皮は実施例の如きリブタイ
プのタイヤだけでなく、ブロックタイプ、ラグタイプ、
リブラグタイプ等あらゆるタイプのタイヤにおいて、タ
イヤ回転軸を含む平面に略平行なサイプ６を有するタイ
ヤに適用することができる。This tread skin is not limited to the rib type tire as in the embodiment, but also a block type, a lug type,
The present invention can be applied to all types of tires such as a rib lug type tire having a sipe 6 that is substantially parallel to a plane including the tire rotation axis.
【００２２】[0022]
【発明の効果】本発明の空気入りラジアルタイヤのトレ
ッド外皮によれば、ショルダーリブ１３及びセンター領
域１２の外側リブのサイド部５又は縦溝３の側壁４に一
端を開口し、他端がリブ内で盲端となっているサイプ６
の末端部からの亀裂の発生を効果的に防止することがで
きる。According to the tread cover of the pneumatic radial tire of the present invention, one end is opened to the side portion 5 of the shoulder rib 13 and the outer rib of the center region 12 or the side wall 4 of the vertical groove 3, and the other end is ribbed. Sipe 6 that is blind inside
It is possible to effectively prevent the occurrence of cracks from the end portion of the.
【図１】従来の空気入りラジアルタイヤのトレッド外皮
の亀裂発生状況を示す斜視図FIG. 1 is a perspective view showing a crack generation state of a tread skin of a conventional pneumatic radial tire.
【図２】本発明のタイヤの断面図FIG. 2 is a sectional view of a tire of the present invention.
【図３】本発明の空気入りラジアルタイヤのトレッド外
皮の一例のトレッドパターン図FIG. 3 is a tread pattern diagram of an example of the tread skin of the pneumatic radial tire of the present invention.
【図４】本発明の空気入りラジアルタイヤのトレッド外
皮の一例の斜視図FIG. 4 is a perspective view of an example of a tread skin of the pneumatic radial tire of the present invention.
【図５】図１のＡ斜視図5 is a perspective view of FIG. 1A.
【図６】本発明の空気入りラジアルタイヤの成形用サイ
プ形成板の斜視図FIG. 6 is a perspective view of a sipe forming plate for forming a pneumatic radial tire of the present invention.
【図７】従来のタイヤ及び本発明の空気入りラジアルタ
イヤのトレッド外皮の亀裂発生の説明図FIG. 7 is an explanatory view of crack generation in a tread skin of a conventional tire and a pneumatic radial tire of the present invention.
１ トレッド ２ 踏面 ３ 縦溝 ４ 側壁 ５ サイド部 ６ サイプ ７ サイプ盲端 ８ サイプ底部開口端 ９ 亀裂 １０ 接地端 １１ ショルダー領域 １２ センター領域 １３ ショルダーリブ １４ 稜線 １５ 折れ曲がり部 １６ リブ １７ サイプ形成板 １８ 屈曲部 1 tread 2 treads 3 vertical grooves 4 side walls 5 side parts 6 sipes 7 Sipe blind end 8 Sipe bottom opening end 9 cracks 10 ground edge 11 Shoulder area 12 Center area 13 Shoulder rib 14 ridge 15 bends 16 ribs 17 Sipe forming plate 18 Bend
Claims (3)
したカーカスコードと該カーカスコードの外側に積層し
て該回転軸に垂直な平面に対して２０°以内の角度で配
列されたコードよりなる複数のベルト層を有する空気入
りラジアルタイヤにおいて、タイヤのトレッドの接地幅
を４等分して両側の各４分の１の部分をそれぞれショル
ダー領域とし、ショルダー領域により挟まれる中央部分
をセンター領域とし、該ショルダー領域またはセンター
領域のタイヤ幅方向外側部分に配置されたリブに、タイ
ヤ回転軸を含む平面に略平行に多数配列され、一端をタ
イヤサイド部に又はトレッドの縦溝の側壁に開放され、
踏面で他端が盲端に形成されたサイプの少なくとも一部
が、該サイド部又は該縦溝側壁のサイプ底部開口端近傍
でタイヤ周方向に鈍角に折れ曲がる折れ曲がり部を有す
ることを特徴とする空気入りラジアルタイヤのトレッド
外皮。1. A carcass cord arranged substantially parallel to a plane including a tire rotation axis and cords laminated outside the carcass cord and arranged at an angle of 20 ° or less with respect to a plane perpendicular to the rotation axis. In a pneumatic radial tire having a plurality of belt layers, the ground contact width of the tread of the tire is divided into four equal parts, and each one-quarter part on both sides is set as a shoulder region, and a central part sandwiched by the shoulder regions is a center region. A plurality of ribs arranged on the outer side in the tire width direction of the shoulder region or the center region are arranged substantially parallel to the plane including the tire rotation axis, and one end is opened to the tire side part or to the side wall of the vertical groove of the tread. Is
At least a part of the sipe whose other end is formed as a blind end on the tread surface has a bent portion that bends at an obtuse angle in the tire circumferential direction near the sipe bottom opening end of the side portion or the vertical groove side wall. The tread skin of the included radial tire.
端近傍でタイヤ周方向に鈍角に折れ曲がる折れ曲がり部
を有する請求項１記載の空気入りラジアルタイヤのトレ
ッド外皮。2. The tread skin of a pneumatic radial tire according to claim 1, wherein the sipe has a bent portion that bends at an obtuse angle in the tire circumferential direction near the blind end of the sipe on the tire tread surface.
れ曲がり方向と、該踏面におけるサイプ盲端近傍の折れ
曲がり方向が、タイヤ回転軸を含む平面に対して同じ向
きである請求項２記載の空気入りラジアルタイヤのトレ
ッド外皮。3. The air according to claim 2, wherein the bending direction of the sipe near the opening end of the sipe bottom and the bending direction of the tread near the blind end of the sipe are the same with respect to a plane including the tire rotation axis. The tread skin of the included radial tire.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3181739A JPH05605A (en) | 1991-06-25 | 1991-06-25 | Tread-outer layer for pneumatic radial tire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3181739A JPH05605A (en) | 1991-06-25 | 1991-06-25 | Tread-outer layer for pneumatic radial tire |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05605A true JPH05605A (en) | 1993-01-08 |
Family
ID=16106043
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3181739A Withdrawn JPH05605A (en) | 1991-06-25 | 1991-06-25 | Tread-outer layer for pneumatic radial tire |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05605A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6923232B1 (en) * | 1999-06-24 | 2005-08-02 | The Goodyear Tire & Rubber Company | Tread for a light truck or automobile tire |
| US8596318B2 (en) * | 2008-06-02 | 2013-12-03 | The Yokohama Rubber Co., Ltd. | Pneumatic tire with tread including circumferential grooves having inclined fine grooves |
-
1991
- 1991-06-25 JP JP3181739A patent/JPH05605A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6923232B1 (en) * | 1999-06-24 | 2005-08-02 | The Goodyear Tire & Rubber Company | Tread for a light truck or automobile tire |
| US8596318B2 (en) * | 2008-06-02 | 2013-12-03 | The Yokohama Rubber Co., Ltd. | Pneumatic tire with tread including circumferential grooves having inclined fine grooves |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19980903 |