JPH02185807A - Pneumatic tire - Google Patents
Pneumatic tireInfo
- Publication number
- JPH02185807A JPH02185807A JP1004265A JP426589A JPH02185807A JP H02185807 A JPH02185807 A JP H02185807A JP 1004265 A JP1004265 A JP 1004265A JP 426589 A JP426589 A JP 426589A JP H02185807 A JPH02185807 A JP H02185807A
- Authority
- JP
- Japan
- Prior art keywords
- tread
- shoulder rib
- shoulder
- tire
- rib
- 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.)
- Granted
Links
- 230000000052 comparative effect Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 101100298222 Caenorhabditis elegans pot-1 gene Proteins 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007373 indentation Methods 0.000 description 1
Landscapes
- Tires In General (AREA)
Abstract
Description
【発明の詳細な説明】
Ｌ１旦立■旦±」
この発明は、ショルダーリブにおける偏摩耗を防止する
ようにした空気入りタイヤに関する。DETAILED DESCRIPTION OF THE INVENTION This invention relates to a pneumatic tire that prevents uneven wear on shoulder ribs.
良法Ｊ口１碧
従来、ショルダーリブにおける偏摩耗を防止するように
した空気入りタイヤとしては、例えば特開昭５１−４７
７０４号公報に記載されているようなものが知られてい
る。このものは、ショルダーリブ全体をラジアル断面に
おけるトレッド輪郭より半径方向外側に突出させるとと
もに、その突出量を主溝からトレッド端に接近するに従
い小さくしたものである。そして、このような航空機用
タイヤは、高圧の内圧が充填されるため、トレッド輪郭
の曲率が小さくなってシ、ルダ一端での接地圧が低下し
、この結果、ショルダ一端に引き摺り偏摩耗が発生し易
いが、このものでは前述のようにショルダーリブを突出
させることで接地圧を均一化させ、前記偏摩耗の発生を
防止するようにしている。Conventionally, as a pneumatic tire designed to prevent uneven wear on the shoulder ribs, for example, Japanese Patent Application Laid-Open No. 51-47
The one described in Publication No. 704 is known. In this tire, the entire shoulder rib protrudes radially outward from the tread contour in the radial cross section, and the amount of protrusion decreases as it approaches the tread end from the main groove. Since such aircraft tires are filled with high internal pressure, the curvature of the tread profile becomes smaller and the ground contact pressure at one end of the shoulder decreases, resulting in uneven drag wear at one end of the shoulder. Although it is easy to do so, in this case, as mentioned above, the shoulder ribs are made to protrude to equalize the ground pressure and prevent the occurrence of uneven wear.
が
しかしながら、このような空気入りタイヤは、前述のよ
うな引き摺りによる偏摩耗を充分に防止することができ
るが、以下に説明するような偏摩耗の防止効果は充分な
ものではないのである。即ち、一般に、航空機は空港内
では直進が殆どであるため問題は少ないが、一般の乗用
車等のラジアルタイヤにおいては直進と旋回とを頻繁に
繰返すため、旋回時において該タイヤは大きな横力を受
けて変形し、その接地形状は第４図に示すように略三角
形となる。ここで、前述のように横力を受けてタイヤが
変形すると、補強ベルトかしわ寄せを受けて変形し、こ
れにより、トレッド端６２からトレッド幅Ｗの １／４
だけ離れた点６３付近のトレッドに、半径方向内側に凹
んだ小さなバックリング部が複数個発生する。そして、
このようなバックリング部８５が発生すると、タイヤ８
７のショルダーリブ８Ｂは第５図に示すように、軸方向
内端部が路面から浮き上がるため、軸方向外端部の極〈
一部だけが接地するようになり、この結果、トレッド端
Ｂ２近傍の接地圧のみが異常に高くなって偏摩耗が発生
してしまうのである。ここで、従来技術のようにショル
ダーリブ６Ｂをその内端部が外端部より突出量が多くな
るよう突出させてやれば、内端部も接地するようになっ
て接地圧の均一化が図れそうであるが、外端部も突出さ
せているため、この外端部の接地圧がさらに高くなり、
前述した内端部の接地による接地圧均一化の効果がかな
りの部分で相殺され、結果的にショルダーリブのトレッ
ド端６２近傍での偏摩耗は残ってしまうのである。However, although such pneumatic tires can sufficiently prevent uneven wear caused by dragging as described above, the effect of preventing uneven wear as described below is not sufficient. In other words, in general, there are few problems because aircraft mostly travel straight inside airports, but radial tires on general passenger cars often repeat straight travel and turns, so the tires are subject to large lateral forces when turning. The ground contact shape becomes approximately triangular as shown in FIG. Here, when the tire deforms due to the lateral force as described above, it is deformed by the reinforcing belt creased, and as a result, 1/4 of the tread width W from the tread end 62
A plurality of small buckling portions that are recessed inward in the radial direction are generated in the tread near the point 63, which is separated by the distance. and,
When such a buckling portion 85 occurs, the tire 8
As shown in FIG.
Only a portion of the tread comes into contact with the ground, and as a result, only the ground contact pressure near the tread end B2 becomes abnormally high, causing uneven wear. Here, if the shoulder rib 6B is made to protrude so that its inner end protrudes more than its outer end as in the prior art, the inner end also comes into contact with the ground and the ground pressure can be made uniform. However, since the outer end is also made to protrude, the ground pressure at this outer end becomes even higher.
The above-described effect of equalizing the ground contact pressure by contacting the inner end with the ground is canceled out to a large extent, and as a result, uneven wear remains in the vicinity of the tread end 62 of the shoulder rib.
この発明は、半径方向内側への凹み（バックリング）に
基ずくトレッド端近傍での偏摩耗を効果的に防止するこ
とができる空気入りタイヤを提供すること目的とする。SUMMARY OF THE INVENTION An object of the present invention is to provide a pneumatic tire that can effectively prevent uneven wear near the tread end due to radially inward denting (buckling).
このような目的は、周方向に延びる複数本の主溝と、こ
れら主溝により区画された複数本のリブと、をトレッド
に有する空気入りタイヤにおいて、トレッド端からトレ
ッド幅の１／４だけ離れた点に最も近接した主溝とトレ
ッド端との間のショルダーリブを、主溝近傍の内端部に
おいて、主溝間に位置するセンターリブのラジアル断面
における輪郭円弧の延長線より半径方向外側に突出させ
るとともに、トレッド端近傍の外端部において前記延長
線より半径方向内側に凹ませ、かつ、これら内、外端部
を滑らかに連ならせてショルダーリブの表面を構成し、
該表面と前記延長線とをショルダーリブの内、外端間に
おいて交差させることにより達成することができる。Such a purpose is to provide a pneumatic tire that has a tread with a plurality of main grooves extending in the circumferential direction and a plurality of ribs partitioned by these main grooves. The shoulder rib between the main groove and the tread edge that is closest to the point where The shoulder rib protrudes and is recessed radially inward from the extension line at the outer end near the tread end, and these inner and outer ends are smoothly connected to form the surface of the shoulder rib,
This can be achieved by intersecting the surface and the extension line between the inner and outer ends of the shoulder rib.
なお、この発明においては、前記ショルダーリブの内端
部での接線とタイヤ軸線に平行な直線との交差角を１５
度以下とし、また、ショルダーリブの外端部での接線と
タイヤ軸線に平行な直線との交差角を１０度から２５度
の範囲内とするとともに、該交差角を前記ショルダーリ
ブの内端部におけ・る交差角以上するとよい。In addition, in this invention, the intersection angle between the tangent at the inner end of the shoulder rib and a straight line parallel to the tire axis is 15
The intersection angle between the tangent at the outer end of the shoulder rib and a straight line parallel to the tire axis is within the range of 10 to 25 degrees, and the intersection angle is set at the inner end of the shoulder rib. It is recommended that the intersection angle be greater than or equal to .
１月
今、空気入りタイヤは前進しながらいずれかの方向に旋
回しているとする。このとき、該タイヤには大きな横力
が作用しているため変形し、トレッド端からトレッド幅
の１／４だけ離れた点近傍に半径方向内側に凹んだバッ
クリング部が発生する。このため、トレッド端からトレ
ッド幅の １／４だけ離れた点に最も近接した主溝とト
レッド端との間のショルダーリブは、主溝近傍の内端部
が路面から浮き上がって接地しなくなり、一方、トレッ
ド端近傍の外端部の極く一部だけが高い接地圧で接地す
るようになる。しかしながら、この発明では、まず、シ
ョルダーリブをトレッド端近傍の外端部において、セン
ターリブのラジアル断面における輪郭円弧の延長線より
半径方向内側に凹ませ、トレッド端近傍での接地圧を低
下させている。寥た、この発明では、ショルダーリブを
主溝近傍の内端部において、センターリブのラジアル断
面における輪郭円弧の延長線より半径方向外側に突出さ
せ、これにより、前記内端部を路面に接地させるように
している。この結果、シ璽ルダーリブの内端部も接地圧
を受けるようになり、ショルダーリブ内での接地圧が分
散される。しかも。Assume that the pneumatic tire is moving forward and turning in either direction. At this time, the tire is deformed due to the large lateral force acting on it, and a buckling portion that is recessed inward in the radial direction is generated near a point located 1/4 of the tread width from the tread edge. For this reason, the inner edge of the shoulder rib between the main groove and the tread edge, which is closest to the point 1/4 of the tread width away from the tread edge, lifts off the road surface and does not touch the ground. , only a small portion of the outer edge near the tread edge comes into contact with the ground with high ground pressure. However, in this invention, first, the shoulder rib is recessed radially inward at the outer end near the tread end from the extension line of the contour arc in the radial cross section of the center rib, thereby reducing the ground contact pressure near the tread end. There is. Additionally, in this invention, the inner end of the shoulder rib near the main groove is made to protrude radially outward from the extension line of the contour arc in the radial cross section of the center rib, thereby grounding the inner end on the road surface. That's what I do. As a result, the inner end of the shoulder rib also receives ground pressure, and the ground pressure within the shoulder rib is dispersed. Moreover.
これらショルダーリブの内、外端部を滑らかに連ならせ
て該ショルダーリブの表面を構成し、該表面と前記延長
線とをショルダーリブの内、外端間において交差させた
ので、ショルダーリブの表面全体が路面に面接触するよ
うになり、接地圧がさらに均一化される。しかも、この
とき、外端部において凹ませるようにしているので、従
来技術のようにショルダーリブ全体を突出させる場合に
比較して、前記延長線からの突出量が小さくなり、該突
出部分の偏摩耗あるいは他の部位に対する悪影響を可能
な限り低減することができる。The inner and outer ends of these shoulder ribs are smoothly connected to form the surface of the shoulder rib, and the surface and the extension line intersect between the inner and outer ends of the shoulder rib. The entire surface comes into surface contact with the road surface, making the ground pressure more even. Moreover, since the outer end is recessed at this time, the amount of protrusion from the extension line is smaller than when the entire shoulder rib is protruded as in the prior art, and the protruding portion is deflected. Wear or adverse effects on other parts can be reduced as much as possible.
また、前記ショルダーリブの内端部での接線とタイヤ軸
線に平行な直線との交差角を１５度以下とし、かつ、シ
ョルダーリブの外端部での接線とタイヤ軸線に平行な直
線との交差角を１０度から２５度の範囲内とするととも
に、該交差角を前記ショルダーリブの内端部における交
差角以上とすれば、ショルダーリブ全体をほぼ均一な接
地圧にすることができる。Further, the intersection angle between the tangent at the inner end of the shoulder rib and a straight line parallel to the tire axis is 15 degrees or less, and the intersection between the tangent at the outer end of the shoulder rib and a straight line parallel to the tire axis is 15 degrees or less. By setting the angle within the range of 10 degrees to 25 degrees and making the intersection angle greater than or equal to the intersection angle at the inner end of the shoulder rib, substantially uniform ground pressure can be achieved over the entire shoulder rib.
１竃１ 以下、この発明の一実施例を図面に基づいて説明する。1 pot 1 Hereinafter, one embodiment of the present invention will be described based on the drawings.
第１．２図において、 ｌは乗用車、バス、トラック等
に用いられる空気入りラジアルタイヤであり、このタイ
ヤ １のトレッド２には周方向に延びる複数本（この実
施例では３本）の主溝３と、これら主溝３により画成さ
れた複数本（この実施例では４本）のリブ４が形成され
ている。ここで、主溝３ａはタイヤ赤道面Ｍ上に配置さ
れ、方、主溝３ｂ、３ｃはトレッド端５、６からトレッ
ド幅Ｗの １／４だけ離れた点Ｐ、Ｑ近傍にそれぞれ配
置されている。また、リブ４は２本のセンターリブ４ａ
、 ４ｂと２本のショルダーリブ４ｃ、４ｄとから構成
され、前記センターリブ４ａ、４ｂは１点Ｐ、Ｑに最も
近接した主溝、ここでは主溝３ｂと３０との間に配置さ
れ、一方、ショルダーリブ４Ｃ１４ｄは、点Ｐ、Ｑに最
も近接した主溝、ここでは主溝３ｂ、３Ｃと、トレッド
端５、８との間にそれぞれ配置されている。これらショ
ルダーリブ４Ｃ１４ｄの表面７Ｃ１７ｄはセンターリブ
４ａ、４ｂのラジアル断面における輪郭円弧７ａ、７ｂ
の延長線Ｒと異なっている。ここで、センターリブ４ａ
、４ｂの輪郭円弧７ａ、７ｂとは、センターリブ４ａ、
４ｂの表面上の代表的な任意の３つの点を通る円弧であ
る。そして、主溝３ｂ、３Ｃ近傍に位置するショルダー
リブ４Ｃ１４ｄの内端部は、前記延長線Ｒより半径方向
外側に突出しており、一方、トレッド端５、６近傍に位
置するショルダーリブ４ｃ、 ４ｄの外端部は、前記延
長線Ｒより半径方向内側に凹んでいる。ここで、前記シ
璽ルダーリブ４ｃ、 ４ｄの内端部での接線Ｓと、タイ
ヤ軸線に平行な直線りとの交差角ａは、 １５度以下の
角度であることが好ましい、その理由は、前記角度ａが
１５度を超えると、タイヤｌ全体での耐摩耗性が低下し
てしまうからである。なお、前記接線Ｓは、ショルダー
リブ４Ｃ１４ｄの内端エツジにおける、シ鵞ルダーリブ
４Ｃ１４ｄ表面の内、外端および軸方向中央の３点を通
る円弧ｒに対する接線である。一方、前記ショルダーリ
ブ４ｃ、 ４ｄの外端部での接線Ｔと、タイヤ軸線に平
行な直線りとの交差角すは、１０度から２５度の範囲内
で、かつ、前記交差角ａより大であることが好ましい。In Fig. 1.2, l is a pneumatic radial tire used for passenger cars, buses, trucks, etc. The tread 2 of this tire 1 has a plurality of main grooves (three in this example) extending in the circumferential direction. 3, and a plurality of (four in this embodiment) ribs 4 defined by these main grooves 3 are formed. Here, the main groove 3a is arranged on the tire equatorial plane M, and the main grooves 3b and 3c are arranged near points P and Q, which are 1/4 of the tread width W away from the tread edges 5 and 6, respectively. There is. In addition, the ribs 4 include two center ribs 4a.
, 4b and two shoulder ribs 4c, 4d, the center ribs 4a, 4b are arranged in the main grooves closest to points P, Q, here between the main grooves 3b and 30, while , the shoulder ribs 4C14d are arranged between the main grooves closest to the points P and Q, here the main grooves 3b and 3C, and the tread ends 5 and 8, respectively. The surfaces 7C17d of these shoulder ribs 4C14d are contour arcs 7a, 7b in the radial cross section of the center ribs 4a, 4b.
It is different from the extension line R of . Here, the center rib 4a
, 4b's contour arcs 7a, 7b are the center rib 4a,
This is an arc passing through three representative arbitrary points on the surface of 4b. The inner end portions of the shoulder ribs 4C14d located near the main grooves 3b and 3C protrude radially outward from the extension line R, while the inner ends of the shoulder ribs 4C and 4d located near the tread ends 5 and 6. The outer end portion is recessed radially inward from the extension line R. Here, the intersection angle a between the tangent S at the inner end of the shield ribs 4c and 4d and a straight line parallel to the tire axis is preferably an angle of 15 degrees or less, and the reason for this is as follows. This is because if the angle a exceeds 15 degrees, the wear resistance of the entire tire l will decrease. The tangent S is a tangent to the arc r at the inner edge of the shoulder rib 4C14d, passing through three points on the surface of the shoulder rib 4C14d: the inner and outer ends, and the center in the axial direction. On the other hand, the intersection angle between the tangent T at the outer end of the shoulder ribs 4c and 4d and a straight line parallel to the tire axis is within the range of 10 degrees to 25 degrees and larger than the intersection angle a. It is preferable that
その理由は、前記交差角すが１０度未満であると、外端
部での接地圧が内端部での接地圧より高くなって接地圧
が不均一となるからであり、一方、２５度を超えると、
内端部での接地圧が外端部での接地圧よく高くなり接地
圧が不均一となるからである。また、交差角すが交差角
ａより大であるとしたのは、ショルダーリブ４ｃ、４ｄ
の表面７ｃ、 ７ｄが半径方向外側に向かって凸に湾曲
させた方が凹に湾曲させた場合に比較して接地圧がより
均一となるからである。なお、前記接線Ｔは、ショルダ
ーリブ４ｃ、 ４ｄの外端エツジ、即ちト・レッド端５
、６における、前記円弧ｒに対する接線である。そして
、ショルダーリブ４ｃ、４ｄの表面７ｃ、７ｄは、前述
した外端部および内端部を滑らかに連ならせることで構
成されており、この結果、ショルダーリブ４Ｃ１４ｄの
表面７ｃ、７ｄは前記延長線Ｒとシ璽ルダーリブ４ｃ、
４ｄの内、外端間において１点で交差することになる
。ここで、ショルダーリブ４Ｃ１４ｄの表面７ｃ、７ｄ
は前述のように湾曲した曲線であってもよいが、直線で
あってもよい、また、前記表面７Ｃ１７ｄと前記延長線
Ｒとの交差点Ｅは、トレッド端５、６からトレッド幅Ｗ
の０．１０倍だけ離れた点Ｆと、トレッド幅Ｗの０．２
０倍だけ離れた点Ｇとの間に位置していることが好まし
い、その理由は、交差点Ｅが点Ｆよりトレッド端８．７
側にあると、外端部での接地圧が内端部での接地圧より
高くなり接地圧が不均一となるからであり、正方、交差
ａ Ｅが点Ｇよりタイヤ赤道面Ｍ側にあると、内端部で
の接地圧が外端部での接地圧より高くなり接地圧が不均
一となるからである。The reason for this is that if the crossing angle is less than 10 degrees, the ground pressure at the outer end will be higher than the ground pressure at the inner end, resulting in uneven ground pressure. If you exceed
This is because the ground pressure at the inner end becomes higher than the ground pressure at the outer end, resulting in uneven ground pressure. Also, the intersection angle s is larger than the intersection angle a because the shoulder ribs 4c and 4d
This is because when the surfaces 7c and 7d are curved convexly toward the outside in the radial direction, the ground pressure becomes more uniform than when the surfaces 7c and 7d are curved concavely. Note that the tangent line T is the outer edge of the shoulder ribs 4c and 4d, that is, the tread edge 5.
, 6, is the tangent to the arc r. The surfaces 7c and 7d of the shoulder ribs 4c and 4d are constructed by smoothly connecting the outer and inner ends described above, and as a result, the surfaces 7c and 7d of the shoulder ribs 4C and 4d are formed by the extensions described above. Line R and seal rib 4c,
4d intersect at one point between the outer ends. Here, the surfaces 7c and 7d of the shoulder ribs 4C14d
may be a curved curve as described above, but may also be a straight line, and the intersection E between the surface 7C17d and the extension line R is the distance from the tread ends 5, 6 to the tread width W.
point F, which is 0.10 times apart from the point F, which is 0.2 times the tread width W.
It is preferable that the intersection E is located between the point G and the point G, which is 0 times farther away than the point F.
This is because if it is on the side, the ground pressure at the outer end will be higher than the ground pressure at the inner end, making the ground pressure uneven. This is because the ground pressure at the inner end becomes higher than the ground pressure at the outer end, resulting in uneven ground pressure.
次に、この発明の一実施例の作用について説明する。Next, the operation of one embodiment of the present invention will be explained.
今、タイヤ １は前進しながらいずれかの方向に旋回し
ているとする。このとき、該タイヤ １には大きな横力
が作用しているため、補強ベルトかしわ寄せを受けて変
形し、点Ｐ、Ｑ近傍において半径方向内側に凹んだパッ
クリング部が発生する。このため、ショルダーリブ４ｃ
、 ４ｄは、その内端部が路面から浮き上がって接地し
なくなり、方、外端部の極く一部だけが高い接地圧で接
地するようになる。しかしながら、この実施例では、ま
ず、ショルダーリブ４ｃ、４ｄの外端部を延長線Ｒより
半径方向内側に凹ませ、トレッド端５、６近傍での接地
圧を低下させている。これに加えて、この実施例では、
ショルダーリブ４ｃ、４ｄの内端部を延長線Ｒより半径
方向外側に突出させ、これにより、ショルダーリブ４ｃ
、４ｄの内端部をも路面に接地させるようにしている。Suppose now that tire 1 is turning in either direction while moving forward. At this time, since a large lateral force is acting on the tire 1, the tire 1 is deformed due to the stiffening of the reinforcing belt, and a pack ring portion that is recessed inward in the radial direction is generated in the vicinity of points P and Q. For this reason, shoulder rib 4c
, 4d, its inner end lifts off the road surface and does not touch the ground, while only a small portion of its outer end comes into contact with the ground with high ground pressure. However, in this embodiment, first, the outer ends of the shoulder ribs 4c and 4d are recessed radially inward from the extension line R to reduce the ground contact pressure near the tread ends 5 and 6. In addition to this, in this example:
The inner ends of the shoulder ribs 4c and 4d are made to protrude outward in the radial direction from the extension line R, so that the shoulder ribs 4c and 4d
, 4d are also brought into contact with the road surface.
この結果、ショルダーリブ４ｃ、４ｄの内端部も接地圧
を受けるようになり、ショルダーリブ４Ｃ１４ｄ内での
接地圧が確実に分散される。そして、これらショルダー
リブ４ｃ、４ｄの内、外端部を滑らかに連ならせて該シ
ョルダーリブ４ｃ、 ４ｄの表面７ｃ、７ｄを構成した
ので、ショルダーリブ４ｃ、４ｄの表面７ｃ、７ｄ全体
が路面に面接触するようになり、接地圧がさらに均一化
される。しかも、このとき、ショルダーリブ４Ｃ１４ｄ
の外端部を前述のように凹ませるようにしているので、
従来技術のようにショルダーリブ全体を突出させる場合
に比較して、延長線Ｒからの突出量が小さくなり、該突
出部分の偏摩耗あるいは他の部位に対する悪影響を可能
な限り低減することができる。As a result, the inner ends of the shoulder ribs 4c and 4d also receive ground pressure, and the ground pressure within the shoulder ribs 4C14d is reliably dispersed. Since the inner and outer ends of these shoulder ribs 4c and 4d are smoothly connected to form the surfaces 7c and 7d of the shoulder ribs 4c and 4d, the entire surfaces 7c and 7d of the shoulder ribs 4c and 4d are covered with the road surface. surface contact, and the ground pressure becomes more even. Moreover, at this time, shoulder rib 4C14d
Since the outer end of the is recessed as mentioned above,
Compared to the case where the entire shoulder rib protrudes as in the prior art, the amount of protrusion from the extension line R is smaller, and uneven wear of the protruding portion or adverse effects on other parts can be reduced as much as possible.
次に、試験例を説明する。この試験に当っては、ショル
ダーリブの表面が前記延長線に重なり合い、前記交差角
ａが５度で交差角すが１２度である比較タイヤｌと、シ
ョルダーリブの表面がいずれの部位においても前記延長
線より半径方向外側に位置している従来技術のような比
較タイヤ２と、ショルダーリブの表面が前記延長線と内
端および外端の２点で交差し、前記交差角ａが５度で交
差角すが３０度（２５度を超えている）である比較タイ
ヤ３と、ショルダーリブの表面と前記延長線とがその内
、外端間の１点で交差し、前記交差角ａが２０度（１５
度を超えている）で交差角すが２５度である供試タイヤ
１と、ショルダーリブの表面と前記延長線とがその内、
外端間の１点で交差し、前記交差角ａが１０度で交差角
すが２５度である供試タイヤ２と、シ璽ルダーリブの表
面と前記延長線とがその内、外端間の１点で交差し、前
記交差角ａが１５度で交差角すが２０度である供試タイ
ヤ３と、ショルダーリブの表面と前記延長線とがその内
、外端間の１点で交差し、前記交差角ａが７度で交差角
すが１８度である供試タイヤ４と、を準備した０次に、
このような各タイヤを車両に装着し１万Ｋｍ走行した後
、各タイヤのトレッドセンターでの摩耗量およびトレッ
ド端での摩耗量を測定した。そして、トレッド端での摩
耗量をトレッドセンターでの摩耗量で除した値の逆数を
指数化し、各タイヤの耐偏摩耗性能とした。その結果は
、比較タイヤｌの耐偏摩耗性能を１００とすると、比較
タイヤ２，３ではそれぞれ８２． １０３であったが、
供試タイヤ１．２．３．４ではそれぞれ １２１． １
４３、 １７８．２３０であった。このように、供試タ
イヤにあっては、耐偏摩耗性が比較タイヤより飛躍的に
向上している。また、前記測定した摩耗量の平均値の逆
数を指数化し、各タイヤの耐摩耗性能とした。その結果
は、比較タイヤｌの耐摩耗性能を １００とすると、比
較タイヤ２．３ではそれぞれ８４、１０４であったが、
供試タイヤｌ、２．３．４ではそれぞれ ｉｏｔ、
１２１． １５３．１７０であった。Next, a test example will be explained. In this test, the surface of the shoulder rib overlapped with the extension line, and the intersection angle a was 5 degrees, and the intersection angle was 12 degrees. In a comparative tire 2 such as the prior art, which is located radially outward from the extension line, the surface of the shoulder rib intersects the extension line at two points, an inner end and an outer end, and the intersection angle a is 5 degrees. Comparative tire 3 whose intersection angle is 30 degrees (exceeding 25 degrees), the surface of the shoulder rib and the extension line intersect at one point between the inner and outer ends, and the intersection angle a is 20 degrees. degrees (15
The test tire 1 has an intersection angle of 25 degrees (more than 25 degrees), and the surface of the shoulder rib and the extension line are
The test tire 2 intersects at one point between the outer ends, and the intersection angle a is 10 degrees and the intersection angle is 25 degrees. The test tire 3 intersects at one point, and the intersection angle a is 15 degrees and the intersection angle is 20 degrees, and the surface of the shoulder rib and the extension line intersect at one point between the inner and outer ends. , a test tire 4 in which the intersection angle a is 7 degrees and the intersection angle is 18 degrees,
After each tire was mounted on a vehicle and traveled for 10,000 km, the amount of wear at the tread center and the amount of wear at the tread edge of each tire was measured. Then, the reciprocal of the value obtained by dividing the amount of wear at the tread edge by the amount of wear at the tread center was converted into an index, and the uneven wear resistance performance of each tire was determined. The results show that, if the uneven wear resistance performance of comparative tire 1 is 100, comparative tires 2 and 3 are each 82. It was 103, but
For test tires 1, 2, 3 and 4, 121. 1
43, 178.230. In this way, the uneven wear resistance of the test tire is dramatically improved compared to the comparative tire. In addition, the reciprocal of the average value of the measured wear amount was converted into an index, and the wear resistance performance of each tire was determined. The results showed that, assuming the wear resistance performance of comparative tire 1 to be 100, comparative tire 2.3 had a wear resistance of 84 and 104, respectively.
Test tire l, iot in 2.3.4, respectively.
121. It was 153.170.
このように、供試タイヤにあっては、耐摩耗性が比較タ
イヤより飛躍的に向上している。As described above, the wear resistance of the test tire is dramatically improved compared to the comparative tire.
なお、この発明においては、第３図に示すように、ショ
ルダーリブ４ｃ、４ｄをトレッド端５、８を越えて軸方
向外側まで延在させ、ショルダ一部１１をなだらかな曲
面としてよい、このようにすれば、旋回時におけるショ
ルダ一部１１での接地面積が増大するので、接地圧をさ
らに均一化することができる。In addition, in this invention, as shown in FIG. 3, the shoulder ribs 4c and 4d may extend beyond the tread ends 5 and 8 to the outside in the axial direction, and the shoulder portion 11 may be formed into a gently curved surface. By doing so, the ground contact area of the shoulder portion 11 during turning increases, so that the ground contact pressure can be made more uniform.
良ｌＪと１１
以上説明したように、この発明によれば、半径方向内側
への凹み（バックリング）に基ずくトレッド端近傍での
偏摩耗を効果的に防止することができる。Good LJ and 11 As explained above, according to the present invention, it is possible to effectively prevent uneven wear in the vicinity of the tread end due to radially inward indentation (buckling).
第１図はこの発明の一実施例を示すトレッド近傍の子午
線断面図、第２図はトレッド端近傍の拡大断面図、１３
図はこの発明の他の実施例を示す第１図と同様の断面図
、第４図は従来の空気入りタイヤのフットプリントを示
す説明図、第５図は従来の空気入りタイヤの旋回時にお
ける変形状態を説明するトレッドの部分断面図である。
１・・・空気入タイヤ ２・・・トレッド３・・・主
ｆＩＩＩ４・・・リブ
４ｃ、４ｄ・・・ショルダーリブ
５、６・・・トレッド端
７Ｃ１７ｄ・・・表面 Ｗ・・・トレッド幅Ｒ・
・・延長線 Ｅ・・・交差点Ｓ、Ｔ・・・接線
Ｌ・・・直線特許出願人 株式会社ブリデス
トン
代理人 弁理士 多 １）敏 雄
第１図
第３図
１・・・空気入りタイヤ
３・・・主溝
４ｃ 、 ４ｄ・・・ショルダーリブ
７ｃ、７ｄ・・清面
Ｒ・・・延長線
２・・・トレッド
４・・・リブ
５．６・・・トレッド端
Ｗ・・・トレッド幅
第４図
Ｌ・・・直線FIG. 1 is a meridian sectional view near the tread showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view near the tread end, 13
The figure is a sectional view similar to FIG. 1 showing another embodiment of the present invention, FIG. 4 is an explanatory diagram showing the footprint of a conventional pneumatic tire, and FIG. 5 is a cross-sectional view of a conventional pneumatic tire when turning. It is a partial sectional view of the tread explaining a deformed state. 1... Pneumatic tire 2... Tread 3... Main fIII4... Rib 4c, 4d... Shoulder rib 5, 6... Tread end 7C17d... Surface W... Tread width R・
...Extension line E...Intersection S, T...Tangential line L...Straight line Patent applicant Brideston Co., Ltd. Agent Patent attorney Ta 1) Toshio Figure 1 Figure 3 1... Pneumatic tire 3 ...Main grooves 4c, 4d...Shoulder ribs 7c, 7d...Front surface R...Extension line 2...Tread 4...Rib 5.6...Tread end W...Tread width Figure 4 L...straight line
Claims (2)
り区画された複数本のリブと、をトレッドに有する空気
入りタイヤにおいて、トレッド端からトレッド幅の１／
４だけ離れた点に最も近接した主溝とトレッド端との間
のショルダーリブを、主溝近傍の内端部において、主溝
間に位置するセンターリブのラジアル断面における輪郭
円弧の延長線より半径方向外側に突出させるとともに、
トレッド端近傍の外端部において前記延長線より半径方
向内側に凹ませ、かつ、これら内、外端部を滑らかに連
ならせてショルダーリブの表面を構成することにより、
該表面と前記延長線とをショルダーリブの内、外端間に
おいて交差させたことを特徴とする空気入りタイヤ。(1) In a pneumatic tire whose tread includes a plurality of main grooves extending in the circumferential direction and a plurality of ribs partitioned by these main grooves, 1/1/2 of the tread width from the tread end.
The radius of the shoulder rib between the main groove and the tread end closest to the point 4 apart from the extension line of the contour arc in the radial cross section of the center rib located between the main grooves at the inner end near the main groove. Along with protruding outward in the direction,
By concave radially inward from the extension line at the outer end near the tread end, and by smoothly connecting these inner and outer ends to form the surface of the shoulder rib,
A pneumatic tire characterized in that the surface and the extension line intersect between the inner and outer ends of the shoulder rib.
線に平行な直線との交差角を１５度以下とし、また、シ
ョルダーリブの外端部での接線とタイヤ軸線に平行な直
線との交差角を１０度から２５度の範囲内とするととも
に、該交差角を前記ショルダーリブの内端部における交
差角以上とした請求項１記載の空気入りタイヤ。(2) The intersection angle between the tangent at the inner end of the shoulder rib and a straight line parallel to the tire axis should be 15 degrees or less, and the intersection angle between the tangent at the outer end of the shoulder rib and a straight line parallel to the tire axis should be 15 degrees or less. The pneumatic tire according to claim 1, wherein the intersection angle is within a range of 10 degrees to 25 degrees, and the intersection angle is greater than or equal to the intersection angle at the inner end of the shoulder rib.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1004265A JP2747832B2 (en) | 1989-01-11 | 1989-01-11 | Pneumatic tire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1004265A JP2747832B2 (en) | 1989-01-11 | 1989-01-11 | Pneumatic tire |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02185807A true JPH02185807A (en) | 1990-07-20 |
| JP2747832B2 JP2747832B2 (en) | 1998-05-06 |
Family
ID=11579711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1004265A Expired - Lifetime JP2747832B2 (en) | 1989-01-11 | 1989-01-11 | Pneumatic tire |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2747832B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5547005A (en) * | 1991-11-05 | 1996-08-20 | Sumitomo Rubber Industries, Ltd. | Radial tire with enhanced bead durability |
| JP2007069692A (en) * | 2005-09-06 | 2007-03-22 | Yokohama Rubber Co Ltd:The | Pneumatic tire |
| JP2017094765A (en) * | 2015-11-18 | 2017-06-01 | 東洋ゴム工業株式会社 | Pneumatic tire |
-
1989
- 1989-01-11 JP JP1004265A patent/JP2747832B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5547005A (en) * | 1991-11-05 | 1996-08-20 | Sumitomo Rubber Industries, Ltd. | Radial tire with enhanced bead durability |
| JP2007069692A (en) * | 2005-09-06 | 2007-03-22 | Yokohama Rubber Co Ltd:The | Pneumatic tire |
| JP4742759B2 (en) * | 2005-09-06 | 2011-08-10 | 横浜ゴム株式会社 | Pneumatic tire |
| JP2017094765A (en) * | 2015-11-18 | 2017-06-01 | 東洋ゴム工業株式会社 | Pneumatic tire |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2747832B2 (en) | 1998-05-06 |
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