JP2000062415A - Pneumatic radial tire - Google Patents
Pneumatic radial tireInfo
- Publication number
- JP2000062415A JP2000062415A JP10234591A JP23459198A JP2000062415A JP 2000062415 A JP2000062415 A JP 2000062415A JP 10234591 A JP10234591 A JP 10234591A JP 23459198 A JP23459198 A JP 23459198A JP 2000062415 A JP2000062415 A JP 2000062415A
- Authority
- JP
- Japan
- Prior art keywords
- tire
- radial
- distance
- crown
- recessed portion
- 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
Landscapes
- Tires In General (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、乗用車、バンと
呼ばれる一連の自動車、ピックアップ、小型トラックな
どの比較的小型の自動車の使途に供する空気入りラジア
ルタイヤに関するもので、特には排水性向上と操縦安定
性向上とを両立させた空気入りラジアルタイヤに関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic radial tire for use in a relatively small automobile such as a series of automobiles called passenger cars and vans, pickups, and light trucks, and particularly to improvement of drainage and steering. The present invention relates to a pneumatic radial tire that has both improved stability.
【０００２】[0002]
【従来の技術】図１０に示すように、従来の空気入りラ
ジアルタイヤ１００において、バットレス部１０２はタ
イヤ外側に向けて凸形状をなしているのが通常であった
が、このような設定の場合、水たまりのある路面の走行
時にバットレス部１０２の排水性が悪くなり、ハイドロ
プレーニング現象を起こしやすくなるという難点があっ
た。2. Description of the Related Art As shown in FIG. 10, in a conventional pneumatic radial tire 100, the buttress portion 102 is normally formed in a convex shape toward the outside of the tire. However, there is a problem in that the drainage of the buttress portion 102 is deteriorated during traveling on a road surface having a puddle, and a hydroplaning phenomenon is likely to occur.
【０００３】[0003]
【発明が解決しようとする課題】排水性を改良するため
トレッドパターンを変更することもなされてきたが、操
縦安定性や摩耗性との両立からトレッドパターンによる
排水性改良には限界があるのが現状である。Although the tread pattern has been changed in order to improve the drainage property, there is a limit to the improvement of the drainage property by the tread pattern in view of compatibility with steering stability and wearability. The current situation.
【０００４】また、クラウンアールを変更して接地形状
前縁部を丸くすることにより排水時の抵抗を少なくする
こともなされてきたが、接地圧分布が大きく変わり、摩
耗性能や操縦安定性などの他性能への影響が大きいため
に、接地形状前縁部を丸くすること以外の排水性改良手
法が望まれているのが現状である。It has also been attempted to reduce the resistance at the time of drainage by changing the crown radius and rounding the front edge of the ground contact shape, but the distribution of the ground contact pressure greatly changes, and wear resistance and steering stability are reduced. At present, there is a demand for a drainage improvement method other than rounding the front edge of the ground contact shape because it has a great influence on other performance.
【０００５】本発明は上記事実に考慮し、操縦安定性や
摩耗性を犠牲にすることなく、クラウンアール形状及び
バットレス形状を適正化することにより、排水性向上と
操縦安定性向上とを両立させた空気入りラジアルタイヤ
を提供することが目的である。In consideration of the above facts, the present invention optimizes the crown radius shape and the buttress shape without sacrificing the steering stability and wearability, thereby achieving both the improvement of drainage and the improvement of steering stability. The purpose is to provide a pneumatic radial tire.
【０００６】[0006]
【課題を解決するための手段】請求項１に記載の発明
は、一対のビード部、一対のサイドウォール部、前記サ
イドウォール部相互間にわたりトロイド状に連なるトレ
ッド部及び一方のビード部から他方のビード部へわたり
トロイド状に連なるラジアルカ−カスを有する空気入り
ラジアルタイヤであって、前記空気入りラジアルタイヤ
を標準リムに組み付けて標準内圧を充填した状態のタイ
ヤ及びリム組立体のタイヤ回転軸に沿った断面で表れる
トレッド部のクラウンは、互いに異なる曲率半径を有す
る少なくとも３種類の円弧を互いに滑らかに連ねた複合
円弧からなり、タイヤ赤道面からクラウン端に向かって
順次センタ領域、中間領域及びショルダ領域に区分けし
た前記クラウンは、タイヤ赤道面からタイヤ回転軸に対
して平行に測った各領域のタイヤ幅方向外端までの距離
Ｌ及び、各領域における円弧の曲率半径Ｒをそれぞれ、
センタ領域は距離Ｌａ及び曲率半径Ｒ1 、中間領域は距
離Ｌｂ及び曲率半径Ｒ2 、ショルダ領域は距離Ｌｃ及び
曲率半径Ｒ3 で表し、前記タイヤ及びリム組立体を標準
荷重負荷の下で平板に押圧した際の接触領域におけるク
ラウン端を、無負荷状態に戻した前記タイヤ及びリム組
立体においてタイヤ赤道面からタイヤ回転軸に対して平
行に計測したときの距離をＷで表したときに、距離Ｌａ
〜Ｌｃ、曲率半径Ｒ1 〜Ｒ3 及び距離Ｗの関係が、Ｌａ
＝（０．４〜０．５）×Ｗ、Ｒ1＝（１５〜４１）×
Ｗ、Ｌｂ＝（０．９〜１．１）×Ｗ、Ｒ2 ＝（１．５〜
２．４）×Ｗ、Ｌｃ＝（１．０〜１．５）×Ｗ、Ｒ3 ＝
（０．３〜２．５）×Ｗの関係を満たし、かつ、タイヤ
規格の最大負荷能力の１００％の荷重を負荷し、かつ、
路面に対して回転軸を平行にして接地させたときの接地
端とタイヤ最大幅点と間のバットレス部にタイヤ外郭に
開口する凹み部を有することを特徴としている。According to a first aspect of the present invention, a pair of bead portions, a pair of sidewall portions, a tread portion continuous in a toroidal shape between the sidewall portions, and one bead portion to another A pneumatic radial tire having a radial arc that extends in a toroid shape across a bead portion, the tire being in a state in which the pneumatic radial tire is assembled to a standard rim and a standard internal pressure is filled, and a tire rotation axis of the rim assembly. The cross section of the crown of the tread portion is composed of a complex arc in which at least three kinds of arcs having different radii of curvature are smoothly connected to each other, and the center area, the intermediate area, and the shoulder area are sequentially arranged from the tire equatorial plane toward the crown end. The crown is divided into, each measured from the tire equatorial plane parallel to the tire rotation axis Distance L and to the tire width direction outer end of the range, the curvature radius R of the arc in each region, respectively,
The center region is represented by the distance La and the radius of curvature R1, the middle region is represented by the distance Lb and the radius of curvature R2, and the shoulder region is represented by the distance Lc and the radius of curvature R3. When the tire and the rim assembly are pressed against a flat plate under a standard load load. When the crown end in the contact area of the tire is measured in parallel with the tire rotation axis from the tire equatorial plane in the tire and rim assembly returned to the unloaded state, the distance La is expressed as La.
~ Lc, the radii of curvature R1 to R3 and the distance W are La
= (0.4 to 0.5) × W, R1 = (15 to 41) ×
W, Lb = (0.9 to 1.1) × W, R2 = (1.5 to
2.4) × W, Lc = (1.0 to 1.5) × W, R3 =
(0.3 to 2.5) × W is satisfied, a load of 100% of the maximum load capacity of the tire standard is applied, and
It is characterized in that a buttress portion between the ground contact end and the tire maximum width point when the rotation axis is parallel to the road surface and the tire is grounded has a recessed portion opening to the tire shell.
【０００７】請求項１に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 1 will be described.
【０００８】まず雨の日など路面に水が溜まり、その上
を高速走行する場合、水はタイヤ接地面前方に進行速度
で衝突してくることになり、タイヤに当たった水はその
運動エネルギーでタイヤ表面を法線方向に押し上げる、
即ち、接地面を浮き上げるハイドロプレーニング現象を
生じさせる。First, when water collects on the road surface on a rainy day and travels at a high speed on the road surface, the water collides in front of the tire contact surface at a traveling speed, and the water hitting the tire uses its kinetic energy. Push up the tire surface in the normal direction,
That is, it causes a hydroplaning phenomenon that lifts the ground plane.
【０００９】タイヤを浮き上がらせる直接の要因はタイ
ヤ接地面前方に水が溜まることによる接地面前方の水圧
の上昇で、これがタイヤ接地圧を上回ると浮き上がり現
象を起こす。A direct factor for lifting the tire is the rise of water pressure in front of the contact surface due to the accumulation of water in front of the contact surface of the tire. If this exceeds the contact pressure of the tire, the phenomenon of lifting occurs.
【００１０】これを回避するにはタイヤ前方の水を排水
する（前方水圧を下げる）ことが必要で、従来はタイヤ
接地形状先端を丸くして接地面直前で横方向に水を排水
させたり、踏面内パターンにより横及び後方に排水させ
ることを行ってきたが、この方法では、水は接地面に到
達する前から凸状のバットレス部に押し出され、その結
果水の流れは接地面近傍で停滞し、大きな水圧上昇を引
き起こす。To avoid this, it is necessary to drain the water in front of the tire (reduce the front water pressure). Conventionally, the tip of the tire grounding shape is rounded to drain water laterally just before the grounding surface, Although we have been draining sideways and backward by the pattern inside the tread, in this method, the water is pushed out to the convex buttress portion before reaching the ground contact surface, and as a result, the water flow stagnates near the ground contact surface. And cause a large rise in water pressure.
【００１１】一方、請求項１に記載の空気入りラジアル
タイヤを水の溜まった路面で走行させると、水は接地面
よりも前方（タイヤが接水し接地するまでの間）でバッ
トレス部の凹み部に流れ込み、その結果、タイヤ接地面
前方に衝突する水の流れが少なくなり、接地面前方の水
圧上昇が少なくなる。このように請求項１に記載の空気
入りラジアルタイヤは排水性が改良されるため接地部が
浮き上がりにくく、ハイドロプレーニング現象を起こし
にくくなる。On the other hand, when the pneumatic radial tire according to claim 1 is run on a road surface in which water is accumulated, water is recessed in the buttress portion in front of the ground contact surface (until the tire is in contact with water and touches the ground). Flow into the section, resulting in less water flow colliding in front of the tire contact surface and less increase in water pressure in front of the contact surface. As described above, the pneumatic radial tire according to the first aspect has improved drainage, so that the ground contact portion is unlikely to be lifted up and the hydroplaning phenomenon is less likely to occur.
【００１２】なお、排水性改良のためには接地面になる
べく近い部分に大きな凹み部を作ることが望ましいが、
タイヤは走行時にスリップ角やキャンバー角が付くため
に横力がかかり、接地端部が横方向に広がることがあ
る。In order to improve the drainage property, it is desirable to make a large recessed portion as close to the ground contact surface as possible.
Since the tire has a slip angle and a camber angle when traveling, a lateral force is applied, and the ground contact end portion may spread laterally.
【００１３】そのため凹み部を直進時の接地端（スリッ
プ角０°、キャンバー角０°のときの接地端）に近づけ
すぎると、横力時に接地部が横方向に広がりにくくな
り、接地端部（旋回回転半径方向外側）で局所的な接地
圧集中部分ができ、操縦安定性に悪影響を及ぼす。Therefore, if the recessed portion is brought too close to the grounding end (the grounding end when the slip angle is 0 ° and the camber angle is 0 °) when the vehicle is traveling straight, the grounding part is less likely to spread laterally when lateral force is applied, and the grounding end ( There is a local ground pressure concentration area at the outside of the turning radius, which adversely affects the steering stability.
【００１４】また、バットレス部に凹み部を設けること
により、バットレス剛性が低下するため、タイヤ荷重時
に、バットレス部がサイド部からの押し込み変形により
タイヤ外側へ張り出す変形の量が、凹み部を設けないと
きよりも小さくなる。そのためタイヤ荷重時の接地端付
近でタイヤ外側形状の曲率半径が小さくなり、横力時の
接地圧集中が起こりやすくなる。Further, since the buttress portion is provided with a recess, the rigidity of the buttress is lowered. Therefore, when the tire is loaded, the amount of deformation of the buttress portion protruding toward the outside of the tire due to the push-in deformation from the side portion provides the recess. It will be smaller than when not. Therefore, the radius of curvature of the outer shape of the tire becomes small near the ground contact end when the tire is loaded, and the ground contact pressure tends to concentrate when lateral force is applied.
【００１５】そこで排水性と操縦安定性を両立させるた
め、請求項１に記載の空気入りラジアルタイヤでは、バ
ットレス部に凹み部を有する空気入りラジアルタイヤの
クラウン形状を、タイヤ赤道面から測った各領域の最外
側までの距離Ｌ及び各領域における円弧の曲率半径Ｒを
それぞれセンタ領域は距離Ｌａ及び曲率半径Ｒ1 、中間
領域は距離Ｌｂ及び曲率半径Ｒ2 、ショルダ領域は距離
Ｌｃ及び曲率半径Ｒ3で表し、この空気入りラジアルタ
イヤを標準のリムに装着して標準内圧を充填したタイヤ
及びリム組立体を標準荷重負荷の下で平板に押圧した際
の接触領域におけるクラウン端を、無負荷状態に戻した
タイヤ及びリム組立体においてタイヤ赤道面からタイヤ
回転軸に対して平行に計測したときの距離をＷで表した
ときに、距離Ｌａ〜Ｌｃ、曲率半径Ｒ1 〜Ｒ3 及び距離
Ｗの関係が、Ｌａ＝（０．４〜０．５）×Ｗ、Ｒ1 ＝
（１５〜４１）×Ｗ、Ｌｂ＝（０．９〜１．１）×Ｗ、
Ｒ2＝（１．５〜２．４）×Ｗ、Ｌｃ＝（１．０〜１．
５）×Ｗ、Ｒ3 ＝（０．３〜２．５）×Ｗの関係を満た
すように設定し、クラウンセンター部の接地圧負担をク
ラウンショルダー部と比べて大きくしたので、予めクラ
ウンショルダー部での接地圧負担が減らされ、接地端付
近の接地圧集中が起こりにくく（例え起こったとしても
タイヤ性能に影響を及ぼしにくく）なり、いかなる走行
時にも、接地圧集中による操縦安定性の低下を招くよう
なことが無くなる。Therefore, in order to achieve both drainage and steering stability, in the pneumatic radial tire according to claim 1, the crown shape of the pneumatic radial tire having a recess in the buttress portion is measured from the tire equatorial plane. The distance L to the outermost side of the region and the radius of curvature R of the arc in each region are represented by the distance La and radius of curvature R1 for the center region, the distance Lb and radius of curvature R2 for the intermediate region, and the distance Lc and radius of curvature R3 for the shoulder region. , The pneumatic radial tire was mounted on a standard rim, and the crown end in the contact area when the tire and the rim assembly filled with standard internal pressure were pressed against a flat plate under a standard load, was returned to an unloaded state. In the tire and rim assembly, when the distance measured from the tire equatorial plane parallel to the tire rotation axis is represented by W, the distance La to c, the relationship between the radius of curvature R1 to R3 and the distance W, La = (0.4~0.5) × W, R1 =
(15 to 41) × W, Lb = (0.9 to 1.1) × W,
R2 = (1.5 to 2.4) × W, Lc = (1.0 to 1.
5) × W, R3 = (0.3 to 2.5) × W is set so as to satisfy the relationship, and the contact pressure load of the crown center portion is made larger than that of the crown shoulder portion. This reduces the load on the ground pressure of the ground, making it difficult for the ground pressure to concentrate near the ground contact end (even if it does not affect the tire performance), which will lead to a reduction in steering stability due to ground pressure concentration during any running. Such things will disappear.
【００１６】また、請求項１に記載の空気入りラジアル
タイヤは、排水性の向上を図るためにトレッドパターン
を変更しないので、操縦安定性や摩耗性等の他の性能を
低下させることが無い。Further, in the pneumatic radial tire according to the first aspect, since the tread pattern is not changed in order to improve drainage, other performances such as steering stability and wear resistance are not deteriorated.
【００１７】ここで、標準荷重とは、下記規格に記載さ
れている適用サイズにおける単輪の最大荷重（最大負荷
能力）のことである。このときの内圧は下記規格に記載
されている適用サイズにおける単輪の最大荷重（最大負
荷能力）に対応する空気圧のことである。また、リムは
下記規格に記載されている適用サイズにおける標準リム
（または、”Approved Rim" 、"Recommended Rim" ）の
ことである。そして、規格とは、タイヤが生産又は使用
される地域に有効な産業規格によって決められている。
例えば、アメリカ合衆国では、”The Tire and Rim Ass
ociation Inc.のYear Book"で、欧州では、"The Europe
an Tire and Rim Technical Organization のStandards
Manual" で、日本では日本自動車タイヤ協会の"JATMA
Year Book" にて規定されている。Here, the standard load is the maximum load (maximum load capacity) of a single wheel in the applicable size described in the following standard. The internal pressure at this time is the air pressure corresponding to the maximum load (maximum load capacity) of a single wheel in the applicable size described in the following standard. The rim is a standard rim (or "Approved Rim" or "Recommended Rim") in the applicable size described in the following standard. The standard is determined by an industrial standard effective in the area where the tire is produced or used.
For example, in the United States, “The Tire and Rim Ass
"The Year Book by ociation Inc."
An Tire and Rim Technical Organization Standards
Manual "in Japan and" JATMA "of Japan Automobile Tire Manufacturers Association
Year Book ".
【００１８】請求項２に記載の発明は、請求項１に記載
の空気入りラジアルタイヤにおいて、前記凹み部のタイ
ヤ半径方向外側の外側開口端を、タイヤ赤道面から前記
クラウン端に向かってタイヤ回転軸に対して平行に測っ
た距離Ｗとなるクラウン上の点よりタイヤ半径方向内側
に配置したことを特徴としている。According to a second aspect of the invention, in the pneumatic radial tire according to the first aspect, the outer opening end of the recessed portion on the outer side in the tire radial direction is rotated from the tire equatorial plane toward the crown end. It is characterized in that it is arranged on the inner side in the tire radial direction from a point on the crown having a distance W measured parallel to the axis.
【００１９】請求項２に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 2 will be described.
【００２０】請求項２に記載の空気入りラジアルタイヤ
では、凹み部のタイヤ半径方向外側の外側開口端を、タ
イヤ赤道面からクラウン端に向かってタイヤ回転軸に対
して平行に測った距離Ｗとなるクラウン上の点よりタイ
ヤ半径方向内側に配置したので、直進が主体の走行での
（スリップ角、キャンバ角が±０度付近での）接地端付
近の接地圧集中を抑えることができる。In the pneumatic radial tire according to the second aspect of the present invention, the outer open end of the recessed portion on the outer side in the tire radial direction is a distance W measured from the tire equatorial plane toward the crown end in parallel with the tire rotation axis. Since it is arranged on the inner side in the tire radial direction from the point on the crown, it is possible to suppress the ground pressure concentration in the vicinity of the ground contact end (when the slip angle and the camber angle are around ± 0 degrees) when traveling mainly in a straight line.
【００２１】請求項３に記載の発明は、請求項２に記載
の空気入りラジアルタイヤにおいて、前記凹み部のタイ
ヤ半径方向外側の外側開口端を、タイヤ赤道面から前記
クラウン端に向かってタイヤ回転軸に対して平行に測っ
た距離１．１Ｗとなるクラウン上の点よりタイヤ半径方
向内側に配置したことを特徴としている。According to a third aspect of the present invention, in the pneumatic radial tire according to the second aspect, the outer opening end of the recessed portion on the outer side in the tire radial direction is rotated from the tire equatorial plane toward the crown end. It is characterized in that it is arranged on the inner side in the tire radial direction from a point on the crown at a distance of 1.1 W measured parallel to the axis.
【００２２】請求項３に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 3 will be described.
【００２３】請求項３に記載の空気入りラジアルタイヤ
では、凹み部のタイヤ半径方向外側の外側開口端を、タ
イヤ赤道面からクラウン端に向かってタイヤ回転軸に対
して平行に測った距離１．１Ｗとなるクラウン上の点よ
りタイヤ半径方向内側に配置したので、直進と横力が主
体の走行での（スリップ角、キャンバ角が±１度以内で
の）接地端付近の接地圧集中を抑えることができる。In the pneumatic radial tire according to the third aspect of the present invention, the outer open end of the recessed portion on the outer side in the tire radial direction is measured in a direction parallel to the tire rotation axis from the tire equatorial plane toward the crown end. Since the tire is placed on the inner side in the tire radial direction from the point on the crown that is 1 W, it suppresses the concentration of ground pressure near the ground contact end (when the slip angle and camber angle are within ± 1 degree) when traveling mainly by straight running and lateral force. be able to.
【００２４】請求項４に記載の発明は、請求項２または
請求項３に記載の空気入りラジアルタイヤにおいて、前
記凹み部のタイヤ半径方向外側の外側開口端を、タイヤ
赤道面から前記クラウン端に向かってタイヤ回転軸に対
して平行に測った距離１．５Ｗとなる点よりタイヤ半径
方向内側に配置したことを特徴としている。According to a fourth aspect of the present invention, in the pneumatic radial tire according to the second or third aspect, the outer open end of the recessed portion on the tire radial outside is located from the tire equatorial plane to the crown end. It is characterized in that it is arranged on the inner side in the tire radial direction from the point where the distance is 1.5 W measured parallel to the tire rotation axis.
【００２５】請求項４に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 4 will be described.
【００２６】請求項４に記載の空気入りラジアルタイヤ
は、凹み部のタイヤ半径方向外側の外側開口端を、タイ
ヤ赤道面から前記クラウン端に向かってタイヤ回転軸に
対して平行に測った距離１．５Ｗとなる点よりタイヤ半
径方向内側に配置したので、直進主体の走行に加え、横
力が主体の走行での（スリップ角、キャンバ角が±３度
付近での）接地端付近の接地圧集中を抑えることができ
る。In the pneumatic radial tire according to a fourth aspect of the invention, a distance 1 is obtained by measuring an outer open end of the recessed portion on the outer side in the tire radial direction from the tire equatorial plane toward the crown end in parallel with the tire rotation axis. Since the tire is placed on the inner side in the tire radial direction from the point of 0.5 W, the ground pressure near the ground contact end (when the slip angle and camber angle are around ± 3 degrees) in addition to straight running You can control your concentration.
【００２７】請求項５に記載の発明は、請求項１乃至請
求項４の何れか１項に記載の空気入りラジアルタイヤに
おいて、前記凹み部のタイヤ半径方向外側の外側開口端
と、タイヤ赤道面から前記クラウン端に向かってタイヤ
回転軸に対して平行に測った距離Ｌｂとなるクラウン上
の点とのタイヤ半径方向距離が６ｍｍ以内であることを
特徴としている。According to a fifth aspect of the present invention, in the pneumatic radial tire according to any one of the first to fourth aspects, the outer open end of the recessed portion on the outer side in the tire radial direction and the tire equatorial plane are provided. Is characterized in that the distance in the tire radial direction from the point on the crown, which is the distance Lb measured in parallel to the tire rotation axis toward the crown end, is within 6 mm.
【００２８】請求項５に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 5 will be described.
【００２９】凹み部のタイヤ半径方向外側の外側開口端
と、タイヤ赤道面からクラウン端に向かってタイヤ回転
軸に対して平行に測った距離Ｌｂとなるクラウン上の点
とのタイヤ半径方向距離を６ｍｍ以内とすることによ
り、凹み部が接地面に近づき、凹み部による排水性が良
好になる。A tire radial direction distance between an outer open end of the recessed portion on the tire radial outer side and a point on the crown, which is a distance Lb measured from the tire equatorial plane toward the crown end in parallel to the tire rotation axis. By setting the distance to be within 6 mm, the recessed part approaches the ground contact surface, and the drainage property of the recessed part becomes good.
【００３０】なお、凹み部で排水させるためには凹み部
がより接地面に近いほうが効果があるため、外側開口端
とタイヤ赤道面からクラウン端に向かってタイヤ回転軸
に対して平行に測った距離Ｌｂとなるクラウン上の点と
のタイヤ半径方向距離は好ましくは５ｍｍ以内、更に好
ましくは３ｍｍ以内とする。Since it is more effective for the recess to be closer to the ground contact surface in order to drain water from the recess, it was measured parallel to the tire rotation axis from the outer opening end and the tire equatorial plane toward the crown end. The distance in the tire radial direction from the point on the crown, which is the distance Lb, is preferably within 5 mm, more preferably within 3 mm.
【００３１】請求項６に記載の発明は、請求項１乃至請
求項５の何れか１項に記載の空気入りラジアルタイヤに
おいて、前記凹み部のタイヤ半径方向内側の内側開口端
を、前記接地端からタイヤ半径方向内側へ１５ｍｍの地
点からタイヤ半径方向内側に配置したことを特徴として
いる。According to a sixth aspect of the present invention, in the pneumatic radial tire according to any one of the first to fifth aspects, the inner open end of the recessed portion on the inner side in the tire radial direction is the ground contact end. Is located inward in the tire radial direction from the point 15 mm inward in the tire radial direction.
【００３２】請求項６に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 6 will be described.
【００３３】凹み部が小さすぎると、凹み部での排水量
が少なくなり、排水性改良の効果が得られない。前記凹
み部のタイヤ半径方向内側の内側開口端を、前記接地端
からタイヤ半径方向内側へ１５ｍｍの地点よりもタイヤ
半径方向内側に配置することにより、排水性を改良する
ために十分な凹み部での排水量を得ることができる。If the recess is too small, the amount of drainage at the recess is small, and the effect of improving drainage cannot be obtained. By disposing the inner opening end of the recessed portion on the inner side in the tire radial direction on the tire radial direction inner side from the point of 15 mm from the ground contact end to the tire radial direction inner side, a sufficient recessed portion is provided for improving drainage performance. It is possible to obtain the discharge amount of.
【００３４】請求項７に記載の発明は、請求項１乃至請
求項６の何れか１項に記載の空気入りラジアルタイヤに
おいて、前記凹み部のタイヤ半径方向内側の内側開口端
を、前記接地端からタイヤ半径方向内側へ２０ｍｍの地
点よりもタイヤ半径方向外側に配置したことを特徴とし
ている。According to a seventh aspect of the present invention, in the pneumatic radial tire according to any one of the first to sixth aspects, the inner open end of the recessed portion on the inner side in the tire radial direction is the ground contact end. Is located on the outer side in the tire radial direction with respect to a point 20 mm inward from the inner side in the tire radial direction.
【００３５】請求項７に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 7 will be described.
【００３６】凹み部が大きすぎるとバットレス部の剛
性、カーカス張力などに影響を及ぼして操縦安定性が悪
化することが考えられる。If the recess is too large, it is thought that the rigidity of the buttress portion, the carcass tension, etc. are affected and the steering stability is deteriorated.
【００３７】そこで、凹み部のタイヤ半径方向内側の内
側開口端を、接地端からタイヤ半径方向内側へ２０ｍｍ
の地点よりもタイヤ半径方向外側に配置することによ
り、操縦安定性を確保することができる。Therefore, the inner opening end of the recess portion on the inner side in the tire radial direction is set to 20 mm from the ground contact end to the inner side in the tire radial direction.
The steering stability can be ensured by arranging the tire on the outer side in the tire radial direction with respect to the point.
【００３８】請求項８に記載の発明は、請求項１乃至請
求項７の何れか１項に記載の空気入りラジアルタイヤに
おいて、前記凹み部の少なくとも一部が、前記タイヤ赤
道面から前記クラウン端に向かってタイヤ回転軸に対し
て平行に測った距離Ｌｂとなるクラウン上の点と前記タ
イヤ最大幅点とを結んだ直線よりもタイヤ内方に位置す
ることを特徴としている。The invention according to claim 8 is the pneumatic radial tire according to any one of claims 1 to 7, wherein at least a part of the recessed portion is located from the tire equatorial plane to the crown end. Is located inward of the tire with respect to a straight line connecting the point on the crown and the maximum width point of the tire, which is a distance Lb measured parallel to the tire rotation axis.
【００３９】請求項８に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 8 will be described.
【００４０】請求項８に記載の空気入りラジアルタイヤ
では、凹み部の少なくとも一部を、タイヤ赤道面からク
ラウン端に向かってタイヤ回転軸に対して平行に測った
距離Ｌｂとなるクラウン上の点とタイヤ最大幅点とを結
んだ直線よりもタイヤ内方に位置させたので、凹み部の
大きさ（深さ）が確保され、排水性が確保される。In the pneumatic radial tire according to the eighth aspect, at least a part of the recess is a point on the crown which is a distance Lb measured in parallel to the tire rotation axis from the tire equatorial plane toward the crown end. Since the tire is located inward of the straight line connecting the maximum width point of the tire and the tire, the size (depth) of the recess is ensured, and drainage is ensured.
【００４１】請求項９に記載の発明は、請求項１乃至請
求項８の何れか１項に記載の空気入りラジアルタイヤに
おいて、前記凹み部のタイヤ半径方向外側の外側開口端
と内側開口端とを結んだ直線からの前記凹み部の最深部
までの距離をＸとしたとき、Ｘ＝２ｍｍ〜１５ｍｍであ
ることを特徴としている。According to a ninth aspect of the present invention, in the pneumatic radial tire according to any one of the first to eighth aspects, the recess has an outer opening end and an inner opening end that are radially outward of the tire. When the distance from the straight line connecting the lines to the deepest part of the recess is X, X = 2 mm to 15 mm.
【００４２】請求項９に記載の空気入りラジアルタイヤ
の作用を説明する。The operation of the pneumatic radial tire of claim 9 will be described.
【００４３】凹み部のタイヤ半径方向外側の外側開口端
と、タイヤ半径方向内側の内側開口端とを結んだ直線か
らの凹み部の最深部までの距離をＸとしたとき、Ｘが２
ｍｍ未満では排水効果が薄く、Ｘが１５ｍｍよりも大き
いとタイヤ製造が困難になる。そこでＸの範囲はＸ＝２
ｍｍ〜１５ｍｍとする。When the distance from the straight line connecting the outer opening end on the tire radial outer side of the depression and the inner opening end on the tire radial inner side to the deepest portion of the depression is X, X is 2
If it is less than mm, the drainage effect is small, and if X is more than 15 mm, tire manufacturing becomes difficult. Therefore, the range of X is X = 2
mm to 15 mm.
【００４４】なお、凹み部の最深部が連続して複数存在
する場合（例えば、凹み部の深さが一定の場合等）に
は、その中間点を最深部とする。When a plurality of deepest portions of the recessed portion are continuously present (for example, when the depth of the recessed portion is constant, etc.), the midpoint thereof is defined as the deepest portion.
【００４５】請求項１０に記載の発明は、請求項９に記
載の空気入りラジアルタイヤにおいて、前記Ｘが５ｍｍ
以上の場合には、前記凹み部と対向する部分の前記トロ
イド状ラジアルカ−カスが、タイヤ外側に曲率中心を有
して湾曲、または直線状に、またはタイヤ内側に曲率中
心を有し前記凹み部のラジアル方向両側の湾曲部分の曲
率半径よりも大きな曲率半径で湾曲していることを特徴
としている。According to a tenth aspect of the present invention, in the pneumatic radial tire according to the ninth aspect, the X is 5 mm.
In the above case, the toroidal radial arc of the portion facing the recessed portion is curved with the center of curvature on the outside of the tire, or is linear, or has the center of curvature on the inside of the tire, and the recessed portion. It is characterized in that it is curved with a radius of curvature larger than the radius of curvature of the curved portions on both sides in the radial direction.
【００４６】請求項１０に記載の空気入りラジアルタイ
ヤの作用を説明する。The operation of the pneumatic radial tire of claim 10 will be described.
【００４７】凹み部のタイヤ半径方向外側の外側開口端
と、タイヤ半径方向内側の内側開口端とを結んだ直線か
らの凹み部の最深部までの距離Ｘが５ｍｍ以上になる
と、距離Ｘがバットレス部のゴム厚さ以上となってタイ
ヤ内部のトロイド状ラジアルカ−カスが露出する虞れが
あり、カットや縁石こすれ等を考慮すると、実際上では
適用不可である。しかしながら、トロイド状ラジアルカ
−カスを、タイヤ外側に曲率中心を有して湾曲、または
直線状に、またはタイヤ内側に曲率中心を有し凹み部の
ラジアル方向両側の湾曲部分の曲率半径よりも大きな曲
率半径で湾曲させれば、凹み部の最深部からカーカスま
での距離を稼ぐことができ、この問題を解消することが
できる。When the distance X from the straight line connecting the outer opening end on the tire radial outer side of the recess and the inner opening end on the tire radial inner side to the deepest part of the recess is 5 mm or more, the distance X becomes the buttress. There is a risk that the toroidal radial arcs inside the tire will be exposed when the rubber thickness of the portion is greater than the thickness of the tire. Considering cuts, curb rubs, etc., this is not practically applicable. However, the toroidal radial arc is curved with the center of curvature on the outside of the tire to be curved or linear, or has the center of curvature on the inside of the tire and has a curvature larger than the radius of curvature of the curved portions on both sides in the radial direction of the recess. If curved with a radius, the distance from the deepest part of the recess to the carcass can be increased, and this problem can be solved.
【００４８】また、カーカスを、タイヤ外側に曲率中心
を有して湾曲、または直線状に、またはタイヤ内側に曲
率中心を有し凹み部のラジアル方向両側の湾曲部分の曲
率半径よりも大きな曲率半径で湾曲させておくと、内圧
充填によりその部分が他の部分よりも膨出し易くなり、
トロイド状ラジラルカーカスに作用する張力が増大し、
これによって凹み部付近のタイヤ剛性が高くなり、操縦
安定性を向上させる効果が期待できる。Further, the carcass is curved or linearly having a center of curvature on the outer side of the tire, or has a radius of curvature larger than the radius of curvature of curved portions on both sides in the radial direction of the recess having a center of curvature on the inner side of the tire. If it is curved with, the part will swell more easily than other parts due to internal pressure filling,
The tension acting on the toroidal radial carcass increases,
As a result, the tire rigidity near the recess is increased, and the effect of improving the steering stability can be expected.
【００４９】請求項１１に記載の発明は、請求項１乃至
請求項１０の何れか１項に記載の空気入りラジアルタイ
ヤにおいて、前記凹み部のタイヤ半径方向外側の外側開
口端と内側開口端との距離が、前記タイヤ赤道面から前
記クラウン端に向かってタイヤ回転軸に対して平行に測
った距離Ｌｂとなるクラウン上の点と前記凹み部のタイ
ヤ半径方向外側の内側開口端との距離の５０％〜１００
％であることを特徴としている。An eleventh aspect of the present invention is the pneumatic radial tire according to any one of the first to tenth aspects, wherein the recess has an outer opening end and an inner opening end that are radially outward of the tire. Is a distance Lb measured from the tire equatorial plane toward the crown end in parallel to the tire rotation axis and the distance between the point on the crown and the inner opening end on the tire radial outer side of the recess. 50% to 100
It is characterized by being%.
【００５０】請求項１１に記載の空気入りラジアルタイ
ヤの作用を説明する。The operation of the pneumatic radial tire of claim 11 will be described.
【００５１】凹み部のタイヤ半径方向外側の外側開口端
と内側開口端との距離を、タイヤ赤道面からクラウン端
に向かってタイヤ回転軸に対して平行に測った距離Ｌｂ
となるクラウン上の点と凹み部のタイヤ半径方向外側の
内側開口端との距離の５０％以上とする理由は、５０％
未満になると、凹み部が小さすぎて排水性改良効果を期
待できなくなるからである。A distance Lb obtained by measuring the distance between the outer opening end and the inner opening end on the tire radial direction outer side of the recessed portion in parallel to the tire rotation axis from the tire equatorial plane toward the crown end.
50% or more of the distance between the point on the crown and the inner opening end of the recessed portion on the tire radial outer side is 50%.
If it is less than this, the recessed portion is too small to expect the effect of improving the drainage property.
【００５２】また、外側開口端と内側開口端との距離
を、タイヤ赤道面からクラウン端に向かってタイヤ回転
軸に対して平行に測った距離Ｌｂとなるクラウン上の点
と凹み部のタイヤ半径方向外側の内側開口端との距離の
１００％以下とする理由は、外側開口端と内側開口端と
の距離がタイヤ赤道面からクラウン端に向かってタイヤ
回転軸に対して平行に測った距離Ｌｂとなるクラウン上
の点と凹み部のタイヤ半径方向外側の内側開口端との距
離の１００％を越えると、凹み部が直進時の接地端に近
づきすぎることになり、横力時に接地部が横方向に広が
りにくくなり、接地端部で局所的な接地圧集中部分がで
き、操縦安定性に悪影響を及ぼすからである。Further, the distance between the outer open end and the inner open end is a distance Lb measured from the tire equatorial plane toward the crown end in parallel with the tire rotation axis. The reason for setting the distance to the inner opening end on the outer side in the direction to 100% or less is that the distance between the outer opening end and the inner opening end is measured in parallel to the tire rotation axis from the tire equatorial plane toward the crown end. Beyond 100% of the distance between the point on the crown and the inner open end of the dent on the outside of the tire in the radial direction of the tire, the dent will be too close to the ground contact end when going straight, and the ground contact part will move laterally when lateral force is applied. This is because it is difficult to spread in the direction and a local contact pressure concentration portion is locally formed at the contact end, which adversely affects the steering stability.
【００５３】そのため、凹み部の外側開口端と内側開口
端との距離を、前記タイヤ赤道面からクラウン端に向か
ってタイヤ回転軸に対して平行に測った距離Ｌｂとなる
クラウン上の点と凹み部のタイヤ半径方向外側の内側開
口端との距離の５０％〜１００％とする。Therefore, the point on the crown and the dent are such that the distance between the outer opening end and the inner opening end of the recess is a distance Lb measured from the tire equatorial plane toward the crown end in parallel to the tire rotation axis. 50% to 100% of the distance from the inner opening end on the outer side in the tire radial direction.
【００５４】請求項１２に記載の発明は、請求項１乃至
請求項１１の何れか１項に記載の空気入りラジアルタイ
ヤにおいて、前記凹み部のタイヤ半径方向外側の外側開
口端から前記凹み部の最深部までのタイヤ半径方向距離
が、前記凹み部のタイヤ半径方向外側の外側開口端から
内側開口端までのタイヤ半径方向距離の２０％〜５０％
であることを特徴としている。According to a twelfth aspect of the present invention, in the pneumatic radial tire according to any one of the first to eleventh aspects, from the outer opening end on the tire radial outer side of the concave portion to the concave portion. The tire radial direction distance to the deepest part is 20% to 50% of the tire radial direction distance from the outer opening end on the tire radial outer side of the recess to the inner opening end.
It is characterized by being.
【００５５】請求項１２に記載の空気入りラジアルタイ
ヤの作用を説明する。The operation of the pneumatic radial tire of claim 12 will be described.
【００５６】凹み部の外側開口端から凹み部の最深部ま
でのタイヤ半径方向距離を、凹み部の外側開口端から内
側開口端までのタイヤ半径方向距離の２０％以上とする
理由は、外側開口端から凹み部の最深部までのタイヤ半
径方向距離が、外側開口端から内側開口端までのタイヤ
半径方向距離の２０％未満になると、凹み部の最深部付
近の曲率変化が大きくなって（最深部付近の形状が鋭利
になる）、最深部付近の歪みが増大して亀裂が発生し耐
久性が劣化し易いからである。The reason why the tire radial distance from the outer open end of the recess to the deepest part of the recess is 20% or more of the tire radial distance from the outer open end of the recess to the inner open end is that the outer opening When the tire radial distance from the end to the deepest part of the recess is less than 20% of the tire radial distance from the outer opening end to the inner opening end, the curvature change near the deepest part of the recess becomes large (the deepest part). This is because the shape in the vicinity of the portion becomes sharp) and the strain in the vicinity of the deepest portion increases, causing cracks and easily degrading the durability.
【００５７】また、外側開口端から凹み部の最深部まで
のタイヤ半径方向距離を、外側開口端から内側開口端ま
でのタイヤ半径方向距離の５０％以下とする理由は、外
側開口端から凹み部の最深部までのタイヤ半径方向距離
が、外側開口端から内側開口端までのタイヤ半径方向距
離の５０％を越えると、凹み部の最深部が路面の水面か
ら遠くなって排水に寄与しにくくなり、接地面付近の水
を充分排水出来なくなるからである。The reason why the tire radial direction distance from the outer opening end to the deepest part of the recess is 50% or less of the tire radial distance from the outer opening end to the inner opening end is that the outer opening end is recessed. If the radial distance to the deepest part of the tire exceeds 50% of the radial distance from the outer open end to the inner open end, the deepest part of the recess will be far from the water surface of the road surface and it will be difficult to contribute to drainage. , Because the water near the ground contact surface cannot be drained sufficiently.
【００５８】そのため、外側開口端から凹み部の最深部
までのタイヤ半径方向距離を、外側開口端から内側開口
端までのタイヤ半径方向距離の２０％〜５０％とする。Therefore, the tire radial direction distance from the outer opening end to the deepest part of the recess is 20% to 50% of the tire radial direction distance from the outer opening end to the inner opening end.
【００５９】請求項１３記載の発明は、請求項１乃至請
求項１２の何れか１項に記載の空気入りラジアルタイヤ
において、前記接地端を通るタイヤ中心軸に平行な直線
と、前記凹み部のタイヤ半径方向内側の内側開口端を通
るタイヤ赤道面に平行な直線と、タイヤ外郭形状とに囲
まれる部分の面積が、１２５ｃｍ2 以上３００ｃｍ2未
満であることを特徴とする。According to a thirteenth aspect of the present invention, in the pneumatic radial tire according to any one of the first to twelfth aspects, a straight line parallel to the tire central axis passing through the ground contact end and the recessed portion are formed. The area of the portion surrounded by the straight line parallel to the equatorial plane of the tire passing through the inner opening end on the inner side in the tire radial direction and the outer shape of the tire is 125 cm 2 or more and less than 300 cm 2 .
【００６０】請求項１３に記載の空気入りラジアルタイ
ヤの作用を説明する。The operation of the pneumatic radial tire of claim 13 will be described.
【００６１】バットレス部の排水性は、タイヤ外郭形状
と水面、接地面に囲まれた領域が広いほど向上する。そ
のため、接地端を通るタイヤ中心軸に平行な直線と、凹
み部のタイヤ半径方向内側の内側開口端を通るタイヤ赤
道面に平行な直線と、タイヤ外郭形状とに囲まれる部分
の面積が大きいほど排水性が改良されることになる。The drainage property of the buttress portion is improved as the area surrounded by the outer shape of the tire, the water surface and the ground contact surface is wider. Therefore, the larger the area of the part surrounded by the straight line parallel to the tire center axis passing through the ground contact end, the straight line parallel to the tire equatorial plane passing through the inner opening end on the tire radial inner side of the recessed portion, and the tire outer shape, the larger the area. Drainage will be improved.
【００６２】しかし、この部分の面積にも最適範囲があ
り、この部分の面積が１２５ｃｍ2未満になると排水効
果が発揮されず、３００ｃｍ2 より大きいとバットレス
部の剛性が低下し、操縦安定性が悪化する。そこでこの
部分の面積を１２５ｃｍ2 以上３００ｃｍ2 未満とす
る。However, there is an optimum range for the area of this portion. If the area of this portion is less than 125 cm 2 , the drainage effect is not exhibited, and if it is greater than 300 cm 2 , the rigidity of the buttress portion decreases and steering stability is reduced. Getting worse. Therefore, the area of this portion is set to 125 cm 2 or more and less than 300 cm 2 .
【００６３】請求項１４に記載の発明は、請求項１乃至
請求項１３の何れか１項に記載の空気入りラジアルタイ
ヤにおいて、前記凹み部のタイヤ半径方向外側の外側開
口端と前記凹み部のタイヤ半径方向内側の内側開口端と
を結ぶ直線と、タイヤ外郭形状と、に囲まれる部分の面
積が、１５ｃｍ2 以上１１０ｃｍ2 未満であることを特
徴としている。According to a fourteenth aspect of the present invention, in the pneumatic radial tire according to any one of the first to thirteenth aspects, the outer open end of the recessed portion on the outer side in the tire radial direction and the recessed portion are formed. It is characterized in that the area surrounded by the straight line connecting the inner opening end on the inner side in the tire radial direction and the outer shape of the tire is 15 cm 2 or more and less than 110 cm 2 .
【００６４】請求項１４に記載の空気入りラジアルタイ
ヤの作用を説明する。The operation of the pneumatic radial tire of claim 14 will be described.
【００６５】バットレス部の排水性は、タイヤ外郭形状
と水面、接地面に囲まれた領域が広いほど向上する。そ
のため、凹み部のタイヤ半径方向外側の外側開口端と凹
み部のタイヤ半径方向内側の内側開口端とを結ぶ直線
と、タイヤ外郭形状と、に囲まれる部分の面積が大きい
ほど排水性が改良されることになる。The drainage performance of the buttress portion is improved as the area surrounded by the outer shape of the tire, the water surface and the ground contact surface is wider. Therefore, the straight line connecting the outer opening end on the tire radial direction outer side of the recessed portion and the inner opening end on the tire radial direction inner side of the recessed portion, the tire outer shape, and the larger the area of the portion surrounded by the drainage property is improved. Will be.
【００６６】しかし、この部分の面積にも最適範囲があ
り、この部分の面積が１５ｃｍ2 未満になると排水効果
が発揮されず、１１０ｃｍ2 より大きいとバットレス部
の剛性が低下して操縦安定性が悪化する。そのためこの
部分の面積を１５ｃｍ2 以上１１０ｃｍ2 未満とする。However, the area of this portion also has an optimum range. If the area of this portion is less than 15 cm 2 , the drainage effect is not exerted, and if it is greater than 110 cm 2 , the rigidity of the buttress portion decreases and steering stability is reduced. Getting worse. Therefore, the area of this portion is set to 15 cm 2 or more and less than 110 cm 2 .
【００６７】請求項１５に記載の発明は、請求項１乃至
請求項１４の何れか１項に記載の空気入りラジアルタイ
ヤにおいて、前記凹み部と前記トロイド状ラジアルカー
カスとの間のゴム層の厚みが、少なくとも２ｍｍ以上で
あることを特徴としている。According to a fifteenth aspect of the present invention, in the pneumatic radial tire according to any one of the first to fourteenth aspects, the thickness of the rubber layer between the recessed portion and the toroidal radial carcass. Is at least 2 mm or more.
【００６８】請求項１５に記載の空気入りラジアルタイ
ヤの作用を説明する。The operation of the pneumatic radial tire of claim 15 will be described.
【００６９】請求項１５に記載の空気入りラジアルタイ
ヤでは、凹み部とトロイド状ラジアルカーカスとの間の
ゴム層の厚みが少なくとも２ｍｍ以上あるので、トロイ
ド状ラジアルカーカスがタイヤ表面に露出せず、縁石と
の擦れ等によるトロイド状ラジアルカーカスの損傷を確
実に防止することができる。In the pneumatic radial tire according to claim 15, since the thickness of the rubber layer between the recess and the toroidal radial carcass is at least 2 mm or more, the toroidal radial carcass is not exposed on the tire surface, and the curbstone is not exposed. It is possible to reliably prevent damage to the toroidal radial carcass due to rubbing or the like.
【００７０】[0070]
【発明の実施の形態】本発明の空気入りタイヤの一実施
形態を図面に基づいて説明する。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the pneumatic tire of the present invention will be described with reference to the drawings.
【００７１】図１に示すように、空気入りタイヤ１０
は、一対のビードコア１２（図１では片側のみ図示。）
と、一方のビードコア１２から他方のビードコア１２に
わたってトロイド状に延びるラジアルカーカス１４とを
有している。As shown in FIG. 1, the pneumatic tire 10
Is a pair of bead cores 12 (only one side is shown in FIG. 1).
And a radial carcass 14 extending in a toroidal shape from one bead core 12 to the other bead core 12.
【００７２】ラジアルカーカス１４のタイヤ軸方向外側
にはサイドウォール部１６を形成するサイドゴム層１８
が配設されている。A side rubber layer 18 forming a side wall portion 16 is provided on the outer side of the radial carcass 14 in the axial direction of the tire.
Is provided.
【００７３】ラジアルカーカス１４のタイヤ半径方向外
側には複数枚のベルト層２０が配設されており、ベルト
層２０のタイヤ半径方向外側には、両サイドゴム層１８
を跨ぐようにトレッド２２を形成するトレッドゴム層２
４が配置されている。A plurality of belt layers 20 are disposed on the outer side of the radial carcass 14 in the tire radial direction, and both side rubber layers 18 are disposed on the outer side of the belt layer 20 in the tire radial direction.
Tread rubber layer 2 forming tread 22 so as to straddle
4 are arranged.
【００７４】図２に示すように、空気入りタイヤ１０を
標準リム（図示せず）に組み付けて標準内圧を充填した
状態のタイヤ及びリム組立体のタイヤ回転軸に沿った断
面で表れるトレッド２２のクラウン（外輪郭）は、互い
に異なる曲率半径を有する３種類の円弧を互いに滑らか
に連ねた複合円弧から構成されている。As shown in FIG. 2, the pneumatic tire 10 is mounted on a standard rim (not shown) and is filled with standard internal pressure. The crown (outer contour) is composed of a complex arc in which three kinds of arcs having different radii of curvature are smoothly connected to each other.
【００７５】上記タイヤ及びリム組立体のトレッド２２
のクラウンを、タイヤ赤道面ＣＬからクラウン端に向か
って（タイヤ幅方向外側に向かって）順次センタ領域２
２Ａ、中間領域２２Ｂ及びショルダ領域２２Ｃに区分け
したとき、タイヤ赤道面ＣＬからタイヤ回転軸（図示せ
ず）に対して平行に測ったセンタ領域２２Ａのタイヤ幅
方向外端までの距離をＬａ、センタ領域２２Ａの曲率半
径をＲ1 、タイヤ赤道面ＣＬからタイヤ回転軸に対して
平行に測った中間領域２２Ｂのタイヤ幅方向外端までの
距離をＬｂ、中間領域２２Ｂの曲率半径をＲ2 、タイヤ
赤道面ＣＬからタイヤ回転軸に対して平行に測ったショ
ルダ領域２２Ｃのタイヤ幅方向外端までの距離をＬｃ、
ショルダ領域２２Ｃの曲率半径をＲ3 で表し、また、こ
のタイヤ及びリム組立体を標準荷重負荷（タイヤ規格の
最大負荷能力の１００％の荷重を負荷した状態）の下で
平板に（タイヤ回転軸と平行に）押圧した際の接触領域
におけるクラウン端（接地端）を、無負荷状態に戻した
上記タイヤ及びリム組立体においてタイヤ赤道面ＣＬか
らタイヤ軸方向外側へタイヤ回転軸に対して平行に計測
したときの距離をＷとしたときに、Ｌａ＝（０．４〜
０．５）×Ｗ、Ｒ1 ＝（１５〜４１）×Ｗ、Ｌｂ＝
（０．９〜１．１）×Ｗ、Ｒ2 ＝（１．５〜２．４）×
Ｗ、Ｌｃ＝（１．０〜１．５）×Ｗ、Ｒ3 ＝（０．３〜
２．５）×Ｗの関係を満たすように各部の寸法が決めら
れている。Tread 22 of the above tire and rim assembly
Center region 2 from the tire equatorial plane CL toward the crown end (outward in the tire width direction).
2A, the intermediate region 22B and the shoulder region 22C, the distance from the tire equatorial plane CL to the outer end in the tire width direction of the center region 22A measured parallel to the tire rotation axis (not shown) is La, the center. The radius of curvature of the region 22A is R1, the distance from the tire equatorial plane CL to the outer end in the tire width direction of the intermediate region 22B measured in parallel to the tire rotation axis is Lb, the radius of curvature of the intermediate region 22B is R2, the tire equatorial face. The distance from CL to the tire width direction outer end of the shoulder region 22C measured parallel to the tire rotation axis is Lc,
The radius of curvature of the shoulder region 22C is represented by R3, and this tire and rim assembly is flat (under the tire rotation axis with the tire rotation axis under a standard load load (a load of 100% of the maximum load capacity of the tire standard). The crown end (ground contact end) in the contact area when pressed in parallel is measured parallel to the tire rotation axis from the tire equatorial plane CL to the tire axial direction outer side in the tire and rim assembly returned to the unloaded state. La = (0.4-
0.5) × W, R1 = (15 to 41) × W, Lb =
(0.9-1.1) x W, R2 = (1.5-2.4) x
W, Lc = (1.0 to 1.5) × W, R3 = (0.3 to
The size of each part is determined so as to satisfy the relationship of 2.5) × W.
【００７６】図１に示す符号ａは、上記タイヤ赤道面Ｃ
Ｌからタイヤ回転軸に対して平行に計測したときの距離
Ｗとなるクラウン上の位置（本発明の接地端。以後第１
の接地端ａという。）を示している。Reference numeral a shown in FIG. 1 indicates the tire equatorial plane C.
The position on the crown that is the distance W when measured in parallel to the tire rotation axis from L (the ground contact end of the present invention.
It is referred to as the ground end a. ) Is shown.
【００７７】この空気入りタイヤ１０には、第１の接地
端ａとタイヤ最大幅点ｗ１と間のバットレス部に、タイ
ヤ外郭に開口する凹み部２６が形成されている。In this pneumatic tire 10, a recess 26 is formed at the buttress portion between the first ground contact end a and the tire maximum width point w1 and is open to the outer contour of the tire.
【００７８】図３に示すように、凹み部２６のタイヤ半
径方向外側（矢印ＯＵＴ方向側）の外側開口端ａ１は、
直進が主体の走行での（スリップ角、キャンバ角が±０
度付近での）トレッド２２の接地端付近の接地圧集中を
抑え、操縦安定性を確保するためには、タイヤ赤道面Ｃ
Ｌからクラウン端（タイヤ軸方向外側へ）に向かってタ
イヤ回転軸に対して平行に測った距離Ｗとなるクラウン
上の点よりタイヤ半径方向内側に配置することが好まし
い。As shown in FIG. 3, the outer opening end a1 of the recess 26 on the outer side in the tire radial direction (arrow OUT side) is:
When driving straight ahead (slip and camber angles are ± 0
In order to suppress the contact pressure concentration near the ground contact end of the tread 22 (in the vicinity of a degree) and ensure steering stability, the tire equatorial plane C is used.
It is preferable to dispose it on the inner side in the tire radial direction from a point on the crown that is a distance W measured parallel to the tire rotation axis from L toward the crown end (outward in the tire axial direction).
【００７９】また、凹み部２６の外側開口端ａ１は、直
進と横力が主体の走行での（スリップ角、キャンバ角が
±１度以内での）トレッド２２の接地端付近の接地圧集
中を抑え、操縦安定性を確保するためには、タイヤ赤道
面ＣＬからクラウン端に向かってタイヤ回転軸に対して
平行に距離１．１Ｗ離れたクラウン上の点（以後、第２
の接地端ａ２という）よりタイヤ半径方向内側に配置す
ることが好ましい。Further, the outer open end a1 of the recessed portion 26 concentrates the contact pressure near the contact end of the tread 22 (when the slip angle and the camber angle are within ± 1 degree) when the vehicle is driven mainly by straight running and lateral force. In order to suppress and ensure steering stability, a point on the crown (hereinafter referred to as the second point) that is 1.1 W away from the tire equatorial plane CL toward the crown end in parallel to the tire rotation axis.
It is preferable to dispose it on the inner side in the tire radial direction with respect to the ground contact end a2).
【００８０】さらに、凹み部２６の外側開口端ａ１は、
直進主体の走行に加え、横力が主体の走行での（スリッ
プ角、キャンバ角が±３度付近での）トレッド２２の接
地端付近の接地圧集中を抑え、操縦安定性を確保するた
めには、タイヤ赤道面ＣＬからクラウン端（タイヤ軸方
向外側へ）に向かってタイヤ回転軸に対して平行に測っ
た距離１．５Ｗとなるクラウン上の点よりタイヤ半径方
向内側に配置することが好ましい。Further, the outer open end a1 of the recess 26 is
In addition to running straight ahead, in order to secure steering stability by suppressing the concentration of ground pressure near the ground contact end of the tread 22 (when the slip angle and camber angle are around ± 3 degrees) when running mainly by lateral force Is preferably arranged on the inner side in the tire radial direction from a point on the crown at which the distance measured from the tire equatorial plane CL toward the crown end (outward in the tire axial direction) is 1.5 W in parallel with the tire rotation axis. .
【００８１】凹み部２６が大きすぎるとバットレス部の
剛性、カーカス張力などに影響を及ぼして操縦安定性が
悪化することが考えられるので、操縦安定性を確保する
ためには、内側開口端ｂ１を、第１の接地端ａからタイ
ヤ半径方向内側へ２０ｍｍの地点よりもタイヤ半径方向
外側に配置することが好ましい。If the recessed portion 26 is too large, the rigidity of the buttress portion, the carcass tension, etc. may be affected and the steering stability may deteriorate. Therefore, in order to ensure steering stability, the inner open end b1 should be It is preferable to dispose the first radial contact point a on the outer side in the tire radial direction with respect to the point 20 mm inward in the tire radial direction.
【００８２】凹み部２６の排水性を確保するために、内
側開口端ｂ１を、第１の接地端ａからタイヤ半径方向内
側へ１５ｍｍの地点よりもタイヤ半径方向内側に配置す
ることが好ましい。In order to secure the drainage property of the recessed portion 26, it is preferable that the inner opening end b1 is arranged on the inner side in the tire radial direction from a point 15 mm inward in the tire radial direction from the first ground contact end a.
【００８３】凹み部２６のタイヤ半径方向外側（矢印Ｏ
ＵＴ方向側）の外側開口端ａ１と、第２の接地端ａ２と
のタイヤ半径方向距離Ｌ１は、凹み部２６の排水性確保
のために６ｍｍ以内とし、好ましくは５ｍｍ以内、更に
好ましくは３ｍｍ以内である。The outer side of the recess 26 in the tire radial direction (arrow O
A tire radial direction distance L1 between the outer opening end a1 (on the UT direction side) and the second ground contact end a2 is 6 mm or less, preferably 5 mm or less, and more preferably 3 mm or less to secure drainage of the recess 26. Is.
【００８４】凹み部２６は、排水性を確保するために、
一部が、第２の接地端ａ２とタイヤ最大幅点ｗ１とを結
んだ直線ａ２・ｗ１よりもタイヤ内方に位置することが
好ましい。In order to secure drainage, the recess 26 is
It is preferable that a part thereof be located inward of the tire with respect to a straight line a2 · w1 that connects the second ground contact end a2 and the tire maximum width point w1.
【００８５】凹み部２６は、図３示すように略一定深さ
の場合と、図４に示すように深さが変化している場合と
がある。There are cases where the recess 26 has a substantially constant depth as shown in FIG. 3 and cases where the depth changes as shown in FIG.
【００８６】外側開口端ａ１と内側開口端ｂ１とを結ん
だ直線ａ１・ｂ１からの凹み部２６の最深部ｃまでの距
離をＸとしたとき、Ｘ＝２ｍｍ〜１５ｍｍとすることが
好ましい。なお、図３に示すように、凹み部２６の深さ
が一定の場合（凹み部２６の最深部が連続して複数存在
する場合）には、その中間点を最深部ｃとする。When the distance from the straight line a1 · b1 connecting the outer open end a1 and the inner open end b1 to the deepest part c of the recess 26 is X, X = 2 mm to 15 mm is preferable. As shown in FIG. 3, when the depth of the recessed portion 26 is constant (when there are a plurality of the deepest portions of the recessed portion 26 continuously), the midpoint thereof is defined as the deepest portion c.
【００８７】また、Ｘが５ｍｍ以上の場合には、図４に
示すように、タイヤ外郭形状の凹み部２６と同方向、即
ち、タイヤ外側が凹となるようにラジアルカーカス１４
を湾曲させ、ラジアルカーカス１４が露出しないように
ラジアルカーカス１４と凹み部２６の最深部ｃとの間の
ゴムゲージを確保することが好ましい。When X is 5 mm or more, as shown in FIG. 4, the radial carcass 14 is in the same direction as the recess 26 of the outer shape of the tire, that is, the outside of the tire is recessed.
Is preferably curved to secure a rubber gauge between the radial carcass 14 and the deepest portion c of the recess 26 so that the radial carcass 14 is not exposed.
【００８８】なお、ラジアルカーカス１４の凹み部２６
と対向している部分を、直線状またはタイヤ内側に曲率
中心を有し凹み部２６のラジアル方向両側の湾曲部分の
曲率半径よりも大きな曲率半径で湾曲させても良い。The recess 26 of the radial carcass 14
The portion opposed to may be curved with a radius of curvature larger than the radius of curvature of the curved portion on the both sides in the radial direction of the recessed portion 26 that has a center of curvature in the straight line or inside the tire.
【００８９】このラジアルカーカス１４と凹み部２６と
の間のゴムゲージは、一番薄いところでも少なくとも２
ｍｍ以上確保することが好ましい。The rubber gauge between the radial carcass 14 and the recess 26 is at least 2 even at the thinnest place.
It is preferable to secure at least mm.
【００９０】外側開口端ａ１と内側開口端ｂ１との直線
距離Ｌ２は、凹み部２６の排水性を確保するために、第
２の接地端ａ２と内側開口端ｂ１との直線距離Ｌ３の５
０％以上１００％未満が好ましい。The linear distance L2 between the outer open end a1 and the inner open end b1 is 5 which is the linear distance L3 between the second ground contact end a2 and the inner open end b1 in order to secure the drainage property of the recess 26.
0% or more and less than 100% is preferable.
【００９１】凹み部２６の排水性を確保して最深部ｃ付
近の歪みを抑えるために、外側開口端ａ１から凹み部２
６の最深部ｃまでのタイヤ半径方向距離Ｌ４は、外側開
口端ａ１から内側開口端ｂ１までのタイヤ半径方向距離
Ｌ５の２０％〜５０％とすることが好ましい。In order to secure the drainage of the recess 26 and suppress the distortion near the deepest portion c, the recess 2 is formed from the outer opening end a1.
The tire radial distance L4 to the deepest portion c of 6 is preferably 20% to 50% of the tire radial distance L5 from the outer opening end a1 to the inner opening end b1.
【００９２】図５に示すように、タイヤ回転軸を通る断
面で空気入りタイヤ１０を見たときに、第１の接地端ａ
を通るタイヤ中心軸に平行な直線ｐと、凹み部２６のタ
イヤ半径方向内側の内側開口端ｂ１を通るタイヤ赤道面
（図示せず）に平行な直線ｑと、タイヤ外郭形状とに囲
まれる部分（図の斜線部分）の面積Ａは、排水性を確保
し、操縦安定性の低下を招かないためには１２５ｃｍ2
以上３００ｃｍ2 未満とすることが好ましい。As shown in FIG. 5, when the pneumatic tire 10 is viewed in a section passing through the tire rotation axis, the first ground contact end a
A portion surrounded by a tire outer shape and a straight line p parallel to the tire central axis, a straight line q parallel to the tire equatorial plane (not shown) passing through the inner opening end b1 on the tire radial inner side of the recess 26. The area A (shaded area in the figure) is 125 cm 2 in order to ensure drainage and not reduce steering stability.
It is preferably not less than 300 cm 2 and more.
【００９３】なお、面積Ａを１２５ｃｍ2 以上３００ｃ
ｍ2 未満とするとき、図５に示すように、第１の接地端
ａと直線ｐと直線ｑとの交点ｄとの直線長さを１５ｍｍ
〜２０ｍｍ、内側開口端ｂ１と交点ｄとの直線長さを１
５ｍｍ〜２０ｍｍとすることが好ましい。The area A is 125 cm 2 or more and 300c.
When it is less than m 2 , as shown in FIG. 5, the straight line length between the first grounding end a and the intersection point d of the straight line p and the straight line q is 15 mm.
-20 mm, the straight line length between the inner opening end b1 and the intersection point d is 1
It is preferably 5 mm to 20 mm.
【００９４】また、図６に示すように、タイヤ回転軸
（図示せず）を通る断面で空気入りタイヤ１０を見たと
きに、凹み部２６の外側開口端ａ１と内側開口端ｂ１と
を結んだ直線ａ１・ｂ１と、タイヤ外郭形状とに囲まれ
る部分（図の斜線部分）の面積Ｂは、排水性を確保し、
操縦安定性の低下を招かないためには１５ｃｍ2 以上１
１０ｃｍ2 未満とすることが好ましい。なお、面積Ｂを
１５ｃｍ2 以上１１０ｃｍ2 未満とする時、直線ａ１・
ｂ１の長さを１５ｍｍ〜２０ｍｍ、Ｘ＝２ｍｍ〜１５ｍ
ｍとすることが好ましい。
（作用）次に、本実施形態の空気入りタイヤ１０の作用
を、従来の空気入りタイヤ１００と比較しながら説明す
る。Further, as shown in FIG. 6, when the pneumatic tire 10 is viewed in a section passing through a tire rotation axis (not shown), the outer opening end a1 and the inner opening end b1 of the recess 26 are connected to each other. The area B of the portion surrounded by the straight lines a1 and b1 and the outer shape of the tire (hatched portion in the figure) ensures drainage,
15 cm 2 or more to prevent deterioration of steering stability 1
It is preferably less than 10 cm 2 . When the area B is 15 cm 2 or more and less than 110 cm 2 , a straight line a1.
The length of b1 is 15 mm to 20 mm, X = 2 mm to 15 m
It is preferably m. (Operation) Next, the operation of the pneumatic tire 10 of the present embodiment will be described in comparison with the conventional pneumatic tire 100.
【００９５】図７（Ａ）は本実施形態の空気入りタイヤ
１０の接地面近傍の水の流れを説明する説明図であり、
図７（Ｂ）は、図７（Ａ）の７Ｂ−７Ｂ線断面図であ
る。FIG. 7A is an explanatory view for explaining the flow of water in the vicinity of the ground contact surface of the pneumatic tire 10 of this embodiment.
7B is a cross-sectional view taken along line 7B-7B of FIG. 7A.
【００９６】一方、図８（Ａ）は従来の空気入りタイヤ
１００の接地面近傍の水の流れを説明する説明図であ
り、図８（Ｂ）は図８（Ａ）の８Ｂ−８Ｂ線断面図であ
る。On the other hand, FIG. 8 (A) is an explanatory view for explaining the flow of water in the vicinity of the ground contact surface of the conventional pneumatic tire 100, and FIG. 8 (B) is a sectional view taken along line 8B-8B of FIG. 8 (A). It is a figure.
【００９７】また、図７及び図８において、符号３０は
接地面を示し、符号３２は接地面３０の前方で水圧が上
昇している水圧上昇部分（斜線部分）を示し、符号３４
は路面を示し、符号３６は路面３４に溜まった水を示
し、矢印Ｄは水の流れ、矢印Ｅはタイヤ進行方向（車両
進行方向）を示している。7 and 8, reference numeral 30 indicates a ground contact surface, reference numeral 32 indicates a water pressure increasing portion (hatched portion) where the water pressure is increasing in front of the ground contact surface 30, and reference numeral 34.
Indicates a road surface, reference numeral 36 indicates water accumulated on the road surface 34, arrow D indicates the flow of water, and arrow E indicates the tire traveling direction (vehicle traveling direction).
【００９８】バットレス部に凹み部２６の無い従来の空
気入りタイヤ１００が水の溜まった路面を転動すると、
水３６は、接地面３０よりも前方（タイヤが接水し接地
するまでの間：矢印Ｅ方向）で接地面３０に向かって衝
突する水の流れが多くなり、図８（Ａ）に示すように、
接地面３０前方の水圧上昇部分３２が大きくなる。When the conventional pneumatic tire 100 having no recess 26 in the buttress portion rolls on a road surface where water is accumulated,
As for the water 36, the flow of water that collides toward the ground contact surface 30 in front of the ground contact surface 30 (until the tire comes into contact with the ground and comes into contact with the ground: the direction of arrow E) increases, and as shown in FIG. To
The water pressure rising portion 32 in front of the ground contact surface 30 becomes large.
【００９９】本実施形態の空気入りタイヤ１０が水の溜
まった路面を転動すると、水３６は、接地面３０よりも
前方でバットレス部の凹み部２６に流れ込み、その結
果、接地面３０に向かって衝突する水の流れが少なくな
り、図７（Ａ）に示すように、接地面３０前方の水圧上
昇部分３２が少なくなる。When the pneumatic tire 10 of this embodiment rolls on a road surface in which water is accumulated, the water 36 flows into the recess 26 of the buttress portion in front of the ground contact surface 30 and, as a result, toward the ground contact surface 30. The flow of water colliding with each other is reduced, and as shown in FIG. 7A, the water pressure rising portion 32 in front of the ground contact surface 30 is reduced.
【０１００】したがって、本実施形態の空気入りタイヤ
１０は、従来の空気入りタイヤ１００よりも、ハイドロ
プレーニング現象を起こしにくくなる。Therefore, the pneumatic tire 10 of this embodiment is less likely to cause the hydroplaning phenomenon than the conventional pneumatic tire 100.
【０１０１】ところで、排水性改良のためには接地面に
なるべく近い部分に凹み部２６を設けることが好ましい
が、他は走行時にスリップ角やキャンバー角が付くため
に横力がかかり、接地端部が横方向に広がることがあ
る。By the way, in order to improve drainage, it is preferable to provide the recess 26 at a portion as close as possible to the ground contact surface. However, other than that, a lateral force is applied due to a slip angle or a camber angle during traveling, and a ground contact end portion is applied. May spread laterally.
【０１０２】そのため、凹み部２６を直進時の接地端に
近づけすぎると、横力時などに接地部が横方向に広がり
にくくなり、接地端部で局所的な接地圧集中部ができ、
操縦安定性に悪影響を及ぼす。Therefore, if the recessed portion 26 is brought too close to the ground contact end when straight ahead, the ground contact part is unlikely to spread laterally due to lateral force, etc., and a local ground pressure concentration part is formed at the ground contact end.
It adversely affects the driving stability.
【０１０３】また、バットレス部に凹み部２６を設ける
ことにより、バットレス剛性が低下するため、タイヤ荷
重時に図９に示すように、バットレス部がサイド部から
の押し込み変形（矢印Ａ方向）によりタイヤ外側（矢印
Ｂ方向側）へ張りだす変形の量（実線〜２点鎖線）が、
凹み分２６を設けないときよりも小さくなる。Further, since the buttress portion is provided with the recessed portion 26, the buttress rigidity is lowered. Therefore, as shown in FIG. 9, when the tire is loaded, the buttress portion is pushed outward from the side portion (in the direction of arrow A) and the tire outer side is pushed. The amount of deformation (solid line to alternate long and two short dashes line) projected to (the arrow B direction side) is
It is smaller than when the recess 26 is not provided.
【０１０４】そのため、タイヤ荷重時の接地端部付近で
タイヤ外側形状の曲率半径が小さくなり、横力時の接地
圧集中がより起こりやすくなる。Therefore, the radius of curvature of the outer shape of the tire becomes small near the ground contact end when the tire is loaded, and the ground contact pressure is more likely to concentrate when lateral force is applied.
【０１０５】そこで、排水性と操縦安定性を両立させる
ために、本発明ではバットレス部に凹み部２６を有する
空気入りタイヤ１０のクラウン形状を、タイヤ赤道面Ｃ
Ｌから測った各領域（２２Ａ〜Ｃ）の最外側までの距離
Ｌ及び各領域における円弧の曲率半径Ｒをそれぞれセン
タ領域２２Ａは距離Ｌａ及び曲率半径Ｒ1 、中間領域２
２Ｂは距離Ｌｂ及び曲率半径Ｒ2 、ショルダ領域２２Ｃ
は距離Ｌｃ及び曲率半径Ｒ3 で表し、この空気入りタイ
ヤ１０を標準のリムに装着して標準内圧を充填したタイ
ヤ及びリム組立体を標準荷重負荷の下で平板に押圧した
際の接触領域におけるクラウン端を、無負荷状態に戻し
たタイヤ及びリム組立体においてタイヤ赤道面ＣＬから
タイヤ回転軸に対して平行に計測したときの距離をＷで
表したときに、距離Ｌａ〜Ｌｃ、曲率半径Ｒ1 〜Ｒ3 及
び距離Ｗの関係が、Ｌａ＝（０．４〜０．５）×Ｗ、Ｒ
1 ＝（１５〜４１）×Ｗ、Ｌｂ＝（０．９〜１．１）×
Ｗ、Ｒ2 ＝（１．５〜２．４）×Ｗ、Ｌｃ＝（１．０〜
１．５）×Ｗ、Ｒ3 ＝（０．３〜２．５）×Ｗの関係を
満たすように設定し、クラウンセンター部の接地圧負担
をクラウンショルダー部と比べて大きくしたので、予め
クラウンショルダー部での接地圧負担が減らされ、接地
端付近の接地圧集中が起こりにくく（例え起こったとし
てもタイヤ性能に影響を及ぼしにくく）なり、いかなる
走行時にも、接地圧集中による操縦安定性の低下を招く
ようなことが無くなる。Therefore, in order to make drainage and steering stability compatible with each other, in the present invention, the crown shape of the pneumatic tire 10 having the recess 26 in the buttress portion is changed to the tire equatorial plane C.
The distance L to the outermost side of each area (22A to C) measured from L and the radius of curvature R of the arc in each area are the distance La and the radius of curvature R1 of the center area 22A, and the intermediate area 2 respectively.
2B is distance Lb, radius of curvature R2, shoulder region 22C
Is represented by a distance Lc and a radius of curvature R3, and a crown in a contact region when the pneumatic tire 10 is mounted on a standard rim and a tire and a rim assembly filled with standard internal pressure are pressed against a flat plate under a standard load load. When the distance when measured in parallel with the tire rotation axis from the tire equatorial plane CL in the tire and the rim assembly in which the ends are returned to the unloaded state is represented by W, the distances La to Lc and the radius of curvature R1 to The relationship between R3 and the distance W is La = (0.4 to 0.5) * W, R
1 = (15 to 41) × W, Lb = (0.9 to 1.1) ×
W, R2 = (1.5 to 2.4) x W, Lc = (1.0 to
1.5) × W, R3 = (0.3 to 2.5) × W, and the contact pressure load on the crown center portion is made larger than that on the crown shoulder portion. The burden of ground pressure on the parts is reduced, ground pressure concentration near the ground contact edge is unlikely to occur (even if it does not affect the tire performance), and the steering stability is reduced due to the ground pressure concentration during any driving. Will not be caused.
【０１０６】ここで、凹み部２６の外側開口端ａ１を、
タイヤ赤道面ＣＬからクラウン端に向かってタイヤ回転
軸に対して平行に測った距離Ｗとなるクラウン上の点よ
りタイヤ半径方向内側に配置した場合には、直進が主体
の走行での（スリップ角、キャンバ角が±０度付近で
の）接地端付近の接地圧集中を抑えることができ好まし
い。Here, the outer open end a1 of the recess 26 is
When the tire is arranged radially inward from the point on the crown, which is the distance W measured in parallel to the tire rotation axis from the tire equatorial plane CL toward the crown end, the straight running is mainly performed (slip angle It is preferable that the ground pressure concentration near the ground contact end (when the camber angle is around ± 0 degrees) can be suppressed.
【０１０７】また、凹み部２６の外側開口端ａ１を、タ
イヤ赤道面ＣＬからクラウン端に向かってタイヤ回転軸
に対して平行に測った距離１．１Ｗとなるクラウン上の
点よりタイヤ半径方向内側に配置した場合には、直進と
横力が主体の走行での（スリップ角、キャンバ角が±１
度以内での）接地端付近の接地圧集中を抑えることがで
き好ましい。Further, the outer opening end a1 of the recessed portion 26 is located inward in the tire radial direction from a point on the crown at a distance of 1.1 W measured from the tire equatorial plane CL toward the crown end in parallel with the tire rotation axis. When the vehicle is placed in a straight line, the vehicle is driven mainly by straight ahead and lateral force (slip angle, camber angle is ± 1
It is preferable because it is possible to suppress the concentration of the ground pressure near the ground end (within 10 degrees).
【０１０８】さらに、凹み部２６の外側開口端ａ１を、
タイヤ赤道面ＣＬからクラウン端に向かってタイヤ回転
軸に対して平行に測った距離１．５Ｗとなるクラウン上
の点よりタイヤ半径方向内側に配置した場合には、直進
主体の走行に加え、横力が主体の走行での（スリップ
角、キャンバ角が±３度付近での）接地端付近の接地圧
集中を抑えることができ好ましい。Further, the outer open end a1 of the recess 26 is
When the tire is arranged radially inward from a point on the crown at a distance of 1.5 W measured in parallel to the tire rotation axis from the tire equatorial plane CL toward the crown end, in addition to running mainly in a straight line, It is preferable because it is possible to suppress the ground pressure concentration near the ground contact end (when the slip angle and the camber angle are around ± 3 degrees) when the vehicle is driven mainly by force.
【０１０９】また、凹み部２６が小さすぎると、凹み部
２６での排水量が少なくなり、排水性改良の効果が得ら
れない。本実施形態では、凹み部２６の内側開口端ｂ１
を、接地端からタイヤ半径方向内側へ１５ｍｍの地点よ
りもタイヤ半径方向内側に配置したので、排水性を改良
するために十分な凹み部２６での排水量を得ることがで
きる。If the recessed portion 26 is too small, the amount of drainage in the recessed portion 26 will be small and the effect of improving drainage will not be obtained. In this embodiment, the inner opening end b1 of the recess 26 is formed.
Is arranged on the inner side in the tire radial direction from the point 15 mm from the ground contact end to the inner side in the tire radial direction, so that it is possible to obtain a sufficient drainage amount at the recessed portion 26 for improving drainage performance.
【０１１０】また、本実施形態の空気入りタイヤ１０
は、排水性の向上を図るためにトレッドパターンを変更
しないので、操縦安定性や摩耗性等の他の性能をトレッ
ドパターンの変更によって低下させることが無い。The pneumatic tire 10 of this embodiment is also used.
Since the tread pattern is not changed in order to improve the drainage, other performances such as steering stability and wearability are not deteriorated by changing the tread pattern.
【０１１１】なお、図４に示すように、ラジアルカーカ
ス１４をタイヤ外側から見て凹に湾曲させた空気入りタ
イヤ１０では、内圧充填により凹み部２６付近がその両
側部分よりも膨出し易くなってラジアルカーカス１４に
作用する張力が増大し、これによって凹み部２６付近の
バットレス部のタイヤ剛性が高くなり、操縦安定性を向
上させることも可能である。特に、凹み部２６が大きい
場合には、その付近の剛性が低下する傾向にあるので、
このように凹み部２６付近でラジアルカーカス１４をタ
イヤ外側から見て凹に湾曲させてタイヤ剛性を高くする
ことが有効である。
（試験例）本発明の効果を確かめるために、従来例のタ
イヤ１種、比較例のタイヤ１９種及び本発明の適用され
た実施例のタイヤ３１種とを用意し、ハイドロプレーニ
ング発生速度と、操縦安定性とを評価した。As shown in FIG. 4, in the pneumatic tire 10 in which the radial carcass 14 is curved in a concave shape when viewed from the outside of the tire, the vicinity of the concave portion 26 is more easily bulged than the both side portions due to the internal pressure filling. The tension acting on the radial carcass 14 is increased, which increases the tire rigidity of the buttress portion near the recess 26, and it is possible to improve the steering stability. In particular, when the recess 26 is large, the rigidity in the vicinity thereof tends to decrease, so
In this way, it is effective to make the radial carcass 14 curved concavely when viewed from the outside of the tire in the vicinity of the recessed portion 26 to increase the tire rigidity. (Test Example) In order to confirm the effect of the present invention, one kind of tire of the conventional example, 19 kinds of tires of the comparative example and 31 kinds of tires of the example to which the present invention was applied were prepared, and a hydroplaning generation rate, The steering stability was evaluated.
【０１１２】従来例のタイヤは、図１０に示すようにバ
ットレス部に凹み部の形成されていないタイヤである。The tire of the conventional example is a tire in which no recess is formed in the buttress portion as shown in FIG.
【０１１３】比較例１〜１９及び実施例１〜３１のタイ
ヤはバットレス部に凹み部を形成したタイヤであり、比
較例５、９〜１９及び実施例１０〜３１のタイヤは、図
３または図４に示すように凹み部２６と対向するラジア
ルカーカス１４をタイヤ内側へ凹むように湾曲させたタ
イヤである。The tires of Comparative Examples 1 to 19 and Examples 1 to 31 are tires having a recessed portion formed in the buttress portion, and the tires of Comparative Examples 5, 9 to 19 and Examples 10 to 31 are shown in FIG. As shown in FIG. 4, the radial carcass 14 facing the recess 26 is curved so as to be recessed inward of the tire.
【０１１４】なお、何れのタイヤもタイヤサイズは２０
５／５５Ｒ１６である。The tire size of each tire is 20.
It is 5 / 55R16.
【０１１５】バットレス部の凹み部の形状は、タイヤ製
造後の形状が表１〜１１に示す狙いの形状となるように
モールド形状を設定し、接地端相当部からタイヤ最大幅
までの形状が変化する部分は複数の曲率半径をもつ曲線
でなめらかにつなげている。The shape of the recessed portion of the buttress portion is set so that the shape after the tire is manufactured is the target shape shown in Tables 1 to 11, and the shape from the portion corresponding to the ground contact end to the maximum width of the tire changes. The part to be connected is smoothly connected by a curve having a plurality of radii of curvature.
【０１１６】試験は上記のタイヤを７Ｊ−１６のリムに
内圧２．２ｋｇ／ｃｍ2 で組み付け、乗用車に装着して
水深１０ｍｍのプールに速度を変えて進入し、テストド
ライバーによるハイドロプレーニング発生速度の評価を
行った。The test was carried out by mounting the above tire on a rim of 7J-16 at an internal pressure of 2.2 kg / cm 2 , mounting it on a passenger car, and entering a pool with a water depth of 10 mm at different speeds to test the hydroplaning generation speed by a test driver. An evaluation was made.
【０１１７】リム及び内圧は、ＪＡＴＭＡ ＹＥＡＲ
ＢＯＯＫ（１９９２、日本自動車タイヤ協会規格）にて
定めるラジアルプライタイヤのサイズに対応する適用リ
ム及び空気圧−負荷能力対応表に基づいている。Rim and internal pressure are JATMA YEAR
It is based on the applicable rim and the pneumatic-load capacity correspondence table corresponding to the size of the radial ply tire defined by BOOK (1992, Japan Automobile Tire Manufacturers Association Standard).
【０１１８】結果はハイドロプレーニング発生速度の指
数で表現し、指数大が良である。The result is expressed by an index of hydroplaning generation speed, and a large index is good.
【０１１９】操縦安定性に関しては同じくタイヤを乗用
車に装着し、テストドライバーがテストコースを走行す
ることで評価を行った。結果はフィーリング評点であ
り、従来例のタイヤを基準（±０）として−は操縦安定
性が低下したことを示し、＋は操縦安定性が向上したこ
とを示している。The steering stability was evaluated by similarly mounting tires on a passenger car and driving a test driver on a test course. The results are feeling scores, where − indicates that the steering stability was lowered and + indicates that the steering stability was improved with the tire of the conventional example as a reference (± 0).
【０１２０】なお、表内の従来例のタイヤの面積Ｂがマ
イナスを示しているのは、実施例のタイヤの直線ａ１・
ｂ１を従来例のタイヤに適用したときに、該直線ａ１・
ｂ１よりもタイヤ外郭が外側へ突出していることを示し
ている。In the table, the area B of the conventional tire is negative because the straight line a1.
When b1 is applied to the tire of the conventional example, the straight line a1.
This indicates that the outer contour of the tire projects outward from b1.
【０１２１】タイヤの諸元、ハイドロプレニーング発生
速度及び操縦安定性の評価は以下の表１〜１１に示す通
りである。The specifications of the tire, the rate of hydropre-kneading occurrence and the steering stability are shown in Tables 1 to 11 below.
【０１２２】[0122]
【表１】 [Table 1]
【０１２３】[0123]
【表２】 [Table 2]
【０１２４】[0124]
【表３】 [Table 3]
【０１２５】[0125]
【表４】 [Table 4]
【０１２６】[0126]
【表５】 [Table 5]
【０１２７】[0127]
【表６】 [Table 6]
【０１２８】[0128]
【表７】 [Table 7]
【０１２９】[0129]
【表８】 [Table 8]
【０１３０】[0130]
【表９】 [Table 9]
【０１３１】[0131]
【表１０】 [Table 10]
【０１３２】[0132]
【表１１】
試験の結果、バットレス部に凹み部を設けることにより
排水性が向上し、凹み部が大きく凹み最深部が接地面に
近いほどより排水性が向上していることがわかる。[Table 11] As a result of the test, it is understood that the drainage property is improved by providing the recessed part in the buttress part, and the drainage property is further improved as the recessed part is larger and the deepest part is closer to the ground contact surface.
【０１３３】また、クラウン形状、凹み部の位置・大き
さを適正に取ることにより、操縦安定性を損なわずに排
水性を向上できることがわかる。Further, it can be seen that the drainage can be improved without impairing the steering stability by properly setting the crown shape and the position and size of the recess.
【０１３４】[0134]
【発明の効果】以上説明したように、請求項１に記載の
空気入りタイヤは上記の構成としたので、操縦安定性を
犠牲にすることなく排水性を改良でき、ハイドロプレー
ニング現象が生じ難くなる、という優れた効果を有す
る。As described above, since the pneumatic tire according to claim 1 has the above-mentioned constitution, drainage can be improved without sacrificing steering stability, and hydroplaning phenomenon hardly occurs. , Which has an excellent effect.
【０１３５】請求項２に記載の空気入りタイヤは上記の
構成としたので、直進が主体の走行での（スリップ角、
キャンバ角が±０度付近での）接地端付近の接地圧集中
を抑えることができる、という優れた効果を有する。Since the pneumatic tire according to claim 2 has the above-mentioned constitution, the straight tire is mainly used for traveling (slip angle,
It has an excellent effect that it is possible to suppress the ground pressure concentration near the ground contact end (when the camber angle is around ± 0 degrees).
【０１３６】請求項３に記載の空気入りタイヤは上記の
構成としたので、直進と横力が主体の走行での（スリッ
プ角、キャンバ角が±１度以内での）接地端付近の接地
圧集中を抑えることができる、という優れた効果を有す
る。Since the pneumatic tire according to claim 3 has the above-mentioned structure, the ground pressure near the ground contact end (when the slip angle and the camber angle are within ± 1 degree) when the vehicle is driven mainly by straight running and lateral force. It has an excellent effect that concentration can be suppressed.
【０１３７】請求項４に記載の空気入りタイヤは上記の
構成としたので、直進主体の走行に加え、横力が主体の
走行での（スリップ角、キャンバ角が±３度付近での）
接地端付近の接地圧集中を抑えることができる、という
優れた効果を有する。Since the pneumatic tire according to claim 4 has the above-mentioned constitution, in addition to the straight running, the lateral force is the main running (slip angle and camber angle are around ± 3 degrees).
It has an excellent effect that the concentration of the ground pressure near the ground end can be suppressed.
【０１３８】請求項５に記載の空気入りタイヤは上記の
構成としたので、凹み部による排水性が良好になる、と
いう優れた効果を有する。Since the pneumatic tire according to claim 5 has the above-mentioned structure, it has an excellent effect that drainage due to the recess is improved.
【０１３９】請求項６に記載の空気入りタイヤは上記の
構成としたので、排水性を改良するために十分な凹み部
での排水量を得ることができる、という優れた効果を有
する。Since the pneumatic tire according to claim 6 has the above-mentioned constitution, it has an excellent effect that it is possible to obtain a sufficient amount of drainage in the concave portion for improving drainage.
【０１４０】請求項７に記載の空気入りタイヤは上記の
構成としたので、操縦安定性を確保することができる、
という優れた効果を有する。Since the pneumatic tire according to claim 7 has the above-mentioned structure, steering stability can be ensured.
It has an excellent effect.
【０１４１】請求項８に記載の空気入りタイヤは上記の
構成としたので、凹み部の大きさ（深さ）が確保され、
排水性が確保される、という優れた効果を有する。Since the pneumatic tire according to claim 8 is configured as described above, the size (depth) of the recessed portion is ensured,
It has the excellent effect of ensuring drainage.
【０１４２】請求項９に記載の空気入りタイヤは上記の
構成としたので、排水性が確保され、製造上で問題を生
じることもない、という優れた効果を有する。Since the pneumatic tire according to claim 9 has the above-mentioned constitution, it has an excellent effect that the drainage property is secured and no problem occurs in manufacturing.
【０１４３】請求項１０に記載の空気入りタイヤは上記
の構成としたので、カーカスが露出してカットや縁石こ
すれを起こすことなく、更に操縦安定性を向上させるこ
とができる、という優れた効果を有する。Since the pneumatic tire according to claim 10 has the above-mentioned constitution, it has an excellent effect that the steering stability can be further improved without exposing the carcass to cause a cut or curb rub. Have.
【０１４４】請求項１１に記載の空気入りタイヤは上記
の構成としたので、操縦安定性に悪影響を及ぼすことな
く排水性を改良できる、という優れた効果を有する。Since the pneumatic tire according to claim 11 has the above-mentioned constitution, it has an excellent effect that the drainage can be improved without adversely affecting the steering stability.
【０１４５】請求項１２に記載の空気入りタイヤは上記
の構成としたので、排水性を確保しつつ凹み部からの亀
裂の発生を防止しできる、という優れた効果を有する。Since the pneumatic tire according to claim 12 has the above structure, it has an excellent effect that cracks can be prevented from being generated from the recessed portion while ensuring drainage.
【０１４６】請求項１３に記載の空気入りタイヤは上記
の構成としたので、操縦安定性を悪化させずに排水性を
確保できる、という優れた効果を有する。Since the pneumatic tire according to claim 13 has the above-mentioned constitution, it has an excellent effect that the drainage can be secured without deteriorating the steering stability.
【０１４７】請求項１４に記載の空気入りタイヤは上記
の構成としたので、操縦安定性を悪化させずに排水性を
確保できる、という優れた効果を有する。Since the pneumatic tire according to claim 14 has the above-mentioned constitution, it has an excellent effect that the drainage can be secured without deteriorating the steering stability.
【０１４８】請求項１５に記載の空気入りタイヤは上記
の構成としたので、トロイド状ラジアルカーカスの損傷
を確実に防止することができる、という優れた効果を有
する。Since the pneumatic tire according to claim 15 has the above-mentioned constitution, it has an excellent effect that damage to the toroidal radial carcass can be surely prevented.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明の一実施形態に係る空気入りタイヤの左
半分の断面図である。FIG. 1 is a sectional view of a left half of a pneumatic tire according to an embodiment of the present invention.
【図２】本発明の一実施形態に係る空気入りタイヤのク
ラウン部の領域及び曲率半径を示す左半分の断面図であ
る。FIG. 2 is a left half sectional view showing a region and a radius of curvature of a crown portion of a pneumatic tire according to an embodiment of the present invention.
【図３】図１に示す空気入りタイヤのバットレス部付近
の拡大図である。FIG. 3 is an enlarged view around the buttress portion of the pneumatic tire shown in FIG.
【図４】他の実施形態に係る空気入りタイヤのバットレ
ス部付近の拡大図である。FIG. 4 is an enlarged view around a buttress portion of a pneumatic tire according to another embodiment.
【図５】図１に示す空気入りタイヤのバットレス部付近
の拡大図である。5 is an enlarged view of the vicinity of the buttress portion of the pneumatic tire shown in FIG.
【図６】図１に示す空気入りタイヤのバットレス部付近
の拡大図である。6 is an enlarged view of the vicinity of the buttress portion of the pneumatic tire shown in FIG.
【図７】（Ａ）は左側の図が路面側から見た実施形態に
係る空気入りタイヤの接地面付近の水の流れを示す説明
図であり、右側の図はその接地面付近の側面図であり、
（Ｂ）は図７（Ａ）の７Ｂ−７Ｂ線断面図である。FIG. 7A is an explanatory diagram showing a flow of water near the ground contact surface of the pneumatic tire according to the embodiment when viewed from the road surface side, and a right side view is a side view near the ground contact surface. And
7B is a sectional view taken along line 7B-7B in FIG.
【図８】（Ａ）は左側の図が路面側から見た従来例のタ
イヤの接地面付近の水の流れを示す説明図であり、右側
の図はその接地面付近の側面図であり、（Ｂ）は図８
（Ａ）の８Ｂ−８Ｂ線断面図である。FIG. 8A is an explanatory view showing a flow of water near the ground contact surface of the conventional tire as viewed from the road surface side, and a right side view is a side view near the ground contact surface; (B) is FIG.
FIG. 8B is a sectional view taken along line 8B-8B in (A).
【図９】バットレス部に凹み部を有するタイヤの荷重時
の変形の様子を示す説明図である。FIG. 9 is an explanatory diagram showing a state of deformation of a tire having a recessed portion in a buttress portion when a load is applied.
【図１０】従来例に係る空気入りタイヤのバットレス部
付近の拡大図である。FIG. 10 is an enlarged view of the vicinity of a buttress portion of a pneumatic tire according to a conventional example.
１０ 空気入りタイヤ
１４ ラジアルカーカス（トロイド状ラジアルカ−カ
ス）
２０ ベルト層
２２ トレッド
２２Ａ センタ領域
２２Ｂ 中間領域
２２Ｃ ショルダ領域
ａ 第１の接地端
ａ１ 外側開口端
ａ２ 第２の接地端
ｂ１ 内側開口端
ｃ 最深部
ｗ１ タイヤ最大幅点10 Pneumatic Tire 14 Radial Carcass (Toroidal Radial Carcass) 20 Belt Layer 22 Tread 22A Center Region 22B Intermediate Region 22C Shoulder Region a First Grounding End a1 Outer Opening End a2 Second Grounding End b1 Inner Opening End c Deepest Part w1 tire maximum width point
Claims (15)
部、前記サイドウォール部相互間にわたりトロイド状に
連なるトレッド部及び一方のビード部から他方のビード
部へわたりトロイド状に連なるラジアルカ−カスを有す
る空気入りラジアルタイヤであって、 前記空気入りラジアルタイヤを標準リムに組み付けて標
準内圧を充填した状態のタイヤ及びリム組立体のタイヤ
回転軸に沿った断面で表れるトレッド部のクラウンは、
互いに異なる曲率半径を有する少なくとも３種類の円弧
を互いに滑らかに連ねた複合円弧からなり、 タイヤ赤道面からクラウン端に向かって順次センタ領
域、中間領域及びショルダ領域に区分けした前記クラウ
ンは、タイヤ赤道面からタイヤ回転軸に対して平行に測
った各領域のタイヤ幅方向外端までの距離Ｌ及び、各領
域における円弧の曲率半径Ｒをそれぞれ、センタ領域は
距離Ｌａ及び曲率半径Ｒ1 、中間領域は距離Ｌｂ及び曲
率半径Ｒ2 、ショルダ領域は距離Ｌｃ及び曲率半径Ｒ3
で表し、 前記タイヤ及びリム組立体を標準荷重負荷の下で平板に
押圧した際の接触領域におけるクラウン端を、無負荷状
態に戻した前記タイヤ及びリム組立体においてタイヤ赤
道面からタイヤ回転軸に対して平行に計測したときの距
離をＷで表したときに、距離Ｌａ〜Ｌｃ、曲率半径Ｒ1
〜Ｒ3 及び距離Ｗの関係が、Ｌａ＝（０．４〜０．５）
×Ｗ、Ｒ1 ＝（１５〜４１）×Ｗ、Ｌｂ＝（０．９〜
１．１）×Ｗ、Ｒ2 ＝（１．５〜２．４）×Ｗ、Ｌｃ＝
（１．０〜１．５）×Ｗ、Ｒ3 ＝（０．３〜２．５）×
Ｗの関係を満たし、かつ、タイヤ規格の最大負荷能力の
１００％の荷重を負荷し、かつ、路面に対して回転軸を
平行にして接地させたときの接地端とタイヤ最大幅点と
間のバットレス部にタイヤ外郭に開口する凹み部を有す
ることを特徴とする空気入りラジアルタイヤ。1. A pair of beads, a pair of sidewalls, a tread which is continuous in a toroidal shape between the sidewalls, and a radial arc which is continuous in a toroidal shape from one bead to the other bead. A pneumatic radial tire, wherein the pneumatic radial tire is assembled on a standard rim and the tire in a state of being filled with standard internal pressure and the crown of the tread portion represented by a cross section along the tire rotation axis of the rim assembly,
The crown is composed of a compound arc in which at least three types of arcs having different radii of curvature are smoothly connected to each other, and the crown is divided into a center region, an intermediate region and a shoulder region from the tire equatorial plane toward the crown end in order. To the outer edge in the tire width direction of each region measured parallel to the tire rotation axis, and the radius of curvature R of the arc in each region. The center region is the distance La and the radius of curvature R1, and the intermediate region is the distance. Lb and radius of curvature R2, the shoulder region is distance Lc and radius of curvature R3
In the contact area when the tire and rim assembly is pressed against a flat plate under a standard load, the crown end in the contact area is returned to the unloaded state from the tire equatorial plane to the tire rotation axis. When the distance measured in parallel with respect to each other is represented by W, the distances La to Lc and the radius of curvature R1
.About.R3 and the distance W is La = (0.4 to 0.5)
XW, R1 = (15 to 41) xW, Lb = (0.9 to
1.1) × W, R2 = (1.5 to 2.4) × W, Lc =
(1.0 to 1.5) x W, R3 = (0.3 to 2.5) x
Between the ground contact end and the tire maximum width point when the relationship of W is satisfied, a load of 100% of the maximum load capacity of the tire standard is applied, and the rotation axis is parallel to the road surface and the tire is grounded. A pneumatic radial tire having a buttress portion that has a recessed portion that opens to the outer contour of the tire.
開口端を、タイヤ赤道面から前記クラウン端に向かって
タイヤ回転軸に対して平行に測った距離Ｗとなるクラウ
ン上の点よりタイヤ半径方向内側に配置したことを特徴
とする請求項１に記載の空気入りラジアルタイヤ。2. The tire radius from the point on the crown at which the outer open end of the recessed portion on the outer side in the tire radial direction is a distance W measured parallel to the tire rotation axis from the tire equatorial plane toward the crown end. The pneumatic radial tire according to claim 1, wherein the pneumatic radial tire is arranged inward in the direction.
開口端を、タイヤ赤道面から前記クラウン端に向かって
タイヤ回転軸に対して平行に測った距離１．１Ｗとなる
クラウン上の点よりタイヤ半径方向内側に配置したこと
を特徴とする請求項１に記載の空気入りラジアルタイ
ヤ。3. A point on the crown at which the outer open end of the recessed portion on the outer side in the tire radial direction is a distance of 1.1 W measured in parallel to the tire rotation axis from the tire equatorial plane toward the crown end. The pneumatic radial tire according to claim 1, wherein the pneumatic radial tire is arranged on the inner side in the tire radial direction.
開口端を、タイヤ赤道面から前記クラウン端に向かって
タイヤ回転軸に対して平行に測った距離１．５Ｗとなる
点よりタイヤ半径方向内側に配置したことを特徴とする
請求項１に記載の空気入りラジアルタイヤ。4. The tire radial direction from the point where the outer open end of the recessed portion on the radially outer side of the tire in the tire radial direction is measured to be 1.5 W parallel to the tire rotation axis from the tire equatorial plane toward the crown end. The pneumatic radial tire according to claim 1, wherein the pneumatic radial tire is arranged inside.
開口端と、タイヤ赤道面から前記クラウン端に向かって
タイヤ回転軸に対して平行に測った距離Ｌｂとなるクラ
ウン上の点とのタイヤ半径方向距離が６ｍｍ以内である
ことを特徴とする請求項１乃至請求項４の何れか１項に
記載の空気入りラジアルタイヤ。5. A tire having an outer open end on the tire radial direction outer side of the recess and a point on the crown having a distance Lb measured from the tire equatorial plane toward the crown end in parallel to the tire rotation axis. The radial radial tire according to any one of claims 1 to 4, wherein the radial distance is within 6 mm.
開口端を、前記接地端からタイヤ半径方向内側へ１５ｍ
ｍの地点からタイヤ半径方向内側に配置したことを特徴
とする請求項１乃至請求項５の何れか１項に記載の空気
入りラジアルタイヤ。6. The inner opening end of the recessed portion on the inner side in the tire radial direction is 15 m from the ground contact end toward the inner side in the tire radial direction.
The pneumatic radial tire according to any one of claims 1 to 5, wherein the pneumatic radial tire is arranged radially inward from a point m.
開口端を、前記接地端からタイヤ半径方向内側へ２０ｍ
ｍの地点よりもタイヤ半径方向外側に配置したことを特
徴とする請求項１乃至請求項６の何れか１項に記載の空
気入りラジアルタイヤ。7. The inner opening end of the recessed portion on the inner side in the tire radial direction is 20 m from the ground contact end toward the inner side in the tire radial direction.
The pneumatic radial tire according to any one of claims 1 to 6, wherein the pneumatic radial tire is arranged on the outer side in the tire radial direction with respect to the point m.
イヤ赤道面から前記クラウン端に向かってタイヤ回転軸
に対して平行に測った距離Ｌｂとなるクラウン上の点と
前記タイヤ最大幅点とを結んだ直線よりもタイヤ内方に
位置することを特徴とする請求項１乃至請求項７の何れ
か１項に記載の空気入りラジアルタイヤ。8. A point on the crown at which at least a part of the recessed portion has a distance Lb measured in parallel to a tire rotation axis from the tire equatorial plane toward the crown end and the tire maximum width point. The pneumatic radial tire according to any one of claims 1 to 7, wherein the pneumatic radial tire is located inward of the straight line connecting the two.
開口端と内側開口端とを結んだ直線からの前記凹み部の
最深部までの距離をＸとしたとき、Ｘ＝２ｍｍ〜１５ｍ
ｍであることを特徴とする請求項１乃至請求項８の何れ
か１項に記載の空気入りラジアルタイヤ。9. When the distance from the straight line connecting the outer opening end and the inner opening end on the tire radial direction outer side of the recessed portion to the deepest part of the recessed portion is X, X = 2 mm to 15 m
The pneumatic radial tire according to any one of claims 1 to 8, wherein m is m.
凹み部と対向する部分の前記トロイド状ラジアルカ−カ
スが、タイヤ外側に曲率中心を有して湾曲、または直線
状に、またはタイヤ内側に曲率中心を有し前記凹み部の
ラジアル方向両側の湾曲部分の曲率半径よりも大きな曲
率半径で湾曲していることを特徴とする請求項９に記載
の空気入りラジアルタイヤ。10. When X is 5 mm or more, a portion of the toroidal radial arc facing the recess has a curvature center on the outside of the tire and is curved or linear, or inside of the tire. The pneumatic radial tire according to claim 9, wherein the pneumatic radial tire has a center of curvature at a radius of curvature greater than a radius of curvature of a curved portion on both sides in the radial direction of the recessed portion.
側開口端と内側開口端との距離が、前記タイヤ赤道面か
ら前記クラウン端に向かってタイヤ回転軸に対して平行
に測った距離Ｌｂとなるクラウン上の点と前記凹み部の
タイヤ半径方向外側の内側開口端との距離の５０％〜１
００％であることを特徴とする請求項１乃至請求項１０
の何れか１項に記載の空気入りラジアルタイヤ。11. The distance Lb between the outer opening end and the inner opening end on the tire radial outer side of the recessed portion is a distance Lb measured from the tire equatorial plane toward the crown end in parallel with a tire rotation axis. 50% to 1 of the distance between the point on the crown and the inner opening end of the recessed portion on the outer side in the tire radial direction.
It is 00%, The claim 1 thru | or 10 characterized by the above-mentioned.
The pneumatic radial tire according to any one of 1.
側開口端から前記凹み部の最深部までのタイヤ半径方向
距離が、前記凹み部のタイヤ半径方向外側の外側開口端
から内側開口端までのタイヤ半径方向距離の２０％〜５
０％であることを特徴とする請求項１乃至請求項１１の
何れか１項に記載の空気入りラジアルタイヤ。12. The tire radial direction distance from the outer opening end on the tire radial outer side of the recessed portion to the deepest part of the recessed portion is from the outer opening end on the tire radial outer side to the inner opening end of the recessed portion. 20% to 5 of tire radial distance
It is 0%, The pneumatic radial tire of any one of Claim 1 thru | or 11 characterized by the above-mentioned.
な直線と、前記凹み部のタイヤ半径方向内側の内側開口
端を通るタイヤ赤道面に平行な直線と、タイヤ外郭形状
とに囲まれる部分の面積が、１２５ｃｍ2 以上３００ｃ
ｍ2 未満であることを特徴とする請求項１乃至請求項１
２の何れか１項に記載の空気入りラジアルタイヤ。13. A portion surrounded by a straight line parallel to a tire central axis passing through the ground contact end, a straight line parallel to a tire equatorial plane passing through an inner opening end of the recessed portion radially inside the tire, and a tire outer shape. Area is over 125cm 2 300c
claim, characterized in that it is less than m 2 1 to claim 1
The pneumatic radial tire according to any one of 2 above.
側開口端と前記凹み部のタイヤ半径方向内側の内側開口
端とを結ぶ直線と、タイヤ外郭形状と、に囲まれる部分
の面積が、１５ｃｍ2 以上１１０ｃｍ2 未満であること
を特徴とする請求項１乃至請求項１３の何れか１項に記
載の空気入りラジアルタイヤ。14. An area of a portion surrounded by a straight line connecting an outer opening end on the tire radial outer side of the depression and an inner opening end on the tire radial inner side of the depression and the outer shape of the tire is 15 cm. The pneumatic radial tire according to any one of claims 1 to 13, wherein the pneumatic radial tire has a size of 2 or more and less than 110 cm 2 .
カーカスとの間のゴム層の厚みが、少なくとも２ｍｍ以
上であることを特徴とする請求項１乃至請求項１４の何
れか１項に記載の空気入りラジアルタイヤ。15. The air according to claim 1, wherein a thickness of the rubber layer between the recessed portion and the toroidal radial carcass is at least 2 mm or more. Radial tires with.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23459198A JP4450439B2 (en) | 1998-08-20 | 1998-08-20 | Pneumatic radial tire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23459198A JP4450439B2 (en) | 1998-08-20 | 1998-08-20 | Pneumatic radial tire |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000062415A true JP2000062415A (en) | 2000-02-29 |
| JP4450439B2 JP4450439B2 (en) | 2010-04-14 |
Family
ID=16973436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23459198A Expired - Fee Related JP4450439B2 (en) | 1998-08-20 | 1998-08-20 | Pneumatic radial tire |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4450439B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006027474A (en) * | 2004-07-16 | 2006-02-02 | Bridgestone Corp | Pneumatic tire |
| JP2011031677A (en) * | 2009-07-30 | 2011-02-17 | Bridgestone Corp | Pneumatic tire for passenger car |
| JP2012086664A (en) * | 2010-10-19 | 2012-05-10 | Sumitomo Rubber Ind Ltd | Pneumatic radial tire |
| JP2013169817A (en) * | 2012-02-17 | 2013-09-02 | Sumitomo Rubber Ind Ltd | Pneumatic tire |
| CN109203863A (en) * | 2017-07-04 | 2019-01-15 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN111448077A (en) * | 2017-12-12 | 2020-07-24 | 株式会社普利司通 | Heavy load tire |
| US10967680B2 (en) * | 2016-06-14 | 2021-04-06 | Bridgestone Corporation | Tire |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04356204A (en) * | 1990-11-16 | 1992-12-09 | Bridgestone Corp | Pneumatic radial tire and its combined unit |
| JPH0971107A (en) * | 1995-04-27 | 1997-03-18 | Bridgestone Corp | Pneumatic radial tire |
-
1998
- 1998-08-20 JP JP23459198A patent/JP4450439B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04356204A (en) * | 1990-11-16 | 1992-12-09 | Bridgestone Corp | Pneumatic radial tire and its combined unit |
| JPH0971107A (en) * | 1995-04-27 | 1997-03-18 | Bridgestone Corp | Pneumatic radial tire |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006027474A (en) * | 2004-07-16 | 2006-02-02 | Bridgestone Corp | Pneumatic tire |
| JP4619053B2 (en) * | 2004-07-16 | 2011-01-26 | 株式会社ブリヂストン | Pneumatic tire |
| JP2011031677A (en) * | 2009-07-30 | 2011-02-17 | Bridgestone Corp | Pneumatic tire for passenger car |
| JP2012086664A (en) * | 2010-10-19 | 2012-05-10 | Sumitomo Rubber Ind Ltd | Pneumatic radial tire |
| JP2013169817A (en) * | 2012-02-17 | 2013-09-02 | Sumitomo Rubber Ind Ltd | Pneumatic tire |
| US10967680B2 (en) * | 2016-06-14 | 2021-04-06 | Bridgestone Corporation | Tire |
| CN109203863A (en) * | 2017-07-04 | 2019-01-15 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN109203863B (en) * | 2017-07-04 | 2022-06-07 | 住友橡胶工业株式会社 | Pneumatic tire |
| CN111448077A (en) * | 2017-12-12 | 2020-07-24 | 株式会社普利司通 | Heavy load tire |
| US11331954B2 (en) | 2017-12-12 | 2022-05-17 | Bridgestone Corporation | Heavy duty tire |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4450439B2 (en) | 2010-04-14 |
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