JP3467097B2 - Pneumatic radial tire - Google Patents

Pneumatic radial tire

Info

Publication number
JP3467097B2
JP3467097B2 JP31092194A JP31092194A JP3467097B2 JP 3467097 B2 JP3467097 B2 JP 3467097B2 JP 31092194 A JP31092194 A JP 31092194A JP 31092194 A JP31092194 A JP 31092194A JP 3467097 B2 JP3467097 B2 JP 3467097B2
Authority
JP
Japan
Prior art keywords
tread
main
area
tire
auxiliary
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.)
Expired - Fee Related
Application number
JP31092194A
Other languages
Japanese (ja)
Other versions
JPH08164715A (en
Inventor
一郎 高橋
静雄 岩崎
一夫 林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bridgestone Corp
Original Assignee
Bridgestone Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Bridgestone Corp filed Critical Bridgestone Corp
Priority to JP31092194A priority Critical patent/JP3467097B2/en
Publication of JPH08164715A publication Critical patent/JPH08164715A/en
Application granted granted Critical
Publication of JP3467097B2 publication Critical patent/JP3467097B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/0083—Tyre tread bands; Tread patterns; Anti-skid inserts characterised by the curvature of the tyre tread
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/03—Tread patterns
    • B60C11/0304—Asymmetric patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/03—Tread patterns
    • B60C2011/0337—Tread patterns characterised by particular design features of the pattern
    • B60C2011/0339—Grooves
    • B60C2011/0374—Slant grooves, i.e. having an angle of about 5 to 35 degrees to the equatorial plane
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/03—Tread patterns
    • B60C2011/0337—Tread patterns characterised by particular design features of the pattern
    • B60C2011/0386—Continuous ribs
    • B60C2011/0388—Continuous ribs provided at the equatorial plane

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Tires In General (AREA)

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、ラジアルタイヤの操縦
安定性の改良に関し、特に、後輪駆動の高速高性能車両
の駆動輪に装着したとき優れた操縦安定性を発揮する乗
用車用扁平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 improvement of steering stability of a radial tire, and more particularly, to a flat air for passenger vehicle which exhibits excellent steering stability when mounted on driving wheels of a rear wheel drive high-speed and high-performance vehicle. The present invention relates to a radial tire that contains a tire.

【０００２】[0002]

【従来の技術】空気入りタイヤにおいて高速性能を向上
させるためには、トレッドのベ−ス部分を非伸長性ベル
ト層で強化したラジアル構造が一般的であり、形状の面
ではタイヤ断面の幅に対する高さの比、即ち扁平比を小
さくすることが行われる。扁平比について、０．６程度
は普通に適用され、高速高性能乗用車用としては０．３
もの超扁平タイヤも出現するに及んでいる。2. Description of the Related Art In order to improve high-speed performance of a pneumatic tire, a radial structure in which the base portion of the tread is reinforced with a non-stretchable belt layer is generally used. The height ratio, that is, the flatness ratio is reduced. A flatness ratio of about 0.6 is normally applied and 0.3 for high-speed high-performance passenger cars.
Ultra flat tires are also appearing.

【０００３】タイヤ断面が扁平になるとタイヤ幅が広く
なり、それに伴ってトレッド幅も広く、且つ平坦に設定
されるが、このようなタイヤの場合、接地面の排水性が
悪化することからウエット路上を高速で走行するとき滑
り易く、そのため排水性向上を目的として複数の周方向
溝と、これら周方向溝と交差してＶ字状に延びる傾斜ラ
グ溝によってブロック状に陸部を区分し、ネガティブ率
増大の方向で同率を特定したトレッド構造が知られてい
る。またこの場合、耐ウエットスキッド性向上のための
上記方策の結果懸念される、トレッドの陸部剛性低下と
それに基づく操縦安定性悪化を考慮し、コ−ナリング時
にサイドフォ−スがシビアに作用するトレッドの車両装
着外側区域と、比較的マイルドな内側区域のネガティブ
率を変えた構造、即ちトレッドの片側区域のネガティブ
率を比較的小さくすることによってコ−ナリング時に作
用するサイドフォ−スに備え、一方残りの区域のネガテ
ィブ率は大きくして排水性が向上するよう機能的に変化
をもたせた非対称構造も知られている。When the tire cross section becomes flat, the tire width becomes wider, and accordingly, the tread width is also made wider and flat. However, in the case of such a tire, the drainage property of the ground contact surface is deteriorated, and therefore, on a wet road. Is slippery when traveling at high speed, and therefore the land is divided into blocks by a plurality of circumferential grooves and inclined lug grooves extending in a V shape intersecting these circumferential grooves for the purpose of improving drainage, There is known a tread structure that specifies the same rate in the direction of increasing rate. Also, in this case, in consideration of the decrease in the land rigidity of the tread and the deterioration of steering stability due to it, which is a concern as a result of the above measures for improving the wet skid resistance, the tread in which the side force acts severely during cornering. In order to prepare for the side force acting during cornering by making the negative ratio of the one side area of the tread relatively small, while the negative ratio of the vehicle mounted outer area and the relatively mild inner area is changed, the remaining It is also known that there is an asymmetric structure in which the negative rate of the area is increased and the function is changed so that drainage is improved.

【０００４】[0004]

【発明が解決しようとする課題】車両のコ−ナリング時
には、旋回外側のタイヤに車両の遠心力によって荷重移
動が生じ、その結果、この外側タイヤのトレッドの外側
区域（車両中心から遠い側）が、作用するサイドフォ−
スの面で厳しい状態に晒されることは上述の通りである
が、発明者が種々詳細に調べたところによると、コ−ナ
リング時の走行条件によっては上記外側タイヤのトレッ
ド外側端部に荷重による接地圧が集中する一方、内側端
部は路面から浮き上がる傾向を示し、その結果トレッド
の接地面積が著しく減少することとなる。トレッド端部
への荷重移動の際、トレッド外側端より先、軸方向外側
へは接地幅は実質上拡大し得ないため、周方向に向かっ
て接地長さがある程度増大はするものの、トレッド内側
端部の浮上による接地面積減少の分を補う程のものでは
ない。接地面積がコ−ナリング時にこのように大幅に減
少すると、作用するサイドフォ−スに対してコ−ナリン
グフォ−スが不足し、操縦安定性においてしばしば問題
が生じることとなる。During cornering of a vehicle, a load is generated in the tire on the outside of the turn due to the centrifugal force of the vehicle, and as a result, the outer region (the side far from the center of the vehicle) of the tread of the outer tire is moved. , Acting side fore
It is as described above that the tire is exposed to severe conditions, but according to various studies conducted by the inventor, depending on driving conditions during cornering, the outer end of the tread of the outer tire may be affected by a load. While the ground contact pressure concentrates, the inner edge tends to float above the road surface, resulting in a significant decrease in the tread ground contact area. When the load is transferred to the tread end, the ground contact width cannot be substantially expanded axially outward beyond the tread outer end, so the ground contact length increases to some extent in the circumferential direction, but the tread inner end It is not enough to compensate for the reduction of the ground contact area due to the floating of the part. Such a significant reduction of the ground contact area during cornering results in a lack of cornering force relative to the acting side force, often causing problems in steering stability.

【０００５】問題の一例として、一般に車両の走行性能
が高ければ高い程扁平比の小さいタイヤが適用される
が、特に後輪駆動の高性能乗用車の場合、駆動力を加え
つつ行う高速コ−ナリング走行時において後輪タイヤが
コ−ナリングフォ−ス不足を来したときは、オ−バア−
ステア現象によってドライバ−はしばしば車両の制御が
困難になる。扁平タイヤにおいて上に述べたトレッドの
ネガティブ率増大構造はともかく、ネガティブ率の非対
称構造によっても、接地面積の減少に伴う問題を解決す
るには、効果の面で自ら限界がある。本発明は上記問題
に鑑みなされたもので、操縦安定性に優れた、特に扁平
空気入りタイヤを提供することを目的とする。As an example of the problem, generally, the higher the running performance of the vehicle, the smaller the flatness of the tire is applied. Particularly, in the case of a rear-wheel drive high-performance passenger car, high-speed cornering is performed while applying driving force. If the rear tires are running out of cornering space while driving,
The steering phenomenon often makes it difficult for the driver to control the vehicle. Aside from the structure for increasing the negative ratio of the tread described above for the flat tire, the asymmetric structure of the negative ratio has its own limit in terms of effectiveness in solving the problems associated with the decrease in the ground contact area. The present invention has been made in view of the above problems, and an object of the present invention is to provide a flat pneumatic tire having excellent steering stability.

【０００６】[0006]

【課題を解決するための手段】本発明は、トロイド状ラ
ジアルカ−カスのクラウン部外周上に非伸長性ベルト層
およびトレッド部を順次備え、上記トレッド部が直進時
に接地する円筒状の主トレッドとその両端から丸みをも
って径方向内側へ夫々連なる補助トレッドより成ると共
に多数の主溝を有し、少なくとも上記主トレッドは、全
体面積に対する溝部分の面積の比率によって定義される
ネガティブ率が左右領域で異なる空気入りラジアルタイ
ヤにおいて、上記トレッド部は、主トレッドの曲率半径
が左右同一であり、上記補助トレッドの丸みをもつ輪郭
の曲率半径が左右異なると共にネガティブ率の小さい主
トレッド領域に連なる側がより大きいことを特徴とする
空気入りラジアルタイヤである。ここで主トレッドと
は、タイヤが直進時に接地するトレッド部の領域を云
い、便宜上ETRTO 規格に基づきタイヤを正規リムに組
み、正規内圧を充填して平板上に設計最大荷重の７０%
を加えたとき接地する領域とする。According to the present invention, a non-stretchable belt layer and a tread portion are sequentially provided on the outer circumference of a crown portion of a toroidal radial arccass, and the tread portion is straight when traveling straight.
It has a cylindrical main tread that is grounded to and an auxiliary tread that is continuous from the both ends to the inside in the radial direction with roundness, and has a large number of main grooves.At least the main tread is defined by the ratio of the area of the groove portion to the entire area. Pneumatic radial ties with different negative ratios in the left and right areas
In the above , the above-mentioned tread is the radius of curvature of the main tread.
Is the same on the left and right, the radius of curvature of the rounded contour of the auxiliary tread is different on the left and right, and the side contiguous to the main tread region having a small negative ratio is larger, the pneumatic radial tire. Here, the main tread is the area of the tread where the tire touches the ground when going straight. For convenience, the tire is assembled on the regular rim based on the ETRTO standard, the regular internal pressure is filled, and 70% of the maximum design load on the flat plate.
The area to be grounded when is added.

【０００７】本発明における好ましい態様として、上記
補助トレッドの曲率半径は、ネガティブ率の大きい主ト
レッドの領域に連なる側に対し、ネガティブ率の小さい
主トレッドの領域に連なる側が１１０〜１５０% とし、
また上記主溝は、主トレッドの中央部側から八の字状に
タイヤの赤道面に対し傾斜して主トレッド端側へ延び、
主トレッド端側で幅を絞り軸方向に向きを変えて補助ト
レッドへと続き、これら周方向に隣接する一対の主溝に
よって区分された陸部は、少なくともネガティブ率が小
さい領域においては主トレッドから補助トレッドにかけ
て続く連続構造である。 In a preferred embodiment of the present invention, the radius of curvature of the auxiliary tread is 110 to 150% on the side connected to the area of the main tread having a large negative ratio, and to the side connected to the area of the main tread having a small negative ratio.
Further, the main groove extends from the central portion side of the main tread to the main tread end side while being inclined with respect to the equatorial plane of the tire in an eight shape.
It continues to assist the tread by changing the orientation of the width in the main tread edge side to the aperture axis, the pair of main grooves adjacent thereto circumferentially
Therefore, the land areas that are classified have at least a small negative rate.
From the main tread to the auxiliary tread
It is a continuous structure that continues.

【０００８】[0008]

【作用】本発明は、円筒状主トレッドの両端より丸みを
もって連なる補助トレッドの曲率半径が左右で異なり、
主トレッドの曲率半径が左右同一であり、ネガティブ率
が小さく形成された主トレッドの領域に連なる側の曲率
半径が、ネガティブ率が大きい主トレッドの領域に連な
る側のそれより大きいことを構造、並びに形状上の特徴
とする。本発明に成るタイヤにつき、曲率半径の大きい
補助トレッドの側を車両の外側に向けて装着しコ−ナリ
ング走行を行ったとき、旋回外側のタイヤの外側トレッ
ド区域、就中その区域の外側トレッド端部に荷重移動が
あっても、主トレッド端を越えて接地端が補助トレッド
内へ移行し、この場合、より大きい輪郭によって形成さ
れた補助トレッドの追加接地によって不足した主トレッ
ドの接地面積を有利に補うことができのである。そのた
め、主トレッド端部への異常な接地圧の集中が緩和され
るので発生するコ−ナリングフォ−スの頭打ちが少な
く、従って特に、後輪駆動の高速高性能乗用車の後輪に
適用したときのスピン防止に対し特に有効である。In the present invention, the radius of curvature of the auxiliary tread, which is continuous from both ends of the cylindrical main tread with roundness, is different on the left and right sides,
The radius of curvature of the main tread is the same on the left and right, and the radius of curvature on the side continuous with the area of the main tread formed with a small negative ratio is larger than that on the side continuous with the area of the main tread with a large negative ratio, and It is a feature of shape. In the tire according to the present invention, when the auxiliary tread having a large radius of curvature is mounted toward the outer side of the vehicle for cornering traveling, the outer tread area of the tire on the outside of the turning, especially the outer tread end of the area. Even if there is load transfer in the section, the ground contact edge moves into the auxiliary tread beyond the main tread edge, and in this case, the ground contact area of the main tread which is insufficient due to the additional grounding of the auxiliary tread formed by the larger contour is favored. Can be compensated for. Therefore, the concentration of abnormal ground pressure on the end of the main tread is alleviated, so that the cornering force is less likely to reach the top, and therefore, especially when applied to the rear wheels of a rear-wheel drive high-speed and high-performance passenger vehicle. Especially effective for preventing spin.

【０００９】補助トレッドの曲率半径は、ネガティブ率
の大きい主トレッドに連なる側に対し同率の小さい主ト
レッドに連なる側が１１０〜１５０% の範囲が好まし
い。この比率が１１０% に満たないときは、本発明の目
的に照らし効果が少なく、他方１５０% を越えると、規
格によって定められたタイヤ最大幅との関係から凡そ決
まる、トレッド部の幅の範囲内において必要な主トレッ
ドの幅をとることができず、この場合直進走行性の面で
好ましくない。なおネガティブ率の大きい主トレッド領
域に連なる補助トレッドの曲率半径を共に大きく設けた
場合も同様である。The radius of curvature of the auxiliary tread is preferably in the range of 110% to 150% on the side connected to the main tread having a small negative ratio to the side connected to the main tread having a large negative ratio. If this ratio is less than 110%, the effect is small in light of the object of the present invention. On the other hand, if it exceeds 150%, it falls within the range of the width of the tread portion which is roughly determined from the relationship with the maximum tire width specified by the standard. In this case, the width of the main tread required can not be secured, and in this case, it is not preferable in terms of straight running performance. The same applies to the case where a large radius of curvature is provided for both auxiliary treads connected to the main tread region having a large negative ratio.

【００１０】トレッド部に設ける陸部は、少なくともネ
ガティブ率が小さい領域において主トレッドから補助ト
レッドにかけ連続配置した場合、コ−ナリング時に軸方
向に拡大した接地面内に作用するサイドフォ−スの方向
に陸部が主トレッドから補助トレッドへ連なることとな
り、主トレッドの端部、またはショルダ−部から補助ト
レッドへ続く陸部の剛性が著しく向上する。The land portion provided on the tread portion has at least a region where the negative ratio is small, from the main tread to the auxiliary tread.
In the case of continuous placement over the red, the land part is connected from the main tread to the auxiliary tread in the direction of the side force acting on the ground contact surface that is enlarged in the axial direction during cornering, and the end of the main tread or the shoulder is connected. The rigidity of the land from the section to the auxiliary tread is significantly improved.

【００１１】[0011]

【実施例】以下図面に基づき説明する。図１は本発明に
おける一実施例を示すタイヤの断面輪郭図、図２は同タ
イヤの平面展開図である。本発明においてタイヤ1 は、
図示を省略しているがトロイド状ラジアルカ−カスのク
ラウン部外周上に非伸長性ベルト層とトレッド部2 を順
次備え、上記トレッド部2 は円筒状の主トレッド3 とそ
の両端EMから丸みをもって径方向内側へ夫々連なる補助
トレッド4 より成ると共に、多数の主溝5 と、これら主
溝によって区分された陸部6 を有し、少なくとも主トレ
ッド3 は、全体面積に対する溝部分の面積の比率によっ
て定義されるネガティブ率が左右領域間で異なってい
る。補助トレッド4 の丸みをもつ輪郭の曲率半径は左右
で異なり、ネガティブ率の小さい主トレッド領域3Sに連
なる側の曲率半径rLがネガティブ率の大きい領域3Lに連
なる側の曲率半径rSより大である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given below with reference to the drawings. FIG. 1 is a sectional outline view of a tire showing an embodiment of the present invention, and FIG. 2 is a plan development view of the tire. In the present invention, the tire 1 is
Although not shown, a non-stretchable belt layer and a tread portion 2 are sequentially provided on the outer circumference of the crown portion of the toroidal radial arcus, and the tread portion 2 is rounded from the cylindrical main tread 3 and its both ends E M. It consists of auxiliary treads 4 that extend inward in the radial direction, and has a large number of main grooves 5 and land portions 6 divided by these main grooves.At least the main tread 3 depends on the ratio of the area of the groove portion to the total area. The defined negative rate differs between the left and right areas. The radius of curvature of the rounded contour of the auxiliary tread 4 is different on the left and right, and the radius of curvature r L on the side linked to the main tread area 3 S with a low negative ratio is smaller than the radius of curvature r S linked to the area 3 L with a high negative ratio. Is large.

【００１２】カ−カスはポリエステル、レ−ヨンで代表
される繊維コ−ドを赤道面O と実質上直交する方向に配
列したプライの少なくとも１枚、通常２枚から成る公知
の構造であり、またベルト層もスチ−ルコ−ドなど非伸
長性コ−ドを赤道面O に対し浅い角度（１５〜３５°）
で傾斜配列した層の複数枚、通常２枚をそれらのコ−ド
が交差するように重ね合わせ、更にその周囲にナイロン
などの熱収縮性コ−ドを複数本並べてゴム引きしたスト
リップの周方向螺旋巻きによって形成したキャップ層を
含む公知の構造である。The carcass has a known structure comprising at least one ply, usually two plies, in which fiber cords represented by polyester and rayon are arranged in a direction substantially perpendicular to the equatorial plane O. The belt layer also has a non-stretchable cord such as a steel cord at a shallow angle (15 to 35 °) with respect to the equatorial plane O.
Circumferential direction of strips made by stacking two or more layers, usually two sheets, which are arranged in a slanted array with the cords intersecting each other, and further arranging a plurality of heat-shrinkable cords such as nylon around the layers to rubberize them. It is a known structure including a cap layer formed by spiral winding.

【００１３】図１および２は335/30ZR18サイズの超扁平
ラジアルタイヤの例であるが、図１において主トレッド
5 は平坦な形状を呈し、ネガティブ率が大きい領域3L側
のトレッド端EMからトレッド部端ETまでの間に形成され
た補助トレッド4 は、端EMに近接し３５mmの曲率半径rS
と端ETに近接してこれよりやや小さい曲率半径の複合輪
郭によって形成し、一方ネガティブ率が比較的小さい領
域3S側のトレッド端EMからトレッド部端ETまでの間に形
成された補助トレッド4 は、４５mmの曲率半径rLによっ
て外面形状を形成している。1 and 2 show an example of a 335 / 30ZR18 size ultra-flat radial tire, the main tread of which is shown in FIG.
5 has a flat shape, and the auxiliary tread 4 formed between the tread edge E M on the region 3 L side where the negative ratio is large and the tread portion edge E T is close to the edge E M and has a radius of curvature r of 35 mm. S
And in proximity to the edge E T formed by the composite contour of slightly smaller radius of curvature than this, whereas formed from the tread end E M of negative ratio is relatively small region 3 S side until tread end E T The auxiliary tread 4 has an outer surface shape with a radius of curvature r L of 45 mm.

【００１４】図２において広幅主溝5 は、主トレッド3
上赤道面O の近くから八の字状に軸方向外側に向って傾
斜して延び、主トレッド端EM近傍の地点7 より幅を絞
り、ほぼ軸方向に向きを変えて補助トレッド4 内へと延
び、陸部6 を区分している。陸部6 は主トレッドのネガ
ティブ率が比較的小さい領域3Sにおいては、更にサイプ
8 （幅１mm）によって見掛け上４個の独立ブロック9 を
区分し、一方ネガティブ率が大きい領域3L内に延びる陸
部6 は細溝10（幅３mm）によって５個の独立ブロックに
区分している。In FIG. 2, the wide main groove 5 is a main tread 3
It extends from the vicinity of the upper equatorial plane O to the outside in the axial direction in the shape of a figure eight, narrows the width from the point 7 near the main tread end E M, and turns in the axial direction into the auxiliary tread 4. The land area 6 is divided. In a relatively small area 3 S is the land portion 6 is negative ratio of the main tread, further sipes
4 independent blocks 9 are apparently divided by 8 (width 1 mm), while the land portion 6 extending in the region 3 L having a large negative ratio is divided into 5 independent blocks by fine grooves 10 (width 3 mm). There is.

【００１５】領域3S内に延びる主溝51は、赤道面O と平
行な線j に対する角度αが平均３５°である。そして同
溝の軸方向内側端部は幅を狭め周方向に向きを変え、更
にやや反転してサイプ8 と結合し、また補助トレッド4
内に続く同溝の軸方向外側端部は、トレッド部端ET近く
で鉤状に向きを変えている。これら主溝によって区分さ
れた陸部6 は、サイプ8 によって見掛け上ブロック9 に
分断されているとは云え、接地面内において作用する外
力、特にサイドフォ−スに対しては、一連の杓子状に連
なる陸部として機能するのである。符号11は主トレッド
3 の端部から補助トレッド4 へ一体に延びる広幅ブロッ
ク9 の周方向屈曲性向上のため、そのほぼ中央に主溝に
沿って設けた補助溝である。[0015] main groove 5 1 extending into the region 3 S, the angle α with respect to the equatorial plane O and a line parallel j is the average 35 °. The inner end of the groove in the axial direction narrows its width and changes its direction in the circumferential direction.
Axially outer end portion of the groove following the inside is turned around like a hook near the tread end E T. It can be said that the land portion 6 divided by these main grooves is apparently divided into the blocks 9 by the sipes 8, but it is formed into a series of scoops with respect to the external force acting on the ground contact surface, particularly the side force. It functions as a continuous land area. Reference numeral 11 is the main tread
An auxiliary groove is provided substantially at the center of the wide block 9 along the main groove so as to improve the circumferential flexibility of the wide block 9 integrally extending from the end portion of 3 to the auxiliary tread 4.

【００１６】領域3L内に延びる主溝52は、赤道面O と平
行な線k に対する角度βが平均１５°である。そして同
溝の軸方向内側端部は、主溝51と同様に幅を狭め周方向
に向きを変え、更に反転して隣の主溝52に開口し、また
地点7 から補助トレッド4 内へ続く同溝の軸方向外側端
部は、幅を狭め軸方向とほぼ平行にトレッド部端ETまで
延びている。主溝52の軸方向に沿って延びる部分に区分
された区域は、トレッド部端ETから主溝と交わるラグ溝
12を中央に１本、その両側に陸部内に先端が止まる補助
溝11を各々１本設けることによって横向きＵ字状ブロッ
クを区画している。なお符号13はＵ字状ブロック内に周
方向に向かって設けた切欠き、符号14は、主溝51、52間
に形成されたエンドレスリブ、そして符号m （図１）は
主溝の底のレベルを連ねた仮想線である。The main groove 5 2 extending into the region 3 L is the angle β relative to a line parallel k and the equatorial plane O is the average 15 °. The inner end of the groove in the axial direction is narrowed in the same direction as the main groove 5 1 and turned in the circumferential direction, further inverted and opened to the adjacent main groove 5 2, and from the point 7 to the auxiliary tread 4 inside. The axially outer end of the groove extending to the narrower side narrows the width and extends substantially parallel to the axial direction to the tread end E T. Partitioned area in the portion extending along the axial direction of the main groove 5 2, lug grooves intersecting the main groove from the tread portion edge E T
A lateral U-shaped block is defined by providing one 12 in the center and one auxiliary groove 11 on both sides of the auxiliary groove 11 where the tip stops in the land. Reference numeral 13 notches provided toward the circumferential direction in the U-shaped block, reference numeral 14 is the main groove 5 1, 5 endless ribs formed between 2 and code m (Fig. 1), is the main grooves It is a virtual line connecting the bottom levels.

【００１７】周上における領域3S内主溝51の本数は、領
域3L内主溝52の本数のほぼ２倍とし、主溝51の長さは主
溝52の長さのほぼ１／２とすることが好ましい。この実
施例の場合主溝51、52は夫々３０本、および１５本、長
さにつき前者を後者の１／２とした。The number of the main grooves 5 1 in the area 3 S on the circumference is approximately twice the number of the main grooves 5 2 in the area 3 L , and the length of the main groove 5 1 is equal to the length of the main groove 5 2 . It is preferable to make it about 1/2. In this embodiment, the main grooves 5 1 and 5 2 are 30 and 15, respectively, and the length is 1/2 of the latter.

【００１８】このようにして成る本実施例のタイヤのネ
ガティブ率につき、主トレッドの領域3Lと、3Sは夫々３
３% 、および３０% とし、また補助トレッド4 のネガテ
ィブ率は、これに連なる上記領域に準じて夫々決定し
た。With respect to the negative ratio of the tire of this embodiment thus constructed, the main tread areas 3 L and 3 S are 3 respectively.
3% and 30%, and the negative rate of the auxiliary tread 4 was determined in accordance with the above-mentioned range.

【００１９】以上述べた本実施例のタイヤは、主溝51、
52のトレッド中央部で収斂する側が、トレッド端部で拡
開する側に先んじて接地するよう回転方向が決まり、ま
た車両へは、曲率半径が大きい補助トレッドが連なるネ
ガティブ率が小さい主トレッドの領域3Sを外側に向けて
装着する。The tire of the present embodiment described above has the main groove 5 1 ,
The direction of rotation is determined so that the side that converges at the center of the tread of 5 2 comes into contact with the side that expands at the end of the tread, and that the auxiliary tread with a large radius of curvature is connected to the vehicle. Mount with area 3 S facing outwards.

【００２０】[0020]

【発明の効果】本発明に成るタイヤの効果を確かめるべ
く後輪用タイヤに335/30ZR18サイズ、前輪用タイヤとし
ては一回り小形の245/35ZR18サイズのラジアル構造を使
用し、比較例を交えて高速高性能乗用車による実車操縦
安定性テストを行い評価した。後輪に使用した実施例の
タイヤは、図１および２に基づき述べた構造、このタイ
ヤと組み合わせて使用した前輪用タイヤは、後輪用タイ
ヤと類似のトレッド構造を適用した。一方後輪に使用し
た比較例のタイヤは、領域3Sに連なる補助トレッド4 の
曲率半径を領域3L側の補助トレッド4 の曲率半径と等し
くする（３５mm）と同時に、領域3Sにおける陸部をサイ
プ8 に代えて細溝10を使用し、領域3L内のブロック9 と
同様の独立ブロックとした点を除いて実施例のタイヤと
同一の構造とした。このタイヤと組み合わせ使用した前
輪用タイヤは、後輪用タイヤと類似のトレッド構造を適
用した。なお後輪用比較例のタイヤのネガティブ率につ
いては、実施例のタイヤの平均ネガティブ率と同一にし
た。[Effects of the Invention] In order to confirm the effect of the tire according to the present invention, the rear wheel tire has a radial structure of 335 / 30ZR18 size, and the front wheel tire has a slightly smaller radial structure of 245 / 35ZR18 size. An actual vehicle steering stability test using a high-speed and high-performance passenger car was conducted and evaluated. The tire of the example used for the rear wheel had the structure described with reference to FIGS. 1 and 2, and the tire for the front wheel used in combination with this tire had a tread structure similar to that of the tire for the rear wheel. On the other hand, in the tire of the comparative example used for the rear wheels, the radius of curvature of the auxiliary tread 4 connected to the region 3 S is made equal to the radius of curvature of the auxiliary tread 4 on the region 3L side (35 mm), and at the same time, the land portion in the region 3 S is using the narrow groove 10 in place of the sipe 8, and the same structure as the tires of examples, except that the same independent block and a block 9 in the area 3 L. The front tire used in combination with this tire had a tread structure similar to that of the rear tire. The negative ratio of the tire for the rear wheel comparative example was the same as the average negative ratio of the tire for the example.

【００２１】テストタイヤは前輪用18×8.5J、後輪用18
×13J リムに夫々組み、前後輪共２．５Kgf/Cm2 の内圧
を充填して、アスファルト舗装の周回路上を各種走行モ
−ドで走行したときの操縦安定性を、ドライバ−のフィ
リングによって評価した。テストの結果、比較例のタイ
ヤを１００としたとき実施例のタイヤは１０５の評価を
得た。Test tires are 18 × 8.5J for front wheels, 18 for rear wheels
Evaluating the steering stability when driving in various driving modes on the asphalt pavement circuit in various driving modes by assembling each to 13X rims and filling the inner pressure of 2.5Kgf / Cm 2 for both front and rear wheels. did. As a result of the test, when the tire of the comparative example is set to 100, the tire of the example has a rating of 105.

【００２２】このように、トレッド部が円筒状の主トレ
ッドとその両端から丸みをもって径方向内側へ夫々連な
る補助トレッドより成ると共に、多数の主溝とこれらの
主溝によって区分された陸部のネガティブ率が左右領域
で異なり、且つネガティブ率の小さい主トレッド領域に
連なる補助トレッドの輪郭の曲率半径がより大きい本発
明のラジアルタイヤは、優れた操縦安定性を発揮するの
である。As described above, the tread portion is composed of the cylindrical main tread and the auxiliary treads which are rounded from both ends thereof and extend inward in the radial direction, and a large number of main grooves and the negative of the land portion divided by these main grooves. The radial tire of the present invention, in which the ratio is different in the left and right regions and the radius of curvature of the contour of the auxiliary tread connected to the main tread region having a small negative ratio is larger, exhibits excellent steering stability.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明における実施例のタイヤの断面輪郭図。FIG. 1 is a cross-sectional outline view of a tire according to an embodiment of the present invention.

【図２】本発明における実施例のタイヤのトレッド平面
展開図。FIG. 2 is a development plan view of a tread of a tire according to an embodiment of the present invention.

【符号の説明】[Explanation of symbols]

1 タイヤ 2 トレッド 3 主トレッド 3L 主トレッドのネガティブ率が大きい領域 3S 主トレッドのネガティブ率が小さい領域 4 補助トレッド 5 主溝 6 陸部 rL 補助トレッドの曲率半径 rS 補助トレッドの曲率半径1 Tire 2 Tread 3 Main tread 3 L Area where the main tread has a large negative ratio 3 S Area where the main tread has a small negative ratio 4 Auxiliary tread 5 Main groove 6 Land area r L Curvature of auxiliary tread r S Curvature of auxiliary tread

───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) B60C 11/00 - 11/24 ─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. 7 , DB name) B60C 11/00-11/24

Claims (3)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 トロイド状ラジアルカ−カスのクラウン
部外周上に非伸長性ベルト層およびトレッド部を順次備
え、上記トレッド部が直進時に接地する円筒状の主トレ
ッドとその両端から丸みをもって径方向内側へ夫々連な
る補助トレッドより成ると共に多数の主溝を有し、少な
くとも上記主トレッドは、全体面積に対する溝部分の面
積の比率によって定義されるネガティブ率が左右領域で
異なる空気入りラジアルタイヤにおいて、上記トレッド部は、主トレッドの曲率半径が左右同一で
あり、 上記補助トレッドの丸みをもつ輪郭の曲率半径が
左右異なると共にネガティブ率の小さい主トレッド領域
に連なる側がより大きいことを特徴とする空気入りラジ
アルタイヤ。1. A cylindrical main training track in which a non-extensible belt layer and a tread portion are sequentially provided on the outer circumference of a crown portion of a toroidal radial arcuate, and the tread portion is in contact with a ground when traveling straight.
It has a plurality of main grooves that are composed of a pad and auxiliary treads that are rounded from both ends inward in a radial direction and have a large number of main grooves.At least the main tread has a negative ratio defined by the ratio of the area of the groove portion to the entire area. In pneumatic radial tires that differ in area , the main tread has the same radius of curvature on the left and right sides of the tread portion.
There, the radius of curvature of the contour with rounded of the auxiliary tread
A pneumatic radial tire that is different on the left and right and has a larger side connected to the main tread area with a low negative ratio. 【請求項２】 上記補助トレッドの曲率半径は、ネガテ
ィブ率の大きい主トレッド領域に連なる側に対しネガテ
ィブ率の小さい主トレッド領域に連なる側が１１０〜１
５０% の範囲にあることを特徴とする請求項１記載の空
気入りラジアルタイヤ。2. The radius of curvature of the auxiliary tread is 110 to 1 on the side connected to the main tread area having a low negative ratio, compared to the side connected to the main tread area having a large negative ratio.
The pneumatic radial tire according to claim 1, which is in a range of 50%. 【請求項３】 上記主溝は、主トレッドの中央部側から
八の字状にタイヤの赤道面に対し傾斜して主トレッド端
側へ延び、主トレッド端側で幅を絞り軸方向に向きを変
えて補助トレッドへと続き、これら周方向に隣接する一
対の主溝によって区分された陸部は、少なくともネガテ
ィブ率が小さい領域においては主トレッドから補助トレ
ッドにかけて連続して延びることを特徴とする請求項１
乃至２記載の空気入りラジアルタイヤ。3. The main groove is inclined from the center side of the main tread in an eight shape with respect to the equatorial plane of the tire, and the main tread end is formed.
Extending to the side, it continues to assist the tread by changing the orientation of the width in the main tread edge side to the aperture axis, adjacent thereto one circumferential
The land area separated by the pair of main grooves should be at least negative.
In areas where the drive ratio is small, the
2. A continuous extension to the pad.
2. A pneumatic radial tire as described in 1 to 2.
JP31092194A 1994-12-14 1994-12-14 Pneumatic radial tire Expired - Fee Related JP3467097B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP31092194A JP3467097B2 (en) 1994-12-14 1994-12-14 Pneumatic radial tire

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP31092194A JP3467097B2 (en) 1994-12-14 1994-12-14 Pneumatic radial tire

Publications (2)

Publication Number Publication Date
JPH08164715A JPH08164715A (en) 1996-06-25
JP3467097B2 true JP3467097B2 (en) 2003-11-17

Family

ID=18010996

Family Applications (1)

Application Number Title Priority Date Filing Date
JP31092194A Expired - Fee Related JP3467097B2 (en) 1994-12-14 1994-12-14 Pneumatic radial tire

Country Status (1)

Country Link
JP (1) JP3467097B2 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2342612T3 (en) * 2004-07-21 2010-07-09 Bridgestone Corporation TIRE.
WO2006030619A1 (en) * 2004-09-13 2006-03-23 Bridgestone Corporation Pneumatic tire
JP4329912B1 (en) * 2009-03-16 2009-09-09 横浜ゴム株式会社 Pneumatic tire

Also Published As

Publication number Publication date
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