JPH0558110A - Pneumatic radial tire - Google Patents

Pneumatic radial tire

Info

Publication number
JPH0558110A
JPH0558110A JP3242389A JP24238991A JPH0558110A JP H0558110 A JPH0558110 A JP H0558110A JP 3242389 A JP3242389 A JP 3242389A JP 24238991 A JP24238991 A JP 24238991A JP H0558110 A JPH0558110 A JP H0558110A
Authority
JP
Japan
Prior art keywords
tire
outer diameter
rde
carcass
bead
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.)
Pending
Application number
JP3242389A
Other languages
Japanese (ja)
Inventor
Tadashi Yamazaki
忠史 山崎
Toshio Ushikubo
寿夫 牛窪
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 JP3242389A priority Critical patent/JPH0558110A/en
Publication of JPH0558110A publication Critical patent/JPH0558110A/en
Pending 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
    • B60C11/01—Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered
    • B60C2011/013—Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered provided with a recessed portion

Landscapes

  • Tires In General (AREA)

Abstract

PURPOSE:To provide the high speed durability and enhance the stability in maneuvering by furnishing a ring-shaped dint between a part near the shoulder of a tire and another part near the bead, and arranging so that the enlargement ratio of the tire outside dia. at the time of filling with internal pressure at the tire equator surface to that at the installation end lies within a specific range. CONSTITUTION:A ring-shaped dint 32 stretching circumferentially is provided at the outer surface of a tire 10 installed on a rim 12 between a part near the tire shoulder and another part near the bead 16. The dia. enlargement ratio of the tire RDE=(DS2-D-S1)/(DC2-DC1) shall be so conditioned as 0.1<RDE<4.0, where DC1 is outside dia. on the tire equator surface X-X when the internal pressure is 0.3kg/cm<2>, DS1 is outside dia. of a part corresponding to the position which becomes the grounding end at the time of service internal pressure and service load, DC2 is the outside dia. on the tire equator line X-X resined with the service pressure, and DS2 is the outside dia. at the grounding end at the time of service load. Thus an excellent high speed durability can be given, and the stability in maneuvering be enhanced.

Description

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

【０００１】[0001]

【産業上の利用分野】この発明は空気入りラジアルタイ
ヤに関し、とくには、すぐれた高速耐久性をもたらして
なお、操縦安定性を有利に向上させるものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic radial tire and, more particularly, to a pneumatic radial tire which provides excellent high-speed durability and advantageously improves steering stability.

【０００２】[0002]

【従来の技術】ラジアル配列のコードプライからなるカ
ーカスと、このカーカスのクラウン部の外周側に配設し
た複数枚のコード配列層からなるベルトとを具える空気
入りラジアルタイヤは、そのベルトのいわゆる「たが」
効果により、バイアスタイヤに比して、タイヤの踏面部
を構成するトレッドゴムの動きが少なく、耐久性、耐摩
耗性および操縦安定性にすぐれ、転がり抵抗が少ないな
どの多くの利点を有することから、近年の高速道路網の
拡充発展の下で、極めて多くの車両に装着されるに至っ
ている。2. Description of the Related Art A pneumatic radial tire having a carcass composed of radial-arranged cord plies and a belt composed of a plurality of cord-arranged layers arranged on the outer peripheral side of the crown portion of the carcass is called a so-called belt. "Taga"
Due to the effect, compared to the bias tire, the tread rubber that constitutes the tread portion of the tire has less movement, has excellent durability, wear resistance and steering stability, and has many advantages such as low rolling resistance. With the recent expansion and development of the expressway network, it has come to be installed in an extremely large number of vehicles.

【０００３】一方において、空気入りラジアルタイヤも
また、近年の車両性能の向上に伴う高速走行に対応すべ
く、トレッド部およびビード部に補強を加えられている
も、最近の車両の一層の高性能化により、タイヤの高速
耐久性とともに、操縦安定性の向上が従来にも増して強
く求められている。そこで、カーカスやベルトを構成す
るコードの打込み数、打込角度などを変更すること、新
たな補強部材を追加することなどによって、故障が生じ
易い箇所の歪や発熱を抑制したり、タイヤケースの剛性
を高めたりする技術が提案されている。On the other hand, pneumatic radial tires have also been reinforced in the tread portion and the bead portion in order to cope with high-speed running accompanying the recent improvement in vehicle performance, but the performance of recent vehicles has been further improved. As a result, the high-speed durability of tires and the improvement of steering stability are strongly demanded more than ever before. Therefore, by changing the number of driving cords that make up the carcass or belt, changing the driving angle, or adding a new reinforcing member, it is possible to suppress distortion or heat generation at locations where failures easily occur, or to Techniques for increasing rigidity have been proposed.

【０００４】[0004]

【発明が解決しようとする課題】ところが、かかる提案
技術にあっては、タイヤケース全体としての剛性が増大
したり、必要以上に剛性が高められる部分が生じたりす
ることとなって、タイヤの運動性能および乗心地性能の
上で好ましくないのみならず、補強部材の増加に伴うタ
イヤのコストの上昇、重量の増加などを生じる不都合が
あった。これがため、この発明は、かかる問題を考慮
し、既知のタイヤに適用しても、それの高速耐久性を損
ねないことはもちろん、操縦安定性を有効に向上させる
ことができる新規な空気入りラジアルタイヤを提供す
る。However, in such a proposed technique, the rigidity of the tire case as a whole is increased, or a portion in which the rigidity is increased more than necessary is generated, which results in the movement of the tire. Not only is it unfavorable in terms of performance and ride comfort, but there is also the inconvenience of increasing the cost of the tire and increasing the weight of the tire as the number of reinforcing members increases. For this reason, the present invention, in consideration of such a problem, does not impair the high-speed durability of the known tire even when applied to the known tire, and it is a novel pneumatic radial that can effectively improve the steering stability. Provide tires.

【０００５】[0005]

【課題を解決するための手段】この発明の空気入りラジ
アルタイヤは、一対のビード部に跨がってトロイド状を
なす、ラジアル配列のコードプライからなるカーカス
の、少なくとも一のコードプライの側端部分を、ビード
コアの周りでタイヤ内側から外側に向けてそれぞれ巻上
げ、また、複数枚のコード配列層からなるベルトを、カ
ーカスのクラウン部で、そのカーカスとトレッドとの間
に配設したところにおいて、ショルダー部付近とビード
部付近との間で、タイヤ外表面に、タイヤ周方向に連続
してのびる少なくとも一条の窪み部を設け、さらに、使
用リムに装着したタイヤに 0.3 Kg/cm2 の内圧を充填し
たタイヤ姿勢の下での、タイヤ赤道面上の外径を DC1と
するとともに、そのタイヤの、使用内圧を充填して使用
荷重を負荷した時における接地端位置に相当する部分で
の外径を DS1とする一方、前記タイヤに使用内圧を充填
したタイヤ姿勢の下で、タイヤ赤道面上の外径を DC2と
するとともに、そのタイヤの、使用荷重の負荷時におけ
る接地端位置での外径を DS2としたときに、タイヤ赤道
面位置と前記接地端位置とにおける、内圧充填に基づく
タイヤ外径の拡径比 (RDE) ＲＤＥ＝(DS2−DS1)／(DC2−DC1) を、 1.0 ＜ＲＤＥ＜ 4.0 としたものである。DISCLOSURE OF THE INVENTION A pneumatic radial tire of the present invention is a side end of at least one cord ply of a carcass consisting of cord plies in a toroidal shape and straddling a pair of beads. The portion is wound around the bead core from the inside of the tire toward the outside, and a belt composed of a plurality of cord arrangement layers is arranged at the crown portion of the carcass between the carcass and the tread, Between the shoulder part and the bead part, at least one recess that extends continuously in the tire circumferential direction is provided on the outer surface of the tire.In addition, an internal pressure of 0.3 Kg / cm 2 is applied to the tire mounted on the rim used. The outer diameter on the equatorial plane of the tire under the filled tire posture is set to DC1, and when the working load is applied by filling the working inner pressure of the tire. The outer diameter at the part corresponding to the ground contact end position is DS1, while the outer diameter on the tire equatorial plane is DC2 and the working load of the tire under the tire posture in which the tire is filled with the inner working pressure. When the outer diameter at the ground contact end position under load is DS2, the tire outer diameter expansion ratio (RDE) RDE = (DS2-DS1 at the tire equatorial plane position and the ground contact end position based on inner pressure filling ) / (DC2-DC1) where 1.0 <RDE <4.0.

【０００６】以下にこのことを図１に示すところに基づ
いて具体的に説明する。図１は、この発明に従うタイヤ
の半径方向断面を示す図であり、タイヤ10が使用リム12
に組付けられ、そこへ 0.3 Kg/cm2 の内圧を充填した状
態を示す。ここではカーカス14を、タイヤの軸線方向に
離隔して位置する一対のビード部16に跨がってトロイド
状をなすラジアル配列のコードプライにより構成する。
なお、図示例では、カーカス14を、一枚のコードプライ
にて構成し、そのコードプライの各側端部分を、ビード
部16に設けたビードコア18の周りで、タイヤの内側から
外側に巻き上げたターンアップ構造としているが、タイ
ヤの仕様に応じて、そのカーカス14を複数枚のコードプ
ライによって構成することもでき、この場合には、少な
くとも一枚のコードプライを、ビードコア18の周りに、
上述したと同様に巻き上げる。This will be specifically described below with reference to FIG. FIG. 1 is a view showing a radial cross section of a tire according to the present invention, in which a tire 10 uses a rim 12
It is assembled into the unit and is filled with an internal pressure of 0.3 Kg / cm 2 . Here, the carcass 14 is constituted by a cord ply of a toroidal radial arrangement that straddles a pair of bead portions 16 that are spaced apart from each other in the tire axial direction.
In the illustrated example, the carcass 14 is composed of one cord ply, and each side end portion of the cord ply is wound around the bead core 18 provided in the bead portion 16 from the inside of the tire to the outside. Although it has a turn-up structure, depending on the tire specifications, the carcass 14 can be composed of a plurality of cord plies.In this case, at least one cord ply is provided around the bead core 18.
Roll up as described above.

【０００７】そして、カーカス14の本体部分とそのター
ンアップ部分との間には、ビードフィラー20および補強
層22をそれぞれ配設し、これらによって、タイヤのビー
ド部16からサイドウォール部を補強する。ところで、補
強層22の枚数および配設位置は、実施例に限定されるこ
となく、所要に応じて適宜に選択することができる。A bead filler 20 and a reinforcing layer 22 are respectively provided between the main body portion of the carcass 14 and its turn-up portion to reinforce the bead portion 16 of the tire to the sidewall portion. By the way, the number of the reinforcing layers 22 and the arrangement positions thereof are not limited to those in the embodiment, and can be appropriately selected as required.

【０００８】また、タイヤ踏面を形成するトレッド部24
で、カーカス14のクラウン部の外周側には、複数枚のコ
ード配列層からなるベルト26を配設し、このベルト26
の、タイヤ幅方向端部分の周りを、既知の高速走行用ラ
ジアルタイヤと同様に、補強層28によって補強する。The tread portion 24 forming the tread surface of the tire
On the outer peripheral side of the crown portion of the carcass 14, a belt 26 composed of a plurality of cord arrangement layers is arranged.
The periphery of the tire width direction end portion is reinforced by the reinforcing layer 28 in the same manner as the known high speed traveling radial tire.

【０００９】ここで、この発明によれば、トレッド部24
に隣接して位置するショルダー部の付近と、ビード部付
近との間で、タイヤ外表面に、タイヤの内面側へ窪ん
で、そのタイヤの周方向に環状に連続してのびる少なく
とも一本の窪み部32を設ける。なお、各窪み部32は、タ
イヤを使用リムに装着して使用内圧を充填した状態の下
で、好ましくは、タイヤの沿面長さＬに対し、４〜25％
の長さの沿面長さＰを有する。Here, according to the present invention, the tread portion 24
Between the vicinity of the shoulder portion located adjacent to, and the vicinity of the bead portion, on the tire outer surface, recessed toward the inner surface side of the tire, at least one recess that continuously extends annularly in the circumferential direction of the tire. A section 32 is provided. It should be noted that each recess 32 is preferably 4 to 25% with respect to the creeping length L of the tire under the condition that the tire is mounted on the rim for use and filled with the internal pressure for use.
Has a creeping length P of

【００１０】ここにおいて、タイヤの沿面長さＬとは、
タイヤの半径方向断面内で、タイヤ赤道面からビードベ
ースに至るタイヤ外輪郭線に沿って測った曲線長さであ
り、トレッド部24に溝が設けられている場合には、溝を
隔てて相互に隣接する陸部の表面を結ぶ線分を通る長さ
である。また、窪み部32の沿面長さＰとは、図２に模式
的に示すように、窪み部32を挟んでタイヤの半径方向の
内外に隣接するそれぞれの部分において、それらの両部
分にともに外接する一本の直線を引いたときの、その直
線との一方の接点から他方の接点までの間の、タイヤ外
輪郭線に沿って測った曲線長さである。Here, the creepage length L of the tire is
Within the radial cross section of the tire, it is the curve length measured along the tire outer contour line from the tire equatorial plane to the bead base, and when the tread portion 24 is provided with grooves, the grooves are separated from each other. Is the length passing through the line segment that connects the surface of the land adjacent to. In addition, the creeping length P of the recessed portion 32 is, as schematically shown in FIG. 2, in the respective portions adjacent to the inside and outside in the radial direction of the tire with the recessed portion 32 sandwiched, both of these portions being circumscribed. Is a curve length measured along the tire outer contour line between one contact point and the other contact point of the straight line when the straight line is drawn.

【００１１】そしてまたここでは、使用リムに装着した
タイヤの、図１に示す状態、すなわち、タイヤに 0.3 K
g/cm2 の内圧を充填した状態の下での、タイヤ赤道面上
の外径を DC1とし、そのタイヤの、使用内圧を充填して
使用荷重を負荷した時に接地端となる位置と対応する部
分の外径を DS1とする一方、タイヤに使用内圧を充填し
て、その外径を図３に実線で示す略線図のように膨脹さ
せた場合におけるタイヤ赤道面上での外径を DC2とし、
そのタイヤの、使用荷重の負荷時における接地端位置で
の外径を DS2としたときに、タイヤ赤道面位置と前記接
地端位置とにおける、内圧充填に基づくタイヤ外径の拡
径比 (RDE) ＲＤＥ＝(DS2−DS1)／(DC2−DC1) を、 1.0 ＜ＲＤＥ＜ 4.0 とする。すなわち、図３に示すところでは、 1.0 ×ΔＬ＜ΔＳ＜ 4.0×ΔＬ とする。Further, here, the condition of the tire mounted on the rim used is as shown in FIG. 1, that is, 0.3 K is applied to the tire.
The outer diameter on the equatorial plane of the tire is DC1 under the condition that the inner pressure of g / cm 2 is filled, and it corresponds to the position of the ground contact end when the working inner pressure is filled and the working load is applied. The outer diameter on the tire equatorial plane is DC2 when the outer diameter of the part is set to DS1 and the tire is filled with the working inner pressure and the outer diameter is inflated as shown by the solid line in Fig. 3. age,
When the outer diameter of the tire at the ground contact end position under load is DS2, the tire outer diameter expansion ratio (RDE) based on internal pressure filling at the tire equatorial plane position and the ground contact end position. RDE = (DS2-DS1) / (DC2-DC1) is 1.0 <RDE <4.0. That is, in the place shown in FIG. 3, 1.0 × ΔL <ΔS <4.0 × ΔL.

【００１２】[0012]

【作用】このような空気入りラジアルタイヤでは、そこ
への充填内圧の増加に伴って、タイヤの外輪郭線が、図
４に示すように、窪み部32を含む部分でタイヤの外側方
向へとくに大きく膨出し、カーカス14は、窪み部32か
ら、それの半径方向の内外に隣接するそれぞれの部分、
たとえば、タイヤ最大幅部分Ｗおよびショルダー部分Ｓ
にかけて、大きな張力を負担することになるため、タイ
ヤ最大幅位置近傍部分でのタイヤ剛性およびベルト端部
分でのタイヤ剛性がともに有利に増加され、併せて、ベ
ルト端部分でのトレッドゴムの動きも有効に抑制される
ことになり、この結果として、タイヤの高速耐久性を十
分に維持してなお、操縦安定性の大きな向上が実現され
ることになる。In such a pneumatic radial tire, as the internal pressure for filling the pneumatic radial tire increases, the outer contour line of the tire, as shown in FIG. Large bulge, the carcass 14 from the recess 32, the respective portions adjacent inward and outward in the radial direction thereof,
For example, the tire maximum width portion W and the shoulder portion S
Since a large amount of tension is applied to the tire, both the tire rigidity in the vicinity of the tire maximum width position and the tire rigidity in the belt end portion are advantageously increased, and the movement of the tread rubber at the belt end portion is also increased. This effectively suppresses the tire, and as a result, the high-speed durability of the tire is sufficiently maintained and the steering stability is greatly improved.

【００１３】ところで、窪み部32を、タイヤのショルダ
ー部付近と、ビード部付近との間に形成するのは、その
窪み部32を、ショルダー部付近を越えてトレッド部内に
位置させた場合には、窪み部32と対応するカーカス部分
の、タイヤの外側方向への膨出に起因するゴム歪みが大
きくなって、ベルトのセパレーションが発生し易く、ま
た、窪み部32を、ビード部内のビードコア18に近づけす
ぎた場合には、窪み部32が、リムフランジに近づきすぎ
もしくは接触して固定されてしまい、タイヤに内圧を充
填しても、タイヤ外側方向への所望する程の膨出をもた
らすことができず、その窪み部32がそれ本来の機能を発
揮し得ないことによる。なお、窪み部32による実質的な
効果を考慮するならば、それの配設位置をショルダー部
付近とタイヤ最大幅位置付近との間とすることが好まし
い。By the way, the recessed portion 32 is formed between the vicinity of the shoulder portion of the tire and the vicinity of the bead portion when the recessed portion 32 is located in the tread portion beyond the vicinity of the shoulder portion. The carcass portion corresponding to the recess 32 has a large rubber strain due to the outward bulging of the tire, and belt separation is likely to occur, and the recess 32 is formed in the bead core 18 in the bead portion. If too close, the recess 32 is too close to or in contact with the rim flange and is fixed, and even if the tire is filled with internal pressure, it may bring about a desired bulge in the tire outer direction. This is because the depression 32 cannot perform its original function. In consideration of the substantial effect of the recessed portion 32, it is preferable to dispose the recessed portion 32 between the vicinity of the shoulder portion and the vicinity of the maximum tire width position.

【００１４】従って、ここでいう窪み部32は、サイドウ
ォールのトレッド側部分でタイヤ外表面をわずかに窪ま
せた、いわゆるデコレーション窪みとは明らかに相違す
るものである。Therefore, the recessed portion 32 here is clearly different from the so-called decoration recessed portion in which the tire outer surface is slightly recessed in the tread side portion of the sidewall.

【００１５】しかも、このタイヤでは、そこへの内圧の
充填による、タイヤ外径の拡径比(RDE) を、 1.0＜ＲＤＥ＜ 4.0 の範囲に特定することにより、図３に示すところから明
らかなように、トレッド接地端位置での膨経量をタイヤ
赤道面上のそれより多くして、トレッド接地端位置、い
いかえればベルト端部分の剛性を適度に高めることがで
き、これがため、ベルト端部分に過度の初期歪みをもた
らすことなしに、負荷転動および脱負荷転動の繰り返し
による変位振幅を十分に抑制して、ベルト端セパレーシ
ョンの発生を有効に防止することができる。また、ベル
ト端部分の剛性の増加は、併せて、接地性の向上ももた
らし、コーナリング性能、耐摩耗性能の改善にも寄与す
ることになる。かくして、このタイヤによれば、高速耐
久性能を損ねることなく、操縦安定性を向上させること
が可能となる。Moreover, in this tire, the expansion ratio (RDE) of the outer diameter of the tire due to the filling of the inner pressure into the tire is specified in the range of 1.0 <RDE <4.0. As described above, the amount of swelling at the tread ground contact end position can be made larger than that on the tire equatorial plane, and the rigidity of the tread ground contact end position, in other words, the belt end part can be appropriately increased. It is possible to sufficiently suppress the displacement amplitude due to repeated load rolling and unloading rolling without causing excessive initial strain to the belt, and effectively prevent the occurrence of belt end separation. In addition, the increase in the rigidity of the belt end portion also improves the ground contact property, and contributes to the improvement of the cornering performance and the wear resistance performance. Thus, according to this tire, steering stability can be improved without impairing high-speed durability.

【００１６】なお、ここで、タイヤ外径の拡径比 (RDE)
を 0.1未満としたときには、負荷転動時の変位振幅が大
きくなりすぎ、また、その拡径比 (RDE)を 4.0を越える
値とすると、上記変位振幅は抑制されるものの、ベルト
端部分の初期歪みが大きくなりすぎ、これらのいずれも
ベルト端セパレーションの原因となって、タイヤの高速
耐久性の低下を余儀なくする。Here, the expansion ratio of the tire outer diameter (RDE)
Is less than 0.1, the displacement amplitude during load rolling becomes too large, and if the expansion ratio (RDE) exceeds 4.0, the above displacement amplitude is suppressed, but the initial belt end The distortion becomes too great, and all of these causes belt end separation, which inevitably reduces the high-speed durability of the tire.

【００１７】またこのタイヤにおいて、窪み部32のタイ
ヤの外側方向への膨出、ひいては、その窪み部32と対応
するカーカス部分の、タイヤの外側方向への膨出をもた
らして、その窪み部32の半径方向の内外に隣接するタイ
ヤ部分の剛性を高めるに当り、その剛性増加をより効果
的なものとするためには、ゴム部材よりも弾性率のはる
かに大きいカーカスのカーカスラインを、図５に示すい
ずれかの態様にて延在させる得る窪み部形状および寸法
を選択することが好ましい。Further, in this tire, the hollow 32 bulges outwardly of the tire, and by extension, the carcass portion corresponding to the hollow 32 bulges outwardly of the tire, resulting in the hollow 32. In order to increase the rigidity of the tire portion adjacent to the inside and outside in the radial direction of the carcass, in order to make the rigidity increase more effective, a carcass line of a carcass having a far larger elastic modulus than that of the rubber member is used. It is preferable to select the shape and size of the recess that can be extended in any of the modes shown in FIG.

【００１８】ここで、図５(a) に示すカーカスライン
は、タイヤを使用リムに装着してその内圧を 0.3 Kg/cm
2 としたところにおいて、窪み部32と対応するカーカス
部分の曲率中心がタイヤの外側に位置する一方、その窪
み部32のタイヤ半径方向の内外に隣接する部分と対応す
るそれぞれのカーカス部分の曲率中心がともに、タイヤ
の内側に位置するものであり、図５(b) に示すカーカス
ラインは、上述したと同一の条件の下において、窪み部
32と対応するカーカス部分が直線状をなし、そして、そ
の窪み部32の、半径方向の内外に隣接する部分と対応す
るそれぞれのカーカス部分の曲率中心がともにタイヤの
内側に位置するものであり、図５(c)に示すカーカスラ
インは、上述したそれぞれのカーカス部分の全ての曲率
中心をタイヤの内側に位置させたところにおいて、窪み
部32と対応するカーカス部分の曲率半径を、他のいずれ
のカーカス部分の曲率半径に対しても100倍を越える値
としたものである。In the carcass line shown in FIG. 5 (a), the tire is mounted on the rim and the internal pressure is 0.3 Kg / cm.
2 , the center of curvature of the carcass portion corresponding to the depression 32 is located outside the tire, while the center of curvature of each carcass portion corresponding to the portion adjacent to the inside and outside of the depression 32 in the tire radial direction. Both are located inside the tire, and the carcass line shown in FIG. 5 (b) has a recessed portion under the same conditions as described above.
The carcass portion corresponding to 32 is linear, and, of the recess 32, the center of curvature of each carcass portion corresponding to the portion adjacent to the inside and outside in the radial direction is located inside the tire together, In the carcass line shown in FIG. 5 (c), when all the centers of curvature of the above-mentioned carcass parts are located inside the tire, the curvature radius of the carcass part corresponding to the recess 32 is The value is more than 100 times the radius of curvature of the carcass.

【００１９】[0019]

【実施例】以下にこの発明の実施例を図面に基づいて説
明する。図１は、この発明に従って製造した、サイズが
255/40 ZR 17 のタイヤの半径方向断面図である。な
お、図に示すところではカーカス14を、ラジアル配列の
コードプライの一枚にて形成することとしているが、実
際には、タイヤ赤道面に対してほぼ 80 °の角度をなし
て相互に斜交する、太さが 1260 d/2 の66ナイロンコー
ドよりなるラジアル配列のコードプライの二枚にてその
カーカス14を形成し、タイヤの内側に位置するコードプ
ライの端部分を、ビードコアの周りでタイヤ内側から外
側に巻き上げ、タイヤ外側に位置するプライの端部分
を、タイヤ外側から内側に向けて巻き上げた。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a size manufactured according to the present invention.
FIG. 8 is a radial cross-sectional view of a 255/40 ZR 17 tire. The carcass 14 shown in the figure is formed of one cord ply in a radial arrangement.However, in reality, the carcass 14 is oblique to the tire equatorial plane at an angle of approximately 80 °. The carcass 14 is formed by two pieces of radial arrangement cord plies made of 66 nylon cord with a thickness of 1260 d / 2, and the end portion of the cord ply located inside the tire is surrounded by the tire around the bead core. The plies were wound from the inside to the outside, and the end portion of the ply located outside the tire was wound from the outside to the inside of the tire.

【００２０】タイヤの内側から外側に巻き上げた内側の
コードプライのターンアップ部分と、ビードコアの周り
に配置したビードフィラー20との間および、そのターン
アップ部分と、外側のコードプライとの間に補強層22を
それぞれ配設した。これらの各補強層22は、タイヤ周方
向線分に対してほぼ30 °の角度で延在させた、太さが1
500d/2 の芳香族ポリアミドコードにて形成し、ビード
ベースから測ったそれの最大高さを43 mm とした。Reinforcement between the turn-up portion of the inner cord ply rolled up from the inside of the tire to the bead filler 20 arranged around the bead core, and between the turn-up portion and the outer cord ply. Each layer 22 was disposed. Each of these reinforcing layers 22 extends at an angle of approximately 30 ° with respect to the tire circumferential line segment and has a thickness of 1
It was formed from a 500d / 2 aromatic polyamide cord and had a maximum height of 43 mm measured from the bead base.

【００２１】ベルト26は、太さが1500 d/2の芳香族ポリ
アミドコードをタイヤ赤道面に対してほぼ35°の角度で
延在させるとともに、相互に対称的に斜交させてなる二
枚のコード配列層で構成し、補強層28は、タイヤ周方向
に螺旋巻回した、太さが1260d/2の66ナイロンコード
で、ベルト26の側端部分を、その幅のほぼ30％の範囲に
わたって覆うことにより構成した。一方、タイヤ外表面
の窪み部32は、タイヤ10を使用リム（９×17) に組付け
て、それに使用内圧 (2.5 Kg/cm2) を充填した時に、窪
み底部32a がビードベースから、タイヤ断面高さ（Ｈ＝
102 mm) のほぼ68.6％ (h)となる位置に形成した。The belt 26 is made of two aromatic polyamide cords each having a thickness of 1500 d / 2 and extending at an angle of approximately 35 ° with respect to the tire equatorial plane and symmetrically crossing each other. The reinforcing layer 28 is made of 66 nylon cord having a thickness of 1260d / 2, which is spirally wound in the tire circumferential direction, and the side end portion of the belt 26 is spread over a range of approximately 30% of its width. It was constructed by covering. On the other hand, the recess 32 on the outer surface of the tire is such that when the tire 10 is mounted on the rim (9 × 17) used and is filled with the working internal pressure (2.5 Kg / cm 2 ), the bottom 32a of the recess is removed from the bead base. Section height (H =
It was formed at a position of approximately 68.6% (h) of 102 mm).

【００２２】そしてまたここでは、タイヤ外径の拡径比
(RDE)を 2.1とした。ちなみに、このように構成してな
る実施例タイヤと、タイヤ外径の拡径比 (RDE)をそれぞ
れ0.8 および 4.5としたそれぞれの比較タイヤＩおよび
IIと、タイヤ外表面に窪み部を設けず、拡径比 (RDE)を
0.7としたこと以外は実施例タイヤと同様の構成の従来
タイヤとのそれぞれにつき、操縦安定性および高速耐久
性に関する比較試験を行ったところ表１に示すような結
果が得られた。なお、操縦安定性は、実車走行時のフィ
ーリングをもって評価し、高速耐久性は、直径２m のド
ラムに、タイヤを 500 Kgfの力で押し付けて、ドラム周
速を時速150 km/hから10 km/h ずつ段階的に増速しつ
つ、各速度段を10分間維持した場合の故障発生速度を調
べ、その時の速度を高速耐久速度とする高速耐久ドラム
試験により評価した。And here, the expansion ratio of the tire outer diameter
(RDE) was set to 2.1. By the way, the example tires having such a configuration and the comparative tires I and I having the tire outer diameter expansion ratio (RDE) of 0.8 and 4.5, respectively.
II, the diameter expansion ratio (RDE)
A comparative test regarding steering stability and high-speed durability was performed on each of the conventional tires having the same configuration as the example tire except that the result was 0.7, and the results shown in Table 1 were obtained. The steering stability is evaluated by the feeling when driving in an actual vehicle, and the high speed durability is determined by pressing the tires against the drum with a diameter of 2 m with a force of 500 Kgf and the drum peripheral speed from 150 km / h to 10 km / h. The speed at which each speed step was maintained for 10 minutes was investigated while increasing the speed in steps of / h, and the speed at that time was evaluated as a high-speed endurance drum test with the speed as the high-speed endurance speed.

【００２３】[0023]

【表１】 [Table 1]

【００２４】表１によれば、実施例タイヤは、従来タイ
ヤに比して高速耐久性および操縦安定性のそれぞれを、
ともに有効に向上させ得ることが明白である。なお、比
較タイヤＩは拡径比 (RDE)が小さすぎるがため、また比
較タイヤIIは逆に、拡径比 (RDE)が大きすぎるがため、
高速耐久性および操縦安定性を、満足し得るほどには向
上させることができない。According to Table 1, the example tires have higher high-speed durability and steering stability than the conventional tires.
It is clear that both can be effectively improved. The comparative tire I had a too large expansion ratio (RDE), and the comparative tire II had a too large expansion ratio (RDE).
High speed durability and steering stability cannot be satisfactorily improved.

【００２５】[0025]

【発明の効果】以上に述べたところから明らかなよう
に、この発明によれば、とくには、タイヤのショルダー
部付近とビード部付近との間に、少なくとも一条の環状
窪み部を設けるとともに、タイヤ赤道面位置と接地端位
置とにおける、内圧充填に基づくタイヤ外径の拡径比
(RDE)を特定範囲内の値とすることにより、タイヤにす
ぐれた高速耐久性を付与することができるとともに、操
縦安定性を大きく向上させることができる。As is apparent from the above description, according to the present invention, in particular, at least one annular recess is provided between the shoulder portion and the bead portion of the tire, and the tire is Expansion ratio of tire outer diameter based on internal pressure filling at equatorial plane position and ground contact end position
By setting the (RDE) to a value within a specific range, excellent high-speed durability can be imparted to the tire, and steering stability can be greatly improved.

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

【図１】この発明の実施例を示すタイヤ半径方向の断面
図である。FIG. 1 is a sectional view in a tire radial direction showing an embodiment of the present invention.

【図２】窪み部の沿面長さの測定方法を示す模式図であ
る。FIG. 2 is a schematic diagram showing a method for measuring the creepage length of a recess.

【図３】タイヤ外径の変化の状態を示す略線図である。FIG. 3 is a schematic diagram showing a state where a tire outer diameter changes.

【図４】タイヤ外輪郭線の膨出状態を示す部分拡大図で
ある。FIG. 4 is a partially enlarged view showing a bulging state of a tire outer contour line.

【図５】カーカスラインの好適例を示す図である。FIG. 5 is a diagram showing a preferred example of a carcass line.

【符号の説明】[Explanation of symbols]

10 タイヤ 12 リム 14 カーカス 16 ビード部 18 ビードコア 24 トレッド部 26 ベルト 32 窪み部 32a 底部 Ｘ−Ｘ タイヤ赤道面 10 tire 12 rim 14 carcass 16 bead 18 bead core 24 tread 26 belt 32 dent 32a bottom XX tire equatorial plane

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 一対のビード部にまたがってトロイド状
をなすラジアル配列のコードプライからなるカーカス
の、少なくとも一のコードプライの側端部分をビードコ
アの周りでタイヤ内側から外側に向けてそれぞれ巻上
げ、複数枚のコード配列層からなるベルトを、前記カー
カスのクラウン部の外周側に配設したラジアルタイヤで
あって、 ショルダー部付近とビード部付近との間で、タイヤ外表
面に、タイヤ周方向に連続してのびる少なくとも一条の
窪み部を設け、 使用リムに装着したタイヤに 0.3kg/cm2の内圧を充填し
たタイヤ姿勢の下での、タイヤ赤道面上の外径を DC1と
するともに、そのタイヤの、使用内圧を充填して使用荷
重を負荷した時における接地端位置に相当する部分での
外径を DS1とする一方、前記タイヤに使用内圧を充填し
たタイヤ姿勢の下での、タイヤ赤道面上の外径を DC2と
するとともに、そのタイヤの、使用荷重の負荷時におけ
る接地端位置での外径を DS2としたときに、タイヤ赤道
面位置と前記接地端位置とにおける、内圧充填に基づく
タイヤ外径の拡径比 (RDE) ＲＤＥ＝(DS2−DS1)／(DC2−DC1) を、 1.0 ＜ＲＤＥ＜ 4.0 としてなる空気入りラジアルタイヤ。1. A carcass consisting of a cord ply of a toroidal radial arrangement straddling a pair of bead parts, at least one side end portion of the cord ply is wound around the bead core from the tire inner side to the outer side, A radial tire in which a belt composed of a plurality of cord arrangement layers is arranged on the outer peripheral side of the crown portion of the carcass, between the vicinity of the shoulder portion and the vicinity of the bead portion, on the tire outer surface, in the tire circumferential direction. continuous at least Article of recess portion is provided extending, under the tire posture filled in tires loaded on use rim internal pressure of 0.3 kg / cm 2, the outer diameter of the tire equatorial plane together with DC1, its The outer diameter of the portion of the tire corresponding to the ground contact end position when the working load is applied and the working load is applied is DS1, while the tire that is filled with the working pressure is used. When the outer diameter on the tire equatorial plane in the ear posture is set to DC2 and the outer diameter of the tire at the ground contact end position when the working load is applied is set to DS2, the tire equatorial plane position and the above A pneumatic radial tire in which the expansion ratio (RDE) RDE = (DS2-DS1) / (DC2-DC1) of the tire outer diameter based on the inner pressure filling at the ground contact end position is 1.0 <RDE <4.0.
JP3242389A 1991-08-29 1991-08-29 Pneumatic radial tire Pending JPH0558110A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3242389A JPH0558110A (en) 1991-08-29 1991-08-29 Pneumatic radial tire

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3242389A JPH0558110A (en) 1991-08-29 1991-08-29 Pneumatic radial tire

Publications (1)

Publication Number Publication Date
JPH0558110A true JPH0558110A (en) 1993-03-09

Family

ID=17088430

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3242389A Pending JPH0558110A (en) 1991-08-29 1991-08-29 Pneumatic radial tire

Country Status (1)

Country Link
JP (1) JPH0558110A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2703454A1 (en) 2012-08-29 2014-03-05 Pemco Brugge BVBA Coating compositions

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2703454A1 (en) 2012-08-29 2014-03-05 Pemco Brugge BVBA Coating compositions
WO2014033098A1 (en) 2012-08-29 2014-03-06 Pemco Brugge Bvba Coating compositions

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