JPH1120423A - Pneumatic radial tire for heavy load - Google Patents
Pneumatic radial tire for heavy loadInfo
- Publication number
- JPH1120423A JPH1120423A JP9171632A JP17163297A JPH1120423A JP H1120423 A JPH1120423 A JP H1120423A JP 9171632 A JP9171632 A JP 9171632A JP 17163297 A JP17163297 A JP 17163297A JP H1120423 A JPH1120423 A JP H1120423A
- Authority
- JP
- Japan
- Prior art keywords
- tire
- bead
- reinforcing layer
- layers
- bead 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、重荷重用空気入
りラジアルタイヤ、より詳細にはトラック及びバスなど
の重車両の使途に供する空気入りラジアルタイヤに関
し、特に、ビード部に余分な補強部材を追加配置するこ
となくビード部耐久性を顕著に向上させた重荷重用空気
入りタイヤに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic radial tire for heavy loads, and more particularly to a pneumatic radial tire for use in heavy vehicles such as trucks and buses, and in particular, an extra reinforcing member is added to a bead portion. The present invention relates to a heavy-duty pneumatic tire in which bead portion durability is significantly improved without being arranged.
【０００２】[0002]
【従来の技術】トラック及びバスなどの重車両に使用す
る空気入りラジアルタイヤの故障発生に関し、特に、カ
ーカスプライの折返し部端からのセパレーション乃至ビ
ード部補強コード層端からのセパレーションに代表され
るビード部故障の発生は、新品タイヤの完走を阻害する
ばかりでなく、再三にわたるリキャップ使用に支障をき
たす深刻な問題として、これまで種々の改善手段が提案
され、実行されている。BACKGROUND OF THE INVENTION The present invention relates to failure of a pneumatic radial tire used for heavy vehicles such as trucks and buses, and more particularly to bead represented by separation from an end of a folded portion of a carcass ply or separation from an end of a bead reinforcing cord layer. The occurrence of a part failure not only hinders the complete running of a new tire, but also as a serious problem that hinders repeated use of recapping, various improvement means have been proposed and implemented.
【０００３】これら改善手段の多くは、タイヤの負荷転
動中の接地域に連なるビード部のタイヤ外側への倒れ込
みを少しでも低減して、ビード部補強コード層端やカー
カス折返し部端に作用するひずみを低減することを狙い
として、ビード部補強コード層を多用したり、ビード部
全体のボリュームを増やすなど、タイヤ重量の増加とコ
スト上昇とを伴うものである。しかしこれらの手段は現
在の軽量化、コスト低減などの要請には到底対応し得な
い状況にある。[0003] Many of these improvement means act on the end of the bead reinforcing cord layer and the end of the carcass turn-back portion by reducing the fall of the bead portion connected to the contact area during the load rolling of the tire to the outside of the tire. In order to reduce the strain, the tire weight is increased and the cost is increased, for example, by using a large number of bead portion reinforcing cord layers or increasing the volume of the entire bead portion. However, these means cannot meet the current demands for weight reduction and cost reduction at all.
【０００４】そこで上記したようなタイヤ重量増加をそ
れほど伴わずにビード部耐久性を向上させる手段の一例
として、特開昭５９−２１６７０９号公報は、要部断面
を示す図１０を参照して、ビード部１の倒れ込み以外に
ビードコア３の「へたり」にも着目し、ビード部１の補
強層としての金属コード層をビードコアの内外にて分割
しそれぞれ独立の外側金属コード層（折返し４ｔ端末保
護層）１５ａと内側金属コード層（支持強化層）１５ｂ
とし、各層１５ａ、１５ｂの１％伸長モジュラスにつ
き、端末保護層１５ａのモジュラスを支持強化層１５ｂ
のモジュラスより小さく設定すること、各層のコードの
傾斜角度を、各層の上端縁を通る円周上にてタイヤの放
射面となす最大角度で４５〜７０°（タイヤ円周線に対
し２０〜４５°）の範囲内とすることを提案し、それま
で見られなかったビード部耐久性向上を達成している。Japanese Patent Laid-Open No. Sho 59-216709 discloses an example of a means for improving the durability of the bead portion without significantly increasing the weight of the tire as described above, with reference to FIG. In addition to the fall of the bead portion 1, attention is paid to the "sag" of the bead core 3, and the metal code layer as a reinforcing layer of the bead portion 1 is divided inside and outside the bead core, and each of the outer metal code layers is independent (turned 4t terminal protection). Layer) 15a and inner metal cord layer (support reinforcement layer) 15b
For each 1% elongation modulus of each of the layers 15a and 15b, the modulus of the terminal protection layer 15a is set to the supporting reinforcement layer 15b.
Is set to be smaller than the modulus of the tire, and the inclination angle of the cord of each layer is set to a maximum angle of 45 to 70 ° with respect to the radial surface of the tire on the circumference passing through the upper edge of each layer (20 to 45 ° with respect to the tire circumferential line). °), to achieve an improvement in bead durability that was not seen before.
【０００５】その理由は、ビード部補強層を折返し４ｔ
端末保護層１５ａと支持強化層１５ｂとに分割（層１５
ａ、１５ｂの分割端ｐ、ｑ）することにより、リムとの
接触部位における各層端末１５ａｅ、１５ｂｅの拘束が
１層の場合に比べて著しく緩やかになり、その結果、タ
イヤの負荷転動時のトレッド接地域の踏み込み部及び蹴
り出し部双方における顕著なタイヤ周方向剪断変形に対
し各層１５ａ、１５ｂが追随し易くなるため、各層のタ
イヤ半径方向外側端部に作用するひずみ集中が大幅に緩
和される効果によるものである。[0005] The reason is that the bead portion reinforcing layer is folded back 4t.
Divided into a terminal protection layer 15a and a support reinforcing layer 15b (layer 15
a, 15b, the restraint of each layer terminal 15ae, 15be at the contact portion with the rim becomes remarkably gentle as compared with the case of one layer, and as a result, the tire rolls during load rolling. Since each layer 15a, 15b easily follows remarkable shear deformation in the tire in both the stepping portion and the kicking portion in the tread contact area, the concentration of strain acting on the tire radially outer end of each layer is greatly reduced. This is due to the effect.
【０００６】[0006]
【発明が解決しようとする課題】しかし近年、重荷重用
空気入りラジアルタイヤ、なかでもトラック及びバス用
タイヤの偏平化傾向が一層進むにつれ、充てん空気圧も
高まり、ビード部への入力条件が厳しくなるにつれ、上
記公報のビード部補強層の両金属コード層１５ａ、１５
ｂはビードコア３の内外で分割されているため、上述の
ようにビードコアとリムのフランジ及びビードシートと
の間での金属コード層１５ａ、１５ｂに対する締め付け
力が殆ど期待できないため、タイヤの負荷転動時に接地
域に係わる両金属コード層１５ａ、１５ｂはビード部１
内で動き易くなる効果が却って下記するような不具合も
同時に発生する。However, in recent years, as the flattening tendency of pneumatic radial tires for heavy loads, especially truck and bus tires, has increased, the filling air pressure has increased and the input conditions to the bead section have become more severe. , The two metal cord layers 15a, 15 of the bead reinforcing layer of the above publication
Since b is divided inside and outside the bead core 3, almost no tightening force can be expected on the metal cord layers 15a and 15b between the bead core and the flange of the rim and the bead sheet as described above. Sometimes, both metal cord layers 15a and 15b related to the contact area are bead portions 1
On the contrary, the following effect occurs at the same time.
【０００７】タイヤへの高圧の充てん空気圧によりカー
カス４のプライには、図１０に矢印Ｔで示す大きな張力
が作用し、この張力Ｔはビードコア３から図の矢印の向
きにカーカ４のスプライを引き抜こうとする力に他なら
ず、この力Ｔと金属コード層１５ａ、１５ｂの動き易さ
とが相まって、特にビード部１がタイヤ外側へ向け倒れ
込む荷重負荷の下でカーカス４はビードコア４に対しそ
の断面図形の重心Ｃｇ周りの矢印ｒの向きに大きく回転
させる作用を及ぼす。この作用がタイヤ１回転毎にビー
ドコア３に及び、かつ車両走行中にビード部１が高温度
となるため、タイヤの走行距離が延びるほどにビードコ
ア３は塑性変形の一種ともいえる「へたり」変形を生
じ、その変形度合いが進む。[0007] A large tension indicated by an arrow T in FIG. 10 acts on the ply of the carcass 4 due to the high-pressure filling air pressure on the tire, and this tension T pulls out the splice of the carcass 4 from the bead core 3 in the direction of the arrow in the figure. This force T is combined with the easiness of movement of the metal cord layers 15a and 15b, so that the carcass 4 moves against the bead core 4 especially under a load load in which the bead portion 1 falls down to the outside of the tire. Has a function of largely rotating in the direction of arrow r around the center of gravity Cg. This effect is applied to the bead core 3 every one rotation of the tire, and since the bead portion 1 becomes high in temperature while the vehicle is running, the bead core 3 becomes a kind of plastic deformation as a kind of plastic deformation as the running distance of the tire increases. And the degree of deformation is advanced.
【０００８】ビードコア３の大きな「へたり」変形はビ
ード部１の断面形状を新品当初から大きく変え、このビ
ード部変形は、カーカス折返し部４ｔ外側に位置するビ
ード部補強金属コード層１５ａのタイヤ半径方向外側端
部に作用するひずみを予め最少とする配置意図から大き
く逸らす不利をもたらし、補強金属コード層１５ａの外
側端１５ａｅ近傍部に大きなひずみを集中させる結果、
この端部にセパレーションが発生し勝ちになる。[0008] A large "set" deformation of the bead core 3 greatly changes the cross-sectional shape of the bead portion 1 from the beginning of the new product, and this bead portion deformation is caused by the tire radius of the bead portion reinforcing metal cord layer 15a located outside the carcass folded portion 4t. As a result, the strain acting on the outer end in the direction is greatly deviated from the intention of the arrangement to be minimized in advance, and as a result, a large strain is concentrated in the vicinity of the outer end 15ae of the reinforcing metal cord layer 15a.
Separation occurs at this end, which is winning.
【０００９】またビード部補強層の両金属コード層１５
ａ、１５ｂの分割位置をビードコア３周辺から外してそ
こからタイヤ半径方向外側として試したところ、ビード
コアを構成するスチールワイヤの巻回数を減らしてより
一層の軽量化としたタイヤではやはりビードコアの「へ
たり」変形度合いが大きくなり、これが上記同様大きな
ビード部形状変化をもたらし、補強金属コード層の外側
端部にセパレーション故障を発生させ、所期のタイヤ寿
命を達成することができないことがわかった。Further, both metal cord layers 15 of the bead portion reinforcing layer are provided.
When the split positions of a and 15b were removed from the periphery of the bead core 3 and tested radially outward from the bead core 3, the number of windings of the steel wire constituting the bead core was reduced to further reduce the weight of the tire. It has been found that the degree of deformation increases, which results in a large change in the bead shape as described above, causing a separation failure at the outer end of the reinforcing metal cord layer and failing to achieve the expected tire life.
【００１０】従ってこの発明の請求項１〜１１に記載し
た発明は、先に掲げた公報の開示内容をさらに発展さ
せ、偏平率の値がいかに小さくとも、チューブ付きタイ
ヤ乃至チューブレスタイヤのいかんを問わず、ビードコ
アのスチールワイヤの巻回数を減じ、これを基礎とする
ビード部ゴム、主としてスティフナゴムの容積を減らし
ても、従来の重量級タイヤのビード部耐久性と同等以上
の耐久性を有する軽量な重荷重用空気入りラジアルタイ
ヤの提供を目的とする。[0010] Therefore, the inventions described in claims 1 to 11 of the present invention further develop the disclosure content of the above-mentioned gazettes, regardless of the value of the flatness ratio, regardless of the tire with a tube or the tubeless tire. Even if the number of turns of the bead core steel wire is reduced and the volume of the bead rubber based on this, mainly the stiffener rubber, is reduced, it has a durability equal to or higher than the bead durability of conventional heavy-duty tires It is intended to provide a pneumatic radial tire for heavy loads.
【００１１】[0011]
【課題を解決するための手段】上記目的を達成するた
め、この発明の請求項１に記載した発明は、一対のビー
ド部内にそれぞれ埋設したビードコア相互間にわたり延
びる１プライ以上のゴム被覆ラジアル配列コードになる
カーカスを備え、少なくとも１プライのカーカスはビー
ドコアの周りを巻上げる折返し部を有し、ビードコアを
挟むビード部内外両側領域でそれぞれ別個に独立させた
２層のゴム被覆スチールコード層よりなるビード部補強
層を備える重荷重用空気入りラジアルタイヤにおいて、
ビード部外側領域に位置するビード部補強層はそのタイ
ヤ半径方向外方端がカーカスの折返し部端を超えて延
び、ビード部補強層は２層のスチールコード層の対向す
る端縁相互がビードコア近傍にて隣り合う配置に成り、
上記ビードコアを挟む内外両側領域に位置する各独立ビ
ード部補強層の上記半径方向外方端部及び内方端部それ
ぞれにおける配列スチールコードのタイヤ円周線に対す
る傾斜角度につき、外方端部が１５〜３０°の範囲内に
あり、内方端部は内外両側領域ビード部補強層の少なく
とも一方の層が３５〜６０°の範囲内にあることを特徴
とする重荷重用空気入りラジアルタイヤである。In order to achieve the above object, the invention according to claim 1 of the present invention provides a rubber-coated radial array code having one or more plies extending between bead cores embedded in a pair of bead portions. A bead comprising two layers of rubber-coated steel cord layers having at least one ply of carcass at least one ply having a folded portion wound around a bead core, and separately provided on both inner and outer sides of the bead portion sandwiching the bead core. In a heavy-duty pneumatic radial tire with a partial reinforcing layer,
The bead reinforcing layer located in the bead outer region has a tire radially outer end extending beyond the turnover end of the carcass, and the opposing edges of the two steel cord layers are near the bead core. It becomes an adjacent arrangement at,
Regarding the inclination angle with respect to the tire circumferential line of the arrayed steel cords at each of the radially outer end and the inner end of each independent bead portion reinforcing layer located on both the inner and outer side regions sandwiching the bead core, the outer end is 15 The pneumatic radial tire for heavy loads, wherein at least one of the inner and outer side bead portion reinforcing layers has an inner end within a range of 35 to 60 °.
【００１２】ここに、上記のビードコア近傍の「近傍」
は、その語義に従い、距離空間で、一点Ｉからの距離が
或る値より小さい全ての点から成る部分集合を指し、こ
こでいう一点Ｉはビードコアの断面図形上に存在する全
ての点とし、さらに一点Ｉからの距離の或る値とは、ビ
ードコアの表面上の点から全方向に測った距離が０．５
〜２５ｍｍの範囲内にある値を指すものとする。また隣
り合う配置とは、端縁相互が接する場合以外に僅か離隔
する場合を含むものとする。これらは以下同じである。Here, the "near vicinity" near the above-mentioned bead core is described.
According to its meaning, refers to a subset of all points in the metric space that are less than a certain distance from one point I, where one point I is all points present on the cross-sectional figure of the bead core, Further, a certain value of the distance from one point I is a distance measured in all directions from a point on the surface of the bead core to 0.5.
It shall mean a value within the range of ２５25 mm. The adjacent arrangement includes a case where the edges are slightly separated from each other in addition to a case where the edges are in contact with each other. These are the same hereinafter.
【００１３】請求項１に記載した発明を実施するに際
し、好適実施例においては請求項２に記載した発明のよ
うに、上記ビード部補強層の２層の対向する端縁相互が
突き合わせ配置に成る。この実施例の場合、好適には請
求項３に記載した発明のように、ビード部補強層の２層
の端縁相互の突き合わせ位置が、ビードコア周辺に存在
するものとする。In practicing the invention as set forth in claim 1, in a preferred embodiment, as in the invention as set forth in claim 2, the opposing edges of the two layers of the bead portion reinforcing layer are abutted with each other. . In the case of this embodiment, preferably, the position where the two edges of the bead portion reinforcing layer abut against each other is present around the bead core.
【００１４】また他の好適実施例では、請求項４に記載
した発明のように、内外両側領域ビード部補強層のスチ
ールコードの配列が、タイヤ半径線に関して互いに同じ
傾斜方向に成る。In another preferred embodiment, the arrangement of the steel cords of the bead portion reinforcing layers on the inner and outer side regions is in the same inclination direction with respect to the tire radial line.
【００１５】また上記とは異なる好適実施例において
は、請求項５に記載した発明のように、内外両側領域ビ
ード部補強層のスチールコードの配列が、タイヤ半径線
に関して互いに異なる傾斜方向に成る。In a preferred embodiment different from the above, the arrangement of the steel cords of the bead portion reinforcing layer on both the inner and outer side regions has inclination directions different from each other with respect to the tire radial line.
【００１６】またさらに他の好適実施例においては、請
求項６に記載した発明のように、ＪＡＴＭＡ規格が定め
る、１５°深底リム又は広幅平底リムを適用リムとする
タイヤにおいて、ビード部補強層の２層の隣り合う端縁
相互位置が、ビードコアの断面図形の重心を通りタイヤ
回転軸に直交する直線と、リムのフランジに接触するビ
ード部表面のタイヤ半径方向最外方端からタイヤ内部に
面するカーカス本体に下ろした法線との間に存在する。
この種のタイヤはＪＡＴＭＡ規格（Ｉ９９７年版、以下
同じ）が定めるトラック及びバス用ラジアルプライタイ
ヤで、適用リムが１５°深底リムのタイヤはチューブレ
スタイヤであり、広幅平底リムのタイヤはチューブ付き
タイヤである。なお上記タイヤ半径方向最外方端とは、
上記タイヤをその適用リムに組付けたタイヤ及びリム組
立体に対し、上記規格が「空気圧−負荷能力対応表」に
て定めるタイヤの最大負荷能力に対応する最高空気圧を
充てんしたときの位置である。According to still another preferred embodiment, a bead portion reinforcing layer is provided for a tire having a 15 ° deep bottom rim or a wide flat bottom rim specified by the JATMA standard according to the invention as set forth in claim 6. The position of the adjacent edges of the two layers is a straight line that passes through the center of gravity of the cross-sectional view of the bead core and is perpendicular to the tire rotation axis, and the tire radially outermost end of the bead surface that contacts the rim flange. Between the facing carcass body and the lowered normal.
This type of tire is a radial ply tire for trucks and buses defined by the JATMA standard (I997 version, the same applies hereinafter). A tire with a 15 ° deep rim is a tubeless tire, and a tire with a wide flat bottom rim is a tube tire. It is. The outermost end in the tire radial direction is
This is the position where the above standard is filled with the maximum air pressure corresponding to the maximum load capacity of the tire specified in the "Air Pressure-Load Capacity Correspondence Table" for the tire and the rim assembly in which the tire is mounted on the applicable rim. .
【００１７】さらに先に述べた目的を達成するための別
の発明は、請求項７に記載した発明のように、一対のビ
ード部内にそれぞれ埋設したビードコア相互間にわたり
延びる１プライ以上のゴム被覆ラジアル配列コードにな
るカーカスを備え、少なくとも１プライのカーカスはビ
ードコアの周りを巻上げる折返し部を有し、ビード部に
て折返し部を含むカーカスを覆う、別個に独立させたゴ
ム被覆スチールコード層のビード部補強層を備える重荷
重用空気入りラジアルタイヤにおいて、上記ビード部補
強層は、タイヤ内部に面するカーカス本体側の内側領域
に配置した内側補強層と、これと対をなし折返し部側の
外側領域に配置した外側補強層と、内側補強層と外側補
強層との間にてビードコアの周りに配置した中間補強層
との３層のゴム被覆スチールコード層よりなり、折返し
部側の外側補強層はそのタイヤ半径方向外方端がカーカ
スの折返し部端を超えて延び、３層のゴム被覆スチール
コード層それぞれで互いに対向する端縁相互はビードコ
ア近傍にて隣り合う配置に成り、ビード部補強層におけ
る配列スチールコードのタイヤ円周線に対する傾斜角度
につき、２層の対をなす外側補強層及び内側補強層のコ
ード傾斜角度がタイヤ半径方向外方端部にて１５〜３０
°の範囲内にあり、かつタイヤ半径方向内方端部にて３
５〜６０°の範囲内にあり、中間補強層のコード配列は
上記２層の対をなす各層のタイヤ半径方向内方端部コー
ド傾斜角度より大きな傾斜角度に成ることを特徴とする
重荷重用空気入りラジアルタイヤである。Another aspect of the present invention to achieve the above-mentioned object is a rubber-coated radial bearing having at least one ply extending between bead cores embedded in a pair of bead portions. A bead of a separately independent rubber-coated steel cord layer comprising a carcass to be an array code, wherein at least one ply of the carcass has a fold that winds around the bead core and covers the carcass including the fold at the bead. In the pneumatic radial tire for heavy load provided with a part reinforcing layer, the bead part reinforcing layer is an inner reinforcing layer arranged in an inner area on the side of the carcass body facing the inside of the tire, and an outer area on the side of the folded part forming a pair with the inner reinforcing layer. Rubber layers, an outer reinforcing layer disposed on the inner side and an intermediate reinforcing layer disposed around the bead core between the inner and outer reinforcing layers. The outer reinforcing layer on the side of the folded portion has a radially outer end extending beyond the end of the folded portion of the carcass, and the edges facing each other in each of the three rubber-coated steel cord layers are bead cores. As for the inclination angle of the arrayed steel cords in the bead part reinforcement layer with respect to the tire circumferential line, the cord inclination angles of the outer reinforcement layer and the inner reinforcement layer forming a pair of the outer reinforcement layer and the outer reinforcement layer in the tire radial direction are adjacent to each other. 15-30 at the end
° and at the radially inner end of the tire
Characterized in that the cord arrangement of the intermediate reinforcing layer has an inclination angle larger than the inclination angle of the cord in the tire radial direction inner end portion of each of the paired layers in the range of 5 to 60 °. It is a radial tire containing.
【００１８】上記請求項７に記載した発明の好適実施例
においては請求項８に記載した発明のように、ビード部
補強層の３層のスチールコード層のうち少なくとも２層
のスチールコードの配列が、タイヤ半径線に関して互い
に同じ傾斜方向に成ることである。In a preferred embodiment of the invention described in claim 7, as in the invention described in claim 8, at least two of the three steel cord layers of the bead portion reinforcing layer have an arrangement of steel cords. , With respect to the tire radius line.
【００１９】また上に述べた発明の変形例では、請求項
９に記載した発明のように、ビード部補強層の少なくと
も１層におけるスチールコード配列が、２本以上のコー
ドを横並びに束ねた束コード配列に成るものである。In the above-mentioned modified example of the invention, the steel cord arrangement in at least one of the bead portion reinforcing layers is a bundle in which two or more cords are bundled side by side. The result is a code sequence.
【００２０】この発明の請求項１〜９に記載した発明全
体にわたり、好適には請求項１０に記載した発明のよう
に、ビード部補強層のうち少なくともビード部外側領域
に位置するスチールコード層の被覆ゴムが、カーカスプ
ライのコード被覆ゴムの１００％モジュラスより小さな
１００％モジュラスを有するのが望ましい。Throughout the invention described in claims 1 to 9 of the present invention, preferably, as in the invention described in claim 10, the steel cord layer located at least in the bead outside region of the bead reinforcement layer. Desirably, the coated rubber has a 100% modulus less than the 100% modulus of the carcass ply cord coated rubber.
【００２１】また上述した発明全般にわたり、負荷荷重
及び走行速度の少なくとも一方の使用条件が厳しい場合
の実施例では、請求項１１に記載した発明のように、ビ
ード部補強層の表層を覆い包む１層以上の有機繊維コー
ド層を有する構成が適合する。Further, in the embodiment in which at least one of the load load and the traveling speed is strictly used throughout the above-mentioned invention, as in the eleventh aspect of the present invention, the first layer covering the surface layer of the bead portion reinforcing layer is provided. A configuration having more than one organic fiber cord layer is suitable.
【００２２】[0022]
【発明の実施の形態】以下、この発明の実施の形態例を
図１〜図８に基づき説明する。図１及び図２は、この発
明による重荷重用空気入りラジアルタイヤ（以下タイヤ
という）のチューブレス（以下Ｔ／Ｌと略す）タイヤの
要部片側を簡略図解した線図的断面図であり、図３は、
この発明によるチューブ付き（以下Ｗ／Ｔと略す）タイ
ヤの要部片側を簡略図解した線図的断面図であり、図４
は、Ｔ／Ｌタイヤとその適用リムとの組立体に先に触れ
た最高空気圧充てん時の組立体要部片側を簡略図解した
線図的断面図であり、図５は、Ｗ／Ｔタイヤとその適用
リムとの組立体に先に触れた最高空気圧充てん時の組立
体要部片側を簡略図解した線図的断面図であり、図６
は、この発明による他の構成をもつＴ／Ｌタイヤの要部
片側を簡略図解した線図的断面図であり、図７は図６に
示す構成と同様な構成をもつＷ／Ｔタイヤの要部片側を
簡略図解した線図的断面図であり、図８は、この発明に
よるビード部補強層のスチールコード配列の変形例の効
果説明図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. FIGS. 1 and 2 are schematic cross-sectional views schematically illustrating one side of a main part of a tubeless (hereinafter abbreviated as T / L) tire of a pneumatic radial tire for heavy loads (hereinafter referred to as a tire) according to the present invention. Is
FIG. 4 is a schematic cross-sectional view schematically illustrating one side of a main part of a tire with a tube (hereinafter abbreviated as W / T) according to the present invention.
FIG. 5 is a schematic cross-sectional view schematically illustrating one side of a main part of the assembly at the time of maximum pneumatic filling, in which the assembly of the T / L tire and the rim to which the tire is applied is first described. FIG. 7 is a schematic cross-sectional view schematically illustrating one side of a main part of the assembly at the time of maximum pneumatic filling, which has already been touched on the assembly with the applicable rim.
FIG. 7 is a schematic cross-sectional view schematically illustrating one side of a main portion of a T / L tire having another configuration according to the present invention. FIG. 7 is a diagrammatic view of a W / T tire having a configuration similar to the configuration shown in FIG. FIG. 8 is a schematic sectional view schematically illustrating one side of the part, and FIG. 8 is an explanatory diagram of an effect of a modified example of the steel cord arrangement of the bead part reinforcing layer according to the present invention.
【００２３】図１〜図７において、符号１はビード部、
符号２はサイドウォール部の一部であり、サイドウォー
ル部のタイヤ半径方向（以下半径方向という）外方部分
とトレッド部との図示は省略した。ここにカーカス４
は、一対のビード部（片側のみ示す）内にそれぞれ埋設
したビードコア３相互間にわたり１プライ以上（図示例
は１プライ）のゴム被覆ラジアル配列コード、１プライ
の場合は望ましくはスチールコードになり、少なくとも
１プライはビードコア３の周りをタイヤ内側から外側に
向け巻上げる折返し部４ｔを有する。1 to 7, reference numeral 1 denotes a bead portion,
Reference numeral 2 denotes a part of the sidewall portion, and the illustration of the outer portion of the sidewall portion in the tire radial direction (hereinafter referred to as radial direction) and the tread portion is omitted. Carcass here 4
Is a rubber-coated radial arrangement cord of one ply or more (one ply in the illustrated example) between bead cores 3 buried in a pair of bead parts (only one side is shown), and preferably a steel cord in the case of one ply, At least one ply has a folded portion 4t wound around the bead core 3 from the inside to the outside of the tire.
【００２４】図１〜図５に示すビード部１は、それぞれ
別個に独立させた２層のゴム被覆スチールコード層から
なるビード部補強層５、６を備え、図６及び図７に示す
ビード部１は、それぞれ別個に独立させた３層のゴム被
覆スチールコード層からなるビード部補強層５、６、７
を備える。図１〜図５に示す２層のビード部補強層５、
６はビードコアを挟むビード部内外両領域に配置し、以
下主として折返し部４ｔ側に位置するビード部補強層５
は外側補強層と呼び、主としてタイヤ内部に面するカー
カス４本体側に位置するビード部補強層６は内側補強層
６と呼ぶ。図６及び図７に示すビード部補強層５は折返
し部４ｔ側の外側領域に配置した外側補強層であり、ビ
ード部補強層６はタイヤ内部に面するカーカス４本体側
の内側領域に配置した内側補強層であり、外側補強層５
と内側補強層６とは互いに対をなす形態を有する。補強
層７は外側補強層５と内側補強層６との間にてビードコ
ア３の周りに配置した中間補強層である。The bead portion 1 shown in FIGS. 1 to 5 includes bead portion reinforcing layers 5 and 6 each composed of two layers of rubber-coated steel cord layers which are separately and independently provided, and the bead portion shown in FIGS. 6 and 7 is provided. 1 is a bead portion reinforcing layer 5, 6, 7 comprising three rubber-coated steel cord layers which are separately and independently formed.
Is provided. 2 bead part reinforcement layers 5 shown in FIGS.
Reference numeral 6 denotes a bead portion reinforcing layer 5 which is disposed in both the inner and outer regions of the bead portion sandwiching the bead core, and is mainly located on the side of the folded portion 4t.
Is referred to as an outer reinforcing layer, and the bead portion reinforcing layer 6 located mainly on the carcass 4 body side facing the inside of the tire is referred to as an inner reinforcing layer 6. The bead portion reinforcing layer 5 shown in FIGS. 6 and 7 is an outer reinforcing layer disposed in the outer region on the side of the folded portion 4t, and the bead portion reinforcing layer 6 is disposed in the inner region on the carcass 4 body side facing the inside of the tire. Inner reinforcing layer, outer reinforcing layer 5
The inner reinforcing layer 6 and the inner reinforcing layer 6 form a pair. The reinforcing layer 7 is an intermediate reinforcing layer disposed around the bead core 3 between the outer reinforcing layer 5 and the inner reinforcing layer 6.
【００２５】これら外側内側補強層５、６及び外側内側
補強層５、６と中間補強層７はそれぞれ独立しているが
あたかも一連りの層のように、タイヤ内部のカーカス４
本体のプライ内面からビードコア３の巻上げ部のプライ
内面を経て折返し部４ｔの外側に至る間に相互隣接配置
するものとし、特にビード部１の外側領域に配置する外
側補強層５はカーカス４の折返し部４ｔに沿いその巻上
げ端４ｔｅを超えて半径方向外方に向け延びる配置とす
る。The outer inner reinforcing layers 5 and 6 and the outer inner reinforcing layers 5 and 6 and the intermediate reinforcing layer 7 are independent of each other, but as if they were a series of layers.
It is arranged adjacent to each other between the inner surface of the ply of the main body and the outside of the folded portion 4t through the inner surface of the ply of the winding portion of the bead core 3. In particular, the outer reinforcing layer 5 arranged in the outer region of the bead portion 1 It is arranged to extend radially outward along the portion 4t and beyond the winding end 4te.
【００２６】ここに、図１〜図５に示す外側内側補強層
５、６及び図６、図７に示す外側内側補強層５、６と中
間補強層７とはそれぞれが相対する端縁をビードコア３
近傍にて隣り合わせ配置とする必要がある。この近傍と
は先に説明した通り、距離空間で、一点Ｉ（図示せず）
からの距離が或る値より小さい全ての点から成る部分集
合を指し、一点Ｉはビードコア３の表面上に存在する全
ての点とし、ビードコア３表面の上の全ての点から全方
向に向け測った距離が０．５〜２５ｍｍの範囲内にある
位置を指すものとする。なおビードコア３周辺といえ
ば、カーカス４のプライを介在させてビードコア３と直
接対向する位置をいい、よって「周辺」とは近傍のうち
比較的僅かな距離内にあることを意味する。Here, the outer inner reinforcing layers 5, 6 shown in FIGS. 1 to 5 and the outer inner reinforcing layers 5, 6 and the intermediate reinforcing layer 7 shown in FIGS. 3
It is necessary to arrange adjacently in the vicinity. As described above, this neighborhood is a point I (not shown) in the metric space.
Refers to a subset consisting of all points whose distance from is less than a certain value, and one point I is defined as all points existing on the surface of the bead core 3 and measured from all points on the surface of the bead core 3 in all directions. The distance shall be a position within the range of 0.5 to 25 mm. Note that the periphery of the bead core 3 refers to a position directly facing the bead core 3 with the ply of the carcass 4 interposed therebetween. Therefore, the “periphery” means within a relatively small distance among the vicinity.
【００２７】図１〜図５に示す外側補強層５の相対端縁
Ｐと、外側補強層６の相対端縁Ｑとは相互に隣り合う関
係を有し、この隣り合いとは相互接触、すなわち突き合
わせの場合と、僅少の離隔の場合との双方を可とし、各
図では理解し易いように僅少の離隔で図解している。The relative edge P of the outer reinforcing layer 5 and the relative edge Q of the outer reinforcing layer 6 shown in FIGS. 1 to 5 have an adjacent relationship to each other. Both the case of butting and the case of slight separation are allowed, and the drawings are illustrated with small separation for easy understanding.
【００２８】この相対端縁Ｐ、Ｑの隣り合わせ位置につ
き、図１ではビードコア３周辺でのタイヤ内側の例を、
図２はビードコア３周辺でのタイヤ外側の例を、図３は
ビードコア近傍でのタイヤ外側の例を、図４はビードコ
ア周辺でのタイヤ外側の例を、そして図５もビードコア
周辺でのタイヤ外側の例をそれぞれ示した。FIG. 1 shows an example of the inner side of the tire around the bead core 3 at the position where the relative edges P and Q are adjacent to each other.
FIG. 2 shows an example of the tire outside around the bead core 3, FIG. 3 shows an example of the tire outside near the bead core, FIG. 4 shows an example of the tire outside around the bead core, and FIG. Examples are shown below.
【００２９】ここで、ビード部１の内外両側領域に位置
する独立外側内側補強層５、６の半径方向外方端５ｅ、
６ｅ近傍部（端部）における層５、６の配列スチールコ
ードのタイヤ円周線に対する傾斜角度は１５〜３０°の
範囲内にあることが必要である一方、層５、６の少なく
ともいずれか一方の半径方向内方端、すなわち相対端縁
Ｐ、Ｑ近傍部（端部）の少なくとも一方における配列ス
チールコードにタイヤ円周線に対する傾斜角度が３５〜
６０°の範囲内にあることが必要である。すなわち同じ
層内にて配列スチールコードの上記傾斜角度を半径方向
外方端部で最少角度とし、そこから相対端縁に向かうに
つれ傾斜角度を増加させ相対端縁近傍部で最大角度とす
る。ここに傾斜角度を定めるタイヤ円周線は角度を特定
する位置を通る円周線であり、以下同じである。Here, the radially outer ends 5e of the independent outer inner reinforcing layers 5, 6 located on both the inner and outer regions of the bead portion 1,
In the vicinity (end) of 6e, the inclination angle of the arrangement of the layers 5 and 6 with respect to the tire circumferential line of the steel cord needs to be within the range of 15 to 30 °, while at least one of the layers 5 and 6 is provided. At the radially inner end, that is, at least one of the edges (ends) near the relative edges P and Q, the steel cord having an inclination angle with respect to the tire circumferential line of 35 to
It needs to be within the range of 60 °. That is, in the same layer, the inclination angle of the arranged steel cords is set to the minimum angle at the radially outer end, and the inclination angle is increased from there toward the relative edge, and is maximized near the relative edge. Here, the tire circumferential line that defines the inclination angle is a circumferential line that passes through the position that specifies the angle, and the same applies hereinafter.
【００３０】このようなスチールコードの傾斜配分は、
未加硫タイヤ成型前に外側内側補強層５、６となる未加
硫部材の両表面に所定量の強制変形加工を施すことで得
ることができる。この加工が必要なため、生産性を考慮
してタイヤにより層５、６のうちいずれか一方の配列ス
チールコードに上記角度差を付すに止める場合と、使用
条件の厳しさを考慮して両層５、６いずれにも角度差を
付す必要がある場合とが併存する。The inclination distribution of such a steel cord is as follows.
It can be obtained by subjecting both surfaces of the unvulcanized members to be the outer and inner reinforcing layers 5 and 6 to a predetermined amount of forced deformation before molding the unvulcanized tire. Since this processing is necessary, in consideration of the productivity, when the tire is stopped by providing one of the steel cords of the layers 5 and 6 with the above-described angle difference, and in consideration of the severe use conditions, both layers are used. A case where it is necessary to add an angle difference to both 5 and 6 coexists.
【００３１】ここに傾斜角度は、外方端５ｅ、６ｅ近傍
部（端部）及び相対端縁Ｐ、Ｑ近傍部（端部）における
配列スチールコードのタイヤ円周線に対する傾斜角度と
は、コードの中心軸とタイヤ円周線との交点における円
周線の接線とコード中心軸の接線とがなす角度のうち鋭
角を採るものと定義する。Here, the inclination angle means the inclination angle of the arrayed steel cords in the vicinity of the outer ends 5e, 6e (ends) and the relative edges P, Q (ends) with respect to the tire circumferential line. Of the tangent of the circumferential line and the tangent of the cord central axis at the intersection of the center axis of the tire and the circumferential line of the tire.
【００３２】以上述べた外側内側補強層５、６の構成
は、以下に述べる効果を奏する。まず、相対端縁Ｐ、Ｑ
近傍部の少なくとも一方にて配列スチールコードのタイ
ヤ円周線に対する傾斜角度が３５〜６０°の範囲内で大
きくすることは、ビードコア３周囲の補強層部分が、カ
ーカス４のプライの引き抜き張力Ｔが及ぼすビードコア
３の断面図形の重心Ｃｇ周りの回転ｒ（図１０参照）に
対して大きな抵抗力を発揮することができる。The configuration of the outer and inner reinforcing layers 5 and 6 described above has the following effects. First, the relative edges P, Q
Increasing the inclination angle of the arrayed steel cords with respect to the tire circumferential line in at least one of the vicinity portions within the range of 35 to 60 ° means that the pulling tension T of the ply of the carcass 4 is reduced by the reinforcing layer portion around the bead core 3. A large resistance can be exerted against the rotation r (see FIG. 10) of the cross section of the bead core 3 around the center of gravity Cg.
【００３３】この抵抗力が、従来タイヤの走行距離の進
行に伴いビード部に不可避的に生じてしたビードコア３
の「へたり」現象を阻止、もしくは大幅に軽減する効果
を奏する。この「へたり」現象の阻止、もしくは大幅軽
減によりタイヤの走行中期〜末期に生じるビード部１の
大きな塑性変形を抑制する結果、特に外側補強層５の半
径方向端５ｅに作用するひずみを軽減することが可能と
なり、耐セパレーション性が大幅に向上する。なお「へ
たり」とはスチールワイヤの巻回体として構成する図示
例の断面六角形のビードコア３を製造する際に必要なス
チールワイヤの極薄い被覆ゴムの塑性変形に基づき生じ
る現象である。なおビードコア３の断面は六角形にこだ
わらず他の多角形でも良い。The bead core 3 which is inevitably generated in the bead portion with the progress of the running distance of the tire in the related art.
This has the effect of preventing or greatly reducing the "fall" phenomenon. As a result of preventing or substantially reducing the "set" phenomenon, large plastic deformation of the bead portion 1 occurring during the middle to final stages of running of the tire is suppressed. As a result, in particular, strain acting on the radial end 5e of the outer reinforcing layer 5 is reduced. And separation resistance is greatly improved. The "set" is a phenomenon that occurs based on the plastic deformation of the extremely thin rubber covering of the steel wire necessary for manufacturing the bead core 3 having a hexagonal cross section in the illustrated example configured as a wound body of the steel wire. The cross section of the bead core 3 is not limited to a hexagon and may be another polygon.
【００３４】ここに傾斜角度が３５°未満の場合は、ビ
ードコア３の上記回転ｒに対する抵抗力が小さくなり過
ぎて「へたり」を十分に抑制することができない一方、
６０°を超えると、傾斜角度が１５〜３０°の範囲内に
ある半径方向外方端５ｅ、６ｅ近傍部（端部）から相対
端縁Ｐ、Ｑ近傍部に至る間にスチールコードを湾曲させ
て傾斜角度を増すのであるから湾曲度合いが大きくなり
過ぎ、タイヤの荷重負荷転動下の接地域に対応するスチ
ールコードの湾曲部に大きな圧縮応力が繰り返し作用
し、結局コード切れが発生し勝ちになるので不可であ
る。If the angle of inclination is less than 35 °, the resistance of the bead core 3 to the rotation r becomes too small to sufficiently suppress the “set”.
When the angle exceeds 60 °, the steel cord is bent from the vicinity (end) of the radially outer ends 5e and 6e in the range of the inclination angle of 15 to 30 ° to the vicinity of the relative edges P and Q. Because the angle of inclination increases, the degree of curvature becomes too large, and large compressive stress repeatedly acts on the curved part of the steel cord corresponding to the contact area under the rolling load of the tire, and eventually the cord breaks and it tends to win It is not possible.
【００３５】次に、外側内側補強層５、６の半径方向外
方端５ｅ、６ｅ近傍部（端部）における各層５、６の配
列スチールコードのタイヤ円周線に対する傾斜角度が１
５〜３０°の範囲内であることが、タイヤの荷重負荷転
動下でトレッド接地域の踏み込み部及び蹴り出し部に対
応するビード部のタイヤ円周線に沿う変形及び半径方向
の変形それぞれに伴い発生する外側内側補強層５、６の
半径方向外方端５ｅ、６ｅ近傍部に作用するひずみを小
さくすることになり、この事実と上述したビード部の塑
性変形の極小化との連携によりビード部耐久性の顕著な
向上が達成できる。Next, the inclination angle of the steel cords arranged in the layers 5 and 6 in the vicinity (ends) of the outer inner reinforcing layers 5 and 6 in the vicinity of the radially outer ends 5e and 6e with respect to the tire circumferential line is 1.
Within the range of 5 to 30 °, the deformation along the tire circumferential line and the radial deformation of the bead portion corresponding to the tread portion and the kick-out portion in the tread contact area under rolling load of the tire, respectively. The resulting strain acting on the outer inner reinforcing layers 5, 6 in the vicinity of the radially outer ends 5e, 6e of the outer and inner reinforcing layers 5, 6 is reduced, and this fact is combined with the above-mentioned minimization of the plastic deformation of the bead portion, whereby the bead is formed. A remarkable improvement in part durability can be achieved.
【００３６】併せて、外側内側補強層５、６それぞれが
相対する端縁をビードコア３近傍にて隣り合わせ配置と
することにより、タイヤ及びリム組立体に対する所定空
気圧充てん時、タイヤの荷重負荷転動時の外側内側補強
層５、６の固定拘束を緩めることが、両層５、６の半径
方向外方端５ｅ、６ｅ近傍部に作用するひずみを小さく
するように働くので、このこともビード部耐久性向上に
大きく寄与する。つまり、この働きと上記二つの働きと
が三位一体となってビードコア３のスチールワイヤの巻
回数を減らし、これに伴いビード部のゴム、例えばステ
ィフナゴム９の使用量を減じて軽量タイヤとしても、従
来の重量が重いタイヤのビード部耐久性に比し遜色がな
く、寧ろより一層向上したビード部耐久性を実現するこ
とができる。なお符号１０はインナーライナであり、Ｔ
／Ｌタイヤの場合は空気不透過性ゴムを適用する。At the same time, by arranging the edges of the outer and inner reinforcing layers 5 and 6 facing each other near the bead core 3, the tire and the rim assembly are filled with a predetermined air pressure, and the tire is loaded with a rolling load. Loosening the fixed restraint of the outer and inner reinforcing layers 5 and 6 of the outer layers 5 and 6 serves to reduce the strain acting on the radially outer ends 5e and 6e of the two layers 5 and 6 in the vicinity thereof. It greatly contributes to the improvement of performance. In other words, this function and the above two functions are integrated into a trinity to reduce the number of turns of the steel wire of the bead core 3, thereby reducing the amount of rubber used in the bead portion, for example, the stiffener rubber 9, to obtain a lightweight tire. As compared with the bead durability of a heavy tire, the bead durability can be further improved. Reference numeral 10 denotes an inner liner, and T
For / L tires, an air-impermeable rubber is applied.
【００３７】外側内側補強層５、６はその半径方向内方
端の対向する相対端縁Ｐ、Ｑを突き合わせ配置とすると
き、タイヤの荷重負荷転動時に両層５、６の動きの拘束
作用が高まるのでビードコア３の「へたり」抑制により
一層効果的であり、特に突き合わせ位置をビードコア３
周辺とするとき「へたり」抑制を効率よく実現すること
ができる。When the outer inner reinforcing layers 5 and 6 are arranged such that their opposing edges P and Q at their radially inner ends are abutted against each other, the movement of the two layers 5 and 6 is restricted when the tire is loaded with a load. Is more effective in suppressing the “sag” of the bead core 3, and particularly, the abutting position is set to the bead core 3.
In the case of a peripheral area, “set” can be efficiently suppressed.
【００３８】外側内側補強層５、６の配列スチールコー
ドの傾斜方向をタイヤ半径線に関して互いに同じ傾斜方
向とすることができ、このタイヤは配列スチールコード
の傾斜方向と逆向きの回転方向を表示して一定の方向か
らのトルク入力とすれば両層５、６の半径方向端５ｅ、
６ｅに対するひずみ入力を軽減することができ、この発
明をより一層有利に活用することができる。例えば長距
離走行トラック用に適合する。The inclination direction of the steel cords arranged on the outer and inner reinforcing layers 5 and 6 can be the same inclination direction with respect to the tire radial line, and the tire displays a rotation direction opposite to the inclination direction of the steel cords arranged. If the torque is input from a certain direction, the radial ends 5e of both layers 5, 6
6e can be reduced, and the present invention can be more advantageously utilized. For example, it is suitable for long-distance traveling trucks.
【００３９】上記とは逆に、外側内側補強層５、６の配
列スチールコードの傾斜方向をタイヤ半径線に関して互
いに異なる傾斜方向とすることもでき、このタイヤは回
転方向に対するビード部１の剛性がほぼ同じであり、回
転方向を表示する必要はない。用途としては発進、停止
の繰り返し頻度が高い市内バス用に適合する。Contrary to the above, the inclination direction of the steel cords arranged on the outer inner reinforcing layers 5 and 6 can be different from each other with respect to the tire radial line. It is almost the same, and there is no need to display the rotation direction. Suitable for city buses where start and stop are frequently repeated.
【００４０】図４にはトラック及びバス用Ｔ／Ｌタイヤ
をＪＡＴＭＡ規格が定める適用リムとしての１５°深底
リム（外側輪郭のみ示す）２０に組付けたタイヤ及びリ
ム組立体に先に述べた最高空気圧を充てんしたときの要
部断面を示し、図５にはトラック及びバス用Ｗ／Ｔタイ
ヤをＪＡＴＭＡ規格が定める適用リムとしての広幅平底
リム（外側輪郭のみ示す）２１に組付けたタイヤ及びリ
ム組立体に先に述べた最高空気圧を充てんしたときの要
部断面を示す。これらの例における外側内側補強層５、
６の相対端縁Ｐ、Ｑ位置は下記の位置とすることができ
る。FIG. 4 shows the tire and rim assembly in which the T / L tire for trucks and buses is mounted on a 15 ° deep rim (only the outer contour is shown) 20 as an applicable rim specified by the JATMA standard. FIG. 5 shows a cross section of a main part when the maximum air pressure is filled. FIG. 5 shows a tire in which a W / T tire for trucks and buses is mounted on a wide flat bottom rim (only an outer contour is shown) 21 as an applicable rim defined by JATMA standards. 2 shows a cross section of a main part when the rim assembly is filled with the above-described maximum air pressure. Outer and inner reinforcement layers 5 in these examples,
The relative edge P and Q positions of 6 can be the following positions.
【００４１】すなわち図４、５に示す例では、ビードコ
ア３の断面図形の重心Ｃｇを通りタイヤ回転軸（図示せ
ず）に直交する直線Ｌ1 と、リム２０、２１のフランジ
２０Ｆ、２１Ｆと接触するビード部１の表面の半径方向
最外方端Ａからタイヤ内部に面するカーカス４の本体に
下ろした法線Ｌ2 との間の挟まれる領域に層５、６の相
対端縁Ｐ、Ｑを位置させる。That is, in the example shown in FIGS. 4 and 5, a straight line L 1 passing through the center of gravity Cg of the cross-sectional view of the bead core 3 and orthogonal to the tire rotation axis (not shown) comes into contact with the flanges 20F and 21F of the rims 20 and 21. the relative edge P of layers 5 and 6 in the region sandwiched between from the radially outermost end a of the surface of the bead portion 1 and the normal line L 2 drawn down into the body of the carcass 4 facing the interior tire, Q Position.
【００４２】図１に示す例は相対端縁Ｐ、Ｑ位置を上記
の領域からより一層タイヤ内方としているが、上記の例
は図２、３に示した２例と同様であり、特に外側領域に
位置する外側補強層５の拘束力を緩和することができ、
タイヤの荷重負荷転動時に外側補強層５の半径方向外方
部分のタイヤ変形に対する追随性に優れ、外側補強層５
の半径方向外方端５ｅ近傍部に作用するひずみをより小
さくする利点を有する。In the example shown in FIG. 1, the positions of the relative edges P and Q are further inside the tire from the above-mentioned region, but the above example is the same as the two examples shown in FIGS. The binding force of the outer reinforcing layer 5 located in the region can be reduced,
The outer reinforcement layer 5 has excellent followability with respect to tire deformation at the time of rolling load of the tire, and the outer reinforcement layer 5
Has an advantage of further reducing the strain acting on the portion near the radially outer end 5e.
【００４３】図６、７に示す外側内側補強層５、６及び
中間補強層７は、上述した外側内側補強層５、６に相当
する各層の相対端縁間を大きく広げ、この広げた位置に
中間補強層７を配置した構成に成る。ビードコア３を挟
むビード部１の内外両側領域に対として配置した外側内
側補強層５、６の外方端５ｅ、６ｅ部における配列スチ
ールコードのタイヤ円周線に対する傾斜角度は１５〜３
０°の範囲内にあり、かつ外側内側補強層５、６の内方
端Ｐ、Ｒ部における配列スチールコードのタイヤ円周線
に対する傾斜角度は３５〜６０°の範囲内にあるものと
し、この点では図１〜図５に示す例と同様である。これ
に対し外側内側補強層５、６との間にてビードコア３の
周りに配置した中間補強層７における配列スチールコー
ドのタイヤ円周線に対する傾斜角度は、上記内方端Ｐ、
Ｒ部における配列スチールコードの傾斜角度３５〜６０
°より大きく９０°以下とする。これら補強層５、６、
７の互いに対向する端縁は、相対端縁Ｐ、Ｑ及び相対端
縁Ｒ、Ｓの２か所にあらわれるが、これらの位置はビー
ドコア３を挟む両側にある他の位置関係及び隣り合わせ
関係は先に述べたところと同じである。The outer inner reinforcing layers 5 and 6 and the intermediate reinforcing layer 7 shown in FIGS. 6 and 7 greatly widen the relative edges between the layers corresponding to the outer inner reinforcing layers 5 and 6 described above, and are located at the expanded positions. It has a configuration in which the intermediate reinforcing layer 7 is arranged. The inclination angles of the arranged steel cords with respect to the tire circumferential line at the outer ends 5e and 6e of the outer inner reinforcing layers 5 and 6 arranged as a pair in both the inner and outer side regions of the bead portion 1 sandwiching the bead core 3 are 15 to 3.
The inclination angle of the arrayed steel cords at the inner ends P and R of the outer inner reinforcing layers 5 and 6 with respect to the tire circumferential line is in the range of 35 to 60 °. This is similar to the examples shown in FIGS. On the other hand, the inclination angle of the arranged steel cords with respect to the tire circumferential line in the intermediate reinforcing layer 7 disposed around the bead core 3 between the outer inner reinforcing layers 5 and 6 is equal to the inner end P,
Tilt angle of the arrayed steel cords in the R section 35-60
The angle is greater than 90 ° and less than 90 °. These reinforcing layers 5, 6,
7, the opposite edges appear at two positions of a relative edge P, Q and a relative edge R, S, but these positions are different from each other on both sides sandwiching the bead core 3 and the side by side relationship. Is the same as described above.
【００４４】この場合予め未加硫部材段階の外側内側補
強層５、６及び中間補強層７の配列スチールコードに形
付け変形加工を施さずともよい工数上の利点を有する一
方、部材数が増える不利な点もあり、合せて先の発明の
実施形態例とさほど工数は変わらず、また作用効果上の
点も図１〜図５に示す外側内側補強層５、６につき先に
述べたところと同じであるが、図６、７に示す外側内側
補強層５、６に作用する拘束力は双方共に緩和される点
で外側内側補強層５、６の半径方向内方端縁Ｐ、Ｒの位
置設定に当り設計上の自由度が増し、補強層を３層に分
離することはビード部耐久性向上がより一層容易となる
利点を有する。In this case, the arrangement of the steel cords of the outer and inner reinforcing layers 5, 6 and the intermediate reinforcing layer 7 in the unvulcanized member stage has the advantage of eliminating the need for shaping and deforming the steel cord, while increasing the number of members. There are disadvantages, and the man-hour is not much different from that of the embodiment of the previous invention, and the operation and effect are the same as those described above for the outer and inner reinforcing layers 5 and 6 shown in FIGS. 1 to 5. The position of the radial inner edges P, R of the outer inner reinforcing layers 5, 6 is the same, except that the restraining forces acting on the outer inner reinforcing layers 5, 6 shown in FIGS. The degree of freedom in design in setting is increased, and the separation of the reinforcing layer into three layers has the advantage that bead portion durability can be more easily improved.
【００４５】また上記３層の外側内側補強層５、６及び
中間補強層７のうち少なくとも２層のスチールコードの
配列はタイヤ半径線に関して互いに同じ傾斜方向とする
ことができる。作用効果と適合用途とは先に述べたとこ
ろと同じである。The arrangement of the steel cords of at least two of the three outer inner reinforcing layers 5 and 6 and the intermediate reinforcing layer 7 may have the same inclination direction with respect to the tire radial line. The working effects and compatible applications are the same as described above.
【００４６】以上述べた外側内側補強層５、６及び中間
補強層７のうち少なくとも１層、１層の場合、望ましく
は外側補強層５のスチールコード配列が図８に示す展開
図のように、２本以上（図示例は２本）のコードを横並
び（層の表面の広がり方向）に束ねた束コード５Ｃ（６
Ｃ）配列とするのが望ましい。図９に通常の補強層のコ
ード配列のありさまを図８同様に展開図として示すが、
従来補強層１５のスチールコード１５Ｃは１本毎の配列
になり、このスチールコード１５Ｃ端１５ａｅ縁に生じ
た亀裂は図示のようにタイヤ円周線にほぼ沿って繋がり
易い。亀裂が一旦繋がると比較的早期にセパレーション
故障に至る。In the case where at least one of the outer inner reinforcing layers 5 and 6 and the intermediate reinforcing layer 7 described above is one layer, preferably, the steel cord arrangement of the outer reinforcing layer 5 is as shown in a developed view in FIG. A bundle code 5C (6) in which two or more (two in the illustrated example) codes are bundled side by side (in the direction in which the surface of the layer spreads).
C) It is desirable to form an array. FIG. 9 is a development view showing the normal arrangement of the cords of the reinforcing layer as in FIG.
Conventionally, the steel cords 15C of the reinforcing layer 15 are arranged one by one, and the cracks generated at the edges 15ae of the ends 15a of the steel cords 15C are easily connected substantially along the tire circumferential line as shown in the figure. Once the crack is connected, separation failure occurs relatively early.
【００４７】これに対し束コード５Ｃ（６Ｃ）では、コ
ード打込数（例えば５ｃｍ当りの本数）が同じ場合、コ
ード間隙（勿論この間隙部分は被覆ゴム）が従来補強層
１５のコード間隔の約２倍と広く、しかも束コード５Ｃ
（６Ｃ）の剛性がより一層高いため、図８に示すように
コード束５Ｃ（６Ｃ）の長さ方向に沿って亀裂が進み、
図９に示すような亀裂の繋がりが生じ難く、容易にセパ
レーション故障発生には至らない利点を有するので、束
コード５Ｃ（６Ｃ）配列はこの発明にうってつけの構成
である。On the other hand, in the bundle cord 5C (6C), when the number of cords (for example, the number of cords per 5 cm) is the same, the gap between the cords (of course, the gap is covered with rubber) is about the same as the cord interval of the conventional reinforcing layer 15. Twice as wide and bundle code 5C
Since the rigidity of (6C) is even higher, the crack progresses along the length direction of the cord bundle 5C (6C) as shown in FIG.
The arrangement of the bundle cords 5C (6C) is suitable for the present invention because it has the advantage that the connection of cracks as shown in FIG. 9 is unlikely to occur and the separation failure does not easily occur.
【００４８】また外側内側補強層５、６及び中間補強層
７のうち少なくともビード部１の外側領域に位置する外
側補強層層５（配置次第で中間補強層７も含む）のスチ
ールコード被覆ゴムの１００％モジュラスが、カーカス
４のプライゴムの１００％モジュラスより小さな値であ
るのが推奨できる。それというのも、タイヤの荷重負荷
転動下におけるビード部１の変形はほぼ定ひずみ変形で
あるから、上記の１００％モジュラス関係を少なくとも
外側補強層５の被覆ゴムに適用すれば応力はより一層小
さくなり、各補強層のなかでも最も亀裂が発生し易い外
側補強層５の端縁５ｅの亀裂発生を抑制することがで
き、ビード部耐久性向上に大きく寄与することに他なら
ないからである。Of the outer inner reinforcing layers 5, 6 and the intermediate reinforcing layer 7, at least the outer reinforcing layer layer 5 (including the intermediate reinforcing layer 7 depending on the arrangement) located at the outer region of the bead portion 1 is made of rubber covered with steel cord. It is recommended that the 100% modulus be less than the 100% modulus of the carcass 4 ply rubber. This is because the deformation of the bead portion 1 under the rolling load of the tire is almost constant strain deformation. Therefore, if the above-mentioned 100% modulus relationship is applied to at least the rubber coating of the outer reinforcing layer 5, the stress is further increased. This is because it is possible to suppress the occurrence of a crack at the edge 5e of the outer reinforcing layer 5 where the crack is most likely to be generated among the respective reinforcing layers, and this contributes greatly to the improvement of the bead portion durability.
【００４９】また図２に破線にて示す有機繊維コードの
ゴム被覆層８を外側内側補強層５、６の表層を覆い包む
ように追加配置すること、特に外側補強層５の半径方向
外方端５ｅを超える高さで配置することが有効な場合が
あり、この場合はビード部１への入力（負荷荷重乃至車
両速度）が厳しい使用条件向けのタイヤ乃至数多くのリ
ッキャップ回数を要求する使用者向けに推奨される。な
おカーカス４の外周にてトレッド部を強化するベルトは
２層以上のスチールコード交差層になる。Further, a rubber coating layer 8 of an organic fiber cord indicated by a broken line in FIG. 2 is additionally disposed so as to cover the surface layers of the outer inner reinforcing layers 5 and 6, particularly, the radially outer end 5 e of the outer reinforcing layer 5. In some cases, it is effective to dispose the tire at a height higher than the above. In this case, tires for use conditions where the input (load load or vehicle speed) to the bead portion 1 is severe or users who require a large number of times of ripping are required. Recommended for The belt for reinforcing the tread portion on the outer periphery of the carcass 4 has two or more steel cord cross layers.
【００５０】[0050]
【実施例】トラック及びバス用Ｔ／Ｌタイヤで、サイズ
が１１／７０Ｒ２２．５であり、カーカス４は１プライ
のラジアル配列スチールコードのゴム被覆プライにな
り、ベルトは４層のスチールコード交差層になる。ビー
ドコア３は各図で示す、いわゆる六角ビードコアであ
り、１５番線スチールワイヤの巻回数を従来の７２回か
ら６５回に減じたものを用いた。このビードコア３のみ
でも約０．４kgの重量減になり、スティフナ９の重量減
０．３kg分を合わせたタイヤ重量は従来タイヤより約
０．７kgの重量減となる。DESCRIPTION OF THE PREFERRED EMBODIMENTS T / L tires for trucks and buses, size 11 / 70R22.5, carcass 4 is a rubber-coated ply of one ply radially arranged steel cord, and belt is a four-layer steel cord cross layer. become. The bead core 3 is a so-called hexagonal bead core shown in each figure, and the number of turns of the No. 15 steel wire is reduced from 72 times to 65 times in the related art. The weight of the bead core 3 alone is reduced by about 0.4 kg, and the weight of the tire including the weight loss of 0.3 kg of the stiffener 9 is reduced by about 0.7 kg from the conventional tire.
【００５１】実施例１〜９のタイヤは図１、２、４に従
い、実施例１０のタイヤは図６に従い、実施例１〜９に
は２層の外側内側補強層５、６を、実施例１０には２層
の外側内側補強層５、６と中間補強層７とをそれぞれ適
用した。層５、６の半径方向外方端５ｅ、６ｅ近傍部、
層５、６、７の相対端縁Ｐ、Ｒ及び相対端縁Ｑ、Ｓ近傍
部それぞれのタイヤ円周線に対する配列スチールコード
の傾斜角度の値（度）を、タイヤを側面から見たときの
傾斜方向を右上がりをＲ、左上がりをＬの符号であらわ
すこととして、これら符号Ｒ、Ｌを傾斜角度の前に付し
て表１に示す。比較例には実施例１〜１０と同じ軽量ビ
ードコア３を適用し、ビード部補強層には先に触れた特
開昭５９−２１６７０９号公報に従う図１０に示す２層
のスチールコード層１５ａ、１５ｂを用い、これら層の
半径方向外方端１５ａｅ、１５ｂｅを実施例と同じ位置
に合わせて表１に記載した。なお表１には各例に対応す
る図番を表記した。The tires of Examples 1 to 9 are in accordance with FIGS. 1, 2 and 4, and the tire of Example 10 is in accordance with FIG. 6. In Examples 1 to 9, two outer inner reinforcing layers 5 and 6 are provided. 10, two outer inner reinforcing layers 5 and 6 and an intermediate reinforcing layer 7 were applied. Near the radially outer ends 5e, 6e of the layers 5, 6;
The values (degrees) of the inclination angles of the arrayed steel cords with respect to the tire circumferential lines in the vicinity of the relative edges P, R and the relative edges Q, S of the layers 5, 6, 7 when the tire is viewed from the side. Assuming that the inclination direction is represented by the symbol R for rising to the right and the symbol L for rising to the left, these symbols R and L are given in front of the inclination angle and are shown in Table 1. The same lightweight bead core 3 as in Examples 1 to 10 was applied to the comparative example, and the two steel cord layers 15a and 15b shown in FIG. 10 according to JP-A-59-216709 mentioned above were used as the bead reinforcing layer. , And the radial outer ends 15ae and 15be of these layers were aligned with the same positions as in the example, and are described in Table 1. Table 1 shows the figure numbers corresponding to each example.
【００５２】[0052]
【表１】 [Table 1]
【００５３】実施例１〜１０及び比較例それぞれを供試
タイヤとして、これらタイヤをＪＡＴＭＡ規格（１９９
７年版）が定める適用リムのうちの許容リム７．５０×
２２．５に組付け、これに先に述べた最高空気圧８．５
０kgf/cm2 を充てんし、直径１．７ｍのドラムに荷重５
０００kg（上記規格での最大負荷能力は、シングル装着
で２７２５kg、デュアル装着で２５００kg）にて押し当
て、速度６０km/hで回転させ、ビード部にセパレーショ
ン故障が生じるまで走行させる耐久性テストを実施し
た。各供試タイヤの走行距離は、比較例を１００とする
指数にてまとめた。値は大なるほど良く、これらの耐久
性テスト結果を表１の下段に示す。Each of Examples 1 to 10 and Comparative Example was used as a test tire, and these tires were used according to the JATMA standard (199).
7.50x among the applicable rims specified by the 7-year version)
22.5, the maximum air pressure of 8.5 mentioned earlier
0 kgf / cm 2 and load 5 m on a 1.7 m diameter drum
A durability test was conducted by pressing at 000 kg (the maximum load capacity in the above standard is 2725 kg for single installation and 2500 kg for dual installation), rotating at a speed of 60 km / h, and running until a separation failure occurs in the bead part. . The running distance of each test tire was summarized by an index with the comparative example being 100. The larger the value, the better. The results of these durability tests are shown in the lower part of Table 1.
【００５４】表１に示す結果から、比較例の傾斜角度配
分に近い実施例１のタイヤでも約５％のビード部耐久性
向上が達成され、傾斜角度配分が比較例から離れるほど
ビード部耐久性が著しく向上していることがわかる。From the results shown in Table 1, the bead durability was improved by about 5% even with the tire of Example 1 which was close to the distribution of the inclination angle of the comparative example. It can be seen that is significantly improved.
【００５５】[0055]
【発明の効果】この発明の請求項１〜１１に記載した発
明によれば、ビードコアの容積（重量）を基礎とするビ
ード部重量を軽減しても、また偏平率の大小を問わず
に、重量が重い従来タイヤのビード部耐久性にいささか
も遜色なく、むしろこれを超える優れたビード部耐久性
を発揮させることが可能な、軽量の重荷重用空気入りラ
ジアルタイヤを提供することができる。According to the first to eleventh aspects of the present invention, even if the weight of the bead portion based on the volume (weight) of the bead core is reduced, and the flatness is small or large, It is possible to provide a lightweight heavy-duty pneumatic radial tire capable of exhibiting excellent bead portion durability that is not inferior to the bead portion durability of a conventional tire having a heavy weight, but rather exceeds this.
【図１】この発明による実施の形態例の要部を線図で示
す断面図である。FIG. 1 is a sectional view schematically showing a main part of an embodiment according to the present invention.
【図２】この発明による別の実施の形態例の要部を線図
で示す断面図である。FIG. 2 is a sectional view schematically showing a main part of another embodiment according to the present invention.
【図３】この発明による他の実施の形態例の要部を線図
で示す断面図である。FIG. 3 is a sectional view schematically showing a main part of another embodiment according to the present invention.
【図４】この発明による実施の形態例の要部を線図で示
す断面図である。FIG. 4 is a sectional view schematically showing a main part of an embodiment according to the present invention;
【図５】この発明による別の実施の形態例の要部を線図
で示す断面図である。FIG. 5 is a sectional view schematically showing a main part of another embodiment according to the present invention.
【図６】この発明による他の実施の形態例の要部を線図
で示す断面図である。FIG. 6 is a sectional view schematically showing a main part of another embodiment according to the present invention.
【図７】この発明によるさらに他の実施の形態例の要部
を線図で示す断面図である。FIG. 7 is a sectional view schematically showing a main part of still another embodiment according to the present invention.
【図８】この発明による実施の一形態例の補強層束コー
ド配列と機能との説明図である。FIG. 8 is an explanatory diagram of a reinforcing layer bundle cord arrangement and functions according to an embodiment of the present invention.
【図９】従来タイヤの補強層コード配列の亀裂進展の説
明図である。FIG. 9 is an explanatory view of crack propagation in a reinforcing layer cord arrangement of a conventional tire.
【図１０】従来タイヤの要部を線図で示す断面図であ
る。FIG. 10 is a cross-sectional view schematically showing a main part of a conventional tire.
１ ビード部 ２ サイドウォール部 ３ ビードコア ４ カーカス ４ｔ 折返し部 ４ｔｅ 折返し部終端 ５ 外側補強層 ５ｅ 外側補強層の半径方向外方端 ６ 内側補強層 ６ｅ 内側補強層の半径方向外方端 ７ 中間補強層 ８ 有機繊維コード層 ９ スティフナ １０ インナーライナ ２０、２１ 適用リム ２０Ｆ、２１Ｆ リムのフランジ Ｐ、Ｑ、Ｒ、Ｓ 各補強層の相対端縁 Ｃｇ ビードコア断面図形の重心 Ａ フランジと接触するビード部最外方表面位置 Ｌ1 重心Ｃｇを通るタイヤ回転軸と直交する直線 Ｌ2 位置Ａからカーカス本体への法線DESCRIPTION OF SYMBOLS 1 Bead part 2 Side wall part 3 Bead core 4 Carcass 4t Folding part 4te Folding part end 5 Outer reinforcing layer 5e Radial outer end of outer reinforcing layer 6 Inner reinforcing layer 6e Radial outer end of inner reinforcing layer 7 Intermediate reinforcing layer Reference Signs List 8 Organic fiber cord layer 9 Stiffener 10 Inner liner 20, 21 Applicable rim 20F, 21F Rim flange P, Q, R, S Relative edge of each reinforcing layer Cg Center of gravity of bead core cross-sectional figure A Outermost bead portion that contacts flange Surface position L 1 A straight line orthogonal to the tire rotation axis passing through the center of gravity Cg L 2 Normal line from position A to the carcass body
Claims (11)
ードコア相互間にわたり延びる１プライ以上のゴム被覆
ラジアル配列コードになるカーカスを備え、少なくとも
１プライのカーカスはビードコアの周りを巻上げる折返
し部を有し、ビードコアを挟むビード部内外両側領域で
それぞれ別個に独立させた２層のゴム被覆スチールコー
ド層よりなるビード部補強層を備える重荷重用空気入り
ラジアルタイヤにおいて、 ビード部外側領域に位置するビード部補強層はそのタイ
ヤ半径方向外方端がカーカスの折返し部端を超えて延
び、 ビード部補強層は２層のスチールコード層の対向する端
縁相互がビードコア近傍にて隣り合う配置に成り、 上記ビードコアを挟む内外両側領域に位置する各独立ビ
ード部補強層の上記半径方向外方端部及び内方端部それ
ぞれにおける配列スチールコードのタイヤ円周線に対す
る傾斜角度につき、外方端部が１５〜３０°の範囲内に
あり、内方端部は内外両側領域ビード部補強層の少なく
とも一方の層が３５〜６０°の範囲内にあることを特徴
とする重荷重用空気入りラジアルタイヤ。1. A carcass comprising at least one ply of rubber-coated radially arranged cords extending between bead cores embedded in a pair of bead portions, and at least one ply of the carcass has a folded portion wound around the bead core. In a heavy-duty pneumatic radial tire having a bead portion reinforcing layer composed of two rubber-coated steel cord layers separately and independently on both sides of the bead portion sandwiching the bead core, the bead portion located in the bead portion outer region The layer has a tire radially outer end extending beyond the turnover end of the carcass, and the bead reinforcing layer is arranged such that opposing edges of the two steel cord layers are adjacent to each other near the bead core. The radially outer end and the inner end of each of the independent bead portion reinforcing layers located on both the inner and outer regions sandwiching the With respect to the inclination angle of the arrayed steel cord with respect to the tire circumferential line in each of the portions, the outer end is in the range of 15 to 30 °, and the inner end is at least one of the inner and outer side region bead portion reinforcing layers having 35%. A pneumatic radial tire for heavy loads characterized by being within the range of 60 °.
縁相互が突き合わせ配置に成る請求項１に記載したタイ
ヤ。2. The tire according to claim 1, wherein the opposing edges of the two layers of the bead portion reinforcing layer are abutted with each other.
合わせ位置が、ビードコア周辺に存在する請求項１又は
２に記載したタイヤ。3. The tire according to claim 1, wherein the position where the two edges of the bead portion reinforcing layer abut against each other exists around the bead core.
コードの配列が、タイヤ半径線に関して互いに同じ傾斜
方向に成る請求項１〜３に記載したタイヤ。4. The tire according to claim 1, wherein the arrangement of the steel cords in the inner and outer side region bead portion reinforcing layers is in the same inclination direction with respect to the tire radial line.
コードの配列が、タイヤ半径線に関して互いに異なる傾
斜方向に成る請求項１〜３に記載したタイヤ。5. The tire according to claim 1, wherein the arrangement of the steel cords of the inner and outer side region bead portion reinforcing layers has different inclination directions with respect to the tire radial line.
ム又は広幅平底リムを適用リムとするタイヤにおいて、
ビード部補強層の２層の隣り合う端縁相互位置が、ビー
ドコアの断面図形の重心を通りタイヤ回転軸に直交する
直線と、リムのフランジに接触するビード部表面のタイ
ヤ半径方向最外方端からタイヤ内部に面するカーカス本
体に下ろした法線との間に存在する請求項１又は２に記
載したタイヤ。6. A tire having a 15 ° deep bottom rim or a wide flat bottom rim specified by JATMA standards,
The adjacent edges of the two layers of the bead portion reinforcing layer are located at a straight line passing through the center of gravity of the cross-sectional view of the bead core and orthogonal to the tire rotation axis, and the outermost radial end of the bead portion surface in contact with the rim flange. 3. The tire according to claim 1, wherein the tire is located between the carcass body facing the inside of the tire and a normal drawn down.
ードコア相互間にわたり延びる１プライ以上のゴム被覆
ラジアル配列コードになるカーカスを備え、少なくとも
１プライのカーカスはビードコアの周りを巻上げる折返
し部を有し、ビード部にて折返し部を含むカーカスを覆
う、別個に独立させたゴム被覆スチールコード層のビー
ド部補強層を備える重荷重用空気入りラジアルタイヤに
おいて、 上記ビード部補強層は、タイヤ内部に面するカーカス本
体側の内側領域に配置した内側補強層と、これと対をな
し折返し部側の外側領域に配置した外側補強層と、内側
補強層と外側補強層との間にてビードコアの周りに配置
した中間補強層との３層のゴム被覆スチールコード層よ
りなり、 折返し部側の外側補強層はそのタイヤ半径方向外方端が
カーカスの折返し部端を超えて延び、 ３層のゴム被覆スチールコード層それぞれで互いに対向
する端縁相互はビードコア近傍にて隣り合う配置に成
り、 ビード部補強層における配列スチールコードのタイヤ円
周線に対する傾斜角度につき、２層の対をなす外側補強
層及び内側補強層のコード傾斜角度がタイヤ半径方向外
方端部にて１５〜３０°の範囲内にあり、かつタイヤ半
径方向内方端部にて３５〜６０°の範囲内にあり、中間
補強層のコード配列は上記２層の対をなす各層のタイヤ
半径方向内方端部コード傾斜角度より大きな傾斜角度に
成ることを特徴とする重荷重用空気入りラジアルタイ
ヤ。7. A carcass comprising at least one ply of rubber-coated radially arranged cords extending between bead cores embedded in a pair of bead portions, wherein at least one ply of the carcass has a folded portion wound around the bead core. In a heavy-duty pneumatic radial tire comprising a bead portion reinforcing layer of a rubber-coated steel cord layer separately covering a carcass including a folded portion at a bead portion, the bead portion reinforcing layer faces the inside of the tire. An inner reinforcing layer arranged in the inner area on the carcass body side, an outer reinforcing layer paired with the inner reinforcing layer and arranged in the outer area on the folded portion side, and arranged around the bead core between the inner reinforcing layer and the outer reinforcing layer. The outer reinforcing layer on the side of the folded portion has a radially outer end at the tire radial side. The three edges of the rubber-coated steel cord layers, which extend beyond the end of the folded portion of the carcass, are located adjacent to each other in the vicinity of the bead core. The cord inclination angle of the outer reinforcing layer and the inner reinforcing layer forming a pair in the pair is within a range of 15 to 30 ° at the tire radially outer end, and the tire radially inner end is Wherein the cord arrangement of the intermediate reinforcing layer has a larger inclination angle than the inclination angle of the cord in the tire radial direction inner end of each of the paired layers. Heavy duty pneumatic radial tire.
層のうち少なくとも２層のスチールコードの配列が、タ
イヤ半径線に関して互いに同じ傾斜方向に成る請求項７
に記載したタイヤ。8. The arrangement of at least two steel cords among the three steel cord layers of the bead portion reinforcing layer have the same inclination direction with respect to the tire radial line.
Tire described in.
るスチールコード配列が、２本以上のコードを横並びに
束ねた束コード配列に成る請求項１〜８に記載したタイ
ヤ。9. The tire according to claim 1, wherein the steel cord arrangement in at least one of the bead portion reinforcing layers is a bundle cord arrangement in which two or more cords are bundled side by side.
ド部外側領域に位置するスチールコード層の被覆ゴム
が、カーカスプライのコード被覆ゴムの１００％モジュ
ラスより小さな１００％モジュラスを有する請求項１〜
９に記載したタイヤ。10. The coating rubber of the steel cord layer located at least in the bead portion outer region of the bead portion reinforcing layer has a 100% modulus smaller than the 100% modulus of the carcass ply cord coating rubber.
9. The tire described in 9 above.
の有機繊維コード層を有する請求項１〜１０に記載した
タイヤ。11. The tire according to claim 1, further comprising at least one organic fiber cord layer covering a surface layer of the bead portion reinforcing layer.
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17163297A JP3808595B2 (en) | 1997-06-27 | 1997-06-27 | Heavy duty pneumatic radial tire |
| ES03011046T ES2310633T3 (en) | 1997-06-12 | 1998-06-09 | HIGH PERFORMANCE RADIAL TIRES. |
| DE69819410T DE69819410T2 (en) | 1997-06-12 | 1998-06-09 | Radial truck tires |
| EP03011046A EP1346853B1 (en) | 1997-06-12 | 1998-06-09 | Heavy duty pneumatic radial tires |
| EP98304546A EP0884200B1 (en) | 1997-06-12 | 1998-06-09 | Heavy duty pneumatic radial tyres |
| ES98304546T ES2210674T3 (en) | 1997-06-12 | 1998-06-09 | RESISTANT RADIAL TIRES. |
| DE69839926T DE69839926D1 (en) | 1997-06-12 | 1998-06-09 | Radial truck tire |
| US09/094,574 US5979528A (en) | 1997-06-12 | 1998-06-12 | Heavy duty pneumatic radial tires with bead portion reinforcing layer having two different cord inclination angles |
| US09/404,788 US6279635B1 (en) | 1997-06-12 | 1999-09-24 | Heavy duty pneumatic radial tires with bead portion reinforcing layer having multiple inclination angles |
| US09/404,545 US6354351B1 (en) | 1997-06-12 | 1999-09-24 | Heavy duty pneumatic radial tires with bead reinforcing cord layer having multiple inclination angles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17163297A JP3808595B2 (en) | 1997-06-27 | 1997-06-27 | Heavy duty pneumatic radial tire |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1120423A true JPH1120423A (en) | 1999-01-26 |
| JP3808595B2 JP3808595B2 (en) | 2006-08-16 |
Family
ID=15926798
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17163297A Expired - Fee Related JP3808595B2 (en) | 1997-06-12 | 1997-06-27 | Heavy duty pneumatic radial tire |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3808595B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002219912A (en) * | 2001-01-29 | 2002-08-06 | Bridgestone Corp | Pneumatic tire |
| US6619729B2 (en) | 2001-06-07 | 2003-09-16 | Mazda Motor Corporation | Side body structure of vehicle |
| WO2006082869A1 (en) * | 2005-02-02 | 2006-08-10 | Bridgestone Corporation | Pneumatic tire |
| WO2007015341A1 (en) * | 2005-08-02 | 2007-02-08 | Bridgestone Corporation | Pneumatic radial tire for heavy load |
| JP2008195169A (en) * | 2007-02-09 | 2008-08-28 | Bridgestone Corp | Pneumatic tire |
| EP2746067A1 (en) | 2012-12-18 | 2014-06-25 | Hankook Tire Co., Ltd. | Bead reinforcing structure for TBR tire |
| JP2015042545A (en) * | 2014-10-27 | 2015-03-05 | 株式会社ブリヂストン | Pneumatic tire |
| WO2020261599A1 (en) * | 2019-06-24 | 2020-12-30 | 株式会社ブリヂストン | Tire |
-
1997
- 1997-06-27 JP JP17163297A patent/JP3808595B2/en not_active Expired - Fee Related
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4703013B2 (en) * | 2001-01-29 | 2011-06-15 | 株式会社ブリヂストン | Pneumatic tire |
| JP2002219912A (en) * | 2001-01-29 | 2002-08-06 | Bridgestone Corp | Pneumatic tire |
| US6619729B2 (en) | 2001-06-07 | 2003-09-16 | Mazda Motor Corporation | Side body structure of vehicle |
| WO2006082869A1 (en) * | 2005-02-02 | 2006-08-10 | Bridgestone Corporation | Pneumatic tire |
| WO2007015341A1 (en) * | 2005-08-02 | 2007-02-08 | Bridgestone Corporation | Pneumatic radial tire for heavy load |
| JPWO2007015341A1 (en) * | 2005-08-02 | 2009-02-19 | 株式会社ブリヂストン | Pneumatic radial tires for heavy loads |
| US8002007B2 (en) | 2005-08-02 | 2011-08-23 | Bridgestone Corporation | Pneumatic radial tire for heavy loads |
| JP4856076B2 (en) * | 2005-08-02 | 2012-01-18 | 株式会社ブリヂストン | Heavy duty pneumatic radial tire |
| JP2008195169A (en) * | 2007-02-09 | 2008-08-28 | Bridgestone Corp | Pneumatic tire |
| EP2746067A1 (en) | 2012-12-18 | 2014-06-25 | Hankook Tire Co., Ltd. | Bead reinforcing structure for TBR tire |
| JP2015042545A (en) * | 2014-10-27 | 2015-03-05 | 株式会社ブリヂストン | Pneumatic tire |
| WO2020261599A1 (en) * | 2019-06-24 | 2020-12-30 | 株式会社ブリヂストン | Tire |
| JP2021000948A (en) * | 2019-06-24 | 2021-01-07 | 株式会社ブリヂストン | tire |
| CN113966283A (en) * | 2019-06-24 | 2022-01-21 | 株式会社普利司通 | Tyre for vehicle wheels |
| EP3988344A4 (en) * | 2019-06-24 | 2023-07-26 | Bridgestone Corporation | Tire |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3808595B2 (en) | 2006-08-16 |
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