JPH0211405A - Pneumatic radial tire for high pressure and heavy load - Google Patents
Pneumatic radial tire for high pressure and heavy loadInfo
- Publication number
- JPH0211405A JPH0211405A JP63157913A JP15791388A JPH0211405A JP H0211405 A JPH0211405 A JP H0211405A JP 63157913 A JP63157913 A JP 63157913A JP 15791388 A JP15791388 A JP 15791388A JP H0211405 A JPH0211405 A JP H0211405A
- Authority
- JP
- Japan
- Prior art keywords
- tire
- bead
- carcass
- load
- internal pressure
- 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
- 239000011324 bead Substances 0.000 claims abstract description 65
- 238000000926 separation method Methods 0.000 claims description 17
- 239000000835 fiber Substances 0.000 claims description 3
- 230000002787 reinforcement Effects 0.000 claims description 2
- DOSMHBDKKKMIEF-UHFFFAOYSA-N 2-[3-(diethylamino)-6-diethylazaniumylidenexanthen-9-yl]-5-[3-[3-[4-(1-methylindol-3-yl)-2,5-dioxopyrrol-3-yl]indol-1-yl]propylsulfamoyl]benzenesulfonate Chemical compound C1=CC(=[N+](CC)CC)C=C2OC3=CC(N(CC)CC)=CC=C3C(C=3C(=CC(=CC=3)S(=O)(=O)NCCCN3C4=CC=CC=C4C(C=4C(NC(=O)C=4C=4C5=CC=CC=C5N(C)C=4)=O)=C3)S([O-])(=O)=O)=C21 DOSMHBDKKKMIEF-UHFFFAOYSA-N 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 7
- 238000005452 bending Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229920002302 Nylon 6,6 Polymers 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
Landscapes
- Tires In General (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
この発明は高内圧、重荷重にて使用される空気入りラジ
アルタイヤ、例えば、航空機用ラジアルタイヤについて
のビード耐久性能の向上に関連する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improving the bead durability of pneumatic radial tires used under high internal pressure and heavy loads, such as radial tires for aircraft.
（従来の技術）
−Ｃにラジアルタイヤの場合、カーカスのプライをビー
ドコアのまわりで内側から外側に巻き返した構造が広（
用いられているが、特に航空機用タイヤのように高内圧
で使用されるタイヤでは、複数プライそれも特に少なく
とも一層はビードコアのまわりでタイヤの内側から外側
へ折り返した内側カーカスと、この内側カーカスをその
巻き返しも含め外包みしてビードコアの少なくとも直下
まで巻込んだ少なくとも一層の外側カーカスとを有する
アップ−ダウン構造が使われ、それというのは長期間高
内圧で使用される際カーカスのブライ巻き返し部でタイ
ヤに充てんした内圧により引き抜けようとする力が働く
ことすなわちカーカスとビードコアとの間に生じる過度
のせん断力を外側カーカスにより軽減でき、巻き返し部
におけるセパレーションの発生を有利に抑制し得るため
である。(Prior art) - In the case of a radial tire, the carcass ply is wound around the bead core from the inside to the outside to create a wide (
However, especially in tires used at high internal pressures such as aircraft tires, multiple plies, especially at least one layer, include an inner carcass that is folded around the bead core from the inside of the tire to the outside; An up-down structure is used having at least one layer of the outer carcass wrapped around the turn-up to at least just below the bead core, which means that during long-term use at high internal pressures, the braai turn-up of the carcass This is because the outer carcass can reduce the excessive shearing force that occurs between the carcass and the bead core due to the internal pressure filled in the tire, which causes the tire to pull out. be.
しかし乍ら重荷重用ラジアルタイヤ、とくに大型航空機
用の空気入りラジアルタイヤでは負荷荷重が著しく高く
従って撓みが大きいので、リムのフランジ上における荷
重下の接触部での接触圧が高く、しかもこの部分での変
形が大きいところ、特にアップ−ダウン構造のカーカス
よりなるタイヤの場合は、ビード下部が内側カーカスと
外側カーカスとで囲まれてビード剛性が高められること
に加えて外側カーカスとリムフランジとの間のゴム部分
に上記の変形が集中するために、このゴム部分と外側カ
ーカスとの間でのセパレーションや、リムフランジとの
接触位置でのゴムのクランクが生じ易く、ひいてはビー
ド耐久性能
えなかった。However, in radial tires for heavy loads, especially pneumatic radial tires for large aircraft, the applied load is extremely high and the deflection is large, so the contact pressure at the contact area under load on the flange of the rim is high. Where deformation is large, especially in the case of tires with an up-down carcass, the lower part of the bead is surrounded by the inner carcass and the outer carcass, increasing bead rigidity. Since the above deformation concentrates on the rubber part, separation between this rubber part and the outer carcass and rubber cranking at the contact position with the rim flange are likely to occur, resulting in poor bead durability.
そこでこの発明は、上記の問題を有利に解決し得る耐久
性に優れたビード構造を提供することがその目的である
。Therefore, an object of the present invention is to provide a bead structure with excellent durability that can advantageously solve the above problems.
（課題を解決するための手段）
この発明は、タイヤ赤道面に対して７０°〜９０゜のコ
ード角度にて配列した有機繊維コードの複数プライより
なり、１対のビードコアのまわりにタイヤの内側から外
側へ巻き返したトロイド状をなす少なくとも一層の内側
カーカスと、この内側カーカスをその巻き返しも含め外
包みしてビードコアの少なくとも直下まで巻き込んだ少
なくとも一層の外側カーカスとをボディ補強としてそな
える空気入リタイヤにおいて、標準内圧のもとで標準荷
重を負荷したタイヤの荷重下におけるビード部ボディ外
皮とリムのフランジとの接触の離反点（ｅ）に相当する
、ビード部ボディ外皮の外断面輪郭上の点（ｅ′）から
上記荷重を除いたタイヤの標準内圧充てん姿勢における
内側カーカスのパスライン上におろした法線（ｎ）上で
の、タイヤ外断面輪郭から内側カーカスの層中心までの
距離（Ａ）に対する、ビードコアの中心を通りタイヤ回
転軸線に平行な基準線（ｍ）上での、ビード部ボディ外
皮の外断面輪郭から内側カーカスの層中心までの距離（
Ｂ）の比（Ｂ） ／（＾）が１．８以上であること、を
特徴とする高内圧重荷重用空気入りラジアルタイヤであ
る。(Means for Solving the Problems) This invention consists of a plurality of plies of organic fiber cords arranged at a cord angle of 70° to 90° with respect to the tire equatorial plane, and is arranged around a pair of bead cores on the inside of the tire. In a pneumatic retirement tire, the pneumatic tire is provided with at least one layer of an inner carcass in a toroidal shape that is rolled back outward from the ground, and at least one layer of outer carcass that is wrapped around the inner carcass including the rolled-back part and rolled up to at least just below the bead core as body reinforcement. , a point ( Distance (A) from the outer cross-sectional contour of the tire to the layer center of the inner carcass on the normal line (n) drawn on the pass line of the inner carcass in the standard internal pressure filling position of the tire with the above load removed from e') , the distance from the outer cross-sectional contour of the bead body outer skin to the layer center of the inner carcass on the reference line (m) passing through the center of the bead core and parallel to the tire rotation axis (
This is a pneumatic radial tire for heavy loads with high internal pressure, characterized in that the ratio (B)/(^) of B) is 1.8 or more.
ここに上記の比Ｂ／Ａをとくに２．０以上にすると、ま
たさらに、標準内圧のもとで標準荷重を負荷したタイヤ
の荷重下におけるビード部ボディ外皮とリムのフランジ
との接触の離反点（ｅ）に相当する、ビード部ボディ外
皮の外断面輪郭上の点（ｅ′）から上記荷重を除いたタ
イヤの標準内圧充てん姿勢における内側カーカスのパス
ライン上におろした法線（ｎ）上での、タイヤ外断面輪
郭から外側カーカスの層中心までの距Ｍ （Ｃ） と、
ビードコアの中心を通りタイヤ回転軸線に平行な基準線
（ｍ）上での、ビード部ボディ外皮の外断面輪郭から外
側カーカスの層中心までの距離（Ｄ）の比、（Ｃ）／（
Ｄ）が２．３以下であるより好ましくは２．０以下であ
ること、加えて標準内圧のもとで標準荷重を負荷したタ
イヤの荷重下におけるビード部ボディ外皮とリムのフラ
ンジとの接触の離反点（ｅ）に相当する、ビード部ボデ
ィ外皮の外断面輪郭上の点（ｅ′）から上記荷重を除い
たタイヤの標準内圧充てん姿勢におけるビード部ボディ
外皮とリムのフランジとの接触の離反点（ｈ）に至るま
での間の領域における、上記荷重を除いたタイヤの標準
内圧充てん姿勢におけるボディ外皮の外断面輪郭が、上
記各点（ｅ′）及び（ｈ）より、上記荷重を除いたタイ
ヤの標準内圧充てん姿勢における内側カーカスのパスラ
イン上にそれぞれおろした法線（ｎｔ ｎ’ ）に囲ま
れる領域における内側カーカスのパスライン曲率に比し
より小さい曲率を有するものとすることがより有利であ
る。Here, if the above ratio B/A is particularly set to 2.0 or more, furthermore, the separation point of the contact between the bead body outer skin and the rim flange under the load of a tire loaded with a standard load under a standard internal pressure. Corresponding to (e), on the normal line (n) drawn on the pass line of the inner carcass in the standard internal pressure filling position of the tire with the above load removed from the point (e') on the outer cross-sectional contour of the bead body outer skin. The distance M (C) from the tire outer cross-sectional contour to the layer center of the outer carcass,
The ratio of the distance (D) from the outer cross-sectional contour of the bead body skin to the layer center of the outer carcass on the reference line (m) passing through the center of the bead core and parallel to the tire rotation axis, (C)/(
D) is 2.3 or less, more preferably 2.0 or less, and in addition, the contact between the bead body outer skin and the rim flange under the load of a tire loaded with a standard load under standard internal pressure. Separation of the contact between the bead body skin and the rim flange in the standard internal pressure filling position of the tire where the above load is removed from the point (e') on the outer cross-sectional contour of the bead body skin, which corresponds to the separation point (e). The outer cross-sectional contour of the body skin in the standard internal pressure filling position of the tire excluding the above load in the area up to point (h) is calculated from each point (e') and (h) above, excluding the above load. It is preferable that the tire has a smaller curvature than the pass line curvature of the inner carcass in the area surrounded by the normal line (nt n') drawn on the pass line of the inner carcass in the standard internal pressure filling position of the tire. It's advantageous.
なお上記したところにおいて「標準内圧」 「標準荷重
」というのはザ・タイヤ・アンド・リム・アソシエージ
ョン・スタンダード（Ｔｈｅ Ｔｉｒｅ ａｎｄＲｉＩ
ＩＩＡｓｓｏｃｉａｔｉｏｎ ５ｔａｎｄａｒｄｓ ）
の規格の無負荷時内圧及び標準内圧充てん下の最大荷重
を意味するものとする。In the above, "standard internal pressure" and "standard load" are defined by The Tire and Rim Association Standard (The Tire and RiI
IIAssociation 5 standards)
It shall mean the maximum load under no-load internal pressure and standard internal pressure filling according to the standard.
カーカスのパスラインとは、タイヤの回転軸を含む断面
で内側及び外側のそれぞれのカーカスを構成するコード
層の厚み中心を通る曲線を指す。The carcass pass line refers to a curve that passes through the center of thickness of the cord layer forming each of the inner and outer carcass in a cross section that includes the rotational axis of the tire.
第１図〜第５図にこの発明に従い、アップ−ダウン構造
カーカスをボディ補強とする航空機用空気入りラジアル
タイヤの具体例を、要部断面にて示し、図中１はリム、
２はビードコア、３ａは内側カーカス、３ｂは外側カー
カスであり、４はビード部ボディ外皮、５はリム１のフ
ランジであって、標準内圧充てん姿勢を実線で、とくに
第１図には標準荷重を負荷することによるビード部の変
形状態を仮想線にて対比しである。FIGS. 1 to 5 show a specific example of a pneumatic radial tire for aircraft according to the present invention in which the body is reinforced by an up-down structure carcass, and 1 in the figure shows a rim,
2 is the bead core, 3a is the inner carcass, 3b is the outer carcass, 4 is the outer skin of the bead body, and 5 is the flange of the rim 1.The solid line indicates the standard internal pressure filling position, and in particular, the standard load is shown in Fig. 1. The state of deformation of the bead portion due to loading is compared using virtual lines.
標準荷重の負荷により、リム１のフランジ５に対するビ
ード部ボディ外皮４の無負荷時における接触の離反点り
は、図のｅ点に移る間にビード部の変形を生じるが、こ
の負荷時離反点ｅに相当する、ビード部ボディ外皮４の
外断面輪郭上の点ｅ′を基準として、無負荷時における
内側カーカス３ａの層中心に至る垂直距離Ａに対して、
ボディ外皮４がリムｌのフランジ５に接する位置から、
タイヤの回転軸と平行なビードコア２の中心を通る基準
線ｍに沿って測った内側カーカス３ａの層中心までの距
離Ｂの比をとり、また同様に、点ｅ′から外側カーカス
３ｂの層中心に至る垂直距離Ｃと、基準線ｍに沿って外
側カーカス３ｂの層中心がフランジ５から隔たる距離り
との比をとって、第１図〜第３図の例ではＡ／Ｂを２．
２、Ｃ／Ｄ は順に１．５．２．０．２．２また第４
図ではＡ／Ｂが１．９、Ｃ／Ｄは２．２であり、これに
対して第６図、第７図の比較例では Ａ／Ｂが順に１．
６．１．４ 、 Ｃ／Ｄはそれぞれ２．９である。Due to the standard load, the contact separation point of the bead part body skin 4 against the flange 5 of the rim 1 under no load will cause deformation of the bead part while moving to point e in the figure. With respect to the vertical distance A to the layer center of the inner carcass 3a under no load, with reference to point e' on the outer cross-sectional contour of the bead body skin 4, which corresponds to e,
From the position where the body skin 4 touches the flange 5 of the rim l,
Take the ratio of the distance B to the layer center of the inner carcass 3a measured along the reference line m passing through the center of the bead core 2 parallel to the rotation axis of the tire, and similarly, calculate the distance B from the point e' to the layer center of the outer carcass 3b. By taking the ratio of the vertical distance C to the flange 5 and the distance separating the layer center of the outer carcass 3b from the flange 5 along the reference line m, A/B is calculated as 2.
2, C/D is 1.5.2.0.2.2 and 4th
In the figure, A/B is 1.9 and C/D is 2.2, whereas in the comparative examples shown in FIGS. 6 and 7, A/B is 1.9 and C/D is 2.2.
6.1.4 and C/D are 2.9, respectively.
まずボディ外皮４の点ｅ’ −ｈ間における外断面輪郭
の曲率は、法線ｎ−ｎ’間での内側カーカス３ａのパス
ラインが通常タイヤの内側に曲率中心を有する外向きに
凸であることがらそれに比して小さいということの中に
、曲率の向き（符号）が反転して外向きに凹をなすよう
な第１図、第２図の場合を当然に含んでいる。First, the curvature of the outer cross-sectional contour between points e' and h of the body skin 4 is such that the pass line of the inner carcass 3a between normal lines n and n' is convex outward with the center of curvature usually inside the tire. 1 and 2, where the direction (sign) of the curvature is reversed and concave outwards is included in the fact that the curve is smaller than that shown in FIGS.
（作 用）
すでに述べたように、重荷重用ラジアルタイヤ、例えば
航空機用ラジアルタイヤの場合に撓みが大きい上にリム
フランジとの接触部での接触圧が高く、ビード部の故障
はこの領域に集中する。(Function) As mentioned above, in the case of heavy-duty radial tires, such as radial tires for aircraft, there is a large amount of deflection and the contact pressure at the contact area with the rim flange is high, and failures at the bead are concentrated in this area. do.
そこでこの接触圧の低減を図るため、種々検討の結果、
タイヤ内部のカーカス構造並びにリムＩのフランジ５と
タイヤのボディ外皮４との接触の離反点りからフランジ
５の外縁に至る空隙の形状が大きく影響することが明ら
かになった。Therefore, in order to reduce this contact pressure, as a result of various studies,
It has become clear that the carcass structure inside the tire and the shape of the gap from the point of separation of contact between the flange 5 of the rim I and the tire body skin 4 to the outer edge of the flange 5 have a large influence.
すなわちタイヤに荷重が負荷されると、無負荷の状Ｍ（
内圧充てん）でのリムｌのフランジ５とタイヤのボディ
外皮４との離反点りを起点にビード部がフランジ５に沿
って折れ曲がる変形をするが、その際に内側カーカス３
ａのパスラインが、よりタイヤの内方に入っている程、
負荷時にビード部曲率変化の大きい折れ曲がり点はより
径方向外側に移動するためにリム１のフランジ５との接
触圧が低下し、さらにその際に無負荷の状態（内圧充て
ん）におけるリム１のフランジ５とタイヤのボディ外皮
４との上記空隙が大きい程、負荷時の接触圧が低下する
ことがつきとめられたわけである。In other words, when a load is applied to the tire, the unloaded state M(
The bead part bends along the flange 5 starting from the point of separation between the flange 5 of the rim l and the tire body skin 4 at the time of internal pressure filling, but at this time the inner carcass 3
The further the pass line of a is inward of the tire,
The bending point where the bead curvature changes significantly when loaded moves further radially outward, so the contact pressure with the flange 5 of the rim 1 decreases, and furthermore, the contact pressure with the flange 5 of the rim 1 in the no-load state (internal pressure filling) decreases. It was found that the larger the gap between the tire body skin 4 and the tire body skin 4, the lower the contact pressure under load.
従ってビード部における内側カーカス３ａのパスライン
をできるだけ内側に入れ、かつ空隙域を大きくするには
ビードコア２の中心を通りタイヤ回転軸線に平行な基準
線ｍ上でのタイヤ外断面輪郭から内側カーカス３ａの層
中心までの距離Ｂと、負荷時に荷重下におけるビード部
のボディ外皮４とリム１のフランジ５との離反点（ｅ）
に相当する、無負荷の状態での点（ｅ′）から、内側カ
ーカス３ａのパスラインにおろした法線ｎ上での内側カ
ーカス３ａＮ中心までの距ＭＡとの比、Ｂ／Ａを大きく
１．８以上、より好ましくは２．０以上とすることで荷
重時のタイヤボディ外皮４とリム１のフランジ５との接
触圧を第５図に実測結果の一例につき図示したごとく、
大幅に低減することができ、ひいては該部分に生じ易い
ゴムのクランクや、外側カーカス層とゴム界面でのセパ
レーションを有利に防ぐことが可能となる。Therefore, in order to place the pass line of the inner carcass 3a in the bead part as far inward as possible and to enlarge the gap area, the inner carcass 3a is measured from the outer cross-sectional contour of the tire on the reference line m passing through the center of the bead core 2 and parallel to the axis of rotation of the tire. The distance B to the center of the layer and the separation point (e) between the body skin 4 of the bead part and the flange 5 of the rim 1 under load.
The ratio of the distance MA from the point (e') under no load to the center of the inner carcass 3aN on the normal n drawn to the pass line of the inner carcass 3a, B/A, is increased by 1. .8 or more, more preferably 2.0 or more, the contact pressure between the tire body outer skin 4 and the flange 5 of the rim 1 under load is as shown in FIG. 5 as an example of the actual measurement results.
This can be significantly reduced, and in turn, it is possible to advantageously prevent rubber cranking and separation at the outer carcass layer and rubber interface, which tend to occur in this area.
また負荷時にタイヤのボディ外皮４とリム１のフランジ
５が接触する領域においては、外側カーカス３ｂの外側
を占めているゴム厚みが厚過ぎると同一の接触圧でも発
熱が高くなり耐久上不利となることから、あまり厚くし
ない方が良く、しかも上記したＢ／Ａの値につき１．８
以上を得るためにも、ビードコア２の中心を通りタイヤ
回転軸線に平行な基準線ｍ上でのタイヤ外断面輪郭から
外側カーカス３ｂ層中心までの距離りに対する、負荷時
に荷重下におけるビード部ボディ外皮４とリム１のフラ
ンジ５との離反点（ｅ）に相当する無負荷の状態での点
（ｅ′）から内側カーカス３ａのパスラインにおろした
法線ｎ上での外側カーカス３ｂの層中心までの距離Ｃの
比Ｃ／Ｄが２．３以下、好ましくは２．０以下であるこ
とが一層望ましいわけである。In addition, in the area where the tire body outer skin 4 and the flange 5 of the rim 1 contact each other during load, if the rubber occupying the outside of the outer carcass 3b is too thick, heat generation will increase even with the same contact pressure, which will be disadvantageous in terms of durability. Therefore, it is better not to make it too thick, and moreover, it is 1.8 for the B/A value mentioned above.
In order to obtain the above, the bead part body outer skin under load is measured with respect to the distance from the tire outer cross-sectional contour to the center of the outer carcass 3b layer on the reference line m passing through the center of the bead core 2 and parallel to the tire rotation axis. The layer center of the outer carcass 3b on the normal n drawn from the no-load state point (e') corresponding to the separation point (e) of the flange 5 of the rim 1 and the flange 5 of the rim 1 to the pass line of the inner carcass 3a. It is even more desirable for the ratio C/D of the distance C to be 2.3 or less, preferably 2.0 or less.
さらに負荷時にタイヤのボディ外皮４とリム１のフラン
ジ５とが接触する領域において、タイヤ外断面輪郭が外
向きに凸であってしがも大きすぎる曲率を有する場合に
は、リム１のフランジ５の形状とは逆の曲率で接触する
ので接触圧が不均一となり、局所的に高い接触圧が生じ
て耐久性をそこねるおそれがある。なおアンプ−ダウン
カーカス構造のビード部変形は、ビード部が荷重を受は
折れ曲がる際に内側カーカス３ａには引張り歪が生じ、
外側カーカス３ｂには圧縮歪が生じるところ、一般に有
機繊維コードは圧縮側の弾性係数が低いことから引張り
側の内側カーカス３ａの方が、曲げ変形の中立軸に近く
なって、ビード下部全体は、より内側カーカス３ａの変
形に沿って曲げられる。Furthermore, in the area where the tire body outer skin 4 and the flange 5 of the rim 1 contact each other during load, if the tire outer cross-sectional contour is outwardly convex and has an excessively large curvature, the flange 5 of the rim 1 Since the contact has a curvature opposite to that of the shape, the contact pressure becomes non-uniform, and there is a risk that locally high contact pressure may occur, which may impair durability. Note that the deformation of the bead part of the amplifier-down carcass structure is caused by tensile strain occurring in the inner carcass 3a when the bead part receives the load and bends.
Compressive strain occurs in the outer carcass 3b, but since organic fiber cords generally have a low elastic modulus on the compression side, the inner carcass 3a on the tension side is closer to the neutral axis of bending deformation, and the entire lower part of the bead is It is bent more along the deformation of the inner carcass 3a.
そこで内圧を充てんし無負荷の状態でのビード部ボディ
外皮４とリム１のフランジ５の離反点（ｈ）から、負荷
時におけるボディ外皮４とリムＩのフランジ５との離反
点（ｅ）に相当する無負荷の状態での点（ｅ′）の間の
領域におけるボディ外皮４の外断面輪郭が、タイヤ外方
に向かって凸の曲率を有する第３図、第４図に示すよう
な場合は、上記各点りとｅ′から、内圧充てんされ無負
荷の状態における内側カーカス３ａのパスラインにそれ
ぞれおろした法線ｎ、ｎ’に囲まれる領域での内側カ−
カス３ａの曲率に比べてより小さい曲率を有するものと
し、さらに好ましくは第１図、第２図のようにタイヤ外
方に向かって凹の曲率を有することが、負荷時のリムフ
ランジとの接触圧を平均化するために適合するので、耐
久性の面で一層望ましい。Therefore, internal pressure is filled to change from the separation point (h) between the bead body skin 4 and the flange 5 of the rim 1 under no load to the separation point (e) between the body skin 4 and the flange 5 of the rim I under load. In the case shown in FIGS. 3 and 4, the outer cross-sectional contour of the body skin 4 in the area between the points (e') in a corresponding no-load state has a convex curvature toward the outside of the tire. From each of the above points and e', the inner carcass in the area surrounded by the normal lines n and n' taken down to the pass line of the inner carcass 3a in a state filled with internal pressure and no load is calculated.
It has a smaller curvature than the curvature of the scrap 3a, and more preferably has a concave curvature toward the outside of the tire as shown in FIGS. 1 and 2 to prevent contact with the rim flange during load. Since it is adapted to equalize pressure, it is more desirable in terms of durability.
（実施例）
第１図にこの発明に従う高内圧重荷重用空気入りラジア
ルタイヤを、要部の断面で示した。(Example) FIG. 1 shows a cross-section of the main parts of a pneumatic radial tire for high internal pressure and heavy loads according to the present invention.
この例のタイヤサイズは、Ｈ４６Ｘ１８．ＯＲ２０（航
空機用）で、内側カーカス３ａ、外側カーカス３ｂはナ
イロン６６ （１８９０ｄ／３ ）コードよりなるプラ
イを用い、何れもタイヤの赤道面に対してほぼ９０″の
コード角度にて配列し、この場合３層の内側カーカス３
ａと２層の外側カーカス３ｂとでアップ−ダウン構造を
構成している。The tire size in this example is H46X18. OR20 (for aircraft), the inner carcass 3a and the outer carcass 3b are made of ply made of nylon 66 (1890d/3) cord, and both are arranged at a cord angle of approximately 90'' with respect to the equatorial plane of the tire. Case 3 layers of inner carcass 3
A and a two-layer outer carcass 3b constitute an up-down structure.
第２図〜第４図には同一サイズになる他の実施例を、ま
た第６図、第７図には２種の比較例を示し、各図中の記
号は、第１図と同様である。すでに触れた第５図には上
記の各実施例及び比較例についてリム１のフランジ５と
ビード部のボディ外皮４との接触圧と、Ｂ／＾の関係を
示し、ここで接触圧とは、内圧１４．１ ｋｇ／ｃｍ”
で荷重４４２００ Ｌｂｓを負荷した場合における点ｅ
−ｈの領域における接触圧の最大値、すなわち無負荷
の状態から負荷状態への接触圧の変化量を示す。Figures 2 to 4 show other examples of the same size, and Figures 6 and 7 show two comparative examples. The symbols in each figure are the same as in Figure 1. be. The already mentioned FIG. 5 shows the relationship between the contact pressure between the flange 5 of the rim 1 and the body outer skin 4 of the bead portion and B/^ for each of the above-mentioned examples and comparative examples, where the contact pressure is: Internal pressure 14.1 kg/cm”
Point e when a load of 44200 Lbs is applied at
It shows the maximum value of the contact pressure in the region -h, that is, the amount of change in the contact pressure from the no-load state to the loaded state.
表１には実施例及び比較例の各タイヤのビード部耐久性
のドラム試験による評価結果を示す。Table 1 shows the evaluation results of the bead part durability of each tire of Examples and Comparative Examples by a drum test.
このドラム試験は以下の条件で、各タイヤをドラム周上
で毎回３５００ ｆｔの走行距離にて繰り返し走行させ
、ビード部にセパレーションが発生するまでの繰り返し
回数を比較例１について１００とした指数で示し、ビー
ド耐久性とした。In this drum test, each tire was repeatedly run on the drum circumference at a distance of 3,500 ft each time under the following conditions, and the number of repetitions until separation occurred at the bead portion was expressed as an index with Comparative Example 1 set as 100. , bead durability.
試験条件 内圧−−−−−−−−１４，１ｋｇ ／ ｃ
ｍ ”荷重−−−−−５３０４０Ｌｂｓ （２４，０５
８ｋｇ）速度−−−−−４０ＭＰ）ｌ （６４，３７４
ｋｍ／ｈ）表１
３ａ・・・内側カーカス ３ｂ・・・外側カーカス
４・・・ビード部ボディ外皮
５・・・フランジ
（発明の効果）
この発明のタイヤは負荷時にリムｌのフランジ５との間
に生じる接触圧を低減でき、ビード部耐久性が大幅に向
上する。Test conditions Internal pressure---14,1kg/c
m” load---53040Lbs (24,05
8kg) Speed---40MP)l (64,374
km/h) Table 1 3a...Inner carcass 3b...Outer carcass 4...Bead part body outer skin 5...Flange (Effects of the invention) The tire of this invention has a flange 5 of the rim l under load. The contact pressure generated between the two parts can be reduced, and the durability of the bead part can be greatly improved.
第１図〜第４図はこの発明に従う空気入りラジアルタイ
ヤのビード部断面図、
第５図は負荷時のリムフランジとビード部ボディ外皮と
の接触圧と、Ｂ／Ａの関係を示すグラフ、また第６図、
第７図は比較試験のための比較タイヤのビード部断面図
である。1 to 4 are cross-sectional views of the bead portion of a pneumatic radial tire according to the present invention. FIG. 5 is a graph showing the relationship between the contact pressure between the rim flange and the outer skin of the bead portion body under load and B/A. Also, Figure 6,
FIG. 7 is a sectional view of a bead portion of a comparative tire for a comparative test.
Claims (1)
にて配列した有機繊維コードの複数プライよりなり、１
対のビードコア（２）のまわりにタイヤの内側から外側
へ巻き返したトロイド状をなす少なくとも一層の内側カ
ーカス（３ａ）と、この内側カーカスをその巻き返しも
含め外包みしてビードコアの少なくとも直下まで巻き込
んだ少なくとも一層の外側カーカス（３ｂ）とをボディ
補強としてそなえる空気入りタイヤにおいて、 標準内圧のもとで標準荷重を負荷したタイ ヤの荷重下におけるビード部ボディ外皮（４）とリム（
１）のフランジ（５）との接触の離反点（ｅ）に相当す
る、ビード部ボディ外皮（４）の外断面輪郭上の点（ｅ
′）から上記荷重を除いたタイヤの標準内圧充てん姿勢
における内側カーカス（３ａ）のパスライン上におろし
た法線（ｎ）上での、タイヤ外断面輪郭から内側カーカ
ス（３ａ）の層中心までの距離（Ａ）に対する、ビード
コア（２）の中心を通りタイヤ回転軸線に平行な基準線
（ｍ）上での、ビード部ボディ外皮（４）の外断面輪郭
から内側カーカス（３ａ）の層中心までの距離（Ｂ）の
比（Ｂ）／（Ａ）が１．８以上であること を特徴とする高内圧重荷重用空気入りラジアルタイヤ。 ２、標準内圧のもとで標準荷重を負荷したタイヤの荷重
下におけるビード部ボディ外皮（４）とリム（１）のフ
ランジ（５）との接触の離反点（ｅ）に相当する、ビー
ド部ボディ外皮（４）の外断面輪郭上の点（ｅ′）から
上記荷重を除いたタイヤの標準内圧充てん姿勢における
内側カーカス（３ａ）のパスライン上におろした法線（
ｎ）上での、タイヤ外断面輪郭から外側カーカス（３ｂ
）の層中心までの距離（Ｃ）と、ビードコア（２）の中
心を通りタイヤ回転軸線に平行な基準線（ｍ）上での、
ビード部ボディ外皮（４）の外断面輪郭から外側カーカ
ス（３ｂ）の層中心までの距離（Ｄ）との比、（Ｃ）／
（Ｄ）が２．３以下であること を特徴とする特許請求の範囲第１項に記載の高内圧重荷
重用空気入りラジアルタイヤ。 ３、標準内圧のもとで標準荷重を負荷したタイヤの荷重
下におけるビード部ボディ外皮（４）とリム（１）のフ
ランジ（５）との接触の離反点（ｅ）に相当する、ビー
ド部ボディ外皮（４）の外断面輪郭上の点（ｅ′）から
上記荷重を除いたタイヤの標準内圧充てん姿勢における
ビード部ボディ外皮（４）とリム（１）のフランジ（５
）との接触の離反点（ｈ）に至るまでの間の領域におけ
る、上記荷重を除いたタイヤの標準内圧充てん姿勢にお
けるボディ外皮（４）の外断面輪郭が、上記各点（ｅ′
）及び（ｈ）より、上記荷重を除いたタイヤの標準内圧
充てん姿勢における内側カーカス（３ａ）のパスライン
上にそれぞれおろした法線（ｎ、ｎ′）に囲まれる領域
における内側カーカス（３ａ）のパスライン曲率に比し
より小さい曲率を有すること を特徴とする特許請求の範囲第１項又は第２項に記載の
高内圧重荷重用空気入りラジアルタイヤ。[Scope of Claims] 1. Consisting of a plurality of plies of organic fiber cords arranged at a cord angle of 70° to 90° with respect to the tire equatorial plane, 1.
At least one inner carcass (3a) in a toroidal shape is wound around the pair of bead cores (2) from the inside to the outside of the tire, and this inner carcass is wrapped around the outside, including the rolled-up part, and rolled up to at least just below the bead cores. In a pneumatic tire having at least one outer carcass (3b) as body reinforcement, the bead body outer skin (4) and the rim (
The point (e) on the outer cross-sectional contour of the bead body outer skin (4) corresponds to the separation point (e) of contact with the flange (5) in 1).
From the outer cross-sectional contour of the tire to the layer center of the inner carcass (3a) on the normal line (n) drawn on the pass line of the inner carcass (3a) in the standard internal pressure filling position of the tire with the above load removed from ') From the outer cross-sectional contour of the bead body skin (4) to the layer center of the inner carcass (3a) on the reference line (m) passing through the center of the bead core (2) and parallel to the tire rotation axis for the distance (A) of A pneumatic radial tire for high internal pressure and heavy loads, characterized in that the ratio (B)/(A) of the distance to (B) is 1.8 or more. 2. Bead portion corresponding to the separation point (e) of contact between the body outer skin (4) and the flange (5) of the rim (1) under the load of a tire loaded with a standard load under standard internal pressure. A normal line (
n) from the tire outer cross-sectional contour to the outer carcass (3b
) on the reference line (m) passing through the center of the bead core (2) and parallel to the tire rotation axis,
The ratio of the distance (D) from the outer cross-sectional contour of the bead body skin (4) to the layer center of the outer carcass (3b), (C)/
The pneumatic radial tire for high internal pressure and heavy loads according to claim 1, wherein (D) is 2.3 or less. 3. The bead portion corresponds to the separation point (e) of the contact between the body outer skin (4) and the flange (5) of the rim (1) under the load of a tire loaded with a standard load under standard internal pressure. The bead part of the body skin (4) and the flange (5) of the rim (1) in the standard internal pressure filling position of the tire with the above load removed from the point (e') on the outer cross-sectional contour of the body skin (4).
) The outer cross-sectional contour of the body skin (4) in the standard internal pressure filling position of the tire excluding the above-mentioned load in the region up to the separation point (h) of contact with the above-mentioned points (e'
) and (h), the inner carcass (3a) in the area surrounded by the normal lines (n, n') placed on the pass line of the inner carcass (3a) in the standard internal pressure filling position of the tire excluding the above load. The high internal pressure, heavy load pneumatic radial tire according to claim 1 or 2, characterized in that the pneumatic radial tire has a smaller curvature than the pass line curvature of the tire.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63157913A JP2713735B2 (en) | 1988-06-28 | 1988-06-28 | Pneumatic radial tires for high internal pressure and heavy loads |
| GB8909687A GB2218676B (en) | 1988-04-28 | 1989-04-27 | Heavy duty pneumatic radial tire. |
| FR8905606A FR2632252B1 (en) | 1988-04-28 | 1989-04-27 | INTERNAL HIGH PRESSURE REINFORCED RADIAL TIRE |
| GB9215787A GB2256174A (en) | 1988-04-28 | 1992-07-24 | Heavy duty pneumatic radial tire. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63157913A JP2713735B2 (en) | 1988-06-28 | 1988-06-28 | Pneumatic radial tires for high internal pressure and heavy loads |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0211405A true JPH0211405A (en) | 1990-01-16 |
| JP2713735B2 JP2713735B2 (en) | 1998-02-16 |
Family
ID=15660192
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63157913A Expired - Lifetime JP2713735B2 (en) | 1988-04-28 | 1988-06-28 | Pneumatic radial tires for high internal pressure and heavy loads |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2713735B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11227423A (en) * | 1998-02-18 | 1999-08-24 | Bridgestone Corp | Pneumatic radial tire for heavy load |
| JP2002036829A (en) * | 2000-07-28 | 2002-02-06 | Bridgestone Corp | Radial tire for airplane |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS638006A (en) * | 1986-06-30 | 1988-01-13 | Yokohama Rubber Co Ltd:The | Radial tyre for small truck |
-
1988
- 1988-06-28 JP JP63157913A patent/JP2713735B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS638006A (en) * | 1986-06-30 | 1988-01-13 | Yokohama Rubber Co Ltd:The | Radial tyre for small truck |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11227423A (en) * | 1998-02-18 | 1999-08-24 | Bridgestone Corp | Pneumatic radial tire for heavy load |
| JP2002036829A (en) * | 2000-07-28 | 2002-02-06 | Bridgestone Corp | Radial tire for airplane |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2713735B2 (en) | 1998-02-16 |
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