JPH04193603A - Radial tire for passenger car - Google Patents
Radial tire for passenger carInfo
- Publication number
- JPH04193603A JPH04193603A JP2331101A JP33110190A JPH04193603A JP H04193603 A JPH04193603 A JP H04193603A JP 2331101 A JP2331101 A JP 2331101A JP 33110190 A JP33110190 A JP 33110190A JP H04193603 A JPH04193603 A JP H04193603A
- Authority
- JP
- Japan
- Prior art keywords
- belt
- tire
- radius
- curvature
- width
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011324 bead Substances 0.000 claims description 9
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 239000004760 aramid Substances 0.000 claims 1
- 229920003235 aromatic polyamide Polymers 0.000 claims 1
- 239000011347 resin Substances 0.000 claims 1
- 229920005989 resin Polymers 0.000 claims 1
- 230000000694 effects Effects 0.000 description 5
- 230000007423 decrease Effects 0.000 description 3
- 230000008602 contraction Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- 229920000297 Rayon Polymers 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 239000002964 rayon Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000004804 winding 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〕
本発明は、車両の片流れを改善でき、直進走行性能を高
めうる乗用車用ラジアルタイヤに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radial tire for a passenger car that can improve one-sided drift of a vehicle and improve straight running performance.
近年の車両の高性能化、道路網の整備に伴い、タイヤに
ついても、耐久性、操縦安定性、乗心地などの諸性能に
加えて、例えばハンドルを平畦した際において所定の距
離を走行する間に、その直進方向線に対して片側に位置
ずれし横流れする、いわゆる車両の片流れを減じ、直進
走行安定性を高めるなど、さらに運転の快適性を改善す
ることが望まれている。In recent years, with the improvement of vehicle performance and the improvement of road networks, tires have not only improved performance such as durability, handling stability, and ride comfort, but also the ability to travel a specified distance when the steering wheel is flattened. In the meantime, it is desired to further improve driving comfort by reducing so-called one-sided drift of the vehicle, in which the vehicle drifts to one side with respect to the straight direction line, and improves straight running stability.
従来、この車両の片流れは、トレッド部のタイヤ軸方向
左右において、特にベルト層の周長が異なることにより
円錐状となる円錐度に起因するものとされ、従って、タ
イヤ軸方向左右の均等性を高めるべく、種々の対策がと
られていた。Conventionally, this one-sided flow of a vehicle is thought to be caused by the degree of conicity in which the tread portion becomes conical on the left and right sides in the axial direction of the tire, especially due to the difference in the circumferential length of the belt layer. Various measures were taken to increase this.
しかしながら、この円錐度のみの改善によっては、車両
の片流れを充分には防止しえないのが判明した。However, it has been found that the one-sided drift of the vehicle cannot be sufficiently prevented by improving only the conicity.
他方、近年のタイヤ測定技術の進歩によって、第４図に
略示するごとく、タイヤ進行方向Ｘに対して微小のスリ
ップ角αを付与したときの、タイヤ横方向Ｙに生じるコ
ーナリングフォース、即ち横力Ｆと、タイヤ中心を通る
垂直軸Ｚまわりでスリップ角αの方向に回転するセルフ
ァライニングトルクＳＡＴとを高精度で計測することが
可能となった。On the other hand, with recent advances in tire measurement technology, as shown schematically in Fig. 4, the cornering force generated in the tire lateral direction Y when a minute slip angle α is applied to the tire traveling direction X, that is, the lateral force. It has become possible to measure with high accuracy F and the self-lining torque SAT that rotates in the direction of the slip angle α around the vertical axis Z passing through the center of the tire.
このような計測結果は、キャンバ−角βをＯとして、例
えば第５図に示すように、横軸にセルファライニングト
ルクＳＡＴを、縦軸に横力Ｆを用いて直線Ｋを用いて示
される。又直線Ｋにおいて、スリップ角αが０度、−０
，２度、＋０．４度の場合、 を黒丸で示している。Such measurement results are shown using a straight line K, with the camber angle β being O, and the self-lining torque SAT on the horizontal axis and the lateral force F on the vertical axis, as shown in FIG. 5, for example. Also, in the straight line K, the slip angle α is 0 degrees, -0
, 2 degrees, and +0.4 degrees are indicated by black circles.
このように、ラジアルタイヤにおいては、一般に、直進
走行状態においても、横力Ｆ１セルファライニングトル
クＳＡＴが発生している。なおスリップ角α、キャンバ
−角βかともにＯであるときの横力Ｆは、ＬＦＤ （ラ
テラルフォースデビエーション）と言われる。As described above, in a radial tire, the lateral force F1 self-lining torque SAT is generally generated even when the vehicle is traveling straight. Note that the lateral force F when both the slip angle α and the camber angle β are O is called LFD (lateral force deviation).
このようなセルファライニングトルクＳＡＴ。Such self-lining torque SAT.
横力Ｆとの関係において、前記直線Ｋが縦軸と交わる交
点に１の横力Ｆ１即ちセルファライニングトルクＳＡＴ
が生じないときの横力Ｆを残余ＣＦと名付けるこの残余
ＣＦが車両の片流れに影響を及ぼすことが判明した。即
ちこの残余ＣＦがプラス方向であるとき車両が右方向に
片流れすることを意味するように、残余ＣＦの向き、大
きさによって車両の片流れ性を評価でき、従って車両の
片流れを防止するには、この残余ＣＦを低下することが
必要となる。In relation to the lateral force F, a lateral force F1 of 1, that is, a self-lining torque SAT, is generated at the intersection of the straight line K and the vertical axis.
The lateral force F when no lateral force F is generated is called the residual CF.It has been found that this residual CF influences the one-sided flow of the vehicle. In other words, when this residual CF is in a positive direction, it means that the vehicle drifts to the right, so the direction and size of the residual CF can be used to evaluate the vehicle's unilateral drift. Therefore, in order to prevent the vehicle from drifting in one direction, It is necessary to reduce this residual CF.
なお、タイヤの組付に際して、前記残余ＣＦ。In addition, when assembling the tire, the residual CF is removed.
セルファライニングトルクＳＡＴは、タイヤ側面を進行
方向に対して右又は左に変化させ、いわゆる表組、表組
をした際においては、第６図に表組の直線に１、表組の
直線に２に示すように、２つの平行な直線となる。又同
図に示すように、ともにスリップ角α、キャンバ−角β
がともにＯの場合における横力の平均値をプライステア
とよび、各平均値からの偏差を、横力Ｆにおけるコニシ
ティと定義している。Self-lining torque SAT changes the side surface of the tire to the right or left with respect to the traveling direction, and when performing so-called table setting or table setting, the self lining torque SAT is 1 for the line of the table set and 2 for the line of the table set as shown in Figure 6. As shown, there are two parallel straight lines. Also, as shown in the same figure, both slip angle α and camber angle β
The average value of lateral force when both are O is called plysteer, and the deviation from each average value is defined as conicity in lateral force F.
さらに車両の片流れと、残余ＣＦ、残余セルファライニ
ングトルクＳＡＴとの関係において、ノ１ンドルを手離
しして走行する際には、合計のセルファライニングトル
クＳＡＴがＯとなるため、従ってこのとき、タイヤには
残余ＣＦが発生することとなる。通常、これにさらにコ
ニシティに基づく力が作用し、車両には、残余ＣＦの合
力とコニシティに基づく横力が、タイヤに関して車両に
発生する。Furthermore, in the relationship between the one-sided flow of the vehicle, the residual CF, and the residual self-lining torque SAT, when driving with the steering wheel released, the total self-lining torque SAT becomes O, so at this time, the tire A residual CF will be generated. Usually, a force based on conicity is further applied to this, and a lateral force based on the resultant force of the residual CF and conicity is generated on the vehicle with respect to the tire.
なお残余ＣＦと、車両流れの一例を第７図に示す。この
車両の片流れ量は、時速５０ｋｍで１００ｍを、ハンド
ルを手離し状態で走行させたときに生じる横ずれ量であ
り、第７図はサイズ２１５ＳＲ１５のタイヤを用いて測
定している。このように残余ＣＦと車両流れとは、相関
関係を有するのがわかる。An example of the remaining CF and vehicle flow is shown in FIG. The amount of one-sided drift of this vehicle is the amount of lateral deviation that occurs when the vehicle is driven for 100 meters at a speed of 50 km/h without the handlebars being held, and is measured using tires of size 215SR15 in FIG. 7. It can thus be seen that the residual CF and the vehicle flow have a correlation.
ここで、コニシティを所定の値以下とすることを前提と
して、残余ＣＦはタイヤのトレッドパターンと、ベルト
層の構造とによって変化することが見出されている。Here, it has been found that the residual CF changes depending on the tread pattern of the tire and the structure of the belt layer, assuming that the conicity is kept below a predetermined value.
しかも、本発明者が車両の片流れについてさらに研究を
行った結果、同じ路面かつ同し距離を走行するときにも
、車両の片流れは、車両速度によって変化することが判
明した。この原因についてさらに考察を加えかつ種々試
験を行った結果、時速１１００ｋと、時速２０ｋｍのと
きとのＬｏｏｍを手離し走行したときの車両の片流れ量
の差として定義される車両の片流れの速度依存性は、残
余ＣＦの速度依存性、即ち時速１１００ｋと、時速２０
ｂのときとの残余ＣＦ量の差に相関することを見出した
。その相関を第２図に示している。このことは、車両の
片流れを減じるには残余ＣＦを減じることが前提である
とはいえ、車両速度の変化による車両の片流れの変化を
減じるためには、残余ＣＦの速度依存性を低減すること
が必要になる。Further, as a result of further research by the present inventor regarding the one-sided flow of a vehicle, it was found that the one-sided flow of a vehicle changes depending on the vehicle speed even when traveling on the same road surface and the same distance. As a result of further consideration of this cause and conducting various tests, we found that the speed dependence of the one-sided flow of the vehicle, defined as the difference in the amount of one-sided flow of the vehicle when driving with hands off at 1100 km/h and 20 km/h. is the speed dependence of the residual CF, i.e. 1100kph and 20kph
It was found that there is a correlation with the difference in the amount of residual CF from the case of b. The correlation is shown in Figure 2. Although this means that reducing the residual CF is a prerequisite to reducing the one-sided flow of the vehicle, in order to reduce the change in the one-sided flow of the vehicle due to changes in vehicle speed, it is necessary to reduce the speed dependence of the residual CF. is required.
なおトレッドパターンが残余ＣＦに及ぼす影響とは、第
８図に示すように、タイヤ赤道ＣＯ寄りとトレッド縁と
における半径差によりブロックに生じるトラクションＦ
Ｔ、ブレーキ力ＦＢとその作用点とによる回転モーメン
トＭの向きに起因すると考えられる。The effect of the tread pattern on the residual CF is the traction F generated on the block due to the radius difference between the tire equator CO and the tread edge, as shown in Figure 8.
This is considered to be caused by the direction of the rotational moment M due to the braking force FB and its point of application.
又第９図に示す右廻りの回転モーメントＭでは一般に残
余ＣＦを正側に、第１０図のものでは負側に移動させる
のが判明している。It has also been found that the clockwise rotational moment M shown in FIG. 9 generally moves the residual CF to the positive side, while that of FIG. 10 moves it to the negative side.
他方、ベルト層の構造が及ぼす残余ＣＦとは、接地部内
におけるベルトの伸縮により生じるものであって、クロ
スブライに配されるラジアルタイヤのベルトは、伸縮に
よってコードが平行移動するような面内剪断変形をうけ
、これによってトレッドゴムが、最外層のベルトプライ
の変形とともに面内の剪断変形が生起されることによっ
て残余ＣＦが生じるものと考えられる。On the other hand, the residual CF exerted by the structure of the belt layer is caused by the expansion and contraction of the belt within the contact area, and the belt of a radial tire placed in a cross-bly has in-plane shear that causes the cord to move in parallel due to expansion and contraction. It is thought that the residual CF is caused by the deformation of the tread rubber, which causes in-plane shear deformation along with the deformation of the outermost belt ply.
このため、第１１図に示すような最外側のベルトブライ
ａのベルトコードｂが正張り、即ち右ネジ張りでは残余
ＣＦは負側に、第１２図に示す逆張り、即ち左ネジ張り
では正側に移動するのが知られている。For this reason, when the belt cord b of the outermost belt bridle a as shown in Fig. 11 is tensioned normally, that is, with the right-hand thread, the residual CF is on the negative side, and when it is tensioned in the reverse direction, that is, with the left-hand thread as shown in Fig. 12, the residual CF is negative. Known to move to the side.
他方、残余ＣＦの速度依存性については次のように推論
した。On the other hand, the speed dependence of the residual CF was inferred as follows.
ラジアルタイヤにあっては、前記のように、トレッド部
においてカーカスの外側にベルトプライからなるベルト
層を設けることによりトレッド部の剛性の増大が図られ
ているとはいえ、とくに偏平率が０．６以下のタイヤに
おいては、その剛性はタイヤ赤道を中心としてショルダ
一部に至って低下し、トレッドがフラット化する傾向に
ある。As mentioned above, in radial tires, although the rigidity of the tread portion is increased by providing a belt layer made of belt ply on the outside of the carcass in the tread portion, the rigidity of the tread portion is particularly increased when the aspect ratio is 0. In tires with a tire size of 6 or less, the rigidity decreases from the tire equator to a portion of the shoulder, and the tread tends to become flat.
又ベルト層は、コードの向きを違えた複数枚のベルトプ
ライを重ね合わせることによってタガ効果が発揮される
とはいえ、高速となるに従って遠心力によりクラウン部
に浮き上がり傾向が生じ、高速と低速とではショルダ一
部と路面との接触度合いが変化する。この変化は、ショ
ルダ一部内のベルト層に作用する荷重が変化し、内面剪
断変形に基づく接地点廻りの回転モーメントによる残余
ＣＦが変化すると考えられる。In addition, although the belt layer has a hoop effect by overlapping multiple belt plies with cords in different directions, as the speed increases, the crown part tends to lift due to centrifugal force, and the difference between high speed and low speed increases. In this case, the degree of contact between part of the shoulder and the road surface changes. This change is thought to be due to a change in the load acting on the belt layer within a portion of the shoulder, and a change in the residual CF due to the rotational moment around the grounding point based on internal shear deformation.
このように、残余ＣＦの速度依存性を減じるには低速、
高速走行時においてトレッド面での接地状況の変化を抑
制する必要となる。In this way, to reduce the speed dependence of the residual CF,
It is necessary to suppress changes in the ground contact situation on the tread surface during high-speed driving.
従って本発明は、車両の片流れの速度依存性を低減しう
る空気入りタイヤの提供を目的としている。Accordingly, an object of the present invention is to provide a pneumatic tire that can reduce the speed dependence of unilateral flow of a vehicle.
本発明は、偏平率が６０％以下かつトレッド部からサイ
ドウオール部をへてビード部のビードコアで折返すカー
カスと、トレッド部の内方かつカーカスの半径方向外側
に配されるとともにスチール又は芳香族ポリアミド樹脂
を用いたベルトコードを有するベルト層とを具えるとと
もに、正規リムにリム組されかつ正規内圧を充填した標
準状態において、前記ベルト層は、該ベルト層のタイヤ
軸方向の巾ＢＷとトレッド巾ＴＷとの比ＢＷ／ＴＷが０
．７５以上かつ１．１０以下であり、かつタイヤ赤道を
中心として前記ベルト巾ＢＷの０．５倍以上かつ０．７
倍以下の巾のクラウン域におけるベルトの曲率半径ＢＲ
Ｉとタイヤ巾Ｗとの比ＢＲＩ／Ｗが５以上かつ１０以下
、クラウン域両側のショルダー域におけるベルトの曲率
半径ＢＲ２を１０５ｍｍよりも大かつ前記中央の曲率半
径ＢＲＩよりも小とした乗用車用ラジアルタイヤである
。The present invention provides a carcass with an aspect ratio of 60% or less, which passes from the tread part through the sidewall part and folds back at the bead core of the bead part, and which is disposed inside the tread part and outside the carcass in the radial direction, and is made of steel or aromatic material. and a belt layer having a belt cord made of polyamide resin, and in a standard state in which the rim is assembled on a regular rim and filled with a regular internal pressure, the belt layer has a width BW in the tire axial direction of the belt layer and a tread. The ratio BW/TW to width TW is 0
．． 75 or more and 1.10 or less, and 0.5 times or more and 0.7 times the belt width BW centered on the tire equator.
Radius of curvature BR of the belt in the crown area of double width or less
A radial for a passenger car in which the ratio BRI/W between I and tire width W is 5 or more and 10 or less, and the radius of curvature BR2 of the belt in the shoulder areas on both sides of the crown area is larger than 105 mm and smaller than the radius of curvature BRI at the center. It's a tire.
クラウン域におけるベルトの曲率半径ＢＲＩと、タイヤ
巾Ｗとの比Ｂ Ｒ１／Ｗを５〜１０としている。本発明
のように偏平率が６０％以下の空気入りタイヤでは、５
よりも小ではタイヤ赤道を含むクラウン部分が過度に突
出して耐摩耗性に劣り、又１ｏよりも大ではトレッドか
フラット化し操縦安定性に劣る。The ratio B R1/W of the radius of curvature BRI of the belt in the crown region to the tire width W is set to 5 to 10. In a pneumatic tire with an aspect ratio of 60% or less as in the present invention, 5
If it is smaller than 1o, the crown portion including the tire equator will protrude excessively, resulting in poor wear resistance.If it is larger than 1o, the tread will become flat, resulting in poor handling stability.
又ショルダ一部のベルトの曲率半径ＢＲ２を１０５ｍｍ
以上であって前記ベルトの曲率半径ＢＲＩよりも小とす
る。１０５ｍｍよりも小では残余ＣＦの速度依存性が悪
化し速度によって車両流れが変化することとなる。又ベ
ルトの曲率半径ＢＲＩよりも大では操縦安定性を損なう
。Also, the radius of curvature BR2 of the shoulder belt is 105mm.
It is assumed that the radius of curvature of the belt is greater than or equal to the radius of curvature BRI of the belt. If it is smaller than 105 mm, the speed dependence of the residual CF will worsen and the vehicle flow will change depending on the speed. Moreover, if the radius of curvature of the belt is larger than BRI, steering stability will be impaired.
これは高速走行によるタイヤの遠心力による膨径に伴う
浮き上がり傾向によって、タイヤのショルダ一部の接地
圧を減じやすい。又この傾向は、ショルダ一部のベルト
の曲率半径ＢＲ２が小、即ち１０５ｍｍよりも小となる
に伴い、ショルダ一部の接地圧が急激に減じ、これによ
りトレッド面全体に亘る残余ＣＦの分布が変化し、残余
ＣＦの速度依存性が犬となるものと考えられる。このた
めにベルトの曲率半径ＢＲ２を１０５ｍｍ以上としてい
る。又曲率半径ＢＲ２が曲率半径ＢＲＩよりも大である
とき、ショルダ一部に偏摩耗を生じる傾向にある。This is due to the tire's tendency to lift as its diameter expands due to centrifugal force caused by high-speed driving, which tends to reduce the ground contact pressure at a portion of the shoulder of the tire. This tendency also shows that as the radius of curvature BR2 of the belt in the shoulder part becomes smaller, that is, smaller than 105 mm, the ground contact pressure in the shoulder part decreases rapidly, and as a result, the distribution of residual CF over the entire tread surface decreases. It is thought that the velocity dependence of the residual CF changes. For this reason, the radius of curvature BR2 of the belt is set to 105 mm or more. Further, when the radius of curvature BR2 is larger than the radius of curvature BRI, uneven wear tends to occur in a portion of the shoulder.
以下本発明の一実施例を図面に基づき説明する。 An embodiment of the present invention will be described below based on the drawings.
図において本発明の乗用車用ラジアルタイヤ１は、ビー
ドコア２が通る両側のビード部３．３と、該ビード部３
からタイヤの半径方向外向きにのびるサイドウオール部
４．４と、その上端を継ぐトレッド部５とを有し、又ト
レッド部５からサイドウオール部４を通りビード部３の
前記ビードコア２の廻りを折返すカーカス６と、前記ト
レッド部５においてカーカス６のタイヤ半径方向外側に
配されるベルト層７とを具える。In the figure, the radial tire 1 for a passenger car of the present invention has bead portions 3.3 on both sides through which the bead core 2 passes, and the bead portions 3.
It has a sidewall part 4.4 that extends outward in the radial direction of the tire, and a tread part 5 that joins the upper end of the sidewall part 4.4. The tire includes a carcass 6 that is folded back, and a belt layer 7 disposed on the outside of the carcass 6 in the tire radial direction in the tread portion 5.
カーカス６は、カーカスコードをタイヤ赤道ＣＯに対し
て６０度〜９０度の角度で配列したセミラジアル又はラ
ジアル方向配列体であり、又カーカスコードとしてスチ
ールコードの他、ナイロン、ポリエステル、レーヨン等
の繊維コードが採用される。The carcass 6 is a semi-radial or radially arranged body in which carcass cords are arranged at an angle of 60 degrees to 90 degrees with respect to the tire equator CO. In addition to steel cords, the carcass cords are made of fibers such as nylon, polyester, and rayon. code is adopted.
前記ベルト層７は、本例ではカーカス６から半径方向外
側１、即ちトレッド部５の外表面１１に向かって順次第
１のベルトプライＢ１、第２のベルトプライＢ２の順に
配される広挟２層のベルトプライからなる。In this example, the belt layer 7 includes a wide band 2 which is arranged in order from the carcass 6 toward the radially outer side 1, that is, toward the outer surface 11 of the tread portion 5, such as a first belt ply B1 and a second belt ply B2. Consisting of layers of belt ply.
第１、第２のベルトプライＢ１、Ｂ２は傾斜して配され
るベルトコードを具え、本実施例では、第１のベルトプ
ライＢ１はそのコードをタイヤ赤道ＣＯに対して例えば
左上りに１５度〜７０度の範囲で傾けて配列する一方、
第２のベルトプライＢ２は、第１のベルトプライＢ１と
は逆に右上りに１５度〜７０度の範囲で傾けて配列する
。従って第１、第２のベルトプライＢ１、Ｂ２は、その
コードが互いに交叉することにより、両ブライＢ１、Ｂ
２によってタガ効果が生じトレッド部５の周方向、軸方
向に対する剛性を高めうる。The first belt ply B1 and the second belt ply B2 include belt cords disposed at an angle, and in this embodiment, the first belt ply B1 has its cord tilted upward at an angle of 15 degrees to the left with respect to the tire equator CO. While arrayed at an angle of ~70 degrees,
The second belt ply B2 is arranged at an angle of 15 degrees to 70 degrees upward to the right, contrary to the first belt ply B1. Therefore, the cords of the first and second belt plies B1 and B2 cross each other, so that both the belt plies B1 and B2
2 causes a hoop effect and can increase the rigidity of the tread portion 5 in the circumferential direction and the axial direction.
又本発明においては、巾が広い方の、本例では前記第１
のベルトプライＢ１はそのタイヤ軸方向の巾ＢＷＩを、
トレッド部５の外縁ｅ１．０２間のタイヤ軸方向の長さ
であるトレッド巾ＴＷとの比、ＢＷ／ＴＷを０．７５以
上かつ１．１以下とする。In addition, in the present invention, the width is wider, in this example, the first
The belt ply B1 has a width BWI in the tire axial direction,
The ratio of BW/TW to the tread width TW, which is the length in the tire axial direction between the outer edge e1.02 of the tread portion 5, is set to be 0.75 or more and 1.1 or less.
なお第２のベルトプライＢ２のタイヤ軸方向の巾ＢＷ２
と前記トレッド巾ＴＷとの比、Ｂ Ｗ ２ ／ＴＷを０
．７〜１．ｏ程度とする。Note that the width BW2 of the second belt ply B2 in the tire axial direction
The ratio of B W 2 /TW to the tread width TW is 0.
．． 7-1. It should be about o.
第１、第２のベルトプライＢ１、Ｂ２の各巾が前記した
それぞれの下限値よりも小の場合には、トレッド部５の
外縁り、Ｄ近傍、即ちショルダ部において剛性が不足す
る。When the widths of the first and second belt plies B1 and B2 are smaller than the respective lower limits described above, the rigidity is insufficient at the outer edge of the tread portion 5, near D, that is, at the shoulder portion.
又第１、第２のベルトプライＢ１、Ｂ２の各巾が前記し
たそれぞれ上限値よりも大の場合には、トレッド部は剛
性が過大となり操縦安定性に劣る。Furthermore, if the widths of the first and second belt plies B1 and B2 are larger than the above-mentioned upper limit values, the tread portion will have excessive rigidity, resulting in poor steering stability.
さらに第２のベルトプライＢ２の巾を第１のベルトプラ
イＢ１のよりも小とする傾向に形成することによって、
第２のベルトプライＢ２端部の過大な側方への張り出し
を防止でき、ベルトプライ端部で生じ勝ちなプライのセ
パレーションを防止することが出来る。Furthermore, by forming the width of the second belt ply B2 to be smaller than that of the first belt ply B1,
Excessive lateral protrusion of the end of the second belt ply B2 can be prevented, and ply separation that tends to occur at the end of the belt ply can be prevented.
又乗用車用ラジアルタイヤ１は、正規リムに装着しかつ
正規内圧を充填した標準状態において、タイヤの断面高
さＨと、タイヤ巾Ｗとの比Ｈ／Ｗである偏平率を６０％
より小とした偏平タイヤとして形成される。In addition, the radial tire 1 for a passenger car has an oblateness ratio of 60%, which is the ratio H/W of the cross-sectional height H of the tire and the tire width W, in a standard state where it is mounted on a regular rim and filled with a regular internal pressure.
It is formed as a smaller flat tire.
又前記標準状態においては、クラウン域ＣＲのベルト７
の曲率半径ＢＲＩとタイヤ巾Ｗとの比、ＢＲＩ／Ｗを５
以上かつ１０以下としている。In addition, in the standard state, the belt 7 in the crown region CR
The ratio of the radius of curvature BRI to the tire width W, BRI/W, is 5.
or more and 10 or less.
ここでクラウン域ＣＲとは、タイヤ赤道ＣＯを中心とし
てタイヤ軸方向の前記ベルト巾ＢＷの０．５倍以上かつ
０．７倍以下として定義され、このように少なくとも０
．５倍の範囲で前記比を保つ。Here, the crown area CR is defined as 0.5 times or more and 0.7 times or less of the belt width BW in the tire axial direction centering on the tire equator CO, and thus at least 0.
．． Keep the ratio within 5 times.
又ベルト７の曲率半径ＢＲとは、ベルト７の厚さ中間位
置を結ぶ曲線の半径であり、複数枚のベルトプライＢ１
、Ｂ２を用いるときには、合計厚さの中間位置を通る半
径を意味する。Further, the radius of curvature BR of the belt 7 is the radius of a curve connecting the thickness intermediate position of the belt 7, and the radius of curvature of the belt 7 is
, B2 means the radius passing through the midpoint of the total thickness.
クラウン域ＣＲのベルト７の曲率半径ＢＲＩとタイヤ巾
Ｗとの比ＢＲＩ／Ｗを５よりも小とするとき、クラウン
域ＣＲが過度に円弧化し、タイヤ赤道ＣＯ付近での接地
圧を増し耐摩耗性に劣る。又１０よりも大のときには逆
にクラウン域ＣＲがフラット化し、操縦安定性を損なう
。When the ratio BRI/W of the curvature radius BRI of the belt 7 in the crown region CR to the tire width W is smaller than 5, the crown region CR becomes excessively arcuate, increasing the ground contact pressure near the tire equator CO and improving wear resistance. inferior to sex. On the other hand, when it is larger than 10, the crown area CR becomes flat, which impairs steering stability.
又前記クラウン域ＣＲ両側でトレッドの外縁ｅ１、ｅ２
に至るショルダー域ＳＨのベルトの曲率半径ＢＲ２を１
０５ｍｍ以上であって前記ベルトの曲率半径ＢＲＩより
も小とする。１０５ｍｍよりも小では残余ＣＦの速度依
存性が悪化し速度によって車両流れが変化することとな
る。これはタイヤサイズ２１５ＳＲ／１５のタイヤにお
いて、ショルダー部ＳＨの曲率半径ＢＲ２を変化させて
残余ＣＦの速度依存性を調査した所、第３図に示す線図
をえたことに基づく。同図に示すように、ショルダー部
のベルト７の曲率半径ＢＲ２が１０５ｍｍ以下では残余
ＣＦの速度依存性が大となることがゎがる。Also, the outer edges e1 and e2 of the tread on both sides of the crown area CR
The radius of curvature BR2 of the belt in the shoulder area SH leading to is 1
05 mm or more and smaller than the radius of curvature BRI of the belt. If it is smaller than 105 mm, the speed dependence of the residual CF will worsen and the vehicle flow will change depending on the speed. This is based on the fact that in a tire with a tire size of 215SR/15, the speed dependence of the residual CF was investigated by changing the radius of curvature BR2 of the shoulder portion SH, and the diagram shown in FIG. 3 was obtained. As shown in the figure, when the radius of curvature BR2 of the belt 7 at the shoulder portion is 105 mm or less, the velocity dependence of the residual CF tends to be large.
又ベルトの曲率半径ＢＲＩよりも大では操縦安定性を損
なう。Moreover, if the radius of curvature of the belt is larger than BRI, steering stability will be impaired.
高速走行によるタイヤの遠心力によって、タイヤのショ
ルダ一部の接地圧を減じやすい。又この傾向は、ショル
ダ一部のベルトの曲率半径ＢＲ２が小、即ち１０５ｍｍ
よりも小となるに伴い、ショルダ一部の接地圧が過度に
減じ、これによりトレッド面全体に亘る残余ＣＦの分布
が変化し、残余ＣＦの速度依存性が大となるものと考え
られる。The centrifugal force of tires caused by high-speed driving tends to reduce ground contact pressure on part of the tire shoulders. This tendency also shows that the radius of curvature BR2 of the shoulder belt is small, that is, 105 mm.
It is thought that as the tire pressure becomes smaller than , the ground contact pressure of a part of the shoulder is excessively reduced, and as a result, the distribution of residual CF over the entire tread surface changes, and the speed dependence of the residual CF becomes large.
このためにベルトの曲率半径ＢＲ２を１０５ｍｍ以上と
している。又曲率半径ＢＲ２が曲率半径ＢＲ１よりも大
であるとき、ショルダ一部に偏摩耗を生じる傾向にある
。For this reason, the radius of curvature BR2 of the belt is set to 105 mm or more. Furthermore, when the radius of curvature BR2 is larger than the radius of curvature BR1, uneven wear tends to occur in a portion of the shoulder.
なお本発明において乗用車用ラジアルタイヤとは、Ｊ
Ｉ ５Ｄ４２０４に規定するラジアルプライの乗用車用
タイヤの内、タイヤ巾が１７５をこえるものに適用され
る。In the present invention, the radial tire for passenger cars refers to J
This applies to radial ply passenger car tires specified in I5D4204 with a tire width exceeding 175mm.
このように本発明は、操縦安定性能、耐摩耗性を損なう
ことなく、残余ＣＦの速度依存性を低下させ、車両流れ
の速度による変化を減じつる。As described above, the present invention reduces the speed dependence of residual CF and reduces changes in vehicle flow due to speed without impairing steering stability performance or wear resistance.
第１図は本発明の一実施例を示す断面図、第２図は残余
ＣＦと車両流れとの速度依存性の相関を例示するグラフ
、第３図はベルトショルダー域の曲率半径と残余ＣＦの
温度依存性の相関を例示するグラフ、第４〜１０図は、
残余ＣＦを説明するための線図、第１１．１２図はベル
トコードの巻き方向を説明する斜視図である。
２・・・トレッド部、 ３・・・サイドウオール部、
４・・・ビード部、 ５・・・ビードコア、６・・・
カーカス、 ７・・・ベルト、７Ａ、７Ｂ・・・ベルト
ブライ。
特許出願人 住友ゴム工業株式会社代理人 弁理
士 苗 村 正第６図
Ｃ爾＠イく―
ｏ ｏ、 ｏ、 。
Ｃｑ ■ ［Ｆ］ の１１嘗
εＪ −Ｈ４国Ｃぐ媚Ｕ山棟）
＃Ｃ″°”’＊゛ｗＷｙ４ｐｅ
第４図
＠５図
第７図
（左方向）
（ｋｇｆ）
Ｑｌｌｌｌ ｆ＆１２ｆｌ＠８図
第１０図
Ｏ
第９５１１
Ｏ
□Fig. 1 is a cross-sectional view showing an embodiment of the present invention, Fig. 2 is a graph illustrating the correlation between the residual CF and the speed dependence on the vehicle flow, and Fig. 3 is a graph showing the relationship between the radius of curvature of the belt shoulder region and the residual CF. Graphs 4 to 10 illustrating temperature-dependent correlations are:
Diagrams for explaining the residual CF, Figures 11 and 12 are perspective views for explaining the winding direction of the belt cord. 2...Tread part, 3...Side wall part,
4... Bead portion, 5... Bead core, 6...
Carcass, 7...belt, 7A, 7B...belt braai. Patent applicant: Sumitomo Rubber Industries, Ltd. Agent: Patent attorney Masashi Naemura Cq ■ [F]'s 11 years εJ - H4 country Cguji U mountain building) #C″°”'*゛wWy4pe Fig. 4 @ Fig. 5 Fig. 7 (left direction) (kgf) Qllll f & 12fl @ Fig. 8 Figure 10 O No. 9511 O □
Claims (1)
ール部をへてビード部のビードコアで折返すカーカスと
、トレッド部の内方かつカーカスの半径方向外側に配さ
れるとともにスチール又は芳香族ポリアミド樹脂を用い
たベルトコードを有するベルト層とを具えるとともに、
正規リムにリム組されかつ正規内圧を充填した標準状態
において、前記ベルト層は、該ベルト層のタイヤ軸方向
の巾ＢＷと、トレッド巾ＴＷとの比ＢＷ／ＴＷが０．７
５以上かつ１．１０以下であり、かつタイヤ赤道を中心
として前記ベルト巾ＢＷの０．５倍以上かつ０．７倍以
下の巾のクラウン域におけるベルトの曲率半径ＢＲ１と
タイヤ巾Ｗとの比ＢＲ１／Ｗが５以上かつ１０以下、ク
ラウン域両側のショルダー域におけるベルトの曲率半径
ＢＲ２を１０５ｍｍよりも大かつ前記中央の曲率半径Ｂ
Ｒ１よりも小とした乗用車用ラジアルタイヤ。1. A carcass with an aspect ratio of 60% or less, which passes from the tread part through the sidewall part and folds back at the bead core of the bead part, and is arranged inside the tread part and outside the carcass in the radial direction, and is made of steel or aromatic polyamide resin. a belt layer having a belt cord used;
In a standard state in which the rim is assembled on a regular rim and filled with regular internal pressure, the belt layer has a ratio BW/TW of the width BW in the tire axial direction of the belt layer to the tread width TW of 0.7.
5 or more and 1.10 or less, and the ratio of the belt curvature radius BR1 to the tire width W in the crown region with a width of 0.5 times or more and 0.7 times or less of the belt width BW centered on the tire equator. BR1/W is 5 or more and 10 or less, the radius of curvature BR2 of the belt in the shoulder areas on both sides of the crown area is larger than 105 mm, and the radius of curvature B at the center is greater than 105 mm.
A radial tire for passenger cars that is smaller than R1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2331101A JPH04193603A (en) | 1990-11-28 | 1990-11-28 | Radial tire for passenger car |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2331101A JPH04193603A (en) | 1990-11-28 | 1990-11-28 | Radial tire for passenger car |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04193603A true JPH04193603A (en) | 1992-07-13 |
Family
ID=18239873
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2331101A Pending JPH04193603A (en) | 1990-11-28 | 1990-11-28 | Radial tire for passenger car |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04193603A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100545889B1 (en) * | 1998-09-18 | 2006-04-06 | 한국타이어 주식회사 | Pneumatic radial tire |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5245964A (en) * | 1975-10-09 | 1977-04-12 | Meisho Kk | Grouting management method by weight recording of cement or other mixt ure |
| JPS60203507A (en) * | 1984-03-28 | 1985-10-15 | Sumitomo Rubber Ind Ltd | Radial-ply tire |
| JPS63166604A (en) * | 1986-12-27 | 1988-07-09 | Sumitomo Rubber Ind Ltd | Radial tire |
| JPH01122702A (en) * | 1987-11-06 | 1989-05-16 | Bridgestone Corp | Pneumatic radial tire |
-
1990
- 1990-11-28 JP JP2331101A patent/JPH04193603A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5245964A (en) * | 1975-10-09 | 1977-04-12 | Meisho Kk | Grouting management method by weight recording of cement or other mixt ure |
| JPS60203507A (en) * | 1984-03-28 | 1985-10-15 | Sumitomo Rubber Ind Ltd | Radial-ply tire |
| JPS63166604A (en) * | 1986-12-27 | 1988-07-09 | Sumitomo Rubber Ind Ltd | Radial tire |
| JPH01122702A (en) * | 1987-11-06 | 1989-05-16 | Bridgestone Corp | Pneumatic radial tire |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100545889B1 (en) * | 1998-09-18 | 2006-04-06 | 한국타이어 주식회사 | Pneumatic radial tire |
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