JP2004345432A - Pneumatic tire - Google Patents

Pneumatic tire Download PDF

Info

Publication number
JP2004345432A
JP2004345432A JP2003142908A JP2003142908A JP2004345432A JP 2004345432 A JP2004345432 A JP 2004345432A JP 2003142908 A JP2003142908 A JP 2003142908A JP 2003142908 A JP2003142908 A JP 2003142908A JP 2004345432 A JP2004345432 A JP 2004345432A
Authority
JP
Japan
Prior art keywords
region
rubber layer
modulus
tire
cap
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
Application number
JP2003142908A
Other languages
Japanese (ja)
Other versions
JP4256720B2 (en
Inventor
Takao Yamaguchi
隆郎 山口
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyo Tire Corp
Original Assignee
Toyo Tire and Rubber Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyo Tire and Rubber Co Ltd filed Critical Toyo Tire and Rubber Co Ltd
Priority to JP2003142908A priority Critical patent/JP4256720B2/en
Publication of JP2004345432A publication Critical patent/JP2004345432A/en
Application granted granted Critical
Publication of JP4256720B2 publication Critical patent/JP4256720B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60CVEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/0041Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers
    • B60C11/005Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers with cap and base layers
    • B60C11/0058Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers with cap and base layers with different cap rubber layers in the axial direction

Landscapes

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

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of securing driveability and riding comfortability, and reducing noise in the cabin such as road noise or the like. <P>SOLUTION: The tread part 4 is divided into five areas X, Y, Z in the tire width direction, and the rubber modulus of the base rubber layers 11x, 11y, 11z is set larger than the cap rubber layer 10 in respective areas. The modulus of the middle areas 10y, 11y is set to be the minimum, the modulus of the center areas 10x, 11x is set to be 1.5 to 2 times of the modulus of the middle areas 10y, 11y and shoulder areas 10z, 11x. Driveability and riding comfortability are secured, and road noise is reduced thereby. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【0001】
【発明の属する技術分野】
本発明は、操縦安定性と乗り心地性を確保し、ロードノイズ等の車内音の低減を図ることができる空気入りタイヤに関するものである。
【0002】
【従来の技術】
車両が比較的荒れた路面を走行すると、車室内においてロードノイズと呼ばれる騒音が発生する。このロードノイズは、タイヤが関係する騒音の一つであり、路面の凹凸がタイヤトレッドへの入力なってタイヤが振動し、この振動が車軸、サスペンション、車体と伝播経路をたどり、最終的に車室内の騒音となって現われる。
【0003】
このロードノイズを低減する方法として、主に、タイヤ振動を減衰させる目的でタイヤトレッド部のゴム厚を厚くする、タイヤサイド部の剛性を下げる等があるが、トレッドゴムのゴム厚を大きくすると、タイヤ質量が増加し、燃費などが悪化する。路面からの入力を緩和させるためにトレッドゴムの硬度を下げる手法や、タイヤサイド部の剛性を下げる手法を採用すると、トレッドのパターン剛性が低下し、操縦安定性が低下することになる。したがって、単一のトレッドのゴム配合や硬度の変更では、ロードノイズの低減と操縦安定性を両立させることは困難であった。
【0004】
この問題を解決するために、特許文献1に示すように、トレッド部をタイヤ軸方向に3分割し、トレッド部の中央部域と両側ショルダー部域とで硬度の異なるゴムを用いる方法が提案されている。この方法では、トレッド部の一部に硬度の低いゴムを使用することによって、ロードノイズ等を低減するとともに、操縦安定性の低下を抑えるようにしている。
【0005】
【特許文献1】特開2001−10308号公報(段落0006参照)
【0006】
【発明が解決しようとする課題】
しかしながら、特許文献1に示す方法では、操縦安定性を維持するにとどまり、またロードノイズの低減や乗り心地性について十分満足できるものではなく、これらの性能を満足し得る空気入りタイヤの出現が望まれている。
【0007】
本発明は、上記課題に鑑み、操縦安定性と乗り心地性を確保し、ロードノイズ等の車内音の低減を図ることができる空気入りタイヤの提供を目的としている。
【0008】
【課題を解決するための手段】
上記目的を達成するため、本発明者は、まず、ロードノイズの低減に主眼をおき、種々検討した。車室騒音として伝播される高周波ロードノイズ(250Hz〜300Hz)はタイヤの空洞共鳴と重なる部分があり、これが原因となって車室騒音が発生する。タイヤの空洞共鳴は、振動モード周波数をずらす、あるいはレベルを下げることで回避できる。その手法としては、トレッドゴムのモジュラスを種々変化させればよいが、この場合、特許文献1に記載されている3分割方式では十分な効果が期待できない。
【0009】
そこで、本発明者は、FEM解析を用いて、トレッド部をタイヤ幅方向に5つの領域に区分し、各領域のゴムモジュラスを所定の範囲に設定し、このときの縦・横・前後の剛性を大きく変化させないようにしたところ、ロードノイズを十分低減できると共に、操縦安定性や乗り心地性も十分満足できる空気入りタイヤを提供できることを見出した。
【0010】
すなわち、本発明に係る空気入りタイヤは、トレッド部が、トレッド面側のキャップゴム層と、その内側に配置されるベースゴム層との2層構造とされると共に、タイヤ幅方向において、タイヤ赤道面が通るセンター領域と、センター領域を挟んでその両側に形成される中間領域と、中間領域のさらに外側に形成されるショルダー領域とから5つの領域に区分され、
ア) 各領域においてベースゴム層がキャップゴム層よりもゴムモジュラスが大に設定され、
イ) キャップゴム層およびベースゴム層の各層において、中間領域のモジュラスが最も小さく、かつセンター領域のモジュラスが中間領域およびショルダー領域のモジュラスの1.5倍〜2倍に設定されていることを特徴としている。
【0011】
上記ア)、イ)の関係を数式化すると、キャップゴム層におけるセンター領域X、中間領域Yおよびショルダー領域ZのそれぞれのゴムモジュラスをXc,Yc,Zcとし、ベースゴム層におけるセンター領域X、中間領域Yおよびショルダー領域ZのそれぞれのゴムモジュラスをXb,Yb,Zbとすると、
ア) Xc<Xb,Yc<Yb,Zc<Zb
イ) Yc≦Zc、1.5*Yc≦Xc≦2*Yc、
1.5*Zc≦Xc≦2*Zc
ウ) Yb≦Zb、1.5*Yb≦Xb≦2*Yb、
1.5*Zb≦Xb≦2*Zb
の関係が成り立つように、各領域のゴムモジュラスを設定することになる。
【0012】
上記構成によると、各領域のゴムモジュラスを変化させることで操縦安定性および乗り心地性の維持とロードノイズの低減が可能となる。これは、各領域におけるゴムモジュラスの変化に対するタイヤ剛性及びロードノイズ等の増加率、すなわち、感度がそれぞれ異なるためである。本発明においてはこれら感度の相違を利用することによって操縦安定性・乗り心地性の維持とロードノイズ等の低減を両立させている。特に、中間領域のゴムモジュラスをショルダー領域のそれ以下にすることで、これらの諸特性の維持・向上が図れる。
【0013】
【発明の実施の形態】
以下、本発明の一実施形態を図面に基づいて説明する。図1は本発明の実施形態を示す空気入りタイヤのうち、ラジアルタイヤの軸(幅)方向の要部断面図であり、タイヤ赤道面Aから一側のトレッド端部Bまでを図示している。
【0014】
このラジアルタイヤ1は、一対のビード部2およびビード部から半径方向外向きに延びるサイドウォール部3と、その上端をつなぐトレッド部4と、これらの内周に沿って両端がビードコア5で折返されて支持されたカーカス6とを備えている。トレッド部4とカーカス6の間にベルト層7を備えており、その補強構造は一般的なラジアルタイヤの場合と同様であるので、詳細な説明は省略する。
【0015】
トレッド部4は、キャップゴム層10とその内方に位置するベースゴム層11の2層からなるキャップ−ベース構造を備えている。キャップゴム層10の外周面にはタイヤ周方向に直線状もしくはジグザグ状をなして延びる複数本の主溝12が形成され、さらに図の断面図では図示を省略しているが、通常、前記の主溝12と交叉する方向の横溝、さらにはタイヤ周方向で主溝より細幅の副溝や横溝を繋ぐ補助溝が形成されて、所定のトレッドパターンが形成されている。
【0016】
キャップゴム層10およびベースゴム層11は、それぞれ赤道面Aを中心に挟んで形成されたセンター領域Xと、センター領域Xを挟んでその両側に形成される中間領域Yと、中間領域Yを挟んでその両側に形成されるショルダー領域Zの合計5つの領域に区分されている。5つの領域は、上下のキャップゴム層10およびベースゴム層11でほぼ一致して区分けされている。図中、キャップゴム層10におけるセンター領域X、中間領域Y、ショルダー領域Zの各部位を10x、10y、10zで示す。また、ベースゴム層11におけるセンター領域X、中間領域Y、ショルダー領域Zの各部位を10x、10y、10zで示す。
【0017】
そして、キャップゴム層10におけるセンター領域X、中間領域Yおよびショルダー領域Zのそれぞれの部位10x、10y、10zのゴムモジュラス(JIS K6251 M100、以下同じ)をXc,Yc,Zcとし、ベースゴム層11におけるセンター領域X、中間領域Yおよびショルダー領域Zのそれぞれの部位11x、11y、11zのゴムモジュラスをXb,Yb,Zbとすると、
ア) Xc<Xb,Yc<Yb,Zc<Zb
イ) Yc≦Zc、1.5*Yc≦Xc≦2*Yc、
1.5*Zc≦Xc≦2*Zc
ウ) Yb≦Zb、1.5*Yb≦Xb≦2*Yb、
1.5*Zb≦Xb≦2*Zb
の関係が成り立つように設定されている。
【0018】
また、センター領域Xと中間領域Yとを区分する第一境界線15は、主溝12の底面に沿って形成されている。中間領域Yとショルダー領域Zとを区分する第二境界線16は、ベルト層端部付近に設定されている。これら第一境界線15および第二境界線16は、それぞれ赤道面Aを挟んで対称位置に一対ずつ形成されている。なお、第一境界線15及び第二境界線16は、トレッド部4の陸部表面に形成してもよい。
【0019】
第一境界線15および第二境界線16の配置は、FEM解析によれば、赤道面を0としてトレッド端部の位置を100とするとき、第一境界線15を5〜60の範囲内に位置させ、第二境界線を30〜90の範囲内に位置させるのが好ましいことが判明した。さらに、第一境界線15を30〜60、第二境界線16を70〜90の範囲内に位置させると、より好ましい結果が得られた。
【0020】
上記構成の空気入りタイヤの実施例について説明する。表1は、6種類のラジアルタイヤを作製してロードノイズ、操縦安定性、乗り心地性能について評価試験を行った結果を示すものである。
【0021】
【表1】

Figure 2004345432
【0022】
実施例1,2はキャップゴム層およびベースゴム層を夫々5領域に区分し、夫々のモジュラスを本発明の範囲に設定したラジアルタイヤの諸特性を示す。キャップゴム層10およびベースゴム層11を、センター領域X、中間領域Yおよびショルダー領域Zの5つの領域に区分し、赤道面Aの位置を0としトレッド端部Bの位置を100とするときに、第一境界線15を50、第二境界線16を80の位置にそれぞれ設定した。
【0023】
比較例1は、キャップゴム層について特許文献1に示すように3分割構成とし、ベースゴム層は5分割構成としたものを示し、比較例2はキャップゴム層及びベースゴム層を共に3分割構成としたものを示す。比較例3はキャップゴム層及びベースゴム層を共に5分割構成としたものの、各部位のモジュラスが本発明の範囲外のものを示す。比較例4は、キャップゴム層及びベースゴム層がそれぞれ単一のゴムを使用したものを示し、これをコントロールとして、各タイヤのロードノイズ、操縦安定性、および乗り心地性の評価を行った。
【0024】
供試タイヤは、タイヤサイズが235/45ZR17のラジアルタイヤを使用し、テスト車両は3000ccのFR車を使用した。操縦安定性および乗り心地性の評価はパネラーによる官能評価である。比較例4を100とした場合の相対値で表しており、数値が高いほど操縦安定性および乗り心地性が優れていることを示す。
【0025】
また、ロードノイズは、空気圧220kPaを充填したタイヤ単体を回転ドラム上において行う単体台上試験により、JASO C 606−81に準拠したタイヤ騒音試験方法を採用した。ただし、騒音測定は、タイヤセンター部に鉛直下向きの荷重が入力したときのタイヤホイール鉛直下向きの伝達関数の235Hz〜280Hzのパーシャル平均レベルを比較例4を「0」として、そのレベル差[dB]により評価した。レベルが低い(−)であるほど、ロードノイズが低減されていることを示す。
【0026】
表1に示すように、キャップゴム層10を5区域に区分した実施例1、2では、いずれも比較例4に比べてロードノイズが「−0.8」「−1.7」と低減されており、操縦安定性は維持あるいは向上しており、乗り心地性も良好になっている。
【0027】
一方、3分割タイプの比較例1および比較例2においては、ロードノイズの低減はみられるものの、比較例1は、そのキャップゴム層10において、センター領域10Xのゴムモジュラスが、中間領域Yおよびショルダー領域Zのそれに比べて所定範囲(Xc/Yc≧1.5、Xc/Zc≧1.5)に設定されていないため、乗り心地性が比較例4に比べて低下している。また、比較例2は、そのベースゴム層11において、センター領域11Xのゴムモジュラスが、中間領域Yおよびショルダー領域Zのそれに比べて所定範囲(Xb/Yb≧1.5、Xb/Zb≧1.5)に設定されていないため、操縦安定性が比較例4に比べて低下している。比較例3は、そのキャップゴム層10およびベースゴム層11において、中間領域Yのゴムモジュラスをセンター領域Yおよびショルダー領域Zのそれに比べて高く設定した例であり、本発明の範囲外に設定されている。それ故、比較例3のタイヤでは、ロードノイズは比較例4に比べて高く(0.7)なり、また、乗り心地性も悪化している。
【0028】
【発明の効果】
以上の説明から明らかなように、本発明によると、キャップゴム層およびベースゴム層を夫々5領域に区分し、各部位のゴムモジュラスを変化させることで、操縦安定性および乗り心地性の維持とロードノイズの低減が可能となる。
【図面の簡単な説明】
【図1】本発明の実施形態を示すラジアルタイヤの要部断面図
【符号の説明】
1 ラジアルタイヤ
2 ビード部
3 サイドウォール部
4 トレッド部
5 ビードコア
6 カーカス
7 ベルト層
10 キャップゴム層
11 ベースゴム層
15 第一境界線
16 第二境界線
A タイヤ赤道面
B トレッド端部
X センター領域
Y 中間領域
Z ショルダー領域[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a pneumatic tire capable of ensuring steering stability and ride comfort and reducing vehicle noise such as road noise.
[0002]
[Prior art]
When a vehicle travels on a relatively rough road surface, noise called road noise is generated in the vehicle interior. This road noise is one of the noises related to the tire, and the unevenness of the road surface is input to the tire tread and the tire vibrates, and this vibration follows the propagation path with the axle, suspension, and vehicle body, and finally the vehicle Appears as room noise.
[0003]
As a method of reducing the road noise, mainly, to increase the rubber thickness of the tire tread portion for the purpose of attenuating tire vibration, lower the rigidity of the tire side portion, and the like, but if the rubber thickness of the tread rubber is increased, The tire mass increases, and fuel efficiency and the like deteriorate. If a method of reducing the hardness of the tread rubber or a method of reducing the rigidity of the tire side portion is used to reduce the input from the road surface, the pattern rigidity of the tread is reduced, and the steering stability is reduced. Therefore, it has been difficult to achieve both a reduction in road noise and steering stability by changing the rubber composition and hardness of a single tread.
[0004]
In order to solve this problem, as shown in Patent Document 1, a method has been proposed in which a tread portion is divided into three in the tire axial direction, and rubbers having different hardnesses are used in a central region of the tread portion and shoulder regions on both sides. ing. In this method, a low-hardness rubber is used for a part of the tread portion, so that road noise and the like are reduced, and a decrease in steering stability is suppressed.
[0005]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-10308 (see paragraph 0006)
[0006]
[Problems to be solved by the invention]
However, the method disclosed in Japanese Patent Application Laid-Open No. H11-157556 only maintains the steering stability, does not sufficiently reduce the road noise and the riding comfort, and the appearance of a pneumatic tire that can satisfy these performances is expected. It is rare.
[0007]
The present invention has been made in view of the above circumstances, and has as its object to provide a pneumatic tire that can ensure steering stability and ride comfort and reduce vehicle interior noise such as road noise.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present inventor first made various studies with a focus on reduction of road noise. High-frequency road noise (250 Hz to 300 Hz) transmitted as vehicle interior noise has a portion that overlaps with cavity resonance of a tire, and this causes vehicle interior noise. Tire cavity resonance can be avoided by shifting or reducing the vibration mode frequency. As a method for this, it is only necessary to change the modulus of the tread rubber in various ways, but in this case, a sufficient effect cannot be expected with the three-division method described in Patent Document 1.
[0009]
Therefore, the present inventor divided the tread portion into five regions in the tire width direction using FEM analysis, set the rubber modulus in each region to a predetermined range, and set the rigidity in the longitudinal, lateral, front and rear directions at this time. It was found that a pneumatic tire capable of sufficiently reducing road noise and also having sufficiently satisfactory steering stability and ride comfort could be provided.
[0010]
That is, the pneumatic tire according to the present invention has a tread portion having a two-layer structure of a cap rubber layer on the tread surface side and a base rubber layer disposed inside the cap rubber layer, and has a tire equator in the tire width direction. The center region through which the surface passes, an intermediate region formed on both sides of the center region, and a shoulder region formed further outside the intermediate region are divided into five regions,
A) In each area, the rubber modulus of the base rubber layer is set larger than that of the cap rubber layer,
B) In each of the cap rubber layer and the base rubber layer, the modulus in the middle region is the smallest, and the modulus in the center region is set to 1.5 to 2 times the modulus in the middle region and the shoulder region. And
[0011]
When the relations of the above (a) and (a) are mathematically expressed, the respective rubber moduli of the center region X, the intermediate region Y and the shoulder region Z in the cap rubber layer are Xc, Yc and Zc, and the center region X and the intermediate region in the base rubber layer. Assuming that the rubber modulus of each of the region Y and the shoulder region Z is Xb, Yb, Zb,
A) Xc <Xb, Yc <Yb, Zc <Zb
B) Yc ≦ Zc, 1.5 * Yc ≦ Xc ≦ 2 * Yc,
1.5 * Zc ≦ Xc ≦ 2 * Zc
C) Yb ≦ Zb, 1.5 * Yb ≦ Xb ≦ 2 * Yb,
1.5 * Zb ≦ Xb ≦ 2 * Zb
The rubber modulus of each region is set so that the relationship of
[0012]
According to the above configuration, it is possible to maintain steering stability and ride comfort and reduce road noise by changing the rubber modulus in each region. This is because the rate of increase in tire stiffness and road noise with respect to the change in rubber modulus in each region, that is, the sensitivity is different. In the present invention, by utilizing these differences in sensitivity, maintenance of steering stability and ride comfort and reduction of road noise and the like are compatible. In particular, by keeping the rubber modulus in the intermediate region less than that in the shoulder region, these characteristics can be maintained and improved.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a principal part of a pneumatic tire according to an embodiment of the present invention in the axial (width) direction of a radial tire, and shows from a tire equatorial plane A to a tread end B on one side. .
[0014]
The radial tire 1 has a pair of bead portions 2 and a sidewall portion 3 extending radially outward from the bead portion, a tread portion 4 connecting the upper ends thereof, and both ends thereof being folded back by a bead core 5 along the inner periphery thereof. And a carcass 6 that is supported. Since a belt layer 7 is provided between the tread portion 4 and the carcass 6, and its reinforcing structure is the same as that of a general radial tire, a detailed description is omitted.
[0015]
The tread portion 4 has a cap-base structure including a cap rubber layer 10 and a base rubber layer 11 located inside the cap rubber layer 10. A plurality of main grooves 12 extending linearly or zigzag in the circumferential direction of the tire are formed on the outer peripheral surface of the cap rubber layer 10, and are not shown in the sectional views of the drawings. A lateral groove in the direction intersecting with the main groove 12, and an auxiliary groove connecting the auxiliary groove and the lateral groove which are narrower than the main groove in the tire circumferential direction are formed, and a predetermined tread pattern is formed.
[0016]
The cap rubber layer 10 and the base rubber layer 11 are respectively formed with a center region X formed with the equatorial plane A as a center, an intermediate region Y formed on both sides of the center region X, and a middle region Y. Are divided into a total of five regions of shoulder regions Z formed on both sides thereof. The five regions are divided by the upper and lower cap rubber layers 10 and the base rubber layer 11 so as to substantially coincide with each other. In the figure, each part of the center region X, the intermediate region Y, and the shoulder region Z in the cap rubber layer 10 is indicated by 10x, 10y, and 10z. In addition, respective portions of the center region X, the intermediate region Y, and the shoulder region Z in the base rubber layer 11 are indicated by 10x, 10y, and 10z.
[0017]
The rubber modulus (JIS K6251 M100, the same applies hereinafter) of each of the center region X, the intermediate region Y, and the shoulder region Z in the cap rubber layer 10 is Xc, Yc, Zc, and the base rubber layer 11 In the case where the rubber moduli of the respective portions 11x, 11y, 11z of the center region X, the intermediate region Y and the shoulder region Z are Xb, Yb, Zb,
A) Xc <Xb, Yc <Yb, Zc <Zb
B) Yc ≦ Zc, 1.5 * Yc ≦ Xc ≦ 2 * Yc,
1.5 * Zc ≦ Xc ≦ 2 * Zc
C) Yb ≦ Zb, 1.5 * Yb ≦ Xb ≦ 2 * Yb,
1.5 * Zb ≦ Xb ≦ 2 * Zb
Is set so that the following relationship holds.
[0018]
Further, the first boundary line 15 that separates the center region X and the intermediate region Y is formed along the bottom surface of the main groove 12. The second boundary line 16 that separates the intermediate region Y and the shoulder region Z is set near the belt layer end. The first boundary line 15 and the second boundary line 16 are respectively formed in pairs symmetrically with respect to the equatorial plane A. Note that the first boundary line 15 and the second boundary line 16 may be formed on the land surface of the tread portion 4.
[0019]
According to FEM analysis, the first boundary 15 and the second boundary 16 are arranged such that when the equator plane is 0 and the position of the tread edge is 100, the first boundary 15 is within the range of 5 to 60. It has been found that it is preferable to position the second boundary line within the range of 30 to 90. Further, when the first boundary 15 was positioned within the range of 30 to 60 and the second boundary 16 was positioned within the range of 70 to 90, more preferable results were obtained.
[0020]
An example of the pneumatic tire having the above configuration will be described. Table 1 shows the results of evaluation tests performed on road noise, steering stability, and riding comfort performance by producing six types of radial tires.
[0021]
[Table 1]
Figure 2004345432
[0022]
Examples 1 and 2 show various characteristics of the radial tire in which the cap rubber layer and the base rubber layer are each divided into five regions, and each modulus is set within the range of the present invention. When the cap rubber layer 10 and the base rubber layer 11 are divided into five regions of a center region X, a middle region Y and a shoulder region Z, and the position of the equatorial plane A is 0 and the position of the tread end B is 100 , The first boundary line 15 was set at 50, and the second boundary line 16 was set at 80.
[0023]
Comparative Example 1 shows a configuration in which the cap rubber layer has a three-part configuration as shown in Patent Document 1, and a base rubber layer has a five-part configuration. Comparative Example 2 has a three-part configuration in which both the cap rubber layer and the base rubber layer are configured. Are shown. Comparative Example 3 shows the case where the cap rubber layer and the base rubber layer were both divided into five parts, but the modulus of each part was out of the range of the present invention. Comparative Example 4 shows a case in which the cap rubber layer and the base rubber layer each used a single rubber, and using this as a control, the road noise, steering stability, and riding comfort of each tire were evaluated.
[0024]
The test tire used was a radial tire having a tire size of 235 / 45ZR17, and the test vehicle was a 3000 cc FR vehicle. Evaluation of steering stability and ride comfort is a sensory evaluation by panelists. The values are shown as relative values when Comparative Example 4 is set to 100, and the higher the numerical value, the more excellent the steering stability and ride comfort.
[0025]
For the road noise, a tire noise test method based on JASO C 606-81 was adopted by a single unit test in which a single tire filled with an air pressure of 220 kPa was performed on a rotating drum. However, in the noise measurement, the partial average level of 235 Hz to 280 Hz of the transfer function of the tire wheel vertically downward when a vertically downward load was input to the tire center portion was set to “0” in Comparative Example 4, and the level difference [dB] Was evaluated. The lower the level (-), the more the road noise is reduced.
[0026]
As shown in Table 1, in Examples 1 and 2 in which the cap rubber layer 10 was divided into five sections, the road noise was reduced to “−0.8” and “−1.7” as compared with Comparative Example 4. The steering stability has been maintained or improved, and the riding comfort has also been improved.
[0027]
On the other hand, in Comparative Examples 1 and 2 of the three-split type, although the road noise is reduced, in Comparative Example 1, the rubber modulus of the center region 10X in the cap rubber layer 10 is reduced by the middle region Y and the shoulder. Since the predetermined range (Xc / Yc ≧ 1.5, Xc / Zc ≧ 1.5) is not set as compared with that of the region Z, the riding comfort is lower than that of the comparative example 4. In Comparative Example 2, in the base rubber layer 11, the rubber modulus of the center region 11X is in a predetermined range (Xb / Yb ≧ 1.5, Xb / Zb ≧ 1. Since it is not set to 5), the steering stability is lower than that of Comparative Example 4. Comparative Example 3 is an example in which the rubber modulus of the intermediate region Y is set higher in the cap rubber layer 10 and the base rubber layer 11 than those of the center region Y and the shoulder region Z, and is set outside the scope of the present invention. ing. Therefore, in the tire of Comparative Example 3, the road noise is higher (0.7) than that of Comparative Example 4, and the riding comfort is deteriorated.
[0028]
【The invention's effect】
As apparent from the above description, according to the present invention, the cap rubber layer and the base rubber layer are each divided into five regions, and the rubber modulus of each part is changed to maintain the steering stability and the riding comfort. Road noise can be reduced.
[Brief description of the drawings]
FIG. 1 is a sectional view of an essential part of a radial tire showing an embodiment of the present invention.
REFERENCE SIGNS LIST 1 radial tire 2 bead portion 3 sidewall portion 4 tread portion 5 bead core 6 carcass 7 belt layer 10 cap rubber layer 11 base rubber layer 15 first boundary line 16 second boundary line A tire equatorial plane B tread edge X center area Y Intermediate area Z Shoulder area

Claims (2)

トレッド部が、トレッド面側のキャップゴム層と、その内側に配置されるベースゴム層との2層構造とされると共に、タイヤ幅方向において、タイヤ赤道面が通るセンター領域と、センター領域を挟んでその両側に形成される中間領域と、中間領域のさらに外側に形成されるショルダー領域とから5つの領域に区分され、
ア) 各領域においてベースゴム層がキャップゴム層よりもゴムモジュラスが大に設定され、
イ) キャップゴム層およびベースゴム層の各層において、中間領域のモジュラスが最も小さく、かつセンター領域のモジュラスが中間領域およびショルダー領域のモジュラスの1.5倍〜2倍に設定されていることを特徴とする空気入りタイヤ。
The tread portion has a two-layer structure including a cap rubber layer on the tread surface side and a base rubber layer disposed inside the cap rubber layer, and sandwiches the center region through which the tire equatorial plane passes in the tire width direction. And divided into five regions from an intermediate region formed on both sides thereof and a shoulder region formed further outside the intermediate region,
A) In each area, the rubber modulus of the base rubber layer is set larger than that of the cap rubber layer,
B) In each of the cap rubber layer and the base rubber layer, the modulus in the middle region is the smallest, and the modulus in the center region is set to 1.5 to 2 times the modulus in the middle region and the shoulder region. And pneumatic tires.
トレッド部が、トレッド面側のキャップゴム層Cと、その内側に配置されるベースゴム層Bとの2層構造とされると共に、タイヤ幅方向において、タイヤ赤道面が通るセンター領域Xと、センター領域を挟んでその両側に形成される中間領域Yと、中間領域のさらに外側に形成されるショルダー領域Zとから5つの領域に区分され、キャップゴム層におけるセンター領域X、中間領域Yおよびショルダー領域ZのそれぞれのゴムモジュラスをXc,Yc,Zcとし、ベースゴム層におけるセンター領域X、中間領域Yおよびショルダー領域ZのそれぞれのゴムモジュラスをXb,Yb,Zbとすると、
Figure 2004345432
の関係が成り立つように、各領域のゴムモジュラスが設定されていることを特徴とする空気入りタイヤ。
The tread portion has a two-layer structure of a cap rubber layer C on the tread surface side and a base rubber layer B disposed inside the cap rubber layer C, and a center region X through which the tire equatorial plane passes in the tire width direction; The center region X, the middle region Y and the shoulder region in the cap rubber layer are divided into five regions from an intermediate region Y formed on both sides of the region and a shoulder region Z formed further outside the intermediate region. Assuming that the respective rubber moduli of Z are Xc, Yc and Zc, and the respective rubber moduli of the center region X, the intermediate region Y and the shoulder region Z in the base rubber layer are Xb, Yb and Zb.
Figure 2004345432
The pneumatic tire is characterized in that the rubber modulus of each region is set so that the following relationship is satisfied.
JP2003142908A 2003-05-21 2003-05-21 Pneumatic tire Expired - Fee Related JP4256720B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003142908A JP4256720B2 (en) 2003-05-21 2003-05-21 Pneumatic tire

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003142908A JP4256720B2 (en) 2003-05-21 2003-05-21 Pneumatic tire

Publications (2)

Publication Number Publication Date
JP2004345432A true JP2004345432A (en) 2004-12-09
JP4256720B2 JP4256720B2 (en) 2009-04-22

Family

ID=33530835

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003142908A Expired - Fee Related JP4256720B2 (en) 2003-05-21 2003-05-21 Pneumatic tire

Country Status (1)

Country Link
JP (1) JP4256720B2 (en)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006273248A (en) * 2005-03-30 2006-10-12 Bridgestone Corp Pneumatic tire for motorcycle
JP2007137309A (en) * 2005-11-21 2007-06-07 Toyo Tire & Rubber Co Ltd Pneumatic tire
JP2008044448A (en) * 2006-08-11 2008-02-28 Bridgestone Corp Pneumatic radial tire for motorcycle
JP2008201310A (en) * 2007-02-21 2008-09-04 Bridgestone Corp Pneumatic tire for two-wheeler
WO2009020065A1 (en) * 2007-08-03 2009-02-12 Sumitomo Rubber Industries, Ltd. Pneumatic tire
JP2009051428A (en) * 2007-08-28 2009-03-12 Bridgestone Corp Pair of tires for motorcycle
EP2127904A1 (en) * 2007-03-08 2009-12-02 Bridgestone Corporation Pneumatic tire for two-wheeled motor vehicle
KR101040622B1 (en) 2008-12-01 2011-06-10 한국타이어 주식회사 Vehicle tire improved rolling resistance
KR101069324B1 (en) 2008-11-17 2011-10-05 한국타이어 주식회사 Vehicle tire improved tread
US8256478B2 (en) 2009-10-28 2012-09-04 The Yokohama Rubber Co., Ltd Pneumatic tire
US20120298271A1 (en) * 2009-11-26 2012-11-29 Michelin Recherche Et Technique S.A. Tire for a vehicle carrying heavy loads
JP2013100031A (en) * 2011-11-08 2013-05-23 Bridgestone Corp Pneumatic tire
JP2014133564A (en) * 2007-10-10 2014-07-24 Company General De Etablisman Michelin Heavy vehicle with tread having multiple parts
US20180170112A1 (en) * 2016-12-21 2018-06-21 Toyo Tire & Rubber Co., Ltd. Tire
CN109968907A (en) * 2017-12-27 2019-07-05 东洋橡胶工业株式会社 Pneumatic tire
US11491821B2 (en) * 2017-12-13 2022-11-08 Bridgestone Corporation Tire

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006273248A (en) * 2005-03-30 2006-10-12 Bridgestone Corp Pneumatic tire for motorcycle
JP4634841B2 (en) * 2005-03-30 2011-02-16 株式会社ブリヂストン Pneumatic tires for motorcycles
JP2007137309A (en) * 2005-11-21 2007-06-07 Toyo Tire & Rubber Co Ltd Pneumatic tire
JP4674809B2 (en) * 2005-11-21 2011-04-20 東洋ゴム工業株式会社 Pneumatic tire
JP2008044448A (en) * 2006-08-11 2008-02-28 Bridgestone Corp Pneumatic radial tire for motorcycle
JP2008201310A (en) * 2007-02-21 2008-09-04 Bridgestone Corp Pneumatic tire for two-wheeler
EP2127904A4 (en) * 2007-03-08 2011-10-26 Bridgestone Corp Pneumatic tire for two-wheeled motor vehicle
EP2127904A1 (en) * 2007-03-08 2009-12-02 Bridgestone Corporation Pneumatic tire for two-wheeled motor vehicle
US8365784B2 (en) 2007-03-08 2013-02-05 Bridgestone Corporation Pneumatic tire for motorcycle
WO2009020065A1 (en) * 2007-08-03 2009-02-12 Sumitomo Rubber Industries, Ltd. Pneumatic tire
JP2009035230A (en) * 2007-08-03 2009-02-19 Sumitomo Rubber Ind Ltd Pneumatic tire
JP2009051428A (en) * 2007-08-28 2009-03-12 Bridgestone Corp Pair of tires for motorcycle
JP2014133564A (en) * 2007-10-10 2014-07-24 Company General De Etablisman Michelin Heavy vehicle with tread having multiple parts
KR101069324B1 (en) 2008-11-17 2011-10-05 한국타이어 주식회사 Vehicle tire improved tread
KR101040622B1 (en) 2008-12-01 2011-06-10 한국타이어 주식회사 Vehicle tire improved rolling resistance
US8256478B2 (en) 2009-10-28 2012-09-04 The Yokohama Rubber Co., Ltd Pneumatic tire
US9358840B2 (en) * 2009-11-26 2016-06-07 Compagnie General Des Etablissements Michelin Tire for a vehicle carrying heavy loads
US20120298271A1 (en) * 2009-11-26 2012-11-29 Michelin Recherche Et Technique S.A. Tire for a vehicle carrying heavy loads
JP2013100031A (en) * 2011-11-08 2013-05-23 Bridgestone Corp Pneumatic tire
US20180170112A1 (en) * 2016-12-21 2018-06-21 Toyo Tire & Rubber Co., Ltd. Tire
US10688829B2 (en) * 2016-12-21 2020-06-23 Toyo Tire Corporation Tire
US11491821B2 (en) * 2017-12-13 2022-11-08 Bridgestone Corporation Tire
CN109968907A (en) * 2017-12-27 2019-07-05 东洋橡胶工业株式会社 Pneumatic tire
JP2019116192A (en) * 2017-12-27 2019-07-18 Toyo Tire株式会社 Pneumatic tire
CN109968907B (en) * 2017-12-27 2021-02-26 东洋橡胶工业株式会社 Pneumatic tire
US10940721B2 (en) 2017-12-27 2021-03-09 Toyo Tire Corporation Pneumatic radial tire
JP7030509B2 (en) 2017-12-27 2022-03-07 Toyo Tire株式会社 Pneumatic tires

Also Published As

Publication number Publication date
JP4256720B2 (en) 2009-04-22

Similar Documents

Publication Publication Date Title
JP4256720B2 (en) Pneumatic tire
JP4071354B2 (en) Pneumatic radial tire
JP4417507B2 (en) Pneumatic radial tire
JP2002052907A (en) Pneumatic radial tire
JP2008307974A (en) Pneumatic tire for motorcycle
JPH07125508A (en) Pneumatic tire
JP4327302B2 (en) Pneumatic radial tire
JP2007191044A (en) Pneumatic tire
JP2003237317A (en) Pneumatic tire
JPH11321245A (en) Pneumatic radial tire
JP3405582B2 (en) Pneumatic tire
JP4313115B2 (en) Pneumatic tire
JP2574971B2 (en) Pneumatic tire
JP4705284B2 (en) Radial tire for ATV
JP2791338B2 (en) Pneumatic tire
JP3978367B2 (en) Pneumatic tire
JP5005978B2 (en) Run flat tire
JP3919298B2 (en) Pneumatic radial tire
JP2006168637A (en) Pneumatic tire
JP4187833B2 (en) Pneumatic tires for motorcycles
JPH11115413A (en) Pneumatic tire
JP4179447B2 (en) Pneumatic radial tire
JP2005001443A (en) Pneumatic tire
JPH08207517A (en) Pneumatic radial tire
JP2002264615A (en) Radial tire for heavy load

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20060314

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20090115

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20090127

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20090130

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120206

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120206

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150206

Year of fee payment: 6

LAPS Cancellation because of no payment of annual fees