JPH11151909A - Pneumatic tire for heavy load - Google Patents
Pneumatic tire for heavy loadInfo
- Publication number
- JPH11151909A JPH11151909A JP9321496A JP32149697A JPH11151909A JP H11151909 A JPH11151909 A JP H11151909A JP 9321496 A JP9321496 A JP 9321496A JP 32149697 A JP32149697 A JP 32149697A JP H11151909 A JPH11151909 A JP H11151909A
- Authority
- JP
- Japan
- Prior art keywords
- tire
- tread
- point
- heavy
- pneumatic tire
- 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
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/01—Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
- Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、主としてトラッ
ク、バス用等の重荷重用空気入りタイヤに関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heavy-duty pneumatic tire for trucks, buses and the like.
【０００２】[0002]
【従来の技術と発明が解決しようとする課題】トラッ
ク、バス用等の重荷重用空気入りタイヤとして、トレッ
ド部にタイヤ周方向に連続する複数本の主溝を有すると
ともに、トレッド両側端部に主としてリブ状の陸部を有
し、主にトレッド端（ショルダー端）がエッジに形成さ
れて全体としてボックス形をなす、所謂スクエアショル
ダータイプのタイヤが知られている。2. Description of the Related Art As a heavy-duty pneumatic tire for trucks, buses, etc., a tread portion has a plurality of main grooves continuous in the tire circumferential direction, and is mainly provided on both side ends of the tread. A so-called square shoulder type tire having a rib-shaped land portion and having a box shape as a whole with a tread end (shoulder end) formed mainly at an edge is known.
【０００３】かかるタイヤは、トレッド幅が広幅のも
の、接地面積の大きいものほど、耐摩耗性や操縦安定性
やグリップ性がよいことから、トレッド幅が広幅化され
る傾向にある。その一方、トレッド幅を大きくすると、
トレッド端部（ショルダー部）の接地圧が局部的に著し
く高くなり、トレッド端部の肩落ち等の偏摩耗が生じ易
くなる。[0003] In such tires, the tread width tends to be wider as the tread width is wider and the tread area is larger because the abrasion resistance, steering stability and grip performance are better. On the other hand, if you increase the tread width,
The contact pressure at the tread end (shoulder) locally becomes extremely high, and uneven wear such as shoulder drop at the tread end is likely to occur.
【０００４】前記の偏摩耗を低減するために、図７のよ
うに、トレッド部（２１）の両側端部（２３）のトレッ
ド端（ｅ）よりやや内側に細溝（２２）を設けて、トレ
ッド端部の接地圧の上昇を抑えるようにしたものがある
が、この場合、実質的なトレッド幅、接地面積が減少す
る上、細溝（２２）で石噛みが生じたり、溝底にクラッ
クが発生したり、トレッド端部の欠けが発生する等の問
題が生じる。In order to reduce the uneven wear described above, as shown in FIG. 7, a narrow groove (22) is provided slightly inside the tread end (e) of both end portions (23) of the tread portion (21). In some cases, an increase in the contact pressure at the end of the tread is suppressed, but in this case, the substantial tread width and the contact area are reduced, and stones are caught in the narrow grooves (22) and cracks are formed on the groove bottoms. This causes problems such as generation of cracks and chipping of the tread edge.
【０００５】そこで、トレッド端部を、本来のショルダ
ーの側面よりも側方へ突出させた形態にしてトレッド幅
を広幅化することにより、大きな接地面積を確保しなが
ら、突出したトレッド端部の動きで該端部の接地圧の上
昇を吸収できる構造のタイヤを提案している（特開平４
−１８９６０４号）。[0005] In view of this, the tread end is formed so as to protrude laterally from the side surface of the original shoulder, and the tread width is widened. Has proposed a tire having a structure capable of absorbing an increase in the contact pressure at the end portion (Japanese Patent Laid-Open No. Hei 4 (Kokai) 4).
-189604).
【０００６】しかしながら、ベルト幅をそのままにし
て、トレッド端部だけを側方へ突出させる形でトレッド
幅を広くした場合、ラジアルタイヤ特有の高剛性の接地
面が維持され難く、そのためトレッド面内の動きが多く
なり、ヒステリシス・ロスにより転がり抵抗が悪化する
上、ショルダー部での偏摩耗の抑制効果も充分に得られ
ない。However, if the width of the tread is widened in such a manner that only the end portion of the tread protrudes laterally while keeping the width of the belt unchanged, it is difficult to maintain the highly rigid contact surface peculiar to the radial tire. The movement increases, the rolling resistance deteriorates due to hysteresis loss, and the effect of suppressing uneven wear at the shoulder cannot be sufficiently obtained.
【０００７】特に、重荷重用空気入りタイヤは、ある程
度の摩耗が進行した時点で、ベルト外側のトレッド部を
更新用トレッドと取替えることにより、更新して再使用
することが一般に行なわれているが、前記の偏摩耗のた
めに早期に更新加工に供する必要がある。In particular, a heavy-duty pneumatic tire is generally renewed and reused by replacing the tread portion on the outer side of the belt with a renewal tread when a certain amount of wear has progressed. Due to the uneven wear described above, it is necessary to provide an early renewal process.
【０００８】また、タイヤの更新加工においては、通
常、タイヤの最外ベルト層の外側に少なくとも２．５ｍ
ｍ程度のゴム厚を残してトレッド部をバフ掛け（削り落
とし）し、この部分に板状の更生用トレッドを貼り付け
て接合一体化する。その方法として、更新加工部分がト
レッド部のみであることから、バフ掛けした台タイヤの
面上に、予め成形した更新用トレッドを接着材層を介し
て貼り付けた状態で、大きな加硫釜に入れて再加硫する
ことにより接合する、いわゆるコールドタイプの更新方
法を採用することが多い。[0008] In the renewal processing of the tire, usually, at least 2.5 m outside the outermost belt layer of the tire.
The tread portion is buffed (cut off) while leaving a rubber thickness of about m, and a plate-shaped tread for rehabilitation is attached to this portion to be joined and integrated. As a method, since the renewal processing portion is only the tread portion, in a state where the preformed renewal tread is pasted on the surface of the buffed base tire via the adhesive layer, the vulcanization tank is large. In many cases, a so-called cold-type renewal method of joining by re-vulcanization is used.
【０００９】この際、前記バフラインのタイヤ側面位置
に凹部が存在していると、もとのトレッド幅に対して、
更新タイヤのトレッド幅が狭くなってしまう。このた
め、更新用トレッドとバフ掛けした台タイヤとの接合面
の幅を合せ難くなったり、当初よりもトレッド幅の狭い
更新タイヤとなり、摩耗ライフを損ねる等といった問題
がある。[0009] At this time, if there is a concave portion at the position of the tire side surface of the buff line, with respect to the original tread width,
The tread width of the updated tire becomes narrow. For this reason, there is a problem that it is difficult to match the width of the joining surface between the renewal tread and the buffed base tire, or the renewed tire has a smaller tread width than the initial one, and thus impairs the wear life.
【００１０】本発明は、上記に鑑みてなしたものであ
り、重荷重用空気入りタイヤとして、所定のトレッド
幅、すなわち接地面積を確保して、耐摩耗性を犠牲にす
ることなく、タイヤの更新性を良好に確保でき、同時に
荷重負荷によるたわみによるショルダー部への応力集中
を防ぎ、ベルト端歪を軽減でき、ひいては低転がり抵抗
化を促進できる重荷重用空気入りタイヤを提供するもの
である。The present invention has been made in view of the above, and as a heavy-duty pneumatic tire, a predetermined tread width, that is, a ground contact area, is secured, and the tire is renewed without sacrificing wear resistance. It is intended to provide a pneumatic tire for heavy loads capable of ensuring good performance, at the same time preventing stress concentration on a shoulder portion due to deflection due to a load, reducing belt end distortion, and promoting low rolling resistance.
【００１１】[0011]
【課題を解決するための手段】上記の課題を解決する本
発明は、トレッド部に複数本のタイヤ周方向に連続する
主溝を有し、少なくともトレッド両側端部にリブ状の陸
部を有する重荷重用空気入りタイヤであって、タイヤ側
面におけるトレッド端よりタイヤ径方向内側のバットレ
ス部に、タイヤ周方向に延びる環状凹陥部が設けられて
なり、前記環状凹陥部は、そのタイヤ径方向内側端が、
タイヤ更新のためにトレッド部をバフ掛けする場合のバ
フラインがタイヤ側面と交わる点（ａ）よりタイヤ径方
向外側の位置にあることを特徴とする。In order to solve the above-mentioned problems, the present invention has a tread portion having a plurality of main grooves continuous in the circumferential direction of the tire, and having a rib-shaped land portion at least at both side ends of the tread. In a heavy-load pneumatic tire, an annular recess extending in the tire circumferential direction is provided at a buttress portion on the tire side surface in the tire radial direction from the tread end, and the annular recess is provided at the tire radial inner end. But,
The buff line for buffing the tread portion for updating the tire is located at a position radially outward from the point (a) intersecting with the tire side surface.
【００１２】前記のバフラインは、最外ベルト層の外側
少なくとも２．５ｍｍのゴム厚を残すように設定される
のが普通である。The buff line is usually set to leave a rubber thickness of at least 2.5 mm outside the outermost belt layer.
【００１３】前記の重荷重用空気入りタイヤであると、
当初は所定のトレッド幅つまりは接地面積を確保して、
高剛性接地面を維持でき、しかもトレッド端部（ショル
ダー部）において局部的な接地圧の上昇が生じたときに
は、その圧力を環状凹陥部で吸収できるため、ショルダ
ー部での応力集中がなく、ころがり抵抗を低減でき、か
つ肩落ち等の偏摩耗が生じ難いものとなる。[0013] In the heavy load pneumatic tire described above,
Initially, secure the prescribed tread width, that is, the ground contact area,
A highly rigid contact surface can be maintained, and when a local increase in contact pressure occurs at the tread end (shoulder), the pressure can be absorbed by the annular recess, so there is no stress concentration at the shoulder and rolling Resistance can be reduced, and uneven wear such as shoulder drop hardly occurs.
【００１４】そして、タイヤに所定以上の摩耗が生じ
て、トレッド部を更新する必要が生じたときには、摩耗
したタイヤのトレッド部を、最外ベルト層のタイヤ径方
向外側に所定のゴム厚、例えば少なくとも２．５ｍｍ程
度のゴム厚を残すようにバフ掛けにより削り落すが、こ
の際、前記タイヤ側面のバットレス部に形成されている
環状凹陥部のタイヤ径方向内側端が、前記のように設定
されるバフライン（Ｌ）がタイヤ側面と交わる点（ａ）
よりタイヤ径方向外側の位置にあるために、更新用トレ
ッドとの接合面は前記環状凹陥部の個所を避ける形で、
本来のタイヤ側面での幅を確保でき、ひいては前記更新
用トレッドと台タイヤの接合面の幅を合せ難くなった
り、更新用トレッドの幅が狭くなったりする問題が生じ
ない。When the tread portion needs to be renewed because the tire has worn out more than a predetermined amount, the tread portion of the worn tire is placed outside the outermost belt layer in the tire radial direction by a predetermined rubber thickness, for example, Buffing is performed to leave a rubber thickness of at least about 2.5 mm. At this time, the tire radially inner end of the annular recess formed in the buttress portion of the tire side surface is set as described above. (B) where the buff line (L) meets the tire side
Because it is located at a position further outside in the tire radial direction, the joining surface with the tread for renewal is in a form to avoid the location of the annular recess,
The original width on the side surface of the tire can be ensured, so that there is no problem in that the width of the joining surface between the renewal tread and the base tire is hardly matched or the width of the renewal tread becomes narrow.
【００１５】したがって、更新タイヤにおいては、当初
の所定のトレッド幅を確保でき、トレッド幅、接地面積
の減少を防止できる。[0015] Therefore, in the updated tire, an initial predetermined tread width can be secured, and a decrease in the tread width and the contact area can be prevented.
【００１６】前記の重荷重用空気入りタイヤにおいて、
前記環状凹陥部のタイヤ径方向内側端が、各主溝の底面
を結ぶ仮想線の延長部分とタイヤ側面とが交わる点
（ｂ）よりタイヤ径方向内側の位置にあるのが特に好適
である。すなわち、前記環状凹陥部の内側端が前記点
（ｂ）よりタイヤ径方向外側の位置にあって、環状凹陥
部のタイヤ径方向の幅が小さくなると、トレッド端部で
の接地圧の上昇を抑える効果が充分に得られなくなる
上、トレッド端部の弾性変形による応力が環状凹陥部の
底部に集中し易くなるので、前記のように環状凹陥部の
タイヤ径方向内側端を前記点（ｂ）よりタイヤ径方向内
側の位置にあるように形成しておくのがよい。In the above-mentioned heavy duty pneumatic tire,
It is particularly preferable that the radial inner end of the annular recess is located radially inward from the point (b) where the extended portion of the imaginary line connecting the bottom surfaces of the main grooves intersects with the tire side surface. That is, when the inner end of the annular concave portion is located outside the point (b) in the tire radial direction and the width of the annular concave portion in the tire radial direction is reduced, an increase in the contact pressure at the tread end is suppressed. The effect is not sufficiently obtained, and the stress due to the elastic deformation of the tread end is easily concentrated on the bottom of the annular recess. Therefore, the tire radially inner end of the annular recess is moved from the point (b) as described above. It is preferable to form it so as to be located on the inner side in the tire radial direction.
【００１７】また前記の重荷重用空気入りタイヤにおい
て、前記環状凹陥部のタイヤ径方向外側端が、トレッド
端から主溝深さの１／３の点より下方位置にあるように
形成されてなるものが特に好適である。すなわち、これ
により、使用当初においては本来のトレッド幅を確保で
きるとともに、この本来のトレッド幅を確保できる期間
が長くなり、タイヤ性能を良好に保持できる。In the heavy-duty pneumatic tire described above, the radially outer end of the annular recessed portion is formed so as to be located at a position below a point of one third of a main groove depth from a tread end. Is particularly preferred. That is, by this, the original tread width can be ensured at the beginning of use, and the period during which the original tread width can be ensured becomes longer, so that the tire performance can be favorably maintained.
【００１８】また前記環状凹陥部は、前記のトレッド端
からトレッド幅の１〜４％タイヤ内方側の点（ｄ）より
タイヤ軸心に対し直角の垂線を下ろしたとき、環状凹陥
部の最深部が該垂線より外側部にあるように形成してお
くのがよい。すなわち、このことと、環状凹陥部のタイ
ヤ径方向内側端が、最外ベルト層の外側に少なくとも
２．５ｍｍ上のゴム厚を保有するように設定されるバフ
ラインがタイヤ側面と交わる点（ａ）よりタイヤ径方向
外側の位置にあることとによって、最外ベルト層の端部
と環状凹陥部との間に充分な間隔を確保でき、ベルト端
の亀裂やセパレーションの発生を防止できる。またショ
ルダー端エッジに若干の丸みを付け、サイプを加える等
の処置を施して、山間部等で生じる横力に対応すること
もできる。The annular concave portion is formed at the deepest point of the annular concave portion when a perpendicular line perpendicular to the tire axis is lowered from a point (d) inward of the tire by 1 to 4% of the tread width from the tread end. Preferably, the portion is formed outside the perpendicular. That is, the point (a) at which the buff line, which is set so that the tire radially inner end of the annular concave portion has a rubber thickness of at least 2.5 mm outside the outermost belt layer, intersects the tire side surface. By being located further outward in the tire radial direction, a sufficient gap can be secured between the end of the outermost belt layer and the annular recessed portion, and cracks and separation at the belt end can be prevented. In addition, the shoulder end edge may be slightly rounded and a sipe may be applied to cope with a lateral force generated in a mountain area or the like.
【００１９】なお、本発明が対象とする重荷重用空気入
りタイヤは、タイヤ幅が１６５ｍｍ以上、扁平率が９０
％以下、リム径が１５インチ以上のトラック、バス用の
タイヤで、主として前輪または遊輪用に使用されるもの
である。The heavy-duty pneumatic tire to which the present invention is applied has a tire width of 165 mm or more and an oblateness of 90%.
%, Rim diameter of 15 inches or more for trucks and buses, mainly used for front wheels or idle wheels.
【００２０】[0020]
【発明の実施の形態】次に本発明の実施の形態を図面に
基いて説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.
【００２１】図１は重荷重用空気入りタイヤ（Ｔ）の１
実施例を示すタイヤ幅方向に沿う断面図である。図２は
同上の一部の拡大断面図である。FIG. 1 shows a heavy-duty pneumatic tire (T).
It is sectional drawing in alignment with the tire width direction which shows an Example. FIG. 2 is an enlarged sectional view of a part of the above.
【００２２】図において、（１）はタイヤ（Ｔ）のトレ
ッド部、（２）はビードコア（３）を備える両側のビー
ド部（４）からタイヤ径方向外向きに延びるサイドウォ
ール部で、その両端がトレッド部（１）でつながれてい
る。これらの内周に沿って両端がビードコア（３）で折
返されて支持されたカーカス（５）を備え、またトレッ
ド部（１）とカーカス（５）の間に複数層よりなるベル
ト層（６）を備えている。なお、必要に応じてベルト
（６）の外側に繊維コード等よりなる補強層が配され
る。このようなタイヤの内部構造は、基本的に従来周知
のラジアルタイヤ構造のタイヤと同じであり、その詳細
な説明は省略する。In the figure, (1) is a tread portion of a tire (T), and (2) is a sidewall portion extending outward in a tire radial direction from both bead portions (4) provided with a bead core (3). Are connected by a tread (1). A carcass (5) supported at both ends by being folded back by a bead core (3) along the inner periphery thereof, and a belt layer (6) comprising a plurality of layers between the tread portion (1) and the carcass (5) It has. In addition, a reinforcing layer made of a fiber cord or the like is disposed outside the belt (6) as necessary. The internal structure of such a tire is basically the same as that of a conventionally known radial tire structure, and a detailed description thereof will be omitted.
【００２３】また前記トレッド部（１）には、図１に示
すように、タイヤ周方向にストレート状あるいはジグザ
グ状に連なる複数本（図の場合は４本）の主溝（７）を
有し、少なくともトレッド部（１）の両側端部にリブ状
の陸部（８）を有するもので、図の場合トレッド部
（１）の中央域も、前記主溝（７）により隔成されたリ
ブ状の陸部（８）を有するリブパターンを基調とするも
のを示している。なお、前記陸部（８）には、必要に応
じて主溝（７）同士をつなぐ比較的細いスリットと称す
る横溝が形成される場合があり、さらにサイプと称する
細溝が形成されることもある。As shown in FIG. 1, the tread portion (1) has a plurality of (four in the figure) main grooves (7) connected in a straight or zigzag shape in the tire circumferential direction. A rib-shaped land portion (8) at least at both end portions of the tread portion (1), and in the case of the figure, a central region of the tread portion (1) is also separated by the main groove (7). The figure shows a pattern based on a rib pattern having a land portion (8) in a shape of a circle. In the land portion (8), a lateral groove called a relatively thin slit connecting the main grooves (7) may be formed as necessary, and a narrow groove called a sipe may be formed as needed. is there.
【００２４】前記トレッド部（１）の両側端部、つまり
最外側の主溝（７）より外側のリブ状の陸部（８）によ
るショルダー部（１３）のトレッド面とタイヤ側面とが
交わるトレッド端（ｅ）が、主にボックス形のエッジに
形成された、所謂スクエアショルダータイプのタイヤと
されている。前記トレッド端（ｅ）に若干の丸みを付け
る場合もある。The tread where the tread surface of the shoulder portion (13) and the side surface of the tire intersect with both end portions of the tread portion (1), that is, the rib-shaped land portion (8) outside the outermost main groove (7). The end (e) is a so-called square shoulder type tire mainly formed with a box-shaped edge. The tread edge (e) may be slightly rounded.
【００２５】そして、本発明の場合、前記トレッド端
（ｅ）のタイヤ径方向内側（図面の下方側）のバットレ
ス部（９）には、断面において本来のタイヤ側面からの
えぐり形状をなしてタイヤ周方向に延びる環状凹陥部
（１０）が設けられている。この環状凹陥部（１０）と
しては、タイヤ周方向に連続した環状をなすものにかぎ
らず、周方向の所々で断続しているもので、全体として
実質的に環状をなすものであればよい。In the case of the present invention, the buttress portion (9) on the inner side in the tire radial direction (the lower side in the drawing) of the tread end (e) has a cross section formed from the original side surface of the tire. An annular recess (10) extending in the circumferential direction is provided. The annular recessed portion (10) is not limited to a continuous annular shape in the tire circumferential direction, but may be a continuous annular shape in the circumferential direction.
【００２６】前記環状凹陥部（１０）は、そのタイヤ径
方向内側端（１１）が、タイヤ更新のために最外ベルト
層（６ａ）の外側に所定のゴム厚（ｔ１）を残してトレ
ッド部（１）をバフ掛けする場合のバフライン（Ｌ）、
例えば従来一般に、タイヤの更新の際には最外ベルト層
（６ａ）の外側に２．５ｍｍ程度のゴム厚を残してバフ
掛けされていることから、最外ベルト層（６ａ）より約
２．５ｍｍタイヤ径方向外側に想定したラインをバフラ
イン（Ｌ）として、該ライン（Ｌ）がタイヤ側面と交わ
る点（ａ）よりタイヤ径方向外側の位置にあるように形
成されている。特に図の実施例においては、前記内側端
（１１）が、各主溝（７）の底面を結ぶ仮想線（７ａ）
の延長部分がタイヤ側面と交わる点（ｂ）よりタイヤ径
方向内側で、前記点（ａ）よりタイヤ径方向外側の位置
にあるように形成されている。The annular concave portion (10) has a radially inner end (11) having a predetermined rubber thickness (t1) outside the outermost belt layer (6a) for renewing the tire. Buff line (L) for buffing (1),
For example, conventionally, when a tire is renewed, the outermost belt layer (6a) is buffed with a rubber thickness of about 2.5 mm outside the outermost belt layer (6a). A line assumed on the outer side in the tire radial direction of 5 mm is defined as a buff line (L) so that the line (L) is located on the outer side in the tire radial direction from the point (a) where the line (L) intersects the tire side surface. In particular, in the illustrated embodiment, the inner end (11) is an imaginary line (7a) connecting the bottom of each main groove (7).
Is formed at a position radially inward of the tire radial direction from the point (b) intersecting the tire side surface and at a position radially outward of the point (a).
【００２７】前記の環状凹陥部（１０）のタイヤ径方向
外側端（１２）については、トレッド端（ｅ）よりタイ
ヤ径方向内側にあればよいが、実施上はトレッド端
（ｅ）から主溝（７）深さの１／３の点（ｃ）よりタイ
ヤ径方向内側の位置にあるのが、当初のトレッド幅（Ｔ
Ｗ）を長く確保でき好ましい。ただし、前記環状凹陥部
（１０）のタイヤ径方向の幅が小さくなる程、該環状凹
陥部（１０）の底部に応力が集中しクラック等が発生し
易くなるので、前記環状凹陥部（１０）の前記外側端
（１２）をあまりタイヤ径方向内側の位置にあるのは好
ましくない。したがって、前記環状凹陥部（１０）の前
記外側端（１２）は、トレッド端（ｅ）から主溝深さの
１／３〜２／３の間に位置させるのが特に好適である。The radially outer end (12) of the annular recess (10) in the tire radial direction may be located radially inward of the tread end (e). However, in practice, the main groove extends from the tread end (e). (7) The initial tread width (T) is located on the inner side in the tire radial direction from the point (c) of 1/3 of the depth.
W) is preferably long. However, as the width of the annular recess (10) in the tire radial direction becomes smaller, stress concentrates on the bottom of the annular recess (10) and cracks and the like are more likely to occur. It is not preferable that the outer end (12) is located too far inward in the tire radial direction. Therefore, it is particularly preferable that the outer end (12) of the annular recess (10) is located between 1/3 and 2/3 of the depth of the main groove from the tread end (e).
【００２８】また前記のえぐり形状の環状凹陥部（１
０）は、トレッド端（ｅ）からトレッド幅の１〜４％タ
イヤ内方側の点（ｄ）、例えば５ｍｍ程度タイヤ内方側
の点よりタイヤ軸心に対し直角の垂線を下ろしたとき、
前記環状凹陥部（１０）の最深部が該垂線より外側部に
あるように形成しておくのがよい。このことと、環状凹
陥部（１０）の前記内側端（１１）が前記バフライン
（Ｌ）がタイヤ側面と交差する点（ａ）よりタイヤ径方
向外側の位置にあることとによって、本来のタイヤ側面
からのえぐり形状をなす環状凹陥部（１０）を有するに
も拘らず、最外ベルト層（６ａ）の端部と環状凹陥部
（１０）およびタイヤ側面との間に充分なゴム厚（通
常、１２ｍｍ以上）を確保できることになる。The undercut annular recess (1)
0) is 1 to 4% of the tread width from the tread end (e) to a point (d) on the inward side of the tire, for example, when a perpendicular line perpendicular to the tire axis is lowered from a point on the inward side of the tire by about 5 mm,
Preferably, the annular recess (10) is formed so that the deepest portion is located outside the perpendicular line. This and the fact that the inner end (11) of the annular concave portion (10) is located at a position radially outside the tire radial direction from the point (a) where the buff line (L) intersects with the tire side surface allows the original tire side surface to be formed. Despite having an annular recess (10) in the form of a hollow, a sufficient rubber thickness (usually, between the end of the outermost belt layer (6a) and the annular recess (10) and the side of the tire) 12 mm or more).
【００２９】上記した環状凹陥部（１０）の形態として
は、図２のもののほか、図３〜図５に例示するように、
タイヤ径方向外側端（１２）と内側端（１１）の位置お
よび深さ等が、上記した条件範囲で種々の形態による実
施が可能である。As the form of the above-mentioned annular concave portion (10), in addition to the one shown in FIG. 2, as shown in FIGS.
The position and depth of the outer end (12) and the inner end (11) in the tire radial direction can be implemented in various forms within the above-mentioned condition ranges.
【００３０】いずれの場合においても、バットレス部
（９）に本来のタイヤ側面からのえぐり形状による環状
凹陥部（１０）があるために、トレッド幅（ＴＷ）が比
較的広幅に設定されていても、環状凹陥部（１０）によ
ってトレッド端部がタイヤ径方向に動き易くなる。また
そのため、トレッド端部での接地圧の上昇を吸収でき、
本来のトレッド幅すなわち接地面積を確保しながら、接
地圧の局部的な上昇を抑え、ころがり抵抗（ＲＲ）を低
減できるとともに、肩落ち等の偏摩耗が生じ難いものと
なる。In any case, even if the tread width (TW) is set to be relatively wide, the buttress portion (9) has the annular recessed portion (10) formed by the original recessed shape from the tire side surface. In addition, the annular recess (10) facilitates movement of the tread end in the tire radial direction. Also, because of this, it is possible to absorb the rise in contact pressure at the tread edge,
While securing the original tread width, that is, the contact area, the local increase in the contact pressure can be suppressed, the rolling resistance (RR) can be reduced, and uneven wear such as shoulder drop can hardly occur.
【００３１】例えば、バットレス部に環状凹陥部を有す
る図２の構造のリブパターンのタイヤで、タイヤサイズ
が２８５／７５Ｒ２４．５ １４ＰＲの実施例のタイヤ
と、バットレス部に環状凹陥部を有さない同サイズの通
常タイヤ（比較例）とを用いて、コーナリングパワー
（ＣＰ）、ころがり抵抗（ＲＲ）および偏摩耗を測定し
比較したところ、下記の表１のとおりとなった。すなわ
ち、実施例のタイヤは、比較例のタイヤと比較して、コ
ーナリングパワー（ＣＰ）は高く、ころがり抵抗（Ｒ
Ｒ）は小さくなり、また偏摩耗についてはほとんど差の
ないものとなった。For example, a tire having a rib pattern of the structure shown in FIG. 2 having an annular recess in the buttress portion and having a tire size of 285 / 75R24.5 14PR and a tire having no annular recess in the buttress portion. The cornering power (CP), the rolling resistance (RR) and the uneven wear were measured and compared with a normal tire (comparative example) of the same size, and the results were as shown in Table 1 below. That is, the tire of the example has a higher cornering power (CP) and a higher rolling resistance (R) than the tire of the comparative example.
R) was small, and there was almost no difference in uneven wear.
【００３２】なお、コーナリングパワー（ＣＰ）は、規
格荷重、規格内圧に設定されたタイヤに、台上試験で左
右に２°のスリップ角を加え、時速１０ｋｍ／ｈで測定
した横力の絶対値の平均をスリップ角２°で割った値で
あり、比較例を１００として指数で表示した。The cornering power (CP) is the absolute value of the lateral force measured at a speed of 10 km / h by adding a slip angle of 2 ° left and right in a bench test to a tire set to a specified load and a specified internal pressure. Is a value obtained by dividing the average of the results by a slip angle of 2 °.
【００３３】ころがり抵抗（ＲＲ）は、「ＪＡＴＭＡ
トラック及びバス用タイヤの転がり抵抗試験方法」の力
測定法により、時速６０ｋｍで１時間のならし走行後に
測定したもので、比較例を１００として指数で示した。The rolling resistance (RR) is calculated according to the formula "JATMA".
It was measured after running for 1 hour at a speed of 60 km / h by a force measurement method described in "Method for Testing Rolling Resistance of Truck and Bus Tires".
【００３４】偏摩耗については、ドラム試験により行な
い、２４．５×８．２５リムで、内圧８５０ｋＰａ、荷
重は規格の１５０％、速度４０ｋｍ／ｈで６７００ｋｍ
走行後のタイヤショルダー端部の状態を目視で評価し、
比較例を１００として指数で表示した。The uneven wear was measured by a drum test. The inner diameter was 850 kPa at a 24.5 × 8.25 rim, the load was 150% of the standard, and the speed was 6700 km at a speed of 40 km / h.
Visually evaluate the condition of the tire shoulder end after running,
The comparative example was expressed as an index with 100 as an index.
【００３５】[0035]
【表１】 そして、所定以上の摩耗が生じた場合等のタイヤの更新
加工において、図６のように、タイヤ（Ｔ）のトレッド
部（１）を、最外ベルト層（６ａ）の外側に２．５ｍｍ
程度のゴム厚（ｔ１）を残すようにバフ掛けにより削り
落し、このバフ掛けした面上に更新用トレッド（１ａ）
を貼り付け接合一体化させるが、この際、本発明のタイ
ヤの場合には、バットレス部（９）に形成された環状凹
陥部（１０）のタイヤ径方向内側端（１１）が、前記バ
フライン（Ｌ）がタイヤ側面と交わる点（ａ）よりタイ
ヤ径方向外側の位置にあるために、更新用トレッド（１
ａ）との接合面に相当するタイヤ側面には前記環状凹陥
部（１０）が存在しないことになる。[Table 1] Then, in the renewal processing of the tire when a predetermined amount of wear or the like occurs, as shown in FIG. 6, the tread portion (1) of the tire (T) is placed 2.5 mm outside the outermost belt layer (6a).
Buffing is performed to leave a rubber thickness (t1) of a certain degree, and the tread for renewal (1a) is placed on the buffed surface.
In this case, in the case of the tire of the present invention, the radially inner end (11) of the annular recess (10) formed in the buttress portion (9) is connected to the buff line (11). L) is located outside the point (a) in the tire radial direction from the point (a) where the tread intersects the tire side surface.
The annular recess (10) does not exist on the tire side surface corresponding to the joint surface with (a).
【００３６】それゆえ、前記更新用トレッドとの接合面
の部分では本来のタイヤ側面による幅を確保できる。ま
たそのため、更新用トレッドと台タイヤの接合面の幅を
合せ難い、あるいは更新用トレッドの幅が狭くなるとい
った問題が生じず、当初のトレッド幅を確保した更新タ
イヤを得ることができる。Therefore, the original width of the side surface of the tire can be secured at the joint surface with the renewal tread. Therefore, there is no problem that it is difficult to match the width of the joining surface between the updating tread and the base tire or the width of the updating tread becomes narrow, and it is possible to obtain an updated tire having the initial tread width secured.
【００３７】[0037]
【発明の効果】上記のように本発明の重荷重用空気入り
タイヤによれば、所定のトレッド幅、すなわち接地面積
を確保して、耐摩耗性を犠牲にすることなく、タイヤの
更新性を良好に確保でき、同時に荷重負荷による撓み変
形に伴うショルダー部の応力集中を防ぎ、ベルト端歪を
軽減でき、ひいては低転がり抵抗化を促進できる重荷重
用空気入りタイヤを得ることができる。As described above, according to the pneumatic tire for heavy load of the present invention, a predetermined tread width, that is, a contact area is ensured, and the renewability of the tire is improved without sacrificing wear resistance. And at the same time, it is possible to obtain a pneumatic tire for heavy load that can prevent stress concentration at the shoulder portion due to bending deformation due to load load, reduce belt end distortion, and promote low rolling resistance.
【図１】本発明の重荷重用タイヤのラジアル方向に沿う
断面図である。FIG. 1 is a sectional view along a radial direction of a heavy duty tire according to the present invention.
【図２】同上の一部の拡大断面図である。FIG. 2 is an enlarged sectional view of a part of the above.
【図３】環状凹陥部の形態を異にする他の実施例の一部
の断面図である。FIG. 3 is a cross-sectional view of a part of another embodiment in which the shape of the annular recess is different.
【図４】環状凹陥部の形態を異にする他の実施例の一部
の断面図である。FIG. 4 is a cross-sectional view of a part of another embodiment in which the shape of the annular recess is different.
【図５】環状凹陥部の形態を異にする他の実施例の一部
の断面図である。FIG. 5 is a partial cross-sectional view of another embodiment in which the shape of the annular recess is different.
【図６】タイヤ更新加工状態の説明図である。FIG. 6 is an explanatory diagram of a tire update processing state.
【図７】従来のタイヤの一部の断面図である。FIG. 7 is a partial cross-sectional view of a conventional tire.
（Ｔ） タイヤ （１） トレッド部 （２） サイドウォール部 （４） ビード部 （５） カーカス （６） ベルト層 （６ａ） 最外ベルト層 （７） 主溝 （７ａ） 主溝の底面を結ぶ仮想線 （８） 陸部 （９） バットレス部 （１０） 環状凹陥部 （１１） 環状凹陥部のタイヤ径方向内側端 （１２） 環状凹陥部のタイヤ径方向外側端 （ａ） バフラインがタイヤ側面と交わる点 （ｂ） 仮想線の延長部分がタイヤ側面と交わる点 （ｃ） 主溝深さの１／３の点 （ｄ） トレッド端よりトレッド幅の１〜４％タイヤ
内方側の点 （ｅ） トレッド端(T) Tire (1) Tread (2) Sidewall (4) Bead (5) Carcass (6) Belt layer (6a) Outermost belt layer (7) Main groove (7a) Connects bottom of main groove Virtual line (8) Land part (9) Buttress part (10) Annular concave part (11) Tire radial inner end of annular concave part (12) Tire radial outer end of annular concave part (a) Buff line is connected to tire side surface Intersecting point (b) Point where the extension of the imaginary line intersects the tire side surface (c) Point of 1/3 of main groove depth (d) Point of 1 to 4% of tread width inward of tire from tread end (e ) Tread edge
─────────────────────────────────────────────────────
────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成１０年１月１２日[Submission date] January 12, 1998
【手続補正１】[Procedure amendment 1]
【補正対象書類名】図面[Document name to be amended] Drawing
【補正対象項目名】全図[Correction target item name] All figures
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【図１】 FIG.
【図２】 FIG. 2
【図３】 FIG. 3
【図４】 FIG. 4
【図５】 FIG. 5
【図６】 FIG. 6
【図７】 FIG. 7
Claims (5)
する主溝を有し、少なくともトレッド両側端部にリブ状
の陸部を有する空気入りタイヤであって、 タイヤ側面におけるトレッド端よりタイヤ径方向内側の
バットレス部に、タイヤ周方向に延びる環状凹陥部が設
けられてなり、 前記環状凹陥部は、そのタイヤ径方向内側端が、タイヤ
更新のためにトレッド部をバフ掛けする場合のバフライ
ンがタイヤ側面と交わる点（ａ）よりタイヤ径方向外側
の位置にあることを特徴とする重荷重用空気入りタイ
ヤ。1. A pneumatic tire having a plurality of main grooves continuous in a circumferential direction in a tread portion, and a rib-shaped land portion at least at both end portions of the tread, wherein the tire is located closer to the tread end than the tread end on the side surface of the tire. A radially inner buttress portion is provided with an annular recess extending in the tire circumferential direction, and the annular recess has a tire radially inner end buffing when a tread portion is buffed for tire renewal. Is located outside the point (a) in the tire radial direction from the point (a) where the tire intersects the side surface of the tire.
くとも２．５ｍｍのゴム厚を残すように設定されてなる
請求項１の記載の重荷重用空気入りタイヤ。2. The heavy duty pneumatic tire according to claim 1, wherein the buff line is set so as to leave a rubber thickness of at least 2.5 mm outside the outermost belt layer.
各主溝の底面を結ぶ仮想線の延長部分とタイヤ側面とが
交わる点（ｂ）よりタイヤ径方向内側の位置にある請求
項１または２に記載の重荷重用空気入りタイヤ。3. A tire radially inner end of the annular concave portion,
The heavy-duty pneumatic tire according to claim 1 or 2, wherein the tire is located radially inward of a point (b) at which an extended portion of an imaginary line connecting the bottom surfaces of the main grooves intersects with the tire side surface.
トレッド端から主溝深さの１／３の点よりタイヤ径方向
内側の位置にある請求項２または３に記載の重荷重用空
気入りタイヤ。4. The tire radially outer end of the annular concave portion,
The pneumatic tire for heavy load according to claim 2 or 3, which is located at a position radially inward of the tire groove from a point of 1/3 of a main groove depth from a tread end.
ヤ内方側の点（ｄ）よりタイヤ軸心に対し直角の垂線を
下ろしたとき、前記環状凹陥部の最深部が該垂線より外
側部にあるように形成されてなる請求項２〜４のいずれ
か１項に記載の重荷重用空気入りタイヤ。5. When a perpendicular line perpendicular to the tire axis is lowered from a point (d) on the inner side of the tire from 1 to 4% of the tread width from the tread end, the deepest part of the annular concave portion is located outside the perpendicular line. The heavy-duty pneumatic tire according to any one of claims 2 to 4, wherein the pneumatic tire is formed so as to be in a portion.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32149697A JP3570182B2 (en) | 1997-11-21 | 1997-11-21 | Heavy duty pneumatic tires |
| DE19853474A DE19853474A1 (en) | 1997-11-21 | 1998-11-19 | Heavy duty pneumatic tire with axial, circumferential grooving of rectangular tread shoulders |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32149697A JP3570182B2 (en) | 1997-11-21 | 1997-11-21 | Heavy duty pneumatic tires |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11151909A true JPH11151909A (en) | 1999-06-08 |
| JP3570182B2 JP3570182B2 (en) | 2004-09-29 |
Family
ID=18133215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32149697A Expired - Lifetime JP3570182B2 (en) | 1997-11-21 | 1997-11-21 | Heavy duty pneumatic tires |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP3570182B2 (en) |
| DE (1) | DE19853474A1 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100593027B1 (en) | 2004-09-30 | 2006-06-26 | 금호타이어 주식회사 | Aircraft tire for preventing Seperation |
| WO2008026600A1 (en) | 2006-08-28 | 2008-03-06 | Bridgestone Corporation | Pneumatic tire |
| WO2009081973A1 (en) * | 2007-12-25 | 2009-07-02 | Bridgestone Corporation | Tire |
| WO2012001830A1 (en) * | 2010-06-28 | 2012-01-05 | 株式会社ブリヂストン | Method for producing tire casing and tire, and tire casing and tire |
| US8191592B2 (en) | 2008-08-04 | 2012-06-05 | The Goodyear Tire & Rubber Company | Two-piece tire |
| US20180065423A1 (en) * | 2016-09-07 | 2018-03-08 | Toyo Tire & Rubber Co., Ltd. | Pneumatic tire |
| JP2020001617A (en) * | 2018-06-29 | 2020-01-09 | Ｔｏｙｏ Ｔｉｒｅ株式会社 | Pneumatic tire |
| JP2021091252A (en) * | 2019-12-06 | 2021-06-17 | Ｔｏｙｏ Ｔｉｒｅ株式会社 | Pneumatic tire |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6164353A (en) * | 1999-07-21 | 2000-12-26 | The Yokohama Rubber Co., Ltd. | Pneumatic tire for passenger cars having shoulder recess |
| JP2010285032A (en) * | 2009-06-10 | 2010-12-24 | Toyo Tire & Rubber Co Ltd | Pneumatic tire |
-
1997
- 1997-11-21 JP JP32149697A patent/JP3570182B2/en not_active Expired - Lifetime
-
1998
- 1998-11-19 DE DE19853474A patent/DE19853474A1/en not_active Withdrawn
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100593027B1 (en) | 2004-09-30 | 2006-06-26 | 금호타이어 주식회사 | Aircraft tire for preventing Seperation |
| WO2008026600A1 (en) | 2006-08-28 | 2008-03-06 | Bridgestone Corporation | Pneumatic tire |
| JP5130217B2 (en) * | 2006-08-28 | 2013-01-30 | 株式会社ブリヂストン | Pneumatic tire |
| WO2009081973A1 (en) * | 2007-12-25 | 2009-07-02 | Bridgestone Corporation | Tire |
| US8191592B2 (en) | 2008-08-04 | 2012-06-05 | The Goodyear Tire & Rubber Company | Two-piece tire |
| WO2012001830A1 (en) * | 2010-06-28 | 2012-01-05 | 株式会社ブリヂストン | Method for producing tire casing and tire, and tire casing and tire |
| US20180065423A1 (en) * | 2016-09-07 | 2018-03-08 | Toyo Tire & Rubber Co., Ltd. | Pneumatic tire |
| US10857840B2 (en) * | 2016-09-07 | 2020-12-08 | Toyo Tire Corporation | Pneumatic tire |
| JP2020001617A (en) * | 2018-06-29 | 2020-01-09 | Ｔｏｙｏ Ｔｉｒｅ株式会社 | Pneumatic tire |
| JP2021091252A (en) * | 2019-12-06 | 2021-06-17 | Ｔｏｙｏ Ｔｉｒｅ株式会社 | Pneumatic tire |
Also Published As
| Publication number | Publication date |
|---|---|
| DE19853474A1 (en) | 1999-05-27 |
| JP3570182B2 (en) | 2004-09-29 |
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