JPH10264609A - Pneumatic tire for heavy load - Google Patents
Pneumatic tire for heavy loadInfo
- Publication number
- JPH10264609A JPH10264609A JP9071516A JP7151697A JPH10264609A JP H10264609 A JPH10264609 A JP H10264609A JP 9071516 A JP9071516 A JP 9071516A JP 7151697 A JP7151697 A JP 7151697A JP H10264609 A JPH10264609 A JP H10264609A
- Authority
- JP
- Japan
- Prior art keywords
- rib
- shoulder
- ribs
- sipe
- 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.)
- 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
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1259—Depth of the sipe
- B60C11/1263—Depth of the sipe different within the same sipe
-
- 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
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
- B60C2011/1213—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe sinusoidal or zigzag at the tread surface
-
- 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
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1259—Depth of the sipe
- B60C2011/1268—Depth of the sipe being different from sipe to sipe
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】この発明は、主には、トラッ
ク、バス等に適用されて、駆動輪、操舵輪等の別なく、
ショルダー陸部にすぐれた耐偏摩耗性をもたらし、ま
た、リブもげ、サイプ端からの割れ等を生じ難い重荷重
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 is mainly applied to trucks, buses, and the like.
The present invention relates to a heavy-duty pneumatic tire that provides excellent uneven wear resistance to a shoulder land portion and is less likely to cause rib bleeding, cracking from a sipe end, and the like.
【0002】[0002]
【従来の技術】トレッド周方向に延びる広幅主溝によっ
て、トレッドを複数本のリブに区画した重荷重用空気入
りタイヤでは、偏摩耗の抑制を目的として、たとえば、
ショルダーリブのリブ幅を、センターリブのリブ幅の約
1.20〜1.35倍とするとともに、ショルダーリブ
に、それを幅方向に二分する環状細溝を設けること、ま
たは、ショルダーリブの外側部に、周方向に延びる側部
周溝を設けること等が従来から広く一般に行われてい
る。2. Description of the Related Art In a heavy-duty pneumatic tire in which a tread is divided into a plurality of ribs by a wide main groove extending in a tread circumferential direction, for the purpose of suppressing uneven wear, for example,
The width of the shoulder rib is set to about 1.20 to 1.35 times the width of the center rib, and the shoulder rib is provided with an annular thin groove that bisects the width of the shoulder rib, or the outer side of the shoulder rib. It has been generally and widely practiced to provide side peripheral grooves extending in the circumferential direction in a portion.
【0003】ここで、ショルダーリブに、図6(a)に
示すような環状細溝を設けたときは、その環状細溝より
外側のリブ部分には、図6(b)に示すように、エッジ
落ち欠損を発端とする径差摩耗に基づく犠牲作用は生じ
るが、これによって内側のリブ部分に向かう偏摩耗はも
とより、その偏摩耗がセンターリブの方へ広がるような
進展が回避されることになり、また、ショルダーリブの
外側部に、図7(a)に示すような側部周溝を設けたは
きは、ショルダーリブの外側部分の剛性低下に基づき、
摩耗初期のエッジ落ちと、それから進展する偏摩耗の発
生が防止され、ショルダーリブは、図7(b)に示すよ
うに、その全体にわたって実質上均等に摩耗されること
になる。Here, when the shoulder rib is provided with an annular narrow groove as shown in FIG. 6 (a), a rib portion outside the annular narrow groove is provided as shown in FIG. 6 (b). A sacrificial action based on radial wear caused by the edge drop defect occurs, but this prevents uneven wear that spreads toward the center ribs as well as uneven wear toward the inner rib part. In addition, in the postcard provided with a side peripheral groove as shown in FIG. 7A on the outer portion of the shoulder rib, the rigidity of the outer portion of the shoulder rib is reduced.
The occurrence of edge drop at the beginning of wear and uneven wear that develops therefrom are prevented, and the shoulder ribs are worn substantially uniformly over the entirety thereof, as shown in FIG. 7 (b).
【0004】[0004]
【発明が解決しようとする課題】しかるに、このような
従来技術にあっては、リブ幅が、センターリブのそれの
約1.20〜1.35倍程度のショルダーリブに対し
て、環状細溝または側部周溝を形成していることから、
ショルダーリブそれ自体の剛性が低くなり、縁石への乗
り降りに起因するリブもげ等の発生によってショルダー
リブが全体的に又は部分的に脱落するおそれがあった
他、とくに、摩耗の中期以降には、ショルダーリブの剛
性不足によって、環状細溝より外側のリブ部分の摩耗段
差が、図8(a)に示すように、環状細溝を越えて内側
リブ部分に進行し、また、図9(a)に示すように、側
部周溝の外周側が摩滅して、ついには、図8(b)およ
び図9(b)に示すように、ショルダーリブの全体に摩
耗が進展する、いわゆるステップダウン摩耗を生じると
いう問題があった。However, in such a prior art, the width of the rib is about 1.20 to 1.35 times as large as that of the center rib. Or because the side peripheral groove is formed,
The rigidity of the shoulder rib itself became low, and there was a risk that the shoulder rib might fall off entirely or partially due to the occurrence of rib baldness etc. due to getting on and off the curb.In particular, after the middle stage of wear, Due to the insufficient rigidity of the shoulder rib, the wear step of the rib portion outside the annular narrow groove advances to the inner rib portion beyond the annular narrow groove as shown in FIG. 8 (a), and FIG. 9 (a). As shown in FIG. 8, the outer peripheral side of the side peripheral groove is worn out, and eventually, as shown in FIGS. 8 (b) and 9 (b), wear progresses on the entire shoulder rib, so-called step-down wear. There was a problem that would occur.
【0005】すなわち、従来技術における環状細溝およ
び側部周溝をもってしては、摩耗の初期には、偏摩耗の
抑制に有効に寄与することができても、摩耗の中期以降
にてはその効果が低下し、一旦偏摩耗が発生した場合に
は、それの早期の進行を阻止することができなかった。[0005] That is, even if the annular narrow groove and the side peripheral groove in the prior art can effectively contribute to the suppression of uneven wear in the early stage of wear, after the middle stage of wear, the annular narrow groove and the side peripheral groove can effectively reduce uneven wear. If the effect is reduced and uneven wear occurs once, it cannot be prevented from proceeding early.
【0006】この発明は、従来技術が抱えるこのような
問題点を解決することを課題として検討した結果なされ
たものであり、それの目的とするところは、トレッド陸
部の摩耗がそれの中期以降に至っても、トレッド陸部の
ショルダーエッジからの偏摩耗の進行を有効に阻止する
ことができる重荷重用空気入りタイヤを提供するにあ
る。[0006] The present invention has been made as a result of studying to solve such problems of the prior art, and it is an object of the present invention to reduce the wear of the tread land portion after the middle stage. Accordingly, it is an object of the present invention to provide a heavy duty pneumatic tire that can effectively prevent the progress of uneven wear from the shoulder edge of the tread land portion.
【0007】[0007]
【課題を解決するための手段】この発明の重荷重用空気
入りタイヤは、トレッド周方向に、直線状もしくはジグ
ザグ状に延びる4本の広幅主溝により、トレッドを、両
側のショルダーリブと、それらの内側に位置する中間リ
ブと、両中間リブ間に位置する1本のセンターリブとに
区画し、それぞれのリブの相対幅を、センターリブ10
0に対して中間リブを98〜105、ショルダーリブを
140〜165とするとともに、少なくとも片側のショ
ルダーリブの外側縁近傍位置で周方向に延びてそのショ
ルダーリブを二分する一本の細溝および、少なくとも片
側のショルダーリブの外側部で周方向に延びる側部周溝
の少なくとも一方を設けたものである。According to the pneumatic tire for heavy load of the present invention, the tread is formed by four wide main grooves extending linearly or zigzag in the circumferential direction of the tread, and the shoulder ribs on both sides are formed. It is divided into an intermediate rib located on the inner side and one center rib located between the two intermediate ribs, and the relative width of each rib is defined by the center rib 10.
0, the intermediate ribs are 98 to 105, the shoulder ribs are 140 to 165, and one narrow groove extending in the circumferential direction at a position near the outer edge of at least one of the shoulder ribs and bisecting the shoulder rib, and At least one of the side circumferential grooves extending in the circumferential direction at the outer side of at least one of the shoulder ribs is provided.
【0008】この空気入りタイヤでは、ショルダーリブ
のリブ幅をセンターリブのそれの140〜165とする
ことにより、そのショルダーリブの剛性を高めて変形を
抑制し、これにより、ショルダーリブの外側縁からの偏
摩耗の進行を有効に防止し、併せて、縁石等への乗り降
りに起因するリブもげの発生、細溝の溝底からの亀裂の
発生を効果的に防止することができる。In this pneumatic tire, the shoulder rib has a rib width of 140 to 165 that of the center rib, thereby increasing the rigidity of the shoulder rib and suppressing deformation. Can effectively prevent uneven wear, and can also effectively prevent the generation of rib baldness and the generation of cracks from the bottom of the narrow groove due to getting on and off the curb.
【0009】またここで、ショルダーリブに一本の細溝
を形成し、好ましくは、その細溝の深さを広幅主溝より
浅くするとともに、細溝の、ショルダーリブ外側縁から
の距離を、細溝の深さ以下とした場合には、その細溝
は、先に述べた環状細溝と同様に機能して、細溝より外
側のリブ部分の犠牲摩耗の下に、偏摩耗の、内側リブ部
分への進行を、有効に阻止することができる。Here, a single narrow groove is formed in the shoulder rib, preferably, the depth of the narrow groove is made shallower than that of the wide main groove, and the distance of the narrow groove from the outer edge of the shoulder rib is set as follows. When the depth is smaller than the depth of the narrow groove, the narrow groove functions in the same manner as the above-described annular narrow groove, and under the sacrificial wear of the rib part outside the narrow groove, the uneven wear, the inner wear Progression to the rib portion can be effectively prevented.
【0010】そしてまた、ショルダーリブの外側部に側
部周溝を形成した場合には、その側部周溝は、先に述べ
た側部周溝と同様に、それの形成個所と対応するショル
ダーリブ外側部分の剛性の低下に基づき、ショルダーリ
ブへの偏摩耗の発生を有効に抑制することができる。In the case where a side peripheral groove is formed on the outer side of the shoulder rib, the side peripheral groove is formed in the same manner as the side peripheral groove described above, and the shoulder corresponding to the formation location is formed. The occurrence of uneven wear on the shoulder rib can be effectively suppressed based on the decrease in the rigidity of the rib outer portion.
【0011】しかも、ここにおけるショルダーリブは、
それの広幅化の下で十分高い剛性を有し、横力の作用時
にもショルダーリブの接地圧を均一化し、これによって
エッジからの偏摩耗が幅方向に進展するのを抑制するの
で、摩耗の中期以降に至ってもなお、そのショルダーリ
ブへのステップダウン摩耗の発生を効果的に防止するこ
とができる。Moreover, the shoulder ribs here are:
It has a sufficiently high stiffness under its widened width and evens out the contact pressure of the shoulder ribs even when a lateral force is applied, thereby suppressing the uneven wear from the edge from developing in the width direction. Even in the middle period or later, the occurrence of step-down wear on the shoulder rib can be effectively prevented.
【0012】ところでこのタイヤにおいて、ショルダー
リブのリブ幅を140〜165とするのは、細溝および
/または側部周溝を形成した場合のショルダーリブ剛性
を、センターリブ剛性と相対的にバランスさせるためで
ある。しかもこのタイヤでは、中間リブのリブ幅を98
〜105とすることで、センターリブ、中間リブおよび
ショルダーリブの剛性バランスを最適化し、接地圧・横
方向変形等を均一化する。すなわち、それが98未満で
はセンターリブおよびショルダーリブに対し、中間リブ
が弱くなり、その中間リブが摩耗しやすく、一方、10
5を越えると、中間リブが、センターリブに対して強く
なりすぎセンターリブが摩耗してしまう。By the way, in this tire, the rib width of the shoulder rib is set to 140 to 165 to make the shoulder rib rigidity when the narrow groove and / or the side peripheral groove are formed relatively balanced with the center rib rigidity. That's why. Moreover, in this tire, the rib width of the intermediate rib is 98
By setting to 105, the rigidity balance of the center rib, the intermediate rib, and the shoulder rib is optimized, and the contact pressure, lateral deformation, and the like are made uniform. That is, when it is less than 98, the intermediate rib is weaker than the center rib and the shoulder rib, and the intermediate rib is liable to be worn.
If it exceeds 5, the intermediate rib becomes too strong with respect to the center rib, and the center rib is worn.
【0013】以上のような空気入りタイヤにおいて好ま
しくは、少なくとも片側のショルダーリブを区画する広
幅主溝に、トレッドの断面輪郭線に対して段下がりをな
す段差陸部を設け、また、少なくともショルダーリブ
に、それのリブ幅の60〜90%の周方向間隔をおくサ
イプを、前記広幅主溝からリブ幅の50〜90%の範囲
内に形成し、各サイプのタイヤ赤道線に対する傾斜角度
を35〜55゜の範囲とする。[0013] In the pneumatic tire as described above, preferably, at least one of the shoulder ribs is provided with a stepped land portion which is stepped down with respect to the cross-sectional contour of the tread in the wide main groove defining the shoulder rib. A sipe having a circumferential interval of 60 to 90% of the rib width is formed within the range of 50 to 90% of the rib width from the wide main groove, and the inclination angle of each sipe with respect to the tire equator is set to 35.゜ 55 °.
【0014】この発明によってショルダーリブの耐偏摩
耗性が向上され、これにより、そのショルダーリブの摩
耗寿命が延びると、ショルダーリブの、それを区画する
広幅主溝側に、その主溝に沿って延びるいわゆるリバー
ウェアが発生するおそれが生じるので、かかるリバーウ
ェアの発生に対しては、前記段差陸部を、それの引摺り
摩耗に基づいて、リブの偏摩耗を肩代わりする偏摩耗犠
牲部として機能させることにより、ショルダーリブおよ
び中間リブのそれぞれを有効に保護する。According to the present invention, the uneven wear resistance of the shoulder rib is improved, and when the wear life of the shoulder rib is extended, the shoulder rib is provided along the main groove on the side of the wide main groove that defines the shoulder rib. In order to prevent the occurrence of so-called river wear, the step land portion functions as an uneven wear sacrifice portion that takes over the uneven wear of the rib based on the sliding wear of the step wear portion. By doing so, each of the shoulder rib and the intermediate rib is effectively protected.
【0015】またここでは、ショルダーリブに、周方向
に間隔をおくサイプを形成して、サイプ間部分に、小さ
なヒールアンドトウ摩耗を作為的に発生させることによ
り、それをもって、ショルダーリブの外側縁側および内
側縁側のそれぞれから発生するおそれのある偏摩耗の、
周方向への進展を阻止し、このことにて、前記細溝、側
部周溝および段差陸部の作用をより実効あるものとす
る。Further, in this case, a sipe is formed on the shoulder rib at intervals in the circumferential direction, and a small heel and toe wear is artificially generated in a portion between the sipe. And uneven wear that may occur from each of the inner edge side,
In this way, the peripheral groove is prevented from progressing in the circumferential direction, so that the action of the narrow groove, the side circumferential groove and the step land portion is made more effective.
【0016】ここにおいて、サイプの周方向間隔は、そ
れが狭すぎるとヒールアンドトウ偏摩耗が悪化する一
方、広すぎるとリブ側縁からの偏摩耗の進行を効果的に
防止し得ないことから、ショルダーリブ幅の60〜90
%の範囲とすることが好ましく、また、サイプの、リブ
幅方向の長さは、それが長すぎると、ヒールアンドトウ
偏摩耗が悪化し、短すぎると、それ本来の機能を十分に
発揮し得ないことから、好ましくは、ショルダーリブを
区画する広幅主溝から、リブ幅の50〜90%の範囲と
する。Here, if the circumferential spacing of the sipe is too narrow, uneven wear of the heel and toe deteriorates, while if it is too wide, the progress of uneven wear from the rib side edge cannot be effectively prevented. , Shoulder rib width 60-90
%, And the length of the sipe in the rib width direction is too long, and uneven wear of the heel and toe is deteriorated. If it is too short, the original function is sufficiently exhibited. Since it cannot be obtained, the width is preferably set to 50 to 90% of the width of the rib from the wide main groove defining the shoulder rib.
【0017】ところでこのタイヤでは、各サイプの、タ
イヤ赤道面に対する傾斜角を35〜55゜の範囲とする
ことによって、ヒールアンドトウ摩耗の大きさを抑制
し、そこから波状摩耗等致命的な偏摩耗へ進行しないよ
うにしている。By the way, in this tire, the size of the heel-and-toe wear is suppressed by setting the inclination angle of each sipe with respect to the tire equatorial plane in the range of 35 to 55 °. It does not progress to wear.
【0018】そして、より一層好ましくは、少なくとも
ショルダーリブに設けたサイプの延在方向の途中に、サ
イプ底から半径方向外方へ突出してサイプ深さを減じる
少なくとも一のプラットフォームを設けるとともに、サ
イプの最大深さおよび、プラットフォームの突出高さの
それぞれを、広幅主溝の深さの0.5〜0.9倍および
0.1〜0.4倍とする。More preferably, at least one platform is provided at least in the middle of the extending direction of the sipe provided on the shoulder rib to project radially outward from the sipe bottom to reduce the sipe depth. The maximum depth and the protruding height of the platform are respectively 0.5 to 0.9 times and 0.1 to 0.4 times the depth of the wide main groove.
【0019】ここで、プラットフォームは、サイプ深さ
が一定である場合の、過剰のヒールアンドトウ摩耗の発
生を阻止すべく機能する。またここで、サイプの最大深
さを広幅主溝のそれの0.5〜0.9倍とするのは、
0.5倍未満では摩耗の中期以降、サイプの効果がなく
なり、0.9倍を越えるとヒールアンドトウ摩耗が大き
くなりすぎるためである。そして、プラットフォームの
突出高さを、主溝深さの0.1〜0.4倍とするのは、
プラットフォームが0.1倍未満では、ヒールアンドト
ウ摩耗の抑制効果が少なく、0.4倍を越えると作為的
なヒールアンドトウ摩耗が起きにくくなり、サイプを入
れる意味が小さくなってしまうからである。Here, the platform functions to prevent the occurrence of excessive heel and toe wear when the sipe depth is constant. Also, here, the maximum depth of the sipe is set to 0.5 to 0.9 times that of the wide main groove,
If it is less than 0.5 times, the sipe effect will be lost after the middle stage of wear, and if it exceeds 0.9 times, heel and toe wear will be too large. And, to make the projecting height of the platform 0.1 to 0.4 times the main groove depth,
If the platform is less than 0.1 times, the effect of suppressing heel and toe wear is small, and if it exceeds 0.4 times, artificial heel and toe wear is less likely to occur and the meaning of inserting a sipe becomes smaller. .
【0020】[0020]
【発明の実施の形態】以下にこの発明の実施の形態を図
面に示すところに基づいて説明する。図1はこの発明の
一の実施形態を、サイズが295/75 R22.5の
タイヤについて示す図であり、図1(a)はトレッドパ
ターンの部分的な展開平面を、図1(b)は横断面をそ
れぞれ示す。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an embodiment of the present invention for a tire having a size of 295/75 R22.5. FIG. 1A shows a partially developed plane of a tread pattern, and FIG. The cross sections are shown respectively.
【0021】タイヤの内部構造は、ラジアルカーカス、
そのクラウン部を取り囲んで配置した剛性の高いベル
ト、ベルトの外周を取り囲むトレッドゴム等を組合わせ
た、この種のタイヤとしてはごく一般的なものであるの
で、具体的な説明は省略する。The internal structure of the tire is a radial carcass,
Since this type of tire is a very common type of tire in which a highly rigid belt disposed around the crown portion and a tread rubber surrounding the outer periphery of the belt are combined, a specific description thereof will be omitted.
【0022】ここではトレッド1を、その周方向に直線
状もしくはジグザグ状、図では直線状に連続して延びる
4本の広幅主溝2,3により、トレッド1の両外側に位
置するそれぞれのショルダーリブ4と、ショルダーリブ
4より中央域側に位置する中間リブ5と、それらの両中
間リブ間に位置するセンターリブ6とに区画するととも
に、それぞれのリブ4,5,6の相対幅を、センターリ
ブ6の幅を100としたときに、中間リブ5を98〜1
05、ショルダーリブ4を140〜165とする。ここ
でちなみに、センターリブ6のリブ幅を、図示のように
27.0mmとしたときは、中間リブ5のそれを27.
0mm、そしてショルダーリブのそれを40.1mmと
することができる。Here, the tread 1 is formed by four wide main grooves 2 and 3 extending linearly or zigzag in the circumferential direction, and linearly continuous in the figure, so that respective shoulders located on both outer sides of the tread 1 are formed. The ribs are divided into a rib 4, an intermediate rib 5 located closer to the center region than the shoulder rib 4, and a center rib 6 located between the intermediate ribs. When the width of the center rib 6 is 100, the intermediate rib 5 is 98-1.
05, the shoulder ribs 4 are set to 140 to 165. Here, when the center rib 6 has a rib width of 27.0 mm as shown in the figure, the intermediate rib 5 has a rib width of 27.0 mm.
0 mm, and that of the shoulder ribs can be 40.1 mm.
【0023】またここでは、両ショルダーリブ4の外側
部で、タイヤのバットレス部に、周方向に連続して延び
る各一本の側部周溝7を設ける。この側部周溝7は、そ
の深さ方向において、図1(b)に示すように、タイヤ
幅方向と半径方向との中間方向に延びて、溝底部分に、
タイヤ半径方向内側に向く拡大部を有するものとするこ
とができる他、図2(a)に示すように、上記の如きの
拡大溝底部分を省いたもの、図2(b)に示すように、
溝底部分を、タイヤの半径方向内側へ折曲させて伸ばし
たもの等とすることもできる。Here, one side circumferential groove 7 extending continuously in the circumferential direction is provided in the buttress portion of the tire outside the shoulder ribs 4. As shown in FIG. 1 (b), the side peripheral groove 7 extends in the depth direction in the middle direction between the tire width direction and the radial direction, and at the groove bottom portion,
In addition to having an enlarged portion facing inward in the tire radial direction, as shown in FIG. 2A, the above-described enlarged groove bottom portion is omitted, and as shown in FIG. ,
The groove bottom portion may be formed by bending and extending radially inward of the tire.
【0024】さらにこの実施形態では、センターリブ6
に、タイヤ赤道線上で折曲してほぼV字状に延びるサイ
プ8を、また、それぞれの中間リブ5およびショルダー
リブ4に、図の上方側で相互に離隔する方向に延びるそ
れぞれのサイプ9,10をそれぞれ形成し、とくには、
ショルダーリブ4に形成したサイプ10の周方向ピッチ
を、そのリブ幅の60〜90%の範囲とするとともに、
それらの各サイプ10の、リブ幅方向の延在長さを、広
幅主溝3からリブ幅の50〜90%の範囲とする。ここ
で、サイプ10の、タイヤ赤道線に対する傾斜角度は3
5〜55゜の範囲とする。Furthermore, in this embodiment, the center rib 6
In addition, a sipe 8 which is bent in a substantially V-shape on the tire equator line, and a respective sipe 9, which extends in a direction separated from each other on the upper side in the figure, is provided on each of the intermediate rib 5 and the shoulder rib 4. 10 respectively, and in particular,
The circumferential pitch of the sipe 10 formed on the shoulder rib 4 is set in the range of 60 to 90% of the rib width, and
The extending length of each of the sipes 10 in the rib width direction is set in a range of 50 to 90% of the rib width from the wide main groove 3. Here, the inclination angle of the sipe 10 with respect to the tire equator is 3
The range is 5 to 55 °.
【0025】なおここにおいて、サイプ10の周方向ピ
ッチは、たとえば29.6mmとし、サイプ10の、リ
ブ幅方向の長さは30.0mmとすることができ、サイ
プ10の、タイヤ赤道線に対する傾斜角は45゜とする
ことができる。Here, the circumferential pitch of the sipe 10 may be, for example, 29.6 mm, the length of the sipe 10 in the rib width direction may be 30.0 mm, and the inclination of the sipe 10 with respect to the tire equator. The angle can be 45 °.
【0026】そしてまた、この実施形態では、両広幅主
溝3の幅方向の中央部分にトレッド1の断面輪郭線に対
して段下がりをなす段差陸部11を周方向に連続させて
設け、併せて、各サイプ8,9,10の延在方向の途中
に、サイプ底から半径方向外方へ突出してサイプ深さを
減じるプラットフォーム8a,8b,9a,9bおよび
10aを設け、とくにサイプ10に関し、それの最大深
さを、広幅主溝3の深さの0.5〜0.9倍とし、少な
くとも一のプラットフォーム10aの突出高さを、上記
深さの0.1〜0.4倍とする。Further, in this embodiment, a step land portion 11 which is stepped down with respect to the cross-sectional contour of the tread 1 is provided at the center portion in the width direction of both wide main grooves 3 so as to be continuous in the circumferential direction. Platforms 8a, 8b, 9a, 9b and 10a projecting radially outward from the sipe bottom to reduce the sipe depth are provided in the middle of the extending direction of each of the sipe 8, 9, 10; The maximum depth thereof is 0.5 to 0.9 times the depth of the wide main groove 3, and the protruding height of at least one platform 10a is 0.1 to 0.4 times the above depth. .
【0027】従ってたとえば、広幅主溝3の深さを1
4.0mmとした場合には、サイプ10の最大深さを
9.0mm、プラットフォーム10aの突出高さを4.
0mmとすることができる。Therefore, for example, the depth of the wide main groove 3 is set to 1
In the case of 4.0 mm, the maximum depth of the sipe 10 is 9.0 mm, and the protruding height of the platform 10a is 4.0.
It can be 0 mm.
【0028】図3は、この発明の他の実施形態を示す図
1と同様の図であり、これは、サイズが295/75
R22.5のタイヤにおいて、たとえば、センターリブ
6のリブ幅を31.8mm、中間リブ5のリブ幅を3
2.8mm、ショルダーリブ4のリブ幅を50.5mm
としたところにおいて、ショルダーリブ4に、それの外
側縁から10mmの位置に、深さが15mmの一本の直
線状細溝12を設け、また、センターリブ6には、図に
おいて傾向的に右上がりの、そして、中間リブ5および
ショルダーリブ4のそれぞれには傾向的に右下がりのそ
れぞれのサイプ13,14,15を形成したものであ
る。FIG. 3 is a view similar to FIG. 1 showing another embodiment of the present invention, which has a size of 295/75.
For example, in the R22.5 tire, the center rib 6 has a rib width of 31.8 mm, and the intermediate rib 5 has a rib width of 31.8 mm.
2.8 mm, shoulder rib 4 rib width 50.5 mm
The shoulder rib 4 is provided with a single linear narrow groove 12 having a depth of 15 mm at a position 10 mm from the outer edge thereof, and the center rib 6 is provided with a right The ascending and intermediate ribs 5 and the shoulder ribs 4 are each formed with a sipe 13, 14, 15 which tends to descend to the right.
【0029】ここで、ショルダーリブ4に形成したサイ
プ15の周方向ピッチは37.5mmであり、それのリ
ブ幅方向の長さは28mmである。また、各サイプ15
は、広幅主溝3の深さ15.0mmに対して、7.8m
mの最大深さを有し、そこに設けた一のプラットフォー
ム15aは3.0mmの突出高さを有する。Here, the circumferential pitch of the sipe 15 formed on the shoulder rib 4 is 37.5 mm, and its length in the rib width direction is 28 mm. In addition, each sipe 15
Is 7.8 m with respect to the depth of 15.0 mm of the wide main groove 3.
m, and one platform 15a provided therein has a projecting height of 3.0 mm.
【0030】[0030]
(実施例1)図1および図3に示すそれぞれのタイヤを
実施例Aおよび実施例Bとし、図4に示すトレッドパタ
ーンを有する、サイズが295/75 R22.5の従
来タイヤをコントローラとして実車走行を行い、操舵輪
につき、ショルダーリブの外側縁から進行する偏摩耗幅
の測定と、偏摩耗によってタイヤを交換するに至るまで
の走行距離の測定とを行ったところ、図5にグラフをも
って示す通りとなった。ここで、それぞれのタイヤの交
換は、偏摩耗から振動が発生し、実際の運転に支障が出
る時点を目処に行った。なお、図中実施例Bのタイヤの
偏摩耗幅は、細溝12より内側のリブ部分に生じた偏摩
耗幅を測定したものであり、グラフ中の各線分の終端
は、タイヤの交換時の状態を示す。(Embodiment 1) The tires shown in FIGS. 1 and 3 are referred to as Embodiments A and B, respectively, and a conventional vehicle having a tread pattern shown in FIG. 4 and having a size of 295/75 R22.5 is used as a controller. Then, for the steered wheels, measurement of the uneven wear width that progresses from the outer edge of the shoulder rib and measurement of the running distance until the tire was replaced due to uneven wear were performed, as shown in the graph of FIG. It became. Here, each tire was replaced at a point when vibration occurred due to uneven wear and hindered actual driving. In the figure, the uneven wear width of the tire of Example B is obtained by measuring the uneven wear width generated in the rib portion inside the narrow groove 12, and the end of each line segment in the graph is at the time of tire replacement. Indicates the status.
【0031】図5によれば、実施例AおよびBのタイヤ
はともに、コントロールタイヤに比して、偏摩耗幅を有
効に低減でき、また、交換に至るまでの走行距離を大き
く延長させることができ、これらのことは、側部周溝7
と、段差陸部11とを併用した実施例Aのタイヤにおい
てとくに顕著であることが明らかである。According to FIG. 5, both the tires of Examples A and B can effectively reduce the uneven wear width as compared with the control tires, and can greatly extend the running distance until replacement. Can do these things,
It is evident that this is particularly noticeable in the tire of Example A in which the step land portion 11 is used in combination.
【0032】(実施例2)上記のそれぞれのタイヤを用
いて、縁石乗り越しの実車走行を行い、各20本づつの
タイヤについての、ショルダーリブでのリブもげおよび
細溝からの割れの発生状況を調べたところ表1に示す通
りとなった。(Example 2) Using each of the above-mentioned tires, a real vehicle was run over a curb, and the occurrence of rib bleeding at the shoulder ribs and cracking from the narrow grooves for each of 20 tires was examined. Upon examination, the results were as shown in Table 1.
【0033】[0033]
【表1】 [Table 1]
【0034】上記表1によれば、ショルダーリブを広げ
ることにより剛性が高くなって、リブもげが抑制され、
細溝からの割れも改良することができ、また、ショルダ
ーリブから細溝を取り除くことで、割れの発生がなくな
ることが解る。According to the above Table 1, the rigidity is increased by expanding the shoulder ribs, and the ribs are prevented from bulging.
It can be seen that cracks from the fine grooves can be improved, and that the cracks disappear by removing the fine grooves from the shoulder ribs.
【0035】[0035]
【発明の効果】この発明によれば、とくに、ショルダー
リブのリブ幅を従来タイヤに比して広幅とし、併せて、
ショルダーリブにそれを二分する一本の細溝および、シ
ョルダーリブの外側部で周方向に延びる側部周溝の少な
くとも一方を設けることで、前記実施例からも明らかな
ように、ショルダーリブにつき、リブティアその他の各
種の亀裂の発生を防止しつつ、摩耗の中期以降に至って
もなお耐偏摩耗性を大きく向上させることができる。According to the present invention, in particular, the width of the shoulder ribs is made wider than that of the conventional tire.
By providing at least one of the shoulder rib and one narrow groove that bisects the shoulder rib, and at least one of the side peripheral grooves extending in the circumferential direction at the outer portion of the shoulder rib, as is apparent from the above-described embodiment, the shoulder rib has: The uneven wear resistance can be greatly improved even after the middle stage of wear while preventing the occurrence of cracks such as rib tear and other various cracks.
【図1】この発明の一の実施形態を示す図である。FIG. 1 is a diagram showing one embodiment of the present invention.
【図2】側部周溝の他の形成態様を示す部分断面図であ
る。FIG. 2 is a partial cross-sectional view showing another mode of forming a side peripheral groove.
【図3】この発明の他の実施形態を示す図である。FIG. 3 is a diagram showing another embodiment of the present invention.
【図4】従来タイヤのトレッドパターンを示す部分展開
平面図である。FIG. 4 is a partially developed plan view showing a tread pattern of a conventional tire.
【図5】それぞれのタイヤの、交換に至るまでの偏摩耗
幅および走行距離を示すグラフである。FIG. 5 is a graph showing the uneven wear width and running distance of each tire until replacement.
【図6】環状細溝およびそれの作用を示す部分断面図で
ある。FIG. 6 is a partial cross-sectional view showing an annular narrow groove and its operation.
【図7】側部周溝およびそれの作用を示す部分断面図で
ある。FIG. 7 is a partial sectional view showing a side peripheral groove and an operation thereof.
【図8】環状細溝を設けた場合のステップダウン摩耗の
発生状態を示す部分断面図である。FIG. 8 is a partial cross-sectional view showing a state in which step-down wear occurs when an annular narrow groove is provided.
【図9】側部周溝を設けた場合のステップダウン摩耗の
発生状態を示す部分断面図である。FIG. 9 is a partial cross-sectional view showing a state in which step-down wear occurs when a side peripheral groove is provided.
1 トレッド 2,3 広幅主溝 4 ショルダーリブ 5 中間リブ 6 センターリブ 7 側部周溝 8,9,10,13,14,15 サイプ 8a,8b,9a,9b,10a,15a プラットフ
ォーム 11 段差陸部 12 細溝Reference Signs List 1 tread 2,3 wide main groove 4 shoulder rib 5 intermediate rib 6 center rib 7 side peripheral groove 8,9,10,13,14,15 sipe 8a, 8b, 9a, 9b, 10a, 15a platform 11 step land portion 12 narrow groove
Claims (3)
り、トレッドを、両側のショルダーリブと、それらの内
側に位置する中間リブと、両中間リブ間に位置する一本
のセンターリブとに区画し、それぞれのリブの相対幅
を、センターリブ100に対して、中間リブを98〜1
05、ショルダーリブを140〜165とするととも
に、少なくとも片側のショルダーリブの外側縁近傍位置
で周方向に延びてそのショルダーリブを二分する一本の
細溝および、少なくとも片側のショルダーリブの外側部
で周方向に延びる側部周溝の少なくとも一方を設けてな
る重荷重用空気入りタイヤ。1. A tread having a wide main groove extending in a circumferential direction of a tread, the tread is partitioned into shoulder ribs on both sides, an intermediate rib located inside the shoulder ribs, and one center rib located between the intermediate ribs. The relative width of each of the ribs is set at 98-1 relative to the center rib with respect to the center rib 100.
05, with the shoulder ribs being 140 to 165, at least one narrow groove extending in the circumferential direction at a position near the outer edge of one of the shoulder ribs and bisecting the shoulder rib, and at least the outer portion of the shoulder rib on one side. A heavy duty pneumatic tire provided with at least one of side circumferential grooves extending in a circumferential direction.
する広幅主溝に、トレッドの断面輪郭線に対して段下が
りをなす段差陸部を設けるとともに、少なくともショル
ダーリブに、それのリブ幅の60〜90%の周方向間隔
をおくサイプを、前記広幅主溝からリブ幅の50〜90
%の範囲内に形成し、各サイプの、タイヤ赤道線に対す
る傾斜角を35〜55゜の範囲としてなる請求項1記載
の重荷重用空気入りタイヤ。2. A wide-width main groove defining at least one side of a shoulder rib is provided with a step land portion which is stepped down with respect to a cross-sectional contour of a tread, and at least the shoulder rib has a rib width of 60 to 90%. % Of the ribs 50 to 90% of the rib width from the wide main groove.
2. The heavy duty pneumatic tire according to claim 1, wherein the inclination angle of each sipe with respect to the tire equator is in the range of 35 to 55 °.
プの延在方向の途中に、サイプ底から半径方向外方へ突
出してサイプ深さを減じる、少なくとも一のプラットフ
ォームを設けるとともに、サイプの最大深さおよび、プ
ラットフォームの突出高さのそれぞれを、広幅主溝の深
さの0.5〜0.9倍および0.1〜0.4倍としてな
る請求項2記載の重荷重用空気入りタイヤ。At least one platform is provided at least in the middle of the extension direction of the sipe provided on the shoulder rib to project radially outward from the sipe bottom to reduce the sipe depth. 3. The pneumatic tire for heavy load according to claim 2, wherein each of the projecting heights of the platform is 0.5 to 0.9 times and 0.1 to 0.4 times the depth of the wide main groove.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP07151697A JP3898267B2 (en) | 1997-03-25 | 1997-03-25 | Heavy duty pneumatic tire |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP07151697A JP3898267B2 (en) | 1997-03-25 | 1997-03-25 | Heavy duty pneumatic tire |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH10264609A true JPH10264609A (en) | 1998-10-06 |
JP3898267B2 JP3898267B2 (en) | 2007-03-28 |
Family
ID=13462967
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Application Number | Title | Priority Date | Filing Date |
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JP07151697A Expired - Fee Related JP3898267B2 (en) | 1997-03-25 | 1997-03-25 | Heavy duty pneumatic tire |
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Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10309910A (en) * | 1997-05-08 | 1998-11-24 | Bridgestone Corp | Pneumatic tire |
US7204281B2 (en) * | 2001-06-29 | 2007-04-17 | Sumitomo Rubber Industries, Ltd. | Studless tire with tread having circumferential portions, blocks and V shaped sipes |
JP2007106255A (en) * | 2005-10-13 | 2007-04-26 | Yokohama Rubber Co Ltd:The | Pneumatic tire |
JP2008260422A (en) * | 2007-04-12 | 2008-10-30 | Bridgestone Corp | Pneumatic radial tire for heavy duty |
WO2009081973A1 (en) * | 2007-12-25 | 2009-07-02 | Bridgestone Corporation | Tire |
JP2010208502A (en) * | 2009-03-10 | 2010-09-24 | Bridgestone Corp | Tire |
JP2010285032A (en) * | 2009-06-10 | 2010-12-24 | Toyo Tire & Rubber Co Ltd | Pneumatic tire |
JP2011084186A (en) * | 2009-10-16 | 2011-04-28 | Bridgestone Corp | Tire |
US7980280B2 (en) | 2006-10-27 | 2011-07-19 | Toyo Tire & Rubber Co., Ltd. | Pneumatic tire with tread including ribs having closed sipes |
US8056591B2 (en) * | 2004-06-23 | 2011-11-15 | Bridgestone Corporation | Pneumatic tire with tread having ground contact shape and uneven wear sacrificial protrusion |
JP2012096782A (en) * | 2010-10-29 | 2012-05-24 | Goodyear Tire & Rubber Co:The | Sipe pattern of tread of winter tire |
JP2014065328A (en) * | 2012-09-24 | 2014-04-17 | Toyo Tire & Rubber Co Ltd | Pneumatic tire |
JP2014213650A (en) * | 2013-04-23 | 2014-11-17 | 株式会社ブリヂストン | Aircraft tire |
JP2015027831A (en) * | 2013-07-30 | 2015-02-12 | 株式会社ブリヂストン | Pneumatic tire |
EP2583839A3 (en) * | 2011-10-20 | 2017-11-15 | Sumitomo Rubber Industries, Ltd. | Heavy duty tire |
JP2021054297A (en) * | 2019-09-30 | 2021-04-08 | 住友ゴム工業株式会社 | Pneumatic tire |
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1997
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Publication number | Priority date | Publication date | Assignee | Title |
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JPH10309910A (en) * | 1997-05-08 | 1998-11-24 | Bridgestone Corp | Pneumatic tire |
US7204281B2 (en) * | 2001-06-29 | 2007-04-17 | Sumitomo Rubber Industries, Ltd. | Studless tire with tread having circumferential portions, blocks and V shaped sipes |
US8056591B2 (en) * | 2004-06-23 | 2011-11-15 | Bridgestone Corporation | Pneumatic tire with tread having ground contact shape and uneven wear sacrificial protrusion |
JP2007106255A (en) * | 2005-10-13 | 2007-04-26 | Yokohama Rubber Co Ltd:The | Pneumatic tire |
US7980280B2 (en) | 2006-10-27 | 2011-07-19 | Toyo Tire & Rubber Co., Ltd. | Pneumatic tire with tread including ribs having closed sipes |
JP2008260422A (en) * | 2007-04-12 | 2008-10-30 | Bridgestone Corp | Pneumatic radial tire for heavy duty |
WO2009081973A1 (en) * | 2007-12-25 | 2009-07-02 | Bridgestone Corporation | Tire |
JP2010208502A (en) * | 2009-03-10 | 2010-09-24 | Bridgestone Corp | Tire |
JP2010285032A (en) * | 2009-06-10 | 2010-12-24 | Toyo Tire & Rubber Co Ltd | Pneumatic tire |
JP2011084186A (en) * | 2009-10-16 | 2011-04-28 | Bridgestone Corp | Tire |
JP2012096782A (en) * | 2010-10-29 | 2012-05-24 | Goodyear Tire & Rubber Co:The | Sipe pattern of tread of winter tire |
EP2583839A3 (en) * | 2011-10-20 | 2017-11-15 | Sumitomo Rubber Industries, Ltd. | Heavy duty tire |
JP2014065328A (en) * | 2012-09-24 | 2014-04-17 | Toyo Tire & Rubber Co Ltd | Pneumatic tire |
JP2014213650A (en) * | 2013-04-23 | 2014-11-17 | 株式会社ブリヂストン | Aircraft tire |
US9873292B2 (en) | 2013-04-23 | 2018-01-23 | Bridgestone Corporation | Aircraft tire |
JP2015027831A (en) * | 2013-07-30 | 2015-02-12 | 株式会社ブリヂストン | Pneumatic tire |
JP2021054297A (en) * | 2019-09-30 | 2021-04-08 | 住友ゴム工業株式会社 | Pneumatic tire |
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