JP2752685B2 - Pneumatic tires for heavy loads that prevent uneven wear - Google Patents
Pneumatic tires for heavy loads that prevent uneven wearInfo
- Publication number
- JP2752685B2 JP2752685B2 JP1063964A JP6396489A JP2752685B2 JP 2752685 B2 JP2752685 B2 JP 2752685B2 JP 1063964 A JP1063964 A JP 1063964A JP 6396489 A JP6396489 A JP 6396489A JP 2752685 B2 JP2752685 B2 JP 2752685B2
- Authority
- JP
- Japan
- Prior art keywords
- tire
- tread
- uneven wear
- step region
- heavy loads
- 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.)
- Expired - Fee Related
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
- B60C2011/013—Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered provided with a recessed portion
Landscapes
- Tires In General (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 車体重量が重いバスやトラックなどに装着される空気
入りラジアルタイヤは、とくにトレッド端部における偏
摩耗が著しい。DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) A pneumatic radial tire mounted on a bus or a truck having a heavy body weight has a considerable uneven wear particularly at an end of a tread.
この発明は、このような車両に装着される空気入りタ
イヤに関し、該タイヤの偏摩耗の効果的な軽減・改善を
図ろうとするものである。The present invention relates to a pneumatic tire mounted on such a vehicle, and aims at effectively reducing and improving uneven wear of the tire.
（従来の技術） トレッドの偏摩耗の軽減・改善に関しては、クラウン
形状やパターンに工夫を加えることについての数多くの
提案が見られるが、特にトレッド端部における偏摩耗
（肩おち摩耗）については未だ的確な防止対策が確立さ
れていないのが現状であった。(Prior art) Regarding the reduction and improvement of uneven tread wear, there have been many proposals for devising crown shapes and patterns, but in particular, uneven wear at the tread edge (shoulder abrasion) has not been solved. At present, accurate preventive measures have not been established.
ちなみに特開昭58−194606号公報には、トレッドの端
部に、幅の狭いほぼ環状の円周方向グループにて側方リ
ブを形成した構造のタイヤが提案されているが、かかる
タイヤについてもリブそのものが円周方向グループへの
石噛みにより欠落してしまい、偏摩耗の進行を遅らせる
ことはできても結局その防止ができなかったのである。Incidentally, Japanese Patent Application Laid-Open No. 58-194606 discloses a tire having a structure in which lateral ribs are formed at the end of the tread in a substantially annular circumferential group having a small width. The ribs themselves were lost due to stone biting in the circumferential group, and although the progress of uneven wear could be delayed, it could not be prevented eventually.
（発明が解決しようとする課題） タイヤのトレッド端部における偏摩耗を、タイヤ性能
に悪影響を与えることなく有利に軽減ないしは防止でき
る重荷重用空気入りタイヤを提案することがこの発明の
目的である。(Problem to be Solved by the Invention) It is an object of the present invention to propose a heavy-duty pneumatic tire that can advantageously reduce or prevent uneven wear at the tread end of the tire without adversely affecting tire performance.
（課題を解決するための手段） この種のタイヤに生じる偏摩耗については、走行条件
や路面の状況などにももちろん依存するが、とくにコー
ナーリング時にタイヤのトレッド端部に路面からの過大
な外力（横力）が作用して偏摩耗の原因となる核が発生
し、これが直進走行において促進されるものと考えら
れ、このような偏摩耗の軽減・改善のためにはこの部位
に作用する外力を極力緩和することが非常に有効である
ことを突き止めた。(Means for Solving the Problems) The uneven wear generated on this type of tire naturally depends on running conditions, road surface conditions, and the like. However, excessive external force from the road surface (particularly at the tread end of the tire during cornering) It is thought that the nucleus which causes uneven wear is generated due to the action of lateral force, and this is promoted in straight running. To reduce or improve such uneven wear, external force acting on this part is required. We have found that mitigating as much as possible is very effective.
この発明は、上記の知見に立脚するものである。 The present invention is based on the above findings.
すなわちこの発明は、トレッドの全表面に溝部とこの
溝部によって隔てられた陸部とを有する重荷重用空気入
りタイヤにおいて、トレッド端部に段下がりをなす段差
領域を形成し、この段差領域とこれにつながる陸部との
境界にトレッドの周りに沿うＬ形又はクランク形の切り
込みを設けたことを特徴とする偏摩耗を防止した重荷重
用空気入りタイヤである。That is, the present invention, in a heavy duty pneumatic tire having a groove on the entire surface of the tread and a land portion separated by the groove, forms a step region having a step at the end of the tread, and this step region and this A heavy-duty pneumatic tire that prevents uneven wear, characterized in that an L-shaped or crank-shaped notch is provided along a tread at a boundary with a connected land portion.
さて第１図に、この発明をとくに重荷重用空気入りラ
ジアルタイヤに適用した場合についてその要部を、トレ
ッド端部の片側のみの断面について示し、図中の１は溝
部、２は溝部１によって隔てられた陸部であり、この溝
部１および陸部２はタイヤトレッドの全表面に配設さ
れ、ブロック、リブ、ラグあるいはリブ・ラグなどのト
レッドパターンを形成する。FIG. 1 shows a main portion of a case where the present invention is applied particularly to a pneumatic radial tire for heavy load, with respect to a cross section of only one side of an end portion of a tread. The groove portion 1 and the land portion 2 are disposed on the entire surface of the tire tread, and form a tread pattern such as a block, a rib, a lug, or a rib lug.
また３はトレッド端部に形成した段下がりをなす段差
領域、そして４は段差領域３とこれにつながる陸部２と
の境界においてトレッドの周りに沿って形成された切り
込みであり、この切り込み４は石噛みなどによって段差
領域３が破損しないようＬ形になっていてその部位にお
ける接地圧を低下させ、コーナーリング時の横力の負担
を段差領域とともに低減する役目を受け持つ。Reference numeral 3 denotes a step region which is formed at the end of the tread and forms a step, and reference numeral 4 denotes a notch formed along the periphery of the tread at the boundary between the step region 3 and the land portion 2 connected thereto. The stepped region 3 is L-shaped so as not to be damaged by stone biting or the like, and has a role of reducing the contact pressure at that portion and reducing the burden of lateral force during cornering together with the stepped region.
また第２図及び第３図に、切り込み４をクランク形と
してその領域の接地圧のより一層の低減を図った例を示
す。2 and 3 show an example in which the notch 4 is formed in a crank shape to further reduce the ground pressure in that region.
なお上掲第１図、第２図および第３図に例示した空気
入りタイヤの内部構造については、一般的な重荷重用空
気入りラジアルタイヤと同様であり、ここでは図示を省
略した。The internal structure of the pneumatic tire illustrated in FIGS. 1, 2 and 3 is the same as that of a general heavy-duty pneumatic radial tire, and is not illustrated here.
（作 用） 一般にタイヤが負荷を受けつつ転動するとき、その踏
面における接地圧は直進走行ではトレッドの幅方向にお
いてほぼ一定であるが、とくにコーナーリング時におて
いは第４図に示すような分布となり、このような横力に
起因した接地圧の局部上昇が偏摩耗やリブティアの主原
因であることが実験により認められた。(Operation) In general, when a tire rolls under a load, the contact pressure on the tread surface is almost constant in the tread width direction in straight running, but especially when cornering, the distribution shown in Fig. 4 is obtained. It has been experimentally confirmed that such a local rise in the contact pressure caused by the lateral force is a main cause of uneven wear and rib tear.
この発明においては、タイヤのトレッド端部にまず接
地面圧の低下に役立つ段差領域３を設け、さらにこの段
差領域３と陸部２との境界に切り込み４を設けることと
したのでトレッド端部の路面から受ける外力は第５図に
示すように効果的に分散・緩和され、従ってタイヤの寿
命に著しい影響を与える偏摩耗が生じるおそれはなく、
またリブティアなどは有利に回避されるとことなる。In the present invention, a step region 3 is firstly provided at the tread end of the tire, which is useful for lowering the contact pressure, and a notch 4 is provided at the boundary between the step region 3 and the land portion 2. The external force received from the road surface is effectively dispersed and moderated as shown in FIG. 5, and therefore there is no possibility that uneven wear which significantly affects the life of the tire may occur.
Also, rib tears and the like are advantageously avoided.
ここで上記段差領域３の段差代Ｃとしては、段差代Ｃ
が小さい場合には、直進走行時に接地するようになり、
切り込み４がかみ合わなくなり、とくに切り込み４が開
く方向に挙動した場合には切り込み４の溝底の応力集中
が起きやすく、リブティアになりやすくなる。このため
その下限はタイヤの正規内圧を充てんした状態でタイヤ
正規荷重の少なくとも1/10の横力によって段差領域の表
面が接地するような値として1.5mm〜3.0mm程度とするの
がよい。一方上限については、通常の走行では、タイヤ
にかかる横力が正規荷重の2/10を超えてしまうことは少
なくことから、横力の入力時に段差領域が接地し、この
横力を負担させるためには、正規荷重の3/10の横力で段
差領域の表面が接地する4.0〜6.0mm程度とするのが望ま
しい。Here, the step allowance C of the step area 3 is the step allowance C
If is small, it comes into contact with the ground when traveling straight,
When the cuts 4 do not engage with each other, and particularly when the cuts 4 behave in the opening direction, stress concentration at the groove bottom of the cuts 4 is likely to occur, and the ribs tend to be ribbed. Therefore, the lower limit is preferably about 1.5 mm to 3.0 mm as a value at which the surface of the step region comes into contact with at least 1/10 of the normal load of the tire when the normal internal pressure of the tire is filled. On the other hand, as for the upper limit, in normal running, the lateral force applied to the tire rarely exceeds 2/10 of the normal load, so the step area touches down when the lateral force is input, and this lateral force is borne In this case, it is preferable that the surface of the step region is approximately 4.0 to 6.0 mm where the lateral force is 3/10 of the normal load and the surface of the step region contacts the ground.
（実施例） 第６図（ａ）（ｂ）（ｃ）（ｄ）に示した構造になる
サイズ11R22.5,14PRの供試タイヤ（内圧7.00kgf/cm2）
を、それぞれ積載が正規荷重が11.5トンで、車軸型式が
2D−４になる車両の前輪に装着して100％舗装路（高速7
0％，一般路30％）を６万km完走した時点でのタイヤト
レッド面の摩耗状況について調査した。なおこの試験で
は、第６図（ａ）に示すタイヤを基準タイヤとした。そ
の結果を表−１に示す。(Example) Test tires of size 11R22.5, 14PR (internal pressure 7.00 kgf / cm 2 ) having the structure shown in FIGS. 6 (a) (b) (c) (d)
Each with a normal load of 11.5 tonnes and an axle model
100% paved road (high speed 7
(0%, 30% on general roads), the tire tread surface was worn when 60,000 km was completed. In this test, the tire shown in FIG. 6A was used as a reference tire. Table 1 shows the results.
この実施例では段差領域の幅は考慮にいれていない
が、上表から明らかなように、この発明に従うタイヤは
偏摩耗指数（小さい程良い）が極めて小さいことが確か
められた。また走行後のタイヤを詳細に観察したところ
基準タイヤは第７図（ａ）に示すようにトレッドの端部
に局部摩耗が生じているのに対し、この発明に従うタイ
ヤでは同じく第７図（ｂ）〜（ｄ）に示すようにほぼ均
一に摩耗していた。 In this example, the width of the step region was not taken into consideration, but as is clear from the above table, it was confirmed that the tire according to the present invention had an extremely small uneven wear index (the smaller, the better). In addition, when the tire after running was observed in detail, the reference tire had local wear at the end of the tread as shown in FIG. 7 (a), whereas the tire according to the present invention similarly had FIG. 7 (b). ) To (d), the wear was almost uniform.
次に、第８図（ａ）（ｂ）に示す供試タイヤを用意し
て、これらのタイヤをそれぞれが2D−４になる車両の前
輪に装着し、正規積載荷重の100％積載した状態で、高
さ10cmの段差を繰返し乗り上げ、乗り下げるリブティア
試験を行った。その結果を表−２に示すが、この発明に
従うタイヤは切り込みにおけるクラック長さが非常に小
さく、しかも段差領域の脱落が全く見られなかった。Next, test tires shown in FIGS. 8 (a) and 8 (b) were prepared, and these tires were mounted on the front wheels of the vehicle, each of which became 2D-4, and loaded with 100% of the normal load. A rebirth test was conducted in which the rider repeatedly climbed and climbed a 10 cm high step. The results are shown in Table 2. As shown in Table 2, the tire according to the present invention had a very small crack length at the cut and no dropout of the step region was observed at all.
（発明の効果） この発明によれば、タイヤの走行性能に悪影響を及ぼ
すことなしにトレッド端部における偏摩耗を軽減してタ
イヤの寿命を大幅に延長できる。 (Effects of the Invention) According to the present invention, uneven wear at the end of the tread can be reduced and the life of the tire can be greatly extended without adversely affecting the running performance of the tire.
第１図、第２図及び第３図はこの発明に従う重荷重用空
気入りタイヤの要部断面図、 第４図、第５図はタイヤのトレッド端部の接地圧の分布
状況を示す図、 第６図（ａ）（ｂ）（ｃ）（ｄ）は実施例において使用
したタイヤの要部断面図、 第７図（ａ）（ｂ）（ｃ）（ｄ）は走行試験後における
タイヤトレッド表面の摩耗状況を示した図、 第８図（ａ）（ｂ）はリブティア試験に用いた供試タイ
ヤの要部断面図である。 １……溝部、２……陸部 ３……段差領域、４……切り込み1, 2, and 3 are cross-sectional views of a main part of a heavy-duty pneumatic tire according to the present invention. FIGS. 4 and 5 are diagrams showing the distribution of the contact pressure at the tread end of the tire. 6 (a), (b), (c), and (d) are cross-sectional views of main parts of the tire used in the examples, and FIGS. 7 (a), (b), (c), and (d) are tire tread surfaces after a running test. FIGS. 8 (a) and 8 (b) are cross-sectional views of main parts of a test tire used for a rib tear test. 1 ... groove part 2 ... land part 3 ... step area 4 ... cut
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭62−6801（ＪＰ，Ａ) 特開 昭61−241203（ＪＰ，Ａ) 特開 昭58−81806（ＪＰ，Ａ) 特開 昭61−235204（ＪＰ，Ａ) 特開 昭58−194606（ＪＰ，Ａ) 特開 昭62−155104（ＪＰ，Ａ) 特公 昭61−14961（ＪＰ，Ｂ２) 特公 平３−11921（ＪＰ，Ｂ２) 特公 平６−15282（ＪＰ，Ｂ２) ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-6801 (JP, A) JP-A-61-241203 (JP, A) JP-A-58-81806 (JP, A) JP-A 61-241 235204 (JP, A) JP-A-58-194606 (JP, A) JP-A-62-155104 (JP, A) JP-B-61-14961 (JP, B2) JP-B-3-11921 (JP, B2) Tokiko Hei 6-15282 (JP, B2)
Claims (1)
て隔てられた陸部とを有する重荷重用空気入りタイヤに
おいて、 トレッド端部に段下がりをなす段差領域を形成し、この
段差領域とこれにつながる陸部との境界にトレッドの周
りに沿うその放射断面がＬ形又はクランク形の切り込み
を設けたことを特徴とする偏摩耗を防止した重荷重用空
気入りタイヤ。In a heavy-duty pneumatic tire having a groove on the entire surface of a tread and a land portion separated by the groove, a step region having a step is formed at an end of the tread, and the step region and the step region are formed on the step region. A pneumatic tire for heavy loads which prevents uneven wear, characterized in that a radial cross section along the tread is provided with an L-shaped or crank-shaped notch at a boundary with a connected land portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1063964A JP2752685B2 (en) | 1989-03-17 | 1989-03-17 | Pneumatic tires for heavy loads that prevent uneven wear |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1063964A JP2752685B2 (en) | 1989-03-17 | 1989-03-17 | Pneumatic tires for heavy loads that prevent uneven wear |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02246806A JPH02246806A (en) | 1990-10-02 |
| JP2752685B2 true JP2752685B2 (en) | 1998-05-18 |
Family
ID=13244493
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1063964A Expired - Fee Related JP2752685B2 (en) | 1989-03-17 | 1989-03-17 | Pneumatic tires for heavy loads that prevent uneven wear |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2752685B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3535238B2 (en) * | 1994-11-14 | 2004-06-07 | 株式会社ブリヂストン | Pneumatic radial tire for heavy loads |
| US6109316A (en) * | 1998-01-26 | 2000-08-29 | Michelin Recherche Et Technique S.A. | Tire having improved tread portion for reducing formation of anomalies causing user dissatisfaction |
| US6412531B1 (en) | 1999-07-15 | 2002-07-02 | Michelin Recherche Et Technique S.A. | Tire tread having groove walls with compound contours |
| KR20040037633A (en) * | 2002-10-29 | 2004-05-07 | 금호타이어 주식회사 | An air-bound radial tire for heavy weight with shoulder mini groove |
| JP4492068B2 (en) * | 2003-09-05 | 2010-06-30 | 横浜ゴム株式会社 | Pneumatic radial tire |
| JP6411007B2 (en) * | 2012-05-29 | 2018-10-24 | 株式会社ブリヂストン | Pneumatic tire |
-
1989
- 1989-03-17 JP JP1063964A patent/JP2752685B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02246806A (en) | 1990-10-02 |
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