JPS6015205A - Pneumatic lug tire for automobile - Google Patents

Abstract

PURPOSE:To lower noises by specifying the length of a lug groove, the quantity of deflection by load and the surface area of the lug groove in a lug tire. CONSTITUTION:The area of the entire surface of the whole lug grooves 5a in a lug tire in which the length l of the lug grooves 5a measured along the meridian of the tire is brought to 33-43% of tire width W and deflection delta at a time when JIS reference load is used as load under reference air pressure is brought to 0.170 or less of the height H of a tire section is brought to 18-27% of the area of the entire surface of a tread surface. The number of pitches of the lug grooves 5a is brought to 3.6(D/S)<1/2>-4.5(D/S)<1/2> [where D represents the diameter (mm.) of the equator of the tire and S the nominal width (inch) of the tire]. A noise level on an actual travelling can be lowered at that time.

Description

【発明の詳細な説明】 この発明け、低騒音の自動車用空気入りラグタイヤに関
する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-noise pneumatic lug tire for automobiles.

トレッド面の溝がタイヤ軸とほぼ平行に設けらねた自動
車用空気入りラグタイヤは、溝がタイヤ周方向に設けら
れたリブタイヤに比べてトラクション性能に優れている
ため、トラックやパス用として多用されているが、その
反面、騒音の大きいことが欠点とされている。すなわち
、ラグタイヤにおいては、周知のように、タイヤトレッ
ドの接地によって圧縮されたラグ溝内の空気が溝外に排
出される際に膨張して疎密波を生じ、さらに上記の溝と
路面とからなる気柱管に共鳴して大きな騒音となり、ま
た上記の溝の存在によってトレッドゴムの厚みと形状が
トレッド円周上の各部で異なるので、溝部が路面と衝突
するときの衝撃によってトレッドやケースが振動して大
きい騒音を発生する。Pneumatic lug tires for automobiles, in which the grooves on the tread surface are not arranged almost parallel to the tire axis, have superior traction performance compared to rib tires, in which the grooves are arranged in the circumferential direction of the tire, so they are often used for trucks and passes. However, on the other hand, the drawback is that it makes a lot of noise. In other words, in lug tires, as is well known, the air in the lug grooves that is compressed by the tire tread's contact with the ground expands when exhausted to the outside of the grooves, creating compression waves, and furthermore, the air formed by the grooves and the road surface is It resonates with the air column pipes, producing a loud noise. Also, due to the presence of the above-mentioned grooves, the thickness and shape of the tread rubber differs at various parts of the tread circumference, so the impact when the grooves collide with the road surface causes the tread and case to vibrate. and generate loud noise.

そして、上記の騒音を軽減するために各種の提案が行な
われている。例えば、タイヤ子午線を含訃断面における
トレッド外面の曲率半径、すなわちクラウン半径を小ζ
くすることにより、ショルダ部の接地圧を低下させてラ
グの衝撃エネルギを緩和するとともに、溝内空気の圧力
を小さくすることである。しかし、この場合はトレッド
中央部の接地圧が強くなり、中央部が他部よりも早く摩
耗してタイヤが早期に使用不能になるという欠点がある
。また、上記ラグ溝の個数を少なくしたり、その長さを
短くしたりすることが知られているが、この場合はラグ
タイヤの特長である湿潤路における制動特性とトラクシ
ョン性能が低下する結果になる。そして、トレッド面の
中央部のみの摩耗やトラクション性能の低下を一定限度
以下に抑えるためて上記ラグ溝の形状や個数の最適範囲
を定める試みも行なわれていた。しかしながら、従来は
、タイヤに加わる負荷とタイヤ騒音の関係、すなわち車
種や積載荷重の程度および空気圧痔によるタイヤの負荷
状況の変化に基く発生騒音の変動機構が明瞭でなく、ま
たタイヤクラウン部の全溝容積の影響が加味されていな
いため、期待どおりの結果が得られなかった。Various proposals have been made to reduce the above noise. For example, the radius of curvature of the outer surface of the tread in the cross section including the tire meridian, that is, the crown radius, can be reduced by ζ
By reducing the ground contact pressure of the shoulder portion, the impact energy of the lug is reduced, and the pressure of the air in the groove is reduced. However, in this case, the ground pressure at the center of the tread becomes stronger, and the center wears out faster than other parts, resulting in the tire becoming unusable sooner. It is also known to reduce the number or length of the lug grooves mentioned above, but in this case, the braking characteristics and traction performance on wet roads, which are the characteristics of lug tires, will deteriorate. . Attempts have also been made to determine the optimal range of the shape and number of the lug grooves in order to suppress wear and deterioration of traction performance only in the central portion of the tread surface to below a certain limit. However, in the past, the relationship between the load applied to the tire and the tire noise, that is, the mechanism by which the generated noise changes based on changes in the tire load situation due to vehicle type, load level, and pneumatic hemorrhoids, was not clear; Because the influence of groove volume was not taken into account, the expected results were not obtained.

この発明は、これらの問題を解決し、実際に走行した際
に低騒音であって、しかもトレッド面の中央部付近が早
く摩耗したり、トラクション性能が低下したりすること
の少ない自動車用空気入りラグタイヤな提供するもので
ある。This invention solves these problems and provides a pneumatic pump for automobiles that produces low noise when actually driving, and that does not cause early wear near the center of the tread surface or reduce traction performance. This is what lug tires offer.

すなわちこの発明は、タイヤ子午線に沿って測定したラ
グ溝の長さがこれと同様に測定したタイヤクラウン幅の
羽〜０％であり、基準空気川下でＪより基準荷重を負荷
したときのたわみδとタイヤ断面局さＨとの比が０１７
０以下である自動車用空気入りラグタイヤにおいて、ト
レッド面における上記ラグ溝の合計表面積がトレッド部
全表面積の摺〜Ｉ％であることを特徴とする自動車用空
気入りラグタイヤである。That is, in this invention, the length of the lug groove measured along the tire meridian is ~0% of the tire crown width measured in the same way, and the deflection δ when a standard load is applied from J under the standard air. and the tire cross-sectional height H is 017
The pneumatic lug tire for automobiles is characterized in that the total surface area of the lug grooves on the tread surface is 1% to 1% of the total surface area of the tread portion.

以下にこの発明の実施例を第１図ないし第８図によって
説明する。Embodiments of the present invention will be described below with reference to FIGS. 1 to 8.

第１図および第２図において、１はビード部、２はザイ
ドウオール、８けショルダ、４けショルダポイント、５
はトレッド、５＆はラグ溝、５ｂはラグ、６はタイヤの
赤道である。また、Ｄはタイヤの赤道６におゆる外径、
Ｈはタイヤ断面高さ、Ｗはタイヤ子午線（赤道６に直交
しトレッド５の表面に沿う円弧）に沿って測ったクラウ
ン幅、４はタイヤ子午線に沿って測ったラグ溝５＆の長
き、ｂはショルダポイント４におけるラグ溝５ａの幅、
ｐけショルダポイント４におけるラグ溝５ａのピッチ長
であり、これらのタイヤ外径Ｄ１断面高さＨ１クラウン
幅Ｗ１ラグ溝５＆の長さβ、幅ｂ１ピッチ長ｐは、いず
れもタイヤをＪ工Ｓ標準リムに装着し、内圧を基準空気
圧に設走した状態で測定（単位は鱈）される。In Figures 1 and 2, 1 is a bead part, 2 is a Zydo wall, 8-piece shoulder, 4-piece shoulder point, 5
is the tread, 5& is the lug groove, 5b is the lug, and 6 is the equator of the tire. In addition, D is the outer diameter of the tire at the equator 6,
H is the tire cross-sectional height, W is the crown width measured along the tire meridian (an arc perpendicular to the equator 6 and along the surface of the tread 5), 4 is the length of the lug groove 5&, measured along the tire meridian, and b is the length of the tire meridian. The width of the lug groove 5a at the shoulder point 4,
This is the pitch length of the lug groove 5a at the shoulder point 4, and these tire outer diameter D1 section height H1 crown width W1 lug groove 5 & length β, width b1 pitch length p are all Measurements are taken with the tire mounted on a standard rim and the internal pressure set to the standard air pressure (unit: cod).

この発明の対象となるラグタイヤは、−ｈ記うグ溝５＆
の長さｌがクラウン幅Ｗのお〜４３％（０，８８Ｗ≦ｌ
≦０．４８　Ｗ　）であり、かつＪ工Ｓ基準（シングル
）荷重を負荷したときのたわみ（タイヤ断面高さの変化
量）δとタイヤ断面高さＨとの比率（タイヤたわみ比）
δ／Ｈが０１７０以下のものである。すなわち、ラグ溝
５＆の長さｌが０８８Ｗ未満の場合にはラグ溝５＆が短
か過ぎて潜潤路における制動特性およびトラクション性
能が不十分となり、反対に０４８Ｗを越えた場合には長
過ぎて騒音を低下させることができず、またタイヤたわ
み比δ／Ｈが０．１７０を越えた場合にはトレッドの接
地に伴うラグ溝内空気の圧縮比が過大になると共に、ト
レッド５およびサイドウオール２の振動に基く騒音が大
島くなるため、いずれの場合も騒音を低下させろことが
内端である。The lug tire to which this invention is applied has grooves 5 &
The length l is ~43% of the crown width W (0.88W≦l
≦0.48 W), and the ratio of the deflection (change amount of tire cross-sectional height) δ and tire cross-sectional height H (tire deflection ratio) when a J-engineering S standard (single) load is applied.
δ/H is 0170 or less. That is, if the length l of the lug groove 5& is less than 088W, the lug groove 5& is too short, resulting in insufficient braking characteristics and traction performance on the wet road, and conversely, if it exceeds 048W, the lug groove 5& is too long. If noise cannot be reduced and the tire deflection ratio δ/H exceeds 0.170, the compression ratio of the air in the lug grooves as the tread contacts the ground becomes excessive, and the tread 5 and sidewall 2 In either case, the bottom line is to reduce the noise, as the noise caused by the vibrations of the engine becomes large.

トレッド部全表面積（ラグ溝５ａの表面積を含む）をＡ
とし、トレッド５０表面におけろ多数個のラグ溝５ａの
合計表面積をＢとしたとき、ラグ溝５＆の面積比α＝　
Ｂ　／　Ａが摺〜η％に設定される。こねはラグ溝の容
積を減少きせ、かつラグ剛性を増大させることによりラ
グ溝の変形を小さくして溝内の空気の吸排気量全減少さ
せ、また溝内の圧力上昇をおきえることにより、発生す
る音圧を低レベルにおさえることが目的であるが、ラグ
溝を小さくすることは、ラグタイヤ本来の特性を失なわ
せる方向にあり、その値は限定されなければならない。The total surface area of the tread portion (including the surface area of the lug grooves 5a) is A
When the total surface area of the many lug grooves 5a on the surface of the tread 50 is B, the area ratio α of the lug grooves 5&
B/A is set to η%. Kneading reduces the volume of the lug groove and increases the rigidity of the lug, thereby reducing the deformation of the lug groove, reducing the total intake and exhaust amount of air in the groove, and also suppressing the pressure increase in the groove. The purpose is to suppress the generated sound pressure to a low level, but making the lug grooves smaller tends to cause the lug tire to lose its original characteristics, so its value must be limited.

ラグ溝ｂ＆のＩＩＩ＆Ｉｂまたはピッチ数が小さくて上
記の面積比αが１８％未満となった場合には湿潤路での
制動特性およびトラクション性能が低下して実用範囲か
ら外れることになる。反対にラグ溝ｂ＆の幅すまたはピ
ッチ数が大きくて上記の面積比αが２７％を越えた場合
には、騒音を低下することができない。なお、上記の面
積比αは、前記タイヤのたわみ比δ／Ｈが０．１２５以
上０１７０未満において止〜幻％、δ／Ｈが０．１１８
以上０．１２５未満において１８〜２５％、δ／Ｈが０
．１１８未満において想〜ｎ％がそれぞれ好ましい。If III & Ib or the pitch number of the lug grooves b& is small and the area ratio α is less than 18%, the braking characteristics and traction performance on wet roads will deteriorate and fall outside the practical range. On the other hand, if the width or pitch of the lug groove b& is large and the area ratio α exceeds 27%, the noise cannot be reduced. In addition, the above area ratio α is % to phantom when the deflection ratio δ/H of the tire is 0.125 or more and less than 0170, and δ/H is 0.118.
18 to 25% when δ/H is less than 0.125 and 0
．． When it is less than 118, it is preferable to have an average molecular weight of about n%.

上記ラグ溝５ａの好ましいピッチ数は、タイヤの呼び幅
を８（インチ）としたとき、８．６ａ〜４．５　Ｊ　Ｄ
　／’Ｎ’である。ラグ溝６ａのピッチ数が８．６−、
ｒ５７ｆ３未満の場合にはタイヤの負端状態における路
面とタイヤの接触面内に入るラグ溝５ａの個数が少な過
ぎて湿潤路での制動特性およびトラクション性能が不十
分きなり、反対に上記ピッチ数が４．５−ｆＴ５７１Ｊ
を越えた場合には、タイヤの振動特性に対するバランス
が悪くなり、すなわちタイヤとその負荷条件で定唸るタ
イヤのラグ溝による加振力および周波数に対する振動特
性が変化し、タイヤの実用速度および負荷範囲でタイヤ
の路面との接地部付近における固有の振動数に共振し易
くなって振動音が太きくなり、またラグ５ｂの剛性が低
下してラグ溝５＆の変形が大きくなるため、ラグ溝から
の空気の１汲排気量が多くなり、騒音の減少が困難であ
る。The preferred pitch number of the lug grooves 5a is 8.6a to 4.5 J D when the nominal width of the tire is 8 (inches).
/'N'. The pitch number of the lug groove 6a is 8.6-,
If it is less than r57f3, the number of lug grooves 5a that enter the contact surface between the tire and the road surface in the negative end state of the tire is too small, resulting in insufficient braking characteristics and traction performance on wet roads; 4.5-fT571J
If it exceeds this, the tire's vibration characteristics will be unbalanced, that is, the vibration characteristics with respect to the excitation force and frequency of the tire's lug grooves, which vibrate at a constant rate depending on the tire and its load conditions, will change, and the tire's practical speed and load range will change. In this case, the tire easily resonates with the unique frequency near the contact point with the road surface, making the vibration sound louder.Also, the rigidity of the lug 5b decreases and the deformation of the lug groove 5& becomes large, so that the vibration from the lug groove increases. The amount of air pumped per pump increases, making it difficult to reduce noise.

上記ラグ１５ａの好ましい幅すは、ピッチ長ｐの２４〜
４３％（０，２４ｐ≦ｂ≦０．４８ｐ）である。すなわ
ち、ラグ溝５１Ｌの幅すがピッチ長ｐの２４％未満の場
合には、排水性が不十分となるため湿潤路での制動特性
が悪くなり、捷だ溝内に保持された土砂の剪断力に対す
る抵抗が減少するため悪路でのトラクション性能が低下
し、反対にピッチ長ｐの４３％を越えた場合には、ショ
ルダ８の剛性が低下すると共に、ショルダ側の接地圧が
増加し、騒音の低下が不十分となる。The preferred width of the lug 15a is 24 to 24 of the pitch length p.
43% (0.24p≦b≦0.48p). In other words, if the width of the lug groove 51L is less than 24% of the pitch length p, the drainage performance will be insufficient, resulting in poor braking characteristics on a wet road, and the shearing of the earth and sand retained in the lug groove. As the resistance to the force decreases, the traction performance on rough roads decreases, and on the other hand, when the pitch length exceeds 43%, the stiffness of the shoulder 8 decreases and the ground pressure on the shoulder side increases, Noise reduction is insufficient.

次に、実験例によってこの発明の詳細な説明する０ 実験例１ 第８図は、タイヤの負荷およびラグ溝５＆のピッチ数が
騒音だ及ばず影響を示すグラフであり、横軸にタイヤ１
輪当りの荷重、縦軸に速度加〜１００ｂ／ｈで走行した
ときの平均の騒音レベルをとり、外径Ｄ・ラグ溝長さｌ
またわみ比δ／Ｈをほぼ一定にしてピッチ数を異にする
８種のラグタイヤ（サイズ１ｏ、ｏｏ−２０１４ｐＲ）
　、すなわち実施例１　（Ｄ　＝　１０５６ｍｍ、δ／
Ｈ＝　０．１１６　、ｌ　＝７８ｍ　。Next, the present invention will be explained in detail with reference to experimental examples.0 Experimental Example 1 Fig. 8 is a graph showing the influence of the tire load and the pitch number of the lug grooves 5& on the noise, and the horizontal axis shows the influence of the tire load and the pitch number of the lug grooves 5&.
Take the load per wheel, the average noise level when traveling at speed acceleration ~ 100 b/h on the vertical axis, and calculate the outer diameter D and lug groove length L.
Also, 8 types of lug tires (size 1o, oo-2014pR) with different pitch numbers with almost constant deflection ratio δ/H
, that is, Example 1 (D = 1056 mm, δ/
H=0.116, l=78m.

ピッチ数祠＝４．２１Ｗ元乃−）、比較例１（Ｄ　＝１
０５７鱈、δ／Ｈ＝　０．１１．６、／＝７９．ｍ、ピ
ッチ数５０＝４．８６Ｖ７冗而−）および比較例２　（
Ｄ　＝　１０５４鶴、δ／Ｈ：Ｓｏ、１１７　、ｌ　＝
　７８龍、ピッチ数５６＝５．４５　Ｊ　Ｄ／Ｓ　’　
）について実験した結果である。この第８図を一見して
１男かなように、負荷によって騒音レベルが変化し、し
かも実用負荷範囲Ｍにおける騒音レベルがピッチ数によ
って異なり、この実用負荷範囲Ｍにおいて実施例１は平
均ノイズレベルが最も低下するが、ピッチ数が過大な比
較例１および２は、双方とも実用負荷範囲Ｍ内の平均ノ
イズレベルが高く、実用負荷範囲Ｍを外れた領域で平均
ノイズレベルが低下している。Pitch number = 4.21W Motono), Comparative example 1 (D = 1
057 cod, δ/H=0.11.6, /=79. m, number of pitches 50 = 4.86V7 redundant) and comparative example 2 (
D = 1054 cranes, δ/H: So, 117, l =
78 dragons, number of pitches 56 = 5.45 J D/S'
) is the result of an experiment. At first glance, this figure 8 shows that the noise level changes depending on the load, and moreover, the noise level in the practical load range M varies depending on the number of pitches. In Comparative Examples 1 and 2, which exhibit the greatest reduction, but have an excessive number of pitches, both have a high average noise level within the practical load range M, and a decrease in the average noise level outside the practical load range M.

実験例２ 下記第１表に示す５種類のラグタイヤ（サイズ１０．０
０−２０　１４ＰＲ）につき、ＪＡＳＯ−０６０６に準
じて実車惰行騒音を測定し、速度節〜１００ｋＩＶ′ｈ
における平均の騒音レベルをめ、第４図に示すように横
軸にラグ溝５＆の面積比αをとり、縦軸に騒音レベルを
とってグラフを描いた。なお、第１表のＫはピッチ数の
式中の−ＪＤ／Ｓに乗する係数の値である。Experimental Example 2 Five types of lug tires shown in Table 1 below (size 10.0
0-20 14PR), the actual vehicle coasting noise was measured according to JASO-0606, and the speed node ~ 100kIV'h
As shown in FIG. 4, a graph was drawn with the area ratio α of the lug grooves 5 & on the horizontal axis and the noise level on the vertical axis. Note that K in Table 1 is the value of the coefficient multiplied by -JD/S in the pitch number formula.

上記の第１表および第４図によって明かなとおり、比較
例８を除〈実施例２．８．４および比較例４はＫが等し
く、すなわちピッチ数が等しく、これらの間ではラグ溝
５ａの面積比αが大きくなる程、騒音レベルが上昇する
。そして、面積比αがＩ％の比較例４は、面積比αが上
限のη％を越えているために騒音が過大となる。一方、
比較例８は、面積比αが限界内にあるにもかかわらずピ
ッチ数が上限４．５　ｖ’Ｌ／ｓ　よりも大きいために
騒音が過大である。これに対して実施例２ないし４は、
いずれも騒音レベルか低くなっている。As is clear from the above Table 1 and FIG. As the area ratio α increases, the noise level increases. In Comparative Example 4 where the area ratio α is I%, the noise is excessive because the area ratio α exceeds the upper limit η%. on the other hand,
Comparative Example 8 has excessive noise because the pitch number is larger than the upper limit of 4.5 v'L/s even though the area ratio α is within the limit. On the other hand, in Examples 2 to 4,
In both cases, the noise level is low.

実験例８ 下記第２表に示す５種類のラグタイヤ（サイズ７．５０
−　Ｘ６　１４　ＰＲ）につき１．ＴＡＳＯ−０６０６
に準じて台上騒音試験を行ない、第５図のグラフを描い
た。Experimental Example 8 Five types of lug tires shown in Table 2 below (size 7.50
- 1 per X6 14 PR). TASO-0606
A bench noise test was conducted in accordance with the above, and the graph shown in Figure 5 was drawn.

上記の第２表および第５図によって明かなように、比較
例５は、ラグ溝５＆の面積比ａが２８％であり、上限値
を越えるので騒音レベルが過大である。これに対して実
施例５〜８は、いずれも騒音レベルが低くなっている。As is clear from Table 2 and FIG. 5 above, in Comparative Example 5, the area ratio a of the lug grooves 5 & is 28%, which exceeds the upper limit, and therefore the noise level is excessive. On the other hand, Examples 5 to 8 all have low noise levels.

以上に説明したようにこの発明は、所定の荷重を負荷し
たときのタイヤたわみ量との関連でラグ溝の表面積を設
定するようにしたものであるから、実際に走行１−た際
の騒音レベルを低下させることができ、しかも１Ｎ！潤
路制動特性とトラクション性能が実用範囲から外れるこ
とがない。As explained above, in this invention, the surface area of the lug groove is set in relation to the amount of tire deflection when a predetermined load is applied, so the noise level during actual driving is determined. can be lowered by 1N! The wet road braking characteristics and traction performance do not fall outside the practical range.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はこの発明の実施例の断面図、第２図は第１図の
トレッドパターン展開図、第８図ないし第５図は騒音レ
ベルの測定結果を示すグラフである０ １：ビード部、２：サイドウオール、３：ショルダ、４
：ショルダポイント、５ニドレツド、５＆；ラグ溝、５
′ｂ：ラグ、６：赤道、Ｄ：タイヤ外径、Ｈ：タイヤ断
面高さ、Ｗ！クラウン幅、ｌ：ラグ溝の長は、ｂ：ラグ
溝の幅、ｐ：ラグ溝のピッチ長。 第３図 ｄＢ（４）　宵７７．イ１１１１ 騒　、−一一一一一〜、 θ−′、／　、 レ　′　゛・１２、゛へ・ぐ−しｂ＊９−イタ′ｊ１よ ル　ぐ〜 ｌ車交１列２ 第４図 第５図 ＋　１−Ｍ〒 タイｔ１輪当りイ苛吏（Ｋｇ） ３１−FIG. 1 is a cross-sectional view of an embodiment of the present invention, FIG. 2 is a developed view of the tread pattern of FIG. 1, and FIGS. 8 to 5 are graphs showing the measurement results of noise levels. 2: side wall, 3: shoulder, 4
: Shoulder point, 5 Nidred, 5 &; Lug groove, 5
'b: Lug, 6: Equator, D: Tire outer diameter, H: Tire cross-sectional height, W! Crown width, l: length of the lug groove, b: width of the lug groove, p: pitch length of the lug groove. Figure 3 dB (4) Evening 77. I1111 No. , -1111~, θ-', / , Re' ゛・12, ゛He・G-shib*9-Ita'j1 Yorug~ l Vehicle traffic 1 row 2 Fig. 4 Figure 5 + 1-M〒 Tie weight per wheel (Kg) 31-

Claims (1)

【特許請求の範囲】 〔１〕タイヤ子午線に沿って測定したラグ溝の長さがこ
れと同様に測定したタイヤクラウン幅の羽〜８％であり
、基準空気圧下でＪ工Ｓ基準荷重を負荷したときのたわ
みδとタイヤ断面高さＨとの比が０１７０以下である自
動車用空気入りラグタイヤにおいて、トレッド面におけ
る上記ラグ溝の合計表面積がトレッド部全表面積のに〜
２７−であることを特徴とする自動車用空気入りラグタ
イヤ。 〔２〕ラグ溝のピッチ数（タイヤの赤道の片側に存在す
るラグ溝の個数）が８．６ｆ卯可〜４．５Ｖ可１−（た
だし、Ｄはタイヤ赤道の直径（Ｗ）、Ｓはタイヤの呼び
幅（インチ））である特許請求の範囲第１項記載の自動
車用空気入りラグタイヤ。 〔３〕シヨルダホ゛インドにおけるラグ溝の幅がシ！ｉ
ｌルダポイントにおけるラグ溝のピッチ長の一〜′穏％
である特許請求の範囲第１項または第２項記載の自動車
用空気入りラグタイヤ。 〔４〕たわみδとタイヤ断面高さＨとの比が０１２５以
上０．１７０未満において、ラグ溝の合計表面積がトレ
ッド部全表面積の謁〜２３％である特許請求の範囲第１
項ないし第８項のいずれかに記載の自動車用空気入りラ
グタイヤ。 〔５〕たわみδとタイヤ断面高さＨとの比が０１１８以
上０．１２５未満において、ラグ溝の合計表面積がトレ
ッド部全表面積の１８〜２５％である特許請求の範囲第
１項ないし第８項のいずれかに記載の自動車用空気入り
ラグタイヤ。 〔６〕たわみδとタイヤ断面高さＨとの比が０１１８未
満において、ラグ溝の合計表面積がトレッド部全表面積
の訪〜２７メである特許請求の範囲第１項ないし第８項
のいずれかに記載の自動車用空気入りラグタイヤ。[Claims] [1] The length of the lug groove measured along the tire meridian is ~8% of the tire crown width measured in the same manner, and the J-engine S standard load is applied under the standard air pressure. In a pneumatic lug tire for automobiles in which the ratio of deflection δ to tire cross-sectional height H is 0170 or less, the total surface area of the lug grooves on the tread surface is equal to
A pneumatic lug tire for an automobile, characterized in that the tire is 27-. [2] The number of lug groove pitches (the number of lug grooves on one side of the tire's equator) is 8.6f to 4.5V (where D is the diameter of the tire equator (W) and S is the The pneumatic lug tire for an automobile according to claim 1, wherein the tire has a nominal width (in inches). [3] Shoulder body: The width of the lug groove in India is small! i
1% to 1% of the pitch length of the lug groove at the luda point
A pneumatic lug tire for an automobile according to claim 1 or 2. [4] Claim 1, wherein the total surface area of the lug grooves is ~23% of the total surface area of the tread portion when the ratio of the deflection δ and the tire cross-sectional height H is 0125 or more and less than 0.170.
The pneumatic lug tire for automobiles according to any one of items 8 to 9. [5] Claims 1 to 8, in which the total surface area of the lug grooves is 18 to 25% of the total surface area of the tread when the ratio of the deflection δ and the tire cross-sectional height H is 0118 or more and less than 0.125. A pneumatic lug tire for automobiles according to any of paragraphs. [6] Any one of claims 1 to 8, wherein when the ratio of deflection δ to tire cross-sectional height H is less than 0118, the total surface area of the lug grooves is between 27 mm and 27 mm of the total surface area of the tread portion. Pneumatic lug tires for automobiles described in .