JPH04243603A - Low aspect ratio pneumatic tire - Google Patents
Low aspect ratio pneumatic tireInfo
- Publication number
- JPH04243603A JPH04243603A JP3025433A JP2543391A JPH04243603A JP H04243603 A JPH04243603 A JP H04243603A JP 3025433 A JP3025433 A JP 3025433A JP 2543391 A JP2543391 A JP 2543391A JP H04243603 A JPH04243603 A JP H04243603A
- Authority
- JP
- Japan
- Prior art keywords
- tire
- width direction
- tread
- land
- annular recess
- 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
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 20
- 239000011324 bead Substances 0.000 description 6
- 238000013459 approach Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 238000004073 vulcanization Methods 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 239000011295 pitch Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
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
- B60C11/0304—Asymmetric patterns
-
- 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
- B60C11/0302—Tread patterns directional pattern, i.e. with main rolling direction
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】この発明は、クラウン部に環状凹
みが形成された偏平率が５０以下の空気入り偏平タイヤ
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat pneumatic tire having an annular recess formed in the crown portion and having an aspect ratio of 50 or less.
【０００２】0002
【従来の技術】従来の空気入りタイヤとしては、例えば
実公昭５０ー２１２０３号公報に記載されているような
ものが知られている。このものは、トロイダル状をした
カーカス層と、カーカス層のクラウン部の半径方向外側
に配置されたブレーカ層と、ブレーカ層の半径方向外側
に配置されたトレッドと、を備え、クラウン部の幅方向
ほぼ中央部におけるカーカス層、ブレーカ層およびトレ
ッドを全体的に半径方向内側に凹ませることにより、ク
ラウン部の幅方向ほぼ中央部に周方向に連続して延びる
環状凹みを形成するとともに、この環状凹みと両トレッ
ド端との間の一対の陸部にそれぞれ、周方向に延びジグ
ザグ状に屈曲した１本の主溝および該主溝の頂点から分
岐し幅方向に延びる複数本の横溝を形成したものである
。そして、このような環状凹みおよび主溝を排水のため
の通路とすることにより、排水性能を向上させるように
しているが、このような環状凹みは、幅広のためにクラ
ウン部の幅方向中央部の排水性能が低下するタイヤ、特
に偏平率が５０以下の空気入りタイヤに設けるとよいの
である。2. Description of the Related Art As a conventional pneumatic tire, for example, one described in Japanese Utility Model Publication No. 50-21203 is known. This product includes a toroidal-shaped carcass layer, a breaker layer disposed radially outward of the crown portion of the carcass layer, and a tread disposed radially outward of the breaker layer. By recessing the carcass layer, breaker layer, and tread generally inward in the radial direction, an annular recess that extends continuously in the circumferential direction is formed approximately in the width direction of the crown part, and this annular recess is A main groove extending in the circumferential direction and bent in a zigzag shape, and a plurality of lateral grooves branching from the apex of the main groove and extending in the width direction are formed in each of the pair of land portions between the tread ends and the tread ends. It is. Drainage performance is improved by using such an annular recess and the main groove as a passage for drainage, but since such an annular recess is wide, It is recommended to provide this in tires whose drainage performance deteriorates, particularly in pneumatic tires with an aspect ratio of 50 or less.
【０００３】0003
【発明が解決しようとする課題】しかしながら、このよ
うな従来の空気入りタイヤにあっては、湿潤路面を走行
する際、両陸部と路面との間に侵入しようとする水の一
部が前記主溝を通じて両陸部の直前に排出されるため、
接地領域の直前の水量が増加し、この結果、水が陸部と
路面との間に奥深く侵入してタイヤの接地面積が減少し
、ウエット性能が低下するという問題点がある。[Problems to be Solved by the Invention] However, in such conventional pneumatic tires, when running on a wet road surface, some of the water that tries to enter between the land area and the road surface is Because it is discharged through the main groove just before the amphibious part,
There is a problem in that the amount of water immediately in front of the contact area increases, and as a result, water penetrates deeply between the land and the road surface, reducing the contact area of the tire and reducing wet performance.
【０００４】この発明は、湿潤路面走行時におけるタイ
ヤ陸部と路面との間への水の侵入を抑制してウエット性
能を向上させることができる空気入り偏平タイヤを提供
することを目的とする。SUMMARY OF THE INVENTION An object of the present invention is to provide a flat pneumatic tire that can improve wet performance by suppressing the intrusion of water between the tire land portion and the road surface when running on a wet road surface.
【０００５】[0005]
【課題を解決するための手段】このような目的は、トロ
イダル状をしたカーカス層と、カーカス層のクラウン部
の半径方向外側に配置されたベルト層と、ベルト層の半
径方向外側に配置されたトレッドと、を備え、クラウン
部の幅方向ほぼ中央部におけるカーカス層、ベルト層お
よびトレッドを全体的に半径方向内側に凹ませることに
より、該クラウン部の幅方向ほぼ中央部に周方向に連続
して延びる環状凹みを形成するようにした偏平率が５０
以下の空気入り偏平タイヤにおいて、前記環状凹みとト
レッド端との間の一対の陸部にそれぞれ、回転方向前方
から回転方向後方に向かうに従い各陸部の幅方向中央か
ら幅方向両端に接近するよう傾斜した複数の傾斜溝を形
成することにより達成することができる。[Means for Solving the Problems] Such an objective is to provide a toroidal carcass layer, a belt layer disposed radially outward of the crown portion of the carcass layer, and a belt layer disposed radially outward of the belt layer. a tread, by recessing the carcass layer, the belt layer and the tread generally inward in the radial direction in the substantially central part of the width direction of the crown part, the tread is continuous in the circumferential direction in the substantially central part of the crown part in the width direction. The aspect ratio is 50 to form an annular recess that extends
In the following pneumatic flat tire, each of the pair of land portions between the annular recess and the tread edge is arranged such that the land portions approach from the center in the width direction to both ends in the width direction from the front in the rotation direction to the rear in the rotation direction. This can be achieved by forming a plurality of inclined grooves.
【０００６】[0006]
【作用】今、内圧が充填されたタイヤによって湿潤路面
を走行しているとする。このとき、このタイヤが偏平率
５０％以下である幅広の偏平タイヤであると、幅方向中
央部の排水性が悪くなるが、この発明のように、タイヤ
のクラウン部の幅方向ほぼ中央部におけるカーカス層、
ベルト層およびトレッドを全体的に半径方向内側に凹ま
せ、該クラウン部の幅方向ほぼ中央部に周方向に連続し
て延びる環状凹みを形成していれば、該環状凹みが通路
となってクラウン部の幅方向中央部と路面との間に侵入
しようとする水が排出され、ウエット性能が向上する。
また、このとき、環状凹みとトレッド端との間に画成さ
れる一対の陸部と路面との間にも水が侵入しようとする
が、この水はこれら陸部に形成された複数の傾斜溝を通
じて排出される。ここで、これら傾斜溝は、タイヤの回
転方向前方から回転方向後方に向かうに従い各陸部の幅
方向中央から幅方向両端に接近するよう傾斜しているた
め、水は各陸部の前方に扇形に分散して排出、即ち、各
陸部の幅方向外側の水の一部は該陸部の斜め外側に、ま
た、各陸部の幅方向内側の水の一部は斜め内側（環状凹
みの直前）に排出される。この結果、タイヤの接地領域
（陸部）の直前における水量が減少して陸部と路面との
間に侵入する水の量が減少し、ウエット性能が向上する
のである。[Operation] Assume that you are currently driving on a wet road with tires filled with internal pressure. At this time, if this tire is a wide flat tire with an aspect ratio of 50% or less, the drainage performance in the center part in the width direction will be poor. carcass layer,
If the entire belt layer and tread are recessed inward in the radial direction, and an annular recess that extends continuously in the circumferential direction is formed approximately in the widthwise center of the crown portion, the annular recess becomes a passage and the crown Water that attempts to enter between the widthwise center of the section and the road surface is discharged, improving wet performance. At this time, water also tries to enter between the road surface and the pair of land areas defined between the annular recess and the tread edge, but this water is absorbed by the slopes formed on these land areas. It is discharged through the groove. Here, these slanted grooves are slanted so that they approach from the center in the width direction of each land section to both ends in the width direction as they go from the front in the rotational direction of the tire to the rear in the rotation direction, so water flows in a fan-shaped manner in front of each land section. In other words, part of the water on the outside in the width direction of each land area is discharged diagonally outside the land part, and part of the water inside in the width direction of each land part is discharged diagonally inward (in the annular depression). (immediately before). As a result, the amount of water immediately before the tire's contact area (land area) is reduced, the amount of water that enters between the land area and the road surface is reduced, and wet performance is improved.
【０００７】[0007]
【実施例】以下、この発明の第１実施例を図面に基づい
て説明する。図１、２において、１１は空気入り偏平タ
イヤであり、このタイヤ１１はビード１２がそれぞれ埋
設された一対のビード部１３と、これらビード部１３か
らほぼ半径方向外側に向かって延びる一対のサイドウォ
ール部１４と、これらサイドウォール部１４の半径方向
外端同士を連ねる略円筒状のクラウン部１５と、を有す
る。そして、前記タイヤ１１は一方のビード部１３から
他方のビード部１３まで延びるトロイダル状をしたカー
カス層２１によって補強され、このカーカス層２１は少
なくとも１枚、この実施例では１枚のカーカスプライ２
２から構成されている。そして、このカーカスプライ２
２の幅方向両端部はビード１２の回りに軸方向内側から
軸方向外側に向かって折り返されている。クラウン部１
５におけるカーカス層２１の半径方向外側には少なくと
も２枚のベルトプライ２８からなるベルト層２９が配置
されており、これらベルトプライ２８に埋設されている
コードは、ベルト折れ耐久性を向上させるため、少なく
とも１枚のベルトプライ２８において有機繊維から構成
されている。また、このベルト層２９の半径方向外側に
はトレッド３３が配置され、このトレッド３３の肉厚、
即ちトレッドゲージは ７ｍｍから１０ｍｍの範囲であ
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. 1 and 2, 11 is a pneumatic flat tire, and this tire 11 has a pair of bead portions 13 in which beads 12 are embedded, and a pair of sidewalls extending approximately radially outward from these bead portions 13. 14, and a substantially cylindrical crown portion 15 that connects the outer ends of the sidewall portions 14 in the radial direction. The tire 11 is reinforced by a toroidal carcass layer 21 extending from one bead part 13 to the other bead part 13, and this carcass layer 21 is made up of at least one carcass ply 2, in this embodiment one carcass ply 2.
It is composed of 2. And this carcass ply 2
Both ends in the width direction of 2 are folded back around the bead 12 from the axially inner side to the axially outer side. Crown part 1
A belt layer 29 consisting of at least two belt plies 28 is disposed on the radially outer side of the carcass layer 21 in No. At least one belt ply 28 is made of organic fibers. Further, a tread 33 is arranged on the radially outer side of this belt layer 29, and the wall thickness of this tread 33 is
That is, the tread gauge ranges from 7mm to 10mm.
【０００８】そして、このタイヤ１１は偏平率、即ちタ
イヤの高さＴをタイヤの幅Ｗで除した後 １００を乗じ
た値が５０以下である偏平タイヤであり、この結果、接
地幅が広く、クラウン部１５の幅方向中央においては排
水性がかなり悪いのである。このため、この実施例では
、タイヤ１１のクラウン部１５の幅方向ほぼ中央部にお
けるカーカス層２１、ベルト層２９およびトレッド３３
を全体的に半径方向内側に凹ませて、該部位に連続して
周方向に延びる環状凹み３５を形成し、この環状凹み３
５を湿潤路面走行時の排水通路とすることによりウエッ
ト性能を向上させている。
ここで、このように半径方向内側に凹ませるためには、
タイヤ１１を加硫する加硫モールドのクラウン部１５の
幅方向中央部に接触する部分に、前記環状凹み３５と補
完関係にある環状突起を設け、このような環状突起によ
り加硫時のタイヤ１１のクラウン部１５の幅方向中央部
を半径方向内側に押し込めばよい。また、この実施例で
は、このような環状凹み３５を内圧充填時、高速走行時
にも確実に維持させるため、クラウン部１５の幅方向中
央部でベルト層２９の半径方向外側に幅狭の補強層３６
を配置している。ここで、この補強層３６は内部に周方
向に延びる有機繊維コード、例えばナイロンコードが多
数本埋設されている。
このようにクラウン部１５の幅方向ほぼ中央部に環状凹
み３５を形成すると、この環状溝３５の両側には、タイ
ヤ１１の最大径部３７、３８がそれぞれ形成されること
になるが、このような最大径部３７、３８の外表面同士
を結ぶ直線Ｌと前記環状凹み３５の最深部３９との間の
距離Ｄは、該タイヤ１１に正規内圧が充填されていると
き、１０ｍｍから１５ｍｍの範囲であることが好ましい
。その理由は、前記距離Ｄが１０ｍｍ未満であると、環
状凹み３５の断面積が小さ過ぎて前述したウエット性能
を十分に向上させることができないからであり、また、
１５ｍｍを超えると、ベルト層２９の屈曲量が大きくな
り過ぎてベルト層間剪断歪が大きくなり、ベルト間セパ
レーションが発生するおそれがあるからである。そして
、このような環状凹み３５はタイヤ１１内に正規内圧を
充填して高速走行したときにも、大部分が凹みとして残
る。ここで、カーカス層２１、ベルト層２９は前述のよ
うに凹まされたとき、その形状が緩やかに変化するため
、距離Ｄが前述のように１０ｍｍから１５ｍｍであると
、最大径部３７、３８間の幅方向距離Ｆは通常トレッド
幅Ｊの１５％から５０％となる。The tire 11 is a flat tire whose aspect ratio, that is, the value obtained by dividing the tire height T by the tire width W and multiplying it by 100, is 50 or less, and as a result, the ground contact width is wide. Drainage performance at the widthwise center of the crown portion 15 is quite poor. Therefore, in this embodiment, the carcass layer 21, the belt layer 29 and the tread 33 in the width direction substantially central part of the crown part 15 of the tire 11 are
is entirely recessed inward in the radial direction to form an annular recess 35 that extends continuously in the circumferential direction at the portion, and this annular recess 3
Wet performance is improved by using 5 as a drainage passage when driving on wet roads. Here, in order to concave radially inward like this,
An annular protrusion complementary to the annular recess 35 is provided at a portion that contacts the widthwise center of the crown part 15 of the vulcanization mold for vulcanizing the tire 11, and such an annular protrusion allows the tire 11 to be vulcanized during vulcanization. The center portion of the crown portion 15 in the width direction may be pushed inward in the radial direction. Further, in this embodiment, in order to ensure that such annular recess 35 is maintained even during internal pressure filling and high-speed running, a narrow reinforcing layer is provided on the radially outer side of the belt layer 29 at the widthwise central portion of the crown portion 15. 36
are placed. Here, a large number of organic fiber cords, such as nylon cords, extending in the circumferential direction are embedded inside the reinforcing layer 36. When the annular recess 35 is formed in the approximate center of the width direction of the crown portion 15 in this way, the maximum diameter portions 37 and 38 of the tire 11 are formed on both sides of the annular groove 35, respectively. The distance D between the straight line L connecting the outer surfaces of the maximum diameter parts 37 and 38 and the deepest part 39 of the annular recess 35 is in the range of 10 mm to 15 mm when the tire 11 is filled with the normal internal pressure. It is preferable that The reason is that if the distance D is less than 10 mm, the cross-sectional area of the annular recess 35 is too small to sufficiently improve the wet performance described above.
This is because if it exceeds 15 mm, the amount of bending of the belt layer 29 becomes too large, resulting in increased shear strain between the belt layers, which may cause separation between the belts. Most of the annular recess 35 remains as a recess even when the tire 11 is filled with the normal internal pressure and the vehicle travels at high speed. Here, when the carcass layer 21 and the belt layer 29 are recessed as described above, their shapes change gently. The width direction distance F is usually 15% to 50% of the tread width J.
【０００９】このようにクラウン部１５の幅方向ほぼ中
央部に環状凹み３５が形成されると、該環状凹み３５と
両トレッド端４１、４２との間のクラウン部１５には、
周方向に連続して延びるリブ状をした一対の陸部４３、
４４が画成される。ここで、このようなタイヤ１１によ
って湿潤路面を走行すると、これら一対の陸部４３、４
４と路面との間にも水が侵入しウエット性能が低下する
ため、この実施例では、各陸部４３、４４の外表面に円
周方向に等距離離れた直線状に延びる複数の傾斜溝４５
、４６、４７、４８を形成するとともに、これらの傾斜
溝４５、４６、４７、４８を回転方向（矢印方向）前方
から回転方向後方に向かうに従い各陸部４３、４４の幅
方向中央から幅方向両端に接近するよう、詳しくは傾斜
溝４５、４８に関しては陸部４３、４４の幅方向中央か
ら幅方向外側端（トレッド端４１、４２に近接する側）
に接近するよう傾斜させ、一方、傾斜溝４６、４７に関
しては陸部４３、４４の幅方向中央から幅方向内側端（
環状凹み３５に近接する側）に接近するよう傾斜させて
いる。この結果、陸部４３、４４と路面との間に侵入し
ようとする水は、前述のように傾斜した傾斜溝４５、４
６、４７、４８により陸部４３、４４の前方に扇形に分
散排出、即ち、各陸部４３、４４の幅方向外側の水の一
部は傾斜溝４５、４８により陸部４３、４４の斜め外側
に、また、各陸部４３、４４の幅方向内側の水の一部は
傾斜溝４６、４７により斜め内側（環状凹み３５の直前
）に排出される。これにより、タイヤ１１の接地領域（
陸部４３、４４）の直前における水量が減少して陸部４
３、４４と路面との間に侵入しようとする水の量が減少
し、ウエット性能が向上するのである。なお、この実施
例では、傾斜溝４５と４６および４７と４８とは １／
２ピッチだけ周方向に位相がずれており、また、傾斜溝
４５、４７のタイヤ赤道面Ｑに対する傾斜角Ａは、傾斜
溝４６、４８のタイヤ赤道面Ｑに対する傾斜角Ｂより小
さい。[0009] When the annular recess 35 is formed in the approximate center of the width direction of the crown portion 15 in this manner, the crown portion 15 between the annular recess 35 and both tread ends 41 and 42 has the following properties:
a pair of rib-shaped land portions 43 that extend continuously in the circumferential direction;
44 is defined. Here, when driving on a wet road surface with such a tire 11, these pair of land parts 43, 4
Since water also enters between the land portions 43 and the road surface and the wet performance deteriorates, in this embodiment, a plurality of inclined grooves are provided on the outer surface of each land portion 43, 44, extending in a straight line at equal distances apart in the circumferential direction. 45
, 46, 47, and 48, and these inclined grooves 45, 46, 47, and 48 are formed from the center in the width direction of each land portion 43, 44 in the width direction from the front in the rotation direction (arrow direction) to the rear in the rotation direction. Specifically, for the inclined grooves 45 and 48, from the center in the width direction of the land portions 43 and 44 to the outer end in the width direction (the side close to the tread ends 41 and 42)
On the other hand, the inclined grooves 46 and 47 are inclined from the widthwise center of the land portions 43 and 44 to the widthwise inner end (
It is inclined so as to approach the side near the annular recess 35). As a result, water that tries to enter between the land portions 43 and 44 and the road surface is prevented from entering the inclined grooves 45 and 45 as described above.
6, 47, and 48, the water is dispersed and discharged in a fan shape in front of the land parts 43, 44. In other words, a part of the water on the outside in the width direction of each land part 43, 44 is discharged diagonally in the land parts 43, 44 by the inclined grooves 45, 48. A portion of the water on the outside and on the widthwise inside of each land portion 43, 44 is discharged diagonally inward (immediately in front of the annular recess 35) by the inclined grooves 46, 47. As a result, the ground contact area of the tire 11 (
The amount of water immediately before the land area 43, 44) decreases
The amount of water that attempts to enter between the tires 3 and 44 and the road surface is reduced, improving wet performance. In addition, in this embodiment, the inclined grooves 45 and 46 and 47 and 48 are 1/
The phases are shifted by two pitches in the circumferential direction, and the inclination angle A of the inclined grooves 45 and 47 with respect to the tire equatorial plane Q is smaller than the inclination angle B of the inclined grooves 46 and 48 with respect to the tire equatorial plane Q.
【００１０】次に、試験例を説明する。この試験に当た
っては、両陸部に周方向に延びる直線状の主溝を形成し
た従来タイヤと、両陸部に図１に示すような傾斜溝を形
成した供試タイヤと、を準備した。ここで、各タイヤの
サイズは３３５／３５ Ｒ１７であった。次に、これ
ら各タイヤに ２．５ｋｇ／ｃｍ２の内圧を充填した後
、牽引されるトレーラーに装着して５０ｋｍ／ｈで湿潤
路面を走行させながらピークμを測定し、その平均値を
ウエットμ指数に換算した。
その結果は、従来タイヤにあっては、指数 １００であ
ったが、供試タイヤにおいては指数 １０８までウエッ
ト性能が向上していた。ここで、ウエットμ指数 １０
０はピークμ指数の平均値０．８３であった。Next, a test example will be explained. For this test, we prepared a conventional tire in which a linear main groove extending in the circumferential direction was formed in both land areas, and a test tire in which inclined grooves as shown in FIG. 1 were formed in both land areas. Here, the size of each tire was 335/35 R17. Next, after filling each of these tires with an internal pressure of 2.5 kg/cm2, the tires are mounted on a trailer being towed and the peak μ is measured while driving on a wet road surface at 50 km/h, and the average value is calculated as the wet μ index. It was converted into As a result, while the conventional tire had an index of 100, the wet performance of the test tire had improved to an index of 108. Here, the wet μ index is 10
0 was the average value of the peak μ index of 0.83.
【００１１】図３はこの発明の第２実施例を示す図であ
る。この実施例においては、環状凹み３５をクラウン部
１５の幅方向中央、即ちタイヤ赤道面Ｑからトレッド端
４２側にずらしている。なお、このずらし量はトレッド
幅Ｊの２０％以内であれば問題はない。また、この実施
例においては、陸部５０に形成される傾斜溝５１、５２
のタイヤ赤道面Ｑに対する傾斜角を共に、陸部５３に形
成される傾斜溝５４、５５のタイヤ赤道面Ｑに対する傾
斜角より小さくしている。ここで、このような傾斜角の
タイヤ１１は、陸部５０が排水性能を向上させ、一方、
陸部５３が旋回性能を向上させるため、旋回時において
大きな横力を受ける装着外側に陸部５３がくるよう装着
するとよい。FIG. 3 is a diagram showing a second embodiment of the invention. In this embodiment, the annular recess 35 is shifted from the widthwise center of the crown portion 15, that is, from the tire equatorial plane Q toward the tread end 42 side. Note that there is no problem as long as this amount of shift is within 20% of the tread width J. Further, in this embodiment, the inclined grooves 51 and 52 formed in the land portion 50 are
Both of the inclination angles with respect to the tire equatorial plane Q are made smaller than the inclination angles with respect to the tire equatorial plane Q of the inclined grooves 54 and 55 formed in the land portion 53. Here, in the tire 11 having such an inclination angle, the land portion 50 improves drainage performance, and on the other hand,
In order to improve the turning performance of the land portion 53, it is preferable to install the land portion 53 so that it is located on the outside of the installation where it receives a large lateral force during turning.
【００１２】図４はこの発明の第３実施例を示す図であ
る。この実施例においては、陸部５７に形成される傾斜
溝５８、５９の幅方向内端同士、および陸部６０に形成
される傾斜溝６１、６２の幅方向内端同士を交差させ、
連続させている。なお、この実施例においては傾斜溝５
８、５９、６１、６２のタイヤ赤道面Ｑに対する傾斜角
は同一である。FIG. 4 is a diagram showing a third embodiment of the present invention. In this embodiment, the inner ends in the width direction of the inclined grooves 58 and 59 formed in the land portion 57 and the inner ends in the width direction of the inclined grooves 61 and 62 formed in the land portion 60 are crossed,
It is continuous. Note that in this embodiment, the inclined groove 5
Tires 8, 59, 61, and 62 have the same inclination angle with respect to the tire equatorial plane Q.
【００１３】なお、前述の実施例においては、傾斜溝４
５、４６、４７、４８が直線状に延びている場合につい
て説明したが、この発明においては、これら傾斜溝は陸
部の幅方向中央から幅方向両端に接近するに従いタイヤ
赤道面Ｑに対する傾斜角が大きくなるよう湾曲していて
もよい。また、前述の発明においては、トレッド３３の
肉厚をクラウン部１５の全幅においてほぼ等厚としたが
、この発明においては、環状凹み３５の部位のトレッド
３３の肉厚を他の部位の肉厚より薄く、例えば最深部３
９に接近するに従い薄くするようにしてもよい。さらに
、この発明においては、各陸部の幅方向外側に形成され
た傾斜溝のタイヤ赤道面Ｑに対する傾斜角を、幅方向内
側に形成された傾斜溝のタイヤ赤道面Ｑに対する傾斜角
より小としてもよく、逆に、各陸部の幅方向内側に形成
された傾斜溝のタイヤ赤道面Ｑに対する傾斜角を、幅方
向外側に形成された傾斜溝のタイヤ赤道面Ｑに対する傾
斜角より小としてもよい。Note that in the above-mentioned embodiment, the inclined groove 4
Although the case where the grooves 5, 46, 47, and 48 extend linearly has been described, in the present invention, these inclined grooves have an inclination angle with respect to the tire equatorial plane Q as they approach both widthwise ends from the widthwise center of the land portion. It may be curved so that it becomes larger. Further, in the above-mentioned invention, the thickness of the tread 33 was made almost equal over the entire width of the crown portion 15, but in this invention, the thickness of the tread 33 at the annular recess 35 is set to be the same as the thickness at other parts. Thinner, for example the deepest part 3
It may be made thinner as it approaches 9. Furthermore, in this invention, the inclination angle with respect to the tire equatorial plane Q of the inclined groove formed on the widthwise outer side of each land portion is made smaller than the inclination angle with respect to the tire equatorial plane Q of the inclined groove formed on the widthwise inner side. Conversely, the angle of inclination of the inclined grooves formed on the inner side of each land portion in the width direction with respect to the tire equatorial plane Q may be smaller than the inclination angle of the inclined grooves formed on the outer side of the width direction with respect to the tire equatorial plane Q. good.
【００１４】[0014]
【発明の効果】以上説明したように、この発明によれば
、湿潤路面走行時におけるタイヤ陸部と路面との間への
水の侵入を抑制してウエット性能を向上させることがで
きる。As described above, according to the present invention, wet performance can be improved by suppressing the intrusion of water between the tire land portion and the road surface when running on a wet road surface.
【図１】この発明の第１実施例を示すトレッドの展開図
である。FIG. 1 is a developed view of a tread showing a first embodiment of the present invention.
【図２】この発明の第１実施例を示すタイヤの子午線断
面図である。FIG. 2 is a meridian cross-sectional view of a tire showing a first embodiment of the present invention.
【図３】この発明の第２実施例を示すトレッドの展開図
である。FIG. 3 is a developed view of a tread showing a second embodiment of the invention.
【図４】この発明の第３実施例を示すトレッドの展開図
である。FIG. 4 is a developed view of a tread showing a third embodiment of the invention.
１１…空気入り偏平タイヤ １５…クラウン部２
１…カーカス層 ２９…ベルト
層３３…トレッド ３５…
環状凹み４１、４２…トレッド端 ４３
、４４…陸部４５、４６、４７、４８…傾斜溝11...Pneumatic flat tire 15...Crown part 2
1... Carcass layer 29... Belt layer 33... Tread 35...
Annular recesses 41, 42...tread end 43
, 44...Land portions 45, 46, 47, 48...Slanted groove
Claims (1)
ス層のクラウン部の半径方向外側に配置されたベルト層
と、ベルト層の半径方向外側に配置されたトレッドと、
を備え、クラウン部の幅方向ほぼ中央部におけるカーカ
ス層、ベルト層およびトレッドを全体的に半径方向内側
に凹ませることにより、該クラウン部の幅方向ほぼ中央
部に周方向に連続して延びる環状凹みを形成するように
した偏平率が５０以下の空気入り偏平タイヤにおいて、
前記環状凹みとトレッド端との間の一対の陸部にそれぞ
れ、回転方向前方から回転方向後方に向かうに従い各陸
部の幅方向中央から幅方向両端に接近するよう傾斜した
複数の傾斜溝を形成するようにしたことを特徴とする空
気入り偏平タイヤ。1. A carcass layer having a toroidal shape, a belt layer disposed radially outward of a crown portion of the carcass layer, and a tread disposed radially outward of the belt layer.
By recessing the carcass layer, the belt layer, and the tread generally inward in the radial direction in the substantially central portion of the crown portion in the width direction, an annular shape continuously extending in the circumferential direction is formed in the substantially central portion of the crown portion in the width direction. In a pneumatic flat tire with an aspect ratio of 50 or less that forms a dent,
A plurality of inclined grooves are formed in each of the pair of land portions between the annular recess and the tread end, each of which slopes from the center in the width direction of each land portion toward both ends in the width direction from the front in the rotation direction to the rear in the rotation direction. A pneumatic flat tire characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3025433A JP2588065B2 (en) | 1991-01-25 | 1991-01-25 | Pneumatic flat tire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3025433A JP2588065B2 (en) | 1991-01-25 | 1991-01-25 | Pneumatic flat tire |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04243603A true JPH04243603A (en) | 1992-08-31 |
| JP2588065B2 JP2588065B2 (en) | 1997-03-05 |
Family
ID=12165847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3025433A Expired - Fee Related JP2588065B2 (en) | 1991-01-25 | 1991-01-25 | Pneumatic flat tire |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2588065B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5411069A (en) * | 1993-03-15 | 1995-05-02 | Bridgestone Corporation | Pneumatic radial tires including an annular recess portion in the tread |
| US5425828A (en) * | 1993-08-09 | 1995-06-20 | Bridgestone Corporation | Process for the manufacture of pneumatic radial tires with initial formation of a central annular groove in the belt-tread band |
| WO2012105425A1 (en) * | 2011-01-31 | 2012-08-09 | 横浜ゴム株式会社 | Pneumatic tire |
| CN110049882A (en) * | 2016-12-13 | 2019-07-23 | 米其林集团总公司 | Tire including the tyre surface comprising reinforcing element |
-
1991
- 1991-01-25 JP JP3025433A patent/JP2588065B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5411069A (en) * | 1993-03-15 | 1995-05-02 | Bridgestone Corporation | Pneumatic radial tires including an annular recess portion in the tread |
| US5425828A (en) * | 1993-08-09 | 1995-06-20 | Bridgestone Corporation | Process for the manufacture of pneumatic radial tires with initial formation of a central annular groove in the belt-tread band |
| WO2012105425A1 (en) * | 2011-01-31 | 2012-08-09 | 横浜ゴム株式会社 | Pneumatic tire |
| JP2012158233A (en) * | 2011-01-31 | 2012-08-23 | Yokohama Rubber Co Ltd:The | Pneumatic tire |
| CN110049882A (en) * | 2016-12-13 | 2019-07-23 | 米其林集团总公司 | Tire including the tyre surface comprising reinforcing element |
| CN110049882B (en) * | 2016-12-13 | 2020-12-25 | 米其林集团总公司 | Tyre comprising a tread comprising reinforcing elements |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2588065B2 (en) | 1997-03-05 |
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| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 19960917 |
|
| LAPS | Cancellation because of no payment of annual fees |