JPH09272312A - Pneumatic tire for heavy load - Google Patents

Pneumatic tire for heavy load

Info

Publication number
JPH09272312A
JPH09272312A JP8082862A JP8286296A JPH09272312A JP H09272312 A JPH09272312 A JP H09272312A JP 8082862 A JP8082862 A JP 8082862A JP 8286296 A JP8286296 A JP 8286296A JP H09272312 A JPH09272312 A JP H09272312A
Authority
JP
Japan
Prior art keywords
sipe
tire
block
wide
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.)
Pending
Application number
JP8082862A
Other languages
Japanese (ja)
Inventor
Osamu Takahashi
修 高橋
Keita Rachi
啓太 良知
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yokohama Rubber Co Ltd
Original Assignee
Yokohama Rubber Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Yokohama Rubber Co Ltd filed Critical Yokohama Rubber Co Ltd
Priority to JP8082862A priority Critical patent/JPH09272312A/en
Publication of JPH09272312A publication Critical patent/JPH09272312A/en
Pending legal-status Critical Current

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
    • B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
    • B60C11/1218—Three-dimensional shape with regard to depth and extending direction
    • 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
    • B60C11/1272—Width of the sipe
    • B60C11/1281—Width of the sipe different within the same sipe, i.e. enlarged width portion at sipe bottom or along its length

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Tires In General (AREA)

Abstract

PROBLEM TO BE SOLVED: To prevent cracks from being generated from the central part of a sipe bottom by widening the width of the sipe arranged in, at least, a block of a tread sensor part in a part including the both ends of the sipe from the tread face to the sipe bottom. SOLUTION: In a straight sipe 5 extended in the tire width direction, three parts or both end parts 5a of the sipe bottom and the central part 5b between them, where cracks are apt to be generated, are widened. Even if a large load is applied to a block 4A, this constitution can distribute the stress to the bottom face of the sipe 5 so as to avoid the high stress concentration and therefore prevent the cracks from being generated in the sipe bottom. While a wide-width parts 5A are formed widely from a tread face 1 to the sipe bottom 5c, narrow sipe parts 5B are arranged in spaces between each of the wide-width parts 5A so that abrasion resistance in the front/rear of the block becomes superior.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、トラックやバス等
に用いられる重荷重用空気入りタイヤに関し、更に詳し
くは、ブロックにタイヤ幅方向に延びるストレート状の
サイプを設けた、特にスタッドレスタイヤとして用いら
れる重荷重用空気入りタイヤにおいて、サイプ底の耐ク
ラック性とブロック前後の耐偏摩耗性とを両立するよう
にした重荷重用空気入りタイヤに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heavy duty pneumatic tire used for trucks, buses and the like, and more particularly, it is used as a studless tire, in which a block is provided with a straight sipe extending in the tire width direction. The present invention relates to a heavy-duty pneumatic tire that has both crack resistance at the sipe bottom and uneven wear resistance before and after the block.

【０００２】[0002]

【従来の技術】トラックやバス等に用いられる重荷重用
空気入りタイヤでは、高い雪上及び氷上性能（制駆動
性）を確保するため、ブロックにタイヤ幅方向に延びる
ストレート状のサイプを設けるようにしている。このよ
うなスタッドレスタイヤは、近年、冬期シーズン終了後
もそのまま使用し続け、シーズンを通して使用する傾向
にある。2. Description of the Related Art In heavy-duty pneumatic tires used for trucks, buses, etc., in order to ensure high snow and ice performance (braking / driving performance), blocks are provided with straight sipes extending in the tire width direction. There is. In recent years, such studless tires continue to be used as they are even after the winter season ends, and tend to be used throughout the season.

【０００３】そのため、冬期シーズン以外では、舗装さ
れた路面に直接タイヤが接触するので、ブロックに大き
な荷重が作用し、細いサイプの底に応力集中を招く。特
に、トレッドセンター部のブロックに高い荷重がかかる
ため、そこのブロックに配置されたサイプ底に高い応力
集中を来し、そのサイプ底両端からクラックが発生する
という問題があった。Therefore, except during the winter season, since the tire comes into direct contact with the paved road surface, a large load acts on the block, resulting in stress concentration at the bottom of the thin sipe. In particular, since a high load is applied to the block of the tread center portion, a high stress concentration is exerted on the sipe bottom arranged in the block, and there is a problem that cracks are generated from both ends of the sipe bottom.

【０００４】そこで、上記解決策として、トレッドセン
ター部のブロックに設けられたサイプの底全域にわたっ
て筒状の底広部を形成し、それによってサイプ底に応力
が集中するのを回避し、クラックを抑制する提案があ
る。しかし、このようにサイプ底に筒状の底広部を設け
ると、ブロックが座屈変形し易くなるため、ブロック前
後に偏摩耗が生じるという問題があった。Therefore, as a solution to the above problem, a cylindrical bottom wide portion is formed over the entire area of the bottom of the sipe provided in the block of the tread center portion, thereby avoiding concentration of stress on the sipe bottom and cracking. There are suggestions to curb. However, when the cylindrical wide bottom portion is provided on the sipe bottom in this manner, the block is easily buckled and deformed, which causes a problem that uneven wear occurs before and after the block.

【０００５】また、サイプ底両端からクラックが発生す
るため、サイプ底の両端部にのみ、筒状の底広部を配置
する提案もある。これにより、サイプの中間部は同じ切
込み幅になっているので、ブロックが容易に座屈変形す
ることがなく、ブロック前後の耐偏摩耗性は良好である
が、しかし、そうすると今度はサイプ底の中央部からク
ラックが発生するという問題があった。Since cracks are generated from both ends of the sipe bottom, there is also a proposal to dispose the cylindrical wide bottom portion only at both ends of the sipe bottom. Because of this, the middle part of the sipe has the same cut width, so the block does not buckle easily and the uneven wear resistance before and after the block is good, but then this time the sipe bottom There was a problem that cracks were generated from the central part.

【０００６】[0006]

【発明が解決しようとする課題】本発明の目的は、少な
くともトレッドセンター部のブロックにタイヤ幅方向に
延びるストレート状のサイプを設けた制駆動性に優れた
重荷重用空気入りタイヤにおいて、サイプの底にクラッ
クが発生するのを抑制すると共に、ブロック前後の耐偏
摩耗性にも優れた重荷重用空気入りタイヤを提供するこ
とにある。SUMMARY OF THE INVENTION An object of the present invention is to provide a pneumatic tire for heavy loads having excellent braking / driving properties, in which a straight sipe extending in the tire width direction is provided in at least the block of the tread center portion, and the bottom of the sipe is provided. It is intended to provide a heavy-duty pneumatic tire which is excellent in uneven wear resistance before and after the block while suppressing the occurrence of cracks in the tire.

【０００７】[0007]

【課題を解決するための手段】上記目的を達成する本発
明の重荷重用空気入りタイヤは、トレッド面にタイヤ周
方向に延びる主溝を設けると共にタイヤ幅方向に延びる
横溝を配置し、それら主溝と横溝により区画された多数
のブロックを形成し、該ブロックにタイヤ幅方向に延び
るストレート状のサイプを成形した重荷重用空気入りタ
イヤにおいて、少なくともトレッドセンター部のブロッ
クに配置されたサイプにおける幅を、該サイプの両端部
を含めた少なくとも３か所でトレッド面からサイプ底ま
で幅広にしたことを特徴とする。A pneumatic tire for heavy loads according to the present invention that achieves the above object has a main groove extending in the tire circumferential direction on a tread surface and a lateral groove extending in the tire width direction. And a large number of blocks partitioned by the lateral groove are formed, and in the heavy-duty pneumatic tire in which a straight sipe extending in the tire width direction is formed in the block, at least the width of the sipe arranged in the block of the tread center portion, It is characterized in that the width is widened from the tread surface to the bottom of the sipe at least at three places including both ends of the sipe.

【０００８】また、本発明の他の重荷重用空気入りタイ
ヤは、トレッド面にタイヤ周方向に延びる主溝を設ける
と共にタイヤ幅方向に延びる横溝を配置し、それら主溝
と横溝により区画された多数のブロックを形成し、該ブ
ロックにタイヤ幅方向に延びるストレート状のサイプを
成形した重荷重用空気入りタイヤにおいて、少なくとも
トレッドセンター部のブロックに配置されたサイプの底
側部をその底面が離間する複数の底側部分から構成し、
かつ該底側部分を交互にタイヤ周方向逆向きとなるよう
に傾斜させたことを特徴とする。In another heavy duty pneumatic tire of the present invention, a main groove extending in the tire circumferential direction is provided on the tread surface and lateral grooves extending in the tire width direction are arranged, and a large number of grooves defined by the main grooves and the lateral grooves are provided. A heavy-duty pneumatic tire in which a straight sipe extending in the tire width direction is formed in the block, a plurality of bottom surfaces of at least the bottom side portion of the sipe arranged in the block of the tread center portion are separated from each other. Consists of the bottom part of
In addition, the bottom side portion is alternately inclined so as to be opposite in the tire circumferential direction.

【０００９】上記のようにタイヤ幅方向に延びるストレ
ート状のサイプの底幅を、クラックが発生し易いサイプ
底両端部と、その間の中間部の少なくとも３か所で幅広
にしたことにより、ブロックに大きな荷重が加わって
も、その幅を広くしたサイプの底面に従来の細いサイプ
のような大きな応力が集中するのを回避させることがで
きるため、サイプ底にクラックが容易に発生することが
ない。As described above, the bottom width of the straight sipe extending in the tire width direction is widened at at least three places, that is, at both end portions of the sipe bottom where cracks are likely to occur and in the middle portion between them. Even if a large load is applied, it is possible to prevent a large stress from being concentrated on the bottom surface of the sipe whose width is wide, unlike the conventional thin sipe, so that cracks do not easily occur at the sipe bottom.

【００１０】また、サイプの幅を少なくとも３か所でト
レッド面からサイプ底まで幅広に形成することにより、
細いサイプの切込み幅の箇所を維持しながら、サイプの
深さ方向において、ブロックが屈曲し易くなるような変
曲点が何ら存在しないので、ブロックが容易に座屈変形
することがない。そのため、ブロック前後における耐偏
摩耗性も良好である。Further, by forming the width of the sipe at least at three places so as to be wide from the tread surface to the bottom of the sipe,
Since there is no inflection point that facilitates the bending of the block in the depth direction of the sipe while maintaining the cut width of the thin sipe, the block does not buckle easily. Therefore, uneven wear resistance before and after the block is also good.

【００１１】一方、サイプの底側部を底面が離間した複
数の底側部分から構成し、それらを交互にタイヤ周方向
逆向きとなるように傾斜する配置にしたことにより、サ
イプの底面を分断してタイヤ周方向の前後に分散させる
ようにするので、ブロックに大きな荷重が作用しても、
サイプの底面に高い応力が集中することがない。従っ
て、サイプ底の耐クラック性を良好にすることができ
る。On the other hand, the bottom side portion of the sipe is divided by arranging the bottom side portion of the sipe from a plurality of bottom side portions spaced apart from each other and arranging them so as to be alternately opposite in the tire circumferential direction. Since it is dispersed in the front and rear of the tire circumferential direction, even if a large load acts on the block,
High stress does not concentrate on the bottom of the sipe. Therefore, the crack resistance of the sipe bottom can be improved.

【００１２】また、サイプの底側部分を交互に逆向きに
傾斜させるだけでよく、細い切込み状のサイプの幅を局
部的に大きくするようなことがないので、ブロックの座
屈変形が容易に起こることがない。そのため、ブロック
前後における良好な耐偏摩耗性を確保することができ
る。Further, since it is only necessary to alternately incline the bottom side portion of the sipe in the opposite direction, and the width of the thin notch-shaped sipe is not locally increased, the buckling deformation of the block is facilitated. It never happens. Therefore, good uneven wear resistance before and after the block can be ensured.

【００１３】[0013]

【発明の実施の形態】以下、本発明の構成について添付
の図面を参照しながら詳細に説明する。図１は本発明の
重荷重用空気入りタイヤの一例を示し、１はトレッド面
で、このトレッド面１にはタイヤ周方向Ｔに沿って延び
る複数（図では７本）の主溝２が設けられると共に、タ
イヤ幅方向に延びる複数の横溝３が配設され、それら主
溝２と横溝３により多数のブロック４が区画形成されて
いる。DETAILED DESCRIPTION OF THE INVENTION The configuration of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an example of a heavy-duty pneumatic tire according to the present invention, in which a tread surface 1 is provided with a plurality (7 in the figure) of main grooves 2 extending along a tire circumferential direction T. At the same time, a plurality of lateral grooves 3 extending in the tire width direction are arranged, and a large number of blocks 4 are defined by the main grooves 2 and the lateral grooves 3.

【００１４】各ブロック４には、そのタイヤ周方向中央
部に、タイヤ幅方向に延び両端が主溝２に連通するスト
レート状のサイプ５が１本形成されている。タイヤ両外
側から２番目の主溝２Ａ間に位置するトレッドセンター
部１Ａには、４列のブロック列が配置され、それらの各
ブロック４Ａには、サイプ５の前後に各１本のブロック
幅の１／２よりも短いサイプ６が設けられている。これ
らサイプ５，６は、タイヤ径方向に沿って切込まれ、そ
の深さは主溝２よりも浅くなっている。Each block 4 is formed with a straight sipe 5 at the center in the tire circumferential direction, the straight sipe 5 extending in the tire width direction and having both ends communicating with the main groove 2. Four block rows are arranged in the tread center portion 1A located between the second main grooves 2A from both outer sides of the tire, and each block 4A has a block width of one block before and after the sipe 5 respectively. Sipe 6 shorter than 1/2 is provided. These sipes 5, 6 are cut along the tire radial direction, and the depth thereof is shallower than that of the main groove 2.

【００１５】タイヤ赤道線ＣＬ上に配置された中央の主
溝２Ｂに面する両ブロック列の各ブロック４A1に形成さ
れたサイプ６はその一端が主溝２Ｂに連通している。２
番目の主溝２Ａに面する各ブロック列の各々のブロック
４A2に形成されたサイプ６はその一端が主溝２Ａに連通
するようになっている。７はタイヤ両外側から３番目の
主溝２Ｃにそれぞれ設けれた細リブ、８はタイヤ両外側
の主溝２Ｄに沿って設けられた小ブロックである。One end of the sipe 6 formed in each block 4A 1 of both block rows facing the central main groove 2B arranged on the tire equator line CL communicates with the main groove 2B. Two
One end of the sipe 6 formed in each block 4A 2 of each block row facing the second main groove 2A communicates with the main groove 2A. Reference numeral 7 is a thin rib provided in each of the third main grooves 2C from both outer sides of the tire, and 8 is a small block provided along the main grooves 2D on both outer sides of the tire.

【００１６】本発明では、上記のようにタイヤ幅方向に
延びるストレート状のサイプ５を設け、雪氷上での制駆
動性を高めるようにした重荷重用空気入りタイヤにおい
て、少なくともトレッドセンター部１Ａのブロック４Ａ
に配置されたサイプ５が、図２に示すように、その幅
を、サイプ５の両端部５ａと中央部５ｂの３か所でトレ
ッド面１からサイプ底５ｃまで略同じ幅広に形成され、
広幅部５Ａになっている。この広幅部５Ａの底面は円弧
状に形成され、これら各広幅部５Ａ間（２か所）には、
トレッド面１からサイプ底５ｃまで幅の狭い切込み状の
狭幅サイプ部５Ｂが位置している。In the present invention, as described above, in the heavy-duty pneumatic tire in which the straight sipe 5 extending in the tire width direction is provided to enhance braking / driving performance on snow and ice, at least the block of the tread center portion 1A. 4A
As shown in FIG. 2, the sipe 5 arranged at the width of the sipe 5 is formed to have substantially the same width from the tread surface 1 to the sipe bottom 5c at three positions of the both ends 5a and the central portion 5b of the sipe 5,
It has a wide portion 5A. The bottom surface of the wide portion 5A is formed in an arc shape, and between the wide portions 5A (two places),
A narrow sipe portion 5B having a narrow cut is located from the tread surface 1 to the sipe bottom 5c.

【００１７】このようにタイヤ幅方向に延設したストレ
ート状のサイプ５において、クラックが発生するサイプ
底の両端部５ａとその間の中央部５ｂとの３か所を幅広
にしたので、ブロック４に大きな荷重が作用しても、サ
イプ５の底面に応力を分散させ、高い応力集中を招くの
を回避することができ、それによってサイプ底にクラッ
クが発生するのを防ぐことができる。In the straight sipe 5 extending in the tire width direction as described above, the width of the sipe bottom where cracks are generated is wide at three points, that is, at both end portions 5a and the central portion 5b between them. Even if a large load is applied, it is possible to disperse the stress on the bottom surface of the sipe 5 and avoid high stress concentration, thereby preventing the sipe bottom from cracking.

【００１８】また、広幅部５Ａをトレッド面１からサイ
プ底５ｃまで幅広に形成する一方、各広幅部５Ａ間に
は、底まで幅の狭い切込み状の従来同様の狭幅サイプ部
５Ｂが位置するので、そのサイプ５により前後に区分さ
れるブロック４が屈曲し易くなるような変曲点を形成す
ることがなく、そのため、ブロック４が容易に座屈変形
せず、ブロック前後における耐偏摩耗性を良好にするこ
とができる。Further, the wide portion 5A is formed wide from the tread surface 1 to the sipe bottom 5c, and a narrow sipe portion 5B having a narrow cut to the bottom is located between the wide portions 5A. Therefore, the block 4 divided into front and rear by the sipe 5 does not form an inflection point that facilitates bending, and therefore the block 4 does not easily buckle and deform, and the uneven wear resistance before and after the block is prevented. Can be good.

【００１９】上記広幅部５Ａは、図２では、その幅Ｗ’
を狭幅サイプ部５Ｂの幅（サイプ５の幅）Ｗに対し、
Ｗ’＝２Ｗの関係にしてあり、これによってサイプを成
形する金型のサイプ成形刃を広幅部５Ａに対応する箇所
を折り曲げ形状にすることで、容易にサイプ成形刃を構
成することができるが、その幅Ｗ’は、ブロック４の大
きさやサイプ５を配置する間隔により適宜設定すること
ができる。The wide portion 5A has a width W'in FIG.
To the width W of the narrow sipe portion 5B (width of sipe 5),
Although W '= 2W, the sipe molding blade of the mold for molding the sipe can be easily configured by bending the sipe molding blade at the portion corresponding to the wide width portion 5A. The width W ′ can be appropriately set depending on the size of the block 4 and the interval at which the sipes 5 are arranged.

【００２０】また、図２では、サイプ５の両端部５ａに
設けられた両広幅部５Ａが、タイヤ周方向の一方側に凸
となるように幅広に形成される一方、中央部５ｂの広幅
部５Ａは、タイヤ周方向の他方側に凸となるよう形成さ
れ、広幅部５Ａの偏りを少なくしてブロックの耐偏摩耗
性により配慮した配置にしたが、これに限定されず、広
幅部５Ａを共に同じ方向に凸となるようにしてもよく、
更に、広幅部５Ａをサイプ５のタイヤ周方向両側に同じ
割合で凸となるようにしてもよい。Further, in FIG. 2, both wide portions 5A provided at both ends 5a of the sipe 5 are formed wide so as to be convex on one side in the tire circumferential direction, while the wide portion of the central portion 5b is formed. 5A is formed so as to be convex on the other side in the tire circumferential direction, and is arranged in consideration of uneven wear resistance of the block by reducing the bias of the wide width portion 5A, but it is not limited to this, and the wide width portion 5A is Both may be convex in the same direction,
Further, the wide portion 5A may be convex on both sides of the sipe 5 in the tire circumferential direction at the same rate.

【００２１】また、広幅部５Ａは、上記実施形態のよう
に、サイプ５の両端部５ａと中央部５ｂの３か所に均等
的に配置するのが好ましいが、それに限定されることが
なく、サイプ５の両端部５ａを含めたその中間部分との
少なくとも３か所に広幅部５Ａを形成するようにして
も、上記と同様の効果を得ることができる。図３は、本
発明の重荷重用空気入りタイヤに用いられる他のサイプ
の例を示す。この実施形態では、上記のようなサイプ形
状に代えて、サイプ５が、その底側部５Ｍをその底面が
離間する複数の底側部分５M1から構成されている。これ
らの各底側部分５M1は、交互にタイヤ周方向逆向きとな
るように（サイプ５の切込み方向に対し逆向きに）傾斜
させた傾斜部に形成されている。サイプ底面は、タイヤ
幅方向で分断されると共に、それら分断されたサイプ底
面５ｎは、サイプ５の切込み方向に対して、タイヤ周方
向の前後の２位置に交互に配置された構成になってい
る。底側部５Ｍは少なくとも３個の底側部分５M1から構
成するのがよい。図では、サイプ５の底側部５Ｍが５個
の底側部分５M1から構成され、両端部と中央部の各底側
部分５M1が、その底部をタイヤ周方向の一方側に向けて
同じ割合で傾斜する一方、両端部と中央部の底側部分に
挟まれた中間部の両底側部分５M1は、その底部をタイヤ
周方向の他方側に向けて同じ傾斜割合で傾斜するように
なっている。サイプ底面がタイヤ幅方向で５つに分断さ
れ、その分断された５つのサイプ底面５ｎがサイプ５の
切込み方向を中心にタイヤ周方向の前後で交互にタイヤ
幅方向に２列に並んでいる。Further, it is preferable that the wide portions 5A are evenly arranged at three positions, that is, both end portions 5a and the central portion 5b of the sipe 5, as in the above embodiment, but the present invention is not limited thereto. Even if the wide portions 5A are formed at least at three places including the both end portions 5a of the sipe 5 and the intermediate portion thereof, the same effect as described above can be obtained. FIG. 3 shows an example of another sipe used in the heavy duty pneumatic tire of the present invention. In this embodiment, instead of the sipe shape as described above, the sipe 5 is composed of a plurality of bottom side portions 5M1 having their bottom surfaces separated from the bottom side portion 5M. Each of the bottom side portions 5M1 is formed in an inclined portion that is alternately inclined in the opposite direction to the tire circumferential direction (opposite to the cutting direction of the sipe 5). The sipe bottom surface is divided in the tire width direction, and the divided sipe bottom surfaces 5n are alternately arranged at two positions in the front and rear of the tire circumferential direction with respect to the cutting direction of the sipe 5. . The bottom side portion 5M is preferably composed of at least three bottom side portions 5M1. In the figure, the bottom side portion 5M of the sipe 5 is composed of five bottom side portions 5M1, and the bottom side portions 5M1 at both ends and the central portion are oriented at the same ratio with the bottom portions directed toward one side in the tire circumferential direction. On the other hand, both middle side bottom portions 5M1 sandwiched between both end portions and the central bottom portion are inclined at the same inclination ratio with the bottom portion directed toward the other side in the tire circumferential direction. . The sipe bottom surface is divided into five pieces in the tire width direction, and the five divided sipe bottom surfaces 5n are alternately arranged in two rows in the tire width direction in the tire circumferential direction around the cutting direction of the sipe 5.

【００２２】このようにサイプ５の底面が離間する複数
の底側部分５M1を交互にタイヤ周方向逆向きとなるよう
に傾斜させる構成にすることにより、サイプ５の底面を
分断してタイヤ周方向の前後に分散させることができる
ので、ブロック４に大きな荷重が負荷された場合であっ
ても、分断されたサイプ底面５ｎに高い応力集中が作用
するのを避けることができ、そのため、サイプ底にクラ
ックが容易に発生することがない。As described above, by arranging the plurality of bottom side portions 5M1 whose bottom surfaces are separated from each other so as to be alternately turned in the tire circumferential direction, the bottom surface of the sipe 5 is divided and the tire circumferential direction is divided. Since it can be dispersed before and after, the high stress concentration can be prevented from acting on the divided sipe bottom surface 5n even when a large load is applied to the block 4, and therefore the sipe bottom can be prevented. Cracks do not easily occur.

【００２３】また、サイプ５の底側部分５M1をサイプの
切込み方向に対し交互に逆向きに傾斜させるだけでよ
く、細いサイプ５の幅を局部的に広くするようなことが
ないため、従来の細い切込み幅のストレート状サイプを
設けた場合と同じようにブロック４が容易に座屈変形す
ることがなく、従って、ブロック前後の耐偏摩耗性を良
好にすることができる。Further, since it is only necessary to incline the bottom side portion 5M1 of the sipe 5 in the opposite direction to the cutting direction of the sipe, the width of the thin sipe 5 is not locally widened. The block 4 is not easily buckled and deformed as in the case where the straight sipe having a narrow cut width is provided, and therefore the uneven wear resistance before and after the block can be improved.

【００２４】[0024]

【実施例】タイヤサイズを１１Ｒ２２．５ １４ＰＲで
共通にし、図１に示すトレッドパターンを有する試験タ
イヤＡ，Ｂをそれぞれ各５本作製した。試験タイヤＡ，
Ｂのトレッド面をタイヤ周上で前後に２分割し、試験タ
イヤＡ，Ｂの一方のトレッド面のセンター部に配置した
ブロックの両主溝に連通する各サイプの形状を一方の試
験タイヤＡが図２（実施例１）、他方の試験タイヤＢが
図３（実施例２）とする一方、図２の形状のサイプを配
置した試験タイヤＡの他方のトレッド面のセンター部に
配置したブロックの両主溝に連通する各サイプの形状
を、サイプ底全域にわたって筒状の底広部に形成（従来
例１）し、また、図３の形状のサイプを配置した試験タ
イヤＢの他方のトレッド面のセンター部に配置したブロ
ックの両主溝に連通する各サイプの形状を、サイプ底の
両端部にのみ、筒状の底広部を形成（従来例１）した。
サイプの深さは共に２０mmである。[Examples] Five test tires A and B each having a tire size of 11R22.5 14PR and having a tread pattern shown in FIG. 1 were produced. Test tire A,
The tread surface of B is divided into two in the front and rear on the tire circumference, and the shape of each sipe communicating with both main grooves of the block arranged at the center of one tread surface of each of the test tires A and B has the shape of one test tire A. 2 (Example 1), while the other test tire B is shown in FIG. 3 (Example 2), the block of the test tire A having the shape of FIG. 2 arranged in the center portion of the other tread surface of the test tire A is arranged. The shape of each sipe communicating with both main grooves is formed in a wide cylindrical bottom portion over the entire sipe bottom (conventional example 1), and the other tread surface of the test tire B in which the sipe having the shape of FIG. 3 is arranged. The shape of each sipe that communicates with both main grooves of the block arranged in the center portion was formed with a cylindrical wide bottom portion only at both ends of the sipe bottom (conventional example 1).
Both sipes have a depth of 20 mm.

【００２５】これら試験タイヤＡ，Ｂ各５本をリムサイ
ズ２２．５×７．５０のリムに装着し、空気圧を７００
kPa 、試験タイヤＡ５本を車両右側、試験タイヤＢ５本
を車両左側にして、１０ｔ積載した１０ｔの車両（２−
Ｄ・４）に取付け、以下に示す測定条件により、サイプ
底の耐クラック性及びブロック前後の耐偏摩耗性の評価
試験を行ったところ、表１に示す結果を得た。Five of each of the test tires A and B were mounted on a rim having a rim size of 22.5 × 7.50 and the air pressure was set to 700.
kPa, with 5 test tires A on the right side of the vehicle and 5 test tires B on the left side of the vehicle, a 10t vehicle with 10t loaded (2-
D.4), the evaluation test of the crack resistance of the sipe bottom and the uneven wear resistance before and after the block was performed under the following measurement conditions, and the results shown in Table 1 were obtained.

【００２６】測定条件 一般車道（高速路４０％、一般舗装路６０％）を３万km
走行後、各試験タイヤのサイプ底に発生したクラックの
数と、ブロック前後の摩耗量差を測定した。これらの数
値は、５本のタイヤの平均である。なお、１．５万km走
行時に、回転方向が変わらないように、左右の試験タイ
ヤを入替え、３万km走行した。Measurement conditions 30,000km on a general road (40% highway, 60% general pavement)
After running, the number of cracks on the sipe bottom of each test tire and the difference in the amount of wear before and after the block were measured. These numbers are the average of 5 tires. In addition, the test tires on the left and right were replaced so that the rotation direction did not change when traveling 15,000 km, and the vehicle traveled 30,000 km.

【００２７】[0027]

【表１】 表１から明らかなように、本発明は、サイプ底にクラッ
クの発生がなく、また、ブロック前後における偏摩耗量
も小さく、サイプ底の耐クラック性及びブロック前後の
耐偏摩耗性に優れ、それらを両立させることができるの
が判る。[Table 1] As is clear from Table 1, the present invention does not cause cracks in the sipe bottom, has a small amount of uneven wear before and after the block, and is excellent in crack resistance of the sipe bottom and uneven wear resistance before and after the block. It turns out that both can be achieved.

【００２８】[0028]

【発明の効果】上述のように本発明は、少なくともトレ
ッドセンター部のブロックにタイヤ幅方向に延びるスト
レート状のサイプを設けた制駆動性に優れた重荷重用空
気入りタイヤにおいて、そのサイプにおける幅を、該サ
イプの両端部を含めた少なくとも３か所でトレッド面か
らサイプ底まで幅広にし、或いは、サイプの底側部をそ
の底面が離間する複数の底側部分から構成し、その底側
部分を交互にタイヤ周方向逆向きとなるように傾斜させ
たので、ブロックに大きな荷重が加わっても、サイプ底
に高い応力集中が発生するのを回避し、サイプ底にクラ
ックが発生するのを抑制することができると共に、該サ
イプによりブロックが座屈変形することがないので、ブ
ロック前後における耐偏摩耗性も良好にすることができ
る。INDUSTRIAL APPLICABILITY As described above, the present invention provides a heavy-duty pneumatic tire excellent in braking / driving property in which a straight sipe extending in the tire width direction is provided in at least the block of the tread center portion, and the width of the sipe is , Widening from the tread surface to the sipe bottom in at least three places including both ends of the sipe, or forming the bottom side part of the sipe from a plurality of bottom side parts whose bottom surfaces are spaced apart from each other, Since the tires are alternately tilted in the opposite direction to the circumferential direction, even if a large load is applied to the block, high stress concentration is avoided at the sipe bottom and cracks are suppressed at the sipe bottom. At the same time, since the block does not buckle and deform due to the sipes, the uneven wear resistance before and after the block can be improved.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の重荷重用空気入りタイヤの一例を示す
トレッド面の要部展開図である。FIG. 1 is a development view of a main portion of a tread surface showing an example of a heavy-duty pneumatic tire of the present invention.

【図２】本発明の重荷重用空気入りタイヤに用いられる
サイプの形状を示し、（ａ）は要部斜視図、（ｂ）は要
部平面図である。FIG. 2 shows the shape of a sipe used in the heavy duty pneumatic tire of the present invention, (a) is a perspective view of a main part, and (b) is a plan view of the main part.

【図３】本発明の重荷重用空気入りタイヤに用いられる
サイプの他の形状を示し、（ａ）は要部斜視図、（ｂ）
は要部平面図である。3A and 3B show another shape of the sipe used in the heavy duty pneumatic tire of the present invention, FIG.
FIG. 3 is a plan view of a main part.

【符号の説明】 １ トレッド面 １Ａ トレッドセ
ンター部 ２ 主溝 ３ 横溝 ４，４Ａ ブロック ５ サイプ ５Ａ 広幅部 ５ａ 両端部 ５ｂ 中央部 ５ｃ サイプ底 ５Ｍ 底側部 ５M1 底側部分 ５ｎ 底面 Ｔ タイヤ周方向[Explanation of Codes] 1 tread surface 1A tread center portion 2 main groove 3 lateral groove 4, 4A block 5 sipes 5A wide width portion 5a both ends 5b center portion 5c sipes bottom 5M bottom side 5M1 bottom side 5n bottom T tire circumferential direction

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 トレッド面にタイヤ周方向に延びる主溝
を設けると共にタイヤ幅方向に延びる横溝を配置し、そ
れら主溝と横溝により区画された多数のブロックを形成
し、該ブロックにタイヤ幅方向に延びるストレート状の
サイプを成形した重荷重用空気入りタイヤにおいて、 少なくともトレッドセンター部のブロックに配置された
サイプにおける幅を、該サイプの両端部を含めた少なく
とも３か所でトレッド面からサイプ底まで幅広にした重
荷重用空気入りタイヤ。1. A main groove extending in the tire circumferential direction is provided on a tread surface and lateral grooves extending in the tire width direction are arranged, and a large number of blocks defined by the main grooves and the lateral grooves are formed, and the blocks are arranged in the tire width direction. In a heavy-duty pneumatic tire in which a straight sipe extending in the direction of the sipe is formed, at least the width of the sipe arranged in the block of the tread center portion should be at least three places including both ends of the sipe from the tread surface to the sipe bottom. Wide pneumatic tire for heavy loads. 【請求項２】 前記サイプの幅を幅広にした広幅部を３
か所に設け、それら広幅部をサイプの両端部と中央部に
配置した請求項１記載の重荷重用空気入りタイヤ。2. The wide portion in which the width of the sipe is wide is 3
The heavy-duty pneumatic tire according to claim 1, wherein the wide portions are provided at locations and are arranged at both end portions and a central portion of the sipe. 【請求項３】 トレッド面にタイヤ周方向に延びる主溝
を設けると共にタイヤ幅方向に延びる横溝を配置し、そ
れら主溝と横溝により区画された多数のブロックを形成
し、該ブロックにタイヤ幅方向に延びるストレート状の
サイプを成形した重荷重用空気入りタイヤにおいて、 少なくともトレッドセンター部のブロックに配置された
サイプの底側部をその底面が離間する複数の底側部分か
ら構成し、かつ該底側部分を交互にタイヤ周方向逆向き
となるように傾斜させた重荷重用空気入りタイヤ。3. A tread surface is provided with a main groove extending in the tire circumferential direction and lateral grooves extending in the tire width direction are arranged to form a large number of blocks partitioned by the main grooves and the lateral grooves, and the blocks are arranged in the tire width direction. In a heavy-duty pneumatic tire formed by molding a straight sipe extending to, at least the bottom side portion of the sipe arranged in the block of the tread center portion is composed of a plurality of bottom side portions whose bottom surfaces are separated from each other, and the bottom side A heavy-duty pneumatic tire in which the parts are alternately inclined so as to be opposite in the tire circumferential direction. 【請求項４】 前記底側部分を５個にした請求項３記載
の重荷重用空気入りタイヤ。4. The heavy duty pneumatic tire according to claim 3, wherein the bottom side portion has five pieces.
JP8082862A 1996-04-04 1996-04-04 Pneumatic tire for heavy load Pending JPH09272312A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8082862A JPH09272312A (en) 1996-04-04 1996-04-04 Pneumatic tire for heavy load

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8082862A JPH09272312A (en) 1996-04-04 1996-04-04 Pneumatic tire for heavy load

Publications (1)

Publication Number Publication Date
JPH09272312A true JPH09272312A (en) 1997-10-21

Family

ID=13786155

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8082862A Pending JPH09272312A (en) 1996-04-04 1996-04-04 Pneumatic tire for heavy load

Country Status (1)

Country Link
JP (1) JPH09272312A (en)

Cited By (19)

* Cited by examiner, † Cited by third party
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EP1029714A2 (en) * 1999-02-18 2000-08-23 Sumitomo Rubber Industries Ltd. Vehicle tyre
EP1190871A2 (en) * 2000-04-25 2002-03-27 Continental Aktiengesellschaft Vehicle tyre with sipes in the tread, vulcanization mould for the manufacture of such a tyre and blade suitable for being introduced into such a mould
JP2002154308A (en) * 2000-07-03 2002-05-28 Soc De Technol Michelin Tread for heavy load support tire
US6561242B2 (en) * 2000-02-21 2003-05-13 Bridgestone Corporation Block structure in pneumatic tire
EP1616721A1 (en) * 2004-07-15 2006-01-18 Continental Aktiengesellschaft Pneumatic tire
JP2006036102A (en) * 2004-07-29 2006-02-09 Toyo Tire & Rubber Co Ltd Pneumatic tire
KR100869025B1 (en) * 2007-07-04 2008-11-17 금호타이어 주식회사 Pneumatic tire with variable type sipe
DE102008039069A1 (en) 2007-09-26 2009-04-02 Toyo Tire & Rubber Co., Ltd., Osaka-shi tire
FR2924981A1 (en) * 2007-12-17 2009-06-19 Michelin Soc Tech TIRE TREAD FOR SNOW TIRE.
JP2009262675A (en) * 2008-04-23 2009-11-12 Toyo Tire & Rubber Co Ltd Pneumatic tire
DE102010005840A1 (en) 2009-03-02 2010-09-09 Toyo Tire & Rubber Co., Ltd. (Toyo Gomu Kogyo K.K.) tire
WO2011120817A1 (en) * 2010-03-31 2011-10-06 Societe De Technologie Michelin Tyre tread having incisions
US20110290392A1 (en) * 2010-06-01 2011-12-01 Toyo Tire & Rubber Co., Ltd. Pneumatic tire
JP2012076660A (en) * 2010-10-04 2012-04-19 Yokohama Rubber Co Ltd:The Pneumatic tire
JP2012101783A (en) * 2010-10-13 2012-05-31 Toyo Tire & Rubber Co Ltd Pneumatic tire
US8307867B2 (en) 2008-10-03 2012-11-13 Toyo Tire & Rubber Co., Ltd. Pneumatic tire with tread including sipe having wide portions located alternately on both side walls
JP2013107501A (en) * 2011-11-21 2013-06-06 Toyo Tire & Rubber Co Ltd Pneumatic tire
CN104029568A (en) * 2014-06-11 2014-09-10 厦门正新橡胶工业有限公司 Tire tread structure of pneumatic tire of motorcycle
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1029714A2 (en) * 1999-02-18 2000-08-23 Sumitomo Rubber Industries Ltd. Vehicle tyre
EP1029714A3 (en) * 1999-02-18 2001-10-24 Sumitomo Rubber Industries Ltd. Vehicle tyre
US6668886B1 (en) 1999-02-18 2003-12-30 Sumitomo Rubber Industries, Ltd. Vehicle tire having sipes
US6561242B2 (en) * 2000-02-21 2003-05-13 Bridgestone Corporation Block structure in pneumatic tire
EP1190871A2 (en) * 2000-04-25 2002-03-27 Continental Aktiengesellschaft Vehicle tyre with sipes in the tread, vulcanization mould for the manufacture of such a tyre and blade suitable for being introduced into such a mould
EP1190871A3 (en) * 2000-04-25 2002-07-10 Continental Aktiengesellschaft Vehicle tyre with sipes in the tread, vulcanization mould for the manufacture of such a tyre and blade suitable for being introduced into such a mould
JP2002154308A (en) * 2000-07-03 2002-05-28 Soc De Technol Michelin Tread for heavy load support tire
EP1616721A1 (en) * 2004-07-15 2006-01-18 Continental Aktiengesellschaft Pneumatic tire
JP2006036102A (en) * 2004-07-29 2006-02-09 Toyo Tire & Rubber Co Ltd Pneumatic tire
KR100869025B1 (en) * 2007-07-04 2008-11-17 금호타이어 주식회사 Pneumatic tire with variable type sipe
DE102008039069A1 (en) 2007-09-26 2009-04-02 Toyo Tire & Rubber Co., Ltd., Osaka-shi tire
DE102008039069B4 (en) * 2007-09-26 2012-02-02 Toyo Tire & Rubber Co., Ltd. tire
US8640751B2 (en) 2007-09-26 2014-02-04 Toyo Tire & Rubber Co., Ltd. Pneumatic tire with tread having sipes
FR2924981A1 (en) * 2007-12-17 2009-06-19 Michelin Soc Tech TIRE TREAD FOR SNOW TIRE.
WO2009077499A1 (en) * 2007-12-17 2009-06-25 Société de Technologie Michelin Snow tyre tread
EA016642B1 (en) * 2007-12-17 2012-06-29 Сосьете Де Текноложи Мишлен Snow tyre tread
JP2009262675A (en) * 2008-04-23 2009-11-12 Toyo Tire & Rubber Co Ltd Pneumatic tire
US8307867B2 (en) 2008-10-03 2012-11-13 Toyo Tire & Rubber Co., Ltd. Pneumatic tire with tread including sipe having wide portions located alternately on both side walls
DE102010005840A1 (en) 2009-03-02 2010-09-09 Toyo Tire & Rubber Co., Ltd. (Toyo Gomu Kogyo K.K.) tire
DE102010005840B4 (en) * 2009-03-02 2018-10-11 Toyo Tire & Rubber Co., Ltd. (Toyo Gomu Kogyo K.K.) tire
US8708011B2 (en) 2009-03-02 2014-04-29 Toyo Tire & Rubber Co., Ltd. Pneumatic tire with tread having sipes
FR2958213A1 (en) * 2010-03-31 2011-10-07 Michelin Soc Tech TIRE TREAD WITH INCISIONS
RU2508205C1 (en) * 2010-03-31 2014-02-27 Компани Женераль Дез Этаблиссман Мишлен Tire tread with dents
CN102844203A (en) * 2010-03-31 2012-12-26 米其林企业总公司 Tyre tread having incisions
WO2011120817A1 (en) * 2010-03-31 2011-10-06 Societe De Technologie Michelin Tyre tread having incisions
US9308780B2 (en) 2010-03-31 2016-04-12 Compagnie Generale Des Etablissements Michelin Tire tread having incisions
US8561660B2 (en) * 2010-06-01 2013-10-22 Toyo Tire & Rubber Co., Ltd. Pneumatic tire
US20110290392A1 (en) * 2010-06-01 2011-12-01 Toyo Tire & Rubber Co., Ltd. Pneumatic tire
JP2012076660A (en) * 2010-10-04 2012-04-19 Yokohama Rubber Co Ltd:The Pneumatic tire
US8973631B2 (en) 2010-10-13 2015-03-10 Toyo Tire & Rubber Co., Ltd. Pneumatic tire
JP2012101783A (en) * 2010-10-13 2012-05-31 Toyo Tire & Rubber Co Ltd Pneumatic tire
JP2013107501A (en) * 2011-11-21 2013-06-06 Toyo Tire & Rubber Co Ltd Pneumatic tire
CN104029568A (en) * 2014-06-11 2014-09-10 厦门正新橡胶工业有限公司 Tire tread structure of pneumatic tire of motorcycle
CN111433051A (en) * 2017-12-28 2020-07-17 横滨橡胶株式会社 Pneumatic tire
CN111433051B (en) * 2017-12-28 2022-07-29 横滨橡胶株式会社 Pneumatic tire

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