JPH07195908A - Pneumatic radial tier for electric vehicle - Google Patents
Pneumatic radial tier for electric vehicleInfo
- Publication number
- JPH07195908A JPH07195908A JP5350692A JP35069293A JPH07195908A JP H07195908 A JPH07195908 A JP H07195908A JP 5350692 A JP5350692 A JP 5350692A JP 35069293 A JP35069293 A JP 35069293A JP H07195908 A JPH07195908 A JP H07195908A
- Authority
- JP
- Japan
- Prior art keywords
- tire
- tread
- carcass
- tread surface
- width
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
- Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction
Landscapes
- Tires In General (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、特に電気三輪自動車の
後輪タイヤとして好適に採用でき、操縦安定性を向上し
つつ転がり抵抗を減じ、燃費を低減しうる電気自動車用
空気入りラジアルタイヤに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic radial tire for an electric vehicle, which can be suitably used particularly as a rear wheel tire of an electric three-wheeled vehicle, which can improve rolling stability while reducing rolling resistance and fuel consumption. .
【０００２】[0002]
【従来の技術】近年、環境保護の見地から、電気自動車
の進歩が著しく、このような電気自動車に用いるタイヤ
としては、１回の充電での走行距離を高めるため、転が
り抵抗を小さくし燃費の節減を図ることが要請されてい
る。2. Description of the Related Art In recent years, electric vehicles have made remarkable progress from the viewpoint of environmental protection. As tires used in such electric vehicles, rolling resistance is reduced and fuel consumption is improved in order to increase the mileage per charge. Savings are required.
【０００３】特に電気三輪自動車の後輪タイヤは、負担
荷重も大きく、転がり抵抗を減じ操縦安定性を向上する
ことに加え、耐摩耗性を高めることが望まれる。Particularly, the rear wheel tire of an electric three-wheeled vehicle has a large load, and it is desired that the rolling resistance be reduced to improve the steering stability and the wear resistance be enhanced.
【０００４】他方、空気入りタイヤにおいてはタイヤ内
圧を高めることにより、接地面積を減じかつ接地時にお
けるトレッド部の変形量を少なくすることにより、走行
時の転がり抵抗を減じることが知られている。又転がり
抵抗の低減には、圧縮剛性の高いトレッドパターンを構
成する必要があること、即ちトレッド溝が少ないトレッ
ドパターンが有利であることも判明している。On the other hand, in a pneumatic tire, it is known that by increasing the tire internal pressure, the ground contact area is reduced and the deformation amount of the tread portion during ground contact is reduced, thereby reducing the rolling resistance during running. It has also been found that it is necessary to form a tread pattern having high compression rigidity, that is, a tread pattern having a small number of tread grooves is advantageous for reducing rolling resistance.
【０００５】従来、このような高内圧で使用されるタイ
ヤｔは、図３に示すように、トレッド面ａを、タイヤ赤
道面点を通りかつカーカスの曲率半径ｒ２よりも大きい
曲率半径ｒ１の単一の円弧によって形成している。ま
た、そのトレッド幅ｄをタイヤの総幅ｗの０．８〜１．
２倍の広幅に形成していた。Conventionally, as shown in FIG. 3, a tire t used at such a high internal pressure has a tread surface a passing through the tire equatorial plane point and having a single radius of curvature r1 larger than the radius of curvature r2 of the carcass. It is formed by one arc. Moreover, the tread width d is 0.8 to 1.
It was formed twice as wide.
【０００６】又従来のタイヤｔのトレッド面ａには、図
４に示すように、比較的広幅の縦溝ｇ１…と横溝ｇ２…
とによってトレッドパターンが設けられていた。Further, on the tread surface a of the conventional tire t, as shown in FIG. 4, a relatively wide vertical groove g1 and lateral groove g2.
The tread pattern was provided by and.
【０００７】[0007]
【発明が解決しようとする課題】しかしこのように、ト
レッド部を広幅にかつトレッド面ａを単一の曲率半径ｒ
１からなる円弧によって形成した場合には、トレッド面
ａにおける接地圧力の分布のバラツキが大となるため、
走行中に接地領域においてすべりが生じることにより操
縦安定性が低下し転がり抵抗を増大させるという問題点
がある。又溝容積の増大によって転がり抵抗が増すこと
にもなる一方、トレッドゴム量が増大しタイヤ重量を重
くする。However, as described above, the tread portion is wide and the tread surface a has a single radius of curvature r.
When it is formed by a circular arc consisting of 1, there is a large variation in the distribution of the ground contact pressure on the tread surface a.
There is a problem in that steering stability is lowered and rolling resistance is increased due to slippage in the ground contact area during traveling. Further, while the rolling resistance increases due to the increase in groove volume, the tread rubber amount increases and the tire weight increases.
【０００８】発明者らはタイヤの軸方向断面におけるト
レッド幅を従来のものより狭くするとともに、トレッド
面の曲率半径をカーカスのそれとほぼ同じにすることに
よってトレッド部の動きを抑制し、操縦安定性を向上し
つつ転がり抵抗及びタイヤ重量を減じうることを見出し
本発明を完成させたのである。The inventors have made the tread width in the axial cross section of the tire narrower than that of the conventional one, and suppress the movement of the tread portion by making the radius of curvature of the tread surface almost the same as that of the carcass, thereby improving steering stability. The inventors have found that the rolling resistance and the weight of the tire can be reduced while improving the above-mentioned properties, and have completed the present invention.
【０００９】本発明は、操縦安定性を向上しつつ転がり
抵抗を減じかつタイヤの重量の軽減を可能とすることに
よって、燃費を節減しうる電気自動車用空気入りラジア
ルタイヤの提供を目的としている。An object of the present invention is to provide a pneumatic radial tire for an electric vehicle, which is capable of reducing rolling resistance and weight of the tire while improving steering stability and thereby reducing fuel consumption.
【００１０】[0010]
【課題を解決するための手段】本発明は、トレッド部か
らサイドウォール部を通りビード部のビードコアの廻り
をタイヤ軸方向内側から外側に折返す有機繊維コードを
用いた２枚のカーカスプライからなるラジアル配列のカ
ーカスと、トレッド部の内部かつカーカスの半径方向外
側に配されかつタイヤ赤道に対して１６°〜２０°の角
度で傾く有機繊維コードからなるベルトコードを有する
１枚のカットプライからなるベルト層と、このベルト層
の半径方向外側に配されかつ有機繊維コードからなるバ
ンドコードをタイヤ赤道に対してほぼ平行に配列したバ
ンド層とを具える電気自動車用空気入りラジアルタイヤ
であって、正規リムに装着しかつ規定の最大内圧を充填
した正規状態において、規定の最大荷重を付加したとき
にタイヤが接地するトレッド面の外縁間のタイヤ軸方向
の長さであるトレッド幅ＴＷは、タイヤの総幅ＡＷの
０．３〜０．６倍であり、タイヤ軸を含む子午断面にお
いて、トレッド面の曲率半径ＲＴをカーカスのトレッド
部での曲率半径ＲＣの０．９５〜１．０５倍としてい
る。SUMMARY OF THE INVENTION The present invention comprises two carcass plies using an organic fiber cord which returns from the tread portion to the sidewall portion and around the bead core of the bead portion from the inner side toward the outer side in the tire axial direction. It consists of a carcass of radial arrangement and one cut ply having a belt cord made of an organic fiber cord arranged inside the tread portion and radially outside the carcass and inclined at an angle of 16 ° to 20 ° with respect to the tire equator. A pneumatic radial tire for an electric vehicle, comprising a belt layer and a band layer arranged on the outer side in the radial direction of the belt layer and having band cords made of organic fiber cords arranged substantially parallel to the tire equator, When the tire is grounded when a specified maximum load is applied in a normal state where the tire is attached to the normal rim and filled with the specified maximum internal pressure. The tread width TW, which is the length in the tire axial direction between the outer edges of the tread surface, is 0.3 to 0.6 times the total width AW of the tire, and the radius of curvature RT of the tread surface is RT in the meridional section including the tire axis. Is 0.95 to 1.05 times the radius of curvature RC at the tread portion of the carcass.
【００１１】なお前記トレッド面に、タイヤ軸方向に対
して０°〜３０°の角度θで傾くサイピングを周方向に
隔設するとともに、このサイピングのタイヤ赤道におけ
る深さＤＡ、前記外縁における深さＤＢを、夫々前記バ
ンド層の半径方向外面からトレッド面までのタイヤ赤
道、外縁におけるトレッド厚さＴＣ、ＴＳの０．３〜
０．５倍とすることが望ましい。The tread surface has circumferentially spaced sipings inclined at an angle θ of 0 ° to 30 ° with respect to the tire axial direction, and the depth DA of the sipings at the tire equator and the depth at the outer edge thereof. DB is the tire equator from the outer surface in the radial direction of the band layer to the tread surface, the tread thickness TC at the outer edge, and TS of 0.3 to 0.3.
It is desirable to set it to 0.5 times.
【００１２】[0012]
【作用】トレッド面の接地するトレッド幅ＴＷをタイヤ
の総幅ＡＷの０．３〜０．６倍とすることにより、トレ
ッド幅ＴＷを狭くすることができ、高内圧の加重によっ
てトレッド面における接地圧力の分布を均一化しうるた
め、走行中に接地領域においてすべりが生じることな
く、操縦安定性、及びグリップ性能を向上しうるととも
に、転がり抵抗を減じうる。The tread width TW can be narrowed by setting the tread width TW at which the tread surface touches the ground to 0.3 to 0.6 times the total width AW of the tire, and the tread surface touches the ground due to the high internal pressure. Since the pressure distribution can be made uniform, slipping does not occur in the ground contact area during traveling, the steering stability and the grip performance can be improved, and the rolling resistance can be reduced.
【００１３】なお比ＴＷ／ＡＷを０．３よりも小さくす
ると、接地領域の面積が過小となり、接地圧が増大する
結果、耐摩耗性に劣り、トレッド面の外縁における肩落
ち摩耗により耐久性が低下する。逆に０．６よりも大き
いと、図３に示す従来のタイヤｔに近づき、接地領域に
すべりが生じ転がり抵抗が増大する。When the ratio TW / AW is smaller than 0.3, the area of the ground contact area becomes too small and the ground contact pressure increases, resulting in poor wear resistance and durability due to shoulder drop wear at the outer edge of the tread surface. descend. On the other hand, when it is larger than 0.6, the tire approaches the conventional tire t shown in FIG. 3, slipping occurs in the ground contact area, and rolling resistance increases.
【００１４】又トレッド面の曲率半径ＲＴ（正規リムに
装着しかつ規定の最大内圧を充填したとき）をカーカス
のトレッド部での曲率半径ＲＣの０．９５〜１．０５倍
としているため、ショルダー部の断面厚さを薄くできタ
イヤ重量を軽減しうるとともに、接地領域を矩形状に形
成でき、タイヤ赤道とトレッド面の外縁とにおける周速
度のズレを僅少化しうる結果、転がり抵抗を一層減じう
る。Since the radius of curvature RT of the tread surface (when mounted on the regular rim and filled with the specified maximum internal pressure) is 0.95 to 1.05 times the radius of curvature RC of the tread portion of the carcass, the shoulder The cross-sectional thickness of the part can be reduced to reduce the weight of the tire, and the ground contact area can be formed in a rectangular shape, so that the deviation of the peripheral speed between the tire equator and the outer edge of the tread surface can be minimized, and the rolling resistance can be further reduced. .
【００１５】なお前記曲率半径ＲＴが曲率半径ＲＣの
０．９５倍未満では、タイヤが接地する面がバットレス
面に及びやすく、タイヤ軸方向の接地幅が大となるた
め、接地領域における中央部と縁部とにおいて周長さの
差が大きくなる結果、走行時にすべりが生じ転がり抵抗
を増大する。If the radius of curvature RT is less than 0.95 times the radius of curvature RC, the surface on which the tire contacts the ground is likely to reach the buttress surface, and the contact width in the axial direction of the tire becomes large. As a result of the large difference in peripheral length between the edge portion and the edge portion, slippage occurs during traveling and rolling resistance increases.
【００１６】逆に１．０５倍よりも大きくすると、ショ
ルダー部でのゴム厚さが大きくなり、タイヤ重量の軽減
を達成できない。On the other hand, if it is larger than 1.05 times, the rubber thickness at the shoulder portion becomes large, and the weight reduction of the tire cannot be achieved.
【００１７】さらにトレッド面に、タイヤ軸方向に対し
て０°〜３０°の角度θで傾くサイピングを周方向に隔
設したときには、グリップ性能を確保しつつトレッド溝
の容積を減少でき、転がり抵抗を減じうるとともに、耐
摩耗性を向上しうる。Further, when sipings inclined at an angle θ of 0 ° to 30 ° with respect to the tire axial direction are provided on the tread surface in the circumferential direction, the volume of the tread groove can be reduced while ensuring gripping performance, and rolling resistance can be improved. And wear resistance can be improved.
【００１８】前記角度θを３０°よりも大きくすると、
接地面におけるグリップ性能が劣りがちとなり、操縦安
定性の低下を招く。When the angle θ is larger than 30 °,
The grip performance on the ground contact surface tends to be poor, leading to a reduction in steering stability.
【００１９】又前記サイピングのタイヤ赤道における深
さＤＡをタイヤ赤道におけるバンド層からトレッド面ま
でのトレッド厚さＴＣの０．３〜０．５倍、サイピング
のトレッド面外縁における深さＤＢを該外縁におけるト
レッド厚さＴＳの０．３〜０．５倍とすることにより、
グリップ性能と耐摩耗性とを両立してバランスよく向上
しうる。The depth DA at the tire equator of the sipe is 0.3 to 0.5 times the tread thickness TC from the band layer to the tread surface at the tire equator, and the depth DB at the outer edge of the tread surface of the sipe is the outer edge. By 0.3 to 0.5 times the tread thickness TS in
Both grip performance and wear resistance can be improved in a well-balanced manner.
【００２０】前記深さＤＡ、ＤＢがトレッド厚さＴＣ、
ＴＳの０．３倍よりも小さいと、グリップ力が不足し、
牽引力及び制動性能に劣る一方、０．５倍をこえると、
走行中のトレッド部の変形が大きくなり、ヒールアンド
トウ摩耗などの偏摩耗が生じやすい。The depths DA and DB are tread thickness TC,
If it is smaller than 0.3 times TS, the grip power will be insufficient,
While it is inferior in traction force and braking performance, if it exceeds 0.5 times,
Deformation of the tread during running becomes large, and uneven wear such as heel and toe wear easily occurs.
【００２１】このように本発明は前記した構成が有機的
に結合することにより、操縦安定性及びグリップ性能を
向上しつつ転がり抵抗を減じかつタイヤ重量の軽減が可
能となり、燃費を節減しうるとともに、耐摩耗性を高め
ることができ、特に電気三輪自動車の後輪タイヤとして
好適に採用しうる。As described above, according to the present invention, by organically combining the above-mentioned constitutions, it becomes possible to reduce rolling resistance and tire weight while improving steering stability and grip performance, and to reduce fuel consumption. In addition, the wear resistance can be enhanced, and it can be suitably used particularly as a rear wheel tire of an electric three-wheeled vehicle.
【００２２】[0022]
【実施例】以下本発明の一実施例を図面に基づき説明す
る。図１、図２において本発明の電気自動車用空気入り
ラジアルタイヤ１は、トレッド部２と、その両端から半
径方向内方に向けてのびるサイドウォール部３、３と、
該サイドウォール部３、３の半径方向内側に設けられる
ビード部４、４とを有するとともに、前記トレッド部２
からサイドウォール部３を通りビード部４のビードコア
５の廻りを折返すカーカス６と、トレッド部２の内部か
つカーカス６の半径方向外側に配されるベルト層７と、
このベルト層７の半径方向外側に配されるバンド層９と
を具える。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, a pneumatic radial tire 1 for an electric vehicle according to the present invention includes a tread portion 2, sidewall portions 3 and 3 extending inward in a radial direction from both ends thereof,
The tread portion 2 has a bead portion 4 and 4 provided inside the sidewall portions 3 and 3 in the radial direction.
A carcass 6 which passes through the sidewall part 3 and folds around the bead core 5 of the bead part 4, and a belt layer 7 which is arranged inside the tread part 2 and on the outer side in the radial direction of the carcass 6,
The belt layer 7 is provided on the outer side in the radial direction of the belt layer 7.
【００２３】カーカス６は、ビードコア５の廻りをタイ
ヤ軸方向内側から外側に向かって巻上げられる２枚のカ
ーカスプライ６Ａ、６Ｂからなり、カーカスプライ６
Ａ、６Ｂは、ナイロン、ポリエステル、芳香族ポリアミ
ド等の有機繊維からなるカーカスコードをタイヤ赤道Ｃ
に対して７０〜９０°の角度で傾けたラジアル配列又は
セミラジアル配列をなす。なお２枚のカーカスプライ６
Ａ、６Ｂの各カーカスコードは互いに交差する向きに配
される。The carcass 6 comprises two carcass plies 6A and 6B which are wound around the bead core 5 from the inner side to the outer side in the tire axial direction.
A and 6B are carcass cords made of organic fibers such as nylon, polyester, and aromatic polyamide, and tire equator C.
To form a radial arrangement or a semi-radial arrangement inclined at an angle of 70 to 90 degrees with respect to. Two carcass plies 6
The carcass cords A and 6B are arranged so as to intersect with each other.
【００２４】又電気自動車用空気入りラジアルタイヤ１
は、正規リムに装着しかつ規定の最大内圧を充填した正
規状態において、規定の最大荷重を付加したときにトレ
ッド部２が平坦路面に接地するトレッド面２Ａのタイヤ
軸方向外縁Ｅ、Ｅ間の長さであるトレッド幅ＴＷを、Ｊ
ＩＳ Ｄ４２０２ 自動車用タイヤの諸元の用語である
タイヤの総幅ＡＷの０．３倍以上かつ０．６倍以下とし
ている。A pneumatic radial tire for an electric vehicle 1
Is a tire axial direction outer edge E of the tread surface 2A where the tread portion 2 comes into contact with a flat road surface when a specified maximum load is applied in a normal state in which the tire is mounted on a normal rim and filled with a specified maximum internal pressure. The tread width TW that is the length is J
IS D4202 It is set to 0.3 times or more and 0.6 times or less of the total width AW of the tire, which is a term used for specifications of automobile tires.
【００２５】又タイヤ最大幅位置Ｍよりも半径方向外側
のタイヤ軸を含む子午断面の輪郭は、トレッド面２Ａを
なす第１の円弧Ｋ１と、曲率半径Ｒ２の円弧からなりバ
ットレス面１０を形成する第２の円弧Ｋ２と、タイヤ外
方に中心を有する曲率半径Ｒ３の円弧からなりかつ第２
の円弧Ｋ２に滑らかに連なるとともに前記外縁Ｅにのび
る第３の円弧Ｋ３とによって形成される。The contour of the meridional section including the tire axis radially outside the maximum tire width position M is composed of a first arc K1 forming the tread surface 2A and an arc having a radius of curvature R2 to form the buttress surface 10. A second arc K2 and an arc having a radius of curvature R3 centered on the outside of the tire, and
Is formed by a third arc K3 that is smoothly connected to the arc K2 and extends to the outer edge E.
【００２６】前記トレッド面２Ａをなす第１の円弧Ｋ１
は、タイヤ軸を含む子午断面において、タイヤ赤道Ｃ上
に中心点を有するカーカス６の厚さ中間位置を通る円弧
のトレッド部２での曲率半径ＲＣの０．９５倍以上かつ
１．０５倍以下の曲率半径ＲＴを有する。A first arc K1 forming the tread surface 2A
Is 0.95 times or more and 1.05 times or less of the radius of curvature RC at the tread portion 2 of the arc passing through the middle thickness position of the carcass 6 having the center point on the tire equator C in the meridional section including the tire axis. With a radius of curvature RT of
【００２７】このようにトレッド面２Ａ（第１の円弧Ｋ
１）の曲率半径ＲＴをカーカス６の曲率半径ＲＣの０．
９５〜１．０５倍とすることによってバットレス面１０
を形成するゴム量を少なくでき、タイヤ重量を軽減しう
るとともに、接地領域の拡がりを安定化しうるため、転
がり抵抗を減じることが出来る。Thus, the tread surface 2A (first arc K
The radius of curvature RT of 1) is 0.
95 to 1.05 times buttress surface 10
It is possible to reduce the amount of rubber forming the tire, reduce the weight of the tire, and stabilize the spread of the ground contact area, so that it is possible to reduce the rolling resistance.
【００２８】又トレッド部２のトレッド面２Ａ及びバッ
トレス面１０を形成する表面のゴム層のゴム硬度はＪＩ
ＳＡ硬度で５５〜７０°の範囲とするのが好ましい。The rubber hardness of the rubber layer on the surface forming the tread surface 2A of the tread portion 2 and the buttress surface 10 is JI.
The SA hardness is preferably in the range of 55 to 70 °.
【００２９】さらにバットレス面１０の第２の円弧Ｋ２
の曲率半径Ｒ２は、前記カーカス６のトレッド部２での
前記曲率半径ＲＣを有する円弧と略同一中心を有する円
弧の半径とするのがよい。Further, the second arc K2 of the buttress surface 10
The radius of curvature R2 is preferably the radius of an arc having substantially the same center as the arc having the radius of curvature RC in the tread portion 2 of the carcass 6.
【００３０】又前記ベルト層７は、１枚のベルトプライ
からなるとともに、ベルトプライとして、ナイロン、ポ
リエステル、芳香族ポリアミド等の有機繊維からなるベ
ルトコードをタイヤ赤道Ｃに対して１６°以上かつ２０
°以下の角度で傾けたカットプライ７Ａが用いられる。The belt layer 7 is composed of one belt ply, and a belt cord made of an organic fiber such as nylon, polyester or aromatic polyamide is used as the belt ply at 16 ° or more with respect to the tire equator C and 20.
The cut ply 7A tilted at an angle equal to or less than ° is used.
【００３１】なお前記カットプライ７Ａのタイヤ軸方向
外縁Ｆ、Ｆは、前記トレッド面２Ａの外縁Ｅ、Ｅの半径
方向内方近傍に位置させるとともに、該外縁Ｆ、Ｆ間の
タイヤ軸方向のベルト幅ＢＷは、前記トレッド幅ＴＷの
１．１倍以上かつ１．３倍以下として、トレッド幅ＴＷ
よりも広くするのがトレッドゴムの動きを抑制し、転が
り抵抗を減じるために好ましい。しかしながら、ベルト
幅ＢＷをトレッド幅ＴＷの１．３倍よりも大きくする
と、トレッド部２の剛性が過度に大きくなり、乗心地性
能等を低下させる。The outer edges F, F of the cut ply 7A in the axial direction of the tire are located near the inner edges of the outer edges E, E of the tread surface 2A in the radial direction, and the belt in the axial direction of the tire between the outer edges F, F. The width BW is 1.1 times or more and 1.3 times or less of the tread width TW, and the tread width TW
It is preferable to make the width wider than that in order to suppress the movement of the tread rubber and reduce the rolling resistance. However, if the belt width BW is made larger than 1.3 times the tread width TW, the rigidity of the tread portion 2 becomes excessively large, which deteriorates riding comfort performance and the like.
【００３２】前記バンド層９は、ナイロン、ポリエステ
ル、芳香族ポリアミド等の有機繊維からなるバンドコー
ドをタイヤ赤道Ｃに対して０°〜５°の角度でほぼ平行
に配列したバンドプライ９Ａ（カットバンド）を、周方
向に１〜２回巻回させることにより形成される。The band layer 9 is a band ply 9A (cut band) in which band cords made of organic fibers such as nylon, polyester, and aromatic polyamide are arranged substantially parallel to the tire equator C at an angle of 0 ° to 5 °. ) Is wound one to two times in the circumferential direction.
【００３３】なお１本以上の平行なバンドコードをゴム
被覆した帯状の長尺プライを前記ベルト層７の一方の外
縁Ｆ近傍を起点として、他方の外縁Ｆ近傍に至る間、タ
イヤ赤道Ｃと略平行に連続して螺旋巻きすることにより
バンドプライ９Ａ（スパイラルバンド）を形成すること
もできる。The belt-shaped long ply having one or more parallel band cords covered with rubber starts from the vicinity of one outer edge F of the belt layer 7 and extends to the vicinity of the other outer edge F and is substantially called the tire equator C. The band ply 9A (spiral band) can also be formed by continuously spirally winding in parallel.
【００３４】又バンド層９のタイヤ軸方向の外縁間の長
さであるバンド幅ＤＷは、前記トレッド幅ＴＷの０．８
倍以上かつ１．０倍以下とするのがよい。０．８倍未満
では、トレッド部２の剛性が不足しがちとなり、接地領
域の不均一性が増し、転がり抵抗を増大させる原因とな
る一方、１．０倍をこえるとトレッド部２の剛性を過度
に高める。The band width DW, which is the length between the outer edges of the band layer 9 in the tire axial direction, is 0.8 of the tread width TW.
It is preferable that the number is at least twice and at most 1.0 times. If it is less than 0.8 times, the rigidity of the tread portion 2 tends to be insufficient, and the non-uniformity of the ground contact area is increased, which causes an increase in rolling resistance. On the other hand, if it exceeds 1.0 times, the rigidity of the tread portion 2 is increased. Increase excessively.
【００３５】さらに前記トレッド面２Ａには、図２に示
すように、タイヤ赤道Ｃを挟んで対称にタイヤ軸方向に
Ｖ字にのびるサイピング１２が周方向に隔設される。サ
イピング１２は、タイヤ軸方向に対して０°以上かつ３
０°以下の角度θで傾くとともに、タイヤ赤道Ｃ両側に
おいて周方向に並ぶ各サイピング１２を互いに平行と
し、図４に示した従来のトレッドパターンに比して耐摩
耗性を向上しうる。Further, as shown in FIG. 2, on the tread surface 2A, sipings 12 extending in a V-shape symmetrically across the tire equator C in the tire axial direction are circumferentially spaced. The siping 12 is 0 ° or more and 3 with respect to the tire axial direction.
While inclining at an angle θ of 0 ° or less and making the sipes 12 arranged in the circumferential direction on both sides of the tire equator C parallel to each other, wear resistance can be improved as compared with the conventional tread pattern shown in FIG.
【００３６】又前記サイピング１２のタイヤ赤道Ｃにお
ける深さＤＡを、タイヤ赤道Ｃにおける前記バンド層９
の半径方向外面からトレッド面２Ａまでの長さであるト
レッド厚さＴＣの０．３倍以上かつ０．５倍以下とする
とともに、サイピング１２の前記外縁Ｅにおける深さＤ
Ｂを、該外縁Ｅにおけるトレッド厚さＴＳの０．３倍以
上かつ０．５倍以下としている。Further, the depth DA of the siping 12 at the tire equator C is defined by the band layer 9 at the tire equator C.
Of the tread thickness TC, which is the length from the outer surface in the radial direction to the tread surface 2A, of 0.3 times or more and 0.5 times or less, and the depth D of the siping 12 at the outer edge E.
B is 0.3 times or more and 0.5 times or less of the tread thickness TS at the outer edge E.
【００３７】なお前記トレッド厚さＴＳは、外縁Ｅにお
いてバンド層９若しくはバンド層９が外縁Ｅまで延在し
ないときベルト層７の半径方向外面とトレッド面２Ａと
の間の距離である。又前記サイピング１２の巾は１．０
mm程度に設定されるとともに、溝底は凹凸なく滑らかに
連なる。The tread thickness TS is the distance between the band layer 9 at the outer edge E or the radially outer surface of the belt layer 7 and the tread surface 2A when the band layer 9 does not extend to the outer edge E. The width of the siping 12 is 1.0
It is set to about mm and the groove bottoms are smooth and continuous.
【００３８】又前記サイピング１２は、トレッド面２Ａ
の一方の外縁Ｅから他方の外縁Ｅまで一直線状に形成さ
れてもよい。（これを仮にストレートサイプという。Ｖ
字に折曲がるものをＶ字サイプという。）The siping 12 has a tread surface 2A.
It may be formed in a straight line from one outer edge E to the other outer edge E. (This is called straight sipe. V
What bends in a letter is called a V-shaped sipe. )
【００３９】[0039]
【具体例】タイヤサイズが１３０／７０Ｒ８でありかつ
図１に示す構成で表１、表２に示す仕様にて実施例タイ
ヤ１〜５を試作するとともにその性能をテストした。な
お図３、図４に示す構成で表１、表２に示す仕様にて従
来例タイヤを、又本発明外の比較例タイヤ１〜５を夫々
試作、テストし、その性能を比較した。SPECIFIC EXAMPLE Tires 1 to 5 of Example 1 having a tire size of 130 / 70R8 and the configuration shown in FIG. 1 and the specifications shown in Table 1 and Table 2 were tested and their performances were tested. The conventional tires having the configurations shown in FIGS. 3 and 4 and the specifications shown in Tables 1 and 2 and the comparative tires 1 to 5 other than the present invention were prototyped and tested, and their performances were compared.
【００４０】[0040]
【表１】 [Table 1]
【００４１】[0041]
【表２】[Table 2]
【００４２】テストは下記要領で行った。 （１）転がり抵抗 転動抵抗試験機を用いて測定し、従来例を１００とする
指数で示した。数値が大きいほど転がり抵抗が少なく良
好である。The test was conducted as follows. (1) Rolling resistance The rolling resistance was measured by using a rolling resistance tester and shown by an index with the conventional example being 100. The larger the value, the less rolling resistance the better.
【００４３】（２）操縦安定性 電気三輪自動車の後輪に装着し、テストコースを周回さ
せるとともに、ドライバーのフィーリングにより判定す
るとともに、従来例を１００とする指数で表示した。数
値が大きいほど良好であることを示す。(2) Steering Stability It was mounted on the rear wheels of an electric three-wheeled vehicle, orbited around the test course, judged by the driver's feeling, and displayed with an index of 100 as the conventional example. The larger the value, the better.
【００４４】（３）耐摩耗性 試供タイヤを電気三輪自動車の後輪に装着し、規定され
る最大荷重を加えてテストコースを６０km／Ｈの速度で
走行させた後、サイピング或いは溝の残深さを測定し、
従来例を１００とする指数で表示した。なおテストに際
してタイヤの接地は乾燥状態で行った。(3) Abrasion resistance After mounting a test tire on the rear wheel of an electric three-wheeled vehicle and running the test course at a speed of 60 km / H with a specified maximum load, the remaining depth of the siping or groove is measured. Measure the
The index is represented by an index with the conventional example being 100. In the test, the tire was grounded in a dry state.
【００４５】（４）グリップ性能 前記テスト車両をテストコースにおいて走行させるとと
もに、直進安定性、応答性、レーンチェンジの際の収斂
性及び接地性などを官能評価し、従来例を１００とする
指数で表示した。数値が大きいほど良好であることを示
す。(4) Grip performance While running the test vehicle on a test course, sensory evaluation of straight running stability, responsiveness, convergence and ground contact at the time of lane change, etc. was carried out. displayed. The larger the value, the better.
【００４６】タイヤ重量も併せて測定し、従来例を１０
０とする指数で示した。数値が小さいほど軽量である。
テスト結果を表２に示す。The tire weight was also measured.
It was shown by an index of 0. The smaller the value, the lighter the weight.
The test results are shown in Table 2.
【００４７】テストの結果、実施例のものは従来例、比
較例のものに比べて、転がり抵抗が小であり、かつタイ
ヤ重量を軽減するとともに操縦安定性、耐摩耗性、グリ
ップ性能を向上していることが確認できた。As a result of the test, compared with the conventional example and the comparative example, the rolling resistance of the example is smaller, the weight of the tire is reduced, and the steering stability, wear resistance and grip performance are improved. I was able to confirm.
【００４８】[0048]
【発明の効果】叙上の如く本発明の電気自動車用空気入
りラジアルタイヤは、操縦安定性を向上しつつ転がり抵
抗を減じうるとともに、タイヤ重量を軽減でき、燃費を
節減しうる。INDUSTRIAL APPLICABILITY As described above, the pneumatic radial tire for an electric vehicle according to the present invention can reduce rolling resistance while improving steering stability, can reduce tire weight, and can reduce fuel consumption.
【図１】本発明の一実施例を示すタイヤ子午断面図であ
る。FIG. 1 is a meridian sectional view of a tire showing an embodiment of the present invention.
【図２】そのトレッドパターンの一例を示す平面図であ
る。FIG. 2 is a plan view showing an example of the tread pattern.
【図３】従来のタイヤを示す断面図である。FIG. 3 is a cross-sectional view showing a conventional tire.
【図４】そのトレッドパターンを示す平面図である。FIG. 4 is a plan view showing the tread pattern.
２ トレッド部 ２Ａ トレッド面 ３ サイドウォール部 ４ ビード部 ５ ビードコア ６ カーカス ７ ベルト層 ９ バンド層 １２ サイピング 2 tread part 2A tread surface 3 sidewall part 4 bead part 5 bead core 6 carcass 7 belt layer 9 band layer 12 siping
【表２】 [Table 2]
【表２】 [Table 2]
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｂ６０Ｃ 11/04 11/12 Ａ 8408−3Ｄ Ｂ 8408−3Ｄ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI technical display location B60C 11/04 11/12 A 8408-3D B 8408-3D
Claims (2)
ード部のビードコアの廻りをタイヤ軸方向内側から外側
に折返す有機繊維コードを用いた２枚のカーカスプライ
からなるラジアル配列のカーカスと、トレッド部の内部
かつカーカスの半径方向外側に配されかつタイヤ赤道に
対して１６°〜２０°の角度で傾く有機繊維コードから
なるベルトコードを有する１枚のカットプライからなる
ベルト層と、このベルト層の半径方向外側に配されかつ
有機繊維コードからなるバンドコードをタイヤ赤道に対
してほぼ平行に配列したバンド層とを具える電気自動車
用空気入りラジアルタイヤであって、 正規リムに装着しかつ規定の最大内圧を充填した正規状
態において、規定の最大荷重を付加したときにタイヤが
接地するトレッド面の外縁間のタイヤ軸方向の長さであ
るトレッド幅ＴＷは、タイヤの総幅ＡＷの０．３〜０．
６倍であり、 タイヤ軸を含む子午断面において、トレッド面の曲率半
径ＲＴをカーカスのトレッド部での曲率半径ＲＣの０．
９５〜１．０５倍としたことを特徴とする電気自動車用
空気入りラジアルタイヤ。1. A carcass of a radial arrangement comprising two carcass plies using an organic fiber cord in which a bead core of a bead part is folded back from the inner side in the tire axial direction to the outer side through a sidewall part from a tread part, and a tread part. A belt layer consisting of a single cut ply having a belt cord made of an organic fiber cord which is arranged inside the carcass and outside in the radial direction of the carcass and is inclined at an angle of 16 ° to 20 ° with respect to the tire equator; A pneumatic radial tire for an electric vehicle, which comprises a band layer arranged on the outer side in the radial direction and made of an organic fiber cord and arranged substantially parallel to the tire equator. In a normal state filled with maximum internal pressure, the tie between the outer edges of the tread surface where the tire touches the ground when a specified maximum load is applied. Tread width TW in the axial direction is the length is from 0.3 to 0 of the total width AW of the tire.
In the meridional section including the tire axis, the radius of curvature RT of the tread surface is 0.
A pneumatic radial tire for an electric vehicle, characterized by having a ratio of 95 to 1.05 times.
０°〜３０°の角度θで傾くサイピングを周方向に隔設
するとともに、このサイピングのタイヤ赤道における深
さＤＡ、前記外縁における深さＤＢを、夫々前記バンド
層の半径方向外面からトレッド面までのタイヤ赤道、外
縁におけるトレッド厚さＴＣ、ＴＳの０．３〜０．５倍
としたことを特徴とする請求項１記載の電気自動車用空
気入りラジアルタイヤ。2. The tread surface has circumferentially spaced sipings inclined at an angle θ of 0 ° to 30 ° with respect to the tire axial direction, and the depth DA of the sipings at the tire equator and the depth at the outer edge thereof. 2. The electricity DB according to claim 1, wherein the height DB is 0.3 to 0.5 times the tire equator from the radially outer surface of the band layer to the tread surface, and the tread thickness TC and TS at the outer edge, respectively. Pneumatic radial tires for automobiles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35069293A JP3308086B2 (en) | 1993-12-29 | 1993-12-29 | Pneumatic radial tire for electric vehicles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35069293A JP3308086B2 (en) | 1993-12-29 | 1993-12-29 | Pneumatic radial tire for electric vehicles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07195908A true JPH07195908A (en) | 1995-08-01 |
| JP3308086B2 JP3308086B2 (en) | 2002-07-29 |
Family
ID=18412200
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35069293A Expired - Fee Related JP3308086B2 (en) | 1993-12-29 | 1993-12-29 | Pneumatic radial tire for electric vehicles |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3308086B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010260378A (en) * | 2009-04-30 | 2010-11-18 | Yokohama Rubber Co Ltd:The | Pneumatic tire |
| CN112055663A (en) * | 2018-05-09 | 2020-12-08 | 横滨橡胶株式会社 | Pneumatic tire |
| WO2021251166A1 (en) * | 2020-06-08 | 2021-12-16 | 株式会社ブリヂストン | Pneumatic tire |
-
1993
- 1993-12-29 JP JP35069293A patent/JP3308086B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010260378A (en) * | 2009-04-30 | 2010-11-18 | Yokohama Rubber Co Ltd:The | Pneumatic tire |
| CN112055663A (en) * | 2018-05-09 | 2020-12-08 | 横滨橡胶株式会社 | Pneumatic tire |
| CN112055663B (en) * | 2018-05-09 | 2022-08-12 | 横滨橡胶株式会社 | Pneumatic tire |
| WO2021251166A1 (en) * | 2020-06-08 | 2021-12-16 | 株式会社ブリヂストン | Pneumatic tire |
| JP2021193008A (en) * | 2020-06-08 | 2021-12-23 | 株式会社ブリヂストン | Pneumatic tire |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3308086B2 (en) | 2002-07-29 |
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