WO2020054798A1 - Pneu radial - Google Patents

Pneu radial Download PDF

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Publication number
WO2020054798A1
WO2020054798A1 PCT/JP2019/035875 JP2019035875W WO2020054798A1 WO 2020054798 A1 WO2020054798 A1 WO 2020054798A1 JP 2019035875 W JP2019035875 W JP 2019035875W WO 2020054798 A1 WO2020054798 A1 WO 2020054798A1
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WO
WIPO (PCT)
Prior art keywords
tire
belt layer
radial
layers
tread
Prior art date
Application number
PCT/JP2019/035875
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English (en)
Japanese (ja)
Inventor
喜宏 多田
中村　圭介
Original Assignee
株式会社ブリヂストン
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 株式会社ブリヂストン filed Critical 株式会社ブリヂストン
Publication of WO2020054798A1 publication Critical patent/WO2020054798A1/fr

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    • 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
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • 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
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
    • 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
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
    • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel

Definitions

  • the present invention relates to a radial tire having improved durability against cuts caused by foreign matter and the like and further having improved uneven wear resistance, particularly to a radial tire for an aircraft.
  • Conventional radial tires (hereinafter, also simply referred to as tires), particularly radial tires for aircraft, are liable to increase the tread tread surface in the radial direction of the tire due to the action of high internal pressure and centrifugal force during high-speed rotation of the tire.
  • the tread tread protrudes in the tire radial direction, the tread rubber forming the tread is stretched in the tire circumferential direction.
  • the radial tire for aircraft is used under the condition of high internal pressure and high load, so that the tread is likely to be damaged due to the entire tire riding on the foreign matter when passing over the foreign matter.
  • a stepped foreign substance easily enters the inside of the tread, and the tire is easily damaged.
  • tire fragments generated by tire damage may damage the aircraft body. Therefore, improving the durability against cuts caused by foreign matters, that is, the cut resistance, is a very important issue especially for aircraft tires.
  • the protrusion amount at the center in the width direction of the tread tends to be larger than the vicinity of both ends in the tread width direction. This leads to a partial drag phenomenon. As a result, so-called uneven wear may occur in the vicinity of the shoulder portion of the tire, which wears earlier than in the center portion in the tire width direction and shortens the life of the tire.
  • Patent Literature 1 describes a tire in which a main belt layer and an intersecting belt layer are sequentially formed on a radially outer side of a carcass.
  • the main belt layer is formed radially outside the crown portion of the carcass to suppress the tread tread from protruding in the tire radial direction, so that cut resistance and uneven wear resistance are reduced. Are satisfied. Furthermore, by arranging the intersecting belt layer on the outer side in the tire radial direction of the main belt layer, foreign substances are prevented from reaching the main belt layer, and the cut resistance is improved by suppressing the progress of cut scratches, The main belt layer is protected to maintain the effect of suppressing uneven wear.
  • a nylon cord is used for the intersecting belt layer. That is, since the nylon cord is excellent in adhesiveness to rubber and fatigue resistance, it is often applied not only to the technique described in Patent Literature 1 but also to a cross belt of an aircraft tire.
  • the intersecting belt layer composed of at least two layers in which the nylon cord is inclined with respect to the circumferential direction and intersects between the layers has a length in the tire width direction smaller than an originally designed value in a tire manufacturing process, In some cases, the desired cut resistance and uneven wear resistance were not maintained.
  • the length of the intersecting belt layer in the tire width direction changes, the rigidity in the tire width direction also changes, which may cause uneven wear.
  • nylon cords have a higher heat shrinkage ratio than cords of other organic fiber materials such as aramid and shrink during vulcanization molding, so that the width of the crossover belt layer in which the nylon cords are inclined is narrow. I found out. Then, it has been found that by appropriately defining the heat shrinkage of the nylon cord, the cut resistance and uneven wear resistance of the tire expected in the intersecting belt layer can be realized, and the present invention has been completed.
  • the gist of the present invention is as follows.
  • a radial tire having a layer of an interleaved belt layer, wherein the nylon cord has a thermal shrinkage at 177 ° C. of 2.0% or more and 6.0% or less.
  • the contact width of the tire means that the tire is mounted on the applicable rim, filled with a specified internal pressure, placed vertically on the flat plate in a stationary state, and the tread of the tread with the flat plate when the specified load is applied. Indicates the maximum linear distance in the tire width direction at the contact surface.
  • the “applicable rim” is an industrial standard effective in the region where the tire is produced and used, and is JATMA (Japan Automobile Tire Association) YEAR BOOK in Japan, ETRTO (European Tire and Rim Technical Technical Organization) in Europe.
  • STANDARD MANUAL in the United States TRA (THE TIRE RIM ASSOCIATION INC.) YEAR BOOK refers to the rim specified, etc.
  • "specified internal pressure” is described in the standards such as JATMA Refers to the maximum load of a single wheel in the applicable size, and the “prescribed internal pressure” refers to the air pressure corresponding to the maximum load.
  • the shoulder portion means a position of 13% of the contact width inward in the width direction of the tire from the contact end of the tread of the tire, and a position of 8% of the contact width outward from the contact end of the tread in the width direction of the tire. Refers to the area between the% position.
  • the grounding ends of the tread refer to both ends in the tire width direction of the contact surface of the tread.
  • a radial tire that has improved durability against cuts due to foreign matter and the like, and that has achieved uneven wear resistance.
  • cut resistance can be improved, and damage to the aircraft body can be prevented.
  • FIG. 2 is an enlarged sectional view showing a part of the tire shown in FIG. 1. It is a figure for explaining a cross belt layer and a main belt layer. It is a figure for explaining a cross belt layer of a tire concerning other embodiments of the present invention.
  • FIG. 1 is a diagram showing a cross section in the width direction of a tire 1 according to an embodiment of the present invention.
  • the tire 1 of the present invention includes a pair of bead cores 2a and 2b, a carcass ply 3 extending in a toroidal shape between the bead cores 2a and 2b, a main belt layer 4, and an intersecting belt layer 5.
  • a pair of bead cores 2a and 2b includes a pair of bead cores 2a and 2b, a carcass ply 3 extending in a toroidal shape between the bead cores 2a and 2b, a main belt layer 4, and an intersecting belt layer 5.
  • FIG. 2 is an enlarged sectional view showing a part of the tire shown in FIG. The configuration of the tire 1 will be described in more detail below with reference to FIG.
  • the tire 1 has at least one carcass ply 3, and in FIG.
  • the tire 1 includes at least one main belt layer 4 that is disposed on the outer side in the tire radial direction of the crown portion 3a of the carcass ply 3 and that is covered with a rubber cord.
  • Eight belt layers 4A, 4B, 4C, 4D, 4E, 4F, 4G and 4H are provided.
  • each of the main belt layers 4A to 4H is formed by spirally winding a rubber-coated cord 6a along the tire circumferential direction. According to the above configuration, sufficient rigidity is given to the main belt layer, so that protrusion of the tread tread in the tire radial direction due to internal pressure filling and the effect of centrifugal force during rolling of the tire can be suppressed.
  • the main belt layer 4A to 4H By arranging the main belt layers 4A to 4H on the outer side in the tire radial direction of the crown portion 3a of the carcass ply 3, the main belt layer exerts an effect in the crown portion 3a, and the inner belt is filled with the inner pressure and the centrifugal force during the rolling of the tire is increased. The protrusion of the tread surface of the tire due to the action of force or the like can be suppressed.
  • the width W1 of the main belt layers 4G and 4H in the tire width direction is a viewpoint to sufficiently suppress the protrusion of the tread tread. Therefore, it is preferable to set the length to 90% or more of the contact width TW of the tire.
  • a cord made of a material having a relatively large tension such as Kevlar fiber, aramid fiber, and steel cord may be used from the viewpoint of suppressing the protrusion of the tread tread. it can. Among them, it is preferable to use a cord made of Kevlar fiber.
  • the tire 1 is formed by rubber-coating a nylon cord disposed outside the main belt layers 4A to 4H in the tire radial direction, inclined with respect to the tire circumferential direction, and extending in a direction crossing each other between the layers. It has an interleaved belt layer 5 composed of two layers, in the illustrated example, interleaved belt layers 5A and 5B.
  • FIG. 3 is a diagram for explaining the main belt layer and the intersecting belt layer.
  • the intersecting belt layers 5A and 5B are sequentially arranged radially outside the main belt layer 4H, and the belt layers arranged radially inside each belt layer are hidden, but the structure of each belt layer will be clarified. Therefore, in FIG. 3, both ends in the circumferential direction of each belt layer are partially omitted, and the structures of the intersecting belt layer 5 ⁇ / b> A arranged radially inside the intersecting belt layer 5 ⁇ / b> B and the main belt layer 4 ⁇ / b> H inside thereof are also shown. I have.
  • the intersecting belt layers 5A and 5B are formed of a plurality of rubber cords coated with a number of nylon cords 7a and 7b that are arranged inclined with respect to the tire circumferential direction, and the nylon cords 7a and 7b are arranged between the layers. Have a structure in which they are overlapped with each other.
  • the cord 6a of the main belt layer 4H extends in the circumferential direction.
  • the intersecting belt layers 5A and 5B fill the gap between the cords 6a included in the main belt layer 4 with the nylon cords 7a and 7b by the configuration in which the nylon cords 7a and 7b are arranged inclined with respect to the tire circumferential direction. Therefore, foreign substances can be prevented from reaching the main belt layer. Furthermore, even if the interlaced belt layers 5A and 5B are damaged by foreign matter or the like, the damage reaches one end or the other end of the belt along the cord, and the development of the damage in the tire circumferential direction can be prevented. Furthermore, since the nylon cords 7a and 7b extend in the direction crossing each other between the layers, the rigidity in the width direction of the tire can be made uniform.
  • the nylon cords 7a and 7b constituting the interlaced belt layers 5A and 5B have a heat shrinkage at 177 ° C. of 2.0 to 6.0%. That is, by setting the heat shrinkage of the nylon cords 7a and 7b to 6.0% or less, the change in the length in the width direction of the interlaced belt layer due to the heat shrinkage of the nylon cords is reduced, and the interlaced expected at the time of design is obtained.
  • the gap between the lengths of the belt layers 5A and 5B in the tire width direction and the lengths of the intersecting belt layers 5A and 5B in the tire width direction when the tire is completed is reduced.
  • the intersecting belt layers 5A and 5B can secure the designed extending area, sufficiently protect the main belt layers 4A to 4H from the tire radial outside, and improve the cut resistance. Further, the effect of suppressing uneven wear can be maintained. Further, by setting the lower limit of the heat shrinkage to 2.0%, the rigidity of the cord can be maintained and the rigidity in the width direction of the tire can be secured.
  • the heat shrinkage of the nylon cords 7a and 7b is preferably 3.0% or more and 4.0% or less. According to the above configuration, the cut resistance and the uneven wear resistance can be improved to the maximum while securing the tire rigidity.
  • the length W2 of the intersecting belt layers 5A and 5B in the tire width direction is It is preferable that it is 70% or more and 95% or less with respect to the contact width TW. That is, by setting the length W2 in the width direction to be 70% or more of the ground width TW, the main belt layers 4A to 4H are sufficiently protected from the tire radial outside, so that the cut resistance can be improved.
  • the main belt layer having the longest length in the width direction is arranged so as to occupy most of the contact width TW, and the cross belt layers 5A and 5B are set to 70% or more, and the main belt layers 4A to 4H are set to a certain value or more.
  • the width W2 is more than 95% of the contact width TW, the tension borne by the intersecting belt layers increases, and the durability of the intersecting belt layers 5A and 5B may decrease. It is preferable that the width W2 be 95% or less of the ground width TW.
  • the inclination angles ⁇ 1 and ⁇ 2 of the nylon cords 7a and 7b with respect to the tire circumferential direction be 2 ° or more and 45 ° or less.
  • the angle By setting it to 2 ° or more, not only rigidity in the circumferential direction of the tire but also rigidity in the width direction of the tire can be ensured.
  • the angle by setting the angle to 45 ° or less, the influence of the shrinkage in the extending direction of the nylon cord in the width direction of the intersecting belt layers 5A and 5B can be reduced. Further, it is possible to prevent a decrease in the rigidity of the tire in the circumferential direction.
  • the shoulder portion SH of the tire 1 preferably has contour lines L1 and L2 formed of arcs AR1 and AR2 having a curvature radius of 20 mm or more and 55 mm or less, respectively.
  • the radii of curvature r1 and r2 of the arcs AR1 and AR2 constituting the contour lines L1 and L2 are improved.
  • the contact pressure at the arc portion increases, and the durability of the belt due to heat generation near the increase of the contact pressure may be reduced. Is preferred.
  • a protective belt layer 8 separated from the intersecting belt layer 5 may be disposed outside the intersecting belt layer 5 in the tire radial direction.
  • the intersecting belt layer 5 shown in FIG. 4 includes a belt-shaped body 10 which is disposed obliquely with respect to the tire circumferential direction C and in which one or more, in the illustrated example, a plurality of nylon cords 9a are covered with rubber.
  • the belt 10 extends from one end BE1 in the width direction of the belt to the other end BE2 while being inclined with respect to the circumferential direction C, and is bent at the other end BE2 so that the inclination with respect to the circumferential direction C is reversed, and one end from the other end BE2.
  • the two-layer structure is formed by winding the band 10 a number of times while shifting the band 10 substantially in the circumferential direction by the width of the band 10 so that no gap is formed between the bands 10.
  • the strip 10 extends in a direction crossing each other between the layers.
  • the belt can be formed without forming a cut end of the cord at one end BE1 and the other end BE2 in the width direction of the belt, and the rubber is peeled off at the end of the cord.
  • it is possible to effectively suppress a failure caused by the progress of rubber peeling and improve the durability of the belt.
  • the inclination angles ⁇ 3 and ⁇ 4 of the nylon cord 9a with respect to the circumferential direction C are preferably 2 ° or more and 45 ° or less.
  • the angle By setting it to 2 ° or more, not only rigidity in the circumferential direction of the tire but also rigidity in the width direction of the tire can be ensured.
  • the angle By setting the angle to 45 ° or less, the influence of the shrinkage in the extending direction of the nylon cord in the width direction of the intersecting belt layer 5 can be reduced. Further, it is possible to prevent a decrease in the rigidity of the tire in the circumferential direction.
  • Inventive tires and comparative tires both having a tire size of 50 ⁇ 20.0R22 were prototyped based on the specifications shown in Table 1, and cut resistance, uneven wear resistance, belt durability, and heat generation durability were evaluated. .

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

Abstract

L'invention concerne un pneu radial comprenant une paire de tringles, au moins une nappe de carcasse s'étendant dans une forme toroïdale entre les tringles, au moins une couche de ceinture principale qui est disposée sur l'extérieur, dans la direction radiale du pneu, d'une partie sommet du ou des plis de carcasse et qui est obtenue par revêtement d'un cordon avec du caoutchouc, et au moins deux couches de ceinture croisées qui sont disposées sur l'extérieur, dans la direction radiale du pneu, de la couche de ceinture principale, sont inclinées par rapport à la direction circonférentielle du pneu et sont obtenues par revêtement, avec du caoutchouc, de fils de nylon s'étendant dans des directions se croisant entre les couches, caractérisé en ce que le retrait thermique des fils de nylon à 177 °C est au moins égal à 2,0 % et au plus égal à 6,0 %.
PCT/JP2019/035875 2018-09-12 2019-09-12 Pneu radial WO2020054798A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018170900A JP7121607B2 (ja) 2018-09-12 2018-09-12 ラジアルタイヤ
JP2018-170900 2018-09-12

Publications (1)

Publication Number Publication Date
WO2020054798A1 true WO2020054798A1 (fr) 2020-03-19

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PCT/JP2019/035875 WO2020054798A1 (fr) 2018-09-12 2019-09-12 Pneu radial

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WO (1) WO2020054798A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2023006887A (ja) * 2021-06-30 2023-01-18 株式会社ブリヂストン タイヤ
WO2023084827A1 (fr) * 2021-11-10 2023-05-19 株式会社ブリヂストン Pneu

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02141502U (fr) * 1989-05-01 1990-11-28
WO2003061991A1 (fr) * 2002-01-24 2003-07-31 Bridgestone Corporation Pneu radial et procede de production
JP2007283827A (ja) * 2006-04-13 2007-11-01 Bridgestone Corp 航空機用タイヤおよびそれの製造方法
JP2008087243A (ja) * 2006-09-29 2008-04-17 Bridgestone Corp 空気入りタイヤ
JP2012214171A (ja) * 2011-04-01 2012-11-08 Bridgestone Corp 航空機用空気入りタイヤ

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02141502U (fr) * 1989-05-01 1990-11-28
WO2003061991A1 (fr) * 2002-01-24 2003-07-31 Bridgestone Corporation Pneu radial et procede de production
JP2007283827A (ja) * 2006-04-13 2007-11-01 Bridgestone Corp 航空機用タイヤおよびそれの製造方法
JP2008087243A (ja) * 2006-09-29 2008-04-17 Bridgestone Corp 空気入りタイヤ
JP2012214171A (ja) * 2011-04-01 2012-11-08 Bridgestone Corp 航空機用空気入りタイヤ

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JP2020040583A (ja) 2020-03-19
JP7121607B2 (ja) 2022-08-18

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