JP2011079401A - Pneumatic tire pair and method for mounting pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new pneumatic tire pair which improves the durability of the tires by preventing the deterioration in the strength of cords buried in belts. <P>SOLUTION: This pneumatic tire pair includes the first belt 7 located just above a carcass layer 5 and the second belt 8 arranged outside in a tire radial direction of the body 7b of the first belt 7 and including the width end 8a inside a folded part 7a of the first belt 7. When the tire is mounted in each of the driving side right and left wheels of a vehicle, a cord array in which the cord 7c of the first belt 7 is inclined right upward and the cord 8b of the second belt 8 is inclined left upward is provided, as for the tire to be mounted on the left wheel. As for the tire to be mounted on the right wheel, a cord array in which the cord 7c of the first belt 7 is inclined left upward and the cord 8b of the second belt 8 is inclined right upward is provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pair of pneumatic tires that are suitable for mounting on a general vehicle such as a passenger car or a heavy vehicle such as a truck. The tire pair is intended to improve the durability of the tire by preventing a decrease in strength of the cord embedded in the belt.

  In conventional pneumatic tires, a plurality of belt layers laminated so that cords are interlaced are provided outside the carcass layer, and the side of one belt is placed on the side of the other belt arranged outside this belt. As a so-called fold structure that is folded back, the durability of the tire is improved, and as a prior art regarding this point, for example, a pneumatic tire disclosed in Patent Document 1 is known.

Japanese Patent Laid-Open No. 2001-2333018

  By the way, in the conventional tire, there is a concern that when the tire at the time of traction is subjected to compressive strain due to the deformation of the cord, the strength of the cord is lowered and the durability of the tire is affected. It was desired to develop a pneumatic tire that can be used.

  The subject of this invention is providing the novel pneumatic tire which can prevent the fall of the strength of the cord embed | buried under a belt and can improve the durability of a tire.

The present invention relates to a carcass layer extending in a toroidal shape from a tread portion through a sidewall portion to a bead portion, and a pneumatic tire reinforced by disposing a belt layer outside the carcass layer in the tire radial direction. A pair of tires, each of which includes a pair of tires mounted on the driving side left and right wheels of the vehicle,
The belt layer is disposed on the outer side in the tire radial direction of the first belt positioned directly above the carcass layer and the main body of the first belt, and includes a width end portion inside the folded portion of the first belt. With a second belt
Of the pneumatic tires mounted on the driving left and right wheels of the vehicle, for the pneumatic tire mounted on the driving left wheel, the cord of the first belt is inclined upward with respect to the direction of rotation of the tire, and The cord arrangement of the second belt is slanted to the left,
The pneumatic tire to be mounted on the right side of the drive wheel is characterized by a cord arrangement in which the cord of the first belt is inclined upward and the cord of the second belt is inclined upward. .

  In the pneumatic tire pair configured as described above, it is preferable that the belt layer includes a belt protective layer on the outer side in the tire radial direction of the folded portion.

A carcass layer extending in a toroidal shape from the tread portion through the sidewall portion to the bead portion, and a pneumatic tire reinforced by arranging a belt layer on the outer side in the tire radial direction of the carcass layer, the pneumatic tire is When mounting on the drive side left and right wheels of the vehicle,
A first belt located immediately above the carcass layer, and a second belt disposed outside the main body of the first belt in the tire radial direction and including a width end portion inside the folded portion of the first belt; A pneumatic tire having a belt layer in which the cord of the first belt is inclined upward to the right with respect to the direction of rotation of the tire and the cord of the second belt is inclined to the left Each of the pneumatic tires is provided with a belt layer that has a cord arrangement in which the cord of the first belt is inclined to the left and the cord of the second belt is inclined to the right.
A pneumatic tire having a belt layer that has a cord arrangement in which the cord of the first belt is inclined upward to the right with respect to the direction of rotation of the tire and the cord of the second belt is inclined upward to the left A pneumatic tire is attached to the right wheel on the driving side of the vehicle. The pneumatic tire has a belt layer that has a cord arrangement in which the cord of the first belt is inclined to the left and the cord of the second belt is inclined to the right. It is desirable.

  In mounting the pneumatic tire having the above-described configuration, it is desirable that the belt layer includes a belt protective layer on the outer side in the tire radial direction of the folded portion.

  Among the pneumatic tires to be mounted on the left and right wheels on the driving side of the vehicle, as the pneumatic tire to be mounted on the left wheel, the cord arrangement of the first belt is right-up and the cord of the second belt is up-left. A pneumatic tire fitted with a belt layer applied to the right wheel has a belt layer in which the cord of the first belt rises to the left and the cord of the second belt rises to the right Even if the inner side of the tire is greatly affected by the shear deformation due to traction, the first cord is not affected by the compressive strain, and the decrease in the cord strength is suppressed to increase the durability of the tire. Can be increased.

  The belt layer has a fold structure in which the width end portion of the second belt is included inside the folded portion of the first belt, and the belt protective layer is provided on the outside of the folded portion, so that the tire has traction. When the belt is acted, the shear deformation of the belt is reduced, and it is possible to further suppress the decrease in the cord strength and increase the durability of the tire.

It is the figure which showed the meridian cross section of one tire about the half part of the tire about embodiment of the pneumatic tire pair made into a set by two according to this invention. It is the figure which showed the cross section of the belt layer of one tire about embodiment of the pneumatic tire pair made into a set by two according to this invention. It is the figure which showed the cord arrangement | positioning of the belt of one tire by the development | deployment attitude | position of the tire seen from the tread part side about embodiment of the pneumatic tire pair which makes two sets according to this invention. It is the figure which showed the cord arrangement | positioning of the belt of the other tire by the development | deployment attitude | position of the tire seen from the tread part side about embodiment of the pneumatic tire pair which makes two sets according to this invention. It is a figure which shows the force concerning each code | cord | chord in the vehicle inner side part A and the vehicle outer side part B at the time of a traction acting and a tire deform | transforming, It is the figure which showed the state before a traction acts. It is a figure which shows the force concerning each code | cord | chord in the vehicle inner part A and the vehicle outer part B when a traction acts and a tire deform | transforms, It is the figure which showed the state which the traction acted. It is the figure which showed the cross section of the belt layer of one tire about other embodiment of the pneumatic tire pair made into a set by two according to this invention. It is the figure which showed the cord arrangement | sequence of the belt of one tire about other embodiment of the pneumatic tire pair made into a set by two according to this invention. It is a figure which shows the relationship of each tire pair about the decreasing rate of the cord strength of a 1st belt. It is a figure which shows the relationship of each tire pair about the decreasing rate of the cord strength of a 2nd belt. It is a figure which shows the relationship of each tire pair about lateral force.

  Hereinafter, the present invention will be described more specifically with reference to the drawings. In accordance with the present invention, two pairs of pneumatic tires have the same basic structure for each tire and differ only in the belt cord arrangement.

  In FIG. 1, 1 is a pair of bead portions connected in the circumferential direction of the tire, 2 is a pair of sidewall portions extending from the bead portions 1 toward the outer side in the radial direction of the tire, and 3 is these It is a tread portion that is connected across the extending end of the sidewall portion 2 and forms a toroidal shape.

  Reference numeral 4 denotes a pair of bead cores disposed in the bead portion 1, and the bead cores 4 extend in the circumferential direction of the tire to form a ring shape.

  Reference numeral 5 denotes a carcass layer formed of at least one carcass ply connected across the pair of bead cores 4. The carcass layer 5 is wound around each bead core 4 with its end portion wound back from the inside to the outside. Yes. In the carcass ply, a reinforcing cord is arranged, and this cord may be extended at any angle with respect to the equator E of the tire, but generally has various performances required for the tire. For satisfaction, the tires are arranged in a direction substantially perpendicular to the equator E of the tire. Here, “substantially orthogonal” specifically means that the angle of the tire with respect to the equator E is in the range of 85 ° to 95 °, and takes into account manufacturing errors. This cord can be selected in various ways, and is adopted from, for example, organic fibers such as aramid, polyethylene, and nylon, glass fibers, and steel.

  Reference numeral 6 denotes a belt layer disposed on the outer side in the radial direction of the tire with respect to the carcass layer 5. As shown in FIG. 2, the belt layer 6 is disposed on the outer side in the tire radial direction of the first belt 7 positioned immediately above the carcass layer 5 and the main body portion 7b of the first belt 7, and the first belt 7 7 has a fold structure including a second belt 8 including a width end portion 8a inside a folded portion 7a. Thereby, the said width | variety edge part 8a is pressed down by the said folding | turning part 7a, the deformation | transformation to the radial direction outer side of the said 2nd belt 8 can be suppressed, and durability of a tire can be improved.

  Each of the first belt 7 and the second belt 8 includes a first belt cord 7c and a second belt cord 8b, which are reinforcing cords, and various materials can be selected. It is employed from organic fibers such as aramid, polyethylene and nylon, glass fibers, steel and the like. The first belt 7 and the second belt 8 are arranged so that the cords 7c and 8b cross each other and incline with the equator E of the tire. Of the tires attached to the left and right wheels on the driving side of the vehicle, the tire attached to the left wheel has the cord 7c of the first belt ascending to the right in the tire deployed position as seen from the tread portion side as shown in FIG. The cord 8b of the second belt has a left-up cord arrangement, and the tire attached to the right wheel has a cord 7c of the first belt rises to the left as shown in FIG. A two-belt cord 8b has a cord arrangement that rises to the right.

  Here, the cord embedded in the belt is easily frayed when compressive strain is applied, and it is peeled off from the rubber covering the cord, or cracks are generated with the void formed inside the frayed cord as the core, and the cord is strong May lead to a decline. Assuming that the tire with the first belt cord 7c rising to the left and the second belt cord 8b rising to the right is attached to the drive-side left wheel of the vehicle and the traction is applied, the tire is in the state shown in FIG. 6 to FIG. 6 (FIG. 6 shows that the amount of deformation is larger than the actual amount of deformation), the vehicle inner portion A of the tire is the cord 7c of the first belt, and the vehicle outer portion B is the second A compressive force is applied to the cord 8b of the belt. At this time, the first belt 7 is folded back at both width ends, and the main body portion 7b of the first belt 7 is hardly displaced even when the tire is deformed. Compared with the second belt 8, the force applied to the cord when traction is applied to the tire is increased. In general, when the tire is mounted on a vehicle, a negative camber is added to the tire, so that the amount of deformation of the tire is increased particularly inside the vehicle. For this reason, when compression distortion occurs in the cord 7c of the first belt on the inner side of the vehicle, the cord strength is likely to decrease.

  A tire having the cord arrangement shown in FIG. 3 in which the cord 7c of the first belt rises to the right and the cord arrangement 8b of the second belt rises to the left is attached to the left wheel of the vehicle. When a tire having a cord arrangement in which the first belt cord 7c rises to the left and the second belt cord 8b rises to the right is mounted on the right wheel of the vehicle, the cord arrangement shown in FIG. Since a tensile force is applied to the cord 7c of the first belt on the inner side of the vehicle, the cord strength can be reduced without being affected by the compressive strain. In the above combination, the folded portion 7a of the first belt 7 is subjected to compressive strain, but the folded portion 7a is narrow and the end portion 7d is not folded and the cord 7c is easily displaced. There is almost no influence of compression distortion.

The inclination angle theta ₁ of the first belt cord 7c is preferably set at 10 ° to 30 ° approximately with respect to the equatorial E of the tire, the inclination angle theta ₂ of the second belt code 8b, the tire The equator E is preferably about 25 ° to 55 °.

  7 and 8 are views showing one tire according to another embodiment of a pair of pneumatic tires according to the present invention, and the belt layer 6 includes the folded portion. A belt protective layer 9 is provided on the outer side in the tire radial direction of 7a, and this belt protective layer 9 is preferably disposed so as to cover the end 7d of the folded portion 7a. The belt protective layer 9 is preferably reinforced with a cord employed from organic fibers such as aramid, polyethylene, nylon, glass fiber, steel, etc., and the cord is arranged in parallel with the equator E of the tire. Is preferred. Thereby, the protrusion deformation of the tire when a centrifugal force acts on the tire is reduced, and uneven wear and excessive heat generation due to contact pressure imbalance can be prevented. FIG. 7 shows a tire in which the cord 7c of the first belt rises to the right and the cord arrangement 8b of the second belt rises to the left, but the direction of the cord arrangement is reversed. Similarly, the tire is preferably provided with the belt protective layer 9 as well.

  Note that tires with belts with crossed cords are subject to shear deformation along the direction of the cord due to the belt layer expanding and contracting at the contact point with the road surface due to traction when mounted on a vehicle and rolled. This deformation is transmitted to the tread portion and the price tear is generated. In the present invention, the direction of the cord 7c of the first belt and the cord 8b of the second belt of the tire to be mounted on the driving side left and right wheels of the vehicle. Since each is symmetrical, the price tear also works symmetrically, and the controllability of the vehicle is stabilized.

  Further, a tire having a cord arrangement shown in FIG. 3 in which the cord 7c of the first belt is raised to the right and the cord arrangement 8b of the second belt is raised to the left is attached to the right wheel of the vehicle, In the case where a tire having the cord arrangement shown in FIG. 4 and the cord 7c of the first belt rising leftward and the cord arrangement 8b of the second belt rising rightward is attached to the left wheel of the vehicle, Although the compression strain is applied to the cord 7c of the first belt on the inner side of the vehicle and the cord strength is reduced, the price tear generated in each tire works toward the outer side of the vehicle to increase the lateral force generated on the tire. It becomes possible. For this reason, when the lateral force of the tire is more important, it may be mounted on the vehicle in the above combination.

  A tire of size 215 / 45R17 with the inclination angle of the belt cord shown in Table 1 is manufactured, assembled to a rim of size 7J, the internal pressure is 200 kPa, the cord of the first belt rises to the right, and the second belt A tire pair (corresponding tire) is mounted on the left wheel of the vehicle with a cord arrangement in which the cords of the first and second belts are raised to the left, and a tire on which the cord arrangement of the first belt and the second belt is symmetrical to the tire is mounted on the right side of the vehicle Cord) and a tire pair (comparative tire pair) in which tires having a cord arrangement in which the cord of the first belt rises to the left and the cord of the second belt rises to the right are mounted on the left and right wheels of the vehicle The strength reduction rate and lateral force were confirmed. The confirmation was made by a laboratory test using a flat belt testing machine for the left wheel of each tire pair. As the cord material, aramid was used for both the cord of the first belt and the cord of the second belt. The results are shown in FIGS.

  The code strength reduction rate was confirmed by a traction input experiment. Specifically, the test was conducted with a flat belt tester under the conditions of a load of 5 kN, a traction of 5 kN, a slip angle of 0 °, a camber angle of 0 °, and an internal pressure of 200 kPa. The result of the cord belt strength reduction rate of the first belt is shown in FIG. 9, and the result of the cord belt strength reduction rate of the second belt is shown in FIG. The smaller the number, the better the performance.

  The lateral force is a flat belt tester, the slip angle is swept in the range of −10 ° to + 10 °, the load is set to 1.5 kN, 3.0 kN, 5.0 kN, 7.0 kN, and the camber angle is set to 0. The maximum lateral force was measured under the conditions of 5 ° and an internal pressure of 200 kPa. The results are shown in FIG. 11 as a percentage of the matching tire pair, with the comparative tire pair as the reference (100%). Larger numbers indicate better performance.

  As a result, as shown in FIG. 11, the conforming tire pair is superior to the comparative tire pair by about 5 to 8% in terms of lateral force, but the decrease in the cord strength of the first belt is as shown in FIG. As compared with the pair of comparative tires, it is improved by about 40%, and the decrease in the cord strength of the second belt is almost the same as shown in FIG. 10, and it is possible to obtain a significant improvement in tire durability. In the case where the durability of the tire is important, it was confirmed that the above code arrangement is very effective.

  According to the present invention, the durability of the tire is improved by optimizing the direction of the cord arrangement of the tire for a pair of tires that are respectively mounted on the left and right wheels on the driving side of the vehicle. Therefore, a new pneumatic tire pair can be stably supplied.

DESCRIPTION OF SYMBOLS 1 Bead part 2 Side wall part 3 Tread part 4 Bead core 5 Carcass layer 6 Belt layer 7 1st belt 7a Folding part 7b Body part 7c 1st belt cord 8 2nd belt 8a Wide end 8b 2nd belt cord 9 Belt Protective layer E Tire equator

Claims (4)

A carcass layer extending in a toroidal shape from the tread portion through the sidewall portion to the bead portion, and a pneumatic tire reinforced by arranging a belt layer on the outer side in the tire radial direction of the carcass layer, the pneumatic tire is A pair of tires, each pair mounted on the drive side left and right wheels of the vehicle,
The belt layer is disposed on the outer side in the tire radial direction of the first belt positioned directly above the carcass layer and the main body of the first belt, and includes a width end portion inside the folded portion of the first belt. With a second belt
Of the pneumatic tires mounted on the driving left and right wheels of the vehicle, for the pneumatic tire mounted on the driving left wheel, the cord of the first belt is inclined upward with respect to the direction of rotation of the tire, and The cord arrangement of the second belt is slanted to the left,
The pneumatic tire mounted on the right side of the drive wheel has a cord arrangement in which the cord of the first belt is inclined upward to the left and the cord of the second belt is inclined upward to the right. versus.   The pneumatic tire pair according to claim 1, wherein the belt layer includes a belt protective layer on an outer side in the tire radial direction of the folded portion. A carcass layer extending in a toroidal shape from the tread portion through the sidewall portion to the bead portion, and a pneumatic tire reinforced by arranging a belt layer on the outer side in the tire radial direction of the carcass layer, the pneumatic tire is When mounting on the drive side left and right wheels of the vehicle,
A first belt located immediately above the carcass layer, and a second belt disposed outside the main body of the first belt in the tire radial direction and including a width end portion inside the folded portion of the first belt; A pneumatic tire having a belt layer in which the cord of the first belt is inclined upward to the right with respect to the direction of rotation of the tire and the cord of the second belt is inclined to the left Each of the pneumatic tires is provided with a belt layer that has a cord arrangement in which the cord of the first belt is inclined to the left and the cord of the second belt is inclined to the right.
A pneumatic tire having a belt layer that has a cord arrangement in which the cord of the first belt is inclined upward to the right with respect to the direction of rotation of the tire and the cord of the second belt is inclined upward to the left Attached to the left wheel, a pneumatic tire equipped with a belt layer with a cord arrangement in which the cord of the first belt tilts upward to the left and the cord of the second belt tilts upward to the right is attached to the right wheel on the driving side of the vehicle A method for mounting a pneumatic tire, characterized in that   The method for mounting a pneumatic tire according to claim 3, wherein the belt layer includes a belt protective layer on the outer side in the tire radial direction of the folded portion.

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