JP2600136Y2 - Pneumatic tire - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire having a flatness of 55% or less, which does not impair ride comfort and enhances steering stability during cornering.

[0002]

2. Description of the Related Art A vehicle designed to increase engine output and improve aerodynamic characteristics of a body, that is, a so-called high-performance vehicle, has a high maximum speed and excellent acceleration performance, and has a higher steering stability when cornering. It is necessary to have This pneumatic tire for high-performance vehicles is generally
A flat tire having a lower tire cross-sectional height than a normal tire is used. In order for the flat tire to obtain excellent steering stability during cornering, it is preferable to increase the lateral rigidity of the tire as much as possible. Therefore, means for increasing the lateral rigidity by reinforcing the belt is often used.

[0003]

However, if the lateral stiffness of the tire is increased by reinforcing the belt, the amount of deformation in the tire radial direction at the time of rolling the load on the tire becomes too small, so that the riding comfort deteriorates. In particular, for a flat radial tire having a lower sectional height than a normal tire, the riding comfort may be significantly deteriorated.

It is an object of the present invention to improve the lateral rigidity of the tire without impairing the riding comfort and to complete a pneumatic tire having good steering stability during cornering.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a toroidal carcass consisting essentially of at least one ply of radially arranged cords having a relatively small angle relative to a plane containing the tread circumference around the crown. A belt consisting of at least two rubberized layers in a crossed cord arrangement, a belt reinforcing layer consisting of at least one rubberized layer of organic fiber cords arranged substantially parallel to the plane, and these belts and belts A pneumatic tire having a tread portion reinforced by a reinforcing layer and having a flatness of 55% or less, and having a tensile resistance substantially orthogonal to the cord of the ply of the toroidal carcass over the entire circumference of the side of the carcass. A side reinforcing layer made of a rubberized layer of a natural cord, and the width of the side reinforcing layer is set to 0. A pneumatic tire, characterized in that a 5 to 0.65 times the.

FIG. 1 shows an example of a typical widthwise cross section of the pneumatic tire of the present invention.
Is a carcass ply cord, 3 is a carcass, 4 is a crown portion, 5 is a belt, 6 is a belt reinforcing layer, 7 is a tread portion, 8 is a cord of a side reinforcing layer, and 9 is a side reinforcing layer. The pneumatic tire 1 shown in FIG. 1 has a relatively small angle around a crown 4 of a toroidal carcass 3 consisting of at least one ply of cords 2 arranged substantially radially with respect to a plane containing the tread circumference. Belt 5 comprising at least two rubberized layers in a crossed cord arrangement
And a belt reinforcing layer 6 made of at least one rubberized layer of an organic fiber cord arranged substantially parallel to the plane, and a tread portion 7 reinforced with the belt 5 and the belt reinforcing layer 6, One side reinforcing layer 9 made of a rubberized layer of a tension-resistant cord 8 is arranged substantially orthogonally to the cord 2 of the ply of the toroidal carcass 3 over the entire side circumference of the carcass 3.

The side reinforcing layer 9 has a width in a range of 0.15 to 0.65 times the sectional height of the tire. If this width is less than 0.15 times the cross-sectional height of the tire, sufficient reinforcement of the carcass side portions 10 and improvement in circumferential rigidity cannot be achieved, and if it exceeds 0.65 times, the rigidity is too high. This is because the response to the steering is too fast and the driver becomes uncomfortable. Further, it is preferable that the side reinforcing layers 9 are provided on both side portions 10 of the carcass 3 so as to cover the carcass region from the position above the bead to the position of the center portion of the sidewall. The number of the side reinforcing layers 9 is preferably one or two, but can be increased or decreased as necessary. As the cord 8 of the side reinforcing layer 9, it is preferable to use an organic fiber cord represented by a steel cord and a nylon cord. Further, if the code 8 arrangement is a plurality of arrangements, a plurality of cords may be arranged along concentric circles having different diameters, or a single cord may be arranged in a spiral shape, and can be appropriately selected. is there. Also,
As a method of arranging the cords of the side reinforcing layers 9 substantially orthogonal to the cords 2 of the ply, the cords 8 of the side reinforcing layers 9 attached to the forming drum before vulcanization molding have a tire circle. A cord arrangement that forms a waveform along the circumference is made, and then when molded into a green case,
It is preferable to arrange the cord 8 in a straight shape substantially along the circumference of the tire by pulling the corrugated cord in the longitudinal direction thereof. In this case, the amplitude of the corrugated cord before vulcanization molding is It is preferable that the larger the cord is, the larger the cord is located on the outside in the radial direction. FIG. 2 shows an example of a cord 8 forming a waveform of the side reinforcing layer 9 when attached to a forming drum. Assuming that the circumferential length at this time is 1, the amplitude is a, and the number of pitches is n, a product tire The circumferential length L of the cord of the side reinforcing layer can be determined by the following equation.

(Equation 1)

The carcass 3 preferably comprises one to two plies, and the ply cord 2 is preferably a rayon cord. The belt 5 is preferably composed of one to three rubberized layers, and the cord of the rubberized layer includes:
It is preferable to use steel or Kevlar cord, and to arrange the cord at an angle of 20 to 50 ° with respect to the tire equatorial plane. The cord of the belt reinforcing layer 6 is preferably a nylon cord, and the belt reinforcing layer 6 is preferably disposed as a cap layer covering the front surface of the belt and a narrow layer layer covering the belt end.

[0009]

According to the present invention, there is provided a side reinforcing layer 9 composed of a rubberized layer of tension-resistant cords 8 arranged in a plurality of arrangements substantially orthogonal to the cords 2 of the plies of the carcass 3 over the entire side circumference of the toroidal carcass 3. The width of the side reinforcing layer 9 is set to 0.15 to 0.6 of the sectional height of the tire.
By setting the range to 5 times, the circumferential rigidity and the torsional rigidity of the carcass side portion 10 of the tire for a high-performance vehicle are improved without deteriorating the riding comfort as in the case where the rigidity is strengthened by the conventional belt. As a result, the lateral rigidity of the tire can be improved. Further, by forming the cords 8 of the side reinforcing layers 9 in a plurality of arrangements substantially orthogonal to the arrangements of the cords 2 of the ply, the cords 8 are particularly injured by sharp projections and blades along the cords 2 of the ply. In this case, the expansion of the wound can be suppressed by the side reinforcing layer 9.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of a pneumatic tire according to the present invention will be described with reference to FIG. In the first embodiment, the tire size is 275 / 40ZR17 and the flat surface is formed around the crown portion 4 of the toroidal carcass 3 composed of one ply of the rayon cord 2 arranged at 90 ° to the plane including the tread circumference. A belt 5 composed of two rubberized layers having a cross cord arrangement at an angle of 20 ° to the belt 5;
A belt reinforcing layer 6 made of one rubberized layer of nylon cords arranged in parallel at an angle of 0 ° with respect to the plane;
The belt 5 and a tread portion 7 reinforced by a belt reinforcing layer 6, and a plurality of pull-resistant cords 8 arranged at a 90 ° angle to the cords 2 of the ply of the toroidal carcass over the entire circumference of the carcass 3. Is provided with one side reinforcing layer 9 made of a rubberized layer.

The width of the side reinforcing layer 9 is set to 0.38 times the sectional height (110 mm) of the tire. Further, the side reinforcing layers were provided on both side portions 10 of the carcass, and were arranged so as to cover the carcass side portions 10 from the position above the bead to the center portion of the sidewall. As the cord 8 of the side reinforcing layer 9, a steel cord was used. In the conventional example, a conventional tire having no side reinforcing layer was used.

The cornering property, riding comfort, and durability during high-speed running were tested. The cornering performance and the riding comfort test during high-speed running were evaluated on a 10-point scale based on the driver's feeling during actual vehicle running.
In the durability test, the expansion of the wound after wedge driving was measured and compared. Table 1 shows the test results. The numerical values in the table indicate that the larger the cornering performance and the higher the riding comfort during high-speed traveling, the better.

[0013]

[Table 1]

From the results in Table 1, it can be seen that the example has the same riding comfort and excellent cornering performance and tire durability during high-speed running as compared with the conventional example.

[0015]

The present invention is directed to a side reinforcement comprising a rubberized layer of a tension-resistant cord 8 which is arranged in a plurality of arrangements substantially orthogonal to the cord 2 of the ply of the carcass 3 over the entire circumference of the side of the toroidal carcass 3. The side reinforcing layer 9 has a width of 0.15 to
By setting the range to 0.65 times, unlike the case where rigidity is reinforced by a conventional belt, the ride comfort is not deteriorated, and the carcass side portion 1 of the tire for a high-performance vehicle is not deteriorated.
The circumferential and torsional stiffness of 0 is increased, so that
The lateral stiffness of the tire is improved, and the steering stability during cornering is improved, and the input to the rotating shaft of the tire is directly and smoothly transmitted to the tread without time loss, and the input from the road surface is also the same. Responsive to the driver. Also, the cord 8 of the side reinforcing layer 9
Is arranged in a plurality of arrangements substantially orthogonal to the cord 2 arrangement of the ply, particularly when a trauma due to a sharp projection, a blade, or the like is given along the cord 2 of the ply, the side reinforcing layer 9 Since the expansion of the wound can be suppressed, the durability of the tire is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a half cross section in the width direction of a devised tire used in Example 1 in which a tread rubber and a side wall rubber are partially cut away.

FIG. 2 is a diagram showing a part of a side reinforcing layer 9 showing only one cord in order to explain an arrangement shape of a cord of a side reinforcing layer before being formed on a forming drum. .

[Explanation of symbols]

 1 Pneumatic tire 2 Ply cord 3 Carcass 4 Crown section 5 Belt 6 Belt reinforcement layer 7 Tread section 8 Side reinforcement layer cord 9 Side reinforcement layer 10 Carcass side

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60C 13/00 B60C 9/08

Claims (1)

(57) [Scope of request for utility model registration] 1. At least two layers of a crossed cord arrangement around a crown of a toroidal carcass consisting of at least one ply of substantially radially arranged cords at a relatively small angle to a plane containing the tread circumference. A belt comprising a rubberized layer, a belt reinforcing layer comprising at least one rubberized layer of organic fiber cords arranged substantially parallel to the plane, and a tread portion reinforced with the belt and the belt reinforcing layer. With a flat rate of 5
A pneumatic tire that is 5% or less, including a side reinforcing layer made of a rubberized layer of a tension-resistant cord that is arranged substantially orthogonally to the cord of the ply of the toroidal carcass around the entire periphery of the carcass; A pneumatic tire wherein the width of the side reinforcing layer is in a range of 0.15 to 0.65 times the cross-sectional height of the tire.