JP2019116178A - Pneumatic tire - Google Patents

Abstract

To improve stable steering performance by enhancing rigidity.SOLUTION: A pneumatic tire includes: a bead core 1 arranged on both sides in a tire width direction; a carcass ply 3 which is formed by covering a plurality of cords arranged side by side with a coating layer and being stretched to the bead core 1; a belt 4 which is wound around an outer side in a tire radial direction of the carcass ply 3; and a reinforcing layer 12 arranged on both sides in the tire width direction of the carcass ply 3. The carcass ply 3 includes a main body part 15 in which the cords extend along a meridian cross section, and a winding-up part 16 in which the cords are wound up on an outer surface side of the tire width direction from the bead core 1 and intersect and extend with respect to the main body part 15. The winding-up part 16 is laminated on the main body part 15 beyond the reinforcing layer 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pneumatic tire.

Conventionally, there is known a pneumatic tire in which a first ply and a second ply are arranged such that cords cross each other (see, for example, Patent Document 1).
Further, there is known a pneumatic tire provided with a cord reinforcing layer having a plurality of cords extending in the tire circumferential direction on the outer side in the tread width direction of the carcass (see, for example, Patent Document 2).

However, in the former pneumatic tire, the weight is large because two plies are stacked. Conversely, if one ply is used to reduce weight, desired rigidity can not be obtained.
On the other hand, in the latter pneumatic tire, only the cord reinforcing layer is provided, and sufficient rigidity can not be obtained as a whole.

JP, 2009-149187, A JP, 2006-192953, A

  An object of the present invention is to provide a pneumatic tire capable of enhancing rigidity and improving steering stability by providing a reinforcing layer and crossing wires inside and outside of a carcass ply to obtain a tag effect. I assume.

The present invention, as means for solving the above problems,
Bead cores disposed on both sides in the tire width direction,
A plurality of juxtaposed cords covered with a covering layer, and a carcass ply which is wound around the bead core;
A belt wound around a tire radial direction of the carcass ply;
Reinforcing layers disposed on both sides of the carcass ply in the tire width direction;
Equipped with
The carcass ply has a body portion in which a cord extends along a meridional section, and a winding portion which is wound up from the bead core to the outer surface side in the tire width direction and the cord extends in a cross direction to the body portion.
Equipped with
The rolled up portion provides a pneumatic tire that is stacked on the main body portion beyond the reinforcing layer.

  According to this configuration, a tag effect is obtained by crossing the cord of the main body and the cord of the winding-up portion stacked on the main body over the reinforcing layer, and although it is a single carcass ply, rigidity is achieved. Can be enhanced. As a result, the steering stability can be enhanced.

  It is preferable that the cord of the reinforcing layer is inclined to the opposite side to the cord of the winding portion at an angle of 20 ° to 80 ° with respect to a straight line extending in the tire radial direction.

  With this configuration, it is possible to cross the cord of the reinforcing layer and the cord of the winding-up portion to exhibit the tag effect also at this portion and to enhance the rigidity.

  The cords of the reinforcing layer are preferably inclined to the same side as the cords of the winding-up portion at an angle of 40 ° to 80 ° with respect to a straight line extending in the tire radial direction.

  With this configuration, it is possible to cross the cord of the reinforcing layer and the cord of the winding-up portion to exhibit the tag effect also at this portion and to enhance the rigidity.

  It is preferable that the winding-up end of the carcass ply be stacked on the main body portion by 10 mm or more beyond the reinforcing layer.

  With this configuration, it is possible to secure a sufficient crossing range of the cords of the main body portion and the winding portion, exert a tag effect, and enhance rigidity.

  It is preferable that the winding-up end of the carcass ply be located in the range of 20 mm from the both ends in the tire width direction of the belt toward the center.

  This configuration can suppress the increase in weight and prevent the restraint by the carcass ply from becoming too strong.

  The angle between the cord of the reinforcing layer and the cord of the winding portion of the carcass ply is preferably 10 ° or more.

  By this configuration, the reinforcing layer and the carcass ply cord can be crossed to obtain a sufficient tag effect.

  According to the present invention, when the carcass ply is wrapped around the bead core, the winding portion is stacked on the main body portion beyond the reinforcing layer, and the cord of the main portion and the cord of the winding portion are crossed. It can be demonstrated. Therefore, even with one carcass ply, the rigidity can be sufficiently increased to improve the steering stability.

It is a meridional semi-cross section of a pneumatic tire concerning this embodiment. It is a partial side view which shows the bead part and sidewall part of FIG. It is a partial side view showing a bead part and a sidewall part of a pneumatic tire concerning other embodiments.

  Hereinafter, an embodiment according to the present invention will be described according to the attached drawings. The following description is merely illustrative in nature, and is not intended to limit the present invention, its applications, or its applications.

  FIG. 1 is a semi-mid-section view of a meridian of a pneumatic tire according to the present embodiment. In this pneumatic tire, bead cores 1 in which a plurality of wires are bundled are respectively disposed on both sides in the tire width direction WD.

  A bead filler 2 made of a rubber material for reinforcing the bead core 1 is disposed on the outer side in the tire radial direction of the bead core 1.

  A carcass ply 3 is stretched around the bead core 1. A plurality of belts 4 and a reinforcing belt 5 are wound around the outer side of the carcass ply 3 in the tire radial direction.

  The tire radial direction outer side of the reinforcing belt 5 is a tread portion 6. Side wall portions 7 are continuous from the tread portion 6 to both sides in the tire width direction WD, and bead portions 9 are from the top of the rim protector 8 to the bead core 1.

  A chafer 10 is wound around the bead core 1 so as to cover the carcass ply 3 which has been bridged. An inner liner 11 is provided on the inner side in the tire radial direction of the carcass ply 3.

  A reinforcing layer 12 is provided on the outer surface of the bead filler 2 and the main body 15 of the carcass ply 3. The reinforcing layer 12 is obtained by coating a plurality of steel reinforcing cords 13 arranged in parallel at predetermined intervals with a rubber material.

  Referring also to FIG. 2, the reinforcing cord 13 has a direction opposite to the inclination direction of the carcass cord 14 b of the winding portion 16 with respect to a straight line (carcass cord 14 a of the main body 15 of the carcass ply 3) extending in the tire radial direction. Is inclined at an inclination angle θ1. The inclination angle θ1 here is set in the range of 20 ° to 80 °, preferably 60 °.

  The carcass ply 3 has a toroidal shape, and is formed of one sheet of a plurality of carcass cords 14 juxtaposed at predetermined intervals and covered with rubber. The carcass cords 14 are made of organic fibers such as nylon fibers. The carcass ply 3 includes a main body portion 15 disposed on the inner side in the tire radial direction, and a winding portion 16 folded back by the bead core 1 and wound up.

  In the main body 15, the carcass cords 14a extend at 0 °, that is, without an inclination angle with respect to a straight line extending in the tire radial direction. In the winding portion 16, the carcass cords 14b are inclined at an inclination angle θ2 with respect to a straight line extending in the tire radial direction. The inclination angle θ2 here is set in the range of 10 ° to 50 °, preferably 30 °.

  The inclination angles θ1 and θ2 are defined as straight directions extending in the left-right direction in the tire circumferential direction CD based on FIG. Therefore, the inclination angle θ1 is based on the lowermost end 12 a on the inner side in the tire radial direction of the reinforcing layer 12. That is, a straight line L1 extending in the tire radial direction RD is a straight line connecting the center of rotation of the tire and the position of the reinforcing cord 13 at the lowermost end 12a inside the tire radial direction RD of the reinforcing layer 12 An angle formed by the reinforcing cord 13 is an inclination angle θ1. On the other hand, the inclination angle θ2 is based on the lowermost end 1 a of the bead core 1. That is, a straight line L extending in the tire radial direction is a straight line connecting the rotation center of the tire and the lowermost end 1a of the bead core 1 of each carcass cord 14b, and an angle formed by the straight line L and the carcass cord 14b is an inclination angle It is assumed that θ2.

  As described above, since the inclination direction of the reinforcing cord 13 is opposite to the inclination direction of the carcass cord 14b with respect to the straight line extending in the tire radial direction, the angle between the reinforcing cord 13 and the carcass cord 14b is surely 10 °. It can be more than.

  The winding portion 16 extends from the bead core 1 over the bead filler 2 to the outer surface of the main body portion 15. The dimension d1 from the tip of the bead filler 2 to the winding end of the winding portion 16 is 10 mm or more. However, as for the position of the winding-up end, the dimension d2 from the base end toward the center side in the tire width direction is up to 20 mm.

  The pneumatic tire having the above configuration has the following advantages.

  The winding portion 16 of the carcass ply 3 is extended beyond the bead filler 2 and laminated on the outer surface of the main body portion 15. The carcass cords 14 have different inclination angles between the main body portion 15 and the winding portion 16. Therefore, although the carcass cords 14a of the main body portion 15 and the carcass cords 14b of the winding-up portion 16 intersect with each other and only one carcass ply 3 is provided, the carcass cords 14a and 14b act on each other. By the effect, rigidity in any of the tire radial direction, the tire circumferential direction and the tire width direction can be enhanced. Therefore, the steering stability of the pneumatic tire can be improved.

  In particular, the position of the winding end of the carcass ply 3 is 10 mm or more from the tip of the bead filler 2. Therefore, the rigidity can be sufficiently enhanced by securing a range in which the carcass cords 14a and 14b intersect. In addition, the position of the winding end of the carcass ply 3 is set to 20 mm from the base end toward the center in the tire width direction. Therefore, the weight does not increase and the fuel consumption is not deteriorated, and the rigidity of the tire is not excessively increased to deteriorate the riding comfort.

  Further, the angle formed between the reinforcing cord 13 and the carcass cord 14 b is 10 ° or more. Therefore, the tag effect can be exerted not only between the carcass cords 14a and 14b but also between the reinforcing cord 13 and the carcass cord 14b. This makes it possible to further increase the rigidity and improve the steering stability.

About the comparative example and the Example which are shown in Table 1, the pneumatic tire of size 285 / 45R20 112Y was attached to SUV (Sport Utility Vehicle), and sensory evaluation was performed about steering stability performance and riding comfort performance. The sensory evaluation was represented by an index when the case of the comparative example was 100. The larger the index, the better the steering stability performance and the riding comfort performance. Moreover, the total weight of the tire was evaluated by the index when the case of Comparative Example is 100. The larger the index, the greater the weight.
In Comparative Example 1, the carcass cords 14 b extend in the same direction as the carcass cords 14 a, that is, in the tire radial direction. And the position of the winding-up end of the carcass ply 3 is made to project 10 mm from the reinforcement layer 12.
In Comparative Example 2, the carcass cords 14b extend in the tire radial direction as in Comparative Example 1, but the position of the winding end of the carcass ply 3 is 20 mm from the belt end toward the center in the tire width direction. ing.
In the embodiment, the carcass cords 14b are inclined at 60 degrees with respect to the carcass cords 14a. The position of the winding end of the carcass ply 3 is projected 10 mm from the reinforcing layer 12.

  As described above, even with one carcass ply 3, sufficient rigidity can be obtained by the tag effect due to the crossed cords, so that the steering stability and the riding ability superior to those of the pneumatic tire of Comparative Example 1 can be obtained. It is possible to demonstrate comfort performance. Further, since the weight does not increase as in the pneumatic tire of Comparative Example 2, the fuel consumption does not deteriorate.

  In addition, this invention is not limited to the structure described in the said embodiment, A various change is possible.

  In the above embodiment, the reinforcing layer 12 is configured to extend beyond the bead filler 2 to the outside in the tire radial direction. However, the reinforcing layer 12 may be configured not to exceed the bead filler 2. In this case, the winding portion 16 of the carcass ply 3 may be wound up to a range of 10 mm or more beyond the bead filler 2.

  In the embodiment described above, the carcass cords 14b at the winding-up portion 16 of the carcass ply 3 are inclined to the opposite side to the straight line extending in the tire radial direction with the reinforcing cords 13 of the reinforcing layer 12. As shown, they may be inclined to the same side. In this case, the inclination angle θ2 formed by the straight line L extending in the tire radial direction and the reinforcing cord 13 is set in the range of 40 ° to 80 °, preferably 60 °. The carcass cords 14 b are in a range of 10 ° to 50 ° with respect to the straight line L extending in the tire radial direction, but set so that an angular difference of 10 ° or more exists between the carcass cords 14 b and the reinforcing cords 13 It is done.

  Also in this configuration, as in the above embodiment, the rigidity can be enhanced by the tag effect, so that excellent steering stability performance can be exhibited.

DESCRIPTION OF SYMBOLS 1 ... bead core 1a ... lower end 2 ... bead filler 3 ... carcass ply 4 ... belt 5 ... reinforcement belt 6 ... tread part 7 ... sidewall part 8 ... rim protector 9 ... bead part 10 ... chafer 11 ... inner liner 12 ... Reinforcement layer 12a ... bottom end 13 ... reinforcement cord 14, 14a, 14b ... carcass cord 15 ... main body part 16 ... winding up part

Claims (6)

Bead cores disposed on both sides in the tire width direction,
A bead filler connected to the bead core and extending outward in the tire radial direction;
A plurality of juxtaposed cords covered with a covering layer, and a carcass ply which is wound around the bead core;
A belt wound around a tire radial direction of the carcass ply;
Reinforcement layers disposed on both sides of the bead filler in the tire width direction;
Equipped with
The carcass ply has a body portion in which a cord extends along a meridional section, and a winding portion which is wound up from the bead core to the outer surface side in the tire width direction and the cord extends in a cross direction to the body portion.
Equipped with
The pneumatic tire, wherein the winding-up portion is stacked on the main body portion beyond the bead filler or the reinforcing layer located on the outer side in the tire radial direction.   The pneumatic tire according to claim 1, wherein the cords of the reinforcing layer are inclined to the opposite side to the cords of the winding-up portion at an angle of 20 ° to 80 ° with respect to a straight line extending in the tire radial direction. .   The pneumatic tire according to claim 1, wherein the cords of the reinforcing layer are inclined on the same side as the cords of the winding-up portion at an angle of 40 ° to 80 ° with respect to a straight line extending in the tire radial direction.   The winding end of the carcass ply is laminated on the main body portion by 10 mm or more beyond that of the bead filler or the reinforcing layer which is located on the outer side in the tire radial direction. The pneumatic tire of description.   The pneumatic tire according to any one of claims 1 to 4, wherein the winding up end of the carcass ply is located in a range from the both ends in the tire width direction of the belt toward the center side to 20 mm.   The pneumatic tire according to any one of claims 1 to 5, wherein an angle formed by the cord of the reinforcing layer and the cord of the winding-up portion of the carcass ply is 10 ° or more.

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