JP6523811B2 - tire - Google Patents

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a tire, and more particularly to a tire according to an improvement of a reinforcing structure of a tread portion.

  In general, a tire is composed of a tread portion forming a tread portion, and a sidewall portion and a bead portion sequentially connected on both sides in the tire width direction, and a carcass which extends in a toroidal shape between both bead portions is used as a framework. Usually, one or more belt layers for exhibiting a tag effect are disposed on the radially outer side of the crown portion tire of the carcass, and further, on the radially outer side of the tire, a belt which covers the entire widthwise direction of the belt layer. A structure is also known in which a reinforcing layer and a belt auxiliary layer covering both end portions in the tire width direction of the belt layer are provided.

  Various techniques have been studied and proposed for the reinforcing structure of the tread portion of the tire, and the belt reinforcing layer and the belt auxiliary layer are used for the long strip along the tire circumferential direction, at least in part in the tire width direction. Techniques for spacing and winding are also known. For example, in Patent Document 1, at least one belt cover layer for reinforcing the belt layer is provided, and the belt cover layer has a lap wound portion in which a jointless belt cover material is overlapped and wound on each tire shoulder side, A jointless belt cover material is wound at a predetermined interval between the respective lap windings, and has a spacing winding, and the strip width of the jointless belt cover material, the spacing of the spacing winding, jointless in the lap winding. A pneumatic radial tire is disclosed in which the width of the overlapping portion of the belt cover material, the maximum width of the belt cover layer, and the total width of the lap winding portion are set to satisfy a predetermined relationship.

Unexamined-Japanese-Patent No. 2005-247070 (patent 4759922)

  However, when a belt reinforcing layer and a belt auxiliary layer as a reinforcing member of the tread portion of a tire are formed by winding a long strip at intervals in the tire width direction in the tire circumferential direction There is a problem that air containing defects are easily generated in the product tire, and it has been required to solve the problem.

  Therefore, an object of the present invention is to generate an air entrapment defect in a belt reinforcing layer and a belt auxiliary layer which are formed by winding a long strip in the tire circumferential direction and having a portion wound at intervals in the tire width direction. To provide a tire with reduced

  As a result of intensive investigations, the inventor of the present invention can solve the above-mentioned problems by defining in advance the winding conditions of the strip in the belt reinforcing layer and the belt auxiliary layer having portions formed at intervals in the tire width direction. To complete the present invention.

That is, the tire according to the present invention has a carcass extending in a toroidal shape between both bead portions as a skeleton, and a belt layer, a belt reinforcing layer, and a belt auxiliary layer are provided on the radially outer side of the crown portion of the carcass. It is a tire sequentially disposed,
The belt reinforcing layer and the belt auxiliary layer are formed by spirally winding a strip made of a rubber-coated cord in the circumferential direction of the tire,
The belt reinforcing layer has a center reinforcing area formed by winding the strip with a gap in the tire width direction, and a shoulder reinforcing area formed by winding the strip without a gap.
When the tread width is equally divided into four in the tire width direction, the area of 1⁄4 of both sides in the tire width direction of the tread width is the shoulder reinforcement area, and the area of 1⁄2 of the center of the tire width direction of the tread width is the above Center reinforcement area,
The amount of clearance at the time of winding of the strip is one strip of strip,
The belt auxiliary layer is formed by tightly winding the strip in the shoulder reinforcement area,
The belt reinforcing layer and the belt auxiliary layer on one side in the tire width direction, and the belt reinforcing layer and the belt auxiliary layer on the other side in the tire width direction are each formed by the one strip, and
The tire width direction inner end of the belt auxiliary layer may be located outside the tire width direction inner end of the shoulder reinforcement region of the belt reinforcing layer in the tire width direction.

  In the tire according to the present invention, the distance w between the tire width direction inner end of the belt auxiliary layer and the tire width direction inner end of the shoulder reinforcing region of the belt reinforcing layer is 1 to 3 of the width ws of the strip. It is preferable that it is twice.

  According to the present invention, the occurrence of air entrapment defects in the belt reinforcing layer and the belt auxiliary layer having a portion formed by winding a long strip circumferentially in the tire circumferential direction and having a space wound in the tire width direction. It has become possible to realize a suppressed tire.

BRIEF DESCRIPTION OF THE DRAWINGS It is width direction sectional drawing which shows an example of the tire of this invention. (A) is a schematic explanatory drawing of a reinforcement structure of a tread part concerning the present invention, and (b) is an explanatory view expanding and showing tire width direction inner end vicinity of the belt auxiliary layer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a widthwise sectional view showing an example of the tire of the present invention. The tire 10 illustrated has a carcass 1 extending in a toroidal shape between both bead portions as a skeleton, and a belt layer 2, a belt reinforcing layer 3, and a belt auxiliary layer 4 on the radially outer side of the crown portion tire. Are arranged sequentially. As shown, the belt reinforcing layer 3 is generally arranged to cover the entire width of the belt layer 2, and the belt auxiliary layer 4 is arranged to cover the tire width direction end of the belt layer 2.

  FIG. 2 (a) is a schematic explanatory view of the reinforcing structure of the tread portion according to the present invention, and FIG. 2 (b) is an explanatory view showing an enlarged vicinity of the tire width direction inner end of the belt auxiliary layer. In the present invention, the belt reinforcing layer 3 and the belt auxiliary layer 4 are formed by spirally winding a strip S made of a rubber-coated cord in the tire circumferential direction. Further, in the present invention, the belt reinforcing layer 3 includes a center reinforcing area 3c formed by winding the strip S with a gap in the tire width direction, and a shoulder reinforcing area 3s formed by winding the strip S without a gap. The belt auxiliary layer 4 is formed by winding the strip S without a gap in the shoulder reinforcing area 3s. In the present invention, as illustrated, the tire width direction inner end 4i of the belt auxiliary layer 4 is located outside the tire width direction inner end 3si of the shoulder reinforcement region 3s of the belt reinforcement layer 3 in the tire width direction. Is important.

  According to the study of the inventor, in the tire thus formed by winding the strip partially open, air tends to remain in the gap portion where the strip is not wound, and in particular, two layers of the strip are formed. It has been found that the problem of inclusion of air becomes apparent when wound around. For example, in the case of a test tire having a tire size of 255 / 40R18, when only one belt reinforcing layer 3 is formed by winding a strip with a gap of 6 mm across the entire tire width direction on the outer side in the tire radial direction of the belt layer. And when two layers of belt reinforcing layer 3 are laminated by winding the strip in the same phase with a gap of 6 mm in the entire tire width direction, that is, when the strip is wound so as to overlap two layers. When the presence or absence of air in the product tire is confirmed, it is confirmed that the increase in air about 5 to 6 times is partially increased in the latter. This is due to the fact that the tread rubber does not easily enter into the gap portion during vulcanization because the size of the step of the gap portion also increases to 2 layers by overlapping the two layers of the strip, and air remains. Conceivable.

  From this point of view, in the present invention, the tire width direction inner end 4i of the belt auxiliary layer 4 is positioned outside the tire width direction inner end 3si of the shoulder reinforcing region 3s of the belt reinforcing layer 3 in the tire width direction. . As a result, the tire width direction inner end 4i of the belt auxiliary layer 4 and the tire width direction inner end 3si of the shoulder reinforcing region 3s of the belt reinforcing layer 3 do not overlap with each other. As a result, it has become possible to prevent the remaining of the air and to reduce the occurrence of air inclusion defects in the product tire.

  In this case, the distance w between the tire width direction inner end 4i of the belt auxiliary layer 4 and the tire width direction inner end 3si of the shoulder reinforcement region 3s of the belt reinforcing layer 3 is 1 to 3 times the width ws of the strip S Is preferred. In the present invention, since the belt reinforcing layer 3 and the belt auxiliary layer 4 are formed by spirally winding the strip S having a predetermined width in the circumferential direction of the tire, substantially one strip per circumference in the circumferential direction of the tire As a result, the end positions of the belt reinforcing layer 3 and the belt auxiliary layer 4 in the tire width direction are shifted. Therefore, the positions of the tire width direction inner end 4i of the belt auxiliary layer 4 and the tire width direction inner end 3si of the belt reinforcing layer 3 may also be shifted by one strip, so this deviation amount and the winding position error In consideration of this, it is preferable that the distance w be equal to or more than one time of the width ws of the strip S. On the other hand, even if the distance w is excessively increased, there is no further effect. If the distance w is excessively increased, the reinforced portion of the belt auxiliary layer 4 may deviate from the design concept. It is preferable to make it 3 times or less of ws.

  Here, in the present invention, when the tread width TW is equally divided into four in the tire width direction, the center reinforcement region 3c and the shoulder reinforcement region 3s of the belt reinforcement layer 3 have 1/4 TW regions on both sides in the tire width direction. The shoulder reinforcement region 3s can be used, and the remaining 1/2 TW of the center in the tire width direction can be used as the center reinforcement region 3c.

  In the present invention, the tread width refers to the length in the tire width direction between the tread ends, which is measured in a non-loaded state, with the tire assembled to the application rim and filled with a prescribed internal pressure. In addition, “application rim” refers to the rim specified in the following standard according to the tire size, and “prescribed internal pressure” refers to the air pressure specified corresponding to the maximum load capacity in the following standard "Maximum load capacity" refers to the maximum load allowed to be applied to the tire according to the following specifications. Furthermore, the standard is an industrial standard effective for the area where the tire is produced or used, for example, in the United States, "YEAR BOOK" of "THE TIRE AND RIM ASSOCIATION INC.", In Europe, "The European Tire and Rim Technical Organization "STANDARDS MANUAL", in Japan "Japan Automobile Tire Association" "JATMA YEAR BOOK" means.

  In the tire according to the present invention, the tire widthwise inner end 4i of the belt auxiliary layer 4 is positioned outside the tire widthwise inner end 3si of the shoulder reinforcing region 3s of the belt reinforcing layer 3 in the tire width direction. Is not particularly limited, and can be constructed according to a conventional method.

  For example, the width ws of the strip S for forming the belt reinforcing layer 3 and the belt auxiliary layer 4 is not particularly limited, but may be, for example, about 1 to 20 mm. In addition, the amount of clearance at the time of winding can usually be set to one strip S.

  Further, a pattern including circumferential grooves 11a, 11b and 11c is usually formed in the tread surface portion of the tire, but in this case, the position of the tire width direction inner end 4i of the belt auxiliary layer 4 is the maximum in the tire width direction. It is preferable to arrange so that the space | interval with the circumferential direction groove 11a (11c) located in the outer side may not be too close. Specifically, for example, between the position of the tire width direction inner end 4i of the belt auxiliary layer 4 and the position of the tire width direction outer groove wall of the circumferential groove 11a (11c) positioned on the outermost side in the tire width direction. The distance x is preferably 5 mm or more, and more preferably in the range of 10 to 30 mm. This is to achieve both the reinforcement of the shoulder reinforcement region 3s and the failure suppression of the tire width direction inner end 4i of the belt auxiliary layer 4.

  Furthermore, in the present invention, the belt reinforcing layer 3 and the belt auxiliary layer 4 may be formed by spirally winding the strip S in the circumferential direction of the tire, and the winding method thereof is particularly limited. It is not something to be done. For example, in the example shown in FIG. 2 (a), the belt reinforcing layer 3 and the belt auxiliary layer 4 sequentially form two strips from the tire width direction inner ends 3ia and 3ib of the belt reinforcing layer 3 in the tire width direction outer side. It is formed by winding in the opposite direction.

  The illustrated tire 10 includes a tread portion 21 forming a tread surface portion of the tire, a pair of sidewall portions 22 continuously extending inward in the tire radial direction continuously on both sides of the tread portion 21, and inner circumferences of the sidewall portions 22. And a continuous bead portion 23 on the side. The tread portion 21, the sidewall portion 22 and the bead portion 23 are reinforced by a carcass 1 made of a carcass ply which extends in a toroid shape from one bead portion 23 to the other bead portion 23. Further, a tread rubber 5 is disposed on the outer side in the tire radial direction of the belt reinforcing layer 3 and the belt auxiliary layer 4, and a tread pattern is formed on the surface thereof.

  The carcass ply constituting the carcass 1 can be disposed at least one or more, and may be two or more. Further, in the illustrated example, the carcass 1 is rolled up and locked outward from the inside in the tire width direction around the bead core 6, but the locking structure of the carcass 1 is not limited thereto. The end of the may be sandwiched by two bead cores (not shown). The carcass 1 can in particular be a radial carcass.

  The belt layer 2 is composed of the first belt 2a and the second belt 2b of at least two layers, two layers in the illustrated example. The belt comprises a rubberized layer of cords extending at an angle of, for example, ± 15 to 40 ° with respect to the circumferential direction of the tire, preferably a rubberized layer of steel cords, and the cords constituting each belt are the tire equatorial plane It is good also as a crossing layer laminated | stacked so that it might cross | intersect each other on either side of CL.

  Furthermore, although not shown, in the tire 10 of the present invention, an inner liner is generally disposed in the innermost layer of the tire. Furthermore, in the tire 10 of the present invention, as the gas to be filled in the tire, normal air or air whose oxygen partial pressure is changed, or an inert gas such as nitrogen can be used. Although the tire of the present invention can be applied to various tires, it is suitable for a passenger car tire or a light truck tire.

Hereinafter, the present invention will be described in more detail using examples.
Example 1
A tire having a structure as shown in FIGS. 1 and 2 was produced at a tire size of 215 / 55R17. The carcass consists of one carcass ply consisting of a rubberized layer of reinforcing cord (material: polyethylene terephthalate), and the belt layer consists of a rubberized layer of steel cord extending at an inclination of ± 16 ° with respect to the tire circumferential direction. It was a thing. Further, the belt reinforcing layer and the belt auxiliary layer were formed by spirally winding a strip (width ws: 6 mm) made of a rubber-coated cord in the tire circumferential direction.

  As shown, the belt reinforcing layer has a center reinforcing area formed by winding the strip with a gap in the tire width direction, and a shoulder reinforcing area formed by winding the strip without a gap, and the shoulder reinforcement thereof The tire width direction inner end of the region was 49 mm from the tire equatorial plane CL to the outside in the tire width direction. In addition, the tire width direction inner end of the belt auxiliary layer was positioned 61 mm outward from the tire equatorial plane CL in the tire width direction. Therefore, the distance w between the tire width direction inner end of the belt auxiliary layer and the tire width direction inner end of the shoulder reinforcing region of the belt reinforcing layer was 12 mm.

(Comparative example 1)
A test tire of Comparative Example 1 was produced in the same manner as Example 1, except that the belt reinforcing layer was formed by winding the strip without gaps for the entire tire width direction.

  Each of the obtained test tires was evaluated for the presence of air over one round of the tire. As a result, also in the test tire of Example 1, the occurrence of air was not generated at the same level as Comparative Example 1. Thereby, even in a tire in which the belt reinforcing layer has a gap, the tire width direction inner end of the belt auxiliary layer is positioned on the outer side in the tire width direction than the tire width direction inner end of the shoulder reinforcing region of the belt reinforcing layer. It has been confirmed that the occurrence of the inclusion of air can be suppressed as in the case of a tire in which the belt reinforcing layer has no gap.

1 Carcass 2 Belt Layer 2a First Belt 2b Second Belt 3 Belt Reinforcement Layers 3ia, 3ib Belt Width End Inner Side 3c of Belt Reinforcement Layer Center Reinforcement Area 3s of Belt Reinforcement Layer Shoulder Reinforcement Area 3si of Belt Reinforcement Layer Shoulder Reinforcement Area Tire width direction inner edge 4 Belt auxiliary layer 4i Belt auxiliary layer inner width direction edge 5 Tread rubber 6 Bead core 10 Tire 11a, 11b, 11c circumferential groove 21 Tread portion 22 Side wall portion 23 Bead portion

Claims (2)

A carcass having a toroidal shape extending between two bead portions as a skeleton, and a belt layer, a belt reinforcing layer, and a belt auxiliary layer are sequentially disposed on the radially outer side of the crown portion tire of the carcass. ,
The belt reinforcing layer and the belt auxiliary layer are formed by spirally winding a strip made of a rubber-coated cord in the circumferential direction of the tire,
The belt reinforcing layer has a center reinforcing area formed by winding the strip with a gap in the tire width direction, and a shoulder reinforcing area formed by winding the strip without a gap.
When the tread width is equally divided into four in the tire width direction, the area of 1⁄4 of both sides in the tire width direction of the tread width is the shoulder reinforcement area, and the area of 1⁄2 of the center of the tire width direction of the tread width is the above Center reinforcement area,
The amount of clearance at the time of winding of the strip is one strip of strip,
The belt auxiliary layer is formed by tightly winding the strip in the shoulder reinforcement area,
The belt reinforcing layer and the belt auxiliary layer on one side in the tire width direction, and the belt reinforcing layer and the belt auxiliary layer on the other side in the tire width direction are each formed by the one strip, and
The tire according to the present invention is characterized in that the tire width direction inner end of the belt auxiliary layer is located outside the tire width direction inner end of the shoulder reinforcement region of the belt reinforcing layer in the tire width direction.   The distance w between the tire width direction inner end of the belt auxiliary layer and the tire width direction inner end of the shoulder reinforcing region of the belt reinforcing layer is 1 to 3 times the width ws of the strip. Tires.

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