JP6133659B2 - tire - Google Patents

Description

  The present invention relates to a tire, and more particularly, to a tire according to an improvement of a reinforcing member disposed in a crown portion.

  Conventionally, as a technique for improving the tire's trauma resistance, an auxiliary reinforcing member made of a composite of cord and rubber spirally arranged on the outermost layer of the crown that forms the ground contact surface It is known to do. As an arrangement form of the reinforcing member, for example, an organic fiber cord covered with rubber is wound with one layer at a certain angle with respect to the tire equator line, or formed with an organic fiber cord or a steel cord. The form which arrange | positioned the corrugated spiral sheet | seat without a gap and duplication etc. can be considered.

  For example, Patent Document 1 includes a cross belt layer, and a lower belt layer provided between the cross belt layer and the carcass layer in Patent Document 1, The difference between the cord angle of the inner side belt layer of the intersecting belt layers adjacent to the lower belt layer and the cord angle of the cord of the lower belt layer with respect to the tire circumferential direction in a predetermined range in the tire width direction centered on A pneumatic tire is disclosed in which the cord breaking strength in the lower belt layer is 90% or more of the cord breaking strength of the cross belt layer within a range of 0 to 10 degrees.

JP 2011-251603 A (Claims etc.)

  However, in the conventional reinforcing member, since the cords are arranged in parallel with each other, the cords that are continuous in a spiral shape are damaged over a wide area when the cord is damaged by a sharp object. In some cases, the durability was lowered. Further, since the conventional reinforcing member is intended only to improve the trauma, the contribution to the strength of the tire is small.

  Accordingly, an object of the present invention is to provide a tire with improved trauma resistance by solving the above-described problems and minimizing the damaged area of the cord when the reinforcing layer is traumad. .

  As a result of intensive studies, the inventor has wound a long sheet made of a composite of a reinforcing cord and a coating rubber around a crown portion to form a reinforcing layer, and the winding direction is within a predetermined angle range. At the same time, the inventors have found that the above problem can be solved by having a portion where the sheets cross each other in the reinforcing layer, and have completed the present invention.

That is, the present invention is a tire provided with a reinforcing layer formed by winding a long sheet made of a composite of a reinforcing cord and a coating rubber around the crown portion.
The reinforcing layer is formed by winding the elongated sheet a plurality of times,
The winding direction of the long sheet forms an angle larger than 0 degrees and smaller than 90 degrees with respect to the tire equator line,
The long sheets have crossing points in the reinforcing layer, and the absolute value of the angle formed with respect to the tire equator line in the winding direction of the long sheets is random. It is characterized by.

  In the tire of the present invention, the width of the long sheet is preferably 50 mm or less, and the winding direction of the long sheet is preferably 10 degrees or more and 45 degrees with respect to the tire equator line. Make the following angles. Moreover, in the tire of this invention, it is preferable that the said elongate sheet | seat is wound so that it may become two or more layers in the whole area | region where the said reinforcement layer is arrange | positioned. Furthermore, in the tire of the present invention, the reinforcing layer may be disposed at a position adjacent to the tread rubber.

  According to the present invention, it is possible to minimize the damaged area of the cord when the reinforcing layer is damaged, and thus it is possible to realize a tire with improved damage resistance.

It is a width direction sectional view showing an example of the tire of the present invention. (A)-(c) is a schematic diagram at the time of seeing the structural example of the reinforcement layer which concerns on this invention from the crown part tire radial direction outer side. It is explanatory drawing which shows the range of the code | cord | chord area | region which loses tension | tensile_strength by damage when damage arises in the reinforcement cord in the sheet | seat which comprises a reinforcement layer. It is a schematic diagram when the reinforcement layer which concerns on a comparative example is seen from the crown part tire radial direction outer side.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view in the width direction showing an example of the tire of the present invention. The illustrated tire 10 of the present invention includes a pair of bead portions 11, a pair of sidewall portions 12 connected to the outer side in the tire radial direction, and a tread portion 13 extending between the pair of sidewall portions 12. Consists of. The illustrated tire has a carcass 2 formed of at least one carcass ply extending in a toroidal shape between bead cores 1 embedded in a pair of bead portions 11, in the illustrated example, a carcass ply, and a crown portion of the carcass 2. On the outer side in the tire radial direction, a belt layer 3 including at least one belt, usually two or more, and in the illustrated example, two belts 3a and 3b is disposed.

  In the tire 10 of the present invention, a reinforcing layer 4 formed by winding a long sheet made of a composite of a reinforcing cord and a coating rubber is disposed on the outer side in the tire radial direction of the belt 3 in the crown portion. . The schematic diagram at the time of seeing the structural example of the reinforcement layer which concerns on FIG. 2 (a)-(c) from the crown part tire radial direction outer side is shown. As shown in the figure, the reinforcing layer 4 according to the present invention is formed by winding a long sheet 4a a plurality of times, and the winding direction is greater than 0 degrees and greater than 90 degrees with respect to the tire equator line CL. It has a small angle θ and is characterized in that the long sheets 4 a have a crossing place in the reinforcing layer 4. In addition, W in a figure shows the arrangement | positioning width | variety of a reinforcement layer.

  As described above, in the conventional reinforcing member, since the cords are formed in parallel with each other, when the cord is damaged due to trauma, the tension decreases in the longitudinal direction of the cord due to the damage. The area was getting bigger. On the other hand, in the present invention, when forming the reinforcing layer 4 by winding the long sheet 4a made of a narrow cord-rubber composite in a spiral shape, the sheet 4a and the sheets 4a are in the reinforcing layer 4 Since the sheet 4a is wound a plurality of times so as to cross each other, the sheets 4a are bound to each other. Therefore, as shown in FIG. 3, even when damage D occurs in the reinforcing cord in the sheet 4a constituting the reinforcing layer 4, the range of the cord region X that loses tension due to the damage can be minimized. The durability against multiple injuries can be dramatically improved. Moreover, the reinforcement layer 4 which concerns on this invention can contribute also to the improvement of the intensity | strength of a tire by having the structure where sheets 4a mutually restrain. Furthermore, when a belt using a steel cord is present below the reinforcing layer 4, rusting of the steel cord occurs due to the ingress of moisture from the road surface into the belt by improving the damage resistance by providing the reinforcing layer 4 This can also improve the effect of suppressing the occurrence of failure due to the rust of the steel cord.

  In the present invention, the winding angle of the sheet 4a needs to be an angle greater than 0 degree and smaller than 90 degrees with respect to the tire equator line, and preferably 10 degrees to 45 degrees. Shall be made. When the winding direction is 0 ° to 90 ° with respect to the tire equator line, the sheet 4a cannot be wound a plurality of times while crossing each other. By setting the winding direction in the range of 10 degrees or more and 45 degrees or less, the length of the sheet 4a existing between the restraint portions, that is, the length of the region where the tension is lowered when damage occurs, And since the number of parts restrained by crossing each other increases, it is more effective in improving durability.

  FIG. 2A shows a case where the reinforcing layer 4 is configured by winding the sheet 4a randomly in a range in which the winding direction forms an angle θ greater than 0 degrees and smaller than 90 degrees with respect to the tire equator line CL. Moreover, FIG.2 (b) shows the case where the reinforcement layer 4 is comprised by winding the sheet | seat 4a at random in the range in which the winding direction makes an angle θ of 10 degrees or more and 45 degrees or less with respect to the tire equator line CL. . Further, FIG. 2 (c) shows that the sheet 4a is wound so that the absolute value of the angle θ is constant within a range in which the winding direction forms an angle θ larger than 0 degree and smaller than 90 degrees with respect to the tire equator line CL. The case where the reinforcement layer 4 is comprised is shown. As shown in the drawing, in the present invention, the absolute value of the angle formed with respect to the tire equator line in the winding direction of the seat 4a may be random or constant, but from the viewpoint of uniformity. Is preferably constant.

  The long sheet 4a used in the present invention is composed of a composite of a reinforcing cord and a coating rubber, and may be composed of a rubberized layer of reinforcing cords arranged in parallel to the longitudinal direction of the sheet. It may be composed of a rubberized layer of reinforcing cords arranged at an angle with respect to the longitudinal direction of the sheet, or may be a rubber-coated canvas fabric in which reinforcing cords are plain-woven. When the sheet 4a is made of a rubberized layer of reinforcing cords arranged in parallel to the sheet longitudinal direction, the number of reinforcing cords constituting the sheet 4a is one or more, preferably 1 to 5. If the number of reinforcing cords is too large, the sheet 4a becomes too wide, and the range of the cord region X that loses tension due to damage is reduced, which makes it impossible to suppress damage resistance.

  The width of the long sheet 4a is preferably 50 mm or less, more preferably 20 mm or less, further preferably 5 mm or less, and preferably 1 mm or more. If the width of the sheet 4a is too large, the range of the cord region X that loses tension due to damage decreases, and the damage resistance cannot be suppressed. Further, the sheet 4a forming the reinforcing layer 4 may be one wound or two or more, for example, two or three, but in the present invention, preferably 1 The reinforcing layer 4 is formed by winding a sheet 4a made of a continuous sheet. The reason for this is to maximize the crossing location in the reinforcing layer 4 and to obtain an effect on the resistance to trauma.

  Since the tire of the present invention only has to have the reinforcing layer 4 formed by winding the sheet 4a a plurality of times in accordance with the above conditions, the number of windings of the sheet 4a, the number of intersections, etc. are not particularly limited. . Preferably, in the present invention, the sheet 4a is wound so as to have two or more layers, particularly three or more layers in the entire region where the reinforcing layer 4 is disposed. This makes it possible to more effectively improve the durability against a plurality of times of trauma.

  In the present invention, the reinforcing cord constituting the reinforcing layer 4 can be appropriately selected from those made of organic fibers, inorganic fibers, etc., which are usually used for reinforcing tires, and is particularly limited. is not. Specifically, examples of the organic fiber include aliphatic polyamide fiber (nylon), aromatic polyamide fiber (aramid), polyester fiber, polyparaphenylenebenzeneoxazole fiber, polyvinyl alcohol-based synthetic fiber, and carbon fiber. Examples of inorganic fibers include metal fibers such as steel filaments and glass fibers. In the present invention, an organic fiber cord is preferably used as the reinforcing cord. Any kind of organic fiber cord may be used. In addition to using a single yarn consisting of only one organic fiber, two or more cords consisting of only one organic fiber may be used. Alternatively, a hybrid cord obtained by twisting two or more kinds of organic fiber filaments may be used, and further, a cord whose raw yarn is composed of two or more kinds of organic fibers may be used.

  In the present invention, the reinforcing layer 4 is disposed for the purpose of improving the damage resistance, and is preferably disposed at a position adjacent to the tread rubber on the outer side in the tire radial direction of the carcass 2 and the belt layer 3. To do. In addition, the reinforcing layer 4 is arranged in a region where the tire is assembled on a prescribed rim, filled with a prescribed allowable lower limit internal pressure, and more than the maximum width of the tire ground contact surface that is grounded when a maximum load allowed by the internal pressure is applied. It is preferable that it is widely arranged all over the circumference. Here, the “specified rim” is a standard rim (or “Approved Rim” or “Recommended Rim”) in an applicable size described in a predetermined industrial standard, and the specified internal pressure is described in the standard. It is the air pressure corresponding to the maximum load (maximum load capacity) of a single wheel at a certain application size. The specified load is the maximum load (maximum load capacity) of a single wheel in the applicable size described in the standard. Predetermined industrial standards are defined respectively in regions where tires are produced or used. For example, in the United States, The Tire and Rim Association Inc. Yearbook (including design guides) from Europe, the European Tire and Rim Technical Organization, Standards Manual of Japan, and Japan, JATMA YEAR BOOK of Japan Automobile Tire Association.

  In the present invention, only the point provided with the reinforcing layer 4 made of the long sheet 4a is important, and the other points are not particularly limited, and can be appropriately configured according to a conventional method. Since the present invention is a technique related to the improvement of the trauma resistance, the present invention can be applied to any kind of tires such as small tires or large tires and radial tires or bias tires.

Hereinafter, the present invention will be described in more detail with reference to examples.
In accordance with the conditions shown in the following table, a tire layer of 205 / 55R16 is provided with a reinforcing layer formed by winding a long sheet made of a composite of a reinforcing cord and a coating rubber around the crown portion a plurality of times. A tire was produced. As the sheet, a sheet composed of a rubberized layer of reinforcing cords arranged in parallel to the longitudinal direction of the sheet was used, and the number of reinforcing cords to be driven was 6/5 mm. In addition, the carcass ply is a single sheet, and the belt layer has a structure in which two layers of belts made of one type of treat are arranged in an intersecting manner at an angle of 30 ° with respect to the tire circumferential direction. The reinforcing layer was disposed on the outer side in the tire radial direction of the crossing belt layer at a position adjacent to the tread rubber.

<Trauma resistance>
In the tread portion of each test tire, the cutter blade was inserted into the portion where the number of wound layers of the sheet was the minimum number of layers, and the internal cord was damaged. After that, each test tire was assembled on a rim with a rim size of 6.5J × 16, filled with the appropriate internal pressure, loaded with the appropriate load, conducted a long ground ram test at a speed of 80 km / h, and the time until failure occurred. It was measured. The results are shown as an index with the time of Comparative Example 1 as 100. The larger the value, the longer the time until failure occurs and the better the trauma resistance.

<High speed durability>
Each test tire is assembled on a rim with a rim size of 6.5 J × 16, filled with the appropriate internal pressure, loaded with the appropriate load, and started at a speed of 120 km / h with a drum tester, and at a speed of 10 km / h every 20 minutes. High-speed durability was evaluated by measuring the speed at the time of failure by running while stepping up by h. The results are shown as an index with the failure occurrence rate of Comparative Example 1 as 100. The higher the value, the higher the high-speed durability and the better.

＊１）図２（ａ）は、シートが、巻付け方向がタイヤ赤道線ＣＬに対し０度より大きく９０度より小さい角度θをなす範囲で、ランダムに巻き付けられている場合である。図２（ｂ）は、シートが、巻付け方向がタイヤ赤道線ＣＬに対し１０度以上４５度以下の角度θをなす範囲で、ランダムに巻き付けられている場合である。図２（ｃ）は、シート４ａが、巻付け方向がタイヤ赤道線ＣＬに対し±１５度の角度となるよう巻き付けられている場合である。図４は、シート４ａが、巻付け方向がタイヤ赤道線ＣＬに対し１度である一定の角度となるよう巻き付けられている場合である。
＊２）適正使用下接地幅とは、タイヤをＪＡＴＭＡ記載の規定リムに組み、規定の許容下限内圧を充填し、その内圧で許容される最大荷重を負荷した際に接地したタイヤ接地面の最大幅をいう。

* 1) FIG. 2A shows a case where the sheet is wound at random in a range in which the winding direction forms an angle θ larger than 0 degree and smaller than 90 degrees with respect to the tire equator line CL. FIG. 2B shows a case where the sheet is randomly wound in a range in which the winding direction forms an angle θ of 10 degrees to 45 degrees with respect to the tire equator line CL. FIG. 2C shows a case where the sheet 4a is wound such that the winding direction is an angle of ± 15 degrees with respect to the tire equator line CL. FIG. 4 shows a case where the sheet 4a is wound so that the winding direction is a constant angle of 1 degree with respect to the tire equator line CL.
* 2) The ground contact width under proper use is the maximum ground contact surface of the tire that is grounded when the tire is assembled on the specified rim described in JATMA, filled with the specified allowable lower limit internal pressure, and the maximum load allowed by the internal pressure is applied. It means a lot.

  As shown in the above table, tires according to the respective embodiments are provided with a reinforcing layer formed by winding a long sheet made of a composite of a reinforcing cord and a coating rubber on a crown portion under predetermined winding conditions. In comparison with the tires of the comparative examples that do not satisfy the above conditions, it was confirmed that good performance was obtained with respect to both the damage resistance and the high-speed durability.

1 Bead core 2 Carcass
3 Belt layer 3a, 3b Belt 4 Reinforcement layer 4a Long sheet 10 Tire 11 Bead part 12 Side wall part 13 Tread part

Claims (5)

In a tire provided with a reinforcing layer formed by winding a long sheet made of a composite of a reinforcing cord and a coating rubber on a crown portion,
The reinforcing layer is formed by winding the elongated sheet a plurality of times,
The winding direction of the long sheet forms an angle larger than 0 degrees and smaller than 90 degrees with respect to the tire equator line ,
Before SL elongated sheet to each other, it has a portion which intersect with the reinforcing layer, and the absolute value of the angle with respect to the winding direction of the tire equator line of the elongated sheets, is random A tire characterized by that. Width of the elongated sheet is, tire according to claim 1, wherein at 50mm or less. The tire according to claim 1 or 2, wherein a winding direction of the long sheet forms an angle of 10 degrees to 45 degrees with respect to the tire equator line. The tire according to any one of claims 1 to 3 , wherein the long sheet is wound so that there are two or more layers in the entire region where the reinforcing layer is disposed. The tire according to any one of claims 1 to 4 , wherein the reinforcing layer is disposed at a position adjacent to the tread rubber.

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