WO2019230765A1

WO2019230765A1 - Pneumatic tire

Info

Publication number: WO2019230765A1
Application number: PCT/JP2019/021229
Authority: WO
Inventors: 誓志今
Original assignee: 株式会社ブリヂストン
Priority date: 2018-05-31
Filing date: 2019-05-29
Publication date: 2019-12-05
Also published as: JP2019209756A

Abstract

This pneumatic tire is provided with a belt in which a cord coated with a coating material is wound in a helical shape in the circumferential direction of the tire, and a resin member which is disposed inside or outside the belt in the radial direction of the tire, and which extends continuously in the width direction of the tire, wherein at least one through hole is provided in at least one of two tire width direction regions of the resin member, extending respectively from the two ends of the belt in the width direction of the tire to positions in the width direction of the tire separated from the two ends by 1/3 of the width of the belt in the width direction of the tire.

Description

Pneumatic tire

The present invention relates to a pneumatic tire.

Conventionally, in a pneumatic tire, a belt is usually disposed outside the carcass in the tire radial direction in order to improve tire performance (for example, Patent Document 1).

The belt may be a belt in which a resin-coated cord or a rubber-coated cord or the like with a cord coated with a coating material such as resin or rubber is spirally wound in the tire circumferential direction (so-called spiral belt). Proposed.

Japanese Patent Laid-Open No. 10-035220

Since the belt in which the resin-coated cord or rubber-coated cord is spirally wound in the tire circumferential direction is inferior in the in-plane shear rigidity of the belt compared to the conventional two-layer crossing belt, a resin member or the like is further arranged. It is possible to reinforce the rigidity.

However, since the resin member deteriorates with time, and a large input is generated particularly at the end portion in the tire width direction, a problem such as a crack in the resin member may occur.

Therefore, an object of the present invention is to provide a pneumatic tire in which the durability of the resin member is improved in the pneumatic tire in which the resin member is arranged.

The gist configuration of the present invention is as follows.
The pneumatic tire of the present invention is arranged in a state in which a cord covered with a coating material is spirally wound in the tire circumferential direction, and is arranged on the inner side or the outer side in the tire radial direction of the belt, and is continuous in the tire width direction. And a resin member extending,
At least of two regions in the tire width direction from the both ends in the tire width direction of the belt of the resin member to the tire width direction position spaced from the both ends by 1/3 of the width in the tire width direction of the belt. One of them is characterized in that one or more through holes are provided.

In this specification, the diameter of the “through hole” refers to the maximum distance among the distances between any two points on the peripheral wall of the through hole in plan view.
Further, the “width in the tire width direction” and other dimensions in the present specification are measured in a state in which the tire is mounted on an applicable rim, filled with a specified internal pressure, and in a no-load state.
However, the “tire contact width” described later refers to the outermost position in the tire width direction of the contact surface when the tire is mounted on the applicable rim, filled with the specified internal pressure, and the maximum load is applied, Mounted on the applicable rim, filled with the specified internal pressure, and defined as the distance in the tire width direction between the ground contact ends in a no-load state.

In this specification, “applicable rim” is an industrial standard effective in the region where tires are produced and used. In Japan, JATMA (Japan Automobile Tire Association) JATMA YEAR BOOK, and in Europe, ETRTO (The European) Tire and Rim Technical Organization's STANDARDDS MANUAL, in the United States TRA (The Tire and Rim Association, Inc.) YEAR BOOK, etc. Standard rim (ETRTOSTANDAND in the applicable size to be described in the future) Refers to Measuring Rim, TRA's YEAR BOOK, Design Rim) (ie, “Rim” above) In addition to the current size, it includes the size that can be included in the above industry standards in the future.As an example of “applicable size to be described in the future”, it is described as “FUTURE DEVELOPMENTS” in ETRTO STANDARDDS MANUAL 2013 edition In the case of a size not described in the industry standard, it means a rim having a width corresponding to the tire bead width. The “specified internal pressure” refers to an air pressure (maximum air pressure) corresponding to the tire maximum load capacity of the standard such as JATMA in a tire of an applicable size. In the case of a size not described in the industry standard, the “specified internal pressure” refers to an air pressure (maximum air pressure) corresponding to a maximum load capacity specified for each vehicle on which a tire is mounted. “Maximum load load” is the tire maximum load capacity of the standard such as JATMA for the tire of the applicable size, or, in the case of a size not described in the industry standard, the maximum load capacity defined for each vehicle on which the tire is mounted. Means the load corresponding to.

According to the present invention, it is possible to provide a pneumatic tire in which the durability of the resin member is improved in the pneumatic tire in which the resin member is arranged.

1 is a schematic cross-sectional view in the tire width direction showing a pneumatic tire according to an embodiment of the present invention. It is a schematic plan view of the resin member of embodiment shown in FIG. It is a figure which shows the 1st modification of a through-hole. It is a figure which shows the 2nd modification of a through-hole. It is a figure which shows the 3rd modification of a through-hole. It is a figure which shows the 4th modification of a through-hole. It is a figure which shows the 5th modification of a through-hole. It is a figure which shows the 6th modification of a through-hole. It is a figure which shows the 7th modification of a through-hole.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view in the tire width direction showing a pneumatic tire according to an embodiment of the present invention. As shown in FIG. 1, the pneumatic tire 1 of the present embodiment (hereinafter also simply referred to as a tire) includes a carcass 3 straddling a bead core 2 a embedded in a pair of bead portions 2 in a toroidal shape. The tire 1 includes a belt 4 and a tread 5 in this order on the outer side in the tire radial direction of the crown portion of the carcass 3. As shown in FIG. 1, the tire 1 of the present embodiment has the same configuration between the half portions in the tire width direction with the tire equatorial plane CL as a boundary, but may be asymmetrical. .

The tire 1 of the present embodiment has a bead core 2a in which steel cords are bundled. The material and shape of the bead core are not particularly limited, or may have a structure without the bead core 2a. Moreover, in this embodiment, although the carcass 3 is comprised by the one carcass ply consisting of organic fiber, the material and the number of carcass plies are not particularly limited.

In this embodiment, the belt 4 is a spiral belt in a state in which a cord 4b covered with a covering rubber 4a that is a covering material is spirally wound in the tire circumferential direction. In the present embodiment, the belt 4 is preferably a single layer. It is because it is preferable from a viewpoint of weight reduction. The width of the belt 4 in the tire width direction can be, for example, 90 to 120% of the tire ground contact width. The thickness (maximum thickness) of the belt 4 is not particularly limited, but may be, for example, 0.3 to 3.5 mm. As the cord 4b, any known material can be used, for example, a steel cord can be used. The steel cord can be made of, for example, steel monofilament or stranded wire. The cord 4b can also use organic fiber, carbon fiber, or the like. For example, nylon or the like can be used as the organic fiber, and a single fiber or a plurality of single fibers twisted together can be used. The covering rubber 4a can be made of any known rubber material such as a rubber material usually used as a belt coating rubber. It should be noted that a rubber-coated cord in which one cord 4b is coated with a coating rubber 4a or a strip in which a plurality of cords 4b is coated with a coating rubber 4a is wound spirally. Can do.

As another embodiment, the belt 4 may be a spiral belt in which a cord 4b covered with a coating resin 4a that is a coating material is spirally wound in the tire circumferential direction. Also in this case, the belt 4 is preferably a single layer. It is because it is preferable from a viewpoint of weight reduction. Also in this case, the width of the belt 4 in the tire width direction can be, for example, 90 to 120% of the tire ground contact width. Also in this case, the thickness (maximum thickness) of the belt 4 is not particularly limited, but may be, for example, 0.3 to 3.5 mm. In this case as well, any known material can be used for the cord 4b. For example, a steel cord can be used. The steel cord can be made of, for example, steel monofilament or stranded wire. The cord 4b can also use organic fiber, carbon fiber, or the like. For example, nylon or the like can be used as the organic fiber, and a single fiber or a plurality of single fibers twisted together can be used. Further, as the coating resin 4a, for example, a thermoplastic elastomer or a thermoplastic resin can be used, and a resin that is cross-linked by heat or an electron beam or a resin that is cured by thermal dislocation can also be used. As thermoplastic elastomers, polyolefin-based thermoplastic elastomer (TPO), polystyrene-based thermoplastic elastomer (TPS), polyamide-based thermoplastic elastomer (TPA), polyurethane-based thermoplastic elastomer (TPU), polyester-based thermoplastic elastomer (TPC) And dynamic crosslinkable thermoplastic elastomer (TPV). Examples of the thermoplastic resin include polyurethane resin, polyolefin resin, vinyl chloride resin, polyamide resin and the like. Further, as the thermoplastic resin, for example, the deflection temperature under load (at the time of 0.45 MPa load) specified in ISO75-2 or ASTM D648 is 78 ° C or more, and the tensile yield strength specified in JIS K7113 is used. A material having a tensile breaking elongation of 50% or more as defined in JIS K7113 and a Vicat softening temperature (Method A) as defined in JIS K7206 of 130 ° C. or more can be used. The tensile elastic modulus (specified in JIS K7113: 1995) of the coating resin 4a that covers the cord 4b is preferably 50 MPa or more. This is because the belt rigidity can be reinforced and increased. The tensile modulus of the coating resin 4a that covers the cord 4b is preferably 1000 MPa or less. It is because riding comfort etc. can be maintained favorable. The coating resin 4a here does not include rubber (an organic polymer substance exhibiting rubber elasticity at room temperature). The resin-coated cord can be formed, for example, by coating a molten coating resin 4a on the outer peripheral side of the cord 4b and solidifying by cooling.

Further, as shown in FIG. 1, the tire 1 includes a resin member 6 that continuously extends in the tire width direction, which is plate-shaped in this example, on the inner side in the tire radial direction of the belt 4. In this embodiment, the resin member 6 is disposed on the inner side in the tire radial direction of the belt 4, but the resin member 6 may be disposed on the outer side in the tire radial direction of the belt 4. As shown in FIG. 1, in the present embodiment, the width of the resin member 6 in the tire width direction is larger than the width of the belt 4 in the tire width direction, but may be the same or smaller. The width of the resin member 6 in the tire width direction can be, for example, 80 to 130% of the tire ground contact width. The resin of the resin member 6 can be the same type of resin as the case where the coating material 4a of the belt cord 4b is a resin, but a different type of resin can also be used.

FIG. 2 is a schematic plan view of the resin member 6 of the embodiment shown in FIG. As shown in FIGS. 1 and 2 (FIG. 1 shows a cross section having no through hole 7), the width of the belt 4 in the tire width direction is 1 from the both ends of the belt 4 in the tire width direction. R is the two tire width direction regions up to the tire width direction position separated by / 3. At this time, in the tire 1 of the present embodiment, at least one (both in the present embodiment) of the resin member 6 in the tire width direction region R has one or more through holes 7 having a diameter of 1 mm or more. Is provided. As shown in FIG. 2, in the present embodiment, a plurality of through-holes 7 (five each in the tire width direction region R in the tire width direction half in the illustrated range) have the two tire width directions. In each region R, one row is arranged at equal intervals along the tire circumferential direction. As shown in FIG. 2, in this embodiment, the plurality of through holes 7 have the same diameter (in this example, the diameter does not change in the penetrating direction and is constant). Further, as shown in FIG. 2, in the present embodiment, the plurality of through holes 7 are all circular in plan view. Such through-holes 7 may be mechanically perforated using, for example, a needle-shaped one, a carbon dioxide laser or the like, or an organic fiber woven or knitted fabric heated and melted. The resin member 7 in which the through hole 7 is formed may be formed.
Hereinafter, the effect of the pneumatic tire of this embodiment is explained.

According to the pneumatic tire of the present embodiment, first, since the resin member 6 extending continuously in the tire width direction is disposed in addition to the belt 4, the rigidity of the belt 4 is sufficiently reinforced and enhanced. The steering stability can be improved.
Furthermore, in the pneumatic tire of this embodiment, since the through hole 7 having a diameter of 1 mm or more is provided in each of the tire width direction regions R of the resin member 6, at the end of the resin member 6 in the tire width direction. A large input that can be generated can be relaxed by the through-hole 7, and the occurrence and progress of cracks in the resin member 6 can be suppressed, and the durability of the resin member 6 can be enhanced. Specifically, with regard to crack propagation suppression, the stress concentration is mitigated by the tip of the generated crack reaching the through-hole 7, and progression can be prevented. Here, when the tire width direction region in which one or more through-holes 7 having a diameter of 1 mm or more are provided is inward in the tire width direction from the tire width direction region R, the resin member 6 is separated from the end in the tire width direction. Therefore, the large input that can occur at the end cannot be sufficiently mitigated. On the other hand, if the tire width direction region in which one or more through-holes 7 having a diameter of 1 mm or more are provided is outside the tire width direction region R in the tire width direction, the tire width direction of the resin member 6 can cause a large input. The rigidity of the end portion may decrease, and the durability of the resin member 6 may decrease. In particular, since the diameter of the through hole 7 is 1 mm or more, the above-described effect of relaxing input can be sufficiently obtained.
Moreover, in this embodiment, since the several through-hole 7 of the magnitude | size of the same diameter is arrange | positioned at equal intervals along the tire peripheral direction, the location where rigidity falls locally by the through-hole 7 does not arise. It is like that. Further, in the present embodiment, since the plurality of through holes 7 are provided in only one row along the tire circumferential direction, the rigidity of the through holes 7 is not reduced excessively. Thereby, steering stability etc. can be maintained favorable.
As described above, according to the pneumatic tire of the present invention, the durability of the resin member 6 can be improved.

FIGS. 3 to 9 are views showing first to seventh modified examples of the through hole 7. In the following modifications, all the diameters of the through holes 7 are 1 mm or more. In addition, from the viewpoint of preventing the rigidity of the resin member 6 from being excessively lowered, it is preferable that the diameters of the through holes 7 are all 12.0 mm or less. The diameter of the through hole 7 is most preferably 1.0 to 6.0 mm. Furthermore, the positions where the through holes 7 are provided are in the region R from the both ends in the tire width direction of the belt 4 to the tire width direction positions separated from the both ends by 1/6 of the width of the belt 4 in the tire width direction. It is more preferable to be within the two tire width direction regions R ′.

As shown in FIG. 3, in the first modification, the through holes 7 are arranged in a staggered manner in two rows in each of the tire width direction regions R. That is, in one tire width direction region R, in one row, the through holes 7 having the same diameter and circular in plan view are arranged at equal intervals along the tire circumferential direction. Are shifted in phase in the tire circumferential direction from the one row (in this example, the through-holes 7 in the other row are exactly the same in the tire circumferential direction of the two through-holes 7 adjacent to each other in the tire circumferential direction). The through-holes 7 having the same diameter and shape are arranged at equal intervals along the tire circumferential direction (to be located at the midpoint). Even with such a configuration, the durability of the resin member 6 can be improved. In particular, since the through holes 7 are provided in two rows in the tire width direction region R in each half of the tire width direction, the input can be more relaxed than in the case of one row. Further, in this configuration, it is possible to prevent a portion where the rigidity is locally lowered by the through-hole 7 from being generated evenly while providing the plurality of rows of the through-holes 7. In addition, even when three or more rows are provided, when they are arranged in a staggered manner, they can be similarly arranged with a phase shifted from the adjacent rows. In this case, although not particularly limited, for example, the phases in the tire circumferential direction can be aligned between the odd rows, and the phases in the tire circumferential direction can be aligned between the even rows. Further, in the first modification shown in FIG. 3, the staggered arrangement of the through holes 7 is symmetric with respect to the tire equator plane CL. However, an asymmetric staggered arrangement may be used.

As shown in FIG. 4, in the second modified example, the through holes 7 are arranged in two rows in each of the tire width direction regions R, have the same diameter, and are circular through holes 7 in plan view. However, one row and the other row are arranged at equal intervals along the tire circumferential direction, and one row and the other row have the same phase in the tire circumferential direction (the other row). The one through-hole 7 is located at the same position in the tire circumferential direction as one through-hole 7 in one row). Even with such a configuration, the durability of the resin member 6 can be improved. In particular, since the through holes 7 are provided in two rows in the tire width direction region R in each half of the tire width direction, the input can be more relaxed than in the case of one row. In addition, in each row, the through holes 7 have the same shape and are arranged at equal intervals along the tire circumferential direction. Therefore, it is possible to prevent a portion where the rigidity is locally lowered from occurring. In the illustrated example, the through holes 7 are arranged in two rows in each tire width direction region R, but may be three or more rows.

As shown in FIG. 5, the third modified example is different from the first modified example shown in FIG. 3 in that the through hole 7 is elliptical in plan view. In this example, the diameter and shape of the ellipse are all the same. In this example, it is an ellipse having a major axis in the tire width direction in plan view. According to this configuration, the durability in the resin member 6 can be improved by particularly relaxing input in the tire width direction. On the other hand, in the present invention, when the through-hole 7 is elliptical, the direction of the major axis is not limited to the tire width direction, and can be any direction. Moreover, when providing the several through-hole 7, it can also differ without aligning the direction of a long axis. Further, in the present invention, the planar shape of the through-hole 7 can be any shape such as a polygonal shape such as a quadrangle shape, but an acute angle portion such as by rounding the corner of the polygonal shape. Is preferably not formed.

As shown in FIG. 6, the fourth modification is different from the example shown in FIG. 2 in that the diameter of the through hole 7 is two types. In the illustrated example, the through holes 7a and 7b having two large and small diameters are alternately arranged in the tire circumferential direction so that a portion where the rigidity of the resin member 6 is locally reduced is not generated. Even with such a configuration, the durability of the resin member 6 can be improved. In this example, the diameter of the through-hole 7 is two types, but can be three or more types.

As shown in FIG. 7, in the fifth modified example, the tire width direction region R in one half portion in the tire width direction and the tire width direction region R in the other half portion in the tire width direction penetrate. The arrangement of the holes is different. Specifically, in the tire width direction region R in one half of the tire width direction, one row of through holes 7 having the same circular diameter in a plan view are arranged at equal intervals along the tire circumferential direction. . In the tire width direction region R in the other half of the tire width direction, the through holes 7 having the same circular diameter in a plan view are arranged in two rows in a staggered manner at equal intervals along the tire circumferential direction in each row. It is arranged. For example, since the input is different between the outside and the inside when the vehicle is mounted, it may be preferable that the through holes 7 are arranged differently between the tire width direction halves.

As shown in FIG. 8, in the sixth modification, the through holes 7 having the same circular diameter in plan view are arranged in one row in each of the tire width direction regions R in a direction inclined with respect to the tire circumferential direction. It is arranged. Even with such a configuration, the durability of the resin member 6 can be improved. In this example, in the tire width direction region R of one half of the tire width direction, the tire width direction is lined up in a direction inclined toward one side in the tire circumferential direction from the outer side in the tire width direction to the inner side, and the tire width In the tire width direction region R in the other half of the direction, the tires are lined up in the same direction inclined toward one side in the tire circumferential direction from the outer side in the tire width direction toward the inner side. On the other hand, as another example, in the tire width direction region R of one half of the tire width direction, the tire width direction is lined up in a row inclined in one direction in the tire circumferential direction from the outer side toward the inner side. In the other half of the tire width direction, the tire width direction region R may be arranged in a direction inclined toward the other side in the tire circumferential direction from the outer side in the tire width direction toward the inner side. In addition, although illustration shows the one part area | region of the tire circumferential direction, in this example, when the arrangement position of the through-hole 7 approaches the tire width direction edge part of the said tire width direction area | region R, it will return | fold, The through holes 7 are arranged in a zigzag shape.

As shown in FIG. 9, in the seventh modification, the circular through holes 7 in plan view are randomly (and uniformly) arranged with random diameters (all 1 mm or more in the illustrated example). Yes. Even with such a configuration, the durability of the resin member 6 can be improved.

In the present invention, the ratio of the total area of the through holes 7 to the total area of the two tire width direction regions R in a plan view is preferably 0.1% to 30%. By making the ratio 0.1% or more, it is possible to obtain an effect of relaxing input more reliably. On the other hand, by making the ratio 30% or less, the rigidity of the resin member 6 is excessively lowered. This is because the durability of the resin member 6 can be further improved within the above range. Similarly, the ratio of the total area of the through holes 7 arranged in the one tire width direction region R to the area of one tire width direction region R in a plan view is 0.1% to 30%. It is preferable that
In the present invention, the resin member 6 is preferably a plate-like member.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment at all. For example, in the embodiment shown in FIG. 1, the resin member 6 is disposed on the inner side in the tire radial direction of the belt 4, but may be disposed on the outer side in the tire radial direction of the belt 4. In the embodiment shown in FIG. 1, the width of the resin member 6 in the tire width direction is larger than the width of the belt 4 in the tire width direction, but the width of the resin member 6 in the tire width direction is the tire width of the belt 4. It may be smaller than the width in the direction or may be substantially the same width. Further, the thickness of the resin member 6 can be made larger, substantially the same as or smaller than the thickness of the belt 4.
Moreover, about the arrangement | positioning aspect of the through-hole 7, when it is set as the arrangement | sequence of multiple rows in the said tire width direction area | region R, the diameter of the through-hole 7 can also be changed with a row | line | column, The diameter of the through hole 7 can be made larger or smaller than the diameter of the through hole 7 in the inner row in the tire width direction. In the present invention, as shown in FIGS. 1 to 9, the through hole 7 is preferably provided only in the tire width direction region R.
In the present invention, as shown in FIGS. 1 to 9, it is preferable that the through hole 7 has one or more through holes 7 arranged in both of the two tire width direction regions R. One or more through-holes 7 may be disposed only in any one of them.
In the present invention, the diameter of the through hole 7 is preferably 1 mm or more.
In the present invention, it is also preferable to arrange the through holes 7 at equal intervals along the tire width direction.
In the embodiment shown in FIG. 1, the circumferential main grooves 8 (four in the illustrated example) continuously extending in the tire circumferential direction are provided, but the number of the circumferential main grooves 8 is particularly limited. Alternatively, the circumferential main groove 8 may not be provided.

1: pneumatic tire, 2: bead part, 2a: bead core, 3: carcass, 4: belt, 4a: coated rubber (coating resin) (coating material), 4b: cord, 5: tread, 6: resin member, 7 7a, 7b: through hole, 8: circumferential main groove, CL: tire equatorial plane

Claims

A belt in which a cord covered with a coating material is spirally wound in the tire circumferential direction;
A resin member disposed inside or outside in the tire radial direction of the belt, and continuously extending in the tire width direction,
At least of two regions in the tire width direction from the both ends in the tire width direction of the belt of the resin member to the tire width direction position spaced from the both ends by 1/3 of the width in the tire width direction of the belt. A pneumatic tire characterized in that one or more through holes are provided in any of them.
The pneumatic tire according to claim 1, wherein the diameter of the through hole is 1 mm or more.
The pneumatic tire according to claim 1 or 2, wherein the plurality of through holes are arranged at equal intervals along the tire circumferential direction.
The pneumatic tire according to any one of claims 1 to 3, wherein the plurality of through holes are arranged at equal intervals along the tire width direction.
The pneumatic tire according to claim 3 or 4, wherein the plurality of through holes have the same diameter.
The pneumatic tire according to claim 3, wherein the plurality of through holes are arranged in a zigzag pattern.
The pneumatic tire according to any one of claims 1 to 6, wherein the resin member is a plate-like member.