WO2019230763A1

WO2019230763A1 - Pneumatic tire

Info

Publication number: WO2019230763A1
Application number: PCT/JP2019/021227
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: JP2019209760A

Abstract

This pneumatic tire is provided with a belt in which a cord coated with a coating material is wound helically in the tire circumferential direction, and a resin member which is disposed outside or inside the belt in the tire radial direction. One or more through-holes are provided in the resin member.

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 has a lower gas permeability than a rubber member or the like, the air embraced at the time of tire molding or the gas emitted from the rubber at the time of vulcanization stays in the vicinity of the resin member, resulting in poor air entry. It can be considered.

Therefore, an object of the present invention is to provide a pneumatic tire in which occurrence of defective air entry is suppressed in a pneumatic tire provided with a resin member.

The gist configuration of the present invention is as follows.
The pneumatic tire of the present invention is a belt in a state where a cord covered with a coating material is spirally wound in the tire circumferential direction, a resin member disposed on the inner side or the outer side of the belt in the tire radial direction, With
The resin member is provided with one or more through holes.

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 occurrence of defective air entry is suppressed 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.

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.

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 FIG. 2 (in FIG. 1, illustration of the through hole 7 is omitted), in the tire 1 of this embodiment, the resin member 6 has one or more (many in the illustrated example) diameters. A through hole 7 of less than 1 mm is provided. As shown in FIG. 2, in the present 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. In the present embodiment, in the plan view of the resin member 6, the plurality of through holes 7 are arranged on an average of 1 to 10,000 per unit area of 10000 mm ² of the resin member 6. Further, as shown in FIG. 2, in the tire according to the present embodiment, a plurality of through holes 7 are arranged 100 to 10,000 per unit area 10000 mm ^{2 at} an arbitrary location of the resin member 6 (uniformly arranged). ing). Specifically, in this example, the through holes 7 are arranged in a staggered manner. That is, 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. In the other row, one row and the tire circumferential direction are arranged. The same diameter with a phase shift (in this example, the through-holes 7 in the other row are positioned at the midpoint of the two circumferentially adjacent through-holes 7 in the tire circumferential direction). And the shape of the through-hole 7 is arrange | positioned at equal intervals along the tire circumferential direction. 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 the present embodiment, the resin member 6 is provided with one or more (a large number in the illustrated example) through-holes 7 having a diameter of less than 1 mm. Air (including gas other than air) can escape through the holes 7, and air accumulation can be suppressed, so that occurrence of poor air entry of the pneumatic tire can be suppressed. Here, in order for air to escape, it is sufficient that the diameter of the through hole 7 is less than 1 mm. By making the diameter less than 1 mm, the rigidity of the resin member 6 can be prevented from being excessively lowered. On the other hand, the diameter of the through hole 7 is preferably set to 0.1 mm or more so that air can be surely removed during vulcanization of the tire.
In the present embodiment, the diameters of the plurality of through-holes 7 are all the same, and the plurality of through-holes 7 are arranged in a staggered manner as described above so that they are uniformly arranged on the resin member 6. . Thereby, while preventing the resin member 6 from having a portion where the rigidity is locally lowered by the through hole 7, it is possible to obtain the effect of letting out the air over the entire surface of the resin member 6, thereby further reducing the air-filling defect. Can be suppressed.
As described above, according to the pneumatic tire of the present embodiment, it is possible to suppress the occurrence of poor air entry.

FIGS. 3 to 6 are views showing first to fourth modified examples of the through-hole 7. In the following modifications, it is preferable that the diameters of the through holes 7 are all 0.1 mm or more and less than 1 mm.

As shown in FIG. 3, in the first modified example, the through holes 7 have the same diameter and are circular through holes 7 in plan view along the tire circumferential direction in one row and the other row, respectively. The one row and the other row have the same phase in the tire circumferential direction (in this example, the through-hole 7 in the other row is connected to the through-hole 7 in one row and the tire). The same position in the circumferential direction). In this example, the plurality of through holes 7 are arranged at equal intervals even in the tire width direction. Even with such a configuration, by uniformly disposing the through holes 7 in the resin member 6, while ensuring the rigidity of the resin member 6, air is exhausted over the entire surface of the resin member 6. The occurrence of defects can be suppressed.

As shown in FIG. 4, in the second modification, the through holes 7 have the same diameter, and the circular through holes 7 in a plan view are arranged randomly and uniformly. Even with such a configuration, by uniformly disposing the through holes 7 in the resin member 6, while ensuring the rigidity of the resin member 6, air is exhausted over the entire surface of the resin member 6. The occurrence of defects can be suppressed.

As shown in FIG. 5, in the third modified example, the through-hole 7 is a circular through-hole 7 in plan view of two types of diameters, and the tire circumferential direction is in one row and the other row, respectively. The one row and the other row are in the same phase in the tire circumferential direction (in this example, the through-hole 7 in the other row is connected to the through-hole 7 in one row and the tire). The same position in the circumferential direction). And the through-hole 7 from which a diameter differs by the through-hole 7 of one row | line | column adjacent to the tire width direction and the through-hole 7 of the other row | line | column is arrange | positioned. In each row, through-holes 7 having large diameters and through-holes 7 having small diameters are alternately arranged in the tire circumferential direction. Even with such a configuration, by uniformly disposing the through holes 7 in the resin member 6, while ensuring the rigidity of the resin member 6, air is exhausted over the entire surface of the resin member 6. The occurrence of defects can be suppressed.

As shown in FIG. 6, in the fourth modification, circular through holes 7 are arranged randomly and uniformly in a plan view of two types of diameters. Even with such a configuration, by uniformly disposing the through holes 7 in the resin member 6, while ensuring the rigidity of the resin member 6, air is exhausted over the entire surface of the resin member 6. The occurrence of defects can be suppressed. In the illustrated example, two types of diameters are used, but three or more types can be used. In any type, the size of the diameter is less than 1 mm, and preferably 0.1 mm or more. .

In the present invention, the resin member 6 has a plate shape, and in the plan view of the resin member 6, a plurality of through holes 7 are arranged on an average of 1 to 10,000 per unit area of 10,000 mm ² of the resin member 6. It is preferable.
By arranging one or more through-holes 7 per unit area 10000 mm ^2, it is possible to suppress the occurrence of poor air entry. On the other hand, by arranging no more than 10,000 through-holes 7 per unit area 10000 mm ² This is because the rigidity of the resin member 6 can be ensured.

In the present invention, the resin member 6 has a plate shape, and in the plan view of the resin member 6, a plurality of through holes 7 are arranged at 100 to 10,000 per unit area of 10,000 mm ^{2 at} an arbitrary portion of the resin member 6. It is preferable to become.
When the number of the through holes 7 per unit area at an arbitrary position is within the above range, the arrangement of the through holes 7 becomes uniform, and the resin member 6 does not have a portion where the rigidity is locally lowered by the through holes 7. This is because, on the other hand, it is possible to obtain the effect that the air escapes over the entire surface of the resin member 6, and it is possible to further suppress the occurrence of air entry defects.

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.
In any of the above-described embodiments and modifications, the planar shape of the through hole 7 is circular. However, in the present invention, the planar shape of the through hole 7 may be an elliptical shape or a polygonal shape such as a rectangular shape. In the case of an ellipse, the direction of the major axis of the ellipse is not particularly limited, and the direction can be aligned or made different between the plurality of through holes 7. Moreover, when setting it as a polygon, it is preferable that an acute angle part is not formed by giving the corner | angular part of the said polygon shape roundness.
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 (coated resin) (coated resin), 4b: cord, 5: tread, 6: resin member, 7 : 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
A pneumatic tire, wherein one or more through holes are provided in the resin member.
The pneumatic tire according to claim 1, wherein the diameter of the through hole is less than 1 mm.
The resin member is plate-shaped,
The pneumatic tire according to claim 1 or 2, wherein, in a plan view of the resin member, a plurality of the through holes are arranged on an average of 1 to 10,000 per unit area of 10,000 mm 2 of the resin member.
The resin member is plate-shaped,
4. The planar view of the resin member, wherein the plurality of through-holes are arranged in an amount of 100 to 10,000 per unit area of 10,000 mm 2 at an arbitrary position of the resin member. Pneumatic tires.