CN114537047B

CN114537047B - Belted and tire

Info

Publication number: CN114537047B
Application number: CN202111119596.3A
Authority: CN
Inventors: 松冈映史
Original assignee: Sumitomo Electric Tochigi Co Ltd
Current assignee: Sumitomo Electric Tochigi Co Ltd
Priority date: 2020-11-26
Filing date: 2021-09-24
Publication date: 2024-06-07
Anticipated expiration: 2041-09-24
Also published as: JP7548561B2; CN114537047A; JP2022084351A

Abstract

The invention aims to provide a belt and a tire which can be light in weight and improve durability when applied to the tire. The belt comprises a plurality of steel wires and rubber embedded with the plurality of steel wires, wherein the steel wires are single-wire steel wires, the section of the steel wires perpendicular to the length direction has a flat shape, the plurality of steel wires are arranged in a row in the section of the belt perpendicular to the length direction of the plurality of steel wires, the steel wires with different inclinations of long shafts are included, and the proportion of the number of the steel wires in the range of-30 DEG to +30 DEG is more than 50%.

Description

Belted and tire

Technical Field

The present disclosure relates to belts and tires.

Background

Patent document 1 proposes a pneumatic tire in which a belt layer including a plurality of aligned single wire wires is embedded on the outer peripheral side of a carcass layer in a tread portion, wherein the single wire wires have a flat cross-sectional shape, and the thickness of rubber under grooves in the tread portion is 1.0mm to 2.0mm.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2018-058515

Disclosure of Invention

Problems to be solved by the invention

According to the invention disclosed in patent document 1, by using a single wire that is not twisted as a reinforcing cord for a belt layer of a pneumatic tire, the amount of coating rubber for the belt layer can be reduced to reduce rolling resistance of the pneumatic radial tire.

However, in recent years, further performance improvement is demanded for tires. Accordingly, for example, in addition to the weight reduction for reducing rolling resistance, the durability of the tire is required to be improved. Further, a belt used for a tire is required to be lightweight and have improved durability when applied to a tire.

Accordingly, an object of the present disclosure is to provide a belt that can be lightweight and improve durability when applied to a tire.

Means for solving the problems

The belt of the present disclosure is provided with a plurality of steel wires and rubber embedding a plurality of the steel wires, wherein,

The steel wire is a single wire steel wire, a cross section of the steel wire perpendicular to the length direction has a flat shape,

In a cross section of the belt perpendicular to the longitudinal direction of the plurality of steel wires,

A plurality of the steel wires are arranged in a row,

Comprising said steel wires with different inclinations of the long axis,

The ratio of the number of the steel wires in a range of-30 DEG or more and +30 DEG or less, in which the inclination of the long axis of the steel wires is 50% or more.

Effects of the invention

According to the present disclosure, a belt that can be lightweight and improve durability when applied to a tire can be provided.

Drawings

Fig. 1 is a cross-sectional view in a plane perpendicular to the longitudinal direction of a steel wire that can be suitably used in a belt of an aspect of the present disclosure.

Fig. 2 is a cross-sectional view in a plane perpendicular to a longitudinal direction of a plurality of steel wires included in the belt of the belt according to an aspect of the present disclosure.

Fig. 3 is a cross-sectional view of a tire of an aspect of the present disclosure.

Fig. 4 is an explanatory diagram of an evaluation method of flexural rigidity.

Fig. 5 is an explanatory diagram of a three-roll fatigue test.

Description of the reference numerals

10. Steel wire

11. First straight line portion

12. A second straight line part

13. First curve part

14. Second curve part

101. Steel wire

102. Coating film

A ₁ Long axis

A ₂ short axis

O center

W width

H height

20. Belt harness

20A one side

20B another face

P plane surface

O _10A、O_10H center

10A-10H steel wire

21. Rubber material

L ₂₀ reference shaft

A _1A、A_1B、A_1C、A_1D、A_1E、A_1F、A_1G、A_1H Long axis

Angle theta _B、θ_C、θ_D、θ_E、θ_F、θ_H

D _10B distance

31. Tire with a tire body

32. Tread portion

33. Sidewall portion

34. Bead portion

35. Lining(s)

36. Carcass (belted)

37. Belted layer (belted)

38. Tire bead wire

CL center line

40. Test piece

41. First roller

42. Second roller

43. Third roller

A frame arrow

Distance between L centers

50. Test piece

51. First roller

52. Second roller

53. Third roller

Arrow B

Detailed Description

[ Description of embodiments of the present disclosure ]

First, embodiments of the present disclosure are exemplified and described. In the following description, the same or corresponding elements are denoted by the same reference numerals, and the same description is not repeated.

(1) The belt according to an aspect of the present disclosure is provided with a plurality of steel wires and rubber embedding the plurality of steel wires, wherein,

A plurality of the steel wires are arranged in a row,

Comprising said steel wires with different inclinations of the long axis,

As described above, as the steel wire, a steel wire having a flat cross section has been used from the past.

However, as described above, further improvement in performance is demanded for the belt and the tire using the belt, and further improvement in weight reduction and durability is demanded in the case of application to the tire.

The inventors of the present invention found that: by providing a belt in which a plurality of steel wires having a flat shape are arranged in a predetermined arrangement in a cross section (hereinafter, also referred to as a "cross section") perpendicular to the longitudinal direction of the plurality of steel wires, the weight can be reduced and the durability can be improved when applied to a tire. Specifically, the following 2 conditions are satisfied in the cross section of the belt perpendicular to the longitudinal direction of the plurality of steel wires, and when applied to a tire, the weight can be reduced and the durability can be improved. As the first condition, there is a steel wire having a belt with a long axis having a different inclination in the cross section. As the second condition, there is mentioned a case where the ratio of the number of steel wires in the range of-30 ° or more and +30° or less in the inclination of the major axis in the cross section among the plurality of steel wires contained in the belt is set to 50% or more.

The inventors of the present invention estimated as follows for the reason that the weight reduction and durability improvement are achieved when the belt is applied to a tire by satisfying the above 2 conditions.

The tire is mounted on an automobile or the like and receives a force from a road surface during running of the automobile. The belt disposed in the tire and the steel wire in the belt receive the same force from the road surface.

The road surface is usually not a completely flat surface, and is formed with irregularities due to small stones or the like, for example. In addition, the relationship between the road surface and the ground contact surface of the tire also changes according to the filling condition of the air of the tire or the like. Therefore, when the tire is mounted on an automobile or the like and driven, the tire and the wire disposed in the tire receive not only a force in a direction perpendicular to the ground contact surface of the tire but also a force inclined in a horizontal direction from the direction perpendicular to the ground contact surface of the tire, for example.

The flat steel wire has a straight portion, and by receiving a force from the road surface side in a direction perpendicular to the straight portion, durability in the case where compressive stress and tensile stress are generated in the steel wire can be improved. However, as described above, when the tire is mounted on an automobile or the like and driven, the wire receives not only a force in a direction perpendicular to the ground contact surface of the tire but also a force inclined in a horizontal direction from the direction perpendicular to the ground contact surface of the tire, for example.

In the case where the belt includes steel wires having different inclinations of the long axis in the cross section as described above, the belt includes steel wires having different inclinations of the straight portion. Thus, the following steel wires are included: the force inclined in the horizontal direction from the direction perpendicular to the ground contact surface of the tire corresponds to the perpendicular direction of the straight portion. As a result, it is considered that the durability of the tire including the belt can be improved. Further, according to the study of the inventors of the present invention, the durability of a tire including the belt can be improved particularly by setting the ratio of the number of steel wires in the range of-30 ° or more and +30° or less, from among the plurality of steel wires, to 50% or more.

The thickness of the belt may be set to a value obtained by adding a predetermined rubber thickness, which is determined so that the steel wire can be embedded, to an average value of the thicknesses of the plurality of steel wires disposed in the belt. As described above, the plurality of steel wires disposed in the belt include steel wires having different inclinations of the long axis. Thus, the average value of the thicknesses of the individual steel wires along the thickness direction of the belt becomes the average value of the thicknesses of the plurality of steel wires disposed in the belt.

When the ratio of the number of steel wires in the range of-30 ° or more and +30° or less, among the plurality of steel wires, is 50% or more, the average value of the thicknesses of the plurality of steel wires disposed in the belt can be suppressed as compared with the case where the ratio is less than 50%. As a result, the thickness of the belt can be suppressed, and the amount of rubber contained in the belt can be suppressed to reduce the weight of the belt, so that the tire including the belt can also be reduced in weight.

(2) The ratio of the number of the steel wires in the range of-70 ° or more and less than-30 ° or more than +30° and +70° or less may be 10% or more and 50% or less.

The steel wire having the inclination of the long axis in the above range has higher bending rigidity when a force is applied in the thickness direction of the belt than the steel wire having the inclination of the long axis of 0 °. Accordingly, by setting the ratio of the number of steel wires having the inclination of the long axis in the above range to 10% or more, the bending rigidity as the belt can be improved as compared with the case where the ratio is less than 10%. Here, the bending rigidity means bending rigidity in the case where a force is applied in the thickness direction of the belt. Therefore, when the belt contains 10% or more of the steel wires whose long axes are inclined in the above range in the ratio of the number of strips, deformation when a force is applied to the belt in the thickness direction can be suppressed. In addition, in the case where the belt is applied to a tire, deformation when a force is applied to the belt in the thickness direction in the tire can be suppressed. Thus, repeated deformation of the belt, breakage of the belt, tire including the belt, and the like can be suppressed.

By setting the ratio of the number of steel wires having the inclination of the major axis in the above range to 50% or less, the ratio of the number of steel wires having the inclination of the major axis in the above cross section in the range of-30 ° or more and +30° or less can be ensured. Thus, the durability of the tire including the belt can be improved. In addition, the belt can be made light, and the tire including the belt can also be made light.

(3) In the case of the steel wire, in a cross section perpendicular to the longitudinal direction of the steel wire,

The profile of the cross section has:

A first straight line portion;

a second linear portion disposed so as to face the first linear portion; and

A first curve part and a second curve part, which connect the first straight line part and the second straight line part,

The first curved portion and the second curved portion are arranged in an opposing manner,

When the maximum distance between the first curved portion and the second curved portion is set to be the width W and the maximum distance between the first straight portion and the second straight portion is set to be the height H,

The ratio of the height H to the width W, i.e., the flattening ratio, is 49% or more and 65% or less.

This is because, when the flattening ratio of the steel wire is 49% or more, the amount of work applied to the steel wire can be suppressed when flattening the steel wire, and the durability of the steel wire can be improved in particular.

For example, a steel wire can be processed into a predetermined shape by pressing and rolling the steel wire before processing, which has a circular cross section perpendicular to the longitudinal direction, with a roll or the like. Thus, the above-mentioned working amount means a working amount, i.e., a deformation amount, until the wire is changed to a predetermined shape from before the working.

By setting the flattening ratio to 65% or less, the thickness of the steel wire can be suppressed, and the thickness of the belt can be suppressed, so that the belt and the tire using the belt are particularly lightweight.

(4) The elastic modulus of the rubber may be 5.0MPa or more and 10.0MPa or less.

When the elastic modulus of the rubber is 5.0MPa or more, it is considered that the riding comfort can be improved when the belt is applied to a tire.

By setting the elastic modulus of the rubber to 10.0MPa or less, deformation of the belt when a force is applied can be suppressed, and particularly durability of the belt and a tire using the belt can be improved.

(5) The density may be 15 bars/5 cm or more and 40 bars/5 cm or less.

By setting the belt density to 15 strips/5 cm or more, the durability of the belt and the tire using the belt can be improved in particular. By setting the belt density to 40 strips/5 cm or less, the amount of rubber between the cords can be ensured, and the riding comfort can be improved for a tire using the belt.

(6) The tire according to an aspect of the present disclosure can include the belt according to any one of (1) to (5).

The steel wire used in the belt according to any one of (1) to (5) has a flat cross section perpendicular to the longitudinal direction of the steel wire. In the belt, the inclination of the long axis of the steel wire falls within a predetermined range. Thus, as described above, the thickness of the belt can be reduced, and the belt and the tire using the belt can be reduced in weight.

In addition, the tire according to the aspect of the present disclosure can improve durability because it includes the aforementioned belt.

[ Details of embodiments of the present disclosure ]

Hereinafter, a specific example of a belt and a tire according to an embodiment of the present disclosure (hereinafter referred to as "the present embodiment") will be described with reference to the drawings. The present invention is not limited to these examples, and is intended to be indicated by the appended claims, with the intention of including all modifications which are equivalent in meaning and scope to the appended claims.

[ Belt shape ]

The belt according to the present embodiment may include a plurality of steel wires and rubber in which the plurality of steel wires are embedded.

The steel wire of the belt according to the present embodiment is a single wire steel wire. The cross section of the steel wire perpendicular to the longitudinal direction has a flat shape, and the plurality of steel wires can be arranged in a row in the cross section of the belt perpendicular to the longitudinal direction of the plurality of steel wires.

The belt according to the present embodiment includes steel wires having different inclinations of the long axes in the cross section of the belt perpendicular to the longitudinal direction of the plurality of steel wires. The ratio of the number of steel wires having a long axis inclination in the range of-30 DEG to +30 DEG can be 50% or more.

Hereinafter, the belt according to the present embodiment will be described with reference to fig. 1 and 2.

First, each member included in the belt of the present embodiment will be described.

(1) With respect to each member provided in the belt

(Steel wire)

Fig. 1 shows a cross-sectional view of a surface perpendicular to the longitudinal direction of a steel wire 10 that can be suitably used in the belt of the present embodiment.

As described above, the steel wire 10 is a single wire, i.e., 1 wire. The steel wire 10 is preferably not twisted in the longitudinal direction. That is, the steel wire 10 is preferably a straight steel wire.

As shown in fig. 1, the steel wire 10 can have a flat shape in a cross section perpendicular to the longitudinal direction. The flat shape means, for example, a shape having a height shorter than a width and being flat.

The steel wire can be disposed in the rubber of the belt. Since the thickness of the belt can be selected so that the steel wires arranged in a row are embedded in the rubber, the thickness of the belt can be suppressed by setting the cross-sectional shape of the steel wires to a flat shape. Therefore, by providing the steel wire having a flat cross-sectional shape, the amount of rubber contained in the belt can be suppressed as compared with the case where a round steel wire having the same cross-sectional area is used. Accordingly, the belt can be reduced in weight by the steel wire having a flat cross-section, and the tire including the belt can be reduced in weight.

As shown in fig. 1, in a cross section perpendicular to the longitudinal direction of the wire 10, the wire 10 has an outer shape having a first linear portion 11 and a second linear portion 12 arranged so as to face the first linear portion 11. The outer shape of the cross section of the steel wire 10 according to the present embodiment may have a first curved portion 13 and a second curved portion 14 that connect the first straight portion 11 and the second straight portion 12.

The first straight portion 11 and the second straight portion 12 are preferably parallel as shown in fig. 1. Here, the term "parallel" does not mean parallel in a strict sense, but means that the 2 straight portions are arranged in parallel.

As shown in fig. 1, the first curved portion 13 and the second curved portion 14 are arranged in an opposing manner. The first curved portion 13 and the second curved portion 14 may be formed by connecting the end of the first straight portion 11 and the end of the second straight portion 12, and the shape thereof is not particularly limited. For example, as shown in fig. 1, each of the first curved portion 13 and the second curved portion 14 may have a curved shape protruding outward of the steel wire 10.

A straight line drawn between the first straight line portion 11 and the second straight line portion 12 so as to have equal distances from both straight line portions becomes the long axis a ₁. The straight line drawn so as to have equal distances from the first curved portion 13 and the second curved portion 14 becomes the short axis a ₂. The intersection of the major axis a ₁ and the minor axis a ₂ becomes the center O.

The maximum distance between the first curved portion 13 and the second curved portion 14 of the wire 10, that is, the specific dimension of the width W of the wire 10 is not particularly limited. The width W of the steel wire 10 is, for example, preferably 0.6mm or more and 1.5mm or less, and more preferably 0.7mm or more and 1.2mm or less. This is because, by setting the width W of the wire 10 to 0.6mm or more, the strength of the durable surface of the wire can be particularly improved.

The maximum distance between the first curved portion 13 and the second curved portion 14 means the distance between the first curved portion 13 and the second curved portion 14 at the longest portion.

In order to avoid the influence of the unevenness of the cross-sectional shape of the steel wire, the width W of the steel wire 10 is preferably an average value of values measured in a plurality of cross-sections of the steel wire perpendicular to the longitudinal direction. The width W of the wire 10 is more preferably an average value of measured values in 3 sections perpendicular to the longitudinal direction of the wire, for example. When the width W, which is the maximum distance between the first curved portion 13 and the second curved portion 14, is measured among a plurality of sections of the steel wire perpendicular to the longitudinal direction, and the average value is calculated, it is preferable to sufficiently set the distance between the adjacent sections. The length of the test piece of the steel wire is also considered, but for example, the distance between adjacent sections is preferably 1cm or more and 5cm or less.

The specific dimension of the height H of the wire 10, which is the maximum distance between the first straight line portion 11 and the second straight line portion 12 of the wire 10, is not particularly limited, but is preferably 0.3mm or more, more preferably 0.4mm or more.

The maximum distance between the first straight line portion 11 and the second straight line portion 12 means the distance between the first straight line portion 11 and the second straight line portion 12 at the longest portion.

This is because the strength of the steel wire can be particularly improved by setting the height H of the steel wire to 0.3mm or more.

The upper limit of the height H of the steel wire is not particularly limited, but is, for example, preferably 1.0mm or less, and more preferably 0.7mm or less. This is because, by setting the height H of the steel wire to 1.0mm or less, the thickness of the belt including the steel wire and the amount of rubber included in the belt can be suppressed, and therefore, the belt using the steel wire and the tire including the belt can be reduced in weight.

The height H is preferably an average value of values measured in a plurality of sections of the wire perpendicular to the longitudinal direction, as in the case of the width W. In particular, the height H is more preferably an average value of measured values in 3 sections of the steel wire perpendicular to the longitudinal direction. When the height H is measured in 3 sections of the wire perpendicular to the longitudinal direction and an average value is calculated, the distance between adjacent sections is preferably 1cm to 5cm, although the length of the test piece of the wire is also considered.

The flattening ratio of the steel wire 10 is not particularly limited, but is preferably 49% or more and 65% or less. The flattening ratio is a ratio of the height H, which is the maximum distance between the first linear portion 11 and the second linear portion 12, to the width W, which is the maximum distance between the first curved portion 13 and the second curved portion 14, and is calculated by (flattening ratio (%)) =h/w×100.

This is because, according to the study of the inventors of the present invention, the flattening ratio is set to 49% or more, and the amount of work applied to the steel wire can be suppressed when flattening the steel wire, so that the durability of the steel wire can be improved in particular.

By setting the flattening ratio to 65% or less, the thickness of the steel wire can be suppressed, and the thickness suppression of the belt can be suppressed, so that the belt and the tire using the belt are particularly lightweight.

The flattening ratio is more preferably 50% or more and 60% or less.

The material of the steel wire 10 is not particularly limited, but the steel wire may have a structure in which a steel wire 101 and a plating film 102 is disposed on the surface of the steel wire 101, as shown in fig. 1, for example.

As the steel wire 101, a high carbon steel wire can be suitably used.

Further, as the plating film 102, for example, a brass plating film which is a plating film whose metal component contains only Cu (copper) and Zn (zinc) may be used, but a metal component other than Cu and Zn may be further contained. The coating film may further contain, for example, 1 or more kinds of elements selected from Co (cobalt) and Ni (nickel) as metal components.

That is, the steel wire can have a brass plating film containing Cu and Zn, for example. The brass plating film may further contain 1 or more kinds of elements selected from Co and Ni. As described above, the brass plating film can be disposed on the surface of the steel wire, for example.

When the steel wire is coated with a brass plating film containing Cu and Zn and vulcanized to form a belt or a tire, an adhesive layer containing Cu ₂ S can be formed on the rubber side of the interface between the steel wire and the rubber. Zn has an effect of promoting the production of Cu ₂ S. By forming the adhesive layer, the adhesion between the steel wire and the rubber can be improved, and the belt and the tire having excellent durability in particular can be obtained.

In addition, co and Ni have a greater ionization tendency than Zn. Therefore, the brass plating film further contains 1 or more kinds of elements selected from Co and Ni, and the 1 or more kinds of elements selected from Co and Ni function as sacrificial corrosion inhibitors, or the synthetic potential of Cu and Zn is made high, whereby the corrosion resistance of the brass plating film can be improved. As a result, the adhesion between the steel wire and the rubber can be further improved, and the durability of the belt and the tire can be further improved.

(Rubber)

The rubber of the belt can be produced by molding a composition of the rubber and vulcanizing if necessary.

The specific composition of the rubber can be selected according to the application of the tire to which the belt according to the present embodiment is applied, the characteristics required for the tire, and the like, and is not particularly limited. The rubber may contain, for example, a rubber component, sulfur, and a vulcanization accelerator.

The rubber component preferably contains 60 mass% or more, more preferably 70 mass% or more, and still more preferably 100 mass% or more of 1 or more kinds of rubber selected from natural rubber (NR: natural rubber) and isoprene rubber (IR: isoprene rubber), for example, in the rubber component.

This is because the ratio of 1 or more kinds of rubber selected from the natural rubber and the isoprene rubber in the rubber component is preferably 60 mass% or more, whereby the breaking strength of the belt or the tire can be improved.

Examples of the rubber component to be used in combination with the natural rubber or the isoprene rubber include 1 or more kinds of rubber selected from styrene-butadiene rubber (SBR), butadiene Rubber (BR), ethylene-propylene-diene rubber (EPDM), chloroprene Rubber (CR), butyl rubber (IIR), and nitrile rubber (NBR).

The sulfur is not particularly limited, but for example, sulfur generally used as a vulcanizing agent in the rubber industry can be used.

The sulfur content of the rubber is not particularly limited, but is preferably set to, for example, 5 mass parts or more and 8 mass parts or less with respect to 100 mass parts of the rubber component.

This is because, by setting the ratio of sulfur to 100 parts by mass of the rubber component to 5 parts by mass or more, the crosslinking density of the obtained rubber can be increased, and in particular, the adhesion force between the steel cord and the rubber can be increased. In addition, the ratio of sulfur to the rubber component 100 mass part is preferably 8 mass parts or less, since sulfur can be dispersed particularly uniformly in rubber, and the occurrence of blooming can be suppressed.

The vulcanization accelerator is not particularly limited, and for example, a sulfenamide accelerator such as N, N' -dicyclohexyl-2-benzothiazolyl sulfenamide, N-cyclohexyl-2-benzothiazolyl sulfenamide, N-t-butyl-2-benzothiazolyl sulfenamide, or N-oxydivinyl-2-benzothiazolyl sulfenamide is suitably used. Further, if desired, thiazole-based accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide, tetrabenzyl thiuram disulfide, tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, tetra (2-ethylhexyl) thiuram sulfide, tetramethyl thiuram monosulfide and the like may be used.

The rubber composition used in the belt of the present embodiment can be produced by kneading, heating, and extruding these components by a common method.

The rubber of the belt according to the present embodiment preferably contains 1 or more kinds selected from cobalt monomers and cobalt-containing compounds.

Examples of the cobalt-containing compound include cobalt organic acid and cobalt inorganic acid.

As the organic acid cobalt, for example, 1 or more kinds selected from cobalt naphthenate, cobalt stearate, cobalt neodecanoate, cobalt rosinate, cobalt versatate, and cobalt tall oil acid can be preferably used.

The cobalt organic acid may be a complex salt obtained by substituting a part of the organic acid with boric acid.

As the inorganic cobalt acid, for example, 1 or more kinds selected from cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt phosphate, and cobalt chromate can be preferably used.

In particular, the belt rubber of the present embodiment more preferably contains cobalt organic acid. This is because the initial adhesion property between the steel wire and the rubber can be particularly improved by containing the organic acid cobalt. The initial adhesion performance means adhesion performance between the steel wire and the rubber immediately after vulcanization, for example, in the production of a tire.

In addition, according to the study of the inventors of the present invention, by adding cobalt to rubber, the proportion of Cu ₂ S in the adhesive layer can be increased, and the adhesion between the steel wire and the rubber can be improved. In addition, when cobalt organic acid is used as the added cobalt, this tendency is remarkable. Accordingly, the rubber of the belt according to the present embodiment preferably contains cobalt, particularly cobalt organic acid, and thus can be used as a belt or a tire having excellent durability in particular.

The rubber may contain any component other than the rubber component, sulfur, a vulcanization accelerator, cobalt, and the like. The rubber may contain a known additive for rubber such as a reinforcing agent (carbon black, silica, etc.), wax, and an aging inhibitor.

The elastic modulus of the rubber used in the belt of the present embodiment is not particularly limited, but is, for example, preferably 5.0MPa to 10.0MPa, more preferably 6.0MPa to 9.0 MPa.

The elastic modulus of rubber is an index indicating the viscoelasticity of rubber. The elastic modulus of rubber is also known as complex elastic modulus, dynamic viscoelasticity. The elastic modulus of the rubber was measured at an initial load of 150g, a vibration frequency of 50Hz, a dynamic strain of 1% and a temperature of 70℃using a spectrometer manufactured by Toyo Seisakusho-ji Co., ltd. With respect to a test piece having a width of 5mm, a thickness of 2mm and a length of 20 mm. The elastic modulus of the rubber can be adjusted by the kind and blending of the rubber composition used.

(2) Structure for belt

As shown in fig. 2, the belt 20 of the present embodiment may have a plurality of steel wires 10 and rubber 21 embedding the steel wires 10. As shown in fig. 2, the section of the steel wire 10 has a flat shape. In fig. 2, the X-axis direction perpendicular to the paper surface is the longitudinal direction of the steel wire 10. In fig. 2, a plurality of steel wires 10 are arranged in a row along the Y-axis direction corresponding to the width direction of the belt. In fig. 2, the Z-axis direction becomes the thickness direction of the belt 20.

The inventors of the present invention found that: by providing a belt in which a plurality of flat-shaped steel wires are arranged in a predetermined arrangement in a cross section perpendicular to the longitudinal direction of the plurality of steel wires, the weight can be reduced and the durability can be improved when applied to a tire. Specifically, the following 2 conditions are satisfied in the cross section of the belt perpendicular to the longitudinal direction of the plurality of steel wires, and when applied to a tire, the weight can be reduced and the durability can be improved. As the first condition, there is a steel wire having a belt with a long axis having a different inclination in the cross section. As the second condition, there is a belt in which the ratio of the number of steel wires in the range of-30 ° or more and +30° or less in the inclination of the major axis in the cross section is set to 50% or more.

The inventors of the present invention estimated as follows for the reason that the weight reduction and durability improvement in the case of applying the belt to a tire are achieved by satisfying the above 2 conditions with the belt.

The road surface is usually not a completely flat surface, and is formed with irregularities due to small stones or the like, for example. In addition, the relationship between the road surface and the ground contact surface of the tire also changes according to the filling condition of the air of the tire or the like. Therefore, when the tire is mounted on an automobile or the like and driven, the tire and the wire disposed in the tire receive not only a force in a direction perpendicular to the ground contact surface of the tire from the road surface side, but also a force inclined in a horizontal direction from the direction perpendicular to the ground contact surface of the tire, for example.

As described above, the flat steel wire has the first straight line portion 11 and the second straight line portion 12, and the durability when compressive stress or tensile stress is generated in the steel wire can be improved by receiving force in a direction perpendicular to the straight line portion from the road surface side.

However, as described above, when the tire is mounted on an automobile or the like and driven, the wire receives not only a force in a direction perpendicular to the ground contact surface of the tire but also a force inclined in a horizontal direction from the direction perpendicular to the ground contact surface of the tire, for example.

As described above, when the belt includes steel wires having different inclinations of the long axis in the cross section, the belt includes steel wires having different inclinations of the straight portions. Therefore, the force inclined in the horizontal direction from the direction perpendicular to the ground contact surface of the tire is included as the steel wire in the perpendicular direction of the straight portion. As a result, it is considered that the durability of the tire including the belt can be improved.

Further, according to the study of the inventors of the present invention, the durability of a tire including the belt can be improved particularly by setting the ratio of the number of steel wires in the range of-30 ° or more and +30° or less, from among the plurality of steel wires, to 50% or more.

The thickness of the belt 20 may be set to a value obtained by adding a predetermined rubber thickness determined so that the steel wire 10 can be embedded to an average value of the thicknesses of the plurality of steel wires 10 disposed in the belt 20. As described above, the plurality of steel wires 10 disposed in the belt 20 include steel wires having different inclinations of the long axis. Accordingly, the average value of the thicknesses of the individual steel wires 10 along the thickness direction of the belt 20 becomes the average value of the thicknesses of the plurality of steel wires 10 arranged in the belt 20.

In the case of the steel wire 10B of fig. 2, the thickness of each steel wire 10 along the thickness direction of the belt 20 corresponds to the distance D _10B between the lowermost end and the uppermost end of the steel wire 10B in the thickness direction of the belt 20 (i.e., the Z-axis direction in fig. 2).

When the ratio of the number of steel wires in the range of-30 ° or more and +30° or less, among the plurality of steel wires, is 50% or more, the average value of the thicknesses of the plurality of steel wires disposed in the belt can be suppressed as compared with the case where the ratio is less than 50%. As a result, the thickness of the belt can be suppressed, the amount of rubber contained in the belt 20 can be suppressed, and the belt 20 can be reduced in weight, so that the tire including the belt can be reduced in weight.

As described above, the ratio of the number of steel wires in the range of-30 ° or more and +30° or less in the inclination of the major axis in the cross section among the plurality of steel wires is preferably 50% or more, more preferably 60% or more.

The ratio of the number of steel wires in the range of-30 ° or more and +30° or less in the inclination of the major axis in the cross section among the plurality of steel wires is preferably 90% or less, more preferably 80% or less. By setting the ratio of the number of steel wires having a long axis inclination in the range of-30 ° or more and +30° or less to 90% or less, the number of steel wires having a long axis inclination in the range of-70 ° or more and less than-30 ° or more and +30° or less than +70° can be sufficiently ensured. Therefore, as will be described later, deformation when a force is applied to the belt in the thickness direction can also be suppressed.

In measurement of the inclination of the long axis of the steel wire in the belt, the belt to be measured is first pressed against a flat surface. Specifically, for example, as shown in fig. 2, the belt 20 is pressed against the flat surface P and is disposed along the flat surface P. At this time, a weight (load) or the like is preferably placed on the other surface 20B of the belt 20 on the opposite side of the one surface 20A that contacts the flat surface P, and the entire belt 20 is pressed against the flat surface P. The weight of the weight is not particularly limited, but for example, a weight of 2kg or more and 10kg or less is preferably disposed for each 100cm ² area of the other surface 20B of the belt 20. By setting the weight of the weight per 100cm ² of the other surface 20B of the belt 20 to 2kg or more, the belt can be uniformly pressed against the flat surface P, and by setting the weight to 10kg or less, excessive deformation of the belt due to the weight can be suppressed. The weight preferably presses the other face 20B of the belt 20 uniformly as a whole.

Next, a reference axis L ₂₀, which is a straight line connecting the center O _10A of the steel wire 10A located at both ends in the arrangement direction of the steel wires 10 of the belt 20 and the center O _10H of the steel wire 10H, is drawn.

The center O _10A、O_10H of each wire 10A, 10H is the intersection point of the long axis a ₁ and the short axis a ₂ (see fig. 1) in the cross section perpendicular to the longitudinal direction of each wire.

Then, the inclination of the long axis of each wire can be obtained with reference to the reference axis L ₂₀. For example, in the case of the wire 10B, an angle θ _B formed by the reference axis L ₂₀ serving as a reference and the long axis a _1B of the wire 10B becomes an inclination of the long axis a _1B. Similarly, with respect to the steel wires 10C, 10D, 10E, 10F, and 10H, the angle θ _C、θ_D、θ_E、θ_F、θ_H formed between the long axes a _1C、A_1D、A_1E、A_1F、A_1H and the reference axis L ₂₀ becomes the inclination of the long axes.

In the steel wires 10A and 10G, the long axes a _1A and a _1G are parallel to the reference axis L ₂₀, so that the inclination of the long axes becomes 0. The inclination of each long axis can be measured in a range of-90 ° or more and +90° or less. For example, when the long axis is positioned to rotate counterclockwise (i.e., in the left-hand direction) as compared with the reference axis L ₂₀ as in the long axis a _1C in fig. 2, the inclination of the long axis becomes negative. In addition, when the long axis is at a position rotated clockwise (i.e., in the rightward direction) with respect to the reference axis L ₂₀ as in the long axis a _1B in fig. 2, the inclination of the long axis becomes positive.

Unlike the case shown in fig. 2, when the reference axis L ₂₀ does not pass through the center of the wire for measuring the inclination of the long axis, a straight line parallel to the reference axis L ₂₀ and passing through the center of the wire for measuring the inclination of the long axis can be drawn, and the inclination of the long axis can be similarly obtained based on the straight line.

In the belt according to the present embodiment, in the above-described cross section, the ratio of the number of steel wires having a long axis inclination in the range of-70 ° or more and less than-30 ° or more than +30° and not more than +70° is preferably 10% or more and 50% or less, more preferably 25% or more and 45% or less.

The steel wire having the inclination of the long axis in the above range has higher bending rigidity when a force is applied in the thickness direction of the belt than the steel wire having the inclination of the long axis of 0 °. Accordingly, by setting the ratio of the number of steel wires having the inclination of the long axis in the above range to 10% or more, the bending rigidity as a belt can be improved as compared with the case where the ratio is less than 10%. Here, the bending rigidity means bending rigidity in the case where a force is applied in the thickness direction of the belt. Therefore, when the belt according to the present embodiment contains steel wires having a long axis inclination of 10% or more in the above range in the ratio of the number of strips, deformation when a force is applied to the belt in the thickness direction can be suppressed. In addition, in the case where the belt is applied to a tire, deformation when a force is applied to the belt in the thickness direction in the tire can be suppressed. Thus, repeated deformation of the belt, breakage of the belt, tire including the belt, and the like can be suppressed.

The number of steel wires included in the belt according to the present embodiment is not particularly limited, and may be selected according to the performance and the like required for the belt and the tire using the belt. Here, the number of steel wires present per 5cm width of the belt in a cross section perpendicular to the longitudinal direction of the steel wires of the belt of the present embodiment is set to be the density. In this case, the density is, for example, preferably 15 or more and 40 or less, more preferably 20 or more and 35 or less, per 5 cm.

By setting the density of the belt according to the present embodiment to 15 strips/5 cm or more, the durability of the belt and the tire using the belt can be improved in particular. By setting the belt to 40 strips/5 cm or less, the rubber amount between the cords can be ensured, and the riding comfort can be improved for a tire using the belt.

[ Tyre ]

Next, a tire according to the present embodiment will be described with reference to fig. 3.

The tire of the present embodiment may include the belt described above.

Fig. 3 shows a cross-sectional view of the tire 31 of the present embodiment in a plane perpendicular to the circumferential direction. In fig. 3, only a portion on the left side of CL (center line) is shown, but the same structure is continuously provided on the right side of CL with CL as the symmetry axis.

As shown in fig. 3, the tire 31 has a tread portion 32, a sidewall portion 33, and a bead portion 34.

The tread portion 32 is a portion that contacts the road surface. The bead portion 34 is provided on the inner diameter side of the tire 31 than the tread portion 32. The bead portion 34 is a portion that contacts the rim of the wheel of the vehicle. The sidewall portion 33 connects the tread portion 32 and the bead portion 34. When the tread portion 32 receives an impact from the road surface, the sidewall portion 33 is elastically deformed to absorb the impact.

The tire 31 includes an inner liner 35, a carcass 36, a belt 37, and bead wires 38.

The inner liner 35 is made of rubber, and closes the space between the tire 31 and the wheel.

The carcass 36 forms the carcass of the tire 31. The carcass 36 is composed of organic fibers or steel wires of polyester, nylon, rayon, etc., and rubber. The aforementioned belt 20 can also be used in the carcass 36.

The bead wire 38 is provided in the bead portion 34. The bead wire 38 receives a tensile force acting on the carcass.

The belt 37 fastens the carcass 36 to increase the rigidity of the tread portion 32. In the example shown in fig. 3, the tire 31 has 2 belt layers 37.

The tire 31 shown in fig. 3 has a 2-layer belt layer 37, and the belt 20 shown in fig. 2 can be used for the belt layer 37.

The cross section of the steel wire 10 perpendicular to the longitudinal direction used in the belt 20 is flat. In the belt 20, the inclination of the long axis of the steel wire 10 is within a predetermined range. Accordingly, as described above, the thickness of the belt 20 can be reduced, and the belt 20 and the tire 31 using the belt 20 can be reduced in weight.

In addition, since the tire 31 includes the belt 20 described above, durability can be improved.

While fig. 3 shows the tire 31 having 2 belt layers 37, the tire of the present embodiment may have 1 or 3 or more belt layers 37.

Although the embodiments have been described in detail, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope described in the claims.

[ Example ]

Specific examples are described below, but the present invention is not limited to these examples.

(Evaluation method)

First, a method for evaluating a steel wire or a belt produced in the following experimental example will be described.

(1) Evaluation of the sectional shape of Steel wire

The steel wires produced in examples 1 to 5 were embedded in a transparent resin, and samples were cut so that the surfaces (cross sections) of the steel wires perpendicular to the longitudinal direction were exposed.

Then, the length and distance of each part in the cross section were measured using a projector.

The measurement of the length and distance of each portion was performed in 3 cross sections, and the average of the measured values of the length of each portion in 3 cross sections was set as the length of each portion of the steel wire. The positions of the 3 cross sections used for measurement were set so that the distance between the adjacent cross sections became 5 cm.

Specifically, the height H, which is the maximum distance between the first straight line portion 11 and the second straight line portion 12, was measured in 3 cross sections, and the average value was set as the height H of the steel wire 10 of each experimental example (see fig. 1).

The width W of the wire 10, which is the maximum distance between the first curved portion 13 and the second curved portion 14, was measured in 3 cross sections, and the average value was set as the width W of the wire 10 in each experimental example (see fig. 1).

The ratio of the height H to the width W, i.e., the flattening (%) was calculated from H/W.times.100.

(2) Inclination of long axis in belt

The belts produced in each experimental example were placed against a flat surface. Specifically, as shown in fig. 2, the belt 20 to be evaluated is disposed on the flat surface P so that one surface 20A is in contact with the flat surface. At this time, as shown in fig. 2, the belt 20 is arranged such that the arrangement direction of the plurality of steel wires 10 included in the belt 20 is along the flat surface P. Further, a weight of 2kg was placed on the other surface 20B of the belt 20 opposite to the surface in contact with the flat surface P. The other face 20B of the belt 20 to be evaluated was square with a side length of 100mm, and the belt 20 contained 40 steel wires 10. The weight is a square plate-like body having a shape of a side of 100mm in contact with the other surface 20B of the belt 20, and the other surface 20B of the belt 20 is covered with the weight as a whole, so that the other surface 20B of the belt 20 is uniformly pressed as a whole.

Next, as shown in fig. 2, a reference axis L ₂₀, which is a straight line connecting the center O _10A of the steel wire 10A located at both ends in the arrangement direction of the steel wires 10 of the belt 20 and the center O _10H of the steel wire 10H, is drawn. The center O _10A、O_10H of each wire 10A, 10H is the intersection point of the long axis a ₁ and the short axis a ₂ (see fig. 1) in the cross section perpendicular to the longitudinal direction of each wire.

Then, the inclination of the long axis of each wire was obtained based on the reference axis L ₂₀. Specifically, the inclination of the long axis of each wire was obtained based on a straight line passing through the center of each wire in parallel with the reference axis L ₂₀.

In the case of the wire 10B, the angle θ _B formed by the reference axis L ₂₀ and the long axis a _1B of the wire 10B becomes the inclination of the long axis a _1B. Similarly, the inclination of the long axis of the other steel wire 10 included in the belt 20 was obtained, and the distribution of inclination of the long axis of 40 steel wires included in the belt was measured.

The inclination of each long axis is measured in a range of-90 DEG to +90 DEG. If the long axis is positioned to rotate counterclockwise (i.e., in the left-hand direction) as compared with the reference axis L ₂₀ as in the long axis a _1C in fig. 2, the inclination of the long axis is set negative. In addition, when the long axis is at a position rotated clockwise (i.e., in the rightward direction) with respect to the reference axis L ₂₀ as in the long axis a _1B in fig. 2, the inclination of the long axis is set to be positive.

The same belt was measured several times, and after the measurement error was confirmed, it was successfully confirmed to be within 1 °.

Each wire has a cross-sectional shape shown in fig. 1, and a straight line drawn between the first straight line portion 11 and the second straight line portion 12 so as to have equal distances from the two straight lines is set as a long axis a ₁.

(3) Flexural rigidity

The test pieces 40 of the belt produced in each experimental example below were arranged on the first roller 41 and the third roller 43 parallel to the Y axis in fig. 4. Then, a second roller 42 is disposed on the upper surface of the belt-equipped test piece 40 in the middle between the first roller 41 and the third roller 43. The second roller 42 is also parallel to the Y axis in the figure. The center-to-center distance L between the first roller 41 and the third roller 43 was 20mm. In the test piece 40 of the belt, the steel wire is disposed such that the longitudinal direction of the steel wire is along the X-axis direction in the drawing.

Then, the test piece 40 was pressed by the second roller 42 with a force of 10N along a frame arrow a parallel to the Z axis in the figure to displace the test piece by 1mm in the Z axis direction, and the bending rigidity of the test piece 40 was obtained.

The results of each experimental example were expressed as relative values with the results of experimental example 1 being 100.

The higher the value of the bending rigidity means that the higher the bending rigidity of the belt, the less likely to be deformed when a force is applied to the belt in the thickness direction.

(4) Three-roll fatigue test

As shown in fig. 5, a test piece 50 of a belt produced in the following experimental example was placed on a first roller 51, a second roller 52, and a third roller 53 each having a roller diameter of 25 mm. The second roller 52 is provided with a groove along the peripheral surface of the roller for preventing the test piece 50 from being greatly displaced in the direction perpendicular to the paper surface (specifically, the longitudinal direction of the roller) in fig. 5. The width of the groove, that is, the length of the groove along the longitudinal direction of the second roller was 22mm, and the width of the test piece 50 was 20mm so as to be accommodated in the groove. The width of the test piece 50 corresponds to the length of the test piece 50 in the direction perpendicular to the paper surface in fig. 5. The longitudinal direction of the test piece 50 described later means a direction perpendicular to the width of the test piece 50.

When the test piece 50 is set up on the 3 rolls, as shown in fig. 5, the positions of the rolls are adjusted so that the test piece 50 between the first roll 51 and the second roll 52 and the test piece 50 between the second roll 52 and the third roll 53 are parallel to each other. Further, a load of 29.4N was applied to the test piece 50 placed on the first to third rollers 51 to 53 along the longitudinal direction of the test piece 50. Then, the first to third rollers 51 to 53 are rotated, and the test piece 50 is first moved in the direction of arrow B in fig. 5. Subsequently, the first to third rollers 51 to 53 are rotated in the reverse direction, and the test piece 50 is moved in the direction opposite to the arrow B in the figure. The test pieces 50 were reciprocated to 1 set, and this operation was repeated. The rotational speed of each roller was set so that the reciprocating motion could be performed in 100 groups within 1 minute. Then, the number of the above-mentioned reciprocating groups of test pieces until cracks were generated on the surface of the test piece 50 was counted.

The test piece 50 as a belt is provided on the first to third rollers 51 to 53 so that the longitudinal direction of the test piece 50 and the longitudinal direction of the steel wire contained in the test piece 50 coincide with the conveyance direction of the test piece 50 at the time of the test.

When the test piece 50 is transported while applying a load along the longitudinal direction of the test piece 50 as described above, a force is applied to the test piece 50, for example, so as to twist the test piece 50 about the longitudinal direction of the test piece 50 as a rotation axis, due to uneven amounts of friction between the test piece 50 and the rollers. Thus, the test piece 50 is slightly deformed during the three-roller fatigue test. As a result, during the three-roller fatigue test, the test piece 50 receives not only a force in the direction perpendicular to the surface of the test piece 50 facing each roller, but also a force inclined in the horizontal direction from the perpendicular direction.

The results of each experimental example were expressed as relative values with the results of experimental example 5 being 100.

The higher the value of the three-roll fatigue test, the more excellent the durability.

(5) Weight index

The weights of the belts produced in each of the examples were measured, and the weights of the belts produced in each of the examples were expressed as an index, with the weight of the belt of example 5 being 100. The weight of each test piece was prepared so that the width and depth of the belt were 100mm, and the weight was measured. The width of the belt is the length in the Y-axis direction in fig. 2, which means the direction in which the plurality of steel wires are aligned. The depth of the belt is the length in the X-axis direction in fig. 2, and corresponds to the length in the longitudinal direction of the steel wire. The test pieces of the belt of each experimental example contained 40 steel wires.

(Experimental example)

The experimental conditions are described below. Examples 1 to 3 were comparative examples, and examples 4 and 5 were comparative examples.

Experimental example 1

A pre-processed wire having a circular cross section with a wire diameter of 0.83mm was prepared. The steel wire before working has a structure in which a brass plating film composed of Cu and Zn as metal components is disposed on the surface of a high-carbon steel wire.

The pre-processed wire is then fed to a rolling device and processed so as to have a flat cross-sectional shape as shown in fig. 1. The obtained steel wire was measured and calculated by the above-described steps, and the height H and width W were 0.55mm, 1.04mm and 52.9% in flatness.

The belt shown in fig. 2 was produced using the produced steel wire having a flat surface perpendicular to the longitudinal direction as a single wire steel wire.

In manufacturing the belt, a rubber composition containing a rubber component and an additive is prepared. The rubber composition contains 100 parts by mass of natural rubber as a rubber component. The rubber composition contained carbon black in an amount of 60 parts by mass, sulfur in an amount of 6 parts by mass, a vulcanization accelerator in an amount of 1 part by mass, zinc oxide in an amount of 10 parts by mass, and cobalt stearate in an amount of 1 part by mass, relative to 100 parts by mass of the rubber component, as an additive.

Then, using the above steel wire and rubber composition, a belt 20 having a structure using fig. 2 was produced. When the belt is manufactured, the inclination of the long axis of the steel wire included in the belt is adjusted by adjusting the force pressing the steel wire in the height direction and the force pulling the steel wire along the length direction thereof. As a result, it was successfully confirmed that the distribution of the inclination of the long axes of the plurality of steel wires was the results shown in table 1 in the cross section of the belt of experimental example 1 perpendicular to the longitudinal direction of the plurality of steel wires contained.

When the number of steel wires present per 5cm width of the belt in a cross section of the belt perpendicular to the longitudinal direction of the steel wires is set to be the density, the steel wires are arranged so that the density becomes 20 wires/5 cm. The thickness of the belt is set to a value obtained by adding a rubber thickness preset so that the steel wires can be embedded to an average value of the thicknesses of the plurality of steel wires arranged in the belt. The average value of the thicknesses of the plurality of steel wires disposed in the belt is already described, and therefore, the description thereof is omitted here.

The test piece for measuring the elastic modulus of the rubber was prepared using the rubber composition used, and after the elastic modulus of the rubber was measured, it was successfully confirmed to be 7.5MPa.

The elastic modulus of the rubber was measured using a spectrometer manufactured by Toyo Seiki Seisaku-Miao, inc. at an initial load of 150g, a vibration frequency of 50Hz, a dynamic strain of 1% and a temperature of 70℃with respect to a test piece having a width of 5mm, a thickness of 2mm and a length of 20 mm.

The evaluation results are shown in table 1.

Experimental example 2 to Experimental example 5

A belt was produced in the same manner as in experimental example 1, except that the inclination of the long axis of the steel wire included in the belt was changed by adjusting the force pressing the steel wire in the height direction and the force pulling the steel wire along the length direction at the time of producing the belt.

The distribution of the inclination of the long axis of the steel wire in the cross section of the belt of each experimental example perpendicular to the longitudinal direction of the plurality of steel wires contained is shown in table 1.

[ Table 1]

From table 1, the belts of examples 1 to 3, which included steel wires having different inclinations of the long axes and the ratio of the number of steel wires having an inclination of the long axes of-30 ° or more and +30° or less was 50% or more, were confirmed to be 117 or more as a result of the three-roll fatigue test. On the other hand, the belts of examples 4 and 5, in which the ratio of the number of steel wires having a long axis inclination of-30 ° or more and +30° or less was less than 50%, were confirmed to be inferior in durability to the belts of examples 1 to 3, as a result of the three-roll fatigue test, to be 103 and 100.

Further, with respect to the belts of the above-mentioned examples 1 to 3, it was confirmed that the belts of examples 4 and 5 having weight indexes of 93 to 96 and weight indexes of 98 and 100 were light. Therefore, it was confirmed that tires using the belts of examples 1 to 3 were lighter than tires using the belts of examples 4 and 5.

From the above results, it was successfully confirmed that the belts of examples 1 to 3 and the tires using the belts were lightweight and excellent in durability.

Claims

1. A belt comprising a plurality of steel wires and rubber embedded with the plurality of steel wires, wherein,

A plurality of the steel wires are arranged in a row,

Comprising said steel wires with different inclinations of the long axis,

The ratio of the number of the steel wires in the range of-30 DEG or more and +30 DEG or less of the inclination of the long axis among the plurality of steel wires is 50% or more,

The ratio of the number of the steel wires in the range of-70 DEG or more and less than-30 DEG or more than +30 DEG and less than +70 DEG to the inclination of the long axis among the plurality of steel wires is 10% or more and 50% or less,

The inclination of the long axis is determined by taking a straight line connecting centers of the steel wires located at both ends in the arrangement direction of the steel wires of the belt as a reference axis and taking the reference axis as a reference.

2. The belt according to claim 1,

In the case of the steel wire, in a section perpendicular to the longitudinal direction of the steel wire,

The profile of the cross section has:

A first straight line portion;

a second linear portion disposed so as to face the first linear portion; and

3. Belt according to claim 1 or 2,

The elastic modulus of the rubber is 5.0MPa or more and 10.0MPa or less.

4. Belt according to claim 1 or 2,

The density is 15 bars/5 cm or more and 40 bars/5 cm or less.

5. Belt according to claim 1 or 2,

The density is 20 bars/5 cm or more and 35 bars/5 cm or less.

6. A tire comprising the belt of any one of claims 1-5.