All-steel radial tire

Abstract

The invention discloses an all-steel radial tire, which relates to the field of radial tires, and comprises a tire tread and four belt layers, wherein the four belt layers comprise a first belt layer, a second belt layer, a third belt layer and a fourth belt layer, wherein the first belt layer comprises a left section, a middle section and a right section, and an outer contour of an axial section of the tire tread is formed by sequentially and smoothly connecting n tread arcs, wherein n is greater than or equal to 6, and the n tread arcs are symmetrically distributed along the center point of the tread, and the axial horizontal widths of the n tread arcs are L1, L2, L3, ..., L4, respectively. n The tread width of the tire tread is L. The present invention has a simple structure, optimizes the tread profile and belt structure, increases the modulus of the belt rubber and controls the tread and shoulder thickness ratio, can reduce the shear strain of the tire belt end points, and ensures uniform tire ground contact shape, reduces tire tread stress, improves tire durability, and thus reduces tire failure rate.

Description

Technical Field

[0001] The invention relates to the field of radial tires, in particular to an all-steel radial tire. Background Art

[0002] With the promulgation of the Chinese market regulations GB1589-2016 and the implementation of the new 921 policy on overweight control, domestic vehicle manufacturers need to reduce the total weight of vehicles and increase the carrying capacity of vehicles, thereby improving the market competitiveness of vehicles. At the same time, China's e-commerce has developed rapidly, greatly driving the development of the express logistics industry. The timeliness of express delivery is the primary indicator of competitiveness. Low-profile wide-base tires replace double tires with single tires, effectively reducing the weight of the vehicle, reducing the chassis height of the trailer, and increasing the volume of the container, thereby improving the vehicle's carrying capacity.

[0003] However, using a single tire instead of a dual tire also means that the single tire has a higher load, greater tire deformation, and higher heat generation. Since it is a single tire, once a failure occurs, it will have a great impact on the timeliness of the vehicle. Therefore, low-profile and wide-base tires have higher requirements for durability. The low-profile and wide-base tires in the existing technology cannot meet actual usage needs. Summary of the invention

[0004] The object of the present invention is to provide an all-steel radial tire, which solves the problems raised in the above-mentioned background technology by improving the tread size and belt layer size of the radial tire.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An all-steel radial tire comprises a tire tread and four belt layers.

[0007] The four belt layers include a first belt layer, a second belt layer, a third belt layer and a fourth belt layer. The first belt layer includes a left section, a middle section and a right section. The width of the left section and the right section of the first belt layer are the same, and the width range is 20% to 30% of the cross-sectional width. The extension directions of the left section, the middle section and the right section are the same as the circumferential direction of the tire. The thickness of the left section and the right section and the angle between the two and the circumferential direction are the same, and the thickness range is 1.6 to 2.0 mm. The extension direction of the middle section is the same as the extension direction of the left and right sections, and the thickness range of the middle section is 1.6 to 2.2 mm. The thickness range of the second belt layer, the third belt layer and the fourth belt layer is 1.8 to 2.2 mm. The extension direction of the second belt layer is the same as the middle section of the first belt layer, and the extension directions of the third belt layer and the fourth belt layer are opposite to the middle section of the first belt layer.

[0008] The outer contour of the tire tread in the axial section is formed by smoothly connecting n tread arcs in sequence, wherein n is greater than or equal to 6, and the n tread arcs are symmetrically distributed along the center point of the tread, and the axial horizontal widths of the n tread arcs are L 1 , L 2 , L 3 …L n The tread width of the tire tread is L, and the maximum height difference between the n tread arcs and the center point of the tire tread is h 1 、h 2 、h 3 …h n The radii of the n tread arcs satisfy R 1 =R n =K 1 *(L / 2) 2 / 8h 1 , R 2 =R n-1 =K 2 *(L / 2-L 1 ) 2 / 8h 2 , R 3 =R n-2 =K 3 *(L / 2-L 1 -L 2 ) 2 / 8h 3 , …, R 2 / n =R (2 / n)+1 =K 2 / n *(2 / LL 1 -L 2 -…-L (2 / n)-1 ) 2 / 8h 2 / n , the K 1 , K 2 , K 3 , …, K 2 / n The values ​​are all within the range of 0.8 to 4.2.

[0009] As a further solution of the present invention: the angle range between the left section and the right section of the first belt layer and the circumferential direction is 0° to 15°, the angle range between the middle section of the first belt layer and the circumferential direction is 45° to 60°, and the angle range between the second belt layer, the third belt layer and the fourth belt layer and the circumferential direction is 10° to 24°.

[0010] As a further solution of the present invention: n=6, the radii of the six tread arcs respectively satisfy R 1 =R 6 =K 1 *(L / 2) 2 / 8h1 , R 2 =R 5 =K 2 *((L / 2-L 1 )) 2 / 8h 2 , R 3 =R 4 =K 3 *(L / 2-L 1 -L 2 ) 2 / 8h 3 , the K 1 The value range of K is 0.8~0.9, 2 The value range of K is 2.0~3.0, 3 The value range is 3.5~4.0.

[0011] As a further solution of the present invention: n=8, the radii of the 8 tread arcs respectively satisfy R 1 =R 8 =K 1 *(L / 2) 2 / 8h 1 , R 2 =R 7 =K 2 *(L / 2-L 1 ) 2 / 8h 2 , R 3 =R 6 =K 3 *(L / 2-L 1 -L 2 ) 2 / 8h 3 , R 4 =R 5 =K 4 *(L / 2-L 1 -L 2 -L 3 ) 2 / 8h 4 , the K 1 The value range of K is 1.0~1.4, 2 The value range of K is 1.0~1.4, 3 The value range of K is 1.3~2.0, 4 The value range is 3.8~4.2.

[0012] As a further solution of the present invention: the value range of n is: 6≤n≤8.

[0013] As a further solution of the present invention: a rubber material is attached to the surface of the four-layer belt layer, and the tensile modulus of the rubber material is 6.0-7.0 MPa.

[0014] As a further solution of the present invention: the tire also includes a shoulder portion, and the thickness ratio of the shoulder portion to the tire tread is in the range of 1.0 to 1.3.

[0015] Compared with the prior art, the beneficial effects of the present invention are: the present invention has a novel structure, optimizes the tread profile and belt structure, increases the modulus of the belt rubber and controls the tread and shoulder thickness ratio, can reduce the shear strain at the end points of the tire belt, and at the same time ensures that the tire ground contact shape is uniform, improves the tire durability, and thus reduces the tire failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of the structure of the tread profile of an all-steel radial tire;

[0017] Figure 2 It is a schematic diagram of a partial structure of a belt layer of an all-steel radial tire;

[0018] In the figure: 1 - first belt layer, 2 - second belt layer, 3 - third belt layer, 4 - fourth belt layer. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiment 1:

[0021] In an embodiment of the present invention, an all-steel radial tire includes a tire tread and four belt layers, wherein the four belt layers include: a first belt layer 1, a second belt layer 2, a third belt layer 3 and a fourth belt layer 4, wherein the first belt layer includes a left section, a middle section and a right section, wherein the extension directions of the left section and the right section are the same as the circumferential direction of the tire, the thickness of the left section and the right section are the same as the angle between the circumferential direction, the thickness range is 1.6 to 2.0 mm, and the angle range with the circumferential direction is 0° to 15°, the extension direction of the middle section is the same as the extension direction of the left and right sections, and the thickness range of the middle section is The second belt layer has a thickness of 1.6-2.2 mm and an angle of 45-60° with the circumferential direction. The extending direction of the second belt layer is the same as that of the middle section. The thickness of the second belt layer has a thickness of 1.8-2.2 mm and an angle of 10-24° with the circumferential direction. The extending direction of the third belt layer is opposite to that of the middle section. The thickness of the third belt layer has a thickness of 1.8-2.2 mm and an angle of 10-24° with the circumferential direction. The extending direction of the fourth belt layer is opposite to that of the middle section. The thickness of the fourth belt layer has a thickness of 1.8-2.2 mm and an angle of 10-24° with the circumferential direction.

[0022] The outer contour of the tire tread in the axial section is formed by smoothly connecting n segments of tread arcs in sequence. When n=6, the radii of the six segments of tread arcs satisfy R 1 =R 6 =K 1 *(L / 2) 2 / 8h 1 , R 2 =R 5 =K 2 *((L / 2-L 1 )) 2 / 8h 2 , R 3 =R 4 =K 3 *(L / 2-L 1 -L 2 ) 2 / 8h 3 , the K 1 The value range of K is 0.8~0.9, 2 The value range of K is 2.0~3.0, 3 The value range of is 3.5~4.0, and the axial horizontal widths of the six tread arcs respectively meet L 1 =L 6 , L 2 =L 5 =(10%~20%)*section width, L 3 =L 4= (15% to 20%) * section width, the maximum height difference between the six tread arcs and the tire tread center point satisfies h 1 =h 6 =(1%~2%)*outer diameter, h 2 =h 5 =(20%~50%)*h 1 、h 3 =h 4 =(5%~15%)*h 1 .

[0023] The rubber material attached to the belt layer has a tensile modulus of 6.0 to 7.0 MPa. A higher rubber material modulus can suppress the shear strain and strain energy density at the end of the belt layer and improve the durability of the tire. When the modulus is lower than 6.0 MPa, the shear strain and strain energy density at the end of the belt layer will increase; when the modulus is higher than 7.0 MPa, the strength and fatigue performance of the rubber material will decrease, resulting in reduced tire performance.

[0024] The above-mentioned belt layer structure can reduce the shear strain at the end points of the belt layer, while ensuring the uniform ground contact shape of the tire, thereby improving the tire durability while ensuring the tire wear performance; the above-mentioned crown arc design can optimize the tire ground contact shape and reduce tread stress.

[0025] In order to verify that the combination of the four-layer belt layer and the 6-segment arc tire tread in this embodiment can achieve the actual effect described after the tire improvement, the following experiment was conducted in this embodiment:

[0026] The prior art is an experimental part in which both the belt layer and the tread are improved; Comparative Example 1 is an experimental part in which only the tread is changed and the belt layer in the prior art is still used; Comparative Example 2 is an experimental part in which only the belt layer is changed and the tire tread in the prior art is still used; Examples 1-3 are all experimental parts in which the belt layer is combined with the tire tread.

[0027]

[0028]

[0029] According to the above experimental results, it can be concluded that:

[0030] 1. According to the comparison of the experimental data of the prior art and comparative example 1, it can be concluded that: on the premise of keeping the size of the four-layer belt layer the same as that of the prior art, only the corresponding size of the tire tread is improved, the ground contact shape of the tire is optimized, and the maximum shear strain and tread stress of the belt layer can be effectively reduced.

[0031] 2. According to the comparison of the experimental data of the prior art and comparative example 2, it can be concluded that: under the premise of adopting the tread size of the tire in the prior art, the four-layer belt layer of the tire is improved. Compared with the belt layer of the prior art, the rubber modulus of the belt layer is increased, and the maximum shear strain and tread stress of the belt layer are effectively reduced.

[0032] 3. According to the comparison of the experimental data of Example 2 and Comparative Example 1, it can be concluded that the tire treads in Example 2 and Comparative Example 1 are both tire treads with improved crown arc size, and the only difference between the two groups of experiments is that the four-layer belt layer in Example 2 is the improved four-layer belt layer of the present invention, wherein the belt layer rubber modulus is 6.5MPa, and the four-layer belt layer in Comparative Example 1 is the belt layer used in the prior art, wherein the belt layer rubber modulus is less than 6MPa. It can be seen from the two groups of experimental data results that the shear strain of the belt layer in Example 2 with increased belt layer rubber modulus is significantly smaller than that of the tire with smaller rubber modulus in Comparative Example 1. It can be further verified that the present invention can suppress the shear strain and strain energy density at the end points of the belt layer by increasing the belt layer rubber modulus.

[0033] 4. According to the comparison of the experimental data of Examples 1-3 and Comparative Example 2, it can be concluded that: when the sizes of the four belt layers remain the same, the size improvement of the tire tread can further reduce the maximum shear strain of the belt layer and the tread stress.

[0034] 5. According to the comparison of experimental data between Examples 1-3 and the prior art and Comparative Examples 1-2, it can be concluded that the present invention can verify the conclusions derived from the above-mentioned theory through experimental data, that is, by improving the belt layer alone, the shear strain at the end points of the belt layer can be reduced and the durability performance can be improved. By improving the crown arc of the tire tread alone, the tire contact shape can be optimized and the tread stress can be reduced. When the experimental tire of the present invention simultaneously improves the tire tread and the tire belt layer, compared with the tire with only the tread or only the belt layer changed, the present invention can further reduce the maximum shear strain of the belt layer and the tread stress.

[0035] In order to verify the particularity of limiting the tensile modulus of the rubber material attached to the belt layer in the present invention to be within the range of 6.0 to 7.0 MPa, and limiting the thickness ratio of the shoulder portion to the tire tread in the present invention to be within the range of 1.0 to 1.3, the present invention conducted the following verification experiments:

[0036]

[0037] According to the above experimental results, it can be verified that:

[0038] Compared with the tire in the prior art, the tire in the present invention has a rubber stretch film amount attached to the belt layer of 6.0-7.0 MPa and a shoulder-to-tire thickness ratio range of 1.0-1.3, which effectively reduces the tread stress and the maximum shear strain of the belt layer. At the same time, when the tensile modulus of the rubber film attached to the belt layer and the thickness ratio of the shoulder to the tire exceed the above range, the tread stress of the tire and the maximum shear strain of the belt layer will increase to a certain extent. By comparing the above experimental data, it can be verified that the above-defined range of the rubber tensile modulus attached to the belt layer and the thickness ratio range of the shoulder to the tire tread have certain particularities, and it can be proved that the rubber tensile modulus attached to the belt layer is 6.0-7.0 MPa. The higher rubber modulus can suppress the shear strain and strain energy density at the end points of the belt layer, thereby improving the durability of the tire. When the modulus is lower than 6.0MPa, the shear strain and strain energy density at the belt layer end points will increase; when the modulus is higher than 7.0MPa, the strength and fatigue performance of the rubber compound will decrease, resulting in reduced tire performance.

[0039] Embodiment 2:

[0040] In an embodiment of the present invention, an all-steel radial tire includes a tire tread and four belt layers, wherein the four belt layers include: a first belt layer 1, a second belt layer 2, a third belt layer 3 and a fourth belt layer 4, wherein the first belt layer includes a left section, a middle section and a right section, wherein the extension directions of the left section and the right section are the same as the circumferential direction of the tire, the thickness of the left section and the right section are the same as the angle between the circumferential direction, the thickness range is 1.6 to 2.0 mm, and the angle range with the circumferential direction is 0° to 15°, the extension direction of the middle section is the same as the extension direction of the left and right sections, and the thickness range of the middle section is The second belt layer has a thickness of 1.6-2.2 mm and an angle of 45-60° with the circumferential direction. The extending direction of the second belt layer is the same as that of the middle section. The thickness of the second belt layer has a thickness of 1.8-2.2 mm and an angle of 10-24° with the circumferential direction. The extending direction of the third belt layer is opposite to that of the middle section. The thickness of the third belt layer has a thickness of 1.8-2.2 mm and an angle of 10-24° with the circumferential direction. The extending direction of the fourth belt layer is opposite to that of the middle section. The thickness of the fourth belt layer has a thickness of 1.8-2.2 mm and an angle of 10-24° with the circumferential direction.

[0041] The outer contour of the tire tread in the axial section is formed by smoothly connecting n segments of tread arcs in sequence. When n=8, the radii of the eight segments of tread arcs satisfy R 1 =R 8 =K 1 *(L / 2) 2 / 8h 1 , R 2 =R7 =K 2 *(L / 2-L 1 ) 2 / 8h 2 , R 3 =R 6 =K 3 *(L / 2-L 1 -L 2 ) 2 / 8h 3 , R 4 =R 5 =K 4 *(L / 2-L 1 -L 2 -L 3 ) 2 / 8h 4 , the K 1 The value range of K is 1.0~1.4, 2 The value range of K is 1.0~1.4, 3 The value range of K is 1.3~2.0, 4 The value range of is 3.8~4.2, and the axial horizontal widths of the 8 tread arcs respectively meet L 1 =L 8 , L 2 =L 7 =(8%~12%)*section width, L 3 =L 6 =(6%~11%)*section width, L 4 =L 5 = (10% to 20%) * section width, the maximum height difference between the 8 tread arcs and the tire tread center point satisfies h 1 =h 8 =(1%~2%)*outer diameter, h 2 =h 7 =(30%~45%)*h 1 、h 3 =h 6 =(5%~15%)*h 1 、h 4 =h 5 =(1%~5%)*h 1 .

[0042] In order to verify that the combination of the four-layer belt layer and the tire tread with eight arcs in this embodiment can achieve the actual effect described after the tire improvement, the following experiment was conducted in this embodiment:

[0043] The experimental data analysis related to the improvement of the tire by combining 8 arcs and belt layers can refer to the experimental data analysis related to the improvement of the tire by combining 6 arcs and belt layers mentioned above.

[0044]

[0045]

[0046] According to the above experimental results, it can be concluded that:

[0047] 1. According to the comparison of the experimental data of the prior art and comparative example 1, it can be concluded that: under the premise that the size range of the four-layer belt layer remains unchanged, only the crown arc size corresponding to the tire tread is improved, which optimizes the ground contact shape of the tire and can effectively reduce the maximum shear strain and tread stress of the belt layer.

[0048] 2. According to the comparison of the experimental data of the prior art and comparative example 2, it can be concluded that: under the premise of adopting the tread size of the tire in the prior art, the four-layer belt layer of the tire is improved. Compared with the belt layer of the prior art, the rubber modulus of the belt layer is increased, and the maximum shear strain and tread stress of the belt layer are effectively reduced.

[0049] 3. According to the comparison of the experimental data of Example 1 and Comparative Example 1, it can be concluded that the tire treads in Example 2 and the comparative example are both tire treads with improved crown arc size, and the only difference between the two groups of experiments is that the four-layer belt layer in Example 2 is the improved four-layer belt layer of the present invention, wherein the belt layer film amount is 6.5MPa, and the four-layer belt layer in Comparative Example 1 is the belt layer used in the prior art, wherein the belt layer film amount is less than 6MPa. It can be seen from the two groups of experimental data results that the shear strain of the belt layer in Example 2 with increased belt layer film amount is significantly smaller than that of the tire with smaller film amount in Comparative Example 1. It can be further verified that the present invention can control the shear strain and strain energy density of the belt layer endpoints by increasing the belt layer film amount.

[0050] 4. According to the comparison of the experimental data of Examples 1-3 and Comparative Example 2, it can be concluded that: when the sizes of the four belt layers remain the same, the size improvement of the tire tread can further reduce the maximum shear strain of the belt layer and the tread stress.

[0051] 5. According to the comparison of experimental data between Examples 1-3 and the prior art and Comparative Examples 1-2, it can be concluded that the present invention can verify the conclusions derived from the above theoretical derivation through experimental data, that is, through the improved design of the belt layer and the crown arc of the tire tread, the shear strain at the end points of the belt layer can be reduced, and at the same time, the ground contact shape can be optimized to ensure that the tire ground contact shape is uniform and the tread stress is reduced.

[0052] The present invention verifies the particularity of limiting the tensile modulus of the rubber material attached to the belt layer to be within the range of 6.0 to 7.0 MPa and the particularity of limiting the thickness ratio of the shoulder portion to the tire tread to be within the range of 1.0 to 1.3. The present invention conducts the following verification experiments:

[0053]

[0054] According to the above experimental results, it can be verified that:

[0055] Compared with the tire in the prior art, the tire in the present invention has a rubber stretch film amount attached to the belt layer of 6.0-7.0 MPa and a shoulder-to-tire thickness ratio range of 1.0-1.3, which effectively reduces the tread stress and the maximum shear strain of the belt layer. At the same time, when the tensile modulus of the rubber film attached to the belt layer and the thickness ratio of the shoulder to the tire exceed the above range, the tread stress of the tire and the maximum shear strain of the belt layer will increase to a certain extent. By comparing the above experimental data, it can be verified that the above-defined range of the rubber tensile modulus attached to the belt layer and the thickness ratio range of the shoulder to the tire tread have certain particularities, and it can be proved that the rubber tensile modulus attached to the belt layer is 6.0-7.0 MPa. The higher rubber modulus can suppress the shear strain and strain energy density at the end points of the belt layer, thereby improving the durability of the tire. When the modulus is lower than 6.0MPa, the shear strain and strain energy density at the belt layer end points will increase; when the modulus is higher than 7.0MPa, the strength and fatigue performance of the rubber compound will decrease, resulting in reduced tire performance.

[0056] The present invention has a novel structure and stable operation. It optimizes the tread profile and belt structure, increases the modulus of the belt rubber and controls the tread to shoulder thickness ratio, can reduce the shear strain at the end points of the tire belt, and ensures uniform ground contact shape of the tire, reduces tire tread stress, improves tire durability, and thus reduces tire failure rate.

[0057] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0058] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An all-steel radial tire, comprising a tire tread and four belt layers, characterized in that: The four belt layers include a first belt layer (1), a second belt layer (2), a third belt layer (3) and a fourth belt layer (4), the first belt layer includes a left section, a middle section and a right section, the left section and the right section of the first belt layer have the same width, and the width range is 20% to 30% of the cross-sectional width, the extension direction of the left section, the middle section and the right section are the same as the circumferential direction of the tire, the thickness of the left section and the right section and the angle between the two and the circumferential direction are the same, and the thickness range is 1.6 to 2.0 mm, the extension direction of the middle section is the same as the extension direction of the left and right sections, and the thickness range of the middle section is 1.6 to 2.2 mm, the thickness range of the second belt layer, the third belt layer and the fourth belt layer are all 1.8 to 2.2 mm, the extension direction of the second belt layer is the same as the middle section of the first belt layer, and the extension directions of the third belt layer and the fourth belt layer are opposite to the middle section of the first belt layer; The outer contour of the tire tread in the axial section is formed by smoothly connecting n tread arcs in sequence, wherein n≥6, and the n tread arcs are symmetrically distributed along the center point of the tread, and the axial horizontal widths of the n tread arcs are L1, L2, L3...L n The tread width of the tire tread is L, and the maximum height differences between the n tread arcs and the center point of the tire tread are h1, h2, h3...h n The radii of the n tread arcs satisfy R1=R n =K1*(L / 2) 2 / 8h1、R2=R n-1 =K2*(L / 2-L1) 2 / 8h2、R3=R n-2 =K3*(L / 2-L1-L2) 2 / 8h3,…,R 2 / n =R (2 / n)+1 =K 2 / n *(2 / L-L1-L2-…-L (2 / n)-1 ) 2 / 8h 2 / n , the K1, K2, K3, ..., K 2 / n The values ​​are all within the range of 0.8 to 4.

2.

2. The all-steel radial tire according to claim 1, characterized in that: The angles between the left and right sections of the first belt layer and the circumferential direction are in the range of 0° to 15°, the angles between the middle section of the first belt layer and the circumferential direction are in the range of 45° to 60°, and the angles between the second belt layer, the third belt layer and the fourth belt layer and the circumferential direction are in the range of 10° to 24°.

3. The all-steel radial tire according to claim 1, characterized in that: The n=6, wherein the radii of the six tread arcs satisfy R1=R6=K1*(L / 2) respectively. 2 / 8h1、R2=R5=K2*((L / 2-L1)) 2 / 8h2、R3=R4=K3*(L / 2-L1-L2) 2 / 8h3, the value range of K1 is 0.8-0.9, the value range of K2 is 2.0-3.0, and the value range of K3 is 3.5-4.

0.

4. The all-steel radial tire according to claim 3, characterized in that: The axial horizontal widths of the six tread arcs respectively satisfy L1=L6, L2=L5=(10%~20%)*section width, L3=L4=(15%~20%)*section width, and the maximum height differences between the six tread arcs and the center point of the tire tread respectively satisfy h1=h6=(1%~2%)*outer diameter, h2=h5=(20%~50%)*h1, h3=h4=(5%~15%)*h1.

5. The all-steel radial tire according to claim 1, characterized in that: n=8, wherein the radii of the 8 tread arcs satisfy R1=R8=K1*(L / 2) respectively. 2 / 8h1, R2=R7=K2*(L / 2-L1) 2 / 8h2、R3=R6=K3*(L / 2-L1-L2) 2 / 8h3、R4=R5=K4*(L / 2-L1-L2-L3) 2 / 8h4, the value range of K1 is 1.0~1.4, the value range of K2 is 1.0~1.4, the value range of K3 is 1.3~2.0, and the value range of K4 is 3.8~4.

2.

6. The all-steel radial tire according to claim 5, characterized in that: The axial horizontal widths of the 8 tread arcs respectively satisfy L1=L8, L2=L7=(8%~12%)*section width, L3=L6=(6%~11%)*section width, L4=L5=(10%~20%)*section width, and the maximum height differences between the 8 tread arcs and the center point of the tire tread respectively satisfy h1=h8=(1%~2%)*outer diameter, h2=h7=(30%~45%)*h1, h3=h6=(5%~15%)*h1, h4=h5=(1%~5%)*h1.

7. The all-steel radial tire according to claim 1, characterized in that: The value range of n is: 6≤n≤8.

8. The all-steel radial tire according to claim 1, characterized in that: The surface of the four-layer belt layer is covered with rubber, and the tensile modulus of the rubber is 6.0-7.0 MPa.

9. The all-steel radial tire according to claim 8, characterized in that: The tire also includes a shoulder portion, and a thickness ratio of the shoulder portion to the tire tread is in the range of 1.0 to 1.3.

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