A tire and a vehicle

Abstract

The present invention provides a tire and a vehicle. The tread of the tire is provided with a plurality of groove-shaped main tread grooves. Each of the main tread grooves is arranged along the radial direction of the tread. A tread block is formed between adjacent main tread grooves. A secondary tread groove is further arranged along the radial direction in the middle of each tread block. One end of each secondary tread groove close to the radial middle of the tread is connected to the main tread groove. Each tread block is further provided with a plurality of fine knife grooves along the circumferential direction. The rubber compound of the tire comprises natural rubber less than or equal to 5%, cis-1,4-polybutadiene rubber less than or equal to 10%, and styrene-butadiene rubber greater than or equal to 85%. With the above structure, by arranging the main tread grooves, secondary tread grooves and fine knife grooves, the comprehensive performance of the tire such as drainage, snow biting and grip can be effectively ensured. By adjusting the rubber compound formula of the tire, the strength of the rubber compound is effectively improved, the toughness of the rubber compound is reduced, and the tear resistance of the tire is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tires, and particularly relates to a tire and a vehicle. Background Art

[0002] When a vehicle brakes, starts, or steers, the tires of the vehicle are prone to problems such as wear, pattern chunking, or tearing. In addition, when driving on extreme road surfaces such as wet roads and snow, the tear resistance and durability of the tires are also severely tested.

[0003] Therefore, how to improve the tear resistance of tires without sacrificing their overall performance is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0004] The object of the present invention is to improve the tear resistance of tires without sacrificing their overall performance.

[0005] To solve the above technical problems, the present invention provides a tire. The tread of the tire is provided with a plurality of groove-shaped main tread grooves. Each of the main tread grooves is arranged along the radial direction of the tread. Pattern blocks are formed between adjacent main tread grooves. Each of the pattern blocks is further provided with secondary tread grooves along the radial direction. One end of each secondary tread groove close to the radial middle of the tread is connected to the main tread groove. Each of the pattern blocks is further provided with a plurality of fine knife grooves along the circumferential direction. The rubber compound of the tire includes natural rubber, cis-butadiene rubber, and styrene-butadiene rubber. Among them, the natural rubber is less than or equal to 5%, the cis-butadiene rubber is less than or equal to 10%, and the styrene-butadiene rubber is greater than or equal to 85%.

[0006] With the above structure, by setting the main tread grooves, secondary tread grooves, and fine knife grooves, the overall performance of the tire such as drainage, snow biting, and grip can be effectively guaranteed. By adjusting the rubber compound formula of the tire, the strength of the rubber compound can be effectively increased, the toughness of the rubber compound can be reduced, and the tear resistance of the tire can be improved.

[0007] Optionally, the rubber thickness difference at the bottom of the main tread grooves between the central region and the shoulder region of the tread is 1 to 1.5 millimeters.

[0008] Optionally, the finished product angle of the steel wire belt layer of the tire is 27 degrees.

[0009] Optionally, the binding force of the nylon belt layer in the central region and the shoulder region of the tire is 5 to 7 N per strand.

[0010] Optionally, the ratio of the ground contact pressure between the shoulder region and the central region of the tire is 1.1 to 1.2.

[0011] Optionally, one side wall of each main pattern groove is an inclined wall, and the included angle β between the inclined wall and the vertical direction is 8 to 12 degrees; the other side wall includes a first groove wall section near the bottom of the main pattern groove and a second groove wall section near the top of the main pattern groove. Both the first groove wall section and the second groove wall section are inclined walls. The first groove wall section has an included angle γ with the vertical direction, and the second groove wall section has an included angle δ with the vertical direction, and γ is less than δ.

[0012] Optionally, δ = 15° to 25°, and γ = 3° to 8°.

[0013] Optionally, the groove depth D1 of each main pattern groove is 7.5 to 8.5 millimeters, and the radius R of the rounded corners on both sides of the groove bottom is 1.5 to 2.5 millimeters.

[0014] Optionally, when the fine knife groove intersects with the secondary pattern groove and the included angle α between them is less than or equal to 15 degrees, within a range of 5 millimeters from the intersection point of the two, the depth D2 of the fine knife groove is less than or equal to 1 millimeter.

[0015] The present invention also provides a vehicle, including the tire described above. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the tread of the tire provided by the embodiment of the present invention;

[0017] Figure 2 is Figure 1 an enlarged structural diagram of part A of the circle in

[0018] Figure 3 is Figure 1 an enlarged structural diagram of part B of the circle in

[0019] Figure 4 is Figure 1 an enlarged structural diagram of part C of the circle in

[0020] Figure 5 is Figure 1 a schematic E-E cross-sectional view in

[0021] Figure 6 is Figures 2 - 4 a schematic X-X cross-sectional view in

[0022] Figures 1 - 6 The reference numerals in

[0023] 1 main pattern groove, 2 pattern block, 3 secondary pattern groove, 4 fine knife groove, D tire ground contact profile, F tire rotation axis, G tread center. Detailed Embodiments

[0024] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] An embodiment of the present invention provides a tire. Please refer to Figures 1 - 6 , the tread of the tire is provided with a plurality of groove-shaped main tread grooves 1. Each main tread groove 1 is arranged along the radial direction of the tread. A tread block 2 is formed between adjacent main tread grooves 1. A secondary tread groove 3 is also arranged along the radial direction in the middle of each tread block 2. One end of each secondary tread groove 3 close to the radial middle of the tread is connected to the main tread groove 1. Each tread block 2 is also provided with a plurality of fine knife grooves 4 along the circumferential direction; the rubber compound of the tire includes less than 5% natural rubber, less than 10% cis-butadiene rubber, and more than 85% styrene-butadiene rubber.

[0026] With the above structure, by setting the main tread groove 1, the secondary tread groove 3, and the fine knife groove 4, the comprehensive performance of the tire such as drainage, snow biting, and grip can be effectively guaranteed. By adjusting the rubber compound formula of the tire, the strength of the rubber compound is effectively improved, the toughness of the rubber compound is reduced, and the tear resistance of the tire is improved.

[0027] Among them, the radial direction of the tread described above refers to the direction of the rotation axis of the tire, that is, Figure 1 the direction (left-right direction) where the tire rotation axis F is located in Figure 1 , and the circumferential direction refers to the direction of tire rotation, that is,

[0028] the direction (up-down direction) where the tread center G is located in Figure 1 . As shown in

[0029] , the tread of the tire is radially distributed with a plurality of groove-shaped main tread grooves 1. Each main tread groove 1 extends from the radial outer side to the radial inner side of the tread, and the main tread grooves 1 on both sides intersect at the radial center position of the tread. The overall shape of each main tread groove 1 is an arc structure. The tread between adjacent main tread grooves 1 forms an arc-shaped tread block 2. The upper surface of each tread block 2 is the contact surface between the tire and the ground; a secondary tread groove 3 arranged along the radial direction is also provided in the middle of each tread block 2. The groove width of each secondary tread groove 3 is smaller, less than the groove width of the main tread groove 1, and is at least partially wavy; a plurality of fine knife grooves 4 are also arranged along the axial direction on each tread block 2. The overall shape in the extending direction of the fine knife grooves 4 is an arc, and at least part of them penetrates the corresponding tread block 2 and is connected to the main tread groove 1.

[0030] As described above, each main tread groove 1, each secondary tread groove 3, and each fine knife groove 4 can effectively improve the grip performance, drainage performance, and snow biting performance of the tire tread, making the tire more anti-slip and still able to meet the use requirements of the tire in extreme weather such as rain and snow.

[0031] Table 1 Tire Rubber Compound Formula Experiment

[0032]

[0033] In Table 1 above, the unit PHR of each rubber component refers to the formulation dosage unit, that is, the dosage of each rubber component in each portion of tire compound, which can be regarded as the percentage of each component in the tire compound; the steel nail impact refers to using the same steel nail and force to puncture the tire to test the strength of the tire tread. The smaller the puncture distance (value), the higher the strength of the tire tread; the anti-crack growth rate refers to simulating the force on the tire during driving and recording the number of cracks in real time to calculate the anti-crack growth rate to measure the anti-tearing performance of the tire tread. The lower the anti-crack growth rate, the better the anti-tearing performance of the tire tread.

[0034] As shown in Table 1, the rubber compound ratio in the prior art is 49% natural rubber, 35% cis-butadiene rubber, and 16% styrene-butadiene rubber, with a steel nail impact distance of 23 cm and an anti-crack growth rate of 111%; in Experiment Group 1, the ratios of natural rubber and cis-butadiene rubber are respectively reduced by 22% and 15%, and the ratio of styrene-butadiene rubber is increased to 63%. The final test results are a steel nail impact distance of 22.3 cm and an anti-crack growth rate of 110%, and both the anti-tearing and anti-impact performances are increased; in Experiment Group 2, the ratios of natural rubber and cis-butadiene rubber are further reduced to 6% and 9%, and the ratio of styrene-butadiene rubber is increased to 85%. The final test results are a steel nail impact distance of 20.2 cm and an anti-crack growth rate of 107%. It can be seen that the increase in anti-tearing and anti-impact properties is more obvious; in Experiment Group 3, the ratio of natural rubber is further reduced to 5%, the ratio of cis-butadiene rubber is 15%, and the ratio of styrene-butadiene rubber is 80%. The final test results are a steel nail impact distance of 21.8 cm and an anti-crack growth rate of 109%. It can be seen that the anti-tearing and anti-impact performances are reduced instead. In Experiment Group 4, the ratio of cis-butadiene rubber is further reduced to 9%, the styrene-butadiene rubber remains 80%, and the ratio of natural rubber is 11%. The changes in anti-impact and anti-crack properties are small; in Experiment Group 5, the styrene-butadiene rubber is increased to 85%, the natural rubber is 4%, and the cis-butadiene rubber is 11%. The anti-impact performance is slightly improved, but the anti-tearing performance decreases.

[0035] In experimental group 6, the proportion of natural rubber is 5%, the proportion of cis-butadiene rubber is 10%, and the proportion of styrene-butadiene rubber is 85%. At this time, the impact resistance and tear resistance start to further decrease compared with experimental groups 1-5. Looking at experimental group 7, the proportions of natural rubber and cis-butadiene rubber are both reduced to 3%, and the proportion of styrene-butadiene rubber is increased to 94%. The final test results show that the impact distance of the steel nail is 19.4 cm and the growth rate of anti-crack is 103%, with obvious improvement. In experimental group 8, the proportion of natural rubber is adjusted to 3%, the proportion of cis-butadiene rubber is adjusted to 7%, and the proportion of styrene-butadiene rubber is adjusted to 90%. It is concluded that the impact distance of the steel nail is further reduced and the growth rate of anti-crack is further decreased. Obviously, experimental group 8 has a better rubber compound proportion than experimental group 7.

[0036] In summary, when the proportion of natural rubber in the tire rubber compound is less than or equal to 5%, the proportion of cis-butadiene rubber is less than or equal to 10%, and the proportion of styrene-butadiene rubber is greater than or equal to 85%, the impact distance of the steel nail and the growth rate of anti-crack of the tire are significantly reduced, that is, the tire has high strength and tear resistance, and is significantly higher than the prior art. The tire in this embodiment preferably uses the rubber compound proportions of experimental groups 6-8 to improve the tear resistance of the tire while ensuring the tire performance.

[0037] In this embodiment, the thickness difference of the rubber at the bottom of the main groove 1 of the tread in the center area and the shoulder area, the finished product angle of the steel wire belt layer of the tire, the binding force of the nylon belt layer in the center area and the shoulder area of the tire, and the grounding pressure ratio of the shoulder area and the center area of the tire are also limited to further improve the tear resistance performance of the tire, and multiple groups of experiments are carried out to obtain the following experimental results:

[0038] Table 2 Experiments on various parameters in the center area and the shoulder area

[0039]

[0040] In the above Table 2, please refer to Figure 1 the tire grounding profile D. The center area is the P2 and P3 parts in the tire grounding profile D, and the shoulder area is the P1 and P4 parts in the tire grounding profile D; the pressure ratio of the grounding pressure is the ratio of the corresponding area to the center area. In this experiment, P3 is used as the reference value of the center area, that is, the pressure ratio of each area Pn is Pn / P3. The grounding pressure ratio of the shoulder area and the center area of this tire is a key parameter affecting the handling performance and tear resistance of the tire; both the handling performance and the tear resistance are compared with the prior art as the reference value, that is, the handling performance or tear resistance of each experimental group is the ratio relative to the prior art.

[0041] As shown in Table 2, in the prior art, the thickness difference of the bottom rubber of the main groove 1 in the center area and the shoulder area of the tire is in the range of 0 to 0.5 mm, the finished angle of the steel wire belt layer of the tire is 25 degrees, the binding force of the nylon belt layer in the center area and the shoulder area of the tire is 5 to 7 N per strand, and the ground contact pressure ratios of the shoulder areas P1 and P4 of the tire are 130% and 133% respectively, within the range of 130% to 135%, and the handling performance and tear resistance are both 100%;

[0042] In Experimental Group 1, the thickness difference of the bottom rubber of the main groove 1 in the center area and the shoulder area of the tire was increased to the range of 1.0 to 1.5 mm, and other parameters remained unchanged compared with the prior art. The ground contact pressure ratios of the shoulder areas P1 and P4 of the tire were measured to be 124% and 126% respectively, within the range of 120% to 130%. The handling performance was reduced to 99% of the prior art, and the tear resistance was increased to 101% of the prior art. Obviously, increasing the thickness difference of the bottom rubber of the main groove 1 in the center area and the shoulder area of the tire can slightly increase the tear resistance of the tire while slightly reducing the handling performance;

[0043] In Experimental Group 2, the finished angle of the steel wire belt layer of the tire was increased to 27 degrees, and other parameters remained unchanged compared with Experimental Group 1. The ground contact pressure ratios of the shoulder areas P1 and P4 of the tire were measured to be 115% and 118% respectively, within the range of 110% to 120%. The handling performance was reduced to 98% of the prior art, and the tear resistance was increased to 108% of the prior art. Obviously, while increasing the thickness difference of the bottom rubber of the main groove 1 in the center area and the shoulder area of the tire, increasing the finished angle of the steel wire belt layer of the tire can significantly increase the tear resistance of the tire while slightly reducing the handling performance;

[0044] In Experimental Group 3, the binding force of the nylon belt layer in the center area and the shoulder area of the tire was increased to 8 to 10 N per strand. The ground contact pressure ratios of the shoulder areas P1 and P4 of the tire were measured to be 101% and 103% respectively, within the range of 100% to 105%. The handling performance was reduced to 95% of the prior art, and the tear resistance was increased to 115% of the prior art. Obviously, after increasing the binding force of the nylon belt layer in the center area and the shoulder area of the tire on the basis of Experimental Group 2, although the tear resistance of the tire can continue to be significantly increased, the handling performance of the tire is also significantly reduced;

[0045] In summary, the ground contact pressure ratio of the shoulder area of ​​the tire is preferably in the range of 110% to 120%. Therefore, this embodiment adopts the scheme of the above-mentioned experimental group 2 as the preferred scheme, that is, the difference in rubber thickness at the bottom of the main groove 1 of the central area of ​​the tread and the shoulder area is 1 to 1.5 mm, the finished angle of the steel wire belt layer of the tire is 27 degrees, and the binding force of the nylon belt layer in the central area and the shoulder area of ​​the tire is 8 to 10 Newtons per strand. This parameter setting can optimize the distribution of ground contact pressure, and greatly improve the tear resistance of the tire while having little effect on the handling performance of the tire.

[0046] In this embodiment, the side walls of each main groove 1 are arranged asymmetrically, and one side of the groove wall ( Figure 5 The left side wall in the figure is an inclined wall, and the angle β between the side groove wall and the vertical direction is 8 to 12 degrees. This setting is conducive to the pattern to grip the snow; the groove wall on the other side ( Figure 5 The cross-sectional profile of the right side wall in the figure is a broken line, including a first groove wall section near the bottom of the main groove 1 and a second groove wall section near the top of the main groove 1. Both the first groove wall section and the second groove wall section are inclined walls, wherein the first groove wall section has an angle γ with the vertical direction, and the second groove wall section has an angle δ with the vertical direction, and γ is less than δ. The broken line setting can ensure the tear resistance of the pattern during braking. Among them, the value range of δ and γ can be δ=15°~25°, γ=3°~8°. It should be noted that the vertical direction here is the direction perpendicular to the bottom of the main groove 1.

[0047] Please refer to Figure 5 , the groove wall of the main groove 1 is inclined relative to the vertical direction. With this arrangement, when the surface of the pattern block 2 touches the ground, the ground pressure it receives will be transmitted along the groove wall of the main groove 1 to the bottom, that is, to the center of the tire. In this process, the groove wall of the main groove 1 set obliquely can better support the pattern block 2. After experimental testing, when the angle β between the top of the groove wall on one side of each main groove 1 and the vertical direction is 8 to 12 degrees, its supporting and conducting effects are better, which is conducive to gripping snow; and the groove wall on the other side is divided into two groove wall sections with different inclination angles, which can further support the pattern block 2, better transmit the ground pressure, effectively improve the rigidity of the pattern block 2, and prevent the pattern block 2 from being torn during the ground pressure transmission process.

[0048] In this embodiment, the groove depth D1 of each pattern main groove 1 is 7.0 to 8.0 mm, and the radius R of the rounded corners on both sides of the groove bottom is 1.5 to 2.5 mm. Figure 5 The groove depth D1 of the pattern main groove 1 is the distance from the upper surface of the pattern block 2 to the bottom of the pattern main groove 1 in the vertical direction. According to experimental tests, when the groove depth D1 is in the range of 7.5 to 8.5 mm, the tire's handling performance and tear resistance are better, and after the groove bottom is rounded on both sides, the ground pressure is transmitted more smoothly, and the groove bottom of the pattern main groove 1 is less likely to be compressed and torn.

[0049] In this embodiment, when some of the fine knife grooves 4 penetrate through the tread blocks 2, they will intersect with the secondary tread grooves 3. When the fine knife groove 4 intersects with the secondary tread groove 3 and the included angle α between them is less than or equal to 15 degrees, within a range of 5 millimeters from the intersection point of the two, the depth D2 of the fine knife groove 4 is less than or equal to 1 millimeter.

[0050] Please refer to Figures 2 - 4 and Figure 6 , Figures 2 - 4 which is a schematic diagram of the fine knife groove 4 intersecting with the secondary tread groove 3 and the included angle α between them being less than 15 degrees. In this case, if the depth of the fine knife groove 4 is relatively large, it may cause insufficient rigidity of the tread block 2 near the intersection point, and it is prone to tearing after driving on the road surface. In this embodiment, within a range of 5 millimeters from the intersection point of the fine knife groove 4 and the secondary tread groove 3, the depth D2 of the fine knife groove 4 is reduced to less than or equal to 1 millimeter, which can effectively improve the rigidity of the tire at this position, and thus improve the overall tear resistance of the tire.

[0051] The influence of the above data on the performance can be understood with reference to the following table:

[0052] Table 3

[0053] Item Prior Art Experimental Group 1 Experimental Group 2 Experimental Group 3 β (degrees) 5 5 10 10 γ (degrees) 5 5 10 5 δ (degrees) 15 15 30 25 D1 (mm) 8.0 7.5 7.5 7.5 D2 (mm) 2 1 1 1 R (mm) 1 1 2 2 Pattern Drainage / Snow Removal Performance 100％ 99％ 95％ 98％ Tear Resistance 100％ 102％ 113％ 110％

[0054] The embodiment of the present invention also provides a vehicle, including the tire described above. Since the tire already has the above technical effects, the vehicle including this tire should also have the same technical effects, so it will not be elaborated here.

[0055] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A tire, characterized in that: the tread of the tire is provided with a plurality of groove-shaped main tread grooves (1), each of the main tread grooves (1) is arranged along the radial direction of the tread, the radial direction is the direction of the rotation axis of the tire, and a tread block (2) is formed between adjacent main tread grooves (1). A secondary tread groove (3) is also arranged along the radial direction in the middle of each tread block (2). One end of each secondary tread groove (3) close to the radial middle of the tread is connected to the main tread groove (1). Each tread block (2) is also provided with a plurality of fine knife grooves (4) along the circumferential direction, and the overall shape in the extending direction of the fine knife grooves (4) is arc-shaped; the rubber compound of the tire comprises natural rubber, cis-butadiene rubber and styrene-butadiene rubber, wherein, the natural rubber is less than or equal to 5%, the cis-butadiene rubber is less than or equal to 10%, and the styrene-butadiene rubber is greater than or equal to 85%; when the fine knife groove (4) intersects with the secondary tread groove (3) and the included angle α between the two is less than or equal to 15 degrees, within a range of 5 millimeters from the intersection point of the two, the depth D2 of the fine knife groove (4) is less than or equal to 1 millimeter.

2. The tire according to claim 1, characterized in that: the thickness difference of the rubber at the bottom of the main tread groove (1) between the central area and the shoulder area of the tread is 1 to 1.5 millimeters.

3. The tire according to claim 1, characterized in that: the finished product angle of the steel wire belt layer of the tire is 27 degrees.

4. The tire according to claim 1, characterized in that: the binding force of the nylon belt layer in the central area and the shoulder area of the tire is 5 to 7 N per strand.

5. The tire according to claim 1, characterized in that: the ratio of the grounding pressure between the shoulder area and the central area of the tire is 1.1 to 1.

2.

6. The tire according to any one of claims 1-5, characterized in that: one side groove wall of each main tread groove (1) is an inclined wall, and the included angle β between the inclined wall and the vertical direction is 8 to 12 degrees; the other side groove wall includes a first groove wall section close to the bottom of the main tread groove (1) and a second groove wall section close to the top of the main tread groove (1). Both the first groove wall section and the second groove wall section are inclined walls. The first groove wall section has an included angle γ with the vertical direction, and the second groove wall section has an included angle δ with the vertical direction, and γ is less than δ.

7. The tire according to claim 6, characterized in that: δ = 15° - 25°, γ = 3° - 8°.

8. The tire according to any one of claims 1-5, characterized in that: the groove depth D1 of each main tread groove (1) is 7.0 to 8.0 millimeters, and the radius R of the rounded corners on both sides of the groove bottom is 1.5 to 2.5 millimeters.

9. A vehicle, characterized in that: it includes the tire according to any one of claims 1-8.

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