Run-flat tire structure and tire

Abstract

The application discloses a run-flat tire structure and a tire, and belongs to the tire field. The run-flat tire structure comprises two symmetrical bead portions, the bead portion contains a bead core, the bead core comprises an inner side core, an outer side core and a middle core, the inner side core is arranged at the inner side of the bead portion, the outer side core is arranged at the outer side of the bead portion and is spaced from the inner side core, and the middle core is arranged at the middle of the inner side core and the outer side core. The height of the inner side core, the middle core and the outer side core decreases in turn. The application solves the technical problem that the existing run-flat tire cannot simultaneously consider the zero air pressure durability and the ride comfort of the run-flat tire, and has the characteristics that the tire can meet the durability performance of the zero air pressure and improve the ride comfort and the NVH performance of the tire.

Description

Technical Field

[0001] This invention belongs to the field of tires, and particularly relates to a run-flat tire structure and tire. Background Technology

[0002] With the development of the automotive industry, people have higher and higher requirements for tire safety performance. According to relevant statistics, nearly 50% of major traffic accidents on highways are caused by chronic tire leakage, and most of them are caused by nail punctures. Leakage leads to tire blowout and loss of control during operation. Therefore, more and more run-flat tires have emerged.

[0003] However, existing run-flat tires typically incorporate a monolithic support material in the sidewall. While this improves tire support, it negatively impacts ride comfort and NVH (noise, vibration, and harshness) performance. Adding a monolithic support material to the sidewall increases radial stiffness, improving run-flat durability, but at the cost of reduced ride comfort and NVH. Therefore, it's impossible to simultaneously achieve the optimal run-flat tire performance in terms of run-flat durability, ride comfort, and NVH.

[0004] Therefore, existing run-flat tires have the technical problem of not being able to simultaneously achieve the zero-pressure durability, ride comfort, and NVH performance of run-flat tires. Summary of the Invention

[0005] Details of one or more embodiments of the present invention are set forth in the following drawings and description to make other features, objects and advantages of the present application more readily apparent.

[0006] This invention proposes a run-flat tire structure and tire, which solves the technical problem that existing run-flat tires cannot simultaneously achieve the zero-pressure durability, ride comfort and NVH performance of run-flat tires. It has the characteristics of satisfying the zero-pressure durability performance of tires, while improving the ride comfort and NVH performance of tires under zero pressure.

[0007] This invention discloses a run-flat tire structure, comprising two symmetrical bead portions, each containing a bead core. Each bead core includes an inner core, an outer core, and a middle core. The inner core is located inside the bead portion; the outer core is spaced apart from the inner core and located outside the bead portion; the middle core is located between the inner and outer cores; wherein the heights of the inner core, the middle core, and the outer core decrease sequentially.

[0008] In some embodiments, the height of the inner core is h1, the height of the middle core is h2, and the height of the outer core is h3, where h1:h2:h3 = 1:(0.6~0.7):(0.5~0.6), h1 = (0.35~0.65)H1, H1 is the rim protection height, and the safety factor of the bead core is S = 2F*N / P*h*(2Ra+h), and 6≤S≤7; where Ra is the inner radius of the tire; h is the total thickness of the center of the tire crown; P is the tire inflation pressure; N is the number of steel wires; and F is the tension of a single steel wire.

[0009] In some embodiments, the run-flat tire structure further includes a tire carcass disposed between two symmetrical bead portions, and the tire carcass wraps around the inner side of the intermediate core to the outer side of the intermediate core, wherein the height H of the wrapping of the tire carcass is greater than the height h3 of the outer core.

[0010] In some embodiments, the run-flat tire structure further includes a support rubber, a sidewall rubber, and a belt layer. The support rubber and the sidewall rubber are respectively disposed on the sidewall of the tire, with the support rubber adhering to the inner side of the tire body and the sidewall rubber adhering to the outer side of the tire body. The upper end point of the sidewall rubber is disposed at the bottom of the belt layer, and the distance d1 between the upper end point of the sidewall rubber and the end point of the belt layer is 12mm to 20mm.

[0011] In some embodiments, the support adhesive includes an outer support adhesive and an inner support adhesive, the outer support adhesive being adhered to the inner side of the tire carcass, and the area of ​​the outer support adhesive being S. 外 The inner support adhesive is bonded to the inner side of the outer support adhesive, and the area of ​​the inner support adhesive is S. 内 The upper end point of the inner support adhesive is located at the bottom of the belt layer, and the distance between the upper end point of the inner support adhesive and the end point of the belt layer is D1 = 15mm~35mm. The distance between the lower end point of the inner support adhesive and the upper end point of the inner core is D2 = (0.2~0.5)h1. Wherein, S 内 = (50%~70%)S 外 And 0.9*SH*(0.1*L I-4.4)≤(S 内 +S 外 )≤1.3*SH*(0.225*LI-16.2), where SH is the tire section height and LI is the tire load index.

[0012] In some embodiments, the tire's normal thickness, measured radially from the top of the tire's rim protection portion towards the tire carcass, is W. 1L The normal thickness of the supporting adhesive is W1, and the normal thickness of the inner supporting adhesive is W. 1a The normal thickness of the external support adhesive is W.1b Where, W1 = W 1a +W 1b = (30%~46%)W 1L W 1a = (0.6~0.9)W 1b .

[0013] In some embodiments, the horizontal thickness of the tire is W, measured horizontally from its maximum width position towards the inside of the tire. 2L The horizontal thickness of the supporting adhesive is W2, and the horizontal thickness of the inner supporting adhesive is W. 2a The horizontal thickness of the external support adhesive is W. 2b Where, W2 = W 2a +W 2b = (52%~67%)W 2L W 2a = (1.0~1.2)W 2b , 8+(LI-97)*0.1≤W2≤8+(LI-97)*0.25, where LI is the load index of the tire.

[0014] In some embodiments, the run-flat tire structure further includes a bead protector and an inner liner. The inner liner is attached to the inside of the inner support rubber. The upper part of the bead protector overlaps with the sidewall rubber, and the lower part of the bead protector wraps around the bead core, the tire carcass, and the inner liner. The distance d2 between the upper end of the bead protector and the lower end of the sidewall rubber is 35% to 55% of the tire's lower section height (LSH). The distance d3 between the wrapped end of the bead protector and the upper end of the inner core is 10 mm to 15 mm.

[0015] In some embodiments, the hardness B1 of the sub-mouth adhesive is greater than the hardness B of the outer support adhesive. 外 The hardness B is greater than that of the internal support adhesive. 内 Furthermore, the hardness B1 of the outer support adhesive is 70-90 degrees, and the hardness B of the outer support adhesive is... 外 The hardness B of the internal support adhesive is 62-80 degrees. 内 The temperature is 60-70 degrees Celsius.

[0016] Another aspect of the present invention discloses a tire manufactured using the run-flat tire structure described above.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. This invention designs the bead core structure of the tire bead portion to consist of an inner core, a middle core, and an outer core. Compared to existing technologies where the rigidity of the tire bead portion is generally ensured by the bead core, the triangular rubber, and the bead protector, where the triangular rubber improves the rigidity of the tire bead portion but reduces ride comfort, this invention eliminates the triangular rubber design. By reinforcing the structure of the bead core and the thickness of the bead protector, the rigidity of the tire bead portion is improved. Because the triangular rubber is removed, the rigidity of the tire bead portion and the sidewall portion becomes more gradual, reducing stress concentration in the tire bead portion and the problem of poor zero-pressure durability. At the same time, it improves ride comfort, achieving the effect of satisfying both the durability performance of the tire at zero pressure and improving the ride comfort of the tire at zero pressure.

[0019] 2. The run-flat tire structure disclosed in this invention sets a range of values ​​for the safety factor S of the bead core in order to ensure tire safety and ride comfort. The larger the safety factor S of the bead core, the greater the rigidity of the bead portion, the better the tire support performance, and the better the safety, but the ride comfort will be worse. Therefore, in order to satisfy both the tire bead portion support performance and improve the tire's zero-pressure durability and ride comfort, this invention sets a range of values ​​for the safety factor S of the bead core, namely 6≤S≤7.

[0020] 3. In order to further improve the tire's zero-pressure durability and ride comfort, the present invention reverses the tire body from the inside to the outside of the center core, so that the inner and outer cores tightly clamp the tire body, effectively preventing the tire body from shifting and affecting the tire's uniform motion performance, thereby improving the tire's ride comfort and NVH performance. By separating the inner, middle, and outer cores through the tire body, it is beneficial to disperse the stress concentration and rigidity of the bead area, thereby improving the tire's zero-pressure durability and ride comfort.

[0021] 4. To balance run-flat tire durability and ride comfort, this invention employs a dual-support rubber structure consisting of an outer support rubber and an inner support rubber. A thicker support rubber increases the tire's radial stiffness, providing greater support and thus better run-flat tire durability. However, increased radial stiffness typically leads to a decline in ride comfort. Conversely, a thinner support rubber improves ride comfort but results in poor run-flat tire durability, failing to meet run-flat tire testing regulations. Therefore, a combined outer and inner support rubber structure is used.

[0022] 5. By designing reasonable thickness, area, and hardness of the inner and outer support rubbers and conducting performance evaluation tests from different perspectives, this invention ultimately determines the thickness and structure of the inner and outer support rubbers, enabling the run-flat tire provided by this invention to not only meet the durability requirements of zero-pressure tires but also improve the ride comfort of zero-pressure tires.

[0023] 6. Since the bead portion of this invention does not have a triangular rubber structure, the rigidity of the bead portion can be further improved by adopting a thicker and harder bead protector design. At the same time, the bead protector wraps around the bead core, carcass, and inner liner, effectively improving the rigidity of the bead portion and also protecting the carcass and inner liner.

[0024] 7. The present invention rationally designs the position of the upper end point of the inner support rubber, the position of the lower end point of the inner support rubber, the position of the upper end point of the bead protector, and the position of the reverse wrapping end point of the bead protector, so that the tire can not only meet the zero-pressure durability requirements but also improve the ride comfort. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 This is a cross-sectional schematic diagram of the contour design provided in an embodiment of the present invention;

[0027] Figure descriptions: Bead core 1; Inner core 101; Middle core 102; Outer core 103; Carcass 2; Support rubber 3; Outer support rubber 301; Inner support rubber 302; Sidewall rubber 4; Belt layer 5; Bead protector 6; Inner liner layer 7. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0029] Obviously, the accompanying drawings described below are merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0030] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention may be combined with other embodiments without conflict.

[0031] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "a," "an," "an," "the," and similar words used in this invention do not indicate quantity limitation and may indicate singular or plural. The terms "comprising," "including," "having," and any variations thereof used in this invention are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms "connected," "linked," "coupled," and similar words used in this invention are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "A plurality" in this invention refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships may exist; for example, "A and / or B" can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects have an "or" relationship. The terms "first," "second," and "third" used in this invention are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0032] This invention provides a run-flat tire structure. Figure 1The cross-sectional view of the outline design according to an embodiment of the present invention shows that the run-flat tire structure includes two symmetrical bead portions, each containing a bead core 1. The bead core 1 includes an inner core 101, an outer core 103, and a middle core 102. The inner core 101 is located on the inner side of the bead portion; the outer core 103 is spaced apart from the inner core 101 and located on the outer side of the bead portion; the middle core 102 is located between the inner core 101 and the outer core 103; wherein the heights of the inner core 101, the middle core 102, and the outer core 103 decrease sequentially. In existing technologies, the rigidity of the bead portion is generally ensured by the bead core 1, the triangular rubber, and the bead protector. If the rigidity of the bead portion is too high, although it ensures the tire's support performance, the ride comfort is poor. If the rigidity of the bead portion is too low, it is easy for the tire to come off the bead, resulting in poor safety. To ensure zero-pressure durability, run-flat tires have an additional support rubber 3 on the sidewall compared to ordinary tires, which increases the radial rigidity of the tire. However, this design will worsen the tire's ride comfort and NVH performance.

[0033] Therefore, to address the issues of run-flat tire durability and ride comfort, this invention designs the bead core 1 structure, consisting of an inner core 101, a middle core 102, and an outer core 103, without any triangular rubber. The absence of triangular rubber in the bead area allows for a smoother transition in rigidity between the bead and sidewall, reducing stress concentration at the bead area and improving ride comfort. Furthermore, the heights of the inner core 101, middle core 102, and outer core 103 decrease sequentially. The height design is the highest, which can effectively ensure the run-flat tire's bead release performance, safety performance, and support performance. Since the bead core 1 is composed of three independent bead cores: inner core 101, middle core 102, and outer core 103, the height of one, two, or three of the inner core 101, middle core 102, and outer core 103 can be adjusted individually to ensure that the rigidity of the bead portion is moderate. This allows the run-flat tire of the present invention to not only meet the tire's zero-pressure durability performance, but also improve the tire's ride comfort and NVH performance.

[0034] In some embodiments, the inner core 101, the middle core 102, and the outer core 103 are columnar bodies of a certain height formed by winding steel wire, and the outside of each is covered with steel wire adhesive to further improve the firmness between the steel wires, so that the inner core 101, the middle core 102, and the outer core 103 can be fixed as a whole, avoiding the steel wires from becoming loose during use.

[0035] In some embodiments, in order to further increase the adhesion between the inner core 101, the middle core 102 and the outer core 103 and to make the inner core 101, the middle core 102 and the outer core 103 bonded more firmly, a transition film is applied to the inner and outer sides of the middle core 102 respectively. This transition film can be a rubber product with a certain shape and thickness.

[0036] Furthermore, the height of the inner core 101 is h1, the height of the middle core 102 is h2, and the height of the outer core 103 is h3, where h1:h2:h3 = 1:(0.6~0.7):(0.5~0.6), h1 = (0.35~0.65)H1, H1 is the rim protection height, and the safety factor of the bead core 1 is S = 2F*N / P*h*(2Ra+h), and 6≤S≤7; where Ra is the inner radius of the tire; h is the total thickness of the center of the tire crown; P is the tire inflation pressure; N is the number of steel wires; and F is the tension of a single steel wire. Since the material selection and arrangement of the bead core 1 directly affect the safety of the tire, the larger the safety factor S of the bead core 1, the greater the rigidity of the bead portion and the better the tire support performance, but the ride comfort will deteriorate. Therefore, in order to satisfy both the tire bead portion support performance and improve the tire zero-pressure durability and ride comfort, this invention sets the range of the safety factor S of the bead core 1, that is, 6≤S≤7.

[0037] In some embodiments, taking a 255 / 50R19 107V run-flat tire as an example, the zero-pressure durability and ride comfort of the run-flat tire were tested by setting relevant values ​​at the bead. Specific test data are shown in Table 1.

[0038] Table 1

[0039]

[0040] As shown in Table 1, through Examples 1 to 5, under the condition that the safety factor of the bead core 1 is 6≤S≤7, the ratios of the height h1 of the inner core 101, the height h2 of the middle core 102, and the height h3 of the outer core 103 are continuously adjusted, and the ratio range of the three can satisfy h1:h2:h3=1:(0.6~0.7):(0.5~0.6). The resulting tires have higher zero-pressure durability performance index and ride comfort performance index than conventional run-flat tires with triangular rubber. The larger the zero-pressure durability performance index and ride comfort performance index, the better the zero-pressure durability performance and ride comfort performance of the tire.

[0041] Furthermore, the run-flat tire structure also includes a tire carcass 2, which is positioned between two symmetrical bead portions. The tire carcass 2 wraps around the inner side of the intermediate core 102 towards the outer side, wherein the wrapping height H of the tire carcass 2 is greater than the height h3 of the outer core 103. To further improve tire zero-pressure durability and ride comfort, this invention wraps the tire carcass 2 around the inner side of the intermediate core 102 towards the outer side, so that the inner core 101 and outer core 103 tightly clamp the tire carcass 2, effectively preventing the tire carcass 2 from shifting and affecting the tire's uniform motion performance. The tire carcass 2 separates the inner core 101, intermediate core 102, and outer core 103, which helps to disperse stress concentration and rigidity in the bead portion, thereby improving tire zero-pressure durability and ride comfort.

[0042] Furthermore, the run-flat tire structure also includes a support rubber 3, a sidewall rubber 4, and a belt layer 5. The support rubber 3 and the sidewall rubber 4 are respectively located on the sidewall of the tire, with the support rubber 3 attached to the inner side of the tire body 2 and the sidewall rubber 4 attached to the outer side of the tire body 2. The upper end point of the sidewall rubber 4 is located at the bottom of the belt layer 5, and the distance d1 between the upper end point of the sidewall rubber 4 and the end point of the belt layer 5 is 12mm to 20mm.

[0043] Furthermore, the support adhesive 3 includes an outer support adhesive 301 and an inner support adhesive 302. The outer support adhesive 301 is attached to the inner side of the tire carcass 2, and the area of ​​the outer support adhesive 301 is S. 外 The inner support adhesive 302 is attached to the inner side of the outer support adhesive 301, and the area of ​​the inner support adhesive 302 is S. 内 The upper end point of the inner support adhesive 302 is located at the bottom of the belt layer 5. The distance between the upper end point of the inner support adhesive 302 and the end point of the belt layer 5 is D1 = 15mm~35mm. The distance between the lower end point of the inner support adhesive 302 and the upper end point of the inner core 101 is D2 = (0.2~0.5)h1. Wherein, S 内 = (50%~70%)S 外 , and 0.9*SH*(0.1*LI-4.4)≤(S 内 +S 外The load index is ≤1.3*SH*(0.225*LI-16.2), where SH is the tire section height and LI is the tire load index. To balance tire run-flat durability and ride comfort, this invention employs a dual-support structure of outer support rubber 301 and inner support rubber 302 for the support rubber 3. A greater thickness of support rubber 3 increases the tire's radial stiffness, resulting in better tire support and run-flat durability. However, increased radial stiffness usually degrades ride comfort. Conversely, a thinner support rubber 3 improves ride comfort but compromises run-flat durability, failing to meet testing regulations. Therefore, a combined structure of outer and inner support rubber 301 is used. The outer support rubber 301 uses a harder compound to provide support and ensure run-flat durability; the inner support rubber 302 uses a softer compound to improve sidewall flexural strength, enhancing ride comfort and NVH performance.

[0044] Furthermore, the tire's normal thickness, measured radially from the top of the tire's rim protection section towards the tire carcass 2, is W. 1L The normal thickness of the support adhesive 3 is W1, and the normal thickness of the inner support adhesive 302 is W. 1a The normal thickness of the outer support adhesive 301 is W. 1b Where, W1 = W 1a +W 1b = (30%~46%)W 1L W 1a = (0.6~0.9)W 1b .

[0045] Furthermore, measuring horizontally from the tire's maximum width position towards the inside of the tire, the tire's horizontal thickness is W. 2L The horizontal thickness of the support adhesive 3 is W2, and the horizontal thickness of the inner support adhesive 302 is W. 2a The horizontal thickness of the outer support adhesive 301 is W. 2b Where, W2 = W 2a +W 2b = (52%~67%)W 2L W 2a = (1.0~1.2)W 2b 8 + (LI - 97) * 0.1 ≤ W2 ≤ 8 + (LI - 97) * 0.25, where LI is the tire load index. This invention, through designing reasonable thicknesses and areas of the inner support rubber 302 and outer support rubber 301, and conducting performance evaluation tests from different angles, ultimately determines the thickness and structure of the inner support rubber 302 and outer support rubber 301. This ensures that the run-flat tire provided by this invention can both meet the durability requirements of a tire with zero air pressure and improve the ride comfort of a tire with zero air pressure.

[0046] Furthermore, the run-flat tire structure also includes a bead protector 6 and an inner liner 7. The inner liner 7 is attached to the inner side of the inner support rubber 302. The upper part of the bead protector 6 overlaps with the sidewall rubber 4, and the lower part of the bead protector 6 wraps around the bead core 1, the tire body 2, and the inner liner 7. The distance d2 between the upper end of the bead protector 6 and the lower end of the sidewall rubber 4 is 35% to 55% of the tire's lower section height (LSH). The distance d3 between the wrapping end of the bead protector 6 and the upper end of the inner core 101 is 10mm to 15mm. This invention rationally designs the positions of the upper and lower ends of the inner support rubber 302, the upper end of the bead protector 6, and the wrapping end of the bead protector 6, further enabling the tire to meet both zero-pressure durability and improve ride comfort.

[0047] Furthermore, the hardness B1 of the outer support adhesive 6 is greater than the hardness B of the outer support adhesive 301. 外 The hardness B is greater than that of the inner support adhesive 302. 内 Furthermore, the hardness B1 of the outer support adhesive 6 is 70-90 degrees, and the hardness B of the outer support adhesive 301 is... 外 The hardness B of the internal support adhesive 302 is 62-80 degrees. 内 The angle is 60-70 degrees. Since the bead portion of the present invention does not have a triangular rubber structure, the rigidity of the bead portion can be further improved by adopting a thickened and harder bead protector 6. At the same time, the bead protector 6 wraps around the bead core 1, the carcass 2 and the inner liner 7, which effectively improves the rigidity of the bead portion and also protects the carcass 2 and the inner liner 7.

[0048] Specifically, taking a 255 / 50R19 107V run-flat tire as an example, with the bead core 1 of this invention already in use, after setting various parameters of the support rubber 3, the zero-pressure durability and ride comfort performance of the run-flat tire were tested. Specific test data are shown in Table 2.

[0049] Table 2

[0050]

[0051]

[0052] As shown in Table 2, through Comparative Examples 1 to 5, W2 is smaller in Comparative Example 1, with a W2:W ratio. 2L = 48% < 52%, indicating that the horizontal thickness W2 of the support rubber 3, measured horizontally from the tire's maximum width position towards the inner side of the tire, is relatively small. The tire's zero-pressure durability index is tested at 96, therefore it cannot meet the durability requirements for run-flat tires; in Comparative Example 2, W1: W 1L=50% > 46%, indicating that the normal thickness W1 of the support rubber 3, measured radially from the top of the tire rim protection section towards the tire body, is similar to the normal thickness W of the tire. 1L The ratio between them is relatively large. The tire's zero-pressure durability index was tested at 98, therefore it cannot meet the durability requirements for run-flat tires; in Comparative Example 3, S... 内 +S 外 =1020, indicating that the total area of ​​the support rubber 3 is relatively large. The tire's zero-pressure durability index is tested and found to be 105, ensuring good radial rigidity and support. However, the tire's ride comfort index is low, therefore it cannot simultaneously meet the requirements for ride comfort. In Comparative Example 4, the hardness B of the inner support rubber 302... 内 =75>70, and S 内 +S 外 =476, indicating that the selected inner support rubber 302 has a relatively high hardness, but the total area of ​​support rubber 3 is small. The tire's zero-pressure durability index is 98, and its ride comfort index is 102. While ride comfort is ensured, zero-pressure durability is not met. In Comparative Example 5, the hardness B of the inner support rubber 302... 内 =56<60, the hardness B of the outer support adhesive 301 外 =60 < 70, indicating that the hardness of the selected inner support rubber 302 and outer support rubber 301 are not within the range of values ​​in this invention. The tire's zero-pressure durability index is 99 and the ride comfort index is 103, which ensures the tire's ride comfort but fails to meet the tire's zero-pressure durability requirements. However, in Examples 1 to 16 of this invention, all parameters are set within the specified range. The tire's zero-pressure durability index and ride comfort index obtained by testing are both greater than those obtained by the single support rubber in the reference example. This proves that the run-flat tire provided by this invention can both meet the tire's zero-pressure durability requirements and improve the tire's ride comfort during zero-pressure operation.

[0053] A tire manufactured using a run-flat tire structure.

[0054] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A run-flat tire structure, characterized in that, It includes two symmetrical bead portions, each containing a bead core, the bead core comprising: Inner core, the inner core being disposed on the inner side of the bead portion; An outer core, which is spaced apart from the inner core and located outside the bead portion; A middle core, wherein the middle core is located between the inner core and the outer core; The heights of the inner core, the middle core, and the outer core decrease sequentially. There is no triangular rubber at the bead area; It also includes a tire carcass, which is disposed between two symmetrical bead portions, and the tire carcass wraps around the inner side of the intermediate core to the outer side of the intermediate core, wherein the wrapping height H of the tire carcass is greater than the height h3 of the outer core; the inner core and the outer core tightly clamp the tire carcass, and the wrapping height H of the tire carcass is greater than the height of the widest part of the tire section; The height of the inner core is h1, the height of the middle core is h2, and the height of the outer core is h3, where h1:h2:h3=1:(0.6~0.7):(0.5~0.6), h1=(0.35~0.65)H1, H1 is the rim protection height, and the safety factor of the tire bead core is S=2F*N / P*h*(2Ra+h), and 6≤S≤7; Where Ra is the inner radius of the tire; h is the total thickness of the center of the tire crown; P is the tire inflation pressure; N is the number of steel wires; and F is the tension of a single steel wire.

2. The run-flat tire structure according to claim 1, characterized in that, It also includes a support rubber, a sidewall rubber, and a belt layer. The support rubber and the sidewall rubber are respectively disposed on the sidewall of the tire, and the support rubber is attached to the inner side of the tire body, while the sidewall rubber is attached to the outer side of the tire body. The upper end point of the sidewall rubber is disposed at the bottom of the belt layer, and the distance d1 between the upper end point of the sidewall rubber and the end point of the belt layer is 12mm to 20mm.

3. The run-flat tire structure according to claim 2, characterized in that, The supporting adhesive includes: An outer support adhesive is attached to the inner side of the tire carcass, and the area of ​​the outer support adhesive is S_outer. An inner support adhesive is attached to the inner side of the outer support adhesive. The area of ​​the inner support adhesive is S_inner. The upper end point of the inner support adhesive is located at the bottom of the belt layer. The distance between the upper end point of the inner support adhesive and the end point of the belt layer is D1 = 15mm to 35mm. The distance between the lower end point of the inner support adhesive and the upper end point of the inner core is D2 = (0.2 to 0.5)h1. Where Sinner = (50%~70%)Souter, and 0.9*SH*(0.1*LI-4.4) ≤ (Sinner + Souter) ≤ 1.3*SH*(0.225*LI-16.2), where SH is the tire section height and LI is the tire load index.

4. The run-flat tire structure according to claim 3, characterized in that, The normal thickness of the tire is W1L, measured from the top of the rim protection portion of the tire towards the radial direction of the tire body. The normal thickness of the tire is W1, the normal thickness of the support rubber is W1, the normal thickness of the inner support rubber is W1a, and the normal thickness of the outer support rubber is W1b, wherein W1 = W1a + W1b = (30%~46%)W1L, and W1a = (0.6~0.9)W1b.

5. The run-flat tire structure according to claim 3, characterized in that, Measured horizontally from the maximum width position of the tire towards the inside of the tire, the horizontal thickness of the tire is W2L, the horizontal thickness of the support rubber is W2, the horizontal thickness of the inner support rubber is W2a, and the horizontal thickness of the outer support rubber is W2b, where W2 = W2a + W2b = (52%~67%)W2L, W2a = (1.0~1.2)W2b, 8 + (LI-97)*0.1 ≤ W2 ≤ 8 + (LI-97)*0.25, and LI is the tire load index.

6. The run-flat tire structure according to claim 3, characterized in that, It also includes a bead protector and an inner liner. The inner liner is attached to the inside of the inner support rubber. The upper part of the bead protector overlaps with the sidewall rubber. The lower part of the bead protector wraps around the bead core, the tire body, and the inner liner. The distance d2 between the upper end of the bead protector and the lower end of the sidewall rubber is 35% to 55% of the tire's lower section height (LSH). The distance d3 between the wrapped end of the bead protector and the upper end of the inner core is 10mm to 15mm.

7. The run-flat tire structure according to claim 6, characterized in that, The hardness B1 of the ferrule protector is greater than the hardness Bout of the outer support adhesive, which is greater than the hardness Bin of the inner support adhesive. The hardness B1 of the ferrule protector is 70-90 degrees, the hardness Bout of the outer support adhesive is 62-80 degrees, and the hardness Bin of the inner support adhesive is 60-70 degrees.

8. A tire, characterized in that, It is manufactured using the run-flat tire structure of any one of claims 1 to 7.

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