Light truck tire having a lightweight bead structure

Abstract

The application discloses a light truck tire with a light-weighted bead structure and relates to the field of all-steel tires. The bead part comprises a tire body, a steel wire ring, lower triangular rubber, upper triangular rubber and wear-resistant rubber. The outer end point of the wear-resistant rubber is higher than the upper end point of the upper triangular rubber. The ratio of the height of the outer end point of the wear-resistant rubber to the height of the tire section is in the range of 0.23-0.53. The ratio of the height of the upper end point of the upper triangular rubber to the height of the tire section is in the range of 0.20-0.50. The outer end point of the wear-resistant rubber is higher than the upper end point of the upper triangular rubber, so that the thickness of the triangular rubber and the height of the triangular rubber are further reduced, the thickness of the bead is reduced, and stress concentration of the end points of the components of the bead part caused by the small difference level is avoided.

Description

Technical Field

[0001] This invention relates to the field of all-steel tires, and more specifically to a light truck tire with a lightweight bead structure. Background Technology

[0002] As my country's road network becomes increasingly sophisticated, the government is intensifying its efforts to combat overloading, particularly in the light truck market, to protect highway lifespan and maintain road safety. This has led to a reduction in the load-bearing capacity requirements for light truck tires. However, given the generally high speeds of light trucks, safety remains a primary concern for customers. Therefore, to enhance the competitiveness of light truck tires, weight reduction is necessary while maintaining product quality.

[0003] In the prior art, patent CN209869972U discloses a lightweight truck tire bead structure that reduces product weight by removing the steel wire wrapping and thinning the bead portion. Patent CN209240797U discloses a steel-blade-less radial tire, which also improves production efficiency without affecting product quality by removing the steel wire wrapping.

[0004] Both of the above existing technologies eliminate the steel wire wrapping, but they still do not meet the market's demand for further weight reduction while ensuring product quality. For further weight reduction, existing technologies can only achieve this by reducing the thickness and height of the triangular rubber. However, reducing the thickness of the triangular rubber makes it too thin and long, causing the ends to curl during manufacturing, leading to an increased scrap rate. Reducing the height of the triangular rubber can solve the curling problem, but it results in stress concentration at the ends of various components in the bead due to insufficient differential pressure. Existing technologies can no longer meet the market's demand for weight reduction while ensuring product quality, necessitating a new bead structure to further achieve weight reduction. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a lightweight truck tire with a lightweight bead structure. By making the outer end of the wear-resistant rubber higher than the upper end of the upper triangular rubber, both the bead portion is made lightweight and the failure rate of the tire during use is reduced, thus solving the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A lightweight truck tire with a lightweight bead structure includes a tire carcass, a steel wire bead, a lower triangular rubber, an upper triangular rubber, and a wear-resistant rubber. The tire carcass is arranged along the tire contour and wraps around the steel wire bead, wrapping back from the axially inward side to the axially outward side. The wear-resistant rubber's outer end point D is higher than the upper end point C of the upper triangular rubber. The ratio of the radial height h4 of the outer end point D of the wear-resistant rubber to the radial section height H of the tire ranges from 0.23 to 0.53, and the ratio of the radial height h3 of the upper end point C of the upper triangular rubber to the radial section height H of the tire ranges from 0.20 to 0.50.

[0008] As a further aspect of the present invention, the reverse end point B of the tire body is lower than the upper end point C of the upper triangular rubber, and the ratio of the radial height h2 of the reverse end point B of the tire body to the radial section height H of the tire is in the range of 0.13 to 0.28.

[0009] As a further embodiment of the present invention, the upper end point A of the lower triangular rubber is lower than the end point B of the tire carcass wrapping, and the ratio of the radial height h1 of the upper end point A of the lower triangular rubber to the radial section height H of the tire is 0.01 to 0.07 lower than the ratio of the radial height h2 of the end point B of the tire carcass wrapping to the radial section height H of the tire.

[0010] As a further aspect of the present invention, with the heel point E as a reference, the maximum value of the bead thickness T is no greater than 25 mm within the range of 10% to 30% of the radial section height of the tire.

[0011] As a further embodiment of the present invention, the lower triangular rubber has a Shore hardness range of 75HA-95HA, the upper triangular rubber 4 has a Shore hardness range of 45HA-65HA, and the abrasion-resistant rubber 5 has a Shore hardness range of 65HA-85HA.

[0012] In this invention, the radial heights of points A, B, C, and D are all based on the tire heel point E. The radial height of point A is the distance between point A and point E in the radial direction of the tire; the radial height of point B is the distance between point B and point E in the radial direction of the tire; the radial height of point C is the distance between point C and point E in the radial direction of the tire; the radial height of point D is the distance between point D and point E in the radial direction of the tire; and the radial section height H of the tire is the distance between the highest point of the tire section and point E in the radial direction of the tire.

[0013] Compared with the prior art, the beneficial technical effects of the present invention are:

[0014] This invention increases the difference in thickness between the endpoints of the wear-resistant rubber and the upper triangular rubber by making the outer end of the wear-resistant rubber higher than the upper end of the upper triangular rubber, thereby reducing the thickness and height of the triangular rubber and thus the bead. Simultaneously, it avoids stress concentration at the endpoints of the bead components due to insufficient thickness difference, reducing the shear strain and strain energy at the inverted end of the tire carcass. This invention also optimizes the overall rigidity distribution of the tire, reducing the shear strain and strain energy at the endpoints of the tread belt layer. This invention has a novel structure and, compared to existing technologies, further achieves lightweighting of the bead section, reducing both tire cost and tire failure rate during use. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the cross-sectional structure of the tire portion where the wear-resistant adhesive is higher than the upper triangular adhesive of the present invention;

[0016] Figure 2 A schematic diagram of the cross-sectional structure of the tire portion where the wear-resistant rubber is lower than the upper triangular rubber in the existing technology;

[0017] Figure 3 The finite element shear strain diagrams for the scheme with 100% air pressure, 100% load, and wear-resistant adhesive lower than triangular adhesive in Table 1 are shown.

[0018] Figure 4 The finite element shear strain diagrams for the scheme with 100% air pressure, 100% load, and wear-resistant adhesive higher than triangular adhesive in Table 1 are shown.

[0019] Figure 5 The finite element strain energy diagrams for the scheme with 100% air pressure, 100% load, and wear-resistant adhesive lower than triangular adhesive in Table 1 are shown.

[0020] Figure 6 The finite element strain energy diagrams for the scheme with 100% air pressure, 100% load, and wear-resistant adhesive higher than triangular adhesive in Table 1 are shown.

[0021] In the diagram: 1-Tire body; 2-Ring wire; 3-Lower triangular rubber; 4-Upper triangular rubber; 5-Abrasion-resistant rubber; 6-First belt layer; 7-Second belt layer. Detailed Implementation

[0022] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] Please see Figure 1This invention discloses a lightweight truck tire with a lightweight bead structure. The bead portion includes a tire body 1, a steel wire bead 2, a lower triangular rubber 3, an upper triangular rubber 4, and a wear-resistant rubber 5. The outer end point D of the wear-resistant rubber is higher than the upper end point C of the upper triangular rubber. In the prior art, the outer end point of the wear-resistant rubber is lower than the upper end point of the upper triangular rubber. Thinning the bead portion is generally achieved by reducing the thickness and height of the triangular rubber. However, reducing the thickness of the triangular rubber makes it too thin and long, causing the end points of the triangular rubber to easily curl during manufacturing, leading to an increased scrap rate. While simultaneously reducing the height of the triangular rubber can solve the curling problem, it results in stress concentration due to the small difference in pressure between the upper end point of the upper triangular rubber, the outer end point of the wear-resistant rubber, the end point of the tire body wrapping, and the upper end point of the lower triangular rubber. This invention increases the height of the outer end point D of the wear-resistant rubber, making it higher than the upper end point C of the upper triangular rubber. This achieves a reduction in the thickness and height of the triangular rubber while avoiding stress concentration caused by the small difference between the upper end point C of the upper triangular rubber, the outer end point D of the wear-resistant rubber, the inverted end point B of the tire carcass, and the upper end point A of the lower triangular rubber. This also reduces the shear strain and strain energy at the inverted end point of the tire carcass.

[0024] Please see Figure 1 The ratio of the radial height h4 of the outer end point D of the wear-resistant rubber to the radial section height H of the tire ranges from 0.23 to 0.53, and the ratio of the radial height h3 of the upper end point C of the upper triangular rubber to the radial section height H of the tire ranges from 0.20 to 0.50. If the height of the outer end point D of the wear-resistant rubber is too high, it will be located in the deformation zone of the tire sidewall. Due to the high hardness of the wear-resistant rubber, repeated bending and deformation of the tire sidewall during tire operation can easily lead to failure at the end point of the wear-resistant rubber. If the height of the outer end point D of the wear-resistant rubber is too low, the stress concentration will occur due to the small difference in height between the endpoints of the various components of the bead. If the height of the upper end point C of the upper triangular rubber is too high, the stress concentration will be caused by the small difference in height between it and the outer end point D of the wear-resistant rubber. If the height of the upper end point C of the upper triangular rubber is too low, the stress concentration will be caused by the small difference in height between it and the end point B of the tire carcass.

[0025] Please see Figure 1 The carcass reversal point B is lower than the upper end point C of the upper triangular rubber. The ratio of the radial height h2 of the carcass reversal point B to the radial section height H of the tire ranges from 0.13 to 0.28. The carcass reversal point B is the end point of the steel wire component in the bead section. If the height of the carcass reversal point B is too high, it will be close to the deformation zone of the tire sidewall. During tire operation, repeated bending and deformation of the tire sidewall will lead to excessive strain energy at the carcass reversal point B, causing malfunction. If the height of the carcass reversal point B is too low, it will be close to the high-stress area where the tire contacts the rim flange, leading to excessive strain energy at the carcass reversal point B, causing malfunction. At the same time, the carcass is a relatively rigid steel wire component. If the height of the carcass reversal point B is too low, it will reduce the rigidity of the tire, reduce the tire's load-bearing capacity, and make the tire more prone to deformation during operation, resulting in higher rolling resistance.

[0026] Please see Figure 1The upper end point A of the lower triangular rubber is lower than the end point B of the tire carcass wrap-around. The ratio of the radial height h1 of the upper end point A of the lower triangular rubber to the radial section height H of the tire is 0.01 to 0.07 smaller than the ratio of the radial height h2 of the end point B of the tire carcass wrap-around to the radial section height H of the tire. If the height of the upper end point A of the lower triangular rubber is higher than or close to the end point B of the tire carcass wrap-around, it will cause stress concentration among the outer end point D of the wear-resistant rubber in the bead, the upper end point C of the upper triangular rubber, the end point B of the tire carcass wrap-around, and the upper end point A of the lower triangular rubber due to the small difference in height. The lower triangular rubber has a high hardness. If the height of the upper end point A of the lower triangular rubber is too low, it will reduce the rigidity of the bead, and the deformation of the bead will increase during tire operation, resulting in excessive strain energy at the end point B of the tire carcass wrap-around, causing failure.

[0027] Please see Figure 1 With the heel point E as a reference, the maximum bead thickness T should not exceed 25 mm within the range of 10% to 30% of the tire's radial section height. Excessive bead thickness leads to excessive tire weight and material waste. This invention places the outer end point D of the wear-resistant rubber above the upper end point C of the upper triangular rubber to further reduce the thickness and height of the triangular rubber. This reduces the bead thickness T within the range of 10% to 30% of the tire's section height H to below 25 mm, achieving lightweighting of the bead portion.

[0028] Please see Figure 1 The lower triangular rubber 3 has a Shore hardness range of 75HA-95HA, the upper triangular rubber 4 has a Shore hardness range of 45HA-65HA, and the abrasion-resistant rubber 5 has a Shore hardness range of 65HA-85HA. The tire needs a smooth transition in rigidity from the high-rigidity area of ​​the bead region, which contacts the rim, to the lower-rigidity sidewall region. This invention increases the hardness of the higher-hardness abrasion-resistant rubber, making the rigidity transition at the bead region smoother, reducing the shear strain and strain energy at the inverted end point B of the tire carcass, and simultaneously making the overall rigidity distribution of the tire more reasonable, reducing the shear strain and strain energy at the end point of the tread belt layer.

[0029] To verify that the lightweight bead structure with a higher wear resistance rubber layer than the triangular rubber layer achieves the effects described in the theoretical derivation, the following experiments were conducted to verify the experimental data:

[0030] Finite element analysis was performed on a 6.50R16LT tire. This tire has two intersecting belt layers in the crown region: a first belt layer (6) and a second belt layer (7). Existing technology's wear-resistant rubber is lower than the triangular rubber, while this invention's wear-resistant rubber is higher than the triangular rubber. The only difference is the structure of the bead region. The ratio of the radial height h2 of the carcass reversal point B to the tire's radial section height H is 0.205 in both cases, and the ratio of the radial height h1 of the upper end point A of the lower triangular rubber to the tire's radial section height H is 0.187 in both cases. Both designs were fitted with 5.50F-16 rims. Under 100% tire pressure and 100% load conditions, the shear strain and strain energy of the carcass reversal point B, the shear strain and strain energy of the first belt layer end point F, the shear strain and strain energy of the second belt layer end point G, tire rolling resistance, tire radial stiffness, lateral stiffness, longitudinal stiffness, and torsional stiffness were analyzed.

[0031] In Table 1, larger values ​​indicate better results.

[0032] A larger bead thickness value indicates a smaller bead thickness T; a larger shear strain value at each end indicates a smaller shear strain; a larger strain energy value at each end indicates a smaller strain energy; a larger rolling resistance value indicates a smaller resistance when the tire rolls; and larger values ​​for tire radial stiffness, lateral stiffness, longitudinal stiffness, and torsional stiffness indicate greater stiffness.

[0033] Table 1

[0034]

[0035] Based on the experimental data results shown in Table 1, we can conclude that:

[0036] Compared to existing technologies where the wear-resistant rubber is lower than the triangular rubber, the present invention, by raising the outer end of the wear-resistant rubber above the upper end of the triangular rubber, further reduces the thickness and height of the triangular rubber. This reduces the bead thickness while simultaneously lowering the shear strain and strain energy at the end point B of the tire carcass, the end point F of the first belt layer, and the end point G of the second belt layer. This reduces the failure rate of the bead and crown during tire use. At the same time, the tire rolling resistance, radial stiffness, lateral stiffness, longitudinal stiffness, and torsional stiffness are comparable to existing technologies, meeting the market demand for lightweighting under strict quality control.

[0037] By comparison Figure 3 and Figure 4 As can be seen from the finite element analysis conducted under 100% air pressure and 100% load conditions, the shear strain and high shear strain area at the end point of the tire carcass in the case where the wear-resistant rubber is higher than the triangular rubber are significantly smaller than those in the case where the wear-resistant rubber is lower than the triangular rubber (the darker the color in the figure, the greater the shear strain).

[0038] By comparison Figure 5 and Figure 6 It can be seen from the finite element analysis conducted under 100% air pressure and 100% load conditions that the strain energy and high strain energy area at the end point of the tire carcass in the case where the wear-resistant rubber is higher than the triangular rubber are significantly smaller than those in the case where the wear-resistant rubber is lower than the triangular rubber (the darker the color in the image, the greater the shear strain).

[0039] The inverted end point B of the tire carcass is lower than the upper end point C of the upper triangular rubber. The ratio of the radial height h2 of the inverted end point B to the radial section height H of the tire ranges from 0.13 to 0.28. The upper end point A of the lower triangular rubber is lower than the inverted end point B of the tire carcass. The ratio of the radial height h1 of the upper end point A of the lower triangular rubber to the radial section height H of the tire is 0.01 to 0.07 smaller than the ratio of the radial height h2 of the inverted end point B to the radial section height H of the tire. To verify the accuracy of the theoretical derivation results obtained after limiting the positions of the above-mentioned end points, this invention verifies the ratio of the height of each end point to the radial section height H of the tire separately:

[0040] Finite element analysis of a 6.50R16LT tire reveals that the tire crown has a first belt layer 6 and a second belt layer 7 with intersecting directions. The existing technology's wear-resistant rubber layer being lower than the triangular rubber layer differs from the present invention's wear-resistant rubber layer being higher than the triangular rubber layer only in the bead structure. In the present invention's wear-resistant rubber layer being higher than the triangular rubber layer, the ratio of the radial height h2 of the tire carcass's inverted end point B to the tire section height H ranges from 0.135 to 0.275, and the ratio of the radial height h1 of the upper end point A of the triangular rubber layer to the tire section height H ranges from 0.117 to 0.187. The tires were fitted with 5.50F-16 rims and, under conditions of 100% tire pressure and 100% load, the shear strain and strain energy of the tire carcass reverse end point B with different radial heights of the radial heights of the upper end point A of the lower triangular rubber, the shear strain and strain energy of the first belt layer end point F, the shear strain and strain energy of the second belt layer end point G, tire rolling resistance, tire radial stiffness, lateral stiffness, longitudinal stiffness, and torsional stiffness were analyzed. The test performance results obtained from the above tests were then compared.

[0041] Table 2

[0042]

[0043]

[0044] In Table 2, larger values ​​indicate better results. The radial height ratio at point B in Table 2 is the ratio of the radial height h2 of the tire carcass reverse end point B to the radial section height H of the tire. The radial height ratio at point A in Table 2 is the ratio of the radial height h1 of the upper end point A of the lower triangular rubber to the radial section height H of the tire.

[0045] Based on the experimental data in Table 2, we can conclude that:

[0046] (1) When the radial height ratio of the upper end of the triangular rubber is 0.187, comparing Examples 1, 2, 3, 4, 5, 10, 11, and 12 with different radial height ratios of the tire carcass reverse end, it can be seen that the overall data of the tire in Example 5, with a radial height ratio of 0.187 at the tire carcass reverse end, is better than that of Examples 1, 2, 3, 4, 10, 11, and 12. When the radial height ratio of the tire carcass reverse end is higher than 0.187, the strain energy of the tire carcass reverse end deteriorates sharply with the increase of the tire carcass reverse end height. When the radial height ratio of the tire carcass reverse end is lower than 0.187, the strain energy of the tire carcass reverse end also deteriorates sharply with the decrease of the tire carcass reverse end height. Within the range of 0.152 to 0.240 of the radial height ratio of the tire carcass reverse end, as the tire carcass reverse end height decreases, the tire rolling resistance, tire radial stiffness, lateral stiffness, longitudinal stiffness, and torsional stiffness all gradually deteriorate. The combined data of shear strain, strain energy, and rolling resistance at the tire carcass in Example 1 (where the radial height ratio at the tire carcass inverted end point is close to the upper limit of 0.28) and Example 12 (where the radial height ratio at the tire carcass inverted end point is close to the lower limit of 0.13) are the worst, proving that the range of 0.13 to 0.28 for the radial height ratio at the tire carcass inverted end point is special.

[0047] (2) When the radial height ratio of the inverted end point of the tire carcass is 0.187, comparing Examples 5, 6, 7, 8, and 9 with different radial height ratios of the upper end point of the lower triangular rubber, it can be seen that the overall tire data of Examples 5 and 6 are comparable and superior to Examples 7, 8, and 9. Since both the inverted end point of the tire carcass and the upper end point of the lower triangular rubber are stress concentration points, stress concentration will occur when the heights of the inverted end point of the tire carcass and the upper end point of the lower triangular rubber are the same. Therefore, Example 6, with a radial height ratio of 0.170 for the upper end point of the lower triangular rubber, is the optimal solution. When the radial height ratio of the upper end point of the lower triangular rubber is less than 0.170, the strain energy of the inverted end point of the tire carcass deteriorates sharply as the height of the upper end point of the lower triangular rubber decreases. Example 6, where the difference between the radial height ratio of the upper end of the lower triangular rubber and the radial height ratio of the inverted end of the tire carcass is 0.017, close to the lower limit of 0.01, has the best overall data. Example 9, where the difference between the radial height ratio of the upper end of the lower triangular rubber and the radial height ratio of the inverted end of the tire carcass is the upper limit of 0.07, has the worst overall data. This proves that the range of 0.01 to 0.07 smaller than the radial height ratio of the upper end of the lower triangular rubber compared to the radial height ratio of the inverted end of the tire carcass is special.

[0048] In the above experimental data, by verifying the values ​​within the range of the ratio of the height of the tire carcass reverse end point and the upper end point of the lower triangular rubber to the tire section height, Example 6 was determined to be the optimal solution. By comparing the experimental results of each example with the prior art, it was demonstrated that the ratio range of the height of the tire carcass reverse end point and the upper end point of the lower triangular rubber to the tire section height in this invention has unique characteristics.

[0049] The production process of a light truck tire with a lightweight bead structure according to the present invention mainly includes the following steps:

[0050] (1) Select tire specifications of 6.50R16LT, outer diameter of 745mm, section width of 188mm, section height of 171mm, maximum rated load of 1060kg, and speed rating of L;

[0051] (2) The sidewall composite is extruded by an extruder, and the Shore hardness of the wear-resistant rubber in the finished tire is 73HA;

[0052] (3) Triangular rubber composite parts are prepared by extruder. The Shore hardness of the lower triangular rubber in the finished tire is 88HA, and the Shore hardness of the upper triangular rubber in the finished tire is 58HA.

[0053] (4) During the molding process, the sidewall, inner liner, steel wire wrapping, and tire body are sequentially attached to the molding drum. The mechanical device transfers the composite steel wire ring, lower triangular rubber, and upper triangular rubber to the molding drum. After the shoulder pad rubber is attached, the mechanical device transfers the composite belt layer and tire crown to the molding drum. The molding drum is inflated and bulged. The pressure roller presses down the tire crown and triangular rubber. Then, the sidewall composite is reverse-wrapped and pressed. After the tire blank is molded, it is vulcanized, inspected, and packaged.

[0054] After both the tires of this invention and those of the prior art are manufactured through the above steps, their durability is then tested.

[0055] The tires of this invention and prior art were mounted on 5.50F-16 rims, inflated to a pressure of 670 kPa, and subjected to durability tests according to GB / T 4501-2016 "Indoor Test Methods for Performance of Heavy-Duty Truck Tires" at an ambient temperature of 38±3℃.

[0056]

[0057]

[0058] According to the above durability test method, both the tires of this invention and the prior art are intact after 47 hours of operation, meeting market demand.

[0059] This invention features a novel structure and stable operation. Addressing the limitation of existing technologies in further reducing tire bead thickness, this invention raises the outer end of the wear-resistant rubber above the upper end of the upper triangular rubber, thereby further reducing the thickness and height of the triangular rubber. This reduction in bead thickness simultaneously avoids stress concentration at the endpoints of various components within the bead region due to excessively small differences in thickness, and reduces shear strain and strain energy at the carcass wrap-around endpoints. Furthermore, this invention optimizes the overall rigidity distribution of the tire, reducing shear strain and strain energy at the endpoints of the tread belt layers. This invention achieves lightweighting of the bead region, reducing both tire cost and tire failure rate during use.

[0060] Compared to existing tire technologies, this invention, by making the outer end of the wear-resistant rubber higher than the upper end of the upper triangular rubber, and simultaneously improving and adjusting the ratio of the aforementioned ends to the tire cross-sectional height, staggers the aforementioned ends in the tire radial direction and increases the difference between the ends. This avoids the problem of tire stress concentration and reduces the shear strain and strain energy at the inverted end of the tire carcass. By rationally setting the hardness of the lower triangular rubber, upper triangular rubber, and wear-resistant rubber, and simultaneously increasing the hardness of the wear-resistant rubber, the rigidity transition of the bead area is smoother, reducing the shear strain and strain energy at the inverted end of the tire carcass. At the same time, it makes the overall rigidity distribution of the tire more reasonable, reducing the shear strain and strain energy at the end of the tread belt layer.

[0061] It will be apparent to those skilled in the art that the present 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 its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0062] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A lightweight truck tire with a lightweight bead structure, wherein the bead portion comprises a tire carcass (1), a steel wire bead (2), a lower triangular rubber (3), an upper triangular rubber (4), and a wear-resistant rubber (5), wherein the tire carcass (1) is arranged along the tire profile and wraps around the steel wire bead (2), and wraps back from the axially inward side of the tire to the axially outward side, characterized in that, The outer end point (D) of the wear-resistant rubber is higher than the upper end point (C) of the upper triangular rubber. The ratio of the radial height h4 of the outer end point (D) of the wear-resistant rubber to the radial section height H of the tire ranges from 0.23 to 0.53, and the ratio of the radial height h3 of the upper end point (C) of the upper triangular rubber to the radial section height H of the tire ranges from 0.20 to 0.

50.

2. The light truck tire with a lightweight bead structure according to claim 1, characterized in that, The end point (B) of the tire carcass is lower than the upper end point (C) of the upper triangular rubber. The ratio of the radial height h2 of the end point (B) of the tire carcass to the radial section height H of the tire is in the range of 0.13 to 0.

28.

3. The light truck tire with a lightweight bead structure according to claim 1, characterized in that, The upper end point (A) of the lower triangular rubber is lower than the end point (B) of the tire carcass. The ratio of the radial height h1 of the upper end point (A) of the lower triangular rubber to the radial section height H of the tire is 0.01 to 0.07 lower than the ratio of the radial height h2 of the end point (B) of the tire carcass to the radial section height H of the tire.

4. The light truck tire with a lightweight bead structure according to claim 1, characterized in that, Based on the heel point E, within the range of 10% to 30% of the tire radial section height, the maximum value of the bead thickness T shall not exceed 25 mm.

5. The light truck tire with a lightweight bead structure according to claim 1, characterized in that, The lower triangular rubber (3) has a Shore hardness range of 75HA-95HA, the upper triangular rubber (4) has a Shore hardness range of 45HA-65HA, and the abrasion-resistant rubber (5) has a Shore hardness range of 65HA-85HA.

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