An all-steel load-bearing radial tire

Abstract

The invention discloses an all-steel load-bearing radial tire and relates to the technical field of radial tires. The present invention optimizes the design of the tire's outer profile section width SW, lower side plate height LSH, and bead positioning line width TTZ. Under the constraints of given technical parameters, the stress deformation of the tire bead area is small. At the same time, in terms of structural design, the carcass cord end point height HSC, the bead chafer outer end point height HWC.O, the bead chafer inner end point height HWC.I, the hard apex rubber upper end point height HHBF, the bead area integral reinforcement layer arranged between the carcass cord, apex rubber and steel ring, and the bead chafer inner reinforcement layer arranged between the carcass cord and the bead chafer inner end point are optimized, and new requirements are set for the strength of the reinforcement layer and the strength and modulus of the cord covering rubber. In terms of formula materials, the deformation and modulus matching of soft and hard apex rubbers are also deeply explored and verified, so that the stress deformation of the entire bead area is reduced, thereby reducing early cracks at the carcass cord end point, the bead chafer outer / inner end point, the hard apex rubber upper end point, and the widest position of the steel ring, effectively extending the service life of the tire.

Description

Technical Field

[0001] The present invention relates to the technical field of radial tires, and in particular to an all-steel load-bearing radial tire capable of improving tire bead durability. Background Art

[0002] In the heavy-duty market, due to the high load environment, tire bead failure is one of the most common failure phenomena, such as external bead cracks, internal bead cracks, and bead cut bursts, which shorten the tire's service life. To address these issues, tire design generally adopts the following two approaches: 1. Increasing the height of the steel wire material to increase bead stiffness; 2. Increasing bead stiffness by adding a reinforcement layer of steel wire material.

[0003] 1. Chinese invention patent CN106956551A discloses a fiber cord radial tire, which adds a layer of fiber cord outside the bead and apex rubber. Its structural characteristics are that the end point height of the carcass cord is higher than the outer end point height of the bead cover, the outer end point height of the fiber cord is higher than the carcass cord end point, and the inner end point height of the fiber cord is higher than the inner end point height of the bead cover. It can form a uniform transition of material hardness and rigidity between the apex rubber and the carcass cord, while reducing the shear stress of the carcass cord end point, solving the problem of failure during use caused by insufficient bead strength or sudden change in rigidity, thereby improving the driving safety and service life of the tire. (This tire structure in which the end point height of the carcass cord is higher than the end point height of the outer side of the bead packing is a tire structure in which a layer of fiber cord is added outside the bead and apex rubber to improve the bead strength and make the rigidity transition uniform. However, there are problems in actual use. First, from a design perspective, ① the structure in which the carcass cord height is higher than the end point height of the outer side of the bead packing will cause the end point of the carcass cord to be stressed, resulting in cracks at the end point of the carcass cord and cracks outside the bead; ② the outer side height of the fiber cord is higher than the carcass cord height. If the fiber cord height is set too low, it will lead to the accumulation of materials, which is easy to cause air pockets. If the fiber cord is set too high and too close to the horizontal axis, where the tire is most deformed, the ends of the cord can be easily damaged by repeated flexing during tire operation, resulting in cracks outside the bead. Furthermore, the cord does not wrap around the carcass ends, failing to effectively protect them, making cracks more likely to occur there. Furthermore, from a manufacturing perspective, adding a layer of cord outside the bead and apex increases the complexity of the molding process, adding steps and impacting production efficiency.

[0004] Second, Chinese invention patent CN103738122A discloses an all-steel radial tire with internal bead reinforcement and its manufacturing method. Specifically, the tire comprises a steel cord turnup layer and a steel cord reinforcement layer on either side of the carcass ply. The steel cord turnup layer is laminated between the carcass ply and the inner liner. The steel cord reinforcement layer is disposed between the carcass ply and the apex on the inner side of the bead. This means that by adding a layer of chafer between the carcass and the apex, the overall strength of the bead is enhanced, thereby improving the tire's high-load resistance and durability. (This method of improving bead durability by adding a layer of steel cord between the carcass and the apex is very limited in practical application, due to two major bottlenecks. First, from a design perspective, the overall stability of the bead is compromised, resulting in uneven stress distribution across the bead area, poor overall bead stability, and cracks at the carcass cord endpoints, as well as external bead cracks. Furthermore, the ratio of steel cord to rubber modulus in the bead area is typically 500 times, and the tire is made of multiple materials and experiences complex stresses. This can easily lead to stress concentration when the tire changes rolling direction under heavy loads, causing damage at the upper and lower endpoints of the steel cord reinforcement layer. This, in turn, can lead to damage to the inner and outer layers of the steel cord turnup, resulting in both external and internal bead cracks. Reinforcement with additional steel wire alone cannot effectively address the poor bead stability associated with all-steel radial tires. Second, from a manufacturing perspective, adding a layer of steel cord between the carcass cord and the apex increases the complexity of the molding process, adding steps and impacting production efficiency.)

[0005] However, both of the above-mentioned improvement methods only improve the bead stiffness by means of a single factor, without taking into account the overall stability of the bead area; in view of this, the present invention proposes an all-steel load-bearing radial tire that can improve the durability of the bead. Summary of the Invention

[0006] The purpose of the present invention is to provide an all-steel load-bearing radial tire to solve the problems raised in the background technology.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An all-steel load-bearing radial tire, comprising a global structure and an internal structure, wherein the global structure comprises a crown, a carcass, sidewalls and beads; the sidewalls are connected to the beads and the crown; the portion of the carcass located inside the sidewalls forms a filling space extending from the beads toward the crown, and the internal structure comprises a carcass cord, an integral reinforcing layer for the bead portion, an inner reinforcing layer for the bead wrapper, a bead wrapper, a soft apex, a hard apex and a wire ring, wherein the hard apex and the soft apex are self- The bead is connected to the upper end of the bead in sequence from bottom to top, and the steel wire ring is arranged inside the bead; the carcass cord covers the outside of the hard apex and the soft apex, and the bead chafer is covered on the outside of the carcass cord, and the carcass cord and the bead chafer form a curved reverse covering on the outside of the carcass; the bead portion integral reinforcement layer is arranged between the carcass cord, the soft apex, the hard apex and the steel wire ring, and the bead chafer inner reinforcement layer is arranged between the carcass cord and the inner end point of the bead chafer;

[0009] The section width of the tire profile is recorded as SW, the lower side plate height is recorded as LSH, and the bead positioning line width is recorded as TTZ;

[0010] The height of the end point of the carcass cord in the vertical direction is recorded as HSC, the height of the inner end point of the integral reinforcement layer of the bead portion in the vertical direction is recorded as H3N.I, the height of the outer end point of the integral reinforcement layer of the bead portion in the vertical direction is recorded as L3N.I, the height of the upper end point of the inner reinforcement layer of the bead wrapper in the vertical direction is recorded as H4N.I, the height of the lower end point of the inner reinforcement layer of the bead wrapper in the vertical direction is recorded as L4N.I, the height of the outer end point of the bead wrapper in the vertical direction is recorded as HWC.O, the height of the inner end point of the bead wrapper in the vertical direction is recorded as HWC.I, and the height of the upper end point of the hard apex rubber in the vertical direction is recorded as HHBF.

[0011] Preferably, the relationship between the lower side plate height LSH and the cross-sectional width SW is: 0.500≤LSH / SW≤0.549; the relationship between the bead portion positioning line width TTZ and the cross-sectional width SW is: 0.140≤TTZ / SW≤0.156.

[0012] Preferably, the relationship between the carcass cord end point height HSC and the lower side plate height LSH is: 0.365≤HSC / LSH≤1.056.

[0013] Preferably, the relationship between the outer endpoint height HWC.O of the bead cover and the end point height HSC of the carcass cord is: 0.79≤HWC.O / HSC≤1.39; the relationship between the inner endpoint height HWC.I of the bead cover and the end point height HSC of the carcass cord is: 1.26≤HWC.I / HSC≤1.67.

[0014] Preferably, the relationship between the upper endpoint height HHBF of the hard apex and the end point height HSC of the carcass cord is: 1.00≤HHBF / HSC≤1.67.

[0015] Preferably, the bead portion integral reinforcement layer wraps the end points of the carcass cord, and the breaking strength of the material of the bead portion integral reinforcement layer meets ≥215.6N, the bonding strength ≥137.2 (N / 10mm), the coating strength M100 meets 2.5Mpa≤M100≤4.3Mpa, and the modulus E * Meet 5.1Mpa≤E * ≤10.1Mpa;

[0016] The inner endpoint height H3N.I of the overall bead reinforcement layer is 20 to 40 mm higher than the upper endpoint HHBF of the hard apex rubber; the outer endpoint height L3N.I of the overall bead reinforcement layer is 10 to 20 mm lower than the carcass cord endpoint HSC; the thickness of the overall bead reinforcement layer is 0.5 mm to 5 mm.

[0017] Preferably, the bead portion integral reinforcement layer is compounded on the carcass cord, and its shape is designed to be wide at the top and narrow at the bottom.

[0018] Preferably, the material of the inner reinforcing layer of the chafer satisfies the breaking strength of ≥215.6N, the bonding strength of ≥137.2 (N / 10mm), the coating strength M100 of 2.5Mpa≤M100≤4.3Mpa, and the modulus E * Meet 5.1Mpa≤E * ≤10.1Mpa;

[0019] The height H4N.I of the upper end point of the inner reinforcing layer of the bead cover is 10 to 30 mm higher than the inner end point HWC.I of the bead cover; the height L4N.I of the lower end point of the inner reinforcing layer of the bead cover is 10 to 30 mm lower than the inner end point HWC.I of the bead cover, and the thickness of the inner reinforcing layer of the bead cover is 0.5 mm to 5 mm.

[0020] Preferably, the inner reinforcing layer of the chafer is compounded on the inner side of the chafer.

[0021] Preferably, the elongation at break Eb1 of the hard apex meets 185%≤Eb1≤295%; the elongation at break Eb2 of the soft apex meets 418%≤Eb1≤534%; and the modulus ratio between the hard apex and the soft apex meets 1.82≤E*hard / E*soft≤4.91.

[0022] Compared with the prior art, the present invention provides an all-steel load-bearing radial tire with the following beneficial effects:

[0023] The present invention proposes an all-steel load-bearing radial tire. Under the premise of ensuring other tire performance, the outer profile section width SW, the lower side plate height LSH, and the bead positioning line width TTZ of the tire are optimized. Under the constraints of the technical parameters given by the present invention, the stress deformation of the tire bead is small; at the same time, in terms of structural design, the carcass cord end point height HSC, the bead cover outer end point height HWC.O, the bead cover inner end point height HWC.I, the hard apex upper end point height HHBF, are set on the carcass cord, apex and The overall reinforcement layer of the bead between the wire rings, as well as the inner reinforcement layer of the bead wrapper arranged between the carcass cord and the inner end point of the bead wrapper, have been optimized, and new requirements have been put forward for the strength of the reinforcement layer and the strength and modulus of the cord covering rubber; the deformation and modulus matching of soft and hard apex rubbers have also been deeply explored and verified in the formula materials, so that the stress deformation of the entire bead area is reduced, thereby reducing the early cracks at the carcass cord end point, the outer / inner end point of the bead wrapper, the upper end point of the hard apex rubber, and the widest position of the wire ring, effectively extending the service life of the tire. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A partial cross-sectional view taken along the meridian direction of a conventional normal tire mentioned in Example 1 of the present invention;

[0025] Figure 2 A partial cross-sectional view in the meridian direction of the all-steel radial truck tire mentioned in Example 1 of the present invention;

[0026] Figure 3 This is a diagram of laying out the carcass cord and chafer mentioned in Example 1 of the present invention.

[0027] Description of the numbers in the figure:

[0028] 1. Carcass cord; 2. Bead overall reinforcement layer; 3. Chafer inner reinforcement layer; 4. Chafer; 5. Soft apex; 6. Hard apex; 7. Wire ring. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] The present invention addresses the problems of existing structures by conducting a detailed analysis of the tire bead's profile and structure. Furthermore, after cutting a section of a faulty tire, it was found that the initial locations of bead damage were primarily ① the carcass cord endpoint, ② the outer endpoint of the chafer, ③ the inner endpoint of the chafer, ④ the upper endpoint of the hard apex, and ⑤ the widest point of the bead ring. By comprehensively considering these issues, the present invention provides a completely new all-steel radial truck tire structure with enhanced bead durability. A preferred embodiment of the present invention is described in detail below, with reference to the accompanying drawings, including the following content.

[0031] Example 1:

[0032] See also Figure 2 , Figure 2 The figure shows a cross-sectional view in the meridian direction of the all-steel load-bearing radial tire structure proposed in the present invention. The outer contour design includes the section width SW, the lower side plate height LSH, and the bead positioning line width TTZ; the internal structure includes a carcass cord 1, a bead integral reinforcement layer 2 arranged between the carcass cord 1, a soft apex 5, a hard apex 6 and a steel ring 7, a bead inner reinforcement layer 3 arranged between the carcass cord 1 and the inner end point of the bead wrapper 4, the bead wrapper 4, the soft apex 5, the hard apex 6, and the steel ring 7; the height of the carcass cord 1 end point in the vertical direction The height of the inner end point of the overall reinforcing layer 2 of the bead portion in the vertical direction is H3N.I, the height of the outer end point of the overall reinforcing layer 2 of the bead portion in the vertical direction is L3N.I, the height of the upper end point of the inner reinforcing layer 3 of the bead wrapper in the vertical direction is H4N.I, the height of the lower end point of the inner reinforcing layer 3 of the bead wrapper in the vertical direction is L4N.I, the height of the outer end point of the bead wrapper 4 in the vertical direction is HWC.O, the height of the inner end point of the bead wrapper 4 in the vertical direction is HWC.I, and the height of the upper end point of the hard apex rubber 6 in the vertical direction is HHBF.

[0033] The relationship between the lower side plate height LSH of the outer contour of the tire structure and the tire cross-sectional width SW is 0.500≤LSH / SW≤0.549, preferably 0.535; when LSH / SW is set too small, that is, the tire horizontal axis height LSH is set too small, the tire deformation area moves downward, and the stress and deformation of each cord end point in the bead area increases, resulting in an increased risk of bead failure; when LSH / SW is set too large, that is, the tire horizontal axis height LSH is set too large, the tire deformation area moves upward, although it is beneficial to the stress and deformation of the bead area, it causes the crown of the tire to be stressed and the shear strain of the belt layer to increase, resulting in an increased risk of crown failure.

[0034] The relationship between the outer contour bead positioning line width TTZ of the tire structure and the tire section width SW is 0.140≤TTZ / SW≤0.156, preferably 0.151; when TTZ / SW is set too small, that is, the bead width TTZ is set too small, the bead stiffness is insufficient, and the stress and deformation of each end point of the bead part increases, resulting in an increased risk of failure of each cord end point of the bead part; when TTZ / SW is set too large, that is, the bead width TTZ is set too large, although the bead stiffness can be increased, the vulcanization time will be increased, the risk of over-vulcanization of the crown part will be increased, and the durability of the crown part will be reduced; at the same time, it will cause a decrease in production efficiency and an increase in cost.

[0035] The relationship between the carcass ply endpoint height HSC and the outer contour lower side plate height LSH of the tire structure is 0.365≤HSC / LSH≤1.056, and the preferred HSC / LSH is 0.365; when HSC / LSH is set too large, that is, the carcass ply endpoint height HSC is set too high, the carcass ply endpoint height is close to the horizontal axis, and the area near the horizontal axis is the area with the maximum tire deformation, which will increase the risk of carcass ply endpoint cracking; when HSC / LSH is set too small, that is, the carcass ply endpoint height HSC is set too small, the rigidity of the bead area will be directly reduced, and the bead durability will be significantly reduced, so the carcass ply endpoint height has a reasonable height range, within this range, the tire bead durability can be guaranteed.

[0036] The relationship between the outer endpoint height HWC.O of the bead wrapper and the end point height HSC of the carcass ply of the tire structure is 0.79≤HWC.O / HSC≤1.39, and the preferred HWC.O / HSC is 1.15; when HWC.O / HSC is set too large, that is, the outer endpoint height HWC.O of the bead wrapper is set too high, although the carcass ply end point can be more effectively protected, the difference between the outer endpoint height of the bead wrapper and the carcass ply end point height is too large, which will cause stress concentration on the outer endpoint of the bead wrapper, resulting in an increased risk of cracking on the outer endpoint of the bead wrapper; when HWC.O / HSC is set too small, that is, the outer endpoint height HWC.O of the bead wrapper is set too small, it cannot effectively protect the carcass ply end point, which will directly reduce the rigidity of the bead area and the durability of the bead will be significantly reduced. Therefore, the outer endpoint height of the bead wrapper has a reasonable height range, and within this range, the bead durability of the tire can be guaranteed.

[0037] The relationship between the inner endpoint height HWC.I of the bead cover and the end point height HSC of the carcass cord of the tire structure is 1.26≤HWC.I / HSC≤1.67, and the preferred HWC.I / HSC is 1.67; when HWC.I / HSC is set too large, that is, the inner endpoint height HWC.I of the bead cover is set too high, the inner endpoint height of the bead cover is close to the horizontal axis, and the area near the horizontal axis is the area with the maximum deformation of the tire, which will increase the risk of cracking of the inner endpoint of the bead cover; when HWC.I / HSC is set too small, that is, the inner endpoint height HWC.I of the bead cover is set too small, the rigidity of the bead area will be directly reduced, and the durability of the bead will be significantly reduced. Therefore, there is a reasonable height range for the inner endpoint height of the bead cover. Within this range, the durability of the tire bead can be guaranteed and the risk of internal cracking is also low;

[0038] The relationship between the upper endpoint height HHBF of the hard apex of the tire structure and the upper endpoint height HSC of the carcass cord is 1.344≤HHBF / HSC≤1.67, with HHBF / HSC preferably being 1.67. When the upper endpoint height of the hard apex exceeds the above range, its upper endpoint is close to the horizontal axis deformation area, which can easily cause delamination between the hard apex and the carcass cord during tire operation. When the upper endpoint height of the hard apex is below the above range, its upper endpoint height is set too low, which will reduce the overall rigidity of the bead area and the durability of the bead.

[0039] The tire structure is provided with an integral reinforcing layer 2 for the bead portion, which is located between the carcass cord 1, the hard apex rubber 6 and the wire ring 7. The main purpose of the reinforcing layer 2 is to solve the following problems: ① The gap between the carcass cord and the hard apex rubber causes the apex rubber to be empty; ② The bead cut bursts due to repeated shearing between the carcass cord and the wire ring; ③ The carcass cord end points are cracked due to repeated deformation. The material of the integral reinforcing layer 2 for the bead portion needs to consider the comprehensive performance of adhesion, fatigue, aging, strength and modulus, preferably nylon 66 with a fineness of 1260D; the breaking strength (N) of the cord meets ≥215.6, and the adhesion strength (N / 10mm) ≥137.2; the rubber coating strength M100 (Mpa) of the integral reinforcing layer 2 for the bead portion meets 2.5≤M100≤4.3, preferably M100 (Mpa) = 2.7; the modulus E * (Mpa) meet 5.1≤E * ≤10.1, preferably E *(Mpa) = 5.3; the height of the inner end point of the overall reinforcing layer 2 of the bead portion needs to be 10 to 30 mm higher than the upper end point of the hard apex rubber 6; when it exceeds the above range, the end point is set too high and close to the horizontal axis deformation area, which may easily cause the overall reinforcing layer 2 of the bead portion to become empty during tire operation; when it is less than the above range, the end point is set too low and close to the upper end point of the hard apex rubber 6, which may also easily cause air pockets; the height of the outer end point of the overall reinforcing layer 2 of the bead portion needs to be 10 to 20 mm lower than the end point of the carcass cord 1; when it exceeds the above range, the width of the overall reinforcing layer 2 of the bead portion is too long, resulting in excessive accumulation of material below the bead portion; when it is less than the above range, the height of the outer end point of the overall reinforcing layer 2 of the bead portion is set too high, and the width of the overall reinforcing layer 2 of the bead portion is too small to fully protect the end point of the carcass cord 1.

[0040] The tire structure has a chafer inner reinforcement layer 3 set between the carcass cord 1 and the inner end point of the chafer 4. The purpose of setting this chafer inner reinforcement layer 3 is mainly to solve the problem of the inner end point of the bead being cracked due to shearing between the inner end point of the chafer 4 and the carcass cord 1. The material of the chafer inner reinforcement layer 3 needs to consider the comprehensive performance of adhesion, fatigue, aging, strength and modulus. Nylon 66 with a fineness of 1260D is preferred. The breaking strength (N) of the cord meets ≥215.6, and the adhesion strength (N / 10mm) is ≥137.2. The rubber coating strength M100 (Mpa) of the overall reinforcement layer 3 of the bead part meets 2.5≤M100≤4.3, preferably M100 (Mpa) = 2.7. The modulus E * (Mpa) meet 5.1≤E * ≤10.1, preferably E * (Mpa) = 5.3; the upper end point height of the inner end point of the bead filler 3 needs to be 10-30mm higher than the inner end point of the bead filler 4; when it exceeds the above range, the end point is set too high and close to the horizontal axis deformation area, which may easily cause the inner reinforcing layer 3 of the bead filler to be empty during tire operation; when it is less than the above range, the end point is set too low and is close to the inner end point of the bead filler 4, which cannot play the role of protecting the inner end point of the bead filler 4; the lower end point height of the inner reinforcing layer 3 of the bead filler 3 needs to be 10-30mm lower than the inner end point of the bead filler 4. When it exceeds the above range, the lower end point height of the inner reinforcing layer 3 of the bead filler 3 is too high, that is, the width of the inner reinforcing layer 3 of the bead filler 3 is too long, resulting in excessive accumulation of bead material; when it is less than the above range, the width of the inner reinforcing layer 3 of the bead filler 3 is too small, and is close to the inner end point of the bead filler 4, which cannot play the role of protecting the inner end point of the bead filler 4.

[0041] The tire structure's hard apex 6 and soft apex 5 formulations are optimized for elongation. The Eb(%) of the hard apex 6 must satisfy 185≤Eb(%)≤295, with an optimal Eb(%) of 207. The Eb(%) of the soft apex 5 must satisfy 418≤Eb(%)≤534, with an optimal Eb(%) of 457. (Here, Eb(%) represents the elongation ratio of the rubber at break.) The modulus ratio between the two must satisfy 1.82≤Eb(%). * Hard / E * Soft≤4.91 ratio, preferably E * Hard / E * The soft one is 2.31; the soft and hard apex rubbers adopt the formula with optimized elongation to effectively reduce the repeated deformation of the tire bead during driving, which leads to the tearing of the soft and hard apex rubbers and the failure of the bead being empty; in addition, the modulus matching between the soft and hard apex rubbers needs to be within a reasonable range. * Hard / E * When the softness exceeds the above range, and the ratio of the modulus of the hard apex 6 to the soft apex 5 is too large, the material rigidity distribution of the bead part will be uneven, which is not good for the durability of the bead. * Hard / E * When the softness is less than the above range, that is, the hard apex rubber 6 modulus is low, the material rigidity of the bead part is insufficient, which will also affect the tire bead durability.

[0042] See also Figure 3 , Figure 3 The diagram shows the laying of the carcass cord and the chafer of the present invention. The bead portion integral reinforcement layer 2 is compounded on the carcass cord 1, and its size is wide at the top and narrow at the bottom; the chafer inner reinforcement layer 3 is compounded on the inner side and upper part of the chafer 4.

[0043] In order to prove the technical effect of the technical solution adopted by the present invention, this embodiment and comparative example were verified and compared. The specific contents are as follows.

[0044] Comparative Examples 1 to 4:

[0045] When the LSH / SW values ​​are 0.500, 0.528, 0.542, and 0.549, respectively, the tire section width changes from the initial state to the loaded state. The greater the change, the greater the tire deformation and the greater the risk of bead failure.

[0046]

[0047] Comparative Examples 5 and 6:

[0048] When the TTZ / SW values ​​are 0.140 and 0.156, the higher the test result data of machine tool 1, the better the tire bead durability performance.

[0049]

[0050] Comparative Example 7:

[0051] When the HSC / LSH value is 1.056, the higher the test result data of machine tool 1, the better the tire bead durability performance.

[0052]

[0053] Comparative Examples 8 and 9:

[0054] When the HWC.O / HSC values ​​are 0.79 and 1.39, the higher the test result data of machine tool 1, the better the tire bead durability performance.

[0055]

[0056] Comparative Examples 10 and 11:

[0057] When the HWC.I / HSC value is 1.26 or 1.51, the shear strain between the inner end point of the bead cover and the tire body is larger, the stress deformation is greater, and the risk of cracking in the bead is greater; the higher the test result data of machine tool 1, the better the durability of the tire bead.

[0058]

[0059] Comparative Examples 12 and 13:

[0060] When the HHBF / HSC values ​​are 1.00 and 1.34, the higher the test result data of machine tool 2, the better the tire bead durability performance.

[0061]

[0062] Comparative Examples 14 and 15:

[0063] When there is no integral reinforcing layer for the bead portion and the integral reinforcing layer for the bead portion is a film, the greater the shear strain is, the greater the stress and deformation of the bead portion is.

[0064]

[0065] Comparative Examples 16 and 17:

[0066] When there is no inner reinforcing layer of the chafer and the inner reinforcing layer of the chafer is a film, the greater the shear strain is, the greater the stress deformation at the inner end point of the bead is.

[0067]

[0068] Comparative Example 18:

[0069] When the soft apex Eb (%) is 493 and the hard apex Eb (%) is 295, the test results of machine tool 2 show that the higher the data, the better the tire bead durability performance.

[0070]

[0071] Comparative Example 19:

[0072] E * Hard / E * When the soft value is 4.91, the experimental results of machine tool 2 show that the higher the data, the better the tire bead durability performance.

[0073]

[0074] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An all-steel load-bearing radial tire, comprising a global structure and an internal structure, wherein the global structure comprises a crown, a carcass, sidewalls, and beads; the sidewalls are connected to the beads and the crown; the portion of the carcass located within the sidewalls forms a filling space extending from the beads toward the crown, characterized in that: The internal structure comprises a carcass cord (1), an integral reinforcing layer for the bead portion (2), an inner reinforcing layer for the bead wrapper (3), a bead wrapper (4), a soft apex rubber (5), a hard apex rubber (6) and a steel ring (7), wherein the hard apex rubber (6) and the soft apex rubber (5) are sequentially connected to the upper end of the bead from bottom to top, and the steel ring (7) is arranged inside the bead; the carcass cord (1) covers the hard apex rubber (6) and the soft apex rubber (5). ), the bead chafer (4) is wrapped around the outside of the carcass cord (1), and the carcass cord (1) and the bead chafer (4) form a curved reverse wrapping on the outside of the carcass; the bead portion integral reinforcement layer (2) is arranged between the carcass cord (1), the soft apex rubber (5), the hard apex rubber (6) and the wire ring (7), and the bead chafer inner reinforcement layer (3) is arranged between the carcass cord (1) and the inner end point of the bead chafer (4); The section width of the tire profile is recorded as SW, the lower side plate height is recorded as LSH, and the bead positioning line width is recorded as TTZ; The height of the end point of the carcass cord (1) in the vertical direction is recorded as HSC, the height of the inner end point of the bead portion integral reinforcement layer (2) in the vertical direction is recorded as H3N.I, the height of the outer end point of the bead portion integral reinforcement layer (2) in the vertical direction is recorded as L3N.I, the height of the upper end point of the inner reinforcement layer (3) of the bead wrapper in the vertical direction is recorded as H4N.I, the height of the lower end point of the inner reinforcement layer (3) of the bead wrapper in the vertical direction is recorded as L4N.I, the height of the outer end point of the bead wrapper (4) in the vertical direction is recorded as HWC.O, the height of the inner end point of the bead wrapper (4) in the vertical direction is recorded as HWC.I, and the height of the upper end point of the hard apex rubber (6) in the vertical direction is recorded as HHBF; The relationship between the lower side plate height LSH and the cross-sectional width SW is: 0.500<LSH / SW<0.549; the relationship between the bead portion positioning line width TTZ and the cross-sectional width SW is: 0.140<TTZ / SW≤0.156; The relationship between the carcass cord end point height HSC and the lower side plate height LSH is: 0.365≤HSC / LSH<1.056; The relationship between the outer endpoint height HWC.O of the bead cover and the end point height HSC of the carcass cord is: 0.79≤HWC.O / HSC≤1.39; the relationship between the inner endpoint height HWC.I of the bead cover and the end point height HSC of the carcass cord is: 1.26<HWC.I / HSC≤1.

67.

2. The all-steel radial truck tire according to claim 1, characterized in that: The relationship between the upper endpoint height HHBF of the hard apex and the end point height HSC of the carcass cord is: 1.00≤HHBF / HSC≤1.

67.

3. The all-steel radial truck tire according to claim 1, characterized in that: The bead portion integral reinforcement layer (2) wraps the end points of the carcass cord (1), and the material of the bead portion integral reinforcement layer (2) has a breaking strength of ≥215.6 N, an adhesive strength of ≥137.2 (N / 10mm), a coating strength M100 of 2.5 Mpa≤M100≤4.3 Mpa, and a modulus E * Meet 5.1 Mpa≤E * ≤10.1 Mpa; The inner endpoint height H3N.I of the integral reinforcement layer of the bead portion is 20 to 40 mm higher than the upper endpoint HHBF of the hard apex rubber; the outer endpoint height L3N.I of the integral reinforcement layer of the bead portion is 10 to 20 mm lower than the endpoint HSC of the carcass cord; the thickness of the integral reinforcement layer of the bead portion is 0.5 mm to 5 mm.

4. The all-steel radial truck tire according to claim 3, characterized in that: The bead portion integral reinforcement layer (2) is composited on the carcass cord (1), and its shape is designed to be wide at the top and narrow at the bottom.

5. The all-steel radial truck tire according to claim 1, characterized in that: The material of the inner reinforcing layer (3) of the tire chafer satisfies the requirements of breaking strength ≥ 215.6 N, bonding strength ≥ 137.2 (N / 10mm), coating strength M100 satisfies 2.5 Mpa ≤ M100 ≤ 4.3 Mpa, modulus E * Meet 5.1 Mpa≤E * ≤10.1 Mpa; The height H4N.I of the upper endpoint of the inner reinforcing layer of the bead cover is 10~30mm higher than the inner endpoint HWC.I of the bead cover; the height L4N.I of the lower endpoint of the inner reinforcing layer of the bead cover is 10~30mm lower than the inner endpoint HWC.I of the bead cover, and the thickness of the inner reinforcing layer of the bead cover is 0.5mm~5mm.

6. The all-steel radial truck tire according to claim 5, characterized in that: The chafer inner side reinforcing layer (3) is compounded on the inner side and upper side of the chafer (4).

7. The all-steel radial truck tire according to claim 1, characterized in that: The elongation at break Eb1 of the hard apex (6) satisfies 185%≤Eb1≤295%; the elongation at break Eb2 of the soft apex (5) satisfies 418%≤Eb1≤534%; and the modulus ratio between the hard apex (6) and the soft apex (5) satisfies 1.82≤E*hard / E*soft≤4.91.

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