Low-rolling-resistance truck radial tire

Abstract

The invention provides a low-rolling-resistance truck radial tire, relates to the technical field of tires, and aims to solve the problem that the service life and driving safety of the tire are affected when rolling resistance is reduced by reducing a tread rubber hysteresis loss factor at present. The outer contour of the tread is in a form of smooth center and smooth transition to the tire shoulder, the ground contact area of the tread can be enlarged, the ground contact pressure is uniformly dispersed to the whole tread, the ratio of the minimum distance JD from the end point of the tire shoulder to the inner contour line of the tire to the middle thickness MT of the tread is limited, the pressure of the tire shoulder and the tread area is balanced, and the four layers of belt ply cords can form gradient support. According to the invention, the local fitting support of the tread is enhanced, and the overall deformation of the tread is controlled, so that the tire can have lower rolling resistance, and the service life and the driving safety of the tire can be ensured.

Description

Technical Field

[0001] This invention relates to the field of tire technology, and specifically to a low rolling resistance heavy-duty radial tire. Background Technology

[0002] There is an urgent market demand for low rolling resistance performance in heavy-duty radial tires, as the logistics and transportation industry seeks to reduce vehicle energy consumption to control operating costs. As the core component that directly contacts the ground, the tread's rolling resistance primarily stems from energy lag losses caused by cyclic deformation during rolling, with this energy mainly dissipated as heat. Therefore, controlling ineffective deformation of the tire under load is the core technical approach to reducing rolling resistance.

[0003] By adjusting the rubber compound formulation to reduce tanδ (hysteresis tangent), the hardness of the rubber compound increases while its toughness decreases, thereby reducing energy loss during use and achieving the effect of reducing rolling resistance. However, relying solely on rubber compound formulation improvements will lead to a decrease in other tire performance. While hardness helps resist wear to some extent, excessively low tanδ will cause the rubber compound to lose the necessary flexibility, affecting tire life and driving safety. Therefore, it is difficult to meet the requirements of heavy-duty radial tires to ensure other performance while reducing rolling resistance. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a low rolling resistance radial tire for heavy loads, which improves rolling resistance performance by adjusting the tire's profile, tread pattern, and structure while ensuring other performance characteristics.

[0005] To achieve the above objectives, the following solution is adopted: A low rolling resistance radial tire for heavy loads includes a carcass, a tread, a shoulder, and a sidewall. The tire crown profile is formed by the tangent of a first arc and a second arc. The first arc is close to the center of the tread, and the second arc connects the first arc and the shoulder. The radius of the first arc is larger than the radius of the second arc. The radial height difference H between the center endpoint of the tread outer profile and the end endpoint of the shoulder satisfies 5.5 mm ≤ H ≤ 7.5 mm. The ratio of the minimum distance JD from the end endpoint of the shoulder to the inner profile line of the tire to the center thickness MT of the tread satisfies 1.34 ≤ ≤1.55; Four belt layers are arranged sequentially from the tire carcass to the tread, and the cord angle ratio of the four belt layers is 2.6:1:1:1.

[0006] Furthermore, along the tire axis, three tread grooves are sequentially arranged on the tire surface to divide the tire surface into four groups of tread blocks, and the width ratio of the four groups of tread blocks is 0.9±3%:1±3%:1±3%:0.9±3%.

[0007] Furthermore, along the tire axial direction, the three tread grooves are arranged sequentially with widths of GW1, GW2, and GW3, where GW1 = GW3 > GW2. The groove depths of the three tread grooves are GD1, GD2, and GD3, where GD1 = GD3 > GD2. The groove width ratio of the three tread grooves is 1 ± 1.5%: 0.16 ± 1.5%: 1 ± 1.5%; the groove depth ratio of the three tread grooves is 1 ± 0.5%: 0.96 ± 0.5%: 1 ± 0.5%.

[0008] Furthermore, the angle α between the walls of the two patterned grooves located on both sides and the vertical direction satisfies 11°≤α≤15°.

[0009] Furthermore, the shoulder area is provided with shoulder pad rubber, and the belt layers are filled with belt interlayer rubber, wherein the ratio of the hysteresis loss tangent of the shoulder pad rubber to the hysteresis loss tangent of the belt interlayer rubber is 1:1.67.

[0010] Furthermore, the ratio of the tread width XSW to the tire section width DMW satisfies: 0.77 ≤ ≤0.9.

[0011] Furthermore, the tire parting line width PW and the driving surface width XSW satisfy the following relationship: 1.03 ≤ ≤1.1.

[0012] Furthermore, the ratio of the upper height H1 to the lower height H2 of the tire horizontal axle satisfies: 1.02 ≤ ≤1.12.

[0013] Furthermore, the tread is arranged with three pitches: S, M, and L. The length ratio of S, M, and L is 1±1.5%:1.08±1.5%:1.183±1.5%.

[0014] Furthermore, the tread compound used in the tread has a hysteresis loss tangent of 0.011 ≤ tanδ ≤ 0.14 at 60°C, and the base compound used in the tread has a hysteresis loss tangent of 0.050 ≤ tanδ ≤ 0.075 at 60°C. The ratio of the elongation at break of the tread compound and the base compound at room temperature is 1.19 ≤ ≤1.35, the ratio of the tensile strength of the tread compound to the base compound at room temperature is 0.98≤ ≤1.09.

[0015] Compared with the prior art, the advantages and positive effects of this invention are: To address the issue that current methods of reducing rolling resistance by lowering the tread rubber hysteresis loss factor negatively impact tire lifespan and driving safety, this invention adjusts the tire profile design. The tread profile consists of two arcs with different radii, the first arc having a larger radius than the second. Combined with a radial height difference of 5.5 mm ≤ H ≤ 7.5 mm, this results in a tread outer profile that is gently sloping towards the shoulder, ensuring a smooth transition and uniform ground pressure distribution. Simultaneously, it reduces radial and circumferential deformation of the tread during tire rolling, lowering rolling resistance. Furthermore, by reducing rubber hysteresis loss, the ratio of the minimum distance JD from the shoulder end to the inner tire profile line to the tread thickness MT is limited to 1.34 ≤ With a profile angle ≤1.55, the tire shoulder area is balanced in terms of support and flexibility. The four-layer belt cord angle ratio is 2.6:1:1:1, creating gradient support. The belt layers closer to the tire carcass have a larger angle, providing stronger radial restraint and suppressing overall tread deformation; the belt layers closer to the tread have a smaller angle, enhancing local tread fit and controlling overall tread deformation. Through the synergistic effect of these three profile and structural designs, the focus of reducing rolling resistance shifts from "improving materials" to "optimizing structure," resulting in a heavy-duty radial truck tire that possesses both low rolling resistance and excellent wear resistance and wet-weather safety performance.

[0016] By adjusting tire profile design parameters such as tread crown height and tread width, the stress on the crown area is reduced, thereby decreasing energy loss at the crown. Simultaneously, self-sealing and longitudinal grooves are designed in the center of the tread to reduce tire deformation under load. Further optimization of the tread and base compound formulations further reduces energy loss at the crown area and improves rolling resistance. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of the cross-sectional structure of a low rolling resistance heavy-duty radial tire in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the parameter distribution of a low rolling resistance heavy-duty radial tire in an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the tread pattern of a low rolling resistance heavy-duty radial tire in an embodiment of the present invention.

[0021] The components are: 1. Tread rubber; 2. Base rubber; 3. Belt layer; 4. Carcass; 5. Sidewall; 6. Bead wrap; 7. Nylon reinforcement layer; 8. Soft triangle rubber; 9. Hard triangle rubber; 10. Steel wire bead. Detailed Implementation

[0022] In a typical embodiment of the present invention, such as Figures 1-3 As shown, a low rolling resistance heavy-duty radial tire is presented.

[0023] While existing heavy-duty radial tires reduce tread energy loss and rolling resistance by lowering the hysteresis loss factor of the tread compound 1, they cannot take into account other tire performance characteristics and cannot meet the industry's requirements for comprehensive tire performance.

[0024] To address the aforementioned core issues, this embodiment achieves its goal by optimizing the key tire structure, providing a low rolling resistance heavy-duty radial tire, such as... Figure 1 As shown, it is mainly divided into three parts: the core area of ​​the tire crown, the sidewall support area, and the bead fixing area.

[0025] The core area of ​​the tire crown includes the tread compound 1, the base compound 2, and the belt layer 3. The tread compound 1, located on the outermost layer of the tire, together with the base compound, forms the tire crown component, directly contacting the ground. It must have low hysteresis loss and is the core component for achieving low rolling resistance. The base compound 2, located below the tread compound 1 and above the belt layer 3, serves to bridge the stress between the tread compound 1 and the belt layer 3, buffering tread deformation, and also helps reduce energy loss from the tire crown through optimized formulation. The belt layer 3, located below the base compound 2 and above the tire carcass 4, is typically a multi-layered cord structure. Its main function is to restrain the tire crown, enhance tread rigidity, reduce tread deformation during rolling, indirectly reducing rolling resistance and improving driving stability.

[0026] The sidewall 5 supports the tire crown and bead, protecting the tire carcass 4. The tire carcass 4, consisting of the entire tire's cord layers, forms the tire's skeleton, bearing the vehicle's weight and impacts during driving, maintaining the tire's basic shape, and transferring stress to other components. The sidewall 5 covers the outside of the tire carcass 4, protecting the tire carcass cords from external impacts and scratches, while also possessing a certain degree of elasticity to accommodate deformation during driving.

[0027] The bead fixing area connects the tire to the rim, ensuring stable assembly. It includes a bead wrap 6, a nylon reinforcement layer 7, soft triangular rubber 8, hard triangular rubber 9, and a steel wire ring 10. The bead wrap 6 wraps around the outside of the bead, close to the rim contact area. Its function is to enhance the wear resistance at the bead-rim contact point, prevent the bead from being scratched by the rim during assembly, and disperse bead stress to avoid stress concentration. The nylon reinforcement layer 7 is mostly located on the outside of the bead, its function being to disperse stress in the bead area, reduce bead cracking, and improve durability. The soft triangular rubber 8 is a soft rubber material filling the transition area between the bead and the sidewall 5. Its function is to buffer stress concentration between the bead and the tire carcass 4, reduce deformation and heat generation in this area during driving, and prevent rubber cracking. The hard triangular rubber 9 is located inside the soft triangular rubber 8, close to the steel wire ring 10. Its harder material serves to fix the position of the steel wire ring 10, enhance bead rigidity, ensure the tire is not easily loosened when mounted on the rim, and improve high-speed driving stability. The innermost ring-shaped steel wire structure of the 10-inch tire is the core component connecting the tire and the rim. Its function is to firmly fix the tire to the rim, bear the tension force during tire assembly and the radial force during driving, and ensure that the tire does not detach from the rim.

[0028] In this embodiment, as Figure 1 and Figure 2 As shown, the outer contour of the tire crown has an arc-shaped structure on the tire interface, consisting of two tangent arcs. The first arc is close to the center of the tread, and the second arc connects the first arc to the tire shoulder. The radius TR1 of the first arc is greater than the radius TR2 of the second arc, satisfying the following relationship: 1.1 ≤ ≤3; at the same time, the radial height difference H between the center endpoint of the outer contour of the tread and the end point of the shoulder is limited, and the height difference satisfies 5.5mm≤H≤7.5mm.

[0029] The shoulder thickness control specifies the minimum distance JD from the shoulder end point to the inner contour line of the tire, and the ratio of the minimum distance JD from the shoulder end point to the center thickness MT of the tread satisfies 1.34 ≤ ≤1.55, the structural thickness of the standard shoulder area. Four belt layers 3 are set sequentially from the tire carcass 4 to the tread, namely belt layer 1#, belt layer 2#, belt layer 3#, and belt layer 4#, and the cord angle ratio of the four belt layers 3 is fixed at 2.6:1:1:1.

[0030] The range of values ​​for the dual-arc tread and height difference H can optimize the ground contact force and make the ground contact pressure distribution more uniform. The tread is the core area that directly contacts the ground, and its contour structure determines the ground contact pressure distribution and the degree of rolling deformation. The more uniform the ground contact pressure, the greater the radial stiffness. Furthermore, the tire structure can be improved while retaining other performance characteristics by reducing rubber hysteresis loss.

[0031] The radius of the first arc segment is larger than that of the second arc segment. Combined with a height difference of 5.5mm≤H≤7.5mm, in this embodiment, H=7.4mm is configured so that the outer contour of the tread has a shape that is "gentle in the center and smoothly transitions to the shoulder". This can increase the tread contact area and allow the contact pressure to be evenly distributed throughout the tread, avoiding the phenomenon of uneven wear caused by local pressure concentration. At the same time, it reduces the radial and circumferential deformation of the tread when the tire rolls, reduces the energy loss of the rubber compound due to deformation, and reduces the rolling resistance of the tire.

[0032] The configuration range of shoulder thickness JD can distribute shoulder stress and prevent excessive stress on the shoulder. The shoulder is the transition area between the tread and the sidewall, and is prone to stress concentration due to unreasonable structural thickness, which increases energy loss and exacerbates rolling resistance. The ratio of the minimum distance JD from the shoulder end point to the inner contour line of the tire to the center tread thickness MT must satisfy 1.34 ≤ A thickness of ≤1.55 can balance the support and flexibility of the tire shoulder and tread area, avoiding both insufficient support and excessive deformation due to excessive thinness, and stress concentration due to excessive thickness. This ensures that the force is evenly distributed between the tire shoulder and the center of the tread, preventing uneven wear and abnormal wear.

[0033] The belt layer 3 is the core support structure of the tire crown. Its cord angle determines the restraining force on the tread. The more reasonable the restraining force, the smaller the deformation of the tread during rolling and the lower the rolling resistance. The cord angle ratio of the four belt layers 3 is 2.6:1:1:1, which can form a "gradient support". The belt layers 3 closer to the tire carcass 4 (such as belt layer 1# 3) have a larger angle, providing stronger radial restraining force and suppressing overall tread deformation; the belt layers 3 closer to the tread (such as belt layers 3# and 4# 3) have a smaller angle, enhancing the local fit and support of the tread and avoiding excessive deformation of the tread pattern blocks. Through layered synergistic support, energy loss during tread rolling is reduced. In this embodiment, structural optimization reduces tread energy loss and rolling resistance, avoids the problem of reduced rubber hardness, ensures wear resistance during tread-ground friction, and extends wear life. This embodiment improves tread stress uniformity and structural stability. The double-arc tread, reasonable H-value, and JD-value ensure uniform tread ground pressure. The four-layer belt layer 3 enhances crown support, reduces local deformation and stress concentration during tire rolling, lowers the risk of tread damage due to uneven pressure distribution, and extends the overall tire life.

[0034] Furthermore, the structural design and parameter selection in this embodiment can adapt to the needs of heavy-duty scenarios. For the high-load use characteristics of heavy-duty radial tires, the tire with optimized structure can still maintain low heat generation and low rolling resistance while bearing a large load pressure, meeting the core requirements of the logistics and transportation industry for low energy consumption and long service life.

[0035] The ratio of tire tread width (XSW) to tire section width (DMW) should satisfy: 0.77 ≤ ≤0.9; The tread travel area ratio is reasonably limited to avoid insufficient contact area due to an excessively small XSW (excessive local pressure and increased heat generation), and excessively wide tread due to an excessively large XSW (excessive deformation of tread edges and increased rolling resistance during rolling). By optimizing the contact area, pressure is evenly distributed and tread heat generation is reduced.

[0036] The ratio of the upper height H1 to the lower height H2 of the tire horizontal axle should satisfy: 1.02 ≤ ≤1.12; This makes the rigidity of the tire sidewall 5 more uniform. Different ratios will lead to different stress and strain distributions in the tire. When the H1 / H2 ratio is too large, the stress and strain will be concentrated in the tire shoulder area, which may cause excessive energy loss in the tire shoulder area. When the ratio is too small, it may cause excessive stress in the tire bead area.

[0037] The tire parting line width PW and the running surface width XSW satisfy the following relationship: 1.03 ≤ ≤1.1. By controlling this ratio, the rigidity of the tread edge can be indirectly controlled, reducing the "warping" deformation of the tread edge during rolling and reducing energy loss.

[0038] The tire tread is divided into four tread blocks A, B, C, and D by three tread grooves. The width ratio of the four tread blocks A, B, C, and D is 0.9±3%: 1±3%: 1±3%: 0.9±3%. The tread blocks are symmetrically distributed with narrow sides and a wider middle section. The two middle groups of tread blocks are the main stress areas, while the side tread blocks provide auxiliary contact. This allows for even distribution of lateral force on the tread, preventing excessive deformation of tread blocks on one side due to overload and thus preventing abnormal tire wear. At the same time, the wider middle tread blocks enhance the overall rigidity of the tread, reduce the compression deformation of the tread blocks during rolling, indirectly reduce frictional heat generation of the rubber compound, and help control rolling resistance.

[0039] The widths of the three tread grooves are GW1, GW2, and GW3, where GW1 = GW3 > GW2, and the width ratio of the three tread grooves is 1 ± 1.5% : 0.16 ± 1.5% : 1 ± 1.5%. The depths of the three tread grooves are GD1, GD2, and GD3, where GD1 = GD3 > GD2, and the width ratio of the three tread grooves is 1 ± 0.5% : 0.96 ± 0.5% : 1 ± 0.5%. The wide and deep tread grooves on both sides can ensure drainage efficiency in rainy weather and avoid a decrease in anti-skid performance. On the other hand, the narrow and shallow tread groove in the middle can reduce the deformation of the "groove wall compression" when the tread rolls, reduce energy loss, and maintain tread rigidity, balancing the requirements of "low rolling resistance" and "anti-skid".

[0040] The groove walls of the GD1 and GD3 tread grooves form an angle α with the vertical direction, and the angle satisfies the following range: 11°≤α≤15°, so that the groove walls have a certain supporting force and can avoid stress concentration, further reducing local heat generation on the tread.

[0041] The tire tread is arranged with three pitches: S, M, and L. The length ratio of the three pitches S, M, and L is 1±1.5%: 1.08±1.5%: 1.183±1.5%. This can break the "periodic resonance" caused by a single pitch, avoid additional noise and energy loss caused by the fixed repetition frequency of the tread pattern when the tire rolls, and make the circumferential ground pressure distribution more uniform, reducing excessive wear and heat generation of local tread blocks.

[0042] The rubber compound used in tread compound 1 has a hysteresis loss tangent of 0.011≤tanδ≤0.14 at 60℃, which can directly reduce the energy loss when the tread rubs against the ground (the smaller the hysteresis loss, the stronger the elastic deformation recovery ability of the rubber compound and the less heat generation), and is the core material guarantee for achieving low rolling resistance. The rubber compound used in base compound 2 has a hysteresis loss tangent of 0.050≤tanδ≤0.075 at 60℃, which is slightly higher than that of tread compound 1. It can buffer the stress difference between the tread and belt layer 3 through moderate elastic deformation, avoid cracking at the interface due to sudden rigidity change, and at the same time help to disperse the energy loss of the tread without increasing the rolling resistance.

[0043] The elongation at break of tread compound 1 at room temperature is AT, and the elongation at break of base compound 2 at room temperature is AB. The ratio of the two is in the range of 1.19 ≤ The elongation of tread compound 1 is ≤1.35, which is higher than that of base compound 2, giving the tread better flexibility during contact deformation and preventing damage to the rubber compound due to excessive stretching. The tensile strength of tread compound 1 at room temperature is CT, and the tensile strength of base compound 2 at room temperature is CB. The ratio of the two is within the range of 0.98 ≤ With a strength of ≤1.09, the two materials have similar strengths, ensuring that the tread and the base rubber 2 deform synchronously when subjected to force, preventing local stress concentration, reducing energy loss due to differences in mechanical properties, and ensuring the integrity of the tread structure while extending service life.

[0044] The tire shoulder area is designed with shoulder pad rubber, where the ratio of the hysteresis loss tangent of the shoulder pad rubber to the hysteresis loss tangent of the belt interlayer is 1:1.67. The shoulder pad rubber is located in the tire shoulder area and directly bears the transition stress between the tire shoulder and the tire crown. The low hysteresis loss tangent can reduce the heat generation of the shoulder pad rubber and prevent the tire shoulder from aging due to high temperature. The belt interlayer is filled between the belt layers 3 and needs to have a certain degree of adhesion to enhance the adhesion of the belt layers 3. A slightly higher hysteresis loss tangent can ensure the stability between the layers.

[0045] Let's take the 12R22.5 tire as an example for explanation.

[0046] Table 1 shows the rolling resistance values ​​simulated under different H and JD / MT conditions using finite element simulation technology.

[0047] Table 1

[0048] Comparative analysis of the results in the table shows that reducing the crown arc height leads to an increase in the overall variable of the crown during rolling, resulting in increased energy loss of the tread rubber and a rise in rolling resistance. Reducing the ratio of the tire shoulder thickness to the tread center thickness (reducing the shoulder pad thickness) reduces the energy value of the shoulder pad rubber, according to the principle of rolling resistance calculation, since the volume of the rubber compound is inversely proportional to the energy loss. At the same time, according to the simulation ground contact results, Comparative Example 15 has a higher rectangularity, better ground contact, and more uniform pressure distribution, thus resulting in a lower rolling resistance.

[0049] Table 2 shows the simulation values ​​for different parting line widths (PW) using finite element simulation technology.

[0050] Table 2

[0051] It can be seen that the decrease in the ratio of the parting line width to the driving surface width increases the stress and energy loss in the tire sidewall area, resulting in an increase in the simulated rolling resistance value.

[0052] Table 3 shows the simulation results obtained by changing the angle of the belt layer.

[0053] Table 3

[0054] The data in the table shows that as the angles of belt layers #2, #3, and #4 increase, the energy loss value of belt layer #3 decreases. This indicates that as the angles of belt layers #2, #3, and #4 increase, the deformation of belt layer #3 decreases, leading to a decrease in rolling resistance.

[0055] Table 4 is a comparative data table of the correlation between the tread rubber hysteresis loss tangent (tanδ) and tire rolling resistance performance.

[0056] Table 4

[0057] As shown in Table 4, with the decrease of the hysteresis loss tangent tanδ, the energy loss of the tread rubber is significantly reduced, thus lowering rolling resistance. This embodiment improves and optimizes the structure while reducing the hysteresis loss of the rubber compound, while retaining other performance characteristics.

[0058] Table 5 shows the measured values ​​of rolling resistance for different products. Table 5

[0059] The data in the comparison table shows that by using low rolling resistance rubber compound, while ensuring other performance characteristics, and through optimization of the profile, pattern, and structural design, the rolling resistance coefficient of the 12R22.5 tire can reach below 4.0, which is a significant reduction compared to competing products of the same specification.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low rolling resistance heavy-duty radial tire, characterized in that, The tire includes the carcass, tread, shoulder, and sidewall. The tire crown profile is formed by the tangent of a first arc and a second arc. The first arc is close to the center of the tread, and the second arc connects the first arc and the shoulder. The radius of the first arc is larger than the radius of the second arc. The radial height difference H between the center endpoint of the tread outer profile and the end point of the shoulder satisfies 5.5 mm ≤ H ≤ 7.5 mm. The ratio of the minimum distance JD from the end point of the shoulder to the inner profile line of the tire to the center thickness MT of the tread satisfies 1.34 ≤ ≤1.55; Four belt layers are arranged sequentially from the tire carcass to the tread, and the cord angle ratio of the four belt layers is 2.6:1:1:

1.

2. The low rolling resistance radial tire for heavy loads as described in claim 1, characterized in that, Along the tire axis, three tread grooves are sequentially arranged on the tire surface to divide the tire surface into four groups of tread blocks, and the width ratio of the four groups of tread blocks is 0.9±3%:1±3%:1±3%:0.9±3%.

3. The low rolling resistance radial tire for heavy loads as described in claim 2, characterized in that, Along the tire axial direction, three tread grooves are arranged sequentially with widths of GW1, GW2, and GW3, where GD1=GD3>GD2. The groove depths of the three tread grooves are GD1, GD2, and GD3, where GD1=GD3>GD2. The groove width ratio of the three tread grooves is 1±1.5%:0.16±1.5%:1±1.5%; the groove depth ratio of the three tread grooves is 1±0.5%:0.96±0.5%:1±0.5%.

4. The low rolling resistance radial tire for heavy loads as described in claim 2 or 3, characterized in that, The angle α between the walls of the two patterned grooves located on both sides and the vertical direction satisfies 11°≤α≤15°.

5. The low rolling resistance radial tire for heavy loads as described in claim 1, characterized in that, The tire shoulder area is equipped with shoulder pad rubber, and the belt layers are filled with belt interlayer rubber. The ratio of the hysteresis loss tangent of the shoulder pad rubber to the hysteresis loss tangent of the belt interlayer rubber is 1:1.

67.

6. The low rolling resistance radial tire for heavy loads as described in claim 1, characterized in that, The ratio of the tread width XSW to the tire section width DMW satisfies: 0.77 ≤ ≤0.

9.

7. The low rolling resistance radial tire for heavy loads as described in claim 5, characterized in that, The tire parting line width PW and the running surface width XSW satisfy the following relationship: 1.03 ≤ ≤1.

1.

8. The low rolling resistance radial tire for heavy loads as described in claim 1, characterized in that, The ratio of the upper height H1 to the lower height H2 of the tire horizontal axle satisfies: 1.02 ≤ ≤1.

12.

9. The low rolling resistance radial tire for heavy loads as described in claim 1, characterized in that, The tread is arranged with three pitches: S, M, and L. The length ratio of S, M, and L is 1±1.5%:1.08±1.5%:1.183±1.5%.

10. The low rolling resistance radial tire for heavy loads as described in claim 1, characterized in that, The tread compound used in the tire tread has a hysteresis loss tangent of 0.011 ≤ tanδ ≤ 0.14 at 60°C, and the base compound used in the tire tread has a hysteresis loss tangent of 0.050 ≤ tanδ ≤ 0.075 at 60°C. The ratio of the elongation at break of the tread compound and the base compound at room temperature is 1.19 ≤ ≤1.35, the ratio of the tensile strength of the tread compound to the base compound at room temperature is 0.98≤ ≤1.09.

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