Passenger car tire with low rolling resistance, high abrasion and high comfort

Abstract

The invention provides a passenger car tire with low rolling resistance, high abrasion and high comfort, and belongs to the technical field of tires. A passenger car tire low in rolling resistance, high in abrasion and high in comfort comprises a tread, a belted layer, a tire body, a tire side and a steel wire ring, four open pattern grooves distributed in the circumferential direction are formed in the tread, each pattern groove adopts a groove bottom groove with a self-closed opening in the loading state, the tread is divided into five pattern blocks by the pattern grooves, and the tread is provided with a groove bottom groove with a self-closed opening in the loading state. The widths of the five pattern blocks from the center of the tread to the two sides are C, B, D, A and E respectively, and meet the following conditions: A = E, B = C = D, A: B = (1.45 + / -2.5%): (1 + / -2.5%) and 0.15 < = A / L < = 0.26, L is the arc length of the outer contour of the tread, a groove bottom groove adopts a vertical grooving mode, the bottom is a full-arc fillet, and the depth H1 and the width w1 of the groove bottom groove meet the condition that H1 / w1 is greater than or equal to 1.0. By optimizing the structural design, the pattern design and the formula design of the tire, the tire has low rolling resistance, high comfort and high abrasion performance.

Description

Technical Field

[0001] This invention relates to the field of tire technology, specifically to a passenger car tire with low rolling resistance, high wear resistance, and high comfort. Background Technology

[0002] With rapid societal development, the demand for buses is increasing daily, especially with the government's strong promotion of green energy. New energy buses are poised to become the mainstream model in the passenger transport market. The core requirements for new energy buses extend beyond safety performance; they also demand high driving range. Tires, as the only component of a bus in contact with the ground, are crucial for driving safety and performance, thus playing a vital role in bus performance requirements. Besides high safety performance, tires must also be energy-efficient to ensure longer driving range. Furthermore, due to the significant driving and braking forces of buses, tires wear out faster, necessitating longer wear life. Moreover, with advancements in automotive technology and rising living standards, the demand for bus comfort is increasing, making improved tire comfort performance essential.

[0003] The following technical methods are commonly used to achieve the above performance requirements: The main technical means used to reduce tire rolling resistance include: structurally, reducing tread thickness and reducing contact patch ratio; compounding with low heat generation; and tread design, mainly reducing groove depth to reduce tire deformation during driving. The main technical means used to improve wear resistance include: increasing wear volume and using high wear-resistant compounds. The main technical means used to improve comfort include: reducing tire radial stiffness.

[0004] However, the main technical means to reduce tire rolling resistance include structurally reducing tread thickness (and rubber usage) and decreasing contact patch performance. While thinning the tread rubber can effectively reduce rolling resistance, it also affects tire wear. Furthermore, a reduced contact patch rectangle ratio leads to uneven pressure distribution at the shoulder, causing uneven wear and affecting the overall tire lifespan. Using a low-heat-generating compound to reduce rolling resistance inevitably leads to a decrease in tire wear resistance, cut resistance, and wet grip. Reducing groove depth and increasing crown rigidity in the tread pattern reduces rolling resistance, but this results in decreased wear and reduced comfort. Increasing wear volume and using a high-wear-resistance compound to improve wear performance increases the volume of the rubber compound, leading to increased energy loss during driving and a significant increase in rolling resistance. Additionally, due to the "devil's triangle" of compound design, a high-wear-resistance compound inevitably increases heat generation in the rubber compound, further increasing rolling resistance. Simply reducing radial rigidity to improve comfort increases tire deformation and heat generation, thus increasing rolling resistance. Furthermore, large deformation during tire use leads to uneven stress distribution, causing uneven wear and reducing tire lifespan. Based on the above performance requirements, it can be seen that wear, rolling resistance, and comfort are independent of each other, and existing conventional technologies cannot achieve them simultaneously. Therefore, it is necessary to provide an all-steel radial tire with low rolling resistance, high wear, and high comfort. Summary of the Invention

[0005] This invention provides a bus tire with low rolling resistance, high wear resistance, and high comfort. By optimizing the tire's structural design, tread pattern design, and compound design, a tire structure with low rolling resistance, high wear resistance, and high comfort is provided.

[0006] A bus tire with low rolling resistance, high wear resistance, and high comfort includes a tread, belt layer, carcass, sidewall, and steel wire bead. The tread has four circumferentially distributed open tread grooves. Each tread groove is a groove bottom that opens and closes under load. The tread grooves divide the tread into five tread blocks. The widths of the five tread blocks from the center of the tread to both sides are C, B, D, A, and E, respectively, and satisfy: A=E, B=C=D, A:B=(1.45±2.5%):(1±2.5%), 0.15≤A / L≤0.26, where L is the outer arc length of the tread.

[0007] Preferably, the trench bottom groove adopts a vertical grooving method, and the bottom is a full circular arc rounded. The depth H1 and width w1 of the trench bottom groove satisfy: H1 / w1≥1.0.

[0008] Preferably, the belt layer includes a second belt layer and a first belt layer arranged sequentially from the inner side of the tread towards the center of the tire, wherein the width of the first belt layer is W1B and the width of the second belt layer is W2B, wherein W1B > W2B.

[0009] Preferably, the projection point of the first belt layer endpoint P on the tire body is Q, the tangent line through point P to the first belt layer is L1, the tangent line through point Q to the tire body is L2, and the angle between tangent line L1 and tangent line L2 is α, where α satisfies: 18°<α<28°.

[0010] Preferably, the horizontal distance between the first belt layer endpoint P and the outer contour of the tire sidewall is b, the intersection of the vertical downward point of the outer contour endpoint of the tire sidewall and the horizontal distance b is K, and the horizontal distance between K and the outer contour of the tire sidewall is b1. b1 and b satisfy: 0.13 < b1 / b < 0.29.

[0011] Preferably, the horizontal distance between the endpoint S of the second belt layer and the center of the bottom of the outer tread groove is SG, and the relationship between SG and the width A of the shoulder tread block satisfies: 0.46 < SG / A < 0.73; the perpendicular distance from point S to the outer contour of the tread is SF, and SG and SF satisfy: 1.2 < SG / SF < 1.9.

[0012] Preferably, the vertical distance between the endpoint of the outer contour of the tread and the intersection point of the tire body is C1, and the vertical distance from the center of the first belt layer to the horizontal axis of the tire is H1B, wherein 0.53 < C1 / H1B < 0.65; the vertical distance between the endpoint of the first belt layer and the intersection point of the tire body is C3, wherein 1.61 < C3 / H1B < 1.73.

[0013] Preferably, the relationship between the width W1B of the first belt layer, the widest distance CW of the radial profile of the tire body, and the height distance H1B from the center of the first belt layer to the horizontal axis of the tire satisfies: 0.75 < W1B / CW < 0.81, 5.3 < (W1B+CW) / H1B < 6.8.

[0014] Preferably, the bus tire with low rolling resistance, high wear, and high comfort also includes a carcass reverse layer and a bead filler. The vertical height from the upper end point I of the bead filler to the rim line M is H3, the vertical distance from the end point J of the carcass reverse layer to the rim line M is H4, and the vertical distance from the end point J of the carcass reverse layer to the inner side of the tire is h, wherein 1.7≤H3 / H4≤2.1 and 6.6≤H3 / h≤11.2.

[0015] Preferably, the tread includes a crown layer and a base layer disposed radially inside the crown layer, wherein the rubber compound used in the crown layer has a hysteresis loss tangent value at 60°C. The modulus is 5.80, and the Akron wear index of the tread layer is... ; The hysteresis loss tangent of the adhesive used in the base layer at 60°C. .

[0016] As can be seen from the above technical solutions, the present invention has the following beneficial effects: In the present invention, by optimizing the tire's structural design, tread design, and compound design, the tire achieves low rolling resistance, high comfort, and high wear performance; specifically, in terms of structural design, the dimensions and tire carcass contour of the first belt layer and the second belt layer are limited to effectively control the tire contour, thereby reducing rolling resistance and ensuring wear performance and comfort; in terms of tread design, by providing four circumferentially distributed open tread grooves on the tread, the tread is divided into five tread blocks, and the width ratio between the tread blocks is limited to ensure a reasonable distribution of tread rigidity in the shoulder and the entire crown, which can ensure both rolling resistance performance and wear performance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the tire structure provided by the present invention; Figure 2 This is a schematic diagram of the tire structure tread pattern blocks provided by the present invention; Figure 3 This is a schematic diagram of the groove bottom of the patterned block. Figure 4 This is a schematic diagram of the tire structure dimensions provided by the present invention; Figure 5 This is a schematic diagram of the tire structure and tread provided by the present invention.

[0018] In the diagram: 10, tread; 110, tread groove; 111, groove bottom; 120, crown layer; 130, base layer; 20, carcass; 30, sidewall; 40, bead wire; 510, second belt layer; 520, first belt layer; 60, carcass reverse wrap layer; 70, bead filler. Detailed Implementation

[0019] A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: (Refer to...) Figure 1 , Figure 2A bus tire with low rolling resistance, high wear resistance, and high comfort includes a tread 10, a belt layer, a carcass 20, a sidewall 30, and a steel wire ring 40. Further, the tread 10 has four circumferentially distributed open tread grooves 110, and each groove has a self-closing groove bottom 111 under load. This divides the tread 10 into five tread blocks, with widths C, B, D, A, and E from the center of the tread to both sides, satisfying the following relationships: A=E, B=C=D, A:B=(1.45±2.5%):(1±2.5%), 0.15≤A / L≤0.26, where L is the arc length of the tread's outer contour. In this embodiment, A / L = 0.19. This tread pattern distribution ensures a reasonable rigidity distribution in the shoulder and crown areas, guaranteeing both rolling resistance and wear resistance.

[0021] Reference Figure 3 As a preferred technical solution in this embodiment, the groove 111 adopts a vertical grooving method with a fully rounded bottom. The groove depth H1 and width w1 satisfy: H1 / w1≥1.0. Specifically, in this embodiment, H1 / w1=1.5. Under loading conditions, the groove opening of this type of groove 111 closes, forming a cavity at the bottom. This allows the rubber on both sides to support each other, similar to reducing the groove depth, effectively reducing rolling resistance. Simultaneously, compared to a completely open tread groove, the tread rubber volume increases, thus increasing wear volume. Furthermore, after the cavity is formed at the bottom of the groove, the high rigidity of the belt layer transitions to the tread through the cavity. Compared to the traditional method where the transition is entirely through rubber, the cavity has a stronger ability to transition rigidity, creating a greater rigidity difference. This results in lower rigidity on the tire crown surface, ultimately significantly reducing the overall rigidity of the crown. Therefore, this groove design reduces rolling resistance and increases wear while simultaneously improving comfort.

[0022] Reference Figure 4 In some embodiments, the belt layer includes a second belt layer 510 and a first belt layer 520 arranged sequentially from the inside of the tread 10 toward the center of the tire. The width of the first belt layer 520 is W1B, and the width of the second belt layer 510 is W2B, wherein W1B > W2B.

[0023] Furthermore, the projection point of the endpoint P of the first belt layer 520 onto the tire carcass 20 is Q. The tangent line between point P and the first belt layer is L1, and the tangent line between point Q and the tire carcass is L2. The angle between tangent lines L1 and L2 is α, where α satisfies: 18° < α < 28°. Specifically, in this embodiment, α is 24°. With this angle design, under the restraining effect of the belt layer, the tire carcass 20 grows uniformly and deforms less under load, which is beneficial for reducing rolling resistance. At the same time, the tire carcass can grow sufficiently, which can prevent uneven wear, make wear uniform, and improve wear life. Conversely, if the angle is too large, the restraining effect of the belt layer is too small, and under load, the tire carcass grows too much, and the tire deforms greatly, which is not conducive to reducing rolling resistance. If the angle is too small, the restraining effect of the belt layer is too large, and the tire carcass grows too little, and the tire is prone to uneven wear, reducing wear life.

[0024] In some embodiments, the horizontal distance between the endpoint P of the first belt layer 520 and the outer contour of the tire sidewall is b, the intersection of the vertical downward point of the endpoint of the outer contour of the tire tread and the horizontal distance b is K, and the horizontal distance between K and the outer contour of the tire sidewall is b1. b1 and b satisfy: 0.13 < b1 / b < 0.29. Specifically, in this embodiment, b1 / b = 0.17. This ensures a uniform transition of the outer contour of the shoulder while maintaining a reasonable distribution of the belt layer and the tread width. This reasonable distribution of materials not only improves the safety performance of the shoulder (reducing shoulder tearing, shoulder delamination, and other faults), but also ensures the tire's contact performance, preventing uneven wear and thus improving wear life. In addition, while ensuring the rigidity of the belt layer and the shoulder, the volume of the shoulder rubber material can be reduced accordingly, which is beneficial for reducing rolling resistance.

[0025] Furthermore, the horizontal distance between the endpoint S of the second belt layer 510 and the center of the bottom of the outer tread groove is SG. The relationship between SG and the width A of the shoulder tread block satisfies: 0.46 < SG / A < 0.73; the perpendicular distance from point S to the outer contour of the tread is SF. The relationship between SG and SF satisfies: 1.2 < SG / SF < 1.9. Specifically, in this embodiment, SG / A = 0.60, SG / SF = 1.6. Thus, the growth and rigidity of the tread shoulder are greatly related to the endpoint position of the second belt layer. If the ratio is too small... If the width of the shoulder tread blocks is too large, the endpoint of the second belt layer is closer to the bottom of the shoulder tread groove, and the tread compound above the second belt layer is relatively thick. This leads to stress and strain concentration at the endpoint of the second belt layer and the bottom of the tread groove, while also increasing the volume of the tread compound and the heat generated by the tread, resulting in decreased safety performance and increased rolling resistance. If the ratio is too large, the endpoint of the second belt layer is closer to the outer contour endpoint of the tread, increasing the rigidity of the belt layer and reducing ground contact performance, affecting comfort performance, and making it prone to uneven wear, thus affecting wear life. With this ratio, the rigidity distribution of the shoulder tread blocks and the shoulder growth are more reasonable, which is beneficial for reducing rolling resistance and ensuring wear and comfort.

[0026] Reference Figure 4 In other embodiments, the tire carcass profile is controlled by three points. The vertical distance between the endpoint of the outer tread profile and the intersection point of the tire carcass is C1. For ease of description, the vertical distance between the endpoint of the outer tread profile and the intersection point of the tire carcass is defined as point 1. The vertical distance from the center of the first belt layer to the horizontal axis of the tire is H1B, where 0.53 < C1 / H1B < 0.65, preferably C1 / H1B = 0.58. The vertical distance between the endpoint of the first belt layer and the intersection point of the tire carcass is C3. Similarly, for ease of description, the vertical distance between the endpoint of the first belt layer and the intersection point of the tire carcass is defined as point 3. Figure 4 As shown, where 1.61 < C3 / H1B < 1.73, and preferably C3 / H1B = 1.65, the tire carcass profile controlled according to this principle results in uniform outward expansion of the tire carcass under load, with minimal overall deformation, which helps reduce rolling resistance. Simultaneously, the uniformly grown tire carcass reduces radial stiffness, thereby improving overall tire comfort performance.

[0027] Furthermore, the relationships between the width W1B of the first belt layer, the widest radial profile distance CW of the tire carcass, and the height distance H1B from the center of the first belt layer to the horizontal axis of the tire satisfy: 0.75 < W1B / CW < 0.81, preferably W1B / CW = 0.78; 5.3 < (W1B+CW) / H1B < 6.8, preferably (W1B+CW) / H1B = 6.0. It should be noted that, for ease of description, the two endpoints of the widest radial profile distance of the tire carcass are defined as two points, such as... Figure 4 As shown, the profile of the tire carcass above the horizontal axis affects the tire's radial stiffness and growth variation. Factors influencing the upper carcass profile include the carcass width above the horizontal axis, the height of the belt layer from the horizontal axis, and the belt layer width. By setting these values ​​and ensuring the belt layer width, under load, this promotes carcass growth and crown stability, prevents uneven wear, reduces rubber thickness, and lowers rolling resistance. Furthermore, this carcass profile also helps reduce radial stiffness and improves ride comfort.

[0028] In some embodiments, the low rolling resistance, high wear, and high comfort bus tire further includes a carcass backing layer 60 and a bead filler 70. The vertical height from the upper end point I of the bead filler to the rim line M is H3, the vertical distance from the end point J of the carcass backing layer to the rim line M is H4, and the vertical distance from the end point J of the carcass backing layer to the inner side of the tire is h. Where 1.7 ≤ H3 / H4 ≤ 2.1, 6.6 ≤ H3 / h ≤ 11.2. To reduce rolling resistance and radial stiffness, this design preferably uses H3 / H4 = 1.7 and H3 / h = 8.7. As a rubber component supporting the bead, appropriately reducing the height and thickness of the bead filler not only reduces the volume of the bead component and lowers the tire's rolling resistance, but also reduces the sidewall thickness, lowers the tire's radial stiffness, and improves tire comfort. By setting these values, radial stiffness can be reduced to the maximum extent while ensuring safety.

[0029] Furthermore, refer to Figure 5 The tread 10 includes a crown layer 120 and a base layer 130 disposed radially inside the crown layer. The rubber compound used in the crown layer 120 has a hysteresis loss tangent value at 60°C. The modulus is 5.80. Modulus reflects the ability of the tread layer 120 to resist deformation. By setting the tread layer modulus to 5.80, rolling resistance performance can be guaranteed. The Akron wear index of the tread layer 120 is... To ensure wear resistance; The base layer 130 mainly serves a heat dissipation function, and the adhesive used in the base layer 130 has a hysteresis loss tangent value at 60°C. This is to ensure the rolling resistance performance of the tires and improve their safety performance.

[0030] To verify the outstanding performance of the tire structure provided by the present invention compared with the existing tire structure, experiments were conducted on the tire structure provided in this embodiment and the existing tire structure, and comparisons were made in terms of rolling resistance, durability, road test / wear mileage and radial stiffness. The test results are shown in Table 1 below. Table 1 shows the comparison index between the tire structure provided in this embodiment and the existing tire structure in terms of the aforementioned test items.

[0031]

[0032] Table 1 - Performance Comparison Table of Tire Structure Provided in This Embodiment and Existing Tire Structures As shown in Table 1, the tire structure provided in this embodiment, through optimization of tire structure design, tread design, and compound design, has low rolling resistance, high comfort, and high wear performance compared to existing tire structures.

[0033] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A bus tire with low rolling resistance, high wear resistance, and high comfort, comprising a tread (10), a belt layer, a carcass (20), a sidewall (30), and a steel wire ring (40), characterized in that, The tread (10) is provided with four circumferentially distributed open tread grooves (110). Each tread groove adopts a groove bottom groove (111) that opens and closes under load. The tread grooves divide the tread (10) into five tread blocks. The widths of the five tread blocks from the center of the tread to both sides are C, B, D, A, and E, respectively, and satisfy: A=E, B=C=D, A:B=(1.45±2.5%):(1±2.5%), 0.15≤A / L≤0.26, where L is the outer contour arc length of the tread.

2. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 1, characterized in that, The trench bottom groove (111) adopts a vertical grooving method, and the bottom is a full circular arc rounded. The depth H1 and width w1 of the trench bottom groove satisfy: H1 / w1≥1.

0.

3. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 1, characterized in that... The belt layer includes a second belt layer (510) and a first belt layer (520) arranged sequentially from the inside of the tread (10) toward the center of the tire. The width of the first belt layer (520) is W1B and the width of the second belt layer (510) is W2B, where W1B > W2B.

4. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 3, characterized in that... The projection point of the first belt layer (520) endpoint P on the carcass (20) is Q. The tangent line between point P and the first belt layer is L1, and the tangent line between point Q and the carcass is L2. The angle between the tangent lines L1 and L2 is α, where α satisfies: 18° < α < 28°.

5. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 4, characterized in that... The horizontal distance between the endpoint P of the first belt layer (520) and the outer contour of the sidewall is b. The intersection of the vertical downward point of the endpoint of the outer contour of the tread and the horizontal distance b is K. The horizontal distance between K and the outer contour of the sidewall is b1. b1 and b satisfy: 0.13 < b1 / b < 0.

29.

6. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 5, characterized in that, The horizontal distance between the endpoint S of the second belt layer (510) and the center of the bottom of the outer tread groove is SG. The relationship between SG and the width A of the shoulder tread block satisfies: 0.46 < SG / A < 0.73; The perpendicular distance from point S to the outer contour of the tread is SF. SG and SF satisfy: 1.2 < SG / SF < 1.

9.

7. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 1, characterized in that, The vertical distance between the endpoint of the outer contour of the tread and the intersection point of the tire body is C1, and the vertical distance from the center of the first belt layer to the horizontal axis of the tire is H1B, where 0.53 < C1 / H1B < 0.65; the vertical distance between the endpoint of the first belt layer and the intersection point of the tire body is C3, where 1.61 < C3 / H1B < 1.

73.

8. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 7, characterized in that, The relationship between the width W1B of the first belt layer, the widest distance CW of the radial profile of the tire body, and the height distance H1B from the center of the first belt layer to the horizontal axis of the tire satisfies: 0.75 < W1B / CW < 0.81, 5.3 < (W1B+CW) / H1B < 6.

8.

9. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 1, characterized in that, The low rolling resistance, high wear, and high comfort bus tire also includes a carcass reverse layer (60) and a bead filler (70). The vertical height from the upper end point I of the bead filler to the rim line M is H3, the vertical distance from the end point J of the carcass reverse layer to the rim line M is H4, and the vertical distance from the end point of the carcass reverse layer to the inner side of the tire is h. Wherein, 1.7≤H3 / H4≤2.1, 6.6≤H3 / h≤11.

2.

10. The bus tire with low rolling resistance, high wear resistance, and high comfort as described in claim 1, characterized in that, The tread (10) includes a crown layer (120) and a base layer (130) disposed radially inside the crown layer. The rubber compound used in the crown layer (120) has a hysteresis loss tangent value at 60°C. The modulus is 5.80, and the Akron wear index of the crown layer (120) is... ; The hysteresis loss tangent of the adhesive used in the base layer (130) at 60°C is... .

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