A method of design, use and tyre for a passenger car tyre with improved high speed performance

Abstract

The application relates to the technical field of tire design, in particular to a design method, application and tire of a passenger car tire with improved high-speed performance. The passenger car tire with improved high-speed performance comprises a tire tread, a nylon belt layer, a steel wire belt layer, a tire side, a tire body ply, an inner liner and a triangular rubber, the dry heat shrinkage rate of the nylon belt layer is C%, A is the elongation rate of the nylon belt layer at the center of the crown, and B is the elongation rate of the nylon belt layer at the end point of the shoulder; A, B and C satisfy the following relations: A=D c / d , A=D s / d , C / 100+A<=1.12, C / 100+B>=1.12, wherein Dc is the diameter of the nylon belt layer at the center of the crown, Ds is the diameter of the nylon belt layer at the end point of the shoulder, and d is the laying diameter of the nylon belt layer in the process of making a green tire. The dry heat shrinkage rate C (%) of the nylon belt is investigated, the values of the elongation rates A and B of the nylon belt at the shoulder and the center of the crown are calculated and designed, and the purpose of improving the high-speed performance of the tire is achieved.

Description

Technical Field

[0001] This invention relates to the field of tire design technology, and in particular to a design method, application, and tire for passenger car tires that improve high-speed performance. Background Technology

[0002] Tires provide a vehicle with load-bearing capacity. During each rotational cycle, a tire undergoes compression and recovery. Under high-speed conditions, due to centrifugal force, the tire's crown expands away from the center of rotation, exacerbating the deformation of the tire crown. At a specific critical speed, the continuous accumulation of heat can cause component damage, leading to high-speed tire performance failure.

[0003] To suppress centrifugal deformation of the tire crown under high-speed conditions, the engineering solution is to add a zero-degree wound nylon belt layer to tighten the entire crown, reduce centrifugal deformation, and decrease heat accumulation, thereby increasing the tire's high-speed critical speed.

[0004] Shortcomings of existing solutions:

[0005] During tire manufacturing, nylon belts are first laid on a flat surface (see...). Figure 1 The nylon belt is made into a green tire, which is then molded to form the final product with the tire crown curvature. During this process, the nylon belt has a designed elongation A at its center (see...). Figure 2 In engineering applications, designers typically adjust the A value to achieve different nylon belt elongation rates. Different nylon belt elongation rates have different clamping effects on the tire crown, thereby adjusting the tire's high-speed performance.

[0006] However, under high-speed conditions, component failure due to heat accumulation often occurs at the end of the belt in the tire shoulder area. Current design values ​​do not consider the elongation (B) of the nylon belt in the tire shoulder. Furthermore, nylon material exhibits dry heat shrinkage; the heating and vulcanization process during tire production leads to dimensional shrinkage (the nylon belt polymer crystallizes under tension, and this crystallization remodels when heated during vulcanization. Simultaneously, because the tire's geometry is constrained by the mold during vulcanization, the nylon belt tends to shrink thermally, thus creating internal stress). Therefore, the clamping effect of the nylon belt on the tire crown originates from the values ​​of A and B (the geometric elongation of the material) and also from the dry heat shrinkage value (the thermal shrinkage of the material). Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a design method for passenger car tires with improved high-speed performance. By examining the dry heat shrinkage rate C (%) of the nylon belt, the elongation rates A and B of the nylon belt at the center of the tire shoulder and tire crown are calculated and designed to achieve the goal of improving the high-speed performance of the tire.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A passenger car tire with improved high-speed performance includes a tread, a nylon belt layer, a steel belt layer, a sidewall, a carcass ply, an inner liner, and a gusset rubber. The dry heat shrinkage rate of the nylon belt layer is C%, A is the elongation rate of the nylon belt layer at the center of the tire crown, and B is the elongation rate of the nylon belt layer at the shoulder end. A, B, and C satisfy the following relationship:

[0010]

[0011]

[0012] C / 100+A≤1.12

[0013] C / 100+B≥1.04;

[0014] Where Dc is the diameter of the nylon belt layer at the center of the tire crown, Ds is the diameter of the nylon belt layer at the end of the tire shoulder, and d is the laying diameter of the nylon belt layer during the green tire manufacturing process.

[0015] Furthermore, this invention discloses a design method for a passenger car tire with improved high-speed performance. The tire includes a tread, a nylon belt layer, a steel belt layer, a sidewall, a carcass ply, an inner liner, and a gusseted rubber layer. The dry heat shrinkage rate of the nylon belt layer is C%, A is the elongation rate of the nylon belt layer at the center of the tire crown, and B is the elongation rate of the nylon belt layer at the shoulder end. A, B, and C satisfy the following relationship:

[0016]

[0017]

[0018] C / 100+A≤1.12

[0019] C / 100+B≥1.04;

[0020] Where Dc is the diameter of the nylon belt layer at the center of the tire crown, Ds is the diameter of the nylon belt layer at the end of the tire shoulder, and d is the laying diameter of the nylon belt layer during the green tire manufacturing process.

[0021] Preferably, the method includes the following steps:

[0022] 1) Based on the dry heat shrinkage value C% of the nylon belt material, the one-sided limit values ​​of A and B are obtained using the formula respectively;

[0023] A≤1.12-C / 100

[0024] B≥1.04-C / 100

[0025] Due to the curvature of the tread, Dc>Ds, A>B, thus the limit range of A / B is determined respectively.

[0026] 2) Based on the component design dimensions, pick out the diameter of the nylon belt located at the center of the tire crown, and use the center of the bottom layer as a reference point to obtain the Dc value; use the following formula to calculate and obtain the lower limit value of the d value;

[0027]

[0028] A≤1.12-C / 100

[0029]

[0030] Take the diameter of the nylon belt at the end of the tire shoulder, and use the bottom layer as a reference point to obtain the Ds value; use the following formula to calculate and obtain the upper limit of the d value.

[0031]

[0032] B≥1.04-C / 100

[0033]

[0034] 3) The A / B value is designed by adjusting the d value.

[0035]

[0036] Furthermore, this invention discloses the application of the design method in designing passenger car tires with improved high-speed performance.

[0037] Furthermore, the present invention discloses a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method.

[0038] Furthermore, the present invention discloses a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implements the method described herein.

[0039] Furthermore, the present invention discloses a computer program product, including a computer program or instructions that, when executed by a processor, implement the method.

[0040] In this invention, the dry heat shrinkage property (C%) of the nylon belt material is as follows: The nylon belt polymer material crystallizes under tension; during tire vulcanization, the cords are heated, causing crystal remodeling. Since the tire's geometry is limited by the mold during vulcanization, the nylon belt tends to shrink thermally, thus creating internal stress.

[0041] Geometric stretching A and B of nylon belt material before and after tire vulcanization, physical changes: the ratio of the diameter of the nylon belt in the finished tire to the diameter of the nylon belt in the green tire. A and B are design parameters; a value greater than 1 indicates that the nylon belt is geometrically stretched; conversely, a value less than 1 indicates that the nylon belt is geometrically compressed.

[0042] The effects of both actions A / B and C on the tightening effect of the tire crown were calculated and considered comprehensively:

[0043] When C / 100+A≧1, the nylon belt provides initial prestress at the center of the tire crown, which can restrain the deformation of the tire crown center under high-speed centrifugal force. However, if C / 100+A is too high, such as when C / 100+A≧1.12, the excessive restraint at the center of the tire crown will result in lower tire contact pressure, leading to abnormal wear at the tire shoulder. From the shape of the tire crown curve, we know that A>B, and the lower limit of A can be limited by the upper limit of B.

[0044] When C / 100+B ≥ 1, the nylon belt provides initial prestress at the tire shoulder, which better restrains the deformation of the tire shoulder under high-speed centrifugal force. However, if C / 100+B is too low, such as C / 100+B ≤ 1.04, the clamping force of the nylon belt is insufficient to restrain the deformation of the tire shoulder under high-speed conditions. From the shape of the tire crown curve, we know that A > B, and the upper limit of B can be limited by the lower limit of A. Attached Figure Description

[0045] Figure 1 Schematic diagram of passenger car tire structure.

[0046] Figure 2 Schematic diagram of Dc-Ds(B>1).

[0047] Figure 3 Schematic diagram of Dc-Ds(B<1). Detailed Implementation

[0048] The present invention will be further described in detail below with reference to the accompanying drawings: This embodiment is implemented under the premise of the technical solution of the present invention, and detailed implementation methods are given, but the protection scope of the present invention is not limited to the following embodiments.

[0049] like Figure 1 A schematic diagram of a passenger tire structure, including 1. tread, 2. nylon belt layer, 3. steel belt layer, 4. sidewall, 5. carcass ply, 6. inner liner, and 7. triangle rubber.

[0050] 1. Based on the dry heat shrinkage value C (%) of the nylon belt material, the one-sided limit values ​​of A and B are obtained using the formula.

[0051] A≤1.12-C / 100

[0052] B≥1.04-C / 100

[0053] The values ​​of A / B directly affect the clamping and restraining effect of the nylon belt on the tire crown, and there is a positive correlation: the higher the value, the better the high-speed performance. It is important to note that an excessively high A value can have a negative impact, as it results in excessive clamping force on the center of the tire crown, leading to lower ground pressure at the center of the crown, which can cause abnormal wear on the tire shoulder. Similarly, an excessively low B value reduces the clamping and restraining effect of the nylon belt on the tire shoulder, thus failing to effectively clamp and restrain the centrifugal deformation of the tire shoulder under high-speed conditions, causing high-speed failure.

[0054] like Figure 2 As shown, due to the curvature of the tire tread, Dc > Ds, and A > B. Therefore, the limit ranges for A / B can be determined.

[0055] 2. According to Figure 2 The component design dimensions are determined by picking the diameter of the nylon belt at the center of the tire crown, using the center of the bottom layer as a reference point, to obtain the Dc value. The lower limit of the d value is then calculated using the following formula.

[0056]

[0057] A≤1.12-C / 100

[0058]

[0059] Similarly, the diameter of the nylon strap at the end of the tire shoulder is taken, and the bottom layer is used as a reference point to obtain the Ds value. The upper limit of the d value is then calculated using the following formula.

[0060]

[0061] B≥1.04-C / 100

[0062]

[0063] 3. The A / B ratio is designed by adjusting the d value. The material's dry heat shrinkage and the clamping effect of the nylon belt throughout the tire crown area are also considered.

[0064]

[0065] Verification example:

[0066] The tire specification is 205 / 55R16 91V, the nylon belt material is 930dtex / 2 / F94, and the dry heat shrinkage rate C = 6.5%. The dry heat shrinkage rate was tested according to GB / T19390-2014, with the specified tire structural dimensions Ds (295.7mm) and Dc (304.65mm) as constant values. A, B, and d are shown in Table 1.

[0067] The high-speed performance of the tires was tested according to the GBT4502-2016 method. After 60 minutes of operation, the speed was increased by 10 km / h every 10 minutes, the test pressure was 300 kPa, and the test load was 449 kg. The total running time and failure rate of the tires in the high-speed test characterized the quality of their high-speed performance.

[0068] The results are shown in Table 1:

[0069]

[0070] As shown in Table 1, in Examples 1-6, under the condition that the dry heat shrinkage of nylon material is uniform, the high-speed performance of the tire continuously decreases as the values ​​of A and B decrease. When the C / 100+B value is 1.04156, the high-speed performance just meets the minimum requirements of GB. Preferably, C / 100+B ≥ 1.04. When the C / 100+A value is 1.12025, although the tire has excellent high-speed performance, its clamping effect on the tire crown is too large, resulting in excessive deformation of the tire shoulder under high-speed centrifugal force, which will lead to abnormal wear in the tire shoulder area. Preferably, C / 100+A ≤ 1.12.

[0071] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A passenger vehicle tire having improved high speed performance, the tire comprising a tread, a nylon belt, a steel cord belt, a sidewall, a carcass ply, an underliner, and a chafer, characterized in that, The dry heat shrinkage rate of the nylon belt layer is C%, A is the elongation rate of the nylon belt layer at the center of the tire crown, and B is the elongation rate of the nylon belt layer at the shoulder end. A, B, and C satisfy the following relationship: ； Where Dc is the diameter of the nylon belt layer at the center of the tire crown, Ds is the diameter of the nylon belt layer at the end of the tire shoulder, and d is the laying diameter of the nylon belt layer during the green tire manufacturing process.

2. A method of designing a passenger vehicle tire having improved high speed performance, the tire comprising a tread, a nylon belt, a steel cord belt, a sidewall, a carcass ply, an underliner, and a chafer, the method comprising: The dry heat shrinkage rate of the nylon belt layer is C%, A is the elongation rate of the nylon belt layer at the center of the tire crown, and B is the elongation rate of the nylon belt layer at the shoulder end. A, B, and C satisfy the following relationship: ； Where Dc is the diameter of the nylon belt layer at the center of the tire crown, Ds is the diameter of the nylon belt layer at the end of the tire shoulder, and d is the laying diameter of the nylon belt layer during the green tire manufacturing process.

3. The design method for a passenger car tire with improved high-speed performance according to claim 2, characterized in that, The method includes the following steps: 1) Based on the dry heat shrinkage value C% of the nylon belt material, the one-sided limit values ​​of A and B are obtained respectively using the formula; ； Due to the curvature of the tread, Dc>Ds, A>B, thus the limit range of A / B is determined respectively. 2) Based on the component design dimensions, pick out the diameter of the nylon belt located at the center of the tire crown, and use the center of the bottom layer as a reference point to obtain the Dc value; use the following formula to calculate and obtain the lower limit value of the d value; ； The diameter of the nylon belt at the end of the tire shoulder is measured, and the bottom layer is used as a reference point to obtain the Ds value; the upper limit of the d value is calculated using the following formula: ； 3) The A / B value is designed by adjusting the d value. 。 4. The application of the design method according to claim 2 or 3 in the design of passenger car tires with improved high-speed performance.

5. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the method of claim 2 or 3.

6. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the method of claim 2 or 3.

7. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the method of claim 2 or 3.

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