Design method, application and tyre for improving the comfort of a passenger car tyre

Abstract

The present application relates to the technical field of tire design, and particularly relates to a design method, application and tire for improving the riding comfort of a passenger vehicle tire. The present application comprehensively considers the influence of alpha and beta effects on the residual stress in the finished cord through calculation. When C=0, the carcass cord has no residual stress; when C>0, the carcass residual stress shows a tensile effect; and vice versa. The change in the geometric size of the material offsets the residual stress of the cord caused by the dry heat shrinkage of the material, thereby reducing the residual stress of the carcass cord in the finished product after vulcanization. The residual stress of the tire cord is low, and the vibration amplitude of the tire cord when excited after inflation loading is reduced, so that the riding comfort of the vehicle can be improved.

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 driving comfort. Background Technology

[0002] The rapid development of the automotive industry has placed increasingly higher demands on tire components, and the demand for comfort as a driving experience has gradually increased. Driving comfort is the degree to which vibrations, after being absorbed by the vehicle's chassis / tires, are perceived by the driver and passengers. Changes in road surface smoothness act as an excitation, generating vibrations that are transmitted to the driver and passengers via the tires / chassis.

[0003] Tires are the only part of a vehicle that touches the ground, making a significant contribution to overall vehicle comfort in terms of both vibration and vibration absorption. Improving vehicle ride comfort can be approached from three aspects: 1- Material solutions: Reducing the hardness of the tread material can effectively reduce impact vibration. Increasing the hysteresis loss of the tread material can enhance vibration absorption. 2- Structural solutions: Reducing the stiffness of the tire sidewall can effectively reduce wheel vibration and increase vibration absorption. 3- Tread pattern solutions: Reducing the stiffness of the tread pattern can also effectively reduce wheel vibration and improve comfort.

[0004] Shortcomings of existing solutions:

[0005] 1- Adjusting the direction of material hardness and hysteresis loss will have a negative impact on tire handling, wear and rolling resistance;

[0006] 2. Reducing tire sidewall stiffness will decrease the vehicle's handling response speed;

[0007] 3. Reducing tread stiffness will decrease tire wear mileage and handling performance. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide a design method for passenger car tires that improves ride comfort. This method effectively improves ride comfort without affecting the tire's handling, wear resistance, and other properties.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A passenger car tire designed to improve ride comfort includes a tread, a nylon belt layer, a steel belt layer, a sidewall, a carcass cord layer, an inner liner, a gusset rubber, a steel wire bead, and a base rubber. The dry heat shrinkage rate of the carcass cord is α, and the elongation rate of the carcass cord is β. The cord length of the finished vulcanized tire is Lc, and the cord length of the unvulcanized tire is Lg. Lg, Lc, α, and β satisfy the following relationship:

[0011]

[0012] In the formula, C is the overall elongation rate of the tire cord, with a value ranging from -1.0% to 0.

[0013] Preferably, the tire cord α = 1%~3%.

[0014] Preferably, the elongation rate of the tire cord is β = -3.0 to -1.5%.

[0015] Furthermore, this invention also discloses a design method for a passenger car tire that improves driving comfort. The tire includes a tread, a nylon belt layer, a steel belt layer, a sidewall, a carcass cord layer, an inner liner, a triangular rubber layer, a steel wire bead, and a base rubber layer. The dry heat shrinkage rate of the carcass cord is α%, and β% is the elongation rate of the carcass cord. The cord length of the finished vulcanized tire is Lc; the cord length of the unvulcanized tire is Lg. Lg, Lc, α, and β satisfy the following relationship:

[0016]

[0017] In the formula, C is the overall elongation rate of the tire cord, with a value ranging from -1.0% to 0.

[0018] Preferably, the tire cord α = 1%~3%.

[0019] Preferably, the elongation rate β of the tire cord is -3.0% to -1.5%.

[0020] Furthermore, the present invention also discloses the application of the design method in designing passenger car tires that improve ride comfort.

[0021] 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.

[0022] 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.

[0023] Furthermore, the present invention discloses a computer program product, including a computer program or instructions that, when executed by a processor, implement the method.

[0024] The dry heat shrinkage property α of tire carcass cord material, chemical change: The polymer material of the tire carcass cord crystallizes under tension. During tire vulcanization, the cord is heated, and the crystals reconstruct. Because the two ends of the cord are fixed by the toe, the cord has a tendency to shrink, thus forming internal stress.

[0025] This invention, by employing the aforementioned technical solution, addresses the geometric stretching β of the tire carcass cords before and after tire vulcanization. Physical changes include the percentage change β between the cord length in the finished tire and the cord length in the green tire. β is a design parameter; β > 0 indicates geometric stretching of the cords, while β < 0 indicates geometric compression of the cords.

[0026] Calculations were performed to comprehensively consider the effects of α and β on the residual stress in the finished tire cord. When C=0, there is no residual stress in the tire cord; when C>0, the residual stress in the tire cord exhibits a tensile effect; conversely, it exhibits a compressive effect. The residual stress in the cord caused by the thermal shrinkage of the material is offset by changes in the material's geometric dimensions, thereby reducing the residual stress in the finished tire cord after vulcanization. Lower residual stress in the tire cord reduces the vibration amplitude under excitation after inflation, improving vehicle ride comfort. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a finished tire component.

[0028] Figure 2 This is a schematic diagram showing the length of the cord in the finished (vulcanized) tire carcass as 1 / 2 Lc.

[0029] Figure 3 A schematic diagram showing the length of the tire cord in a green tire (before vulcanization) of 1 / 2Lg;

[0030] Figure 4 This is a schematic diagram comparing the 1 / 2Lc and 1 / 2Lg of the tire carcass cords before and after vulcanization. Detailed Implementation

[0031] 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.

[0032] like Figure 1 A schematic diagram of a passenger tire structure, including tread 1, nylon belt layer 2, steel belt layer 3, sidewall 4, carcass cord layer 5, inner liner 6, triangular rubber 7, steel wire ring 8, and base rubber 9.

[0033] The length of the tire cord in the finished product, Lc. For tires of a specific size and structure, Lc is a constant value. In a single-layer tire structure, Lc is obtained by measuring the curve length between the left and right toes along the center line of the tire cords. In a double-layer tire structure, Lc is also obtained by measuring the curve between the left and right toes along the center line of the two tire cord layers. For example... Figure 2 As shown.

[0034] The value of α is determined based on the dry heat shrinkage rate of the tire cord material; for commonly used tire cords, α = 1%~3%. Using equation (1.1),

[0035] α+β=C

[0036] Calculate β (Note: If the C value is too small, it will cause the finished cord to bend or pleat. The C value should be between -1.0% and 0).

[0037] Using equation 2 in relation (1.1) and the value of Lc

[0038]

[0039] Find the range of values ​​for Lg.

[0040] The green tire carcass cord length Lg is defined as the length of the curve between the left and right toes, taken from the molding drum of the green tire during the assembly process before vulcanization. The width DW of the molding drum is adjusted to ensure that the value of Lg matches the range calculated in step 3. The paths of Lg and Lc are consistent: in a single-layer tire structure, the curve length between the left and right toes is taken along the center line of the carcass cords; in a double-layer tire structure, the curve length between the left and right toes is taken along the center line of the two carcass cords. Figure 3 As shown.

[0041] Verification example:

[0042] The tire specification is 225 / 60R18, the tire structure is a double-layer carcass, the carcass cord material is 1100dtex / 2DSP, and the dry heat shrinkage rate α=1.8. The dry heat shrinkage rate was tested according to GB / T 19390-2014, and the geometric elongation β and the comprehensive elongation C of the carcass cord are designed as shown in Table 1.

[0043] Tire ride comfort was assessed using a subjective evaluation method, with the driver's perception of impact and vibration filtering characterizing the tire's ride comfort. The test vehicle was a Geely Vision X6, the test site was the CATARC Yancheng Proving Ground, the vehicle was half-loaded, the test tire pressure was 230 kPa, and the test speed was 60 km / h.

[0044] The results are shown in Table 1:

[0045] As shown in Table 1, the β value in Examples 1 changed from positive to negative compared to the reference example, indicating that the tire carcass cords changed from a geometrically stretched state to a geometrically compressed state. After incorporating the dry heat shrinkage of the cords, the overall elongation of the cords became negative, meaning the finished cords were in a compressed state, reducing the internal stress of the cords under inflation. The comfort scores of Examples 1-3 were all improved to varying degrees compared to the reference example. Furthermore, the three examples did not involve adjustments to the tread material or tire structure, maintaining the tire's handling, wear resistance, and other performance characteristics.

[0046] 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 car tire for improving ride comfort, the tire comprising a tread, a nylon belt layer, a steel belt layer, a sidewall, a carcass cord layer, an inner liner, a gusset rubber, a steel wire bead, and a base rubber; characterized in that, The dry heat shrinkage rate of the tire carcass cord is α, and the elongation rate of the tire carcass cord is β; the cord length of the finished tire after vulcanization is Lc; the cord length of the green tire before vulcanization is Lg; Lg, Lc, α, and β satisfy the following relationship: ； In the formula, C is the overall elongation rate of the tire cord, with a value ranging from -1.0% to 0. The β value is negative. The length of the green tire carcass cord, Lg, is defined as the length of the curve between the left and right toes on the molding drum of the green tire during the assembly process before vulcanization.

2. A passenger car tire for improving ride comfort according to claim 1, characterized in that, The percentage of cord cord in the fetal body is α = 1%~3%.

3. A passenger car tire for improving driving comfort according to claim 1, characterized in that, β=-3.0%~-1.5%。 4. A design method for a passenger car tire to improve ride comfort, the tire comprising a tread, a nylon belt layer, a steel belt layer, a sidewall, a carcass cord layer, an inner liner, a gusset rubber, a steel wire bead, and a base rubber; characterized in that, The dry heat shrinkage rate of the tire carcass cord is α, and the elongation rate of the tire carcass cord is β; the cord length of the finished tire after vulcanization is Lc; the cord length of the green tire before vulcanization is Lg; Lg, Lc, α, and β satisfy the following relationship: ； In the formula, C is the overall elongation rate of the tire cord, with a value ranging from -1.0% to 0. The β value is negative. The length of the green tire carcass cord, Lg, is defined as the length of the curve between the left and right toes on the molding drum of the green tire during the assembly process before vulcanization.

5. The design method according to claim 4, characterized in that, The percentage of cord cord in the fetal body is α = 1%~3%.

6. The design method according to claim 4, characterized in that, β=-3.0%~-1.5%。 7. The application of the design method according to any one of claims 4-6 in the design of passenger car tires that improve ride comfort.

8. 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 according to any one of claims 4-6.

9. 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 described in any one of claims 4-6.

10. 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 described in any one of claims 4-6.

Images