A tire that improves handling

Abstract

The invention relates to the field of tires, and in particular to a tire with improved handling performance. The tire comprises a tread portion, a sidewall portion, a bead portion, a carcass cord, a reinforcing sheet and an outer protective rubber, wherein at least one layer of carcass cord extends from the bead portion through the sidewall portion to the tread portion; the bead portion is provided with an apex rubber, the sidewall portion is provided with a sidewall rubber, and the sidewall rubber connects the outer protective rubber and the tread portion; the reinforcing sheet is located between the carcass cord and the sidewall rubber, and its upper end point is above the carcass cord turn-up end point, and the lower end point is below the apex rubber end point; the thickness t5 of the reinforcing sheet is 0.6-0.8 of the thickness of the carcass cord, and the 100% modulus of the reinforcing sheet 5 is 3.12-12.5 MPa; the tire section height is H, the height h7 of the apex rubber is H*(0.15-0.25), and the 100% modulus of the apex rubber is 5.0 MPa-20 MPa; the interface distance d6tb between the outer protective rubber and the sidewall rubber is 25-30 mm, and the 100% modulus of the reinforcing sheet is between the apex rubber and the outer protective rubber. The tire improves the tire's cornering stiffness while maintaining tire comfort.

Description

Technical Field

[0001] The invention relates to the field of tires, and in particular to a tire with improved handling performance. Background Art

[0002] With the development of my country's automobile industry, the use of automobiles has increased rapidly, and OEMs and consumers have higher requirements for vehicle controllability. The driver operates the steering wheel according to his own will to achieve straight-line driving, acceleration, braking and steering. The subjective feeling in this process is controllability, such as the movement of the vehicle felt by the body when turning, the movement of the steering wheel felt by the hand, and the feedback of the steering wheel.

[0003] After the driver turns the steering wheel, an angle will appear between the center line of the rim and the actual direction of travel of the tire, and the contact patch is still facing the direction of travel due to friction. At this time, the tire contact patch undergoes elastic deformation, generating lateral force. The angle between the tire's direction of travel and the rim's direction is called the slip angle (SA), and the lateral force occurring on the tire is called the cornering force (CF). When the slip angle is relatively small, the lateral force that occurs is basically concentrated in the adhesion friction area of ​​the tire's contact patch, and CF and SA are basically linearly related. The slope of the CF / SA curve close to the 0-degree angle area is generally used to express the characteristics of the tire. This slope is called the cornering stiffness (CP). Under normal circumstances, the slip angle of the vehicle during driving is relatively small, so the cornering stiffness can be used to characterize the handling of the tire. The greater the cornering stiffness, the better the handling.

[0004] The comfort of a tire is reflected in its absorption and filtering of vibration (excitation). The tire characteristics are generally expressed by the ratio of the tire's vertical load to its sinking amount, which is called radial rigidity. The lower the radial rigidity, the better the comfort.

[0005] As the only part of a vehicle that contacts the ground, tires have a great impact on the handling of the vehicle. Existing methods for improving tire handling: 1. Improving the rigidity of the crown, including increasing the rigidity of a single tread block of the tire, increasing the modulus of the steel belt layer, and increasing the tire contact area; 2. Improving the rigidity of the sidewall, including increasing the height and modulus of the apex rubber, and enhancing fiber reinforcement (metal, rayon). Such as the Chinese invention patent application (publication number CN111163948A, publication date 20200515), the Chinese utility model patent application (publication number CN213228212U, publication date 20210518) and the Chinese invention patent application (publication number CN108099507A, publication date 20180601).

[0006] The prior art has the following deficiencies: In the prior art, by increasing the tire crown rigidity and the tire sidewall rigidity, the tire's radial rigidity is increased while the tire's lateral rigidity is increased to improve the tire's handling, thereby reducing the tire's comfort. Summary of the invention

[0007] The purpose of the present invention is to solve the above problems by optimizing the structure and matching the material properties, setting a reinforcing sheet between the carcass cord and the sidewall rubber, whose modulus is between the apex rubber and the outer rubber; and increasing the outer rubber height to improve the cornering stiffness of the tire. In addition, by optimizing the material properties and size of the apex rubber, a tire with improved handling is provided to maintain the comfort of the tire.

[0008] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0009] A tire with improved handling performance, the tire comprising a tread portion, a sidewall portion, a bead portion, a carcass cord, a reinforcing sheet and an outer protective rubber, at least one layer of carcass cord extending from the bead portion through the sidewall portion to the tread portion; the bead portion is provided with an apex rubber, the sidewall portion is provided with a sidewall rubber, and the sidewall rubber connects the outer protective rubber and the tread portion; the reinforcing sheet is located between the carcass cord and the sidewall rubber, the upper end point of the reinforcing sheet is above the end point of the carcass cord turn-up, and the lower end point is below the end point of the apex rubber; the thickness of the reinforcing sheet t5 is 0.6-0.8 of the carcass cord thickness, and the 100% modulus of the reinforcing sheet 5 is 3.12-12.5 MPa; the tire section height is H, the height of the apex rubber h7=H*(0.15-0.25), and the 100% modulus of the apex rubber is 5.0 MPa-20 MPa; the interface distance between the outer protective rubber and the sidewall rubber d6tb=25-30 mm, and the 100% modulus of the reinforcing sheet is between the apex rubber and the outer protective rubber.

[0010] Preferably, the distance between the upper end point and the lower end point of the reinforcing sheet is greater than 5 mm.

[0011] Preferably, the thickness t5 of the reinforcing sheet is 0.5 to 1.1 mm.

[0012] Preferably, the distance between the reinforcing plate and the carcass cord is d45=10-15 mm; the distance between the reinforcing plate and the apex is d57=5-10 mm.

[0013] Preferably, the 100% modulus ratio of the reinforcing sheet, the outer protective rubber and the apex rubber is 5:3:8.

[0014] Preferably, the tensile elongation at break of the reinforcing sheet is 300% to 500%.

[0015] Preferably, the height of the turned-up end point of the carcass cord is h4=H*(0.35-0.55), and the distance between the two end points of the carcass cord is greater than 5 mm.

[0016] Preferably, the height of the outer protective rubber h6b=18-20 mm.

[0017] Preferably, the thickness of the outer rubber and the sidewall rubber is t6:t4=1.1~1.2, and the thickness of the outer rubber is t6=2.2~3.5mm.

[0018] The advantages of the tire with improved handling performance using the above technical solution of the present invention are:

[0019] By optimizing the structure and matching the material properties, a reinforcing sheet is set between the carcass cord and the sidewall rubber, and its modulus is between the apex rubber and the outer rubber. At the same time, the outer rubber height is increased to improve the tire's cornering stiffness. In addition, by optimizing the material properties and size of the apex rubber, the tire's comfort is maintained, so that this type of tire improves tire handling while maintaining tire comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention.

[0021] Figure 2 It is a structural diagram of the tire section height.

[0022] Figure 3 It is a structural schematic diagram of the distance between the reinforcement plate and the carcass cord and the distance between the reinforcement plate and the apex rubber.

[0023] Figure 4 It is a structural schematic diagram of the height of the turned-up end point of the carcass cord, the height of the apex rubber and the height of the outer protective rubber.

[0024] Figure 5 It is a structural schematic diagram of the interface distance between the outer protective rubber and the sidewall rubber.

[0025] 9-wire ring, 10-steel belt layer. DETAILED DESCRIPTION

[0026] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0027] Example 1

[0028] like Figure 1 , Figure 2 , Figure 4 , Figure 5A tire with improved handling performance is shown, the tire comprises a tread portion 1, a sidewall portion 2, a bead portion 3, a carcass cord 4, a reinforcing sheet 5 and an outer protective rubber 6, at least one layer of carcass cord 4 extends from the bead portion 3 through the sidewall portion 2 to the tread portion 1; the bead portion 3 is provided with an apex rubber 7, the sidewall portion 2 is provided with a sidewall rubber 8, and the sidewall rubber 8 connects the outer protective rubber 6 and the tread portion 1; the reinforcing sheet 5 is located between the carcass cord 4 and the sidewall rubber 8, the upper end point of the reinforcing sheet 5 is above the end point of the carcass cord 4, and the lower end point is below the end point of the apex rubber 7; the thickness t5 of the reinforcing sheet 5 is the carcass cord 4. The thickness of the reinforcing sheet 5 is 0.6-0.8 of the thickness of the cord 4. The test results show that the increase in the thickness of the reinforcing sheet 5 can significantly improve the tire cornering stiffness, but has a negative effect on the tire shoulder durability. The preferred thickness is 0.7mm; the 100% modulus of the reinforcing sheet 5 is 3.12-12.5MPa; the test results show that the increase in the 100% modulus of the reinforcing sheet 5 can effectively improve the tire cornering stiffness, but the radial rigidity of the tire also increases at the same time, which tends to deteriorate the comfort of the tire. The preferred 100% modulus of the reinforcing sheet is 12MPa. The tire section height is H, and the height of the apex 7 is h7=H*(0.15-0.25). An overly high apex is not conducive to maintaining the radial rigidity of the tire, resulting in a reduction in comfort. Preferably, h7=H*0.22; the 100% modulus of the apex 7 is 5.0MPa-20MPa; preferably, its 100% modulus is 16MPa; the interface distance d6tb between the outer rubber 6 and the side rubber 8 is 25-30mm, and the 100% modulus of the reinforcing sheet 5 is between the apex 7 and the outer rubber 6. In this way, through the optimization of the structural form and the matching of the material properties, a reinforcing sheet 5 is arranged between the carcass cord 4 and the side rubber 8, and its modulus is between the apex 7 and the outer rubber 6; at the same time, the height of the outer rubber 6 is increased to improve the lateral stiffness of the tire. In addition, by optimizing the material properties and size of the apex 7, the comfort of the tire is maintained; thereby, this type of tire maintains the comfort of the tire while improving the handling of the tire.

[0029] The distance between the upper end point and the lower end point of the reinforcing sheet 5 is greater than 5 mm.

[0030] The thickness t5 of the reinforcing sheet 5 is 0.5 to 1.1 mm.

[0031] like Figure 3 As shown, the distance d45 between the reinforcing sheet 5 and the carcass cord 4 is 10-15 mm, and the distance d57 between the reinforcing sheet 5 and the apex 7 is 5-10 mm. The reinforcing sheet 5 runs through the tire sidewall 2, effectively improving the rigidity of the tire sidewall 2 and the tire cornering stiffness.

[0032] The 100% modulus ratio of the reinforcing sheet 5, the outer protective rubber 6 and the apex rubber 7 is 5:3:8. The moduli of the reinforcing sheet 5, the outer protective rubber 6 and the apex rubber 7 are combined with the matching of their geometric shapes to form a gradual decrease in modulus from the lower sidewall to the upper sidewall of the tire, which can effectively improve the rigidity of the sidewall portion 2 and the lateral stiffness of the tire, while weakening the stress concentration at the end points of the components.

[0033] The tensile elongation of the reinforcing sheet 5 is 300% to 500%. While improving the rigidity of the tire sidewall, the flexural resistance of the sidewall is maintained to avoid early damage to the tire.

[0034] The height of the turned-up end point of the carcass cord 4 is h4=H*0.35-0.55, and the distance between the two end points of the carcass cord 4 is greater than 5 mm.

[0035] The height h6b of the outer protective rubber 6 is 18-20 mm, which is consistent with the height of the wheel flange of the rim.

[0036] The thickness t6 of the outer rubber 6 and the sidewall rubber 8 is: t4=1.1-1.2, and the thickness t6 of the outer rubber 6 is 2.2-3.5 mm.

[0037] The tire specification selected is 205 / 55R16 91V, and the dimensions, positions and material properties of the components such as the reinforcing sheet, apex rubber and outer rubber are defined as in Table 1. In addition, the 100% modulus and elongation at break are determined according to GB / T 528-2009.

[0038] Test method for tire cornering stiffness: Tires of different schemes are respectively mounted on the rims specified in GB-T 2977, with an inflation pressure of 200kPa, a tire load of 80% of the maximum load specified in GB, and a test speed of 80km / h. The tire cornering stiffness is tested on a tire six-component force testing machine. The greater the cornering stiffness, the better the handling performance. With the cornering stiffness of the reference tire scheme as 100, the ratio of the cornering stiffness of the tires of each scheme to the cornering stiffness of the reference tire is compared relatively.

[0039] Radial rigidity test method: The ratio of the maximum tire load to its corresponding load sinking amount (kg / mm) is used as the representation. The lower the value, the lower the radial rigidity and the better the comfort of the tire. The radial rigidity of the reference tire solution is 100, and the ratio of the radial rigidity of each solution tire to the radial rigidity of the reference tire is compared relatively.

[0040] The results are shown in Table 1:

[0041]

[0042] Table 1

[0043] As can be seen from Table 1, the tires of Schemes 1 to 12 have improved cornering stiffness, that is, handling, to varying degrees compared with the reference tires; at the same time, the difference in radial rigidity with the reference tire is within 4%, maintaining the comfort of the tires.

Claims

1. A tire with improved handling, characterized in that: The tire comprises a tread portion (1), a sidewall portion (2), a bead portion (3), a carcass cord (4), a reinforcing sheet (5) and an outer protective rubber (6), wherein at least one layer of carcass cord (4) extends from the bead portion (3) through the sidewall portion (2) to the tread portion (1); the bead portion (3) is provided with an apex rubber (7), the sidewall portion (2) is provided with a sidewall rubber (8), and the sidewall rubber (8) connects the outer protective rubber (6) and the tread portion (1); the reinforcing sheet (5) is located between the carcass cord (4) and the bead portion (3); The upper end point of the reinforcing sheet (5) is above the end point of the carcass cord (4) and the lower end point is below the end point of the apex rubber (7); the thickness t5 of the reinforcing sheet (5) is 0.6 to 0.8 of the thickness of the carcass cord (4), and the 100% modulus of the reinforcing sheet (5) is 3.12 to 12.5 MPa; the tire section height is H, the height of the apex rubber (7) is h7 = H*(0.15 to 0.25), and the 100% modulus of the apex rubber (7) is 5.0 MPa to 20.5 MPa. MPa; the interface distance d6tb between the outer protective rubber (6) and the sidewall rubber (8) is 25-30 mm, and the 100% modulus of the reinforcing sheet (5) is between the apex rubber (7) and the outer protective rubber (6); the distance d45 between the upper end point of the reinforcing sheet (5) and the turn-up point of the carcass cord (4) is 10-15 mm; the distance d57 between the lower end point of the reinforcing sheet (5) and the end point of the apex rubber (7) is 5-10 mm; and the thickness t5 of the reinforcing sheet (5) is 0.5-1.1 mm.

2. A tire with improved handling according to claim 1, characterized in that: The 100% modulus ratio of the reinforcing sheet (5), the outer protective rubber (6) and the apex rubber (7) is 5:3:

8.

3. A tire with improved handling according to claim 1, characterized in that: The tensile elongation of the reinforcing sheet (5) is 300% to 500%.

4. A tire with improved handling performance according to claim 1, characterized in that: The height of the turned-up end point of the carcass cord (4) is h4=H*(0.35~0.55).

5. The tire with improved handling performance according to claim 1, characterized in that: The height of the outer protective rubber (6) is h6b = 18 ~ 20 mm.

6. The tire with improved handling performance according to claim 1, characterized in that: The thickness of the outer rubber (6) and the sidewall rubber (8) is t6:t4=1.1~1.2, and the thickness of the outer rubber (6) is t6=2.2~3.5mm.

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